Imported from libpng-1.0.4-pre3.tar

ANNOUNCE

@@ -1,76 +1,57 @@
 
-Libpng 1.0.1e - June 6, 1998
+Libpng 1.0.4 - September 18, 1999
 
-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:
+Changes since the last public release (1.0.3):
 
-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 11, 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_WRITE_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
-  Made some corrections to grammar (which, it's) in documentation (Greg).
-  Corrected example.c, use of row_pointers in png_write_image().
-version 1.0.1d [May 24, 1998]
-  Corrected several statements that used side effects illegally in pngrutil.c
-    and pngtrans.c, that were introduced in version 1.0.1b
-  Revised png_read_rows() to avoid repeated if-testing for NULL (A Kleinert)
-  More corrections to example.c, use of row_pointers in png_write_image()
-    and png_read_rows().
-  Added pngdll.mak and pngdef.pas to scripts directory, contributed by
-    Bob Dellaca, to make a png32bd.dll with Borland C++ 4.5
-  Fixed error in example.c with png_set_text: num_text is 3, not 2 (Guido V.)
-  Changed several loops from count-down to count-up, for consistency.
-version 1.0.1e [June 5, 1998]
-  Revised libpng.txt and libpng.3 description of png_set_read|write_fn(), and
-    added warnings when people try to set png_read_fn and png_write_fn in
-    the same structure.
-  Added a test such that png_do_gamma will be done when num_trans==0
-    for truecolor images that have defined a background.  This corrects an
-    error that was introduced in libpng-0.90 that can cause gamma processing
-    to be skipped.
-  Added tests in png.h to include "trans" and "trans_values" in structures
-    when PNG_READ_BACKGROUND_SUPPORTED or PNG_READ_EXPAND_SUPPORTED is defined.
-  Add png_free(png_ptr->time_buffer) in png_destroy_read_struct()
-  Moved png_convert_to_rfc_1123() from pngwrite.c to png.c
-  Added capability for user-provided malloc_fn() and free_fn() functions,
-    and revised pngtest.c to demonstrate their use, replacing the
-    PNGTEST_DEBUG_MEM feature.
+  Added check for PNG_READ_INTERLACE_SUPPORTED in pngread.c; issue a warning
+     if an attempt is made to read an interlaced image when it's not supported.
+  Added check if png_ptr->trans is defined before free'ing it in pngread.c
+  Modified the Y2K statement to include versions back to version 0.71
+  Fixed a bug in the check for valid IHDR bit_depth/color_types in pngrutil.c
+  Modified makefile.wat (added -zp8 flag, ".symbolic", changed some comments)
+  Replaced leading blanks with tab characters in makefile.hux
+  Changed "dworkin.wustl.edu" to "ccrc.wustl.edu" in various documents.
+  Changed (float)red and (float)green to (double)red, (double)green
+     in png_set_rgb_to_gray() to avoid "promotion" problems in AIX.
+  Fixed a bug in pngconf.h that omitted <stdio.h> when PNG_DEBUG==0 (K Bracey).
+  Reformatted libpng.3 and libpngpf.3 with proper fonts (script by J. vanZandt).
+  Updated documentation to refer to the PNG-1.2 specification.
+  Removed ansi2knr.c and left pointers to the latest source for ansi2knr.c
+    in makefile.knr, INSTALL, and README (L. Peter Deutsch)
+  Fixed bugs in calculation of the length of rowbytes when adding alpha
+    channels to 16-bit images, in pngrtran.c (Chris Nokleberg)
+  Added function png_set_user_transform_info() to store user_transform_ptr,
+    user_depth, and user_channels into the png_struct, and a function
+    png_get_user_transform_ptr() to retrieve the pointer (Chris Nokleberg)
+  Added function png_set_empty_plte_permitted() to make libpng useable
+    in MNG applications.
+  Corrected the typedef for png_free_ptr in png.h (Jesse Jones).
+  Correct gamma with srgb is 45455 instead of 45000 in pngrutil.c, to be
+    consistent with PNG-1.2, and allow variance of 500 before complaining.
+  Added assembler code contributed by Intel in file pngvcrd.c and modified
+    makefile.w32 to use it (Nirav Chhatrapati, INTEL Corporation, Gilles Vollant)
+  Define PNG_USE_PNGVCRD in makefile.w32, to get MMX assembler code.
+  Changed "ln -s -f" to "ln -f -s" in the makefiles to make Solaris happy.
+  Added makefile.beo for BEOS on X86, contributed by Sander Stok.
+  Replaced 2147483647L several places with PNG_MAX_UINT macro, defined in png.h
+  Changed leading blanks to tabs in all makefiles.
+  Made alternate versions of  png_set_expand() in pngrtran.c, namely
+    png_set_gray_1_2_4_to_8, png_set_palette_to_rgb, and png_set_tRNS_to_alpha
+    (Greg Roelofs, in "PNG: The Definitive Guide").
+  Relocated start of 'extern "C"' block in png.h so it doesn't include pngconf.h
+  Revised calculation of num_blocks in pngmem.c to avoid a potentially
+    negative shift distance, whose results are undefined in the C language.
+  Added a check in pngset.c to prevent writing multiple tIME chunks.
+  Added a check in pngwrite.c to detect invalid small window_bits sizes.
+  Added a demo read_user_transform_fn that examines the row filters in pngtest.c
+  Define PNG_ALWAYS_EXTERN in pngconf.h if __STDC__ is defined
+  Made several minor corrections to pngtest.c
+  Changed "hptr += 16L" to "hptr = hptr + 16L" in pngmem.c for Turbo 3.0
+  Renamed the makefiles with longer but more user friendly extensions
 
 Send comments/corrections/commendations to
-png-implement@dworkin.wustl.edu or to randeg@alumni.rpi.edu
+png-implement@ccrc.wustl.edu or to randeg@alum.rpi.edu
 
 Glenn R-P

CHANGES

@@ -89,7 +89,7 @@ version 0.89 [July, 1996]
      so that people are aware that they need to change their code
   changed filter selection API to allow selection of multiple filters
      since it didn't work in previous versions of libpng anyways
-  optimized filter selection code    
+  optimized filter selection code
   fixed png_set_background() to allow using an arbitrary RGB color for
      paletted images
   fixed gamma and background correction for paletted images, so
@@ -256,7 +256,7 @@ version 0.99g [March 6, 1998, morning]
   Minor changes to pngtest.c to suppress compiler warnings.
   Removed "beta" language from documentation.
 version 0.99h [March 6, 1998, evening]
-  Minor changes to previous minor changes to pngtest.c 
+  Minor changes to previous minor changes to pngtest.c
   Changed PNG_READ_NOT_FULLY_SUPPORTED to PNG_READ_TRANSFORMS_NOT_SUPPORTED
   and added PNG_PROGRESSIVE_READ_NOT_SUPPORTED macro
 version 1.00 [March 7, 1998]
@@ -349,3 +349,95 @@ version 1.0.1e [June 6, 1998]
   Added capability for user-provided malloc_fn() and free_fn() functions,
     and revised pngtest.c to demonstrate their use, replacing the
     PNGTEST_DEBUG_MEM feature.
+  Added makefile.w32, for Microsoft C++ 4.0 and later (Tim Wegner).
+version 1.0.2 [June 14, 1998]
+  Fixed two bugs in makefile.bor .
+version 1.0.2a [December 30, 1998]
+  Replaced and extended code that was removed from png_set_filler() in 1.0.1a.
+  Fixed a bug in png_do_filler() that made it fail to write filler bytes in
+    the left-most pixel of each row (Kevin Bracey).
+  Changed "static pngcharp tIME_string" to "static char tIME_string[30]"
+    in pngtest.c (Duncan Simpson).
+  Fixed a bug in pngtest.c that caused pngtest to try to write a tIME chunk
+    even when no tIME chunk was present in the source file.
+  Fixed a problem in pngrutil.c: gray_to_rgb didn't always work with 16-bit.
+  Fixed a problem in png_read_push_finish_row(), which would not skip some
+    passes that it should skip, for images that are less than 3 pixels high.
+  Interchanged the order of calls to png_do_swap() and png_do_shift()
+    in pngwtran.c (John Cromer).
+  Added #ifdef PNG_DEBUG/#endif surrounding use of PNG_DEBUG in png.h .
+  Changed "bad adaptive filter type" from error to warning in pngrutil.c .
+  Fixed a documentation error about default filtering with 8-bit indexed-color.
+  Separated the PNG_NO_STDIO macro into PNG_NO_STDIO and PNG_NO_CONSOLE_IO
+    (L. Peter Deutsch).
+  Added png_set_rgb_to_gray() and png_get_rgb_to_gray_status() functions.
+  Added png_get_copyright() and png_get_header_version() functions.
+  Revised comments on png_set_progressive_read_fn() in libpng.txt and example.c
+  Added information about debugging in libpng.txt and libpng.3 .
+  Changed "ln -sf" to "ln -s -f" in makefile.s2x, makefile.lnx, and makefile.sco.
+  Removed lines after Dynamic Dependencies" in makefile.aco .
+  Revised makefile.dec to make a shared library (Jeremie Petit).
+  Removed trailing blanks from all files. 
+version 1.0.2a [January 6, 1999]
+  Removed misplaced #endif and #ifdef PNG_NO_EXTERN near the end of png.h
+  Added "if" tests to silence complaints about unused png_ptr in png.h and png.c
+  Changed "check_if_png" function in example.c to return true (nonzero) if PNG.
+  Changed libpng.txt to demonstrate png_sig_cmp() instead of png_check_sig()
+    which is obsolete.
+version 1.0.3 [January 14, 1999]
+  Added makefile.hux, for Hewlett Packard HPUX 10.20 and 11.00 (Jim Rice)
+  Added a statement of Y2K compliance in png.h, libpng.3, and Y2KINFO.
+version 1.0.3a [August 12, 1999]
+  Added check for PNG_READ_INTERLACE_SUPPORTED in pngread.c; issue a warning
+     if an attempt is made to read an interlaced image when it's not supported.
+  Added check if png_ptr->trans is defined before free'ing it in pngread.c
+  Modified the Y2K statement to include versions back to version 0.71
+  Fixed a bug in the check for valid IHDR bit_depth/color_types in pngrutil.c
+  Modified makefile.wat (added -zp8 flag, ".symbolic", changed some comments)
+  Replaced leading blanks with tab characters in makefile.hux
+  Changed "dworkin.wustl.edu" to "ccrc.wustl.edu" in various documents.
+  Changed (float)red and (float)green to (double)red, (double)green
+     in png_set_rgb_to_gray() to avoid "promotion" problems in AIX.
+  Fixed a bug in pngconf.h that omitted <stdio.h> when PNG_DEBUG==0 (K Bracey).
+  Reformatted libpng.3 and libpngpf.3 with proper fonts (script by J. vanZandt).
+  Updated documentation to refer to the PNG-1.2 specification.
+  Removed ansi2knr.c and left pointers to the latest source for ansi2knr.c
+    in makefile.knr, INSTALL, and README (L. Peter Deutsch)
+  Fixed bugs in calculation of the length of rowbytes when adding alpha
+    channels to 16-bit images, in pngrtran.c (Chris Nokleberg)
+  Added function png_set_user_transform_info() to store user_transform_ptr,
+    user_depth, and user_channels into the png_struct, and a function
+    png_get_user_transform_ptr() to retrieve the pointer (Chris Nokleberg)
+  Added function png_set_empty_plte_permitted() to make libpng useable
+    in MNG applications.
+  Corrected the typedef for png_free_ptr in png.h (Jesse Jones).
+  Correct gamma with srgb is 45455 instead of 45000 in pngrutil.c, to be
+    consistent with PNG-1.2, and allow variance of 500 before complaining.
+  Added assembler code contributed by Intel in file pngvcrd.c and modified
+    makefile.w32 to use it (Nirav Chhatrapati, INTEL Corporation, Gilles Vollant)
+  Changed "ln -s -f" to "ln -f -s" in the makefiles to make Solaris happy.
+  Added some aliases for png_set_expand() in pngrtran.c, namely
+    png_set_expand_PLTE(), png_set_expand_depth(), and png_set_expand_tRNS()
+    (Greg Roelofs, in "PNG: The Definitive Guide").
+  Added makefile.beo for BEOS on X86, contributed by Sander Stok.
+version 1.0.3b [August 26, 1999]
+  Replaced 2147483647L several places with PNG_MAX_UINT macro, defined in png.h
+  Changed leading blanks to tabs in all makefiles.
+  Define PNG_USE_PNGVCRD in makefile.w32, to get MMX assembler code.
+  Made alternate versions of  png_set_expand() in pngrtran.c, namely
+    png_set_gray_1_2_4_to_8, png_set_palette_to_rgb, and png_set_tRNS_to_alpha
+    (Greg Roelofs, in "PNG: The Definitive Guide").  Deleted the 1.0.3a aliases.
+  Relocated start of 'extern "C"' block in png.h so it doesn't include pngconf.h
+  Revised calculation of num_blocks in pngmem.c to avoid a potentially
+    negative shift distance, whose results are undefined in the C language.
+  Added a check in pngset.c to prevent writing multiple tIME chunks.
+  Added a check in pngwrite.c to detect invalid small window_bits sizes.
+version 1.0.3d [September 4, 1999]
+  Fixed type casting of igamma in pngrutil.c
+  Added new png_expand functions to scripts/pngdef.pas and pngos2.def
+  Added a demo read_user_transform_fn that examines the row filters in pngtest.c
+version 1.0.4 [September 18, 1999]
+  Define PNG_ALWAYS_EXTERN in pngconf.h if __STDC__ is defined
+  Delete #define PNG_INTERNAL and include "png.h" from pngasmrd.h
+  Made several minor corrections to pngtest.c
+  Renamed the makefiles with longer but more user friendly extensions

INSTALL

@@ -1,17 +1,17 @@
 
-Installing libpng version 1.0.1e - June 6, 1998
+Installing libpng version 1.0.4 - September 18, 1999
 
 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, 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.
 
 You can rename the directories that you downloaded (they
-might be called "libpng-1.0.1e" or "lpng102" and "zlib-1.1.2"
-or "zlib112") so that you have directories called "zlib" and "libpng".
+might be called "libpng-1.0.4" or "lpng103" and "zlib-1.1.3"
+or "zlib113") so that you have directories called "zlib" and "libpng".
 
 Your directory structure should look like this:
 
@@ -38,31 +38,38 @@ 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
-      pngdll.mak    =>  To make a png32bd.dll with Borland C++ 4.5
-      pngdef.pas    =>  Defines for a png32bd.dll with Borland C++ 4.5
+ descrip.mms      =>  VMS makefile for MMS or MMK
+ makefile.std     =>  Generic UNIX makefile
+ makefile.knr     =>  Archaic UNIX Makefile that converts files with
+                      ansi2knr (Requires ansi2knr.c from
+                      ftp://ftp.cs.wisc.edu/ghost)
+ makefile.dec     =>  DEC Alpha UNIX makefile
+ makefile.hpux    =>  HPUX (10.20 and 11.00) makefile
+ makefile.sgi     =>  Silicon Graphics IRIX makefile
+ makefile.sunos   =>  Sun makefile
+ makefile.solaris =>  Solaris 2.X makefile (gcc, creates libpng.so.2.1.0.4)
+ makefile.linux   =>  Linux/ELF makefile (gcc, creates libpng.so.2.1.0.4)
+ 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.borland =>  Borland makefile
+ build.bat        =>  MS-DOS batch file for Borland compiler
+ makefile.dj2     =>  DJGPP 2 makefile
+ makefile.msc     =>  Microsoft C makefile
+ makefile.win32vc =>  makefile for Microsoft Visual C++ 4.0 and later
+ makefile.turboc3 =>  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.watcom  =>  Watcom 10a+ Makefile, 32-bit flat memory model
+ makevms.com      =>  VMS build script
+ pngdll.mak       =>  To make a png32bd.dll with Borland C++ 4.5
+ pngdef.pas       =>  Defines for a png32bd.dll with Borland C++ 4.5
+ SCOPTIONS.ppc    =>  Used with smakefile.ppc
 
 Copy the file (or files) that you need from the
 scripts directory into this directory, for example

KNOWNBUG

@@ -1,196 +1,40 @@
 
-Known bugs and suggested enhancements in libpng-1.0.1
+Known bugs and suggested enhancements in libpng-1.0.4
 
-1. March 13, 1998 -- BUG -- pngtrans.c:
 
-   row_info->channels should be updated --
-   row_info->color_type should be updated --
-
-   STATUS: I think this is all fixed in libpng-1.0.1a but needs
-   to be tested.
-
-2. March 14, 1998 -- ENHANCEMENT -- Glenn
-
-   We should add the G>GA, G>GX, G>AG, and G>XG transformations
-   in png_do_read_filler()
-
-   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
+1. 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
+   Make them count down instead of up -- Kevin Bracey
 
-      Question whether i-- or --i is better.
+   Optimizing compilers don't need this, and making
+   the change would be error prone -- Tom Lane, Glenn R-P
 
-      STATUS: Under investigation.  About 150 loops turned around
-      in libpng-1.0.1d, for testing.  Object files and executables
-      are about 20k smaller in SGI and gcc-compiled codes.  
+   Question whether i-- or --i is better.
 
-   b. Remove products and structure members from loop tests -- Glenn R-P
+   STATUS: Under investigation, postponed until after
+   libpng-1.0.4.  About 160 loops will be turned around
+   in libpng-1.0.Nn, for testing.
 
-      Can be accomplished without messing with loop guts.  This
-      was shown to be effective on optimized SGI compiler:
+2. July 4, 1998 -- ENHANCEMENT -- Glenn R-P
 
-              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++)
+   libpng-1.0.4 and earlier transform colors to gamma=1.0 space for
+   merging with background, and then back to the image's gamma.  The
+   bit_depth of the intermediate (gamma=1.0) representation is probably
+   not sufficient.  In the typical gamma=1/2.2 situation, the linear
+   pixels need about 4 more bits than the gamma-encoded ones, to avoid
+   loss of precision.  A similar situation exists with the rgb_to_gray
+   operation.
 
-      STATUS: Mostly done in libpng-1.0.1a, done for all important loops.
-              More done in libpng-1.0.1b.
+   STATUS: under development.
 
-   c. Replace abs() with intrinsic ternary operations in Paeth
-      filtering -- Glenn R-P
+3. September 1999 -- ENHANCEMENT --
 
-      STATUS: Done in libpng-1.0.1a
-      (can be restored to original behavior with #define PNG_USE_ABS)
+   It should be possible to use libpng without floating-point aritmetic.
 
-   d. In pngwutil.c, make separate simple loops to use when filter 
-      heuristic sums aren't needed. -- Glenn R-P
+   STATUS: Under investigation, implementation postponed until after
+   libpng-1.0.4.  The application interface will change because replacements
+   for the png_set_gAMA(), png_set_cHRM(), and corresponding png_get_()
+   functions will be needed.
 
-      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
-
-17. May 10, 1998 -- DOCUMENTATION -- Greg
-
-   There are a number of incorrect usages of "which" and "it's" in the
-   comments.
-
-   STATUS:
-
-   Fixed in libpng-1.0.1c
-
-18. May 20, 1998 -- BUG -- illegal use of side effects -- Magnus Holmgren
-
-   In libpng-1.0.1b several illegal uses of side effects were
-   introduced while tuning loops in pngrutil.c; also one in pngtrans.c.
-
-   STATUS:
-
-   Fixed in libpng-1.0.1d
-
-19. May 20, 1998 -- ENHANCEMENT --  script for making DLL -- Bob Dellaca
-
-   Bob Dellaca contributed script for making PNG DLL on Borland C++ 4.5
-
-   STATUS:
-
-   Added to distribution in libpng-1.0.1d 
-
-20. May 26, 1998 -- BUG -- png_do_gamma is skipped -- Magnus Holmgren
-
-   When a background color is defined for a truecolor image, but no
-   transparent color is defined, gamma correction is not done.
-   The test in pngrtran should include " && !png_ptr->trans_values"
-
-   STATUS:
-
-   Fixed in libpng-1.0.1e

README

@@ -1,4 +1,4 @@
-README for libpng 1.0.1e - June 6, 1998 (shared library 2.1)
+README for libpng 1.0.4 - September 18, 1999 (shared library 2.1)
 See the note about version numbers near the top of png.h
 
 See INSTALL for instructions on how to install libpng.
@@ -49,7 +49,7 @@ 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>
+on the PNG implementation mailing list <png-implement@ccrc.wustl.edu>
 and not on material submitted to Guy.
 
 For a detailed description on using libpng, read libpng.txt.  For
@@ -98,8 +98,8 @@ 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
+randeg@alum.rpi.edu
+png-implement@ccrc.wustl.edu
 
 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
@@ -108,7 +108,7 @@ addressed to the png-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
+or to png-implement@ccrc.wustl.edu.  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,
@@ -126,8 +126,6 @@ Files in this distribution:
       CHANGES       =>  Description of changes between libpng versions
       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
       example.c     =>  Example code for using libpng functions
@@ -155,36 +153,46 @@ Files in this distribution:
       pngwtran.c    =>  Write data transformations
       pngwutil.c    =>  Write utility functions
       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
-        pngdll.mak    =>  To make a png32bd.dll with Borland C++ 4.5
-        pngdef.pas    =>  Defines for a png32bd.dll with Borland C++ 4.5
+       descrip.mms      =>  VMS makefile for MMS or MMK
+       makefile.std     =>  Generic UNIX makefile
+       makefile.knr     =>  Archaic UNIX Makefile that converts files with
+                            ansi2knr (Requires ansi2knr.c from
+                            ftp://ftp.cs.wisc.edu/ghost)
+       makefile.dec     =>  DEC Alpha UNIX makefile
+       makefile.hpux    =>  HPUX (10.20 and 11.00) makefile
+       makefile.sgi     =>  Silicon Graphics IRIX makefile
+       makefile.sunos   =>  Sun makefile
+       makefile.solaris =>  Solaris 2.X makefile
+                            (gcc, creates libpng.so.2.1.0.4)
+       makefile.linux   =>  Linux/ELF makefile
+                            (gcc, creates libpng.so.2.1.0.4)
+       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.borland =>  Borland makefile
+       build.bat        =>  MS-DOS batch file for Borland compiler
+       makefile.dj2     =>  DJGPP 2 makefile
+       makefile.msc     =>  Microsoft C makefile
+       makefile.win32vc =>  makefile for Microsoft Visual C++ 4.0 and later
+       makefile.turboc3 =>  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.watcom  =>  Watcom 10a+ Makefile, 32-bit flat memory model
+       makevms.com      =>  VMS build script
+       pngdll.mak       =>  To make a png32bd.dll with Borland C++ 4.5
+       pngdef.pas       =>  Defines for a png32bd.dll with Borland C++ 4.5
+       SCOPTIONS.ppc    =>  Used with smakefile.ppc
 
 Good luck, and happy coding.
 
 -Glenn Randers-Pehrson
- Internet: randeg@alumni.rpi.edu
+ Internet: randeg@alum.rpi.edu
  Web: http://www.rpi.edu/~randeg/index.html
 
 -Andreas Eric Dilger

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 "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)
-improve API by hiding the info_ptr
+Final bug fixes.
+Fix problem with C++ and EXTERN "C".
+Better C++ wrapper/full C++ implementation?
+Keep up with public chunks.
+sPLT chunk handling.
+cHRM transformation.
+Support for application-defined chunk handlers.
+Improve setjmp/longjmp usage or remove it in favor of returning error codes.
+High-level API for reading images.
+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?).
+Optional palette (sPLT) creation.
+Histogram creation.
+Text conversion between different code pages (Latin-1 -> Mac and DOS).
+Improve API by hiding the info_ptr.
+Make a no-floating-point version.

Y2KINFO

@@ -0,0 +1,55 @@
+   Y2K compliance in libpng:
+   =========================
+      
+      January 13, 1999
+      
+      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 1.0.4 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.
-
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-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
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-			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
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-Distributed by Free Software Foundation, Inc." (or with whatever year is
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-Paragraph 1 above, provided that you also do the following:
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-    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
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-    corresponding source code, to be distributed under the terms of
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-    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.)
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-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
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-  5. If you wish to incorporate parts of Ghostscript into other free
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-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
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-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
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-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;
-}

example.c

@@ -15,8 +15,11 @@
 
 #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.
+/* 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
@@ -41,12 +44,14 @@ int check_if_png(char *file_name, FILE **fp)
    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
@@ -146,7 +151,7 @@ void read_png(FILE *fp, unsigned int sig_read)  /* file is already open */
    /* 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);
@@ -220,11 +225,14 @@ void read_png(FILE *fp, unsigned int sig_read)  /* file is already open */
 
    if (png_get_sRGB(png_ptr, info_ptr, &intent))
       png_set_sRGB(png_ptr, intent, 0);
-   else 
+   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.
@@ -324,13 +332,13 @@ void read_png(FILE *fp, unsigned int sig_read)  /* file is already open */
       {
 #ifdef sparkle /* Read the image using the "sparkle" effect. */
          png_read_rows(png_ptr, &row_pointers[y], NULL, number_of_rows);
-        
+
          png_read_rows(png_ptr, NULL, row_pointers[y], number_of_rows);
 #else no_sparkle /* Read the image using the "rectangle" effect */
          png_read_rows(png_ptr, 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 */
@@ -384,8 +392,11 @@ initialize_png_reader(png_structp *png_ptr, png_infop *info_ptr)
       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
@@ -565,7 +576,7 @@ 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.
     */

libpng.txt

@@ -1,16 +1,16 @@
 libpng.txt - A description on how to use and modify libpng
 
- libpng version 1.0.1e - June 6, 1998
+ libpng version 1.0.4 - September 18, 1999
  Updated and distributed by Glenn Randers-Pehrson
- <randeg@alumni.rpi.edu>
- Copyright (c) 1998, Glenn Randers-Pehrson
+ <randeg@alum.rpi.edu>
+ Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  For conditions of distribution and use, see copyright
  notice in png.h.
 
  based on:
 
  libpng 1.0 beta 6  version 0.96 May 28, 1997
- Updated and distributed by Andreas Dilger 
+ Updated and distributed by Andreas Dilger
  Copyright (c) 1996, 1997 Andreas Dilger
 
  libpng 1.0 beta 2 - version 0.88  January 26, 1996
@@ -22,6 +22,7 @@ libpng.txt - A description on how to use and modify libpng
  Copyright (c) 1995 Frank J. T. Wojcik
  December 18, 1995 && January 20, 1996
 
+ *
 I. Introduction
 
 This file describes how to use and modify the PNG reference library
@@ -35,12 +36,19 @@ INSTALL file for instructions on how to install libpng.
 
 Libpng was written as a companion to the PNG specification, as a way
 of reducing the amount of time and effort it takes to support the PNG
-file format in application programs.  The PNG specification is available
+file format in application programs.
+
+The PNG-1.2 specification is available at <http://www.cdrom.com/png>.
+
+The PNG-1.0 specification is available
 as RFC 2083 <ftp://ftp.uu.net/graphics/png/documents/> and as a
 W3C Recommendation <http://www.w3.org/TR/REC.png.html>. Some
 additional chunks are described in the special-purpose public chunks
-documents at <ftp://ftp.uu.net/graphics/png/documents/>.  Other information
-about PNG can be found at the PNG home page, <http://www.cdrom.com/pub/png/>.
+documents at <ftp://ftp.uu.net/graphics/png/documents/>.
+
+Other information
+about PNG, and the latest version of libpng, can be found at the PNG home
+page, <http://www.cdrom.com/pub/png/>.
 
 Most users will not have to modify the library significantly; advanced
 users may want to modify it more.  All attempts were made to make it as
@@ -57,6 +65,8 @@ work to be done (see the TODO file), libpng should cover the
 majority of the needs of its users.
 
 Libpng uses zlib for its compression and decompression of PNG files.
+Further information about zlib, and the latest version of zlib, can
+be found at the zlib home page, <http://www.cdrom.com/pub/infozip/zlib/>.
 The zlib compression utility is a general purpose utility that is
 useful for more than PNG files, and can be used without libpng.
 See the documentation delivered with zlib for more details.
@@ -126,7 +136,7 @@ Customizing libpng.
         return;
     }
     fread(header, 1, number, fp);
-    is_png = png_check_sig(header, 0, number);
+    is_png = !png_sig_cmp(header, 0, number);
     if (!is_png)
     {
         return;
@@ -179,8 +189,8 @@ are only necessary if you are not using the libpng supplied error
 handling and memory alloc/free functions.
 
 When libpng encounters an error, it expects to longjmp back
-to your routine.  Therefore, you will need to call setjmp and pass the
-jmpbuf field of your png_struct.  If you read the file from different
+to your routine.  Therefore, you will need to call setjmp and pass
+your png_ptr->jmpbuf.  If you read the file from different
 routines, you will need to update the jmpbuf field every time you enter
 a new routine that will call a png_ function.
 
@@ -253,11 +263,26 @@ with
 You must supply the function
 
     void read_transform_fn(png_ptr ptr, row_info_ptr
-       row_info, png_bytep data) 
+       row_info, png_bytep data)
 
 See pngtest.c for a working example.  Your function will be called
 after all of the other transformations have been processed.
 
+You can also set up a pointer to a user structure for use by your
+callback function, and you can inform libpng that your transform
+function will change the number of channels or bit depth with the
+function
+
+    png_set_user_transform_info(png_ptr, user_ptr,
+       user_depth, user_channels);
+
+
+You can retrieve the pointer via the function
+png_get_user_transform_ptr().  For example:
+
+    voidp read_user_transform_ptr =
+       png_get_user_transform_ptr(png_ptr);
+
 You are now ready to read all the file information up to the actual
 image data.  You do this with a call to png_read_info().
 
@@ -282,7 +307,7 @@ Functions are used to get the information from the info_ptr:
                          are present.
                      PNG_COLOR_TYPE_GRAY
                         (bit depths 1, 2, 4, 8, 16)
-                     PNG_COLOR_TYPE_GRAY_ALPHA  
+                     PNG_COLOR_TYPE_GRAY_ALPHA
                         (bit depths 8, 16)
                      PNG_COLOR_TYPE_PALETTE
                         (bit depths 1, 2, 4, 8)
@@ -503,13 +528,18 @@ grayscale images with bit depths of 2 or 4 or if there is a multiple-image
 viewing application that wishes to treat all images in the same way.
 
     if (color_type == PNG_COLOR_TYPE_PALETTE &&
-        bit_depth <= 8) png_set_expand(png_ptr);
+        bit_depth <= 8) png_set_palette_to_rgb(png_ptr);
 
     if (color_type == PNG_COLOR_TYPE_GRAY &&
-        bit_depth < 8) png_set_expand(png_ptr);
+        bit_depth < 8) png_set_gray_1_2_4_to_8(png_ptr);
 
     if (png_get_valid(png_ptr, info_ptr,
-        PNG_INFO_tRNS)) png_set_expand(png_ptr);
+        PNG_INFO_tRNS)) png_set_tRNS_to_alpha(png_ptr);
+
+These three functions are actually aliases for png_set_expand(), added
+in libpng version 1.0.4, with the function names expanded to improve code
+readability.  In some future version they may actually do different
+things.
 
 PNG can have files with 16 bits per channel.  If you only can handle
 8 bits per channel, this will strip the pixels down to 8 bit.
@@ -588,7 +618,65 @@ RGB.  This code will do that conversion:
         color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
           png_set_gray_to_rgb(png_ptr);
 
-If you have a grayscale and you are using png_set_expand() to change to
+Conversely, you can convert an RGB or RGBA image to grayscale or grayscale
+with alpha.  This is intended for conversion of images that really are
+gray (red == green == blue), so the function simply strips out the red
+and blue channels, leaving the green channel in the gray position.
+
+    if (color_type == PNG_COLOR_TYPE_RGB ||
+        color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+          png_set_rgb_to_gray(png_ptr, error_action,
+             double red_weight, double green_weight);
+
+    error_action = 1: silently do the conversion
+    error_action = 2: issue a warning if the original
+                      image has any pixel where
+                      red != green or red != blue
+    error_action = 3: issue an error and abort the
+                      conversion if the original
+                      image has any pixel where
+                      red != green or red != blue
+
+    red_weight:       weight of red component
+                      (NULL -> default 54/256)
+    green_weight:     weight of green component
+                      (NULL -> default 183/256)
+
+If you have set error_action = 1 or 2, you can
+later check whether the image really was gray, after processing
+the image rows, with the png_get_rgb_to_gray_status(png_ptr) function.
+It will return a png_byte that is zero if the image was gray or
+1 if there were any non-gray pixels.  bKGD and sBIT data
+will be silently converted to grayscale, using the green channel
+data, regardless of the error_action setting.
+
+With 0.0<=red_weight+green_weight<=1.0,
+the normalized graylevel is computed:
+
+    int rw = red_weight * 256;
+    int gw = green_weight * 256;
+    int bw = 256 - (rw + gw);
+    gray = (rw*red + gw*green + bw*blue)/256;
+
+The default values approximate those recommended in the Charles
+Poynton's Color FAQ, <http://www.inforamp.net/~poynton/>
+Copyright (c) 1998-01-04 Charles Poynton poynton@inforamp.net
+
+    Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
+
+Libpng approximates this with
+
+    Y = 0.211 * R    + 0.715 * G    + 0.074 * B
+
+which can be expressed with integers as
+
+    Y = (54 * R + 183 * G + 19 * B)/256
+
+The calculation is done in a linear colorspace, if the image gamma
+is known.
+
+If you have a grayscale and you are using png_set_expand_depth() or
+png_set_expand() to change to
 a higher bit-depth, you must either supply the background color as a gray
 value at the original file bit-depth (need_expand = 1) or else supply the
 background color as an RGB triplet at the final, expanded bit depth
@@ -621,6 +709,8 @@ the amount of additional gamma correction needed to compensate for
 a (viewing_gamma=1.25) environment.  In a dim or brightly lit room, no
 compensation other than the display_gamma is needed (viewing_gamma=1.0).
 
+   double gamma, screen_gamma;
+
    if (/* We have a user-defined screen
        gamma value */)
    {
@@ -631,7 +721,7 @@ compensation other than the display_gamma is needed (viewing_gamma=1.0).
    else if ((gamma_str = getenv("SCREEN_GAMMA"))
       != NULL)
    {
-      screen_gamma = atof(gamma_str);
+      screen_gamma = (double)atof(gamma_str);
    }
    /* If we don't have another value */
    else
@@ -647,7 +737,7 @@ compensation other than the display_gamma is needed (viewing_gamma=1.0).
 The png_set_gamma() function handles gamma transformations of the data.
 Pass both the file gamma and the current screen_gamma.  If the file does
 not have a gamma value, you can pass one anyway if you have an idea what
-it is (usually 0.50 is a good guess for GIF images on PCs).  Note
+it is (usually 0.45455 is a good guess for GIF images on PCs).  Note
 that file gammas are inverted from screen gammas.  See the discussions
 on gamma in the PNG specification for an excellent description of what
 gamma is, and why all applications should support it.  It is strongly
@@ -656,7 +746,7 @@ recommended that PNG viewers support gamma correction.
    if (png_get_gAMA(png_ptr, info_ptr, &gamma))
       png_set_gamma(png_ptr, screen_gamma, gamma);
    else
-      png_set_gamma(png_ptr, screen_gamma, 0.50);
+      png_set_gamma(png_ptr, screen_gamma, 0.45455);
 
 If you need to reduce an RGB file to a paletted file, or if a paletted
 file has more entries then will fit on your screen, png_set_dither()
@@ -771,7 +861,7 @@ row_pointers:
     png_read_row(png_ptr, &row_pointers, NULL);
 
 If the file is interlaced (info_ptr->interlace_type != 0), things get
-somewhat harder.  The only current (PNG Specification version 1.0)
+somewhat harder.  The only current (PNG Specification version 1.2)
 interlacing type for PNG is (interlace_type == PNG_INTERLACE_ADAM7)
 is a somewhat complicated 2D interlace scheme, known as Adam7, that
 breaks down an image into seven smaller images of varying size, based
@@ -907,7 +997,9 @@ png_infop info_ptr;
        to be called when the header info is valid,
        when each row is completed, and when the image
        is finished.  If you aren't using all functions,
-       you can specify a NULL parameter.  You can use
+       you can specify NULL parameters.  Even when all
+       three functions are NULL, you need to call
+       png_set_progressive_read_fn().  You can use
        any struct as the user_ptr (cast to a void pointer
        for the function call), and retrieve the pointer
        from inside the callbacks using the function
@@ -939,21 +1031,21 @@ png_infop info_ptr;
        of data from the file stream (in order, of
        course).  On machines with segmented memory
        models machines, don't give it any more than
-       64K.  The library seems to run fine with sizes 
+       64K.  The library seems to run fine with sizes
        of 4K. Although you can give it much less if
        necessary (I assume you can give it chunks of
        1 byte, I haven't tried less then 256 bytes
        yet).  When this function returns, you may
        want to display any rows that were generated
        in the row callback if you don't already do
-       so there. 
+       so there.
      */
     png_process_data(png_ptr, info_ptr, buffer, length);
     return 0;
  }
 
  /* This function is called (as set by
-    png_set_progressive_fn() above) when enough data
+    png_set_progressive_read_fn() above) when enough data
     has been supplied so all of the header has been
     read.
  */
@@ -1003,14 +1095,14 @@ png_infop info_ptr;
           new_row);
 
     /* where old_row is what was displayed for
-       previous rows.  Note that the first pass
-       (pass == 0, really) will completely cover
+       previously for the row.  Note 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.
-    */  
+    */
  }
 
  void
@@ -1040,7 +1132,7 @@ You will want to do the I/O initialization before you get into libpng,
 so if it doesn't work, you don't have anything to undo. If you are not
 using the standard I/O functions, you will need to replace them with
 custom writing functions.  See the discussion under Customizing libpng.
-    
+
     FILE *fp = fopen(file_name, "wb");
     if (!fp)
     {
@@ -1081,20 +1173,22 @@ png_create_write_struct_2() instead of png_create_read_struct():
 After you have these structures, you will need to set up the
 error handling.  When libpng encounters an error, it expects to
 longjmp() back to your routine.  Therefore, you will need to call
-setjmp and pass the jmpbuf field of your png_struct.  If you
+setjmp() and pass the png_ptr->jmpbuf.  If you
 write the file from different routines, you will need to update
 the jmpbuf field every time you enter a new routine that will
 call a png_ function.  See your documentation of setjmp/longjmp
 for your compiler for more information on setjmp/longjmp.  See
 the discussion on libpng error handling in the Customizing Libpng
 section below for more information on the libpng error handling.
-    
+
     if (setjmp(png_ptr->jmpbuf))
-    {    
+    {
         png_destroy_write_struct(&png_ptr, &info_ptr);
         fclose(fp);
         return;
     }
+    ...
+    return;
 
 Now you need to set up the output code.  The default for libpng is to
 use the C function fwrite().  If you use this, you will need to pass a
@@ -1130,12 +1224,12 @@ have no special needs in this area, let the library do what it wants by
 not calling this function at all, as it has been tuned to deliver a good
 speed/compression ratio. The second parameter to png_set_filter() is
 the filter method, for which the only valid value is '0' (as of the
-October 1996 PNG specification, version 1.0).  The third parameter is a
+July 1999 PNG specification, version 1.2).  The third parameter is a
 flag that indicates which filter type(s) are to be tested for each
 scanline.  See the Compression Library for details on the specific filter
 types.
 
-    
+
     /* turn on or off filtering, and/or choose
        specific filters */
     png_set_filter(png_ptr, 0,
@@ -1162,7 +1256,7 @@ data.  See the Compression Library for details on the compression levels.
 You now need to fill in the png_info structure with all the data you
 wish to write before the actual image.  Note that the only thing you
 are allowed to write after the image is the text chunks and the time
-chunk (as of PNG Specification 1.0, anyway).  See png_write_end() and
+chunk (as of PNG Specification 1.2, anyway).  See png_write_end() and
 the latest PNG specification for more information on that.  If you
 wish to write them before the image, fill them in now, and flag that
 data as being valid.  If you want to wait until after the data, don't
@@ -1234,7 +1328,7 @@ Some of the more important parts of the png_info are:
                      PNG_SRGB_INTENT_PERCEPTUAL,
                      PNG_SRGB_INTENT_ABSOLUTE, or
                      PNG_SRGB_INTENT_RELATIVE.
-                        
+
 
     png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr,
        srgb_intent);
@@ -1325,7 +1419,7 @@ png_text structure holds a keyword-text value, and a compression type.
 The compression types have the same valid numbers as the compression
 types of the image data.  Currently, the only valid number is zero.
 However, you can store text either compressed or uncompressed, unlike
-images which always have to be compressed.  So if you don't want the
+images, which always have to be compressed.  So if you don't want the
 text compressed, set the compression type to PNG_TEXT_COMPRESSION_NONE.
 Until text gets around 1000 bytes, it is not worth compressing it.
 After the text has been written out to the file, the compression type
@@ -1385,7 +1479,7 @@ depending on whether you mean the PNG file, the time the image was
 created in a non-PNG format, a still photo from which the image was
 scanned, or possibly the subject matter itself.  In order to facilitate
 machine-readable dates, it is recommended that the "Creation Time"
-tEXt chunk use RFC 1123 format dates (e.g. 22 May 1997 18:07:10 GMT"),
+tEXt chunk use RFC 1123 format dates (e.g. "22 May 1997 18:07:10 GMT"),
 although this isn't a requirement.  Unlike the tIME chunk, the
 "Creation Time" tEXt chunk is not expected to be automatically changed
 by the software.  To facilitate the use of RFC 1123 dates, a function
@@ -1427,7 +1521,7 @@ correctly pack the pixels into a single byte:
 PNG files reduce possible bit depths to 1, 2, 4, 8, and 16.  If your
 data is of another bit depth, you can write an sBIT chunk into the
 file so that decoders can get the original data if desired.
-    
+
     /* Set the true bit depth of the image data */
     if (color_type & PNG_COLOR_MASK_COLOR)
     {
@@ -1488,10 +1582,24 @@ with
 You must supply the function
 
     void write_transform_fn(png_ptr ptr, row_info_ptr
-       row_info, png_bytep data) 
+       row_info, png_bytep data)
 
 See pngtest.c for a working example.  Your function will be called
-before any of the other transformations have been processed.
+before any of the other transformations are processed.
+
+You can also set up a pointer to a user structure for use by your
+callback function.
+
+    png_set_user_transform_info(png_ptr, user_ptr, 0, 0);
+
+The user_channels and user_depth parameters of this function are ignored
+when writing; you can set them to zero as shown.
+
+You can retrieve the pointer via the function
+png_get_user_transform_ptr().  For example:
+
+    voidp write_user_transform_ptr =
+       png_get_user_transform_ptr(png_ptr);
 
 It is possible to have libpng flush any pending output, either manually,
 or automatically after a certain number of lines have been written.  To
@@ -1548,8 +1656,8 @@ row_pointers:
     png_write_row(png_ptr, &row_pointer);
 
 When the file is interlaced, things can get a good deal more
-complicated.  The only currently (as of February 1998 -- PNG Specification
-version 1.0, dated October 1996) defined interlacing scheme for PNG files
+complicated.  The only currently (as of August 1999 -- PNG Specification
+version 1.2, dated July 1999) defined interlacing scheme for PNG files
 is the "Adam7" interlace scheme, that breaks down an
 image into seven smaller images of varying size.  libpng will build
 these images for you, or you can do them yourself.  If you want to
@@ -1594,7 +1702,6 @@ palette, or histogram, before the call to png_destroy_write_struct();
 
 For a more compact example of writing a PNG image, see the file example.c.
 
-
 V. Modifying/Customizing libpng:
 
 There are two issues here.  The first is changing how libpng does
@@ -1603,7 +1710,7 @@ The second deals with more complicated things like adding new chunks,
 adding new transformations, and generally changing how libpng works.
 
 All of the memory allocation, input/output, and error handling in libpng
-goes through callbacks which are user settable.  The default routines are
+goes through callbacks that are user settable.  The default routines are
 in pngmem.c, pngrio.c, pngwio.c, and pngerror.c respectively.  To change
 these functions, call the appropriate png_set_???_fn() function.
 
@@ -1621,7 +1728,8 @@ which currently just call fread() and fwrite().  The FILE * is stored in
 png_struct and is initialized via png_init_io().  If you wish to change
 the method of I/O, the library supplies callbacks that you can set
 through the function png_set_read_fn() and png_set_write_fn() at run
-time, instead of calling the png_init_io() function.  These functions
+time, instead of calling the png_init_io() function.
+These functions
 also provide a void pointer that can be retrieved via the function
 png_get_io_ptr().  For example:
 
@@ -1645,7 +1753,7 @@ The replacement I/O functions should have prototypes as follows:
 
 Supplying NULL for the read, write, or flush functions sets them back
 to using the default C stream functions.  It is an error to read from
-a write stream, and vice versa. 
+a write stream, and vice versa.
 
 Error handling in libpng is done through png_error() and png_warning().
 Errors handled through png_error() are fatal, meaning that png_error()
@@ -1712,7 +1820,7 @@ won't be accessible.  So limit zlib and libpng to 64K by defining MAXSEG_64K.
 
 Configuring for DOS:
 
-For DOS users which only have access to the lower 640K, you will
+For DOS users who only have access to the lower 640K, you will
 have to limit zlib's memory usage via a png_set_compression_mem_level()
 call.  See zlib.h or zconf.h in the zlib library for more information.
 
@@ -1724,7 +1832,7 @@ defined, and FAR gets defined to far in pngconf.h, and you should be
 all set.  Everything in the library (except for zlib's structure) is
 expecting far data.  You must use the typedefs with the p or pp on
 the end for pointers (or at least look at them and be careful).  Make
-note that the row's of data are defined as png_bytepp which is a
+note that the row's of data are defined as png_bytepp, which is an
 unsigned char far * far *.
 
 Configuring for gui/windowing platforms:
@@ -1784,11 +1892,11 @@ can call one of these functions.  The selection and configuration
 of row filters can have a significant impact on the size and
 encoding speed and a somewhat lesser impact on the decoding speed
 of an image.  Filtering is enabled by default for RGB and grayscale
-images (with and without alpha), and for 8-bit paletted images, but
-not for paletted images with bit depths less than 8 bits/pixel.
+images (with and without alpha), but not for paletted images nor
+for any images with bit depths less than 8 bits/pixel.
 
 The 'method' parameter sets the main filtering method, which is
-currently only '0' in the PNG 1.0 specification.  The 'filters'
+currently only '0' in the PNG 1.2 specification.  The 'filters'
 parameter sets which filter(s), if any, should be used for each
 scanline.  Possible values are PNG_ALL_FILTERS and PNG_NO_FILTERS
 to turn filtering on and off, respectively.
@@ -1820,10 +1928,10 @@ by telling it the relative computational costs of the filters.
        PNG_FILTER_SELECTION_WEIGHTED, 3,
        weights, costs);
 
-The weights are multiplying factors which indicate to libpng that row
-should be the same for successive rows unless another row filter is that
-many times better than the previous filter.  In the above example, if
-the previous 3 filters were SUB, SUB, NONE, the SUB filter could have a
+The weights are multiplying factors that indicate to libpng that the
+row filter should be the same for successive rows unless another row filter
+is that many times better than the previous filter.  In the above example,
+if the previous 3 filters were SUB, SUB, NONE, the SUB filter could have a
 "sum of absolute differences" 1.5 x 1.3 times higher than other filters
 and still be chosen, while the NONE filter could have a sum 1.1 times
 higher than other filters and still be chosen.  Unspecified weights are
@@ -1878,10 +1986,46 @@ or DLL file), you should not remove or disable any parts of the library,
 as this will cause applications linked with different versions of the
 library to fail if they call functions not available in your library.
 The size of the library itself should not be an issue, because only
-those sections which are actually used will be loaded into memory.
+those sections that are actually used will be loaded into memory.
 
+Requesting debug printout:
 
-Changes to Libpng from version 0.88
+The macro definition PNG_DEBUG can be used to request debugging
+printout.  Set it to an integer value in the range 0 to 3.  Higher
+numbers result in increasing amounts of debugging information.  The
+information is printed to the "stderr" file, unless another file
+name is specified in the PNG_DEBUG_FILE macro definition.
+
+When PNG_DEBUG > 0, the following functions (macros) become available:
+
+   png_debug(level, message)
+   png_debug1(level, message, p1)
+   png_debug2(level, message, p1, p2)
+
+in which "level" is compared to PNG_DEBUG to decide whether to print
+the message, "message" is the formatted string to be printed,
+and p1 and p2 are parameters that are to be embedded in the string
+according to printf-style formatting directives.  For example,
+
+   png_debug1(2, "foo=%d\n", foo);
+
+is expanded to
+
+   if(PNG_DEBUG > 2)
+     fprintf(PNG_DEBUG_FILE, "foo=%d\n", foo);
+
+When PNG_DEBUG is defined but is zero, the macros aren't defined, but you
+can still use PNG_DEBUG to control your own debugging:
+
+   #ifdef PNG_DEBUG
+       fprintf(stderr, ...
+   #endif
+
+When PNG_DEBUG = 1, the macros are defined, but only png_debug statements
+having level = 0 will be printed.  There aren't any such statements in
+this version of libpng, but if you insert some they will be printed.
+
+VI.  Changes to Libpng from version 0.88
 
 It should be noted that versions of libpng later than 0.96 are not
 distributed by the original libpng author, Guy Schalnat, nor by
@@ -1907,9 +2051,64 @@ allocating and freeing the png_struct for each image read.
 
 Setting the error callbacks via png_set_message_fn() before
 png_read_init() as was suggested in libpng-0.88 is no longer supported
-because this caused applications which do not use custom error functions
+because this caused applications that do not use custom error functions
 to fail if the png_ptr was not initialized to zero.  It is still possible
 to set the error callbacks AFTER png_read_init(), or to change them with
 png_set_error_fn(), which is essentially the same function, but with a
 new name to force compilation errors with applications that try to use
 the old method.
+
+VII. Y2K Compliance in libpng
+
+January 13, 1999
+
+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 1.0.4 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

libpngpf.3

@@ -1,339 +1,497 @@
-.TH LIBPNGPF 3 "June 6, 1998"
+.TH LIBPNGPF 3 "September 18, 1999"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.0.1e - June 6, 1998
+libpng \- Portable Network Graphics (PNG) Reference Library 1.0.4 - September 18, 1999
 (private functions)
 .SH SYNOPSIS
-#include <png.h>
+\fB#include <png.h>\fP
 
-void png_build_gamma_table (png_structp png_ptr);
+\fI\fB
 
-void png_build_grayscale_palette (int bit_depth, png_colorp
-palette);
+\fBvoid png_build_gamma_table (png_structp \fIpng_ptr\fP\fB);\fP
 
-void png_calculate_crc (png_structp png_ptr, png_bytep ptr,
-png_size_t length);
-void png_check_chunk_name (png_structp png_ptr, png_bytep
-chunk_name);
+\fI\fB
 
-png_size_t png_check_keyword (png_structp png_ptr, png_charp
-key, png_charpp new_key);
+\fBvoid png_build_grayscale_palette (int \fP\fIbit_depth\fP\fB, png_colorp \fIpalette\fP\fB);\fP
 
-void png_combine_row (png_structp png_ptr, png_bytep row, int
-mask);
+\fI\fB
 
-void png_correct_palette (png_structp png_ptr, png_colorp
-palette, int num_palette);
+\fBvoid png_calculate_crc (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIptr\fP\fB, png_size_t \fIlength\fP\fB);\fP
 
-int png_crc_error (png_structp png_ptr);
+\fI\fB
 
-int png_crc_finish (png_structp png_ptr, png_uint_32 skip);
+\fBvoid png_check_chunk_name (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIchunk_name\fP\fB);\fP
 
-void png_crc_read (png_structp png_ptr, png_bytep buf,
-png_size_t length);
+\fI\fB
 
-png_voidp png_create_struct (int type, png_malloc_ptr malloc_fn);
+\fBpng_size_t png_check_keyword (png_structp \fP\fIpng_ptr\fP\fB, png_charp \fP\fIkey\fP\fB, png_charpp \fInew_key\fP\fB);\fP
 
-png_voidp png_create_struct_2 (int type);
+\fI\fB
 
-void png_destroy_struct (png_voidp struct_ptr);
+\fBvoid png_combine_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIrow\fP\fB, int \fImask\fP\fB);\fP
 
-void png_destroy_struct_2 (png_voidp struct_ptr, png_free_ptr
-free_fn);
+\fI\fB
 
-void png_do_background (png_row_infop row_info, png_bytep row,
-png_color_16p trans_values, png_color_16p background,
-png_color_16p background_1, png_bytep gamma_table, png_bytep
-gamma_from_1, png_bytep gamma_to_1, png_uint_16pp gamma_16,
-png_uint_16pp gamma_16_from_1, png_uint_16pp gamma_16_to_1, int
-gamma_shift);
+\fBvoid png_correct_palette (png_structp \fP\fIpng_ptr\fP\fB, png_colorp \fP\fIpalette\fP\fB, int \fInum_palette\fP\fB);\fP
 
-void png_do_bgr (png_row_infop row_info, png_bytep row);
+\fI\fB
 
-void png_do_chop (png_row_infop row_info, png_bytep row);
+\fBint png_crc_error (png_structp \fIpng_ptr\fP\fB);\fP
 
-void png_do_dither (png_row_infop row_info, png_bytep row,
-png_bytep palette_lookup, png_bytep dither_lookup);
+\fI\fB
 
-void png_do_expand (png_row_infop row_info, png_bytep row,
-png_color_16p trans_value);
+\fBint png_crc_finish (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIskip\fP\fB);\fP
 
-void png_do_expand_palette (png_row_infop row_info, png_bytep
-row, png_colorp palette, png_bytep trans, int num_trans);
+\fI\fB
 
-void png_do_gamma (png_row_infop row_info, png_bytep row,
-png_bytep gamma_table, png_uint_16pp gamma_16_table, int
-gamma_shift);
+\fBvoid png_crc_read (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIbuf\fP\fB, png_size_t \fIlength\fP\fB);\fP
 
-void png_do_gray_to_rgb (png_row_infop row_info, png_bytep
-row);
+\fI\fB
 
-void png_do_invert (png_row_infop row_info, png_bytep row);
+\fBpng_voidp png_create_struct (int \fP\fItype\fP\fB, png_malloc_ptr \fImalloc_fn\fP\fB);\fP
 
-void png_do_pack (png_row_infop row_info, png_bytep row,
-png_uint_32 bit_depth);
+\fI\fB
 
-void png_do_packswap (png_row_infop row_info, png_bytep row);
+\fBpng_voidp png_create_struct_2 (int \fItype\fP\fB);\fP
 
-void png_do_read_filler (png_row_infop row_info, png_bytep row,
-png_uint_32 filler, png_uint_32 flags);
+\fI\fB
 
-void png_do_read_interlace (png_row_infop row_info, png_bytep
-row, int pass, png_uint_32 transformations);
+\fBvoid png_destroy_struct (png_voidp \fIstruct_ptr\fP\fB);\fP
 
-void png_do_read_invert_alpha (png_row_infop row_info,
-png_bytep row);
+\fI\fB
 
-void png_do_read_swap_alpha (png_row_infop row_info, png_bytep
-row);
+\fBvoid png_destroy_struct_2 (png_voidp \fP\fIstruct_ptr\fP\fB, png_free_ptr \fIfree_fn\fP\fB);\fP
 
-void png_do_read_transformations (png_structp png_ptr);
+\fI\fB
 
-void png_do_rgb_to_gray (png_row_infop row_info, png_bytep
-row);
+\fBvoid png_do_background (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_color_16p \fP\fItrans_values\fP\fB, png_color_16p \fP\fIbackground\fP\fB, png_color_16p \fP\fIbackground_1\fP\fB, png_bytep \fP\fIgamma_table\fP\fB, png_bytep \fP\fIgamma_from_1\fP\fB, png_bytep \fP\fIgamma_to_1\fP\fB, png_uint_16pp \fP\fIgamma_16\fP\fB, png_uint_16pp \fP\fIgamma_16_from_1\fP\fB, png_uint_16pp \fP\fIgamma_16_to_1\fP\fB, int \fIgamma_shift\fP\fB);\fP
 
-void png_do_shift (png_row_infop row_info, png_bytep row,
-png_color_8p bit_depth);
+\fI\fB
 
-void png_do_strip_filler (png_row_infop row_info, png_bytep
-row, png_uint_32 flags);
+\fBvoid png_do_bgr (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
 
-void png_do_swap (png_row_infop row_info, png_bytep row);
+\fI\fB
 
-void png_do_unpack (png_row_infop row_info, png_bytep row);
+\fBvoid png_do_chop (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
 
-void png_do_unshift (png_row_infop row_info, png_bytep row,
-png_color_8p sig_bits);
+\fI\fB
 
-void png_do_write_interlace (png_row_infop row_info, png_bytep
-row, int pass);
+\fBvoid png_do_dither (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_bytep \fP\fIpalette_lookup\fP\fB, png_bytep \fIdither_lookup\fP\fB);\fP
 
-void png_do_write_invert_alpha (png_row_infop row_info,
-png_bytep row);
+\fI\fB
 
-void png_do_write_swap_alpha (png_row_infop row_info, png_bytep
-row);
+\fBvoid png_do_expand (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_color_16p \fItrans_value\fP\fB);\fP
 
-void png_do_write_transformations (png_structp png_ptr);
+\fI\fB
 
-void *png_far_to_near (png_structp png_ptr,png_voidp ptr,
-int check);
+\fBvoid png_do_expand_palette (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_colorp \fP\fIpalette\fP\fB, png_bytep \fP\fItrans\fP\fB, int \fInum_trans\fP\fB);\fP
 
-void png_flush (png_structp png_ptr);
+\fI\fB
 
-png_int_32 png_get_int_32 (png_bytep buf);
+\fBvoid png_do_gamma (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_bytep \fP\fIgamma_table\fP\fB, png_uint_16pp \fP\fIgamma_16_table\fP\fB, int \fIgamma_shift\fP\fB);\fP
 
-png_uint_16 png_get_uint_16 (png_bytep buf);
+\fI\fB
 
-png_uint_32 png_get_uint_32 (png_bytep buf);
+\fBvoid png_do_gray_to_rgb (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
 
-void png_handle_bKGD (png_structp png_ptr, png_infop info_ptr,
-png_uint_32 length);
+\fI\fB
 
-void png_handle_cHRM (png_structp png_ptr, png_infop info_ptr,
-png_uint_32 length);
+\fBvoid png_do_invert (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
 
-void png_handle_gAMA (png_structp png_ptr, png_infop info_ptr,
-png_uint_32 length);
+\fI\fB
 
-void png_handle_hIST (png_structp png_ptr, png_infop info_ptr,
-png_uint_32 length);
+\fBvoid png_do_pack (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_uint_32 \fIbit_depth\fP\fB);\fP
 
-void png_handle_IEND (png_structp png_ptr, png_infop info_ptr,
-png_uint_32 length);
+\fI\fB
 
-void png_handle_IHDR (png_structp png_ptr, png_infop info_ptr,
-png_uint_32 length);
+\fBvoid png_do_packswap (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
 
-void png_handle_oFFs (png_structp png_ptr, png_infop info_ptr,
-png_uint_32 length);
+\fI\fB
 
-void png_handle_pCAL (png_structp png_ptr, png_infop info_ptr,
-png_uint_32 length);
+\fBvoid png_do_read_filler (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_uint_32 \fP\fIfiller\fP\fB, png_uint_32 \fIflags\fP\fB);\fP
 
-void png_handle_pHYs (png_structp png_ptr, png_infop info_ptr,
-png_uint_32 length);
+\fI\fB
 
-void png_handle_PLTE (png_structp png_ptr, png_infop info_ptr,
-png_uint_32 length);
+\fBvoid png_do_read_interlace (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, int \fP\fIpass\fP\fB, png_uint_32 \fItransformations\fP\fB);\fP
 
-void png_handle_sBIT (png_structp png_ptr, png_infop info_ptr,
-png_uint_32 length);
+\fI\fB
 
-void png_handle_sRGB (png_structp png_ptr, png_infop info_ptr,
-png_uint_32 length);
+\fBvoid png_do_read_invert_alpha (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
 
-void png_handle_tEXt (png_structp png_ptr, png_infop info_ptr,
-png_uint_32 length);
+\fI\fB
 
-void png_handle_tIME (png_structp png_ptr, png_infop info_ptr,
-png_uint_32 length);
+\fBvoid png_do_read_swap_alpha (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
 
-void png_handle_tRNS (png_structp png_ptr, png_infop info_ptr,
-png_uint_32 length);
+\fI\fB
 
-void png_handle_unknown (png_structp png_ptr, png_infop
-info_ptr, png_uint_32 length);
+\fBvoid png_do_read_transformations (png_structp \fIpng_ptr\fP\fB);\fP
 
-void png_handle_zTXt (png_structp png_ptr, png_infop info_ptr,
-png_uint_32 length);
+\fI\fB
 
-void png_info_destroy (png_structp png_ptr, png_infop
-info_ptr);
+\fBint png_do_rgb_to_gray (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
 
-void png_init_read_transformations (png_structp png_ptr);
+\fI\fB
 
-void png_process_IDAT_data (png_structp png_ptr, png_bytep
-buffer, png_size_t buffer_length);
+\fBvoid png_do_shift (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_color_8p \fIbit_depth\fP\fB);\fP
 
-void png_process_some_data (png_structp png_ptr, png_infop
-info_ptr);
+\fI\fB
 
-void png_push_check_crc (png_structp png_ptr);
+\fBvoid png_do_strip_filler (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_uint_32 \fIflags\fP\fB);\fP
 
-void png_push_crc_finish (png_structp png_ptr);
+\fI\fB
 
-void png_push_crc_skip (png_structp png_ptr, png_uint_32
-length);
+\fBvoid png_do_swap (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
 
-void png_push_fill_buffer (png_structp png_ptr, png_bytep
-buffer, png_size_t length);
+\fI\fB
 
-void png_push_handle_tEXt (png_structp png_ptr, png_infop
-info_ptr, png_uint_32 length);
+\fBvoid png_do_unpack (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
 
-void png_push_handle_unknown (png_structp png_ptr, png_infop
-info_ptr, png_uint_32 length);
+\fI\fB
 
-void png_push_handle_zTXt (png_structp png_ptr, png_infop
-info_ptr, png_uint_32 length);
+\fBvoid png_do_unshift (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_color_8p \fIsig_bits\fP\fB);\fP
 
-void png_push_have_end (png_structp png_ptr, png_infop
-info_ptr);
+\fI\fB
 
-void png_push_have_info (png_structp png_ptr, png_infop
-info_ptr);
+\fBvoid png_do_write_interlace (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, int \fIpass\fP\fB);\fP
 
-void png_push_have_row (png_structp png_ptr, png_bytep row);
+\fI\fB
 
-void png_push_process_row (png_structp png_ptr);
+\fBvoid png_do_write_invert_alpha (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
 
-void png_push_read_chunk (png_structp png_ptr, png_infop
-info_ptr);
+\fI\fB
 
-void png_push_read_end (png_structp png_ptr, png_infop
-info_ptr);
+\fBvoid png_do_write_swap_alpha (png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fIrow\fP\fB);\fP
 
-void png_push_read_IDAT (png_structp png_ptr);
+\fI\fB
 
-void png_push_read_sig (png_structp png_ptr, png_infop
-info_ptr);
+\fBvoid png_do_write_transformations (png_structp \fIpng_ptr\fP\fB);\fP
 
-void png_push_read_tEXt (png_structp png_ptr, png_infop
-info_ptr);
+\fI\fB
 
-void png_push_read_zTXt (png_structp png_ptr, png_infop
-info_ptr);
+\fBvoid *png_far_to_near (png_structp png_ptr,png_voidp \fP\fIptr\fP\fB, int \fIcheck\fP\fB);\fP
 
-void png_push_restore_buffer (png_structp png_ptr, png_bytep
-buffer, png_size_t buffer_length);
+\fI\fB
 
-void png_push_save_buffer (png_structp png_ptr);
+\fBvoid png_flush (png_structp \fIpng_ptr\fP\fB);\fP
 
-void png_read_data (png_structp png_ptr, png_bytep data,
-png_size_t length);
+\fI\fB
 
-void png_read_filter_row (png_structp png_ptr, png_row_infop
-row_info, png_bytep row, png_bytep prev_row, int filter);
+\fBpng_int_32 png_get_int_32 (png_bytep \fIbuf\fP\fB);\fP
 
-void png_read_finish_row (png_structp png_ptr);
+\fI\fB
 
-void png_read_init (png_structp png_ptr);
+\fBpng_uint_16 png_get_uint_16 (png_bytep \fIbuf\fP\fB);\fP
 
-void png_read_push_finish_row (png_structp png_ptr);
+\fI\fB
 
-void png_read_start_row (png_structp png_ptr);
+\fBpng_uint_32 png_get_uint_32 (png_bytep \fIbuf\fP\fB);\fP
 
-void png_read_transform_info (png_structp png_ptr, png_infop
-info_ptr);
+\fI\fB
 
-void png_reset_crc (png_structp png_ptr);
+\fBvoid png_handle_bKGD (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
-void png_save_int_32 (png_bytep buf, png_int_32 i);
+\fI\fB
 
-void png_save_uint_16 (png_bytep buf, unsigned int i);
+\fBvoid png_handle_cHRM (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
-void png_save_uint_32 (png_bytep buf, png_uint_32 i);
+\fI\fB
 
-void png_write_bKGD (png_structp png_ptr, png_color_16p values,
-int color_type);
+\fBvoid png_handle_gAMA (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
-void png_write_cHRM (png_structp png_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);
+\fI\fB
 
-void png_write_data (png_structp png_ptr, png_bytep data,
-png_size_t length);
-void png_write_filtered_row (png_structp png_ptr, png_bytep
-filtered_row);
+\fBvoid png_handle_hIST (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
-void png_write_find_filter (png_structp png_ptr, png_row_infop
-row_info);
+\fI\fB
 
-void png_write_finish_row (png_structp png_ptr);
+\fBvoid png_handle_IEND (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
-void png_write_gAMA (png_structp png_ptr, double file_gamma);
+\fI\fB
 
-void png_write_hIST (png_structp png_ptr, png_uint_16p hist,
-int num_hist);
+\fBvoid png_handle_IHDR (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
-void png_write_init (png_structp png_ptr);
+\fI\fB
 
-void png_write_IDAT (png_structp png_ptr, png_bytep data,
-png_size_t length);
+\fBvoid png_handle_oFFs (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
-void png_write_IEND (png_structp png_ptr);
+\fI\fB
 
-void png_write_IHDR (png_structp png_ptr, png_uint_32 width,
-png_uint_32 height, int bit_depth, int color_type, int
-compression_type, int filter_type, int interlace_type);
+\fBvoid png_handle_pCAL (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
-void png_write_oFFs (png_structp png_ptr, png_uint_32 x_offset,
-png_uint_32 y_offset, int unit_type);
+\fI\fB
 
-void png_write_pCAL (png_structp png_ptr, png_charp purpose,
-png_int_32 X0, png_int_32 X1, int type, int nparams, png_charp
-units, png_charpp params);
+\fBvoid png_handle_pHYs (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
-void png_write_pHYs (png_structp png_ptr, png_uint_32
-x_pixels_per_unit, png_uint_32 y_pixels_per_unit, int
-unit_type);
+\fI\fB
 
-void png_write_PLTE (png_structp png_ptr, png_colorp palette,
-png_uint_32 num_pal);
+\fBvoid png_handle_PLTE (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
-void png_write_sBIT (png_structp png_ptr, png_color_8p sbit,
-int color_type);
+\fI\fB
 
-void png_write_sig (png_structp png_ptr);
+\fBvoid png_handle_sBIT (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
-void png_write_sRGB (png_structp png_ptr, int intent);
+\fI\fB
 
-void png_write_start_row (png_structp png_ptr);
+\fBvoid png_handle_sRGB (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
-void png_write_tEXt (png_structp png_ptr, png_charp key,
-png_charp text, png_size_t text_len);
+\fI\fB
 
-void png_write_tIME (png_structp png_ptr, png_timep mod_time);
+\fBvoid png_handle_tEXt (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
-void png_write_tRNS (png_structp png_ptr, png_bytep trans,
-png_color_16p values, int number, int color_type);
+\fI\fB
 
-void png_write_zTXt (png_structp png_ptr, png_charp key,
-png_charp text, png_size_t text_len, int compression);
+\fBvoid png_handle_tIME (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
-voidpf png_zalloc (voidpf png_ptr, uInt items, uInt size);
+\fI\fB
 
-void png_zfree (voidpf png_ptr, voidpf ptr);
+\fBvoid png_handle_tRNS (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_handle_unknown (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_handle_zTXt (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_info_destroy (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_init_read_transformations (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_process_IDAT_data (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIbuffer\fP\fB, png_size_t \fIbuffer_length\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_process_some_data (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_check_crc (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_crc_finish (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_crc_skip (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_fill_buffer (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIbuffer\fP\fB, png_size_t \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_handle_tEXt (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_handle_unknown (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_handle_zTXt (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_have_end (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_have_info (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_have_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIrow\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_process_row (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_read_chunk (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_read_end (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_read_IDAT (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_read_sig (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_read_tEXt (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_read_zTXt (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_restore_buffer (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIbuffer\fP\fB, png_size_t \fIbuffer_length\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_push_save_buffer (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_read_data (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIdata\fP\fB, png_size_t \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_read_filter_row (png_structp \fP\fIpng_ptr\fP\fB, png_row_infop \fP\fIrow_info\fP\fB, png_bytep \fP\fIrow\fP\fB, png_bytep \fP\fIprev_row\fP\fB, int \fIfilter\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_read_finish_row (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_read_init (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_read_push_finish_row (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_read_start_row (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_read_transform_info (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_reset_crc (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_save_int_32 (png_bytep \fP\fIbuf\fP\fB, png_int_32 \fIi\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_save_uint_16 (png_bytep \fP\fIbuf\fP\fB, unsigned int \fIi\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_save_uint_32 (png_bytep \fP\fIbuf\fP\fB, png_uint_32 \fIi\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_bKGD (png_structp \fP\fIpng_ptr\fP\fB, png_color_16p \fP\fIvalues\fP\fB, int \fIcolor_type\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_cHRM (png_structp \fP\fIpng_ptr\fP\fB, double \fP\fIwhite_x\fP\fB, double \fP\fIwhite_y\fP\fB, double \fP\fIred_x\fP\fB, double \fP\fIred_y\fP\fB, double \fP\fIgreen_x\fP\fB, double \fP\fIgreen_y\fP\fB, double \fP\fIblue_x\fP\fB, double \fIblue_y\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_data (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIdata\fP\fB, png_size_t \fIlength\fP\fB);\fP
+
+\fBvoid png_write_filtered_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIfiltered_row\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_find_filter (png_structp \fP\fIpng_ptr\fP\fB, png_row_infop \fIrow_info\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_finish_row (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_gAMA (png_structp \fP\fIpng_ptr\fP\fB, double \fIfile_gamma\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_hIST (png_structp \fP\fIpng_ptr\fP\fB, png_uint_16p \fP\fIhist\fP\fB, int \fInum_hist\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_init (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_IDAT (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIdata\fP\fB, png_size_t \fIlength\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_IEND (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_IHDR (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIwidth\fP\fB, png_uint_32 \fP\fIheight\fP\fB, int \fP\fIbit_depth\fP\fB, int \fP\fIcolor_type\fP\fB, int \fP\fIcompression_type\fP\fB, int \fP\fIfilter_type\fP\fB, int \fIinterlace_type\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_oFFs (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIx_offset\fP\fB, png_uint_32 \fP\fIy_offset\fP\fB, int \fIunit_type\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_pCAL (png_structp \fP\fIpng_ptr\fP\fB, png_charp \fP\fIpurpose\fP\fB, png_int_32 \fP\fIX0\fP\fB, png_int_32 \fP\fIX1\fP\fB, int \fP\fItype\fP\fB, int \fP\fInparams\fP\fB, png_charp \fP\fIunits\fP\fB, png_charpp \fIparams\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_pHYs (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIx_pixels_per_unit\fP\fB, png_uint_32 \fP\fIy_pixels_per_unit\fP\fB, int \fIunit_type\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_PLTE (png_structp \fP\fIpng_ptr\fP\fB, png_colorp \fP\fIpalette\fP\fB, png_uint_32 \fInum_pal\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_sBIT (png_structp \fP\fIpng_ptr\fP\fB, png_color_8p \fP\fIsbit\fP\fB, int \fIcolor_type\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_sig (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_sRGB (png_structp \fP\fIpng_ptr\fP\fB, int \fIintent\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_start_row (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_tEXt (png_structp \fP\fIpng_ptr\fP\fB, png_charp \fP\fIkey\fP\fB, png_charp \fP\fItext\fP\fB, png_size_t \fItext_len\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_tIME (png_structp \fP\fIpng_ptr\fP\fB, png_timep \fImod_time\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_tRNS (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fItrans\fP\fB, png_color_16p \fP\fIvalues\fP\fB, int \fP\fInumber\fP\fB, int \fIcolor_type\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_zTXt (png_structp \fP\fIpng_ptr\fP\fB, png_charp \fP\fIkey\fP\fB, png_charp \fP\fItext\fP\fB, png_size_t \fP\fItext_len\fP\fB, int \fIcompression\fP\fB);\fP
+
+\fI\fB
+
+\fBvoidpf png_zalloc (voidpf \fP\fIpng_ptr\fP\fB, uInt \fP\fIitems\fP\fB, uInt \fIsize\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_zfree (voidpf \fP\fIpng_ptr\fP\fB, voidpf \fIptr\fP\fB);\fP
+
+\fI\fB
 
 .SH DESCRIPTION
 The functions listed above are used privately by libpng

png.5

@@ -1,4 +1,4 @@
-.TH PNG 5 "June 6, 1998"
+.TH PNG 5 "September 18, 1999"
 .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
@@ -15,12 +15,19 @@ 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)
 .LP
-PNG specification:
+PNG 1.1 specification, January 1999:
+.IP
+.br
+http://www.cdrom.com/pub/png
+.LP
+PNG 1.0 specification, October 1996:
+.IP
+.br
 RFC 2083
 .IP
 .br
@@ -32,12 +39,19 @@ http://www.w3.org/TR/REC-png.html
 .SH AUTHORS
 This man page: Glenn Randers-Pehrson
 .LP
+Portable Network Graphics (PNG) Specification Version 1.2 (July 8, 1999):
+Glenn Randers-Pehrson and others (png-list@ccrc.wustl.edu).
+.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@ccrc.wustl.edu).
 .LP
 
+
 .SH COPYRIGHT NOTICE
-The PNG specification is copyright (c) 1996 Massachussets Institute of
+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 Massachussets Institute of
 Technology.  See the specification for conditions of use and distribution.
 .LP
 .\" end of man page

png.c

@@ -1,11 +1,11 @@
 
 /* png.c - location for general purpose libpng functions
  *
- * libpng 1.0.1e - June 6, 1998
- * For conditions of distribution and use, see copyright notice in png.h
+ * libpng version 1.0.4 - September 18, 1999
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
+ * 
  */
 
 #define PNG_INTERNAL
@@ -15,7 +15,8 @@
 /* Version information for C files.  This had better match the version
  * string defined in png.h.
  */
-char png_libpng_ver[12] = "1.0.1e";
+
+char png_libpng_ver[12] = "1.0.4";
 
 /* Place to hold the signature string for a PNG file. */
 png_byte FARDATA png_sig[8] = {137, 80, 78, 71, 13, 10, 26, 10};
@@ -114,8 +115,8 @@ png_sig_cmp(png_bytep sig, png_size_t start, png_size_t num_to_check)
 }
 
 /* (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 a PNG.
  */
 int
 png_check_sig(png_bytep sig, int num)
@@ -317,8 +318,8 @@ png_charp
 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"};
+        {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
+         "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
 
    if (png_ptr->time_buffer == NULL)
    {
@@ -345,3 +346,14 @@ png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime)
    return ((png_charp)png_ptr->time_buffer);
 }
 #endif /* PNG_TIME_RFC1123_SUPPORTED */
+
+png_charp
+png_get_copyright(png_structp png_ptr)
+{
+   if(png_ptr == NULL)
+     /* silence compiler warning about unused png_ptr */ ;
+   return("\n libpng version 1.0.4 - September 18, 1999\n\
+   Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.\n\
+   Copyright (c) 1996, 1997 Andreas Dilger\n\
+   Copyright (c) 1998, 1999 Glenn Randers-Pehrson\n");
+}

png.h

@@ -1,43 +1,108 @@
 
 /* png.h - header file for PNG reference library
  *
- * libpng 1.0.1e - June 6, 1998
- * For conditions of distribution and use, see the COPYRIGHT NOTICE below.
+ * libpng version 1.0.4 - September 18, 1999
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998 Glenn Randers-Pehrson
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  *
+ * Authors and maintainers:
+ *  libpng versions 0.71, May 1995, through 0.89c, May 1996: Guy Schalnat
+ *  libpng versions 0.90, December 1996, through 0.96, May 1997: Andreas Dilger
+ *  libpng versions 0.97, January 1998, through 1.0.4 - September 18, 1999: Glenn R-P
+ *  See also "Contributing Authors", below.
+ *
+ * Y2K compliance in libpng:
+ * =========================
+ *    
+ *    January 13, 1999
+ *    
+ *    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 1.0.4 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.c: 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 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
+ * 
  * Note about libpng version numbers:
- *
+ * 
  *    Due to various miscommunications, unforeseen code incompatibilities
  *    and occasional factors outside the authors' control, version numbering
  *    on the library has not always been consistent and straightforward.
  *    The following table summarizes matters since version 0.89c, which was
  *    the first widely used release:
  *
- *    source                    png.h    png.h   shared-lib
- *    version                   string     int   version
- *    -------                   ------   -----  ----------
- *    0.89c ("1.0 beta 3")      0.89        89  1.0.89
- *    0.90  ("1.0 beta 4")      0.90        90  0.90  [should have been 2.0.90]
- *    0.95  ("1.0 beta 5")      0.95        95  0.95  [should have been 2.0.95]
- *    0.96  ("1.0 beta 6")      0.96        96  0.96  [should have been 2.0.96]
- *    0.97b ("1.00.97 beta 7")  1.00.97     97  1.0.1 [should have been 2.0.97]
- *    0.97c                     0.97        97  2.0.97
- *    0.98                      0.98        98  2.0.98
- *    0.99                      0.99        98  2.0.99
- *    0.99a-m                   0.99        99  2.0.99
- *    1.00                      1.00       100  2.1.0 [int should be 10000]
- *    1.0.0                     1.0.0      100  2.1.0 [int should be 10000]
- *    1.0.1                     1.0.1    10001  2.1.0
- *    1.0.1a-e                  1.0.1a-e 10002  2.1.0.1a-e
+ *    source                   png.h    png.h   shared-lib
+ *    version                  string     int   version
+ *    -------                  ------   -----  ----------
+ *    0.89c ("1.0 beta 3")     0.89        89  1.0.89
+ *    0.90  ("1.0 beta 4")     0.90        90  0.90  [should have been 2.0.90]
+ *    0.95  ("1.0 beta 5")     0.95        95  0.95  [should have been 2.0.95]
+ *    0.96  ("1.0 beta 6")     0.96        96  0.96  [should have been 2.0.96]
+ *    0.97b ("1.00.97 beta 7") 1.00.97     97  1.0.1 [should have been 2.0.97]
+ *    0.97c                    0.97        97  2.0.97
+ *    0.98                     0.98        98  2.0.98
+ *    0.99                     0.99        98  2.0.99
+ *    0.99a-m                  0.99        99  2.0.99
+ *    1.00                     1.00       100  2.1.0 [int should be 10000]
+ *    1.0.0                    1.0.0      100  2.1.0 [int should be 10000]
+ *    1.0.1                    1.0.1    10001  2.1.0
+ *    1.0.1a-e                 1.0.1a-e 10002  2.1.0.1a-e
+ *    1.0.2                    1.0.2    10002  2.1.0.2
+ *    1.0.2a-b                 1.0.2a-b 10003  2.1.0.2a-b
+ *    1.0.3                    1.0.3    10003  2.1.0.3
+ *    1.0.3a-d                 1.0.3a-d 10004  2.1.0.3a-d
+ *    1.0.4                    1.0.4    10004  2.1.0.4
  *
  *    Henceforth the source version will match the shared-library minor
  *    and patch numbers; the shared-library major version number will be
  *    used for changes in backward compatibility, as it is intended.  The
  *    PNG_PNGLIB_VER macro, which is not used within libpng but is available
  *    for applications, is an unsigned integer of the form xyyzz corresponding
- *    to the source version x.y.z (leading zeros in y and z).
+ *    to the source version x.y.z (leading zeros in y and z).  Internal
+ *    png-group versions (x.y.z[a-z]) will be given the next higher number.
  *
  * See libpng.txt or libpng.3 for more information.  The PNG specification
  * is available as RFC 2083 <ftp://ftp.uu.net/graphics/png/documents/>
@@ -67,6 +132,13 @@
  *
  * COPYRIGHT NOTICE:
  *
+ * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+ * (libpng versions 0.5, May 1995, through 0.89c, May 1996)
+ * Copyright (c) 1996, 1997 Andreas Dilger
+ * (libpng versions 0.90, December 1996, through 0.96, May 1997)
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
+ * (libpng versions 0.97, January 1998, through 1.0.4 - September 18, 1999)
+ *
  * 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
@@ -91,13 +163,10 @@
  * appreciated.
  */
 
+
 #ifndef _PNG_H
 #define _PNG_H
 
-#ifdef __cplusplus
-extern "C" {
-#endif /* __cplusplus */
-
 /* This is not the place to learn how to use libpng.  The file libpng.txt
  * describes how to use libpng, and the file example.c summarizes it
  * with some code on which to build.  This file is useful for looking
@@ -110,6 +179,11 @@ extern "C" {
 /* include all user configurable info */
 #include "pngconf.h"
 
+/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
 /* This file is arranged in several sections.  The first section contains
  * structure and type definitions.  The second section contains the external
  * library functions, while the third has the internal library functions,
@@ -117,14 +191,14 @@ extern "C" {
  */
 
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.0.1e"
+#define PNG_LIBPNG_VER_STRING "1.0.4"
 
 /* Careful here.  At one time, Guy wanted to use 082, but that would be octal.
  * We must not include leading zeros.
  * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
  * version 1.0.0 was mis-numbered 100 instead of 10000).  From
  * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=bugfix */
-#define PNG_LIBPNG_VER    10002  /* 1.0.2 */
+#define PNG_LIBPNG_VER    10004  /* 1.0.4 */
 
 /* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
 #if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
@@ -144,6 +218,7 @@ extern int FARDATA png_pass_dsp_mask[7];
 extern int FARDATA png_pass_width[7];
 extern int FARDATA png_pass_height[7];
 */
+
 #endif /* PNG_NO_EXTERN */
 
 /* Three color definitions.  The order of the red, green, and blue, (and the
@@ -404,6 +479,9 @@ typedef struct png_info_struct
 typedef png_info FAR * png_infop;
 typedef png_info FAR * FAR * png_infopp;
 
+/* Maximum positive integer used in PNG is (2^31)-1 */
+#define PNG_MAX_UINT ((png_uint_32)0x7fffffffL)
+
 /* These describe the color_type field in png_info. */
 /* color type masks */
 #define PNG_COLOR_MASK_PALETTE    1
@@ -417,11 +495,11 @@ typedef png_info FAR * FAR * png_infopp;
 #define PNG_COLOR_TYPE_RGB_ALPHA  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
 
-/* This is for compression type. PNG 1.0 only defines the single type. */
+/* This is for compression type. PNG 1.0-1.2 only define the single type. */
 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
 
-/* This is for filter type. PNG 1.0 only defines the single type. */
+/* This is for filter type. PNG 1.0-1.2 only define the single type. */
 #define PNG_FILTER_TYPE_BASE      0 /* Single row per-byte filtering */
 #define PNG_FILTER_TYPE_DEFAULT   PNG_FILTER_TYPE_BASE
 
@@ -453,7 +531,7 @@ typedef png_info FAR * FAR * png_infopp;
 #define PNG_sRGB_INTENT_ABSOLUTE   2
 #define PNG_sRGB_INTENT_RELATIVE   3
 #define PNG_sRGB_INTENT_LAST       4 /* Not a valid value */
-                        
+
 
 
 /* These determine if an ancillary chunk's data has been successfully read
@@ -519,7 +597,7 @@ typedef void (*png_user_transform_ptr) PNGARG((png_structp,
 #endif /* PNG_READ|WRITE_USER_TRANSFORM_SUPPORTED */
 
 typedef png_voidp (*png_malloc_ptr) PNGARG((png_structp, png_size_t));
-typedef void (*png_free_ptr) PNGARG((png_structp, png_structp));
+typedef void (*png_free_ptr) PNGARG((png_structp, png_voidp));
 
 /* The structure that holds the information to read and write PNG files.
  * The only people who need to care about what is inside of this are the
@@ -537,12 +615,19 @@ struct png_struct_def
    png_voidp error_ptr;       /* user supplied struct for error functions */
    png_rw_ptr write_data_fn;  /* function for writing output data */
    png_rw_ptr read_data_fn;   /* function for reading input data */
-#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
-    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+   png_voidp io_ptr;          /* ptr to application struct for I/O functions*/
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
    png_user_transform_ptr read_user_transform_fn; /* user read transform */
+#endif
+#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
    png_user_transform_ptr write_user_transform_fn; /* user write transform */
 #endif
-   png_voidp io_ptr;          /* ptr to application struct for I/O functions*/
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+   png_voidp user_transform_ptr; /* user supplied struct for user transform */
+   int user_transform_depth;    /* bit depth of user transformed pixels */
+   int user_transform_channels; /* channels in user transformed pixels */
+#endif
 
    png_uint_32 mode;          /* tells us where we are in the PNG file */
    png_uint_32 flags;         /* flags indicating various things to libpng */
@@ -614,10 +699,10 @@ struct png_struct_def
    float screen_gamma;   /* screen gamma value (display_gamma/viewing_gamma */
 #endif /* PNG_READ_GAMMA_SUPPORTED */
 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
-   png_bytep gamma_table;     /* gamma table for 8 bit depth files */
+   png_bytep gamma_table;     /* gamma table for 8-bit depth files */
    png_bytep gamma_from_1;    /* converts from 1.0 to screen */
    png_bytep gamma_to_1;      /* converts from file to 1.0 */
-   png_uint_16pp gamma_16_table; /* gamma table for 16 bit depth files */
+   png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */
    png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */
    png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */
 #endif /* PNG_READ_GAMMA_SUPPORTED || PNG_WRITE_GAMMA_SUPPORTED */
@@ -689,6 +774,16 @@ struct png_struct_def
    png_malloc_ptr malloc_fn;         /* function for allocating memory */
    png_free_ptr free_fn;             /* function for freeing memory */
 #endif /* PNG_USER_MEM_SUPPORTED */
+#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+   png_byte rgb_to_gray_status;
+   png_byte rgb_to_gray_red_coeff;
+   png_byte rgb_to_gray_green_coeff;
+   png_byte rgb_to_gray_blue_coeff;
+#endif
+#if defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
+    defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
+   png_byte empty_plte_permitted;
+#endif
 };
 
 typedef png_struct FAR * FAR * png_structpp;
@@ -734,7 +829,7 @@ extern PNG_EXPORT(png_structp,png_create_read_struct_2)
    png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
    png_malloc_ptr malloc_fn, png_free_ptr free_fn));
 extern PNG_EXPORT(png_structp,png_create_write_struct_2)
-   PNGARG((png_const_charp user_png_ver, png_voidp error_ptr, 
+   PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
    png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
    png_malloc_ptr malloc_fn, png_free_ptr free_fn));
 #endif
@@ -785,8 +880,11 @@ extern PNG_EXPORT(void,png_convert_from_time_t) PNGARG((png_timep ptime,
 #endif /* PNG_WRITE_tIME_SUPPORTED */
 
 #if defined(PNG_READ_EXPAND_SUPPORTED)
-/* Expand data to 24 bit RGB, or 8 bit grayscale, with alpha if available. */
+/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
 extern PNG_EXPORT(void,png_set_expand) PNGARG((png_structp png_ptr));
+extern PNG_EXPORT(void,png_set_gray_1_2_4_to_8) PNGARG((png_structp png_ptr));
+extern PNG_EXPORT(void,png_set_palette_to_rgb) PNGARG((png_structp png_ptr));
+extern PNG_EXPORT(void,png_set_tRNS_to_alpha) PNGARG((png_structp png_ptr));
 #endif /* PNG_READ_EXPAND_SUPPORTED */
 
 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
@@ -795,13 +893,16 @@ extern PNG_EXPORT(void,png_set_bgr) PNGARG((png_structp png_ptr));
 #endif /* PNG_READ_BGR_SUPPORTED || PNG_WRITE_BGR_SUPPORTED */
 
 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
-/* Expand the grayscale to 24 bit RGB if necessary. */
+/* Expand the grayscale to 24-bit RGB if necessary. */
 extern PNG_EXPORT(void,png_set_gray_to_rgb) PNGARG((png_structp png_ptr));
 #endif /* PNG_READ_GRAY_TO_RGB_SUPPORTED */
 
 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
-/* Reduce RGB to grayscale. (Not yet implemented) */
-extern PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr));
+/* Reduce RGB to grayscale. */
+extern PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr,
+   int error_action, double red, double green ));
+extern PNG_EXPORT(png_byte,png_get_rgb_to_gray_status) PNGARG((png_structp
+   png_ptr));
 #endif /* PNG_READ_RGB_TO_GRAY_SUPPORTED */
 
 extern PNG_EXPORT(void,png_build_grayscale_palette) PNGARG((int bit_depth,
@@ -832,19 +933,19 @@ extern PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr,
 #endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
 
 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
-/* Swap bytes in 16 bit depth files. */
+/* Swap bytes in 16-bit depth files. */
 extern PNG_EXPORT(void,png_set_swap) PNGARG((png_structp png_ptr));
 #endif /* PNG_READ_SWAP_SUPPORTED || PNG_WRITE_SWAP_SUPPORTED */
 
 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
-/* Use 1 byte per pixel in 1, 2, or 4 bit depth files. */
+/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
 extern PNG_EXPORT(void,png_set_packing) PNGARG((png_structp png_ptr));
 #endif /* PNG_READ_PACK_SUPPORTED || PNG_WRITE_PACK_SUPPORTED */
 
 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
 /* Swap packing order of pixels in bytes. */
 extern PNG_EXPORT(void,png_set_packswap) PNGARG((png_structp png_ptr));
-#endif /* PNG_READ_PACKSWAP_SUPPORTED || PNG_WRITE_PACKSWAP_SUPPOR */
+#endif /* PNG_READ_PACKSWAP_SUPPORTED || PNG_WRITE_PACKSWAP_SUPPORTED */
 
 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
 /* Converts files to legal bit depths. */
@@ -875,7 +976,7 @@ extern PNG_EXPORT(void,png_set_background) PNGARG((png_structp png_ptr,
 #endif /* PNG_READ_BACKGROUND_SUPPORTED */
 
 #if defined(PNG_READ_16_TO_8_SUPPORTED)
-/* strip the second byte of information from a 16 bit depth file. */
+/* strip the second byte of information from a 16-bit depth file. */
 extern PNG_EXPORT(void,png_set_strip_16) PNGARG((png_structp png_ptr));
 #endif /* PNG_READ_16_TO_8_SUPPORTED */
 
@@ -892,6 +993,13 @@ extern PNG_EXPORT(void,png_set_gamma) PNGARG((png_structp png_ptr,
    double screen_gamma, double default_file_gamma));
 #endif /* PNG_READ_GAMMA_SUPPORTED */
 
+#if defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
+    defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
+/* Permit or disallow empty PLTE (0: not permitted, 1: permitted) */
+extern PNG_EXPORT(void,png_permit_empty_plte) PNGARG((png_structp png_ptr,
+   int empty_plte_permitted));
+#endif /* PNG_READ_EMPTY_PLTE_SUPPORTED */
+
 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
 /* Set how many lines between output flushes - 0 for no flushing */
 extern PNG_EXPORT(void,png_set_flush) PNGARG((png_structp png_ptr, int nrows));
@@ -1105,6 +1213,7 @@ extern PNG_EXPORT(void,png_init_io) PNGARG((png_structp png_ptr, FILE *fp));
  * method of error handling.  If error_fn or warning_fn is NULL, the
  * default function will be used.
  */
+
 extern PNG_EXPORT(void,png_set_error_fn) PNGARG((png_structp png_ptr,
    png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
 
@@ -1151,6 +1260,16 @@ extern PNG_EXPORT(void,png_set_write_user_transform_fn) PNGARG((png_structp
    png_ptr, png_user_transform_ptr write_user_transform_fn));
 #endif
 
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+extern PNG_EXPORT(void,png_set_user_transform_info) PNGARG((png_structp
+   png_ptr, png_voidp user_transform_ptr, int user_transform_depth,
+   int user_transform_channels));
+/* Return the user pointer associated with the user transform functions */
+extern PNG_EXPORT(png_voidp,png_get_user_transform_ptr)
+   PNGARG((png_structp png_ptr));
+#endif
+
 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
 /* Sets the function callbacks for the push reader, and a pointer to a
  * user-defined structure available to the callback functions.
@@ -1343,7 +1462,7 @@ extern PNG_EXPORT(png_uint_32,png_get_IHDR) PNGARG((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));
-  
+
 extern PNG_EXPORT(void,png_set_IHDR) PNGARG((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));
@@ -1449,28 +1568,46 @@ extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
  * only been added since version 0.95 so it is not implemented throughout
  * libpng yet, but more support will be added as needed.
  */
+#ifdef PNG_DEBUG
 #if (PNG_DEBUG > 0)
-#ifdef PNG_NO_STDIO
-#include <stdio.h>
-#endif
 #ifndef PNG_DEBUG_FILE
 #define PNG_DEBUG_FILE stderr
 #endif /* PNG_DEBUG_FILE */
 
 #define png_debug(l,m)        if (PNG_DEBUG > l) \
                                  fprintf(PNG_DEBUG_FILE,"%s"m,(l==1 ? "\t" : \
-                                    (l==2 ? "\t\t":(l==3 ? "\t\t\t":""))))
+                                    (l==2 ? "\t\t":(l>2 ? "\t\t\t":""))))
 #define png_debug1(l,m,p1)    if (PNG_DEBUG > l) \
                                  fprintf(PNG_DEBUG_FILE,"%s"m,(l==1 ? "\t" : \
-                                    (l==2 ? "\t\t":(l==3 ? "\t\t\t":""))),p1)
+                                    (l==2 ? "\t\t":(l>2 ? "\t\t\t":""))),p1)
 #define png_debug2(l,m,p1,p2) if (PNG_DEBUG > l) \
                                  fprintf(PNG_DEBUG_FILE,"%s"m,(l==1 ? "\t" : \
-                                    (l==2 ? "\t\t":(l==3 ? "\t\t\t":""))),p1,p2)
-#else
-#define png_debug(l, m)
-#define png_debug1(l, m, p1)
-#define png_debug2(l, m, p1, p2)
+                                    (l==2 ? "\t\t":(l>2 ? "\t\t\t":""))),p1,p2)
 #endif /* (PNG_DEBUG > 0) */
+#endif /* PNG_DEBUG */
+#ifndef png_debug
+#define png_debug(l, m)
+#endif
+#ifndef png_debug1
+#define png_debug1(l, m, p1)
+#endif
+#ifndef png_debug2
+#define png_debug2(l, m, p1, p2)
+#endif
+
+extern PNG_EXPORT(png_charp,png_get_copyright) PNGARG((png_structp png_ptr));
+extern PNG_EXPORT(png_charp,png_get_header_version) PNGARG((png_structp png_ptr));
+
+#ifdef PNG_NO_EXTERN
+/* this only gets included in png.c */
+png_charp
+png_get_header_version(png_structp png_ptr)
+{
+   if(png_ptr == NULL)
+     /* silence compiler warning about unused png_ptr */ ;
+   return("\n libpng version 1.0.4 - September 18, 1999 (header)\n");
+}
+#endif
 
 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
 /* With these routines we avoid an integer divide, which will be slower on
@@ -1485,28 +1622,30 @@ extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
  * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
  */
 
-   /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
-#  define png_composite(composite, fg, alpha, bg) \
-     { png_uint_16 temp = ((png_uint_16)(fg) * (png_uint_16)(alpha) + \
-                        (png_uint_16)(bg)*(png_uint_16)(255 - \
-                        (png_uint_16)(alpha)) + (png_uint_16)128); \
+ /* fg and bg should be in `gamma 1.0' space; alpha is the opacity          */
+
+#  define png_composite(composite, fg, alpha, bg)                            \
+     { png_uint_16 temp = ((png_uint_16)(fg) * (png_uint_16)(alpha) +        \
+                        (png_uint_16)(bg)*(png_uint_16)(255 -                \
+                        (png_uint_16)(alpha)) + (png_uint_16)128);           \
        (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
-#  define png_composite_16(composite, fg, alpha, bg) \
-     { png_uint_32 temp = ((png_uint_32)(fg) * (png_uint_32)(alpha) + \
-                        (png_uint_32)(bg)*(png_uint_32)(65535L - \
-                        (png_uint_32)(alpha)) + (png_uint_32)32768L); \
+
+#  define png_composite_16(composite, fg, alpha, bg)                         \
+     { png_uint_32 temp = ((png_uint_32)(fg) * (png_uint_32)(alpha) +        \
+                        (png_uint_32)(bg)*(png_uint_32)(65535L -             \
+                        (png_uint_32)(alpha)) + (png_uint_32)32768L);        \
        (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
 
 #else  /* standard method using integer division */
 
-   /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
-#  define png_composite(composite, fg, alpha, bg) \
-     (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \
-       (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
+#  define png_composite(composite, fg, alpha, bg)                            \
+     (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) +    \
+       (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) +       \
        (png_uint_16)127) / 255)
-#  define png_composite_16(composite, fg, alpha, bg) \
+
+#  define png_composite_16(composite, fg, alpha, bg)                         \
      (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
-       (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) + \
+       (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) +      \
        (png_uint_32)32767) / (png_uint_32)65535L)
 
 #endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
@@ -1552,7 +1691,7 @@ extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
 #define PNG_DITHER             0x0040
 #define PNG_BACKGROUND         0x0080
 #define PNG_BACKGROUND_EXPAND  0x0100
-#define PNG_RGB_TO_GRAY        0x0200 /* Not currently implemented */
+                          /*   0x0200 unused */
 #define PNG_16_TO_8            0x0400
 #define PNG_RGBA               0x0800
 #define PNG_EXPAND             0x1000
@@ -1564,6 +1703,9 @@ extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
 #define PNG_STRIP_ALPHA       0x40000L
 #define PNG_INVERT_ALPHA      0x80000L
 #define PNG_USER_TRANSFORM   0x100000L
+#define PNG_RGB_TO_GRAY_ERR  0x200000L
+#define PNG_RGB_TO_GRAY_WARN 0x400000L
+#define PNG_RGB_TO_GRAY      0x600000L  /* two bits, RGB_TO_GRAY_ERR|WARN */
 
 /* flags for png_create_struct */
 #define PNG_STRUCT_PNG   0x0001
@@ -1725,8 +1867,8 @@ PNG_EXTERN void png_flush PNGARG((png_structp png_ptr));
 #endif
 
 /* Place a 32-bit number into a buffer in PNG byte order (big-endian).
- * The only currently known PNG chunk that uses signed numbers is
- * the ancillary extension chunk, pCAL.
+ * The only currently known PNG chunks that use signed numbers are
+ * the ancillary extension chunks, oFFs and pCAL.
  */
 PNG_EXTERN void png_save_uint_32 PNGARG((png_bytep buf, png_uint_32 i));
 
@@ -1734,7 +1876,7 @@ PNG_EXTERN void png_save_uint_32 PNGARG((png_bytep buf, png_uint_32 i));
 PNG_EXTERN void png_save_int_32 PNGARG((png_bytep buf, png_int_32 i));
 #endif
 
-/* Place a 16 bit number into a buffer in PNG byte order.
+/* Place a 16-bit number into a buffer in PNG byte order.
  * The parameter is declared unsigned int, not png_uint_16,
  * just to avoid potential problems on pre-ANSI C compilers.
  */
@@ -1922,8 +2064,8 @@ PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info, png_bytep row));
 #endif
 
 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
-PNG_EXTERN void png_do_rgb_to_gray PNGARG((png_row_infop row_info,
-   png_bytep row));
+PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr, png_row_infop
+   row_info, png_bytep row));
 #endif
 
 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)

pngasmrd.h

@@ -0,0 +1,32 @@
+/* pngasmrd.h - assembler version of utilities to read a PNG file
+ *
+ * libpng 1.0.4 - September 18, 1999
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1999 Glenn Randers-Pehrson
+ *
+ */
+
+#ifdef PNG_ASSEMBLER_CODE_SUPPORTED
+
+/* Set this in the makefile for VC++ on Pentium, not in pngconf.h */
+#ifdef PNG_USE_PNGVCRD
+/* Platform must be Pentium.  Makefile must assemble and load pngvcrd.c .
+ * MMX will be detected at run time and used if present.
+ */
+#define PNG_HAVE_ASSEMBLER_COMBINE_ROW
+#define PNG_HAVE_ASSEMBLER_READ_INTERLACE
+#define PNG_HAVE_ASSEMBLER_READ_FILTER_ROW
+#endif
+
+/* Set this in the makefile for gcc on Pentium, not in pngconf.h */
+#ifdef PNG_USE_PNGGCCRD
+/* Platform must be Pentium.  Makefile must assemble and load pnggccrd.c
+ * (not available in libpng 1.0.4).
+ * MMX will be detected at run time and used if present.
+ */
+#define PNG_HAVE_ASSEMBLER_COMBINE_ROW
+#define PNG_HAVE_ASSEMBLER_READ_INTERLACE
+#define PNG_HAVE_ASSEMBLER_READ_FILTER_ROW
+#endif
+
+#endif

pngconf.h

@@ -1,11 +1,11 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng 1.0.1e - June 6, 1998
+ * libpng 1.0.4 - September 18, 1999
  * 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
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  */
 
 /* Any machine specific code is near the front of this file, so if you
@@ -17,6 +17,7 @@
 #ifndef PNGCONF_H
 #define PNGCONF_H
 
+
 /* This is the size of the compression buffer, and thus the size of
  * an IDAT chunk.  Make this whatever size you feel is best for your
  * machine.  One of these will be allocated per png_struct.  When this
@@ -49,14 +50,28 @@
 /* This protects us against compilers that run on a windowing system
  * and thus don't have or would rather us not use the stdio types:
  * stdin, stdout, and stderr.  The only one currently used is stderr
- * in png_error() and png_warning().  #defining PNG_NO_STDIO will
- * prevent these from being compiled and used.
+ * in png_error() and png_warning().  #defining PNG_NO_CONSOLE_IO will
+ * prevent these from being compiled and used. #defining PNG_NO_STDIO
+ * will also prevent these, plus will prevent the entire set of stdio
+ * macros and functions (FILE *, printf, etc.) from being compiled and used,
+ * unless (PNG_DEBUG > 0) has been #defined.
+ *
+ * #define PNG_NO_CONSOLE_IO
  * #define PNG_NO_STDIO
  */
 
-#ifndef PNG_NO_STDIO 
-#include <stdio.h>
-#endif
+#  ifdef PNG_NO_STDIO
+#    ifndef PNG_NO_CONSOLE_IO
+#      define PNG_NO_CONSOLE_IO
+#    endif
+#    ifdef PNG_DEBUG
+#      if (PNG_DEBUG > 0)
+#        include <stdio.h>
+#      endif
+#    endif
+#  else
+#    include <stdio.h>
+#  endif
 
 /* This macro protects us against machines that don't have function
  * prototypes (ie K&R style headers).  If your compiler does not handle
@@ -157,7 +172,7 @@ __dont__ include it again
 #endif
 
 /* Codewarrior on NT has linking problems without this. */
-#if defined(__MWERKS__) && defined(WIN32)
+#if (defined(__MWERKS__) && defined(WIN32)) || defined(__STDC__)
 #define PNG_ALWAYS_EXTERN
 #endif
 
@@ -307,11 +322,9 @@ __dont__ include it again
 #ifndef PNG_NO_READ_USER_TRANSFORM
 #define PNG_READ_USER_TRANSFORM_SUPPORTED
 #endif
-/* the following aren't implemented yet
 #ifndef PNG_NO_READ_RGB_TO_GRAY
 #define PNG_READ_RGB_TO_GRAY_SUPPORTED
 #endif
- */
 #endif /* PNG_READ_TRANSFORMS_SUPPORTED */
 
 #if !defined(PNG_NO_PROGRESSIVE_READ) && \
@@ -325,6 +338,10 @@ __dont__ include it again
 #define PNG_READ_COMPOSITE_NODIV_SUPPORTED    /* well tested on Intel and SGI */
 #endif
 
+#ifndef PNG_NO_READ_EMPTY_PLTE
+#define PNG_READ_EMPTY_PLTE_SUPPORTED  /* useful for MNG applications */
+#endif
+
 #ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
 #ifndef PNG_NO_WRITE_SHIFT
 #define PNG_WRITE_SHIFT_SUPPORTED
@@ -370,6 +387,10 @@ __dont__ include it again
 #define PNG_WRITE_FLUSH_SUPPORTED
 #endif
 
+#ifndef PNG_NO_WRITE_EMPTY_PLTE
+#define PNG_WRITE_EMPTY_PLTE_SUPPORTED  /* useful for MNG applications */
+#endif
+
 #ifndef PNG_NO_STDIO
 #define PNG_TIME_RFC1123_SUPPORTED
 #endif
@@ -394,6 +415,10 @@ __dont__ include it again
 #define PNG_EASY_ACCESS_SUPPORTED
 #endif
 
+#ifndef PNG_NO_ASSEMBLER_CODE
+#define PNG_ASSEMBLER_CODE_SUPPORTED
+#endif
+
 /* These are currently experimental features, define them if you want */
 
 /* very little testing */
@@ -631,25 +656,33 @@ typedef char            FAR * FAR * FAR * png_charppp;
  */
 typedef charf *         png_zcharp;
 typedef charf * FAR *   png_zcharpp;
-typedef z_stream FAR *  png_zstreamp; 
+typedef z_stream FAR *  png_zstreamp;
 
-/* allow for compilation as dll under MS Windows */
-#ifdef __WIN32DLL__
-#define PNG_EXPORT(type,symbol) __declspec(dllexport) type symbol
-#endif
 
-/* allow for compilation as dll with BORLAND C++ 5.0 */
-#if defined(__BORLANDC__) && defined(_Windows) && defined(__DLL__)
-#   define PNG_EXPORT(type,symbol) type _export symbol
-#endif
+#ifndef PNG_EXPORT
+   /* allow for compilation as dll under MS Windows */
+#  ifdef __WIN32DLL__
+#    define PNG_EXPORT(type,symbol) __declspec(dllexport) type symbol
+#  endif
 
-/* allow for compilation as shared lib under BeOS */
-#ifdef __BEOSDLL__
-#define PNG_EXPORT(type,symbol) __declspec(export) type symbol
+   /* this variant is used in Mozilla; may correspond to MSVC++ 6.0 changes */
+#  ifdef ALT_WIN32_DLL
+#    define PNG_EXPORT(type,symbol) type __attribute__((dllexport)) symbol
+#  endif
+
+   /* allow for compilation as dll with Borland C++ 5.0 */
+#  if defined(__BORLANDC__) && defined(_Windows) && defined(__DLL__)
+#    define PNG_EXPORT(type,symbol) type _export symbol
+#  endif
+
+   /* allow for compilation as shared lib under BeOS */
+#  ifdef __BEOSDLL__
+#    define PNG_EXPORT(type,symbol) __declspec(export) type symbol
+#  endif
 #endif
 
 #ifndef PNG_EXPORT
-#define PNG_EXPORT(type,symbol) type symbol
+#  define PNG_EXPORT(type,symbol) type symbol
 #endif
 
 
@@ -680,7 +713,7 @@ typedef z_stream FAR *  png_zstreamp;
 /* End of memory model independent support */
 
 /* Just a double check that someone hasn't tried to define something
- * contradictory. 
+ * contradictory.
  */
 #if (PNG_ZBUF_SIZE > 65536) && defined(PNG_MAX_MALLOC_64K)
 #undef PNG_ZBUF_SIZE

pngerror.c

@@ -1,11 +1,11 @@
 
 /* pngerror.c - stub functions for i/o and memory allocation
  *
- * libpng 1.0.1e - June 6, 1998
+ * libpng 1.0.4 - September 18, 1999
  * 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
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  *
  * This file provides a location for all error handling.  Users who
  * need special error handling are expected to write replacement functions
@@ -113,7 +113,7 @@ png_chunk_warning(png_structp png_ptr, png_const_charp message)
 static void
 png_default_error(png_structp png_ptr, png_const_charp message)
 {
-#ifndef PNG_NO_STDIO
+#ifndef PNG_NO_CONSOLE_IO
    fprintf(stderr, "libpng error: %s\n", message);
 #endif
 
@@ -130,18 +130,17 @@ png_default_error(png_structp png_ptr, png_const_charp message)
 
 /* 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)
 {
-   if (png_ptr == NULL)
-      return;
-
-#ifndef PNG_NO_STDIO
+#ifndef PNG_NO_CONSOLE_IO
    fprintf(stderr, "libpng warning: %s\n", message);
 #endif
+   if (png_ptr == NULL)
+      return;
 }
 
 /* This function is called when the application wants to use another method

pngget.c

@@ -1,11 +1,11 @@
 
 /* pngget.c - retrieval of values from info struct
  *
- * libpng 1.0.1e - June 6, 1998
+ * libpng 1.0.4 - September 18, 1999
  * 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
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  */
 
 #define PNG_INTERNAL
@@ -423,7 +423,7 @@ 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)
@@ -454,7 +454,7 @@ png_get_IHDR(png_structp png_ptr, png_infop info_ptr,
          channels++;
       pixel_depth = *bit_depth * channels;
       rowbytes_per_pixel = (pixel_depth + 7) >> 3;
-      if ((*width > (png_uint_32)2147483647L/rowbytes_per_pixel))
+      if ((*width > PNG_MAX_UINT/rowbytes_per_pixel))
       {
          png_warning(png_ptr,
             "Width too large for libpng to process image data.");
@@ -641,3 +641,10 @@ png_get_tRNS(png_structp png_ptr, png_infop info_ptr,
 }
 #endif
 
+#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+png_byte
+png_get_rgb_to_gray_status (png_structp png_ptr)
+{
+   return png_ptr->rgb_to_gray_status;
+}
+#endif

pngmem.c

@@ -1,15 +1,17 @@
 
 /* pngmem.c - stub functions for memory allocation
  *
- * libpng 1.0.1e - June 6, 1998
+ * libpng 1.0.4 - September 18, 1999
  * 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
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  *
  * 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
@@ -128,7 +130,7 @@ png_voidp
 png_malloc_default(png_structp png_ptr, png_uint_32 size)
 {
    png_voidp ret;
-#endif PNG_USER_MEM_SUPPORTED
+#endif /* PNG_USER_MEM_SUPPORTED */
 
 #ifdef PNG_MAX_MALLOC_64K
    if (size > (png_uint_32)65536L)
@@ -155,8 +157,9 @@ png_malloc_default(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));
@@ -190,12 +193,12 @@ png_malloc_default(png_structp png_ptr, png_uint_32 size)
             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;
@@ -243,7 +246,7 @@ void
 png_free_default(png_structp png_ptr, png_voidp ptr)
 {
 #endif /* PNG_USER_MEM_SUPPORTED */
-      
+
    if (png_ptr->offset_table != NULL)
    {
       int i;
@@ -466,7 +469,7 @@ 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.");
-  
+
    return(png_memcpy (s1, s2, size));
 }
 

pngpread.c

@@ -1,11 +1,11 @@
 
 /* pngpread.c - read a png file in push mode
  *
- * libpng 1.0.1e - June 6, 1998
+ * libpng 1.0.4 - September 18, 1999
  * 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
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  */
 
 #define PNG_INTERNAL
@@ -77,8 +77,9 @@ png_process_some_data(png_structp png_ptr, png_infop info_ptr)
 
 /* Read any remaining signature bytes from the stream and compare them with
  * the correct PNG signature.  It is possible that this routine is called
- * with bytes already read from the signature, whether because they have been
- * checked by the calling application, or from multiple calls to this routine.
+ * with bytes already read from the signature, either because they have been
+ * checked by the calling application, or because of multiple calls to this
+ * routine.
  */
 void
 png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
@@ -91,7 +92,7 @@ png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
       num_to_check = png_ptr->buffer_size;
    }
 
-   png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]), 
+   png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]),
       num_to_check);
    png_ptr->sig_bytes += num_to_check;
 
@@ -465,7 +466,7 @@ png_push_save_buffer(png_structp png_ptr)
 
       new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256;
       old_buffer = png_ptr->save_buffer;
-      png_ptr->save_buffer = (png_bytep)png_malloc(png_ptr, 
+      png_ptr->save_buffer = (png_bytep)png_malloc(png_ptr,
          (png_uint_32)new_max);
       png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
       png_free(png_ptr, old_buffer);
@@ -629,7 +630,7 @@ png_push_process_row(png_structp png_ptr)
    png_ptr->row_info.channels = png_ptr->channels;
    png_ptr->row_info.bit_depth = png_ptr->bit_depth;
    png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
-   
+
    png_ptr->row_info.rowbytes = ((png_ptr->row_info.width *
       (png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3);
 
@@ -780,6 +781,7 @@ png_read_push_finish_row(png_structp png_ptr)
          png_ptr->pass++;
          if (png_ptr->pass >= 7)
             break;
+
          png_ptr->iwidth = (png_ptr->width +
             png_pass_inc[png_ptr->pass] - 1 -
             png_pass_start[png_ptr->pass]) /
@@ -788,18 +790,15 @@ png_read_push_finish_row(png_structp png_ptr)
          png_ptr->irowbytes = ((png_ptr->iwidth *
             png_ptr->pixel_depth + 7) >> 3) + 1;
 
-         if (!(png_ptr->transformations & PNG_INTERLACE))
-         {
-            png_ptr->num_rows = (png_ptr->height +
-               png_pass_yinc[png_ptr->pass] - 1 -
-               png_pass_ystart[png_ptr->pass]) /
-               png_pass_yinc[png_ptr->pass];
-            if (!(png_ptr->num_rows))
-               continue;
-         }
          if (png_ptr->transformations & PNG_INTERLACE)
             break;
-      } while (png_ptr->iwidth == 0);
+
+         png_ptr->num_rows = (png_ptr->height +
+            png_pass_yinc[png_ptr->pass] - 1 -
+            png_pass_ystart[png_ptr->pass]) /
+            png_pass_yinc[png_ptr->pass];
+
+      } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
    }
 }
 
@@ -825,7 +824,7 @@ png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length
    }
 #endif
 
-   png_ptr->current_text = (png_charp)png_malloc(png_ptr, 
+   png_ptr->current_text = (png_charp)png_malloc(png_ptr,
          (png_uint_32)(length+1));
    png_ptr->current_text[length] = '\0';
    png_ptr->current_text_ptr = png_ptr->current_text;
@@ -1116,7 +1115,7 @@ void
 png_progressive_combine_row (png_structp png_ptr,
    png_bytep old_row, png_bytep new_row)
 {
-   if (new_row != NULL)
+   if (new_row != NULL)    /* new_row must == png_ptr->row_buf here. */
       png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]);
 }
 

pngread.c

@@ -1,11 +1,11 @@
 
 /* pngread.c - read a PNG file
  *
- * libpng 1.0.1e - June 6, 1998
+ * libpng 1.0.4 - September 18, 1999
  * 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
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  *
  * This file contains routines that an application calls directly to
  * read a PNG file or stream.
@@ -188,7 +188,8 @@ png_read_info(png_structp png_ptr, png_infop info_ptr)
       png_reset_crc(png_ptr);
       png_crc_read(png_ptr, png_ptr->chunk_name, 4);
 
-      png_debug1(0, "Reading %s chunk.\n", png_ptr->chunk_name);
+      png_debug2(0, "Reading %s chunk, length=%d.\n", png_ptr->chunk_name,
+         length);
 
       /* This should be a binary subdivision search or a hash for
        * matching the chunk name rather than a linear search.
@@ -281,7 +282,7 @@ png_read_update_info(png_structp png_ptr, png_infop info_ptr)
 
 /* Initialize palette, background, etc, after transformations
  * are set, but before any reading takes place.  This allows
- * the user to obtail a gamma corrected palette, for example.
+ * the user to obtain a gamma-corrected palette, for example.
  * If the user doesn't call this, we will do it ourselves.
  */
 void
@@ -515,7 +516,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
  * image has alpha or transparency, and png_handle_alpha()[*] has been
  * called, the rows contents must be initialized to the contents of the
  * screen.
- * 
+ *
  * "row" holds the actual image, and pixels are placed in it
  * as they arrive.  If the image is displayed after each pass, it will
  * appear to "sparkle" in.  "display_row" can be used to display a
@@ -530,7 +531,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
  * not called png_set_interlace_handling(), the display_row buffer will
  * be ignored, so pass NULL to it.
  *
- * [*] png_handle_alpha() does not exist yet, as of libpng version 1.0.1e.
+ * [*] png_handle_alpha() does not exist yet, as of libpng version 1.0.4.
  */
 
 void
@@ -550,7 +551,7 @@ png_read_rows(png_structp png_ptr, png_bytepp row,
       {
          png_bytep rptr = *rp++;
          png_bytep dptr = *dp++;
-   
+
          png_read_row(png_ptr, rptr, dptr);
       }
    else if(rp != NULL)
@@ -570,7 +571,7 @@ png_read_rows(png_structp png_ptr, png_bytepp row,
 }
 
 /* Read the entire image.  If the image has an alpha channel or a tRNS
- * chunk, and you have called png_handle_alpha(), you will need to
+ * chunk, and you have called png_handle_alpha()[*], you will need to
  * initialize the image to the current image that PNG will be overlaying.
  * We set the num_rows again here, in case it was incorrectly set in
  * png_read_start_row() by a call to png_read_update_info() or
@@ -578,6 +579,8 @@ png_read_rows(png_structp png_ptr, png_bytepp row,
  * prior to either of these functions like it should have been.  You can
  * only call this function once.  If you desire to have an image for
  * each pass of a interlaced image, use png_read_rows() instead.
+ *
+ * [*] png_handle_alpha() does not exist yet, as of libpng version 1.0.4.
  */
 void
 png_read_image(png_structp png_ptr, png_bytepp image)
@@ -588,7 +591,16 @@ png_read_image(png_structp png_ptr, png_bytepp image)
 
    png_debug(1, "in png_read_image\n");
    /* save jump buffer and error functions */
+
+#ifdef PNG_READ_INTERLACING_SUPPORTED
    pass = png_set_interlace_handling(png_ptr);
+#else
+   if (png_ptr->interlaced)
+      png_error(png_ptr,
+        "Cannot read interlaced image -- interlace handler disabled.");
+   pass = 1;
+#endif
+
 
    image_height=png_ptr->height;
    png_ptr->num_rows = image_height; /* Make sure this is set correctly */
@@ -803,8 +815,11 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
 #endif
    if (png_ptr->flags & PNG_FLAG_FREE_PALETTE)
       png_zfree(png_ptr, png_ptr->palette);
+#if defined(PNG_READ_tRNS_SUPPORTED) || defined(PNG_WRITE_tRNS_SUPPORTED) || \
+    defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
    if (png_ptr->flags & PNG_FLAG_FREE_TRANS)
       png_free(png_ptr, png_ptr->trans);
+#endif
 #if defined(PNG_READ_hIST_SUPPORTED)
    if (png_ptr->flags & PNG_FLAG_FREE_HIST)
       png_free(png_ptr, png_ptr->hist);
@@ -818,9 +833,9 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
       {
          png_free(png_ptr, png_ptr->gamma_16_table[i]);
       }
+   png_free(png_ptr, png_ptr->gamma_16_table);
    }
 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
-   png_free(png_ptr, png_ptr->gamma_16_table);
    if (png_ptr->gamma_16_from_1 != NULL)
    {
       int i;
@@ -829,8 +844,8 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
       {
          png_free(png_ptr, png_ptr->gamma_16_from_1[i]);
       }
-   }
    png_free(png_ptr, png_ptr->gamma_16_from_1);
+   }
    if (png_ptr->gamma_16_to_1 != NULL)
    {
       int i;
@@ -839,8 +854,8 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
       {
          png_free(png_ptr, png_ptr->gamma_16_to_1[i]);
       }
-   }
    png_free(png_ptr, png_ptr->gamma_16_to_1);
+   }
 #endif
 #endif
 #if defined(PNG_TIME_RFC1123_SUPPORTED)

pngrio.c

@@ -1,11 +1,11 @@
 
 /* pngrio.c - functions for data input
  *
- * libpng 1.0.1e - June 6, 1998
+ * libpng 1.0.4 - September 18, 1999
  * 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
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  *
  * This file provides a location for all input.  Users who need
  * special handling are expected to write a function that has the same
@@ -60,10 +60,10 @@ png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
    can't handle far buffers in the medium and small models, we have to copy
    the data.
 */
- 
+
 #define NEAR_BUF_SIZE 1024
 #define MIN(a,b) (a <= b ? a : b)
- 
+
 static void
 png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
 {

pngrtran.c

@@ -1,13 +1,13 @@
 
 /* pngrtran.c - transforms the data in a row for PNG readers
  *
- * libpng 1.0.1e - June 6, 1998
+ * libpng 1.0.4 - September 18, 1999
  * 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
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  *
- * This file contains functions optionally called by an application 
+ * This file contains functions optionally called by an application
  * in order to tell libpng how to handle data when reading a PNG.
  * Transformations that are used in both reading and writing are
  * in pngtrans.c.
@@ -284,8 +284,8 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
             don't always behave themselves with only a few colors
             as input.  So we will just find the closest two colors,
             and throw out one of them (chosen somewhat randomly).
-            [I don't understand this at all, so if someone wants to
-             work on improving it, be my guest - AED]
+            [We don't understand this at all, so if someone wants to
+             work on improving it, be our guest - AED, GRP]
             */
          int i;
          int max_d;
@@ -309,7 +309,7 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
             palette_to_index[i] = (png_byte)i;
          }
 
-         hash = (png_dsortpp)png_malloc(png_ptr, (png_uint_32)(769 * 
+         hash = (png_dsortpp)png_malloc(png_ptr, (png_uint_32)(769 *
             sizeof (png_dsortp)));
          for (i = 0; i < 769; i++)
             hash[i] = NULL;
@@ -522,8 +522,8 @@ png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma)
 #endif
 
 #if defined(PNG_READ_EXPAND_SUPPORTED)
-/* Expand paletted images to rgb, expand grayscale images of
- * less then 8 bit depth to 8 bit depth, and expand tRNS chunks
+/* Expand paletted images to RGB, expand grayscale images of
+ * less than 8-bit depth to 8-bit depth, and expand tRNS chunks
  * to alpha channels.
  */
 void
@@ -532,7 +532,45 @@ png_set_expand(png_structp png_ptr)
    png_debug(1, "in png_set_expand\n");
    png_ptr->transformations |= PNG_EXPAND;
 }
-#endif
+
+/* GRR 19990627:  the following three functions currently are identical
+ *  to png_set_expand().  However, it is entirely reasonable that someone
+ *  might wish to expand an indexed image to RGB but *not* expand a single,
+ *  fully transparent palette entry to a full alpha channel--perhaps instead
+ *  convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace
+ *  the transparent color with a particular RGB value, or drop tRNS entirely.
+ *  IOW, a future version of the library may make the transformations flag
+ *  a bit more fine-grained, with separate bits for each of these three
+ *  functions.
+ *
+ *  More to the point, these functions make it obvious what libpng will be
+ *  doing, whereas "expand" can (and does) mean any number of things.
+ */
+
+/* Expand paletted images to RGB. */
+void
+png_set_palette_to_rgb(png_structp png_ptr)
+{
+   png_debug(1, "in png_set_expand\n");
+   png_ptr->transformations |= PNG_EXPAND;
+}
+
+/* Expand grayscale images of less than 8-bit depth to 8 bits. */
+void
+png_set_gray_1_2_4_to_8(png_structp png_ptr)
+{
+   png_debug(1, "in png_set_expand\n");
+   png_ptr->transformations |= PNG_EXPAND;
+}
+
+/* Expand tRNS chunks to alpha channels. */
+void
+png_set_tRNS_to_alpha(png_structp png_ptr)
+{
+   png_debug(1, "in png_set_expand\n");
+   png_ptr->transformations |= PNG_EXPAND;
+}
+#endif /* defined(PNG_READ_EXPAND_SUPPORTED) */
 
 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
 void
@@ -544,17 +582,49 @@ png_set_gray_to_rgb(png_structp png_ptr)
 #endif
 
 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
-/* Convert a RGB image to a grayscale of the given width.  This would
- * allow us, for example, to convert a 24 bpp RGB image into an 8 or
- * 16 bpp grayscale image. (Not yet implemented.)
+/* Convert a RGB image to a grayscale of the same width.  This allows us,
+ * for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image.
  */
 void
-png_set_rgb_to_gray(png_structp png_ptr, int gray_bits)
+png_set_rgb_to_gray(png_structp png_ptr, int error_action, double red,
+  double green)
 {
    png_debug(1, "in png_set_rgb_to_gray\n");
-   png_ptr->transformations |= PNG_RGB_TO_GRAY;
-   /* Need to do something with gray_bits here. */
-   png_warning(png_ptr, "RGB to GRAY transformation is not yet implemented.");
+   switch(error_action)
+   {
+      case 1: png_ptr->transformations |= PNG_RGB_TO_GRAY;
+              break;
+      case 2: png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN;
+              break;
+      case 3: png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR;
+   }
+   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+#if defined(PNG_READ_EXPAND_SUPPORTED)
+      png_ptr->transformations |= PNG_EXPAND;
+#else
+   {
+      png_warning(png_ptr, "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED.");
+      png_ptr->transformations &= ~PNG_RGB_TO_GRAY;
+   }
+#endif
+   {
+      png_byte red_byte = (png_byte)((float)red*255.0 + 0.5);
+      png_byte green_byte = (png_byte)((float)green*255.0 + 0.5);
+      if(red < 0.0 || green < 0.0)
+      {
+         red_byte = 54;
+         green_byte = 183;
+      }
+      else if(red_byte + green_byte > 255)
+      {
+         png_warning(png_ptr, "ignoring out of range rgb_to_gray coefficients");
+         red_byte = 54;
+         green_byte = 183;
+      }
+      png_ptr->rgb_to_gray_red_coeff   = red_byte;
+      png_ptr->rgb_to_gray_green_coeff = green_byte;
+      png_ptr->rgb_to_gray_blue_coeff  = 255 - red_byte - green_byte;
+   }
 }
 #endif
 
@@ -631,7 +701,7 @@ png_init_read_transformations(png_structp png_ptr)
            if (!(png_ptr->transformations & PNG_EXPAND))
 #endif
            {
-           /* invert the alpha channel (in tRNS) unless the pixels are 
+           /* invert the alpha channel (in tRNS) unless the pixels are
               going to be expanded, in which case leave it for later */
               int i,istop;
               istop=(int)png_ptr->num_trans;
@@ -649,7 +719,7 @@ png_init_read_transformations(png_structp png_ptr)
    png_ptr->background_1 = png_ptr->background;
 #endif
 #if defined(PNG_READ_GAMMA_SUPPORTED)
-   if (png_ptr->transformations & PNG_GAMMA)
+   if (png_ptr->transformations & (PNG_GAMMA | PNG_RGB_TO_GRAY))
    {
       png_build_gamma_table(png_ptr);
 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
@@ -958,6 +1028,11 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
       info_ptr->color_type |= PNG_COLOR_MASK_COLOR;
 #endif
 
+#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+   if (png_ptr->transformations & PNG_RGB_TO_GRAY)
+      info_ptr->color_type &= ~PNG_COLOR_MASK_COLOR;
+#endif
+
    if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
       info_ptr->channels = 1;
    else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR)
@@ -981,6 +1056,16 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
       ++info_ptr->channels;
 #endif
 
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
+   if(png_ptr->transformations & PNG_USER_TRANSFORM)
+     {
+       if(info_ptr->bit_depth < png_ptr->user_transform_depth)
+         info_ptr->bit_depth = png_ptr->user_transform_depth;
+       if(info_ptr->channels < png_ptr->user_transform_channels)
+         info_ptr->channels = png_ptr->user_transform_channels;
+     }
+#endif
+
    info_ptr->pixel_depth = (png_byte)(info_ptr->channels *
       info_ptr->bit_depth);
    info_ptr->rowbytes = ((info_ptr->width * info_ptr->pixel_depth + 7) >> 3);
@@ -1035,12 +1120,28 @@ png_do_read_transformations(png_structp png_ptr)
          PNG_FLAG_FILLER_AFTER);
 #endif
 
+#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+   if (png_ptr->transformations & PNG_RGB_TO_GRAY)
+   {
+      int rgb_error =
+         png_do_rgb_to_gray(png_ptr, &(png_ptr->row_info), png_ptr->row_buf + 1);
+      if(rgb_error)
+      {
+         png_ptr->rgb_to_gray_status=1;
+         if(png_ptr->transformations == PNG_RGB_TO_GRAY_WARN)
+            png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel");
+         if(png_ptr->transformations == PNG_RGB_TO_GRAY_ERR)
+            png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel");
+      }
+   }
+#endif
+
 /*
 From Andreas Dilger e-mail to png-implement, 26 March 1998:
 
   In most cases, the "simple transparency" should be done prior to doing
   gray-to-RGB, or you will have to test 3x as many bytes to check if a
-  pixel is transparent.  You would also need to make sure that the 
+  pixel is transparent.  You would also need to make sure that the
   transparency information is upgraded to RGB.
 
   To summarize, the current flow is:
@@ -1099,11 +1200,6 @@ From Andreas Dilger e-mail to png-implement, 26 March 1998:
          png_ptr->gamma_shift);
 #endif
 
-#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
-   if (png_ptr->transformations & PNG_RGB_TO_GRAY)
-      png_do_rgb_to_gray(&(png_ptr->row_info), png_ptr->row_buf + 1);
-#endif
-
 #if defined(PNG_READ_16_TO_8_SUPPORTED)
    if (png_ptr->transformations & PNG_16_TO_8)
       png_do_chop(&(png_ptr->row_info), png_ptr->row_buf + 1);
@@ -1175,6 +1271,7 @@ From Andreas Dilger e-mail to png-implement, 26 March 1998:
 
 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
    if (png_ptr->transformations & PNG_USER_TRANSFORM)
+    {
       if(png_ptr->read_user_transform_fn != NULL)
         (*(png_ptr->read_user_transform_fn)) /* user read transform function */
           (png_ptr,                    /* png_ptr */
@@ -1186,6 +1283,15 @@ From Andreas Dilger e-mail to png-implement, 26 March 1998:
              /*  png_byte channels;          number of channels (1-4) */
              /*  png_byte pixel_depth;       bits per pixel (depth*channels) */
            png_ptr->row_buf + 1);      /* start of pixel data for row */
+      if(png_ptr->user_transform_depth)
+         png_ptr->row_info.bit_depth = png_ptr->user_transform_depth;
+      if(png_ptr->user_transform_channels)
+         png_ptr->row_info.channels = png_ptr->user_transform_channels;
+      png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth *
+         png_ptr->row_info.channels);
+      png_ptr->row_info.rowbytes = (png_ptr->row_info.width * 
+         png_ptr->row_info.pixel_depth+7)>>3;
+   }
 #endif
 
 }
@@ -1359,7 +1465,6 @@ png_do_unshift(png_row_infop row_info, png_bytep row, png_color_8p sig_bits)
             }
             break;
          }
-#ifndef PNG_SLOW_SHIFT
          case 8:
          {
             png_bytep bp = row;
@@ -1387,43 +1492,6 @@ png_do_unshift(png_row_infop row_info, png_bytep row, png_color_8p sig_bits)
             }
             break;
          }
-#else
-         case 8:
-         {
-            png_bytep bp;
-            png_uint_32 i;
-            int cstop;
-
-            cstop=(int)row_info->channels;
-            for (bp = row, i = 0; i < row_width; i++)
-            {
-               for (c = 0; c < cstop; c++, bp++)
-               {
-                  *bp >>= shift[c];
-               }
-            }
-            break;
-         }
-         case 16:
-         {
-            png_bytep bp;
-            png_size_t i;
-            int cstop;
-
-            cstop=(int)row_info->channels;
-            for (bp = row, i = 0; i < row_width; i++)
-            {
-               for (c = 0; c < cstop; c++, bp += 2)
-               {
-                  value = (png_uint_16)((*bp << 8) + *(bp + 1));
-                  value >>= shift[c];
-                  *bp = (png_byte)(value >> 8);
-                  *(bp + 1) = (png_byte)(value & 0xff);
-               }
-            }
-            break;
-         }
-#endif
       }
    }
 }
@@ -1668,7 +1736,7 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
    png_uint_32 row_width = row_info->width;
 
    png_byte hi_filler = (png_byte)((filler>>8) & 0xff);
-   png_byte low_filler = (png_byte)(filler & 0xff);
+   png_byte lo_filler = (png_byte)(filler & 0xff);
 
    png_debug(1, "in png_do_read_filler\n");
    if (
@@ -1686,9 +1754,10 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
             png_bytep dp =  sp + (png_size_t)row_width;
             for (i = 1; i < row_width; i++)
             {
-               *(--dp) = low_filler;
+               *(--dp) = lo_filler;
                *(--dp) = *(--sp);
             }
+            *(--dp) = lo_filler;
             row_info->channels = 2;
             row_info->pixel_depth = 16;
             row_info->rowbytes = row_width * 2;
@@ -1701,7 +1770,7 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
             for (i = 0; i < row_width; i++)
             {
                *(--dp) = *(--sp);
-               *(--dp) = low_filler;
+               *(--dp) = lo_filler;
             }
             row_info->channels = 2;
             row_info->pixel_depth = 16;
@@ -1718,13 +1787,15 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
             for (i = 1; i < row_width; i++)
             {
                *(--dp) = hi_filler;
-               *(--dp) = low_filler;
+               *(--dp) = lo_filler;
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
             }
+            *(--dp) = hi_filler;
+            *(--dp) = lo_filler;
             row_info->channels = 2;
             row_info->pixel_depth = 32;
-            row_info->rowbytes = row_width * 2;
+            row_info->rowbytes = row_width * 4;
          }
          /* This changes the data from GG to XXGG */
          else
@@ -1736,11 +1807,11 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
                *(--dp) = hi_filler;
-               *(--dp) = low_filler;
+               *(--dp) = lo_filler;
             }
             row_info->channels = 2;
-            row_info->pixel_depth = 16;
-            row_info->rowbytes = row_width * 2;
+            row_info->pixel_depth = 32;
+            row_info->rowbytes = row_width * 4;
          }
       }
    } /* COLOR_TYPE == GRAY */
@@ -1755,11 +1826,12 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
             png_bytep dp = sp  + (png_size_t)row_width;
             for (i = 1; i < row_width; i++)
             {
-               *(--dp) = low_filler;
+               *(--dp) = lo_filler;
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
             }
+            *(--dp) = lo_filler;
             row_info->channels = 4;
             row_info->pixel_depth = 32;
             row_info->rowbytes = row_width * 4;
@@ -1774,7 +1846,7 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
-               *(--dp) = low_filler;
+               *(--dp) = lo_filler;
             }
             row_info->channels = 4;
             row_info->pixel_depth = 32;
@@ -1791,7 +1863,7 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
             for (i = 1; i < row_width; i++)
             {
                *(--dp) = hi_filler;
-               *(--dp) = low_filler;
+               *(--dp) = lo_filler;
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
@@ -1799,9 +1871,11 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
             }
+            *(--dp) = hi_filler;
+            *(--dp) = lo_filler;
             row_info->channels = 4;
             row_info->pixel_depth = 64;
-            row_info->rowbytes = row_width * 4;
+            row_info->rowbytes = row_width * 8;
          }
          /* This changes the data from RRGGBB to XXRRGGBB */
          else
@@ -1817,11 +1891,11 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
                *(--dp) = hi_filler;
-               *(--dp) = low_filler;
+               *(--dp) = lo_filler;
             }
             row_info->channels = 4;
             row_info->pixel_depth = 64;
-            row_info->rowbytes = row_width * 4;
+            row_info->rowbytes = row_width * 8;
          }
       }
    } /* COLOR_TYPE == RGB */
@@ -1853,8 +1927,7 @@ png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
             {
                *(dp--) = *sp;
                *(dp--) = *sp;
-               *(dp--) = *sp;
-               sp--;
+               *(dp--) = *(sp--);
             }
          }
          else
@@ -1867,10 +1940,8 @@ png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
                *(dp--) = *(sp - 1);
                *(dp--) = *sp;
                *(dp--) = *(sp - 1);
-               *(dp--) = *sp;
-               *(dp--) = *(sp - 1);
-               sp--;
-               sp--;
+               *(dp--) = *(sp--);
+               *(dp--) = *(sp--);
             }
          }
       }
@@ -1885,8 +1956,7 @@ png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
                *(dp--) = *(sp--);
                *(dp--) = *sp;
                *(dp--) = *sp;
-               *(dp--) = *sp;
-               sp--;
+               *(dp--) = *(sp--);
             }
          }
          else
@@ -1901,10 +1971,8 @@ png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
                *(dp--) = *(sp - 1);
                *(dp--) = *sp;
                *(dp--) = *(sp - 1);
-               *(dp--) = *sp;
-               *(dp--) = *(sp - 1);
-               sp--;
-               sp--;
+               *(dp--) = *(sp--);
+               *(dp--) = *(sp--);
             }
          }
       }
@@ -1918,6 +1986,261 @@ png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
 }
 #endif
 
+#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+/* reduce RGB files to grayscale, with or without alpha 
+ * using the equation given in Poynton's ColorFAQ at
+ * <http://www.inforamp.net/~poynton/>
+ * Copyright (c) 1998-01-04 Charles Poynton poynton@inforamp.net
+ *
+ *     Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
+ *
+ *  We approximate this with
+ * 
+ *     Y = 0.211 * R    + 0.715 * G    + 0.074 * B
+ *
+ *  which can be expressed with integers as
+ *
+ *     Y = (54 * R + 183 * G + 19 * B)/256
+ *
+ *  The calculation is to be done in a linear colorspace.
+ *
+ *  Other integer coefficents can be used via png_set_rgb_to_gray().
+ */
+int
+png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
+
+{
+   png_uint_32 i;
+
+   png_uint_32 row_width = row_info->width;
+   int rgb_error = 0;
+
+   png_debug(1, "in png_do_rgb_to_gray\n");
+   if (
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+       row != NULL && row_info != NULL &&
+#endif
+      (row_info->color_type & PNG_COLOR_MASK_COLOR))
+   {
+      png_byte rc = png_ptr->rgb_to_gray_red_coeff;
+      png_byte gc = png_ptr->rgb_to_gray_green_coeff;
+      png_byte bc = png_ptr->rgb_to_gray_blue_coeff;
+
+      if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+      {
+         if (row_info->bit_depth == 8)
+         {
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+            if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL)
+            {
+               png_bytep sp = row;
+               png_bytep dp = row;
+
+               for (i = 0; i < row_width; i++)
+               {
+                  png_byte red   = png_ptr->gamma_to_1[*(sp++)];
+                  png_byte green = png_ptr->gamma_to_1[*(sp++)];
+                  png_byte blue  = png_ptr->gamma_to_1[*(sp++)];
+                  if(red != green || red != blue)
+                  {
+                     rgb_error |= 1;
+                     *(dp++) = png_ptr->gamma_from_1[
+                       (rc*red+gc*green+bc*blue)>>8];
+                  }
+                  else
+                     *(dp++) = *(sp-1);
+               }
+            }
+            else
+#endif
+            {
+               png_bytep sp = row;
+               png_bytep dp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  png_byte red   = *(sp++);
+                  png_byte green = *(sp++);
+                  png_byte blue  = *(sp++);
+                  if(red != green || red != blue)
+                  {
+                     rgb_error |= 1;
+                     *(dp++) = (rc*red+gc*green+bc*blue)>>8;
+                  }
+                  else
+                     *(dp++) = *(sp-1);
+               }
+            }
+         }
+ 
+         else /* RGB bit_depth == 16 */
+         {
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+            if (png_ptr->gamma_16_to_1 != NULL &&
+                png_ptr->gamma_16_from_1 != NULL)
+            {
+               png_bytep sp = row;
+               png_bytep dp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  png_uint_16 red, green, blue, w;
+
+                  red   = ((*(sp))<<8) | *(sp+1); sp+=2;
+                  green = ((*(sp))<<8) | *(sp+1); sp+=2;
+                  blue  = ((*(sp))<<8) | *(sp+1); sp+=2;
+
+                  if(red == green && red == blue)
+                     w = red;
+                  else
+                  {
+                     png_uint_16 red_1   = png_ptr->gamma_16_to_1[(red&0xff) >>
+                                  png_ptr->gamma_shift][red>>8];
+                     png_uint_16 green_1 = png_ptr->gamma_16_to_1[(green&0xff) >>
+                                  png_ptr->gamma_shift][green>>8];
+                     png_uint_16 blue_1  = png_ptr->gamma_16_to_1[(blue&0xff) >> 
+                                  png_ptr->gamma_shift][blue>>8];
+                     png_uint_16 gray16  =  (rc * red_1 + gc * green_1
+                                  + bc * blue_1)>>8;
+                     w = png_ptr->gamma_16_from_1[(gray16&0xff) >>
+                         png_ptr->gamma_shift][gray16 >> 8];
+                     rgb_error |= 1;
+                  }
+                  
+                  *(dp++) = (w>>8) & 0xff;
+                  *(dp++) = w & 0xff;
+               }
+            }
+            else
+#endif
+            {
+               png_bytep sp = row;
+               png_bytep dp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  png_uint_16 red, green, blue, gray16;
+
+                  red   = ((*(sp))<<8) | *(sp+1); sp+=2;
+                  green = ((*(sp))<<8) | *(sp+1); sp+=2;
+                  blue  = ((*(sp))<<8) | *(sp+1); sp+=2;
+
+                  if(red != green || red != blue)
+                     rgb_error |= 1;
+                  gray16  =  (rc * red + gc * green + bc * blue)>>8;
+                  *(dp++) = (gray16>>8) & 0xff;
+                  *(dp++) = gray16 & 0xff;
+               }
+            }
+         }
+      }
+      if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+      {
+         if (row_info->bit_depth == 8)
+         {
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+            if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL)
+            {
+               png_bytep sp = row;
+               png_bytep dp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  png_byte red   = png_ptr->gamma_to_1[*(sp++)];
+                  png_byte green = png_ptr->gamma_to_1[*(sp++)];
+                  png_byte blue  = png_ptr->gamma_to_1[*(sp++)];
+                  if(red != green || red != blue)
+                     rgb_error |= 1;
+                  *(dp++) =  png_ptr->gamma_from_1
+                             [(rc*red + gc*green + bc*blue)>>8];
+                  *(dp++) = *(sp++);  /* alpha */
+               }
+            }
+            else
+#endif
+            {
+               png_bytep sp = row;
+               png_bytep dp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  png_byte red   = *(sp++);
+                  png_byte green = *(sp++);
+                  png_byte blue  = *(sp++);
+                  if(red != green || red != blue)
+                     rgb_error |= 1;
+                  *(dp++) =  (gc*red + gc*green + bc*blue)>>8;
+                  *(dp++) = *(sp++);  /* alpha */
+               }
+            }
+         }
+         else /* RGBA bit_depth == 16 */
+         {
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+            if (png_ptr->gamma_16_to_1 != NULL &&
+                png_ptr->gamma_16_from_1 != NULL)
+            {
+               png_bytep sp = row;
+               png_bytep dp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  png_uint_16 red, green, blue, w;
+
+                  red   = ((*(sp))<<8) | *(sp+1); sp+=2;
+                  green = ((*(sp))<<8) | *(sp+1); sp+=2;
+                  blue  = ((*(sp))<<8) | *(sp+1); sp+=2;
+
+                  if(red == green && red == blue)
+                     w = red;
+                  else
+                  {
+                     png_uint_16 red_1   = png_ptr->gamma_16_to_1[(red&0xff) >>
+                                  png_ptr->gamma_shift][red>>8];
+                     png_uint_16 green_1 = png_ptr->gamma_16_to_1[(green&0xff) >>
+                                  png_ptr->gamma_shift][green>>8];
+                     png_uint_16 blue_1  = png_ptr->gamma_16_to_1[(blue&0xff) >> 
+                                  png_ptr->gamma_shift][blue>>8];
+                     png_uint_16 gray16  =  (rc * red_1 + gc * green_1
+                                  + bc * blue_1)>>8;
+                     w = png_ptr->gamma_16_from_1[(gray16&0xff) >>
+                         png_ptr->gamma_shift][gray16 >> 8];
+                     rgb_error |= 1;
+                  }
+                  
+                  *(dp++) = (w>>8) & 0xff;
+                  *(dp++) = w & 0xff;
+                  *(dp++) = *(sp++);  /* alpha */
+                  *(dp++) = *(sp++);
+               }
+            }
+            else
+#endif
+            {
+               png_bytep sp = row;
+               png_bytep dp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  png_uint_16 red, green, blue, gray16;
+                  red   = (*(sp)<<8) | *(sp+1); sp+=2;
+                  green = (*(sp)<<8) | *(sp+1); sp+=2;
+                  blue  = (*(sp)<<8) | *(sp+1); sp+=2;
+                  if(red != green || red != blue)
+                     rgb_error |= 1;
+                  gray16  =  (rc * red + gc * green + bc * blue)>>8;
+                  *(dp++) = (gray16>>8) & 0xff;
+                  *(dp++) = gray16 & 0xff;
+                  *(dp++) = *(sp++);  /* alpha */
+                  *(dp++) = *(sp++);
+               }
+            }
+         }
+      }
+   row_info->channels -= (png_byte)2;
+      row_info->color_type &= ~PNG_COLOR_MASK_COLOR;
+      row_info->pixel_depth = (png_byte)(row_info->channels *
+         row_info->bit_depth);
+      row_info->rowbytes = ((row_width *
+         row_info->pixel_depth + 7) >> 3);
+   }
+   return rgb_error;
+}
+#endif
+
 /* Build a grayscale palette.  Palette is assumed to be 1 << bit_depth
  * large of png_color.  This lets grayscale images be treated as
  * paletted.  Most useful for gamma correction and simplification
@@ -1975,8 +2298,7 @@ png_correct_palette(png_structp png_ptr, png_colorp palette,
 {
    png_debug(1, "in png_correct_palette\n");
 #if defined(PNG_READ_BACKGROUND_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
-   if ((png_ptr->transformations & (PNG_GAMMA)) &&
-      (png_ptr->transformations & (PNG_BACKGROUND)))
+   if (png_ptr->transformations & (PNG_GAMMA | PNG_BACKGROUND))
    {
       png_color back, back_1;
 
@@ -2819,8 +3141,8 @@ png_do_background(png_row_infop row_info, png_bytep row,
 
 #if defined(PNG_READ_GAMMA_SUPPORTED)
 /* Gamma correct the image, avoiding the alpha channel.  Make sure
- * you do this after you deal with the trasparency issue on grayscale
- * or rgb images. If your bit depth is 8, use gamma_table, if it
+ * you do this after you deal with the transparency issue on grayscale
+ * or RGB images. If your bit depth is 8, use gamma_table, if it
  * is 16, use gamma_16_table and gamma_shift.  Build these with
  * build_gamma_table().
  */
@@ -3002,7 +3324,7 @@ png_do_gamma(png_row_infop row_info, png_bytep row,
 #endif
 
 #if defined(PNG_READ_EXPAND_SUPPORTED)
-/* Expands a palette row to an rgb or rgba row depending
+/* Expands a palette row to an RGB or RGBA row depending
  * upon whether you supply trans and num_trans.
  */
 void
@@ -3451,13 +3773,18 @@ static int png_gamma_shift[] =
 void
 png_build_gamma_table(png_structp png_ptr)
 {
-   png_debug(1, "in png_build_gamma_table\n");
+  png_debug(1, "in png_build_gamma_table\n");
+  if(png_ptr->gamma != 0.0)
+  {
    if (png_ptr->bit_depth <= 8)
    {
       int i;
       double g;
 
-      g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
+      if (png_ptr->screen_gamma > .000001)
+         g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
+      else
+         g = 1.0;
 
       png_ptr->gamma_table = (png_bytep)png_malloc(png_ptr,
          (png_uint_32)256);
@@ -3468,9 +3795,11 @@ png_build_gamma_table(png_structp png_ptr)
             g) * 255.0 + .5);
       }
 
-#if defined(PNG_READ_BACKGROUND_SUPPORTED)
-      if (png_ptr->transformations & PNG_BACKGROUND)
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+    defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+      if (png_ptr->transformations & (PNG_BACKGROUND | PNG_RGB_TO_GRAY))
       {
+
          g = 1.0 / (png_ptr->gamma);
 
          png_ptr->gamma_to_1 = (png_bytep)png_malloc(png_ptr,
@@ -3482,18 +3811,23 @@ png_build_gamma_table(png_structp png_ptr)
                g) * 255.0 + .5);
          }
 
-         g = 1.0 / (png_ptr->screen_gamma);
-
+         
          png_ptr->gamma_from_1 = (png_bytep)png_malloc(png_ptr,
             (png_uint_32)256);
 
+         if(png_ptr->screen_gamma > 0.000001)
+            g = 1.0 / png_ptr->screen_gamma;
+         else
+            g = png_ptr->gamma;   /* probably doing rgb_to_gray */
+
          for (i = 0; i < 256; i++)
          {
             png_ptr->gamma_from_1[i] = (png_byte)(pow((double)i / 255.0,
                g) * 255.0 + .5);
+
          }
       }
-#endif /* PNG_BACKGROUND_SUPPORTED */
+#endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */
    }
    else
    {
@@ -3535,13 +3869,15 @@ png_build_gamma_table(png_structp png_ptr)
 
       num = (1 << (8 - shift));
 
-      g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
+      if (png_ptr->screen_gamma > .000001)
+         g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
+      else
+         g = 1.0;
 
       png_ptr->gamma_16_table = (png_uint_16pp)png_malloc(png_ptr,
          (png_uint_32)(num * sizeof (png_uint_16p)));
 
-      if ((png_ptr->transformations & PNG_16_TO_8) &&
-         !(png_ptr->transformations & PNG_BACKGROUND))
+      if (png_ptr->transformations & (PNG_16_TO_8 | PNG_BACKGROUND))
       {
          double fin, fout;
          png_uint_32 last, max;
@@ -3591,9 +3927,11 @@ png_build_gamma_table(png_structp png_ptr)
          }
       }
 
-#if defined(PNG_READ_BACKGROUND_SUPPORTED)
-      if (png_ptr->transformations & PNG_BACKGROUND)
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+    defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+      if (png_ptr->transformations & (PNG_BACKGROUND | PNG_RGB_TO_GRAY))
       {
+
          g = 1.0 / (png_ptr->gamma);
 
          png_ptr->gamma_16_to_1 = (png_uint_16pp)png_malloc(png_ptr,
@@ -3613,7 +3951,11 @@ png_build_gamma_table(png_structp png_ptr)
                      65535.0, g) * 65535.0 + .5);
             }
          }
-         g = 1.0 / (png_ptr->screen_gamma);
+
+         if(png_ptr->screen_gamma > 0.000001)
+            g = 1.0 / png_ptr->screen_gamma;
+         else
+            g = png_ptr->gamma;   /* probably doing rgb_to_gray */
 
          png_ptr->gamma_16_from_1 = (png_uint_16pp)png_malloc(png_ptr,
             (png_uint_32)(num * sizeof (png_uint_16p)));
@@ -3633,8 +3975,9 @@ png_build_gamma_table(png_structp png_ptr)
             }
          }
       }
-#endif /* PNG_BACKGROUND_SUPPORTED */
+#endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */
    }
+ }
 }
 #endif
 

pngrutil.c

@@ -1,11 +1,11 @@
 
 /* pngrutil.c - utilities to read a PNG file
  *
- * libpng 1.0.1e - June 6, 1998
+ * libpng 1.0.4 - September 18, 1999
  * 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
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  *
  * This file contains routines that are only called from within
  * libpng itself during the course of reading an image.
@@ -14,6 +14,10 @@
 #define PNG_INTERNAL
 #include "png.h"
 
+#ifdef PNG_ASSEMBLER_CODE_SUPPORTED
+#include "pngasmrd.h"
+#endif
+
 #ifndef PNG_READ_BIG_ENDIAN_SUPPORTED
 /* Grab an unsigned 32-bit integer from a buffer in big-endian format. */
 png_uint_32
@@ -165,8 +169,8 @@ png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    interlace_type = buf[12];
 
    /* check for width and height valid values */
-   if (width == 0 || width > (png_uint_32)2147483647L || height == 0 ||
-        height > (png_uint_32)2147483647L)
+   if (width == 0 || width > PNG_MAX_UINT || height == 0 ||
+        height > PNG_MAX_UINT)
       png_error(png_ptr, "Invalid image size in IHDR");
 
    /* check other values */
@@ -178,7 +182,7 @@ png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       color_type == 5 || color_type > 6)
       png_error(png_ptr, "Invalid color type in IHDR");
 
-   if ((color_type == PNG_COLOR_TYPE_PALETTE && bit_depth) > 8 ||
+   if (((color_type == PNG_COLOR_TYPE_PALETTE) && bit_depth > 8) ||
        ((color_type == PNG_COLOR_TYPE_RGB ||
          color_type == PNG_COLOR_TYPE_GRAY_ALPHA ||
          color_type == PNG_COLOR_TYPE_RGB_ALPHA) && bit_depth < 8))
@@ -420,11 +424,11 @@ png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 
 #if defined(PNG_READ_sRGB_SUPPORTED)
    if (info_ptr->valid & PNG_INFO_sRGB)
-      if(igamma != (png_uint_32)45000L)
+      if(fabs((float)igamma - 45455.)>500.)
       {
          png_warning(png_ptr,
            "Ignoring incorrect gAMA value when sRGB is also present");
-#ifndef PNG_NO_STDIO
+#ifndef PNG_NO_CONSOLE_IO
          fprintf(stderr, "igamma = %lu\n", igamma);
 #endif
          return;
@@ -496,6 +500,9 @@ png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    else
    {
       png_ptr->sig_bit.gray = buf[0];
+      png_ptr->sig_bit.red = buf[0];
+      png_ptr->sig_bit.green = buf[0];
+      png_ptr->sig_bit.blue = buf[0];
       png_ptr->sig_bit.alpha = buf[1];
    }
    png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit));
@@ -624,7 +631,7 @@ png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 
             png_warning(png_ptr,
               "Ignoring incorrect cHRM value when sRGB is also present");
-#ifndef PNG_NO_STDIO
+#ifndef PNG_NO_CONSOLE_IO
             fprintf(stderr,"wx=%f, wy=%f, rx=%f, ry=%f\n",
                white_x, white_y, red_x, red_y);
             fprintf(stderr,"gx=%f, gy=%f, bx=%f, by=%f\n",
@@ -689,11 +696,11 @@ png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 
 #if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
    if ((info_ptr->valid & PNG_INFO_gAMA))
-      if((png_uint_32)(png_ptr->gamma*(float)100000.+.5) != (png_uint_32)45000L)
+      if(fabs((png_ptr->gamma*(float)100000.+.5)-45455.) > 500.)
       {
          png_warning(png_ptr,
            "Ignoring incorrect gAMA value when sRGB is also present");
-#ifndef PNG_NO_STDIO
+#ifndef PNG_NO_CONSOLE_IO
            fprintf(stderr,"gamma=%f\n",png_ptr->gamma);
 #endif
       }
@@ -868,9 +875,21 @@ png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
    {
       png_ptr->background.index = buf[0];
-      png_ptr->background.red = (png_uint_16)png_ptr->palette[buf[0]].red;
-      png_ptr->background.green = (png_uint_16)png_ptr->palette[buf[0]].green;
-      png_ptr->background.blue = (png_uint_16)png_ptr->palette[buf[0]].blue;
+      if(info_ptr->num_palette)
+      {
+          if(buf[0] > info_ptr->num_palette)
+          {
+             png_warning(png_ptr, "Incorrect bKGD chunk index value");
+             png_crc_finish(png_ptr, length);
+             return;
+          }
+          png_ptr->background.red =
+             (png_uint_16)png_ptr->palette[buf[0]].red;
+          png_ptr->background.green =
+             (png_uint_16)png_ptr->palette[buf[0]].green;
+          png_ptr->background.blue =
+             (png_uint_16)png_ptr->palette[buf[0]].blue;
+      }
    }
    else if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) /* GRAY */
    {
@@ -1466,19 +1485,23 @@ png_check_chunk_name(png_structp png_ptr, png_bytep chunk_name)
    }
 }
 
-/* Combines the row recently read in with the previous row.
-   This routine takes care of alpha and transparency if requested.
+/* Combines the row recently read in with the existing pixels in the
+   row.  This routine takes care of alpha and transparency if requested.
    This routine also handles the two methods of progressive display
    of interlaced images, depending on the mask value.
    The mask value describes which pixels are to be combined with
    the row.  The pattern always repeats every 8 pixels, so just 8
-   bits are needed.  A one indicates the pixels is to be combined,
+   bits are needed.  A one indicates the pixel is to be combined,
    a zero indicates the pixel is to be skipped.  This is in addition
    to any alpha or transparency value associated with the pixel.  If
    you want all pixels to be combined, pass 0xff (255) in mask.  */
 void
-png_combine_row(png_structp png_ptr, png_bytep row,
-   int mask)
+#ifdef PNG_HAVE_ASSEMBLER_COMBINE_ROW
+png_combine_row_c
+#else
+png_combine_row
+#endif /* PNG_HAVE_ASSEMBLER_COMBINE_ROW */
+   (png_structp png_ptr, png_bytep row, int mask)
 {
    png_debug(1,"in png_combine_row\n");
    if (mask == 0xff)
@@ -1681,7 +1704,12 @@ png_combine_row(png_structp png_ptr, png_bytep row,
 
 #if defined(PNG_READ_INTERLACING_SUPPORTED)
 void
-png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
+#ifdef PNG_HAVE_ASSEMBLER_READ_INTERLACE
+png_do_read_interlace_c
+#else
+png_do_read_interlace
+#endif /* PNG_HAVE_ASSEMBLER_READ_INTERLACE */
+   (png_row_infop row_info, png_bytep row, int pass,
    png_uint_32 transformations)
 {
    png_debug(1,"in png_do_read_interlace\n");
@@ -1890,15 +1918,17 @@ png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
 }
 #endif
 
-#ifndef PNG_READ_SLOW_FILTERING
 void
-png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row,
+#ifdef PNG_HAVE_ASSEMBLER_READ_FILTER_ROW
+png_read_filter_row_c
+#else
+png_read_filter_row
+#endif /* PNG_HAVE_ASSEMBLER_READ_FILTER_ROW */
+   (png_structp png_ptr, png_row_infop row_info, png_bytep row,
    png_bytep prev_row, int filter)
 {
    png_debug(1, "in png_read_filter_row\n");
    png_debug2(2,"row = %d, filter = %d\n", png_ptr->row_number, filter);
-
-
    switch (filter)
    {
       case PNG_FILTER_VALUE_NONE:
@@ -1947,7 +1977,7 @@ png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row,
                ((int)(*pp++) / 2)) & 0xff);
             rp++;
          }
-        
+
          for (i = 0; i < istop; i++)
          {
             *rp = (png_byte)(((int)(*rp) +
@@ -2010,118 +2040,11 @@ png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row,
          break;
       }
       default:
-         png_error(png_ptr, "Bad adaptive filter type");
+         png_warning(png_ptr, "Ignoring bad adaptive filter type");
+         *row=0;
          break;
    }
 }
-#else /* PNG_READ_SLOW_FILTERING */
-void
-png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row,
-   png_bytep prev_row, int filter)
-{
-   png_debug(1, "in png_read_filter_row\n");
-   png_debug2(2,"row = %d, filter = %d\n", png_ptr->row_number, filter);
-
-
-   switch (filter)
-   {
-      case PNG_FILTER_VALUE_NONE:
-         break;
-      case PNG_FILTER_VALUE_SUB:
-      {
-         png_uint_32 i;
-         int bpp = (row_info->pixel_depth + 7) / 8;
-         png_bytep rp;
-         png_bytep lp;
-
-         for (i = (png_uint_32)bpp, rp = row + bpp, lp = row;
-            i < row_info->rowbytes; i++, rp++, lp++)
-         {
-            *rp = (png_byte)(((int)(*rp) + (int)(*lp)) & 0xff);
-         }
-         break;
-      }
-      case PNG_FILTER_VALUE_UP:
-      {
-         png_uint_32 i;
-         png_bytep rp;
-         png_bytep pp;
-
-         for (i = 0, rp = row, pp = prev_row;
-            i < row_info->rowbytes; i++, rp++, pp++)
-         {
-            *rp = (png_byte)(((int)(*rp) + (int)(*pp)) & 0xff);
-         }
-         break;
-      }
-      case PNG_FILTER_VALUE_AVG:
-      {
-         png_uint_32 i;
-         int bpp = (row_info->pixel_depth + 7) / 8;
-         png_bytep rp;
-         png_bytep pp;
-         png_bytep lp;
-
-         for (i = 0, rp = row, pp = prev_row;
-            i < (png_uint_32)bpp; i++, rp++, pp++)
-         {
-            *rp = (png_byte)(((int)(*rp) +
-               ((int)(*pp) / 2)) & 0xff);
-         }
-         for (lp = row; i < row_info->rowbytes; i++, rp++, lp++, pp++)
-         {
-            *rp = (png_byte)(((int)(*rp) +
-               (int)(*pp + *lp) / 2) & 0xff);
-         }
-         break;
-      }
-      case PNG_FILTER_VALUE_PAETH:
-      {
-         int bpp = (row_info->pixel_depth + 7) / 8;
-         png_uint_32 i;
-         png_bytep rp;
-         png_bytep pp;
-         png_bytep lp;
-         png_bytep cp;
-
-         for (i = 0, rp = row, pp = prev_row,
-            lp = row - bpp, cp = prev_row - bpp;
-            i < row_info->rowbytes; i++, rp++, pp++, lp++, cp++)
-         {
-            int a, b, c, pa, pb, pc, p;
-
-            b = *pp;
-            if (i >= (png_uint_32)bpp)
-            {
-               c = *cp;
-               a = *lp;
-            }
-            else
-            {
-               a = c = 0;
-            }
-            p = a + b - c;
-            pa = abs(p - a);
-            pb = abs(p - b);
-            pc = abs(p - c);
-
-            if (pa <= pb && pa <= pc)
-               p = a;
-            else if (pb <= pc)
-               p = b;
-            else
-               p = c;
-
-            *rp = (png_byte)(((int)(*rp) + p) & 0xff);
-         }
-         break;
-      }
-      default:
-         png_error(png_ptr, "Bad adaptive filter type");
-         break;
-   }
-}
-#endif /* PNG_READ_SLOW_FILTERING */
 
 void
 png_read_finish_row(png_structp png_ptr)
@@ -2156,7 +2079,7 @@ png_read_finish_row(png_structp png_ptr)
             if (!(png_ptr->num_rows))
                continue;
          }
-         if (png_ptr->transformations & PNG_INTERLACE)
+         else  /* if (png_ptr->transformations & PNG_INTERLACE) */
             break;
       } while (png_ptr->iwidth == 0);
 
@@ -2320,19 +2243,25 @@ png_read_start_row(png_structp png_ptr)
 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
    if (png_ptr->transformations & PNG_GRAY_TO_RGB)
    {
-      if ((png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) ||
-         png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+      if (
+#if defined(PNG_READ_EXPAND_SUPPORTED)
+        (png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) ||
+#endif
+#if defined(PNG_READ_FILLER_SUPPORTED)
+        (png_ptr->transformations & (PNG_FILLER)) ||
+#endif
+        png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
       {
          if (max_pixel_depth <= 16)
             max_pixel_depth = 32;
-         else if (max_pixel_depth <= 32)
+         else
             max_pixel_depth = 64;
       }
       else
       {
          if (max_pixel_depth <= 8)
             max_pixel_depth = 24;
-         else if (max_pixel_depth <= 16)
+         else
             max_pixel_depth = 48;
       }
    }

pngset.c

@@ -1,11 +1,11 @@
 
 /* pngset.c - storage of image information into info struct
  *
- * libpng 1.0.1e - June 6, 1998
+ * libpng 1.0.4 - September 18, 1999
  * 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
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  *
  * The functions here are used during reads to store data from the file
  * into the info struct, and during writes to store application data
@@ -107,7 +107,7 @@ png_set_IHDR(png_structp png_ptr, png_infop info_ptr,
 
    /* check for overflow */
    rowbytes_per_pixel = (info_ptr->pixel_depth + 7) >> 3;
-   if (( width > (png_uint_32)2147483647L/rowbytes_per_pixel))
+   if (( width > PNG_MAX_UINT/rowbytes_per_pixel))
    {
       png_warning(png_ptr,
          "Width too large to process image data; rowbytes will overflow.");
@@ -344,7 +344,8 @@ void
 png_set_tIME(png_structp png_ptr, png_infop info_ptr, png_timep mod_time)
 {
    png_debug1(1, "in %s storage function\n", "tIME");
-   if (png_ptr == NULL || info_ptr == NULL)
+   if (png_ptr == NULL || info_ptr == NULL ||
+       (png_ptr->flags & PNG_FLAG_WROTE_tIME))
       return;
 
    png_memcpy(&(info_ptr->mod_time), mod_time, sizeof (png_time));
@@ -378,3 +379,13 @@ png_set_tRNS(png_structp png_ptr, png_infop info_ptr,
 }
 #endif
 
+#if defined(PNG_READ_EMPTY_PLTE_SUPPORTED)
+void
+png_permit_empty_plte (png_structp png_ptr, int empty_plte_permitted)
+{
+   png_debug1(1, "in png_permit_empty_plte\n", "");
+   if (png_ptr == NULL)
+      return;
+   png_ptr->empty_plte_permitted=(png_byte)empty_plte_permitted;
+}
+#endif

pngtest.c

@@ -1,11 +1,11 @@
 
 /* pngtest.c - a simple test program to test libpng
  *
- * libpng 1.0.1e -June 6, 1998
+ * libpng 1.0.4 - September 18, 1999
  * 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
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  *
  * This program reads in a PNG image, writes it out again, and then
  * compares the two files.  If the files are identical, this shows that
@@ -13,7 +13,7 @@
  * properly.  It does not currently test all of the transforms, although
  * it probably should.
  *
- * The program will fail in certain legitimate cases:
+ * The program will report "FAIL" in certain legitimate cases:
  * 1) when the compression level or filter selection method is changed.
  * 2) when the chunk size is not 8K.
  * 3) unknown ancillary chunks exist in the input file.
@@ -39,9 +39,11 @@
 
 #if defined(PNG_TIME_RFC1123_SUPPORTED)
 static int tIME_chunk_present=0;
-static png_charp tIME_string = "no tIME chunk present in file";
+static char tIME_string[30] = "no tIME chunk present in file";
 #endif /* PNG_TIME_RFC1123_SUPPORTED */
 
+static int verbose = 0;
+
 int test_one_file PNGARG((PNG_CONST char *inname, PNG_CONST char *outname));
 
 #ifdef __TURBOC__
@@ -60,12 +62,12 @@ static int status_dots=1;
 void
 read_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass)
 {
-    if(png_ptr == NULL || row_number > 0x3fffffffL) return;
+    if(png_ptr == NULL || row_number > PNG_MAX_UINT) return;
     if(status_pass != pass)
     {
        fprintf(stdout,"\n Pass %d: ",pass);
        status_pass = pass;
-       status_dots = 30;
+       status_dots = 31;
     }
     status_dots--;
     if(status_dots == 0)
@@ -79,11 +81,24 @@ read_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass)
 void
 write_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass)
 {
-    if(png_ptr == NULL || row_number > 0x3fffffffL || pass > 7) return;
+    if(png_ptr == NULL || row_number > PNG_MAX_UINT || pass > 7) return;
     fprintf(stdout, "w");
 }
 
 
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
+/* Example of using user transform callback (we don't transform anything,
+   but merely examine the row filters.  We set this to 256 rather than
+   5 in case illegal filter values are present.) */
+static png_uint_32 filters_used[256];
+void
+count_filters(png_structp png_ptr, png_row_infop row_info, png_bytep data)
+{
+    if(png_ptr != NULL && row_info != NULL)
+      ++filters_used[*(data-1)];
+}
+#endif
+
 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
 /* example of using user transform callback (we don't transform anything,
    but merely count the zero samples) */
@@ -94,7 +109,7 @@ void
 count_zero_samples(png_structp png_ptr, png_row_infop row_info, png_bytep data)
 {
    png_bytep dp = data;
-   if(png_ptr == NULL)return; 
+   if(png_ptr == NULL)return;
 
    /* contents of row_info:
     *  png_uint_32 width      width of row
@@ -105,6 +120,7 @@ count_zero_samples(png_structp png_ptr, png_row_infop row_info, png_bytep data)
     *  png_byte pixel_depth   bits per pixel (depth*channels)
     */
 
+
     /* counts the number of zero samples (or zero pixels if color_type is 3 */
 
     if(row_info->color_type == 0 || row_info->color_type == 3)
@@ -178,7 +194,6 @@ count_zero_samples(png_structp png_ptr, png_row_infop row_info, png_bytep data)
 }
 #endif /* PNG_WRITE_USER_TRANSFORM_SUPPORTED */
 
-static int verbose = 0;
 static int wrote_question = 0;
 
 #if defined(PNG_NO_STDIO)
@@ -211,10 +226,10 @@ png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
    can't handle far buffers in the medium and small models, we have to copy
    the data.
 */
- 
+
 #define NEAR_BUF_SIZE 1024
 #define MIN(a,b) (a <= b ? a : b)
- 
+
 static void
 png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
 {
@@ -474,7 +489,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 #ifdef USE_FAR_KEYWORD
    jmp_buf jmpbuf;
 #endif   
-   
+
    char inbuf[256], outbuf[256];
 
    row_buf = (png_bytep)NULL;
@@ -538,10 +553,12 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       fclose(fpout);
       return (1);
    }
+#ifdef USE_FAR_KEYWORD
+   png_memcpy(read_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf));
+#endif
 
    png_debug(0, "Setting jmpbuf for write struct\n");
 #ifdef USE_FAR_KEYWORD
-   png_memcpy(read_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf));
    if (setjmp(jmpbuf))
 #else
    if (setjmp(write_ptr->jmpbuf))
@@ -554,10 +571,10 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       fclose(fpout);
       return (1);
    }
-
 #ifdef USE_FAR_KEYWORD
    png_memcpy(write_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf));
 #endif
+
    png_debug(0, "Initializing input and output streams\n");
 #if !defined(PNG_NO_STDIO)
    png_init_io(read_ptr, fpin);
@@ -582,10 +599,18 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       png_set_read_status_fn(read_ptr, NULL);
    }
 
-#  if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
-     zero_samples=0;
-     png_set_write_user_transform_fn(write_ptr, count_zero_samples);
-#  endif
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
+   {
+     int i;
+     for(i=0; i<256; i++)
+        filters_used[i]=0;
+     png_set_read_user_transform_fn(read_ptr, count_filters);
+   }
+#endif
+#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+   zero_samples=0;
+   png_set_write_user_transform_fn(write_ptr, count_zero_samples);
+#endif
 
    png_debug(0, "Reading info struct\n");
    png_read_info(read_ptr, read_info_ptr);
@@ -733,16 +758,14 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       if (png_get_tIME(read_ptr, read_info_ptr, &mod_time))
       {
          png_set_tIME(write_ptr, write_info_ptr, mod_time);
-      }
 #if defined(PNG_TIME_RFC1123_SUPPORTED)
-      {
          /* we have to use png_strcpy instead of "=" because the string
             pointed to by png_convert_to_rfc1123() gets free'ed before
             we use it */
          png_strcpy(tIME_string,png_convert_to_rfc1123(read_ptr, mod_time));
          tIME_chunk_present++;
-      }
 #endif /* PNG_TIME_RFC1123_SUPPORTED */
+      }
    }
 #endif
 #if defined(PNG_READ_tRNS_SUPPORTED) && defined(PNG_WRITE_tRNS_SUPPORTED)
@@ -764,7 +787,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    png_write_info(write_ptr, write_info_ptr);
 
    png_debug(0, "\nAllocating row buffer \n");
-   row_buf = (png_bytep)png_malloc(read_ptr, 
+   row_buf = (png_bytep)png_malloc(read_ptr,
       png_get_rowbytes(read_ptr, read_info_ptr));
    if (row_buf == NULL)
    {
@@ -793,7 +816,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    png_debug(0, "Reading and writing end_info data\n");
    png_read_end(read_ptr, end_info_ptr);
    png_write_end(write_ptr, end_info_ptr);
- 
+
 #ifdef PNG_EASY_ACCESS_SUPPORTED
    if(verbose)
    {
@@ -859,7 +882,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 
       if (png_memcmp(inbuf, outbuf, num_in))
       {
-         fprintf(STDERR, "Files %s and %s are different\n", inname, outname);
+         fprintf(STDERR, "\nFiles %s and %s are different\n", inname, outname);
          if(wrote_question == 0)
          {
             fprintf(STDERR,
@@ -885,8 +908,8 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 
 /* input and output filenames */
 #ifdef RISCOS
-PNG_CONST char *inname = "pngtest/png";
-PNG_CONST char *outname = "pngout/png";
+static PNG_CONST char *inname = "pngtest/png";
+static PNG_CONST char *outname = "pngout/png";
 #else
 static PNG_CONST char *inname = "pngtest.png";
 static PNG_CONST char *outname = "pngout.png";
@@ -900,6 +923,7 @@ main(int argc, char *argv[])
 
    fprintf(STDERR, "Testing libpng version %s\n", PNG_LIBPNG_VER_STRING);
    fprintf(STDERR, "   with zlib   version %s\n", ZLIB_VERSION);
+   fprintf(STDERR,"%s",png_get_copyright(NULL));
 
    /* Do some consistency checking on the memory allocation settings, I'm
       not sure this matters, but it is nice to know, the first of these
@@ -972,16 +996,22 @@ main(int argc, char *argv[])
 #endif
       for (i=2; i<argc; ++i)
       {
-         int kerror;
+         int k, kerror;
          fprintf(STDERR, "Testing %s:",argv[i]);
          kerror = test_one_file(argv[i], outname);
-         if (kerror == 0) 
+         if (kerror == 0)
          {
 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
             fprintf(STDERR, " PASS (%lu zero samples)\n",zero_samples);
 #else
             fprintf(STDERR, " PASS\n");
-#endif 
+#endif
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
+            for (k=0; k<256; k++)
+               if(filters_used[k])
+                  fprintf(STDERR, " Filter %d was used %lu times\n",
+                     k,filters_used[k]);
+#endif
 #if defined(PNG_TIME_RFC1123_SUPPORTED)
          if(tIME_chunk_present != 0)
             fprintf(STDERR, " tIME = %s\n",tIME_string);
@@ -1031,14 +1061,21 @@ main(int argc, char *argv[])
          {
             if(verbose == 1 || i == 2)
             {
+                int k;
 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
                 fprintf(STDERR, " PASS (%lu zero samples)\n",zero_samples);
 #else
                 fprintf(STDERR, " PASS\n");
 #endif
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
+                for (k=0; k<256; k++)
+                   if(filters_used[k])
+                      fprintf(STDERR, " Filter %d was used %lu times\n",
+                         k,filters_used[k]);
+#endif
 #if defined(PNG_TIME_RFC1123_SUPPORTED)
-         if(tIME_chunk_present != 0)
-            fprintf(STDERR, " tIME = %s\n",tIME_string);
+             if(tIME_chunk_present != 0)
+                fprintf(STDERR, " tIME = %s\n",tIME_string);
 #endif /* PNG_TIME_RFC1123_SUPPORTED */
             }
          }
@@ -1055,7 +1092,7 @@ main(int argc, char *argv[])
                current_allocation-allocation_now);
          if (current_allocation != 0) {
              memory_infop pinfo = pinformation;
-   
+
              fprintf(STDERR, "MEMORY ERROR: %d bytes still allocated\n",
                 current_allocation);
              while (pinfo != NULL) {

pngtrans.c

@@ -1,18 +1,18 @@
 
 /* pngtrans.c - transforms the data in a row (used by both readers and writers)
  *
- * libpng 1.0.1e - June 6, 1998
+ * libpng 1.0.4 - September 18, 1999
  * 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
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  */
 
 #define PNG_INTERNAL
 #include "png.h"
 
 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
-/* turn on bgr to rgb mapping */
+/* turn on BGR-to-RGB mapping */
 void
 png_set_bgr(png_structp png_ptr)
 {
@@ -99,6 +99,24 @@ png_set_filler(png_structp png_ptr, png_uint_32 filler, int filler_loc)
       png_ptr->flags |= PNG_FLAG_FILLER_AFTER;
    else
       png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER;
+
+   /* This should probably go in the "do_filler" routine.
+    * I attempted to do that in libpng-1.0.1a but that caused problems
+    * so I restored it in libpng-1.0.2a
+   */
+
+   if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
+   {
+      png_ptr->usr_channels = 4;
+   }
+
+   /* Also I added this in libpng-1.0.2a (what happens when we expand
+    * a less-than-8-bit grayscale to GA? */
+
+   if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY && png_ptr->bit_depth >= 8)
+   {
+      png_ptr->usr_channels = 2;
+   }
 }
 #endif
 
@@ -130,7 +148,7 @@ png_set_invert_mono(png_structp png_ptr)
    png_ptr->transformations |= PNG_INVERT_MONO;
 }
 
-/* invert monocrome grayscale data */
+/* invert monochrome grayscale data */
 void
 png_do_invert(png_row_infop row_info, png_bytep row)
 {
@@ -552,3 +570,26 @@ png_do_bgr(png_row_infop row_info, png_bytep row)
 }
 #endif /* PNG_READ_BGR_SUPPORTED or PNG_WRITE_BGR_SUPPORTED */
 
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
+void
+png_set_user_transform_info(png_structp png_ptr, png_voidp
+   user_transform_ptr, int user_transform_depth, int user_transform_channels)
+{
+   png_debug(1, "in png_set_user_transform_info\n");
+   png_ptr->user_transform_ptr = user_transform_ptr;
+   png_ptr->user_transform_depth = user_transform_depth;
+   png_ptr->user_transform_channels = user_transform_channels;
+}
+
+/* This function returns a pointer to the user_transform_ptr associated with
+ * the user transform functions.  The application should free any memory
+ * associated with this pointer before png_write_destroy and png_read_destroy
+ * are called.
+ */
+png_voidp
+png_get_user_transform_ptr(png_structp png_ptr)
+{
+   return ((png_voidp)png_ptr->user_transform_ptr);
+}
+#endif

pngwio.c

@@ -1,11 +1,11 @@
 
 /* pngwio.c - functions for data output
  *
- * libpng 1.0.1e - June 6, 1998
+ * libpng 1.0.4 - September 18, 1999
  * 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
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  *
  * This file provides a location for all output.  Users who need
  * special handling are expected to write functions that have the same
@@ -22,7 +22,7 @@
    writes to a file pointer.  Note that this routine sometimes gets called
    with very small lengths, so you should implement some kind of simple
    buffering if you are using unbuffered writes.  This should never be asked
-   to write more then 64K on a 16 bit machine.  */
+   to write more than 64K on a 16 bit machine.  */
 
 void
 png_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
@@ -184,11 +184,11 @@ png_set_write_fn(png_structp png_ptr, png_voidp io_ptr,
    }
 }
 
-#if defined(USE_FAR_KEYWORD) 
-#if defined(_MSC_VER)   
+#if defined(USE_FAR_KEYWORD)
+#if defined(_MSC_VER)
 void *png_far_to_near(png_structp png_ptr,png_voidp ptr, int check)
 {
-   void *near_ptr;   
+   void *near_ptr;
    void FAR *far_ptr;
    FP_OFF(near_ptr) = FP_OFF(ptr);
    far_ptr = (void FAR *)near_ptr;
@@ -200,7 +200,7 @@ void *png_far_to_near(png_structp png_ptr,png_voidp ptr, int check)
 #  else
 void *png_far_to_near(png_structp png_ptr,png_voidp ptr, int check)
 {
-   void *near_ptr;   
+   void *near_ptr;
    void FAR *far_ptr;
    near_ptr = (void FAR *)ptr;
    far_ptr = (void FAR *)near_ptr;

pngwrite.c

@@ -1,11 +1,11 @@
-   
+
 /* pngwrite.c - general routines to write a PNG file
  *
- * libpng 1.0.1e - June 6, 1998
+ * libpng 1.0.4 - September 18, 1999
  * 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
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  */
 
 /* get internal access to png.h */
@@ -15,7 +15,7 @@
 /* Writes all the PNG information.  This is the suggested way to use the
  * library.  If you have a new chunk to add, make a function to write it,
  * and put it in the correct location here.  If you want the chunk written
- * after the image data, put it in png_write_end().  I strongly encurage
+ * after the image data, put it in png_write_end().  I strongly encourage
  * you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing
  * the chunk, as that will keep the code from breaking if you want to just
  * write a plain PNG file.  If you have long comments, I suggest writing
@@ -971,6 +971,8 @@ png_set_compression_window_bits(png_structp png_ptr, int window_bits)
 {
    if (window_bits > 15)
       png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
+   else if (window_bits < 8)
+      png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
    png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS;
    png_ptr->zlib_window_bits = window_bits;
 }
@@ -1001,4 +1003,3 @@ png_set_write_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
    png_ptr->write_user_transform_fn = write_user_transform_fn;
 }
 #endif
-

pngwtran.c

@@ -1,17 +1,17 @@
 
 /* pngwtran.c - transforms the data in a row for PNG writers
  *
- * libpng 1.0.1e - June 6, 1998
+ * libpng 1.0.4 - September 18, 1999
  * 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
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  */
 
 #define PNG_INTERNAL
 #include "png.h"
 
-/* Transform the data according to the users wishes.  The order of
+/* Transform the data according to the user's wishes.  The order of
  * transformations is significant.
  */
 void
@@ -47,15 +47,15 @@ png_do_write_transformations(png_structp png_ptr)
       png_do_pack(&(png_ptr->row_info), png_ptr->row_buf + 1,
          (png_uint_32)png_ptr->bit_depth);
 #endif
+#if defined(PNG_WRITE_SWAP_SUPPORTED)
+   if (png_ptr->transformations & PNG_SWAP_BYTES)
+      png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
 #if defined(PNG_WRITE_SHIFT_SUPPORTED)
    if (png_ptr->transformations & PNG_SHIFT)
       png_do_shift(&(png_ptr->row_info), png_ptr->row_buf + 1,
          &(png_ptr->shift));
 #endif
-#if defined(PNG_WRITE_SWAP_SUPPORTED)
-   if (png_ptr->transformations & PNG_SWAP_BYTES)
-      png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1);
-#endif
 #if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
    if (png_ptr->transformations & PNG_INVERT_ALPHA)
       png_do_write_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
@@ -102,7 +102,7 @@ png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
             dp = row;
             mask = 0x80;
             v = 0;
-           
+
             for (i = 0; i < row_width; i++)
             {
                if (*sp != 0)

pngwutil.c

@@ -1,11 +1,11 @@
 
 /* pngwutil.c - utilities to write a PNG file
  *
- * libpng 1.0.1e - June 6, 1998
+ * libpng 1.0.4 - September 18, 1999
  * 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
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  */
 
 #define PNG_INTERNAL
@@ -273,7 +273,7 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
 }
 
 /* write the palette.  We are careful not to trust png_color to be in the
- * correct order for PNG, so people can redefine it to any convient
+ * correct order for PNG, so people can redefine it to any convenient
  * structure.
  */
 void
@@ -284,17 +284,21 @@ png_write_PLTE(png_structp png_ptr, png_colorp palette, png_uint_32 num_pal)
    png_byte buf[3];
 
    png_debug(1, "in png_write_PLTE\n");
-   if (num_pal == 0 || num_pal > 256)
-   {
-      if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
-      {
-         png_error(png_ptr, "Invalid number of colors in palette");
-      }
-      else
-      {
-         png_warning(png_ptr, "Invalid number of colors in palette");
-         return;
-      }
+   if ((
+#ifdef PNG_WRITE_EMPTY_PLTE_SUPPORTED
+        !png_ptr->empty_plte_permitted &&
+#endif
+        num_pal == 0) || num_pal > 256)
+     {
+       if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+         {
+           png_error(png_ptr, "Invalid number of colors in palette");
+         }
+       else
+         {
+           png_warning(png_ptr, "Invalid number of colors in palette");
+           return;
+         }
    }
 
    png_ptr->num_palette = (png_uint_16)num_pal;
@@ -376,9 +380,9 @@ png_write_sBIT(png_structp png_ptr, png_color_8p sbit, int color_type)
    {
       png_byte maxbits;
 
-      maxbits = color_type==PNG_COLOR_TYPE_PALETTE ? 8:png_ptr->usr_bit_depth;
-      if (sbit->red == 0 || sbit->red > maxbits || 
-          sbit->green == 0 || sbit->green > maxbits || 
+      maxbits = color_type==PNG_COLOR_TYPE_PALETTE ? 8 : png_ptr->usr_bit_depth;
+      if (sbit->red == 0 || sbit->red > maxbits ||
+          sbit->green == 0 || sbit->green > maxbits ||
           sbit->blue == 0 || sbit->blue > maxbits)
       {
          png_warning(png_ptr, "Invalid sBIT depth specified");
@@ -524,7 +528,12 @@ png_write_bKGD(png_structp png_ptr, png_color_16p back, int color_type)
    png_debug(1, "in png_write_bKGD\n");
    if (color_type == PNG_COLOR_TYPE_PALETTE)
    {
-      if (back->index > png_ptr->num_palette)
+      if (
+#ifdef PNG_WRITE_EMPTY_PLTE_SUPPORTED
+          (!png_ptr->empty_plte_permitted ||
+          (png_ptr->empty_plte_permitted && png_ptr->num_palette)) &&
+#endif
+         back->index > png_ptr->num_palette)
       {
          png_warning(png_ptr, "Invalid background palette index");
          return;
@@ -713,6 +722,11 @@ png_write_tEXt(png_structp png_ptr, png_charp key, png_charp text,
 
    /* make sure we include the 0 after the key */
    png_write_chunk_start(png_ptr, png_tEXt, (png_uint_32)key_len+text_len+1);
+   /*
+    * We leave it to the application to meet PNG-1.0 requirements on the
+    * contents of the text.  PNG-1.0 through PNG-1.2 discourage the use of
+    * any non-Latin-1 characters except for NEWLINE.  ISO PNG will forbid them.
+    */
    png_write_chunk_data(png_ptr, (png_bytep)new_key, key_len + 1);
    if (text_len)
       png_write_chunk_data(png_ptr, (png_bytep)text, text_len);
@@ -835,7 +849,7 @@ png_write_zTXt(png_structp png_ptr, png_charp key, png_charp text,
          png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
          png_ptr->zstream.next_out = png_ptr->zbuf;
       }
-   /* continue until we don't have anymore to compress */
+   /* continue until we don't have any more to compress */
    } while (png_ptr->zstream.avail_in);
 
    /* finish the compression */
@@ -952,7 +966,7 @@ void
 png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0,
    png_int_32 X1, int type, int nparams, png_charp units, png_charpp params)
 {
-   png_size_t purpose_len, units_len, total_len; 
+   png_size_t purpose_len, units_len, total_len;
    png_uint_32p params_len;
    png_byte buf[10];
    png_charp new_purpose;
@@ -1180,7 +1194,7 @@ png_write_finish_row(png_structp png_ptr)
       if (png_ptr->pass < 7)
       {
          if (png_ptr->prev_row != NULL)
-            png_memset(png_ptr->prev_row, 0, 
+            png_memset(png_ptr->prev_row, 0,
                (png_size_t) (((png_uint_32)png_ptr->usr_channels *
                (png_uint_32)png_ptr->usr_bit_depth *
                png_ptr->width + 7) >> 3) + 1);
@@ -1772,7 +1786,7 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
       }
       for (lp = row_buf + 1; i < row_bytes; i++)
       {
-         v = *dp++ = 
+         v = *dp++ =
           (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff);
 
          sum += (v < 128) ? v : 256 - v;

scripts/makefile.aco

@@ -1,221 +0,0 @@
-# Project:   libpng
-
-
-# Toolflags:
-CCflags = -c -depend !Depend -IC:,Zlib: -g -throwback  -DRISCOS  -fnah 
-C++flags = -c -depend !Depend -IC: -throwback
-Linkflags = -aif -c++ -o $@
-ObjAsmflags = -throwback -NoCache -depend !Depend
-CMHGflags = 
-LibFileflags = -c -l -o $@ 
-Squeezeflags = -o $@
-
-
-# Final targets:
-@.libpng-lib:   @.o.png @.o.pngerror @.o.pngrio @.o.pngwio @.o.pngmem \
-        @.o.pngpread @.o.pngset @.o.pngget @.o.pngread @.o.pngrtran \
-        @.o.pngrutil @.o.pngtrans @.o.pngwrite @.o.pngwtran @.o.pngwutil 
-        LibFile $(LibFileflags) @.o.png @.o.pngerror @.o.pngrio @.o.pngrtran \
-        @.o.pngmem @.o.pngpread @.o.pngset @.o.pngget @.o.pngread @.o.pngwio \
-        @.o.pngrutil @.o.pngtrans  @.o.pngwrite @.o.pngwtran @.o.pngwutil 
-@.mm-libpng-lib:   @.mm.png @.mm.pngerror @.mm.pngrio @.mm.pngwio @.mm.pngmem \
-        @.mm.pngpread @.mm.pngset @.mm.pngget @.mm.pngread @.mm.pngrtran \
-        @.mm.pngrutil @.mm.pngtrans @.mm.pngwrite @.mm.pngwtran @.mm.pngwutil 
-        LibFile $(LibFileflags) @.mm.png @.mm.pngerror @.mm.pngrio \
-        @.mm.pngwio @.mm.pngmem @.mm.pngpread @.mm.pngset @.mm.pngget \
-        @.mm.pngread @.mm.pngrtran @.mm.pngrutil @.mm.pngtrans @.mm.pngwrite \
-        @.mm.pngwtran @.mm.pngwutil 
-
-
-# User-editable dependencies:
-# (C) Copyright 1997 Tom Tanner
-Test: @.pngtest 
-        <Prefix$Dir>.pngtest
-        @remove <Prefix$Dir>.pngtest
-
-#It would be nice if you could stop "make" listing from here on!
-@.pngtest:   @.o.pngtest @.libpng-lib C:o.Stubs Zlib:zlib_lib 
-        Link $(Linkflags) @.o.pngtest @.libpng-lib C:o.Stubs Zlib:zlib_lib 
-
-.SUFFIXES: .o .mm .c
-
-.c.mm:
-        MemCheck.CC cc $(ccflags) -o $@ LibPng:$<
-.c.o:
-        cc $(ccflags) -o $@ $<
-
-
-# Static dependencies:
-
-
-# Dynamic dependencies:
-o.pngtest:	c.pngtest
-o.pngtest:	h.png
-o.pngtest:	Zlib:h.zlib
-o.pngtest:	Zlib:h.zconf
-o.pngtest:	h.pngconf
-mm.png:		LibPng:c.png
-mm.png:		LibPng:h.png
-mm.png:		Zlib:h.zlib
-mm.png:		Zlib:h.zconf
-mm.png:		LibPng:h.pngconf
-mm.png:		MemCheck:ANSI.h.stdio
-mm.pngerror:	LibPng:c.pngerror
-mm.pngerror:	LibPng:h.png
-mm.pngerror:	Zlib:h.zlib
-mm.pngerror:	Zlib:h.zconf
-mm.pngerror:	LibPng:h.pngconf
-mm.pngerror:	MemCheck:ANSI.h.stdio
-mm.pngrio:	LibPng:c.pngrio
-mm.pngrio:	LibPng:h.png
-mm.pngrio:	Zlib:h.zlib
-mm.pngrio:	Zlib:h.zconf
-mm.pngrio:	LibPng:h.pngconf
-mm.pngrio:	MemCheck:ANSI.h.stdio
-mm.pngwio:	LibPng:c.pngwio
-mm.pngwio:	LibPng:h.png
-mm.pngwio:	Zlib:h.zlib
-mm.pngwio:	Zlib:h.zconf
-mm.pngwio:	LibPng:h.pngconf
-mm.pngwio:	MemCheck:ANSI.h.stdio
-mm.pngmem:	LibPng:c.pngmem
-mm.pngmem:	LibPng:h.png
-mm.pngmem:	Zlib:h.zlib
-mm.pngmem:	Zlib:h.zconf
-mm.pngmem:	LibPng:h.pngconf
-mm.pngmem:	MemCheck:ANSI.h.stdio
-mm.pngpread:	LibPng:c.pngpread
-mm.pngpread:	LibPng:h.png
-mm.pngpread:	Zlib:h.zlib
-mm.pngpread:	Zlib:h.zconf
-mm.pngpread:	LibPng:h.pngconf
-mm.pngpread:	MemCheck:ANSI.h.stdio
-mm.pngset:	LibPng:c.pngset
-mm.pngset:	LibPng:h.png
-mm.pngset:	Zlib:h.zlib
-mm.pngset:	Zlib:h.zconf
-mm.pngset:	LibPng:h.pngconf
-mm.pngset:	MemCheck:ANSI.h.stdio
-mm.pngget:	LibPng:c.pngget
-mm.pngget:	LibPng:h.png
-mm.pngget:	Zlib:h.zlib
-mm.pngget:	Zlib:h.zconf
-mm.pngget:	LibPng:h.pngconf
-mm.pngget:	MemCheck:ANSI.h.stdio
-mm.pngread:	LibPng:c.pngread
-mm.pngread:	LibPng:h.png
-mm.pngread:	Zlib:h.zlib
-mm.pngread:	Zlib:h.zconf
-mm.pngread:	LibPng:h.pngconf
-mm.pngread:	MemCheck:ANSI.h.stdio
-mm.pngrtran:	LibPng:c.pngrtran
-mm.pngrtran:	LibPng:h.png
-mm.pngrtran:	Zlib:h.zlib
-mm.pngrtran:	Zlib:h.zconf
-mm.pngrtran:	LibPng:h.pngconf
-mm.pngrtran:	MemCheck:ANSI.h.stdio
-mm.pngrutil:	LibPng:c.pngrutil
-mm.pngrutil:	LibPng:h.png
-mm.pngrutil:	Zlib:h.zlib
-mm.pngrutil:	Zlib:h.zconf
-mm.pngrutil:	LibPng:h.pngconf
-mm.pngrutil:	MemCheck:ANSI.h.stdio
-mm.pngtrans:	LibPng:c.pngtrans
-mm.pngtrans:	LibPng:h.png
-mm.pngtrans:	Zlib:h.zlib
-mm.pngtrans:	Zlib:h.zconf
-mm.pngtrans:	LibPng:h.pngconf
-mm.pngtrans:	MemCheck:ANSI.h.stdio
-mm.pngwrite:	LibPng:c.pngwrite
-mm.pngwrite:	LibPng:h.png
-mm.pngwrite:	Zlib:h.zlib
-mm.pngwrite:	Zlib:h.zconf
-mm.pngwrite:	LibPng:h.pngconf
-mm.pngwrite:	MemCheck:ANSI.h.stdio
-mm.pngwtran:	LibPng:c.pngwtran
-mm.pngwtran:	LibPng:h.png
-mm.pngwtran:	Zlib:h.zlib
-mm.pngwtran:	Zlib:h.zconf
-mm.pngwtran:	LibPng:h.pngconf
-mm.pngwtran:	MemCheck:ANSI.h.stdio
-mm.pngwutil:	LibPng:c.pngwutil
-mm.pngwutil:	LibPng:h.png
-mm.pngwutil:	Zlib:h.zlib
-mm.pngwutil:	Zlib:h.zconf
-mm.pngwutil:	LibPng:h.pngconf
-mm.pngwutil:	MemCheck:ANSI.h.stdio
-o.png:		c.png
-o.png:		h.png
-o.png:		Zlib:h.zlib
-o.png:		Zlib:h.zconf
-o.png:		h.pngconf
-o.pngerror:	c.pngerror
-o.pngerror:	h.png
-o.pngerror:	Zlib:h.zlib
-o.pngerror:	Zlib:h.zconf
-o.pngerror:	h.pngconf
-o.pngrio:	c.pngrio
-o.pngrio:	h.png
-o.pngrio:	Zlib:h.zlib
-o.pngrio:	Zlib:h.zconf
-o.pngrio:	h.pngconf
-o.pngwio:	c.pngwio
-o.pngwio:	h.png
-o.pngwio:	Zlib:h.zlib
-o.pngwio:	Zlib:h.zconf
-o.pngwio:	h.pngconf
-o.pngmem:	c.pngmem
-o.pngmem:	h.png
-o.pngmem:	Zlib:h.zlib
-o.pngmem:	Zlib:h.zconf
-o.pngmem:	h.pngconf
-o.pngpread:	c.pngpread
-o.pngpread:	h.png
-o.pngpread:	Zlib:h.zlib
-o.pngpread:	Zlib:h.zconf
-o.pngpread:	h.pngconf
-o.pngset:	c.pngset
-o.pngset:	h.png
-o.pngset:	Zlib:h.zlib
-o.pngset:	Zlib:h.zconf
-o.pngset:	h.pngconf
-o.pngget:	c.pngget
-o.pngget:	h.png
-o.pngget:	Zlib:h.zlib
-o.pngget:	Zlib:h.zconf
-o.pngget:	h.pngconf
-o.pngread:	c.pngread
-o.pngread:	h.png
-o.pngread:	Zlib:h.zlib
-o.pngread:	Zlib:h.zconf
-o.pngread:	h.pngconf
-o.pngrtran:	c.pngrtran
-o.pngrtran:	h.png
-o.pngrtran:	Zlib:h.zlib
-o.pngrtran:	Zlib:h.zconf
-o.pngrtran:	h.pngconf
-o.pngrutil:	c.pngrutil
-o.pngrutil:	h.png
-o.pngrutil:	Zlib:h.zlib
-o.pngrutil:	Zlib:h.zconf
-o.pngrutil:	h.pngconf
-o.pngtrans:	c.pngtrans
-o.pngtrans:	h.png
-o.pngtrans:	Zlib:h.zlib
-o.pngtrans:	Zlib:h.zconf
-o.pngtrans:	h.pngconf
-o.pngwrite:	c.pngwrite
-o.pngwrite:	h.png
-o.pngwrite:	Zlib:h.zlib
-o.pngwrite:	Zlib:h.zconf
-o.pngwrite:	h.pngconf
-o.pngwtran:	c.pngwtran
-o.pngwtran:	h.png
-o.pngwtran:	Zlib:h.zlib
-o.pngwtran:	Zlib:h.zconf
-o.pngwtran:	h.pngconf
-o.pngwutil:	c.pngwutil
-o.pngwutil:	h.png
-o.pngwutil:	Zlib:h.zlib
-o.pngwutil:	Zlib:h.zconf
-o.pngwutil:	h.pngconf

scripts/makefile.acorn

@@ -0,0 +1,51 @@
+# Project:   libpng
+
+
+# Toolflags:
+CCflags = -c -depend !Depend -IC:,Zlib: -g -throwback  -DRISCOS  -fnah 
+C++flags = -c -depend !Depend -IC: -throwback
+Linkflags = -aif -c++ -o $@
+ObjAsmflags = -throwback -NoCache -depend !Depend
+CMHGflags = 
+LibFileflags = -c -l -o $@ 
+Squeezeflags = -o $@
+
+
+# Final targets:
+@.libpng-lib:   @.o.png @.o.pngerror @.o.pngrio @.o.pngwio @.o.pngmem \
+	@.o.pngpread @.o.pngset @.o.pngget @.o.pngread @.o.pngrtran \
+	@.o.pngrutil @.o.pngtrans @.o.pngwrite @.o.pngwtran @.o.pngwutil 
+	LibFile $(LibFileflags) @.o.png @.o.pngerror @.o.pngrio @.o.pngrtran \
+	@.o.pngmem @.o.pngpread @.o.pngset @.o.pngget @.o.pngread @.o.pngwio \
+	@.o.pngrutil @.o.pngtrans  @.o.pngwrite @.o.pngwtran @.o.pngwutil 
+@.mm-libpng-lib:   @.mm.png @.mm.pngerror @.mm.pngrio @.mm.pngwio @.mm.pngmem \
+	@.mm.pngpread @.mm.pngset @.mm.pngget @.mm.pngread @.mm.pngrtran \
+	@.mm.pngrutil @.mm.pngtrans @.mm.pngwrite @.mm.pngwtran @.mm.pngwutil 
+	LibFile $(LibFileflags) @.mm.png @.mm.pngerror @.mm.pngrio \
+	@.mm.pngwio @.mm.pngmem @.mm.pngpread @.mm.pngset @.mm.pngget \
+	@.mm.pngread @.mm.pngrtran @.mm.pngrutil @.mm.pngtrans @.mm.pngwrite \
+	@.mm.pngwtran @.mm.pngwutil 
+
+
+# User-editable dependencies:
+# (C) Copyright 1997 Tom Tanner
+Test: @.pngtest 
+	<Prefix$Dir>.pngtest
+	@remove <Prefix$Dir>.pngtest
+
+#It would be nice if you could stop "make" listing from here on!
+@.pngtest:   @.o.pngtest @.libpng-lib C:o.Stubs Zlib:zlib_lib 
+	Link $(Linkflags) @.o.pngtest @.libpng-lib C:o.Stubs Zlib:zlib_lib 
+
+.SUFFIXES: .o .mm .c
+
+.c.mm:
+	MemCheck.CC cc $(ccflags) -o $@ LibPng:$<
+.c.o:
+	cc $(ccflags) -o $@ $<
+
+
+# Static dependencies:
+
+
+# Dynamic dependencies:

scripts/makefile.amiga

@@ -8,7 +8,7 @@ CC=sc
 # WARNING: a bug in V6.51 causes bad code with OPTGO
 #          So use V6.55 or set NOOPTGO!!!!!!!!!
 CFLAGS= NOSTKCHK PARMS=REG OPTIMIZE OPTGO OPTPEEP OPTINLOCAL OPTINL\
-        OPTLOOP OPTRDEP=4 OPTDEP=4 OPTCOMP=4 DEFINE=PNG_INTERNAL
+	OPTLOOP OPTRDEP=4 OPTDEP=4 OPTCOMP=4 DEFINE=PNG_INTERNAL
 #linker flags
 LDFLAGS= SD ND BATCH
 #link libs

scripts/makefile.atari

@@ -9,6 +9,7 @@ LBR = png.lib
 LDFLAGS=-lpng -lz -lm
 
 # where make install puts libpng.a and png.h
+prefix=/usr/local
 
 OBJS = $(LBR)(png.o) $(LBR)(pngset.o) $(LBR)(pngget.o) $(LBR)(pngrutil.o)\
 	$(LBR)(pngtrans.o) $(LBR)(pngwutil.o)\
@@ -28,4 +29,5 @@ install: libpng.a
 	-@mkdir $(prefix)/lib
 	cp png.h $(prefix)/include
 	cp pngconf.h $(prefix)/include
-	chmod 644 $(prefix)/include/p
+	chmod 644 $(prefix)/include/png.h
+	chmod 644 $(prefix)/include/pngconf.h

scripts/makefile.beos

@@ -0,0 +1,104 @@
+# makefile for libpng on BeOS x86 ELF with gcc
+# modified from makefile.lnx by Sander Stoks
+# Copyright (C) 1996, 1997 Andreas Dilger
+# Copyright (C) 1999 Greg Roelofs
+# For conditions of distribution and use, see copyright notice in png.h
+
+CC=gcc
+
+# Where the zlib library and include files are located
+ZLIBLIB=/usr/local/lib
+ZLIBINC=/usr/local/include
+
+ALIGN=
+# For i386:
+# ALIGN=-malign-loops=2 -malign-functions=2
+
+WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
+	-Wmissing-declarations -Wtraditional -Wcast-align \
+	-Wstrict-prototypes -Wmissing-prototypes #-Wconversion
+
+# On BeOS, -O1 is actually better than -O3.  This is a known bug but it's
+# still here in R4.5
+CFLAGS=-I$(ZLIBINC) -Wall -O1 -funroll-loops \
+	$(ALIGN) # $(WARNMORE) -g -DPNG_DEBUG=5
+# LDFLAGS=-L. -Wl,-rpath,. -L$(ZLIBLIB) -Wl,-rpath,$(ZLIBLIB) -lpng -lz -lm
+LDFLAGS=-L. -Wl,-soname=libpng.so.$(PNGMAJ) -L$(ZLIBLIB) -lz -lm
+
+RANLIB=ranlib
+#RANLIB=echo
+
+# read libpng.txt or png.h to see why PNGMAJ is 2.  You should not
+# have to change it.
+PNGMAJ = 2
+PNGMIN = 1.0.4
+PNGVER = $(PNGMAJ).$(PNGMIN)
+
+# where make install puts libpng.a, libpng.so*, and png.h
+prefix=/usr/local
+INCPATH=$(prefix)/include
+LIBPATH=$(prefix)/lib
+
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+	pngwtran.o pngmem.o pngerror.o pngpread.o
+
+OBJSDLL = $(OBJS)
+
+.SUFFIXES:      .c .o
+
+all: libpng.a libpng.so pngtest
+
+libpng.a: $(OBJS)
+	ar rc $@ $(OBJS)
+	$(RANLIB) $@
+
+libpng.so: libpng.so.$(PNGMAJ)
+	ln -sf libpng.so.$(PNGMAJ) libpng.so
+	cp libpng.so* /boot/home/config/lib
+
+libpng.so.$(PNGMAJ): libpng.so.$(PNGVER)
+	ln -sf libpng.so.$(PNGVER) libpng.so.$(PNGMAJ)
+
+libpng.so.$(PNGVER): $(OBJSDLL)
+	$(CC) -L$(ZLIBLIB) -lz -nostart -Wl,-soname,libpng.so.$(PNGMAJ) -o
+libpng.so.$(PNGVER) \
+	 $(OBJSDLL)
+
+pngtest: pngtest.o libpng.so
+	$(CC) -L$(ZLIBLIB) -lz -lpng -o pngtest pngtest.o
+
+test: pngtest
+	./pngtest
+
+install: libpng.a libpng.so.$(PNGVER)
+	-@mkdir $(INCPATH) $(LIBPATH)
+	cp png.h pngconf.h $(INCPATH)
+	chmod 644 $(INCPATH)/png.h $(INCPATH)/pngconf.h
+	cp libpng.a libpng.so.$(PNGVER) $(LIBPATH)
+	chmod 755 $(LIBPATH)/libpng.so.$(PNGVER)
+	-@/bin/rm -f $(LIBPATH)/libpng.so.$(PNGMAJ) $(LIBPATH)/libpng.so
+	(cd $(LIBPATH); ln -sf libpng.so.$(PNGVER) libpng.so.$(PNGMAJ); \
+	 ln -sf libpng.so.$(PNGMAJ) libpng.so)
+
+clean:
+	/bin/rm -f *.o libpng.a libpng.so* pngtest pngout.png
+
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+
+png.o png.pic.o: png.h pngconf.h
+pngerror.o pngerror.pic.o: png.h pngconf.h
+pngrio.o pngrio.pic.o: png.h pngconf.h
+pngwio.o pngwio.pic.o: png.h pngconf.h
+pngmem.o pngmem.pic.o: png.h pngconf.h
+pngset.o pngset.pic.o: png.h pngconf.h
+pngget.o pngget.pic.o: png.h pngconf.h
+pngread.o pngread.pic.o: png.h pngconf.h
+pngrtran.o pngrtran.pic.o: png.h pngconf.h
+pngrutil.o pngrutil.pic.o: png.h pngconf.h
+pngtrans.o pngtrans.pic.o: png.h pngconf.h
+pngwrite.o pngwrite.pic.o: png.h pngconf.h
+pngwtran.o pngwtran.pic.o: png.h pngconf.h
+pngwutil.o pngwutil.pic.o: png.h pngconf.h
+pngpread.o pngpread.pic.o: png.h pngconf.h
+pngtest.o: png.h pngconf.h

scripts/makefile.borland

@@ -70,38 +70,38 @@ O=obj
 
 ## variables
 OBJS = \
- png.$(O) \
- pngerror.$(O) \
- pngmem.$(O) \
- pngpread.$(O) \
- pngset.$(O) \
- pngget.$(O) \
- pngread.$(O) \
- pngrio.$(O) \
- pngrtran.$(O) \
- pngrutil.$(O) \
- pngtrans.$(O) \
- pngwrite.$(O) \
- pngwtran.$(O) \
- pngwio.$(O) \
- pngwutil.$(O)
+	png.$(O) \
+	pngerror.$(O) \
+	pngmem.$(O) \
+	pngpread.$(O) \
+	pngset.$(O) \
+	pngget.$(O) \
+	pngread.$(O) \
+	pngrio.$(O) \
+	pngrtran.$(O) \
+	pngrutil.$(O) \
+	pngtrans.$(O) \
+	pngwrite.$(O) \
+	pngwtran.$(O) \
+	pngwio.$(O) \
+	pngwutil.$(O)
 
 LIBOBJS = \
- +png.$(O) \
- +pngerror.$(O) \
- +pngmem.$(O) \
- +pngpread.$(O) \
- +pngread.$(O) \
- +pngset.$(O) \
- +pngget.$(O) \
- +pngrio.$(O) \
- +pngrtran.$(O) \
- +pngrutil.$(O) \
- +pngtrans.$(O) \
- +pngwrite.$(O) \
- +pngwtran.$(O) \
- +pngwio.$(O)
- +pngwutil.$(O)
+	+png.$(O) \
+	+pngerror.$(O) \
+	+pngmem.$(O) \
+	+pngpread.$(O) \
+	+pngread.$(O) \
+	+pngset.$(O) \
+	+pngget.$(O) \
+	+pngrio.$(O) \
+	+pngrtran.$(O) \
+	+pngrutil.$(O) \
+	+pngtrans.$(O) \
+	+pngwrite.$(O) \
+	+pngwtran.$(O) \
+	+pngwio.$(O) \
+	+pngwutil.$(O)
 
 LIBNAME=libpng$(MODEL).lib
 
@@ -121,7 +121,7 @@ libpng: $(LIBNAME)
 
 pngtest: pngtest$(MODEL).exe
 
-test:
+test: pngtest$(MODEL).exe
 	pngtest$(MODEL)
 
 
@@ -146,7 +146,7 @@ pngwutil.obj: pngwutil.c
 
 $(LIBNAME): $(OBJS)
 	-del $(LIBNAME)
-        $(LIB) $(LIBNAME) @&&|
+	$(LIB) $(LIBNAME) @&&|
 $(LIBOBJS), libpng$(MODEL)
 |
 

scripts/makefile.dec

@@ -2,12 +2,21 @@
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
 # For conditions of distribution and use, see copyright notice in png.h
 
+# where make install puts libpng.a and png.h
+prefix=/usr/local
+
 # Where the zlib library and include files are located
 #ZLIBLIB=/usr/local/lib
 #ZLIBINC=/usr/local/include
 ZLIBLIB=../zlib
 ZLIBINC=../zlib
 
+# read libpng.txt or png.h to see why PNGMAJ is 2.  You should not
+# have to change it.
+PNGMAJ = 2
+PNGMIN = 1.0.4
+PNGVER = $(PNGMAJ).$(PNGMIN)
+
 CC=cc
 CFLAGS=-std -w1 -I$(ZLIBINC) -O # -g -DPNG_DEBUG=1
 LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm
@@ -15,26 +24,33 @@ LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm
 #RANLIB=echo
 RANLIB=ranlib
 
-# where make install puts libpng.a and png.h
-prefix=/usr/local
 
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o
 
-all: libpng.a pngtest
+all: libpng.so libpng.a pngtest
 
 libpng.a: $(OBJS)
 	ar rc $@  $(OBJS)
 	$(RANLIB) $@
 
+libpng.so: libpng.so.$(PNGMAJ)
+	ln -f -s libpng.so.$(PNGMAJ) libpng.so
+
+libpng.so.$(PNGMAJ): libpng.so.$(PNGVER)
+	ln -f -s libpng.so.$(PNGVER) libpng.so.$(PNGMAJ)
+
+libpng.so.$(PNGVER): $(OBJS)
+	$(CC) -shared -o $@ $(OBJS) -L$(ZLIBLIB) -lz -lm
+
 pngtest: pngtest.o libpng.a
 	$(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
 
 test: pngtest
 	./pngtest
 
-install: libpng.a
+install: libpng.a libpng.so.$(PNGVER)
 	-@mkdir $(prefix)/include
 	-@mkdir $(prefix)/lib
 	cp png.h $(prefix)/include
@@ -42,10 +58,15 @@ install: libpng.a
 	chmod 644 $(prefix)/include/png.h
 	chmod 644 $(prefix)/include/pngconf.h
 	cp libpng.a $(prefix)/lib
+	cp libpng.so.$(PNGVER) $(prefix)/lib
 	chmod 644 $(prefix)/lib/libpng.a
+	chmod 644 $(prefix)/lib/libpng.so.$(PNGVER)
+	-@/bin/rm -f $(LIBPATH)/libpng.so.$(PNGMAJ) $(LIBPATH)/libpng.so
+	(cd $(LIBPATH); ln -f -s libpng.so.$(PNGVER) libpng.so.$(PNGMAJ); \
+	 ln -f -s libpng.so.$(PNGMAJ) libpng.so)
 
 clean:
-	rm -f *.o libpng.a pngtest pngout.png
+	rm -f *.o libpng.a pngtest pngout.png libpng.so*
 
 # DO NOT DELETE THIS LINE -- make depend depends on it.
 

scripts/makefile.dj2

@@ -2,16 +2,16 @@
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
 # For conditions of distribution and use, see copyright notice in png.h
 
+# where make install puts libpng.a and png.h
+#prefix=/usr/local
+prefix=.
+
 CC=gcc
 CFLAGS=-I../zlib -O
 LDFLAGS=-L. -L../zlib/ -lpng -lz -lm
 
 RANLIB=ranlib
 
-# where make install puts libpng.a and png.h
-#prefix=/usr/local
-prefix=.
-
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o pngwtran.o \
 	pngmem.o pngerror.o pngpread.o

scripts/makefile.hpux

@@ -0,0 +1,67 @@
+# makefile for libpng, HPUX (10.20 and 11.00)
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42
+# Copyright (C) 1999 Glenn Randers-Pehrson
+# contributed by Jim Rice, Hewlett Packard
+# For conditions of distribution and use, see copyright notice in png.h
+
+# Where the zlib library and include files are located
+ZLIBLIB=/opt/zlib/lib
+ZLIBINC=/opt/zlib/include
+
+CC=cc
+CFLAGS=-I$(ZLIBINC) -O -Ae +DA1.1 +DS2.0
+CCFLAGS=-I$(ZLIBINC) -O -Ae +DA1.1 +DS2.0
+LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm
+
+RANLIB=ranlib
+
+# where make install puts libpng.a and png.h
+prefix=/opt/libpng
+
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+	pngwtran.o pngmem.o pngerror.o pngpread.o
+
+all: libpng.a pngtest
+
+libpng.a: $(OBJS)
+	ar rc $@  $(OBJS)
+	$(RANLIB) $@
+
+pngtest: pngtest.o libpng.a
+	$(CC) -o pngtest $(CCFLAGS) pngtest.o $(LDFLAGS)
+
+test: pngtest
+	./pngtest
+
+install: libpng.a
+	-@mkdir $(prefix)/include
+	-@mkdir $(prefix)/lib
+	cp png.h $(prefix)/include
+	cp pngconf.h $(prefix)/include
+	chmod 644 $(prefix)/include/png.h
+	chmod 644 $(prefix)/include/pngconf.h
+	cp libpng.a $(prefix)/lib
+	chmod 644 $(prefix)/lib/libpng.a
+
+clean:
+	rm -f *.o libpng.a pngtest pngout.png
+
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+
+png.o: png.h pngconf.h
+pngerror.o: png.h pngconf.h
+pngrio.o: png.h pngconf.h
+pngwio.o: png.h pngconf.h
+pngmem.o: png.h pngconf.h
+pngset.o: png.h pngconf.h
+pngget.o: png.h pngconf.h
+pngread.o: png.h pngconf.h
+pngrtran.o: png.h pngconf.h
+pngrutil.o: png.h pngconf.h
+pngtest.o: png.h pngconf.h
+pngtrans.o: png.h pngconf.h
+pngwrite.o: png.h pngconf.h
+pngwtran.o: png.h pngconf.h
+pngwutil.o: png.h pngconf.h
+pngpread.o: png.h pngconf.h

scripts/makefile.knr

@@ -2,6 +2,14 @@
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
 # For conditions of distribution and use, see copyright notice in png.h
 
+# This makefile requires file file ansi2knr.c, which you can get
+# from the Ghostscript ftp site at ftp://ftp.cs.wisc.edu/ghost/
+# If you have libjpeg, you probably already have ansi2knr.c in the jpeg
+# source distribution.
+
+# where make install puts libpng.a and png.h
+prefix=/usr/local
+
 CC=cc
 CFLAGS=-I../zlib -O
 LDFLAGS=-L. -L../zlib/ -lpng -lz -lm
@@ -11,9 +19,6 @@ ANSI2KNRFLAGS=
 RANLIB=ranlib
 #RANLIB=echo
 
-# where make install puts libpng.a and png.h
-prefix=/usr/local
-
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o

scripts/makefile.linux

@@ -1,10 +1,13 @@
 # makefile for libpng on Linux ELF with gcc
 # Copyright (C) 1996, 1997 Andreas Dilger
-# Copyright (C) 1998 Greg Roelofs
+# Copyright (C) 1998, 1999 Greg Roelofs
 # For conditions of distribution and use, see copyright notice in png.h
 
 CC=gcc
 
+# where "make install" puts libpng.a, libpng.so*, png.h and pngconf.h
+prefix=/usr/local
+
 # Where the zlib library and include files are located
 #ZLIBLIB=/usr/local/lib
 #ZLIBINC=/usr/local/include
@@ -12,15 +15,15 @@ ZLIBLIB=../zlib
 ZLIBINC=../zlib
 
 ALIGN=
-# For I-386:
+# for i386:
 #ALIGN=-malign-loops=2 -malign-functions=2
 
 WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
-         -Wmissing-declarations -Wtraditional -Wcast-align \
-         -Wstrict-prototypes -Wmissing-prototypes #-Wconversion
+	-Wmissing-declarations -Wtraditional -Wcast-align \
+	-Wstrict-prototypes -Wmissing-prototypes #-Wconversion
 
 CFLAGS=-I$(ZLIBINC) -Wall -O3 -funroll-loops \
-     $(ALIGN) # $(WARNMORE) -g -DPNG_DEBUG=5
+	$(ALIGN) # $(WARNMORE) -g -DPNG_DEBUG=5
 LDFLAGS=-L. -Wl,-rpath,. -L$(ZLIBLIB) -Wl,-rpath,$(ZLIBLIB) -lpng -lz -lm
 
 RANLIB=ranlib
@@ -29,17 +32,15 @@ RANLIB=ranlib
 # read libpng.txt or png.h to see why PNGMAJ is 2.  You should not
 # have to change it.
 PNGMAJ = 2
-PNGMIN = 1.0.1e
+PNGMIN = 1.0.4
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
-# where make install puts libpng.a, libpng.so*, and png.h
-prefix=/usr/local
 INCPATH=$(prefix)/include
 LIBPATH=$(prefix)/lib
 
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
-       pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
-       pngwtran.o pngmem.o pngerror.o pngpread.o
+	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+	pngwtran.o pngmem.o pngerror.o pngpread.o
 
 OBJSDLL = $(OBJS:.o=.pic.o)
 
@@ -62,7 +63,7 @@ libpng.so.$(PNGMAJ): libpng.so.$(PNGVER)
 
 libpng.so.$(PNGVER): $(OBJSDLL)
 	$(CC) -shared -Wl,-soname,libpng.so.$(PNGMAJ) -o libpng.so.$(PNGVER) \
-	 $(OBJSDLL)
+	 $(OBJSDLL) -L$(ZLIBLIB) -lz -lm -lc
 
 pngtest: pngtest.o libpng.so
 	$(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)

scripts/makefile.mips

@@ -2,6 +2,9 @@
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
 # For conditions of distribution and use, see copyright notice in png.h
 
+# where make install puts libpng.a and png.h
+prefix=/usr/local
+
 CC=cc
 CFLAGS=-I../zlib -O -systype sysv -DSYSV -w -Dmips
 #CFLAGS=-O
@@ -10,9 +13,6 @@ LDFLAGS=-L. -L../zlib/ -lpng -lz -lm
 #RANLIB=ranlib
 RANLIB=echo
 
-# where make install puts libpng.a and png.h
-prefix=/usr/local
-
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o

scripts/makefile.msc

@@ -26,52 +26,52 @@ png$(O): png.h pngconf.h
 		  $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
 
 pngset$(O): png.h pngconf.h
-        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
 
 pngget$(O): png.h pngconf.h
-        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
 
 pngread$(O): png.h pngconf.h
-        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
 
 pngpread$(O): png.h pngconf.h
 		  $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
 
 pngrtran$(O): png.h pngconf.h
-        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
 
 pngrutil$(O): png.h pngconf.h
-        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
 
 pngerror$(O): png.h pngconf.h
-        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
 
 pngmem$(O): png.h pngconf.h
-        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
 
 pngrio$(O): png.h pngconf.h
-        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
 
 pngwio$(O): png.h pngconf.h
-        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
 
 pngtest$(O): png.h pngconf.h
-        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
 
 pngtrans$(O): png.h pngconf.h
-        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
 
 pngwrite$(O): png.h pngconf.h
-        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
 
 pngwtran$(O): png.h pngconf.h
-        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
 
 pngwutil$(O): png.h pngconf.h
-        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
 
 libpng.lib: $(OBJS1) $(OBJS2) $(OBJS3)
-        del libpng.lib
+	del libpng.lib
 	lib libpng $(OBJS1);
 	lib libpng $(OBJS2);
 	lib libpng $(OBJS3);

scripts/makefile.os2

@@ -10,10 +10,10 @@ ZLIBLIB=../zlib
 ZLIBINC=../zlib
 
 WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
-         -Wmissing-declarations -Wtraditional -Wcast-align \
-         -Wstrict-prototypes -Wmissing-prototypes #-Wconversion
+	-Wmissing-declarations -Wtraditional -Wcast-align \
+	-Wstrict-prototypes -Wmissing-prototypes #-Wconversion
 CFLAGS=-I$(ZLIBINC) -Wall -O6 -funroll-loops -malign-loops=2 \
-       -malign-functions=2 #$(WARNMORE) -g -DPNG_DEBUG=5
+	-malign-functions=2 #$(WARNMORE) -g -DPNG_DEBUG=5
 LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lzdll -Zcrtdll
 AR=emxomfar
 
@@ -23,8 +23,8 @@ SHAREDLIB=png.dll
 SHAREDLIBIMP=pngdll.lib
 
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
-       pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
-       pngwtran.o pngmem.o pngerror.o pngpread.o
+	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+	pngwtran.o pngmem.o pngerror.o pngpread.o
 
 .SUFFIXES:      .c .o
 

scripts/makefile.sco

@@ -7,6 +7,9 @@
 
 CC=cc
 
+# where make install puts libpng.a, libpng.so*, and png.h
+prefix=/usr/local
+
 # Where the zlib library and include files are located
 #ZLIBLIB=/usr/local/lib
 #ZLIBINC=/usr/local/include
@@ -22,17 +25,15 @@ RANLIB=echo
 # read libpng.txt or png.h to see why PNGMAJ is 2.  You should not
 # have to change it.
 PNGMAJ = 2
-PNGMIN = 1.0.1e
+PNGMIN = 1.0.4
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
-# where make install puts libpng.a, libpng.so*, and png.h
-prefix=/usr/local
 INCPATH=$(prefix)/include
 LIBPATH=$(prefix)/lib
 
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
-       pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
-       pngwtran.o pngmem.o pngerror.o pngpread.o
+	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+	pngwtran.o pngmem.o pngerror.o pngpread.o
 
 OBJSDLL = $(OBJS:.o=.pic.o)
 
@@ -48,10 +49,10 @@ libpng.a: $(OBJS)
 	$(RANLIB) $@
 
 libpng.so: libpng.so.$(PNGMAJ)
-	ln -sf libpng.so.$(PNGMAJ) libpng.so
+	ln -f -s libpng.so.$(PNGMAJ) libpng.so
 
 libpng.so.$(PNGMAJ): libpng.so.$(PNGVER)
-	ln -sf libpng.so.$(PNGVER) libpng.so.$(PNGMAJ)
+	ln -f -s libpng.so.$(PNGVER) libpng.so.$(PNGMAJ)
 
 libpng.so.$(PNGVER): $(OBJSDLL)
 	$(CC) -G  -Wl,-h,libpng.so.$(PNGMAJ) -o libpng.so.$(PNGVER) \
@@ -70,8 +71,8 @@ install: libpng.a libpng.so.$(PNGVER)
 	cp libpng.a libpng.so.$(PNGVER) $(LIBPATH)
 	chmod 755 $(LIBPATH)/libpng.so.$(PNGVER)
 	-@/bin/rm -f $(LIBPATH)/libpng.so.$(PNGMAJ) $(LIBPATH)/libpng.so
-	(cd $(LIBPATH); ln -sf libpng.so.$(PNGVER) libpng.so.$(PNGMAJ); \
-	 ln -sf libpng.so.$(PNGMAJ) libpng.so)
+	(cd $(LIBPATH); ln -f -s libpng.so.$(PNGVER) libpng.so.$(PNGMAJ); \
+	 ln -f -s libpng.so.$(PNGMAJ) libpng.so)
 
 clean:
 	/bin/rm -f *.o libpng.a libpng.so* pngtest pngout.png

scripts/makefile.sgi

@@ -2,6 +2,9 @@
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
 # For conditions of distribution and use, see copyright notice in png.h
 
+# where make install puts libpng.a and png.h
+prefix=/usr/local
+
 # Where the zlib library and include files are located
 #ZLIBLIB=/usr/local/lib
 #ZLIBINC=/usr/local/include
@@ -11,15 +14,13 @@ ZLIBINC=../zlib
 CC=cc
 
 WARNMORE=-fullwarn
+# You can add the -n32 option; then zlib must also be compiled with -n32
 CFLAGS=-I$(ZLIBINC) -O $(WARNMORE) # -g -DPNG_DEBUG=5
 LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm
 
 RANLIB=echo
 #RANLIB=ranlib
 
-# where make install puts libpng.a and png.h
-prefix=/usr/local
-
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o

scripts/makefile.solaris

@@ -6,6 +6,14 @@
 
 CC=gcc
 
+# The commands "CC" and "LD" must NOT refer to /usr/ucb/cc and /usr/ucb/ld.
+# If they do, you need to adjust your PATH environment variable.
+# The environment variable LD_LIBRARY_PATH should not be set at all.  If
+# it is, things are likely to break.
+
+# Where make install puts libpng.a, libpng.so*, and png.h
+prefix=/usr/local
+
 # Where the zlib library and include files are located
 # Changing these to ../zlib poses a security risk.  If you want
 # to have zlib in an adjacent directory, specify the full path instead of "..".
@@ -15,12 +23,11 @@ CC=gcc
 ZLIBLIB=/usr/local/lib
 ZLIBINC=/usr/local/include
 
-
 WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
-         -Wmissing-declarations -Wtraditional -Wcast-align \
-         -Wstrict-prototypes -Wmissing-prototypes #-Wconversion
+	-Wmissing-declarations -Wtraditional -Wcast-align \
+	-Wstrict-prototypes -Wmissing-prototypes #-Wconversion
 CFLAGS=-I$(ZLIBINC) -Wall -O3 \
-      # $(WARNMORE) -g -DPNG_DEBUG=5
+	# $(WARNMORE) -g -DPNG_DEBUG=5
 LDFLAGS=-L. -R. -L$(ZLIBLIB) -R$(ZLIBLIB) -lpng -lz -lm
 
 #RANLIB=ranlib
@@ -29,17 +36,15 @@ RANLIB=echo
 # read libpng.txt or png.h to see why PNGMAJ is 2.  You should not
 # have to change it.
 PNGMAJ = 2
-PNGMIN = 1.0.1e
+PNGMIN = 1.0.4
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
-# where make install puts libpng.a, libpng.so*, and png.h
-prefix=/usr/local
 INCPATH=$(prefix)/include
 LIBPATH=$(prefix)/lib
 
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
-       pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
-       pngwtran.o pngmem.o pngerror.o pngpread.o
+	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+	pngwtran.o pngmem.o pngerror.o pngpread.o
 
 OBJSDLL = $(OBJS:.o=.pic.o)
 
@@ -55,10 +60,10 @@ libpng.a: $(OBJS)
 	$(RANLIB) $@
 
 libpng.so: libpng.so.$(PNGMAJ)
-	ln -sf libpng.so.$(PNGMAJ) libpng.so
+	ln -f -s libpng.so.$(PNGMAJ) libpng.so
 
 libpng.so.$(PNGMAJ): libpng.so.$(PNGVER)
-	ln -sf libpng.so.$(PNGVER) libpng.so.$(PNGMAJ)
+	ln -f -s libpng.so.$(PNGVER) libpng.so.$(PNGMAJ)
 
 libpng.so.$(PNGVER): $(OBJSDLL)
 	$(LD) -G -L$(ZLIBLIB) -R$(ZLIBLIB) -h libpng.so.$(PNGMAJ) \
@@ -77,8 +82,8 @@ install: libpng.a libpng.so.$(PNGVER)
 	cp libpng.a libpng.so.$(PNGVER) $(LIBPATH)
 	chmod 755 $(LIBPATH)/libpng.so.$(PNGVER)
 	-@/bin/rm -f $(LIBPATH)/libpng.so.$(PNGMAJ) $(LIBPATH)/libpng.so
-	(cd $(LIBPATH); ln -sf libpng.so.$(PNGVER) libpng.so.$(PNGMAJ); \
-	 ln -sf libpng.so.$(PNGMAJ) libpng.so)
+	(cd $(LIBPATH); ln -f -s libpng.so.$(PNGVER) libpng.so.$(PNGMAJ); \
+	 ln -f -s libpng.so.$(PNGMAJ) libpng.so)
 
 clean:
 	/bin/rm -f *.o libpng.a libpng.so* pngtest pngout.png

scripts/makefile.std

@@ -2,6 +2,9 @@
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
 # For conditions of distribution and use, see copyright notice in png.h
 
+# where make install puts libpng.a and png.h
+prefix=/usr/local
+
 # Where the zlib library and include files are located
 #ZLIBLIB=/usr/local/lib
 #ZLIBINC=/usr/local/include
@@ -15,9 +18,6 @@ LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm
 #RANLIB=echo
 RANLIB=ranlib
 
-# where make install puts libpng.a and png.h
-prefix=/usr/local
-
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o

scripts/makefile.sunos

@@ -2,6 +2,9 @@
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
 # For conditions of distribution and use, see copyright notice in png.h
 
+# where make install puts libpng.a and png.h
+prefix=/usr/local
+
 # Where the zlib library and include files are located
 #ZLIBLIB=/usr/local/lib
 #ZLIBINC=/usr/local/include
@@ -10,8 +13,8 @@ ZLIBINC=../zlib
 
 
 WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow -Wconversion \
-         -Wmissing-declarations -Wtraditional -Wcast-align \
-         -Wstrict-prototypes -Wmissing-prototypes
+	-Wmissing-declarations -Wtraditional -Wcast-align \
+	-Wstrict-prototypes -Wmissing-prototypes
 CC=gcc
 CFLAGS=-I$(ZLIBINC) -O # $(WARNMORE) -DPNG_DEBUG=5
 LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm
@@ -19,9 +22,6 @@ LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm
 RANLIB=ranlib
 #RANLIB=echo
 
-# where make install puts libpng.a and png.h
-prefix=/usr/local
-
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o

scripts/makefile.turboc3

@@ -45,38 +45,38 @@ pngrutil$(O): png.h pngconf.h
 		  $(CC) -c $(CFLAGS) $*.c
 
 pngerror$(O): png.h pngconf.h
-        $(CC) -c $(CFLAGS) $*.c
+	$(CC) -c $(CFLAGS) $*.c
 
 pngmem$(O): png.h pngconf.h
-        $(CC) -c $(CFLAGS) $*.c
+	$(CC) -c $(CFLAGS) $*.c
 
 pngrio$(O): png.h pngconf.h
-        $(CC) -c $(CFLAGS) $*.c
+	$(CC) -c $(CFLAGS) $*.c
 
 pngwio$(O): png.h pngconf.h
-        $(CC) -c $(CFLAGS) $*.c
+	$(CC) -c $(CFLAGS) $*.c
 
 pngtest$(O): png.h pngconf.h
-        $(CC) -c $(CFLAGS) $*.c
+	$(CC) -c $(CFLAGS) $*.c
 
 pngtrans$(O): png.h pngconf.h
-        $(CC) -c $(CFLAGS) $*.c
+	$(CC) -c $(CFLAGS) $*.c
 
 pngwrite$(O): png.h pngconf.h
-        $(CC) -c $(CFLAGS) $*.c
+	$(CC) -c $(CFLAGS) $*.c
 
 pngwtran$(O): png.h pngconf.h
-        $(CC) -c $(CFLAGS) $*.c
+	$(CC) -c $(CFLAGS) $*.c
 
 pngwutil$(O): png.h pngconf.h
-        $(CC) -c $(CFLAGS) $*.c
+	$(CC) -c $(CFLAGS) $*.c
 
 libpng.lib: $(OBJS1) $(OBJS2) $(OBJS3)
-        $(LIB) libpng +$(OBJSL1)
-        $(LIB) libpng +$(OBJSL2)
-        $(LIB) libpng +$(OBJSL3)
+	$(LIB) libpng +$(OBJSL1)
+	$(LIB) libpng +$(OBJSL2)
+	$(LIB) libpng +$(OBJSL3)
 
 pngtest$(E): pngtest$(O) libpng.lib
-        $(CC) $(LDFLAGS) pngtest.obj libpng.lib zlib.lib
+	$(CC) $(LDFLAGS) pngtest.obj libpng.lib zlib.lib
 
 # End of makefile for libpng

scripts/makefile.watcom

@@ -1,15 +1,15 @@
 # Makefile for libpng
-# Watcom 10.0a and later 32-bit protected mode flat memory model
+# Watcom 10.0 and later 32-bit protected mode flat memory model
 
 # Adapted by Pawel Mrochen, based on makefile.msc
 # For conditions of distribution and use, see copyright notice in png.h
 # Assumes that zlib.lib, zconf.h, and zlib.h have been copied to ..\zlib
 
-# To use, do "wmake -f makefile.wat"
+# To use, do "wmake /f scripts\makefile.wat"
 
-# ------------- Watcom 10.0a and later -------------
+# ------------- Watcom 10.0 and later -------------
 MODEL=-mf
-CFLAGS= $(MODEL) -5r -fp5 -fpi87 -oneatx -zp8 -i=..\zlib
+CFLAGS= $(MODEL) -5r -fp5 -fpi87 -oneatx -i=..\zlib
 CC=wcc386
 LD=wcl386
 LIB=wlib -b -c
@@ -82,7 +82,7 @@ libpng.lib: $(OBJS1) $(OBJS2) $(OBJS3)
 pngtest.exe: pngtest.obj libpng.lib
 	$(LD) $(LDFLAGS) pngtest.obj libpng.lib ..\zlib\zlib.lib
 
-test: pngtest.exe
+test: pngtest.exe .symbolic
 	pngtest
 
 # End of makefile for libpng

scripts/makefile.win32vc

@@ -0,0 +1,88 @@
+# makefile for libpng
+# Copyright (C) 1998 Tim Wegner
+# For conditions of distribution and use, see copyright notice in png.h
+# Assumes that zlib.lib, zconf.h, and zlib.h have been copied to ..\zlib
+# To use, do "nmake /f scripts\makefile.w32"
+
+# ------------- Microsoft Visual C++ 4.0 and later -------------
+MODEL=- 
+CFLAGS=-DPNG_USE_PNGVCRD -Ox -GA3s -nologo -W3 -I..\zlib
+
+CC=cl
+LD=link
+LDFLAGS= 
+O=.obj
+
+#uncomment next to put error messages in a file
+#ERRFILE= >> pngerrs
+
+# variables
+OBJS1 = png$(O) pngset$(O) pngget$(O) pngrutil$(O) pngtrans$(O) pngwutil$(O)
+OBJS2 = pngmem$(O) pngpread$(O) pngread$(O) pngerror$(O) pngwrite$(O)
+OBJS3 = pngrtran$(O) pngwtran$(O) pngrio$(O) pngwio$(O) pngvcrd$(O)
+
+all: libpng.lib
+
+png$(O): png.h pngconf.h
+		  $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngset$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngget$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngread$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngpread$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngrtran$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngrutil$(O): png.h pngconf.h pngasmrd.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngvcrd$(O): png.h pngconf.h pngasmrd.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngerror$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngmem$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngrio$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngwio$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngtest$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngtrans$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngwrite$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngwtran$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngwutil$(O): png.h pngconf.h
+	$(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+libpng.lib: $(OBJS1) $(OBJS2) $(OBJS3)
+	del libpng.lib
+	lib /OUT:libpng.lib $(OBJS1) $(OBJS2) $(OBJS3)
+
+pngtest.exe: pngtest.obj libpng.lib 
+	$(LD) $(LDFLAGS) pngtest.obj libpng.lib ..\zlib\zlib.lib /OUT:pngtest.exe /SUBSYSTEM:CONSOLE
+
+test: pngtest.exe
+	pngtest
+
+# End of makefile for libpng
+

scripts/makevms.com

@@ -35,45 +35,45 @@ $ if f$search("SYS$SYSTEM:MMS.EXE").eqs.""
 $  then
 $   dele pngtest.obj;*
 $   CALL MAKE png.OBJ "cc ''CCOPT' png" -
-                png.c png.h pngconf.h   
+	png.c png.h pngconf.h   
 $   CALL MAKE pngpread.OBJ "cc ''CCOPT' pngpread" -
 					 pngpread.c png.h pngconf.h
 $   CALL MAKE pngset.OBJ "cc ''CCOPT' pngset" -
-                pngset.c png.h pngconf.h
+	pngset.c png.h pngconf.h
 $   CALL MAKE pngget.OBJ "cc ''CCOPT' pngget" -
-                pngget.c png.h pngconf.h
+	pngget.c png.h pngconf.h
 $   CALL MAKE pngread.OBJ "cc ''CCOPT' pngread" -
-                pngread.c png.h pngconf.h
+	pngread.c png.h pngconf.h
 $   CALL MAKE pngpread.OBJ "cc ''CCOPT' pngpread" -
 					 pngpread.c png.h pngconf.h
 $   CALL MAKE pngrtran.OBJ "cc ''CCOPT' pngrtran" -
-                pngrtran.c png.h pngconf.h
+	pngrtran.c png.h pngconf.h
 $   CALL MAKE pngrutil.OBJ "cc ''CCOPT' pngrutil" -
-                pngrutil.c png.h pngconf.h
+	pngrutil.c png.h pngconf.h
 $   CALL MAKE pngerror.OBJ "cc ''CCOPT' pngerror" -
-                pngerror.c png.h pngconf.h
+	pngerror.c png.h pngconf.h
 $   CALL MAKE pngmem.OBJ "cc ''CCOPT' pngmem" -
-                pngmem.c png.h pngconf.h
+	pngmem.c png.h pngconf.h
 $   CALL MAKE pngrio.OBJ "cc ''CCOPT' pngrio" -
-                pngrio.c png.h pngconf.h
+	pngrio.c png.h pngconf.h
 $   CALL MAKE pngwio.OBJ "cc ''CCOPT' pngwio" -
-                pngwio.c png.h pngconf.h
+	pngwio.c png.h pngconf.h
 $   CALL MAKE pngtrans.OBJ "cc ''CCOPT' pngtrans" -
-                pngtrans.c png.h pngconf.h
+	pngtrans.c png.h pngconf.h
 $   CALL MAKE pngwrite.OBJ "cc ''CCOPT' pngwrite" -
-                pngwrite.c png.h pngconf.h
+	pngwrite.c png.h pngconf.h
 $   CALL MAKE pngwtran.OBJ "cc ''CCOPT' pngwtran" -
-                pngwtran.c png.h pngconf.h
+	pngwtran.c png.h pngconf.h
 $   CALL MAKE pngwutil.OBJ "cc ''CCOPT' pngwutil" -
-                pngwutil.c png.h pngconf.h
+	pngwutil.c png.h pngconf.h
 $   write sys$output "Building Libpng ..."
 $   CALL MAKE libpng.OLB "lib/crea libpng.olb *.obj" *.OBJ
 $   write sys$output "Building pngtest..."
 $   CALL MAKE pngtest.OBJ "cc ''CCOPT' pngtest" -
-                pngtest.c png.h pngconf.h
+	pngtest.c png.h pngconf.h
 $   call make pngtest.exe - 
-                "LINK pngtest,libpng.olb/lib,''zlibsrc'libgz.olb/lib" - 
-                pngtest.obj libpng.olb
+	"LINK pngtest,libpng.olb/lib,''zlibsrc'libgz.olb/lib" - 
+	pngtest.obj libpng.olb
 $   write sys$output "Testing Libpng..."
 $   run pngtest
 $  else

scripts/pngdef.pas

@@ -3,8 +3,8 @@ unit pngdef;
 interface
 
 const
-  PNG_LIBPNG_VER_STRING = '1.0.1e';
-  PNG_LIBPNG_VER        =  10001;
+  PNG_LIBPNG_VER_STRING = '1.0.4';
+  PNG_LIBPNG_VER        =  10004;
 
 type
   png_uint_32 = Cardinal;
@@ -259,6 +259,10 @@ function png_create_read_struct(user_png_ver: png_charp;
              error_ptr: user_error_ptr; error_fn: png_error_ptr;
              warn_fn: png_error_ptr): png_structp;
              stdcall;
+function png_get_copyright(png_ptr: png_structp): png_charp;
+             stdcall;
+function png_get_header_version(png_ptr: png_structp): png_charp;
+             stdcall;
 function png_create_write_struct(user_png_ver: png_charp;
              error_ptr: user_error_ptr; error_fn: png_error_ptr;
              warn_fn: png_error_ptr): png_structp;
@@ -343,6 +347,8 @@ function png_get_pixels_per_meter(png_ptr: png_structp;
              stdcall;
 function png_get_progressive_ptr(png_ptr: png_structp): png_voidp;
              stdcall;
+function png_get_rgb_to_gray_status(png_ptr: png_structp);
+             stdcall;
 function png_get_rowbytes(png_ptr: png_structp; info_ptr: png_infop):
              png_uint_32;
              stdcall;
@@ -469,6 +475,8 @@ procedure png_set_gAMA(png_ptr: png_structp; info_ptr: png_infop;
 procedure png_set_gamma(png_ptr: png_structp; screen_gamma,
              default_file_gamma: double);
              stdcall;
+procedure png_set_gray_1_2_4_to_8(png_ptr: png_structp);
+             stdcall;
 procedure png_set_gray_to_rgb(png_ptr: png_structp);
              stdcall;
 procedure png_set_hIST(png_ptr: png_structp; info_ptr: png_infop;
@@ -483,6 +491,8 @@ procedure png_set_invert_mono(png_ptr: png_structp);
 procedure png_set_oFFs(png_ptr: png_structp; info_ptr: png_infop;
              offset_x, offset_y: png_uint_32; unit_type: int);
              stdcall;
+procedure png_set_palette_to_rgb(png_ptr: png_structp);
+             stdcall;
 procedure png_set_pCAL(png_ptr: png_structp; info_ptr: png_infop;
              purpose: png_charp; X0, X1: png_int_32;
              typ, nparams: int; units: png_charp;
@@ -510,6 +520,8 @@ procedure png_set_read_status_fn(png_ptr: png_structp;
 procedure png_set_read_user_transform_fn(png_ptr: png_structp;
              read_user_transform_fn: png_user_transform_ptr);
              stdcall;
+procedure png_set_rgb_to_gray(png_ptr: png_structp; int: error_action);
+             stdcall;
 procedure png_set_sBIT(png_ptr: png_structp; info_ptr: png_infop;
              sig_bits: png_color_8p);
              stdcall;
@@ -538,6 +550,8 @@ procedure png_set_tRNS(png_ptr: png_structp; info_ptr: png_infop;
              trans: png_bytep; num_trans: int;
              trans_values: png_color_16p);
              stdcall;
+procedure png_set_tRNS_to_alpha(png_ptr: png_structp);
+             stdcall;
 procedure png_set_text(png_ptr: png_structp; info_ptr: png_infop;
              text_ptr: png_textp; num_text: int);
              stdcall;

scripts/pngos2.def

@@ -29,7 +29,7 @@ EXPORTS
   png_set_expand
   png_set_bgr
   png_set_gray_to_rgb
-; png_set_rgb_to_gray
+  png_set_rgb_to_gray
   png_build_grayscale_palette
   png_set_strip_alpha
   png_set_swap_alpha
@@ -72,8 +72,10 @@ EXPORTS
   png_set_compression_window_bits
   png_set_compression_method
   png_init_io
+  png_get_copyright
   png_set_error_fn
   png_get_error_ptr
+  png_get_header_version
 ; png_get_mem_fn
 ; png_set_mem_fn
   png_set_write_fn
@@ -112,6 +114,7 @@ EXPORTS
   png_get_compression_type
   png_get_pixels_per_meter
   png_get_pixel_aspect_ratio
+  png_get_rgb_to_gray_status
   png_get_x_offset_pixels
   png_get_y_offset_pixels
   png_get_x_offset_microns
@@ -146,6 +149,9 @@ EXPORTS
   png_set_tIME
   png_get_tRNS
   png_set_tRNS
+  png_set_gray_1_2_4_to_8
+  png_set_tRNS_to_alpha
+  png_set_palette_to_rgb
 
   png_create_struct
   png_destroy_struct
@@ -202,7 +208,7 @@ EXPORTS
   png_do_strip_filler
   png_do_swap
   png_do_packswap
-; png_do_rgb_to_gray
+  png_do_rgb_to_gray
   png_do_gray_to_rgb
   png_do_unpack
   png_do_unshift

scripts/zlibdef.pas

@@ -1,169 +0,0 @@
-unit zlibdef;
-
-interface
-
-uses
-  Windows;
-
-const
-  ZLIB_VERSION = '1.1.2';
-
-type
-  voidpf = Pointer;
-  int    = Integer;
-  uInt   = Cardinal;
-  pBytef = PChar;
-  uLong  = Cardinal;
-
-  alloc_func = function(opaque: voidpf; items, size: uInt): voidpf;
-                    stdcall;
-  free_func  = procedure(opaque, address: voidpf);
-                    stdcall;
-
-  internal_state = Pointer;
-
-  z_streamp = ^z_stream;
-  z_stream = packed record
-    next_in: pBytef;          // next input byte
-    avail_in: uInt;           // number of bytes available at next_in
-    total_in: uLong;          // total nb of input bytes read so far
-
-    next_out: pBytef;         // next output byte should be put there
-    avail_out: uInt;          // remaining free space at next_out
-    total_out: uLong;         // total nb of bytes output so far
-
-    msg: PChar;               // last error message, NULL if no error
-    state: internal_state;    // not visible by applications
-
-    zalloc: alloc_func;       // used to allocate the internal state
-    zfree: free_func;         // used to free the internal state
-    opaque: voidpf;           // private data object passed to zalloc and zfree
-
-    data_type: int;           // best guess about the data type: ascii or binary
-    adler: uLong;             // adler32 value of the uncompressed data
-    reserved: uLong;          // reserved for future use
-    end;
-
-const
-  Z_NO_FLUSH      = 0;
-  Z_SYNC_FLUSH    = 2;
-  Z_FULL_FLUSH    = 3;
-  Z_FINISH        = 4;
-
-  Z_OK            = 0;
-  Z_STREAM_END    = 1;
-
-  Z_NO_COMPRESSION         =  0;
-  Z_BEST_SPEED             =  1;
-  Z_BEST_COMPRESSION       =  9;
-  Z_DEFAULT_COMPRESSION    = -1;
-
-  Z_FILTERED            = 1;
-  Z_HUFFMAN_ONLY        = 2;
-  Z_DEFAULT_STRATEGY    = 0;
-
-  Z_BINARY   = 0;
-  Z_ASCII    = 1;
-  Z_UNKNOWN  = 2;
-
-  Z_DEFLATED    = 8;
-
-  MAX_MEM_LEVEL = 9;
-
-function adler32(adler: uLong; const buf: pBytef; len: uInt): uLong;
-             stdcall;
-function crc32(crc: uLong; const buf: pBytef; len: uInt): uLong;
-             stdcall;
-function deflate(strm: z_streamp; flush: int): int;
-             stdcall;
-function deflateCopy(dest, source: z_streamp): int;
-             stdcall;
-function deflateEnd(strm: z_streamp): int;
-             stdcall;
-function deflateInit2_(strm: z_streamp; level, method,
-                       windowBits, memLevel, strategy: int;
-                       const version: PChar; stream_size: int): int;
-             stdcall;
-function deflateInit_(strm: z_streamp; level: int;
-                      const version: PChar; stream_size: int): int;
-             stdcall;
-function deflateParams(strm: z_streamp; level, strategy: int): int;
-             stdcall;
-function deflateReset(strm: z_streamp): int;
-             stdcall;
-function deflateSetDictionary(strm: z_streamp;
-                              const dictionary: pBytef;
-                              dictLength: uInt): int;
-             stdcall;
-function inflate(strm: z_streamp; flush: int): int;
-             stdcall;
-function inflateEnd(strm: z_streamp): int;
-             stdcall;
-function inflateInit2_(strm: z_streamp; windowBits: int;
-                       const version: PChar; stream_size: int): int;
-             stdcall;
-function inflateInit_(strm: z_streamp; const version: PChar;
-                      stream_size: int): int;
-             stdcall;
-function inflateReset(strm: z_streamp): int;
-             stdcall;
-function inflateSetDictionary(strm: z_streamp;
-                              const dictionary: pBytef;
-                              dictLength: uInt): int;
-             stdcall;
-function inflateSync(strm: z_streamp): int;
-             stdcall;
-
-function deflateInit(strm: z_streamp; level: int): int;
-function deflateInit2(strm: z_streamp; level, method, windowBits,
-                      memLevel, strategy: int): int;
-function inflateInit(strm: z_streamp): int;
-function inflateInit2(strm: z_streamp; windowBits: int): int;
-
-implementation
-
-function deflateInit(strm: z_streamp; level: int): int;
-begin
-  Result := deflateInit_(strm, level, ZLIB_VERSION, sizeof(z_stream));
-end;
-
-function deflateInit2(strm: z_streamp; level, method, windowBits,
-                      memLevel, strategy: int): int;
-begin
-  Result := deflateInit2_(strm, level, method, windowBits, memLevel,
-                          strategy, ZLIB_VERSION, sizeof(z_stream));
-end;
-
-function inflateInit(strm: z_streamp): int;
-begin
-  Result := inflateInit_(strm, ZLIB_VERSION, sizeof(z_stream));
-end;
-
-function inflateInit2(strm: z_streamp; windowBits: int): int;
-begin
-  Result := inflateInit2_(strm, windowBits, ZLIB_VERSION,
-                          sizeof(z_stream));
-end;
-
-const
-  zlibDLL = 'png32bd.dll';
-
-function adler32; external zlibDLL;
-function crc32; external zlibDLL;
-function deflate; external zlibDLL;
-function deflateCopy; external zlibDLL;
-function deflateEnd; external zlibDLL;
-function deflateInit2_; external zlibDLL;
-function deflateInit_; external zlibDLL;
-function deflateParams; external zlibDLL;
-function deflateReset; external zlibDLL;
-function deflateSetDictionary; external zlibDLL;
-function inflate; external zlibDLL;
-function inflateEnd; external zlibDLL;
-function inflateInit2_; external zlibDLL;
-function inflateInit_; external zlibDLL;
-function inflateReset; external zlibDLL;
-function inflateSetDictionary; external zlibDLL;
-function inflateSync; external zlibDLL;
-
-end.

scripts/zlibdll.mak

@@ -1,36 +0,0 @@
-# Makefile for zlib32bd.lib
-# ------------- Borland C++ 4.5 -------------
-
-# The (32-bit) zlib32bd.lib made with this makefile is intended for use 
-# in making the (32-bit) DLL, png32bd.dll. It uses the "stdcall" calling 
-# convention.
-
-CFLAGS= -ps -O2 -C -K -N- -k- -d -3 -r- -w-par -w-aus -WDE
-CC=f:\bc45\bin\bcc32
-LIBFLAGS= /C
-LIB=f:\bc45\bin\tlib
-ZLIB=zlib32bd.lib
-
-.autodepend
-.c.obj:
-        $(CC) -c $(CFLAGS) $<
-
-OBJ1=adler32.obj compress.obj crc32.obj deflate.obj gzio.obj infblock.obj 
-OBJ2=infcodes.obj inflate.obj inftrees.obj infutil.obj inffast.obj 
-OBJ3=trees.obj uncompr.obj zutil.obj
-pOBJ1=+adler32.obj+compress.obj+crc32.obj+deflate.obj+gzio.obj+infblock.obj 
-pOBJ2=+infcodes.obj+inflate.obj+inftrees.obj+infutil.obj+inffast.obj 
-pOBJ3=+trees.obj+uncompr.obj+zutil.obj
-
-all: $(ZLIB)
-
-$(ZLIB): $(OBJ1) $(OBJ2) $(OBJ3)
-        @if exist $@ del $@
-        $(LIB) @&&|
-$@ $(LIBFLAGS) &
-$(pOBJ1) &
-$(pOBJ2) &
-$(pOBJ3)
-|
-
-# End of makefile for zlib32bd.lib