[libpng10] Imported from libpng-1.0.41.tar

ANNOUNCE

@@ -1,49 +1,57 @@
 
-Libpng 1.0.1c May 9, 1998
+Libpng 1.0.41 - October 31, 2008
 
-This is not intended to be a public release.  It will be replaced
-within a few weeks by a public version or by another test version.
+This is a public release of libpng, intended for use in production codes.
 
-Changes since the last public release:
+Files available for download:
 
-version 1.0.1a [April 21, 1998]
-  Optimized Paeth calculations by replacing abs() function calls with intrinsics
-  plus other loop optimizations. Improves avg decoding speed by about 20%.
-  Commented out i386istic "align" compiler flags in makefile.lnx.
-  Reduced the default warning level in some makefiles, to make them consistent.
-  Removed references to IJG and JPEG in the ansi2knr.c copyright statement.
-  Fixed a bug in png_do_strip_filler with XXRRGGBB => RRGGBB transformation.
-  Added grayscale and 16-bit capability to png_do_read_filler().
-  Fixed a bug in pngset.c, introduced in version 0.99c, that sets rowbytes
-    too large when writing an image with bit_depth < 8 (Bob Dellaca).
-  Corrected some bugs in the experimental weighted filtering heuristics.
-  Moved a misplaced pngrutil code block that truncates tRNS if it has more
-    than num_palette entries -- test was done before num_palette was defined.
-  Fixed a png_convert_to_rfc1123() bug that converts day 31 to 0 (Steve Eddins).
-  Changed compiler flags in makefile.wat for better optimization (Pawel Mrochen).
-version 1.0.1b [May 2, 1998]
-  Relocated png_do_gray_to_rgb() within png_do_read_transformations() (Greg).
-  Relocated the png_composite macros from pngrtran.c to png.h (Greg).
-  Added makefile.sco (contributed by Mike Hopkirk).
-  Fixed two bugs (missing definitions of "istop") introduced in libpng-1.0.1a.
-  Fixed a bug in pngrtran.c that would set channels=5 under some circumstances.
-  More work on the Paeth-filtering, achieving imperceptible speedup (A Kleinert).
-  More work on loop optimization which may help when compiled with C++ compilers.
-  Added warnings when people try to use transforms they've defined out.
-  Collapsed 4 "i" and "c" loops into single "i" loops in pngrtran and pngwtran.
-  Revised paragraph about png_set_expand() in libpng.txt and libpng.3 (Greg)
-version 1.0.1c [May 9, 1998]
-  Fixed a bug in pngrtran.c (introduced in libpng-1.0.1a) where the masks for
-    filler bytes should have been 0xff instead of 0xf.
-  Added max_pixel_depth=32 in pngrutil.c when using FILLER with palette images.
-  Moved PNG_WRIGHT_WEIGHTED_FILTER_SUPPORTED and PNG_WRITE_FLUSH_SUPPORTED
-    out of the PNG_WRITE_TRANSFORMS_NOT_SUPPORTED block of pngconf.h
-  Added "PNG_NO_WRITE_TRANSFORMS" etc., as alternatives for *_NOT_SUPPORTED,
-    for consistency, in pngconf.h
-  Added individual "ifndef PNG_NO_CAPABILITY" for the capabilities in pngconf.h
-    to make it easier to remove unwanted capabilities via the compile line
+Source files with LF line endings (for Unix/Linux) and with a
+"configure" script
 
-Send comments/corrections/commendations to
-png-implement@dworkin.wustl.edu or to randeg@alumni.rpi.edu
+   libpng-1.0.41.tar.gz
+   libpng-1.0.41.tar.lzma
+     (Get the lzma codec from <http://tukaani.org/lzma>).
+   libpng-1.0.41.tar.bz2
+
+Source files with LF line endings (for Unix/Linux) without the
+"configure" script
+
+   libpng-1.0.41-no-config.tar.gz
+   libpng-1.0.41-no-config.tar.lzma
+   libpng-1.0.41-no-config.tar.bz2
+
+Source files with CRLF line endings (for Windows), without the
+"configure" script
+
+   lpng1041.zip
+   lpng1041.7z
+   lpng1041.tar.bz2
+
+Project files
+
+   libpng-1.0.41-project-netware.zip
+   libpng-1.0.41-project-wince.zip
+
+Other information:
+
+   libpng-1.0.41-README.txt
+   libpng-1.0.41-KNOWNBUGS.txt
+   libpng-1.0.41-LICENSE.txt
+   libpng-1.0.41-Y2K-compliance.txt
+
+Changes since the last public release (1.0.40):
+
+version 1.0.41 [October 31, 2008]
+
+  Revised makefile.darwin to fix shared library numbering.
+  Change png_set_gray_1_2_4_to_8() to png_set_expand_gray_1_2_4_to_8()
+    in example.c (debian bug report)
+  Changed remaining "key" to "png_ptr->chunkdata" in png_handle_tEXt()
+    to avoid memory leak after memory failure while reading tEXt chunk.`
+
+Send comments/corrections/commendations to png-mng-implement at lists.sf.net
+(subscription required; visit 
+https://lists.sourceforge.net/lists/listinfo/png-mng-implement
+to subscribe) or to glennrp at users.sourceforge.net
 
 Glenn R-P

INSTALL

@@ -1,17 +1,51 @@
 
-Installing libpng version %VER% %DATE%
+Installing libpng version 1.0.41 - October 31, 2008
 
-Before installing libpng, you must first install zlib.  zlib
-can usually be found wherever you got libpng.  zlib can be
-placed in another directory, at the same level as libpng.
-Note that your system might already have a preinstalled
-zlib, but you will still need to have access to the 
-zlib.h and zconf.h include files that correspond to the
-version of zlib that's installed.
+On Unix/Linux and similar systems, you can simply type
+
+    ./configure [--prefix=/path]
+    make check
+    make install
+
+and ignore the rest of this document.
+
+If configure does not work on your system and you have a reasonably
+up-to-date set of tools, running ./autogen.sh before running ./configure
+may fix the problem.  You can also run the individual commands in
+autogen.sh with the --force option, if supported by your version of
+the tools.  If you run 'libtoolize --force', though, this will replace
+the distributed, patched, version of ltmain.sh with an unpatched version
+and your shared library builds may fail to produce libraries with the
+correct version numbers.
+
+Instead, you can use one of the custom-built makefiles in the
+"scripts" directory
+
+    cp scripts/makefile.system makefile
+    make test
+    make install
+
+Or you can use one of the "projects" in the "projects" directory.
+
+If you want to use "cmake" (see www.cmake.org), copy CMakeLists.txt
+from the "scripts" directory to this directory and type
+
+   cmake . [-DPNG_MMX=YES] -DCMAKE_INSTALL_PREFIX=/path
+   make
+   make install
+
+Before installing libpng, you must first install zlib, if it
+is not already on your system.  zlib can usually be found
+wherever you got libpng.  zlib can be placed in another directory,
+at the same level as libpng.
+
+If your system already has a preinstalled zlib you will still need
+to have access to the zlib.h and zconf.h include files that
+correspond to the version of zlib that's installed.
 
 You can rename the directories that you downloaded (they
-might be called "libpng-%VER% or "lpng100" and "zlib-1.1.1"
-or "zlib111") so that you have directories called "zlib" and "libpng".
+might be called "libpng-1.0.41" or "lpng109" and "zlib-1.2.1"
+or "zlib121") so that you have directories called "zlib" and "libpng".
 
 Your directory structure should look like this:
 
@@ -21,6 +55,17 @@ Your directory structure should look like this:
           README
           *.h
           *.c
+          contrib
+             gregbook
+             pngminus
+             pngsuite
+             visupng
+          projects
+             beos
+             c5builder (Borland)
+             visualc6 (msvc)
+             netware.txt
+             wince.txt
           scripts
              makefile.*
           pngtest.png
@@ -32,40 +77,89 @@ Your directory structure should look like this:
           contrib
           etc.
 
-First enter the zlib directory and follow the instructions
-in zlib/README.  Then come back here and choose the
-appropriate makefile.sys in the scripts directory.
+If the line endings in the files look funny, you may wish to get the other
+distribution of libpng.  It is available in both tar.gz (UNIX style line
+endings) and zip (DOS style line endings) formats.
+
+If you are building libpng with MSVC, you can enter the
+libpng projects\visualc6 directory and follow the instructions in
+projects\visualc6\README.txt.
+
+You can build libpng for WindowsCE by downloading and installing
+the projects\wince directory as instructed in the projects\wince.txt file, and
+then following the instructions in the README* files.  Similarly, you can
+build libpng for Netware or Beos as instructed in projects\netware.txt
+or projects\beos.
+
+Else enter the zlib directory and follow the instructions in zlib/README,
+then come back here and run "configure" or choose the appropriate
+makefile.sys in the scripts directory.
+
 The files that are presently available in the scripts directory
 include
 
-      descrip.mms   =>  VMS makefile for MMS or MMK
-      makefile.std  =>  Generic UNIX makefile
-      makefile.knr  =>  Archaic UNIX Makefile that converts files with ansi2knr
-      makefile.dec  =>  DEC Alpha UNIX makefile
-      makefile.sgi  =>  Silicon Graphics IRIX makefile
-      makefile.sun  =>  Sun makefile
-      makefile.s2x  =>  Solaris 2.X makefile (gcc, creates libpng.so.2.1.0)
-      makefile.lnx  =>  Linux/ELF makefile (gcc, creates libpng.so.2.1.0)
-      makefile.mip  =>  MIPS makefile
-      makefile.aco  =>  Acorn makefile
-      makefile.ama  =>  Amiga makefile
-      smakefile.ppc =>  AMIGA smakefile for SAS C V6.58/7.00 PPC compiler
-                        (Requires SCOPTIONS, copied from scripts/SCOPTIONS.ppc)
-      makefile.atr  =>  Atari makefile
-      makefile.bor  =>  Borland makefile
-      build.bat     =>  MS-DOS batch file for Borland compiler
-      makefile.dj2  =>  DJGPP 2 makefile
-      makefile.msc  =>  Microsoft C makefile
-      makefile.tc3  =>  Turbo C 3.0 makefile
-      makefile.os2  =>  OS/2 Makefile (gcc and emx, requires pngos2.def)
-      pngos2.def    =>  OS/2 module definition file used by makefile.os2
-      makefile.wat  =>  Watcom 10a+ Makefile, 32-bit flat memory model
-      makevms.com   =>  VMS build script
+ CMakeLists.txt    =>  "cmake" script
+ makefile.std      =>  Generic UNIX makefile (cc, creates static libpng.a)
+ makefile.elf      =>  Linux/ELF makefile symbol versioning,
+                       gcc, creates libpng10.so.0.1.0.41)
+ makefile.linux    =>  Linux/ELF makefile
+                       (gcc, creates libpng10.so.0.1.0.41)
+ makefile.gcc      =>  Generic makefile (gcc, creates static libpng.a)
+ makefile.knr      =>  Archaic UNIX Makefile that converts files with
+                       ansi2knr (Requires ansi2knr.c from
+                       ftp://ftp.cs.wisc.edu/ghost)
+ makefile.aix      =>  AIX/gcc makefile
+ makefile.cygwin   =>  Cygwin/gcc makefile
+ makefile.darwin   =>  Darwin makefile, can use on MacosX
+ makefile.dec      =>  DEC Alpha UNIX makefile
+ makefile.freebsd  =>  FreeBSD makefile
+ makefile.hpgcc    =>  HPUX makefile using gcc
+ makefile.hpux     =>  HPUX (10.20 and 11.00) makefile
+ makefile.hp64     =>  HPUX (10.20 and 11.00) makefile, 64-bit
+ makefile.ibmc     =>  IBM C/C++ version 3.x for Win32 and OS/2 (static)
+ makefile.intel    =>  Intel C/C++ version 4.0 and later
+ libpng.icc        =>  Project file for IBM VisualAge/C++ version 4.0 or later
+ makefile.netbsd   =>  NetBSD/cc makefile, uses PNGGCCRD, makes libpng.so.
+ makefile.ne10bsd  =>  NetBSD/cc makefile, uses PNGGCCRD,
+                       makes libpng10.so
+ makefile.openbsd  =>  OpenBSD makefile
+ makefile.sgi      =>  Silicon Graphics IRIX makefile (cc, creates static lib)
+ makefile.sggcc    =>  Silicon Graphics (gcc,
+                       creates libpng10.so.0.1.0.41)
+ makefile.sunos    =>  Sun makefile
+ makefile.solaris  =>  Solaris 2.X makefile (gcc,
+                       creates libpng10.so.0.1.0.41)
+ makefile.solaris-x86 =>  Solaris/intelMMX 2.X makefile (gcc,
+                       creates libpng10.so.0.1.0.41)
+ makefile.so9      =>  Solaris 9 makefile (gcc,
+                       creates libpng10.so.0.1.0.41)
+ makefile.32sunu   =>  Sun Ultra 32-bit makefile
+ makefile.64sunu   =>  Sun Ultra 64-bit makefile
+ makefile.sco      =>  For SCO OSr5  ELF and Unixware 7 with Native cc
+ makefile.mips     =>  MIPS makefile
+ makefile.acorn    =>  Acorn makefile
+ makefile.amiga    =>  Amiga makefile
+ smakefile.ppc     =>  AMIGA smakefile for SAS C V6.58/7.00 PPC compiler
+                       (Requires SCOPTIONS, copied from scripts/SCOPTIONS.ppc)
+ makefile.atari    =>  Atari makefile
+ makefile.beos     =>  BEOS makefile for X86
+ makefile.bor      =>  Borland makefile (uses bcc)
+ makefile.bc32     =>  32-bit Borland C++ (all modules compiled in C mode)
+ makefile.tc3      =>  Turbo C 3.0 makefile
+ makefile.dj2      =>  DJGPP 2 makefile
+ makefile.msc      =>  Microsoft C makefile
+ makefile.vcwin32  =>  makefile for Microsoft Visual C++ 4.0 and later
+ makefile.os2      =>  OS/2 Makefile (gcc and emx, requires pngos2.def)
+ pngos2.def        =>  OS/2 module definition file used by makefile.os2
+ makefile.watcom   =>  Watcom 10a+ Makefile, 32-bit flat memory model
+ makevms.com       =>  VMS build script
+ descrip.mms       =>  VMS makefile for MMS or MMK
+ SCOPTIONS.ppc     =>  Used with smakefile.ppc
 
 Copy the file (or files) that you need from the
 scripts directory into this directory, for example
 
-   MSDOS example: copy scripts\makefile.msd makefile
+   MSDOS example: copy scripts\makefile.msc makefile
    UNIX example:    cp scripts/makefile.std makefile
 
 Read the makefile to see if you need to change any source or
@@ -74,14 +168,52 @@ target directories to match your preferences.
 Then read pngconf.h to see if you want to make any configuration
 changes.
 
-Then just run "make test" which will create the libpng library in
-this directory and run a quick test that reads the "pngtest.png"
-file and writes a "pngout.png" file that should be identical to it.
+Then just run "make" which will create the libpng library in
+this directory and "make test" which will run a quick test that reads
+the "pngtest.png" file and writes a "pngout.png" file that should be
+identical to it.  Look for "9782 zero samples" in the output of the
+test.  For more confidence, you can run another test by typing
+"pngtest pngnow.png" and looking for "289 zero samples" in the output.
+Also, you can run "pngtest -m contrib/pngsuite/*.png" and compare
+your output with the result shown in contrib/pngsuite/README.
 
 Most of the makefiles will allow you to run "make install" to
 put the library in its final resting place (if you want to
 do that, run "make install" in the zlib directory first if necessary).
+Some also allow you to run "make test-installed" after you have
+run "make install".
+
+If you encounter a compiler error message complaining about the
+lines
+      __png.h__ already includes setjmp.h;
+      __dont__ include it again.;
+This means you have compiled another module that includes setjmp.h,
+which is hazardous because the two modules might not include exactly
+the same setjmp.h.  If you are sure that you know what you are doing
+and that they are exactly the same, then you can comment out or
+delete the two lines.  Better yet, use the cexcept interface
+instead, as demonstrated in contrib/visupng of the libpng distribution.
 
 Further information can be found in the README and libpng.txt
-files, in the individual makefiles, and in png.h, and the manual
-pages libpng.3 and png.5.
+files, in the individual makefiles, in png.h, and the manual pages
+libpng.3 and png.5.
+
+
+Using the ./configure script -- 16 December 2002.
+=================================================
+
+
+The ./configure script should work compatibly with what scripts/makefile.*
+did, however there are some options you need to add to configure explicitly,
+which previously was done semi-automatically (if you didn't edit
+scripts/makefile.* yourself, that is)
+
+
+CFLAGS="-Wall -O -funroll-loops \
+-malign-loops=2 -malign-functions=2" ./configure --prefix=/usr/include \
+--with-pkgconfigdir=/usr/lib/pkgconfig --includedir=/usr/include
+
+You can alternatively specify --includedir=/usr/include, /usr/local/include,
+/usr/include/png12, or whatever.
+
+

KNOWNBUG

@@ -1,158 +1,22 @@
 
-Known bugs and suggested enhancements in libpng-1.0.1
+Known bugs in libpng version 1.0.41
 
-1. March 13, 1998 -- BUG -- pngtrans.c:
+1. February 23, 2006: The custom makefiles don't build libpng with -lz.
 
-   row_info->channels should be updated --
-   row_info->color_type should be updated --
+   STATUS: This is a subject of debate. The change will probably be made
+   as a part of a major overhaul of the makefiles in libpng version 1.4.0.
 
-   STATUS: I think this is all fixed in libpng-1.0.1a but needs
-   to be tested.
+2. February 24, 2006: The Makefile generated by the "configure" script
+   fails to install symbolic links
+   libpng12.so => libpng12.so.0.1.2.9betaN
+   that are generated by the custom makefiles.
 
-2. March 14, 1998 -- ENHANCEMENT -- Glenn
+3. September 4, 2007:  There is a report that pngtest crashes on MacOS 10.
 
-   We should add the G>GA, G>GX, G>AG, and G>XG transformations
-   in png_do_read_filler()
+   STATUS: workarounds are
+      1) Compile without optimization (crashes are observed with
+         -arch i386 and -O2 or -O3, using gcc-4.0.1).
+      2) Compile pngtest.c with PNG_DEBUG defined (the bug goes away if
+         you try to look at it).
+      3) Ignore the crash.  The library itself seems to be OK.
 
-   STATUS:  Implemented in libpng-1.0.1a
-
-3. March 14, 1998 -- BUG? -- Greg Roelofs
-
-   pngrtran.c:  if-test for channels/FILLER may be incorrect
-
-   STATUS: Under investigation.  Appears to be working correctly
-   in libpng-1.0.1c.
-
-4. March 15, 1998 -- BUG -- Kevin Bracey
-
-   pngwtran.c:
-      line 306: loop should count to row_info->width, not to
-             row_info->width*row_info->channnels
-
-   STATUS: Fixed in libpng-1.0.1a
-
-5. March 15, 1998 -- OPTIMIZATION -- Kevin Bracey
-
-   Loops need to be optimized everywhere
-
-   a. Make them count down instead of up -- Kevin Bracey
-   
-      Optimizing compilers don't need this, and making
-      the change would be error prone -- Tom Lane, Glenn R-P
-
-      Question whether i-- or --i is better.
-
-      STATUS: Under investigation.
-
-   b. Remove products and structure members from loop tests -- Glenn R-P
-
-      Can be accomplished without messing with loop guts.  This
-      was shown to be effective on optimized SGI compiler:
-
-              replace
-                  png_uint_32 i;
-                  for(i=0; i < s->a*s->b; i++)
-              with
-                  png_uint_32 i, istop;
-                  istop = s->a*s->b;
-                  for(i=0; i<istop; i++)
-
-      STATUS: Mostly done in libpng-1.0.1a, done for all important loops.
-              More done in libpng-1.0.1b.
-
-   c. Replace abs() with intrinsic ternary operations in Paeth
-      filtering -- Glenn R-P
-
-      STATUS: Done in libpng-1.0.1a
-      (can be restored to original behavior with #define PNG_USE_ABS)
-
-   d. In pngwutil.c, make separate simple loops to use when filter 
-      heuristic sums aren't needed. -- Glenn R-P
-
-      STATUS: Done in libpng-1.0.1a
-
-6. April 6, 1998 -- BUG -- bug in pngset.c (rowbytes too large) -- Bob Dellaca
-
-   pngset.c has a bug, introduced in version 0.99c, that sets rowbytes
-     too large when writing an image with bit_depth < 8
-
-   STATUS: Fixed in libpng-1.0.1a
-              
-7. April 10, 1998 -- BUG -- pngwutil weighted filtering bugs -- Glenn R-P
-
-   pngwutil.c has some bugs in the experimental weighted filter
-   algorithm (PNG_FILTER_XXX should be PNG_FILTER_VALUE_XXX in
-   several places)
-
-   STATUS: Andreas concurs.  Fixed in libpng-1.0.1a
-
-8. April 10, 1998 -- ENHANCEMENT -- run-time selection of malloc function
-   -- Bob Dellaca
-
-   pngmem.c currently provides a compile-time option to replace
-   png_malloc() and png_free().  It's been requested that these
-   be made possible at run time, via calls to new png_set_malloc_fn()
-   and png_set_free_fn() functions.
-
-   STATUS: Under consideration
-
-9. April 11, 1998 -- BUG -- incorrect truncation of tRNS data in
-   illegal PNG file where tRNS precedes PLTE -- Larry Reeve
-
-   There is a misplaced pngrutil code block that truncates tRNS if it has
-   more than num_palette entries -- test was done before num_palette was
-   defined.  Although the PNG file is illegal, it shouldn't crash apps.
-   There is a simple fix; just moving the test to the point after
-   num_palette has been defined.
-
-   STATUS: Fixed in libpng-1.0.1a
-
-10. April 16, 1998 -- BUG -- incorrect operation of png_convert_to_rfc1123
-   with 31st day of the month -- Steve Eddins
-
-   The "ptime->date % 31" is wrong, should be "ptime->date % 32".
-
-   STATUS: Fixed in libpng-1.0.1a
-
-11. April 21, 1998 -- ENHANCEMENT -- relocation of composite macros
-
-   png_composite() and png_composite_16() relocated to png.h
-
-   STATUS: Done in libpng-1.0.1b
-
-12. April 22, 1998 -- ENHANCEMENT -- makefile.sco
-
-   Mike Hopkirk contributed a makefile for SCO osr5 and sco UW7
-
-   STATUS: Added to libpng-1.0.1b distribution
-
-13: April 30, 1998 -- ENHANCEMENT -- warnings
-
-   When people define out some of the read transformations and then
-   try to use them, the request is silently ignored.  It was suggested
-   that a warning be issued in such cases.
-
-   STATUS: Done in libpng-1.0.1b
-
-14. May 2, 1998 -- BUG -- incorrect mask for filler bytes
-
-   In pngrtran.c, png_do_filler(), the masks for hi_filler and low_filler
-   should be 0xff instead of 0xf
-
-   STATUS: Fixed in libpng-1.0.1c
-
-15. May 3, 1998 -- BUG -- buffer overflow in png_do_read_filler()
-
-   In pngrutil.c, max_pixel_depth needs to be set to 32 when using
-   png_do_read_filler with palette images.
-
-   STATUS: Fixed in libpng-1.0.1c (see also items 1 and 3 above).
-
-16. May 3, 1998 -- BUG -- type definitions wrong on error functions -- Tom Lane
-
-   In png_create_xxx_struct(), the error functions should have typedef
-   png_voidp instead of (void *).  Needs to be corrected in the functions,
-   the prototypes in png.h, the example.c file, and libpng.txt and libpng.3
-
-   
-   STATUS: Fixed in libpng-1.0.1c

LICENSE

@@ -0,0 +1,109 @@
+
+This copy of the libpng notices is provided for your convenience.  In case of
+any discrepancy between this copy and the notices in the file png.h that is
+included in the libpng distribution, the latter shall prevail.
+
+COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
+
+If you modify libpng you may insert additional notices immediately following
+this sentence.
+
+libpng versions 1.2.6, August 15, 2004, through 1.0.41, October 31, 2008, are
+Copyright (c) 2004, 2006-2008 Glenn Randers-Pehrson, and are
+distributed according to the same disclaimer and license as libpng-1.2.5
+with the following individual added to the list of Contributing Authors
+
+   Cosmin Truta
+
+libpng versions 1.0.7, July 1, 2000, through 1.2.5 - October 3, 2002, are
+Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
+distributed according to the same disclaimer and license as libpng-1.0.6
+with the following individuals added to the list of Contributing Authors
+
+   Simon-Pierre Cadieux
+   Eric S. Raymond
+   Gilles Vollant
+
+and with the following additions to the disclaimer:
+
+   There is no warranty against interference with your enjoyment of the
+   library or against infringement.  There is no warranty that our
+   efforts or the library will fulfill any of your particular purposes
+   or needs.  This library is provided with all faults, and the entire
+   risk of satisfactory quality, performance, accuracy, and effort is with
+   the user.
+
+libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
+Copyright (c) 1998, 1999 Glenn Randers-Pehrson, and are
+distributed according to the same disclaimer and license as libpng-0.96,
+with the following individuals added to the list of Contributing Authors:
+
+   Tom Lane
+   Glenn Randers-Pehrson
+   Willem van Schaik
+
+libpng versions 0.89, June 1996, through 0.96, May 1997, are
+Copyright (c) 1996, 1997 Andreas Dilger
+Distributed according to the same disclaimer and license as libpng-0.88,
+with the following individuals added to the list of Contributing Authors:
+
+   John Bowler
+   Kevin Bracey
+   Sam Bushell
+   Magnus Holmgren
+   Greg Roelofs
+   Tom Tanner
+
+libpng versions 0.5, May 1995, through 0.88, January 1996, are
+Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+
+For the purposes of this copyright and license, "Contributing Authors"
+is defined as the following set of individuals:
+
+   Andreas Dilger
+   Dave Martindale
+   Guy Eric Schalnat
+   Paul Schmidt
+   Tim Wegner
+
+The PNG Reference Library is supplied "AS IS".  The Contributing Authors
+and Group 42, Inc. disclaim all warranties, expressed or implied,
+including, without limitation, the warranties of merchantability and of
+fitness for any purpose.  The Contributing Authors and Group 42, Inc.
+assume no liability for direct, indirect, incidental, special, exemplary,
+or consequential damages, which may result from the use of the PNG
+Reference Library, even if advised of the possibility of such damage.
+
+Permission is hereby granted to use, copy, modify, and distribute this
+source code, or portions hereof, for any purpose, without fee, subject
+to the following restrictions:
+
+1. The origin of this source code must not be misrepresented.
+
+2. Altered versions must be plainly marked as such and must not
+   be misrepresented as being the original source.
+
+3. This Copyright notice may not be removed or altered from any
+   source or altered source distribution.
+
+The Contributing Authors and Group 42, Inc. specifically permit, without
+fee, and encourage the use of this source code as a component to
+supporting the PNG file format in commercial products.  If you use this
+source code in a product, acknowledgment is not required but would be
+appreciated.
+
+
+A "png_get_copyright" function is available, for convenient use in "about"
+boxes and the like:
+
+   printf("%s",png_get_copyright(NULL));
+
+Also, the PNG logo (in PNG format, of course) is supplied in the
+files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
+
+Libpng is OSI Certified Open Source Software.  OSI Certified Open Source is a
+certification mark of the Open Source Initiative.
+
+Glenn Randers-Pehrson
+glennrp at users.sourceforge.net
+October 31, 2008

Makefile.am

@@ -0,0 +1,152 @@
+# Makefile.am:
+#   Source file for Makefile.in (and hence Makefile)
+#
+# Makefile.am need only be changed on a major version number
+# change (e.g. libpng12 --> libpng13).  In that case seach
+# this file for every instance of the old base name (libpng12)
+# and change to the new one (libpng13), then change the
+# -version-number settings below so that the new values have
+# the correct major part (first field).
+
+PNGLIB_BASENAME= libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@
+
+# libpng does not follow GNU file name conventions
+AUTOMAKE_OPTIONS = foreign
+
+# test programs - run on make check, make distcheck
+check_PROGRAMS= pngtest
+pngtest_SOURCES = pngtest.c
+pngtest_LDADD = libpng10.la
+TESTS = test-pngtest.sh
+TESTS_ENVIRONMENT= srcdir=$(srcdir) 
+
+# man pages
+dist_man_MANS= libpng.3 libpngpf.3 png.5
+
+# generate the -config scripts if required
+binconfigs= libpng10-config 
+EXTRA_SCRIPTS= libpng-config libpng10-config
+bin_SCRIPTS= @binconfigs@
+
+# rules to build libpng, only build the old library on request
+lib_LTLIBRARIES=libpng10.la @compatlib@
+EXTRA_LTLIBRARIES= libpng.la
+libpng10_la_SOURCES = png.c pngset.c pngget.c pngrutil.c pngtrans.c pngwutil.c \
+	pngread.c pngrio.c pngwio.c pngwrite.c pngrtran.c \
+	pngwtran.c pngmem.c pngerror.c pngpread.c \
+	png.h pngconf.h
+libpng_la_SOURCES = $(libpng10_la_SOURCES)
+
+libpng_la_CPPFLAGS = @LIBPNG_DEFINES@
+libpng10_la_CPPFLAGS = @LIBPNG_DEFINES@
+
+# MAJOR UPGRADE: the version-number settings below must be changed.
+libpng10_la_LDFLAGS = -no-undefined -export-dynamic \
+	-version-number 0:@PNGLIB_RELEASE@:0
+# -rpath is needed as automake doesn't know the directory
+libpng_la_LDFLAGS = -rpath '$(libdir)' -no-undefined -export-dynamic \
+	-version-number 2:@PNGLIB_RELEASE@:0
+
+if HAVE_LD_VERSION_SCRIPT
+  # Versioned symbols and restricted exports
+  libpng10_la_LDFLAGS += -Wl,--version-script=libpng.vers
+  libpng10_la_DEPENDENCIES = libpng.vers
+else
+  # Only restricted exports when possible
+  libpng10_la_LDFLAGS += -export-symbols libpng.sym
+  libpng10_la_DEPENDENCIES = libpng.sym
+endif
+libpng_la_DEPENDENCIES = $(libpng10_la_DEPENDENCIES)
+
+# Avoid depending upon Character Ranges.
+AN = '_abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'
+
+#distribute headers in /usr/include/libpng/*
+pkgincludedir= $(includedir)/$(PNGLIB_BASENAME)
+pkginclude_HEADERS= png.h pngconf.h
+
+# pkg-config stuff, note that libpng.pc is always required in order
+# to get the correct library
+pkgconfigdir = @pkgconfigdir@
+pkgconfig_DATA = libpng10.pc
+
+#extra source distribution files.
+EXTRA_DIST= \
+	ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO \
+	pngtest.png pngbar.png pngnow.png pngbar.jpg autogen.sh \
+	${srcdir}/projects/cbuilder5/* \
+	${srcdir}/projects/beos/* \
+	${srcdir}/projects/visualc6/* \
+	${srcdir}/projects/visualc71/* \
+	${srcdir}/projects/wince.txt \
+	${srcdir}/projects/netware.txt \
+	${srcdir}/scripts/* \
+	${srcdir}/contrib/gregbook/* \
+	${srcdir}/contrib/pngminus/* \
+	${srcdir}/contrib/pngsuite/* \
+	${srcdir}/contrib/visupng/* \
+	$(TESTS) \
+	example.c libpng-1.0.41.txt pngvcrd.c 
+
+CLEANFILES= pngout.png libpng10.pc libpng10-config libpng.vers \
+libpng.sym
+
+MAINTAINERCLEANFILES = Makefile.in aclocal.m4 config.guess config.h.in \
+config.sub configure depcomp install-sh ltmain.sh missing
+
+$(PNGLIB_BASENAME).pc: libpng.pc
+	cp libpng.pc $@
+
+$(PNGLIB_BASENAME)-config: libpng-config
+	cp libpng-config $@
+
+libpng.sym: png.h pngconf.h
+	rm -f $@ $@.new
+	$(CPP) @LIBPNG_DEFINES@ $(CPPFLAGS) -DPNG_BUILDSYMS $(srcdir)/png.h | \
+		$(SED) -n -e \
+		's|^.*PNG_FUNCTION_EXPORT[ 	]*\([$(AN)]*\).*$$|$(SYMBOL_PREFIX)\1|p' \
+		-e 's|^.*PNG_DATA_EXPORT[ 	]*\([$(AN)]*\).*$$|$(SYMBOL_PREFIX)\1|p' \
+			>$@.new
+	mv $@.new $@
+
+libpng.vers: libpng.sym
+	rm -f $@ $@.new
+	echo PNG@PNGLIB_MAJOR@@PNGLIB_MINOR@_0 '{global:' > $@.new
+	$(SED) s/$$/\;/ libpng.sym >> $@.new
+	echo 'local: *; };' >> $@.new
+	mv $@.new $@
+
+test: check
+
+# install the .../include headers as links to the new ones
+install-data-hook:
+	cd $(DESTDIR)$(includedir); rm -f png.h pngconf.h
+	cd $(DESTDIR)$(includedir); $(LN_S) $(PNGLIB_BASENAME)/png.h png.h
+	cd $(DESTDIR)$(includedir); $(LN_S) $(PNGLIB_BASENAME)/pngconf.h pngconf.h
+	cd $(DESTDIR)$(pkgconfigdir); rm -f libpng.pc
+	cd $(DESTDIR)$(pkgconfigdir); $(LN_S) $(PNGLIB_BASENAME).pc libpng.pc
+
+# do evil things to libpng to cause libpng10 to be used
+install-exec-hook:
+	cd $(DESTDIR)$(bindir); rm -f libpng-config
+	cd $(DESTDIR)$(bindir); $(LN_S) $(PNGLIB_BASENAME)-config libpng-config
+	@set -x;\
+	cd $(DESTDIR)$(libdir);\
+	for ext in a la so sl dylib; do\
+		rm -f libpng.$$ext;\
+                if test -f $(PNGLIB_BASENAME).$$ext; then\
+                       $(LN_S) $(PNGLIB_BASENAME).$$ext libpng.$$ext;\
+                fi;\
+	done
+
+uninstall-hook:
+	cd $(DESTDIR)$(includedir); rm -f png.h pngconf.h
+	rm -f $(DESTDIR)$(pkgconfigdir)/libpng.pc
+	rm -f $(DESTDIR)$(bindir)/libpng-config
+	@if test -n "@compatlib@"; then\
+		set -x;\
+		cd $(DESTDIR)$(libdir);\
+		for ext in a la so sl dylib; do\
+			rm -f libpng.$$ext;\
+		done;\
+	fi

README

@@ -1,14 +1,23 @@
-README for libpng %VER% (shared library 2.1)
+README for libpng version 1.0.41 - October 31, 2008 (shared library 10.0)
 See the note about version numbers near the top of png.h
 
 See INSTALL for instructions on how to install libpng.
 
-This is the first official release of libpng.  Don't let the fact that
-it's the first release fool you.  The libpng library has been in
-extensive use and testing for about two and a half years.  However, it's
-finally gotten to the stage where there haven't been significant
+Libpng comes in several distribution formats.  Get libpng-*.tar.gz,
+libpng-*.tar.lzma, or libpng-*.tar.bz2 if you want UNIX-style line
+endings in the text files, or lpng*.7z or lpng*.zip if you want DOS-style
+line endings.  You can get UNIX-style line endings from the *.zip file
+by using "unzip -a" but there seems to be no simple way to recover
+UNIX-style line endings from the *.7z file.  The *.tar.lzma file is
+recommended for *NIX users instead.
+
+Version 0.89 was the first official release of libpng.  Don't let the
+fact that it's the first release fool you.  The libpng library has been in
+extensive use and testing since mid-1995.  By late 1997 it had
+finally gotten to the stage where there hadn't been significant
 changes to the API in some time, and people have a bad feeling about
-libraries with versions < 1.0.
+libraries with versions < 1.0.  Version 1.0.0 was released in
+March 1998.
 
 ****
 Note that some of the changes to the png_info structure render this
@@ -28,8 +37,8 @@ directly, to avoid such problems in the future.
 It is important to note that the APIs do not make current programs
 that access the info struct directly incompatible with the new
 library.  However, it is strongly suggested that new programs use
-the new APIs (as shown in example.c), and older programs be converted
-to the new format, to facilitate upgrades in the future.
+the new APIs (as shown in example.c and pngtest.c), and older programs
+be converted to the new format, to facilitate upgrades in the future.
 ****
 
 Additions since 0.90 include the ability to compile libpng as a
@@ -49,8 +58,9 @@ to set different actions based on whether the CRC error occurred in a
 critical or an ancillary chunk.
 
 The changes made to the library, and bugs fixed are based on discussions
-on the PNG implementation mailing list <png-implement@dworking.wustl.edu>
-and not on material submitted to Guy.
+on the png-mng-implement mailing list
+and not on material submitted privately to Guy, Andreas, or Glenn.  They will
+forward any good suggestions to the list.
 
 For a detailed description on using libpng, read libpng.txt.  For
 examples of libpng in a program, see example.c and pngtest.c.  For usage
@@ -71,16 +81,15 @@ compression library that is useful for more things than just PNG files.
 You can use zlib as a drop-in replacement for fread() and fwrite() if
 you are so inclined.
 
-zlib should be available at the same place that libpng is.
-If not, it should be at ftp.uu.net in /graphics/png
-Eventually, it will be at ftp.uu.net in /pub/archiving/zip/zlib
+zlib should be available at the same place that libpng is, or at
+ftp://ftp.simplesystems.org/pub/png/src/
 
 You may also want a copy of the PNG specification.  It is available
-as an RFC and a W3C Recommendation.  Failing
-these resources you can try ftp.uu.net in the /graphics/png directory.
+as an RFC, a W3C Recommendation, and an ISO/IEC Standard.  You can find
+these at http://www.libpng.org/pub/png/pngdocs.html
 
-This code is currently being archived at ftp.uu.net in the
-/graphics/png directory, and on CompuServe, Lib 20 (PNG SUPPORT)
+This code is currently being archived at libpng.sf.net in the
+[DOWNLOAD] area, and on CompuServe, Lib 20 (PNG SUPPORT)
 at GO GRAPHSUP.  If you can't find it in any of those places,
 e-mail me, and I'll help you find it.
 
@@ -98,17 +107,21 @@ fix.  Please mention "libpng" somewhere in the subject line.  Thanks.
 This release was created and will be supported by myself (of course
 based in a large way on Guy's and Andreas' earlier work), and the PNG group.
 
-randeg@alumni.rpi.edu
-png-implement@dworkin.wustl.edu
+Send comments/corrections/commendations to png-mng-implement at lists.sf.net
+(subscription required; visit 
+https://lists.sourceforge.net/lists/listinfo/png-mng-implement
+to subscribe) or to glennrp at users.sourceforge.net
 
 You can't reach Guy, the original libpng author, at the addresses
 given in previous versions of this document.  He and Andreas will read mail
-addressed to the png-implement list, however.
+addressed to the png-mng-implement list, however.
 
 Please do not send general questions about PNG.  Send them to
-the address in the specification (png-group@w3.org).  At the same
-time, please do not send libpng questions to that address, send them to me
-or to png-implement@dworkin.wustl.edu.  I'll
+the (png-mng-misc at lists.sourceforge.net, subscription required, visit
+https://lists.sourceforge.net/lists/listinfo/png-mng-implement to subscribe)
+On the other hand,
+please do not send libpng questions to that address, send them to me
+or to the png-mng-implement list.  I'll
 get them in the end anyway.  If you have a question about something
 in the PNG specification that is related to using libpng, send it
 to me.  Send me any questions that start with "I was using libpng,
@@ -116,22 +129,23 @@ and ...".  If in doubt, send questions to me.  I'll bounce them
 to others, if necessary.
 
 Please do not send suggestions on how to change PNG.  We have
-been discussing PNG for three years now, and it is official and
+been discussing PNG for twelve years now, and it is official and
 finished.  If you have suggestions for libpng, however, I'll
-gladly listen.  Even if your suggestion is not used for version
-1.0, it may be used later.
+gladly listen.  Even if your suggestion is not used immediately,
+it may be used later.
 
 Files in this distribution:
 
+      ANNOUNCE      =>  Announcement of this version, with recent changes
       CHANGES       =>  Description of changes between libpng versions
+      KNOWNBUG      =>  List of known bugs and deficiencies
+      LICENSE       =>  License to use and redistribute libpng
       README        =>  This file
       TODO          =>  Things not implemented in the current library
-      ansi2knr.1    =>  Manual page for ansi2knr
-      ansi2knr.c    =>  Converts files to K&R style function declarations
-      build.bat     =>  MS-DOS batch file for Borland compiler
-      descrip.mms   =>  VMS project file
+      Y2KINFO       =>  Statement of Y2K compliance
       example.c     =>  Example code for using libpng functions
-      libpng.3      =>  manual page for libpng
+      libpng-*-*-diff.txt => Diff from previous release
+      libpng.3      =>  manual page for libpng (includes libpng.txt)
       libpng.txt    =>  Description of libpng and its functions
       libpngpf.3    =>  manual page for libpng's private functions
       png.5         =>  manual page for the PNG format
@@ -141,6 +155,8 @@ Files in this distribution:
       pngerror.c    =>  Error/warning message I/O functions
       pngget.c      =>  Functions for retrieving info from struct
       pngmem.c      =>  Memory handling functions
+      pngbar.png    =>  PNG logo, 88x31
+      pngnow.png    =>  PNG logo, 98x31
       pngpread.c    =>  Progressive reading functions
       pngread.c     =>  Read data/helper high-level functions
       pngrio.c      =>  Lowest-level data read I/O functions
@@ -154,41 +170,98 @@ Files in this distribution:
       pngwrite.c    =>  High-level write functions
       pngwtran.c    =>  Write data transformations
       pngwutil.c    =>  Write utility functions
+      contrib       =>  Contributions
+       gregbook         =>  source code for PNG reading and writing, from
+                            Greg Roelofs' "PNG: The Definitive Guide",
+                            O'Reilly, 1999
+       msvctest     =>  Builds and runs pngtest using a MSVC workspace
+       pngminus     =>  Simple pnm2png and png2pnm programs
+       pngsuite     =>  Test images
+       visupng      =>  Contains a MSVC workspace for VisualPng
+      projects      =>  Contains project files and workspaces for building DLL
+       beos             =>  Contains a Beos workspace for building libpng
+       c5builder        =>  Contains a Borland workspace for building libpng
+                            and zlib
+       visualc6         =>  Contains a Microsoft Visual C++ (MSVC) workspace
+                            for building libpng and zlib
+       netware.txt      =>  Contains instructions for downloading a set of
+                            project files for building libpng and zlib on
+                            Netware.
+       wince.txt        =>  Contains instructions for downloading a Microsoft
+                            Visual C++ (Windows CD Toolkit) workspace for
+                            building libpng and zlib on WindowsCE
       scripts       =>  Directory containing scripts for building libpng:
-        descrip.mms   =>  VMS makefile for MMS or MMK
-        makefile.std  =>  Generic UNIX makefile
-        makefile.knr  =>  Archaic UNIX Makefile that converts files with ansi2knr
-        makefile.dec  =>  DEC Alpha UNIX makefile
-        makefile.sgi  =>  Silicon Graphics IRIX makefile
-        makefile.sun  =>  Sun makefile
-        makefile.s2x  =>  Solaris 2.X makefile (gcc, creates libpng.so.2.1.0)
-        makefile.lnx  =>  Linux/ELF makefile (gcc, creates libpng.so.2.1.0)
-        makefile.mip  =>  MIPS makefile
-        makefile.aco  =>  Acorn makefile
-        makefile.ama  =>  Amiga makefile
-        smakefile.ppc =>  AMIGA smakefile for SAS C V6.58/7.00 PPC compiler
-                          (Requires SCOPTIONS, copied from scripts/SCOPTIONS.ppc)
-        makefile.atr  =>  Atari makefile
-        makefile.bor  =>  Borland makefile
-        build.bat     =>  MS-DOS batch file for Borland compiler
-        makefile.dj2  =>  DJGPP 2 makefile
-        makefile.msc  =>  Microsoft C makefile
-        makefile.tc3  =>  Turbo C 3.0 makefile
-        makefile.os2  =>  OS/2 Makefile (gcc and emx, requires pngos2.def)
-        makefile.wat  =>  Watcom 10a+ Makefile, 32-bit flat memory model
-        pngos2.def    =>  OS/2 module definition file used by makefile.os2
-        makevms.com   =>  VMS build script
+       descrip.mms      =>  VMS makefile for MMS or MMK
+       makefile.std     =>  Generic UNIX makefile (cc, creates static libpng.a)
+       makefile.elf     =>  Linux/ELF makefile symbol versioning,
+                            gcc, creates libpng10.so.0.1.0.41)
+       makefile.linux   =>  Linux/ELF makefile
+                            (gcc, creates libpng10.so.0.1.0.41)
+       makefile.gcmmx   =>  Linux/ELF makefile
+                            (gcc, creates libpng10.so.0.1.0.41,
+                            uses assembler code tuned for Intel MMX platform)
+       makefile.gcc     =>  Generic makefile (gcc, creates static libpng.a)
+       makefile.knr     =>  Archaic UNIX Makefile that converts files with
+                            ansi2knr (Requires ansi2knr.c from
+                            ftp://ftp.cs.wisc.edu/ghost)
+       makefile.aix     =>  AIX makefile
+       makefile.cygwin  =>  Cygwin/gcc makefile
+       makefile.darwin  =>  Darwin makefile
+       makefile.dec     =>  DEC Alpha UNIX makefile
+       makefile.freebsd =>  FreeBSD makefile
+       makefile.hpgcc   =>  HPUX makefile using gcc
+       makefile.hpux    =>  HPUX (10.20 and 11.00) makefile
+       makefile.hp64    =>  HPUX (10.20 and 11.00) makefile, 64 bit
+       makefile.ibmc    =>  IBM C/C++ version 3.x for Win32 and OS/2 (static)
+       makefile.intel   =>  Intel C/C++ version 4.0 and later
+       libpng.icc       =>  Project file, IBM VisualAge/C++ 4.0 or later
+       makefile.netbsd  =>  NetBSD/cc makefile, PNGGCCRD, makes libpng.so.
+       makefile.ne10bsd  =>  NetBSD/cc makefile, PNGGCCRD, makes libpng10.so
+       makefile.openbsd =>  OpenBSD makefile
+       makefile.sgi     =>  Silicon Graphics IRIX (cc, creates static lib)
+       makefile.sggcc   =>  Silicon Graphics
+                            (gcc, creates libpng10.so.0.1.0.41)
+       makefile.sunos   =>  Sun makefile
+       makefile.solaris =>  Solaris 2.X makefile
+                            (gcc, creates libpng10.so.0.1.0.41)
+       makefile.so9     =>  Solaris 9 makefile
+                            (gcc, creates libpng10.so.0.1.0.41)
+       makefile.32sunu  =>  Sun Ultra 32-bit makefile
+       makefile.64sunu  =>  Sun Ultra 64-bit makefile
+       makefile.sco     =>  For SCO OSr5  ELF and Unixware 7 with Native cc
+       makefile.mips    =>  MIPS makefile
+       makefile.acorn   =>  Acorn makefile
+       makefile.amiga   =>  Amiga makefile
+       smakefile.ppc    =>  AMIGA smakefile for SAS C V6.58/7.00 PPC
+                            compiler (Requires SCOPTIONS, copied from
+                            scripts/SCOPTIONS.ppc)
+       makefile.atari   =>  Atari makefile
+       makefile.beos    =>  BEOS makefile for X86
+       makefile.bor     =>  Borland makefile (uses bcc)
+       makefile.bc32    =>  32-bit Borland C++ (all modules compiled in C mode)
+       makefile.tc3     =>  Turbo C 3.0 makefile
+       makefile.dj2     =>  DJGPP 2 makefile
+       makefile.msc     =>  Microsoft C makefile
+       makefile.vcawin32=>  makefile for Microsoft Visual C++ 5.0 and
+                            later (uses assembler code tuned for Intel MMX
+                            platform)
+       makefile.vcwin32 =>  makefile for Microsoft Visual C++ 4.0 and
+                            later (does not use assembler code)
+       makefile.os2     =>  OS/2 Makefile (gcc and emx, requires pngos2.def)
+       pngos2.def       =>  OS/2 module definition file used by makefile.os2
+       makefile.watcom  =>  Watcom 10a+ Makefile, 32-bit flat memory model
+       makevms.com      =>  VMS build script
+       SCOPTIONS.ppc    =>  Used with smakefile.ppc
 
 Good luck, and happy coding.
 
--Glenn Randers-Pehrson
- Internet: randeg@alumni.rpi.edu
- Web: http://www.rpi.edu/~randeg/index.html
+-Glenn Randers-Pehrson (current maintainer)
+ Internet: glennrp at users.sourceforge.net
 
--Andreas Eric Dilger
- Internet: adilger@enel.ucalgary.ca
- Web: http://www-mddsp.enel.ucalgary.ca/People/adilger/
+-Andreas Eric Dilger (former maintainer, 1996-1997)
+ Internet: adilger at enel.ucalgary.ca
+ Web: http://members.shaw.ca/adilger/
 
--Guy Eric Schalnat
+-Guy Eric Schalnat (original author and former maintainer, 1995-1996)
  (formerly of Group 42, Inc)
- Internet: gschal@infinet.com
+ Internet: gschal at infinet.com

TODO

@@ -1,23 +1,24 @@
-TODO - list of things to do for libpng
+TODO - list of things to do for libpng:
 
-fix problem with C++ and EXTERN "C"
-add capability to set user malloc/free functions at run time
-add "grayscale->palette" transformation and "palette->grayscale" detection
-color to gray transformation
-improved dithering
-multi-lingual error and warning message support
-sPLT chunk handling
-cHRM transformation
-complete sRGB transformation (presently it simply uses gamma=0.45)
-man pages for function calls
-high-level API for reading images
-final bug fixes
-better documentation
-better filter selection
-   (counting huffman bits/precompression?  filter inertia?  filter costs?)
-optional palette creation
-histogram creation
-support for application-defined chunk handlers
-keep up with public chunks
-better C++ wrapper/full C++ implementation?
-text conversion between different code pages (Latin-1 -> Mac and DOS)
+Final bug fixes.
+Improve API by hiding the png_struct and png_info structs.
+Finish work on the no-floating-point version (including gamma compensation)
+Better C++ wrapper/full C++ implementation?
+Fix problem with C++ and EXTERN "C".
+cHRM transformation.
+Improve setjmp/longjmp usage or remove it in favor of returning error codes.
+Add "grayscale->palette" transformation and "palette->grayscale" detection.
+Improved dithering.
+Multi-lingual error and warning message support.
+Complete sRGB transformation (presently it simply uses gamma=0.45455).
+Man pages for function calls.
+Better documentation.
+Better filter selection
+   (counting huffman bits/precompression?  filter inertia?  filter costs?).
+Histogram creation.
+Text conversion between different code pages (Latin-1 -> Mac and DOS).
+Should we always malloc 2^bit_depth PLTE/tRNS/hIST entries for safety?
+Build gamma tables using fixed point (and do away with floating point entirely).
+Use greater precision when changing to linear gamma for compositing against
+  background and doing rgb-to-gray transformation.
+Investigate pre-incremented loop counters and other loop constructions.

Y2KINFO

@@ -0,0 +1,55 @@
+   Y2K compliance in libpng:
+   =========================
+
+      October 31, 2008
+
+      Since the PNG Development group is an ad-hoc body, we can't make
+      an official declaration.
+
+      This is your unofficial assurance that libpng from version 0.71 and
+      upward through 1.0.41 are Y2K compliant.  It is my belief that earlier
+      versions were also Y2K compliant.
+
+      Libpng only has three year fields.  One is a 2-byte unsigned integer
+      that will hold years up to 65535.  The other two hold the date in text
+      format, and will hold years up to 9999.
+
+      The integer is
+          "png_uint_16 year" in png_time_struct.
+
+      The strings are
+          "png_charp time_buffer" in png_struct and
+          "near_time_buffer", which is a local character string in png.c.
+
+      There are seven time-related functions:
+
+          png_convert_to_rfc_1123() in png.c
+            (formerly png_convert_to_rfc_1152() in error)
+          png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
+          png_convert_from_time_t() in pngwrite.c
+          png_get_tIME() in pngget.c
+          png_handle_tIME() in pngrutil.c, called in pngread.c
+          png_set_tIME() in pngset.c
+          png_write_tIME() in pngwutil.c, called in pngwrite.c
+
+      All appear to handle dates properly in a Y2K environment.  The
+      png_convert_from_time_t() function calls gmtime() to convert from system
+      clock time, which returns (year - 1900), which we properly convert to
+      the full 4-digit year.  There is a possibility that applications using
+      libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
+      function, or that they are incorrectly passing only a 2-digit year
+      instead of "year - 1900" into the png_convert_from_struct_tm() function,
+      but this is not under our control.  The libpng documentation has always
+      stated that it works with 4-digit years, and the APIs have been
+      documented as such.
+
+      The tIME chunk itself is also Y2K compliant.  It uses a 2-byte unsigned
+      integer to hold the year, and can hold years as large as 65535.
+
+      zlib, upon which libpng depends, is also Y2K compliant.  It contains
+      no date-related code.
+
+
+         Glenn Randers-Pehrson
+         libpng maintainer
+         PNG Development Group

ansi2knr.1

@@ -1,36 +0,0 @@
-.TH ANSI2KNR 1 "19 Jan 1996"
-.SH NAME
-ansi2knr \- convert ANSI C to Kernighan & Ritchie C
-.SH SYNOPSIS
-.I ansi2knr
-[--varargs] input_file [output_file]
-.SH DESCRIPTION
-If no output_file is supplied, output goes to stdout.
-.br
-There are no error messages.
-.sp
-.I ansi2knr
-recognizes function definitions by seeing a non-keyword identifier at the left
-margin, followed by a left parenthesis, with a right parenthesis as the last
-character on the line, and with a left brace as the first token on the
-following line (ignoring possible intervening comments).  It will recognize a
-multi-line header provided that no intervening line ends with a left or right
-brace or a semicolon.  These algorithms ignore whitespace and comments, except
-that the function name must be the first thing on the line.
-.sp
-The following constructs will confuse it:
-.br
-     - Any other construct that starts at the left margin and follows the
-above syntax (such as a macro or function call).
-.br
-     - Some macros that tinker with the syntax of the function header.
-.sp
-The --varargs switch is obsolete, and is recognized only for
-backwards compatibility.  The present version of
-.I ansi2knr
-will always attempt to convert a ... argument to va_alist and va_dcl.
-.SH AUTHOR
-L. Peter Deutsch <ghost@aladdin.com> wrote the original ansi2knr and
-continues to maintain the current version; most of the code in the current
-version is his work.  ansi2knr also includes contributions by Francois
-Pinard <pinard@iro.umontreal.ca> and Jim Avera <jima@netcom.com>.

ansi2knr.c

@@ -1,695 +0,0 @@
-/* ansi2knr.c */
-
-/* Convert ANSI C function definitions to K&R ("traditional C") syntax
-Copyright (C) 1989 Aladdin Enterprises.  All rights reserved.
-Copyright (C) 1988 Richard M. Stallman
-
-ansi2knr is distributed in the hope that it will be useful, but WITHOUT ANY
-WARRANTY.  No author or distributor accepts responsibility to anyone for the
-consequences of using it or for whether it serves any particular purpose or
-works at all, unless he says so in writing.  Refer to the GNU General Public
-License (the "GPL") for full details.
-
-Everyone is granted permission to copy, modify and redistribute ansi2knr,
-but only under the conditions described in the GPL.  A copy of this license
-is supposed to have been given to you along with ansi2knr so you can know
-your rights and responsibilities.  It should be in a file named COPYLEFT.
-[In the LIBPNG distribution, the GPL appears below, not in a separate file.]
-Among other things, the copyright notice and this notice must be preserved
-on all copies.
-
-We explicitly state here what we believe is already implied by the GPL: if
-the ansi2knr program is distributed as a separate source file and a
-separate executable file which are aggregated on a storage medium together
-with another program, this in itself does not bring the other program under
-the GPL, nor does the mere fact that such a program or the procedures for
-constructing it invoke the ansi2knr executable bring any other part of the
-program under the GPL.
-*/
-
-/*
----------- Here is the GNU GPL file COPYLEFT, referred to above ----------
------ These terms do NOT apply to the LIBPNG software itself; see README ------
-
-		    GHOSTSCRIPT GENERAL PUBLIC LICENSE
-		    (Clarified 11 Feb 1988)
-
- Copyright (C) 1988 Richard M. Stallman
- Everyone is permitted to copy and distribute verbatim copies of this
- license, but changing it is not allowed.  You can also use this wording
- to make the terms for other programs.
-
-  The license agreements of most software companies keep you at the
-mercy of those companies.  By contrast, our general public license is
-intended to give everyone the right to share Ghostscript.  To make sure
-that you get the rights we want you to have, we need to make
-restrictions that forbid anyone to deny you these rights or to ask you
-to surrender the rights.  Hence this license agreement.
-
-  Specifically, we want to make sure that you have the right to give
-away copies of Ghostscript, that you receive source code or else can get
-it if you want it, that you can change Ghostscript or use pieces of it
-in new free programs, and that you know you can do these things.
-
-  To make sure that everyone has such rights, we have to forbid you to
-deprive anyone else of these rights.  For example, if you distribute
-copies of Ghostscript, you must give the recipients all the rights that
-you have.  You must make sure that they, too, receive or can get the
-source code.  And you must tell them their rights.
-
-  Also, for our own protection, we must make certain that everyone finds
-out that there is no warranty for Ghostscript.  If Ghostscript is
-modified by someone else and passed on, we want its recipients to know
-that what they have is not what we distributed, so that any problems
-introduced by others will not reflect on our reputation.
-
-  Therefore we (Richard M. Stallman and the Free Software Foundation,
-Inc.) make the following terms which say what you must do to be allowed
-to distribute or change Ghostscript.
-
-
-			COPYING POLICIES
-
-  1. You may copy and distribute verbatim copies of Ghostscript source
-code as you receive it, in any medium, provided that you conspicuously
-and appropriately publish on each copy a valid copyright and license
-notice "Copyright (C) 1989 Aladdin Enterprises.  All rights reserved.
-Distributed by Free Software Foundation, Inc." (or with whatever year is
-appropriate); keep intact the notices on all files that refer to this
-License Agreement and to the absence of any warranty; and give any other
-recipients of the Ghostscript program a copy of this License Agreement
-along with the program.  You may charge a distribution fee for the
-physical act of transferring a copy.
-
-  2. You may modify your copy or copies of Ghostscript or any portion of
-it, and copy and distribute such modifications under the terms of
-Paragraph 1 above, provided that you also do the following:
-
-    a) cause the modified files to carry prominent notices stating
-    that you changed the files and the date of any change; and
-
-    b) cause the whole of any work that you distribute or publish,
-    that in whole or in part contains or is a derivative of Ghostscript
-    or any part thereof, to be licensed at no charge to all third
-    parties on terms identical to those contained in this License
-    Agreement (except that you may choose to grant more extensive
-    warranty protection to some or all third parties, at your option).
-
-    c) You may charge a distribution fee for the physical act of
-    transferring a copy, and you may at your option offer warranty
-    protection in exchange for a fee.
-
-Mere aggregation of another unrelated program with this program (or its
-derivative) on a volume of a storage or distribution medium does not bring
-the other program under the scope of these terms.
-
-  3. You may copy and distribute Ghostscript (or a portion or derivative
-of it, under Paragraph 2) in object code or executable form under the
-terms of Paragraphs 1 and 2 above provided that you also do one of the
-following:
-
-    a) accompany it with the complete corresponding machine-readable
-    source code, which must be distributed under the terms of
-    Paragraphs 1 and 2 above; or,
-
-    b) accompany it with a written offer, valid for at least three
-    years, to give any third party free (except for a nominal
-    shipping charge) a complete machine-readable copy of the
-    corresponding source code, to be distributed under the terms of
-    Paragraphs 1 and 2 above; or,
-
-    c) accompany it with the information you received as to where the
-    corresponding source code may be obtained.  (This alternative is
-    allowed only for noncommercial distribution and only if you
-    received the program in object code or executable form alone.)
-
-For an executable file, complete source code means all the source code for
-all modules it contains; but, as a special exception, it need not include
-source code for modules which are standard libraries that accompany the
-operating system on which the executable file runs.
-
-  4. You may not copy, sublicense, distribute or transfer Ghostscript
-except as expressly provided under this License Agreement.  Any attempt
-otherwise to copy, sublicense, distribute or transfer Ghostscript is
-void and your rights to use the program under this License agreement
-shall be automatically terminated.  However, parties who have received
-computer software programs from you with this License Agreement will not
-have their licenses terminated so long as such parties remain in full
-compliance.
-
-  5. If you wish to incorporate parts of Ghostscript into other free
-programs whose distribution conditions are different, write to the Free
-Software Foundation at 675 Mass Ave, Cambridge, MA 02139.  We have not
-yet worked out a simple rule that can be stated here, but we will often
-permit this.  We will be guided by the two goals of preserving the free
-status of all derivatives of our free software and of promoting the
-sharing and reuse of software.
-
-Your comments and suggestions about our licensing policies and our
-software are welcome!  Please contact the Free Software Foundation,
-Inc., 675 Mass Ave, Cambridge, MA 02139, or call (617) 876-3296.
-
-		       NO WARRANTY
-
-  BECAUSE GHOSTSCRIPT IS LICENSED FREE OF CHARGE, WE PROVIDE ABSOLUTELY
-NO WARRANTY, TO THE EXTENT PERMITTED BY APPLICABLE STATE LAW.  EXCEPT
-WHEN OTHERWISE STATED IN WRITING, FREE SOFTWARE FOUNDATION, INC, RICHARD
-M. STALLMAN, ALADDIN ENTERPRISES, L. PETER DEUTSCH, AND/OR OTHER PARTIES
-PROVIDE GHOSTSCRIPT "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER
-EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE
-ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF GHOSTSCRIPT IS WITH
-YOU.  SHOULD GHOSTSCRIPT PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL
-NECESSARY SERVICING, REPAIR OR CORRECTION.
-
-  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW WILL RICHARD M.
-STALLMAN, THE FREE SOFTWARE FOUNDATION, INC., L. PETER DEUTSCH, ALADDIN
-ENTERPRISES, AND/OR ANY OTHER PARTY WHO MAY MODIFY AND REDISTRIBUTE
-GHOSTSCRIPT AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING
-ANY LOST PROFITS, LOST MONIES, OR OTHER SPECIAL, INCIDENTAL OR
-CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE
-(INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED
-INACCURATE OR LOSSES SUSTAINED BY THIRD PARTIES OR A FAILURE OF THE
-PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS) GHOSTSCRIPT, EVEN IF YOU
-HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES, OR FOR ANY CLAIM
-BY ANY OTHER PARTY.
-
--------------------- End of file COPYLEFT ------------------------------
-*/
-
-/*
- * Usage:
-	ansi2knr input_file [output_file]
- * If no output_file is supplied, output goes to stdout.
- * There are no error messages.
- *
- * ansi2knr recognizes function definitions by seeing a non-keyword
- * identifier at the left margin, followed by a left parenthesis,
- * with a right parenthesis as the last character on the line,
- * and with a left brace as the first token on the following line
- * (ignoring possible intervening comments).
- * It will recognize a multi-line header provided that no intervening
- * line ends with a left or right brace or a semicolon.
- * These algorithms ignore whitespace and comments, except that
- * the function name must be the first thing on the line.
- * The following constructs will confuse it:
- *	- Any other construct that starts at the left margin and
- *	    follows the above syntax (such as a macro or function call).
- *	- Some macros that tinker with the syntax of the function header.
- */
-
-/*
- * The original and principal author of ansi2knr is L. Peter Deutsch
- * <ghost@aladdin.com>.  Other authors are noted in the change history
- * that follows (in reverse chronological order):
-	lpd 96-01-21 added code to cope with not HAVE_CONFIG_H and with
-		compilers that don't understand void, as suggested by
-		Tom Lane
-	lpd 96-01-15 changed to require that the first non-comment token
-		on the line following a function header be a left brace,
-		to reduce sensitivity to macros, as suggested by Tom Lane
-		<tgl@sss.pgh.pa.us>
-	lpd 95-06-22 removed #ifndefs whose sole purpose was to define
-		undefined preprocessor symbols as 0; changed all #ifdefs
-		for configuration symbols to #ifs
-	lpd 95-04-05 changed copyright notice to make it clear that
-		including ansi2knr in a program does not bring the entire
-		program under the GPL
-	lpd 94-12-18 added conditionals for systems where ctype macros
-		don't handle 8-bit characters properly, suggested by
-		Francois Pinard <pinard@iro.umontreal.ca>;
-		removed --varargs switch (this is now the default)
-	lpd 94-10-10 removed CONFIG_BROKETS conditional
-	lpd 94-07-16 added some conditionals to help GNU `configure',
-		suggested by Francois Pinard <pinard@iro.umontreal.ca>;
-		properly erase prototype args in function parameters,
-		contributed by Jim Avera <jima@netcom.com>;
-		correct error in writeblanks (it shouldn't erase EOLs)
-	lpd 89-xx-xx original version
- */
-
-/* Most of the conditionals here are to make ansi2knr work with */
-/* or without the GNU configure machinery. */
-
-#if HAVE_CONFIG_H
-# include <config.h>
-#endif
-
-#include <stdio.h>
-#include <ctype.h>
-
-#if HAVE_CONFIG_H
-
-/*
-   For properly autoconfiguring ansi2knr, use AC_CONFIG_HEADER(config.h).
-   This will define HAVE_CONFIG_H and so, activate the following lines.
- */
-
-# if STDC_HEADERS || HAVE_STRING_H
-#  include <string.h>
-# else
-#  include <strings.h>
-# endif
-
-#else /* not HAVE_CONFIG_H */
-
-/* Otherwise do it the hard way */
-
-# ifdef BSD
-#  include <strings.h>
-# else
-#  ifdef VMS
-    extern int strlen(), strncmp();
-#  else
-#   include <string.h>
-#  endif
-# endif
-
-#endif /* not HAVE_CONFIG_H */
-
-#if STDC_HEADERS
-# include <stdlib.h>
-#else
-/*
-   malloc and free should be declared in stdlib.h,
-   but if you've got a K&R compiler, they probably aren't.
- */
-# ifdef MSDOS
-#  include <malloc.h>
-# else
-#  ifdef VMS
-     extern char *malloc();
-     extern void free();
-#  else
-     extern char *malloc();
-     extern int free();
-#  endif
-# endif
-
-#endif
-
-/*
- * The ctype macros don't always handle 8-bit characters correctly.
- * Compensate for this here.
- */
-#ifdef isascii
-#  undef HAVE_ISASCII		/* just in case */
-#  define HAVE_ISASCII 1
-#else
-#endif
-#if STDC_HEADERS || !HAVE_ISASCII
-#  define is_ascii(c) 1
-#else
-#  define is_ascii(c) isascii(c)
-#endif
-
-#define is_space(c) (is_ascii(c) && isspace(c))
-#define is_alpha(c) (is_ascii(c) && isalpha(c))
-#define is_alnum(c) (is_ascii(c) && isalnum(c))
-
-/* Scanning macros */
-#define isidchar(ch) (is_alnum(ch) || (ch) == '_')
-#define isidfirstchar(ch) (is_alpha(ch) || (ch) == '_')
-
-/* Forward references */
-char *skipspace();
-int writeblanks();
-int test1();
-int convert1();
-
-/* The main program */
-int
-main(argc, argv)
-    int argc;
-    char *argv[];
-{	FILE *in, *out;
-#define bufsize 5000			/* arbitrary size */
-	char *buf;
-	char *line;
-	char *more;
-	/*
-	 * In previous versions, ansi2knr recognized a --varargs switch.
-	 * If this switch was supplied, ansi2knr would attempt to convert
-	 * a ... argument to va_alist and va_dcl; if this switch was not
-	 * supplied, ansi2knr would simply drop any such arguments.
-	 * Now, ansi2knr always does this conversion, and we only
-	 * check for this switch for backward compatibility.
-	 */
-	int convert_varargs = 1;
-
-	if ( argc > 1 && argv[1][0] == '-' )
-	  {	if ( !strcmp(argv[1], "--varargs") )
-		  {	convert_varargs = 1;
-			argc--;
-			argv++;
-		  }
-		else
-		  {	fprintf(stderr, "Unrecognized switch: %s\n", argv[1]);
-			exit(1);
-		  }
-	  }
-	switch ( argc )
-	   {
-	default:
-		printf("Usage: ansi2knr input_file [output_file]\n");
-		exit(0);
-	case 2:
-		out = stdout;
-		break;
-	case 3:
-		out = fopen(argv[2], "w");
-		if ( out == NULL )
-		   {	fprintf(stderr, "Cannot open output file %s\n", argv[2]);
-			exit(1);
-		   }
-	   }
-	in = fopen(argv[1], "r");
-	if ( in == NULL )
-	   {	fprintf(stderr, "Cannot open input file %s\n", argv[1]);
-		exit(1);
-	   }
-	fprintf(out, "#line 1 \"%s\"\n", argv[1]);
-	buf = malloc(bufsize);
-	line = buf;
-	while ( fgets(line, (unsigned)(buf + bufsize - line), in) != NULL )
-	   {
-test:		line += strlen(line);
-		switch ( test1(buf) )
-		   {
-		case 2:			/* a function header */
-			convert1(buf, out, 1, convert_varargs);
-			break;
-		case 1:			/* a function */
-			/* Check for a { at the start of the next line. */
-			more = ++line;
-f:			if ( line >= buf + (bufsize - 1) ) /* overflow check */
-			  goto wl;
-			if ( fgets(line, (unsigned)(buf + bufsize - line), in) == NULL )
-			  goto wl;
-			switch ( *skipspace(more, 1) )
-			  {
-			  case '{':
-			    /* Definitely a function header. */
-			    convert1(buf, out, 0, convert_varargs);
-			    fputs(more, out);
-			    break;
-			  case 0:
-			    /* The next line was blank or a comment: */
-			    /* keep scanning for a non-comment. */
-			    line += strlen(line);
-			    goto f;
-			  default:
-			    /* buf isn't a function header, but */
-			    /* more might be. */
-			    fputs(buf, out);
-			    strcpy(buf, more);
-			    line = buf;
-			    goto test;
-			  }
-			break;
-		case -1:		/* maybe the start of a function */
-			if ( line != buf + (bufsize - 1) ) /* overflow check */
-			  continue;
-			/* falls through */
-		default:		/* not a function */
-wl:			fputs(buf, out);
-			break;
-		   }
-		line = buf;
-	   }
-	if ( line != buf )
-	  fputs(buf, out);
-	free(buf);
-	fclose(out);
-	fclose(in);
-	return 0;
-}
-
-/* Skip over space and comments, in either direction. */
-char *
-skipspace(p, dir)
-    register char *p;
-    register int dir;			/* 1 for forward, -1 for backward */
-{	for ( ; ; )
-	   {	while ( is_space(*p) )
-		  p += dir;
-		if ( !(*p == '/' && p[dir] == '*') )
-		  break;
-		p += dir;  p += dir;
-		while ( !(*p == '*' && p[dir] == '/') )
-		   {	if ( *p == 0 )
-			  return p;	/* multi-line comment?? */
-			p += dir;
-		   }
-		p += dir;  p += dir;
-	   }
-	return p;
-}
-
-/*
- * Write blanks over part of a string.
- * Don't overwrite end-of-line characters.
- */
-int
-writeblanks(start, end)
-    char *start;
-    char *end;
-{	char *p;
-	for ( p = start; p < end; p++ )
-	  if ( *p != '\r' && *p != '\n' )
-	    *p = ' ';
-	return 0;
-}
-
-/*
- * Test whether the string in buf is a function definition.
- * The string may contain and/or end with a newline.
- * Return as follows:
- *	0 - definitely not a function definition;
- *	1 - definitely a function definition;
- *	2 - definitely a function prototype (NOT USED);
- *	-1 - may be the beginning of a function definition,
- *		append another line and look again.
- * The reason we don't attempt to convert function prototypes is that
- * Ghostscript's declaration-generating macros look too much like
- * prototypes, and confuse the algorithms.
- */
-int
-test1(buf)
-    char *buf;
-{	register char *p = buf;
-	char *bend;
-	char *endfn;
-	int contin;
-
-	if ( !isidfirstchar(*p) )
-	  return 0;		/* no name at left margin */
-	bend = skipspace(buf + strlen(buf) - 1, -1);
-	switch ( *bend )
-	   {
-	   case ';': contin = 0 /*2*/; break;
-	   case ')': contin = 1; break;
-	   case '{': return 0;		/* not a function */
-	   case '}': return 0;		/* not a function */
-	   default: contin = -1;
-	   }
-	while ( isidchar(*p) )
-	  p++;
-	endfn = p;
-	p = skipspace(p, 1);
-	if ( *p++ != '(' )
-	  return 0;		/* not a function */
-	p = skipspace(p, 1);
-	if ( *p == ')' )
-	  return 0;		/* no parameters */
-	/* Check that the apparent function name isn't a keyword. */
-	/* We only need to check for keywords that could be followed */
-	/* by a left parenthesis (which, unfortunately, is most of them). */
-	   {	static char *words[] =
-		   {	"asm", "auto", "case", "char", "const", "double",
-			"extern", "float", "for", "if", "int", "long",
-			"register", "return", "short", "signed", "sizeof",
-			"static", "switch", "typedef", "unsigned",
-			"void", "volatile", "while", 0
-		   };
-		char **key = words;
-		char *kp;
-		int len = endfn - buf;
-
-		while ( (kp = *key) != 0 )
-		   {	if ( strlen(kp) == len && !strncmp(kp, buf, len) )
-			  return 0;	/* name is a keyword */
-			key++;
-		   }
-	   }
-	return contin;
-}
-
-/* Convert a recognized function definition or header to K&R syntax. */
-int
-convert1(buf, out, header, convert_varargs)
-    char *buf;
-    FILE *out;
-    int header;			/* Boolean */
-    int convert_varargs;	/* Boolean */
-{	char *endfn;
-	register char *p;
-	char **breaks;
-	unsigned num_breaks = 2;	/* for testing */
-	char **btop;
-	char **bp;
-	char **ap;
-	char *vararg = 0;
-
-	/* Pre-ANSI implementations don't agree on whether strchr */
-	/* is called strchr or index, so we open-code it here. */
-	for ( endfn = buf; *(endfn++) != '('; )
-	  ;
-top:	p = endfn;
-	breaks = (char **)malloc(sizeof(char *) * num_breaks * 2);
-	if ( breaks == 0 )
-	   {	/* Couldn't allocate break table, give up */
-		fprintf(stderr, "Unable to allocate break table!\n");
-		fputs(buf, out);
-		return -1;
-	   }
-	btop = breaks + num_breaks * 2 - 2;
-	bp = breaks;
-	/* Parse the argument list */
-	do
-	   {	int level = 0;
-		char *lp = NULL;
-		char *rp;
-		char *end = NULL;
-
-		if ( bp >= btop )
-		   {	/* Filled up break table. */
-			/* Allocate a bigger one and start over. */
-			free((char *)breaks);
-			num_breaks <<= 1;
-			goto top;
-		   }
-		*bp++ = p;
-		/* Find the end of the argument */
-		for ( ; end == NULL; p++ )
-		   {	switch(*p)
-			   {
-			   case ',':
-				if ( !level ) end = p;
-				break;
-			   case '(':
-				if ( !level ) lp = p;
-				level++;
-				break;
-			   case ')':
-				if ( --level < 0 ) end = p;
-				else rp = p;
-				break;
-			   case '/':
-				p = skipspace(p, 1) - 1;
-				break;
-			   default:
-				;
-			   }
-		   }
-		/* Erase any embedded prototype parameters. */
-		if ( lp )
-		  writeblanks(lp + 1, rp);
-		p--;			/* back up over terminator */
-		/* Find the name being declared. */
-		/* This is complicated because of procedure and */
-		/* array modifiers. */
-		for ( ; ; )
-		   {	p = skipspace(p - 1, -1);
-			switch ( *p )
-			   {
-			   case ']':	/* skip array dimension(s) */
-			   case ')':	/* skip procedure args OR name */
-			   {	int level = 1;
-				while ( level )
-				 switch ( *--p )
-				   {
-				   case ']': case ')': level++; break;
-				   case '[': case '(': level--; break;
-				   case '/': p = skipspace(p, -1) + 1; break;
-				   default: ;
-				   }
-			   }
-				if ( *p == '(' && *skipspace(p + 1, 1) == '*' )
-				   {	/* We found the name being declared */
-					while ( !isidfirstchar(*p) )
-					  p = skipspace(p, 1) + 1;
-					goto found;
-				   }
-				break;
-			   default:
-				goto found;
-			   }
-		   }
-found:		if ( *p == '.' && p[-1] == '.' && p[-2] == '.' )
-		  {	if ( convert_varargs )
-			  {	*bp++ = "va_alist";
-				vararg = p-2;
-			  }
-			else
-			  {	p++;
-				if ( bp == breaks + 1 )	/* sole argument */
-				  writeblanks(breaks[0], p);
-				else
-				  writeblanks(bp[-1] - 1, p);
-				bp--;
-			  }
-		   }
-		else
-		   {	while ( isidchar(*p) ) p--;
-			*bp++ = p+1;
-		   }
-		p = end;
-	   }
-	while ( *p++ == ',' );
-	*bp = p;
-	/* Make a special check for 'void' arglist */
-	if ( bp == breaks+2 )
-	   {	p = skipspace(breaks[0], 1);
-		if ( !strncmp(p, "void", 4) )
-		   {	p = skipspace(p+4, 1);
-			if ( p == breaks[2] - 1 )
-			   {	bp = breaks;	/* yup, pretend arglist is empty */
-				writeblanks(breaks[0], p + 1);
-			   }
-		   }
-	   }
-	/* Put out the function name and left parenthesis. */
-	p = buf;
-	while ( p != endfn ) putc(*p, out), p++;
-	/* Put out the declaration. */
-	if ( header )
-	  {	fputs(");", out);
-		for ( p = breaks[0]; *p; p++ )
-		  if ( *p == '\r' || *p == '\n' )
-		    putc(*p, out);
-	  }
-	else
-	  {	for ( ap = breaks+1; ap < bp; ap += 2 )
-		  {	p = *ap;
-			while ( isidchar(*p) )
-			  putc(*p, out), p++;
-			if ( ap < bp - 1 )
-			  fputs(", ", out);
-		  }
-		fputs(")  ", out);
-		/* Put out the argument declarations */
-		for ( ap = breaks+2; ap <= bp; ap += 2 )
-		  (*ap)[-1] = ';';
-		if ( vararg != 0 )
-		  {	*vararg = 0;
-			fputs(breaks[0], out);		/* any prior args */
-			fputs("va_dcl", out);		/* the final arg */
-			fputs(bp[0], out);
-		  }
-		else
-		  fputs(breaks[0], out);
-	  }
-	free((char *)breaks);
-	return 0;
-}

autogen.sh

@@ -0,0 +1,25 @@
+#! /bin/sh
+# a quick hack script to generate necessary files from 
+# auto* tools.
+#
+# WARNING: if you run this you will change the versions
+# of the tools which are used and, maybe, required!
+        touch Makefile.am configure.ac
+{
+	echo "running libtoolize" >&2
+	libtoolize --force --copy --automake
+} && {
+	echo "running aclocal" >&2
+	aclocal
+} && {
+	echo "running autoheader [ignore the warnings]" >&2
+	autoheader
+} && {
+	echo "running automake" >&2
+	automake --force-missing --foreign -a -c
+} && {
+	echo "running autoconf" >&2
+	autoconf
+} &&
+	echo "autogen complete" >&2 ||
+	echo "ERROR: autogen.sh failed, autogen is incomplete" >&2

config.h.in

@@ -0,0 +1,83 @@
+/* config.h.in.  Generated from configure.ac by autoheader.  */
+
+/* Define to 1 if you have the <dlfcn.h> header file. */
+#undef HAVE_DLFCN_H
+
+/* Define to 1 if you have the <inttypes.h> header file. */
+#undef HAVE_INTTYPES_H
+
+/* Define to 1 if you have the `m' library (-lm). */
+#undef HAVE_LIBM
+
+/* Define to 1 if you have the `z' library (-lz). */
+#undef HAVE_LIBZ
+
+/* Define to 1 if you have the <malloc.h> header file. */
+#undef HAVE_MALLOC_H
+
+/* Define to 1 if you have the <memory.h> header file. */
+#undef HAVE_MEMORY_H
+
+/* Define to 1 if you have the `memset' function. */
+#undef HAVE_MEMSET
+
+/* Define to 1 if you have the `pow' function. */
+#undef HAVE_POW
+
+/* Define to 1 if you have the <stdint.h> header file. */
+#undef HAVE_STDINT_H
+
+/* Define to 1 if you have the <stdlib.h> header file. */
+#undef HAVE_STDLIB_H
+
+/* Define to 1 if you have the <strings.h> header file. */
+#undef HAVE_STRINGS_H
+
+/* Define to 1 if you have the <string.h> header file. */
+#undef HAVE_STRING_H
+
+/* Define to 1 if you have the <sys/stat.h> header file. */
+#undef HAVE_SYS_STAT_H
+
+/* Define to 1 if you have the <sys/types.h> header file. */
+#undef HAVE_SYS_TYPES_H
+
+/* Define to 1 if you have the <unistd.h> header file. */
+#undef HAVE_UNISTD_H
+
+/* Define to the sub-directory in which libtool stores uninstalled libraries.
+   */
+#undef LT_OBJDIR
+
+/* Name of package */
+#undef PACKAGE
+
+/* Define to the address where bug reports for this package should be sent. */
+#undef PACKAGE_BUGREPORT
+
+/* Define to the full name of this package. */
+#undef PACKAGE_NAME
+
+/* Define to the full name and version of this package. */
+#undef PACKAGE_STRING
+
+/* Define to the one symbol short name of this package. */
+#undef PACKAGE_TARNAME
+
+/* Define to the version of this package. */
+#undef PACKAGE_VERSION
+
+/* Define to 1 if you have the ANSI C header files. */
+#undef STDC_HEADERS
+
+/* Define to 1 if your <sys/time.h> declares `struct tm'. */
+#undef TM_IN_SYS_TIME
+
+/* Version number of package */
+#undef VERSION
+
+/* Define to empty if `const' does not conform to ANSI C. */
+#undef const
+
+/* Define to `unsigned int' if <sys/types.h> does not define. */
+#undef size_t

configure.ac

@@ -0,0 +1,148 @@
+# configure.ac
+
+dnl Process this file with autoconf to produce a configure script.
+dnl
+dnl Minor upgrades (compatible ABI): increment the package version
+dnl (third field in two places below) and set the PNGLIB_RELEASE
+dnl variable.
+dnl
+dnl Major upgrades (incompatible ABI): increment the package major
+dnl version (second field, or first if desired), set the minor
+dnl to 0, set PNGLIB_MAJOR below *and* follow the instructions in
+dnl Makefile.am to upgrade the package name.
+
+dnl This is here to prevent earlier autoconf from being used, it
+dnl should not be necessary to regenerate configure if the time
+dnl stamps are correct
+AC_PREREQ(2.59)
+
+dnl Version number stuff here:
+
+AC_INIT([libpng], [1.0.41], [png-mng-implement@lists.sourceforge.net])
+AM_INIT_AUTOMAKE
+dnl stop configure from automagically running automake
+AM_MAINTAINER_MODE
+
+PNGLIB_VERSION=1.0.41
+PNGLIB_MAJOR=1
+PNGLIB_MINOR=0
+PNGLIB_RELEASE=41
+
+dnl End of version number stuff
+
+AC_CONFIG_SRCDIR([pngget.c])
+AM_CONFIG_HEADER(config.h)
+
+# Checks for programs.
+AC_PROG_CC
+AC_PROG_LD
+AC_PROG_CPP
+AC_CHECK_TOOL(SED, sed, :)
+AC_LIBTOOL_WIN32_DLL
+AC_PROG_INSTALL
+AC_PROG_LN_S
+AC_PROG_MAKE_SET
+AC_PROG_LIBTOOL
+
+# Checks for header files.
+AC_HEADER_STDC
+AC_CHECK_HEADERS([malloc.h stdlib.h string.h strings.h])
+
+# Checks for typedefs, structures, and compiler characteristics.
+AC_C_CONST
+AC_TYPE_SIZE_T
+AC_STRUCT_TM
+
+# Checks for library functions.
+AC_FUNC_STRTOD
+AC_CHECK_FUNCS([memset], , AC_ERROR([memset not found in libc]))
+AC_CHECK_FUNCS([pow], , AC_CHECK_LIB(m, pow, , AC_ERROR([cannot find pow])) )
+AC_CHECK_LIB(z, zlibVersion, , AC_ERROR([zlib not installed]))
+
+LIBPNG_DEFINES=-DPNG_CONFIGURE_LIBPNG
+AC_MSG_CHECKING(
+  [if assembler code in pnggccrd.c can be compiled without PNG_NO_MMX_CODE])
+AC_TRY_COMPILE(
+  [#include "$srcdir/pnggccrd.c"],
+  [return 0;],
+  AC_MSG_RESULT(yes)
+  LIBPNG_NO_MMX="",
+  AC_MSG_RESULT(no)
+  LIBPNG_NO_MMX=-DPNG_NO_MMX_CODE)
+LIBPNG_DEFINES=$LIBPNG_DEFINES\ $LIBPNG_NO_MMX
+AC_SUBST(LIBPNG_DEFINES)
+AC_SUBST(LIBPNG_NO_MMX)
+
+AC_MSG_CHECKING([if libraries can be versioned])
+GLD=`$LD --help < /dev/null 2>/dev/null | grep version-script`
+if test "$GLD"; then
+    have_ld_version_script=yes
+    AC_MSG_RESULT(yes)
+else
+    have_ld_version_script=no
+    AC_MSG_RESULT(no)
+    AC_MSG_WARN(*** You have not enabled versioned symbols.)
+fi
+AM_CONDITIONAL(HAVE_LD_VERSION_SCRIPT, test "$have_ld_version_script" = "yes")
+
+if test "$have_ld_version_script" = "yes"; then
+    AC_MSG_CHECKING([for symbol prefix])
+    SYMBOL_PREFIX=`echo "PREFIX=__USER_LABEL_PREFIX__" \
+                   | ${CPP-${CC-gcc} -E} - 2>&1 \
+                   | ${EGREP-grep} "^PREFIX=" \
+                   | ${SED-sed} "s:^PREFIX=::"`
+    AC_SUBST(SYMBOL_PREFIX)
+    AC_MSG_RESULT($SYMBOL_PREFIX)
+fi
+
+# Substitutions for .in files
+AC_SUBST(PNGLIB_VERSION)
+AC_SUBST(PNGLIB_MAJOR)
+AC_SUBST(PNGLIB_MINOR)
+AC_SUBST(PNGLIB_RELEASE)
+
+# Additional arguments (and substitutions)
+# Allow the pkg-config directory to be set
+AC_ARG_WITH(pkgconfigdir,
+	AC_HELP_STRING([--with-pkgconfigdir],
+	[Use the specified pkgconfig dir (default is libdir/pkgconfig)]),
+	[pkgconfigdir=${withval}],
+	[pkgconfigdir='${libdir}/pkgconfig'])
+
+AC_SUBST([pkgconfigdir])
+AC_MSG_NOTICE([pkgconfig directory is ${pkgconfigdir}])
+
+# Make the *-config binary config scripts optional
+AC_ARG_WITH(binconfigs,
+	AC_HELP_STRING([--with-binconfigs],
+		[Generate shell libpng-config scripts as well as pkg-config data]
+		[@<:@default=yes@:>@]),
+	[if test "${withval}" = no; then
+		binconfigs=
+		AC_MSG_NOTICE([libpng-config scripts will not be built])
+	else
+		binconfigs='${binconfigs}'
+	fi],
+	[binconfigs='${binconfigs}'])
+AC_SUBST([binconfigs])
+
+# Allow the old version number library, libpng.so, to be removed from
+# the build
+AC_ARG_WITH(libpng-compat,
+	AC_HELP_STRING([--with-libpng-compat],
+		[Generate the obsolete libpng.so library @<:@default=yes@:>@]),
+	[if test "${withval}" = no; then
+		compatlib=
+		AC_MSG_NOTICE([libpng.so will not be built])
+	else
+		compatlib=libpng.la
+	fi],
+	[compatlib=libpng.la])
+AC_SUBST([compatlib])
+
+# Config files, substituting as above
+AC_CONFIG_FILES([Makefile libpng.pc:scripts/libpng.pc-configure.in])
+AC_CONFIG_FILES([libpng-config:scripts/libpng-config.in],
+		[chmod +x libpng-config])
+
+AC_OUTPUT

contrib/gregbook/COPYING

@@ -0,0 +1,340 @@
+		    GNU GENERAL PUBLIC LICENSE
+		       Version 2, June 1991
+
+ Copyright (C) 1989, 1991 Free Software Foundation, Inc.
+     59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+			    Preamble
+
+  The licenses for most software are designed to take away your
+freedom to share and change it.  By contrast, the GNU General Public
+License is intended to guarantee your freedom to share and change free
+software--to make sure the software is free for all its users.  This
+General Public License applies to most of the Free Software
+Foundation's software and to any other program whose authors commit to
+using it.  (Some other Free Software Foundation software is covered by
+the GNU Library General Public License instead.)  You can apply it to
+your programs, too.
+
+  When we speak of free software, we are referring to freedom, not
+price.  Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+this service if you wish), that you receive source code or can get it
+if you want it, that you can change the software or use pieces of it
+in new free programs; and that you know you can do these things.
+
+  To protect your rights, we need to make restrictions that forbid
+anyone to deny you these rights or to ask you to surrender the rights.
+These restrictions translate to certain responsibilities for you if you
+distribute copies of the software, or if you modify it.
+
+  For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must give the recipients all the rights that
+you have.  You must make sure that they, too, receive or can get the
+source code.  And you must show them these terms so they know their
+rights.
+
+  We protect your rights with two steps: (1) copyright the software, and
+(2) offer you this license which gives you legal permission to copy,
+distribute and/or modify the software.
+
+  Also, for each author's protection and ours, we want to make certain
+that everyone understands that there is no warranty for this free
+software.  If the software is modified by someone else and passed on, we
+want its recipients to know that what they have is not the original, so
+that any problems introduced by others will not reflect on the original
+authors' reputations.
+
+  Finally, any free program is threatened constantly by software
+patents.  We wish to avoid the danger that redistributors of a free
+program will individually obtain patent licenses, in effect making the
+program proprietary.  To prevent this, we have made it clear that any
+patent must be licensed for everyone's free use or not licensed at all.
+
+  The precise terms and conditions for copying, distribution and
+modification follow.
+
+		    GNU GENERAL PUBLIC LICENSE
+   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+
+  0. This License applies to any program or other work which contains
+a notice placed by the copyright holder saying it may be distributed
+under the terms of this General Public License.  The "Program", below,
+refers to any such program or work, and a "work based on the Program"
+means either the Program or any derivative work under copyright law:
+that is to say, a work containing the Program or a portion of it,
+either verbatim or with modifications and/or translated into another
+language.  (Hereinafter, translation is included without limitation in
+the term "modification".)  Each licensee is addressed as "you".
+
+Activities other than copying, distribution and modification are not
+covered by this License; they are outside its scope.  The act of
+running the Program is not restricted, and the output from the Program
+is covered only if its contents constitute a work based on the
+Program (independent of having been made by running the Program).
+Whether that is true depends on what the Program does.
+
+  1. You may copy and distribute verbatim copies of the Program's
+source code as you receive it, in any medium, provided that you
+conspicuously and appropriately publish on each copy an appropriate
+copyright notice and disclaimer of warranty; keep intact all the
+notices that refer to this License and to the absence of any warranty;
+and give any other recipients of the Program a copy of this License
+along with the Program.
+
+You may charge a fee for the physical act of transferring a copy, and
+you may at your option offer warranty protection in exchange for a fee.
+
+  2. You may modify your copy or copies of the Program or any portion
+of it, thus forming a work based on the Program, and copy and
+distribute such modifications or work under the terms of Section 1
+above, provided that you also meet all of these conditions:
+
+    a) You must cause the modified files to carry prominent notices
+    stating that you changed the files and the date of any change.
+
+    b) You must cause any work that you distribute or publish, that in
+    whole or in part contains or is derived from the Program or any
+    part thereof, to be licensed as a whole at no charge to all third
+    parties under the terms of this License.
+
+    c) If the modified program normally reads commands interactively
+    when run, you must cause it, when started running for such
+    interactive use in the most ordinary way, to print or display an
+    announcement including an appropriate copyright notice and a
+    notice that there is no warranty (or else, saying that you provide
+    a warranty) and that users may redistribute the program under
+    these conditions, and telling the user how to view a copy of this
+    License.  (Exception: if the Program itself is interactive but
+    does not normally print such an announcement, your work based on
+    the Program is not required to print an announcement.)
+
+These requirements apply to the modified work as a whole.  If
+identifiable sections of that work are not derived from the Program,
+and can be reasonably considered independent and separate works in
+themselves, then this License, and its terms, do not apply to those
+sections when you distribute them as separate works.  But when you
+distribute the same sections as part of a whole which is a work based
+on the Program, the distribution of the whole must be on the terms of
+this License, whose permissions for other licensees extend to the
+entire whole, and thus to each and every part regardless of who wrote it.
+
+Thus, it is not the intent of this section to claim rights or contest
+your rights to work written entirely by you; rather, the intent is to
+exercise the right to control the distribution of derivative or
+collective works based on the Program.
+
+In addition, mere aggregation of another work not based on the Program
+with the Program (or with a work based on the Program) on a volume of
+a storage or distribution medium does not bring the other work under
+the scope of this License.
+
+  3. You may copy and distribute the Program (or a work based on it,
+under Section 2) in object code or executable form under the terms of
+Sections 1 and 2 above provided that you also do one of the following:
+
+    a) Accompany it with the complete corresponding machine-readable
+    source code, which must be distributed under the terms of Sections
+    1 and 2 above on a medium customarily used for software interchange; or,
+
+    b) Accompany it with a written offer, valid for at least three
+    years, to give any third party, for a charge no more than your
+    cost of physically performing source distribution, a complete
+    machine-readable copy of the corresponding source code, to be
+    distributed under the terms of Sections 1 and 2 above on a medium
+    customarily used for software interchange; or,
+
+    c) Accompany it with the information you received as to the offer
+    to distribute corresponding source code.  (This alternative is
+    allowed only for noncommercial distribution and only if you
+    received the program in object code or executable form with such
+    an offer, in accord with Subsection b above.)
+
+The source code for a work means the preferred form of the work for
+making modifications to it.  For an executable work, complete source
+code means all the source code for all modules it contains, plus any
+associated interface definition files, plus the scripts used to
+control compilation and installation of the executable.  However, as a
+special exception, the source code distributed need not include
+anything that is normally distributed (in either source or binary
+form) with the major components (compiler, kernel, and so on) of the
+operating system on which the executable runs, unless that component
+itself accompanies the executable.
+
+If distribution of executable or object code is made by offering
+access to copy from a designated place, then offering equivalent
+access to copy the source code from the same place counts as
+distribution of the source code, even though third parties are not
+compelled to copy the source along with the object code.
+
+  4. You may not copy, modify, sublicense, or distribute the Program
+except as expressly provided under this License.  Any attempt
+otherwise to copy, modify, sublicense or distribute the Program is
+void, and will automatically terminate your rights under this License.
+However, parties who have received copies, or rights, from you under
+this License will not have their licenses terminated so long as such
+parties remain in full compliance.
+
+  5. You are not required to accept this License, since you have not
+signed it.  However, nothing else grants you permission to modify or
+distribute the Program or its derivative works.  These actions are
+prohibited by law if you do not accept this License.  Therefore, by
+modifying or distributing the Program (or any work based on the
+Program), you indicate your acceptance of this License to do so, and
+all its terms and conditions for copying, distributing or modifying
+the Program or works based on it.
+
+  6. Each time you redistribute the Program (or any work based on the
+Program), the recipient automatically receives a license from the
+original licensor to copy, distribute or modify the Program subject to
+these terms and conditions.  You may not impose any further
+restrictions on the recipients' exercise of the rights granted herein.
+You are not responsible for enforcing compliance by third parties to
+this License.
+
+  7. If, as a consequence of a court judgment or allegation of patent
+infringement or for any other reason (not limited to patent issues),
+conditions are imposed on you (whether by court order, agreement or
+otherwise) that contradict the conditions of this License, they do not
+excuse you from the conditions of this License.  If you cannot
+distribute so as to satisfy simultaneously your obligations under this
+License and any other pertinent obligations, then as a consequence you
+may not distribute the Program at all.  For example, if a patent
+license would not permit royalty-free redistribution of the Program by
+all those who receive copies directly or indirectly through you, then
+the only way you could satisfy both it and this License would be to
+refrain entirely from distribution of the Program.
+
+If any portion of this section is held invalid or unenforceable under
+any particular circumstance, the balance of the section is intended to
+apply and the section as a whole is intended to apply in other
+circumstances.
+
+It is not the purpose of this section to induce you to infringe any
+patents or other property right claims or to contest validity of any
+such claims; this section has the sole purpose of protecting the
+integrity of the free software distribution system, which is
+implemented by public license practices.  Many people have made
+generous contributions to the wide range of software distributed
+through that system in reliance on consistent application of that
+system; it is up to the author/donor to decide if he or she is willing
+to distribute software through any other system and a licensee cannot
+impose that choice.
+
+This section is intended to make thoroughly clear what is believed to
+be a consequence of the rest of this License.
+
+  8. If the distribution and/or use of the Program is restricted in
+certain countries either by patents or by copyrighted interfaces, the
+original copyright holder who places the Program under this License
+may add an explicit geographical distribution limitation excluding
+those countries, so that distribution is permitted only in or among
+countries not thus excluded.  In such case, this License incorporates
+the limitation as if written in the body of this License.
+
+  9. The Free Software Foundation may publish revised and/or new versions
+of the General Public License from time to time.  Such new versions will
+be similar in spirit to the present version, but may differ in detail to
+address new problems or concerns.
+
+Each version is given a distinguishing version number.  If the Program
+specifies a version number of this License which applies to it and "any
+later version", you have the option of following the terms and conditions
+either of that version or of any later version published by the Free
+Software Foundation.  If the Program does not specify a version number of
+this License, you may choose any version ever published by the Free Software
+Foundation.
+
+  10. If you wish to incorporate parts of the Program into other free
+programs whose distribution conditions are different, write to the author
+to ask for permission.  For software which is copyrighted by the Free
+Software Foundation, write to the Free Software Foundation; we sometimes
+make exceptions for this.  Our decision will be guided by the two goals
+of preserving the free status of all derivatives of our free software and
+of promoting the sharing and reuse of software generally.
+
+			    NO WARRANTY
+
+  11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
+FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
+OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
+PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
+OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS
+TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
+PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
+REPAIR OR CORRECTION.
+
+  12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
+REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
+INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
+OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
+TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
+YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
+PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGES.
+
+		     END OF TERMS AND CONDITIONS
+
+	    How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+convey the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+
+Also add information on how to contact you by electronic and paper mail.
+
+If the program is interactive, make it output a short notice like this
+when it starts in an interactive mode:
+
+    Gnomovision version 69, Copyright (C) year  name of author
+    Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, the commands you use may
+be called something other than `show w' and `show c'; they could even be
+mouse-clicks or menu items--whatever suits your program.
+
+You should also get your employer (if you work as a programmer) or your
+school, if any, to sign a "copyright disclaimer" for the program, if
+necessary.  Here is a sample; alter the names:
+
+  Yoyodyne, Inc., hereby disclaims all copyright interest in the program
+  `Gnomovision' (which makes passes at compilers) written by James Hacker.
+
+  <signature of Ty Coon>, 1 April 1989
+  Ty Coon, President of Vice
+
+This General Public License does not permit incorporating your program into
+proprietary programs.  If your program is a subroutine library, you may
+consider it more useful to permit linking proprietary applications with the
+library.  If this is what you want to do, use the GNU Library General
+Public License instead of this License.

contrib/gregbook/LICENSE

@@ -0,0 +1,50 @@
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      The contents of this file are DUAL-LICENSED.  You may modify and/or
+      redistribute this software according to the terms of one of the
+      following two licenses (at your option):
+
+
+      LICENSE 1 ("BSD-like with advertising clause"):
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+
+      LICENSE 2 (GNU GPL v2 or later):
+
+      This program is free software; you can redistribute it and/or modify
+      it under the terms of the GNU General Public License as published by
+      the Free Software Foundation; either version 2 of the License, or
+      (at your option) any later version.
+
+      This program is distributed in the hope that it will be useful,
+      but WITHOUT ANY WARRANTY; without even the implied warranty of
+      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+      GNU General Public License for more details.
+
+      You should have received a copy of the GNU General Public License
+      along with this program; if not, write to the Free Software Foundation,
+      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+  ---------------------------------------------------------------------------

contrib/gregbook/Makefile.mingw32

@@ -0,0 +1,130 @@
+# Sample makefile for rpng-win / rpng2-win / wpng using mingw32-gcc and make.
+# Greg Roelofs
+# Last modified:  2 June 2007
+#
+#	The programs built by this makefile are described in the book,
+#	"PNG:  The Definitive Guide," by Greg Roelofs (O'Reilly and
+#	Associates, 1999).  Go buy a copy, eh?  Well, OK, it's not
+#	generally for sale anymore, but it's the thought that counts,
+#	right?  (Hint:  http://www.libpng.org/pub/png/book/ )
+#
+# Invoke this makefile from a DOS-prompt window via:
+#
+#	make -f Makefile.mingw32
+#
+# This makefile assumes libpng and zlib have already been built or downloaded
+# and are in subdirectories at the same level as the current subdirectory
+# (as indicated by the PNGDIR and ZDIR macros below).  It makes no assumptions
+# at all about the mingw32 installation tree (W32DIR).  Edit as appropriate.
+#
+# Note that the names of the dynamic and static libpng and zlib libraries
+# used below may change in later releases of the libraries.  This makefile
+# builds both statically and dynamically linked executables by default.
+# (You need only one set, but for testing it can be handy to have both.)
+
+
+# macros --------------------------------------------------------------------
+
+#PNGDIR = ../..#		for libpng-x.y.z/contrib/gregbook builds
+PNGDIR = ../libpng-win32
+PNGINC = -I$(PNGDIR)
+PNGLIBd = $(PNGDIR)/libpng.dll.a	# dynamically linked
+PNGLIBs = $(PNGDIR)/libpng.a		# statically linked, local libpng
+
+#ZDIR = ../../../zlib-win32#	for libpng-x.y.z/contrib/gregbook builds
+ZDIR = ../zlib-win32
+ZINC = -I$(ZDIR)
+ZLIBd = $(ZDIR)/libzdll.a
+ZLIBs = $(ZDIR)/libz.a
+
+# change this to be the path where mingw32 installs its stuff:
+W32DIR =
+#W32DIR = /usr/local/cross-tools/i386-mingw32msvc
+W32INC = -I$(W32DIR)/include
+W32LIB = $(W32DIR)/lib/libuser32.a $(W32DIR)/lib/libgdi32.a
+
+CC = gcc
+#CC = i386-mingw32msvc-gcc #	e.g., Linux -> Win32 cross-compilation
+LD = $(CC)
+RM = rm -f
+CFLAGS = -O -Wall $(INCS) $(MINGW_CCFLAGS)
+# [note that -Wall is a gcc-specific compilation flag ("most warnings on")]
+# [-ansi, -pedantic and -W can also be used]
+LDFLAGS = $(MINGW_LDFLAGS)
+O = .o
+E = .exe
+
+INCS = $(PNGINC) $(ZINC) $(W32INC)
+RLIBSd = $(PNGLIBd) $(ZLIBd) $(W32LIB) -lm
+RLIBSs = $(PNGLIBs) $(ZLIBs) $(W32LIB) -lm
+WLIBSd = $(PNGLIBd) $(ZLIBd)
+WLIBSs = $(PNGLIBs) $(ZLIBs)
+
+RPNG   = rpng-win
+RPNG2  = rpng2-win
+WPNG   = wpng
+
+ROBJSd  = $(RPNG)$(O) readpng.pic$(O)
+ROBJS2d = $(RPNG2)$(O) readpng2.pic$(O)
+WOBJSd  = $(WPNG)$(O) writepng.pic$(O)
+
+RPNGs  = $(RPNG)-static
+RPNG2s = $(RPNG2)-static
+WPNGs  = $(WPNG)-static
+
+ROBJSs  = $(RPNG)$(O) readpng$(O)
+ROBJS2s = $(RPNG2)$(O) readpng2$(O)
+WOBJSs  = $(WPNG)$(O) writepng$(O)
+
+STATIC_EXES  = $(RPNGs)$(E) $(RPNG2s)$(E) $(WPNGs)$(E)
+DYNAMIC_EXES = $(RPNG)$(E) $(RPNG2)$(E) $(WPNG)$(E)
+
+EXES = $(STATIC_EXES) $(DYNAMIC_EXES)
+
+
+# implicit make rules -------------------------------------------------------
+
+.c$(O):
+	$(CC) -c $(CFLAGS) $<
+
+%.pic$(O): %.c
+	$(CC) -c $(CFLAGS) -DPNG_BUILD_DLL -o $@ $<
+
+
+# dependencies --------------------------------------------------------------
+
+all:  $(EXES)
+
+$(RPNGs)$(E): $(ROBJSs)
+	$(LD) $(LDFLAGS) -o $@ $(ROBJSs) $(RLIBSs)
+
+$(RPNG)$(E): $(ROBJSd)
+	$(LD) $(LDFLAGS) -o $@ $(ROBJSd) $(RLIBSd)
+
+$(RPNG2s)$(E): $(ROBJS2s)
+	$(LD) $(LDFLAGS) -o $@ $(ROBJS2s) $(RLIBSs)
+
+$(RPNG2)$(E): $(ROBJS2d)
+	$(LD) $(LDFLAGS) -o $@ $(ROBJS2d) $(RLIBSd)
+
+$(WPNGs)$(E): $(WOBJSs)
+	$(LD) $(LDFLAGS) -o $@ $(WOBJSs) $(WLIBSs)
+
+$(WPNG)$(E): $(WOBJSd)
+	$(LD) $(LDFLAGS) -o $@ $(WOBJSd) $(WLIBSd)
+
+$(RPNG)$(O):	$(RPNG).c readpng.h
+$(RPNG2)$(O):	$(RPNG2).c readpng2.h
+$(WPNG)$(O):	$(WPNG).c writepng.h
+
+readpng$(O) readpng.pic$(O):	readpng.c readpng.h
+readpng2$(O) readpng2.pic$(O):	readpng2.c readpng2.h
+writepng$(O) writepng.pic$(O):	writepng.c writepng.h
+
+
+# maintenance ---------------------------------------------------------------
+
+clean:
+	$(RM) $(EXES)
+	$(RM) $(ROBJSs) $(ROBJS2s) $(WOBJSs)
+	$(RM) $(ROBJSd) $(ROBJS2d) $(WOBJSd)

contrib/gregbook/Makefile.sgi

@@ -0,0 +1,104 @@
+# Sample makefile for rpng-x / rpng2-x / wpng for SGI using cc and make.
+# Greg Roelofs
+# Last modified:  7 March 2002
+#
+#	The programs built by this makefile are described in the book,
+#	"PNG:  The Definitive Guide," by Greg Roelofs (O'Reilly and
+#	Associates, 1999).  Go buy a copy, eh?  Buy some for friends
+#	and family, too.  (Not that this is a blatant plug or anything.)
+#
+# Invoke this makefile from a shell prompt in the usual way; for example:
+#
+#	make -f Makefile.sgi
+#
+# This makefile assumes libpng and zlib have already been built or downloaded
+# and are both installed in /usr/local/{include,lib} (as indicated by the
+# PNG* and Z* macros below).  Edit as appropriate--choose only ONE each of
+# the PNGINC, PNGLIB, ZINC and ZLIB lines.
+#
+# This makefile builds dynamically linked executables (against libpng and zlib,
+# that is), but that can be changed by uncommenting the appropriate PNGLIB and
+# ZLIB lines.
+
+
+# macros --------------------------------------------------------------------
+
+PNGINC = -I/usr/local/include/libpng12
+PNGLIB = -L/usr/local/lib -lpng12	  # dynamically linked against libpng
+#PNGLIB = /usr/local/lib/libpng12.a # statically linked against libpng
+# or:
+#PNGINC = -I../..
+#PNGLIB = -L../.. -lpng
+#PNGLIB = ../../libpng.a
+
+ZINC = -I/usr/local/include
+ZLIB = -L/usr/local/lib -lz		# dynamically linked against zlib
+#ZLIB = /usr/local/lib/libz.a		# statically linked against zlib
+#ZINC = -I../zlib
+#ZLIB = -L../zlib -lz
+#ZLIB = ../../../zlib/libz.a
+
+XINC = -I/usr/include/X11		# old-style, stock X distributions
+XLIB = -L/usr/lib/X11 -lX11
+#XINC = -I/usr/openwin/include    	# Sun workstations (OpenWindows)
+#XLIB = -L/usr/openwin/lib -lX11
+#XINC = -I/usr/X11R6/include		# new X distributions (XFree86, etc.)
+#XLIB = -L/usr/X11R6/lib -lX11
+
+INCS = $(PNGINC) $(ZINC) $(XINC)
+RLIBS = $(PNGLIB) $(ZLIB) $(XLIB) -lm
+WLIBS = $(PNGLIB) $(ZLIB)
+
+CC = cc
+LD = cc
+RM = rm -f
+# ABI must be the same as that used to build libpng.
+ABI=
+CFLAGS = $(ABI) -O -fullwarn $(INCS)
+LDFLAGS = $(ABI)
+O = .o
+E =
+
+RPNG  = rpng-x
+RPNG2 = rpng2-x
+WPNG  = wpng
+
+ROBJS  = $(RPNG)$(O) readpng$(O)
+ROBJS2 = $(RPNG2)$(O) readpng2$(O)
+WOBJS  = $(WPNG)$(O) writepng$(O)
+
+EXES = $(RPNG)$(E) $(RPNG2)$(E) $(WPNG)$(E)
+
+
+# implicit make rules -------------------------------------------------------
+
+.c$(O):
+	$(CC) -c $(CFLAGS) $<
+
+
+# dependencies --------------------------------------------------------------
+
+all:  $(EXES)
+
+$(RPNG)$(E): $(ROBJS)
+	$(LD) $(LDFLAGS) -o $@ $(ROBJS) $(RLIBS)
+
+$(RPNG2)$(E): $(ROBJS2)
+	$(LD) $(LDFLAGS) -o $@ $(ROBJS2) $(RLIBS)
+
+$(WPNG)$(E): $(WOBJS)
+	$(LD) $(LDFLAGS) -o $@ $(WOBJS) $(WLIBS)
+
+$(RPNG)$(O):	$(RPNG).c readpng.h
+$(RPNG2)$(O):	$(RPNG2).c readpng2.h
+$(WPNG)$(O):	$(WPNG).c writepng.h
+
+readpng$(O):	readpng.c readpng.h
+readpng2$(O):	readpng2.c readpng2.h
+writepng$(O):	writepng.c writepng.h
+
+
+# maintenance ---------------------------------------------------------------
+
+clean:
+	$(RM) $(EXES) $(ROBJS) $(ROBJS2) $(WOBJS)

contrib/gregbook/Makefile.unx

@@ -0,0 +1,132 @@
+# Sample makefile for rpng-x / rpng2-x / wpng using gcc and make.
+# Greg Roelofs
+# Last modified:  2 June 2007
+#
+#	The programs built by this makefile are described in the book,
+#	"PNG:  The Definitive Guide," by Greg Roelofs (O'Reilly and
+#	Associates, 1999).  Go buy a copy, eh?  Well, OK, it's not
+#	generally for sale anymore, but it's the thought that counts,
+#	right?  (Hint:  http://www.libpng.org/pub/png/book/ )
+#
+# Invoke this makefile from a shell prompt in the usual way; for example:
+#
+#	make -f Makefile.unx
+#
+# This makefile assumes libpng and zlib have already been built or downloaded
+# and are installed in /usr/local/{include,lib} or as otherwise indicated by
+# the PNG* and Z* macros below.  Edit as appropriate--choose only ONE each of
+# the PNGINC, PNGLIBd, PNGLIBs, ZINC, ZLIBd and ZLIBs lines.
+#
+# This makefile builds both dynamically and statically linked executables
+# (against libpng and zlib, that is), but that can be changed by modifying
+# the "EXES =" line.  (You need only one set, but for testing it can be handy
+# to have both.)
+
+
+# macros --------------------------------------------------------------------
+
+#PNGDIR = /usr/local/lib
+#PNGINC = -I/usr/local/include/libpng12
+#PNGLIBd = -L$(PNGDIR) -lpng12 # dynamically linked, installed libpng
+#PNGLIBs = $(PNGDIR)/libpng12.a # statically linked, installed libpng
+# or:
+PNGDIR = ../..#	this one is for libpng-x.y.z/contrib/gregbook builds
+#PNGDIR = ../libpng
+PNGINC = -I$(PNGDIR)
+PNGLIBd = -Wl,-rpath,$(PNGDIR) -L$(PNGDIR) -lpng12	# dynamically linked
+PNGLIBs = $(PNGDIR)/libpng.a		# statically linked, local libpng
+
+ZDIR = /usr/local/lib
+#ZDIR = /usr/lib64
+ZINC = -I/usr/local/include
+ZLIBd = -L$(ZDIR) -lz			# dynamically linked against zlib
+ZLIBs = $(ZDIR)/libz.a			# statically linked against zlib
+# or:
+#ZDIR = ../zlib
+#ZINC = -I$(ZDIR)
+#ZLIBd = -Wl,-rpath,$(ZDIR) -L$(ZDIR) -lz  # -rpath allows in-place testing
+#ZLIBs = $(ZDIR)/libz.a
+
+#XINC = -I/usr/include			# old-style, stock X distributions
+#XLIB = -L/usr/lib/X11 -lX11		#  (including SGI IRIX)
+#XINC = -I/usr/openwin/include		# Sun workstations (OpenWindows)
+#XLIB = -L/usr/openwin/lib -lX11
+XINC = -I/usr/X11R6/include		# new X distributions (X.org, etc.)
+XLIB = -L/usr/X11R6/lib -lX11
+#XLIB = -L/usr/X11R6/lib64 -lX11	# e.g., Red Hat on AMD64
+
+INCS = $(PNGINC) $(ZINC) $(XINC)
+RLIBSd = $(PNGLIBd) $(ZLIBd) $(XLIB) -lm
+RLIBSs = $(PNGLIBs) $(ZLIBs) $(XLIB) -lm
+WLIBSd = $(PNGLIBd) $(ZLIBd) -lm
+WLIBSs = $(PNGLIBs) $(ZLIBs)
+
+CC = gcc
+LD = gcc
+RM = rm -f
+CFLAGS = -O -Wall $(INCS) -DFEATURE_LOOP
+# [note that -Wall is a gcc-specific compilation flag ("most warnings on")]
+# [-ansi, -pedantic and -W can also be used]
+LDFLAGS =
+O = .o
+E =
+
+RPNG   = rpng-x
+RPNG2  = rpng2-x
+WPNG   = wpng
+
+RPNGs  = $(RPNG)-static
+RPNG2s = $(RPNG2)-static
+WPNGs  = $(WPNG)-static
+
+ROBJS  = $(RPNG)$(O) readpng$(O)
+ROBJS2 = $(RPNG2)$(O) readpng2$(O)
+WOBJS  = $(WPNG)$(O) writepng$(O)
+
+STATIC_EXES  = $(RPNGs)$(E) $(RPNG2s)$(E) $(WPNGs)$(E)
+DYNAMIC_EXES = $(RPNG)$(E) $(RPNG2)$(E) $(WPNG)$(E)
+
+EXES = $(STATIC_EXES) $(DYNAMIC_EXES)
+
+
+# implicit make rules -------------------------------------------------------
+
+.c$(O):
+	$(CC) -c $(CFLAGS) $<
+
+
+# dependencies --------------------------------------------------------------
+
+all:  $(EXES)
+
+$(RPNGs)$(E): $(ROBJS)
+	$(LD) $(LDFLAGS) -o $@ $(ROBJS) $(RLIBSs)
+
+$(RPNG)$(E): $(ROBJS)
+	$(LD) $(LDFLAGS) -o $@ $(ROBJS) $(RLIBSd)
+
+$(RPNG2s)$(E): $(ROBJS2)
+	$(LD) $(LDFLAGS) -o $@ $(ROBJS2) $(RLIBSs)
+
+$(RPNG2)$(E): $(ROBJS2)
+	$(LD) $(LDFLAGS) -o $@ $(ROBJS2) $(RLIBSd)
+
+$(WPNGs)$(E): $(WOBJS)
+	$(LD) $(LDFLAGS) -o $@ $(WOBJS) $(WLIBSs)
+
+$(WPNG)$(E): $(WOBJS)
+	$(LD) $(LDFLAGS) -o $@ $(WOBJS) $(WLIBSd)
+
+$(RPNG)$(O):	$(RPNG).c readpng.h
+$(RPNG2)$(O):	$(RPNG2).c readpng2.h
+$(WPNG)$(O):	$(WPNG).c writepng.h
+
+readpng$(O):	readpng.c readpng.h
+readpng2$(O):	readpng2.c readpng2.h
+writepng$(O):	writepng.c writepng.h
+
+
+# maintenance ---------------------------------------------------------------
+
+clean:
+	$(RM) $(EXES) $(ROBJS) $(ROBJS2) $(WOBJS)

contrib/gregbook/Makefile.w32

@@ -0,0 +1,113 @@
+# Sample makefile for rpng-win / rpng2-win / wpng using MSVC and NMAKE.
+# Greg Roelofs
+# Last modified:  2 June 2007
+#
+#	The programs built by this makefile are described in the book,
+#	"PNG:  The Definitive Guide," by Greg Roelofs (O'Reilly and
+#	Associates, 1999).  Go buy a copy, eh?  Well, OK, it's not
+#	generally for sale anymore, but it's the thought that counts,
+#	right?  (Hint:  http://www.libpng.org/pub/png/book/ )
+#
+# Invoke this makefile from a DOS prompt window via:
+#
+#	%devstudio%\vc\bin\vcvars32.bat
+#	nmake -nologo -f Makefile.w32
+#
+# where %devstudio% is the installation directory for MSVC / DevStudio.  If
+# you get "environment out of space" errors, create a desktop shortcut with
+# "c:\windows\command.com /e:4096" as the program command line and set the
+# working directory to this directory.  Then double-click to open the new
+# DOS-prompt window with a bigger environment and retry the commands above.
+# 
+# This makefile assumes libpng and zlib have already been built or downloaded
+# and are in subdirectories at the same level as the current subdirectory
+# (as indicated by the PNGPATH and ZPATH macros below).  Edit as appropriate.
+#
+# Note that the names of the dynamic and static libpng and zlib libraries
+# used below may change in later releases of the libraries.  This makefile
+# builds statically linked executables, but that can be changed by uncom-
+# menting the appropriate PNGLIB and ZLIB lines.
+
+!include <ntwin32.mak>
+
+
+# macros --------------------------------------------------------------------
+
+PNGPATH = ../libpng
+PNGINC = -I$(PNGPATH)
+#PNGLIB = $(PNGPATH)/pngdll.lib
+PNGLIB = $(PNGPATH)/libpng.lib
+
+ZPATH = ../zlib
+ZINC = -I$(ZPATH)
+#ZLIB = $(ZPATH)/zlibdll.lib
+ZLIB = $(ZPATH)/zlibstat.lib
+
+WINLIBS = -defaultlib:user32.lib gdi32.lib
+# ["real" apps may also need comctl32.lib, comdlg32.lib, winmm.lib, etc.]
+
+INCS = $(PNGINC) $(ZINC)
+RLIBS = $(PNGLIB) $(ZLIB) $(WINLIBS)
+WLIBS = $(PNGLIB) $(ZLIB)
+
+CC = cl
+LD = link
+RM = del
+CFLAGS = -nologo -O -W3 $(INCS) $(cvars)
+# [note that -W3 is an MSVC-specific compilation flag ("all warnings on")]
+# [see %devstudio%\vc\include\win32.mak for cvars macro definition]
+O = .obj
+E = .exe
+
+RLDFLAGS = -nologo -subsystem:windows
+WLDFLAGS = -nologo
+
+RPNG  = rpng-win
+RPNG2 = rpng2-win
+WPNG  = wpng
+
+ROBJS  = $(RPNG)$(O) readpng$(O)
+ROBJS2 = $(RPNG2)$(O) readpng2$(O)
+WOBJS  = $(WPNG)$(O) writepng$(O)
+
+EXES = $(RPNG)$(E) $(RPNG2)$(E) $(WPNG)$(E)
+
+
+# implicit make rules -------------------------------------------------------
+
+.c$(O):
+	$(CC) -c $(CFLAGS) $<
+
+
+# dependencies --------------------------------------------------------------
+
+all:  $(EXES)
+
+$(RPNG)$(E): $(ROBJS)
+	$(LD) $(RLDFLAGS) -out:$@ $(ROBJS) $(RLIBS)
+
+$(RPNG2)$(E): $(ROBJS2)
+	$(LD) $(RLDFLAGS) -out:$@ $(ROBJS2) $(RLIBS)
+
+$(WPNG)$(E): $(WOBJS)
+	$(LD) $(WLDFLAGS) -out:$@ $(WOBJS) $(WLIBS)
+
+$(RPNG)$(O):	$(RPNG).c readpng.h
+$(RPNG2)$(O):	$(RPNG2).c readpng2.h
+$(WPNG)$(O):	$(WPNG).c writepng.h
+
+readpng$(O):	readpng.c readpng.h
+readpng2$(O):	readpng2.c readpng2.h
+writepng$(O):	writepng.c writepng.h
+
+
+# maintenance ---------------------------------------------------------------
+
+clean:
+#	ideally we could just do this:
+#	$(RM) $(EXES) $(ROBJS) $(ROBJS2) $(WOBJS)
+#	...but the Windows "DEL" command is none too bright, so:
+	$(RM) r*$(E)
+	$(RM) w*$(E)
+	$(RM) r*$(O)
+	$(RM) w*$(O)

contrib/gregbook/README

@@ -0,0 +1,186 @@
+                     ===========================
+                      PNG: The Definitive Guide
+                     ===========================
+
+                             Source Code
+
+Chapters 13, 14 and 15 of "PNG: The Definitive Guide" discuss three free,
+cross-platform demo programs that show how to use the libpng reference
+library:  rpng, rpng2 and wpng.  rpng and rpng2 are viewers; the first is
+a very simple example that that shows how a standard file-viewer might use
+libpng, while the second is designed to process streaming data and shows
+how a web browser might be written.  wpng is a simple command-line program
+that reads binary PGM and PPM files (the ``raw'' grayscale and RGB subsets
+of PBMPLUS/NetPBM) and converts them to PNG.
+
+The source code for all three demo programs currently compiles under
+Unix, OpenVMS, and 32-bit Windows.  (Special thanks to Martin Zinser,
+zinser@decus.de, for making the necessary changes for OpenVMS and for
+providing an appropriate build script.)  Build instructions can be found
+below.
+
+Files:
+
+   README             this file
+   LICENSE            terms of distribution and reuse (BSD-like or GNU GPL)
+   COPYING            GNU General Public License (GPL)
+
+   Makefile.unx       Unix makefile
+   Makefile.w32       Windows (MSVC) makefile
+   makevms.com        OpenVMS build script
+
+   rpng-win.c         Windows front end for the basic viewer
+   rpng-x.c           X Window System (Unix, OpenVMS) front end
+   readpng.c          generic back end for the basic viewer
+   readpng.h          header file for the basic viewer
+
+   rpng2-win.c        Windows front end for the progressive viewer
+   rpng2-x.c          X front end for the progressive viewer
+   readpng2.c         generic back end for the progressive viewer
+   readpng2.h         header file for the progressive viewer
+
+   wpng.c             generic (text) front end for the converter
+   writepng.c         generic back end for the converter
+   writepng.h         header file for the converter
+
+   toucan.png         transparent PNG for testing (by Stefan Schneider)
+
+Note that, although the programs are designed to be functional, their
+primary purpose is to illustrate how to use libpng to add PNG support to
+other programs.  As such, their user interfaces are crude and definitely
+are not intended for everyday use.
+
+Please see http://www.libpng.org/pub/png/pngbook.html for further infor-
+mation and links to the latest version of the source code, and Chapters
+13-15 of the book for detailed discussion of the three programs.
+
+Greg Roelofs
+http://pobox.com/~newt/greg_contact.html
+16 March 2008
+
+
+BUILD INSTRUCTIONS
+
+ - Prerequisites (in order of compilation):
+
+      - zlib		http://zlib.net/
+      - libpng		http://www.libpng.org/pub/png/libpng.html
+      - pngbook		http://www.libpng.org/pub/png/book/sources.html
+
+     The pngbook demo programs are explicitly designed to demonstrate proper
+     coding techniques for using the libpng reference library.  As a result,
+     you need to download and build both zlib (on which libpng depends) and
+     libpng.  A common build setup is to place the zlib, libpng and pngbook
+     subdirectory trees ("folders") in the same parent directory.  Then the
+     libpng build can refer to files in ../zlib (or ..\zlib or [-.zlib]),
+     and similarly for the pngbook build.
+
+     Note that all three packages are designed to be built from a command
+     line by default; those who wish to use a graphical or other integrated
+     development environments are on their own.
+
+
+ - Unix:
+
+     Unpack the latest pngbook sources (which should correspond to this
+     README file) into a directory and change into that directory.
+
+     Copy Makefile.unx to Makefile and edit the PNG* and Z* variables
+     appropriately (possibly also the X* variables if necessary).
+
+     make
+
+     There is no "install" target, so copy the three executables somewhere
+     in your path or run them from the current directory.  All three will
+     print a basic usage screen when run without any command-line arguments;
+     see the book for more details.
+
+
+ - Windows:
+
+     Unpack the latest pngbook sources (which should correspond to this
+     README file) into a folder, open a "DOS shell" or "command prompt"
+     or equivalent command-line window, and cd into the folder where you
+     unpacked the source code.
+
+     For MSVC, set up the necessary environment variables by invoking
+ 
+        %devstudio%\vc\bin\vcvars32.bat
+
+     where where %devstudio% is the installation directory for MSVC /
+     DevStudio.  If you get "environment out of space" errors under 95/98,
+     create a desktop shortcut with "c:\windows\command.com /e:4096" as
+     the program command line and set the working directory to the pngbook
+     directory.  Then double-click to open the new DOS-prompt window with
+     a bigger environment and retry the commands above.
+
+     Copy Makefile.w32 to Makefile and edit the PNGPATH and ZPATH variables
+     appropriately (possibly also the "INC" and "LIB" variables if needed).
+     Note that the names of the dynamic and static libpng and zlib libraries
+     used in the makefile may change in later releases of the libraries.
+     Also note that, as of libpng version 1.0.5, MSVC DLL builds do not work.
+     This makefile therefore builds statically linked executables, but if
+     the DLL problems ever get fixed, uncommenting the appropriate PNGLIB
+     and ZLIB lines will build dynamically linked executables instead.
+
+     Do the build by typing
+
+        nmake
+
+     The result should be three executables:  rpng-win.exe, rpng2-win.exe,
+     and wpng.exe.  Copy them somewhere in your PATH or run them from the
+     current folder.  Like the Unix versions, the two windowed programs
+     (rpng and rpng2) now display a usage screen in a console window when
+     invoked without command-line arguments; this is new behavior as of
+     the June 2001 release.  Note that the programs use the Unix-style "-"
+     character to specify options, instead of the more common DOS/Windows
+     "/" character.  (For example:  "rpng2-win -bgpat 4 foo.png", not
+     "rpng2-win /bgpat 4 foo.png")
+
+
+ - OpenVMS:
+
+     Unpack the pngbook sources into a subdirectory and change into that
+     subdirectory.
+
+     Edit makevms.com appropriately, specifically the zpath and pngpath
+     variables.
+
+     @makevms
+
+     To run the programs, they probably first need to be set up as "foreign
+     symbols," with "disk" and "dir" set appropriately:
+
+     $ rpng  == "$disk:[dir]rpng-x.exe"
+     $ rpng2 == "$disk:[dir]rpng2-x.exe"
+     $ wpng  == "$disk:[dir]wpng.exe"
+
+     All three will print a basic usage screen when run without any command-
+     line arguments; see the book for more details.  Note that the options
+     style is Unix-like, i.e., preceded by "-" rather than "/".
+
+
+RUNNING THE PROGRAMS:  (VERY) BRIEF INTRO
+
+     rpng is a simple PNG viewer that can display transparent PNGs with a
+     specified background color; for example,
+
+	rpng -bgcolor #ff0000 toucan.png
+
+     would display the image with a red background.  rpng2 is a progressive
+     viewer that simulates a web browser in some respects; it can display
+     images against either a background color or a dynamically generated
+     background image.  For example:
+
+	rpng2 -bgpat 16 toucan.png
+
+     wpng is a purely command-line image converter from binary PBMPLUS/NetPBM
+     format (.pgm or .ppm) to PNG; for example,
+
+	wpng -time < toucan-notrans.ppm > toucan-notrans.png
+
+     would convert the specified PPM file (using redirection) to PNG, auto-
+     matically setting the PNG modification-time chunk.
+
+     All options can be abbreviated to the shortest unique value; for example,
+     "-bgc" for -bgcolor (versus "-bgp" for -bgpat), or "-g" for -gamma.

contrib/gregbook/makevms.com

@@ -0,0 +1,132 @@
+$!------------------------------------------------------------------------------
+$! make "PNG: The Definitive Guide" demo programs (for X) under OpenVMS
+$!
+$! Script created by Martin Zinser for libpng; modified by Greg Roelofs
+$! for standalone pngbook source distribution.
+$!
+$!
+$!    Set locations where zlib and libpng sources live.
+$!
+$ zpath   = ""
+$ pngpath = ""
+$!
+$ if f$search("[---.zlib]zlib.h").nes."" then zpath = "[---.zlib]"
+$ if f$search("[--]png.h").nes."" then pngpath = "[--]"
+$!
+$ if f$search("[-.zlib]zlib.h").nes."" then zpath = "[-.zlib]"
+$ if f$search("[-.libpng]png.h").nes."" then pngpath = "[-.libpng]"
+$!
+$ if zpath .eqs. ""
+$ then
+$   write sys$output "zlib include not found. Exiting..."
+$   exit 2
+$ endif 
+$!
+$ if pngpath .eqs. ""
+$ then
+$   write sys$output "libpng include not found. Exiting..."
+$   exit 2
+$ endif 
+$!
+$!    Look for the compiler used.
+$!
+$ ccopt="/include=(''zpath',''pngpath')"
+$ if f$getsyi("HW_MODEL").ge.1024
+$ then
+$  ccopt = "/prefix=all"+ccopt
+$  comp  = "__decc__=1"
+$  if f$trnlnm("SYS").eqs."" then define sys sys$library:
+$ else
+$  if f$search("SYS$SYSTEM:DECC$COMPILER.EXE").eqs.""
+$   then
+$    if f$trnlnm("SYS").eqs."" then define sys sys$library:
+$    if f$search("SYS$SYSTEM:VAXC.EXE").eqs.""
+$     then
+$      comp  = "__gcc__=1"
+$      CC :== GCC
+$     else
+$      comp = "__vaxc__=1"
+$     endif
+$   else
+$    if f$trnlnm("SYS").eqs."" then define sys decc$library_include:
+$    ccopt = "/decc/prefix=all"+ccopt
+$    comp  = "__decc__=1"
+$  endif
+$ endif
+$ open/write lopt lib.opt
+$ write lopt "''pngpath'libpng.olb/lib"
+$ write lopt "''zpath'libz.olb/lib"
+$ close lopt
+$ open/write xopt x11.opt
+$ write xopt "sys$library:decw$xlibshr.exe/share"
+$ close xopt
+$!
+$!    Build 'em.
+$!
+$ write sys$output "Compiling PNG book programs ..."
+$   CALL MAKE readpng.OBJ "cc ''CCOPT' readpng" -
+	readpng.c readpng.h
+$   CALL MAKE readpng2.OBJ "cc ''CCOPT' readpng2" -
+	readpng2.c readpng2.h
+$   CALL MAKE writepng.OBJ "cc ''CCOPT' writepng" -
+	writepng.c writepng.h
+$   write sys$output "Building rpng-x..."
+$   CALL MAKE rpng-x.OBJ "cc ''CCOPT' rpng-x" -
+	rpng-x.c readpng.h
+$   call make rpng-x.exe -
+	"LINK rpng-x,readpng,lib.opt/opt,x11.opt/opt" -
+	rpng-x.obj readpng.obj
+$   write sys$output "Building rpng2-x..."
+$   CALL MAKE rpng2-x.OBJ "cc ''CCOPT' rpng2-x" -
+	rpng2-x.c readpng2.h
+$   call make rpng2-x.exe -
+	"LINK rpng2-x,readpng2,lib.opt/opt,x11.opt/opt" -
+	rpng2-x.obj readpng2.obj
+$   write sys$output "Building wpng..."
+$   CALL MAKE wpng.OBJ "cc ''CCOPT' wpng" -
+	wpng.c writepng.h
+$   call make wpng.exe -
+	"LINK wpng,writepng,lib.opt/opt" -
+	wpng.obj writepng.obj
+$ exit
+$!
+$!
+$MAKE: SUBROUTINE   !SUBROUTINE TO CHECK DEPENDENCIES
+$ V = 'F$Verify(0)
+$! P1 = What we are trying to make
+$! P2 = Command to make it
+$! P3 - P8  What it depends on
+$
+$ If F$Search(P1) .Eqs. "" Then Goto Makeit
+$ Time = F$CvTime(F$File(P1,"RDT"))
+$arg=3
+$Loop:
+$       Argument = P'arg
+$       If Argument .Eqs. "" Then Goto Exit
+$       El=0
+$Loop2:
+$       File = F$Element(El," ",Argument)
+$       If File .Eqs. " " Then Goto Endl
+$       AFile = ""
+$Loop3:
+$       OFile = AFile
+$       AFile = F$Search(File)
+$       If AFile .Eqs. "" .Or. AFile .Eqs. OFile Then Goto NextEl
+$       If F$CvTime(F$File(AFile,"RDT")) .Ges. Time Then Goto Makeit
+$       Goto Loop3
+$NextEL:
+$       El = El + 1
+$       Goto Loop2
+$EndL:
+$ arg=arg+1
+$ If arg .Le. 8 Then Goto Loop
+$ Goto Exit
+$
+$Makeit:
+$ VV=F$VERIFY(0)
+$ write sys$output P2
+$ 'P2
+$ VV='F$Verify(VV)
+$Exit:
+$ If V Then Set Verify
+$ENDSUBROUTINE

contrib/gregbook/readpng.c

@@ -0,0 +1,304 @@
+/*---------------------------------------------------------------------------
+
+   rpng - simple PNG display program                              readpng.c
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      The contents of this file are DUAL-LICENSED.  You may modify and/or
+      redistribute this software according to the terms of one of the
+      following two licenses (at your option):
+
+
+      LICENSE 1 ("BSD-like with advertising clause"):
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+
+      LICENSE 2 (GNU GPL v2 or later):
+
+      This program is free software; you can redistribute it and/or modify
+      it under the terms of the GNU General Public License as published by
+      the Free Software Foundation; either version 2 of the License, or
+      (at your option) any later version.
+
+      This program is distributed in the hope that it will be useful,
+      but WITHOUT ANY WARRANTY; without even the implied warranty of
+      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+      GNU General Public License for more details.
+
+      You should have received a copy of the GNU General Public License
+      along with this program; if not, write to the Free Software Foundation,
+      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+  ---------------------------------------------------------------------------*/
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "png.h"        /* libpng header; includes zlib.h */
+#include "readpng.h"    /* typedefs, common macros, public prototypes */
+
+/* future versions of libpng will provide this macro: */
+#ifndef png_jmpbuf
+#  define png_jmpbuf(png_ptr)   ((png_ptr)->jmpbuf)
+#endif
+
+
+static png_structp png_ptr = NULL;
+static png_infop info_ptr = NULL;
+
+png_uint_32  width, height;
+int  bit_depth, color_type;
+uch  *image_data = NULL;
+
+
+void readpng_version_info(void)
+{
+    fprintf(stderr, "   Compiled with libpng %s; using libpng %s.\n",
+      PNG_LIBPNG_VER_STRING, png_libpng_ver);
+    fprintf(stderr, "   Compiled with zlib %s; using zlib %s.\n",
+      ZLIB_VERSION, zlib_version);
+}
+
+
+/* return value = 0 for success, 1 for bad sig, 2 for bad IHDR, 4 for no mem */
+
+int readpng_init(FILE *infile, ulg *pWidth, ulg *pHeight)
+{
+    uch sig[8];
+
+
+    /* first do a quick check that the file really is a PNG image; could
+     * have used slightly more general png_sig_cmp() function instead */
+
+    fread(sig, 1, 8, infile);
+    if (!png_check_sig(sig, 8))
+        return 1;   /* bad signature */
+
+
+    /* could pass pointers to user-defined error handlers instead of NULLs: */
+
+    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+    if (!png_ptr)
+        return 4;   /* out of memory */
+
+    info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr) {
+        png_destroy_read_struct(&png_ptr, NULL, NULL);
+        return 4;   /* out of memory */
+    }
+
+
+    /* we could create a second info struct here (end_info), but it's only
+     * useful if we want to keep pre- and post-IDAT chunk info separated
+     * (mainly for PNG-aware image editors and converters) */
+
+
+    /* setjmp() must be called in every function that calls a PNG-reading
+     * libpng function */
+
+    if (setjmp(png_jmpbuf(png_ptr))) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        return 2;
+    }
+
+
+    png_init_io(png_ptr, infile);
+    png_set_sig_bytes(png_ptr, 8);  /* we already read the 8 signature bytes */
+
+    png_read_info(png_ptr, info_ptr);  /* read all PNG info up to image data */
+
+
+    /* alternatively, could make separate calls to png_get_image_width(),
+     * etc., but want bit_depth and color_type for later [don't care about
+     * compression_type and filter_type => NULLs] */
+
+    png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
+      NULL, NULL, NULL);
+    *pWidth = width;
+    *pHeight = height;
+
+
+    /* OK, that's all we need for now; return happy */
+
+    return 0;
+}
+
+
+
+
+/* returns 0 if succeeds, 1 if fails due to no bKGD chunk, 2 if libpng error;
+ * scales values to 8-bit if necessary */
+
+int readpng_get_bgcolor(uch *red, uch *green, uch *blue)
+{
+    png_color_16p pBackground;
+
+
+    /* setjmp() must be called in every function that calls a PNG-reading
+     * libpng function */
+
+    if (setjmp(png_jmpbuf(png_ptr))) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        return 2;
+    }
+
+
+    if (!png_get_valid(png_ptr, info_ptr, PNG_INFO_bKGD))
+        return 1;
+
+    /* it is not obvious from the libpng documentation, but this function
+     * takes a pointer to a pointer, and it always returns valid red, green
+     * and blue values, regardless of color_type: */
+
+    png_get_bKGD(png_ptr, info_ptr, &pBackground);
+
+
+    /* however, it always returns the raw bKGD data, regardless of any
+     * bit-depth transformations, so check depth and adjust if necessary */
+
+    if (bit_depth == 16) {
+        *red   = pBackground->red   >> 8;
+        *green = pBackground->green >> 8;
+        *blue  = pBackground->blue  >> 8;
+    } else if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) {
+        if (bit_depth == 1)
+            *red = *green = *blue = pBackground->gray? 255 : 0;
+        else if (bit_depth == 2)
+            *red = *green = *blue = (255/3) * pBackground->gray;
+        else /* bit_depth == 4 */
+            *red = *green = *blue = (255/15) * pBackground->gray;
+    } else {
+        *red   = (uch)pBackground->red;
+        *green = (uch)pBackground->green;
+        *blue  = (uch)pBackground->blue;
+    }
+
+    return 0;
+}
+
+
+
+
+/* display_exponent == LUT_exponent * CRT_exponent */
+
+uch *readpng_get_image(double display_exponent, int *pChannels, ulg *pRowbytes)
+{
+    double  gamma;
+    png_uint_32  i, rowbytes;
+    png_bytepp  row_pointers = NULL;
+
+
+    /* setjmp() must be called in every function that calls a PNG-reading
+     * libpng function */
+
+    if (setjmp(png_jmpbuf(png_ptr))) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        return NULL;
+    }
+
+
+    /* expand palette images to RGB, low-bit-depth grayscale images to 8 bits,
+     * transparency chunks to full alpha channel; strip 16-bit-per-sample
+     * images to 8 bits per sample; and convert grayscale to RGB[A] */
+
+    if (color_type == PNG_COLOR_TYPE_PALETTE)
+        png_set_expand(png_ptr);
+    if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
+        png_set_expand(png_ptr);
+    if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
+        png_set_expand(png_ptr);
+    if (bit_depth == 16)
+        png_set_strip_16(png_ptr);
+    if (color_type == PNG_COLOR_TYPE_GRAY ||
+        color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+        png_set_gray_to_rgb(png_ptr);
+
+
+    /* unlike the example in the libpng documentation, we have *no* idea where
+     * this file may have come from--so if it doesn't have a file gamma, don't
+     * do any correction ("do no harm") */
+
+    if (png_get_gAMA(png_ptr, info_ptr, &gamma))
+        png_set_gamma(png_ptr, display_exponent, gamma);
+
+
+    /* all transformations have been registered; now update info_ptr data,
+     * get rowbytes and channels, and allocate image memory */
+
+    png_read_update_info(png_ptr, info_ptr);
+
+    *pRowbytes = rowbytes = png_get_rowbytes(png_ptr, info_ptr);
+    *pChannels = (int)png_get_channels(png_ptr, info_ptr);
+
+    if ((image_data = (uch *)malloc(rowbytes*height)) == NULL) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        return NULL;
+    }
+    if ((row_pointers = (png_bytepp)malloc(height*sizeof(png_bytep))) == NULL) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        free(image_data);
+        image_data = NULL;
+        return NULL;
+    }
+
+    Trace((stderr, "readpng_get_image:  channels = %d, rowbytes = %ld, height = %ld\n", *pChannels, rowbytes, height));
+
+
+    /* set the individual row_pointers to point at the correct offsets */
+
+    for (i = 0;  i < height;  ++i)
+        row_pointers[i] = image_data + i*rowbytes;
+
+
+    /* now we can go ahead and just read the whole image */
+
+    png_read_image(png_ptr, row_pointers);
+
+
+    /* and we're done!  (png_read_end() can be omitted if no processing of
+     * post-IDAT text/time/etc. is desired) */
+
+    free(row_pointers);
+    row_pointers = NULL;
+
+    png_read_end(png_ptr, NULL);
+
+    return image_data;
+}
+
+
+void readpng_cleanup(int free_image_data)
+{
+    if (free_image_data && image_data) {
+        free(image_data);
+        image_data = NULL;
+    }
+
+    if (png_ptr && info_ptr) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        png_ptr = NULL;
+        info_ptr = NULL;
+    }
+}

contrib/gregbook/readpng.h

@@ -0,0 +1,88 @@
+/*---------------------------------------------------------------------------
+
+   rpng - simple PNG display program                              readpng.h
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      The contents of this file are DUAL-LICENSED.  You may modify and/or
+      redistribute this software according to the terms of one of the
+      following two licenses (at your option):
+
+
+      LICENSE 1 ("BSD-like with advertising clause"):
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+
+      LICENSE 2 (GNU GPL v2 or later):
+
+      This program is free software; you can redistribute it and/or modify
+      it under the terms of the GNU General Public License as published by
+      the Free Software Foundation; either version 2 of the License, or
+      (at your option) any later version.
+
+      This program is distributed in the hope that it will be useful,
+      but WITHOUT ANY WARRANTY; without even the implied warranty of
+      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+      GNU General Public License for more details.
+
+      You should have received a copy of the GNU General Public License
+      along with this program; if not, write to the Free Software Foundation,
+      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+  ---------------------------------------------------------------------------*/
+
+#ifndef TRUE
+#  define TRUE 1
+#  define FALSE 0
+#endif
+
+#ifndef MAX
+#  define MAX(a,b)  ((a) > (b)? (a) : (b))
+#  define MIN(a,b)  ((a) < (b)? (a) : (b))
+#endif
+
+#ifdef DEBUG
+#  define Trace(x)  {fprintf x ; fflush(stderr); fflush(stdout);}
+#else
+#  define Trace(x)  ;
+#endif
+
+typedef unsigned char   uch;
+typedef unsigned short  ush;
+typedef unsigned long   ulg;
+
+
+/* prototypes for public functions in readpng.c */
+
+void readpng_version_info(void);
+
+int readpng_init(FILE *infile, ulg *pWidth, ulg *pHeight);
+
+int readpng_get_bgcolor(uch *bg_red, uch *bg_green, uch *bg_blue);
+
+uch *readpng_get_image(double display_exponent, int *pChannels,
+                       ulg *pRowbytes);
+
+void readpng_cleanup(int free_image_data);

contrib/gregbook/readpng2.c

@@ -0,0 +1,645 @@
+/*---------------------------------------------------------------------------
+
+   rpng2 - progressive-model PNG display program                 readpng2.c
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      The contents of this file are DUAL-LICENSED.  You may modify and/or
+      redistribute this software according to the terms of one of the
+      following two licenses (at your option):
+
+
+      LICENSE 1 ("BSD-like with advertising clause"):
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+
+      LICENSE 2 (GNU GPL v2 or later):
+
+      This program is free software; you can redistribute it and/or modify
+      it under the terms of the GNU General Public License as published by
+      the Free Software Foundation; either version 2 of the License, or
+      (at your option) any later version.
+
+      This program is distributed in the hope that it will be useful,
+      but WITHOUT ANY WARRANTY; without even the implied warranty of
+      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+      GNU General Public License for more details.
+
+      You should have received a copy of the GNU General Public License
+      along with this program; if not, write to the Free Software Foundation,
+      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+  ---------------------------------------------------------------------------*/
+
+
+#include <stdlib.h>     /* for exit() prototype */
+
+#include "png.h"        /* libpng header; includes zlib.h and setjmp.h */
+#include "readpng2.h"   /* typedefs, common macros, public prototypes */
+
+
+/* local prototypes */
+
+static void readpng2_info_callback(png_structp png_ptr, png_infop info_ptr);
+static void readpng2_row_callback(png_structp png_ptr, png_bytep new_row,
+                                 png_uint_32 row_num, int pass);
+static void readpng2_end_callback(png_structp png_ptr, png_infop info_ptr);
+static void readpng2_error_handler(png_structp png_ptr, png_const_charp msg);
+
+
+
+
+void readpng2_version_info(void)
+{
+#if defined(PNG_ASSEMBLER_CODE_SUPPORTED) && \
+    (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__)) && \
+    defined(PNG_LIBPNG_VER) && (PNG_LIBPNG_VER >= 10200)
+    /*
+     * WARNING:  This preprocessor approach means that the following code
+     *           cannot be used with a libpng DLL older than 1.2.0--the
+     *           compiled-in symbols for the new functions will not exist.
+     *           (Could use dlopen() and dlsym() on Unix and corresponding
+     *           calls for Windows, but not portable...)
+     */
+    {
+        int mmxsupport = png_mmx_support();
+        if (mmxsupport < 0)
+            fprintf(stderr, "   Compiled with libpng %s; using libpng %s "
+              "without MMX support.\n", PNG_LIBPNG_VER_STRING, png_libpng_ver);
+        else {
+            int compilerID;
+            png_uint_32 mmx_mask = png_get_mmx_flagmask(
+              PNG_SELECT_READ | PNG_SELECT_WRITE, &compilerID);
+
+            fprintf(stderr, "   Compiled with libpng %s; using libpng %s "
+              "with MMX support\n   (%s version).", PNG_LIBPNG_VER_STRING,
+              png_libpng_ver, compilerID == 1? "MSVC++" :
+              (compilerID == 2? "GNU C" : "unknown"));
+            fprintf(stderr, "  Processor (x86%s) %s MMX instructions.\n",
+#if defined(__x86_64__)
+              "_64",
+#else
+              "",
+#endif
+              mmxsupport? "supports" : "does not support");
+            if (mmxsupport > 0) {
+                int num_optims = 0;
+
+                fprintf(stderr,
+                  "      Potential MMX optimizations supported by libpng:\n");
+                if (mmx_mask & PNG_ASM_FLAG_MMX_READ_FILTER_SUB)
+                    ++num_optims;
+                if (mmx_mask & PNG_ASM_FLAG_MMX_READ_FILTER_UP)
+                    ++num_optims;
+                if (mmx_mask & PNG_ASM_FLAG_MMX_READ_FILTER_AVG)
+                    ++num_optims;
+                if (mmx_mask & PNG_ASM_FLAG_MMX_READ_FILTER_PAETH)
+                    ++num_optims;
+                if (num_optims)
+                    fprintf(stderr,
+                      "         decoding %s row filters (reading)\n",
+                      (num_optims == 4)? "all non-trivial" : "some");
+                if (mmx_mask & PNG_ASM_FLAG_MMX_READ_COMBINE_ROW) {
+                    fprintf(stderr, "         combining rows (reading)\n");
+                    ++num_optims;
+                }
+                if (mmx_mask & PNG_ASM_FLAG_MMX_READ_INTERLACE) {
+                    fprintf(stderr,
+                      "         expanding interlacing (reading)\n");
+                    ++num_optims;
+                }
+                mmx_mask &= ~( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW  \
+                             | PNG_ASM_FLAG_MMX_READ_INTERLACE    \
+                             | PNG_ASM_FLAG_MMX_READ_FILTER_SUB   \
+                             | PNG_ASM_FLAG_MMX_READ_FILTER_UP    \
+                             | PNG_ASM_FLAG_MMX_READ_FILTER_AVG   \
+                             | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH );
+                if (mmx_mask) {
+                    fprintf(stderr, "         other (unknown)\n");
+                    ++num_optims;
+                }
+                if (num_optims == 0)
+                    fprintf(stderr, "         (none)\n");
+            }
+        }
+    }
+#else
+    fprintf(stderr, "   Compiled with libpng %s; using libpng %s "
+      "without MMX support.\n", PNG_LIBPNG_VER_STRING, png_libpng_ver);
+#endif
+
+    fprintf(stderr, "   Compiled with zlib %s; using zlib %s.\n",
+      ZLIB_VERSION, zlib_version);
+}
+
+
+
+
+int readpng2_check_sig(uch *sig, int num)
+{
+    return png_check_sig(sig, num);
+}
+
+
+
+
+/* returns 0 for success, 2 for libpng problem, 4 for out of memory */
+
+int readpng2_init(mainprog_info *mainprog_ptr)
+{
+    png_structp  png_ptr;       /* note:  temporary variables! */
+    png_infop  info_ptr;
+
+
+    /* could also replace libpng warning-handler (final NULL), but no need: */
+
+    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, mainprog_ptr,
+      readpng2_error_handler, NULL);
+    if (!png_ptr)
+        return 4;   /* out of memory */
+
+    info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr) {
+        png_destroy_read_struct(&png_ptr, NULL, NULL);
+        return 4;   /* out of memory */
+    }
+
+
+    /* we could create a second info struct here (end_info), but it's only
+     * useful if we want to keep pre- and post-IDAT chunk info separated
+     * (mainly for PNG-aware image editors and converters) */
+
+
+    /* setjmp() must be called in every function that calls a PNG-reading
+     * libpng function, unless an alternate error handler was installed--
+     * but compatible error handlers must either use longjmp() themselves
+     * (as in this program) or exit immediately, so here we are: */
+
+    if (setjmp(mainprog_ptr->jmpbuf)) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        return 2;
+    }
+
+
+#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
+    /* prepare the reader to ignore all recognized chunks whose data won't be
+     * used, i.e., all chunks recognized by libpng except for IHDR, PLTE, IDAT,
+     * IEND, tRNS, bKGD, gAMA, and sRGB (small performance improvement) */
+    {
+        /* These byte strings were copied from png.h.  If a future libpng
+         * version recognizes more chunks, add them to this list.  If a
+         * future version of readpng2.c recognizes more chunks, delete them
+         * from this list. */
+        static const png_byte chunks_to_ignore[] = {
+             99,  72,  82,  77, '\0',  /* cHRM */
+            104,  73,  83,  84, '\0',  /* hIST */
+            105,  67,  67,  80, '\0',  /* iCCP */
+            105,  84,  88, 116, '\0',  /* iTXt */
+            111,  70,  70, 115, '\0',  /* oFFs */
+            112,  67,  65,  76, '\0',  /* pCAL */
+            112,  72,  89, 115, '\0',  /* pHYs */
+            115,  66,  73,  84, '\0',  /* sBIT */
+            115,  67,  65,  76, '\0',  /* sCAL */
+            115,  80,  76,  84, '\0',  /* sPLT */
+            115,  84,  69,  82, '\0',  /* sTER */
+            116,  69,  88, 116, '\0',  /* tEXt */
+            116,  73,  77,  69, '\0',  /* tIME */
+            122,  84,  88, 116, '\0'   /* zTXt */
+        };
+
+        png_set_keep_unknown_chunks(png_ptr, 1 /* PNG_HANDLE_CHUNK_NEVER */,
+          chunks_to_ignore, sizeof(chunks_to_ignore)/5);
+    }
+#endif /* PNG_UNKNOWN_CHUNKS_SUPPORTED */
+
+
+    /* instead of doing png_init_io() here, now we set up our callback
+     * functions for progressive decoding */
+
+    png_set_progressive_read_fn(png_ptr, mainprog_ptr,
+      readpng2_info_callback, readpng2_row_callback, readpng2_end_callback);
+
+
+    /*
+     * may as well enable or disable MMX routines here, if supported;
+     *
+     * to enable all:  mask = png_get_mmx_flagmask (
+     *                   PNG_SELECT_READ | PNG_SELECT_WRITE, &compilerID);
+     *                 flags = png_get_asm_flags (png_ptr);
+     *                 flags |= mask;
+     *                 png_set_asm_flags (png_ptr, flags);
+     *
+     * to disable all:  mask = png_get_mmx_flagmask (
+     *                   PNG_SELECT_READ | PNG_SELECT_WRITE, &compilerID);
+     *                  flags = png_get_asm_flags (png_ptr);
+     *                  flags &= ~mask;
+     *                  png_set_asm_flags (png_ptr, flags);
+     */
+
+#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__)) && \
+    defined(PNG_LIBPNG_VER) && (PNG_LIBPNG_VER >= 10200)
+    /*
+     * WARNING:  This preprocessor approach means that the following code
+     *           cannot be used with a libpng DLL older than 1.2.0--the
+     *           compiled-in symbols for the new functions will not exist.
+     *           (Could use dlopen() and dlsym() on Unix and corresponding
+     *           calls for Windows, but not portable...)
+     */
+    {
+#ifdef PNG_ASSEMBLER_CODE_SUPPORTED
+        png_uint_32 mmx_disable_mask = 0;
+        png_uint_32 asm_flags, mmx_mask;
+        int compilerID;
+
+        if (mainprog_ptr->nommxfilters)
+            mmx_disable_mask |= ( PNG_ASM_FLAG_MMX_READ_FILTER_SUB   \
+                                | PNG_ASM_FLAG_MMX_READ_FILTER_UP    \
+                                | PNG_ASM_FLAG_MMX_READ_FILTER_AVG   \
+                                | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH );
+        if (mainprog_ptr->nommxcombine)
+            mmx_disable_mask |= PNG_ASM_FLAG_MMX_READ_COMBINE_ROW;
+        if (mainprog_ptr->nommxinterlace)
+            mmx_disable_mask |= PNG_ASM_FLAG_MMX_READ_INTERLACE;
+        asm_flags = png_get_asm_flags(png_ptr);
+        png_set_asm_flags(png_ptr, asm_flags & ~mmx_disable_mask);
+
+
+        /* Now query libpng's asm settings, just for yuks.  Note that this
+         * differs from the querying of its *potential* MMX capabilities
+         * in readpng2_version_info(); this is true runtime verification. */
+
+        asm_flags = png_get_asm_flags(png_ptr);
+        mmx_mask = png_get_mmx_flagmask(PNG_SELECT_READ | PNG_SELECT_WRITE,
+          &compilerID);
+        if (asm_flags & PNG_ASM_FLAG_MMX_SUPPORT_COMPILED)
+            fprintf(stderr,
+              "  MMX support (%s version) is compiled into libpng\n",
+              compilerID == 1? "MSVC++" :
+              (compilerID == 2? "GNU C" : "unknown"));
+        else
+            fprintf(stderr, "  MMX support is not compiled into libpng\n");
+        fprintf(stderr, "  MMX instructions are %ssupported by CPU\n",
+          (asm_flags & PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU)? "" : "not ");
+        fprintf(stderr, "  MMX read support for combining rows is %sabled\n",
+          (asm_flags & PNG_ASM_FLAG_MMX_READ_COMBINE_ROW)? "en" : "dis");
+        fprintf(stderr,
+          "  MMX read support for expanding interlacing is %sabled\n",
+          (asm_flags & PNG_ASM_FLAG_MMX_READ_INTERLACE)? "en" : "dis");
+        fprintf(stderr, "  MMX read support for \"sub\" filter is %sabled\n",
+          (asm_flags & PNG_ASM_FLAG_MMX_READ_FILTER_SUB)? "en" : "dis");
+        fprintf(stderr, "  MMX read support for \"up\" filter is %sabled\n",
+          (asm_flags & PNG_ASM_FLAG_MMX_READ_FILTER_UP)? "en" : "dis");
+        fprintf(stderr, "  MMX read support for \"avg\" filter is %sabled\n",
+          (asm_flags & PNG_ASM_FLAG_MMX_READ_FILTER_AVG)? "en" : "dis");
+        fprintf(stderr, "  MMX read support for \"Paeth\" filter is %sabled\n",
+          (asm_flags & PNG_ASM_FLAG_MMX_READ_FILTER_PAETH)? "en" : "dis");
+        asm_flags &= (mmx_mask & ~( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW  \
+                                  | PNG_ASM_FLAG_MMX_READ_INTERLACE    \
+                                  | PNG_ASM_FLAG_MMX_READ_FILTER_SUB   \
+                                  | PNG_ASM_FLAG_MMX_READ_FILTER_UP    \
+                                  | PNG_ASM_FLAG_MMX_READ_FILTER_AVG   \
+                                  | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH ));
+        if (asm_flags)
+            fprintf(stderr,
+              "  additional MMX support is also enabled (0x%02lx)\n",
+              asm_flags);
+#else  /* !PNG_ASSEMBLER_CODE_SUPPORTED */
+        fprintf(stderr, "  MMX querying is disabled in libpng.\n");
+#endif /* ?PNG_ASSEMBLER_CODE_SUPPORTED */
+    }
+#endif
+
+
+    /* make sure we save our pointers for use in readpng2_decode_data() */
+
+    mainprog_ptr->png_ptr = png_ptr;
+    mainprog_ptr->info_ptr = info_ptr;
+
+
+    /* and that's all there is to initialization */
+
+    return 0;
+}
+
+
+
+
+/* returns 0 for success, 2 for libpng (longjmp) problem */
+
+int readpng2_decode_data(mainprog_info *mainprog_ptr, uch *rawbuf, ulg length)
+{
+    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
+    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
+
+
+    /* setjmp() must be called in every function that calls a PNG-reading
+     * libpng function */
+
+    if (setjmp(mainprog_ptr->jmpbuf)) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        mainprog_ptr->png_ptr = NULL;
+        mainprog_ptr->info_ptr = NULL;
+        return 2;
+    }
+
+
+    /* hand off the next chunk of input data to libpng for decoding */
+
+    png_process_data(png_ptr, info_ptr, rawbuf, length);
+
+    return 0;
+}
+
+
+
+
+static void readpng2_info_callback(png_structp png_ptr, png_infop info_ptr)
+{
+    mainprog_info  *mainprog_ptr;
+    int  color_type, bit_depth;
+    double  gamma;
+
+
+    /* setjmp() doesn't make sense here, because we'd either have to exit(),
+     * longjmp() ourselves, or return control to libpng, which doesn't want
+     * to see us again.  By not doing anything here, libpng will instead jump
+     * to readpng2_decode_data(), which can return an error value to the main
+     * program. */
+
+
+    /* retrieve the pointer to our special-purpose struct, using the png_ptr
+     * that libpng passed back to us (i.e., not a global this time--there's
+     * no real difference for a single image, but for a multithreaded browser
+     * decoding several PNG images at the same time, one needs to avoid mixing
+     * up different images' structs) */
+
+    mainprog_ptr = png_get_progressive_ptr(png_ptr);
+
+    if (mainprog_ptr == NULL) {         /* we be hosed */
+        fprintf(stderr,
+          "readpng2 error:  main struct not recoverable in info_callback.\n");
+        fflush(stderr);
+        return;
+        /*
+         * Alternatively, we could call our error-handler just like libpng
+         * does, which would effectively terminate the program.  Since this
+         * can only happen if png_ptr gets redirected somewhere odd or the
+         * main PNG struct gets wiped, we're probably toast anyway.  (If
+         * png_ptr itself is NULL, we would not have been called.)
+         */
+    }
+
+
+    /* this is just like in the non-progressive case */
+
+    png_get_IHDR(png_ptr, info_ptr, &mainprog_ptr->width,
+      &mainprog_ptr->height, &bit_depth, &color_type, NULL, NULL, NULL);
+
+
+    /* since we know we've read all of the PNG file's "header" (i.e., up
+     * to IDAT), we can check for a background color here */
+
+    if (mainprog_ptr->need_bgcolor &&
+        png_get_valid(png_ptr, info_ptr, PNG_INFO_bKGD))
+    {
+        png_color_16p pBackground;
+
+        /* it is not obvious from the libpng documentation, but this function
+         * takes a pointer to a pointer, and it always returns valid red,
+         * green and blue values, regardless of color_type: */
+        png_get_bKGD(png_ptr, info_ptr, &pBackground);
+
+        /* however, it always returns the raw bKGD data, regardless of any
+         * bit-depth transformations, so check depth and adjust if necessary */
+        if (bit_depth == 16) {
+            mainprog_ptr->bg_red   = pBackground->red   >> 8;
+            mainprog_ptr->bg_green = pBackground->green >> 8;
+            mainprog_ptr->bg_blue  = pBackground->blue  >> 8;
+        } else if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) {
+            if (bit_depth == 1)
+                mainprog_ptr->bg_red = mainprog_ptr->bg_green =
+                  mainprog_ptr->bg_blue = pBackground->gray? 255 : 0;
+            else if (bit_depth == 2)
+                mainprog_ptr->bg_red = mainprog_ptr->bg_green =
+                  mainprog_ptr->bg_blue = (255/3) * pBackground->gray;
+            else /* bit_depth == 4 */
+                mainprog_ptr->bg_red = mainprog_ptr->bg_green =
+                  mainprog_ptr->bg_blue = (255/15) * pBackground->gray;
+        } else {
+            mainprog_ptr->bg_red   = (uch)pBackground->red;
+            mainprog_ptr->bg_green = (uch)pBackground->green;
+            mainprog_ptr->bg_blue  = (uch)pBackground->blue;
+        }
+    }
+
+
+    /* as before, let libpng expand palette images to RGB, low-bit-depth
+     * grayscale images to 8 bits, transparency chunks to full alpha channel;
+     * strip 16-bit-per-sample images to 8 bits per sample; and convert
+     * grayscale to RGB[A] */
+
+    if (color_type == PNG_COLOR_TYPE_PALETTE)
+        png_set_expand(png_ptr);
+    if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
+        png_set_expand(png_ptr);
+    if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
+        png_set_expand(png_ptr);
+    if (bit_depth == 16)
+        png_set_strip_16(png_ptr);
+    if (color_type == PNG_COLOR_TYPE_GRAY ||
+        color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+        png_set_gray_to_rgb(png_ptr);
+
+
+    /* Unlike the basic viewer, which was designed to operate on local files,
+     * this program is intended to simulate a web browser--even though we
+     * actually read from a local file, too.  But because we are pretending
+     * that most of the images originate on the Internet, we follow the recom-
+     * mendation of the sRGB proposal and treat unlabelled images (no gAMA
+     * chunk) as existing in the sRGB color space.  That is, we assume that
+     * such images have a file gamma of 0.45455, which corresponds to a PC-like
+     * display system.  This change in assumptions will have no effect on a
+     * PC-like system, but on a Mac, SGI, NeXT or other system with a non-
+     * identity lookup table, it will darken unlabelled images, which effec-
+     * tively favors images from PC-like systems over those originating on
+     * the local platform.  Note that mainprog_ptr->display_exponent is the
+     * "gamma" value for the entire display system, i.e., the product of
+     * LUT_exponent and CRT_exponent. */
+
+    if (png_get_gAMA(png_ptr, info_ptr, &gamma))
+        png_set_gamma(png_ptr, mainprog_ptr->display_exponent, gamma);
+    else
+        png_set_gamma(png_ptr, mainprog_ptr->display_exponent, 0.45455);
+
+
+    /* we'll let libpng expand interlaced images, too */
+
+    mainprog_ptr->passes = png_set_interlace_handling(png_ptr);
+
+
+    /* all transformations have been registered; now update info_ptr data and
+     * then get rowbytes and channels */
+
+    png_read_update_info(png_ptr, info_ptr);
+
+    mainprog_ptr->rowbytes = (int)png_get_rowbytes(png_ptr, info_ptr);
+    mainprog_ptr->channels = png_get_channels(png_ptr, info_ptr);
+
+
+    /* Call the main program to allocate memory for the image buffer and
+     * initialize windows and whatnot.  (The old-style function-pointer
+     * invocation is used for compatibility with a few supposedly ANSI
+     * compilers that nevertheless barf on "fn_ptr()"-style syntax.) */
+
+    (*mainprog_ptr->mainprog_init)();
+
+
+    /* and that takes care of initialization */
+
+    return;
+}
+
+
+
+
+
+static void readpng2_row_callback(png_structp png_ptr, png_bytep new_row,
+                                  png_uint_32 row_num, int pass)
+{
+    mainprog_info  *mainprog_ptr;
+
+
+    /* first check whether the row differs from the previous pass; if not,
+     * nothing to combine or display */
+
+    if (!new_row)
+        return;
+
+
+    /* retrieve the pointer to our special-purpose struct so we can access
+     * the old rows and image-display callback function */
+
+    mainprog_ptr = png_get_progressive_ptr(png_ptr);
+
+
+    /* save the pass number for optional use by the front end */
+
+    mainprog_ptr->pass = pass;
+
+
+    /* have libpng either combine the new row data with the existing row data
+     * from previous passes (if interlaced) or else just copy the new row
+     * into the main program's image buffer */
+
+    png_progressive_combine_row(png_ptr, mainprog_ptr->row_pointers[row_num],
+      new_row);
+
+
+    /* finally, call the display routine in the main program with the number
+     * of the row we just updated */
+
+    (*mainprog_ptr->mainprog_display_row)(row_num);
+
+
+    /* and we're ready for more */
+
+    return;
+}
+
+
+
+
+
+static void readpng2_end_callback(png_structp png_ptr, png_infop info_ptr)
+{
+    mainprog_info  *mainprog_ptr;
+
+
+    /* retrieve the pointer to our special-purpose struct */
+
+    mainprog_ptr = png_get_progressive_ptr(png_ptr);
+
+
+    /* let the main program know that it should flush any buffered image
+     * data to the display now and set a "done" flag or whatever, but note
+     * that it SHOULD NOT DESTROY THE PNG STRUCTS YET--in other words, do
+     * NOT call readpng2_cleanup() either here or in the finish_display()
+     * routine; wait until control returns to the main program via
+     * readpng2_decode_data() */
+
+    (*mainprog_ptr->mainprog_finish_display)();
+
+
+    /* all done */
+
+    return;
+}
+
+
+
+
+
+void readpng2_cleanup(mainprog_info *mainprog_ptr)
+{
+    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
+    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
+
+    if (png_ptr && info_ptr)
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+
+    mainprog_ptr->png_ptr = NULL;
+    mainprog_ptr->info_ptr = NULL;
+}
+
+
+
+
+
+static void readpng2_error_handler(png_structp png_ptr, png_const_charp msg)
+{
+    mainprog_info  *mainprog_ptr;
+
+    /* This function, aside from the extra step of retrieving the "error
+     * pointer" (below) and the fact that it exists within the application
+     * rather than within libpng, is essentially identical to libpng's
+     * default error handler.  The second point is critical:  since both
+     * setjmp() and longjmp() are called from the same code, they are
+     * guaranteed to have compatible notions of how big a jmp_buf is,
+     * regardless of whether _BSD_SOURCE or anything else has (or has not)
+     * been defined. */
+
+    fprintf(stderr, "readpng2 libpng error: %s\n", msg);
+    fflush(stderr);
+
+    mainprog_ptr = png_get_error_ptr(png_ptr);
+    if (mainprog_ptr == NULL) {         /* we are completely hosed now */
+        fprintf(stderr,
+          "readpng2 severe error:  jmpbuf not recoverable; terminating.\n");
+        fflush(stderr);
+        exit(99);
+    }
+
+    longjmp(mainprog_ptr->jmpbuf, 1);
+}

contrib/gregbook/readpng2.h

@@ -0,0 +1,121 @@
+/*---------------------------------------------------------------------------
+
+   rpng2 - progressive-model PNG display program                 readpng2.h
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      The contents of this file are DUAL-LICENSED.  You may modify and/or
+      redistribute this software according to the terms of one of the
+      following two licenses (at your option):
+
+
+      LICENSE 1 ("BSD-like with advertising clause"):
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+
+      LICENSE 2 (GNU GPL v2 or later):
+
+      This program is free software; you can redistribute it and/or modify
+      it under the terms of the GNU General Public License as published by
+      the Free Software Foundation; either version 2 of the License, or
+      (at your option) any later version.
+
+      This program is distributed in the hope that it will be useful,
+      but WITHOUT ANY WARRANTY; without even the implied warranty of
+      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+      GNU General Public License for more details.
+
+      You should have received a copy of the GNU General Public License
+      along with this program; if not, write to the Free Software Foundation,
+      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+  ---------------------------------------------------------------------------*/
+
+#ifndef TRUE
+#  define TRUE 1
+#  define FALSE 0
+#endif
+
+#ifndef MAX
+#  define MAX(a,b)  ((a) > (b)? (a) : (b))
+#  define MIN(a,b)  ((a) < (b)? (a) : (b))
+#endif
+
+#ifdef DEBUG
+#  define Trace(x)  {fprintf x ; fflush(stderr); fflush(stdout);}
+#else
+#  define Trace(x)  ;
+#endif
+
+enum rpng2_states {
+    kPreInit = 0,
+    kWindowInit,
+    kDone
+};
+
+typedef unsigned char   uch;
+typedef unsigned short  ush;
+typedef unsigned long   ulg;
+
+typedef struct _mainprog_info {
+    double display_exponent;
+    ulg width;
+    ulg height;
+    void *png_ptr;
+    void *info_ptr;
+    void (*mainprog_init)(void);
+    void (*mainprog_display_row)(ulg row_num);
+    void (*mainprog_finish_display)(void);
+    uch *image_data;
+    uch **row_pointers;
+    jmp_buf jmpbuf;
+    int passes;              /* not used */
+    int pass;
+    int rowbytes;
+    int channels;
+    int need_bgcolor;
+#if (defined(__i386__) || defined(_M_IX86) || defined(__x86_64__))
+    int nommxfilters;
+    int nommxcombine;
+    int nommxinterlace;
+#endif
+    int state;
+    uch bg_red;
+    uch bg_green;
+    uch bg_blue;
+} mainprog_info;
+
+
+/* prototypes for public functions in readpng2.c */
+
+void readpng2_version_info(void);
+
+int readpng2_check_sig(uch *sig, int num);
+
+int readpng2_init(mainprog_info *mainprog_ptr);
+
+int readpng2_decode_data(mainprog_info *mainprog_ptr, uch *rawbuf, ulg length);
+
+void readpng2_cleanup(mainprog_info *mainprog_ptr);

contrib/gregbook/readppm.c

@@ -0,0 +1,179 @@
+/*---------------------------------------------------------------------------
+
+   rpng - simple PNG display program                              readppm.c
+
+  ---------------------------------------------------------------------------
+
+   This is a special-purpose replacement for readpng.c that allows binary
+   PPM files to be used in place of PNG images.
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      The contents of this file are DUAL-LICENSED.  You may modify and/or
+      redistribute this software according to the terms of one of the
+      following two licenses (at your option):
+
+
+      LICENSE 1 ("BSD-like with advertising clause"):
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+
+      LICENSE 2 (GNU GPL v2 or later):
+
+      This program is free software; you can redistribute it and/or modify
+      it under the terms of the GNU General Public License as published by
+      the Free Software Foundation; either version 2 of the License, or
+      (at your option) any later version.
+
+      This program is distributed in the hope that it will be useful,
+      but WITHOUT ANY WARRANTY; without even the implied warranty of
+      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+      GNU General Public License for more details.
+
+      You should have received a copy of the GNU General Public License
+      along with this program; if not, write to the Free Software Foundation,
+      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+  ---------------------------------------------------------------------------*/
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "readpng.h"    /* typedefs, common macros, public prototypes */
+
+
+ulg  width, height;
+int  bit_depth, color_type, channels;
+uch  *image_data = NULL;
+FILE *saved_infile;
+
+
+void readpng_version_info()
+{
+    fprintf(stderr, "   Compiled without libpng, zlib or PBMPLUS/NetPBM.\n");
+}
+
+
+/* return value = 0 for success, 1 for bad sig, 2 for bad IHDR, 4 for no mem */
+
+int readpng_init(FILE *infile, ulg *pWidth, ulg *pHeight)
+{
+    static uch ppmline[256];
+    int maxval;
+
+
+    saved_infile = infile;
+
+    fgets(ppmline, 256, infile);
+    if (ppmline[0] != 'P' || ppmline[1] != '6') {
+        fprintf(stderr, "ERROR:  not a PPM file\n");
+        return 1;
+    }
+    /* possible color types:  P5 = grayscale (0), P6 = RGB (2), P8 = RGBA (6) */
+    if (ppmline[1] == '6') {
+        color_type = 2;
+        channels = 3;
+    } else if (ppmline[1] == '8') {
+        color_type = 6;
+        channels = 4;
+    } else /* if (ppmline[1] == '5') */ {
+        color_type = 0;
+        channels = 1;
+    }
+
+    do {
+        fgets(ppmline, 256, infile);
+    } while (ppmline[0] == '#');
+    sscanf(ppmline, "%lu %lu", &width, &height);
+
+    do {
+        fgets(ppmline, 256, infile);
+    } while (ppmline[0] == '#');
+    sscanf(ppmline, "%d", &maxval);
+    if (maxval != 255) {
+        fprintf(stderr, "ERROR:  maxval = %d\n", maxval);
+        return 2;
+    }
+    bit_depth = 8;
+
+    *pWidth = width;
+    *pHeight = height;
+
+    return 0;
+}
+
+
+
+
+/* returns 0 if succeeds, 1 if fails due to no bKGD chunk, 2 if libpng error;
+ * scales values to 8-bit if necessary */
+
+int readpng_get_bgcolor(uch *red, uch *green, uch *blue)
+{
+    return 1;
+}
+
+
+
+
+/* display_exponent == LUT_exponent * CRT_exponent */
+
+uch *readpng_get_image(double display_exponent, int *pChannels, ulg *pRowbytes)
+{
+    ulg  rowbytes;
+
+
+    /* expand palette images to RGB, low-bit-depth grayscale images to 8 bits,
+     * transparency chunks to full alpha channel; strip 16-bit-per-sample
+     * images to 8 bits per sample; and convert grayscale to RGB[A] */
+
+    /* GRR WARNING:  grayscale needs to be expanded and channels reset! */
+
+    *pRowbytes = rowbytes = channels*width;
+    *pChannels = channels;
+
+    if ((image_data = (uch *)malloc(rowbytes*height)) == NULL) {
+        return NULL;
+    }
+
+    Trace((stderr, "readpng_get_image:  rowbytes = %ld, height = %ld\n", rowbytes, height));
+
+
+    /* now we can go ahead and just read the whole image */
+
+    fread(image_data, 1L, rowbytes*height, saved_infile);
+
+
+    return image_data;
+}
+
+
+void readpng_cleanup(int free_image_data)
+{
+    if (free_image_data && image_data) {
+        free(image_data);
+        image_data = NULL;
+    }
+}

contrib/gregbook/rpng-win.c

@@ -0,0 +1,684 @@
+/*---------------------------------------------------------------------------
+
+   rpng - simple PNG display program                             rpng-win.c
+
+   This program decodes and displays PNG images, with gamma correction and
+   optionally with a user-specified background color (in case the image has
+   transparency).  It is very nearly the most basic PNG viewer possible.
+   This version is for 32-bit Windows; it may compile under 16-bit Windows
+   with a little tweaking (or maybe not).
+
+   to do:
+    - handle quoted command-line args (especially filenames with spaces)
+    - have minimum window width:  oh well
+    - use %.1023s to simplify truncation of title-bar string?
+
+  ---------------------------------------------------------------------------
+
+   Changelog:
+    - 1.00:  initial public release
+    - 1.01:  modified to allow abbreviated options; fixed long/ulong mis-
+              match; switched to png_jmpbuf() macro
+    - 1.02:  added extra set of parentheses to png_jmpbuf() macro; fixed
+              command-line parsing bug
+    - 1.10:  enabled "message window"/console (thanks to David Geldreich)
+    - 2.00:  dual-licensed (added GNU GPL)
+    - 2.01:  fixed improper display of usage screen on PNG error(s)
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      The contents of this file are DUAL-LICENSED.  You may modify and/or
+      redistribute this software according to the terms of one of the
+      following two licenses (at your option):
+
+
+      LICENSE 1 ("BSD-like with advertising clause"):
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+
+      LICENSE 2 (GNU GPL v2 or later):
+
+      This program is free software; you can redistribute it and/or modify
+      it under the terms of the GNU General Public License as published by
+      the Free Software Foundation; either version 2 of the License, or
+      (at your option) any later version.
+
+      This program is distributed in the hope that it will be useful,
+      but WITHOUT ANY WARRANTY; without even the implied warranty of
+      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+      GNU General Public License for more details.
+
+      You should have received a copy of the GNU General Public License
+      along with this program; if not, write to the Free Software Foundation,
+      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+  ---------------------------------------------------------------------------*/
+
+#define PROGNAME  "rpng-win"
+#define LONGNAME  "Simple PNG Viewer for Windows"
+#define VERSION   "2.01 of 16 March 2008"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <windows.h>
+#include <conio.h>      /* only for _getch() */
+
+/* #define DEBUG  :  this enables the Trace() macros */
+
+#include "readpng.h"    /* typedefs, common macros, readpng prototypes */
+
+
+/* could just include png.h, but this macro is the only thing we need
+ * (name and typedefs changed to local versions); note that side effects
+ * only happen with alpha (which could easily be avoided with
+ * "ush acopy = (alpha);") */
+
+#define alpha_composite(composite, fg, alpha, bg) {               \
+    ush temp = ((ush)(fg)*(ush)(alpha) +                          \
+                (ush)(bg)*(ush)(255 - (ush)(alpha)) + (ush)128);  \
+    (composite) = (uch)((temp + (temp >> 8)) >> 8);               \
+}
+
+
+/* local prototypes */
+static int        rpng_win_create_window(HINSTANCE hInst, int showmode);
+static int        rpng_win_display_image(void);
+static void       rpng_win_cleanup(void);
+LRESULT CALLBACK  rpng_win_wndproc(HWND, UINT, WPARAM, LPARAM);
+
+
+static char titlebar[1024];
+static char *progname = PROGNAME;
+static char *appname = LONGNAME;
+static char *filename;
+static FILE *infile;
+
+static char *bgstr;
+static uch bg_red=0, bg_green=0, bg_blue=0;
+
+static double display_exponent;
+
+static ulg image_width, image_height, image_rowbytes;
+static int image_channels;
+static uch *image_data;
+
+/* Windows-specific variables */
+static ulg wimage_rowbytes;
+static uch *dib;
+static uch *wimage_data;
+static BITMAPINFOHEADER *bmih;
+
+static HWND global_hwnd;
+
+
+
+
+int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode)
+{
+    char *args[1024];                 /* arbitrary limit, but should suffice */
+    char *p, *q, **argv = args;
+    int argc = 0;
+    int rc, alen, flen;
+    int error = 0;
+    int have_bg = FALSE;
+    double LUT_exponent;              /* just the lookup table */
+    double CRT_exponent = 2.2;        /* just the monitor */
+    double default_display_exponent;  /* whole display system */
+    MSG msg;
+
+
+    filename = (char *)NULL;
+
+
+    /* First reenable console output, which normally goes to the bit bucket
+     * for windowed apps.  Closing the console window will terminate the
+     * app.  Thanks to David.Geldreich@realviz.com for supplying the magical
+     * incantation. */
+
+    AllocConsole();
+    freopen("CONOUT$", "a", stderr);
+    freopen("CONOUT$", "a", stdout);
+
+
+    /* Next set the default value for our display-system exponent, i.e.,
+     * the product of the CRT exponent and the exponent corresponding to
+     * the frame-buffer's lookup table (LUT), if any.  This is not an
+     * exhaustive list of LUT values (e.g., OpenStep has a lot of weird
+     * ones), but it should cover 99% of the current possibilities.  And
+     * yes, these ifdefs are completely wasted in a Windows program... */
+
+#if defined(NeXT)
+    LUT_exponent = 1.0 / 2.2;
+    /*
+    if (some_next_function_that_returns_gamma(&next_gamma))
+        LUT_exponent = 1.0 / next_gamma;
+     */
+#elif defined(sgi)
+    LUT_exponent = 1.0 / 1.7;
+    /* there doesn't seem to be any documented function to get the
+     * "gamma" value, so we do it the hard way */
+    infile = fopen("/etc/config/system.glGammaVal", "r");
+    if (infile) {
+        double sgi_gamma;
+
+        fgets(tmpline, 80, infile);
+        fclose(infile);
+        sgi_gamma = atof(tmpline);
+        if (sgi_gamma > 0.0)
+            LUT_exponent = 1.0 / sgi_gamma;
+    }
+#elif defined(Macintosh)
+    LUT_exponent = 1.8 / 2.61;
+    /*
+    if (some_mac_function_that_returns_gamma(&mac_gamma))
+        LUT_exponent = mac_gamma / 2.61;
+     */
+#else
+    LUT_exponent = 1.0;   /* assume no LUT:  most PCs */
+#endif
+
+    /* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */
+    default_display_exponent = LUT_exponent * CRT_exponent;
+
+
+    /* If the user has set the SCREEN_GAMMA environment variable as suggested
+     * (somewhat imprecisely) in the libpng documentation, use that; otherwise
+     * use the default value we just calculated.  Either way, the user may
+     * override this via a command-line option. */
+
+    if ((p = getenv("SCREEN_GAMMA")) != NULL)
+        display_exponent = atof(p);
+    else
+        display_exponent = default_display_exponent;
+
+
+    /* Windows really hates command lines, so we have to set up our own argv.
+     * Note that we do NOT bother with quoted arguments here, so don't use
+     * filenames with spaces in 'em! */
+
+    argv[argc++] = PROGNAME;
+    p = cmd;
+    for (;;) {
+        if (*p == ' ')
+            while (*++p == ' ')
+                ;
+        /* now p points at the first non-space after some spaces */
+        if (*p == '\0')
+            break;    /* nothing after the spaces:  done */
+        argv[argc++] = q = p;
+        while (*q && *q != ' ')
+            ++q;
+        /* now q points at a space or the end of the string */
+        if (*q == '\0')
+            break;    /* last argv already terminated; quit */
+        *q = '\0';    /* change space to terminator */
+        p = q + 1;
+    }
+    argv[argc] = NULL;   /* terminate the argv array itself */
+
+
+    /* Now parse the command line for options and the PNG filename. */
+
+    while (*++argv && !error) {
+        if (!strncmp(*argv, "-gamma", 2)) {
+            if (!*++argv)
+                ++error;
+            else {
+                display_exponent = atof(*argv);
+                if (display_exponent <= 0.0)
+                    ++error;
+            }
+        } else if (!strncmp(*argv, "-bgcolor", 2)) {
+            if (!*++argv)
+                ++error;
+            else {
+                bgstr = *argv;
+                if (strlen(bgstr) != 7 || bgstr[0] != '#')
+                    ++error;
+                else
+                    have_bg = TRUE;
+            }
+        } else {
+            if (**argv != '-') {
+                filename = *argv;
+                if (argv[1])   /* shouldn't be any more args after filename */
+                    ++error;
+            } else
+                ++error;   /* not expecting any other options */
+        }
+    }
+
+    if (!filename)
+        ++error;
+
+
+    /* print usage screen if any errors up to this point */
+
+    if (error) {
+        int ch;
+
+        fprintf(stderr, "\n%s %s:  %s\n\n", PROGNAME, VERSION, appname);
+        readpng_version_info();
+        fprintf(stderr, "\n"
+          "Usage:  %s [-gamma exp] [-bgcolor bg] file.png\n"
+          "    exp \ttransfer-function exponent (``gamma'') of the display\n"
+          "\t\t  system in floating-point format (e.g., ``%.1f''); equal\n"
+          "\t\t  to the product of the lookup-table exponent (varies)\n"
+          "\t\t  and the CRT exponent (usually 2.2); must be positive\n"
+          "    bg  \tdesired background color in 7-character hex RGB format\n"
+          "\t\t  (e.g., ``#ff7700'' for orange:  same as HTML colors);\n"
+          "\t\t  used with transparent images\n"
+          "\nPress Q, Esc or mouse button 1 after image is displayed to quit.\n"
+          "Press Q or Esc to quit this usage screen.\n"
+          "\n", PROGNAME, default_display_exponent);
+        do
+            ch = _getch();
+        while (ch != 'q' && ch != 'Q' && ch != 0x1B);
+        exit(1);
+    }
+
+
+    if (!(infile = fopen(filename, "rb"))) {
+        fprintf(stderr, PROGNAME ":  can't open PNG file [%s]\n", filename);
+        ++error;
+    } else {
+        if ((rc = readpng_init(infile, &image_width, &image_height)) != 0) {
+            switch (rc) {
+                case 1:
+                    fprintf(stderr, PROGNAME
+                      ":  [%s] is not a PNG file: incorrect signature\n",
+                      filename);
+                    break;
+                case 2:
+                    fprintf(stderr, PROGNAME
+                      ":  [%s] has bad IHDR (libpng longjmp)\n", filename);
+                    break;
+                case 4:
+                    fprintf(stderr, PROGNAME ":  insufficient memory\n");
+                    break;
+                default:
+                    fprintf(stderr, PROGNAME
+                      ":  unknown readpng_init() error\n");
+                    break;
+            }
+            ++error;
+        }
+        if (error)
+            fclose(infile);
+    }
+
+
+    if (error) {
+        int ch;
+
+        fprintf(stderr, PROGNAME ":  aborting.\n");
+        do
+            ch = _getch();
+        while (ch != 'q' && ch != 'Q' && ch != 0x1B);
+        exit(2);
+    } else {
+        fprintf(stderr, "\n%s %s:  %s\n", PROGNAME, VERSION, appname);
+        fprintf(stderr,
+          "\n   [console window:  closing this window will terminate %s]\n\n",
+          PROGNAME);
+    }
+
+
+    /* set the title-bar string, but make sure buffer doesn't overflow */
+
+    alen = strlen(appname);
+    flen = strlen(filename);
+    if (alen + flen + 3 > 1023)
+        sprintf(titlebar, "%s:  ...%s", appname, filename+(alen+flen+6-1023));
+    else
+        sprintf(titlebar, "%s:  %s", appname, filename);
+
+
+    /* if the user didn't specify a background color on the command line,
+     * check for one in the PNG file--if not, the initialized values of 0
+     * (black) will be used */
+
+    if (have_bg) {
+        unsigned r, g, b;   /* this approach quiets compiler warnings */
+
+        sscanf(bgstr+1, "%2x%2x%2x", &r, &g, &b);
+        bg_red   = (uch)r;
+        bg_green = (uch)g;
+        bg_blue  = (uch)b;
+    } else if (readpng_get_bgcolor(&bg_red, &bg_green, &bg_blue) > 1) {
+        readpng_cleanup(TRUE);
+        fprintf(stderr, PROGNAME
+          ":  libpng error while checking for background color\n");
+        exit(2);
+    }
+
+
+    /* do the basic Windows initialization stuff, make the window and fill it
+     * with the background color */
+
+    if (rpng_win_create_window(hInst, showmode))
+        exit(2);
+
+
+    /* decode the image, all at once */
+
+    Trace((stderr, "calling readpng_get_image()\n"))
+    image_data = readpng_get_image(display_exponent, &image_channels,
+      &image_rowbytes);
+    Trace((stderr, "done with readpng_get_image()\n"))
+
+
+    /* done with PNG file, so clean up to minimize memory usage (but do NOT
+     * nuke image_data!) */
+
+    readpng_cleanup(FALSE);
+    fclose(infile);
+
+    if (!image_data) {
+        fprintf(stderr, PROGNAME ":  unable to decode PNG image\n");
+        exit(3);
+    }
+
+
+    /* display image (composite with background if requested) */
+
+    Trace((stderr, "calling rpng_win_display_image()\n"))
+    if (rpng_win_display_image()) {
+        free(image_data);
+        exit(4);
+    }
+    Trace((stderr, "done with rpng_win_display_image()\n"))
+
+
+    /* wait for the user to tell us when to quit */
+
+    printf(
+      "Done.  Press Q, Esc or mouse button 1 (within image window) to quit.\n");
+    fflush(stdout);
+
+    while (GetMessage(&msg, NULL, 0, 0)) {
+        TranslateMessage(&msg);
+        DispatchMessage(&msg);
+    }
+
+
+    /* OK, we're done:  clean up all image and Windows resources and go away */
+
+    rpng_win_cleanup();
+
+    return msg.wParam;
+}
+
+
+
+
+
+static int rpng_win_create_window(HINSTANCE hInst, int showmode)
+{
+    uch *dest;
+    int extra_width, extra_height;
+    ulg i, j;
+    WNDCLASSEX wndclass;
+
+
+/*---------------------------------------------------------------------------
+    Allocate memory for the display-specific version of the image (round up
+    to multiple of 4 for Windows DIB).
+  ---------------------------------------------------------------------------*/
+
+    wimage_rowbytes = ((3*image_width + 3L) >> 2) << 2;
+
+    if (!(dib = (uch *)malloc(sizeof(BITMAPINFOHEADER) +
+                              wimage_rowbytes*image_height)))
+    {
+        return 4;   /* fail */
+    }
+
+/*---------------------------------------------------------------------------
+    Initialize the DIB.  Negative height means to use top-down BMP ordering
+    (must be uncompressed, but that's what we want).  Bit count of 1, 4 or 8
+    implies a colormap of RGBX quads, but 24-bit BMPs just use B,G,R values
+    directly => wimage_data begins immediately after BMP header.
+  ---------------------------------------------------------------------------*/
+
+    memset(dib, 0, sizeof(BITMAPINFOHEADER));
+    bmih = (BITMAPINFOHEADER *)dib;
+    bmih->biSize = sizeof(BITMAPINFOHEADER);
+    bmih->biWidth = image_width;
+    bmih->biHeight = -((long)image_height);
+    bmih->biPlanes = 1;
+    bmih->biBitCount = 24;
+    bmih->biCompression = 0;
+    wimage_data = dib + sizeof(BITMAPINFOHEADER);
+
+/*---------------------------------------------------------------------------
+    Fill in background color (black by default); data are in BGR order.
+  ---------------------------------------------------------------------------*/
+
+    for (j = 0;  j < image_height;  ++j) {
+        dest = wimage_data + j*wimage_rowbytes;
+        for (i = image_width;  i > 0;  --i) {
+            *dest++ = bg_blue;
+            *dest++ = bg_green;
+            *dest++ = bg_red;
+        }
+    }
+
+/*---------------------------------------------------------------------------
+    Set the window parameters.
+  ---------------------------------------------------------------------------*/
+
+    memset(&wndclass, 0, sizeof(wndclass));
+
+    wndclass.cbSize = sizeof(wndclass);
+    wndclass.style = CS_HREDRAW | CS_VREDRAW;
+    wndclass.lpfnWndProc = rpng_win_wndproc;
+    wndclass.hInstance = hInst;
+    wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
+    wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
+    wndclass.hbrBackground = (HBRUSH)GetStockObject(DKGRAY_BRUSH);
+    wndclass.lpszMenuName = NULL;
+    wndclass.lpszClassName = progname;
+    wndclass.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
+
+    RegisterClassEx(&wndclass);
+
+/*---------------------------------------------------------------------------
+    Finally, create the window.
+  ---------------------------------------------------------------------------*/
+
+    extra_width  = 2*(GetSystemMetrics(SM_CXBORDER) +
+                      GetSystemMetrics(SM_CXDLGFRAME));
+    extra_height = 2*(GetSystemMetrics(SM_CYBORDER) +
+                      GetSystemMetrics(SM_CYDLGFRAME)) +
+                      GetSystemMetrics(SM_CYCAPTION);
+
+    global_hwnd = CreateWindow(progname, titlebar, WS_OVERLAPPEDWINDOW,
+      CW_USEDEFAULT, CW_USEDEFAULT, image_width+extra_width,
+      image_height+extra_height, NULL, NULL, hInst, NULL);
+
+    ShowWindow(global_hwnd, showmode);
+    UpdateWindow(global_hwnd);
+
+    return 0;
+
+} /* end function rpng_win_create_window() */
+
+
+
+
+
+static int rpng_win_display_image()
+{
+    uch *src, *dest;
+    uch r, g, b, a;
+    ulg i, row, lastrow;
+    RECT rect;
+
+
+    Trace((stderr, "beginning display loop (image_channels == %d)\n",
+      image_channels))
+    Trace((stderr, "(width = %ld, rowbytes = %ld, wimage_rowbytes = %d)\n",
+      image_width, image_rowbytes, wimage_rowbytes))
+
+
+/*---------------------------------------------------------------------------
+    Blast image data to buffer.  This whole routine takes place before the
+    message loop begins, so there's no real point in any pseudo-progressive
+    display...
+  ---------------------------------------------------------------------------*/
+
+    for (lastrow = row = 0;  row < image_height;  ++row) {
+        src = image_data + row*image_rowbytes;
+        dest = wimage_data + row*wimage_rowbytes;
+        if (image_channels == 3) {
+            for (i = image_width;  i > 0;  --i) {
+                r = *src++;
+                g = *src++;
+                b = *src++;
+                *dest++ = b;
+                *dest++ = g;   /* note reverse order */
+                *dest++ = r;
+            }
+        } else /* if (image_channels == 4) */ {
+            for (i = image_width;  i > 0;  --i) {
+                r = *src++;
+                g = *src++;
+                b = *src++;
+                a = *src++;
+                if (a == 255) {
+                    *dest++ = b;
+                    *dest++ = g;
+                    *dest++ = r;
+                } else if (a == 0) {
+                    *dest++ = bg_blue;
+                    *dest++ = bg_green;
+                    *dest++ = bg_red;
+                } else {
+                    /* this macro (copied from png.h) composites the
+                     * foreground and background values and puts the
+                     * result into the first argument; there are no
+                     * side effects with the first argument */
+                    alpha_composite(*dest++, b, a, bg_blue);
+                    alpha_composite(*dest++, g, a, bg_green);
+                    alpha_composite(*dest++, r, a, bg_red);
+                }
+            }
+        }
+        /* display after every 16 lines */
+        if (((row+1) & 0xf) == 0) {
+            rect.left = 0L;
+            rect.top = (LONG)lastrow;
+            rect.right = (LONG)image_width;      /* possibly off by one? */
+            rect.bottom = (LONG)lastrow + 16L;   /* possibly off by one? */
+            InvalidateRect(global_hwnd, &rect, FALSE);
+            UpdateWindow(global_hwnd);     /* similar to XFlush() */
+            lastrow = row + 1;
+        }
+    }
+
+    Trace((stderr, "calling final image-flush routine\n"))
+    if (lastrow < image_height) {
+        rect.left = 0L;
+        rect.top = (LONG)lastrow;
+        rect.right = (LONG)image_width;      /* possibly off by one? */
+        rect.bottom = (LONG)image_height;    /* possibly off by one? */
+        InvalidateRect(global_hwnd, &rect, FALSE);
+        UpdateWindow(global_hwnd);     /* similar to XFlush() */
+    }
+
+/*
+    last param determines whether or not background is wiped before paint
+    InvalidateRect(global_hwnd, NULL, TRUE);
+    UpdateWindow(global_hwnd);
+ */
+
+    return 0;
+}
+
+
+
+
+
+static void rpng_win_cleanup()
+{
+    if (image_data) {
+        free(image_data);
+        image_data = NULL;
+    }
+
+    if (dib) {
+        free(dib);
+        dib = NULL;
+    }
+}
+
+
+
+
+
+LRESULT CALLBACK rpng_win_wndproc(HWND hwnd, UINT iMsg, WPARAM wP, LPARAM lP)
+{
+    HDC         hdc;
+    PAINTSTRUCT ps;
+    int rc;
+
+    switch (iMsg) {
+        case WM_CREATE:
+            /* one-time processing here, if any */
+            return 0;
+
+        case WM_PAINT:
+            hdc = BeginPaint(hwnd, &ps);
+                    /*                    dest                          */
+            rc = StretchDIBits(hdc, 0, 0, image_width, image_height,
+                    /*                    source                        */
+                                    0, 0, image_width, image_height,
+                                    wimage_data, (BITMAPINFO *)bmih,
+                    /*              iUsage: no clue                     */
+                                    0, SRCCOPY);
+            EndPaint(hwnd, &ps);
+            return 0;
+
+        /* wait for the user to tell us when to quit */
+        case WM_CHAR:
+            switch (wP) {      /* only need one, so ignore repeat count */
+                case 'q':
+                case 'Q':
+                case 0x1B:     /* Esc key */
+                    PostQuitMessage(0);
+            }
+            return 0;
+
+        case WM_LBUTTONDOWN:   /* another way of quitting */
+        case WM_DESTROY:
+            PostQuitMessage(0);
+            return 0;
+    }
+
+    return DefWindowProc(hwnd, iMsg, wP, lP);
+}

contrib/gregbook/rpng-x.c

@@ -0,0 +1,904 @@
+/*---------------------------------------------------------------------------
+
+   rpng - simple PNG display program                               rpng-x.c
+
+   This program decodes and displays PNG images, with gamma correction and
+   optionally with a user-specified background color (in case the image has
+   transparency).  It is very nearly the most basic PNG viewer possible.
+   This version is for the X Window System (tested by author under Unix and
+   by Martin Zinser under OpenVMS; may work under OS/2 with some tweaking).
+
+   to do:
+    - 8-bit (colormapped) X support
+    - use %.1023s to simplify truncation of title-bar string?
+
+  ---------------------------------------------------------------------------
+
+   Changelog:
+    - 1.01:  initial public release
+    - 1.02:  modified to allow abbreviated options; fixed long/ulong mis-
+              match; switched to png_jmpbuf() macro
+    - 1.10:  added support for non-default visuals; fixed X pixel-conversion
+    - 1.11:  added extra set of parentheses to png_jmpbuf() macro; fixed
+              command-line parsing bug
+    - 1.12:  fixed some small X memory leaks (thanks to Fran<61>ois Petitjean)
+    - 1.13:  fixed XFreeGC() crash bug (thanks to Patrick Welche)
+    - 1.14:  added support for X resources (thanks to Gerhard Niklasch)
+    - 2.00:  dual-licensed (added GNU GPL)
+    - 2.01:  fixed improper display of usage screen on PNG error(s)
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2008 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      The contents of this file are DUAL-LICENSED.  You may modify and/or
+      redistribute this software according to the terms of one of the
+      following two licenses (at your option):
+
+
+      LICENSE 1 ("BSD-like with advertising clause"):
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+
+      LICENSE 2 (GNU GPL v2 or later):
+
+      This program is free software; you can redistribute it and/or modify
+      it under the terms of the GNU General Public License as published by
+      the Free Software Foundation; either version 2 of the License, or
+      (at your option) any later version.
+
+      This program is distributed in the hope that it will be useful,
+      but WITHOUT ANY WARRANTY; without even the implied warranty of
+      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+      GNU General Public License for more details.
+
+      You should have received a copy of the GNU General Public License
+      along with this program; if not, write to the Free Software Foundation,
+      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+  ---------------------------------------------------------------------------*/
+
+#define PROGNAME  "rpng-x"
+#define LONGNAME  "Simple PNG Viewer for X"
+#define VERSION   "2.01 of 16 March 2008"
+#define RESNAME   "rpng"	/* our X resource application name */
+#define RESCLASS  "Rpng"	/* our X resource class name */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <X11/Xlib.h>
+#include <X11/Xutil.h>
+#include <X11/Xos.h>
+#include <X11/keysym.h>
+
+/* #define DEBUG  :  this enables the Trace() macros */
+
+#include "readpng.h"   /* typedefs, common macros, readpng prototypes */
+
+
+/* could just include png.h, but this macro is the only thing we need
+ * (name and typedefs changed to local versions); note that side effects
+ * only happen with alpha (which could easily be avoided with
+ * "ush acopy = (alpha);") */
+
+#define alpha_composite(composite, fg, alpha, bg) {               \
+    ush temp = ((ush)(fg)*(ush)(alpha) +                          \
+                (ush)(bg)*(ush)(255 - (ush)(alpha)) + (ush)128);  \
+    (composite) = (uch)((temp + (temp >> 8)) >> 8);               \
+}
+
+
+/* local prototypes */
+static int  rpng_x_create_window(void);
+static int  rpng_x_display_image(void);
+static void rpng_x_cleanup(void);
+static int  rpng_x_msb(ulg u32val);
+
+
+static char titlebar[1024], *window_name = titlebar;
+static char *appname = LONGNAME;
+static char *icon_name = PROGNAME;
+static char *res_name = RESNAME;
+static char *res_class = RESCLASS;
+static char *filename;
+static FILE *infile;
+
+static char *bgstr;
+static uch bg_red=0, bg_green=0, bg_blue=0;
+
+static double display_exponent;
+
+static ulg image_width, image_height, image_rowbytes;
+static int image_channels;
+static uch *image_data;
+
+/* X-specific variables */
+static char *displayname;
+static XImage *ximage;
+static Display *display;
+static int depth;
+static Visual *visual;
+static XVisualInfo *visual_list;
+static int RShift, GShift, BShift;
+static ulg RMask, GMask, BMask;
+static Window window;
+static GC gc;
+static Colormap colormap;
+
+static int have_nondefault_visual = FALSE;
+static int have_colormap = FALSE;
+static int have_window = FALSE;
+static int have_gc = FALSE;
+/*
+ulg numcolors=0, pixels[256];
+ush reds[256], greens[256], blues[256];
+ */
+
+
+
+
+int main(int argc, char **argv)
+{
+#ifdef sgi
+    char tmpline[80];
+#endif
+    char *p;
+    int rc, alen, flen;
+    int error = 0;
+    int have_bg = FALSE;
+    double LUT_exponent;               /* just the lookup table */
+    double CRT_exponent = 2.2;         /* just the monitor */
+    double default_display_exponent;   /* whole display system */
+    XEvent e;
+    KeySym k;
+
+
+    displayname = (char *)NULL;
+    filename = (char *)NULL;
+
+
+    /* First set the default value for our display-system exponent, i.e.,
+     * the product of the CRT exponent and the exponent corresponding to
+     * the frame-buffer's lookup table (LUT), if any.  This is not an
+     * exhaustive list of LUT values (e.g., OpenStep has a lot of weird
+     * ones), but it should cover 99% of the current possibilities. */
+
+#if defined(NeXT)
+    LUT_exponent = 1.0 / 2.2;
+    /*
+    if (some_next_function_that_returns_gamma(&next_gamma))
+        LUT_exponent = 1.0 / next_gamma;
+     */
+#elif defined(sgi)
+    LUT_exponent = 1.0 / 1.7;
+    /* there doesn't seem to be any documented function to get the
+     * "gamma" value, so we do it the hard way */
+    infile = fopen("/etc/config/system.glGammaVal", "r");
+    if (infile) {
+        double sgi_gamma;
+
+        fgets(tmpline, 80, infile);
+        fclose(infile);
+        sgi_gamma = atof(tmpline);
+        if (sgi_gamma > 0.0)
+            LUT_exponent = 1.0 / sgi_gamma;
+    }
+#elif defined(Macintosh)
+    LUT_exponent = 1.8 / 2.61;
+    /*
+    if (some_mac_function_that_returns_gamma(&mac_gamma))
+        LUT_exponent = mac_gamma / 2.61;
+     */
+#else
+    LUT_exponent = 1.0;   /* assume no LUT:  most PCs */
+#endif
+
+    /* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */
+    default_display_exponent = LUT_exponent * CRT_exponent;
+
+
+    /* If the user has set the SCREEN_GAMMA environment variable as suggested
+     * (somewhat imprecisely) in the libpng documentation, use that; otherwise
+     * use the default value we just calculated.  Either way, the user may
+     * override this via a command-line option. */
+
+    if ((p = getenv("SCREEN_GAMMA")) != NULL)
+        display_exponent = atof(p);
+    else
+        display_exponent = default_display_exponent;
+
+
+    /* Now parse the command line for options and the PNG filename. */
+
+    while (*++argv && !error) {
+        if (!strncmp(*argv, "-display", 2)) {
+            if (!*++argv)
+                ++error;
+            else
+                displayname = *argv;
+        } else if (!strncmp(*argv, "-gamma", 2)) {
+            if (!*++argv)
+                ++error;
+            else {
+                display_exponent = atof(*argv);
+                if (display_exponent <= 0.0)
+                    ++error;
+            }
+        } else if (!strncmp(*argv, "-bgcolor", 2)) {
+            if (!*++argv)
+                ++error;
+            else {
+                bgstr = *argv;
+                if (strlen(bgstr) != 7 || bgstr[0] != '#')
+                    ++error; 
+                else 
+                    have_bg = TRUE;
+            }
+        } else {
+            if (**argv != '-') {
+                filename = *argv;
+                if (argv[1])   /* shouldn't be any more args after filename */
+                    ++error;
+            } else
+                ++error;   /* not expecting any other options */
+        }
+    }
+
+    if (!filename)
+        ++error;
+
+
+    /* print usage screen if any errors up to this point */
+
+    if (error) {
+        fprintf(stderr, "\n%s %s:  %s\n", PROGNAME, VERSION, appname);
+        readpng_version_info();
+        fprintf(stderr, "\n"
+          "Usage:  %s [-display xdpy] [-gamma exp] [-bgcolor bg] file.png\n"
+          "    xdpy\tname of the target X display (e.g., ``hostname:0'')\n"
+          "    exp \ttransfer-function exponent (``gamma'') of the display\n"
+          "\t\t  system in floating-point format (e.g., ``%.1f''); equal\n"
+          "\t\t  to the product of the lookup-table exponent (varies)\n"
+          "\t\t  and the CRT exponent (usually 2.2); must be positive\n"
+          "    bg  \tdesired background color in 7-character hex RGB format\n"
+          "\t\t  (e.g., ``#ff7700'' for orange:  same as HTML colors);\n"
+          "\t\t  used with transparent images\n"
+          "\nPress Q, Esc or mouse button 1 (within image window, after image\n"
+          "is displayed) to quit.\n"
+          "\n", PROGNAME, default_display_exponent);
+        exit(1);
+    }
+
+
+    if (!(infile = fopen(filename, "rb"))) {
+        fprintf(stderr, PROGNAME ":  can't open PNG file [%s]\n", filename);
+        ++error;
+    } else {
+        if ((rc = readpng_init(infile, &image_width, &image_height)) != 0) {
+            switch (rc) {
+                case 1:
+                    fprintf(stderr, PROGNAME
+                      ":  [%s] is not a PNG file: incorrect signature\n",
+                      filename);
+                    break;
+                case 2:
+                    fprintf(stderr, PROGNAME
+                      ":  [%s] has bad IHDR (libpng longjmp)\n", filename);
+                    break;
+                case 4:
+                    fprintf(stderr, PROGNAME ":  insufficient memory\n");
+                    break;
+                default:
+                    fprintf(stderr, PROGNAME
+                      ":  unknown readpng_init() error\n");
+                    break;
+            }
+            ++error;
+        } else {
+            display = XOpenDisplay(displayname);
+            if (!display) {
+                readpng_cleanup(TRUE);
+                fprintf(stderr, PROGNAME ":  can't open X display [%s]\n",
+                  displayname? displayname : "default");
+                ++error;
+            }
+        }
+        if (error)
+            fclose(infile);
+    }
+
+
+    if (error) {
+        fprintf(stderr, PROGNAME ":  aborting.\n");
+        exit(2);
+    }
+
+
+    /* set the title-bar string, but make sure buffer doesn't overflow */
+
+    alen = strlen(appname);
+    flen = strlen(filename);
+    if (alen + flen + 3 > 1023)
+        sprintf(titlebar, "%s:  ...%s", appname, filename+(alen+flen+6-1023));
+    else
+        sprintf(titlebar, "%s:  %s", appname, filename);
+
+
+    /* if the user didn't specify a background color on the command line,
+     * check for one in the PNG file--if not, the initialized values of 0
+     * (black) will be used */
+
+    if (have_bg) {
+        unsigned r, g, b;   /* this approach quiets compiler warnings */
+
+        sscanf(bgstr+1, "%2x%2x%2x", &r, &g, &b);
+        bg_red   = (uch)r;
+        bg_green = (uch)g;
+        bg_blue  = (uch)b;
+    } else if (readpng_get_bgcolor(&bg_red, &bg_green, &bg_blue) > 1) {
+        readpng_cleanup(TRUE);
+        fprintf(stderr, PROGNAME
+          ":  libpng error while checking for background color\n");
+        exit(2);
+    }
+
+
+    /* do the basic X initialization stuff, make the window and fill it
+     * with the background color */
+
+    if (rpng_x_create_window())
+        exit(2);
+
+
+    /* decode the image, all at once */
+
+    Trace((stderr, "calling readpng_get_image()\n"))
+    image_data = readpng_get_image(display_exponent, &image_channels,
+      &image_rowbytes);
+    Trace((stderr, "done with readpng_get_image()\n"))
+
+
+    /* done with PNG file, so clean up to minimize memory usage (but do NOT
+     * nuke image_data!) */
+
+    readpng_cleanup(FALSE);
+    fclose(infile);
+
+    if (!image_data) {
+        fprintf(stderr, PROGNAME ":  unable to decode PNG image\n");
+        exit(3);
+    }
+
+
+    /* display image (composite with background if requested) */
+
+    Trace((stderr, "calling rpng_x_display_image()\n"))
+    if (rpng_x_display_image()) {
+        free(image_data);
+        exit(4);
+    }
+    Trace((stderr, "done with rpng_x_display_image()\n"))
+
+
+    /* wait for the user to tell us when to quit */
+
+    printf(
+      "Done.  Press Q, Esc or mouse button 1 (within image window) to quit.\n");
+    fflush(stdout);
+
+    do
+        XNextEvent(display, &e);
+    while (!(e.type == ButtonPress && e.xbutton.button == Button1) &&
+           !(e.type == KeyPress &&    /*  v--- or 1 for shifted keys */
+             ((k = XLookupKeysym(&e.xkey, 0)) == XK_q || k == XK_Escape) ));
+
+
+    /* OK, we're done:  clean up all image and X resources and go away */
+
+    rpng_x_cleanup();
+
+    return 0;
+}
+
+
+
+
+
+static int rpng_x_create_window(void)
+{
+    uch *xdata;
+    int need_colormap = FALSE;
+    int screen, pad;
+    ulg bg_pixel = 0L;
+    ulg attrmask;
+    Window root;
+    XEvent e;
+    XGCValues gcvalues;
+    XSetWindowAttributes attr;
+    XTextProperty windowName, *pWindowName = &windowName;
+    XTextProperty iconName, *pIconName = &iconName;
+    XVisualInfo visual_info;
+    XSizeHints *size_hints;
+    XWMHints *wm_hints;
+    XClassHint *class_hints;
+
+
+    screen = DefaultScreen(display);
+    depth = DisplayPlanes(display, screen);
+    root = RootWindow(display, screen);
+
+#ifdef DEBUG
+    XSynchronize(display, True);
+#endif
+
+#if 0
+/* GRR:  add 8-bit support */
+    if (/* depth != 8 && */ depth != 16 && depth != 24 && depth != 32) {
+        fprintf(stderr,
+          "screen depth %d not supported (only 16-, 24- or 32-bit TrueColor)\n",
+          depth);
+        return 2;
+    }
+
+    XMatchVisualInfo(display, screen, depth,
+      (depth == 8)? PseudoColor : TrueColor, &visual_info);
+    visual = visual_info.visual;
+#else
+    if (depth != 16 && depth != 24 && depth != 32) {
+        int visuals_matched = 0;
+
+        Trace((stderr, "default depth is %d:  checking other visuals\n",
+          depth))
+
+        /* 24-bit first */
+        visual_info.screen = screen;
+        visual_info.depth = 24;
+        visual_list = XGetVisualInfo(display,
+          VisualScreenMask | VisualDepthMask, &visual_info, &visuals_matched);
+        if (visuals_matched == 0) {
+/* GRR:  add 15-, 16- and 32-bit TrueColor visuals (also DirectColor?) */
+            fprintf(stderr, "default screen depth %d not supported, and no"
+              " 24-bit visuals found\n", depth);
+            return 2;
+        }
+        Trace((stderr, "XGetVisualInfo() returned %d 24-bit visuals\n",
+          visuals_matched))
+        visual = visual_list[0].visual;
+        depth = visual_list[0].depth;
+/*
+        colormap_size = visual_list[0].colormap_size;
+        visual_class = visual->class;
+        visualID = XVisualIDFromVisual(visual);
+ */
+        have_nondefault_visual = TRUE;
+        need_colormap = TRUE;
+    } else {
+        XMatchVisualInfo(display, screen, depth, TrueColor, &visual_info);
+        visual = visual_info.visual;
+    }
+#endif
+
+    RMask = visual->red_mask;
+    GMask = visual->green_mask;
+    BMask = visual->blue_mask;
+
+/* GRR:  add/check 8-bit support */
+    if (depth == 8 || need_colormap) {
+        colormap = XCreateColormap(display, root, visual, AllocNone);
+        if (!colormap) {
+            fprintf(stderr, "XCreateColormap() failed\n");
+            return 2;
+        }
+        have_colormap = TRUE;
+    }
+    if (depth == 15 || depth == 16) {
+        RShift = 15 - rpng_x_msb(RMask);    /* these are right-shifts */
+        GShift = 15 - rpng_x_msb(GMask);
+        BShift = 15 - rpng_x_msb(BMask);
+    } else if (depth > 16) {
+#define NO_24BIT_MASKS
+#ifdef NO_24BIT_MASKS
+        RShift = rpng_x_msb(RMask) - 7;     /* these are left-shifts */
+        GShift = rpng_x_msb(GMask) - 7;
+        BShift = rpng_x_msb(BMask) - 7;
+#else
+        RShift = 7 - rpng_x_msb(RMask);     /* these are right-shifts, too */
+        GShift = 7 - rpng_x_msb(GMask);
+        BShift = 7 - rpng_x_msb(BMask);
+#endif
+    }
+    if (depth >= 15 && (RShift < 0 || GShift < 0 || BShift < 0)) {
+        fprintf(stderr, "rpng internal logic error:  negative X shift(s)!\n");
+        return 2;
+    }
+
+/*---------------------------------------------------------------------------
+    Finally, create the window.
+  ---------------------------------------------------------------------------*/
+
+    attr.backing_store = Always;
+    attr.event_mask = ExposureMask | KeyPressMask | ButtonPressMask;
+    attrmask = CWBackingStore | CWEventMask;
+    if (have_nondefault_visual) {
+        attr.colormap = colormap;
+        attr.background_pixel = 0;
+        attr.border_pixel = 1;
+        attrmask |= CWColormap | CWBackPixel | CWBorderPixel;
+    }
+
+    window = XCreateWindow(display, root, 0, 0, image_width, image_height, 0,
+      depth, InputOutput, visual, attrmask, &attr);
+
+    if (window == None) {
+        fprintf(stderr, "XCreateWindow() failed\n");
+        return 2;
+    } else
+        have_window = TRUE;
+
+    if (depth == 8)
+        XSetWindowColormap(display, window, colormap);
+
+    if (!XStringListToTextProperty(&window_name, 1, pWindowName))
+        pWindowName = NULL;
+    if (!XStringListToTextProperty(&icon_name, 1, pIconName))
+        pIconName = NULL;
+
+    /* OK if any hints allocation fails; XSetWMProperties() allows NULLs */
+
+    if ((size_hints = XAllocSizeHints()) != NULL) {
+        /* window will not be resizable */
+        size_hints->flags = PMinSize | PMaxSize;
+        size_hints->min_width = size_hints->max_width = (int)image_width;
+        size_hints->min_height = size_hints->max_height = (int)image_height;
+    }
+
+    if ((wm_hints = XAllocWMHints()) != NULL) {
+        wm_hints->initial_state = NormalState;
+        wm_hints->input = True;
+     /* wm_hints->icon_pixmap = icon_pixmap; */
+        wm_hints->flags = StateHint | InputHint  /* | IconPixmapHint */ ;
+    }
+
+    if ((class_hints = XAllocClassHint()) != NULL) {
+        class_hints->res_name = res_name;
+        class_hints->res_class = res_class;
+    }
+
+    XSetWMProperties(display, window, pWindowName, pIconName, NULL, 0,
+      size_hints, wm_hints, class_hints);
+
+    /* various properties and hints no longer needed; free memory */
+    if (pWindowName)
+       XFree(pWindowName->value);
+    if (pIconName)
+       XFree(pIconName->value);
+    if (size_hints)
+        XFree(size_hints);
+    if (wm_hints)
+       XFree(wm_hints);
+    if (class_hints)
+       XFree(class_hints);
+
+    XMapWindow(display, window);
+
+    gc = XCreateGC(display, window, 0, &gcvalues);
+    have_gc = TRUE;
+
+/*---------------------------------------------------------------------------
+    Fill window with the specified background color.
+  ---------------------------------------------------------------------------*/
+
+    if (depth == 24 || depth == 32) {
+        bg_pixel = ((ulg)bg_red   << RShift) |
+                   ((ulg)bg_green << GShift) |
+                   ((ulg)bg_blue  << BShift);
+    } else if (depth == 16) {
+        bg_pixel = ((((ulg)bg_red   << 8) >> RShift) & RMask) |
+                   ((((ulg)bg_green << 8) >> GShift) & GMask) |
+                   ((((ulg)bg_blue  << 8) >> BShift) & BMask);
+    } else /* depth == 8 */ {
+
+        /* GRR:  add 8-bit support */
+
+    }
+
+    XSetForeground(display, gc, bg_pixel);
+    XFillRectangle(display, window, gc, 0, 0, image_width, image_height);
+
+/*---------------------------------------------------------------------------
+    Wait for first Expose event to do any drawing, then flush.
+  ---------------------------------------------------------------------------*/
+
+    do
+        XNextEvent(display, &e);
+    while (e.type != Expose || e.xexpose.count);
+
+    XFlush(display);
+
+/*---------------------------------------------------------------------------
+    Allocate memory for the X- and display-specific version of the image.
+  ---------------------------------------------------------------------------*/
+
+    if (depth == 24 || depth == 32) {
+        xdata = (uch *)malloc(4*image_width*image_height);
+        pad = 32;
+    } else if (depth == 16) {
+        xdata = (uch *)malloc(2*image_width*image_height);
+        pad = 16;
+    } else /* depth == 8 */ {
+        xdata = (uch *)malloc(image_width*image_height);
+        pad = 8;
+    }
+
+    if (!xdata) {
+        fprintf(stderr, PROGNAME ":  unable to allocate image memory\n");
+        return 4;
+    }
+
+    ximage = XCreateImage(display, visual, depth, ZPixmap, 0,
+      (char *)xdata, image_width, image_height, pad, 0);
+
+    if (!ximage) {
+        fprintf(stderr, PROGNAME ":  XCreateImage() failed\n");
+        free(xdata);
+        return 3;
+    }
+
+    /* to avoid testing the byte order every pixel (or doubling the size of
+     * the drawing routine with a giant if-test), we arbitrarily set the byte
+     * order to MSBFirst and let Xlib worry about inverting things on little-
+     * endian machines (like Linux/x86, old VAXen, etc.)--this is not the most
+     * efficient approach (the giant if-test would be better), but in the
+     * interest of clarity, we take the easy way out... */
+
+    ximage->byte_order = MSBFirst;
+
+    return 0;
+
+} /* end function rpng_x_create_window() */
+
+
+
+
+
+static int rpng_x_display_image(void)
+{
+    uch *src;
+    char *dest;
+    uch r, g, b, a;
+    ulg i, row, lastrow = 0;
+    ulg pixel;
+    int ximage_rowbytes = ximage->bytes_per_line;
+/*  int bpp = ximage->bits_per_pixel;  */
+
+
+    Trace((stderr, "beginning display loop (image_channels == %d)\n",
+      image_channels))
+    Trace((stderr, "   (width = %ld, rowbytes = %ld, ximage_rowbytes = %d)\n",
+      image_width, image_rowbytes, ximage_rowbytes))
+    Trace((stderr, "   (bpp = %d)\n", ximage->bits_per_pixel))
+    Trace((stderr, "   (byte_order = %s)\n", ximage->byte_order == MSBFirst?
+      "MSBFirst" : (ximage->byte_order == LSBFirst? "LSBFirst" : "unknown")))
+
+    if (depth == 24 || depth == 32) {
+        ulg red, green, blue;
+
+        for (lastrow = row = 0;  row < image_height;  ++row) {
+            src = image_data + row*image_rowbytes;
+            dest = ximage->data + row*ximage_rowbytes;
+            if (image_channels == 3) {
+                for (i = image_width;  i > 0;  --i) {
+                    red   = *src++;
+                    green = *src++;
+                    blue  = *src++;
+#ifdef NO_24BIT_MASKS
+                    pixel = (red   << RShift) |
+                            (green << GShift) |
+                            (blue  << BShift);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    /* GRR BUG:  this assumes bpp == 32, but may be 24: */
+                    *dest++ = (char)((pixel >> 24) & 0xff);
+                    *dest++ = (char)((pixel >> 16) & 0xff);
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+#else
+                    red   = (RShift < 0)? red   << (-RShift) : red   >> RShift;
+                    green = (GShift < 0)? green << (-GShift) : green >> GShift;
+                    blue  = (BShift < 0)? blue  << (-BShift) : blue  >> BShift;
+                    pixel = (red & RMask) | (green & GMask) | (blue & BMask);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    *dest++ = (char)((pixel >> 24) & 0xff);
+                    *dest++ = (char)((pixel >> 16) & 0xff);
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+#endif
+                }
+            } else /* if (image_channels == 4) */ {
+                for (i = image_width;  i > 0;  --i) {
+                    r = *src++;
+                    g = *src++;
+                    b = *src++;
+                    a = *src++;
+                    if (a == 255) {
+                        red   = r;
+                        green = g;
+                        blue  = b;
+                    } else if (a == 0) {
+                        red   = bg_red;
+                        green = bg_green;
+                        blue  = bg_blue;
+                    } else {
+                        /* this macro (from png.h) composites the foreground
+                         * and background values and puts the result into the
+                         * first argument */
+                        alpha_composite(red,   r, a, bg_red);
+                        alpha_composite(green, g, a, bg_green);
+                        alpha_composite(blue,  b, a, bg_blue);
+                    }
+                    pixel = (red   << RShift) |
+                            (green << GShift) |
+                            (blue  << BShift);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    *dest++ = (char)((pixel >> 24) & 0xff);
+                    *dest++ = (char)((pixel >> 16) & 0xff);
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+                }
+            }
+            /* display after every 16 lines */
+            if (((row+1) & 0xf) == 0) {
+                XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
+                  (int)lastrow, image_width, 16);
+                XFlush(display);
+                lastrow = row + 1;
+            }
+        }
+
+    } else if (depth == 16) {
+        ush red, green, blue;
+
+        for (lastrow = row = 0;  row < image_height;  ++row) {
+            src = image_data + row*image_rowbytes;
+            dest = ximage->data + row*ximage_rowbytes;
+            if (image_channels == 3) {
+                for (i = image_width;  i > 0;  --i) {
+                    red   = ((ush)(*src) << 8);
+                    ++src;
+                    green = ((ush)(*src) << 8);
+                    ++src;
+                    blue  = ((ush)(*src) << 8);
+                    ++src;
+                    pixel = ((red   >> RShift) & RMask) |
+                            ((green >> GShift) & GMask) |
+                            ((blue  >> BShift) & BMask);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+                }
+            } else /* if (image_channels == 4) */ {
+                for (i = image_width;  i > 0;  --i) {
+                    r = *src++;
+                    g = *src++;
+                    b = *src++;
+                    a = *src++;
+                    if (a == 255) {
+                        red   = ((ush)r << 8);
+                        green = ((ush)g << 8);
+                        blue  = ((ush)b << 8);
+                    } else if (a == 0) {
+                        red   = ((ush)bg_red   << 8);
+                        green = ((ush)bg_green << 8);
+                        blue  = ((ush)bg_blue  << 8);
+                    } else {
+                        /* this macro (from png.h) composites the foreground
+                         * and background values and puts the result back into
+                         * the first argument (== fg byte here:  safe) */
+                        alpha_composite(r, r, a, bg_red);
+                        alpha_composite(g, g, a, bg_green);
+                        alpha_composite(b, b, a, bg_blue);
+                        red   = ((ush)r << 8);
+                        green = ((ush)g << 8);
+                        blue  = ((ush)b << 8);
+                    }
+                    pixel = ((red   >> RShift) & RMask) |
+                            ((green >> GShift) & GMask) |
+                            ((blue  >> BShift) & BMask);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+                }
+            }
+            /* display after every 16 lines */
+            if (((row+1) & 0xf) == 0) {
+                XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
+                  (int)lastrow, image_width, 16);
+                XFlush(display);
+                lastrow = row + 1;
+            }
+        }
+
+    } else /* depth == 8 */ {
+
+        /* GRR:  add 8-bit support */
+
+    }
+
+    Trace((stderr, "calling final XPutImage()\n"))
+    if (lastrow < image_height) {
+        XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
+          (int)lastrow, image_width, image_height-lastrow);
+        XFlush(display);
+    }
+
+    return 0;
+}
+
+
+
+
+static void rpng_x_cleanup(void)
+{
+    if (image_data) {
+        free(image_data);
+        image_data = NULL;
+    }
+
+    if (ximage) {
+        if (ximage->data) {
+            free(ximage->data);           /* we allocated it, so we free it */
+            ximage->data = (char *)NULL;  /*  instead of XDestroyImage() */
+        }
+        XDestroyImage(ximage);
+        ximage = NULL;
+    }
+
+    if (have_gc)
+        XFreeGC(display, gc);
+
+    if (have_window)
+        XDestroyWindow(display, window);
+
+    if (have_colormap)
+        XFreeColormap(display, colormap);
+
+    if (have_nondefault_visual)
+        XFree(visual_list);
+}
+
+
+
+
+
+static int rpng_x_msb(ulg u32val)
+{
+    int i;
+
+    for (i = 31;  i >= 0;  --i) {
+        if (u32val & 0x80000000L)
+            break;
+        u32val <<= 1;
+    }
+    return i;
+}

contrib/gregbook/wpng.c

@@ -0,0 +1,853 @@
+/*---------------------------------------------------------------------------
+
+   wpng - simple PNG-writing program                                 wpng.c
+
+   This program converts certain NetPBM binary files (grayscale and RGB,
+   maxval = 255) to PNG.  Non-interlaced PNGs are written progressively;
+   interlaced PNGs are read and written in one memory-intensive blast.
+
+   Thanks to Jean-loup Gailly for providing the necessary trick to read
+   interactive text from the keyboard while stdin is redirected.  Thanks
+   to Cosmin Truta for Cygwin fixes.
+
+   NOTE:  includes provisional support for PNM type "8" (portable alphamap)
+          images, presumed to be a 32-bit interleaved RGBA format; no pro-
+          vision for possible interleaved grayscale+alpha (16-bit) format.
+          THIS IS UNLIKELY TO BECOME AN OFFICIAL NETPBM ALPHA FORMAT!
+
+   to do:
+    - delete output file if quit before calling any writepng routines
+    - process backspace with -text option under DOS/Win? (currently get ^H)
+
+  ---------------------------------------------------------------------------
+
+   Changelog:
+    - 1.01:  initial public release
+    - 1.02:  modified to allow abbreviated options
+    - 1.03:  removed extraneous character from usage screen; fixed bug in
+              command-line parsing
+    - 1.04:  fixed DOS/OS2/Win32 detection, including partial Cygwin fix
+              (see http://home.att.net/~perlspinr/diffs/GregBook_cygwin.diff)
+    - 2.00:  dual-licensed (added GNU GPL)
+
+        [REPORTED BUG (win32 only):  "contrib/gregbook/wpng.c - cmd line
+         dose not work!  In order to do something useful I needed to redirect
+         both input and output, with cygwin and with bcc32 as well.  Under
+         Linux, the same wpng appears to work fine.  I don't know what is
+         the problem."]
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      The contents of this file are DUAL-LICENSED.  You may modify and/or
+      redistribute this software according to the terms of one of the
+      following two licenses (at your option):
+
+
+      LICENSE 1 ("BSD-like with advertising clause"):
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+
+      LICENSE 2 (GNU GPL v2 or later):
+
+      This program is free software; you can redistribute it and/or modify
+      it under the terms of the GNU General Public License as published by
+      the Free Software Foundation; either version 2 of the License, or
+      (at your option) any later version.
+
+      This program is distributed in the hope that it will be useful,
+      but WITHOUT ANY WARRANTY; without even the implied warranty of
+      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+      GNU General Public License for more details.
+
+      You should have received a copy of the GNU General Public License
+      along with this program; if not, write to the Free Software Foundation,
+      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+  ---------------------------------------------------------------------------*/
+
+#define PROGNAME  "wpng"
+#define VERSION   "2.00 of 2 June 2007"
+#define APPNAME   "Simple PGM/PPM/PAM to PNG Converter"
+
+#if defined(__MSDOS__) || defined(__OS2__)
+#  define DOS_OS2_W32
+#elif defined(WIN32) || defined(_WIN32) || defined(__WIN32__)
+#  ifndef __GNUC__   /* treat Win32 native ports of gcc as Unix environments */
+#    define DOS_OS2_W32
+#  endif
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <setjmp.h>     /* for jmpbuf declaration in writepng.h */
+#include <time.h>
+
+#ifdef DOS_OS2_W32
+#  include <io.h>       /* for isatty(), setmode() prototypes */
+#  include <fcntl.h>    /* O_BINARY for fdopen() without text translation */
+#  ifdef __EMX__
+#    ifndef getch
+#      define getch() _read_kbd(0, 1, 0)    /* need getche() */
+#    endif
+#  else /* !__EMX__ */
+#    ifdef __GO32__
+#      include <pc.h>
+#      define getch() getkey()  /* GRR:  need getche() */
+#    else
+#      include <conio.h>        /* for getche() console input */
+#    endif
+#  endif /* ?__EMX__ */
+#  define FGETS(buf,len,stream)  dos_kbd_gets(buf,len)
+#else
+#  include <unistd.h>           /* for isatty() prototype */
+#  define FGETS fgets
+#endif
+
+/* #define DEBUG  :  this enables the Trace() macros */
+
+/* #define FORBID_LATIN1_CTRL  :  this requires the user to re-enter any
+   text that includes control characters discouraged by the PNG spec; text
+   that includes an escape character (27) must be re-entered regardless */
+
+#include "writepng.h"   /* typedefs, common macros, writepng prototypes */
+
+
+
+/* local prototypes */
+
+static int  wpng_isvalid_latin1(uch *p, int len);
+static void wpng_cleanup(void);
+
+#ifdef DOS_OS2_W32
+   static char *dos_kbd_gets(char *buf, int len);
+#endif
+
+
+
+static mainprog_info wpng_info;   /* lone global */
+
+
+
+int main(int argc, char **argv)
+{
+#ifndef DOS_OS2_W32
+    FILE *keybd;
+#endif
+#ifdef sgi
+    FILE *tmpfile;      /* or we could just use keybd, since no overlap */
+    char tmpline[80];
+#endif
+    char *inname = NULL, outname[256];
+    char *p, pnmchar, pnmline[256];
+    char *bgstr, *textbuf = NULL;
+    ulg rowbytes;
+    int rc, len = 0;
+    int error = 0;
+    int text = FALSE;
+    int maxval;
+    double LUT_exponent;                /* just the lookup table */
+    double CRT_exponent = 2.2;          /* just the monitor */
+    double default_display_exponent;    /* whole display system */
+    double default_gamma = 0.0;
+
+
+    wpng_info.infile = NULL;
+    wpng_info.outfile = NULL;
+    wpng_info.image_data = NULL;
+    wpng_info.row_pointers = NULL;
+    wpng_info.filter = FALSE;
+    wpng_info.interlaced = FALSE;
+    wpng_info.have_bg = FALSE;
+    wpng_info.have_time = FALSE;
+    wpng_info.have_text = 0;
+    wpng_info.gamma = 0.0;
+
+
+    /* First get the default value for our display-system exponent, i.e.,
+     * the product of the CRT exponent and the exponent corresponding to
+     * the frame-buffer's lookup table (LUT), if any.  If the PNM image
+     * looks correct on the user's display system, its file gamma is the
+     * inverse of this value.  (Note that this is not an exhaustive list
+     * of LUT values--e.g., OpenStep has a lot of weird ones--but it should
+     * cover 99% of the current possibilities.  This section must ensure
+     * that default_display_exponent is positive.) */
+
+#if defined(NeXT)
+    /* third-party utilities can modify the default LUT exponent */
+    LUT_exponent = 1.0 / 2.2;
+    /*
+    if (some_next_function_that_returns_gamma(&next_gamma))
+        LUT_exponent = 1.0 / next_gamma;
+     */
+#elif defined(sgi)
+    LUT_exponent = 1.0 / 1.7;
+    /* there doesn't seem to be any documented function to
+     * get the "gamma" value, so we do it the hard way */
+    tmpfile = fopen("/etc/config/system.glGammaVal", "r");
+    if (tmpfile) {
+        double sgi_gamma;
+
+        fgets(tmpline, 80, tmpfile);
+        fclose(tmpfile);
+        sgi_gamma = atof(tmpline);
+        if (sgi_gamma > 0.0)
+            LUT_exponent = 1.0 / sgi_gamma;
+    }
+#elif defined(Macintosh)
+    LUT_exponent = 1.8 / 2.61;
+    /*
+    if (some_mac_function_that_returns_gamma(&mac_gamma))
+        LUT_exponent = mac_gamma / 2.61;
+     */
+#else
+    LUT_exponent = 1.0;   /* assume no LUT:  most PCs */
+#endif
+
+    /* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */
+    default_display_exponent = LUT_exponent * CRT_exponent;
+
+
+    /* If the user has set the SCREEN_GAMMA environment variable as suggested
+     * (somewhat imprecisely) in the libpng documentation, use that; otherwise
+     * use the default value we just calculated.  Either way, the user may
+     * override this via a command-line option. */
+
+    if ((p = getenv("SCREEN_GAMMA")) != NULL) {
+        double exponent = atof(p);
+
+        if (exponent > 0.0)
+            default_gamma = 1.0 / exponent;
+    }
+
+    if (default_gamma == 0.0)
+        default_gamma = 1.0 / default_display_exponent;
+
+
+    /* Now parse the command line for options and the PNM filename. */
+
+    while (*++argv && !error) {
+        if (!strncmp(*argv, "-i", 2)) {
+            wpng_info.interlaced = TRUE;
+        } else if (!strncmp(*argv, "-time", 3)) {
+            wpng_info.modtime = time(NULL);
+            wpng_info.have_time = TRUE;
+        } else if (!strncmp(*argv, "-text", 3)) {
+            text = TRUE;
+        } else if (!strncmp(*argv, "-gamma", 2)) {
+            if (!*++argv)
+                ++error;
+            else {
+                wpng_info.gamma = atof(*argv);
+                if (wpng_info.gamma <= 0.0)
+                    ++error;
+                else if (wpng_info.gamma > 1.01)
+                    fprintf(stderr, PROGNAME
+                      " warning:  file gammas are usually less than 1.0\n");
+            }
+        } else if (!strncmp(*argv, "-bgcolor", 4)) {
+            if (!*++argv)
+                ++error;
+            else {
+                bgstr = *argv;
+                if (strlen(bgstr) != 7 || bgstr[0] != '#')
+                    ++error;
+                else {
+                    unsigned r, g, b;  /* this way quiets compiler warnings */
+
+                    sscanf(bgstr+1, "%2x%2x%2x", &r, &g, &b);
+                    wpng_info.bg_red   = (uch)r;
+                    wpng_info.bg_green = (uch)g;
+                    wpng_info.bg_blue  = (uch)b;
+                    wpng_info.have_bg = TRUE;
+                }
+            }
+        } else {
+            if (**argv != '-') {
+                inname = *argv;
+                if (argv[1])   /* shouldn't be any more args after filename */
+                    ++error;
+            } else
+                ++error;   /* not expecting any other options */
+        }
+    }
+
+
+    /* open the input and output files, or register an error and abort */
+
+    if (!inname) {
+        if (isatty(0)) {
+            fprintf(stderr, PROGNAME
+              ":  must give input filename or provide image data via stdin\n");
+            ++error;
+        } else {
+#ifdef DOS_OS2_W32
+            /* some buggy C libraries require BOTH setmode() and fdopen(bin) */
+            setmode(fileno(stdin), O_BINARY);
+            setmode(fileno(stdout), O_BINARY);
+#endif
+            if ((wpng_info.infile = fdopen(fileno(stdin), "rb")) == NULL) {
+                fprintf(stderr, PROGNAME
+                  ":  unable to reopen stdin in binary mode\n");
+                ++error;
+            } else
+            if ((wpng_info.outfile = fdopen(fileno(stdout), "wb")) == NULL) {
+                fprintf(stderr, PROGNAME
+                  ":  unable to reopen stdout in binary mode\n");
+                fclose(wpng_info.infile);
+                ++error;
+            } else
+                wpng_info.filter = TRUE;
+        }
+    } else if ((len = strlen(inname)) > 250) {
+        fprintf(stderr, PROGNAME ":  input filename is too long [%d chars]\n",
+          len);
+        ++error;
+    } else if (!(wpng_info.infile = fopen(inname, "rb"))) {
+        fprintf(stderr, PROGNAME ":  can't open input file [%s]\n", inname);
+        ++error;
+    }
+
+    if (!error) {
+        fgets(pnmline, 256, wpng_info.infile);
+        if (pnmline[0] != 'P' || ((pnmchar = pnmline[1]) != '5' &&
+            pnmchar != '6' && pnmchar != '8'))
+        {
+            fprintf(stderr, PROGNAME
+              ":  input file [%s] is not a binary PGM, PPM or PAM file\n",
+              inname);
+            ++error;
+        } else {
+            wpng_info.pnmtype = (int)(pnmchar - '0');
+            if (wpng_info.pnmtype != 8)
+                wpng_info.have_bg = FALSE;  /* no need for bg if opaque */
+            do {
+                fgets(pnmline, 256, wpng_info.infile);  /* lose any comments */
+            } while (pnmline[0] == '#');
+            sscanf(pnmline, "%ld %ld", &wpng_info.width, &wpng_info.height);
+            do {
+                fgets(pnmline, 256, wpng_info.infile);  /* more comment lines */
+            } while (pnmline[0] == '#');
+            sscanf(pnmline, "%d", &maxval);
+            if (wpng_info.width <= 0L || wpng_info.height <= 0L ||
+                maxval != 255)
+            {
+                fprintf(stderr, PROGNAME
+                  ":  only positive width/height, maxval == 255 allowed \n");
+                ++error;
+            }
+            wpng_info.sample_depth = 8;  /* <==> maxval 255 */
+
+            if (!wpng_info.filter) {
+                /* make outname from inname */
+                if ((p = strrchr(inname, '.')) == NULL ||
+                    (p - inname) != (len - 4))
+                {
+                    strcpy(outname, inname);
+                    strcpy(outname+len, ".png");
+                } else {
+                    len -= 4;
+                    strncpy(outname, inname, len);
+                    strcpy(outname+len, ".png");
+                }
+                /* check if outname already exists; if not, open */
+                if ((wpng_info.outfile = fopen(outname, "rb")) != NULL) {
+                    fprintf(stderr, PROGNAME ":  output file exists [%s]\n",
+                      outname);
+                    fclose(wpng_info.outfile);
+                    ++error;
+                } else if (!(wpng_info.outfile = fopen(outname, "wb"))) {
+                    fprintf(stderr, PROGNAME ":  can't open output file [%s]\n",
+                      outname);
+                    ++error;
+                }
+            }
+        }
+        if (error) {
+            fclose(wpng_info.infile);
+            wpng_info.infile = NULL;
+            if (wpng_info.filter) {
+                fclose(wpng_info.outfile);
+                wpng_info.outfile = NULL;
+            }
+        }
+    }
+
+
+    /* if we had any errors, print usage and die horrible death...arrr! */
+
+    if (error) {
+        fprintf(stderr, "\n%s %s:  %s\n", PROGNAME, VERSION, APPNAME);
+        writepng_version_info();
+        fprintf(stderr, "\n"
+"Usage:  %s [-gamma exp] [-bgcolor bg] [-text] [-time] [-interlace] pnmfile\n"
+"or: ... | %s [-gamma exp] [-bgcolor bg] [-text] [-time] [-interlace] | ...\n"
+         "    exp \ttransfer-function exponent (``gamma'') of the image in\n"
+         "\t\t  floating-point format (e.g., ``%.5f''); if image looks\n"
+         "\t\t  correct on given display system, image gamma is equal to\n"
+         "\t\t  inverse of display-system exponent, i.e., 1 / (LUT * CRT)\n"
+         "\t\t  (where LUT = lookup-table exponent and CRT = CRT exponent;\n"
+         "\t\t  first varies, second is usually 2.2, all are positive)\n"
+         "    bg  \tdesired background color for alpha-channel images, in\n"
+         "\t\t  7-character hex RGB format (e.g., ``#ff7700'' for orange:\n"
+         "\t\t  same as HTML colors)\n"
+         "    -text\tprompt interactively for text info (tEXt chunks)\n"
+         "    -time\tinclude a tIME chunk (last modification time)\n"
+         "    -interlace\twrite interlaced PNG image\n"
+         "\n"
+"pnmfile or stdin must be a binary PGM (`P5'), PPM (`P6') or (extremely\n"
+"unofficial and unsupported!) PAM (`P8') file.  Currently it is required\n"
+"to have maxval == 255 (i.e., no scaling).  If pnmfile is specified, it\n"
+"is converted to the corresponding PNG file with the same base name but a\n"
+"``.png'' extension; files read from stdin are converted and sent to stdout.\n"
+"The conversion is progressive (low memory usage) unless interlacing is\n"
+"requested; in that case the whole image will be buffered in memory and\n"
+"written in one call.\n"
+         "\n", PROGNAME, PROGNAME, default_gamma);
+        exit(1);
+    }
+
+
+    /* prepare the text buffers for libpng's use; note that even though
+     * PNG's png_text struct includes a length field, we don't have to fill
+     * it out */
+
+    if (text &&
+#ifndef DOS_OS2_W32
+        (keybd = fdopen(fileno(stderr), "r")) != NULL &&
+#endif
+        (textbuf = (char *)malloc((5 + 9)*75)) != NULL)
+    {
+        int i, valid, result;
+
+        fprintf(stderr,
+          "Enter text info (no more than 72 characters per line);\n");
+        fprintf(stderr, "to skip a field, hit the <Enter> key.\n");
+        /* note:  just <Enter> leaves len == 1 */
+
+        do {
+            valid = TRUE;
+            p = textbuf + TEXT_TITLE_OFFSET;
+            fprintf(stderr, "  Title: ");
+            fflush(stderr);
+            if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) {
+                if (p[len-1] == '\n')
+                    p[--len] = '\0';
+                wpng_info.title = p;
+                wpng_info.have_text |= TEXT_TITLE;
+                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
+                    fprintf(stderr, "    " PROGNAME " warning:  character code"
+                      " %u is %sdiscouraged by the PNG\n    specification "
+                      "[first occurrence was at character position #%d]\n",
+                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
+                      result+1);
+                    fflush(stderr);
+#ifdef FORBID_LATIN1_CTRL
+                    wpng_info.have_text &= ~TEXT_TITLE;
+                    valid = FALSE;
+#else
+                    if (p[result] == 27) {    /* escape character */
+                        wpng_info.have_text &= ~TEXT_TITLE;
+                        valid = FALSE;
+                    }
+#endif
+                }
+            }
+        } while (!valid);
+
+        do {
+            valid = TRUE;
+            p = textbuf + TEXT_AUTHOR_OFFSET;
+            fprintf(stderr, "  Author: ");
+            fflush(stderr);
+            if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) {
+                if (p[len-1] == '\n')
+                    p[--len] = '\0';
+                wpng_info.author = p;
+                wpng_info.have_text |= TEXT_AUTHOR;
+                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
+                    fprintf(stderr, "    " PROGNAME " warning:  character code"
+                      " %u is %sdiscouraged by the PNG\n    specification "
+                      "[first occurrence was at character position #%d]\n",
+                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
+                      result+1);
+                    fflush(stderr);
+#ifdef FORBID_LATIN1_CTRL
+                    wpng_info.have_text &= ~TEXT_AUTHOR;
+                    valid = FALSE;
+#else
+                    if (p[result] == 27) {    /* escape character */
+                        wpng_info.have_text &= ~TEXT_AUTHOR;
+                        valid = FALSE;
+                    }
+#endif
+                }
+            }
+        } while (!valid);
+
+        do {
+            valid = TRUE;
+            p = textbuf + TEXT_DESC_OFFSET;
+            fprintf(stderr, "  Description (up to 9 lines):\n");
+            for (i = 1;  i < 10;  ++i) {
+                fprintf(stderr, "    [%d] ", i);
+                fflush(stderr);
+                if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1)
+                    p += len;   /* now points at NULL; char before is newline */
+                else
+                    break;
+            }
+            if ((len = p - (textbuf + TEXT_DESC_OFFSET)) > 1) {
+                if (p[-1] == '\n') {
+                    p[-1] = '\0';
+                    --len;
+                }
+                wpng_info.desc = textbuf + TEXT_DESC_OFFSET;
+                wpng_info.have_text |= TEXT_DESC;
+                p = textbuf + TEXT_DESC_OFFSET;
+                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
+                    fprintf(stderr, "    " PROGNAME " warning:  character code"
+                      " %u is %sdiscouraged by the PNG\n    specification "
+                      "[first occurrence was at character position #%d]\n",
+                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
+                      result+1);
+                    fflush(stderr);
+#ifdef FORBID_LATIN1_CTRL
+                    wpng_info.have_text &= ~TEXT_DESC;
+                    valid = FALSE;
+#else
+                    if (p[result] == 27) {    /* escape character */
+                        wpng_info.have_text &= ~TEXT_DESC;
+                        valid = FALSE;
+                    }
+#endif
+                }
+            }
+        } while (!valid);
+
+        do {
+            valid = TRUE;
+            p = textbuf + TEXT_COPY_OFFSET;
+            fprintf(stderr, "  Copyright: ");
+            fflush(stderr);
+            if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) {
+                if (p[len-1] == '\n')
+                    p[--len] = '\0';
+                wpng_info.copyright = p;
+                wpng_info.have_text |= TEXT_COPY;
+                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
+                    fprintf(stderr, "    " PROGNAME " warning:  character code"
+                      " %u is %sdiscouraged by the PNG\n    specification "
+                      "[first occurrence was at character position #%d]\n",
+                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
+                      result+1);
+                    fflush(stderr);
+#ifdef FORBID_LATIN1_CTRL
+                    wpng_info.have_text &= ~TEXT_COPY;
+                    valid = FALSE;
+#else
+                    if (p[result] == 27) {    /* escape character */
+                        wpng_info.have_text &= ~TEXT_COPY;
+                        valid = FALSE;
+                    }
+#endif
+                }
+            }
+        } while (!valid);
+
+        do {
+            valid = TRUE;
+            p = textbuf + TEXT_EMAIL_OFFSET;
+            fprintf(stderr, "  E-mail: ");
+            fflush(stderr);
+            if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) {
+                if (p[len-1] == '\n')
+                    p[--len] = '\0';
+                wpng_info.email = p;
+                wpng_info.have_text |= TEXT_EMAIL;
+                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
+                    fprintf(stderr, "    " PROGNAME " warning:  character code"
+                      " %u is %sdiscouraged by the PNG\n    specification "
+                      "[first occurrence was at character position #%d]\n",
+                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
+                      result+1);
+                    fflush(stderr);
+#ifdef FORBID_LATIN1_CTRL
+                    wpng_info.have_text &= ~TEXT_EMAIL;
+                    valid = FALSE;
+#else
+                    if (p[result] == 27) {    /* escape character */
+                        wpng_info.have_text &= ~TEXT_EMAIL;
+                        valid = FALSE;
+                    }
+#endif
+                }
+            }
+        } while (!valid);
+
+        do {
+            valid = TRUE;
+            p = textbuf + TEXT_URL_OFFSET;
+            fprintf(stderr, "  URL: ");
+            fflush(stderr);
+            if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) {
+                if (p[len-1] == '\n')
+                    p[--len] = '\0';
+                wpng_info.url = p;
+                wpng_info.have_text |= TEXT_URL;
+                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
+                    fprintf(stderr, "    " PROGNAME " warning:  character code"
+                      " %u is %sdiscouraged by the PNG\n    specification "
+                      "[first occurrence was at character position #%d]\n",
+                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
+                      result+1);
+                    fflush(stderr);
+#ifdef FORBID_LATIN1_CTRL
+                    wpng_info.have_text &= ~TEXT_URL;
+                    valid = FALSE;
+#else
+                    if (p[result] == 27) {    /* escape character */
+                        wpng_info.have_text &= ~TEXT_URL;
+                        valid = FALSE;
+                    }
+#endif
+                }
+            }
+        } while (!valid);
+
+#ifndef DOS_OS2_W32
+        fclose(keybd);
+#endif
+
+    } else if (text) {
+        fprintf(stderr, PROGNAME ":  unable to allocate memory for text\n");
+        text = FALSE;
+        wpng_info.have_text = 0;
+    }
+
+
+    /* allocate libpng stuff, initialize transformations, write pre-IDAT data */
+
+    if ((rc = writepng_init(&wpng_info)) != 0) {
+        switch (rc) {
+            case 2:
+                fprintf(stderr, PROGNAME
+                  ":  libpng initialization problem (longjmp)\n");
+                break;
+            case 4:
+                fprintf(stderr, PROGNAME ":  insufficient memory\n");
+                break;
+            case 11:
+                fprintf(stderr, PROGNAME
+                  ":  internal logic error (unexpected PNM type)\n");
+                break;
+            default:
+                fprintf(stderr, PROGNAME
+                  ":  unknown writepng_init() error\n");
+                break;
+        }
+        exit(rc);
+    }
+
+
+    /* free textbuf, since it's a completely local variable and all text info
+     * has just been written to the PNG file */
+
+    if (text && textbuf) {
+        free(textbuf);
+        textbuf = NULL;
+    }
+
+
+    /* calculate rowbytes on basis of image type; note that this becomes much
+     * more complicated if we choose to support PBM type, ASCII PNM types, or
+     * 16-bit-per-sample binary data [currently not an official NetPBM type] */
+
+    if (wpng_info.pnmtype == 5)
+        rowbytes = wpng_info.width;
+    else if (wpng_info.pnmtype == 6)
+        rowbytes = wpng_info.width * 3;
+    else /* if (wpng_info.pnmtype == 8) */
+        rowbytes = wpng_info.width * 4;
+
+
+    /* read and write the image, either in its entirety (if writing interlaced
+     * PNG) or row by row (if non-interlaced) */
+
+    fprintf(stderr, "Encoding image data...\n");
+    fflush(stderr);
+
+    if (wpng_info.interlaced) {
+        long i;
+        ulg bytes;
+        ulg image_bytes = rowbytes * wpng_info.height;   /* overflow? */
+
+        wpng_info.image_data = (uch *)malloc(image_bytes);
+        wpng_info.row_pointers = (uch **)malloc(wpng_info.height*sizeof(uch *));
+        if (wpng_info.image_data == NULL || wpng_info.row_pointers == NULL) {
+            fprintf(stderr, PROGNAME ":  insufficient memory for image data\n");
+            writepng_cleanup(&wpng_info);
+            wpng_cleanup();
+            exit(5);
+        }
+        for (i = 0;  i < wpng_info.height;  ++i)
+            wpng_info.row_pointers[i] = wpng_info.image_data + i*rowbytes;
+        bytes = fread(wpng_info.image_data, 1, image_bytes, wpng_info.infile);
+        if (bytes != image_bytes) {
+            fprintf(stderr, PROGNAME ":  expected %lu bytes, got %lu bytes\n",
+              image_bytes, bytes);
+            fprintf(stderr, "  (continuing anyway)\n");
+        }
+        if (writepng_encode_image(&wpng_info) != 0) {
+            fprintf(stderr, PROGNAME
+              ":  libpng problem (longjmp) while writing image data\n");
+            writepng_cleanup(&wpng_info);
+            wpng_cleanup();
+            exit(2);
+        }
+
+    } else /* not interlaced:  write progressively (row by row) */ {
+        long j;
+        ulg bytes;
+
+        wpng_info.image_data = (uch *)malloc(rowbytes);
+        if (wpng_info.image_data == NULL) {
+            fprintf(stderr, PROGNAME ":  insufficient memory for row data\n");
+            writepng_cleanup(&wpng_info);
+            wpng_cleanup();
+            exit(5);
+        }
+        error = 0;
+        for (j = wpng_info.height;  j > 0L;  --j) {
+            bytes = fread(wpng_info.image_data, 1, rowbytes, wpng_info.infile);
+            if (bytes != rowbytes) {
+                fprintf(stderr, PROGNAME
+                  ":  expected %lu bytes, got %lu bytes (row %ld)\n", rowbytes,
+                  bytes, wpng_info.height-j);
+                ++error;
+                break;
+            }
+            if (writepng_encode_row(&wpng_info) != 0) {
+                fprintf(stderr, PROGNAME
+                  ":  libpng problem (longjmp) while writing row %ld\n",
+                  wpng_info.height-j);
+                ++error;
+                break;
+            }
+        }
+        if (error) {
+            writepng_cleanup(&wpng_info);
+            wpng_cleanup();
+            exit(2);
+        }
+        if (writepng_encode_finish(&wpng_info) != 0) {
+            fprintf(stderr, PROGNAME ":  error on final libpng call\n");
+            writepng_cleanup(&wpng_info);
+            wpng_cleanup();
+            exit(2);
+        }
+    }
+
+
+    /* OK, we're done (successfully):  clean up all resources and quit */
+
+    fprintf(stderr, "Done.\n");
+    fflush(stderr);
+
+    writepng_cleanup(&wpng_info);
+    wpng_cleanup();
+
+    return 0;
+}
+
+
+
+
+
+static int wpng_isvalid_latin1(uch *p, int len)
+{
+    int i, result = -1;
+
+    for (i = 0;  i < len;  ++i) {
+        if (p[i] == 10 || (p[i] > 31 && p[i] < 127) || p[i] > 160)
+            continue;           /* character is completely OK */
+        if (result < 0 || (p[result] != 27 && p[i] == 27))
+            result = i;         /* mark location of first questionable one */
+    }                           /*  or of first escape character (bad) */
+
+    return result;
+}
+
+
+
+
+
+static void wpng_cleanup(void)
+{
+    if (wpng_info.outfile) {
+        fclose(wpng_info.outfile);
+        wpng_info.outfile = NULL;
+    }
+
+    if (wpng_info.infile) {
+        fclose(wpng_info.infile);
+        wpng_info.infile = NULL;
+    }
+
+    if (wpng_info.image_data) {
+        free(wpng_info.image_data);
+        wpng_info.image_data = NULL;
+    }
+
+    if (wpng_info.row_pointers) {
+        free(wpng_info.row_pointers);
+        wpng_info.row_pointers = NULL;
+    }
+}
+
+
+
+
+#ifdef DOS_OS2_W32
+
+static char *dos_kbd_gets(char *buf, int len)
+{
+    int ch, count=0;
+
+    do {
+        buf[count++] = ch = getche();
+    } while (ch != '\r' && count < len-1);
+
+    buf[count--] = '\0';        /* terminate string */
+    if (buf[count] == '\r')     /* Enter key makes CR, so change to newline */
+        buf[count] = '\n';
+
+    fprintf(stderr, "\n");      /* Enter key does *not* cause a newline */
+    fflush(stderr);
+
+    return buf;
+}
+
+#endif /* DOS_OS2_W32 */

contrib/gregbook/writepng.c

@@ -0,0 +1,392 @@
+/*---------------------------------------------------------------------------
+
+   wpng - simple PNG-writing program                             writepng.c
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      The contents of this file are DUAL-LICENSED.  You may modify and/or
+      redistribute this software according to the terms of one of the
+      following two licenses (at your option):
+
+
+      LICENSE 1 ("BSD-like with advertising clause"):
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+
+      LICENSE 2 (GNU GPL v2 or later):
+
+      This program is free software; you can redistribute it and/or modify
+      it under the terms of the GNU General Public License as published by
+      the Free Software Foundation; either version 2 of the License, or
+      (at your option) any later version.
+
+      This program is distributed in the hope that it will be useful,
+      but WITHOUT ANY WARRANTY; without even the implied warranty of
+      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+      GNU General Public License for more details.
+
+      You should have received a copy of the GNU General Public License
+      along with this program; if not, write to the Free Software Foundation,
+      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+  ---------------------------------------------------------------------------*/
+
+
+#include <stdlib.h>     /* for exit() prototype */
+
+#include "png.h"        /* libpng header; includes zlib.h and setjmp.h */
+#include "writepng.h"   /* typedefs, common macros, public prototypes */
+
+
+/* local prototype */
+
+static void writepng_error_handler(png_structp png_ptr, png_const_charp msg);
+
+
+
+void writepng_version_info(void)
+{
+  fprintf(stderr, "   Compiled with libpng %s; using libpng %s.\n",
+    PNG_LIBPNG_VER_STRING, png_libpng_ver);
+  fprintf(stderr, "   Compiled with zlib %s; using zlib %s.\n",
+    ZLIB_VERSION, zlib_version);
+}
+
+
+
+
+/* returns 0 for success, 2 for libpng problem, 4 for out of memory, 11 for
+ *  unexpected pnmtype; note that outfile might be stdout */
+
+int writepng_init(mainprog_info *mainprog_ptr)
+{
+    png_structp  png_ptr;       /* note:  temporary variables! */
+    png_infop  info_ptr;
+    int color_type, interlace_type;
+
+
+    /* could also replace libpng warning-handler (final NULL), but no need: */
+
+    png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, mainprog_ptr,
+      writepng_error_handler, NULL);
+    if (!png_ptr)
+        return 4;   /* out of memory */
+
+    info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr) {
+        png_destroy_write_struct(&png_ptr, NULL);
+        return 4;   /* out of memory */
+    }
+
+
+    /* setjmp() must be called in every function that calls a PNG-writing
+     * libpng function, unless an alternate error handler was installed--
+     * but compatible error handlers must either use longjmp() themselves
+     * (as in this program) or exit immediately, so here we go: */
+
+    if (setjmp(mainprog_ptr->jmpbuf)) {
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+        return 2;
+    }
+
+
+    /* make sure outfile is (re)opened in BINARY mode */
+
+    png_init_io(png_ptr, mainprog_ptr->outfile);
+
+
+    /* set the compression levels--in general, always want to leave filtering
+     * turned on (except for palette images) and allow all of the filters,
+     * which is the default; want 32K zlib window, unless entire image buffer
+     * is 16K or smaller (unknown here)--also the default; usually want max
+     * compression (NOT the default); and remaining compression flags should
+     * be left alone */
+
+    png_set_compression_level(png_ptr, Z_BEST_COMPRESSION);
+/*
+    >> this is default for no filtering; Z_FILTERED is default otherwise:
+    png_set_compression_strategy(png_ptr, Z_DEFAULT_STRATEGY);
+    >> these are all defaults:
+    png_set_compression_mem_level(png_ptr, 8);
+    png_set_compression_window_bits(png_ptr, 15);
+    png_set_compression_method(png_ptr, 8);
+ */
+
+
+    /* set the image parameters appropriately */
+
+    if (mainprog_ptr->pnmtype == 5)
+        color_type = PNG_COLOR_TYPE_GRAY;
+    else if (mainprog_ptr->pnmtype == 6)
+        color_type = PNG_COLOR_TYPE_RGB;
+    else if (mainprog_ptr->pnmtype == 8)
+        color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+    else {
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+        return 11;
+    }
+
+    interlace_type = mainprog_ptr->interlaced? PNG_INTERLACE_ADAM7 :
+                                               PNG_INTERLACE_NONE;
+
+    png_set_IHDR(png_ptr, info_ptr, mainprog_ptr->width, mainprog_ptr->height,
+      mainprog_ptr->sample_depth, color_type, interlace_type,
+      PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
+
+    if (mainprog_ptr->gamma > 0.0)
+        png_set_gAMA(png_ptr, info_ptr, mainprog_ptr->gamma);
+
+    if (mainprog_ptr->have_bg) {   /* we know it's RGBA, not gray+alpha */
+        png_color_16  background;
+
+        background.red = mainprog_ptr->bg_red;
+        background.green = mainprog_ptr->bg_green;
+        background.blue = mainprog_ptr->bg_blue;
+        png_set_bKGD(png_ptr, info_ptr, &background);
+    }
+
+    if (mainprog_ptr->have_time) {
+        png_time  modtime;
+
+        png_convert_from_time_t(&modtime, mainprog_ptr->modtime);
+        png_set_tIME(png_ptr, info_ptr, &modtime);
+    }
+
+    if (mainprog_ptr->have_text) {
+        png_text  text[6];
+        int  num_text = 0;
+
+        if (mainprog_ptr->have_text & TEXT_TITLE) {
+            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
+            text[num_text].key = "Title";
+            text[num_text].text = mainprog_ptr->title;
+            ++num_text;
+        }
+        if (mainprog_ptr->have_text & TEXT_AUTHOR) {
+            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
+            text[num_text].key = "Author";
+            text[num_text].text = mainprog_ptr->author;
+            ++num_text;
+        }
+        if (mainprog_ptr->have_text & TEXT_DESC) {
+            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
+            text[num_text].key = "Description";
+            text[num_text].text = mainprog_ptr->desc;
+            ++num_text;
+        }
+        if (mainprog_ptr->have_text & TEXT_COPY) {
+            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
+            text[num_text].key = "Copyright";
+            text[num_text].text = mainprog_ptr->copyright;
+            ++num_text;
+        }
+        if (mainprog_ptr->have_text & TEXT_EMAIL) {
+            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
+            text[num_text].key = "E-mail";
+            text[num_text].text = mainprog_ptr->email;
+            ++num_text;
+        }
+        if (mainprog_ptr->have_text & TEXT_URL) {
+            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
+            text[num_text].key = "URL";
+            text[num_text].text = mainprog_ptr->url;
+            ++num_text;
+        }
+        png_set_text(png_ptr, info_ptr, text, num_text);
+    }
+
+
+    /* write all chunks up to (but not including) first IDAT */
+
+    png_write_info(png_ptr, info_ptr);
+
+
+    /* if we wanted to write any more text info *after* the image data, we
+     * would set up text struct(s) here and call png_set_text() again, with
+     * just the new data; png_set_tIME() could also go here, but it would
+     * have no effect since we already called it above (only one tIME chunk
+     * allowed) */
+
+
+    /* set up the transformations:  for now, just pack low-bit-depth pixels
+     * into bytes (one, two or four pixels per byte) */
+
+    png_set_packing(png_ptr);
+/*  png_set_shift(png_ptr, &sig_bit);  to scale low-bit-depth values */
+
+
+    /* make sure we save our pointers for use in writepng_encode_image() */
+
+    mainprog_ptr->png_ptr = png_ptr;
+    mainprog_ptr->info_ptr = info_ptr;
+
+
+    /* OK, that's all we need to do for now; return happy */
+
+    return 0;
+}
+
+
+
+
+
+/* returns 0 for success, 2 for libpng (longjmp) problem */
+
+int writepng_encode_image(mainprog_info *mainprog_ptr)
+{
+    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
+    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
+
+
+    /* as always, setjmp() must be called in every function that calls a
+     * PNG-writing libpng function */
+
+    if (setjmp(mainprog_ptr->jmpbuf)) {
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+        mainprog_ptr->png_ptr = NULL;
+        mainprog_ptr->info_ptr = NULL;
+        return 2;
+    }
+
+
+    /* and now we just write the whole image; libpng takes care of interlacing
+     * for us */
+
+    png_write_image(png_ptr, mainprog_ptr->row_pointers);
+
+
+    /* since that's it, we also close out the end of the PNG file now--if we
+     * had any text or time info to write after the IDATs, second argument
+     * would be info_ptr, but we optimize slightly by sending NULL pointer: */
+
+    png_write_end(png_ptr, NULL);
+
+    return 0;
+}
+
+
+
+
+
+/* returns 0 if succeeds, 2 if libpng problem */
+
+int writepng_encode_row(mainprog_info *mainprog_ptr)  /* NON-interlaced only! */
+{
+    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
+    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
+
+
+    /* as always, setjmp() must be called in every function that calls a
+     * PNG-writing libpng function */
+
+    if (setjmp(mainprog_ptr->jmpbuf)) {
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+        mainprog_ptr->png_ptr = NULL;
+        mainprog_ptr->info_ptr = NULL;
+        return 2;
+    }
+
+
+    /* image_data points at our one row of image data */
+
+    png_write_row(png_ptr, mainprog_ptr->image_data);
+
+    return 0;
+}
+
+
+
+
+
+/* returns 0 if succeeds, 2 if libpng problem */
+
+int writepng_encode_finish(mainprog_info *mainprog_ptr)   /* NON-interlaced! */
+{
+    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
+    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
+
+
+    /* as always, setjmp() must be called in every function that calls a
+     * PNG-writing libpng function */
+
+    if (setjmp(mainprog_ptr->jmpbuf)) {
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+        mainprog_ptr->png_ptr = NULL;
+        mainprog_ptr->info_ptr = NULL;
+        return 2;
+    }
+
+
+    /* close out PNG file; if we had any text or time info to write after
+     * the IDATs, second argument would be info_ptr: */
+
+    png_write_end(png_ptr, NULL);
+
+    return 0;
+}
+
+
+
+
+
+void writepng_cleanup(mainprog_info *mainprog_ptr)
+{
+    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
+    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
+
+    if (png_ptr && info_ptr)
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+}
+
+
+
+
+
+static void writepng_error_handler(png_structp png_ptr, png_const_charp msg)
+{
+    mainprog_info  *mainprog_ptr;
+
+    /* This function, aside from the extra step of retrieving the "error
+     * pointer" (below) and the fact that it exists within the application
+     * rather than within libpng, is essentially identical to libpng's
+     * default error handler.  The second point is critical:  since both
+     * setjmp() and longjmp() are called from the same code, they are
+     * guaranteed to have compatible notions of how big a jmp_buf is,
+     * regardless of whether _BSD_SOURCE or anything else has (or has not)
+     * been defined. */
+
+    fprintf(stderr, "writepng libpng error: %s\n", msg);
+    fflush(stderr);
+
+    mainprog_ptr = png_get_error_ptr(png_ptr);
+    if (mainprog_ptr == NULL) {         /* we are completely hosed now */
+        fprintf(stderr,
+          "writepng severe error:  jmpbuf not recoverable; terminating.\n");
+        fflush(stderr);
+        exit(99);
+    }
+
+    longjmp(mainprog_ptr->jmpbuf, 1);
+}

contrib/gregbook/writepng.h

@@ -0,0 +1,133 @@
+/*---------------------------------------------------------------------------
+
+   wpng - simple PNG-writing program                             writepng.h
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2007 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      The contents of this file are DUAL-LICENSED.  You may modify and/or
+      redistribute this software according to the terms of one of the
+      following two licenses (at your option):
+
+
+      LICENSE 1 ("BSD-like with advertising clause"):
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+
+      LICENSE 2 (GNU GPL v2 or later):
+
+      This program is free software; you can redistribute it and/or modify
+      it under the terms of the GNU General Public License as published by
+      the Free Software Foundation; either version 2 of the License, or
+      (at your option) any later version.
+
+      This program is distributed in the hope that it will be useful,
+      but WITHOUT ANY WARRANTY; without even the implied warranty of
+      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+      GNU General Public License for more details.
+
+      You should have received a copy of the GNU General Public License
+      along with this program; if not, write to the Free Software Foundation,
+      Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+  ---------------------------------------------------------------------------*/
+
+#ifndef TRUE
+#  define TRUE 1
+#  define FALSE 0
+#endif
+
+#ifndef MAX
+#  define MAX(a,b)  ((a) > (b)? (a) : (b))
+#  define MIN(a,b)  ((a) < (b)? (a) : (b))
+#endif
+
+#ifdef DEBUG
+#  define Trace(x)  {fprintf x ; fflush(stderr); fflush(stdout);}
+#else
+#  define Trace(x)  ;
+#endif
+
+#define TEXT_TITLE    0x01
+#define TEXT_AUTHOR   0x02
+#define TEXT_DESC     0x04
+#define TEXT_COPY     0x08
+#define TEXT_EMAIL    0x10
+#define TEXT_URL      0x20
+
+#define TEXT_TITLE_OFFSET        0
+#define TEXT_AUTHOR_OFFSET      72
+#define TEXT_COPY_OFFSET     (2*72)
+#define TEXT_EMAIL_OFFSET    (3*72)
+#define TEXT_URL_OFFSET      (4*72)
+#define TEXT_DESC_OFFSET     (5*72)
+
+typedef unsigned char   uch;
+typedef unsigned short  ush;
+typedef unsigned long   ulg;
+
+typedef struct _mainprog_info {
+    double gamma;
+    long width;
+    long height;
+    time_t modtime;
+    FILE *infile;
+    FILE *outfile;
+    void *png_ptr;
+    void *info_ptr;
+    uch *image_data;
+    uch **row_pointers;
+    char *title;
+    char *author;
+    char *desc;
+    char *copyright;
+    char *email;
+    char *url;
+    int filter;    /* command-line-filter flag, not PNG row filter! */
+    int pnmtype;
+    int sample_depth;
+    int interlaced;
+    int have_bg;
+    int have_time;
+    int have_text;
+    jmp_buf jmpbuf;
+    uch bg_red;
+    uch bg_green;
+    uch bg_blue;
+} mainprog_info;
+
+
+/* prototypes for public functions in writepng.c */
+
+void writepng_version_info(void);
+
+int writepng_init(mainprog_info *mainprog_ptr);
+
+int writepng_encode_image(mainprog_info *mainprog_ptr);
+
+int writepng_encode_row(mainprog_info *mainprog_ptr);
+
+int writepng_encode_finish(mainprog_info *mainprog_ptr);
+
+void writepng_cleanup(mainprog_info *mainprog_ptr);

contrib/pngminus/README

@@ -0,0 +1,153 @@
+PngMinus
+--------
+(copyright Willem van Schaik, 1999)
+
+
+License
+-------
+
+Permission to use, copy, modify, and distribute this software and
+its documentation for any purpose and without fee is hereby granted,
+provided that the above copyright notice appear in all copies and
+that both that copyright notice and this permission notice appear in
+supporting documentation. This software is provided "as is" without
+express or implied warranty.
+
+
+Some history
+------------
+Soon after the creation of PNG in 1995, the need was felt for a set of
+pnmtopng / pngtopnm utilities. Independantly Alexander Lehmann and I
+(Willem van Schaik) started such a project. Luckily we discovered this
+and merged the two together into pnmtopng.tar.gz, which is available
+from a/o ftp://ftp.simplesystems.org/pub/libpng/png/.
+
+These two utilities have many, many options and make use of most of the
+features of PNG, like gamma, alpha, sbit, text-chunks, etc. This makes
+the utilities quite complex and by now not anymore very maintainable.
+When we wrote these programs, libpng was still in an early stage.
+Therefore, lots of the functionality that we put in our software can now
+be done using transform-functions in libpng.
+
+Finally, to compile these programs, you need to have installed and
+compiled three libraries: libpng, zlib and netpbm. Especially the latter
+makes the whole setup a bit bulky. But that's unavoidable given the many
+features of pnmtopng.
+
+
+What now
+--------
+At this moment libpng is in a very stable state and can do much of the
+work done in pnmtopng. Also, pnmtopng needs to be upgraded to the new
+interface of libpng. Hence, it is time for a rewrite from the ground up
+of pnmtopng and pngtopnm. This will happen in the near future (stay
+tuned). The new package will get a different name to distinguish it from
+the old one: PngPlus.
+
+To experiment a bit with the new interface of libpng, I started off with
+a small prototype that contains only the basic functionality. It doesn't
+have any of the options to read or write special chunks and it will do
+no gamma correction. But this makes it also a simple program that is
+quite easy to understand and can serve well as a template for other
+software developments. (By now there are of course a couple of programs,
+like Greg Roelofs' rpng/wpng, that can be used just as good.)
+
+
+Can and can not
+---------------
+As this is the small brother of the future PngPlus, I called this fellow
+PngMinus. Because I started this development in good-old Turbo-C, I
+avoided the use the netpbm library, which requires DOS extenders. Again,
+another reason to call it PngMinus (minus netpbm :-). So, part of the
+program are some elementary routines to read / write pgm- and ppm-files.
+It does not read b&w pbm-files.
+
+The downside of this approach is that you can not use them on images
+that require blocks of memory bigger than 64k (the DOS version). For
+larger images you will get an out-of-memory error.
+
+As said before, PngMinus doesn't correct for gamma. When reading
+png-files you can do this just as well by piping the output of png2pnm
+to pnmgamma, one of the standard PbmPlus tools. This same scenario will
+most probably also be followed in the full-blown future PngPlus, with
+the addition of course of the possibility to create gamma-chunks when
+writing png-files.
+
+On the other hand it supports alpha-channels. When reading a png-image
+you can write the alpha-channel into a pgm-file. And when creating an
+RGB+A png-image, you just combine a ppm-file with a corresponding
+pgm-file containing the alpha-channel. When reading, transparency chunks
+are converted into an alpha-channel and from there on treated the same
+way.
+
+Finally you can opt for writing ascii or binary pgm- and ppm-files. When
+the bit-depth is 16, the format will always be ascii.
+
+
+Using it
+--------
+To distinguish them from pnmtopng and PngPlus, the utilities are named
+png2pnm and pnm2png (2 instead of to). The input- and output-files can
+be given as parameters or through redirection. Therefore the programs
+can be part of a pipe.
+
+To list the options type "png2pnm -h" or "pnm2png -h".
+
+
+Just like Scandinavian furniture
+--------------------------------
+You have to put it together yourself. I did test the software under
+MS-DOS with Turbo-C 3.0 and under RedHat Linux 4.2 with gcc. In both
+cases I used libpng-1.0.4 and zlib-1.1.3. Later versions should be OK,
+however some older libpng versions have a bug in pngmem.c when using
+Turbo-C 3.0 (see below).
+
+You can build it using one of the two makefiles (make -f makefile.###)
+or use the batch/script files pngminus.bat / pngminus.sh. This assumes
+that you have built the libraries in ../libpng and ../zlib. Using Linux,
+make sure that you have built libpng with makefile.std and not
+makefile.linux (also called .lnx in earlier versions of libpng). The
+latter creates a .so shared-library, while the PngMinus makefile assumes
+a normal .a static library.
+
+If you create a ../pngsuite directory and then store the basn####.png
+files from PngSuite (http://www.schaik.com/pngsuite/) in there, you can
+test in one go the proper functioning of PngMinus, see png2pnm.bat and
+pnm2png.bat (or the .sh versions).
+
+
+Warranty
+-------
+Please, remember that this was just a small experiment to learn a few
+things. It will have many unforeseen features <vbg>. Who said bugs? Use
+it when you are in need for something simple or when you want to start
+developing your own stuff.
+
+
+The Turbo bug
+-------------
+** pngmem.old
+          hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L);
+          hptr += 16L;
+** pngmem.c
+          hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L);
+          hptr = hptr + 16L;
+**
+
+** pngmem.old
+          png_ptr->offset_table_ptr[i] = (png_bytep)hptr;
+          hptr += (png_uint_32)65536L;
+** pngmem.c
+          png_ptr->offset_table_ptr[i] = (png_bytep)hptr;
+          hptr = hptr + 65536L;
+**
+
+
+The end
+-------
+Willem van Schaik
+mailto:willem@schaik.com
+http://www.schaik.com/png/
+-------
+Oct 1999
+

contrib/pngminus/makefile.std

@@ -0,0 +1,65 @@
+# Makefile for PngMinus (png2pnm and pnm2png)
+# Linux / Unix
+
+#CC=cc
+CC=gcc
+LD=$(CC)
+
+RM=rm -f
+
+#PNGPATH = /usr/local
+#PNGINC = -I$(PNGPATH)/include/libpng12
+#PNGLIB = -L$(PNGPATH)/lib -lpng12
+#PNGLIBS = $(PNGPATH)/lib/libpng12.a
+PNGINC = -I../..
+PNGLIB = -L../.. -lpng
+PNGLIBS = ../../libpng.a
+
+#ZPATH = /usr/local
+#ZINC = -I$(ZPATH)/include
+#ZLIB = -L$(ZPATH)/lib -lz
+#ZLIBS = $(ZPATH)/lib/libz.a
+ZINC = -I../../../zlib
+ZLIB = -L../../../zlib -lz
+ZLIBS = ../../../zlib/libz.a
+
+CFLAGS=-O3 $(PNGINC) $(ZINC)
+LDFLAGS=$(PNGLIB) $(ZLIB)
+LDFLAGSS=$(PNGLIBS) $(ZLIBS)
+C=.c
+O=.o
+L=.a
+E=
+
+# dependencies
+
+#all: png2pnm$(E) pnm2png$(E)
+all: png2pnm$(E) pnm2png$(E) png2pnm-static$(E) pnm2png-static$(E)
+
+png2pnm$(O): png2pnm$(C)
+	$(CC) -c $(CFLAGS) png2pnm$(C)
+
+png2pnm$(E): png2pnm$(O)
+	$(LD) -o png2pnm$(E) png2pnm$(O) $(LDFLAGS) -lm
+
+png2pnm-static$(E): png2pnm$(O)
+	$(LD) -o png2pnm-static$(E) png2pnm$(O) $(LDFLAGSS) -lm
+
+pnm2png$(O): pnm2png$(C)
+	$(CC) -c $(CFLAGS) pnm2png$(C)
+
+pnm2png$(E): pnm2png$(O)
+	$(LD) -o pnm2png$(E) pnm2png$(O) $(LDFLAGS) -lm
+
+pnm2png-static$(E): pnm2png$(O)
+	$(LD) -o pnm2png-static$(E) pnm2png$(O) $(LDFLAGSS) -lm
+
+clean:
+	$(RM) png2pnm$(O)
+	$(RM) pnm2png$(O)
+	$(RM) png2pnm$(E)
+	$(RM) pnm2png$(E)
+	$(RM) png2pnm-static$(E)
+	$(RM) pnm2png-static$(E)
+
+# End of makefile for png2pnm / pnm2png

contrib/pngminus/makefile.tc3

@@ -0,0 +1,38 @@
+# Makefile for PngMinus (png2pnm and pnm2png)
+# TurboC++ 3.0
+
+CC=tcc -Ic:\tc3\inc
+LD=tcc -Lc:\tc3\lib
+LB=tlib
+RM=del
+CP=copy
+MODEL=l
+CCFLAGS=-O -m$(MODEL) -I..\libpng -I..\zlib
+LDFLAGS=-m$(MODEL) -L..\libpng -L..\zlib
+C=.c
+O=.obj
+L=.lib
+E=.exe
+
+# dependencies
+
+all: png2pnm$(E) pnm2png$(E)
+
+png2pnm$(O): png2pnm$(C)
+        $(CC) -c $(CCFLAGS) png2pnm$(C)
+
+png2pnm$(E): png2pnm$(O)
+        $(LD) $(LDFLAGS) png2pnm$(O) libpng$(L) zlib$(L)
+
+pnm2png$(O): pnm2png$(C)
+        $(CC) -c $(CCFLAGS) pnm2png$(C)
+
+pnm2png$(E): pnm2png$(O)
+        $(LD) $(LDFLAGS) pnm2png$(O) libpng$(L) zlib$(L)
+
+clean:
+        $(RM) *$(O)
+        $(RM) *$(E)
+
+# End of makefile for png2pnm / pnm2png
+

contrib/pngminus/makevms.com

@@ -0,0 +1,92 @@
+$!------------------------------------------------------------------------------
+$! make Contrib programs of libpng under OpenVMS
+$!
+$!
+$! Look for the compiler used
+$!
+$ zlibsrc = "[---.zlib]"
+$ ccopt="/include=(''zlibsrc',[--])"
+$ if f$getsyi("HW_MODEL").ge.1024
+$ then
+$  ccopt = "/prefix=all"+ccopt
+$  comp  = "__decc__=1"
+$  if f$trnlnm("SYS").eqs."" then define sys sys$library:
+$ else
+$  if f$search("SYS$SYSTEM:DECC$COMPILER.EXE").eqs.""
+$   then
+$    if f$trnlnm("SYS").eqs."" then define sys sys$library:
+$    if f$search("SYS$SYSTEM:VAXC.EXE").eqs.""
+$     then
+$      comp  = "__gcc__=1"
+$      CC :== GCC
+$     else
+$      comp = "__vaxc__=1"
+$     endif
+$   else
+$    if f$trnlnm("SYS").eqs."" then define sys decc$library_include:
+$    ccopt = "/decc/prefix=all"+ccopt
+$    comp  = "__decc__=1"
+$  endif
+$ endif
+$ open/write lopt lib.opt
+$ write lopt "[--]libpng.olb/lib"
+$ write lopt "''zlibsrc'libz.olb/lib"
+$ close lopt
+$ open/write xopt x11.opt
+$ write xopt "sys$library:decw$xlibshr.exe/share"
+$ close xopt
+$ write sys$output "Compiling PNG contrib programs ..."
+$   write sys$output "Building pnm2png..."
+$   CALL MAKE pnm2png.OBJ "cc ''CCOPT' pnm2png" -
+	pnm2png.c
+$   call make pnm2png.exe -
+	"LINK pnm2png,lib.opt/opt" -
+	pnm2png.obj
+$   write sys$output "Building png2pnm..."
+$   CALL MAKE png2pnm.OBJ "cc ''CCOPT' png2pnm" -
+	png2pnm.c
+$   call make png2pnm.exe -
+	"LINK png2pnm,lib.opt/opt" -
+	png2pnm.obj
+$ exit
+$!
+$!
+$MAKE: SUBROUTINE   !SUBROUTINE TO CHECK DEPENDENCIES
+$ V = 'F$Verify(0)
+$! P1 = What we are trying to make
+$! P2 = Command to make it
+$! P3 - P8  What it depends on
+$
+$ If F$Search(P1) .Eqs. "" Then Goto Makeit
+$ Time = F$CvTime(F$File(P1,"RDT"))
+$arg=3
+$Loop:
+$       Argument = P'arg
+$       If Argument .Eqs. "" Then Goto Exit
+$       El=0
+$Loop2:
+$       File = F$Element(El," ",Argument)
+$       If File .Eqs. " " Then Goto Endl
+$       AFile = ""
+$Loop3:
+$       OFile = AFile
+$       AFile = F$Search(File)
+$       If AFile .Eqs. "" .Or. AFile .Eqs. OFile Then Goto NextEl
+$       If F$CvTime(F$File(AFile,"RDT")) .Ges. Time Then Goto Makeit
+$       Goto Loop3
+$NextEL:
+$       El = El + 1
+$       Goto Loop2
+$EndL:
+$ arg=arg+1
+$ If arg .Le. 8 Then Goto Loop
+$ Goto Exit
+$
+$Makeit:
+$ VV=F$VERIFY(0)
+$ write sys$output P2
+$ 'P2
+$ VV='F$Verify(VV)
+$Exit:
+$ If V Then Set Verify
+$ENDSUBROUTINE

contrib/pngminus/png2pnm.bat

@@ -0,0 +1,41 @@
+REM -- grayscale
+png2pnm.exe -noraw ..\pngsuite\basn0g01.png basn0g01.pgm
+png2pnm.exe -noraw ..\pngsuite\basn0g02.png basn0g02.pgm
+png2pnm.exe -noraw ..\pngsuite\basn0g04.png basn0g04.pgm
+png2pnm.exe -noraw ..\pngsuite\basn0g08.png basn0g08.pgm
+png2pnm.exe -noraw ..\pngsuite\basn0g16.png basn0g16.pgm
+REM -- full-color
+png2pnm.exe -noraw ..\pngsuite\basn2c08.png basn2c08.ppm
+png2pnm.exe -noraw ..\pngsuite\basn2c16.png basn2c16.ppm
+REM -- palletted
+png2pnm.exe -noraw ..\pngsuite\basn3p01.png basn3p01.ppm
+png2pnm.exe -noraw ..\pngsuite\basn3p02.png basn3p02.ppm
+png2pnm.exe -noraw ..\pngsuite\basn3p04.png basn3p04.ppm
+png2pnm.exe -noraw ..\pngsuite\basn3p08.png basn3p08.ppm
+REM -- gray with alpha-channel
+png2pnm.exe -noraw ..\pngsuite\basn4a08.png basn4a08.pgm
+png2pnm.exe -noraw ..\pngsuite\basn4a16.png basn4a16.pgm
+REM -- color with alpha-channel
+png2pnm.exe -noraw -alpha basn6a08.pgm ..\pngsuite\basn6a08.png basn6a08.ppm
+png2pnm.exe -noraw -alpha basn6a16.pgm ..\pngsuite\basn6a16.png basn6a16.ppm
+REM -- grayscale
+png2pnm.exe -raw ..\pngsuite\basn0g01.png rawn0g01.pgm
+png2pnm.exe -raw ..\pngsuite\basn0g02.png rawn0g02.pgm
+png2pnm.exe -raw ..\pngsuite\basn0g04.png rawn0g04.pgm
+png2pnm.exe -raw ..\pngsuite\basn0g08.png rawn0g08.pgm
+png2pnm.exe -raw ..\pngsuite\basn0g16.png rawn0g16.pgm
+REM -- full-color
+png2pnm.exe -raw ..\pngsuite\basn2c08.png rawn2c08.ppm
+png2pnm.exe -raw ..\pngsuite\basn2c16.png rawn2c16.ppm
+REM -- palletted
+png2pnm.exe -raw ..\pngsuite\basn3p01.png rawn3p01.ppm
+png2pnm.exe -raw ..\pngsuite\basn3p02.png rawn3p02.ppm
+png2pnm.exe -raw ..\pngsuite\basn3p04.png rawn3p04.ppm
+png2pnm.exe -raw ..\pngsuite\basn3p08.png rawn3p08.ppm
+REM -- gray with alpha-channel
+png2pnm.exe -raw ..\pngsuite\basn4a08.png rawn4a08.pgm
+png2pnm.exe -raw ..\pngsuite\basn4a16.png rawn4a16.pgm
+REM -- color with alpha-channel
+png2pnm.exe -noraw -alpha rawn6a08.pgm ..\pngsuite\basn6a08.png rawn6a08.ppm
+png2pnm.exe -noraw -alpha rawn6a16.pgm ..\pngsuite\basn6a16.png rawn6a16.ppm
+

contrib/pngminus/png2pnm.c

@@ -0,0 +1,430 @@
+/*
+ *  png2pnm.c --- conversion from PNG-file to PGM/PPM-file
+ *  copyright (C) 1999 by Willem van Schaik <willem@schaik.com>
+ *
+ *  version 1.0 - 1999.10.15 - First version.
+ *
+ *  Permission to use, copy, modify, and distribute this software and
+ *  its documentation for any purpose and without fee is hereby granted,
+ *  provided that the above copyright notice appear in all copies and
+ *  that both that copyright notice and this permission notice appear in
+ *  supporting documentation. This software is provided "as is" without
+ *  express or implied warranty.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#ifdef __TURBOC__
+#include <mem.h>
+#include <fcntl.h>
+#endif
+
+#ifndef BOOL
+#define BOOL unsigned char
+#endif
+#ifndef TRUE
+#define TRUE (BOOL) 1
+#endif
+#ifndef FALSE
+#define FALSE (BOOL) 0
+#endif
+
+#ifdef __TURBOC__
+#define STDIN  0
+#define STDOUT 1
+#define STDERR 2
+#endif
+
+/* to make png2pnm verbose so we can find problems (needs to be before png.h) */
+#ifndef PNG_DEBUG
+#define PNG_DEBUG 0
+#endif
+
+#include "png.h"
+
+/* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */
+#ifndef png_jmpbuf
+#  define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
+#endif
+
+/* function prototypes */
+
+int  main (int argc, char *argv[]);
+void usage ();
+BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL alpha);
+
+/*
+ *  main
+ */
+
+int main(int argc, char *argv[])
+{
+  FILE *fp_rd = stdin;
+  FILE *fp_wr = stdout;
+  FILE *fp_al = NULL;
+  BOOL raw = TRUE;
+  BOOL alpha = FALSE;
+  int argi;
+
+  for (argi = 1; argi < argc; argi++)
+  {
+    if (argv[argi][0] == '-')
+    {
+      switch (argv[argi][1])
+      {
+        case 'n':
+          raw = FALSE;
+          break;
+        case 'r':
+          raw = TRUE;
+          break;
+        case 'a':
+          alpha = TRUE;
+          argi++;
+          if ((fp_al = fopen (argv[argi], "wb")) == NULL)
+          {
+            fprintf (stderr, "PNM2PNG\n");
+            fprintf (stderr, "Error:  can not create alpha-channel file %s\n", argv[argi]);
+            exit (1);
+          }
+          break;
+        case 'h':
+        case '?':
+          usage();
+          exit(0);
+          break;
+        default:
+          fprintf (stderr, "PNG2PNM\n");
+          fprintf (stderr, "Error:  unknown option %s\n", argv[argi]);
+          usage();
+          exit(1);
+          break;
+      } /* end switch */
+    }
+    else if (fp_rd == stdin)
+    {
+      if ((fp_rd = fopen (argv[argi], "rb")) == NULL)
+      {
+             fprintf (stderr, "PNG2PNM\n");
+            fprintf (stderr, "Error:  file %s does not exist\n", argv[argi]);
+            exit (1);
+      }
+    }
+    else if (fp_wr == stdout)
+    {
+      if ((fp_wr = fopen (argv[argi], "wb")) == NULL)
+      {
+        fprintf (stderr, "PNG2PNM\n");
+        fprintf (stderr, "Error:  can not create file %s\n", argv[argi]);
+        exit (1);
+      }
+    }
+    else
+    {
+      fprintf (stderr, "PNG2PNM\n");
+      fprintf (stderr, "Error:  too many parameters\n");
+      usage();
+      exit(1);
+    }
+  } /* end for */
+
+#ifdef __TURBOC__
+  /* set stdin/stdout if required to binary */
+  if (fp_rd == stdin)
+  {
+    setmode (STDIN, O_BINARY);
+  }
+  if ((raw) && (fp_wr == stdout))
+  {
+    setmode (STDOUT, O_BINARY);
+  }
+#endif
+
+  /* call the conversion program itself */
+  if (png2pnm (fp_rd, fp_wr, fp_al, raw, alpha) == FALSE)
+  {
+    fprintf (stderr, "PNG2PNM\n");
+    fprintf (stderr, "Error:  unsuccessful convertion of PNG-image\n");
+    exit(1);
+  }
+
+  /* close input file */
+  fclose (fp_rd);
+  /* close output file */
+  fclose (fp_wr);
+  /* close alpha file */
+  if (alpha)
+    fclose (fp_al);
+
+  return 0;
+}
+
+/*
+ *  usage
+ */
+
+void usage()
+{
+  fprintf (stderr, "PNG2PNM\n");
+  fprintf (stderr, "   by Willem van Schaik, 1999\n");
+#ifdef __TURBOC__
+  fprintf (stderr, "   for Turbo-C and Borland-C compilers\n");
+#else
+  fprintf (stderr, "   for Linux (and Unix) compilers\n");
+#endif
+  fprintf (stderr, "Usage:  png2pnm [options] <file>.png [<file>.pnm]\n");
+  fprintf (stderr, "   or:  ... | png2pnm [options]\n");
+  fprintf (stderr, "Options:\n");
+  fprintf (stderr, "   -r[aw]   write pnm-file in binary format (P4/P5/P6) (default)\n");
+  fprintf (stderr, "   -n[oraw] write pnm-file in ascii format (P1/P2/P3)\n");
+  fprintf (stderr, "   -a[lpha] <file>.pgm write PNG alpha channel as pgm-file\n");
+  fprintf (stderr, "   -h | -?  print this help-information\n");
+}
+
+/*
+ *  png2pnm
+ */
+
+BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL alpha)
+{
+  png_struct    *png_ptr = NULL;
+  png_info	*info_ptr = NULL;
+  png_byte      buf[8];
+  png_byte      *png_pixels = NULL;
+  png_byte      **row_pointers = NULL;
+  png_byte      *pix_ptr = NULL;
+  png_uint_32   row_bytes;
+
+  png_uint_32   width;
+  png_uint_32   height;
+  int           bit_depth;
+  int           channels;
+  int           color_type;
+  int           alpha_present;
+  int           row, col;
+  int           ret;
+  int           i;
+  long          dep_16;
+
+  /* read and check signature in PNG file */
+  ret = fread (buf, 1, 8, png_file);
+  if (ret != 8)
+    return FALSE;
+
+  ret = png_check_sig (buf, 8);
+  if (!ret)
+    return FALSE;
+
+  /* create png and info structures */
+
+  png_ptr = png_create_read_struct (PNG_LIBPNG_VER_STRING,
+    NULL, NULL, NULL);
+  if (!png_ptr)
+    return FALSE;   /* out of memory */
+
+  info_ptr = png_create_info_struct (png_ptr);
+  if (!info_ptr)
+  {
+    png_destroy_read_struct (&png_ptr, NULL, NULL);
+    return FALSE;   /* out of memory */
+  }
+
+  if (setjmp (png_jmpbuf(png_ptr)))
+  {
+    png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
+    return FALSE;
+  }
+
+  /* set up the input control for C streams */
+  png_init_io (png_ptr, png_file);
+  png_set_sig_bytes (png_ptr, 8);  /* we already read the 8 signature bytes */
+
+  /* read the file information */
+  png_read_info (png_ptr, info_ptr);
+
+  /* get size and bit-depth of the PNG-image */
+  png_get_IHDR (png_ptr, info_ptr,
+    &width, &height, &bit_depth, &color_type,
+    NULL, NULL, NULL);
+
+  /* set-up the transformations */
+
+  /* transform paletted images into full-color rgb */
+  if (color_type == PNG_COLOR_TYPE_PALETTE)
+    png_set_expand (png_ptr);
+  /* expand images to bit-depth 8 (only applicable for grayscale images) */
+  if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
+    png_set_expand (png_ptr);
+  /* transform transparency maps into full alpha-channel */
+  if (png_get_valid (png_ptr, info_ptr, PNG_INFO_tRNS))
+    png_set_expand (png_ptr);
+
+#ifdef NJET
+  /* downgrade 16-bit images to 8 bit */
+  if (bit_depth == 16)
+    png_set_strip_16 (png_ptr);
+  /* transform grayscale images into full-color */
+  if (color_type == PNG_COLOR_TYPE_GRAY ||
+    color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+    png_set_gray_to_rgb (png_ptr);
+  /* only if file has a file gamma, we do a correction */
+  if (png_get_gAMA (png_ptr, info_ptr, &file_gamma))
+    png_set_gamma (png_ptr, (double) 2.2, file_gamma);
+#endif
+
+  /* all transformations have been registered; now update info_ptr data,
+   * get rowbytes and channels, and allocate image memory */
+
+  png_read_update_info (png_ptr, info_ptr);
+
+  /* get the new color-type and bit-depth (after expansion/stripping) */
+  png_get_IHDR (png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
+    NULL, NULL, NULL);
+
+  /* check for 16-bit files */
+  if (bit_depth == 16)
+  {
+    raw = FALSE;
+#ifdef __TURBOC__
+    pnm_file->flags &= ~((unsigned) _F_BIN);
+#endif
+  }
+
+  /* calculate new number of channels and store alpha-presence */
+  if (color_type == PNG_COLOR_TYPE_GRAY)
+    channels = 1;
+  else if (color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+    channels = 2;
+  else if (color_type == PNG_COLOR_TYPE_RGB)
+    channels = 3;
+  else if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+    channels = 4;
+  else
+    channels = 0; /* should never happen */
+  alpha_present = (channels - 1) % 2;
+
+  /* check if alpha is expected to be present in file */
+  if (alpha && !alpha_present)
+  {
+    fprintf (stderr, "PNG2PNM\n");
+    fprintf (stderr, "Error:  PNG-file doesn't contain alpha channel\n");
+    exit (1);
+  }
+
+  /* row_bytes is the width x number of channels x (bit-depth / 8) */
+  row_bytes = png_get_rowbytes (png_ptr, info_ptr);
+
+  if ((png_pixels = (png_byte *) malloc (row_bytes * height * sizeof (png_byte))) == NULL) {
+    png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
+    return FALSE;
+  }
+
+  if ((row_pointers = (png_byte **) malloc (height * sizeof (png_bytep))) == NULL)
+  {
+    png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
+    free (png_pixels);
+    png_pixels = NULL;
+    return FALSE;
+  }
+
+  /* set the individual row_pointers to point at the correct offsets */
+  for (i = 0; i < (height); i++)
+    row_pointers[i] = png_pixels + i * row_bytes;
+
+  /* now we can go ahead and just read the whole image */
+  png_read_image (png_ptr, row_pointers);
+
+  /* read rest of file, and get additional chunks in info_ptr - REQUIRED */
+  png_read_end (png_ptr, info_ptr);
+
+  /* clean up after the read, and free any memory allocated - REQUIRED */
+  png_destroy_read_struct (&png_ptr, &info_ptr, (png_infopp) NULL);
+
+  /* write header of PNM file */
+
+  if ((color_type == PNG_COLOR_TYPE_GRAY) ||
+      (color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
+  {
+    fprintf (pnm_file, "%s\n", (raw) ? "P5" : "P2");
+    fprintf (pnm_file, "%d %d\n", (int) width, (int) height);
+    fprintf (pnm_file, "%ld\n", ((1L << (int) bit_depth) - 1L));
+  }
+  else if ((color_type == PNG_COLOR_TYPE_RGB) ||
+           (color_type == PNG_COLOR_TYPE_RGB_ALPHA))
+  {
+    fprintf (pnm_file, "%s\n", (raw) ? "P6" : "P3");
+    fprintf (pnm_file, "%d %d\n", (int) width, (int) height);
+    fprintf (pnm_file, "%ld\n", ((1L << (int) bit_depth) - 1L));
+  }
+
+  /* write header of PGM file with alpha channel */
+
+  if ((alpha) &&
+      ((color_type == PNG_COLOR_TYPE_GRAY_ALPHA) ||
+       (color_type == PNG_COLOR_TYPE_RGB_ALPHA)))
+  {
+    fprintf (alpha_file, "%s\n", (raw) ? "P5" : "P2");
+    fprintf (alpha_file, "%d %d\n", (int) width, (int) height);
+    fprintf (alpha_file, "%ld\n", ((1L << (int) bit_depth) - 1L));
+  }
+
+  /* write data to PNM file */
+  pix_ptr = png_pixels;
+
+  for (row = 0; row < height; row++)
+  {
+    for (col = 0; col < width; col++)
+    {
+      for (i = 0; i < (channels - alpha_present); i++)
+      {
+        if (raw)
+          fputc ((int) *pix_ptr++ , pnm_file);
+        else
+          if (bit_depth == 16){
+	    dep_16 = (long) *pix_ptr++;
+            fprintf (pnm_file, "%ld ", (dep_16 << 8) + ((long) *pix_ptr++));
+          }
+          else
+            fprintf (pnm_file, "%ld ", (long) *pix_ptr++);
+      }
+      if (alpha_present)
+      {
+        if (!alpha)
+        {
+          pix_ptr++; /* alpha */
+          if (bit_depth == 16)
+            pix_ptr++;
+        }
+        else /* output alpha-channel as pgm file */
+        {
+          if (raw)
+            fputc ((int) *pix_ptr++ , alpha_file);
+          else
+            if (bit_depth == 16){
+	      dep_16 = (long) *pix_ptr++;
+              fprintf (alpha_file, "%ld ", (dep_16 << 8) + (long) *pix_ptr++);
+	    }  
+            else
+              fprintf (alpha_file, "%ld ", (long) *pix_ptr++);
+        }
+      } /* if alpha_present */
+
+      if (!raw)
+        if (col % 4 == 3)
+          fprintf (pnm_file, "\n");
+    } /* end for col */
+
+    if (!raw)
+      if (col % 4 != 0)
+        fprintf (pnm_file, "\n");
+  } /* end for row */
+
+  if (row_pointers != (unsigned char**) NULL)
+    free (row_pointers);
+  if (png_pixels != (unsigned char*) NULL)
+    free (png_pixels);
+
+  return TRUE;
+
+} /* end of source */
+

contrib/pngminus/png2pnm.sh

@@ -0,0 +1,42 @@
+#!/bin/sh
+# -- grayscale
+./png2pnm -noraw ../pngsuite/basn0g01.png basn0g01.pgm
+./png2pnm -noraw ../pngsuite/basn0g02.png basn0g02.pgm
+./png2pnm -noraw ../pngsuite/basn0g04.png basn0g04.pgm
+./png2pnm -noraw ../pngsuite/basn0g08.png basn0g08.pgm
+./png2pnm -noraw ../pngsuite/basn0g16.png basn0g16.pgm
+# -- full-color
+./png2pnm -noraw ../pngsuite/basn2c08.png basn2c08.ppm
+./png2pnm -noraw ../pngsuite/basn2c16.png basn2c16.ppm
+# -- palletted
+./png2pnm -noraw ../pngsuite/basn3p01.png basn3p01.ppm
+./png2pnm -noraw ../pngsuite/basn3p02.png basn3p02.ppm
+./png2pnm -noraw ../pngsuite/basn3p04.png basn3p04.ppm
+./png2pnm -noraw ../pngsuite/basn3p08.png basn3p08.ppm
+# -- gray with alpha-channel
+./png2pnm -noraw ../pngsuite/basn4a08.png basn4a08.pgm
+./png2pnm -noraw ../pngsuite/basn4a16.png basn4a16.pgm
+# -- color with alpha-channel
+./png2pnm -noraw -alpha basn6a08.pgm ../pngsuite/basn6a08.png basn6a08.ppm
+./png2pnm -noraw -alpha basn6a16.pgm ../pngsuite/basn6a16.png basn6a16.ppm
+# -- grayscale
+./png2pnm -raw ../pngsuite/basn0g01.png rawn0g01.pgm
+./png2pnm -raw ../pngsuite/basn0g02.png rawn0g02.pgm
+./png2pnm -raw ../pngsuite/basn0g04.png rawn0g04.pgm
+./png2pnm -raw ../pngsuite/basn0g08.png rawn0g08.pgm
+./png2pnm -raw ../pngsuite/basn0g16.png rawn0g16.pgm
+# -- full-color
+./png2pnm -raw ../pngsuite/basn2c08.png rawn2c08.ppm
+./png2pnm -raw ../pngsuite/basn2c16.png rawn2c16.ppm
+# -- palletted
+./png2pnm -raw ../pngsuite/basn3p01.png rawn3p01.ppm
+./png2pnm -raw ../pngsuite/basn3p02.png rawn3p02.ppm
+./png2pnm -raw ../pngsuite/basn3p04.png rawn3p04.ppm
+./png2pnm -raw ../pngsuite/basn3p08.png rawn3p08.ppm
+# -- gray with alpha-channel
+./png2pnm -raw ../pngsuite/basn4a08.png rawn4a08.pgm
+./png2pnm -raw ../pngsuite/basn4a16.png rawn4a16.pgm
+# -- color with alpha-channel
+./png2pnm -noraw -alpha rawn6a08.pgm ../pngsuite/basn6a08.png rawn6a08.ppm
+./png2pnm -noraw -alpha rawn6a16.pgm ../pngsuite/basn6a16.png rawn6a16.ppm
+

contrib/pngminus/pngminus.bat

@@ -0,0 +1,4 @@
+make -f makefile.tc3
+call png2pnm.bat
+call pnm2png.bat
+

contrib/pngminus/pngminus.sh

@@ -0,0 +1,5 @@
+#!/bin/sh
+make -f makefile.std
+sh png2pnm.sh
+sh pnm2png.sh
+

contrib/pngminus/pnm2png.bat

@@ -0,0 +1,41 @@
+REM -- grayscale
+pnm2png.exe basn0g01.pgm basn0g01.png
+pnm2png.exe basn0g02.pgm basn0g02.png
+pnm2png.exe basn0g04.pgm basn0g04.png
+pnm2png.exe basn0g08.pgm basn0g08.png
+pnm2png.exe basn0g16.pgm basn0g16.png
+REM -- full-color
+pnm2png.exe basn2c08.ppm basn2c08.png
+pnm2png.exe basn2c16.ppm basn2c16.png
+REM -- palletted
+pnm2png.exe basn3p01.ppm basn3p01.png
+pnm2png.exe basn3p02.ppm basn3p02.png
+pnm2png.exe basn3p04.ppm basn3p04.png
+pnm2png.exe basn3p08.ppm basn3p08.png
+REM -- gray with alpha-channel
+pnm2png.exe -alpha basn6a08.pgm basn4a08.pgm basn4a08.png
+pnm2png.exe -alpha basn6a16.pgm basn4a16.pgm basn4a16.png
+REM -- color with alpha-channel
+pnm2png.exe -alpha basn6a08.pgm basn6a08.ppm basn6a08.png
+pnm2png.exe -alpha basn6a16.pgm basn6a16.ppm basn6a16.png
+REM -- grayscale
+pnm2png.exe rawn0g01.pgm rawn0g01.png
+pnm2png.exe rawn0g02.pgm rawn0g02.png
+pnm2png.exe rawn0g04.pgm rawn0g04.png
+pnm2png.exe rawn0g08.pgm rawn0g08.png
+pnm2png.exe rawn0g16.pgm rawn0g16.png
+REM -- full-color
+pnm2png.exe rawn2c08.ppm rawn2c08.png
+pnm2png.exe rawn2c16.ppm rawn2c16.png
+REM -- palletted
+pnm2png.exe rawn3p01.ppm rawn3p01.png
+pnm2png.exe rawn3p02.ppm rawn3p02.png
+pnm2png.exe rawn3p04.ppm rawn3p04.png
+pnm2png.exe rawn3p08.ppm rawn3p08.png
+REM -- gray with alpha-channel
+pnm2png.exe -alpha rawn6a08.pgm rawn4a08.pgm rawn4a08.png
+pnm2png.exe -alpha rawn6a16.pgm rawn4a16.pgm rawn4a16.png
+REM -- color with alpha-channel
+pnm2png.exe -alpha rawn6a08.pgm rawn6a08.ppm rawn6a08.png
+pnm2png.exe -alpha rawn6a16.pgm rawn6a16.ppm rawn6a16.png
+

contrib/pngminus/pnm2png.c

@@ -0,0 +1,533 @@
+/*
+ *  pnm2png.c --- conversion from PBM/PGM/PPM-file to PNG-file
+ *  copyright (C) 1999 by Willem van Schaik <willem@schaik.com>
+ *
+ *  version 1.0 - 1999.10.15 - First version.
+ *
+ *  Permission to use, copy, modify, and distribute this software and
+ *  its documentation for any purpose and without fee is hereby granted,
+ *  provided that the above copyright notice appear in all copies and
+ *  that both that copyright notice and this permission notice appear in
+ *  supporting documentation. This software is provided "as is" without
+ *  express or implied warranty.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#ifdef __TURBOC__
+#include <mem.h>
+#include <fcntl.h>
+#endif
+
+#ifndef BOOL
+#define BOOL unsigned char
+#endif
+#ifndef TRUE
+#define TRUE (BOOL) 1
+#endif
+#ifndef FALSE
+#define FALSE (BOOL) 0
+#endif
+
+#define STDIN  0
+#define STDOUT 1
+#define STDERR 2
+
+/* to make pnm2png verbose so we can find problems (needs to be before png.h) */
+#ifndef PNG_DEBUG
+#define PNG_DEBUG 0
+#endif
+
+#include "png.h"
+
+/* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */
+#ifndef png_jmpbuf
+#  define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
+#endif
+
+/* function prototypes */
+
+int  main (int argc, char *argv[]);
+void usage ();
+BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace, BOOL alpha);
+void get_token(FILE *pnm_file, char *token);
+png_uint_32 get_data (FILE *pnm_file, int depth);
+png_uint_32 get_value (FILE *pnm_file, int depth);
+
+/*
+ *  main
+ */
+
+int main(int argc, char *argv[])
+{
+  FILE *fp_rd = stdin;
+  FILE *fp_al = NULL;
+  FILE *fp_wr = stdout;
+  BOOL interlace = FALSE;
+  BOOL alpha = FALSE;
+  int argi;
+
+  for (argi = 1; argi < argc; argi++)
+  {
+    if (argv[argi][0] == '-')
+    {
+      switch (argv[argi][1])
+      {
+        case 'i':
+          interlace = TRUE;
+          break;
+        case 'a':
+          alpha = TRUE;
+          argi++;
+          if ((fp_al = fopen (argv[argi], "rb")) == NULL)
+          {
+            fprintf (stderr, "PNM2PNG\n");
+            fprintf (stderr, "Error:  alpha-channel file %s does not exist\n",
+               argv[argi]);
+            exit (1);
+          }
+          break;
+        case 'h':
+        case '?':
+          usage();
+          exit(0);
+          break;
+        default:
+          fprintf (stderr, "PNM2PNG\n");
+          fprintf (stderr, "Error:  unknown option %s\n", argv[argi]);
+          usage();
+          exit(1);
+          break;
+      } /* end switch */
+    }
+    else if (fp_rd == stdin)
+    {
+      if ((fp_rd = fopen (argv[argi], "rb")) == NULL)
+      {
+        fprintf (stderr, "PNM2PNG\n");
+        fprintf (stderr, "Error:  file %s does not exist\n", argv[argi]);
+        exit (1);
+      }
+    }
+    else if (fp_wr == stdout)
+    {
+      if ((fp_wr = fopen (argv[argi], "wb")) == NULL)
+      {
+        fprintf (stderr, "PNM2PNG\n");
+        fprintf (stderr, "Error:  can not create PNG-file %s\n", argv[argi]);
+        exit (1);
+      }
+    }
+    else
+    {
+      fprintf (stderr, "PNM2PNG\n");
+      fprintf (stderr, "Error:  too many parameters\n");
+      usage();
+      exit (1);
+    }
+  } /* end for */
+
+#ifdef __TURBOC__
+  /* set stdin/stdout to binary, we're reading the PNM always! in binary format */
+  if (fp_rd == stdin)
+  {
+    setmode (STDIN, O_BINARY);
+  }
+  if (fp_wr == stdout)
+  {
+    setmode (STDOUT, O_BINARY);
+  }
+#endif
+
+  /* call the conversion program itself */
+  if (pnm2png (fp_rd, fp_wr, fp_al, interlace, alpha) == FALSE)
+  {
+    fprintf (stderr, "PNM2PNG\n");
+    fprintf (stderr, "Error:  unsuccessful converting to PNG-image\n");
+    exit (1);
+  }
+
+  /* close input file */
+  fclose (fp_rd);
+  /* close output file */
+  fclose (fp_wr);
+  /* close alpha file */
+  if (alpha)
+    fclose (fp_al);
+
+  return 0;
+}
+
+/*
+ *  usage
+ */
+
+void usage()
+{
+  fprintf (stderr, "PNM2PNG\n");
+  fprintf (stderr, "   by Willem van Schaik, 1999\n");
+#ifdef __TURBOC__
+  fprintf (stderr, "   for Turbo-C and Borland-C compilers\n");
+#else
+  fprintf (stderr, "   for Linux (and Unix) compilers\n");
+#endif
+  fprintf (stderr, "Usage:  pnm2png [options] <file>.<pnm> [<file>.png]\n");
+  fprintf (stderr, "   or:  ... | pnm2png [options]\n");
+  fprintf (stderr, "Options:\n");
+  fprintf (stderr, "   -i[nterlace]   write png-file with interlacing on\n");
+  fprintf (stderr, "   -a[lpha] <file>.pgm read PNG alpha channel as pgm-file\n");
+  fprintf (stderr, "   -h | -?  print this help-information\n");
+}
+
+/*
+ *  pnm2png
+ */
+
+BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace, BOOL alpha)
+{
+  png_struct    *png_ptr = NULL;
+  png_info      *info_ptr = NULL;
+  png_byte      *png_pixels = NULL;
+  png_byte      **row_pointers = NULL;
+  png_byte      *pix_ptr = NULL;
+  png_uint_32   row_bytes;
+
+  char          type_token[16];
+  char          width_token[16];
+  char          height_token[16];
+  char          maxval_token[16];
+  int           color_type;
+  png_uint_32   width, alpha_width;
+  png_uint_32   height, alpha_height;
+  png_uint_32   maxval;
+  int           bit_depth = 0;
+  int           channels;
+  int           alpha_depth = 0;
+  int           alpha_present;
+  int           row, col;
+  BOOL          raw, alpha_raw = FALSE;
+  png_uint_32   tmp16;
+  int           i;
+
+  /* read header of PNM file */
+
+  get_token(pnm_file, type_token);
+  if (type_token[0] != 'P')
+  {
+    return FALSE;
+  }
+  else if ((type_token[1] == '1') || (type_token[1] == '4'))
+  {
+    raw = (type_token[1] == '4');
+    color_type = PNG_COLOR_TYPE_GRAY;
+    bit_depth = 1;
+  }
+  else if ((type_token[1] == '2') || (type_token[1] == '5'))
+  {
+    raw = (type_token[1] == '5');
+    color_type = PNG_COLOR_TYPE_GRAY;
+    get_token(pnm_file, width_token);
+    sscanf (width_token, "%lu", &width);
+    get_token(pnm_file, height_token);
+    sscanf (height_token, "%lu", &height);
+    get_token(pnm_file, maxval_token);
+    sscanf (maxval_token, "%lu", &maxval);
+    if (maxval <= 1)
+      bit_depth = 1;
+    else if (maxval <= 3)
+      bit_depth = 2;
+    else if (maxval <= 15)
+      bit_depth = 4;
+    else if (maxval <= 255)
+      bit_depth = 8;
+    else /* if (maxval <= 65535) */
+      bit_depth = 16;
+  }
+  else if ((type_token[1] == '3') || (type_token[1] == '6'))
+  {
+    raw = (type_token[1] == '6');
+    color_type = PNG_COLOR_TYPE_RGB;
+    get_token(pnm_file, width_token);
+    sscanf (width_token, "%lu", &width);
+    get_token(pnm_file, height_token);
+    sscanf (height_token, "%lu", &height);
+    get_token(pnm_file, maxval_token);
+    sscanf (maxval_token, "%lu", &maxval);
+    if (maxval <= 1)
+      bit_depth = 1;
+    else if (maxval <= 3)
+      bit_depth = 2;
+    else if (maxval <= 15)
+      bit_depth = 4;
+    else if (maxval <= 255)
+      bit_depth = 8;
+    else /* if (maxval <= 65535) */
+      bit_depth = 16;
+  }
+  else
+  {
+    return FALSE;
+  }
+
+  /* read header of PGM file with alpha channel */
+
+  if (alpha)
+  {
+    if (color_type == PNG_COLOR_TYPE_GRAY)
+      color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
+    if (color_type == PNG_COLOR_TYPE_RGB)
+      color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+
+    get_token(alpha_file, type_token);
+    if (type_token[0] != 'P')
+    {
+      return FALSE;
+    }
+    else if ((type_token[1] == '2') || (type_token[1] == '5'))
+    {
+      alpha_raw = (type_token[1] == '5');
+      get_token(alpha_file, width_token);
+      sscanf (width_token, "%lu", &alpha_width);
+      if (alpha_width != width)
+        return FALSE;
+      get_token(alpha_file, height_token);
+      sscanf (height_token, "%lu", &alpha_height);
+      if (alpha_height != height)
+        return FALSE;
+      get_token(alpha_file, maxval_token);
+      sscanf (maxval_token, "%lu", &maxval);
+      if (maxval <= 1)
+        alpha_depth = 1;
+      else if (maxval <= 3)
+        alpha_depth = 2;
+      else if (maxval <= 15)
+        alpha_depth = 4;
+      else if (maxval <= 255)
+        alpha_depth = 8;
+      else /* if (maxval <= 65535) */
+        alpha_depth = 16;
+      if (alpha_depth != bit_depth)
+        return FALSE;
+    }
+    else
+    {
+      return FALSE;
+    }
+  } /* end if alpha */
+
+  /* calculate the number of channels and store alpha-presence */
+  if (color_type == PNG_COLOR_TYPE_GRAY)
+    channels = 1;
+  else if (color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+    channels = 2;
+  else if (color_type == PNG_COLOR_TYPE_RGB)
+    channels = 3;
+  else if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+    channels = 4;
+  else
+    channels = 0; /* should not happen */
+
+  alpha_present = (channels - 1) % 2;
+
+  /* row_bytes is the width x number of channels x (bit-depth / 8) */
+  row_bytes = width * channels * ((bit_depth <= 8) ? 1 : 2);
+
+  if ((png_pixels = (png_byte *) malloc (row_bytes * height * sizeof (png_byte))) == NULL)
+    return FALSE;
+
+  /* read data from PNM file */
+  pix_ptr = png_pixels;
+
+  for (row = 0; row < height; row++)
+  {
+    for (col = 0; col < width; col++)
+    {
+      for (i = 0; i < (channels - alpha_present); i++)
+      {
+        if (raw)
+          *pix_ptr++ = get_data (pnm_file, bit_depth);
+        else
+          if (bit_depth <= 8)
+            *pix_ptr++ = get_value (pnm_file, bit_depth);
+          else
+          {
+            tmp16 = get_value (pnm_file, bit_depth);
+            *pix_ptr = (png_byte) ((tmp16 >> 8) & 0xFF);
+            pix_ptr++;
+            *pix_ptr = (png_byte) (tmp16 & 0xFF);
+            pix_ptr++;
+          }
+      }
+
+      if (alpha) /* read alpha-channel from pgm file */
+      {
+        if (alpha_raw)
+          *pix_ptr++ = get_data (alpha_file, alpha_depth);
+        else
+          if (alpha_depth <= 8)
+            *pix_ptr++ = get_value (alpha_file, bit_depth);
+          else
+          {
+            tmp16 = get_value (alpha_file, bit_depth);
+            *pix_ptr++ = (png_byte) ((tmp16 >> 8) & 0xFF);
+            *pix_ptr++ = (png_byte) (tmp16 & 0xFF);
+          }
+      } /* if alpha */
+
+    } /* end for col */
+  } /* end for row */
+
+  /* prepare the standard PNG structures */
+  png_ptr = png_create_write_struct (PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+  if (!png_ptr)
+  {
+    return FALSE;
+  }
+  info_ptr = png_create_info_struct (png_ptr);
+  if (!info_ptr)
+  {
+    png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
+    return FALSE;
+  }
+
+  /* setjmp() must be called in every function that calls a PNG-reading libpng function */
+  if (setjmp (png_jmpbuf(png_ptr)))
+  {
+    png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
+    return FALSE;
+  }
+
+  /* initialize the png structure */
+  png_init_io (png_ptr, png_file);
+
+  /* we're going to write more or less the same PNG as the input file */
+  png_set_IHDR (png_ptr, info_ptr, width, height, bit_depth, color_type,
+    (!interlace) ? PNG_INTERLACE_NONE : PNG_INTERLACE_ADAM7,
+    PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+
+  /* write the file header information */
+  png_write_info (png_ptr, info_ptr);
+
+  /* if needed we will allocate memory for an new array of row-pointers */
+  if (row_pointers == (unsigned char**) NULL)
+  {
+    if ((row_pointers = (png_byte **) malloc (height * sizeof (png_bytep))) == NULL)
+    {
+      png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
+      return FALSE;
+    }
+  }
+
+  /* set the individual row_pointers to point at the correct offsets */
+  for (i = 0; i < (height); i++)
+    row_pointers[i] = png_pixels + i * row_bytes;
+
+  /* write out the entire image data in one call */
+  png_write_image (png_ptr, row_pointers);
+
+  /* write the additional chuncks to the PNG file (not really needed) */
+  png_write_end (png_ptr, info_ptr);
+
+  /* clean up after the write, and free any memory allocated */
+  png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
+
+  if (row_pointers != (unsigned char**) NULL)
+    free (row_pointers);
+  if (png_pixels != (unsigned char*) NULL)
+    free (png_pixels);
+
+  return TRUE;
+} /* end of pnm2png */
+
+/*
+ * get_token() - gets the first string after whitespace
+ */
+
+void get_token(FILE *pnm_file, char *token)
+{
+  int i = 0;
+
+  /* remove white-space */
+  do
+  {
+    token[i] = (unsigned char) fgetc (pnm_file);
+  }
+  while ((token[i] == '\n') || (token[i] == '\r') || (token[i] == ' '));
+
+  /* read string */
+  do
+  {
+    i++;
+    token[i] = (unsigned char) fgetc (pnm_file);
+  }
+  while ((token[i] != '\n') && (token[i] != '\r') && (token[i] != ' '));
+
+  token[i] = '\0';
+
+  return;
+}
+
+/*
+ * get_data() - takes first byte and converts into next pixel value,
+ *        taking as much bits as defined by bit-depth and
+ *        using the bit-depth to fill up a byte (0Ah -> AAh)
+ */
+
+png_uint_32 get_data (FILE *pnm_file, int depth)
+{
+  static int bits_left = 0;
+  static int old_value = 0;
+  static int mask = 0;
+  int i;
+  png_uint_32 ret_value;
+
+  if (mask == 0)
+    for (i = 0; i < depth; i++)
+      mask = (mask >> 1) | 0x80;
+
+  if (bits_left <= 0)
+  {
+    old_value = fgetc (pnm_file);
+    bits_left = 8;
+  }
+
+  ret_value = old_value & mask;
+  for (i = 1; i < (8 / depth); i++)
+    ret_value = ret_value || (ret_value >> depth);
+
+  old_value = (old_value << depth) & 0xFF;
+  bits_left -= depth;
+
+  return ret_value;
+}
+
+/*
+ * get_value() - takes first (numeric) string and converts into number,
+ *         using the bit-depth to fill up a byte (0Ah -> AAh)
+ */
+
+png_uint_32 get_value (FILE *pnm_file, int depth)
+{
+  static png_uint_32 mask = 0;
+  png_byte token[16];
+  png_uint_32 ret_value;
+  int i = 0;
+
+  if (mask == 0)
+    for (i = 0; i < depth; i++)
+      mask = (mask << 1) | 0x01;
+
+  get_token (pnm_file, (char *) token);
+  sscanf ((const char *) token, "%lu", &ret_value);
+
+  ret_value &= mask;
+
+  if (depth < 8)
+    for (i = 0; i < (8 / depth); i++)
+      ret_value = (ret_value << depth) || ret_value;
+
+  return ret_value;
+}
+
+/* end of source */
+

contrib/pngminus/pnm2png.sh

@@ -0,0 +1,42 @@
+#!/bin/sh
+# -- grayscale
+./pnm2png basn0g01.pgm basn0g01.png
+./pnm2png basn0g02.pgm basn0g02.png
+./pnm2png basn0g04.pgm basn0g04.png
+./pnm2png basn0g08.pgm basn0g08.png
+./pnm2png basn0g16.pgm basn0g16.png
+# -- full-color
+./pnm2png basn2c08.ppm basn2c08.png
+./pnm2png basn2c16.ppm basn2c16.png
+# -- palletted
+./pnm2png basn3p01.ppm basn3p01.png
+./pnm2png basn3p02.ppm basn3p02.png
+./pnm2png basn3p04.ppm basn3p04.png
+./pnm2png basn3p08.ppm basn3p08.png
+# -- gray with alpha-channel
+./pnm2png -alpha basn6a08.pgm basn4a08.pgm basn4a08.png
+./pnm2png -alpha basn6a16.pgm basn4a16.pgm basn4a16.png
+# -- color with alpha-channel
+./pnm2png -alpha basn6a08.pgm basn6a08.ppm basn6a08.png
+./pnm2png -alpha basn6a16.pgm basn6a16.ppm basn6a16.png
+# -- grayscale
+./pnm2png rawn0g01.pgm rawn0g01.png
+./pnm2png rawn0g02.pgm rawn0g02.png
+./pnm2png rawn0g04.pgm rawn0g04.png
+./pnm2png rawn0g08.pgm rawn0g08.png
+./pnm2png rawn0g16.pgm rawn0g16.png
+# -- full-color
+./pnm2png rawn2c08.ppm rawn2c08.png
+./pnm2png rawn2c16.ppm rawn2c16.png
+# -- palletted
+./pnm2png rawn3p01.ppm rawn3p01.png
+./pnm2png rawn3p02.ppm rawn3p02.png
+./pnm2png rawn3p04.ppm rawn3p04.png
+./pnm2png rawn3p08.ppm rawn3p08.png
+# -- gray with alpha-channel
+./pnm2png -alpha rawn6a08.pgm rawn4a08.pgm rawn4a08.png
+./pnm2png -alpha rawn6a16.pgm rawn4a16.pgm rawn4a16.png
+# -- color with alpha-channel
+./pnm2png -alpha rawn6a08.pgm rawn6a08.ppm rawn6a08.png
+./pnm2png -alpha rawn6a16.pgm rawn6a16.ppm rawn6a16.png
+

contrib/pngsuite/README

@@ -0,0 +1,85 @@
+
+pngsuite
+--------
+(c) Willem van Schaik, 1999
+
+Permission to use, copy, and distribute these images for any purpose and
+without fee is hereby granted.
+
+These 15 images are part of the much larger PngSuite test-set of 
+images, available for developers of PNG supporting software. The 
+complete set, available at http:/www.schaik.com/pngsuite/, contains 
+a variety of images to test interlacing, gamma settings, ancillary
+chunks, etc.
+
+The images in this directory represent the basic PNG color-types:
+grayscale (1-16 bit deep), full color (8 or 16 bit), paletted
+(1-8 bit) and grayscale or color images with alpha channel. You
+can use them to test the proper functioning of PNG software.
+
+    filename      depth type
+    ------------ ------ --------------
+    basn0g01.png  1-bit grayscale
+    basn0g02.png  2-bit grayscale
+    basn0g04.png  4-bit grayscale
+    basn0g08.png  8-bit grayscale
+    basn0g16.png 16-bit grayscale
+    basn2c08.png  8-bit truecolor
+    basn2c16.png 16-bit truecolor
+    basn3p01.png  1-bit paletted
+    basn3p02.png  2-bit paletted
+    basn3p04.png  4-bit paletted
+    basn3p08.png  8-bit paletted
+    basn4a08.png  8-bit gray with alpha
+    basn4a16.png 16-bit gray with alpha
+    basn6a08.png  8-bit RGBA
+    basn6a16.png 16-bit RGBA
+
+Here is the correct result of typing "pngtest -m *.png" in
+this directory:
+
+Testing basn0g01.png: PASS (524 zero samples)
+ Filter 0 was used 32 times
+Testing basn0g02.png: PASS (448 zero samples)
+ Filter 0 was used 32 times
+Testing basn0g04.png: PASS (520 zero samples)
+ Filter 0 was used 32 times
+Testing basn0g08.png: PASS (3 zero samples)
+ Filter 1 was used 9 times
+ Filter 4 was used 23 times
+Testing basn0g16.png: PASS (1 zero samples)
+ Filter 1 was used 1 times
+ Filter 2 was used 31 times
+Testing basn2c08.png: PASS (6 zero samples)
+ Filter 1 was used 5 times
+ Filter 4 was used 27 times
+Testing basn2c16.png: PASS (592 zero samples)
+ Filter 1 was used 1 times
+ Filter 4 was used 31 times
+Testing basn3p01.png: PASS (512 zero samples)
+ Filter 0 was used 32 times
+Testing basn3p02.png: PASS (448 zero samples)
+ Filter 0 was used 32 times
+Testing basn3p04.png: PASS (544 zero samples)
+ Filter 0 was used 32 times
+Testing basn3p08.png: PASS (4 zero samples)
+ Filter 0 was used 32 times
+Testing basn4a08.png: PASS (32 zero samples)
+ Filter 1 was used 1 times
+ Filter 4 was used 31 times
+Testing basn4a16.png: PASS (64 zero samples)
+ Filter 0 was used 1 times
+ Filter 1 was used 2 times
+ Filter 2 was used 1 times
+ Filter 4 was used 28 times
+Testing basn6a08.png: PASS (160 zero samples)
+ Filter 1 was used 1 times
+ Filter 4 was used 31 times
+Testing basn6a16.png: PASS (1072 zero samples)
+ Filter 1 was used 4 times
+ Filter 4 was used 28 times
+libpng passes test
+
+Willem van Schaik
+<willem@schaik.com>
+October 1999

contrib/visupng/PngFile.c

@@ -0,0 +1,439 @@
+//-------------------------------------
+//  PNGFILE.C -- Image File Functions
+//-------------------------------------
+
+// Copyright 2000, Willem van Schaik.  For conditions of distribution and
+// use, see the copyright/license/disclaimer notice in png.h
+
+#include <windows.h>
+#include <commdlg.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "png.h"
+#include "pngfile.h"
+#include "cexcept.h"
+
+define_exception_type(const char *);
+extern struct exception_context the_exception_context[1];
+struct exception_context the_exception_context[1];
+png_const_charp msg;
+
+static OPENFILENAME ofn;
+
+static png_structp png_ptr = NULL;
+static png_infop info_ptr = NULL;
+
+
+// cexcept interface
+
+static void
+png_cexcept_error(png_structp png_ptr, png_const_charp msg)
+{
+   if(png_ptr)
+     ;
+#ifndef PNG_NO_CONSOLE_IO
+   fprintf(stderr, "libpng error: %s\n", msg);
+#endif
+   {
+      Throw msg;
+   }
+}
+
+// Windows open-file functions
+
+void PngFileInitialize (HWND hwnd)
+{
+    static TCHAR szFilter[] = TEXT ("PNG Files (*.PNG)\0*.png\0")
+        TEXT ("All Files (*.*)\0*.*\0\0");
+
+    ofn.lStructSize       = sizeof (OPENFILENAME);
+    ofn.hwndOwner         = hwnd;
+    ofn.hInstance         = NULL;
+    ofn.lpstrFilter       = szFilter;
+    ofn.lpstrCustomFilter = NULL;
+    ofn.nMaxCustFilter    = 0;
+    ofn.nFilterIndex      = 0;
+    ofn.lpstrFile         = NULL;          // Set in Open and Close functions
+    ofn.nMaxFile          = MAX_PATH;
+    ofn.lpstrFileTitle    = NULL;          // Set in Open and Close functions
+    ofn.nMaxFileTitle     = MAX_PATH;
+    ofn.lpstrInitialDir   = NULL;
+    ofn.lpstrTitle        = NULL;
+    ofn.Flags             = 0;             // Set in Open and Close functions
+    ofn.nFileOffset       = 0;
+    ofn.nFileExtension    = 0;
+    ofn.lpstrDefExt       = TEXT ("png");
+    ofn.lCustData         = 0;
+    ofn.lpfnHook          = NULL;
+    ofn.lpTemplateName    = NULL;
+}
+
+BOOL PngFileOpenDlg (HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName)
+{
+    ofn.hwndOwner         = hwnd;
+    ofn.lpstrFile         = pstrFileName;
+    ofn.lpstrFileTitle    = pstrTitleName;
+    ofn.Flags             = OFN_HIDEREADONLY;
+
+    return GetOpenFileName (&ofn);
+}
+
+BOOL PngFileSaveDlg (HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName)
+{
+    ofn.hwndOwner         = hwnd;
+    ofn.lpstrFile         = pstrFileName;
+    ofn.lpstrFileTitle    = pstrTitleName;
+    ofn.Flags             = OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT;
+
+    return GetSaveFileName (&ofn);
+}
+
+// PNG image handler functions
+
+BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData,
+                   int *piWidth, int *piHeight, int *piChannels, png_color *pBkgColor)
+{
+    static FILE        *pfFile;
+    png_byte            pbSig[8];
+    int                 iBitDepth;
+    int                 iColorType;
+    double              dGamma;
+    png_color_16       *pBackground;
+    png_uint_32         ulChannels;
+    png_uint_32         ulRowBytes;
+    png_byte           *pbImageData = *ppbImageData;
+    static png_byte   **ppbRowPointers = NULL;
+    int                 i;
+
+    // open the PNG input file
+
+    if (!pstrFileName)
+    {
+        *ppbImageData = pbImageData = NULL;
+        return FALSE;
+    }
+
+    if (!(pfFile = fopen(pstrFileName, "rb")))
+    {
+        *ppbImageData = pbImageData = NULL;
+        return FALSE;
+    }
+
+    // first check the eight byte PNG signature
+
+    fread(pbSig, 1, 8, pfFile);
+    if (!png_check_sig(pbSig, 8))
+    {
+        *ppbImageData = pbImageData = NULL;
+        return FALSE;
+    }
+
+    // create the two png(-info) structures
+
+    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL,
+      (png_error_ptr)png_cexcept_error, (png_error_ptr)NULL);
+    if (!png_ptr)
+    {
+        *ppbImageData = pbImageData = NULL;
+        return FALSE;
+    }
+
+    info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr)
+    {
+        png_destroy_read_struct(&png_ptr, NULL, NULL);
+        *ppbImageData = pbImageData = NULL;
+        return FALSE;
+    }
+
+    Try
+    {
+        
+        // initialize the png structure
+        
+#if !defined(PNG_NO_STDIO)
+        png_init_io(png_ptr, pfFile);
+#else
+        png_set_read_fn(png_ptr, (png_voidp)pfFile, png_read_data);
+#endif
+        
+        png_set_sig_bytes(png_ptr, 8);
+        
+        // read all PNG info up to image data
+        
+        png_read_info(png_ptr, info_ptr);
+        
+        // get width, height, bit-depth and color-type
+        
+        png_get_IHDR(png_ptr, info_ptr, piWidth, piHeight, &iBitDepth,
+            &iColorType, NULL, NULL, NULL);
+        
+        // expand images of all color-type and bit-depth to 3x8 bit RGB images
+        // let the library process things like alpha, transparency, background
+        
+        if (iBitDepth == 16)
+            png_set_strip_16(png_ptr);
+        if (iColorType == PNG_COLOR_TYPE_PALETTE)
+            png_set_expand(png_ptr);
+        if (iBitDepth < 8)
+            png_set_expand(png_ptr);
+        if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
+            png_set_expand(png_ptr);
+        if (iColorType == PNG_COLOR_TYPE_GRAY ||
+            iColorType == PNG_COLOR_TYPE_GRAY_ALPHA)
+            png_set_gray_to_rgb(png_ptr);
+        
+        // set the background color to draw transparent and alpha images over.
+        if (png_get_bKGD(png_ptr, info_ptr, &pBackground))
+        {
+            png_set_background(png_ptr, pBackground, PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
+            pBkgColor->red   = (byte) pBackground->red;
+            pBkgColor->green = (byte) pBackground->green;
+            pBkgColor->blue  = (byte) pBackground->blue;
+        }
+        else
+        {
+            pBkgColor = NULL;
+        }
+        
+        // if required set gamma conversion
+        if (png_get_gAMA(png_ptr, info_ptr, &dGamma))
+            png_set_gamma(png_ptr, (double) 2.2, dGamma);
+        
+        // after the transformations have been registered update info_ptr data
+        
+        png_read_update_info(png_ptr, info_ptr);
+        
+        // get again width, height and the new bit-depth and color-type
+        
+        png_get_IHDR(png_ptr, info_ptr, piWidth, piHeight, &iBitDepth,
+            &iColorType, NULL, NULL, NULL);
+        
+        
+        // row_bytes is the width x number of channels
+        
+        ulRowBytes = png_get_rowbytes(png_ptr, info_ptr);
+        ulChannels = png_get_channels(png_ptr, info_ptr);
+        
+        *piChannels = ulChannels;
+        
+        // now we can allocate memory to store the image
+        
+        if (pbImageData)
+        {
+            free (pbImageData);
+            pbImageData = NULL;
+        }
+        if ((pbImageData = (png_byte *) malloc(ulRowBytes * (*piHeight)
+                            * sizeof(png_byte))) == NULL)
+        {
+            png_error(png_ptr, "Visual PNG: out of memory");
+        }
+        *ppbImageData = pbImageData;
+        
+        // and allocate memory for an array of row-pointers
+        
+        if ((ppbRowPointers = (png_bytepp) malloc((*piHeight)
+                            * sizeof(png_bytep))) == NULL)
+        {
+            png_error(png_ptr, "Visual PNG: out of memory");
+        }
+        
+        // set the individual row-pointers to point at the correct offsets
+        
+        for (i = 0; i < (*piHeight); i++)
+            ppbRowPointers[i] = pbImageData + i * ulRowBytes;
+        
+        // now we can go ahead and just read the whole image
+        
+        png_read_image(png_ptr, ppbRowPointers);
+        
+        // read the additional chunks in the PNG file (not really needed)
+        
+        png_read_end(png_ptr, NULL);
+        
+        // and we're done
+        
+        free (ppbRowPointers);
+        ppbRowPointers = NULL;
+        
+        // yepp, done
+    }
+
+    Catch (msg)
+    {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+
+        *ppbImageData = pbImageData = NULL;
+        
+        if(ppbRowPointers)
+            free (ppbRowPointers);
+
+        fclose(pfFile);
+
+        return FALSE;
+    }
+
+    fclose (pfFile);
+
+    return TRUE;
+}
+
+
+BOOL PngSaveImage (PTSTR pstrFileName, png_byte *pDiData,
+                   int iWidth, int iHeight, png_color bkgColor)
+{
+    const int           ciBitDepth = 8;
+    const int           ciChannels = 3;
+
+    static FILE        *pfFile;
+    png_uint_32         ulRowBytes;
+    static png_byte   **ppbRowPointers = NULL;
+    int                 i;
+
+    // open the PNG output file
+
+    if (!pstrFileName)
+        return FALSE;
+
+    if (!(pfFile = fopen(pstrFileName, "wb")))
+        return FALSE;
+
+    // prepare the standard PNG structures
+
+    png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL,
+      (png_error_ptr)png_cexcept_error, (png_error_ptr)NULL);
+    if (!png_ptr)
+    {
+        fclose(pfFile);
+        return FALSE;
+    }
+
+    info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr) {
+        fclose(pfFile);
+        png_destroy_write_struct(&png_ptr, (png_infopp) NULL);
+        return FALSE;
+    }
+
+    Try
+    {
+        // initialize the png structure
+        
+#if !defined(PNG_NO_STDIO)
+        png_init_io(png_ptr, pfFile);
+#else
+        png_set_write_fn(png_ptr, (png_voidp)pfFile, png_write_data, png_flush);
+#endif
+        
+        // we're going to write a very simple 3x8 bit RGB image
+        
+        png_set_IHDR(png_ptr, info_ptr, iWidth, iHeight, ciBitDepth,
+            PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE,
+            PNG_FILTER_TYPE_BASE);
+        
+        // write the file header information
+        
+        png_write_info(png_ptr, info_ptr);
+        
+        // swap the BGR pixels in the DiData structure to RGB
+        
+        png_set_bgr(png_ptr);
+        
+        // row_bytes is the width x number of channels
+        
+        ulRowBytes = iWidth * ciChannels;
+        
+        // we can allocate memory for an array of row-pointers
+        
+        if ((ppbRowPointers = (png_bytepp) malloc(iHeight * sizeof(png_bytep))) == NULL)
+            Throw "Visualpng: Out of memory";
+        
+        // set the individual row-pointers to point at the correct offsets
+        
+        for (i = 0; i < iHeight; i++)
+            ppbRowPointers[i] = pDiData + i * (((ulRowBytes + 3) >> 2) << 2);
+        
+        // write out the entire image data in one call
+        
+        png_write_image (png_ptr, ppbRowPointers);
+        
+        // write the additional chunks to the PNG file (not really needed)
+        
+        png_write_end(png_ptr, info_ptr);
+        
+        // and we're done
+        
+        free (ppbRowPointers);
+        ppbRowPointers = NULL;
+        
+        // clean up after the write, and free any memory allocated
+        
+        png_destroy_write_struct(&png_ptr, (png_infopp) NULL);
+        
+        // yepp, done
+    }
+
+    Catch (msg)
+    {
+        png_destroy_write_struct(&png_ptr, (png_infopp) NULL);
+
+        if(ppbRowPointers)
+            free (ppbRowPointers);
+
+        fclose(pfFile);
+
+        return FALSE;
+    }
+    
+    fclose (pfFile);
+    
+    return TRUE;
+}
+
+#ifdef PNG_NO_STDIO
+
+static void
+png_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_size_t check;
+
+   /* fread() returns 0 on error, so it is OK to store this in a png_size_t
+    * instead of an int, which is what fread() actually returns.
+    */
+   check = (png_size_t)fread(data, (png_size_t)1, length,
+      (FILE *)png_ptr->io_ptr);
+
+   if (check != length)
+   {
+      png_error(png_ptr, "Read Error");
+   }
+}
+
+static void
+png_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
+{
+   png_uint_32 check;
+
+   check = fwrite(data, 1, length, (FILE *)(png_ptr->io_ptr));
+   if (check != length)
+   {
+      png_error(png_ptr, "Write Error");
+   }
+}
+
+static void
+png_flush(png_structp png_ptr)
+{
+   FILE *io_ptr;
+   io_ptr = (FILE *)CVT_PTR((png_ptr->io_ptr));
+   if (io_ptr != NULL)
+      fflush(io_ptr);
+}
+
+#endif
+
+//-----------------
+//  end of source
+//-----------------

contrib/visupng/PngFile.h

@@ -0,0 +1,27 @@
+//------------------------------------------
+//  PNGFILE.H -- Header File for pngfile.c
+//------------------------------------------
+
+// Copyright 2000, Willem van Schaik.  For conditions of distribution and
+// use, see the copyright/license/disclaimer notice in png.h
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <windows.h>
+
+void PngFileInitialize (HWND hwnd) ;
+BOOL PngFileOpenDlg (HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName) ;
+BOOL PngFileSaveDlg (HWND hwnd, PTSTR pstrFileName, PTSTR pstrTitleName) ;
+
+BOOL PngLoadImage (PTSTR pstrFileName, png_byte **ppbImageData, 
+                   int *piWidth, int *piHeight, int *piChannels, png_color *pBkgColor);
+BOOL PngSaveImage (PTSTR pstrFileName, png_byte *pDiData,
+                   int iWidth, int iHeight, png_color BkgColor);
+
+#if defined(PNG_NO_STDIO)
+static void png_read_data(png_structp png_ptr, png_bytep data, png_size_t length);
+static void png_write_data(png_structp png_ptr, png_bytep data, png_size_t length);
+static void png_flush(png_structp png_ptr);
+#endif
+

contrib/visupng/README.txt

@@ -0,0 +1,58 @@
+Microsoft Developer Studio Build File, Format Version 6.00 for VisualPng
+------------------------------------------------------------------------
+
+Copyright 2000, Willem van Schaik.  For conditions of distribution and
+use, see the copyright/license/disclaimer notice in png.h
+
+As a PNG .dll demo VisualPng is finished. More features would only hinder
+the program's objective. However, further extensions (like support for other 
+graphics formats) are in development. To get these, or for pre-compiled 
+binaries, go to "http://www.schaik.com/png/visualpng.html".
+
+------------------------------------------------------------------------
+
+Assumes that
+
+   libpng DLLs and LIBs are in ..\..\projects\msvc\win32\libpng
+   zlib DLLs and LIBs are in   ..\..\projects\msvc\win32\zlib
+   libpng header files are in  ..\..\..\libpng
+   zlib header files are in    ..\..\..\zlib
+   the pngsuite images are in  ..\pngsuite
+
+To build:
+
+1) On the main menu Select "Build|Set Active configuration".
+   Choose the configuration that corresponds to the library you want to test.
+   This library must have been built using the libpng MS project located in
+   the "..\..\mscv" subdirectory.
+
+2) Select "Build|Clean"
+
+3) Select "Build|Rebuild All"
+
+4) After compiling and linking VisualPng will be started to view an image
+   from the PngSuite directory.  Press Ctrl-N (and Ctrl-V) for other images.
+
+
+To install:
+
+When distributing VisualPng (or a further development) the following options
+are available:
+
+1) Build the program with the configuration "Win32 LIB" and you only need to
+   include the executable from the ./lib directory in your distribution.
+
+2) Build the program with the configuration "Win32 DLL" and you need to put
+   in your distribution the executable from the ./dll directory and the dll's
+   libpng1.dll, zlib.dll and msvcrt.dll.  These need to be in the user's PATH.
+
+
+Willem van Schaik
+Calgary, June 6th 2000
+
+P.S. VisualPng was written based on preliminary work of:
+
+    - Simon-Pierre Cadieux
+    - Glenn Randers-Pehrson
+    - Greg Roelofs
+

contrib/visupng/VisualPng.c

@@ -0,0 +1,961 @@
+//------------------------------------
+//  VisualPng.C -- Shows a PNG image
+//------------------------------------
+
+// Copyright 2000, Willem van Schaik.  For conditions of distribution and
+// use, see the copyright/license/disclaimer notice in png.h
+
+// switches
+
+// defines
+
+#define PROGNAME  "VisualPng"
+#define LONGNAME  "Win32 Viewer for PNG-files"
+#define VERSION   "1.0 of 2000 June 07"
+
+// constants
+
+#define MARGIN 8
+
+// standard includes
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <windows.h>
+
+// application includes
+
+#include "png.h"
+#include "pngfile.h"
+#include "resource.h"
+
+// macros
+
+// function prototypes
+
+LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM);
+BOOL    CALLBACK AboutDlgProc (HWND, UINT, WPARAM, LPARAM) ;
+
+BOOL CenterAbout (HWND hwndChild, HWND hwndParent);
+
+BOOL BuildPngList (PTSTR pstrPathName, TCHAR **ppFileList, int *pFileCount,
+        int *pFileIndex);
+
+BOOL SearchPngList (TCHAR *pFileList, int FileCount, int *pFileIndex,
+        PTSTR pstrPrevName, PTSTR pstrNextName);
+
+BOOL LoadImageFile(HWND hwnd, PTSTR pstrPathName,
+        png_byte **ppbImage, int *pxImgSize, int *pyImgSize, int *piChannels,
+        png_color *pBkgColor);
+
+BOOL DisplayImage (HWND hwnd, BYTE **ppDib,
+        BYTE **ppDiData, int cxWinSize, int cyWinSize,
+        BYTE *pbImage, int cxImgSize, int cyImgSize, int cImgChannels,
+        BOOL bStretched);
+
+BOOL InitBitmap (
+        BYTE *pDiData, int cxWinSize, int cyWinSize);
+
+BOOL FillBitmap (
+        BYTE *pDiData, int cxWinSize, int cyWinSize,
+        BYTE *pbImage, int cxImgSize, int cyImgSize, int cImgChannels,
+        BOOL bStretched);
+
+// a few global variables
+
+static char *szProgName = PROGNAME;
+static char *szAppName = LONGNAME;
+static char *szIconName = PROGNAME;
+static char szCmdFileName [MAX_PATH];
+
+// MAIN routine
+
+int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
+                    PSTR szCmdLine, int iCmdShow)
+{
+    HACCEL   hAccel;
+    HWND     hwnd;
+    MSG      msg;
+    WNDCLASS wndclass;
+    int ixBorders, iyBorders;
+
+    wndclass.style         = CS_HREDRAW | CS_VREDRAW;
+    wndclass.lpfnWndProc   = WndProc;
+    wndclass.cbClsExtra    = 0;
+    wndclass.cbWndExtra    = 0;
+    wndclass.hInstance     = hInstance;
+    wndclass.hIcon         = LoadIcon (hInstance, szIconName) ;
+    wndclass.hCursor       = LoadCursor (NULL, IDC_ARROW);
+    wndclass.hbrBackground = NULL; // (HBRUSH) GetStockObject (GRAY_BRUSH);
+    wndclass.lpszMenuName  = szProgName;
+    wndclass.lpszClassName = szProgName;
+
+    if (!RegisterClass (&wndclass))
+    {
+        MessageBox (NULL, TEXT ("Error: this program requires Windows NT!"),
+            szProgName, MB_ICONERROR);
+        return 0;
+    }
+
+    // if filename given on commandline, store it
+    if ((szCmdLine != NULL) && (*szCmdLine != '\0'))
+        if (szCmdLine[0] == '"')
+            strncpy (szCmdFileName, szCmdLine + 1, strlen(szCmdLine) - 2);
+        else
+            strcpy (szCmdFileName, szCmdLine);
+    else
+        strcpy (szCmdFileName, "");
+
+    // calculate size of window-borders
+    ixBorders = 2 * (GetSystemMetrics (SM_CXBORDER) +
+                     GetSystemMetrics (SM_CXDLGFRAME));
+    iyBorders = 2 * (GetSystemMetrics (SM_CYBORDER) +
+                     GetSystemMetrics (SM_CYDLGFRAME)) +
+                     GetSystemMetrics (SM_CYCAPTION) +
+                     GetSystemMetrics (SM_CYMENUSIZE) +
+                     1; /* WvS: don't ask me why? */
+
+    hwnd = CreateWindow (szProgName, szAppName,
+        WS_OVERLAPPEDWINDOW,
+        CW_USEDEFAULT, CW_USEDEFAULT,
+        512 + 2 * MARGIN + ixBorders, 384 + 2 * MARGIN + iyBorders,
+//      CW_USEDEFAULT, CW_USEDEFAULT,
+        NULL, NULL, hInstance, NULL);
+
+    ShowWindow (hwnd, iCmdShow);
+    UpdateWindow (hwnd);
+
+    hAccel = LoadAccelerators (hInstance, szProgName);
+
+    while (GetMessage (&msg, NULL, 0, 0))
+    {
+        if (!TranslateAccelerator (hwnd, hAccel, &msg))
+        {
+            TranslateMessage (&msg);
+            DispatchMessage (&msg);
+        }
+    }
+    return msg.wParam;
+}
+
+LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam,
+        LPARAM lParam)
+{
+    static HINSTANCE          hInstance ;
+    static HDC                hdc;
+    static PAINTSTRUCT        ps;
+    static HMENU              hMenu;
+
+    static BITMAPFILEHEADER  *pbmfh;
+    static BITMAPINFOHEADER  *pbmih;
+    static BYTE              *pbImage;
+    static int                cxWinSize, cyWinSize;
+    static int                cxImgSize, cyImgSize;
+    static int                cImgChannels;
+    static png_color          bkgColor = {127, 127, 127};
+
+    static BOOL               bStretched = TRUE;
+
+    static BYTE              *pDib = NULL;
+    static BYTE              *pDiData = NULL;
+
+    static TCHAR              szImgPathName [MAX_PATH];
+    static TCHAR              szTitleName [MAX_PATH];
+
+    static TCHAR             *pPngFileList = NULL;
+    static int                iPngFileCount;
+    static int                iPngFileIndex;
+
+    BOOL                      bOk;
+
+    switch (message)
+    {
+    case WM_CREATE:
+        hInstance = ((LPCREATESTRUCT) lParam)->hInstance ;
+        PngFileInitialize (hwnd);
+
+        strcpy (szImgPathName, "");
+
+        // in case we process file given on command-line
+
+        if (szCmdFileName[0] != '\0')
+        {
+            strcpy (szImgPathName, szCmdFileName);
+
+            // read the other png-files in the directory for later
+            // next/previous commands
+
+            BuildPngList (szImgPathName, &pPngFileList, &iPngFileCount,
+                          &iPngFileIndex);
+
+            // load the image from file
+
+            if (!LoadImageFile (hwnd, szImgPathName,
+                &pbImage, &cxImgSize, &cyImgSize, &cImgChannels, &bkgColor))
+                return 0;
+
+            // invalidate the client area for later update
+
+            InvalidateRect (hwnd, NULL, TRUE);
+
+            // display the PNG into the DIBitmap
+
+            DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
+                pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
+        }
+
+        return 0;
+
+    case WM_SIZE:
+        cxWinSize = LOWORD (lParam);
+        cyWinSize = HIWORD (lParam);
+
+        // invalidate the client area for later update
+
+        InvalidateRect (hwnd, NULL, TRUE);
+
+        // display the PNG into the DIBitmap
+
+        DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
+            pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
+
+        return 0;
+
+    case WM_INITMENUPOPUP:
+        hMenu = GetMenu (hwnd);
+
+        if (pbImage)
+            EnableMenuItem (hMenu, IDM_FILE_SAVE, MF_ENABLED);
+        else
+            EnableMenuItem (hMenu, IDM_FILE_SAVE, MF_GRAYED);
+
+        return 0;
+
+    case WM_COMMAND:
+        hMenu = GetMenu (hwnd);
+
+        switch (LOWORD (wParam))
+        {
+        case IDM_FILE_OPEN:
+
+            // show the File Open dialog box
+
+            if (!PngFileOpenDlg (hwnd, szImgPathName, szTitleName))
+                return 0;
+
+            // read the other png-files in the directory for later
+            // next/previous commands
+
+            BuildPngList (szImgPathName, &pPngFileList, &iPngFileCount,
+                          &iPngFileIndex);
+
+            // load the image from file
+
+            if (!LoadImageFile (hwnd, szImgPathName,
+                &pbImage, &cxImgSize, &cyImgSize, &cImgChannels, &bkgColor))
+                return 0;
+
+            // invalidate the client area for later update
+
+            InvalidateRect (hwnd, NULL, TRUE);
+
+            // display the PNG into the DIBitmap
+
+            DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
+                pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
+
+            return 0;
+
+        case IDM_FILE_SAVE:
+
+            // show the File Save dialog box
+
+            if (!PngFileSaveDlg (hwnd, szImgPathName, szTitleName))
+                return 0;
+
+            // save the PNG to a disk file
+
+            SetCursor (LoadCursor (NULL, IDC_WAIT));
+            ShowCursor (TRUE);
+
+            bOk = PngSaveImage (szImgPathName, pDiData, cxWinSize, cyWinSize,
+                  bkgColor);
+
+            ShowCursor (FALSE);
+            SetCursor (LoadCursor (NULL, IDC_ARROW));
+
+            if (!bOk)
+                MessageBox (hwnd, TEXT ("Error in saving the PNG image"),
+                szProgName, MB_ICONEXCLAMATION | MB_OK);
+            return 0;
+
+        case IDM_FILE_NEXT:
+
+            // read next entry in the directory
+
+            if (SearchPngList (pPngFileList, iPngFileCount, &iPngFileIndex,
+                NULL, szImgPathName))
+            {
+                if (strcmp (szImgPathName, "") == 0)
+                    return 0;
+                
+                // load the image from file
+                
+                if (!LoadImageFile (hwnd, szImgPathName, &pbImage,
+                        &cxImgSize, &cyImgSize, &cImgChannels, &bkgColor))
+                    return 0;
+                
+                // invalidate the client area for later update
+                
+                InvalidateRect (hwnd, NULL, TRUE);
+                
+                // display the PNG into the DIBitmap
+                
+                DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
+                    pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
+            }
+            
+            return 0;
+
+        case IDM_FILE_PREVIOUS:
+
+            // read previous entry in the directory
+
+            if (SearchPngList (pPngFileList, iPngFileCount, &iPngFileIndex,
+                szImgPathName, NULL))
+            {
+                
+                if (strcmp (szImgPathName, "") == 0)
+                    return 0;
+                
+                // load the image from file
+                
+                if (!LoadImageFile (hwnd, szImgPathName, &pbImage, &cxImgSize,
+                    &cyImgSize, &cImgChannels, &bkgColor))
+                    return 0;
+                
+                // invalidate the client area for later update
+                
+                InvalidateRect (hwnd, NULL, TRUE);
+                
+                // display the PNG into the DIBitmap
+                
+                DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
+                    pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
+            }
+
+            return 0;
+
+        case IDM_FILE_EXIT:
+
+            // more cleanup needed...
+
+            // free image buffer
+
+            if (pDib != NULL)
+            {
+                free (pDib);
+                pDib = NULL;
+            }
+
+            // free file-list
+
+            if (pPngFileList != NULL)
+            {
+                free (pPngFileList);
+                pPngFileList = NULL;
+            }
+
+            // let's go ...
+
+            exit (0);
+
+            return 0;
+
+        case IDM_OPTIONS_STRETCH:
+            bStretched = !bStretched;
+            if (bStretched)
+                CheckMenuItem (hMenu, IDM_OPTIONS_STRETCH, MF_CHECKED);
+            else
+                CheckMenuItem (hMenu, IDM_OPTIONS_STRETCH, MF_UNCHECKED);
+
+            // invalidate the client area for later update
+
+            InvalidateRect (hwnd, NULL, TRUE);
+
+            // display the PNG into the DIBitmap
+
+            DisplayImage (hwnd, &pDib, &pDiData, cxWinSize, cyWinSize,
+                pbImage, cxImgSize, cyImgSize, cImgChannels, bStretched);
+
+            return 0;
+
+        case IDM_HELP_ABOUT:
+            DialogBox (hInstance, TEXT ("AboutBox"), hwnd, AboutDlgProc) ;
+            return 0;
+
+        } // end switch
+
+        break;
+
+    case WM_PAINT:
+        hdc = BeginPaint (hwnd, &ps);
+
+        if (pDib)
+            SetDIBitsToDevice (hdc, 0, 0, cxWinSize, cyWinSize, 0, 0,
+                0, cyWinSize, pDiData, (BITMAPINFO *) pDib, DIB_RGB_COLORS);
+
+        EndPaint (hwnd, &ps);
+        return 0;
+
+    case WM_DESTROY:
+        if (pbmfh)
+        {
+            free (pbmfh);
+            pbmfh = NULL;
+        }
+
+        PostQuitMessage (0);
+        return 0;
+    }
+
+    return DefWindowProc (hwnd, message, wParam, lParam);
+}
+
+BOOL CALLBACK AboutDlgProc (HWND hDlg, UINT message,
+                            WPARAM wParam, LPARAM lParam)
+{
+     switch (message)
+     {
+     case WM_INITDIALOG :
+          ShowWindow (hDlg, SW_HIDE);
+          CenterAbout (hDlg, GetWindow (hDlg, GW_OWNER));
+          ShowWindow (hDlg, SW_SHOW);
+          return TRUE ;
+
+     case WM_COMMAND :
+          switch (LOWORD (wParam))
+          {
+          case IDOK :
+          case IDCANCEL :
+               EndDialog (hDlg, 0) ;
+               return TRUE ;
+          }
+          break ;
+     }
+     return FALSE ;
+}
+
+//---------------
+//  CenterAbout
+//---------------
+
+BOOL CenterAbout (HWND hwndChild, HWND hwndParent)
+{
+   RECT    rChild, rParent, rWorkArea;
+   int     wChild, hChild, wParent, hParent;
+   int     xNew, yNew;
+   BOOL  bResult;
+
+   // Get the Height and Width of the child window
+   GetWindowRect (hwndChild, &rChild);
+   wChild = rChild.right - rChild.left;
+   hChild = rChild.bottom - rChild.top;
+
+   // Get the Height and Width of the parent window
+   GetWindowRect (hwndParent, &rParent);
+   wParent = rParent.right - rParent.left;
+   hParent = rParent.bottom - rParent.top;
+
+   // Get the limits of the 'workarea'
+   bResult = SystemParametersInfo(
+      SPI_GETWORKAREA,  // system parameter to query or set
+      sizeof(RECT),
+      &rWorkArea,
+      0);
+   if (!bResult) {
+      rWorkArea.left = rWorkArea.top = 0;
+      rWorkArea.right = GetSystemMetrics(SM_CXSCREEN);
+      rWorkArea.bottom = GetSystemMetrics(SM_CYSCREEN);
+   }
+
+   // Calculate new X position, then adjust for workarea
+   xNew = rParent.left + ((wParent - wChild) /2);
+   if (xNew < rWorkArea.left) {
+      xNew = rWorkArea.left;
+   } else if ((xNew+wChild) > rWorkArea.right) {
+      xNew = rWorkArea.right - wChild;
+   }
+
+   // Calculate new Y position, then adjust for workarea
+   yNew = rParent.top  + ((hParent - hChild) /2);
+   if (yNew < rWorkArea.top) {
+      yNew = rWorkArea.top;
+   } else if ((yNew+hChild) > rWorkArea.bottom) {
+      yNew = rWorkArea.bottom - hChild;
+   }
+
+   // Set it, and return
+   return SetWindowPos (hwndChild, NULL, xNew, yNew, 0, 0, SWP_NOSIZE |
+          SWP_NOZORDER);
+}
+
+//----------------
+//  BuildPngList
+//----------------
+
+BOOL BuildPngList (PTSTR pstrPathName, TCHAR **ppFileList, int *pFileCount,
+     int *pFileIndex)
+{
+    static TCHAR              szImgPathName [MAX_PATH];
+    static TCHAR              szImgFileName [MAX_PATH];
+    static TCHAR              szImgFindName [MAX_PATH];
+
+    WIN32_FIND_DATA           finddata;
+    HANDLE                    hFind;
+
+    static TCHAR              szTmp [MAX_PATH];
+    BOOL                      bOk;
+    int                       i, ii;
+    int                       j, jj;
+
+    // free previous file-list
+
+    if (*ppFileList != NULL)
+    {
+        free (*ppFileList);
+        *ppFileList = NULL;
+    }
+
+    // extract foldername, filename and search-name
+
+    strcpy (szImgPathName, pstrPathName);
+    strcpy (szImgFileName, strrchr (pstrPathName, '\\') + 1);
+
+    strcpy (szImgFindName, szImgPathName);
+    *(strrchr (szImgFindName, '\\') + 1) = '\0';
+    strcat (szImgFindName, "*.png");
+
+    // first cycle: count number of files in directory for memory allocation
+
+    *pFileCount = 0;
+
+    hFind = FindFirstFile(szImgFindName, &finddata);
+    bOk = (hFind != (HANDLE) -1);
+
+    while (bOk)
+    {
+        *pFileCount += 1;
+        bOk = FindNextFile(hFind, &finddata);
+    }
+    FindClose(hFind);
+
+    // allocation memory for file-list
+
+    *ppFileList = (TCHAR *) malloc (*pFileCount * MAX_PATH);
+
+    // second cycle: read directory and store filenames in file-list
+
+    hFind = FindFirstFile(szImgFindName, &finddata);
+    bOk = (hFind != (HANDLE) -1);
+
+    i = 0;
+    ii = 0;
+    while (bOk)
+    {
+        strcpy (*ppFileList + ii, szImgPathName);
+        strcpy (strrchr(*ppFileList + ii, '\\') + 1, finddata.cFileName);
+
+        if (strcmp(pstrPathName, *ppFileList + ii) == 0)
+            *pFileIndex = i;
+
+        ii += MAX_PATH;
+        i++;
+
+        bOk = FindNextFile(hFind, &finddata);
+    }
+    FindClose(hFind);
+
+    // finally we must sort the file-list
+
+    for (i = 0; i < *pFileCount - 1; i++)
+    {
+        ii = i * MAX_PATH;
+        for (j = i+1; j < *pFileCount; j++)
+        {
+            jj = j * MAX_PATH;
+            if (strcmp (*ppFileList + ii, *ppFileList + jj) > 0)
+            {
+                strcpy (szTmp, *ppFileList + jj);
+                strcpy (*ppFileList + jj, *ppFileList + ii);
+                strcpy (*ppFileList + ii, szTmp);
+
+                // check if this was the current image that we moved
+
+                if (*pFileIndex == i)
+                    *pFileIndex = j;
+                else
+                    if (*pFileIndex == j)
+                        *pFileIndex = i;
+            }
+        }
+    }
+
+    return TRUE;
+}
+
+//----------------
+//  SearchPngList
+//----------------
+
+BOOL SearchPngList (
+        TCHAR *pFileList, int FileCount, int *pFileIndex,
+        PTSTR pstrPrevName, PTSTR pstrNextName)
+{
+    if (FileCount > 0)
+    {
+        // get previous entry
+        
+        if (pstrPrevName != NULL)
+        {
+            if (*pFileIndex > 0)
+                *pFileIndex -= 1;
+            else
+                *pFileIndex = FileCount - 1;
+            
+            strcpy (pstrPrevName, pFileList + (*pFileIndex * MAX_PATH));
+        }
+        
+        // get next entry
+        
+        if (pstrNextName != NULL)
+        {
+            if (*pFileIndex < FileCount - 1)
+                *pFileIndex += 1;
+            else
+                *pFileIndex = 0;
+            
+            strcpy (pstrNextName, pFileList + (*pFileIndex * MAX_PATH));
+        }
+        
+        return TRUE;
+    }
+    else
+    {
+        return FALSE;
+    }
+}
+
+//-----------------
+//  LoadImageFile
+//-----------------
+
+BOOL LoadImageFile (HWND hwnd, PTSTR pstrPathName,
+                png_byte **ppbImage, int *pxImgSize, int *pyImgSize,
+                int *piChannels, png_color *pBkgColor)
+{
+    static TCHAR szTmp [MAX_PATH];
+
+    // if there's an existing PNG, free the memory
+
+    if (*ppbImage)
+    {
+        free (*ppbImage);
+        *ppbImage = NULL;
+    }
+
+    // Load the entire PNG into memory
+
+    SetCursor (LoadCursor (NULL, IDC_WAIT));
+    ShowCursor (TRUE);
+
+    PngLoadImage (pstrPathName, ppbImage, pxImgSize, pyImgSize, piChannels,
+                  pBkgColor);
+
+    ShowCursor (FALSE);
+    SetCursor (LoadCursor (NULL, IDC_ARROW));
+
+    if (*ppbImage != NULL)
+    {
+        sprintf (szTmp, "VisualPng - %s", strrchr(pstrPathName, '\\') + 1);
+        SetWindowText (hwnd, szTmp);
+    }
+    else
+    {
+        MessageBox (hwnd, TEXT ("Error in loading the PNG image"),
+            szProgName, MB_ICONEXCLAMATION | MB_OK);
+        return FALSE;
+    }
+
+    return TRUE;
+}
+
+//----------------
+//  DisplayImage
+//----------------
+
+BOOL DisplayImage (HWND hwnd, BYTE **ppDib,
+        BYTE **ppDiData, int cxWinSize, int cyWinSize,
+        BYTE *pbImage, int cxImgSize, int cyImgSize, int cImgChannels,
+        BOOL bStretched)
+{
+    BYTE                       *pDib = *ppDib;
+    BYTE                       *pDiData = *ppDiData;
+    // BITMAPFILEHEADER        *pbmfh;
+    BITMAPINFOHEADER           *pbmih;
+    WORD                        wDIRowBytes;
+    png_color                   bkgBlack = {0, 0, 0};
+    png_color                   bkgGray  = {127, 127, 127};
+    png_color                   bkgWhite = {255, 255, 255};
+
+    // allocate memory for the Device Independant bitmap
+
+    wDIRowBytes = (WORD) ((3 * cxWinSize + 3L) >> 2) << 2;
+
+    if (pDib)
+    {
+        free (pDib);
+        pDib = NULL;
+    }
+
+    if (!(pDib = (BYTE *) malloc (sizeof(BITMAPINFOHEADER) +
+        wDIRowBytes * cyWinSize)))
+    {
+        MessageBox (hwnd, TEXT ("Error in displaying the PNG image"),
+            szProgName, MB_ICONEXCLAMATION | MB_OK);
+        *ppDib = pDib = NULL;
+        return FALSE;
+    }
+    *ppDib = pDib;
+    memset (pDib, 0, sizeof(BITMAPINFOHEADER));
+
+    // initialize the dib-structure
+
+    pbmih = (BITMAPINFOHEADER *) pDib;
+    pbmih->biSize = sizeof(BITMAPINFOHEADER);
+    pbmih->biWidth = cxWinSize;
+    pbmih->biHeight = -((long) cyWinSize);
+    pbmih->biPlanes = 1;
+    pbmih->biBitCount = 24;
+    pbmih->biCompression = 0;
+    pDiData = pDib + sizeof(BITMAPINFOHEADER);
+    *ppDiData = pDiData;
+
+    // first fill bitmap with gray and image border
+
+    InitBitmap (pDiData, cxWinSize, cyWinSize);
+
+    // then fill bitmap with image
+
+    if (pbImage)
+    {
+        FillBitmap (
+            pDiData, cxWinSize, cyWinSize,
+            pbImage, cxImgSize, cyImgSize, cImgChannels,
+            bStretched);
+    }
+
+    return TRUE;
+}
+
+//--------------
+//  InitBitmap
+//--------------
+
+BOOL InitBitmap (BYTE *pDiData, int cxWinSize, int cyWinSize)
+{
+    BYTE *dst;
+    int x, y, col;
+
+    // initialize the background with gray
+
+    dst = pDiData;
+    for (y = 0; y < cyWinSize; y++)
+    {
+        col = 0;
+        for (x = 0; x < cxWinSize; x++)
+        {
+            // fill with GRAY
+            *dst++ = 127;
+            *dst++ = 127;
+            *dst++ = 127;
+            col += 3;
+        }
+        // rows start on 4 byte boundaries
+        while ((col % 4) != 0)
+        {
+            dst++;
+            col++;
+        }
+    }
+
+    return TRUE;
+}
+
+//--------------
+//  FillBitmap
+//--------------
+
+BOOL FillBitmap (
+        BYTE *pDiData, int cxWinSize, int cyWinSize,
+        BYTE *pbImage, int cxImgSize, int cyImgSize, int cImgChannels,
+        BOOL bStretched)
+{
+    BYTE *pStretchedImage;
+    BYTE *pImg;
+    BYTE *src, *dst;
+    BYTE r, g, b, a;
+    const int cDIChannels = 3;
+    WORD wImgRowBytes;
+    WORD wDIRowBytes;
+    int cxNewSize, cyNewSize;
+    int cxImgPos, cyImgPos;
+    int xImg, yImg;
+    int xWin, yWin;
+    int xOld, yOld;
+    int xNew, yNew;
+
+    if (bStretched)
+    {
+        cxNewSize = cxWinSize - 2 * MARGIN;
+        cyNewSize = cyWinSize - 2 * MARGIN;
+
+        // stretch the image to it's window determined size
+
+        // the following two are the same, but the first has side-effects
+        // because of rounding
+//      if ((cyNewSize / cxNewSize) > (cyImgSize / cxImgSize))
+        if ((cyNewSize * cxImgSize) > (cyImgSize * cxNewSize))
+        {
+            cyNewSize = cxNewSize * cyImgSize / cxImgSize;
+            cxImgPos = MARGIN;
+            cyImgPos = (cyWinSize - cyNewSize) / 2;
+        }
+        else
+        {
+            cxNewSize = cyNewSize * cxImgSize / cyImgSize;
+            cyImgPos = MARGIN;
+            cxImgPos = (cxWinSize - cxNewSize) / 2;
+        }
+
+        pStretchedImage = malloc (cImgChannels * cxNewSize * cyNewSize);
+        pImg = pStretchedImage;
+
+        for (yNew = 0; yNew < cyNewSize; yNew++)
+        {
+            yOld = yNew * cyImgSize / cyNewSize;
+            for (xNew = 0; xNew < cxNewSize; xNew++)
+            {
+                xOld = xNew * cxImgSize / cxNewSize;
+
+                r = *(pbImage + cImgChannels * ((yOld * cxImgSize) + xOld) + 0);
+                g = *(pbImage + cImgChannels * ((yOld * cxImgSize) + xOld) + 1);
+                b = *(pbImage + cImgChannels * ((yOld * cxImgSize) + xOld) + 2);
+                *pImg++ = r;
+                *pImg++ = g;
+                *pImg++ = b;
+                if (cImgChannels == 4)
+                {
+                    a = *(pbImage + cImgChannels * ((yOld * cxImgSize) + xOld)
+                        + 3);
+                    *pImg++ = a;
+                }
+            }
+        }
+
+        // calculate row-bytes
+
+        wImgRowBytes = cImgChannels * cxNewSize;
+        wDIRowBytes = (WORD) ((cDIChannels * cxWinSize + 3L) >> 2) << 2;
+
+        // copy image to screen
+
+        for (yImg = 0, yWin = cyImgPos; yImg < cyNewSize; yImg++, yWin++)
+        {
+            if (yWin >= cyWinSize - cyImgPos)
+                break;
+            src = pStretchedImage + yImg * wImgRowBytes;
+            dst = pDiData + yWin * wDIRowBytes + cxImgPos * cDIChannels;
+
+            for (xImg = 0, xWin = cxImgPos; xImg < cxNewSize; xImg++, xWin++)
+            {
+                if (xWin >= cxWinSize - cxImgPos)
+                    break;
+                r = *src++;
+                g = *src++;
+                b = *src++;
+                *dst++ = b; /* note the reverse order */
+                *dst++ = g;
+                *dst++ = r;
+                if (cImgChannels == 4)
+                {
+                    a = *src++;
+                }
+            }
+        }
+
+        // free memory
+
+        if (pStretchedImage != NULL)
+        {
+            free (pStretchedImage);
+            pStretchedImage = NULL;
+        }
+
+    }
+
+    // process the image not-stretched
+
+    else
+    {
+        // calculate the central position
+
+        cxImgPos = (cxWinSize - cxImgSize) / 2;
+        cyImgPos = (cyWinSize - cyImgSize) / 2;
+
+        // check for image larger than window
+
+        if (cxImgPos < MARGIN)
+            cxImgPos = MARGIN;
+        if (cyImgPos < MARGIN)
+            cyImgPos = MARGIN;
+
+        // calculate both row-bytes
+
+        wImgRowBytes = cImgChannels * cxImgSize;
+        wDIRowBytes = (WORD) ((cDIChannels * cxWinSize + 3L) >> 2) << 2;
+
+        // copy image to screen
+
+        for (yImg = 0, yWin = cyImgPos; yImg < cyImgSize; yImg++, yWin++)
+        {
+            if (yWin >= cyWinSize - MARGIN)
+                break;
+            src = pbImage + yImg * wImgRowBytes;
+            dst = pDiData + yWin * wDIRowBytes + cxImgPos * cDIChannels;
+
+            for (xImg = 0, xWin = cxImgPos; xImg < cxImgSize; xImg++, xWin++)
+            {
+                if (xWin >= cxWinSize - MARGIN)
+                    break;
+                r = *src++;
+                g = *src++;
+                b = *src++;
+                *dst++ = b; /* note the reverse order */
+                *dst++ = g;
+                *dst++ = r;
+                if (cImgChannels == 4)
+                {
+                    a = *src++;
+                }
+            }
+        }
+    }
+
+    return TRUE;
+}
+
+//-----------------
+//  end of source
+//-----------------

contrib/visupng/VisualPng.dsp

@@ -0,0 +1,147 @@
+# Microsoft Developer Studio Project File - Name="VisualPng" - Package Owner=<4>
+# Microsoft Developer Studio Generated Build File, Format Version 6.00
+# ** DO NOT EDIT **
+
+# TARGTYPE "Win32 (x86) Application" 0x0101
+
+CFG=VisualPng - Win32 Debug
+!MESSAGE This is not a valid makefile. To build this project using NMAKE,
+!MESSAGE use the Export Makefile command and run
+!MESSAGE 
+!MESSAGE NMAKE /f "VisualPng.mak".
+!MESSAGE 
+!MESSAGE You can specify a configuration when running NMAKE
+!MESSAGE by defining the macro CFG on the command line. For example:
+!MESSAGE 
+!MESSAGE NMAKE /f "VisualPng.mak" CFG="VisualPng - Win32 Debug"
+!MESSAGE 
+!MESSAGE Possible choices for configuration are:
+!MESSAGE 
+!MESSAGE "VisualPng - Win32 Release" (based on "Win32 (x86) Application")
+!MESSAGE "VisualPng - Win32 Debug" (based on "Win32 (x86) Application")
+!MESSAGE 
+
+# Begin Project
+# PROP AllowPerConfigDependencies 0
+# PROP Scc_ProjName ""
+# PROP Scc_LocalPath ""
+CPP=cl.exe
+MTL=midl.exe
+RSC=rc.exe
+
+!IF  "$(CFG)" == "VisualPng - Win32 Release"
+
+# PROP BASE Use_MFC 0
+# PROP BASE Use_Debug_Libraries 0
+# PROP BASE Output_Dir "Release"
+# PROP BASE Intermediate_Dir "Release"
+# PROP BASE Ignore_Export_Lib 0
+# PROP BASE Target_Dir ""
+# PROP Use_MFC 0
+# PROP Use_Debug_Libraries 0
+# PROP Output_Dir "Release"
+# PROP Intermediate_Dir "Release"
+# PROP Ignore_Export_Lib 0
+# PROP Target_Dir ""
+# ADD BASE CPP /nologo /W3 /O2 /I "..\.." /I "..\..\..\zlib" /D "WIN32" /D "NDEBUG" /D "PNG_NO_STDIO" /D "PNG_NO_GLOBAL_ARRAYS" /FD /c
+# SUBTRACT BASE CPP /YX
+# ADD CPP /nologo /MD /W3 /O2 /I "..\.." /I "..\..\..\zlib" /D "WIN32" /D "NDEBUG" /D "PNG_NO_STDIO" /D "PNG_NO_GLOBAL_ARRAYS" /FD /c
+# SUBTRACT CPP /YX
+# ADD BASE MTL /nologo /D "NDEBUG" /mktyplib203 /win32
+# ADD MTL /nologo /D "NDEBUG" /mktyplib203 /win32
+# ADD BASE RSC /l 0x409 /d "NDEBUG"
+# ADD RSC /l 0x409 /d "NDEBUG"
+BSC32=bscmake.exe
+# ADD BASE BSC32 /nologo
+# ADD BSC32 /nologo
+LINK32=link.exe
+# ADD BASE LINK32 kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /nologo /subsystem:windows /machine:I386
+# ADD LINK32 ..\..\projects\visualc6\Win32_LIB_Release\libpng.lib ..\..\..\zlib\projects\visualc6\Win32_LIB_Release\zlib.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /nologo /subsystem:windows /machine:I386
+# Begin Special Build Tool
+OutDir=.\Release
+SOURCE="$(InputPath)"
+PostBuild_Cmds=$(outdir)\VisualPng.exe ..\..\contrib\pngsuite\basn6a16.png
+# End Special Build Tool
+
+!ELSEIF  "$(CFG)" == "VisualPng - Win32 Debug"
+
+# PROP BASE Use_MFC 0
+# PROP BASE Use_Debug_Libraries 1
+# PROP BASE Output_Dir "Debug"
+# PROP BASE Intermediate_Dir "Debug"
+# PROP BASE Ignore_Export_Lib 0
+# PROP BASE Target_Dir ""
+# PROP Use_MFC 0
+# PROP Use_Debug_Libraries 1
+# PROP Output_Dir "Debug"
+# PROP Intermediate_Dir "Debug"
+# PROP Ignore_Export_Lib 0
+# PROP Target_Dir ""
+# ADD BASE CPP /nologo /W3 /Gm /ZI /Od /I "..\.." /I "..\..\..\zlib" /D "WIN32" /D "_DEBUG" /D "PNG_NO_STDIO" /D "PNG_NO_GLOBAL_ARRAYS" /FD /GZ /c
+# SUBTRACT BASE CPP /YX
+# ADD CPP /nologo /MDd /W3 /Gm /ZI /Od /I "..\.." /I "..\..\..\zlib" /D "WIN32" /D "_DEBUG" /D "PNG_NO_STDIO" /D "PNG_NO_GLOBAL_ARRAYS" /FD /GZ /c
+# SUBTRACT CPP /YX
+# ADD BASE MTL /nologo /D "_DEBUG" /mktyplib203 /win32
+# ADD MTL /nologo /D "_DEBUG" /mktyplib203 /win32
+# ADD BASE RSC /l 0x409 /d "_DEBUG"
+# ADD RSC /l 0x409 /d "_DEBUG"
+BSC32=bscmake.exe
+# ADD BASE BSC32 /nologo
+# ADD BSC32 /nologo
+LINK32=link.exe
+# ADD BASE LINK32 kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /nologo /subsystem:windows /debug /machine:I386 /pdbtype:sept
+# ADD LINK32 ..\..\projects\visualc6\Win32_LIB_Release\libpng.lib ..\..\..\zlib\projects\visualc6\Win32_LIB_Release\zlib.lib kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib uuid.lib odbc32.lib odbccp32.lib /nologo /subsystem:windows /debug /machine:I386 /nodefaultlib:"msvcrt.lib" /pdbtype:sept
+# Begin Special Build Tool
+OutDir=.\Debug
+SOURCE="$(InputPath)"
+PostBuild_Cmds=$(outdir)\VisualPng.exe ..\..\contrib\pngsuite\basn6a16.png
+# End Special Build Tool
+
+!ENDIF 
+
+# Begin Target
+
+# Name "VisualPng - Win32 Release"
+# Name "VisualPng - Win32 Debug"
+# Begin Group "Source Files"
+
+# PROP Default_Filter "cpp;c;cxx;rc;def;r;odl;idl;hpj;bat"
+# Begin Source File
+
+SOURCE=.\PngFile.c
+# End Source File
+# Begin Source File
+
+SOURCE=.\VisualPng.c
+# End Source File
+# End Group
+# Begin Group "Header Files"
+
+# PROP Default_Filter "h;hpp;hxx;hm;inl"
+# Begin Source File
+
+SOURCE=.\cexcept.h
+# End Source File
+# Begin Source File
+
+SOURCE=.\PngFile.h
+# End Source File
+# Begin Source File
+
+SOURCE=.\resource.h
+# End Source File
+# End Group
+# Begin Group "Resource Files"
+
+# PROP Default_Filter "ico;cur;bmp;dlg;rc2;rct;bin;rgs;gif;jpg;jpeg;jpe"
+# Begin Source File
+
+SOURCE=.\VisualPng.ico
+# End Source File
+# Begin Source File
+
+SOURCE=.\VisualPng.rc
+# End Source File
+# End Group
+# End Target
+# End Project

contrib/visupng/VisualPng.dsw

@@ -0,0 +1,29 @@
+Microsoft Developer Studio Workspace File, Format Version 6.00
+# WARNING: DO NOT EDIT OR DELETE THIS WORKSPACE FILE!
+
+###############################################################################
+
+Project: "VisualPng"=.\VisualPng.dsp - Package Owner=<4>
+
+Package=<5>
+{{{
+}}}
+
+Package=<4>
+{{{
+}}}
+
+###############################################################################
+
+Global:
+
+Package=<5>
+{{{
+}}}
+
+Package=<3>
+{{{
+}}}
+
+###############################################################################
+

contrib/visupng/VisualPng.rc

@@ -0,0 +1,152 @@
+//Microsoft Developer Studio generated resource script.
+//
+#include "resource.h"
+
+#define APSTUDIO_READONLY_SYMBOLS
+/////////////////////////////////////////////////////////////////////////////
+//
+// Generated from the TEXTINCLUDE 2 resource.
+//
+#include "afxres.h"
+
+/////////////////////////////////////////////////////////////////////////////
+#undef APSTUDIO_READONLY_SYMBOLS
+
+/////////////////////////////////////////////////////////////////////////////
+// English (U.S.) resources
+
+#if !defined(AFX_RESOURCE_DLL) || defined(AFX_TARG_ENU)
+#ifdef _WIN32
+LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US
+#pragma code_page(1252)
+#endif //_WIN32
+
+#ifdef APSTUDIO_INVOKED
+/////////////////////////////////////////////////////////////////////////////
+//
+// TEXTINCLUDE
+//
+
+1 TEXTINCLUDE DISCARDABLE 
+BEGIN
+    "resource.h\0"
+END
+
+2 TEXTINCLUDE DISCARDABLE 
+BEGIN
+    "#include ""afxres.h""\r\n"
+    "\0"
+END
+
+3 TEXTINCLUDE DISCARDABLE 
+BEGIN
+    "\r\n"
+    "\0"
+END
+
+#endif    // APSTUDIO_INVOKED
+
+
+/////////////////////////////////////////////////////////////////////////////
+//
+// Menu
+//
+
+VISUALPNG MENU DISCARDABLE 
+BEGIN
+    POPUP "&File"
+    BEGIN
+        MENUITEM "&Open Image...\tCtrl+O",      IDM_FILE_OPEN
+        MENUITEM "Save &As...",                 IDM_FILE_SAVE
+        MENUITEM SEPARATOR
+        MENUITEM "&Next Image\tCtrl+N",         IDM_FILE_NEXT
+        MENUITEM "Pre&vious Image\tCtrl+V",     IDM_FILE_PREVIOUS
+        MENUITEM SEPARATOR
+        MENUITEM "E&xit\tAlt+X",                IDM_FILE_EXIT
+    END
+    POPUP "&Options"
+    BEGIN
+        MENUITEM "&Stretch",                    IDM_OPTIONS_STRETCH, CHECKED
+    END
+    POPUP "&Help"
+    BEGIN
+        MENUITEM "&About",                      IDM_HELP_ABOUT
+    END
+END
+
+
+/////////////////////////////////////////////////////////////////////////////
+//
+// Accelerator
+//
+
+VISUALPNG ACCELERATORS DISCARDABLE 
+BEGIN
+    "N",            IDM_FILE_NEXT,          VIRTKEY, CONTROL, NOINVERT
+    "O",            IDM_FILE_OPEN,          VIRTKEY, CONTROL, NOINVERT
+    "P",            IDM_FILE_PREVIOUS,      VIRTKEY, CONTROL, NOINVERT
+    "V",            IDM_FILE_PREVIOUS,      VIRTKEY, CONTROL, NOINVERT
+    "X",            IDM_FILE_EXIT,          VIRTKEY, ALT, NOINVERT
+END
+
+
+/////////////////////////////////////////////////////////////////////////////
+//
+// Icon
+//
+
+// Icon with lowest ID value placed first to ensure application icon
+// remains consistent on all systems.
+VISUALPNG               ICON    DISCARDABLE     "VisualPng.ico"
+
+/////////////////////////////////////////////////////////////////////////////
+//
+// Dialog
+//
+
+ABOUTBOX DIALOG DISCARDABLE  0, 0, 186, 94
+STYLE DS_MODALFRAME | WS_POPUP
+FONT 8, "MS Sans Serif"
+BEGIN
+    DEFPUSHBUTTON   "OK",IDOK,68,67,50,14
+    CTEXT           "VisualPng 1.0  -  June 2000",IDC_STATIC,49,14,88,8
+    LTEXT           "a PNG image viewer",IDC_STATIC,60,30,66,8
+    LTEXT           "(c) Willem van Schaik, 2000",IDC_STATIC,48,52,90,8
+    LTEXT           "to demonstrate the use of libpng in Visual C",
+                    IDC_STATIC,25,38,136,8
+END
+
+
+/////////////////////////////////////////////////////////////////////////////
+//
+// DESIGNINFO
+//
+
+#ifdef APSTUDIO_INVOKED
+GUIDELINES DESIGNINFO DISCARDABLE 
+BEGIN
+    "ABOUTBOX", DIALOG
+    BEGIN
+        LEFTMARGIN, 7
+        RIGHTMARGIN, 179
+        TOPMARGIN, 7
+        BOTTOMMARGIN, 87
+    END
+END
+#endif    // APSTUDIO_INVOKED
+
+#endif    // English (U.S.) resources
+/////////////////////////////////////////////////////////////////////////////
+
+
+
+#ifndef APSTUDIO_INVOKED
+/////////////////////////////////////////////////////////////////////////////
+//
+// Generated from the TEXTINCLUDE 3 resource.
+//
+
+
+/////////////////////////////////////////////////////////////////////////////
+#endif    // not APSTUDIO_INVOKED
+

contrib/visupng/cexcept.h

@@ -0,0 +1,248 @@
+/*===
+cexcept.h 2.0.1 (2008-Jul-19-Sat)
+http://www.nicemice.net/cexcept/
+Adam M. Costello
+http://www.nicemice.net/amc/
+
+An interface for exception-handling in ANSI C (C89 and subsequent ISO
+standards), developed jointly with Cosmin Truta.
+
+    Copyright (c) 2000-2008 Adam M. Costello and Cosmin Truta.
+    This software may be modified only if its author and version
+    information is updated accurately, and may be redistributed
+    only if accompanied by this unaltered notice.  Subject to those
+    restrictions, permission is granted to anyone to do anything
+    with this software.  The copyright holders make no guarantees
+    regarding this software, and are not responsible for any damage
+    resulting from its use.
+
+The cexcept interface is not compatible with and cannot interact
+with system exceptions (like division by zero or memory segmentation
+violation), compiler-generated exceptions (like C++ exceptions), or
+other exception-handling interfaces.
+
+When using this interface across multiple .c files, do not include
+this header file directly.  Instead, create a wrapper header file that
+includes this header file and then invokes the define_exception_type
+macro (see below).  The .c files should then include that header file.
+
+The interface consists of one type, one well-known name, and six macros.
+
+
+define_exception_type(type_name);
+
+    This macro is used like an external declaration.  It specifies
+    the type of object that gets copied from the exception thrower to
+    the exception catcher.  The type_name can be any type that can be
+    assigned to, that is, a non-constant arithmetic type, struct, union,
+    or pointer.  Examples:
+
+        define_exception_type(int);
+
+        enum exception { out_of_memory, bad_arguments, disk_full };
+        define_exception_type(enum exception);
+
+        struct exception { int code; const char *msg; };
+        define_exception_type(struct exception);
+
+    Because throwing an exception causes the object to be copied (not
+    just once, but twice), programmers may wish to consider size when
+    choosing the exception type.
+
+
+struct exception_context;
+
+    This type may be used after the define_exception_type() macro has
+    been invoked.  A struct exception_context must be known to both
+    the thrower and the catcher.  It is expected that there be one
+    context for each thread that uses exceptions.  It would certainly
+    be dangerous for multiple threads to access the same context.
+    One thread can use multiple contexts, but that is likely to be
+    confusing and not typically useful.  The application can allocate
+    this structure in any way it pleases--automatic, static, or dynamic.
+    The application programmer should pretend not to know the structure
+    members, which are subject to change.
+
+
+struct exception_context *the_exception_context;
+
+    The Try/Catch and Throw statements (described below) implicitly
+    refer to a context, using the name the_exception_context.  It is
+    the application's responsibility to make sure that this name yields
+    the address of a mutable (non-constant) struct exception_context
+    wherever those statements are used.  Subject to that constraint, the
+    application may declare a variable of this name anywhere it likes
+    (inside a function, in a parameter list, or externally), and may
+    use whatever storage class specifiers (static, extern, etc) or type
+    qualifiers (const, volatile, etc) it likes.  Examples:
+
+        static struct exception_context
+          * const the_exception_context = &foo;
+
+        { struct exception_context *the_exception_context = bar; ... }
+
+        int blah(struct exception_context *the_exception_context, ...);
+
+        extern struct exception_context the_exception_context[1];
+
+    The last example illustrates a trick that avoids creating a pointer
+    object separate from the structure object.
+
+    The name could even be a macro, for example:
+
+        struct exception_context ec_array[numthreads];
+        #define the_exception_context (ec_array + thread_id)
+
+    Be aware that the_exception_context is used several times by the
+    Try/Catch/Throw macros, so it shouldn't be expensive or have side
+    effects.  The expansion must be a drop-in replacement for an
+    identifier, so it's safest to put parentheses around it.
+
+
+void init_exception_context(struct exception_context *ec);
+
+    For context structures allocated statically (by an external
+    definition or using the "static" keyword), the implicit
+    initialization to all zeros is sufficient, but contexts allocated
+    by other means must be initialized using this macro before they
+    are used by a Try/Catch statement.  It does no harm to initialize
+    a context more than once (by using this macro on a statically
+    allocated context, or using this macro twice on the same context),
+    but a context must not be re-initialized after it has been used by a
+    Try/Catch statement.
+
+
+Try statement
+Catch (expression) statement
+
+    The Try/Catch/Throw macros are capitalized in order to avoid
+    confusion with the C++ keywords, which have subtly different
+    semantics.
+
+    A Try/Catch statement has a syntax similar to an if/else statement,
+    except that the parenthesized expression goes after the second
+    keyword rather than the first.  As with if/else, there are two
+    clauses, each of which may be a simple statement ending with a
+    semicolon or a brace-enclosed compound statement.  But whereas
+    the else clause is optional, the Catch clause is required.  The
+    expression must be a modifiable lvalue (something capable of being
+    assigned to) of the same type (disregarding type qualifiers) that
+    was passed to define_exception_type().
+
+    If a Throw that uses the same exception context as the Try/Catch is
+    executed within the Try clause (typically within a function called
+    by the Try clause), and the exception is not caught by a nested
+    Try/Catch statement, then a copy of the exception will be assigned
+    to the expression, and control will jump to the Catch clause.  If no
+    such Throw is executed, then the assignment is not performed, and
+    the Catch clause is not executed.
+
+    The expression is not evaluated unless and until the exception is
+    caught, which is significant if it has side effects, for example:
+
+        Try foo();
+        Catch (p[++i].e) { ... }
+
+    IMPORTANT: Jumping into or out of a Try clause (for example via
+    return, break, continue, goto, longjmp) is forbidden--the compiler
+    will not complain, but bad things will happen at run-time.  Jumping
+    into or out of a Catch clause is okay, and so is jumping around
+    inside a Try clause.  In many cases where one is tempted to return
+    from a Try clause, it will suffice to use Throw, and then return
+    from the Catch clause.  Another option is to set a flag variable and
+    use goto to jump to the end of the Try clause, then check the flag
+    after the Try/Catch statement.
+
+    IMPORTANT: The values of any non-volatile automatic variables
+    changed within the Try clause are undefined after an exception is
+    caught.  Therefore, variables modified inside the Try block whose
+    values are needed later outside the Try block must either use static
+    storage or be declared with the "volatile" type qualifier.
+
+
+Throw expression;
+
+    A Throw statement is very much like a return statement, except that
+    the expression is required.  Whereas return jumps back to the place
+    where the current function was called, Throw jumps back to the Catch
+    clause of the innermost enclosing Try clause.  The expression must
+    be compatible with the type passed to define_exception_type().  The
+    exception must be caught, otherwise the program may crash.
+
+    Slight limitation:  If the expression is a comma-expression, it must
+    be enclosed in parentheses.
+
+
+Try statement
+Catch_anonymous statement
+
+    When the value of the exception is not needed, a Try/Catch statement
+    can use Catch_anonymous instead of Catch (expression).
+
+
+Everything below this point is for the benefit of the compiler.  The
+application programmer should pretend not to know any of it, because it
+is subject to change.
+
+===*/
+
+
+#ifndef CEXCEPT_H
+#define CEXCEPT_H
+
+
+#include <setjmp.h>
+
+#define define_exception_type(etype) \
+struct exception_context { \
+  jmp_buf *penv; \
+  int caught; \
+  volatile struct { etype etmp; } v; \
+}
+
+/* etmp must be volatile because the application might use automatic */
+/* storage for the_exception_context, and etmp is modified between   */
+/* the calls to setjmp() and longjmp().  A wrapper struct is used to */
+/* avoid warnings about a duplicate volatile qualifier in case etype */
+/* already includes it.                                              */
+
+#define init_exception_context(ec) ((void)((ec)->penv = 0))
+
+#define Try \
+  { \
+    jmp_buf *exception__prev, exception__env; \
+    exception__prev = the_exception_context->penv; \
+    the_exception_context->penv = &exception__env; \
+    if (setjmp(exception__env) == 0) { \
+      do
+
+#define exception__catch(action) \
+      while (the_exception_context->caught = 0, \
+             the_exception_context->caught); \
+    } \
+    else { \
+      the_exception_context->caught = 1; \
+    } \
+    the_exception_context->penv = exception__prev; \
+  } \
+  if (!the_exception_context->caught || action) { } \
+  else
+
+#define Catch(e) exception__catch(((e) = the_exception_context->v.etmp, 0))
+#define Catch_anonymous exception__catch(0)
+
+/* Try ends with do, and Catch begins with while(0) and ends with     */
+/* else, to ensure that Try/Catch syntax is similar to if/else        */
+/* syntax.                                                            */
+/*                                                                    */
+/* The 0 in while(0) is expressed as x=0,x in order to appease        */
+/* compilers that warn about constant expressions inside while().     */
+/* Most compilers should still recognize that the condition is always */
+/* false and avoid generating code for it.                            */
+
+#define Throw \
+  for (;; longjmp(*the_exception_context->penv, 1)) \
+    the_exception_context->v.etmp =
+
+
+#endif /* CEXCEPT_H */

contrib/visupng/resource.h

@@ -0,0 +1,23 @@
+//{{NO_DEPENDENCIES}}
+// Microsoft Developer Studio generated include file.
+// Used by VisualPng.rc
+//
+#define IDM_FILE_OPEN                   40001
+#define IDM_FILE_SAVE                   40002
+#define IDM_FILE_NEXT                   40003
+#define IDM_FILE_PREVIOUS               40004
+#define IDM_FILE_EXIT                   40005
+#define IDM_OPTIONS_BACKGROUND          40006
+#define IDM_OPTIONS_STRETCH             40007
+#define IDM_HELP_ABOUT                  40008
+
+// Next default values for new objects
+// 
+#ifdef APSTUDIO_INVOKED
+#ifndef APSTUDIO_READONLY_SYMBOLS
+#define _APS_NEXT_RESOURCE_VALUE        113
+#define _APS_NEXT_COMMAND_VALUE         40009
+#define _APS_NEXT_CONTROL_VALUE         1001
+#define _APS_NEXT_SYMED_VALUE           101
+#endif
+#endif

depcomp

@@ -0,0 +1,589 @@
+#! /bin/sh
+# depcomp - compile a program generating dependencies as side-effects
+
+scriptversion=2007-03-29.01
+
+# Copyright (C) 1999, 2000, 2003, 2004, 2005, 2006, 2007 Free Software
+# Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+# 02110-1301, USA.
+
+# As a special exception to the GNU General Public License, if you
+# distribute this file as part of a program that contains a
+# configuration script generated by Autoconf, you may include it under
+# the same distribution terms that you use for the rest of that program.
+
+# Originally written by Alexandre Oliva <oliva@dcc.unicamp.br>.
+
+case $1 in
+  '')
+     echo "$0: No command.  Try \`$0 --help' for more information." 1>&2
+     exit 1;
+     ;;
+  -h | --h*)
+    cat <<\EOF
+Usage: depcomp [--help] [--version] PROGRAM [ARGS]
+
+Run PROGRAMS ARGS to compile a file, generating dependencies
+as side-effects.
+
+Environment variables:
+  depmode     Dependency tracking mode.
+  source      Source file read by `PROGRAMS ARGS'.
+  object      Object file output by `PROGRAMS ARGS'.
+  DEPDIR      directory where to store dependencies.
+  depfile     Dependency file to output.
+  tmpdepfile  Temporary file to use when outputing dependencies.
+  libtool     Whether libtool is used (yes/no).
+
+Report bugs to <bug-automake@gnu.org>.
+EOF
+    exit $?
+    ;;
+  -v | --v*)
+    echo "depcomp $scriptversion"
+    exit $?
+    ;;
+esac
+
+if test -z "$depmode" || test -z "$source" || test -z "$object"; then
+  echo "depcomp: Variables source, object and depmode must be set" 1>&2
+  exit 1
+fi
+
+# Dependencies for sub/bar.o or sub/bar.obj go into sub/.deps/bar.Po.
+depfile=${depfile-`echo "$object" |
+  sed 's|[^\\/]*$|'${DEPDIR-.deps}'/&|;s|\.\([^.]*\)$|.P\1|;s|Pobj$|Po|'`}
+tmpdepfile=${tmpdepfile-`echo "$depfile" | sed 's/\.\([^.]*\)$/.T\1/'`}
+
+rm -f "$tmpdepfile"
+
+# Some modes work just like other modes, but use different flags.  We
+# parameterize here, but still list the modes in the big case below,
+# to make depend.m4 easier to write.  Note that we *cannot* use a case
+# here, because this file can only contain one case statement.
+if test "$depmode" = hp; then
+  # HP compiler uses -M and no extra arg.
+  gccflag=-M
+  depmode=gcc
+fi
+
+if test "$depmode" = dashXmstdout; then
+   # This is just like dashmstdout with a different argument.
+   dashmflag=-xM
+   depmode=dashmstdout
+fi
+
+case "$depmode" in
+gcc3)
+## gcc 3 implements dependency tracking that does exactly what
+## we want.  Yay!  Note: for some reason libtool 1.4 doesn't like
+## it if -MD -MP comes after the -MF stuff.  Hmm.
+## Unfortunately, FreeBSD c89 acceptance of flags depends upon
+## the command line argument order; so add the flags where they
+## appear in depend2.am.  Note that the slowdown incurred here
+## affects only configure: in makefiles, %FASTDEP% shortcuts this.
+  for arg
+  do
+    case $arg in
+    -c) set fnord "$@" -MT "$object" -MD -MP -MF "$tmpdepfile" "$arg" ;;
+    *)  set fnord "$@" "$arg" ;;
+    esac
+    shift # fnord
+    shift # $arg
+  done
+  "$@"
+  stat=$?
+  if test $stat -eq 0; then :
+  else
+    rm -f "$tmpdepfile"
+    exit $stat
+  fi
+  mv "$tmpdepfile" "$depfile"
+  ;;
+
+gcc)
+## There are various ways to get dependency output from gcc.  Here's
+## why we pick this rather obscure method:
+## - Don't want to use -MD because we'd like the dependencies to end
+##   up in a subdir.  Having to rename by hand is ugly.
+##   (We might end up doing this anyway to support other compilers.)
+## - The DEPENDENCIES_OUTPUT environment variable makes gcc act like
+##   -MM, not -M (despite what the docs say).
+## - Using -M directly means running the compiler twice (even worse
+##   than renaming).
+  if test -z "$gccflag"; then
+    gccflag=-MD,
+  fi
+  "$@" -Wp,"$gccflag$tmpdepfile"
+  stat=$?
+  if test $stat -eq 0; then :
+  else
+    rm -f "$tmpdepfile"
+    exit $stat
+  fi
+  rm -f "$depfile"
+  echo "$object : \\" > "$depfile"
+  alpha=ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz
+## The second -e expression handles DOS-style file names with drive letters.
+  sed -e 's/^[^:]*: / /' \
+      -e 's/^['$alpha']:\/[^:]*: / /' < "$tmpdepfile" >> "$depfile"
+## This next piece of magic avoids the `deleted header file' problem.
+## The problem is that when a header file which appears in a .P file
+## is deleted, the dependency causes make to die (because there is
+## typically no way to rebuild the header).  We avoid this by adding
+## dummy dependencies for each header file.  Too bad gcc doesn't do
+## this for us directly.
+  tr ' ' '
+' < "$tmpdepfile" |
+## Some versions of gcc put a space before the `:'.  On the theory
+## that the space means something, we add a space to the output as
+## well.
+## Some versions of the HPUX 10.20 sed can't process this invocation
+## correctly.  Breaking it into two sed invocations is a workaround.
+    sed -e 's/^\\$//' -e '/^$/d' -e '/:$/d' | sed -e 's/$/ :/' >> "$depfile"
+  rm -f "$tmpdepfile"
+  ;;
+
+hp)
+  # This case exists only to let depend.m4 do its work.  It works by
+  # looking at the text of this script.  This case will never be run,
+  # since it is checked for above.
+  exit 1
+  ;;
+
+sgi)
+  if test "$libtool" = yes; then
+    "$@" "-Wp,-MDupdate,$tmpdepfile"
+  else
+    "$@" -MDupdate "$tmpdepfile"
+  fi
+  stat=$?
+  if test $stat -eq 0; then :
+  else
+    rm -f "$tmpdepfile"
+    exit $stat
+  fi
+  rm -f "$depfile"
+
+  if test -f "$tmpdepfile"; then  # yes, the sourcefile depend on other files
+    echo "$object : \\" > "$depfile"
+
+    # Clip off the initial element (the dependent).  Don't try to be
+    # clever and replace this with sed code, as IRIX sed won't handle
+    # lines with more than a fixed number of characters (4096 in
+    # IRIX 6.2 sed, 8192 in IRIX 6.5).  We also remove comment lines;
+    # the IRIX cc adds comments like `#:fec' to the end of the
+    # dependency line.
+    tr ' ' '
+' < "$tmpdepfile" \
+    | sed -e 's/^.*\.o://' -e 's/#.*$//' -e '/^$/ d' | \
+    tr '
+' ' ' >> $depfile
+    echo >> $depfile
+
+    # The second pass generates a dummy entry for each header file.
+    tr ' ' '
+' < "$tmpdepfile" \
+   | sed -e 's/^.*\.o://' -e 's/#.*$//' -e '/^$/ d' -e 's/$/:/' \
+   >> $depfile
+  else
+    # The sourcefile does not contain any dependencies, so just
+    # store a dummy comment line, to avoid errors with the Makefile
+    # "include basename.Plo" scheme.
+    echo "#dummy" > "$depfile"
+  fi
+  rm -f "$tmpdepfile"
+  ;;
+
+aix)
+  # The C for AIX Compiler uses -M and outputs the dependencies
+  # in a .u file.  In older versions, this file always lives in the
+  # current directory.  Also, the AIX compiler puts `$object:' at the
+  # start of each line; $object doesn't have directory information.
+  # Version 6 uses the directory in both cases.
+  dir=`echo "$object" | sed -e 's|/[^/]*$|/|'`
+  test "x$dir" = "x$object" && dir=
+  base=`echo "$object" | sed -e 's|^.*/||' -e 's/\.o$//' -e 's/\.lo$//'`
+  if test "$libtool" = yes; then
+    tmpdepfile1=$dir$base.u
+    tmpdepfile2=$base.u
+    tmpdepfile3=$dir.libs/$base.u
+    "$@" -Wc,-M
+  else
+    tmpdepfile1=$dir$base.u
+    tmpdepfile2=$dir$base.u
+    tmpdepfile3=$dir$base.u
+    "$@" -M
+  fi
+  stat=$?
+
+  if test $stat -eq 0; then :
+  else
+    rm -f "$tmpdepfile1" "$tmpdepfile2" "$tmpdepfile3"
+    exit $stat
+  fi
+
+  for tmpdepfile in "$tmpdepfile1" "$tmpdepfile2" "$tmpdepfile3"
+  do
+    test -f "$tmpdepfile" && break
+  done
+  if test -f "$tmpdepfile"; then
+    # Each line is of the form `foo.o: dependent.h'.
+    # Do two passes, one to just change these to
+    # `$object: dependent.h' and one to simply `dependent.h:'.
+    sed -e "s,^.*\.[a-z]*:,$object:," < "$tmpdepfile" > "$depfile"
+    # That's a tab and a space in the [].
+    sed -e 's,^.*\.[a-z]*:[	 ]*,,' -e 's,$,:,' < "$tmpdepfile" >> "$depfile"
+  else
+    # The sourcefile does not contain any dependencies, so just
+    # store a dummy comment line, to avoid errors with the Makefile
+    # "include basename.Plo" scheme.
+    echo "#dummy" > "$depfile"
+  fi
+  rm -f "$tmpdepfile"
+  ;;
+
+icc)
+  # Intel's C compiler understands `-MD -MF file'.  However on
+  #    icc -MD -MF foo.d -c -o sub/foo.o sub/foo.c
+  # ICC 7.0 will fill foo.d with something like
+  #    foo.o: sub/foo.c
+  #    foo.o: sub/foo.h
+  # which is wrong.  We want:
+  #    sub/foo.o: sub/foo.c
+  #    sub/foo.o: sub/foo.h
+  #    sub/foo.c:
+  #    sub/foo.h:
+  # ICC 7.1 will output
+  #    foo.o: sub/foo.c sub/foo.h
+  # and will wrap long lines using \ :
+  #    foo.o: sub/foo.c ... \
+  #     sub/foo.h ... \
+  #     ...
+
+  "$@" -MD -MF "$tmpdepfile"
+  stat=$?
+  if test $stat -eq 0; then :
+  else
+    rm -f "$tmpdepfile"
+    exit $stat
+  fi
+  rm -f "$depfile"
+  # Each line is of the form `foo.o: dependent.h',
+  # or `foo.o: dep1.h dep2.h \', or ` dep3.h dep4.h \'.
+  # Do two passes, one to just change these to
+  # `$object: dependent.h' and one to simply `dependent.h:'.
+  sed "s,^[^:]*:,$object :," < "$tmpdepfile" > "$depfile"
+  # Some versions of the HPUX 10.20 sed can't process this invocation
+  # correctly.  Breaking it into two sed invocations is a workaround.
+  sed 's,^[^:]*: \(.*\)$,\1,;s/^\\$//;/^$/d;/:$/d' < "$tmpdepfile" |
+    sed -e 's/$/ :/' >> "$depfile"
+  rm -f "$tmpdepfile"
+  ;;
+
+hp2)
+  # The "hp" stanza above does not work with aCC (C++) and HP's ia64
+  # compilers, which have integrated preprocessors.  The correct option
+  # to use with these is +Maked; it writes dependencies to a file named
+  # 'foo.d', which lands next to the object file, wherever that
+  # happens to be.
+  # Much of this is similar to the tru64 case; see comments there.
+  dir=`echo "$object" | sed -e 's|/[^/]*$|/|'`
+  test "x$dir" = "x$object" && dir=
+  base=`echo "$object" | sed -e 's|^.*/||' -e 's/\.o$//' -e 's/\.lo$//'`
+  if test "$libtool" = yes; then
+    tmpdepfile1=$dir$base.d
+    tmpdepfile2=$dir.libs/$base.d
+    "$@" -Wc,+Maked
+  else
+    tmpdepfile1=$dir$base.d
+    tmpdepfile2=$dir$base.d
+    "$@" +Maked
+  fi
+  stat=$?
+  if test $stat -eq 0; then :
+  else
+     rm -f "$tmpdepfile1" "$tmpdepfile2"
+     exit $stat
+  fi
+
+  for tmpdepfile in "$tmpdepfile1" "$tmpdepfile2"
+  do
+    test -f "$tmpdepfile" && break
+  done
+  if test -f "$tmpdepfile"; then
+    sed -e "s,^.*\.[a-z]*:,$object:," "$tmpdepfile" > "$depfile"
+    # Add `dependent.h:' lines.
+    sed -ne '2,${; s/^ *//; s/ \\*$//; s/$/:/; p;}' "$tmpdepfile" >> "$depfile"
+  else
+    echo "#dummy" > "$depfile"
+  fi
+  rm -f "$tmpdepfile" "$tmpdepfile2"
+  ;;
+
+tru64)
+   # The Tru64 compiler uses -MD to generate dependencies as a side
+   # effect.  `cc -MD -o foo.o ...' puts the dependencies into `foo.o.d'.
+   # At least on Alpha/Redhat 6.1, Compaq CCC V6.2-504 seems to put
+   # dependencies in `foo.d' instead, so we check for that too.
+   # Subdirectories are respected.
+   dir=`echo "$object" | sed -e 's|/[^/]*$|/|'`
+   test "x$dir" = "x$object" && dir=
+   base=`echo "$object" | sed -e 's|^.*/||' -e 's/\.o$//' -e 's/\.lo$//'`
+
+   if test "$libtool" = yes; then
+      # With Tru64 cc, shared objects can also be used to make a
+      # static library.  This mechanism is used in libtool 1.4 series to
+      # handle both shared and static libraries in a single compilation.
+      # With libtool 1.4, dependencies were output in $dir.libs/$base.lo.d.
+      #
+      # With libtool 1.5 this exception was removed, and libtool now
+      # generates 2 separate objects for the 2 libraries.  These two
+      # compilations output dependencies in $dir.libs/$base.o.d and
+      # in $dir$base.o.d.  We have to check for both files, because
+      # one of the two compilations can be disabled.  We should prefer
+      # $dir$base.o.d over $dir.libs/$base.o.d because the latter is
+      # automatically cleaned when .libs/ is deleted, while ignoring
+      # the former would cause a distcleancheck panic.
+      tmpdepfile1=$dir.libs/$base.lo.d   # libtool 1.4
+      tmpdepfile2=$dir$base.o.d          # libtool 1.5
+      tmpdepfile3=$dir.libs/$base.o.d    # libtool 1.5
+      tmpdepfile4=$dir.libs/$base.d      # Compaq CCC V6.2-504
+      "$@" -Wc,-MD
+   else
+      tmpdepfile1=$dir$base.o.d
+      tmpdepfile2=$dir$base.d
+      tmpdepfile3=$dir$base.d
+      tmpdepfile4=$dir$base.d
+      "$@" -MD
+   fi
+
+   stat=$?
+   if test $stat -eq 0; then :
+   else
+      rm -f "$tmpdepfile1" "$tmpdepfile2" "$tmpdepfile3" "$tmpdepfile4"
+      exit $stat
+   fi
+
+   for tmpdepfile in "$tmpdepfile1" "$tmpdepfile2" "$tmpdepfile3" "$tmpdepfile4"
+   do
+     test -f "$tmpdepfile" && break
+   done
+   if test -f "$tmpdepfile"; then
+      sed -e "s,^.*\.[a-z]*:,$object:," < "$tmpdepfile" > "$depfile"
+      # That's a tab and a space in the [].
+      sed -e 's,^.*\.[a-z]*:[	 ]*,,' -e 's,$,:,' < "$tmpdepfile" >> "$depfile"
+   else
+      echo "#dummy" > "$depfile"
+   fi
+   rm -f "$tmpdepfile"
+   ;;
+
+#nosideeffect)
+  # This comment above is used by automake to tell side-effect
+  # dependency tracking mechanisms from slower ones.
+
+dashmstdout)
+  # Important note: in order to support this mode, a compiler *must*
+  # always write the preprocessed file to stdout, regardless of -o.
+  "$@" || exit $?
+
+  # Remove the call to Libtool.
+  if test "$libtool" = yes; then
+    while test $1 != '--mode=compile'; do
+      shift
+    done
+    shift
+  fi
+
+  # Remove `-o $object'.
+  IFS=" "
+  for arg
+  do
+    case $arg in
+    -o)
+      shift
+      ;;
+    $object)
+      shift
+      ;;
+    *)
+      set fnord "$@" "$arg"
+      shift # fnord
+      shift # $arg
+      ;;
+    esac
+  done
+
+  test -z "$dashmflag" && dashmflag=-M
+  # Require at least two characters before searching for `:'
+  # in the target name.  This is to cope with DOS-style filenames:
+  # a dependency such as `c:/foo/bar' could be seen as target `c' otherwise.
+  "$@" $dashmflag |
+    sed 's:^[  ]*[^: ][^:][^:]*\:[    ]*:'"$object"'\: :' > "$tmpdepfile"
+  rm -f "$depfile"
+  cat < "$tmpdepfile" > "$depfile"
+  tr ' ' '
+' < "$tmpdepfile" | \
+## Some versions of the HPUX 10.20 sed can't process this invocation
+## correctly.  Breaking it into two sed invocations is a workaround.
+    sed -e 's/^\\$//' -e '/^$/d' -e '/:$/d' | sed -e 's/$/ :/' >> "$depfile"
+  rm -f "$tmpdepfile"
+  ;;
+
+dashXmstdout)
+  # This case only exists to satisfy depend.m4.  It is never actually
+  # run, as this mode is specially recognized in the preamble.
+  exit 1
+  ;;
+
+makedepend)
+  "$@" || exit $?
+  # Remove any Libtool call
+  if test "$libtool" = yes; then
+    while test $1 != '--mode=compile'; do
+      shift
+    done
+    shift
+  fi
+  # X makedepend
+  shift
+  cleared=no
+  for arg in "$@"; do
+    case $cleared in
+    no)
+      set ""; shift
+      cleared=yes ;;
+    esac
+    case "$arg" in
+    -D*|-I*)
+      set fnord "$@" "$arg"; shift ;;
+    # Strip any option that makedepend may not understand.  Remove
+    # the object too, otherwise makedepend will parse it as a source file.
+    -*|$object)
+      ;;
+    *)
+      set fnord "$@" "$arg"; shift ;;
+    esac
+  done
+  obj_suffix="`echo $object | sed 's/^.*\././'`"
+  touch "$tmpdepfile"
+  ${MAKEDEPEND-makedepend} -o"$obj_suffix" -f"$tmpdepfile" "$@"
+  rm -f "$depfile"
+  cat < "$tmpdepfile" > "$depfile"
+  sed '1,2d' "$tmpdepfile" | tr ' ' '
+' | \
+## Some versions of the HPUX 10.20 sed can't process this invocation
+## correctly.  Breaking it into two sed invocations is a workaround.
+    sed -e 's/^\\$//' -e '/^$/d' -e '/:$/d' | sed -e 's/$/ :/' >> "$depfile"
+  rm -f "$tmpdepfile" "$tmpdepfile".bak
+  ;;
+
+cpp)
+  # Important note: in order to support this mode, a compiler *must*
+  # always write the preprocessed file to stdout.
+  "$@" || exit $?
+
+  # Remove the call to Libtool.
+  if test "$libtool" = yes; then
+    while test $1 != '--mode=compile'; do
+      shift
+    done
+    shift
+  fi
+
+  # Remove `-o $object'.
+  IFS=" "
+  for arg
+  do
+    case $arg in
+    -o)
+      shift
+      ;;
+    $object)
+      shift
+      ;;
+    *)
+      set fnord "$@" "$arg"
+      shift # fnord
+      shift # $arg
+      ;;
+    esac
+  done
+
+  "$@" -E |
+    sed -n -e '/^# [0-9][0-9]* "\([^"]*\)".*/ s:: \1 \\:p' \
+       -e '/^#line [0-9][0-9]* "\([^"]*\)".*/ s:: \1 \\:p' |
+    sed '$ s: \\$::' > "$tmpdepfile"
+  rm -f "$depfile"
+  echo "$object : \\" > "$depfile"
+  cat < "$tmpdepfile" >> "$depfile"
+  sed < "$tmpdepfile" '/^$/d;s/^ //;s/ \\$//;s/$/ :/' >> "$depfile"
+  rm -f "$tmpdepfile"
+  ;;
+
+msvisualcpp)
+  # Important note: in order to support this mode, a compiler *must*
+  # always write the preprocessed file to stdout, regardless of -o,
+  # because we must use -o when running libtool.
+  "$@" || exit $?
+  IFS=" "
+  for arg
+  do
+    case "$arg" in
+    "-Gm"|"/Gm"|"-Gi"|"/Gi"|"-ZI"|"/ZI")
+	set fnord "$@"
+	shift
+	shift
+	;;
+    *)
+	set fnord "$@" "$arg"
+	shift
+	shift
+	;;
+    esac
+  done
+  "$@" -E |
+  sed -n '/^#line [0-9][0-9]* "\([^"]*\)"/ s::echo "`cygpath -u \\"\1\\"`":p' | sort | uniq > "$tmpdepfile"
+  rm -f "$depfile"
+  echo "$object : \\" > "$depfile"
+  . "$tmpdepfile" | sed 's% %\\ %g' | sed -n '/^\(.*\)$/ s::	\1 \\:p' >> "$depfile"
+  echo "	" >> "$depfile"
+  . "$tmpdepfile" | sed 's% %\\ %g' | sed -n '/^\(.*\)$/ s::\1\::p' >> "$depfile"
+  rm -f "$tmpdepfile"
+  ;;
+
+none)
+  exec "$@"
+  ;;
+
+*)
+  echo "Unknown depmode $depmode" 1>&2
+  exit 1
+  ;;
+esac
+
+exit 0
+
+# Local Variables:
+# mode: shell-script
+# sh-indentation: 2
+# eval: (add-hook 'write-file-hooks 'time-stamp)
+# time-stamp-start: "scriptversion="
+# time-stamp-format: "%:y-%02m-%02d.%02H"
+# time-stamp-end: "$"
+# End:

example.c

@@ -1,22 +1,44 @@
 
-/* example.c - an example of using libpng */
+#if 0 /* in case someone actually tries to compile this */
+
+/* example.c - an example of using libpng
+ * Last changed in libpng 1.2.33 [October 31, 2008]
+ * This file has been placed in the public domain by the authors.
+ * Maintained 1998-2008 Glenn Randers-Pehrson
+ * Maintained 1996, 1997 Andreas Dilger)
+ * Written 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ */
 
 /* This is an example of how to use libpng to read and write PNG files.
  * The file libpng.txt is much more verbose then this.  If you have not
  * read it, do so first.  This was designed to be a starting point of an
- * implementation.  This is not officially part of libpng, and therefore
- * does not require a copyright notice.
+ * implementation.  This is not officially part of libpng, is hereby placed
+ * in the public domain, and therefore does not require a copyright notice.
  *
  * This file does not currently compile, because it is missing certain
  * parts, like allocating memory to hold an image.  You will have to
  * supply these parts to get it to compile.  For an example of a minimal
- * working PNG reader/writer, see pngtest.c, included in this distribution.
+ * working PNG reader/writer, see pngtest.c, included in this distribution;
+ * see also the programs in the contrib directory.
  */
 
 #include "png.h"
 
-/* Check to see if a file is a PNG file using png_sig_cmp().  Returns
- * non-zero if the image is a PNG, and 0 if it isn't a PNG.
+ /* The png_jmpbuf() macro, used in error handling, became available in
+  * libpng version 1.0.6.  If you want to be able to run your code with older
+  * versions of libpng, you must define the macro yourself (but only if it
+  * is not already defined by libpng!).
+  */
+
+#ifndef png_jmpbuf
+#  define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
+#endif
+
+/* Check to see if a file is a PNG file using png_sig_cmp().  png_sig_cmp()
+ * returns zero if the image is a PNG and nonzero if it isn't a PNG.
+ *
+ * The function check_if_png() shown here, but not used, returns nonzero (true)
+ * if the file can be opened and is a PNG, 0 (false) otherwise.
  *
  * If this call is successful, and you are going to keep the file open,
  * you should call png_set_sig_bytes(png_ptr, PNG_BYTES_TO_CHECK); once
@@ -38,15 +60,17 @@ int check_if_png(char *file_name, FILE **fp)
    char buf[PNG_BYTES_TO_CHECK];
 
    /* Open the prospective PNG file. */
-   if ((*fp = fopen(file_name, "rb")) != NULL);
+   if ((*fp = fopen(file_name, "rb")) == NULL)
       return 0;
 
-   /* Read in the signature bytes */
+   /* Read in some of the signature bytes */
    if (fread(buf, 1, PNG_BYTES_TO_CHECK, *fp) != PNG_BYTES_TO_CHECK)
       return 0;
 
-   /* Compare the first PNG_BYTES_TO_CHECK bytes of the signature. */
-   return(png_sig_cmp(buf, (png_size_t)0, PNG_BYTES_TO_CHECK));
+   /* Compare the first PNG_BYTES_TO_CHECK bytes of the signature.
+      Return nonzero (true) if they match */
+
+   return(!png_sig_cmp(buf, (png_size_t)0, PNG_BYTES_TO_CHECK));
 }
 
 /* Read a PNG file.  You may want to return an error code if the read
@@ -66,7 +90,7 @@ void read_png(char *file_name)  /* We need to open the file */
    FILE *fp;
 
    if ((fp = fopen(file_name, "rb")) == NULL)
-      return;
+      return (ERROR);
 #else no_open_file /* prototype 2 */
 void read_png(FILE *fp, unsigned int sig_read)  /* file is already open */
 {
@@ -88,7 +112,7 @@ void read_png(FILE *fp, unsigned int sig_read)  /* file is already open */
    if (png_ptr == NULL)
    {
       fclose(fp);
-      return;
+      return (ERROR);
    }
 
    /* Allocate/initialize the memory for image information.  REQUIRED. */
@@ -96,21 +120,22 @@ void read_png(FILE *fp, unsigned int sig_read)  /* file is already open */
    if (info_ptr == NULL)
    {
       fclose(fp);
-      png_destroy_read_struct(&png_ptr, (png_infopp)NULL, (png_infopp)NULL);
-      return;
+      png_destroy_read_struct(&png_ptr, png_infopp_NULL, png_infopp_NULL);
+      return (ERROR);
    }
 
    /* Set error handling if you are using the setjmp/longjmp method (this is
     * the normal method of doing things with libpng).  REQUIRED unless you
     * set up your own error handlers in the png_create_read_struct() earlier.
     */
-   if (setjmp(png_ptr->jmpbuf))
+
+   if (setjmp(png_jmpbuf(png_ptr)))
    {
       /* Free all of the memory associated with the png_ptr and info_ptr */
-      png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
+      png_destroy_read_struct(&png_ptr, &info_ptr, png_infopp_NULL);
       fclose(fp);
       /* If we get here, we had a problem reading the file */
-      return;
+      return (ERROR);
    }
 
    /* One of the following I/O initialization methods is REQUIRED */
@@ -129,24 +154,37 @@ void read_png(FILE *fp, unsigned int sig_read)  /* file is already open */
    /* If we have already read some of the signature */
    png_set_sig_bytes(png_ptr, sig_read);
 
+#ifdef hilevel
+   /*
+    * If you have enough memory to read in the entire image at once,
+    * and you need to specify only transforms that can be controlled
+    * with one of the PNG_TRANSFORM_* bits (this presently excludes
+    * dithering, filling, setting background, and doing gamma
+    * adjustment), then you can read the entire image (including
+    * pixels) into the info structure with this call:
+    */
+   png_read_png(png_ptr, info_ptr, png_transforms, png_voidp_NULL);
+#else
+   /* OK, you're doing it the hard way, with the lower-level functions */
+
    /* The call to png_read_info() gives us all of the information from the
     * PNG file before the first IDAT (image data chunk).  REQUIRED
     */
    png_read_info(png_ptr, info_ptr);
 
    png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
-       &interlace_type, NULL, NULL);
+       &interlace_type, int_p_NULL, int_p_NULL);
 
-/**** Set up the data transformations you want.  Note that these are all
- **** optional.  Only call them if you want/need them.  Many of the
- **** transformations only work on specific types of images, and many
- **** are mutually exclusive.
- ****/
+/* Set up the data transformations you want.  Note that these are all
+ * optional.  Only call them if you want/need them.  Many of the
+ * transformations only work on specific types of images, and many
+ * are mutually exclusive.
+ */
 
    /* tell libpng to strip 16 bit/color files down to 8 bits/color */
    png_set_strip_16(png_ptr);
 
-   /* Strip alpha bytes from the input data without combining with th
+   /* Strip alpha bytes from the input data without combining with the
     * background (not recommended).
     */
    png_set_strip_alpha(png_ptr);
@@ -162,17 +200,17 @@ void read_png(FILE *fp, unsigned int sig_read)  /* file is already open */
 
    /* Expand paletted colors into true RGB triplets */
    if (color_type == PNG_COLOR_TYPE_PALETTE)
-      png_set_expand(png_ptr);
+      png_set_palette_to_rgb(png_ptr);
 
    /* Expand grayscale images to the full 8 bits from 1, 2, or 4 bits/pixel */
    if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
-      png_set_expand(png_ptr);
+      png_set_expand_gray_1_2_4_to_8(png_ptr);
 
    /* Expand paletted or RGB images with transparency to full alpha channels
     * so the data will be available as RGBA quartets.
     */
    if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
-      png_set_expand(png_ptr);
+      png_set_tRNS_to_alpha(png_ptr);
 
    /* Set the background color to draw transparent and alpha images over.
     * It is possible to set the red, green, and blue components directly
@@ -192,7 +230,8 @@ void read_png(FILE *fp, unsigned int sig_read)  /* file is already open */
 
    /* Some suggestions as to how to get a screen gamma value */
 
-   /* Note that screen gamma is (display_gamma/viewing_gamma) */
+   /* Note that screen gamma is the display_exponent, which includes
+    * the CRT_exponent and any correction for viewing conditions */
    if (/* We have a user-defined screen gamma value */)
    {
       screen_gamma = user-defined screen_gamma;
@@ -210,7 +249,7 @@ void read_png(FILE *fp, unsigned int sig_read)  /* file is already open */
       screen_gamma = 1.7 or 1.0;  /* A good guess for Mac systems */
    }
 
-   /* Tell libpng to handle the gamma conversion for you.  The second call
+   /* Tell libpng to handle the gamma conversion for you.  The final call
     * is a good guess for PC generated images, but it should be configurable
     * by the user at run time by the user.  It is strongly suggested that
     * your application support gamma correction.
@@ -219,19 +258,22 @@ void read_png(FILE *fp, unsigned int sig_read)  /* file is already open */
    int intent;
 
    if (png_get_sRGB(png_ptr, info_ptr, &intent))
-      png_set_sRGB(png_ptr, intent, 0);
-   else 
+      png_set_gamma(png_ptr, screen_gamma, 0.45455);
+   else
+   {
+      double image_gamma;
       if (png_get_gAMA(png_ptr, info_ptr, &image_gamma))
          png_set_gamma(png_ptr, screen_gamma, image_gamma);
       else
-         png_set_gamma(png_ptr, screen_gamma, 0.50);
+         png_set_gamma(png_ptr, screen_gamma, 0.45455);
+   }
 
    /* Dither RGB files down to 8 bit palette or reduce palettes
     * to the number of colors available on your screen.
     */
    if (color_type & PNG_COLOR_MASK_COLOR)
    {
-      png_uint_32 num_palette;
+      int num_palette;
       png_colorp palette;
 
       /* This reduces the image to the application supplied palette */
@@ -241,12 +283,12 @@ void read_png(FILE *fp, unsigned int sig_read)  /* file is already open */
          png_color std_color_cube[MAX_SCREEN_COLORS];
 
          png_set_dither(png_ptr, std_color_cube, MAX_SCREEN_COLORS,
-            MAX_SCREEN_COLORS, NULL, 0);
+            MAX_SCREEN_COLORS, png_uint_16p_NULL, 0);
       }
       /* This reduces the image to the palette supplied in the file */
       else if (png_get_PLTE(png_ptr, info_ptr, &palette, &num_palette))
       {
-         png_color16p histogram;
+         png_uint_16p histogram = NULL;
 
          png_get_hIST(png_ptr, info_ptr, &histogram);
 
@@ -255,7 +297,7 @@ void read_png(FILE *fp, unsigned int sig_read)  /* file is already open */
       }
    }
 
-   /* invert monocrome files to have 0 as white and 1 as black */
+   /* invert monochrome files to have 0 as white and 1 as black */
    png_set_invert_mono(png_ptr);
 
    /* If you want to shift the pixel values from the range [0,255] or
@@ -264,14 +306,15 @@ void read_png(FILE *fp, unsigned int sig_read)  /* file is already open */
     */
    if (png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT))
    {
-      png_color8p sig_bit;
+      png_color_8p sig_bit;
 
       png_get_sBIT(png_ptr, info_ptr, &sig_bit);
       png_set_shift(png_ptr, sig_bit);
    }
 
    /* flip the RGB pixels to BGR (or RGBA to BGRA) */
-   png_set_bgr(png_ptr);
+   if (color_type & PNG_COLOR_MASK_COLOR)
+      png_set_bgr(png_ptr);
 
    /* swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */
    png_set_swap_alpha(png_ptr);
@@ -301,7 +344,8 @@ void read_png(FILE *fp, unsigned int sig_read)  /* file is already open */
 
    for (row = 0; row < height; row++)
    {
-      row_pointers[row] = malloc(png_get_rowbytes(png_ptr, info_ptr));
+      row_pointers[row] = png_malloc(png_ptr, png_get_rowbytes(png_ptr,
+         info_ptr));
    }
 
    /* Now it's time to read the image.  One of these methods is REQUIRED */
@@ -316,21 +360,21 @@ void read_png(FILE *fp, unsigned int sig_read)  /* file is already open */
 #ifdef single /* Read the image a single row at a time */
       for (y = 0; y < height; y++)
       {
-         png_bytep row_pointers = row[y];
-         png_read_rows(png_ptr, &row_pointers, NULL, 1);
+         png_read_rows(png_ptr, &row_pointers[y], png_bytepp_NULL, 1);
       }
 
 #else no_single /* Read the image several rows at a time */
       for (y = 0; y < height; y += number_of_rows)
       {
 #ifdef sparkle /* Read the image using the "sparkle" effect. */
-         png_read_rows(png_ptr, row_pointers, NULL, number_of_rows);
-        
+         png_read_rows(png_ptr, &row_pointers[y], png_bytepp_NULL,
+            number_of_rows);
 #else no_sparkle /* Read the image using the "rectangle" effect */
-         png_read_rows(png_ptr, NULL, row_pointers, number_of_rows);
+         png_read_rows(png_ptr, png_bytepp_NULL, &row_pointers[y],
+            number_of_rows);
 #endif no_sparkle /* use only one of these two methods */
       }
-     
+
       /* if you want to display the image after every pass, do
          so here */
 #endif no_single /* use only one of these two methods */
@@ -339,15 +383,18 @@ void read_png(FILE *fp, unsigned int sig_read)  /* file is already open */
 
    /* read rest of file, and get additional chunks in info_ptr - REQUIRED */
    png_read_end(png_ptr, info_ptr);
+#endif hilevel
+
+   /* At this point you have read the entire image */
 
    /* clean up after the read, and free any memory allocated - REQUIRED */
-   png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
+   png_destroy_read_struct(&png_ptr, &info_ptr, png_infopp_NULL);
 
    /* close the file */
    fclose(fp);
 
    /* that's it */
-   return;
+   return (OK);
 }
 
 /* progressively read a file */
@@ -367,25 +414,28 @@ initialize_png_reader(png_structp *png_ptr, png_infop *info_ptr)
    if (*png_ptr == NULL)
    {
       *info_ptr = NULL;
-      return ERROR;
+      return (ERROR);
    }
 
    *info_ptr = png_create_info_struct(png_ptr);
 
    if (*info_ptr == NULL)
    {
-      png_destroy_read_struct(png_ptr, info_ptr, (png_infopp)NULL);
-      return ERROR;
+      png_destroy_read_struct(png_ptr, info_ptr, png_infopp_NULL);
+      return (ERROR);
    }
 
-   if (setjmp((*png_ptr)->jmpbuf))
+   if (setjmp(png_jmpbuf((*png_ptr))))
    {
-      png_destroy_read_struct(png_ptr, info_ptr, (png_infopp)NULL);
-      return ERROR;
+      png_destroy_read_struct(png_ptr, info_ptr, png_infopp_NULL);
+      return (ERROR);
    }
 
-   /* this one's new.  You will need to provide all three
+   /* This one's new.  You will need to provide all three
     * function callbacks, even if you aren't using them all.
+    * If you aren't using all functions, you can specify NULL
+    * parameters.  Even when all three functions are NULL,
+    * you need to call png_set_progressive_read_fn().
     * These functions shouldn't be dependent on global or
     * static variables if you are decoding several images
     * simultaneously.  You should store stream specific data
@@ -396,18 +446,18 @@ initialize_png_reader(png_structp *png_ptr, png_infop *info_ptr)
    png_set_progressive_read_fn(*png_ptr, (void *)stream_data,
       info_callback, row_callback, end_callback);
 
-   return OK;
+   return (OK);
 }
 
 int
 process_data(png_structp *png_ptr, png_infop *info_ptr,
    png_bytep buffer, png_uint_32 length)
 {
-   if (setjmp((*png_ptr)->jmpbuf))
+   if (setjmp(png_jmpbuf((*png_ptr))))
    {
       /* Free the png_ptr and info_ptr memory on error */
-      png_destroy_read_struct(png_ptr, info_ptr, (png_infopp)NULL);
-      return ERROR;
+      png_destroy_read_struct(png_ptr, info_ptr, png_infopp_NULL);
+      return (ERROR);
    }
 
    /* This one's new also.  Simply give it chunks of data as
@@ -421,7 +471,7 @@ process_data(png_structp *png_ptr, png_infop *info_ptr,
     * callback, if you aren't already displaying them there.
     */
    png_process_data(*png_ptr, *info_ptr, buffer, length);
-   return OK;
+   return (OK);
 }
 
 info_callback(png_structp png_ptr, png_infop info)
@@ -438,21 +488,47 @@ info_callback(png_structp png_ptr, png_infop info)
 row_callback(png_structp png_ptr, png_bytep new_row,
    png_uint_32 row_num, int pass)
 {
-/* this function is called for every row in the image.  If the
- * image is interlacing, and you turned on the interlace handler,
+/*
+ * This function is called for every row in the image.  If the
+ * image is interlaced, and you turned on the interlace handler,
  * this function will be called for every row in every pass.
- * Some of these rows will not be changed from the previous pass.
- * When the row is not changed, the new_row variable will be NULL.
+ *
+ * In this function you will receive a pointer to new row data from
+ * libpng called new_row that is to replace a corresponding row (of
+ * the same data format) in a buffer allocated by your application.
+ *
+ * The new row data pointer new_row may be NULL, indicating there is
+ * no new data to be replaced (in cases of interlace loading).
+ *
+ * If new_row is not NULL then you need to call
+ * png_progressive_combine_row() to replace the corresponding row as
+ * shown below:
+ */
+   /* Check if row_num is in bounds. */
+   if ((row_num >= 0) && (row_num < height))
+   {
+     /* Get pointer to corresponding row in our
+      * PNG read buffer.
+      */
+     png_bytep old_row = ((png_bytep *)our_data)[row_num];
+
+     /* If both rows are allocated then copy the new row
+      * data to the corresponding row data.
+      */
+     if ((old_row != NULL) && (new_row != NULL))
+     png_progressive_combine_row(png_ptr, old_row, new_row);
+   }
+/*
  * The rows and passes are called in order, so you don't really
  * need the row_num and pass, but I'm supplying them because it
  * may make your life easier.
  *
  * For the non-NULL rows of interlaced images, you must call
- * png_progressive_combine_row() passing in the row and the
- * old row.  You can call this function for NULL rows (it will
- * just return) and for non-interlaced images (it just does the
- * memcpy for you) if it will make the code easier.  Thus, you
- * can just do this for all cases:
+ * png_progressive_combine_row() passing in the new row and the
+ * old row, as demonstrated above.  You can call this function for
+ * NULL rows (it will just return) and for non-interlaced images
+ * (it just does the png_memcpy for you) if it will make the code
+ * easier.  Thus, you can just do this for all cases:
  */
 
    png_progressive_combine_row(png_ptr, old_row, new_row);
@@ -461,8 +537,8 @@ row_callback(png_structp png_ptr, png_bytep new_row,
  * that the first pass (pass == 0 really) will completely cover
  * the old row, so the rows do not have to be initialized.  After
  * the first pass (and only for interlaced images), you will have
- * to pass the current row, and the function will combine the
- * old row and the new row.
+ * to pass the current row as new_row, and the function will combine
+ * the old row and the new row.
  */
 }
 
@@ -485,11 +561,12 @@ void write_png(char *file_name /* , ... other image information ... */)
    FILE *fp;
    png_structp png_ptr;
    png_infop info_ptr;
+   png_colorp palette;
 
    /* open the file */
    fp = fopen(file_name, "wb");
    if (fp == NULL)
-      return;
+      return (ERROR);
 
    /* Create and initialize the png_struct with the desired error handler
     * functions.  If you want to use the default stderr and longjump method,
@@ -503,7 +580,7 @@ void write_png(char *file_name /* , ... other image information ... */)
    if (png_ptr == NULL)
    {
       fclose(fp);
-      return;
+      return (ERROR);
    }
 
    /* Allocate/initialize the image information data.  REQUIRED */
@@ -511,19 +588,19 @@ void write_png(char *file_name /* , ... other image information ... */)
    if (info_ptr == NULL)
    {
       fclose(fp);
-      png_destroy_write_struct(&png_ptr,  (png_infopp)NULL);
-      return;
+      png_destroy_write_struct(&png_ptr,  png_infopp_NULL);
+      return (ERROR);
    }
 
    /* Set error handling.  REQUIRED if you aren't supplying your own
-    * error hadnling functions in the png_create_write_struct() call.
+    * error handling functions in the png_create_write_struct() call.
     */
-   if (setjmp(png_ptr->jmpbuf))
+   if (setjmp(png_jmpbuf(png_ptr)))
    {
       /* If we get here, we had a problem reading the file */
       fclose(fp);
-      png_destroy_write_struct(&png_ptr,  (png_infopp)NULL);
-      return;
+      png_destroy_write_struct(&png_ptr, &info_ptr);
+      return (ERROR);
    }
 
    /* One of the following I/O initialization functions is REQUIRED */
@@ -531,13 +608,22 @@ void write_png(char *file_name /* , ... other image information ... */)
    /* set up the output control if you are using standard C streams */
    png_init_io(png_ptr, fp);
 #else no_streams /* I/O initialization method 2 */
-   /* If you are using replacement read functions, instead of calling
+   /* If you are using replacement write functions, instead of calling
     * png_init_io() here you would call */
    png_set_write_fn(png_ptr, (void *)user_io_ptr, user_write_fn,
       user_IO_flush_function);
    /* where user_io_ptr is a structure you want available to the callbacks */
 #endif no_streams /* only use one initialization method */
 
+#ifdef hilevel
+   /* This is the easy way.  Use it if you already have all the
+    * image info living info in the structure.  You could "|" many
+    * PNG_TRANSFORM flags into the png_transforms integer here.
+    */
+   png_write_png(png_ptr, info_ptr, png_transforms, png_voidp_NULL);
+#else
+   /* This is the hard way */
+
    /* Set the image information here.  Width and height are up to 2^31,
     * bit_depth is one of 1, 2, 4, 8, or 16, but valid values also depend on
     * the color_type selected. color_type is one of PNG_COLOR_TYPE_GRAY,
@@ -550,9 +636,13 @@ void write_png(char *file_name /* , ... other image information ... */)
       PNG_INTERLACE_????, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
 
    /* set the palette if there is one.  REQUIRED for indexed-color images */
-   palette = (png_colorp)png_malloc(png_ptr, 256 * sizeof (png_color));
+   palette = (png_colorp)png_malloc(png_ptr, PNG_MAX_PALETTE_LENGTH
+             * png_sizeof(png_color));
    /* ... set palette colors ... */
-   png_set_PLTE(png_ptr, info_ptr, palette, 256);
+   png_set_PLTE(png_ptr, info_ptr, palette, PNG_MAX_PALETTE_LENGTH);
+   /* You must not free palette here, because png_set_PLTE only makes a link to
+      the palette that you malloced.  Wait until you are about to destroy
+      the png structure. */
 
    /* optional significant bit chunk */
    /* if we are dealing with a grayscale image then */
@@ -565,7 +655,7 @@ void write_png(char *file_name /* , ... other image information ... */)
    sig_bit.alpha = true_alpha_bit_depth;
    png_set_sBIT(png_ptr, info_ptr, sig_bit);
 
-  
+
    /* Optional gamma chunk is strongly suggested if you have any guess
     * as to the correct gamma of the image.
     */
@@ -581,15 +671,31 @@ void write_png(char *file_name /* , ... other image information ... */)
    text_ptr[2].key = "Description";
    text_ptr[2].text = "<long text>";
    text_ptr[2].compression = PNG_TEXT_COMPRESSION_zTXt;
-   png_set_text(png_ptr, info_ptr, text_ptr, 2);
+#ifdef PNG_iTXt_SUPPORTED
+   text_ptr[0].lang = NULL;
+   text_ptr[1].lang = NULL;
+   text_ptr[2].lang = NULL;
+#endif
+   png_set_text(png_ptr, info_ptr, text_ptr, 3);
 
    /* other optional chunks like cHRM, bKGD, tRNS, tIME, oFFs, pHYs, */
-   /* note that if sRGB is present the cHRM chunk must be ignored
+   /* note that if sRGB is present the gAMA and cHRM chunks must be ignored
     * on read and must be written in accordance with the sRGB profile */
 
    /* Write the file header information.  REQUIRED */
    png_write_info(png_ptr, info_ptr);
 
+   /* If you want, you can write the info in two steps, in case you need to
+    * write your private chunk ahead of PLTE:
+    *
+    *   png_write_info_before_PLTE(write_ptr, write_info_ptr);
+    *   write_my_chunk();
+    *   png_write_info(png_ptr, info_ptr);
+    *
+    * However, given the level of known- and unknown-chunk support in 1.1.0
+    * and up, this should no longer be necessary.
+    */
+
    /* Once we write out the header, the compression type on the text
     * chunks gets changed to PNG_TEXT_COMPRESSION_NONE_WR or
     * PNG_TEXT_COMPRESSION_zTXt_WR, so it doesn't get written out again
@@ -600,7 +706,7 @@ void write_png(char *file_name /* , ... other image information ... */)
     * all optional.  Only call them if you want them.
     */
 
-   /* invert monocrome pixels */
+   /* invert monochrome pixels */
    png_set_invert_mono(png_ptr);
 
    /* Shift the pixels up to a legal bit depth and fill in
@@ -638,7 +744,15 @@ void write_png(char *file_name /* , ... other image information ... */)
     * layout, however, so choose what fits your needs best).  You need to
     * use the first method if you aren't handling interlacing yourself.
     */
-   png_byte row_pointers[height][width];
+   png_uint_32 k, height, width;
+   png_byte image[height][width*bytes_per_pixel];
+   png_bytep row_pointers[height];
+
+   if (height > PNG_UINT_32_MAX/png_sizeof(png_bytep))
+     png_error (png_ptr, "Image is too tall to process in memory");
+
+   for (k = 0; k < height; k++)
+     row_pointers[k] = image + k*width*bytes_per_pixel;
 
    /* One of the following output methods is REQUIRED */
 #ifdef entire /* write out the entire image data in one call */
@@ -653,36 +767,48 @@ void write_png(char *file_name /* , ... other image information ... */)
    for (pass = 0; pass < number_passes; pass++)
    {
       /* Write a few rows at a time. */
-      png_write_rows(png_ptr, row_pointers, number_of_rows);
+      png_write_rows(png_ptr, &row_pointers[first_row], number_of_rows);
 
       /* If you are only writing one row at a time, this works */
       for (y = 0; y < height; y++)
       {
-         png_bytep row_pointers = row[y];
-         png_write_rows(png_ptr, &row_pointers, 1);
+         png_write_rows(png_ptr, &row_pointers[y], 1);
       }
    }
 #endif no_entire /* use only one output method */
 
    /* You can write optional chunks like tEXt, zTXt, and tIME at the end
-    * as well.
+    * as well.  Shouldn't be necessary in 1.1.0 and up as all the public
+    * chunks are supported and you can use png_set_unknown_chunks() to
+    * register unknown chunks into the info structure to be written out.
     */
 
    /* It is REQUIRED to call this to finish writing the rest of the file */
    png_write_end(png_ptr, info_ptr);
+#endif hilevel
 
-   /* if you malloced the palette, free it here */
-   free(info_ptr->palette);
+   /* If you png_malloced a palette, free it here (don't free info_ptr->palette,
+      as recommended in versions 1.0.5m and earlier of this example; if
+      libpng mallocs info_ptr->palette, libpng will free it).  If you
+      allocated it with malloc() instead of png_malloc(), use free() instead
+      of png_free(). */
+   png_free(png_ptr, palette);
+   palette = NULL;
 
-   /* if you allocated any text comments, free them here */
+   /* Similarly, if you png_malloced any data that you passed in with
+      png_set_something(), such as a hist or trans array, free it here,
+      when you can be sure that libpng is through with it. */
+   png_free(png_ptr, trans);
+   trans = NULL;
 
    /* clean up after the write, and free any memory allocated */
-   png_destroy_write_struct(&png_ptr, (png_infopp)NULL);
+   png_destroy_write_struct(&png_ptr, &info_ptr);
 
    /* close the file */
    fclose(fp);
 
    /* that's it */
-   return;
+   return (OK);
 }
 
+#endif /* if 0 */

install-sh

@@ -0,0 +1,519 @@
+#!/bin/sh
+# install - install a program, script, or datafile
+
+scriptversion=2006-12-25.00
+
+# This originates from X11R5 (mit/util/scripts/install.sh), which was
+# later released in X11R6 (xc/config/util/install.sh) with the
+# following copyright and license.
+#
+# Copyright (C) 1994 X Consortium
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to
+# deal in the Software without restriction, including without limitation the
+# rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+# sell copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+# X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+# AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNEC-
+# TION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+#
+# Except as contained in this notice, the name of the X Consortium shall not
+# be used in advertising or otherwise to promote the sale, use or other deal-
+# ings in this Software without prior written authorization from the X Consor-
+# tium.
+#
+#
+# FSF changes to this file are in the public domain.
+#
+# Calling this script install-sh is preferred over install.sh, to prevent
+# `make' implicit rules from creating a file called install from it
+# when there is no Makefile.
+#
+# This script is compatible with the BSD install script, but was written
+# from scratch.
+
+nl='
+'
+IFS=" ""	$nl"
+
+# set DOITPROG to echo to test this script
+
+# Don't use :- since 4.3BSD and earlier shells don't like it.
+doit=${DOITPROG-}
+if test -z "$doit"; then
+  doit_exec=exec
+else
+  doit_exec=$doit
+fi
+
+# Put in absolute file names if you don't have them in your path;
+# or use environment vars.
+
+chgrpprog=${CHGRPPROG-chgrp}
+chmodprog=${CHMODPROG-chmod}
+chownprog=${CHOWNPROG-chown}
+cmpprog=${CMPPROG-cmp}
+cpprog=${CPPROG-cp}
+mkdirprog=${MKDIRPROG-mkdir}
+mvprog=${MVPROG-mv}
+rmprog=${RMPROG-rm}
+stripprog=${STRIPPROG-strip}
+
+posix_glob='?'
+initialize_posix_glob='
+  test "$posix_glob" != "?" || {
+    if (set -f) 2>/dev/null; then
+      posix_glob=
+    else
+      posix_glob=:
+    fi
+  }
+'
+
+posix_mkdir=
+
+# Desired mode of installed file.
+mode=0755
+
+chgrpcmd=
+chmodcmd=$chmodprog
+chowncmd=
+mvcmd=$mvprog
+rmcmd="$rmprog -f"
+stripcmd=
+
+src=
+dst=
+dir_arg=
+dst_arg=
+
+copy_on_change=false
+no_target_directory=
+
+usage="\
+Usage: $0 [OPTION]... [-T] SRCFILE DSTFILE
+   or: $0 [OPTION]... SRCFILES... DIRECTORY
+   or: $0 [OPTION]... -t DIRECTORY SRCFILES...
+   or: $0 [OPTION]... -d DIRECTORIES...
+
+In the 1st form, copy SRCFILE to DSTFILE.
+In the 2nd and 3rd, copy all SRCFILES to DIRECTORY.
+In the 4th, create DIRECTORIES.
+
+Options:
+     --help     display this help and exit.
+     --version  display version info and exit.
+
+  -c            (ignored)
+  -C            install only if different (preserve the last data modification time)
+  -d            create directories instead of installing files.
+  -g GROUP      $chgrpprog installed files to GROUP.
+  -m MODE       $chmodprog installed files to MODE.
+  -o USER       $chownprog installed files to USER.
+  -s            $stripprog installed files.
+  -t DIRECTORY  install into DIRECTORY.
+  -T            report an error if DSTFILE is a directory.
+
+Environment variables override the default commands:
+  CHGRPPROG CHMODPROG CHOWNPROG CMPPROG CPPROG MKDIRPROG MVPROG
+  RMPROG STRIPPROG
+"
+
+while test $# -ne 0; do
+  case $1 in
+    -c) ;;
+
+    -C) copy_on_change=true;;
+
+    -d) dir_arg=true;;
+
+    -g) chgrpcmd="$chgrpprog $2"
+	shift;;
+
+    --help) echo "$usage"; exit $?;;
+
+    -m) mode=$2
+	case $mode in
+	  *' '* | *'	'* | *'
+'*	  | *'*'* | *'?'* | *'['*)
+	    echo "$0: invalid mode: $mode" >&2
+	    exit 1;;
+	esac
+	shift;;
+
+    -o) chowncmd="$chownprog $2"
+	shift;;
+
+    -s) stripcmd=$stripprog;;
+
+    -t) dst_arg=$2
+	shift;;
+
+    -T) no_target_directory=true;;
+
+    --version) echo "$0 $scriptversion"; exit $?;;
+
+    --)	shift
+	break;;
+
+    -*)	echo "$0: invalid option: $1" >&2
+	exit 1;;
+
+    *)  break;;
+  esac
+  shift
+done
+
+if test $# -ne 0 && test -z "$dir_arg$dst_arg"; then
+  # When -d is used, all remaining arguments are directories to create.
+  # When -t is used, the destination is already specified.
+  # Otherwise, the last argument is the destination.  Remove it from $@.
+  for arg
+  do
+    if test -n "$dst_arg"; then
+      # $@ is not empty: it contains at least $arg.
+      set fnord "$@" "$dst_arg"
+      shift # fnord
+    fi
+    shift # arg
+    dst_arg=$arg
+  done
+fi
+
+if test $# -eq 0; then
+  if test -z "$dir_arg"; then
+    echo "$0: no input file specified." >&2
+    exit 1
+  fi
+  # It's OK to call `install-sh -d' without argument.
+  # This can happen when creating conditional directories.
+  exit 0
+fi
+
+if test -z "$dir_arg"; then
+  trap '(exit $?); exit' 1 2 13 15
+
+  # Set umask so as not to create temps with too-generous modes.
+  # However, 'strip' requires both read and write access to temps.
+  case $mode in
+    # Optimize common cases.
+    *644) cp_umask=133;;
+    *755) cp_umask=22;;
+
+    *[0-7])
+      if test -z "$stripcmd"; then
+	u_plus_rw=
+      else
+	u_plus_rw='% 200'
+      fi
+      cp_umask=`expr '(' 777 - $mode % 1000 ')' $u_plus_rw`;;
+    *)
+      if test -z "$stripcmd"; then
+	u_plus_rw=
+      else
+	u_plus_rw=,u+rw
+      fi
+      cp_umask=$mode$u_plus_rw;;
+  esac
+fi
+
+for src
+do
+  # Protect names starting with `-'.
+  case $src in
+    -*) src=./$src;;
+  esac
+
+  if test -n "$dir_arg"; then
+    dst=$src
+    dstdir=$dst
+    test -d "$dstdir"
+    dstdir_status=$?
+  else
+
+    # Waiting for this to be detected by the "$cpprog $src $dsttmp" command
+    # might cause directories to be created, which would be especially bad
+    # if $src (and thus $dsttmp) contains '*'.
+    if test ! -f "$src" && test ! -d "$src"; then
+      echo "$0: $src does not exist." >&2
+      exit 1
+    fi
+
+    if test -z "$dst_arg"; then
+      echo "$0: no destination specified." >&2
+      exit 1
+    fi
+
+    dst=$dst_arg
+    # Protect names starting with `-'.
+    case $dst in
+      -*) dst=./$dst;;
+    esac
+
+    # If destination is a directory, append the input filename; won't work
+    # if double slashes aren't ignored.
+    if test -d "$dst"; then
+      if test -n "$no_target_directory"; then
+	echo "$0: $dst_arg: Is a directory" >&2
+	exit 1
+      fi
+      dstdir=$dst
+      dst=$dstdir/`basename "$src"`
+      dstdir_status=0
+    else
+      # Prefer dirname, but fall back on a substitute if dirname fails.
+      dstdir=`
+	(dirname "$dst") 2>/dev/null ||
+	expr X"$dst" : 'X\(.*[^/]\)//*[^/][^/]*/*$' \| \
+	     X"$dst" : 'X\(//\)[^/]' \| \
+	     X"$dst" : 'X\(//\)$' \| \
+	     X"$dst" : 'X\(/\)' \| . 2>/dev/null ||
+	echo X"$dst" |
+	    sed '/^X\(.*[^/]\)\/\/*[^/][^/]*\/*$/{
+		   s//\1/
+		   q
+		 }
+		 /^X\(\/\/\)[^/].*/{
+		   s//\1/
+		   q
+		 }
+		 /^X\(\/\/\)$/{
+		   s//\1/
+		   q
+		 }
+		 /^X\(\/\).*/{
+		   s//\1/
+		   q
+		 }
+		 s/.*/./; q'
+      `
+
+      test -d "$dstdir"
+      dstdir_status=$?
+    fi
+  fi
+
+  obsolete_mkdir_used=false
+
+  if test $dstdir_status != 0; then
+    case $posix_mkdir in
+      '')
+	# Create intermediate dirs using mode 755 as modified by the umask.
+	# This is like FreeBSD 'install' as of 1997-10-28.
+	umask=`umask`
+	case $stripcmd.$umask in
+	  # Optimize common cases.
+	  *[2367][2367]) mkdir_umask=$umask;;
+	  .*0[02][02] | .[02][02] | .[02]) mkdir_umask=22;;
+
+	  *[0-7])
+	    mkdir_umask=`expr $umask + 22 \
+	      - $umask % 100 % 40 + $umask % 20 \
+	      - $umask % 10 % 4 + $umask % 2
+	    `;;
+	  *) mkdir_umask=$umask,go-w;;
+	esac
+
+	# With -d, create the new directory with the user-specified mode.
+	# Otherwise, rely on $mkdir_umask.
+	if test -n "$dir_arg"; then
+	  mkdir_mode=-m$mode
+	else
+	  mkdir_mode=
+	fi
+
+	posix_mkdir=false
+	case $umask in
+	  *[123567][0-7][0-7])
+	    # POSIX mkdir -p sets u+wx bits regardless of umask, which
+	    # is incompatible with FreeBSD 'install' when (umask & 300) != 0.
+	    ;;
+	  *)
+	    tmpdir=${TMPDIR-/tmp}/ins$RANDOM-$$
+	    trap 'ret=$?; rmdir "$tmpdir/d" "$tmpdir" 2>/dev/null; exit $ret' 0
+
+	    if (umask $mkdir_umask &&
+		exec $mkdirprog $mkdir_mode -p -- "$tmpdir/d") >/dev/null 2>&1
+	    then
+	      if test -z "$dir_arg" || {
+		   # Check for POSIX incompatibilities with -m.
+		   # HP-UX 11.23 and IRIX 6.5 mkdir -m -p sets group- or
+		   # other-writeable bit of parent directory when it shouldn't.
+		   # FreeBSD 6.1 mkdir -m -p sets mode of existing directory.
+		   ls_ld_tmpdir=`ls -ld "$tmpdir"`
+		   case $ls_ld_tmpdir in
+		     d????-?r-*) different_mode=700;;
+		     d????-?--*) different_mode=755;;
+		     *) false;;
+		   esac &&
+		   $mkdirprog -m$different_mode -p -- "$tmpdir" && {
+		     ls_ld_tmpdir_1=`ls -ld "$tmpdir"`
+		     test "$ls_ld_tmpdir" = "$ls_ld_tmpdir_1"
+		   }
+		 }
+	      then posix_mkdir=:
+	      fi
+	      rmdir "$tmpdir/d" "$tmpdir"
+	    else
+	      # Remove any dirs left behind by ancient mkdir implementations.
+	      rmdir ./$mkdir_mode ./-p ./-- 2>/dev/null
+	    fi
+	    trap '' 0;;
+	esac;;
+    esac
+
+    if
+      $posix_mkdir && (
+	umask $mkdir_umask &&
+	$doit_exec $mkdirprog $mkdir_mode -p -- "$dstdir"
+      )
+    then :
+    else
+
+      # The umask is ridiculous, or mkdir does not conform to POSIX,
+      # or it failed possibly due to a race condition.  Create the
+      # directory the slow way, step by step, checking for races as we go.
+
+      case $dstdir in
+	/*) prefix='/';;
+	-*) prefix='./';;
+	*)  prefix='';;
+      esac
+
+      eval "$initialize_posix_glob"
+
+      oIFS=$IFS
+      IFS=/
+      $posix_glob set -f
+      set fnord $dstdir
+      shift
+      $posix_glob set +f
+      IFS=$oIFS
+
+      prefixes=
+
+      for d
+      do
+	test -z "$d" && continue
+
+	prefix=$prefix$d
+	if test -d "$prefix"; then
+	  prefixes=
+	else
+	  if $posix_mkdir; then
+	    (umask=$mkdir_umask &&
+	     $doit_exec $mkdirprog $mkdir_mode -p -- "$dstdir") && break
+	    # Don't fail if two instances are running concurrently.
+	    test -d "$prefix" || exit 1
+	  else
+	    case $prefix in
+	      *\'*) qprefix=`echo "$prefix" | sed "s/'/'\\\\\\\\''/g"`;;
+	      *) qprefix=$prefix;;
+	    esac
+	    prefixes="$prefixes '$qprefix'"
+	  fi
+	fi
+	prefix=$prefix/
+      done
+
+      if test -n "$prefixes"; then
+	# Don't fail if two instances are running concurrently.
+	(umask $mkdir_umask &&
+	 eval "\$doit_exec \$mkdirprog $prefixes") ||
+	  test -d "$dstdir" || exit 1
+	obsolete_mkdir_used=true
+      fi
+    fi
+  fi
+
+  if test -n "$dir_arg"; then
+    { test -z "$chowncmd" || $doit $chowncmd "$dst"; } &&
+    { test -z "$chgrpcmd" || $doit $chgrpcmd "$dst"; } &&
+    { test "$obsolete_mkdir_used$chowncmd$chgrpcmd" = false ||
+      test -z "$chmodcmd" || $doit $chmodcmd $mode "$dst"; } || exit 1
+  else
+
+    # Make a couple of temp file names in the proper directory.
+    dsttmp=$dstdir/_inst.$$_
+    rmtmp=$dstdir/_rm.$$_
+
+    # Trap to clean up those temp files at exit.
+    trap 'ret=$?; rm -f "$dsttmp" "$rmtmp" && exit $ret' 0
+
+    # Copy the file name to the temp name.
+    (umask $cp_umask && $doit_exec $cpprog "$src" "$dsttmp") &&
+
+    # and set any options; do chmod last to preserve setuid bits.
+    #
+    # If any of these fail, we abort the whole thing.  If we want to
+    # ignore errors from any of these, just make sure not to ignore
+    # errors from the above "$doit $cpprog $src $dsttmp" command.
+    #
+    { test -z "$chowncmd" || $doit $chowncmd "$dsttmp"; } &&
+    { test -z "$chgrpcmd" || $doit $chgrpcmd "$dsttmp"; } &&
+    { test -z "$stripcmd" || $doit $stripcmd "$dsttmp"; } &&
+    { test -z "$chmodcmd" || $doit $chmodcmd $mode "$dsttmp"; } &&
+
+    # If -C, don't bother to copy if it wouldn't change the file.
+    if $copy_on_change &&
+       old=`LC_ALL=C ls -dlL "$dst"	2>/dev/null` &&
+       new=`LC_ALL=C ls -dlL "$dsttmp"	2>/dev/null` &&
+
+       eval "$initialize_posix_glob" &&
+       $posix_glob set -f &&
+       set X $old && old=:$2:$4:$5:$6 &&
+       set X $new && new=:$2:$4:$5:$6 &&
+       $posix_glob set +f &&
+
+       test "$old" = "$new" &&
+       $cmpprog "$dst" "$dsttmp" >/dev/null 2>&1
+    then
+      rm -f "$dsttmp"
+    else
+      # Rename the file to the real destination.
+      $doit $mvcmd -f "$dsttmp" "$dst" 2>/dev/null ||
+
+      # The rename failed, perhaps because mv can't rename something else
+      # to itself, or perhaps because mv is so ancient that it does not
+      # support -f.
+      {
+	# Now remove or move aside any old file at destination location.
+	# We try this two ways since rm can't unlink itself on some
+	# systems and the destination file might be busy for other
+	# reasons.  In this case, the final cleanup might fail but the new
+	# file should still install successfully.
+	{
+	  test ! -f "$dst" ||
+	  $doit $rmcmd -f "$dst" 2>/dev/null ||
+	  { $doit $mvcmd -f "$dst" "$rmtmp" 2>/dev/null &&
+	    { $doit $rmcmd -f "$rmtmp" 2>/dev/null; :; }
+	  } ||
+	  { echo "$0: cannot unlink or rename $dst" >&2
+	    (exit 1); exit 1
+	  }
+	} &&
+
+	# Now rename the file to the real destination.
+	$doit $mvcmd "$dsttmp" "$dst"
+      }
+    fi || exit 1
+
+    trap '' 0
+  fi
+done
+
+# Local variables:
+# eval: (add-hook 'write-file-hooks 'time-stamp)
+# time-stamp-start: "scriptversion="
+# time-stamp-format: "%:y-%02m-%02d.%02H"
+# time-stamp-end: "$"
+# End:

missing

@@ -0,0 +1,367 @@
+#! /bin/sh
+# Common stub for a few missing GNU programs while installing.
+
+scriptversion=2006-05-10.23
+
+# Copyright (C) 1996, 1997, 1999, 2000, 2002, 2003, 2004, 2005, 2006
+#   Free Software Foundation, Inc.
+# Originally by Fran,cois Pinard <pinard@iro.umontreal.ca>, 1996.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+# 02110-1301, USA.
+
+# As a special exception to the GNU General Public License, if you
+# distribute this file as part of a program that contains a
+# configuration script generated by Autoconf, you may include it under
+# the same distribution terms that you use for the rest of that program.
+
+if test $# -eq 0; then
+  echo 1>&2 "Try \`$0 --help' for more information"
+  exit 1
+fi
+
+run=:
+sed_output='s/.* --output[ =]\([^ ]*\).*/\1/p'
+sed_minuso='s/.* -o \([^ ]*\).*/\1/p'
+
+# In the cases where this matters, `missing' is being run in the
+# srcdir already.
+if test -f configure.ac; then
+  configure_ac=configure.ac
+else
+  configure_ac=configure.in
+fi
+
+msg="missing on your system"
+
+case $1 in
+--run)
+  # Try to run requested program, and just exit if it succeeds.
+  run=
+  shift
+  "$@" && exit 0
+  # Exit code 63 means version mismatch.  This often happens
+  # when the user try to use an ancient version of a tool on
+  # a file that requires a minimum version.  In this case we
+  # we should proceed has if the program had been absent, or
+  # if --run hadn't been passed.
+  if test $? = 63; then
+    run=:
+    msg="probably too old"
+  fi
+  ;;
+
+  -h|--h|--he|--hel|--help)
+    echo "\
+$0 [OPTION]... PROGRAM [ARGUMENT]...
+
+Handle \`PROGRAM [ARGUMENT]...' for when PROGRAM is missing, or return an
+error status if there is no known handling for PROGRAM.
+
+Options:
+  -h, --help      display this help and exit
+  -v, --version   output version information and exit
+  --run           try to run the given command, and emulate it if it fails
+
+Supported PROGRAM values:
+  aclocal      touch file \`aclocal.m4'
+  autoconf     touch file \`configure'
+  autoheader   touch file \`config.h.in'
+  autom4te     touch the output file, or create a stub one
+  automake     touch all \`Makefile.in' files
+  bison        create \`y.tab.[ch]', if possible, from existing .[ch]
+  flex         create \`lex.yy.c', if possible, from existing .c
+  help2man     touch the output file
+  lex          create \`lex.yy.c', if possible, from existing .c
+  makeinfo     touch the output file
+  tar          try tar, gnutar, gtar, then tar without non-portable flags
+  yacc         create \`y.tab.[ch]', if possible, from existing .[ch]
+
+Send bug reports to <bug-automake@gnu.org>."
+    exit $?
+    ;;
+
+  -v|--v|--ve|--ver|--vers|--versi|--versio|--version)
+    echo "missing $scriptversion (GNU Automake)"
+    exit $?
+    ;;
+
+  -*)
+    echo 1>&2 "$0: Unknown \`$1' option"
+    echo 1>&2 "Try \`$0 --help' for more information"
+    exit 1
+    ;;
+
+esac
+
+# Now exit if we have it, but it failed.  Also exit now if we
+# don't have it and --version was passed (most likely to detect
+# the program).
+case $1 in
+  lex|yacc)
+    # Not GNU programs, they don't have --version.
+    ;;
+
+  tar)
+    if test -n "$run"; then
+       echo 1>&2 "ERROR: \`tar' requires --run"
+       exit 1
+    elif test "x$2" = "x--version" || test "x$2" = "x--help"; then
+       exit 1
+    fi
+    ;;
+
+  *)
+    if test -z "$run" && ($1 --version) > /dev/null 2>&1; then
+       # We have it, but it failed.
+       exit 1
+    elif test "x$2" = "x--version" || test "x$2" = "x--help"; then
+       # Could not run --version or --help.  This is probably someone
+       # running `$TOOL --version' or `$TOOL --help' to check whether
+       # $TOOL exists and not knowing $TOOL uses missing.
+       exit 1
+    fi
+    ;;
+esac
+
+# If it does not exist, or fails to run (possibly an outdated version),
+# try to emulate it.
+case $1 in
+  aclocal*)
+    echo 1>&2 "\
+WARNING: \`$1' is $msg.  You should only need it if
+         you modified \`acinclude.m4' or \`${configure_ac}'.  You might want
+         to install the \`Automake' and \`Perl' packages.  Grab them from
+         any GNU archive site."
+    touch aclocal.m4
+    ;;
+
+  autoconf)
+    echo 1>&2 "\
+WARNING: \`$1' is $msg.  You should only need it if
+         you modified \`${configure_ac}'.  You might want to install the
+         \`Autoconf' and \`GNU m4' packages.  Grab them from any GNU
+         archive site."
+    touch configure
+    ;;
+
+  autoheader)
+    echo 1>&2 "\
+WARNING: \`$1' is $msg.  You should only need it if
+         you modified \`acconfig.h' or \`${configure_ac}'.  You might want
+         to install the \`Autoconf' and \`GNU m4' packages.  Grab them
+         from any GNU archive site."
+    files=`sed -n 's/^[ ]*A[CM]_CONFIG_HEADER(\([^)]*\)).*/\1/p' ${configure_ac}`
+    test -z "$files" && files="config.h"
+    touch_files=
+    for f in $files; do
+      case $f in
+      *:*) touch_files="$touch_files "`echo "$f" |
+				       sed -e 's/^[^:]*://' -e 's/:.*//'`;;
+      *) touch_files="$touch_files $f.in";;
+      esac
+    done
+    touch $touch_files
+    ;;
+
+  automake*)
+    echo 1>&2 "\
+WARNING: \`$1' is $msg.  You should only need it if
+         you modified \`Makefile.am', \`acinclude.m4' or \`${configure_ac}'.
+         You might want to install the \`Automake' and \`Perl' packages.
+         Grab them from any GNU archive site."
+    find . -type f -name Makefile.am -print |
+	   sed 's/\.am$/.in/' |
+	   while read f; do touch "$f"; done
+    ;;
+
+  autom4te)
+    echo 1>&2 "\
+WARNING: \`$1' is needed, but is $msg.
+         You might have modified some files without having the
+         proper tools for further handling them.
+         You can get \`$1' as part of \`Autoconf' from any GNU
+         archive site."
+
+    file=`echo "$*" | sed -n "$sed_output"`
+    test -z "$file" && file=`echo "$*" | sed -n "$sed_minuso"`
+    if test -f "$file"; then
+	touch $file
+    else
+	test -z "$file" || exec >$file
+	echo "#! /bin/sh"
+	echo "# Created by GNU Automake missing as a replacement of"
+	echo "#  $ $@"
+	echo "exit 0"
+	chmod +x $file
+	exit 1
+    fi
+    ;;
+
+  bison|yacc)
+    echo 1>&2 "\
+WARNING: \`$1' $msg.  You should only need it if
+         you modified a \`.y' file.  You may need the \`Bison' package
+         in order for those modifications to take effect.  You can get
+         \`Bison' from any GNU archive site."
+    rm -f y.tab.c y.tab.h
+    if test $# -ne 1; then
+        eval LASTARG="\${$#}"
+	case $LASTARG in
+	*.y)
+	    SRCFILE=`echo "$LASTARG" | sed 's/y$/c/'`
+	    if test -f "$SRCFILE"; then
+	         cp "$SRCFILE" y.tab.c
+	    fi
+	    SRCFILE=`echo "$LASTARG" | sed 's/y$/h/'`
+	    if test -f "$SRCFILE"; then
+	         cp "$SRCFILE" y.tab.h
+	    fi
+	  ;;
+	esac
+    fi
+    if test ! -f y.tab.h; then
+	echo >y.tab.h
+    fi
+    if test ! -f y.tab.c; then
+	echo 'main() { return 0; }' >y.tab.c
+    fi
+    ;;
+
+  lex|flex)
+    echo 1>&2 "\
+WARNING: \`$1' is $msg.  You should only need it if
+         you modified a \`.l' file.  You may need the \`Flex' package
+         in order for those modifications to take effect.  You can get
+         \`Flex' from any GNU archive site."
+    rm -f lex.yy.c
+    if test $# -ne 1; then
+        eval LASTARG="\${$#}"
+	case $LASTARG in
+	*.l)
+	    SRCFILE=`echo "$LASTARG" | sed 's/l$/c/'`
+	    if test -f "$SRCFILE"; then
+	         cp "$SRCFILE" lex.yy.c
+	    fi
+	  ;;
+	esac
+    fi
+    if test ! -f lex.yy.c; then
+	echo 'main() { return 0; }' >lex.yy.c
+    fi
+    ;;
+
+  help2man)
+    echo 1>&2 "\
+WARNING: \`$1' is $msg.  You should only need it if
+	 you modified a dependency of a manual page.  You may need the
+	 \`Help2man' package in order for those modifications to take
+	 effect.  You can get \`Help2man' from any GNU archive site."
+
+    file=`echo "$*" | sed -n "$sed_output"`
+    test -z "$file" && file=`echo "$*" | sed -n "$sed_minuso"`
+    if test -f "$file"; then
+	touch $file
+    else
+	test -z "$file" || exec >$file
+	echo ".ab help2man is required to generate this page"
+	exit 1
+    fi
+    ;;
+
+  makeinfo)
+    echo 1>&2 "\
+WARNING: \`$1' is $msg.  You should only need it if
+         you modified a \`.texi' or \`.texinfo' file, or any other file
+         indirectly affecting the aspect of the manual.  The spurious
+         call might also be the consequence of using a buggy \`make' (AIX,
+         DU, IRIX).  You might want to install the \`Texinfo' package or
+         the \`GNU make' package.  Grab either from any GNU archive site."
+    # The file to touch is that specified with -o ...
+    file=`echo "$*" | sed -n "$sed_output"`
+    test -z "$file" && file=`echo "$*" | sed -n "$sed_minuso"`
+    if test -z "$file"; then
+      # ... or it is the one specified with @setfilename ...
+      infile=`echo "$*" | sed 's/.* \([^ ]*\) *$/\1/'`
+      file=`sed -n '
+	/^@setfilename/{
+	  s/.* \([^ ]*\) *$/\1/
+	  p
+	  q
+	}' $infile`
+      # ... or it is derived from the source name (dir/f.texi becomes f.info)
+      test -z "$file" && file=`echo "$infile" | sed 's,.*/,,;s,.[^.]*$,,'`.info
+    fi
+    # If the file does not exist, the user really needs makeinfo;
+    # let's fail without touching anything.
+    test -f $file || exit 1
+    touch $file
+    ;;
+
+  tar)
+    shift
+
+    # We have already tried tar in the generic part.
+    # Look for gnutar/gtar before invocation to avoid ugly error
+    # messages.
+    if (gnutar --version > /dev/null 2>&1); then
+       gnutar "$@" && exit 0
+    fi
+    if (gtar --version > /dev/null 2>&1); then
+       gtar "$@" && exit 0
+    fi
+    firstarg="$1"
+    if shift; then
+	case $firstarg in
+	*o*)
+	    firstarg=`echo "$firstarg" | sed s/o//`
+	    tar "$firstarg" "$@" && exit 0
+	    ;;
+	esac
+	case $firstarg in
+	*h*)
+	    firstarg=`echo "$firstarg" | sed s/h//`
+	    tar "$firstarg" "$@" && exit 0
+	    ;;
+	esac
+    fi
+
+    echo 1>&2 "\
+WARNING: I can't seem to be able to run \`tar' with the given arguments.
+         You may want to install GNU tar or Free paxutils, or check the
+         command line arguments."
+    exit 1
+    ;;
+
+  *)
+    echo 1>&2 "\
+WARNING: \`$1' is needed, and is $msg.
+         You might have modified some files without having the
+         proper tools for further handling them.  Check the \`README' file,
+         it often tells you about the needed prerequisites for installing
+         this package.  You may also peek at any GNU archive site, in case
+         some other package would contain this missing \`$1' program."
+    exit 1
+    ;;
+esac
+
+exit 0
+
+# Local variables:
+# eval: (add-hook 'write-file-hooks 'time-stamp)
+# time-stamp-start: "scriptversion="
+# time-stamp-format: "%:y-%02m-%02d.%02H"
+# time-stamp-end: "$"
+# End:

mkinstalldirs

@@ -0,0 +1,161 @@
+#! /bin/sh
+# mkinstalldirs --- make directory hierarchy
+
+scriptversion=2006-05-11.19
+
+# Original author: Noah Friedman <friedman@prep.ai.mit.edu>
+# Created: 1993-05-16
+# Public domain.
+#
+# This file is maintained in Automake, please report
+# bugs to <bug-automake@gnu.org> or send patches to
+# <automake-patches@gnu.org>.
+
+nl='
+'
+IFS=" ""	$nl"
+errstatus=0
+dirmode=
+
+usage="\
+Usage: mkinstalldirs [-h] [--help] [--version] [-m MODE] DIR ...
+
+Create each directory DIR (with mode MODE, if specified), including all
+leading file name components.
+
+Report bugs to <bug-automake@gnu.org>."
+
+# process command line arguments
+while test $# -gt 0 ; do
+  case $1 in
+    -h | --help | --h*)         # -h for help
+      echo "$usage"
+      exit $?
+      ;;
+    -m)                         # -m PERM arg
+      shift
+      test $# -eq 0 && { echo "$usage" 1>&2; exit 1; }
+      dirmode=$1
+      shift
+      ;;
+    --version)
+      echo "$0 $scriptversion"
+      exit $?
+      ;;
+    --)                         # stop option processing
+      shift
+      break
+      ;;
+    -*)                         # unknown option
+      echo "$usage" 1>&2
+      exit 1
+      ;;
+    *)                          # first non-opt arg
+      break
+      ;;
+  esac
+done
+
+for file
+do
+  if test -d "$file"; then
+    shift
+  else
+    break
+  fi
+done
+
+case $# in
+  0) exit 0 ;;
+esac
+
+# Solaris 8's mkdir -p isn't thread-safe.  If you mkdir -p a/b and
+# mkdir -p a/c at the same time, both will detect that a is missing,
+# one will create a, then the other will try to create a and die with
+# a "File exists" error.  This is a problem when calling mkinstalldirs
+# from a parallel make.  We use --version in the probe to restrict
+# ourselves to GNU mkdir, which is thread-safe.
+case $dirmode in
+  '')
+    if mkdir -p --version . >/dev/null 2>&1 && test ! -d ./--version; then
+      echo "mkdir -p -- $*"
+      exec mkdir -p -- "$@"
+    else
+      # On NextStep and OpenStep, the `mkdir' command does not
+      # recognize any option.  It will interpret all options as
+      # directories to create, and then abort because `.' already
+      # exists.
+      test -d ./-p && rmdir ./-p
+      test -d ./--version && rmdir ./--version
+    fi
+    ;;
+  *)
+    if mkdir -m "$dirmode" -p --version . >/dev/null 2>&1 &&
+       test ! -d ./--version; then
+      echo "mkdir -m $dirmode -p -- $*"
+      exec mkdir -m "$dirmode" -p -- "$@"
+    else
+      # Clean up after NextStep and OpenStep mkdir.
+      for d in ./-m ./-p ./--version "./$dirmode";
+      do
+        test -d $d && rmdir $d
+      done
+    fi
+    ;;
+esac
+
+for file
+do
+  case $file in
+    /*) pathcomp=/ ;;
+    *)  pathcomp= ;;
+  esac
+  oIFS=$IFS
+  IFS=/
+  set fnord $file
+  shift
+  IFS=$oIFS
+
+  for d
+  do
+    test "x$d" = x && continue
+
+    pathcomp=$pathcomp$d
+    case $pathcomp in
+      -*) pathcomp=./$pathcomp ;;
+    esac
+
+    if test ! -d "$pathcomp"; then
+      echo "mkdir $pathcomp"
+
+      mkdir "$pathcomp" || lasterr=$?
+
+      if test ! -d "$pathcomp"; then
+	errstatus=$lasterr
+      else
+	if test ! -z "$dirmode"; then
+	  echo "chmod $dirmode $pathcomp"
+	  lasterr=
+	  chmod "$dirmode" "$pathcomp" || lasterr=$?
+
+	  if test ! -z "$lasterr"; then
+	    errstatus=$lasterr
+	  fi
+	fi
+      fi
+    fi
+
+    pathcomp=$pathcomp/
+  done
+done
+
+exit $errstatus
+
+# Local Variables:
+# mode: shell-script
+# sh-indentation: 2
+# eval: (add-hook 'write-file-hooks 'time-stamp)
+# time-stamp-start: "scriptversion="
+# time-stamp-format: "%:y-%02m-%02d.%02H"
+# time-stamp-end: "$"
+# End:

png.5

@@ -1,4 +1,4 @@
-.TH PNG 5 "May 9, 1998"
+.TH PNG 5 "October 31, 2008"
 .SH NAME
 png \- Portable Network Graphics (PNG) format
 .SH DESCRIPTION
@@ -7,7 +7,7 @@ lossless, portable, well-compressed storage of raster images. PNG provides
 a patent-free replacement for GIF and can also replace many
 common uses of TIFF. Indexed-color, grayscale, and truecolor images are
 supported, plus an optional alpha channel. Sample depths range from
-1 to 16 bits. 
+1 to 16 bits.
 .br
 
 PNG is designed to work well in online viewing applications, such as the
@@ -15,16 +15,27 @@ World Wide Web, so it is fully streamable with a progressive display
 option. PNG is robust, providing both full file integrity checking and
 fast, simple detection of common transmission errors. Also, PNG can store
 gamma and chromaticity data for improved color matching on heterogeneous
-platforms. 
+platforms.
 
 .SH "SEE ALSO"
-.IR libpng(3), zlib(3), deflate(5), and zlib(5)
+.IR libpng(3) ", " zlib(3) ", " deflate(5) ", and " zlib(5)
 .LP
-PNG specification:
+PNG specification (second edition), November 2003:
+.IP
+.br
+  <http://www.w3.org/TR/2003/REC-PNG-20031110/
+PNG 1.2 specification, July 1999:
+.IP
+.br
+http://www.libpng.org/pub/png
+.LP
+PNG 1.0 specification, October 1996:
+.IP
+.br
 RFC 2083
 .IP
 .br
-ftp://ds.internic.net/rfc/rfc2083.txt
+ftp://ftp.rfc-editor.org:/in-notes/rfc2083.txt
 .br
 or (as a W3C Recommendation) at
 .br
@@ -32,12 +43,31 @@ http://www.w3.org/TR/REC-png.html
 .SH AUTHORS
 This man page: Glenn Randers-Pehrson
 .LP
+Portable Network Graphics (PNG) Specification (Second Edition)
+Information technology - Computer graphics and image processing -
+Portable Network Graphics (PNG): Functional specification.
+ISO/IEC 15948:2003 (E) (November 10, 2003): David Duce and others.
+.LP
+Portable Network Graphics (PNG) Specification Version 1.2 (July 8, 1999):
+Glenn Randers-Pehrson and others (png-list).
+.LP
 Portable Network Graphics (PNG) Specification Version 1.0 (October 1, 1996):
-Thomas Boutell and others (png-list@dworkin.wustl.edu).
+Thomas Boutell and others (png-list).
 .LP
 
+
 .SH COPYRIGHT NOTICE
-The PNG specification is copyright (c) 1996 Massachussets Institute of
+.LP
+This man page is Copyright (c) 1998-2006 Glenn Randers-Pehrson.  See png.h
+for conditions of use and distribution.
+.LP
+The PNG Specification (Second Edition) is
+Copyright (c) 2003 W3C. (MIT, ERCIM, Keio), All Rights Reserved.
+.LP
+The PNG-1.2 specification is copyright (c) 1999 Glenn Randers-Pehrson.
+See the specification for conditions of use and distribution.
+.LP
+The PNG-1.0 specification is copyright (c) 1996 Massachusetts Institute of
 Technology.  See the specification for conditions of use and distribution.
 .LP
 .\" end of man page

png.c

@@ -1,92 +1,103 @@
 
 /* png.c - location for general purpose libpng functions
  *
- * libpng 1.0.1c
+ * Last changed in libpng 1.2.30 [August 15, 2008]
  * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
- * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
- * May 9, 1998
+ * Copyright (c) 1998-2008 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  */
 
 #define PNG_INTERNAL
 #define PNG_NO_EXTERN
 #include "png.h"
 
+/* Generate a compiler error if there is an old png.h in the search path. */
+typedef version_1_0_41 Your_png_h_is_not_version_1_0_41;
+
 /* Version information for C files.  This had better match the version
- * string defined in png.h.
- */
-char png_libpng_ver[12] = "1.0.1c";
+ * string defined in png.h.  */
 
+#ifdef PNG_USE_GLOBAL_ARRAYS
+/* png_libpng_ver was changed to a function in version 1.0.5c */
+PNG_CONST char png_libpng_ver[18] = PNG_LIBPNG_VER_STRING;
+
+#ifdef PNG_READ_SUPPORTED
+
+/* png_sig was changed to a function in version 1.0.5c */
 /* Place to hold the signature string for a PNG file. */
-png_byte FARDATA png_sig[8] = {137, 80, 78, 71, 13, 10, 26, 10};
+PNG_CONST png_byte FARDATA png_sig[8] = {137, 80, 78, 71, 13, 10, 26, 10};
+#endif /* PNG_READ_SUPPORTED */
 
-/* Constant strings for known chunk types.  If you need to add a chunk,
- * add a string holding the name here.  If you want to make the code
- * portable to EBCDIC machines, use ASCII numbers, not characters.
- */
-png_byte FARDATA png_IHDR[5] = { 73,  72,  68,  82, '\0'};
-png_byte FARDATA png_IDAT[5] = { 73,  68,  65,  84, '\0'};
-png_byte FARDATA png_IEND[5] = { 73,  69,  78,  68, '\0'};
-png_byte FARDATA png_PLTE[5] = { 80,  76,  84,  69, '\0'};
-png_byte FARDATA png_bKGD[5] = { 98,  75,  71,  68, '\0'};
-png_byte FARDATA png_cHRM[5] = { 99,  72,  82,  77, '\0'};
-png_byte FARDATA png_gAMA[5] = {103,  65,  77,  65, '\0'};
-png_byte FARDATA png_hIST[5] = {104,  73,  83,  84, '\0'};
-png_byte FARDATA png_oFFs[5] = {111,  70,  70, 115, '\0'};
-png_byte FARDATA png_pCAL[5] = {112,  67,  65,  76, '\0'};
-png_byte FARDATA png_pHYs[5] = {112,  72,  89, 115, '\0'};
-png_byte FARDATA png_sBIT[5] = {115,  66,  73,  84, '\0'};
-png_byte FARDATA png_sRGB[5] = {115,  82,  71,  66, '\0'};
-png_byte FARDATA png_tEXt[5] = {116,  69,  88, 116, '\0'};
-png_byte FARDATA png_tIME[5] = {116,  73,  77,  69, '\0'};
-png_byte FARDATA png_tRNS[5] = {116,  82,  78,  83, '\0'};
-png_byte FARDATA png_zTXt[5] = {122,  84,  88, 116, '\0'};
+/* Invoke global declarations for constant strings for known chunk types */
+PNG_IHDR;
+PNG_IDAT;
+PNG_IEND;
+PNG_PLTE;
+PNG_bKGD;
+PNG_cHRM;
+PNG_gAMA;
+PNG_hIST;
+PNG_iCCP;
+PNG_iTXt;
+PNG_oFFs;
+PNG_pCAL;
+PNG_sCAL;
+PNG_pHYs;
+PNG_sBIT;
+PNG_sPLT;
+PNG_sRGB;
+PNG_tEXt;
+PNG_tIME;
+PNG_tRNS;
+PNG_zTXt;
 
+#ifdef PNG_READ_SUPPORTED
 /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
 
 /* start of interlace block */
-int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
+PNG_CONST int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
 
 /* offset to next interlace block */
-int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
+PNG_CONST int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
 
 /* start of interlace block in the y direction */
-int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
+PNG_CONST int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
 
 /* offset to next interlace block in the y direction */
-int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
-
-/* Width of interlace block.  This is not currently used - if you need
- * it, uncomment it here and in png.h
-int FARDATA png_pass_width[] = {8, 4, 4, 2, 2, 1, 1};
-*/
+PNG_CONST int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
 
 /* Height of interlace block.  This is not currently used - if you need
  * it, uncomment it here and in png.h
-int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
+PNG_CONST int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
 */
 
 /* Mask to determine which pixels are valid in a pass */
-int FARDATA png_pass_mask[] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
+PNG_CONST int FARDATA png_pass_mask[] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
 
 /* Mask to determine which pixels to overwrite while displaying */
-int FARDATA png_pass_dsp_mask[] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
+PNG_CONST int FARDATA png_pass_dsp_mask[]
+   = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
 
+#endif /* PNG_READ_SUPPORTED */
+#endif /* PNG_USE_GLOBAL_ARRAYS */
 
 /* Tells libpng that we have already handled the first "num_bytes" bytes
  * of the PNG file signature.  If the PNG data is embedded into another
  * stream we can set num_bytes = 8 so that libpng will not attempt to read
  * or write any of the magic bytes before it starts on the IHDR.
  */
-void
+
+#ifdef PNG_READ_SUPPORTED
+void PNGAPI
 png_set_sig_bytes(png_structp png_ptr, int num_bytes)
 {
+   if (png_ptr == NULL) return;
    png_debug(1, "in png_set_sig_bytes\n");
    if (num_bytes > 8)
       png_error(png_ptr, "Too many bytes for PNG signature.");
 
-   png_ptr->sig_bytes = num_bytes < 0 ? 0 : num_bytes;
+   png_ptr->sig_bytes = (png_byte)(num_bytes < 0 ? 0 : num_bytes);
 }
 
 /* Checks whether the supplied bytes match the PNG signature.  We allow
@@ -97,43 +108,68 @@ png_set_sig_bytes(png_structp png_ptr, int num_bytes)
  * respectively, to be less than, to match, or be greater than the correct
  * PNG signature (this is the same behaviour as strcmp, memcmp, etc).
  */
-int
+int PNGAPI
 png_sig_cmp(png_bytep sig, png_size_t start, png_size_t num_to_check)
 {
+   png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
    if (num_to_check > 8)
       num_to_check = 8;
    else if (num_to_check < 1)
-      return (0);
+      return (-1);
 
    if (start > 7)
-      return (0);
+      return (-1);
 
    if (start + num_to_check > 8)
       num_to_check = 8 - start;
 
-   return ((int)(png_memcmp(&sig[start], &png_sig[start], num_to_check)));
+   return ((int)(png_memcmp(&sig[start], &png_signature[start], num_to_check)));
 }
 
+#if defined(PNG_1_0_X) || defined(PNG_1_2_X)
 /* (Obsolete) function to check signature bytes.  It does not allow one
- * to check a partial signature.  This function will be removed in the
- * future - use png_sig_cmp().
+ * to check a partial signature.  This function might be removed in the
+ * future - use png_sig_cmp().  Returns true (nonzero) if the file is PNG.
  */
-int
+int PNGAPI
 png_check_sig(png_bytep sig, int num)
 {
   return ((int)!png_sig_cmp(sig, (png_size_t)0, (png_size_t)num));
 }
+#endif
+#endif /* PNG_READ_SUPPORTED */
 
-/* Function to allocate memory for zlib. */
-voidpf
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+/* Function to allocate memory for zlib and clear it to 0. */
+#ifdef PNG_1_0_X
+voidpf PNGAPI
+#else
+voidpf /* private */
+#endif
 png_zalloc(voidpf png_ptr, uInt items, uInt size)
 {
    png_voidp ptr;
+   png_structp p=(png_structp)png_ptr;
+   png_uint_32 save_flags=p->flags;
    png_uint_32 num_bytes;
 
+   if (png_ptr == NULL) return (NULL);
+   if (items > PNG_UINT_32_MAX/size)
+   {
+     png_warning (p, "Potential overflow in png_zalloc()");
+     return (NULL);
+   }
    num_bytes = (png_uint_32)items * size;
+
+   p->flags|=PNG_FLAG_MALLOC_NULL_MEM_OK;
    ptr = (png_voidp)png_malloc((png_structp)png_ptr, num_bytes);
-   if (num_bytes > (png_uint_32)0x8000)
+   p->flags=save_flags;
+
+#if defined(PNG_1_0_X) && !defined(PNG_NO_ZALLOC_ZERO)
+   if (ptr == NULL)
+       return ((voidpf)ptr);
+
+   if (num_bytes > (png_uint_32)0x8000L)
    {
       png_memset(ptr, 0, (png_size_t)0x8000L);
       png_memset((png_bytep)ptr + (png_size_t)0x8000L, 0,
@@ -143,11 +179,16 @@ png_zalloc(voidpf png_ptr, uInt items, uInt size)
    {
       png_memset(ptr, 0, (png_size_t)num_bytes);
    }
+#endif
    return ((voidpf)ptr);
 }
 
 /* function to free memory for zlib */
-void
+#ifdef PNG_1_0_X
+void PNGAPI
+#else
+void /* private */
+#endif
 png_zfree(voidpf png_ptr, voidpf ptr)
 {
    png_free((png_structp)png_ptr, (png_voidp)ptr);
@@ -156,7 +197,7 @@ png_zfree(voidpf png_ptr, voidpf ptr)
 /* Reset the CRC variable to 32 bits of 1's.  Care must be taken
  * in case CRC is > 32 bits to leave the top bits 0.
  */
-void
+void /* PRIVATE */
 png_reset_crc(png_structp png_ptr)
 {
    png_ptr->crc = crc32(0, Z_NULL, 0);
@@ -167,7 +208,7 @@ png_reset_crc(png_structp png_ptr)
  * also check that this data will actually be used before going to the
  * trouble of calculating it.
  */
-void
+void /* PRIVATE */
 png_calculate_crc(png_structp png_ptr, png_bytep ptr, png_size_t length)
 {
    int need_crc = 1;
@@ -190,21 +231,25 @@ png_calculate_crc(png_structp png_ptr, png_bytep ptr, png_size_t length)
 
 /* Allocate the memory for an info_struct for the application.  We don't
  * really need the png_ptr, but it could potentially be useful in the
- * future.  This should be used in favour of malloc(sizeof(png_info))
+ * future.  This should be used in favour of malloc(png_sizeof(png_info))
  * and png_info_init() so that applications that want to use a shared
  * libpng don't have to be recompiled if png_info changes size.
  */
-png_infop
+png_infop PNGAPI
 png_create_info_struct(png_structp png_ptr)
 {
    png_infop info_ptr;
 
    png_debug(1, "in png_create_info_struct\n");
-   if(png_ptr == NULL) return (NULL);
-   if ((info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO)) != NULL)
-   {
-      png_info_init(info_ptr);
-   }
+   if (png_ptr == NULL) return (NULL);
+#ifdef PNG_USER_MEM_SUPPORTED
+   info_ptr = (png_infop)png_create_struct_2(PNG_STRUCT_INFO,
+      png_ptr->malloc_fn, png_ptr->mem_ptr);
+#else
+   info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO);
+#endif
+   if (info_ptr != NULL)
+      png_info_init_3(&info_ptr, png_sizeof(png_info));
 
    return (info_ptr);
 }
@@ -214,10 +259,11 @@ png_create_info_struct(png_structp png_ptr)
  * png_destroy_write_struct() to free an info struct, but this may be
  * useful for some applications.
  */
-void
+void PNGAPI
 png_destroy_info_struct(png_structp png_ptr, png_infopp info_ptr_ptr)
 {
    png_infop info_ptr = NULL;
+   if (png_ptr == NULL) return;
 
    png_debug(1, "in png_destroy_info_struct\n");
    if (info_ptr_ptr != NULL)
@@ -227,8 +273,13 @@ png_destroy_info_struct(png_structp png_ptr, png_infopp info_ptr_ptr)
    {
       png_info_destroy(png_ptr, info_ptr);
 
+#ifdef PNG_USER_MEM_SUPPORTED
+      png_destroy_struct_2((png_voidp)info_ptr, png_ptr->free_fn,
+          png_ptr->mem_ptr);
+#else
       png_destroy_struct((png_voidp)info_ptr);
-      *info_ptr_ptr = (png_infop)NULL;
+#endif
+      *info_ptr_ptr = NULL;
    }
 }
 
@@ -236,69 +287,513 @@ png_destroy_info_struct(png_structp png_ptr, png_infopp info_ptr_ptr)
  * and applications using it are urged to use png_create_info_struct()
  * instead.
  */
-void
+#if defined(PNG_1_0_X) || defined(PNG_1_2_X)
+#undef png_info_init
+void PNGAPI
 png_info_init(png_infop info_ptr)
 {
-   png_debug(1, "in png_info_init\n");
+   /* We only come here via pre-1.0.12-compiled applications */
+   png_info_init_3(&info_ptr, 0);
+}
+#endif
+
+void PNGAPI
+png_info_init_3(png_infopp ptr_ptr, png_size_t png_info_struct_size)
+{
+   png_infop info_ptr = *ptr_ptr;
+
+   if (info_ptr == NULL) return;
+
+   png_debug(1, "in png_info_init_3\n");
+
+   if (png_sizeof(png_info) > png_info_struct_size)
+     {
+       png_destroy_struct(info_ptr);
+       info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO);
+       *ptr_ptr = info_ptr;
+     }
+
    /* set everything to 0 */
-   png_memset(info_ptr, 0, sizeof (png_info));
+   png_memset(info_ptr, 0, png_sizeof(png_info));
+}
+
+#ifdef PNG_FREE_ME_SUPPORTED
+void PNGAPI
+png_data_freer(png_structp png_ptr, png_infop info_ptr,
+   int freer, png_uint_32 mask)
+{
+   png_debug(1, "in png_data_freer\n");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+   if (freer == PNG_DESTROY_WILL_FREE_DATA)
+      info_ptr->free_me |= mask;
+   else if (freer == PNG_USER_WILL_FREE_DATA)
+      info_ptr->free_me &= ~mask;
+   else
+      png_warning(png_ptr,
+         "Unknown freer parameter in png_data_freer.");
+}
+#endif
+
+void PNGAPI
+png_free_data(png_structp png_ptr, png_infop info_ptr, png_uint_32 mask,
+   int num)
+{
+   png_debug(1, "in png_free_data\n");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+#if defined(PNG_TEXT_SUPPORTED)
+/* free text item num or (if num == -1) all text items */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_TEXT) & info_ptr->free_me)
+#else
+if (mask & PNG_FREE_TEXT)
+#endif
+{
+   if (num != -1)
+   {
+     if (info_ptr->text && info_ptr->text[num].key)
+     {
+         png_free(png_ptr, info_ptr->text[num].key);
+         info_ptr->text[num].key = NULL;
+     }
+   }
+   else
+   {
+       int i;
+       for (i = 0; i < info_ptr->num_text; i++)
+           png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, i);
+       png_free(png_ptr, info_ptr->text);
+       info_ptr->text = NULL;
+       info_ptr->num_text=0;
+   }
+}
+#endif
+
+#if defined(PNG_tRNS_SUPPORTED)
+/* free any tRNS entry */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_TRNS) & info_ptr->free_me)
+#else
+if ((mask & PNG_FREE_TRNS) && (png_ptr->flags & PNG_FLAG_FREE_TRNS))
+#endif
+{
+    png_free(png_ptr, info_ptr->trans);
+    info_ptr->trans = NULL;
+    info_ptr->valid &= ~PNG_INFO_tRNS;
+#ifndef PNG_FREE_ME_SUPPORTED
+    png_ptr->flags &= ~PNG_FLAG_FREE_TRNS;
+#endif
+}
+#endif
+
+#if defined(PNG_sCAL_SUPPORTED)
+/* free any sCAL entry */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_SCAL) & info_ptr->free_me)
+#else
+if (mask & PNG_FREE_SCAL)
+#endif
+{
+#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
+    png_free(png_ptr, info_ptr->scal_s_width);
+    png_free(png_ptr, info_ptr->scal_s_height);
+    info_ptr->scal_s_width = NULL;
+    info_ptr->scal_s_height = NULL;
+#endif
+    info_ptr->valid &= ~PNG_INFO_sCAL;
+}
+#endif
+
+#if defined(PNG_pCAL_SUPPORTED)
+/* free any pCAL entry */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_PCAL) & info_ptr->free_me)
+#else
+if (mask & PNG_FREE_PCAL)
+#endif
+{
+    png_free(png_ptr, info_ptr->pcal_purpose);
+    png_free(png_ptr, info_ptr->pcal_units);
+    info_ptr->pcal_purpose = NULL;
+    info_ptr->pcal_units = NULL;
+    if (info_ptr->pcal_params != NULL)
+    {
+        int i;
+        for (i = 0; i < (int)info_ptr->pcal_nparams; i++)
+        {
+          png_free(png_ptr, info_ptr->pcal_params[i]);
+          info_ptr->pcal_params[i]=NULL;
+        }
+        png_free(png_ptr, info_ptr->pcal_params);
+        info_ptr->pcal_params = NULL;
+    }
+    info_ptr->valid &= ~PNG_INFO_pCAL;
+}
+#endif
+
+#if defined(PNG_iCCP_SUPPORTED)
+/* free any iCCP entry */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_ICCP) & info_ptr->free_me)
+#else
+if (mask & PNG_FREE_ICCP)
+#endif
+{
+    png_free(png_ptr, info_ptr->iccp_name);
+    png_free(png_ptr, info_ptr->iccp_profile);
+    info_ptr->iccp_name = NULL;
+    info_ptr->iccp_profile = NULL;
+    info_ptr->valid &= ~PNG_INFO_iCCP;
+}
+#endif
+
+#if defined(PNG_sPLT_SUPPORTED)
+/* free a given sPLT entry, or (if num == -1) all sPLT entries */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_SPLT) & info_ptr->free_me)
+#else
+if (mask & PNG_FREE_SPLT)
+#endif
+{
+   if (num != -1)
+   {
+      if (info_ptr->splt_palettes)
+      {
+          png_free(png_ptr, info_ptr->splt_palettes[num].name);
+          png_free(png_ptr, info_ptr->splt_palettes[num].entries);
+          info_ptr->splt_palettes[num].name = NULL;
+          info_ptr->splt_palettes[num].entries = NULL;
+      }
+   }
+   else
+   {
+       if (info_ptr->splt_palettes_num)
+       {
+         int i;
+         for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
+            png_free_data(png_ptr, info_ptr, PNG_FREE_SPLT, i);
+
+         png_free(png_ptr, info_ptr->splt_palettes);
+         info_ptr->splt_palettes = NULL;
+         info_ptr->splt_palettes_num = 0;
+       }
+       info_ptr->valid &= ~PNG_INFO_sPLT;
+   }
+}
+#endif
+
+#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+  if (png_ptr->unknown_chunk.data)
+  {
+    png_free(png_ptr, png_ptr->unknown_chunk.data);
+    png_ptr->unknown_chunk.data = NULL;
+  }
+
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_UNKN) & info_ptr->free_me)
+#else
+if (mask & PNG_FREE_UNKN)
+#endif
+{
+   if (num != -1)
+   {
+       if (info_ptr->unknown_chunks)
+       {
+          png_free(png_ptr, info_ptr->unknown_chunks[num].data);
+          info_ptr->unknown_chunks[num].data = NULL;
+       }
+   }
+   else
+   {
+       int i;
+
+       if (info_ptr->unknown_chunks_num)
+       {
+         for (i = 0; i < (int)info_ptr->unknown_chunks_num; i++)
+            png_free_data(png_ptr, info_ptr, PNG_FREE_UNKN, i);
+
+         png_free(png_ptr, info_ptr->unknown_chunks);
+         info_ptr->unknown_chunks = NULL;
+         info_ptr->unknown_chunks_num = 0;
+       }
+   }
+}
+#endif
+
+#if defined(PNG_hIST_SUPPORTED)
+/* free any hIST entry */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_HIST)  & info_ptr->free_me)
+#else
+if ((mask & PNG_FREE_HIST) && (png_ptr->flags & PNG_FLAG_FREE_HIST))
+#endif
+{
+    png_free(png_ptr, info_ptr->hist);
+    info_ptr->hist = NULL;
+    info_ptr->valid &= ~PNG_INFO_hIST;
+#ifndef PNG_FREE_ME_SUPPORTED
+    png_ptr->flags &= ~PNG_FLAG_FREE_HIST;
+#endif
+}
+#endif
+
+/* free any PLTE entry that was internally allocated */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_PLTE) & info_ptr->free_me)
+#else
+if ((mask & PNG_FREE_PLTE) && (png_ptr->flags & PNG_FLAG_FREE_PLTE))
+#endif
+{
+    png_zfree(png_ptr, info_ptr->palette);
+    info_ptr->palette = NULL;
+    info_ptr->valid &= ~PNG_INFO_PLTE;
+#ifndef PNG_FREE_ME_SUPPORTED
+    png_ptr->flags &= ~PNG_FLAG_FREE_PLTE;
+#endif
+    info_ptr->num_palette = 0;
+}
+
+#if defined(PNG_INFO_IMAGE_SUPPORTED)
+/* free any image bits attached to the info structure */
+#ifdef PNG_FREE_ME_SUPPORTED
+if ((mask & PNG_FREE_ROWS) & info_ptr->free_me)
+#else
+if (mask & PNG_FREE_ROWS)
+#endif
+{
+    if (info_ptr->row_pointers)
+    {
+       int row;
+       for (row = 0; row < (int)info_ptr->height; row++)
+       {
+          png_free(png_ptr, info_ptr->row_pointers[row]);
+          info_ptr->row_pointers[row]=NULL;
+       }
+       png_free(png_ptr, info_ptr->row_pointers);
+       info_ptr->row_pointers=NULL;
+    }
+    info_ptr->valid &= ~PNG_INFO_IDAT;
+}
+#endif
+
+#ifdef PNG_FREE_ME_SUPPORTED
+   if (num == -1)
+     info_ptr->free_me &= ~mask;
+   else
+     info_ptr->free_me &= ~(mask & ~PNG_FREE_MUL);
+#endif
 }
 
 /* This is an internal routine to free any memory that the info struct is
  * pointing to before re-using it or freeing the struct itself.  Recall
  * that png_free() checks for NULL pointers for us.
  */
-void
+void /* PRIVATE */
 png_info_destroy(png_structp png_ptr, png_infop info_ptr)
 {
-#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED)
-   int i;
-
    png_debug(1, "in png_info_destroy\n");
-   if (info_ptr->text != NULL)
+
+   png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
+
+#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+   if (png_ptr->num_chunk_list)
    {
-      for (i = 0; i < info_ptr->num_text; i++)
-      {
-         png_free(png_ptr, info_ptr->text[i].key);
-      }
-      png_free(png_ptr, info_ptr->text);
-   }
-#endif
-#if defined(PNG_READ_pCAL_SUPPORTED)
-   png_free(png_ptr, info_ptr->pcal_purpose);
-   png_free(png_ptr, info_ptr->pcal_units);
-   if (info_ptr->pcal_params != NULL)
-   {
-      for (i = 0; i < (int)info_ptr->pcal_nparams; i++)
-      {
-         png_free(png_ptr, info_ptr->pcal_params[i]);
-      }
-      png_free(png_ptr, info_ptr->pcal_params);
+       png_free(png_ptr, png_ptr->chunk_list);
+       png_ptr->chunk_list=NULL;
+       png_ptr->num_chunk_list = 0;
    }
 #endif
 
-   png_info_init(info_ptr);
+   png_info_init_3(&info_ptr, png_sizeof(png_info));
 }
+#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
 
 /* This function returns a pointer to the io_ptr associated with the user
  * functions.  The application should free any memory associated with this
  * pointer before png_write_destroy() or png_read_destroy() are called.
  */
-png_voidp
+png_voidp PNGAPI
 png_get_io_ptr(png_structp png_ptr)
 {
+   if (png_ptr == NULL) return (NULL);
    return (png_ptr->io_ptr);
 }
 
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
 #if !defined(PNG_NO_STDIO)
 /* Initialize the default input/output functions for the PNG file.  If you
  * use your own read or write routines, you can call either png_set_read_fn()
- * or png_set_write_fn() instead of png_init_io().
+ * or png_set_write_fn() instead of png_init_io().  If you have defined
+ * PNG_NO_STDIO, you must use a function of your own because "FILE *" isn't
+ * necessarily available.
  */
-void
-png_init_io(png_structp png_ptr, FILE *fp)
+void PNGAPI
+png_init_io(png_structp png_ptr, png_FILE_p fp)
 {
    png_debug(1, "in png_init_io\n");
+   if (png_ptr == NULL) return;
    png_ptr->io_ptr = (png_voidp)fp;
 }
 #endif
+
+#if defined(PNG_TIME_RFC1123_SUPPORTED)
+/* Convert the supplied time into an RFC 1123 string suitable for use in
+ * a "Creation Time" or other text-based time string.
+ */
+png_charp PNGAPI
+png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime)
+{
+   static PNG_CONST char short_months[12][4] =
+        {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
+         "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
+
+   if (png_ptr == NULL) return (NULL);
+   if (png_ptr->time_buffer == NULL)
+   {
+      png_ptr->time_buffer = (png_charp)png_malloc(png_ptr, (png_uint_32)(29*
+         png_sizeof(char)));
+   }
+
+#if defined(_WIN32_WCE)
+   {
+      wchar_t time_buf[29];
+      wsprintf(time_buf, TEXT("%d %S %d %02d:%02d:%02d +0000"),
+          ptime->day % 32, short_months[(ptime->month - 1) % 12],
+        ptime->year, ptime->hour % 24, ptime->minute % 60,
+          ptime->second % 61);
+      WideCharToMultiByte(CP_ACP, 0, time_buf, -1, png_ptr->time_buffer, 29,
+          NULL, NULL);
+   }
+#else
+#ifdef USE_FAR_KEYWORD
+   {
+      char near_time_buf[29];
+      png_snprintf6(near_time_buf, 29, "%d %s %d %02d:%02d:%02d +0000",
+          ptime->day % 32, short_months[(ptime->month - 1) % 12],
+          ptime->year, ptime->hour % 24, ptime->minute % 60,
+          ptime->second % 61);
+      png_memcpy(png_ptr->time_buffer, near_time_buf,
+          29*png_sizeof(char));
+   }
+#else
+   png_snprintf6(png_ptr->time_buffer, 29, "%d %s %d %02d:%02d:%02d +0000",
+       ptime->day % 32, short_months[(ptime->month - 1) % 12],
+       ptime->year, ptime->hour % 24, ptime->minute % 60,
+       ptime->second % 61);
+#endif
+#endif /* _WIN32_WCE */
+   return ((png_charp)png_ptr->time_buffer);
+}
+#endif /* PNG_TIME_RFC1123_SUPPORTED */
+
+#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
+
+png_charp PNGAPI
+png_get_copyright(png_structp png_ptr)
+{
+   png_ptr = png_ptr;  /* silence compiler warning about unused png_ptr */
+   return ((png_charp) "\n libpng version 1.0.41 - October 31, 2008\n\
+   Copyright (c) 1998-2008 Glenn Randers-Pehrson\n\
+   Copyright (c) 1996-1997 Andreas Dilger\n\
+   Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.\n");
+}
+
+/* The following return the library version as a short string in the
+ * format 1.0.0 through 99.99.99zz.  To get the version of *.h files
+ * used with your application, print out PNG_LIBPNG_VER_STRING, which
+ * is defined in png.h.
+ * Note: now there is no difference between png_get_libpng_ver() and
+ * png_get_header_ver().  Due to the version_nn_nn_nn typedef guard,
+ * it is guaranteed that png.c uses the correct version of png.h.
+ */
+png_charp PNGAPI
+png_get_libpng_ver(png_structp png_ptr)
+{
+   /* Version of *.c files used when building libpng */
+   png_ptr = png_ptr;  /* silence compiler warning about unused png_ptr */
+   return ((png_charp) PNG_LIBPNG_VER_STRING);
+}
+
+png_charp PNGAPI
+png_get_header_ver(png_structp png_ptr)
+{
+   /* Version of *.h files used when building libpng */
+   png_ptr = png_ptr;  /* silence compiler warning about unused png_ptr */
+   return ((png_charp) PNG_LIBPNG_VER_STRING);
+}
+
+png_charp PNGAPI
+png_get_header_version(png_structp png_ptr)
+{
+   /* Returns longer string containing both version and date */
+   png_ptr = png_ptr;  /* silence compiler warning about unused png_ptr */
+   return ((png_charp) PNG_HEADER_VERSION_STRING
+#ifndef PNG_READ_SUPPORTED
+   "     (NO READ SUPPORT)"
+#endif
+   "\n");
+}
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+int PNGAPI
+png_handle_as_unknown(png_structp png_ptr, png_bytep chunk_name)
+{
+   /* check chunk_name and return "keep" value if it's on the list, else 0 */
+   int i;
+   png_bytep p;
+   if (png_ptr == NULL || chunk_name == NULL || png_ptr->num_chunk_list<=0)
+      return 0;
+   p = png_ptr->chunk_list + png_ptr->num_chunk_list*5 - 5;
+   for (i = png_ptr->num_chunk_list; i; i--, p -= 5)
+      if (!png_memcmp(chunk_name, p, 4))
+        return ((int)*(p + 4));
+   return 0;
+}
+#endif
+
+/* This function, added to libpng-1.0.6g, is untested. */
+int PNGAPI
+png_reset_zstream(png_structp png_ptr)
+{
+   if (png_ptr == NULL) return Z_STREAM_ERROR;
+   return (inflateReset(&png_ptr->zstream));
+}
+#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
+
+/* This function was added to libpng-1.0.7 */
+png_uint_32 PNGAPI
+png_access_version_number(void)
+{
+   /* Version of *.c files used when building libpng */
+   return((png_uint_32) PNG_LIBPNG_VER);
+}
+
+
+#if defined(PNG_READ_SUPPORTED) && defined(PNG_ASSEMBLER_CODE_SUPPORTED)
+#if !defined(PNG_1_0_X)
+/* this function was added to libpng 1.2.0 */
+int PNGAPI
+png_mmx_support(void)
+{
+   /* obsolete, to be removed from libpng-1.4.0 */
+    return -1;
+}
+#endif /* PNG_1_0_X */
+#endif /* PNG_READ_SUPPORTED && PNG_ASSEMBLER_CODE_SUPPORTED */
+
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+#ifdef PNG_SIZE_T
+/* Added at libpng version 1.2.6 */
+   PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size));
+png_size_t PNGAPI
+png_convert_size(size_t size)
+{
+  if (size > (png_size_t)-1)
+     PNG_ABORT();  /* We haven't got access to png_ptr, so no png_error() */
+  return ((png_size_t)size);
+}
+#endif /* PNG_SIZE_T */
+#endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */

pngerror.c

@@ -1,14 +1,13 @@
 
 /* pngerror.c - stub functions for i/o and memory allocation
  *
- * libpng 1.0.1c
+ * Last changed in libpng 1.2.30 [August 15, 2008]
  * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
- * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
- * May 9, 1998
+ * Copyright (c) 1998-2008 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
- * This file provides a location for all error handling.  Users which
+ * This file provides a location for all error handling.  Users who
  * need special error handling are expected to write replacement functions
  * and use png_set_error_fn() to use those functions.  See the instructions
  * at each function.
@@ -16,144 +15,303 @@
 
 #define PNG_INTERNAL
 #include "png.h"
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
 
-static void png_default_error PNGARG((png_structp png_ptr,
-                                      png_const_charp message));
-static void png_default_warning PNGARG((png_structp png_ptr,
-                                        png_const_charp message));
+static void /* PRIVATE */
+png_default_error PNGARG((png_structp png_ptr,
+  png_const_charp error_message));
+#ifndef PNG_NO_WARNINGS
+static void /* PRIVATE */
+png_default_warning PNGARG((png_structp png_ptr,
+  png_const_charp warning_message));
+#endif /* PNG_NO_WARNINGS */
 
 /* This function is called whenever there is a fatal error.  This function
  * should not be changed.  If there is a need to handle errors differently,
  * you should supply a replacement error function and use png_set_error_fn()
  * to replace the error function at run-time.
  */
-void
-png_error(png_structp png_ptr, png_const_charp message)
+#ifndef PNG_NO_ERROR_TEXT
+void PNGAPI
+png_error(png_structp png_ptr, png_const_charp error_message)
 {
-   if (png_ptr->error_fn != NULL)
-      (*(png_ptr->error_fn))(png_ptr, message);
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+   char msg[16];
+   if (png_ptr != NULL)
+   {
+     if (png_ptr->flags&
+       (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
+     {
+       if (*error_message == '#')
+       {
+         /* Strip "#nnnn " from beginning of error message. */
+           int offset;
+           for (offset = 1; offset<15; offset++)
+              if (error_message[offset] == ' ')
+                  break;
+           if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
+           {
+              int i;
+              for (i = 0; i < offset - 1; i++)
+                 msg[i] = error_message[i + 1];
+              msg[i - 1] = '\0';
+              error_message = msg;
+           }
+           else
+              error_message += offset;
+       }
+       else
+       {
+           if (png_ptr->flags&PNG_FLAG_STRIP_ERROR_TEXT)
+           {
+              msg[0] = '0';
+              msg[1] = '\0';
+              error_message = msg;
+           }
+       }
+     }
+   }
+#endif
+   if (png_ptr != NULL && png_ptr->error_fn != NULL)
+      (*(png_ptr->error_fn))(png_ptr, error_message);
 
-   /* if the following returns or doesn't exist, use the default function,
-      which will not return */
-   png_default_error(png_ptr, message);
+   /* If the custom handler doesn't exist, or if it returns,
+      use the default handler, which will not return. */
+   png_default_error(png_ptr, error_message);
 }
+#else
+void PNGAPI
+png_err(png_structp png_ptr)
+{
+   if (png_ptr != NULL && png_ptr->error_fn != NULL)
+      (*(png_ptr->error_fn))(png_ptr, '\0');
 
+   /* If the custom handler doesn't exist, or if it returns,
+      use the default handler, which will not return. */
+   png_default_error(png_ptr, '\0');
+}
+#endif /* PNG_NO_ERROR_TEXT */
+
+#ifndef PNG_NO_WARNINGS
 /* This function is called whenever there is a non-fatal error.  This function
  * should not be changed.  If there is a need to handle warnings differently,
  * you should supply a replacement warning function and use
  * png_set_error_fn() to replace the warning function at run-time.
  */
-void
-png_warning(png_structp png_ptr, png_const_charp message)
+void PNGAPI
+png_warning(png_structp png_ptr, png_const_charp warning_message)
 {
-   if (png_ptr->warning_fn != NULL)
-      (*(png_ptr->warning_fn))(png_ptr, message);
+   int offset = 0;
+   if (png_ptr != NULL)
+   {
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+   if (png_ptr->flags&
+     (PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))
+#endif
+     {
+       if (*warning_message == '#')
+       {
+           for (offset = 1; offset < 15; offset++)
+              if (warning_message[offset] == ' ')
+                  break;
+       }
+     }
+     if (png_ptr != NULL && png_ptr->warning_fn != NULL)
+        (*(png_ptr->warning_fn))(png_ptr, warning_message + offset);
+   }
    else
-      png_default_warning(png_ptr, message);
+      png_default_warning(png_ptr, warning_message + offset);
 }
+#endif /* PNG_NO_WARNINGS */
 
-/* These utilities are used internally to build an error message which relates
+
+/* These utilities are used internally to build an error message that relates
  * to the current chunk.  The chunk name comes from png_ptr->chunk_name,
  * this is used to prefix the message.  The message is limited in length
  * to 63 bytes, the name characters are output as hex digits wrapped in []
  * if the character is invalid.
  */
-#define isnonalpha(c) ((c) < 41 || (c) > 122 || ((c) > 90 && (c) < 97))
+#define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
 static PNG_CONST char png_digit[16] = {
-   '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'
+   '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
+   'A', 'B', 'C', 'D', 'E', 'F'
 };
 
-static void
-png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp message)
+#define PNG_MAX_ERROR_TEXT 64
+
+#if !defined(PNG_NO_WARNINGS) || !defined(PNG_NO_ERROR_TEXT)
+static void /* PRIVATE */
+png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp
+   error_message)
 {
    int iout = 0, iin = 0;
 
-   while (iin < 4) {
+   while (iin < 4)
+   {
       int c = png_ptr->chunk_name[iin++];
-      if (isnonalpha(c)) {
+      if (isnonalpha(c))
+      {
          buffer[iout++] = '[';
          buffer[iout++] = png_digit[(c & 0xf0) >> 4];
-         buffer[iout++] = png_digit[c & 0xf];
+         buffer[iout++] = png_digit[c & 0x0f];
          buffer[iout++] = ']';
-      } else {
-         buffer[iout++] = c;
+      }
+      else
+      {
+         buffer[iout++] = (png_byte)c;
       }
    }
 
-   if (message == NULL)
-      buffer[iout] = 0;
-   else {
+   if (error_message == NULL)
+      buffer[iout] = '\0';
+   else
+   {
       buffer[iout++] = ':';
       buffer[iout++] = ' ';
-      png_memcpy(buffer+iout, message, 64);
-      buffer[iout+63] = 0;
+      png_memcpy(buffer + iout, error_message, PNG_MAX_ERROR_TEXT);
+      buffer[iout + PNG_MAX_ERROR_TEXT - 1] = '\0';
    }
 }
 
-void
-png_chunk_error(png_structp png_ptr, png_const_charp message)
+#ifdef PNG_READ_SUPPORTED
+void PNGAPI
+png_chunk_error(png_structp png_ptr, png_const_charp error_message)
 {
-   char msg[16+64];
-   png_format_buffer(png_ptr, msg, message);
-   png_error(png_ptr, msg);
+   char msg[18+PNG_MAX_ERROR_TEXT];
+   if (png_ptr == NULL)
+     png_error(png_ptr, error_message);
+   else
+   {
+     png_format_buffer(png_ptr, msg, error_message);
+     png_error(png_ptr, msg);
+   }
 }
+#endif /* PNG_READ_SUPPORTED */
+#endif /* !defined(PNG_NO_WARNINGS) || !defined(PNG_NO_ERROR_TEXT) */
 
-void
-png_chunk_warning(png_structp png_ptr, png_const_charp message)
+#ifndef PNG_NO_WARNINGS
+void PNGAPI
+png_chunk_warning(png_structp png_ptr, png_const_charp warning_message)
 {
-   char msg[16+64];
-   png_format_buffer(png_ptr, msg, message);
-   png_warning(png_ptr, msg);
+   char msg[18+PNG_MAX_ERROR_TEXT];
+   if (png_ptr == NULL)
+     png_warning(png_ptr, warning_message);
+   else
+   {
+     png_format_buffer(png_ptr, msg, warning_message);
+     png_warning(png_ptr, msg);
+   }
 }
+#endif /* PNG_NO_WARNINGS */
+
 
 /* This is the default error handling function.  Note that replacements for
  * this function MUST NOT RETURN, or the program will likely crash.  This
  * function is used by default, or if the program supplies NULL for the
  * error function pointer in png_set_error_fn().
  */
-static void
-png_default_error(png_structp png_ptr, png_const_charp message)
+static void /* PRIVATE */
+png_default_error(png_structp png_ptr, png_const_charp error_message)
 {
-#ifndef PNG_NO_STDIO
-   fprintf(stderr, "libpng error: %s\n", message);
+#ifndef PNG_NO_CONSOLE_IO
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+   if (*error_message == '#')
+   {
+     /* Strip "#nnnn " from beginning of warning message. */
+     int offset;
+     char error_number[16];
+     for (offset = 0; offset<15; offset++)
+     {
+         error_number[offset] = error_message[offset + 1];
+         if (error_message[offset] == ' ')
+             break;
+     }
+     if ((offset > 1) && (offset < 15))
+     {
+       error_number[offset - 1] = '\0';
+       fprintf(stderr, "libpng error no. %s: %s\n", error_number,
+          error_message + offset + 1);
+     }
+     else
+       fprintf(stderr, "libpng error: %s, offset=%d\n", error_message, offset);
+   }
+   else
+#endif
+   fprintf(stderr, "libpng error: %s\n", error_message);
 #endif
 
-#ifdef USE_FAR_KEYWORD
+#ifdef PNG_SETJMP_SUPPORTED
+   if (png_ptr)
+   {
+#  ifdef USE_FAR_KEYWORD
    {
       jmp_buf jmpbuf;
-      png_memcpy(jmpbuf,png_ptr->jmpbuf,sizeof(jmp_buf));
+      png_memcpy(jmpbuf, png_ptr->jmpbuf, png_sizeof(jmp_buf));
       longjmp(jmpbuf, 1);
    }
-#else
+#  else
    longjmp(png_ptr->jmpbuf, 1);
+#  endif
+   }
+#else
+   PNG_ABORT();
+#endif
+#ifdef PNG_NO_CONSOLE_IO
+   error_message = error_message; /* make compiler happy */
 #endif
 }
 
+#ifndef PNG_NO_WARNINGS
 /* This function is called when there is a warning, but the library thinks
  * it can continue anyway.  Replacement functions don't have to do anything
- * here if you don't want to.  In the default configuration, png_ptr is
+ * here if you don't want them to.  In the default configuration, png_ptr is
  * not used, but it is passed in case it may be useful.
  */
-static void
-png_default_warning(png_structp png_ptr, png_const_charp message)
+static void /* PRIVATE */
+png_default_warning(png_structp png_ptr, png_const_charp warning_message)
 {
-   if (png_ptr == NULL)
-      return;
-
-#ifndef PNG_NO_STDIO
-   fprintf(stderr, "libpng warning: %s\n", message);
+#ifndef PNG_NO_CONSOLE_IO
+#  ifdef PNG_ERROR_NUMBERS_SUPPORTED
+   if (*warning_message == '#')
+   {
+     int offset;
+     char warning_number[16];
+     for (offset = 0; offset < 15; offset++)
+     {
+        warning_number[offset] = warning_message[offset + 1];
+        if (warning_message[offset] == ' ')
+            break;
+     }
+     if ((offset > 1) && (offset < 15))
+     {
+       warning_number[offset + 1] = '\0';
+       fprintf(stderr, "libpng warning no. %s: %s\n", warning_number,
+          warning_message + offset);
+     }
+     else
+       fprintf(stderr, "libpng warning: %s\n", warning_message);
+   }
+   else
+#  endif
+     fprintf(stderr, "libpng warning: %s\n", warning_message);
+#else
+   warning_message = warning_message; /* make compiler happy */
 #endif
+   png_ptr = png_ptr; /* make compiler happy */
 }
+#endif /* PNG_NO_WARNINGS */
 
 /* This function is called when the application wants to use another method
  * of handling errors and warnings.  Note that the error function MUST NOT
  * return to the calling routine or serious problems will occur.  The return
  * method used in the default routine calls longjmp(png_ptr->jmpbuf, 1)
  */
-void
+void PNGAPI
 png_set_error_fn(png_structp png_ptr, png_voidp error_ptr,
    png_error_ptr error_fn, png_error_ptr warning_fn)
 {
+   if (png_ptr == NULL)
+      return;
    png_ptr->error_ptr = error_ptr;
    png_ptr->error_fn = error_fn;
    png_ptr->warning_fn = warning_fn;
@@ -164,11 +322,24 @@ png_set_error_fn(png_structp png_ptr, png_voidp error_ptr,
  * functions.  The application should free any memory associated with this
  * pointer before png_write_destroy and png_read_destroy are called.
  */
-png_voidp
+png_voidp PNGAPI
 png_get_error_ptr(png_structp png_ptr)
 {
+   if (png_ptr == NULL)
+      return NULL;
    return ((png_voidp)png_ptr->error_ptr);
 }
 
 
-
+#ifdef PNG_ERROR_NUMBERS_SUPPORTED
+void PNGAPI
+png_set_strip_error_numbers(png_structp png_ptr, png_uint_32 strip_mode)
+{
+   if (png_ptr != NULL)
+   {
+     png_ptr->flags &=
+       ((~(PNG_FLAG_STRIP_ERROR_NUMBERS|PNG_FLAG_STRIP_ERROR_TEXT))&strip_mode);
+   }
+}
+#endif
+#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */

pnggccrd.c

@@ -0,0 +1,103 @@
+/* pnggccrd.c was removed from libpng-1.2.20. */
+
+/* This code snippet is for use by configure's compilation test. */
+
+#if (!defined _MSC_VER) && \
+    defined(PNG_ASSEMBLER_CODE_SUPPORTED) && \
+    defined(PNG_MMX_CODE_SUPPORTED)
+
+int PNGAPI png_dummy_mmx_support(void);
+
+static int _mmx_supported = 2; // 0: no MMX; 1: MMX supported; 2: not tested
+
+int PNGAPI
+png_dummy_mmx_support(void) __attribute__((noinline));
+
+int PNGAPI
+png_dummy_mmx_support(void)
+{
+   int result;
+#if defined(PNG_MMX_CODE_SUPPORTED)  // superfluous, but what the heck
+    __asm__ __volatile__ (
+#if defined(__x86_64__)
+        "pushq %%rbx          \n\t"  // rbx gets clobbered by CPUID instruction
+        "pushq %%rcx          \n\t"  // so does rcx...
+        "pushq %%rdx          \n\t"  // ...and rdx (but rcx & rdx safe on Linux)
+        "pushfq               \n\t"  // save Eflag to stack
+        "popq %%rax           \n\t"  // get Eflag from stack into rax
+        "movq %%rax, %%rcx    \n\t"  // make another copy of Eflag in rcx
+        "xorl $0x200000, %%eax \n\t" // toggle ID bit in Eflag (i.e., bit 21)
+        "pushq %%rax          \n\t"  // save modified Eflag back to stack
+        "popfq                \n\t"  // restore modified value to Eflag reg
+        "pushfq               \n\t"  // save Eflag to stack
+        "popq %%rax           \n\t"  // get Eflag from stack
+        "pushq %%rcx          \n\t"  // save original Eflag to stack
+        "popfq                \n\t"  // restore original Eflag
+#else
+        "pushl %%ebx          \n\t"  // ebx gets clobbered by CPUID instruction
+        "pushl %%ecx          \n\t"  // so does ecx...
+        "pushl %%edx          \n\t"  // ...and edx (but ecx & edx safe on Linux)
+        "pushfl               \n\t"  // save Eflag to stack
+        "popl %%eax           \n\t"  // get Eflag from stack into eax
+        "movl %%eax, %%ecx    \n\t"  // make another copy of Eflag in ecx
+        "xorl $0x200000, %%eax \n\t" // toggle ID bit in Eflag (i.e., bit 21)
+        "pushl %%eax          \n\t"  // save modified Eflag back to stack
+        "popfl                \n\t"  // restore modified value to Eflag reg
+        "pushfl               \n\t"  // save Eflag to stack
+        "popl %%eax           \n\t"  // get Eflag from stack
+        "pushl %%ecx          \n\t"  // save original Eflag to stack
+        "popfl                \n\t"  // restore original Eflag
+#endif
+        "xorl %%ecx, %%eax    \n\t"  // compare new Eflag with original Eflag
+        "jz 0f                \n\t"  // if same, CPUID instr. is not supported
+
+        "xorl %%eax, %%eax    \n\t"  // set eax to zero
+//      ".byte  0x0f, 0xa2    \n\t"  // CPUID instruction (two-byte opcode)
+        "cpuid                \n\t"  // get the CPU identification info
+        "cmpl $1, %%eax       \n\t"  // make sure eax return non-zero value
+        "jl 0f                \n\t"  // if eax is zero, MMX is not supported
+
+        "xorl %%eax, %%eax    \n\t"  // set eax to zero and...
+        "incl %%eax           \n\t"  // ...increment eax to 1.  This pair is
+                                     // faster than the instruction "mov eax, 1"
+        "cpuid                \n\t"  // get the CPU identification info again
+        "andl $0x800000, %%edx \n\t" // mask out all bits but MMX bit (23)
+        "cmpl $0, %%edx       \n\t"  // 0 = MMX not supported
+        "jz 0f                \n\t"  // non-zero = yes, MMX IS supported
+
+        "movl $1, %%eax       \n\t"  // set return value to 1
+        "jmp  1f              \n\t"  // DONE:  have MMX support
+
+    "0:                       \n\t"  // .NOT_SUPPORTED: target label for jump instructions
+        "movl $0, %%eax       \n\t"  // set return value to 0
+    "1:                       \n\t"  // .RETURN: target label for jump instructions
+#if defined(__x86_64__)
+        "popq %%rdx           \n\t"  // restore rdx
+        "popq %%rcx           \n\t"  // restore rcx
+        "popq %%rbx           \n\t"  // restore rbx
+#else
+        "popl %%edx           \n\t"  // restore edx
+        "popl %%ecx           \n\t"  // restore ecx
+        "popl %%ebx           \n\t"  // restore ebx
+#endif
+
+//      "ret                  \n\t"  // DONE:  no MMX support
+                                     // (fall through to standard C "ret")
+
+        : "=a" (result)              // output list
+
+        :                            // any variables used on input (none)
+
+                                     // no clobber list
+//      , "%ebx", "%ecx", "%edx"     // GRR:  we handle these manually
+//      , "memory"   // if write to a variable gcc thought was in a reg
+//      , "cc"       // "condition codes" (flag bits)
+    );
+    _mmx_supported = result;
+#else
+    _mmx_supported = 0;
+#endif /* PNG_MMX_CODE_SUPPORTED */
+
+    return _mmx_supported;
+}
+#endif

pngget.c

@@ -1,18 +1,18 @@
 
 /* pngget.c - retrieval of values from info struct
  *
- * libpng 1.0.1c
+ * Last changed in libpng 1.2.30 [August 15, 2008]
  * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
- * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
- * May 9, 1998
+ * Copyright (c) 1998-2008 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  */
 
 #define PNG_INTERNAL
 #include "png.h"
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
 
-png_uint_32
+png_uint_32 PNGAPI
 png_get_valid(png_structp png_ptr, png_infop info_ptr, png_uint_32 flag)
 {
    if (png_ptr != NULL && info_ptr != NULL)
@@ -21,7 +21,7 @@ png_get_valid(png_structp png_ptr, png_infop info_ptr, png_uint_32 flag)
       return(0);
 }
 
-png_uint_32
+png_uint_32 PNGAPI
 png_get_rowbytes(png_structp png_ptr, png_infop info_ptr)
 {
    if (png_ptr != NULL && info_ptr != NULL)
@@ -30,9 +30,20 @@ png_get_rowbytes(png_structp png_ptr, png_infop info_ptr)
       return(0);
 }
 
+#if defined(PNG_INFO_IMAGE_SUPPORTED)
+png_bytepp PNGAPI
+png_get_rows(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return(info_ptr->row_pointers);
+   else
+      return(0);
+}
+#endif
+
 #ifdef PNG_EASY_ACCESS_SUPPORTED
 /* easy access to info, added in libpng-0.99 */
-png_uint_32
+png_uint_32 PNGAPI
 png_get_image_width(png_structp png_ptr, png_infop info_ptr)
 {
    if (png_ptr != NULL && info_ptr != NULL)
@@ -42,7 +53,7 @@ png_get_image_width(png_structp png_ptr, png_infop info_ptr)
    return (0);
 }
 
-png_uint_32
+png_uint_32 PNGAPI
 png_get_image_height(png_structp png_ptr, png_infop info_ptr)
 {
    if (png_ptr != NULL && info_ptr != NULL)
@@ -52,7 +63,7 @@ png_get_image_height(png_structp png_ptr, png_infop info_ptr)
    return (0);
 }
 
-png_byte
+png_byte PNGAPI
 png_get_bit_depth(png_structp png_ptr, png_infop info_ptr)
 {
    if (png_ptr != NULL && info_ptr != NULL)
@@ -62,7 +73,7 @@ png_get_bit_depth(png_structp png_ptr, png_infop info_ptr)
    return (0);
 }
 
-png_byte
+png_byte PNGAPI
 png_get_color_type(png_structp png_ptr, png_infop info_ptr)
 {
    if (png_ptr != NULL && info_ptr != NULL)
@@ -72,7 +83,7 @@ png_get_color_type(png_structp png_ptr, png_infop info_ptr)
    return (0);
 }
 
-png_byte
+png_byte PNGAPI
 png_get_filter_type(png_structp png_ptr, png_infop info_ptr)
 {
    if (png_ptr != NULL && info_ptr != NULL)
@@ -82,7 +93,7 @@ png_get_filter_type(png_structp png_ptr, png_infop info_ptr)
    return (0);
 }
 
-png_byte
+png_byte PNGAPI
 png_get_interlace_type(png_structp png_ptr, png_infop info_ptr)
 {
    if (png_ptr != NULL && info_ptr != NULL)
@@ -92,7 +103,7 @@ png_get_interlace_type(png_structp png_ptr, png_infop info_ptr)
    return (0);
 }
 
-png_byte
+png_byte PNGAPI
 png_get_compression_type(png_structp png_ptr, png_infop info_ptr)
 {
    if (png_ptr != NULL && info_ptr != NULL)
@@ -102,181 +113,199 @@ png_get_compression_type(png_structp png_ptr, png_infop info_ptr)
    return (0);
 }
 
-png_uint_32
+png_uint_32 PNGAPI
 png_get_x_pixels_per_meter(png_structp png_ptr, png_infop info_ptr)
 {
-#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED)
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+   if (png_ptr != NULL && info_ptr != NULL)
+#if defined(PNG_pHYs_SUPPORTED)
+   if (info_ptr->valid & PNG_INFO_pHYs)
    {
       png_debug1(1, "in %s retrieval function\n", "png_get_x_pixels_per_meter");
-      if(info_ptr->phys_unit_type != PNG_RESOLUTION_METER)
+      if (info_ptr->phys_unit_type != PNG_RESOLUTION_METER)
           return (0);
       else return (info_ptr->x_pixels_per_unit);
    }
-   else
+#else
+   return (0);
 #endif
    return (0);
 }
 
-png_uint_32
+png_uint_32 PNGAPI
 png_get_y_pixels_per_meter(png_structp png_ptr, png_infop info_ptr)
 {
-#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED)
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+   if (png_ptr != NULL && info_ptr != NULL)
+#if defined(PNG_pHYs_SUPPORTED)
+   if (info_ptr->valid & PNG_INFO_pHYs)
    {
       png_debug1(1, "in %s retrieval function\n", "png_get_y_pixels_per_meter");
-      if(info_ptr->phys_unit_type != PNG_RESOLUTION_METER)
+      if (info_ptr->phys_unit_type != PNG_RESOLUTION_METER)
           return (0);
       else return (info_ptr->y_pixels_per_unit);
    }
-   else
+#else
+   return (0);
 #endif
    return (0);
 }
 
-png_uint_32
+png_uint_32 PNGAPI
 png_get_pixels_per_meter(png_structp png_ptr, png_infop info_ptr)
 {
-#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED)
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+   if (png_ptr != NULL && info_ptr != NULL)
+#if defined(PNG_pHYs_SUPPORTED)
+   if (info_ptr->valid & PNG_INFO_pHYs)
    {
       png_debug1(1, "in %s retrieval function\n", "png_get_pixels_per_meter");
-      if(info_ptr->phys_unit_type != PNG_RESOLUTION_METER ||
+      if (info_ptr->phys_unit_type != PNG_RESOLUTION_METER ||
          info_ptr->x_pixels_per_unit != info_ptr->y_pixels_per_unit)
           return (0);
       else return (info_ptr->x_pixels_per_unit);
    }
-   else
+#else
+   return (0);
 #endif
    return (0);
 }
 
-float
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+float PNGAPI
 png_get_pixel_aspect_ratio(png_structp png_ptr, png_infop info_ptr)
    {
-#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED)
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
+   if (png_ptr != NULL && info_ptr != NULL)
+#if defined(PNG_pHYs_SUPPORTED)
+   if (info_ptr->valid & PNG_INFO_pHYs)
    {
       png_debug1(1, "in %s retrieval function\n", "png_get_aspect_ratio");
       if (info_ptr->x_pixels_per_unit == 0)
          return ((float)0.0);
       else
-         return ((float)info_ptr->y_pixels_per_unit
-            /(float)info_ptr->x_pixels_per_unit);
+         return ((float)((float)info_ptr->y_pixels_per_unit
+            /(float)info_ptr->x_pixels_per_unit));
    }
-   else
+#else
+   return (0.0);
 #endif
-      return ((float)0.0);
+   return ((float)0.0);
 }
+#endif
 
-png_uint_32
+png_int_32 PNGAPI
 png_get_x_offset_microns(png_structp png_ptr, png_infop info_ptr)
 {
-#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED)
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
+   if (png_ptr != NULL && info_ptr != NULL)
+#if defined(PNG_oFFs_SUPPORTED)
+   if (info_ptr->valid & PNG_INFO_oFFs)
    {
       png_debug1(1, "in %s retrieval function\n", "png_get_x_offset_microns");
-      if(info_ptr->offset_unit_type != PNG_OFFSET_MICROMETER)
+      if (info_ptr->offset_unit_type != PNG_OFFSET_MICROMETER)
           return (0);
       else return (info_ptr->x_offset);
    }
-   else
+#else
+   return (0);
 #endif
    return (0);
 }
 
-png_uint_32
+png_int_32 PNGAPI
 png_get_y_offset_microns(png_structp png_ptr, png_infop info_ptr)
 {
-#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED)
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
+   if (png_ptr != NULL && info_ptr != NULL)
+#if defined(PNG_oFFs_SUPPORTED)
+   if (info_ptr->valid & PNG_INFO_oFFs)
    {
       png_debug1(1, "in %s retrieval function\n", "png_get_y_offset_microns");
-      if(info_ptr->offset_unit_type != PNG_OFFSET_MICROMETER)
+      if (info_ptr->offset_unit_type != PNG_OFFSET_MICROMETER)
           return (0);
       else return (info_ptr->y_offset);
    }
-   else
+#else
+   return (0);
 #endif
    return (0);
 }
 
-png_uint_32
+png_int_32 PNGAPI
 png_get_x_offset_pixels(png_structp png_ptr, png_infop info_ptr)
 {
-#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED)
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
+   if (png_ptr != NULL && info_ptr != NULL)
+#if defined(PNG_oFFs_SUPPORTED)
+   if (info_ptr->valid & PNG_INFO_oFFs)
    {
       png_debug1(1, "in %s retrieval function\n", "png_get_x_offset_microns");
-      if(info_ptr->offset_unit_type != PNG_OFFSET_PIXEL)
+      if (info_ptr->offset_unit_type != PNG_OFFSET_PIXEL)
           return (0);
       else return (info_ptr->x_offset);
    }
-   else
+#else
+   return (0);
 #endif
    return (0);
 }
 
-png_uint_32
+png_int_32 PNGAPI
 png_get_y_offset_pixels(png_structp png_ptr, png_infop info_ptr)
 {
-#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED)
-   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
+   if (png_ptr != NULL && info_ptr != NULL)
+#if defined(PNG_oFFs_SUPPORTED)
+   if (info_ptr->valid & PNG_INFO_oFFs)
    {
       png_debug1(1, "in %s retrieval function\n", "png_get_y_offset_microns");
-      if(info_ptr->offset_unit_type != PNG_OFFSET_PIXEL)
+      if (info_ptr->offset_unit_type != PNG_OFFSET_PIXEL)
           return (0);
       else return (info_ptr->y_offset);
    }
-   else
+#else
+   return (0);
 #endif
    return (0);
 }
 
-#ifdef PNG_INCH_CONVERSIONS
-png_uint_32
+#if defined(PNG_INCH_CONVERSIONS) && defined(PNG_FLOATING_POINT_SUPPORTED)
+png_uint_32 PNGAPI
 png_get_pixels_per_inch(png_structp png_ptr, png_infop info_ptr)
 {
    return ((png_uint_32)((float)png_get_pixels_per_meter(png_ptr, info_ptr)
-     *.03937 +.5)
+     *.0254 +.5));
 }
 
-png_uint_32
+png_uint_32 PNGAPI
 png_get_x_pixels_per_inch(png_structp png_ptr, png_infop info_ptr)
 {
    return ((png_uint_32)((float)png_get_x_pixels_per_meter(png_ptr, info_ptr)
-     *.03937 +.5)
+     *.0254 +.5));
 }
 
-png_uint_32
+png_uint_32 PNGAPI
 png_get_y_pixels_per_inch(png_structp png_ptr, png_infop info_ptr)
 {
    return ((png_uint_32)((float)png_get_y_pixels_per_meter(png_ptr, info_ptr)
-     *.03937 +.5)
+     *.0254 +.5));
 }
 
-float
+float PNGAPI
 png_get_x_offset_inches(png_structp png_ptr, png_infop info_ptr)
 {
    return ((float)png_get_x_offset_microns(png_ptr, info_ptr)
-     *.03937/1000000. +.5)
+     *.00003937);
 }
 
-float
+float PNGAPI
 png_get_y_offset_inches(png_structp png_ptr, png_infop info_ptr)
 {
    return ((float)png_get_y_offset_microns(png_ptr, info_ptr)
-     *.03937/1000000. +.5)
+     *.00003937);
 }
 
-#if defined(PNG_READ_pHYs_SUPPORTED)
-png_uint_32
+#if defined(PNG_pHYs_SUPPORTED)
+png_uint_32 PNGAPI
 png_get_pHYs_dpi(png_structp png_ptr, png_infop info_ptr,
    png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)
 {
    png_uint_32 retval = 0;
 
-   if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_pHYs)
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
    {
       png_debug1(1, "in %s retrieval function\n", "pHYs");
       if (res_x != NULL)
@@ -293,23 +322,23 @@ png_get_pHYs_dpi(png_structp png_ptr, png_infop info_ptr,
       {
          *unit_type = (int)info_ptr->phys_unit_type;
          retval |= PNG_INFO_pHYs;
-         if(unit_type == 1)
+         if (*unit_type == 1)
          {
-            if (res_x != NULL) *res_x = (png_uint_32)(*res_x * 39.37 + .50);
-            if (res_y != NULL) *res_y = (png_uint_32)(*res_y * 39.37 + .50);
+            if (res_x != NULL) *res_x = (png_uint_32)(*res_x * .0254 + .50);
+            if (res_y != NULL) *res_y = (png_uint_32)(*res_y * .0254 + .50);
          }
       }
    }
    return (retval);
 }
-#endif
-
-#endif  /* PNG_INCH_CONVERSIONS */
+#endif /* PNG_pHYs_SUPPORTED */
+#endif  /* PNG_INCH_CONVERSIONS && PNG_FLOATING_POINT_SUPPORTED */
 
 /* png_get_channels really belongs in here, too, but it's been around longer */
+
 #endif  /* PNG_EASY_ACCESS_SUPPORTED */
 
-png_byte
+png_byte PNGAPI
 png_get_channels(png_structp png_ptr, png_infop info_ptr)
 {
    if (png_ptr != NULL && info_ptr != NULL)
@@ -318,7 +347,7 @@ png_get_channels(png_structp png_ptr, png_infop info_ptr)
       return (0);
 }
 
-png_bytep
+png_bytep PNGAPI
 png_get_signature(png_structp png_ptr, png_infop info_ptr)
 {
    if (png_ptr != NULL && info_ptr != NULL)
@@ -327,8 +356,8 @@ png_get_signature(png_structp png_ptr, png_infop info_ptr)
       return (NULL);
 }
 
-#if defined(PNG_READ_bKGD_SUPPORTED)
-png_uint_32
+#if defined(PNG_bKGD_SUPPORTED)
+png_uint_32 PNGAPI
 png_get_bKGD(png_structp png_ptr, png_infop info_ptr,
    png_color_16p *background)
 {
@@ -343,8 +372,9 @@ png_get_bKGD(png_structp png_ptr, png_infop info_ptr,
 }
 #endif
 
-#if defined(PNG_READ_cHRM_SUPPORTED)
-png_uint_32
+#if defined(PNG_cHRM_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+png_uint_32 PNGAPI
 png_get_cHRM(png_structp png_ptr, png_infop info_ptr,
    double *white_x, double *white_y, double *red_x, double *red_y,
    double *green_x, double *green_y, double *blue_x, double *blue_y)
@@ -373,9 +403,42 @@ png_get_cHRM(png_structp png_ptr, png_infop info_ptr,
    return (0);
 }
 #endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_cHRM_fixed(png_structp png_ptr, png_infop info_ptr,
+   png_fixed_point *white_x, png_fixed_point *white_y, png_fixed_point *red_x,
+   png_fixed_point *red_y, png_fixed_point *green_x, png_fixed_point *green_y,
+   png_fixed_point *blue_x, png_fixed_point *blue_y)
+{
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
+   {
+      png_debug1(1, "in %s retrieval function\n", "cHRM");
+      if (white_x != NULL)
+         *white_x = info_ptr->int_x_white;
+      if (white_y != NULL)
+         *white_y = info_ptr->int_y_white;
+      if (red_x != NULL)
+         *red_x = info_ptr->int_x_red;
+      if (red_y != NULL)
+         *red_y = info_ptr->int_y_red;
+      if (green_x != NULL)
+         *green_x = info_ptr->int_x_green;
+      if (green_y != NULL)
+         *green_y = info_ptr->int_y_green;
+      if (blue_x != NULL)
+         *blue_x = info_ptr->int_x_blue;
+      if (blue_y != NULL)
+         *blue_y = info_ptr->int_y_blue;
+      return (PNG_INFO_cHRM);
+   }
+   return (0);
+}
+#endif
+#endif
 
-#if defined(PNG_READ_gAMA_SUPPORTED)
-png_uint_32
+#if defined(PNG_gAMA_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+png_uint_32 PNGAPI
 png_get_gAMA(png_structp png_ptr, png_infop info_ptr, double *file_gamma)
 {
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)
@@ -388,9 +451,25 @@ png_get_gAMA(png_structp png_ptr, png_infop info_ptr, double *file_gamma)
    return (0);
 }
 #endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_gAMA_fixed(png_structp png_ptr, png_infop info_ptr,
+    png_fixed_point *int_file_gamma)
+{
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)
+      && int_file_gamma != NULL)
+   {
+      png_debug1(1, "in %s retrieval function\n", "gAMA");
+      *int_file_gamma = info_ptr->int_gamma;
+      return (PNG_INFO_gAMA);
+   }
+   return (0);
+}
+#endif
+#endif
 
-#if defined(PNG_READ_sRGB_SUPPORTED)
-png_uint_32
+#if defined(PNG_sRGB_SUPPORTED)
+png_uint_32 PNGAPI
 png_get_sRGB(png_structp png_ptr, png_infop info_ptr, int *file_srgb_intent)
 {
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB)
@@ -404,8 +483,44 @@ png_get_sRGB(png_structp png_ptr, png_infop info_ptr, int *file_srgb_intent)
 }
 #endif
 
-#if defined(PNG_READ_hIST_SUPPORTED)
-png_uint_32
+#if defined(PNG_iCCP_SUPPORTED)
+png_uint_32 PNGAPI
+png_get_iCCP(png_structp png_ptr, png_infop info_ptr,
+             png_charpp name, int *compression_type,
+             png_charpp profile, png_uint_32 *proflen)
+{
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP)
+      && name != NULL && profile != NULL && proflen != NULL)
+   {
+      png_debug1(1, "in %s retrieval function\n", "iCCP");
+      *name = info_ptr->iccp_name;
+      *profile = info_ptr->iccp_profile;
+      /* compression_type is a dummy so the API won't have to change
+         if we introduce multiple compression types later. */
+      *proflen = (int)info_ptr->iccp_proflen;
+      *compression_type = (int)info_ptr->iccp_compression;
+      return (PNG_INFO_iCCP);
+   }
+   return (0);
+}
+#endif
+
+#if defined(PNG_sPLT_SUPPORTED)
+png_uint_32 PNGAPI
+png_get_sPLT(png_structp png_ptr, png_infop info_ptr,
+             png_sPLT_tpp spalettes)
+{
+   if (png_ptr != NULL && info_ptr != NULL && spalettes != NULL)
+   {
+     *spalettes = info_ptr->splt_palettes;
+     return ((png_uint_32)info_ptr->splt_palettes_num);
+   }
+   return (0);
+}
+#endif
+
+#if defined(PNG_hIST_SUPPORTED)
+png_uint_32 PNGAPI
 png_get_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_16p *hist)
 {
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST)
@@ -419,24 +534,25 @@ png_get_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_16p *hist)
 }
 #endif
 
-png_uint_32
+png_uint_32 PNGAPI
 png_get_IHDR(png_structp png_ptr, png_infop info_ptr,
    png_uint_32 *width, png_uint_32 *height, int *bit_depth,
    int *color_type, int *interlace_type, int *compression_type,
    int *filter_type)
-   
+
 {
    if (png_ptr != NULL && info_ptr != NULL && width != NULL && height != NULL &&
       bit_depth != NULL && color_type != NULL)
    {
-      int pixel_depth, channels;
-      png_uint_32 rowbytes_per_pixel;
-
       png_debug1(1, "in %s retrieval function\n", "IHDR");
       *width = info_ptr->width;
       *height = info_ptr->height;
       *bit_depth = info_ptr->bit_depth;
+      if (info_ptr->bit_depth < 1 || info_ptr->bit_depth > 16)
+        png_error(png_ptr, "Invalid bit depth");
       *color_type = info_ptr->color_type;
+      if (info_ptr->color_type > 6)
+        png_error(png_ptr, "Invalid color type");
       if (compression_type != NULL)
          *compression_type = info_ptr->compression_type;
       if (filter_type != NULL)
@@ -445,17 +561,16 @@ png_get_IHDR(png_structp png_ptr, png_infop info_ptr,
          *interlace_type = info_ptr->interlace_type;
 
       /* check for potential overflow of rowbytes */
-      if (*color_type == PNG_COLOR_TYPE_PALETTE)
-         channels = 1;
-      else if (*color_type & PNG_COLOR_MASK_COLOR)
-         channels = 3;
-      else
-         channels = 1;
-      if (*color_type & PNG_COLOR_MASK_ALPHA)
-         channels++;
-      pixel_depth = *bit_depth * channels;
-      rowbytes_per_pixel = (pixel_depth + 7) >> 3;
-      if ((*width > (png_uint_32)2147483647L/rowbytes_per_pixel))
+      if (*width == 0 || *width > PNG_UINT_31_MAX)
+        png_error(png_ptr, "Invalid image width");
+      if (*height == 0 || *height > PNG_UINT_31_MAX)
+        png_error(png_ptr, "Invalid image height");
+      if (info_ptr->width > (PNG_UINT_32_MAX
+                 >> 3)      /* 8-byte RGBA pixels */
+                 - 64       /* bigrowbuf hack */
+                 - 1        /* filter byte */
+                 - 7*8      /* rounding of width to multiple of 8 pixels */
+                 - 8)       /* extra max_pixel_depth pad */
       {
          png_warning(png_ptr,
             "Width too large for libpng to process image data.");
@@ -465,10 +580,10 @@ png_get_IHDR(png_structp png_ptr, png_infop info_ptr,
    return (0);
 }
 
-#if defined(PNG_READ_oFFs_SUPPORTED)
-png_uint_32
+#if defined(PNG_oFFs_SUPPORTED)
+png_uint_32 PNGAPI
 png_get_oFFs(png_structp png_ptr, png_infop info_ptr,
-   png_uint_32 *offset_x, png_uint_32 *offset_y, int *unit_type)
+   png_int_32 *offset_x, png_int_32 *offset_y, int *unit_type)
 {
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)
       && offset_x != NULL && offset_y != NULL && unit_type != NULL)
@@ -483,14 +598,14 @@ png_get_oFFs(png_structp png_ptr, png_infop info_ptr,
 }
 #endif
 
-#if defined(PNG_READ_pCAL_SUPPORTED)
-png_uint_32
+#if defined(PNG_pCAL_SUPPORTED)
+png_uint_32 PNGAPI
 png_get_pCAL(png_structp png_ptr, png_infop info_ptr,
    png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type, int *nparams,
    png_charp *units, png_charpp *params)
 {
-   if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_pCAL &&
-      purpose != NULL && X0 != NULL && X1 != NULL && type != NULL &&
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL)
+      && purpose != NULL && X0 != NULL && X1 != NULL && type != NULL &&
       nparams != NULL && units != NULL && params != NULL)
    {
       png_debug1(1, "in %s retrieval function\n", "pCAL");
@@ -507,14 +622,51 @@ png_get_pCAL(png_structp png_ptr, png_infop info_ptr,
 }
 #endif
 
-#if defined(PNG_READ_pHYs_SUPPORTED)
-png_uint_32
+#if defined(PNG_sCAL_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_sCAL(png_structp png_ptr, png_infop info_ptr,
+             int *unit, double *width, double *height)
+{
+    if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_sCAL))
+    {
+        *unit = info_ptr->scal_unit;
+        *width = info_ptr->scal_pixel_width;
+        *height = info_ptr->scal_pixel_height;
+        return (PNG_INFO_sCAL);
+    }
+    return(0);
+}
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+png_uint_32 PNGAPI
+png_get_sCAL_s(png_structp png_ptr, png_infop info_ptr,
+             int *unit, png_charpp width, png_charpp height)
+{
+    if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_sCAL))
+    {
+        *unit = info_ptr->scal_unit;
+        *width = info_ptr->scal_s_width;
+        *height = info_ptr->scal_s_height;
+        return (PNG_INFO_sCAL);
+    }
+    return(0);
+}
+#endif
+#endif
+#endif
+
+#if defined(PNG_pHYs_SUPPORTED)
+png_uint_32 PNGAPI
 png_get_pHYs(png_structp png_ptr, png_infop info_ptr,
    png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)
 {
    png_uint_32 retval = 0;
 
-   if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_pHYs)
+   if (png_ptr != NULL && info_ptr != NULL &&
+      (info_ptr->valid & PNG_INFO_pHYs))
    {
       png_debug1(1, "in %s retrieval function\n", "pHYs");
       if (res_x != NULL)
@@ -537,12 +689,12 @@ png_get_pHYs(png_structp png_ptr, png_infop info_ptr,
 }
 #endif
 
-png_uint_32
+png_uint_32 PNGAPI
 png_get_PLTE(png_structp png_ptr, png_infop info_ptr, png_colorp *palette,
    int *num_palette)
 {
-   if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_PLTE &&
-       palette != NULL)
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_PLTE)
+       && palette != NULL)
    {
       png_debug1(1, "in %s retrieval function\n", "PLTE");
       *palette = info_ptr->palette;
@@ -553,12 +705,12 @@ png_get_PLTE(png_structp png_ptr, png_infop info_ptr, png_colorp *palette,
    return (0);
 }
 
-#if defined(PNG_READ_sBIT_SUPPORTED)
-png_uint_32
+#if defined(PNG_sBIT_SUPPORTED)
+png_uint_32 PNGAPI
 png_get_sBIT(png_structp png_ptr, png_infop info_ptr, png_color_8p *sig_bit)
 {
-   if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_sBIT &&
-       sig_bit != NULL)
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT)
+      && sig_bit != NULL)
    {
       png_debug1(1, "in %s retrieval function\n", "sBIT");
       *sig_bit = &(info_ptr->sig_bit);
@@ -568,8 +720,8 @@ png_get_sBIT(png_structp png_ptr, png_infop info_ptr, png_color_8p *sig_bit)
 }
 #endif
 
-#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED)
-png_uint_32
+#if defined(PNG_TEXT_SUPPORTED)
+png_uint_32 PNGAPI
 png_get_text(png_structp png_ptr, png_infop info_ptr, png_textp *text_ptr,
    int *num_text)
 {
@@ -584,16 +736,18 @@ png_get_text(png_structp png_ptr, png_infop info_ptr, png_textp *text_ptr,
          *num_text = info_ptr->num_text;
       return ((png_uint_32)info_ptr->num_text);
    }
+   if (num_text != NULL)
+     *num_text = 0;
    return(0);
 }
 #endif
 
-#if defined(PNG_READ_tIME_SUPPORTED)
-png_uint_32
+#if defined(PNG_tIME_SUPPORTED)
+png_uint_32 PNGAPI
 png_get_tIME(png_structp png_ptr, png_infop info_ptr, png_timep *mod_time)
 {
-   if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_tIME &&
-       mod_time != NULL)
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME)
+       && mod_time != NULL)
    {
       png_debug1(1, "in %s retrieval function\n", "tIME");
       *mod_time = &(info_ptr->mod_time);
@@ -603,13 +757,13 @@ png_get_tIME(png_structp png_ptr, png_infop info_ptr, png_timep *mod_time)
 }
 #endif
 
-#if defined(PNG_READ_tRNS_SUPPORTED)
-png_uint_32
+#if defined(PNG_tRNS_SUPPORTED)
+png_uint_32 PNGAPI
 png_get_tRNS(png_structp png_ptr, png_infop info_ptr,
    png_bytep *trans, int *num_trans, png_color_16p *trans_values)
 {
    png_uint_32 retval = 0;
-   if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_tRNS)
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
    {
       png_debug1(1, "in %s retrieval function\n", "tRNS");
       if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
@@ -629,10 +783,10 @@ png_get_tRNS(png_structp png_ptr, png_infop info_ptr,
              *trans_values = &(info_ptr->trans_values);
              retval |= PNG_INFO_tRNS;
           }
-          if(trans != NULL)
+          if (trans != NULL)
              *trans = NULL;
       }
-      if(num_trans != NULL)
+      if (num_trans != NULL)
       {
          *num_trans = info_ptr->num_trans;
          retval |= PNG_INFO_tRNS;
@@ -642,3 +796,105 @@ png_get_tRNS(png_structp png_ptr, png_infop info_ptr,
 }
 #endif
 
+#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+png_uint_32 PNGAPI
+png_get_unknown_chunks(png_structp png_ptr, png_infop info_ptr,
+             png_unknown_chunkpp unknowns)
+{
+   if (png_ptr != NULL && info_ptr != NULL && unknowns != NULL)
+   {
+     *unknowns = info_ptr->unknown_chunks;
+     return ((png_uint_32)info_ptr->unknown_chunks_num);
+   }
+   return (0);
+}
+#endif
+
+#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+png_byte PNGAPI
+png_get_rgb_to_gray_status (png_structp png_ptr)
+{
+   return (png_byte)(png_ptr? png_ptr->rgb_to_gray_status : 0);
+}
+#endif
+
+#if defined(PNG_USER_CHUNKS_SUPPORTED)
+png_voidp PNGAPI
+png_get_user_chunk_ptr(png_structp png_ptr)
+{
+   return (png_ptr? png_ptr->user_chunk_ptr : NULL);
+}
+#endif
+
+#ifdef PNG_WRITE_SUPPORTED
+png_uint_32 PNGAPI
+png_get_compression_buffer_size(png_structp png_ptr)
+{
+   return (png_uint_32)(png_ptr? png_ptr->zbuf_size : 0L);
+}
+#endif
+
+#ifdef PNG_ASSEMBLER_CODE_SUPPORTED
+#ifndef PNG_1_0_X
+/* this function was added to libpng 1.2.0 and should exist by default */
+png_uint_32 PNGAPI
+png_get_asm_flags (png_structp png_ptr)
+{
+    /* obsolete, to be removed from libpng-1.4.0 */
+    return (png_ptr? 0L: 0L);
+}
+
+/* this function was added to libpng 1.2.0 and should exist by default */
+png_uint_32 PNGAPI
+png_get_asm_flagmask (int flag_select)
+{
+    /* obsolete, to be removed from libpng-1.4.0 */
+    flag_select=flag_select;
+    return 0L;
+}
+
+    /* GRR:  could add this:   && defined(PNG_MMX_CODE_SUPPORTED) */
+/* this function was added to libpng 1.2.0 */
+png_uint_32 PNGAPI
+png_get_mmx_flagmask (int flag_select, int *compilerID)
+{
+    /* obsolete, to be removed from libpng-1.4.0 */
+    flag_select=flag_select;
+    *compilerID = -1;   /* unknown (i.e., no asm/MMX code compiled) */
+    return 0L;
+}
+
+/* this function was added to libpng 1.2.0 */
+png_byte PNGAPI
+png_get_mmx_bitdepth_threshold (png_structp png_ptr)
+{
+    /* obsolete, to be removed from libpng-1.4.0 */
+    return (png_ptr? 0: 0);
+}
+
+/* this function was added to libpng 1.2.0 */
+png_uint_32 PNGAPI
+png_get_mmx_rowbytes_threshold (png_structp png_ptr)
+{
+    /* obsolete, to be removed from libpng-1.4.0 */
+    return (png_ptr? 0L: 0L);
+}
+#endif /* ?PNG_1_0_X */
+#endif /* ?PNG_ASSEMBLER_CODE_SUPPORTED */
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+/* these functions were added to libpng 1.2.6 */
+png_uint_32 PNGAPI
+png_get_user_width_max (png_structp png_ptr)
+{
+    return (png_ptr? png_ptr->user_width_max : 0);
+}
+png_uint_32 PNGAPI
+png_get_user_height_max (png_structp png_ptr)
+{
+    return (png_ptr? png_ptr->user_height_max : 0);
+}
+#endif /* ?PNG_SET_USER_LIMITS_SUPPORTED */
+ 
+
+#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */

pngmem.c

@@ -1,30 +1,22 @@
 
 /* pngmem.c - stub functions for memory allocation
  *
- * libpng 1.0.1c
+ * Last changed in libpng 1.2.30 [August 15, 2008]
  * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
- * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
- * May 9, 1998
+ * Copyright (c) 1998-2008 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
  * This file provides a location for all memory allocation.  Users who
- * need special memory handling are expected to modify the code in this file
- * to meet their needs.  See the instructions at each function.
+ * need special memory handling are expected to supply replacement
+ * functions for png_malloc() and png_free(), and to use
+ * png_create_read_struct_2() and png_create_write_struct_2() to
+ * identify the replacement functions.
  */
 
 #define PNG_INTERNAL
 #include "png.h"
-
-/* The following "hides" PNG_MALLOC and PNG_FREE thus allowing the pngtest
-   application to put a wrapper on top of them. */
-#ifdef PNGTEST_MEMORY_DEBUG
-#define PNG_MALLOC png_debug_malloc
-#define PNG_FREE   png_debug_free
-#else
-#define PNG_MALLOC png_malloc
-#define PNG_FREE   png_free
-#endif
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
 
 /* Borland DOS special memory handler */
 #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
@@ -32,36 +24,71 @@
 
 /* Allocate memory for a png_struct.  The malloc and memset can be replaced
    by a single call to calloc() if this is thought to improve performance. */
-png_voidp
+png_voidp /* PRIVATE */
 png_create_struct(int type)
 {
+#ifdef PNG_USER_MEM_SUPPORTED
+   return (png_create_struct_2(type, png_malloc_ptr_NULL, png_voidp_NULL));
+}
+
+/* Alternate version of png_create_struct, for use with user-defined malloc. */
+png_voidp /* PRIVATE */
+png_create_struct_2(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr)
+{
+#endif /* PNG_USER_MEM_SUPPORTED */
    png_size_t size;
    png_voidp struct_ptr;
 
    if (type == PNG_STRUCT_INFO)
-     size = sizeof(png_info);
+     size = png_sizeof(png_info);
    else if (type == PNG_STRUCT_PNG)
-     size = sizeof(png_struct);
+     size = png_sizeof(png_struct);
    else
-     return ((png_voidp)NULL);
+     return (png_get_copyright(NULL));
 
-   if ((struct_ptr = (png_voidp)farmalloc(size)) != NULL)
+#ifdef PNG_USER_MEM_SUPPORTED
+   if (malloc_fn != NULL)
    {
-      png_memset(struct_ptr, 0, size);
+      png_struct dummy_struct;
+      png_structp png_ptr = &dummy_struct;
+      png_ptr->mem_ptr=mem_ptr;
+      struct_ptr = (*(malloc_fn))(png_ptr, (png_uint_32)size);
    }
-
+   else
+#endif /* PNG_USER_MEM_SUPPORTED */
+      struct_ptr = (png_voidp)farmalloc(size);
+   if (struct_ptr != NULL)
+      png_memset(struct_ptr, 0, size);
    return (struct_ptr);
 }
 
-
 /* Free memory allocated by a png_create_struct() call */
-void
+void /* PRIVATE */
 png_destroy_struct(png_voidp struct_ptr)
 {
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_destroy_struct_2(struct_ptr, png_free_ptr_NULL, png_voidp_NULL);
+}
+
+/* Free memory allocated by a png_create_struct() call */
+void /* PRIVATE */
+png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn,
+    png_voidp mem_ptr)
+{
+#endif
    if (struct_ptr != NULL)
    {
+#ifdef PNG_USER_MEM_SUPPORTED
+      if (free_fn != NULL)
+      {
+         png_struct dummy_struct;
+         png_structp png_ptr = &dummy_struct;
+         png_ptr->mem_ptr=mem_ptr;
+         (*(free_fn))(png_ptr, struct_ptr);
+         return;
+      }
+#endif /* PNG_USER_MEM_SUPPORTED */
       farfree (struct_ptr);
-      struct_ptr = NULL;
    }
 }
 
@@ -72,7 +99,7 @@ png_destroy_struct(png_voidp struct_ptr)
  * have the ability to do that.
  *
  * Borland seems to have a problem in DOS mode for exactly 64K.
- * It gives you a segment with an offset of 8 (perhaps to store it's
+ * It gives you a segment with an offset of 8 (perhaps to store its
  * memory stuff).  zlib doesn't like this at all, so we have to
  * detect and deal with it.  This code should not be needed in
  * Windows or OS/2 modes, and only in 16 bit mode.  This code has
@@ -84,19 +111,46 @@ png_destroy_struct(png_voidp struct_ptr)
  * result, we would be truncating potentially larger memory requests
  * (which should cause a fatal error) and introducing major problems.
  */
-png_voidp
-PNG_MALLOC(png_structp png_ptr, png_uint_32 size)
+
+png_voidp PNGAPI
+png_malloc(png_structp png_ptr, png_uint_32 size)
 {
    png_voidp ret;
+
    if (png_ptr == NULL || size == 0)
-      return ((png_voidp)NULL);
+      return (NULL);
+
+#ifdef PNG_USER_MEM_SUPPORTED
+   if (png_ptr->malloc_fn != NULL)
+       ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, (png_size_t)size));
+   else
+       ret = (png_malloc_default(png_ptr, size));
+   if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+       png_error(png_ptr, "Out of memory!");
+   return (ret);
+}
+
+png_voidp PNGAPI
+png_malloc_default(png_structp png_ptr, png_uint_32 size)
+{
+   png_voidp ret;
+#endif /* PNG_USER_MEM_SUPPORTED */
+
+   if (png_ptr == NULL || size == 0)
+      return (NULL);
 
 #ifdef PNG_MAX_MALLOC_64K
    if (size > (png_uint_32)65536L)
-      png_error(png_ptr, "Cannot Allocate > 64K");
+   {
+      png_warning(png_ptr, "Cannot Allocate > 64K");
+      ret = NULL;
+   }
+   else
 #endif
 
-   if (size == (png_uint_32)65536L)
+   if (size != (size_t)size)
+     ret = NULL;
+   else if (size == (png_uint_32)65536L)
    {
       if (png_ptr->offset_table == NULL)
       {
@@ -116,8 +170,9 @@ PNG_MALLOC(png_structp png_ptr, png_uint_32 size)
                ret = NULL;
             }
 
-            num_blocks = (int)(1 << (png_ptr->zlib_window_bits - 14));
-            if (num_blocks < 1)
+            if (png_ptr->zlib_window_bits > 14)
+               num_blocks = (int)(1 << (png_ptr->zlib_window_bits - 14));
+            else
                num_blocks = 1;
             if (png_ptr->zlib_mem_level >= 7)
                num_blocks += (int)(1 << (png_ptr->zlib_mem_level - 7));
@@ -130,33 +185,53 @@ PNG_MALLOC(png_structp png_ptr, png_uint_32 size)
 
             if (table == NULL)
             {
-               png_error(png_ptr, "Out Of Memory."); /* Note "O" and "M" */
+#ifndef PNG_USER_MEM_SUPPORTED
+               if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+                  png_error(png_ptr, "Out Of Memory."); /* Note "O" and "M" */
+               else
+                  png_warning(png_ptr, "Out Of Memory.");
+#endif
+               return (NULL);
             }
 
             if ((png_size_t)table & 0xfff0)
             {
-               png_error(png_ptr, "Farmalloc didn't return normalized pointer");
+#ifndef PNG_USER_MEM_SUPPORTED
+               if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+                  png_error(png_ptr,
+                    "Farmalloc didn't return normalized pointer");
+               else
+                  png_warning(png_ptr,
+                    "Farmalloc didn't return normalized pointer");
+#endif
+               return (NULL);
             }
 
             png_ptr->offset_table = table;
             png_ptr->offset_table_ptr = farmalloc(num_blocks *
-               sizeof (png_bytep));
+               png_sizeof(png_bytep));
 
             if (png_ptr->offset_table_ptr == NULL)
             {
-               png_error(png_ptr, "Out Of memory.");
+#ifndef PNG_USER_MEM_SUPPORTED
+               if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+                  png_error(png_ptr, "Out Of memory."); /* Note "O" and "M" */
+               else
+                  png_warning(png_ptr, "Out Of memory.");
+#endif
+               return (NULL);
             }
 
             hptr = (png_byte huge *)table;
             if ((png_size_t)hptr & 0xf)
             {
                hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L);
-               hptr += 16L;
+               hptr = hptr + 16L;  /* "hptr += 16L" fails on Turbo C++ 3.0 */
             }
             for (i = 0; i < num_blocks; i++)
             {
                png_ptr->offset_table_ptr[i] = (png_bytep)hptr;
-               hptr += (png_uint_32)65536L;
+               hptr = hptr + (png_uint_32)65536L;  /* "+=" fails on TC++3.0 */
             }
 
             png_ptr->offset_table_number = num_blocks;
@@ -166,30 +241,60 @@ PNG_MALLOC(png_structp png_ptr, png_uint_32 size)
       }
 
       if (png_ptr->offset_table_count >= png_ptr->offset_table_number)
-         png_error(png_ptr, "Out of Memory.");
+      {
+#ifndef PNG_USER_MEM_SUPPORTED
+         if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+            png_error(png_ptr, "Out of Memory."); /* Note "o" and "M" */
+         else
+            png_warning(png_ptr, "Out of Memory.");
+#endif
+         return (NULL);
+      }
 
       ret = png_ptr->offset_table_ptr[png_ptr->offset_table_count++];
    }
    else
       ret = farmalloc(size);
 
+#ifndef PNG_USER_MEM_SUPPORTED
    if (ret == NULL)
    {
-      png_error(png_ptr, "Out of memory."); /* Note "o" and "m" */
+      if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+         png_error(png_ptr, "Out of memory."); /* Note "o" and "m" */
+      else
+         png_warning(png_ptr, "Out of memory."); /* Note "o" and "m" */
    }
+#endif
 
    return (ret);
 }
 
-/* free a pointer allocated by PNG_MALLOC().  In the default
+/* free a pointer allocated by png_malloc().  In the default
    configuration, png_ptr is not used, but is passed in case it
    is needed.  If ptr is NULL, return without taking any action. */
-void
-PNG_FREE(png_structp png_ptr, png_voidp ptr)
+
+void PNGAPI
+png_free(png_structp png_ptr, png_voidp ptr)
 {
    if (png_ptr == NULL || ptr == NULL)
       return;
 
+#ifdef PNG_USER_MEM_SUPPORTED
+   if (png_ptr->free_fn != NULL)
+   {
+      (*(png_ptr->free_fn))(png_ptr, ptr);
+      return;
+   }
+   else png_free_default(png_ptr, ptr);
+}
+
+void PNGAPI
+png_free_default(png_structp png_ptr, png_voidp ptr)
+{
+#endif /* PNG_USER_MEM_SUPPORTED */
+
+   if (png_ptr == NULL || ptr == NULL) return;
+
    if (png_ptr->offset_table != NULL)
    {
       int i;
@@ -215,7 +320,6 @@ PNG_FREE(png_structp png_ptr, png_voidp ptr)
    if (ptr != NULL)
    {
       farfree(ptr);
-      ptr = NULL;
    }
 }
 
@@ -223,43 +327,86 @@ PNG_FREE(png_structp png_ptr, png_voidp ptr)
 
 /* Allocate memory for a png_struct or a png_info.  The malloc and
    memset can be replaced by a single call to calloc() if this is thought
-   to improve performance noticably.*/
-png_voidp
+   to improve performance noticably. */
+png_voidp /* PRIVATE */
 png_create_struct(int type)
 {
+#ifdef PNG_USER_MEM_SUPPORTED
+   return (png_create_struct_2(type, png_malloc_ptr_NULL, png_voidp_NULL));
+}
+
+/* Allocate memory for a png_struct or a png_info.  The malloc and
+   memset can be replaced by a single call to calloc() if this is thought
+   to improve performance noticably. */
+png_voidp /* PRIVATE */
+png_create_struct_2(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr)
+{
+#endif /* PNG_USER_MEM_SUPPORTED */
    png_size_t size;
    png_voidp struct_ptr;
 
    if (type == PNG_STRUCT_INFO)
-      size = sizeof(png_info);
+      size = png_sizeof(png_info);
    else if (type == PNG_STRUCT_PNG)
-      size = sizeof(png_struct);
+      size = png_sizeof(png_struct);
    else
-      return ((png_voidp)NULL);
+      return (NULL);
+
+#ifdef PNG_USER_MEM_SUPPORTED
+   if (malloc_fn != NULL)
+   {
+      png_struct dummy_struct;
+      png_structp png_ptr = &dummy_struct;
+      png_ptr->mem_ptr=mem_ptr;
+      struct_ptr = (*(malloc_fn))(png_ptr, size);
+      if (struct_ptr != NULL)
+         png_memset(struct_ptr, 0, size);
+      return (struct_ptr);
+   }
+#endif /* PNG_USER_MEM_SUPPORTED */
 
 #if defined(__TURBOC__) && !defined(__FLAT__)
-   if ((struct_ptr = (png_voidp)farmalloc(size)) != NULL)
+   struct_ptr = (png_voidp)farmalloc(size);
 #else
 # if defined(_MSC_VER) && defined(MAXSEG_64K)
-   if ((struct_ptr = (png_voidp)halloc(size,1)) != NULL)
+   struct_ptr = (png_voidp)halloc(size, 1);
 # else
-   if ((struct_ptr = (png_voidp)malloc(size)) != NULL)
+   struct_ptr = (png_voidp)malloc(size);
 # endif
 #endif
-   {
+   if (struct_ptr != NULL)
       png_memset(struct_ptr, 0, size);
-   }
 
    return (struct_ptr);
 }
 
 
 /* Free memory allocated by a png_create_struct() call */
-void
+void /* PRIVATE */
 png_destroy_struct(png_voidp struct_ptr)
 {
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_destroy_struct_2(struct_ptr, png_free_ptr_NULL, png_voidp_NULL);
+}
+
+/* Free memory allocated by a png_create_struct() call */
+void /* PRIVATE */
+png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn,
+    png_voidp mem_ptr)
+{
+#endif /* PNG_USER_MEM_SUPPORTED */
    if (struct_ptr != NULL)
    {
+#ifdef PNG_USER_MEM_SUPPORTED
+      if (free_fn != NULL)
+      {
+         png_struct dummy_struct;
+         png_structp png_ptr = &dummy_struct;
+         png_ptr->mem_ptr=mem_ptr;
+         (*(free_fn))(png_ptr, struct_ptr);
+         return;
+      }
+#endif /* PNG_USER_MEM_SUPPORTED */
 #if defined(__TURBOC__) && !defined(__FLAT__)
       farfree(struct_ptr);
 #else
@@ -272,53 +419,103 @@ png_destroy_struct(png_voidp struct_ptr)
    }
 }
 
-
 /* Allocate memory.  For reasonable files, size should never exceed
    64K.  However, zlib may allocate more then 64K if you don't tell
    it not to.  See zconf.h and png.h for more information.  zlib does
    need to allocate exactly 64K, so whatever you call here must
    have the ability to do that. */
 
-png_voidp
-PNG_MALLOC(png_structp png_ptr, png_uint_32 size)
+png_voidp PNGAPI
+png_malloc(png_structp png_ptr, png_uint_32 size)
 {
    png_voidp ret;
 
+#ifdef PNG_USER_MEM_SUPPORTED
    if (png_ptr == NULL || size == 0)
-      return ((png_voidp)NULL);
+      return (NULL);
+
+   if (png_ptr->malloc_fn != NULL)
+       ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, (png_size_t)size));
+   else
+       ret = (png_malloc_default(png_ptr, size));
+   if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+       png_error(png_ptr, "Out of Memory!");
+   return (ret);
+}
+
+png_voidp PNGAPI
+png_malloc_default(png_structp png_ptr, png_uint_32 size)
+{
+   png_voidp ret;
+#endif /* PNG_USER_MEM_SUPPORTED */
+
+   if (png_ptr == NULL || size == 0)
+      return (NULL);
 
 #ifdef PNG_MAX_MALLOC_64K
    if (size > (png_uint_32)65536L)
-      png_error(png_ptr, "Cannot Allocate > 64K");
+   {
+#ifndef PNG_USER_MEM_SUPPORTED
+      if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
+         png_error(png_ptr, "Cannot Allocate > 64K");
+      else
+#endif
+         return NULL;
+   }
 #endif
 
+ /* Check for overflow */
 #if defined(__TURBOC__) && !defined(__FLAT__)
+ if (size != (unsigned long)size)
+   ret = NULL;
+ else
    ret = farmalloc(size);
 #else
 # if defined(_MSC_VER) && defined(MAXSEG_64K)
+ if (size != (unsigned long)size)
+   ret = NULL;
+ else
    ret = halloc(size, 1);
 # else
+ if (size != (size_t)size)
+   ret = NULL;
+ else
    ret = malloc((size_t)size);
 # endif
 #endif
 
-   if (ret == NULL)
-   {
+#ifndef PNG_USER_MEM_SUPPORTED
+   if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
       png_error(png_ptr, "Out of Memory");
-   }
+#endif
 
    return (ret);
 }
 
-/* Free a pointer allocated by PNG_MALLOC().  In the default
-  configuration, png_ptr is not used, but is passed in case it
-  is needed.  If ptr is NULL, return without taking any action. */
-void
-PNG_FREE(png_structp png_ptr, png_voidp ptr)
+/* Free a pointer allocated by png_malloc().  If ptr is NULL, return
+   without taking any action. */
+void PNGAPI
+png_free(png_structp png_ptr, png_voidp ptr)
 {
    if (png_ptr == NULL || ptr == NULL)
       return;
 
+#ifdef PNG_USER_MEM_SUPPORTED
+   if (png_ptr->free_fn != NULL)
+   {
+      (*(png_ptr->free_fn))(png_ptr, ptr);
+      return;
+   }
+   else png_free_default(png_ptr, ptr);
+}
+void PNGAPI
+png_free_default(png_structp png_ptr, png_voidp ptr)
+{
+   if (png_ptr == NULL || ptr == NULL)
+      return;
+
+#endif /* PNG_USER_MEM_SUPPORTED */
+
 #if defined(__TURBOC__) && !defined(__FLAT__)
    farfree(ptr);
 #else
@@ -332,7 +529,30 @@ PNG_FREE(png_structp png_ptr, png_voidp ptr)
 
 #endif /* Not Borland DOS special memory handler */
 
-png_voidp
+#if defined(PNG_1_0_X)
+#  define png_malloc_warn png_malloc
+#else
+/* This function was added at libpng version 1.2.3.  The png_malloc_warn()
+ * function will set up png_malloc() to issue a png_warning and return NULL
+ * instead of issuing a png_error, if it fails to allocate the requested
+ * memory.
+ */
+png_voidp PNGAPI
+png_malloc_warn(png_structp png_ptr, png_uint_32 size)
+{
+   png_voidp ptr;
+   png_uint_32 save_flags;
+   if (png_ptr == NULL) return (NULL);
+
+   save_flags = png_ptr->flags;
+   png_ptr->flags|=PNG_FLAG_MALLOC_NULL_MEM_OK;
+   ptr = (png_voidp)png_malloc((png_structp)png_ptr, size);
+   png_ptr->flags=save_flags;
+   return(ptr);
+}
+#endif
+
+png_voidp PNGAPI
 png_memcpy_check (png_structp png_ptr, png_voidp s1, png_voidp s2,
    png_uint_32 length)
 {
@@ -340,12 +560,12 @@ png_memcpy_check (png_structp png_ptr, png_voidp s1, png_voidp s2,
 
    size = (png_size_t)length;
    if ((png_uint_32)size != length)
-      png_error(png_ptr,"Overflow in png_memcpy_check.");
-  
+      png_error(png_ptr, "Overflow in png_memcpy_check.");
+
    return(png_memcpy (s1, s2, size));
 }
 
-png_voidp
+png_voidp PNGAPI
 png_memset_check (png_structp png_ptr, png_voidp s1, int value,
    png_uint_32 length)
 {
@@ -353,8 +573,37 @@ png_memset_check (png_structp png_ptr, png_voidp s1, int value,
 
    size = (png_size_t)length;
    if ((png_uint_32)size != length)
-      png_error(png_ptr,"Overflow in png_memset_check.");
+      png_error(png_ptr, "Overflow in png_memset_check.");
 
    return (png_memset (s1, value, size));
 
 }
+
+#ifdef PNG_USER_MEM_SUPPORTED
+/* This function is called when the application wants to use another method
+ * of allocating and freeing memory.
+ */
+void PNGAPI
+png_set_mem_fn(png_structp png_ptr, png_voidp mem_ptr, png_malloc_ptr
+  malloc_fn, png_free_ptr free_fn)
+{
+   if (png_ptr != NULL)
+   {
+      png_ptr->mem_ptr = mem_ptr;
+      png_ptr->malloc_fn = malloc_fn;
+      png_ptr->free_fn = free_fn;
+   }
+}
+
+/* This function returns a pointer to the mem_ptr associated with the user
+ * functions.  The application should free any memory associated with this
+ * pointer before png_write_destroy and png_read_destroy are called.
+ */
+png_voidp PNGAPI
+png_get_mem_ptr(png_structp png_ptr)
+{
+   if (png_ptr == NULL) return (NULL);
+   return ((png_voidp)png_ptr->mem_ptr);
+}
+#endif /* PNG_USER_MEM_SUPPORTED */
+#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */