Imported from libpng-1.0.6d.tar

ANNOUNCE

@@ -1,83 +1,20 @@
 
-Libpng 1.0.4c - October 1, 1999
+Libpng 1.0.6d - April 7, 2000
 
 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.
 
-Changes since the last public release (1.0.3):
+Changes since the last public release (1.0.6):
 
-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 24, 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
-  Changed "hptr += 16L" to "hptr = hptr + 16L" in pngmem.c for Turbo 3.0
-  Renamed the makefiles with longer but more user friendly extensions.
-  Copied the PNG copyright and license to a separate LICENSE file.
-  Revised documentation, png.h, and example.c to remove reference to
-    "viewing_gamma" which no longer appears in the PNG specification.
-  Revised pngvcrd.c to use MMX code for interlacing only on the final pass.
-  Updated pngvcrd.c to use the faster C filter algorithms from libpng-1.0.1a
-  Split makefile.win32vc into two versions, makefile.vcawin32 (uses MMX
-    assembler code) and makefile.vcwin32 (doesn't).
-  Added a CPU timing report to pngtest.c (enabled by defining PNGTEST_TIMING)
-version 1.0.4a September 25, 1999
-  Increase max_pixel_depth in pngrutil.c if a user transform needs it.
-  Changed several division operations to right-shifts in pngvcrd.c
-version 1.0.4b September 30, 1999
-  Added parentheses in line 3732 of pngvcrd.c
-  Added a comment in makefile.linux warning about buggy -O3 in pgcc 2.95.1
-version 1.0.4c [October 1, 1999]
-  Added a "png_check_version" function in png.c and pngtest.c that will generate
-    a helpful compiler error if an old png.h is found in the search path.
+version 1.0.6d [April 7, 2000]
+  Changed sprintf() to strcpy() in png_write_sCAL_s() to work without STDIO
+  Added data_length parameter to png_decompress_chunk() function
+  Revised documentation to remove reference to abandoned png_free_chnk functions
+  Fixed an error in png_rgb_to_gray_fixed()
+  Revised example.c, usage of png_destroy_write_struct().
+  Renamed makefile.ibmvac3 to makefile.ibmc, added libpng.icc IBM project file
+  Added a check for info_ptr->free_me&PNG_FREE_TEXT when free'ing text in png.c
+  Simplify png_sig_bytes() function to remove use of non-ISO-C strdup().
 
 Send comments/corrections/commendations to
 png-implement@ccrc.wustl.edu or to randeg@alum.rpi.edu

CHANGES

@@ -449,6 +449,7 @@ version 1.0.4 [September 24, 1999]
   Split makefile.win32vc into two versions, makefile.vcawin32 (uses MMX
     assembler code) and makefile.vcwin32 (doesn't).
   Added a CPU timing report to pngtest.c (enabled by defining PNGTEST_TIMING)
+  Added a copy of pngnow.png to the distribution.
 version 1.0.4a [September 25, 1999]
   Increase max_pixel_depth in pngrutil.c if a user transform needs it.
   Changed several division operations to right-shifts in pngvcrd.c
@@ -458,3 +459,218 @@ version 1.0.4b [September 30, 1999]
 version 1.0.4c [October 1, 1999]
   Added a "png_check_version" function in png.c and pngtest.c that will generate
     a helpful compiler error if an old png.h is found in the search path.
+  Changed type of png_user_transform_depth|channels from int to png_byte.
+version 1.0.4d [October 6, 1999]
+  Changed 0.45 to 0.45455 in png_set_sRGB()
+  Removed unused PLTE entries from pngnow.png
+  Re-enabled some parts of pngvcrd.c (png_combine_row) that work properly.
+version 1.0.4e [October 10, 1999]
+  Fixed sign error in pngvcrd.c (Greg Roelofs)
+  Replaced some instances of memcpy with simple assignments in pngvcrd (GR-P)
+version 1.0.4f [October 15, 1999]
+  Surrounded example.c code with #if 0 .. #endif to prevent people from
+    inadvertently trying to compile it.
+  Changed png_get_header_version() from a function to a macro in png.h
+  Added type casting mostly in pngrtran.c and pngwtran.c
+  Removed some pointless "ptr = NULL" in pngmem.c
+  Added a "contrib" directory containing the source code from Greg's book.
+version 1.0.5 [October 15, 1999]
+  Minor editing of the INSTALL and README files.
+version 1.0.5a [October 23, 1999]
+  Added contrib/pngsuite and contrib/pngminus (Willem van Schaik)
+  Fixed a typo in the png_set_sRGB() function call in example.c (Jan Nijtmans)
+  Further optimization and bugfix of pngvcrd.c
+  Revised pngset.c so that it does not allocate or free memory in the user's
+    text_ptr structure.  Instead, it makes its own copy.
+  Created separate write_end_info_struct in pngtest.c for a more severe test.
+  Added code in pngwrite.c to free info_ptr->text[i].key to stop a memory leak.
+version 1.0.5b [November 23, 1999]
+  Moved PNG_FLAG_HAVE_CHUNK_HEADER, PNG_FLAG_BACKGROUND_IS_GRAY and
+    PNG_FLAG_WROTE_tIME from flags to mode.
+  Added png_write_info_before_PLTE() function.
+  Fixed some typecasting in contrib/gregbook/*.c
+  Updated scripts/makevms.com and added makevms.com to contrib/gregbook
+    and contrib/pngminus (Martin Zinser)
+version 1.0.5c [November 26, 1999]
+  Moved png_get_header_version from png.h to png.c, to accomodate ansi2knr.
+  Removed all global arrays (according to PNG_NO_GLOBAL_ARRAYS macro), to
+    accomodate making DLL's: Moved usr_png_ver from global variable to function
+    png_get_header_ver() in png.c.  Moved png_sig to png_sig_bytes in png.c and
+    eliminated use of png_sig in pngwutil.c.  Moved the various png_CHNK arrays
+    into pngtypes.h.  Eliminated use of global png_pass arrays.  Declared the
+    png_CHNK and png_pass arrays to be "const".  Made the global arrays
+    available to applications (although none are used in libpng itself) when
+    PNG_NO_GLOBAL_ARRAYS is not defined or when PNG_GLOBAL_ARRAYS is defined.
+  Removed some extraneous "-I" from contrib/pngminus/makefile.std
+  Changed the PNG_sRGB_INTENT macros in png.h to be consistent with PNG-1.2.
+  Change PNG_SRGB_INTENT to PNG_sRGB_INTENT in libpng.txt and libpng.3
+version 1.0.5d [November 29, 1999]
+  Add type cast (png_const_charp) two places in png.c
+  Eliminated pngtypes.h; use macros instead to declare PNG_CHNK arrays.
+  Renamed "PNG_GLOBAL_ARRAYS" to "PNG_USE_GLOBAL_ARRAYS" and made available
+    to applications a macro "PNG_USE_LOCAL_ARRAYS".
+  #ifdef out all the new declarations when PNG_USE_GLOBAL_ARRAYS is defined.
+  Added PNG_EXPORT_VAR macro to accommodate making DLL's.
+version 1.0.5e [November 30, 1999]
+  Added iCCP, iTXt, and sPLT support; added "lang" member to the png_text
+    structure; refactored the inflate/deflate support to make adding new chunks
+    with trailing compressed parts easier in the future, and added new functions
+    png_free_iCCP, png_free_pCAL, png_free_sPLT, png_free_text, png_get_iCCP,
+    png_get_spalettes, png_set_iCCP, png_set_spalettes (Eric S. Raymond).
+  NOTE: Applications that write text chunks MUST define png_text->lang
+    before calling png_set_text(). It must be set to NULL if you want to
+    write tEXt or zTXt chunks.  If you want your application to be able to
+    run with older versions of libpng, use
+
+      #ifdef PNG_iTXt_SUPPORTED
+         png_text[i].lang = NULL;
+      #endif
+
+  Changed png_get_oFFs() and png_set_oFFs() to use signed rather than unsigned
+    offsets (Eric S. Raymond).
+  Combined PNG_READ_cHNK_SUPPORTED and PNG_WRITE_cHNK_SUPPORTED macros into
+    PNG_cHNK_SUPPORTED and combined the three types of PNG_text_SUPPORTED
+    macros, leaving the separate macros also available.
+  Removed comments on #endifs at the end of many short, non-nested #if-blocks.
+version 1.0.5f [December 6, 1999]
+  Changed makefile.solaris to issue a warning about potential problems when
+    the ucb "ld" is in the path ahead of the ccs "ld".
+  Removed "- [date]" from the "synopsis" line in libpng.3 and libpngpf.3.
+  Added sCAL chunk support (Eric S. Raymond).
+version 1.0.5g [December 7, 1999]
+  Fixed "png_free_spallettes" typo in png.h
+  Added code to handle new chunks in pngpread.c
+  Moved PNG_CHNK string macro definitions outside of PNG_NO_EXTERN block
+  Added "translated_key" to png_text structure and png_write_iTXt().
+  Added code in pngwrite.c to work around a newly discovered zlib bug.
+version 1.0.5h [December 10, 1999]
+  NOTE: regarding the note for version 1.0.5e, the following must also
+    be included in your code:
+        png_text[i].translated_key = NULL;
+  Unknown chunk handling is now supported.
+  Option to eliminate all floating point support was added.  Some new
+    fixed-point functions such as png_set_gAMA_fixed() were added.
+  Expanded tabs and removed trailing blanks in source files.
+version 1.0.5i [December 13, 1999]
+  Added some type casts to silence compiler warnings.
+  Renamed "png_free_spalette" to "png_free_spalettes" for consistency.
+  Removed leading blanks from a #define in pngvcrd.c
+  Added some parameters to the new png_set_keep_unknown_chunks() function.
+  Added a test for up->location != 0 in the first instance of writing
+    unknown chunks in pngwrite.c
+  Changed "num" to "i" in png_free_spalettes() and png_free_unknowns() to
+    prevent recursion.
+  Added png_free_hIST() function.
+  Various patches to fix bugs in the sCAL and integer cHRM processing,
+    and to add some convenience macros for use with sCAL.
+version 1.0.5j [December 21, 1999]
+  Changed "unit" parameter of png_write_sCAL from png_byte to int, to work
+    around buggy compilers.
+  Added new type "png_fixed_point" for integers that hold float*100000 values
+  Restored backward compatibility of tEXt/zTXt chunk processing:
+    Restored the first four members of png_text to the same order as v.1.0.5d.
+    Added members "lang_key" and "itxt_length" to png_text struct.  Set
+    text_length=0 when "text" contains iTXt data.  Use the "compression"
+    member to distinguish among tEXt/zTXt/iTXt types.  Added
+    PNG_ITXT_COMPRESSION_NONE (1) and PNG_ITXT_COMPRESSION_zTXt(2) macros.
+    The "Note" above, about backward incompatibility of libpng-1.0.5e, no
+    longer applies.
+  Fixed png_read|write_iTXt() to read|write parameters in the right order,
+    and to write the iTXt chunk after IDAT if it appears in the end_ptr.
+  Added pnggccrd.c, version of pngvcrd.c Intel assembler for gcc (Greg Roelofs)
+  Reversed the order of trying to write floating-point and fixed-point gAMA.
+version 1.0.5k [December 27, 1999]
+  Added many parentheses, e.g., "if (a && b & c)" becomes "if (a && (b & c))"
+  Added png_handle_as_unknown() function (Glenn)
+  Added png_free_chunk_list() function and chunk_list and num_chunk_list members
+    of png_ptr.
+  Eliminated erroneous warnings about multiple sPLT chunks and sPLT-after-PLTE.
+  Fixed a libpng-1.0.5h bug in pngrutil.c that was issuing erroneous warnings
+    about ignoring incorrect gAMA with sRGB (gAMA was in fact not ignored)
+  Added png_free_tRNS(); png_set_tRNS() now malloc's its own trans array (ESR).
+  Define png_get_int_32 when oFFs chunk is supported as well as when pCAL is.
+  Changed type of proflen from png_int_32 to png_uint_32 in png_get_iCCP().
+version 1.0.5l [January 1, 2000]
+  Added functions png_set_read_user_chunk_fn() and png_get_user_chunk_ptr()
+    for setting a callback function to handle unknown chunks and for
+    retrieving the associated user pointer (Glenn).
+version 1.0.5m [January 7, 2000]
+  Added high-level functions png_read_png(), png_write_png(), png_free_pixels().
+version 1.0.5n [January 9, 2000]
+  Added png_free_PLTE() function, and modified png_set_PLTE() to malloc its
+    own memory for info_ptr->palette.  This makes it safe for the calling
+    application to free its copy of the palette any time after it calls
+    png_set_PLTE().
+version 1.0.5o [January 20, 2000]
+  Cosmetic changes only (removed some trailing blanks and TABs)
+version 1.0.5p [January 31, 2000]
+  Renamed pngdll.mak to makefile.bd32
+  Cosmetic changes in pngtest.c
+version 1.0.5q [February 5, 2000]
+  Relocated the makefile.solaris warning about PATH problems.
+  Fixed pngvcrd.c bug by pushing/popping registers in mmxsupport (Bruce Oberg)
+  Revised makefile.gcmmx
+  Added PNG_SETJMP_SUPPORTED, PNG_SETJMP_NOT_SUPPORTED, and PNG_ABORT() macros
+version 1.0.5r [February 7, 2000]
+  Removed superfluous prototype for png_get_itxt from png.h
+  Fixed a bug in pngrtran.c that improperly expanded the background color.
+  Return *num_text=0 from png_get_text() when appropriate, and fix documentation
+    of png_get_text() in libpng.txt/libpng.3.
+version 1.0.5s [February 18, 2000]
+  Added "png_jmp_env()" macro to pngconf.h, to help people migrate to the
+    new error handler that's planned for the next libpng release, and changed
+    example.c, pngtest.c, and contrib programs to use this macro.
+  Revised some of the DLL-export macros in pngconf.h (Greg Roelofs)
+  Fixed a bug in png_read_png() that caused it to fail to expand some images
+    that it should have expanded.
+  Fixed some mistakes in the unused and undocumented INCH_CONVERSIONS functions
+    in pngget.c
+  Changed the allocation of palette, history, and trans arrays back to
+    the version 1.0.5 method (linking instead of copying) which restores
+    backward compatibility with version 1.0.5.  Added some remarks about
+    that in example.c.  Added "free_me" member to info_ptr and png_ptr
+    and added png_free_data() function.
+  Updated makefile.linux and makefile.gccmmx to make directories conditionally.
+  Made cosmetic changes to pngasmrd.h
+  Added png_set_rows() and png_get_rows(), for use with png_read|write_png().
+  Modified png_read_png() to allocate info_ptr->row_pointers only if it
+    hasn't already been allocated.
+version 1.0.5t [March 4, 2000]
+  Changed png_jmp_env() migration aiding macro to png_jmpbuf().
+  Fixed "interlace" typo (should be "interlaced") in contrib/gregbook/read2-x.c
+  Fixed bug with use of PNG_BEFORE_IHDR bit in png_ptr->mode, introduced when
+    PNG_FLAG_HAVE_CHUNK_HEADER was moved into png_ptr->mode in version 1.0.5b
+  Files in contrib/gregbook were revised to use png_jmpbuf() and to select
+    a 24-bit visual if one is available, and to allow abbreviated options.
+  Files in contrib/pngminus were revised to use the png_jmpbuf() macro.
+  Removed spaces in makefile.linux and makefile.gcmmx, introduced in 1.0.5s
+version 1.0.5u [March 5, 2000]
+  Simplified the code that detects old png.h in png.c and pngtest.c
+  Renamed png_spalette (_p, _pp) to png_sPLT_t (_tp, _tpp)
+  Increased precision of rgb_to_gray calculations from 8 to 15 bits and
+    added png_set_rgb_to_gray_fixed() function.
+  Added makefile.bc32 (32-bit Borland C++, C mode)
+version 1.0.5v [March 11, 2000]
+  Added some parentheses to the png_jmpbuf macro definition.
+  Updated references to the zlib home page, which has moved to freesoftware.com.
+  Corrected bugs in documentation regarding png_read_row() and png_write_row().
+  Updated documentation of png_rgb_to_gray calculations in libpng.3/libpng.txt.
+  Renamed makefile.borland,turboc3 back to makefile.bor,tc3 as in version 1.0.3,
+    revised borland makefiles; added makefile.ibmvac3 and makefile.gcc (Cosmin)
+version 1.0.6 [March 20, 2000]
+  Minor revisions of makefile.bor, libpng.txt, and gregbook/rpng2-win.c
+  Added makefile.sggcc (SGI IRIX with gcc)
+version 1.0.6d [April 7, 2000]
+  Changed sprintf() to strcpy() in png_write_sCAL_s() to work without STDIO
+  Added data_length parameter to png_decompress_chunk() function
+  Revised documentation to remove reference to abandoned png_free_chnk functions
+  Fixed an error in png_rgb_to_gray_fixed()
+  Revised example.c, usage of png_destroy_write_struct().
+  Renamed makefile.ibmvac3 to makefile.ibmc, added libpng.icc IBM project file
+  Added a check for info_ptr->free_me&PNG_FREE_TEXT when free'ing text in png.c
+  Simplify png_sig_bytes() function to remove use of non-ISO-C strdup().
+
+Send comments/corrections/commendations to
+png-implement@ccrc.wustl.edu or to randeg@alum.rpi.edu
+
+Glenn R-P

INSTALL

@@ -1,5 +1,5 @@
 
-Installing libpng version 1.0.4c - October 1, 1999
+Installing libpng version 1.0.6d - April 7, 2000
 
 Before installing libpng, you must first install zlib.  zlib
 can usually be found wherever you got libpng.  zlib can be
@@ -10,7 +10,7 @@ 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-1.0.4c" or "lpng103" and "zlib-1.1.3"
+might be called "libpng-1.0.6d" or "lpng106" and "zlib-1.1.3"
 or "zlib113") so that you have directories called "zlib" and "libpng".
 
 Your directory structure should look like this:
@@ -21,6 +21,10 @@ Your directory structure should look like this:
           README
           *.h
           *.c
+          contrib
+             gregbook
+             pngminus
+             pngsuite
           scripts
              makefile.*
           pngtest.png
@@ -32,52 +36,62 @@ Your directory structure should look like this:
           contrib
           etc.
 
-First enter the zlib directory and follow the instructions
-in zlib/README.  Then come back here and choose the
-appropriate makefile.sys in the scripts directory.
+If the line endings in the files look funny, you may wish to get the other
+distribution of libpng.  It is available in both tar.gz (UNIX style line
+endings) and zip (DOS style line endings) formats.
+
+First enter the zlib directory and follow the instructions in zlib/README.
+Then come back here and choose the appropriate makefile.sys in the scripts
+directory.  
 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 (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.2.1.0.4c)
- makefile.linux   =>  Linux/ELF makefile (gcc, creates libpng.so.2.1.0.4c)
- 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.vcawin32 => makefile for Microsoft Visual C++ 5.0 and later (uses
-                      assembler code)
- makefile.vcwin32 =>  makefile for Microsoft Visual C++ 4.0 and later (does not
-                      use assembler code)
- 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
+ makefile.std      =>  Generic UNIX makefile (cc, creates static libpng.a)
+ makefile.linux    =>  Linux/ELF makefile (gcc, creates libpng.so.2.1.0.6d)
+ makefile.gcmmx    =>  Linux/ELF makefile (gcc, creates libpng.so.2.1.0.6d,
+                       uses assembler code tuned for Intel MMX platform)
+ makefile.gcc      =>  Generic makefile (gcc, creates static libpng.a)
+ makefile.knr      =>  Archaic UNIX Makefile that converts files with
+                       ansi2knr (Requires ansi2knr.c from
+                       ftp://ftp.cs.wisc.edu/ghost)
+ makefile.dec      =>  DEC Alpha UNIX makefile
+ makefile.hpux     =>  HPUX (10.20 and 11.00) makefile
+ makefile.ibmc     =>  IBM C/C++ version 3.x for Win32 and OS/2 (static)
+ libpng.icc        =>  Project file for IBM VisualAge/C++ version 4.0 or later
+ makefile.sgi      =>  Silicon Graphics IRIX makefile (cc, creates static lib)
+ makefile.sggcc    =>  Silicon Graphics (gcc, creates libpng.so.2.1.0.6d)
+ makefile.sunos    =>  Sun makefile
+ makefile.solaris  =>  Solaris 2.X makefile (gcc, creates libpng.so.2.1.0.6d)
+ makefile.sco      =>  For SCO OSr5  ELF and Unixware 7 with Native cc
+ makefile.mips     =>  MIPS makefile
+ makefile.acorn    =>  Acorn makefile
+ makefile.amiga    =>  Amiga makefile
+ smakefile.ppc     =>  AMIGA smakefile for SAS C V6.58/7.00 PPC compiler
+                       (Requires SCOPTIONS, copied from scripts/SCOPTIONS.ppc)
+ makefile.atari    =>  Atari makefile
+ makefile.beos     =>  BEOS makefile for X86
+ makefile.bor      =>  Borland makefile (uses bcc)
+ makefile.bc32     =>  32-bit Borland C++ (all modules compiled in C mode)
+ makefile.bd32     =>  To make a png32bd.dll with Borland C++ 4.5
+ makefile.tc3      =>  Turbo C 3.0 makefile
+ makefile.dj2      =>  DJGPP 2 makefile
+ makefile.msc      =>  Microsoft C makefile
+ makefile.vcawin32 =>  makefile for Microsoft Visual C++ 5.0 and later (uses
+                       assembler code tuned for Intel MMX platform)
+ makefile.vcwin32  =>  makefile for Microsoft Visual C++ 4.0 and later (does
+                       not use assembler code)
+ makefile.os2      =>  OS/2 Makefile (gcc and emx, requires pngos2.def)
+ pngos2.def        =>  OS/2 module definition file used by makefile.os2
+ makefile.watcom   =>  Watcom 10a+ Makefile, 32-bit flat memory model
+ makevms.com       =>  VMS build script
+ descrip.mms       =>  VMS makefile for MMS or MMK
+ 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
 
-   MSDOS example: copy scripts\makefile.msd makefile
+   MSDOS example: copy scripts\makefile.msc makefile
    UNIX example:    cp scripts/makefile.std makefile
 
 Read the makefile to see if you need to change any source or
@@ -89,11 +103,16 @@ changes.
 Then just run "make test" which will create the libpng library in
 this directory and run a quick test that reads the "pngtest.png"
 file and writes a "pngout.png" file that should be identical to it.
+Look for "9782 zero samples" in the output of the test.  For more
+confidence, you can run another test by typing "pngtest pngnow.png"
+and looking for "289 zero samples" in the output.  Also, you can
+run "pngtest -m *.png" in the "contrib/pngsuite" directory and compare
+your output with the result shown in contrib/pngsuite/README.
 
 Most of the makefiles will allow you to run "make install" to
 put the library in its final resting place (if you want to
 do that, run "make install" in the zlib directory first if necessary).
 
 Further information can be found in the README and libpng.txt
-files, in the individual makefiles, and in png.h, and the manual
-pages libpng.3 and png.5.
+files, in the individual makefiles, in png.h, and the manual pages
+libpng.3 and png.5.

KNOWNBUG

@@ -1,8 +1,47 @@
 
-Known bugs and suggested enhancements in libpng-1.0.4
+Known bugs and suggested enhancements in libpng-1.0.6
 
+1. April 1, 2000 -- BUG
 
-1. March 15, 1998 -- OPTIMIZATION -- Kevin Bracey
+   Under some circumstances old applications that make direct access to
+   the info_ptr->text and its members might free the same memory that
+   is also free'ed by libpng during the png_destroy_struct process.
+
+   Fixed in libpng-1.0.6-patch-03 and libpng-1.0.6d.  The PNG_FREE_TEXT flag
+   bit in info_ptr->free_me is now checked to make sure libpng is responsible
+   for freeing the memory.
+
+2. April 1, 2000 -- BUG
+
+   The non-ISO-C "strdup()" function is used in png.c
+
+   STATUS: The function has been simplified and no longer uses strdup()
+   in libpng-1.0.6-patch-03 and libpng-1.0.6d.
+
+3. March 24, 2000 -- BUG
+
+   The png_set_rgb_to_gray_fixed() function is setting incorrect weighting
+   factors.
+
+   STATUS: Fixed in libpng-1.0.6-patch-02 and libpng-1.0.6d.
+
+4. March 22, 2000 -- BUG
+
+   There are some printf() and fprintf() statements active in pngwutil.c
+   when PNG_NO_STDIO and PNG_sCAL_SUPPORTED are both defined.
+
+   STATUS: Fixed in libpng-1.0.6-patch-01 and libpng-1.0.6d.  The strcpy()
+   function is used instead.
+
+5. March 22, 2000 -- BUG
+
+   The length of the iCCP chunk data is calculated incorrectly; because
+   it can contain zeroes, strlen() doesn't work.
+
+   STATUS: Fixed in libpng-1.0.6-patch-01 and libpng-1.0.6d by adding a
+   data_length parameter to the png_decompress_chunk() function.
+
+6. March 15, 1998 -- OPTIMIZATION -- Kevin Bracey
 
    Loops need to be optimized everywhere
 
@@ -14,10 +53,10 @@ Known bugs and suggested enhancements in libpng-1.0.4
    Question whether i-- or --i is better.
 
    STATUS: Under investigation, postponed until after
-   libpng-1.0.5.  About 160 loops will be turned around
-   in libpng-1.0.Nn, for testing.
+   libpng-1.1.0.  About 160 loops will be turned around
+   in libpng-1.1.Nn, for testing.
 
-2. July 4, 1998 -- ENHANCEMENT -- Glenn R-P
+7. July 4, 1998 -- ENHANCEMENT -- Glenn R-P
 
    libpng-1.0.5 and earlier transform colors to gamma=1.0 space for
    merging with background, and then back to the image's gamma.  The
@@ -29,12 +68,15 @@ Known bugs and suggested enhancements in libpng-1.0.4
 
    STATUS: under development.
 
-3. September 1999 -- ENHANCEMENT --
+8. September 1999 -- ENHANCEMENT --
 
    It should be possible to use libpng without floating-point aritmetic.
 
    STATUS: Under investigation, implementation postponed until after
-   libpng-1.0.5.  The application interface will change because replacements
+   libpng-1.0.6.  The application interface will change because replacements
    for the png_set_gAMA(), png_set_cHRM(), and corresponding png_get_()
    functions will be needed.
 
+   Much of this was completed in libpng-1.0.6, but gamma compensation
+   is not yet done in fixed-point arithmetic.
+

LICENSE

@@ -4,8 +4,8 @@ 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 1.0.4c, October 1, 1999)
+Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson
+(libpng versions 0.97, January 1998, through 1.0.6d, April 7, 2000)
 
 For the purposes of this copyright and license, "Contributing Authors"
 is defined as the following set of individuals:
@@ -18,6 +18,7 @@ is defined as the following set of individuals:
    Tom Lane
    Dave Martindale
    Glenn Randers-Pehrson
+   Eric S. Raymond
    Greg Roelofs
    Guy Eric Schalnat
    Paul Schmidt
@@ -54,6 +55,17 @@ supporting the PNG file format in commercial products.  If you use this
 source code in a product, acknowledgment is not required but would be
 appreciated.
 
+A "png_get_copyright" function is available, for convenient use in "about"
+boxes and the like:
+
+   printf("%s",png_get_copyright(NULL));
+
+Also, the PNG logo (in PNG format, of course) is supplied in the
+file "pngnow.png".
+
+Libpng is OSI Certified Open Source Software.  OSI Certified Open Source is a
+certification mark of the Open Source Initiative.
+
 Glenn Randers-Pehrson
 randeg@alum.rpi.edu
-October 1, 1999
+April 7, 2000

README

@@ -1,14 +1,19 @@
-README for libpng 1.0.4c - October 1, 1999 (shared library 2.1)
+README for libpng 1.0.6d - April 7, 2000 (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.
 
-This is the first official release of libpng.  Don't let the fact that
-it's the first release fool you.  The libpng library has been in
-extensive use and testing for about two and a half years.  However, it's
-finally gotten to the stage where there haven't been significant
+Libpng comes in two distribution formats.  Get libpng-*.tar.gz if you
+want UNIX-style line endings in the text files, or lpng*.zip if you want
+DOS-style line endings.
+
+Version 0.89 was the first official release of libpng.  Don't let the
+fact that it's the first release fool you.  The libpng library has been in
+extensive use and testing since mid-1995.  By late 1997 it had
+finally gotten to the stage where there hadn't been significant
 changes to the API in some time, and people have a bad feeling about
-libraries with versions < 1.0.
+libraries with versions < 1.0.  Version 1.0.0 was released in
+March 1998.
 
 ****
 Note that some of the changes to the png_info structure render this
@@ -28,8 +33,8 @@ directly, to avoid such problems in the future.
 It is important to note that the APIs do not make current programs
 that access the info struct directly incompatible with the new
 library.  However, it is strongly suggested that new programs use
-the new APIs (as shown in example.c), and older programs be converted
-to the new format, to facilitate upgrades in the future.
+the new APIs (as shown in example.c and pngtest.c), and older programs
+be converted to the new format, to facilitate upgrades in the future.
 ****
 
 Additions since 0.90 include the ability to compile libpng as a
@@ -50,7 +55,8 @@ 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@ccrc.wustl.edu>
-and not on material submitted to Guy.
+and not on material submitted privately to Guy, Andreas, or Glenn.  They will
+forward any good suggestions to the list.
 
 For a detailed description on using libpng, read libpng.txt.  For
 examples of libpng in a program, see example.c and pngtest.c.  For usage
@@ -123,22 +129,26 @@ gladly listen.  Even if your suggestion is not used for version
 
 Files in this distribution:
 
+      ANNOUNCE      =>  Announcement of this version, with recent changes
       CHANGES       =>  Description of changes between libpng versions
+      KNOWNBUG      =>  List of known bugs and deficiencies
+      LICENSE       =>  License to use and redistribute libpng
       README        =>  This file
       TODO          =>  Things not implemented in the current library
-      build.bat     =>  MS-DOS batch file for Borland compiler
-      descrip.mms   =>  VMS project file
+      Y2KINFO       =>  Statement of Y2K compliance
       example.c     =>  Example code for using libpng functions
-      libpng.3      =>  manual page for libpng
+      libpng.3      =>  manual page for libpng (includes libpng.txt)
       libpng.txt    =>  Description of libpng and its functions
       libpngpf.3    =>  manual page for libpng's private functions
       png.5         =>  manual page for the PNG format
       png.c         =>  Basic interface functions common to library
       png.h         =>  Library function and interface declarations
       pngconf.h     =>  System specific library configuration
+      pngasmrd.h    =>  Header file for assembler-coded functions
       pngerror.c    =>  Error/warning message I/O functions
       pngget.c      =>  Functions for retrieving info from struct
       pngmem.c      =>  Memory handling functions
+      pngnow.png    =>  PNG logo
       pngpread.c    =>  Progressive reading functions
       pngread.c     =>  Read data/helper high-level functions
       pngrio.c      =>  Lowest-level data read I/O functions
@@ -152,20 +162,33 @@ Files in this distribution:
       pngwrite.c    =>  High-level write functions
       pngwtran.c    =>  Write data transformations
       pngwutil.c    =>  Write utility functions
+      contrib       =>  Contributions
+       gregbook         =>  source code for PNG reading and writing, from
+                            Greg Roelofs' "PNG: The Definitive Guide",
+                            O'Reilly, 1999
+       pngminus     =>  Simple pnm2png and png2pnm programs
+       pngsuite     =>  Test images
       scripts       =>  Directory containing scripts for building libpng:
        descrip.mms      =>  VMS makefile for MMS or MMK
-       makefile.std     =>  Generic UNIX makefile
+       makefile.std     =>  Generic UNIX makefile (cc, creates static libpng.a)
+       makefile.linux   =>  Linux/ELF makefile
+                            (gcc, creates libpng.so.2.1.0.6d)
+       makefile.gcmmx   =>  Linux/ELF makefile (gcc, creates
+                            libpng.so.2.1.0.6d, uses assembler code
+                            tuned for Intel MMX platform)
+       makefile.gcc     =>  Generic makefile (gcc, creates static libpng.a)
        makefile.knr     =>  Archaic UNIX Makefile that converts files with
                             ansi2knr (Requires ansi2knr.c from
                             ftp://ftp.cs.wisc.edu/ghost)
        makefile.dec     =>  DEC Alpha UNIX makefile
        makefile.hpux    =>  HPUX (10.20 and 11.00) makefile
-       makefile.sgi     =>  Silicon Graphics IRIX makefile
+       makefile.ibmc    =>  IBM C/C++ version 3.x for Win32 and OS/2 (static)
+       libpng.icc       =>  Project file, IBM VisualAge/C++ 4.0 or later
+       makefile.sgi     =>  Silicon Graphics IRIX (cc, creates static lib)
+       makefile.sggcc   =>  Silicon Graphics (gcc, creates libpng.so.2.1.0.6d)
        makefile.sunos   =>  Sun makefile
        makefile.solaris =>  Solaris 2.X makefile
-                            (gcc, creates libpng.so.2.1.0.4c)
-       makefile.linux   =>  Linux/ELF makefile
-                            (gcc, creates libpng.so.2.1.0.4c)
+                            (gcc, creates libpng.so.2.1.0.6d)
        makefile.sco     =>  For SCO OSr5  ELF and Unixware 7 with Native cc
        makefile.mips    =>  MIPS makefile
        makefile.acorn   =>  Acorn makefile
@@ -175,20 +198,21 @@ Files in this distribution:
                             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.bor     =>  Borland makefile (uses bcc)
+       makefile.bc32    =>  32-bit Borland C++ (all modules compiled in C mode)
+       makefile.bd32    =>  To make a png32bd.dll with Borland C++ 4.5
+       makefile.tc3     =>  Turbo C 3.0 makefile
        makefile.dj2     =>  DJGPP 2 makefile
        makefile.msc     =>  Microsoft C makefile
        makefile.vcawin32 => makefile for Microsoft Visual C++ 5.0 and
-                            later (uses assembler code)
+                            later (uses assembler code tuned for Intel MMX
+                            platform)
        makefile.vcwin32 =>  makefile for Microsoft Visual C++ 4.0 and
                             later (does not use assembler code)
-       makefile.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
 

TODO

@@ -1,14 +1,11 @@
 TODO - list of things to do for libpng:
 
 Final bug fixes.
-Fix problem with C++ and EXTERN "C".
+Finish work on the no-floating-point version (including gamma compensation)
 Better C++ wrapper/full C++ implementation?
-Keep up with public chunks.
-sPLT chunk handling.
+Fix problem with C++ and EXTERN "C".
 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.
@@ -17,8 +14,6 @@ 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

@@ -1,29 +1,29 @@
    Y2K compliance in libpng:
    =========================
-      
-      October 1, 1999
-      
+
+      April 7, 2000
+
       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 1.0.4c are Y2K compliant.  It is my belief that earlier
+      upward through 1.0.6d 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 
+          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
@@ -31,8 +31,8 @@
           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 
+
+      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
@@ -42,14 +42,14 @@
       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

configure

@@ -0,0 +1,6 @@
+echo "
+  There is no \"configure\" script for Libpng-1.0.6d.  Instead, please
+  copy the appropriate makefile for your system from the \"scripts\"
+  directory.  Read the INSTALL file for more details.
+"
+

contrib/gregbook/LICENSE

@@ -0,0 +1,26 @@
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2000 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+  ---------------------------------------------------------------------------

contrib/gregbook/Makefile.unx

@@ -0,0 +1,104 @@
+# Sample makefile for rpng-x / rpng2-x / wpng using gcc and make.
+# Greg Roelofs
+# Last modified:  28 February 2000
+#
+#	The programs built by this makefile are described in the book,
+#	"PNG:  The Definitive Guide," by Greg Roelofs (O'Reilly and
+#	Associates, 1999).  Go buy a copy, eh?  Buy some for friends
+#	and family, too.  (Not that this is a blatant plug or anything.)
+#
+# Invoke this makefile from a shell prompt in the usual way; for example:
+#
+#	make -f Makefile.unx
+#
+# This makefile assumes libpng and zlib have already been built or downloaded
+# and are both installed in /usr/local/{include,lib} (as indicated by the
+# PNG* and Z* macros below).  Edit as appropriate--choose only ONE each of
+# the PNGINC, PNGLIB, ZINC and ZLIB lines.
+#
+# This makefile builds statically linked executables (against libpng and zlib,
+# that is), but that can be changed by uncommenting the appropriate PNGLIB and
+# ZLIB lines.
+
+
+# macros --------------------------------------------------------------------
+
+PNGINC = -I/usr/local/include
+#PNGLIB = -L/usr/local/lib -lpng	# dynamically linked against libpng
+PNGLIB = /usr/local/lib/libpng.a	# statically linked against libpng
+# or:
+#PNGINC = -I../..
+#PNGLIB = -L../.. -lpng
+#PNGLIB = ../../libpng.a
+
+ZINC = -I/usr/local/include
+#ZLIB = -L/usr/local/lib -lz		# dynamically linked against zlib
+ZLIB = /usr/local/lib/libz.a		# statically linked against zlib
+#ZINC = -I../zlib
+#ZLIB = -L../zlib -lz
+#ZLIB = ../../../zlib/libz.a
+
+#XINC = -I/usr/include/X11		# old-style, stock X distributions
+#XLIB = -L/usr/lib/X11 -lX11
+#XINC = -I/usr/openwin/include/X11	# Sun workstations (OpenWindows)
+#XLIB = -L/usr/openwin/lib -lX11
+XINC = -I/usr/X11R6/include		# new X distributions (XFree86, etc.)
+XLIB = -L/usr/X11R6/lib -lX11
+
+INCS = $(PNGINC) $(ZINC) $(XINC)
+RLIBS = $(PNGLIB) $(ZLIB) $(XLIB) -lm
+WLIBS = $(PNGLIB) $(ZLIB)
+
+CC = gcc
+LD = gcc
+RM = rm -f
+CFLAGS = -O -Wall $(INCS)
+# [note that -Wall is a gcc-specific compilation flag ("most warnings on")]
+# [-ansi, -pedantic and -W can also be used]
+LDFLAGS =
+O = .o
+E =
+
+RPNG  = rpng-x
+RPNG2 = rpng2-x
+WPNG  = wpng
+
+ROBJS  = $(RPNG)$(O) readpng$(O)
+ROBJS2 = $(RPNG2)$(O) readpng2$(O)
+WOBJS  = $(WPNG)$(O) writepng$(O)
+
+EXES = $(RPNG)$(E) $(RPNG2)$(E) $(WPNG)$(E)
+
+
+# implicit make rules -------------------------------------------------------
+
+.c$(O):
+	$(CC) -c $(CFLAGS) $<
+
+
+# dependencies --------------------------------------------------------------
+
+all:  $(EXES)
+
+$(RPNG)$(E): $(ROBJS)
+	$(LD) $(LDFLAGS) -o $@ $(ROBJS) $(RLIBS)
+
+$(RPNG2)$(E): $(ROBJS2)
+	$(LD) $(LDFLAGS) -o $@ $(ROBJS2) $(RLIBS)
+
+$(WPNG)$(E): $(WOBJS)
+	$(LD) $(LDFLAGS) -o $@ $(WOBJS) $(WLIBS)
+
+$(RPNG)$(O):	$(RPNG).c readpng.h
+$(RPNG2)$(O):	$(RPNG2).c readpng2.h
+$(WPNG)$(O):	$(WPNG).c writepng.h
+
+readpng$(O):	readpng.c readpng.h
+readpng2$(O):	readpng2.c readpng2.h
+writepng$(O):	writepng.c writepng.h
+
+
+# maintenance ---------------------------------------------------------------
+
+clean:
+	$(RM) $(EXES) $(ROBJS) $(ROBJS2) $(WOBJS)

contrib/gregbook/Makefile.w32

@@ -0,0 +1,112 @@
+# Sample makefile for rpng-win / rpng2-win / wpng using MSVC and NMAKE.
+# Greg Roelofs
+# Last modified:  16 February 1999
+#
+#	The programs built by this makefile are described in the book,
+#	"PNG:  The Definitive Guide," by Greg Roelofs (O'Reilly and
+#	Associates, 1999).  Go buy a copy, eh?  Buy some for friends
+#	and family, too.  (Not that this is a blatant plug or anything.)
+#
+# Invoke this makefile from a DOS prompt window via:
+#
+#	%devstudio%\vc\bin\vcvars32.bat
+#	nmake -nologo -f Makefile.w32
+#
+# where %devstudio% is the installation directory for MSVC / DevStudio.  If
+# you get "environment out of space" errors, create a desktop shortcut with
+# "c:\windows\command.com /e:4096" as the program command line and set the
+# working directory to this directory.  Then double-click to open the new
+# DOS-prompt window with a bigger environment and retry the commands above.
+# 
+# This makefile assumes libpng and zlib have already been built or downloaded
+# and are in subdirectories at the same level as the current subdirectory
+# (as indicated by the PNGPATH and ZPATH macros below).  Edit as appropriate.
+#
+# Note that the names of the dynamic and static libpng and zlib libraries
+# used below may change in later releases of the libraries.  This makefile
+# builds statically linked executables, but that can be changed by uncom-
+# menting the appropriate PNGLIB and ZLIB lines.
+
+!include <ntwin32.mak>
+
+
+# macros --------------------------------------------------------------------
+
+PNGPATH = ../..
+PNGINC = -I$(PNGPATH)
+#PNGLIB = $(PNGPATH)/pngdll.lib
+PNGLIB = $(PNGPATH)/libpng.lib
+
+ZPATH = ../../../zlib
+ZINC = -I$(ZPATH)
+#ZLIB = $(ZPATH)/zlibdll.lib
+ZLIB = $(ZPATH)/zlibstat.lib
+
+WINLIBS = -defaultlib:user32.lib gdi32.lib
+# ["real" apps may also need comctl32.lib, comdlg32.lib, winmm.lib, etc.]
+
+INCS = $(PNGINC) $(ZINC)
+RLIBS = $(PNGLIB) $(ZLIB) $(WINLIBS)
+WLIBS = $(PNGLIB) $(ZLIB)
+
+CC = cl
+LD = link
+RM = del
+CFLAGS = -nologo -O -W3 $(INCS) $(cvars)
+# [note that -Wall is an MSVC-specific compilation flag ("all warnings on")]
+# [see %devstudio%\vc\include\win32.mak for cvars macro definition]
+O = .obj
+E = .exe
+
+RLDFLAGS = -nologo -subsystem:windows
+WLDFLAGS = -nologo
+
+RPNG  = rpng-win
+RPNG2 = rpng2-win
+WPNG  = wpng
+
+ROBJS  = $(RPNG)$(O) readpng$(O)
+ROBJS2 = $(RPNG2)$(O) readpng2$(O)
+WOBJS  = $(WPNG)$(O) writepng$(O)
+
+EXES = $(RPNG)$(E) $(RPNG2)$(E) $(WPNG)$(E)
+
+
+# implicit make rules -------------------------------------------------------
+
+.c$(O):
+	$(CC) -c $(CFLAGS) $<
+
+
+# dependencies --------------------------------------------------------------
+
+all:  $(EXES)
+
+$(RPNG)$(E): $(ROBJS)
+	$(LD) $(RLDFLAGS) -out:$@ $(ROBJS) $(RLIBS)
+
+$(RPNG2)$(E): $(ROBJS2)
+	$(LD) $(RLDFLAGS) -out:$@ $(ROBJS2) $(RLIBS)
+
+$(WPNG)$(E): $(WOBJS)
+	$(LD) $(WLDFLAGS) -out:$@ $(WOBJS) $(WLIBS)
+
+$(RPNG)$(O):	$(RPNG).c readpng.h
+$(RPNG2)$(O):	$(RPNG2).c readpng2.h
+$(WPNG)$(O):	$(WPNG).c writepng.h
+
+readpng$(O):	readpng.c readpng.h
+readpng2$(O):	readpng2.c readpng2.h
+writepng$(O):	writepng.c writepng.h
+
+
+# maintenance ---------------------------------------------------------------
+
+clean:
+#	ideally we could just do this:
+#	$(RM) $(EXES) $(ROBJS) $(ROBJS2) $(WOBJS)
+#	...but the Windows "DEL" command is none too bright, so:
+	$(RM) r*$(E)
+	$(RM) w*$(E)
+	$(RM) r*$(O)
+	$(RM) w*$(O)

contrib/gregbook/README

@@ -0,0 +1,183 @@
+                     ===========================
+                      PNG: The Definitive Guide
+                     ===========================
+
+                             Source Code
+
+Chapters 13, 14 and 15 of "PNG: The Definitive Guide" discuss three free,
+cross-platform demo programs that show how to use the libpng reference
+library:  rpng, rpng2 and wpng.  rpng and rpng2 are viewers; the first is
+a very simple example that that shows how a standard file-viewer might use
+libpng, while the second is designed to process streaming data and shows
+how a web browser might be written.  wpng is a simple command-line program
+that reads binary PGM and PPM files (the ``raw'' grayscale and RGB subsets
+of PBMPLUS/NetPBM) and converts them to PNG.
+
+The source code for all three demo programs currently compiles under
+Unix, OpenVMS, and 32-bit Windows.  (Special thanks to Martin Zinser,
+zinser@decus.de, for making the necessary changes for OpenVMS and for
+providing an appropriate build script.)  Build instructions can be
+found below.
+
+Files:
+
+   README             this file
+   README.w32         additional Windows-specific information
+   LICENSE            terms of distribution and reuse (BSD-like)
+
+   Makefile.unx       Unix makefile
+   Makefile.w32       Windows (MSVC) makefile
+   makevms.com        OpenVMS build script
+
+   rpng-win.c         Windows front end for the basic viewer
+   rpng-x.c           X Window System (Unix, OpenVMS) front end
+   readpng.c          generic back end for the basic viewer
+   readpng.h          header file for the basic viewer
+
+   rpng2-win.c        Windows front end for the progressive viewer
+   rpng2-x.c          X front end for the progressive viewer
+   readpng2.c         generic back end for the progressive viewer
+   readpng2.h         header file for the progressive viewer
+
+   wpng.c             generic (text) front end for the converter
+   writepng.c         generic back end for the converter
+   writepng.h         header file for the converter
+
+   toucan.png         transparent PNG for testing (by Stefan Schneider)
+
+Note that the programs are designed to be functional, but their primary
+purpose is to demonstrate how to use libpng to add PNG support to other
+programs.  As such, their user interfaces are crude and definitely not
+intended for everyday use.
+
+Please see http://www.cdrom.com/pub/png/pngbook.html for further infor-
+mation and links to the latest version of the source code, and Chapters
+13-15 of the book for detailed discussion of the three programs.
+
+Greg Roelofs
+19 March 2000
+
+
+BUILD INSTRUCTIONS
+
+ - Prerequisites:
+
+      - zlib		ftp://ftp.cdrom.com/pub/infozip/zlib/zlib.html
+      - libpng		http://www.cdrom.com/pub/png/pngcode.html
+      - pngbook		http://www.cdrom.com/pub/png/book/sources.html
+
+     The pngbook demo programs are explicitly designed to demonstrate proper
+     coding techniques for using the libpng reference library.  As a result,
+     you need to download and build both zlib (on which libpng depends) and
+     libpng.  A common build setup is to place the zlib, libpng and pngbook
+     subdirectory trees ("folders") in the same parent directory.  Then the
+     libpng build can refer to files in ../zlib (or ..\zlib or [-.zlib]),
+     and similarly for the pngbook build.
+
+     Note that all three packages are designed to be built from a command
+     line by default; those who wish to use a graphical or other integrated
+     development environments are on their own.
+
+
+ - Unix:
+
+     Unpack the latest pngbook sources (which should correspond to this
+     README file) into a directory and change into that directory.
+
+     Copy Makefile.unx to Makefile and edit the PNG* and Z* variables
+     appropriately (possibly also the X* variables if necessary).
+
+     make
+
+     There is no "install" target, so copy the three executables somewhere
+     in your path or run them from the current directory.  All three will
+     print a basic usage screen when run without any command-line arguments;
+     see the book for more details.
+
+
+ - Windows:
+
+     Unpack the latest pngbook sources (which should correspond to this
+     README file) into a folder, open a "DOS shell" or "command prompt"
+     or equivalent command-line window, and cd into the folder where you
+     unpacked the source code.
+
+     For MSVC, set up the necessary environment variables by invoking
+ 
+        %devstudio%\vc\bin\vcvars32.bat
+
+     where where %devstudio% is the installation directory for MSVC /
+     DevStudio.  If you get "environment out of space" errors under 95/98,
+     create a desktop shortcut with "c:\windows\command.com /e:4096" as
+     the program command line and set the working directory to the pngbook
+     directory.  Then double-click to open the new DOS-prompt window with
+     a bigger environment and retry the commands above.
+
+     Copy Makefile.w32 to Makefile and edit the PNGPATH and ZPATH variables
+     appropriately (possibly also the "INC" and "LIB" variables if needed).
+     Note that the names of the dynamic and static libpng and zlib libraries
+     used in the makefile may change in later releases of the libraries.
+     Also note that, as of libpng version 1.0.5, MSVC DLL builds do not work.
+     This makefile therefore builds statically linked executables, but if
+     the DLL problems ever get fixed, uncommenting the appropriate PNGLIB
+     and ZLIB lines will build dynamically linked executables instead.
+
+     Do the build by typing
+
+        nmake
+
+     The result should be three executables:  rpng-win.exe, rpng2-win.exe,
+     and wpng.exe.  Copy them somewhere in your PATH or run them from the
+     current folder.  Unlike the Unix versions, the two windowed programs
+     (rpng and rpng2) do not display a usage screen when invoked without
+     command-line arguments; see README.w32 for brief help or the book for
+     details.  Note that the programs use the Unix-style "-" character to
+     specify options, instead of the more common DOS/Windows "/" character.
+
+
+ - OpenVMS:
+
+     Unpack the pngbook sources into a subdirectory and change into that
+     subdirectory.
+
+     Edit makevms.com appropriately, specifically the zpath and pngpath
+     variables.
+
+     @makevms
+
+     To run the programs, they probably first need to be set up as "foreign
+     symbols," with "disk" and "dir" set appropriately:
+
+     $ rpng == "$disk:[dir]rpng-x.exe"
+     $ rpng2 == "$disk:[dir]rpng2-x.exe"
+     $ wpng == "$disk:[dir]wpng.exe"
+
+     All three will print a basic usage screen when run without any command-
+     line arguments; see the book for more details.  Note that the options
+     style is Unix-like, i.e., preceded by "-" rather than "/".
+
+
+RUNNING THE PROGRAMS:  (VERY) BRIEF INTRO
+
+     rpng is a simple PNG viewer that can display transparent PNGs with a
+     specified background color; for example,
+
+	rpng -bgcolor #ff0000 toucan.png
+
+     would display the image with a red background.  rpng2 is a progressive
+     viewer that simulates a web browser in some respects; it can display
+     images against either a background color or a dynamically generated
+     background image.  For example:
+
+	rpng2 -bgpat 16 toucan.png
+
+     wpng is a purely command-line image converter from binary PBMPLUS/NetPBM
+     format (.pgm or .ppm) to PNG; for example,
+
+	wpng -time < toucan.ppm > toucan.png
+
+     would convert the specified PPM file (using redirection) to PNG, auto-
+     matically setting the PNG modification-time chunk.
+
+     All options can be abbreviated to the shortest unique value; for example,
+     "-bgc" for -bgcolor (versus "-bgp" for -bgpat), or "-g" for -gamma.

contrib/gregbook/README.w32

@@ -0,0 +1,53 @@
+See the main README file for basic instructions on compiling and running
+the programs.  See http://www.cdrom.com/pub/png/pngbook.html for further
+information and links to the source code, and Chapters 13-15 of the book
+for detailed discussion of the three programs.
+
+Since the two viewers, rpng and rpng2, are both designed to write infor-
+mation to the console (i.e., a DOS-window command line) while displaying
+the image in a graphical window--and since I haven't yet figured out how
+to do that under Windows--here are the usage screens for the two programs:
+
+
+rpng-win 1.02 of 19 March 2000:  Simple PNG Viewer for Windows
+   Compiled with libpng 1.0.5; using libpng 1.0.5.
+   Compiled with zlib 1.1.3; using zlib 1.1.3.
+
+Usage:  rpng-win [-gamma exp] [-bgcolor bg] file.png
+    exp 	transfer-function exponent (``gamma'') of the display
+		  system in floating-point format (e.g., ``2.2''); equal
+		  to the product of the lookup-table exponent (varies)
+		  and the CRT exponent (usually 2.2); must be positive
+    bg  	desired background color in 7-character hex RGB format
+		  (e.g., ``#ff7f00'' for orange:  same as HTML colors);
+		  used with transparent images
+
+Press Q, Esc or mouse button 1 after image is displayed to quit.
+
+
+rpng2-win 1.04 of 19 March 2000:  Progressive PNG Viewer for Windows
+   Compiled with libpng 1.0.5; using libpng 1.0.5.
+   Compiled with zlib 1.1.3; using zlib 1.1.3.
+
+Usage:  rpng2-win [-gamma exp] [-bgcolor bg | -bgpat pat] [-timing] file.png
+
+    exp 	transfer-function exponent (``gamma'') of the display
+		  system in floating-point format (e.g., ``2.2''); equal
+		  to the product of the lookup-table exponent (varies)
+		  and the CRT exponent (usually 2.2); must be positive
+    bg  	desired background color in 7-character hex RGB format
+		  (e.g., ``#ff7f00'' for orange:  same as HTML colors);
+		  used with transparent images; overrides -bgpat
+    pat 	desired background pattern number (1-16); used with
+		  transparent images; overrides -bgcolor
+    -timing	enables delay for every block read, to simulate modem
+		  download of image (~36 Kbps)
+
+Press Q, Esc or mouse button 1 after image is displayed to quit.
+
+
+The usage screen for the third (non-windowed) program, wpng, can be seen
+simply by invoking it without any parameters (``wpng'').
+
+Greg Roelofs
+19 March 2000

contrib/gregbook/makevms.com

@@ -0,0 +1,118 @@
+$!------------------------------------------------------------------------------
+$! make "PNG: The Definitive Guide" demo programs (for X) under OpenVMS
+$!
+$! Script created by Martin Zinser for libpng; modified by Greg Roelofs
+$! for standalone pngbook source distribution.
+$!
+$!
+$!    Set locations where zlib and libpng sources live.
+$!
+$ zpath = "[-.zlib]"
+$ pngpath = "[-.libpng]"
+$!
+$! USE THESE INSTEAD if building from libpng's [.contrib.gregbook] directory:
+$! zpath = "[---.zlib]"
+$! pngpath = "[--]"
+$!
+$!    Look for the compiler used.
+$!
+$ ccopt="/include=(''zpath',''pngpath')"
+$ if f$getsyi("HW_MODEL").ge.1024
+$ then
+$  ccopt = "/prefix=all"+ccopt
+$  comp  = "__decc__=1"
+$  if f$trnlnm("SYS").eqs."" then define sys sys$library:
+$ else
+$  if f$search("SYS$SYSTEM:DECC$COMPILER.EXE").eqs.""
+$   then
+$    if f$trnlnm("SYS").eqs."" then define sys sys$library:
+$    if f$search("SYS$SYSTEM:VAXC.EXE").eqs.""
+$     then
+$      comp  = "__gcc__=1"
+$      CC :== GCC
+$     else
+$      comp = "__vaxc__=1"
+$     endif
+$   else
+$    if f$trnlnm("SYS").eqs."" then define sys decc$library_include:
+$    ccopt = "/decc/prefix=all"+ccopt
+$    comp  = "__decc__=1"
+$  endif
+$ endif
+$ open/write lopt lib.opt
+$ write lopt "''pngpath'libpng.olb/lib"
+$ write lopt "''zpath'libz.olb/lib"
+$ close lopt
+$ open/write xopt x11.opt
+$ write xopt "sys$library:decw$xlibshr.exe/share"
+$ close xopt
+$!
+$!    Build 'em.
+$!
+$ write sys$output "Compiling PNG book programs ..."
+$   CALL MAKE readpng.OBJ "cc ''CCOPT' readpng" -
+	readpng.c readpng.h
+$   CALL MAKE readpng2.OBJ "cc ''CCOPT' readpng2" -
+	readpng2.c readpng2.h
+$   CALL MAKE writepng.OBJ "cc ''CCOPT' writepng" -
+	writepng.c writepng.h
+$   write sys$output "Building rpng-x..."
+$   CALL MAKE rpng-x.OBJ "cc ''CCOPT' rpng-x" -
+	rpng-x.c readpng.h
+$   call make rpng-x.exe -
+	"LINK rpng-x,readpng,lib.opt/opt,x11.opt/opt" -
+	rpng-x.obj readpng.obj
+$   write sys$output "Building rpng2-x..."
+$   CALL MAKE rpng2-x.OBJ "cc ''CCOPT' rpng2-x" -
+	rpng2-x.c readpng2.h
+$   call make rpng2-x.exe -
+	"LINK rpng2-x,readpng2,lib.opt/opt,x11.opt/opt" -
+	rpng2-x.obj readpng2.obj
+$   write sys$output "Building wpng..."
+$   CALL MAKE wpng.OBJ "cc ''CCOPT' wpng" -
+	wpng.c writepng.h
+$   call make wpng.exe -
+	"LINK wpng,writepng,lib.opt/opt" -
+	wpng.obj writepng.obj
+$ exit
+$!
+$!
+$MAKE: SUBROUTINE   !SUBROUTINE TO CHECK DEPENDENCIES
+$ V = 'F$Verify(0)
+$! P1 = What we are trying to make
+$! P2 = Command to make it
+$! P3 - P8  What it depends on
+$
+$ If F$Search(P1) .Eqs. "" Then Goto Makeit
+$ Time = F$CvTime(F$File(P1,"RDT"))
+$arg=3
+$Loop:
+$       Argument = P'arg
+$       If Argument .Eqs. "" Then Goto Exit
+$       El=0
+$Loop2:
+$       File = F$Element(El," ",Argument)
+$       If File .Eqs. " " Then Goto Endl
+$       AFile = ""
+$Loop3:
+$       OFile = AFile
+$       AFile = F$Search(File)
+$       If AFile .Eqs. "" .Or. AFile .Eqs. OFile Then Goto NextEl
+$       If F$CvTime(F$File(AFile,"RDT")) .Ges. Time Then Goto Makeit
+$       Goto Loop3
+$NextEL:
+$       El = El + 1
+$       Goto Loop2
+$EndL:
+$ arg=arg+1
+$ If arg .Le. 8 Then Goto Loop
+$ Goto Exit
+$
+$Makeit:
+$ VV=F$VERIFY(0)
+$ write sys$output P2
+$ 'P2
+$ VV='F$Verify(VV)
+$Exit:
+$ If V Then Set Verify
+$ENDSUBROUTINE

contrib/gregbook/readpng.c

@@ -0,0 +1,280 @@
+/*---------------------------------------------------------------------------
+
+   rpng - simple PNG display program                              readpng.c
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2000 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+  ---------------------------------------------------------------------------*/
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "png.h"        /* libpng header; includes zlib.h */
+#include "readpng.h"    /* typedefs, common macros, public prototypes */
+
+/* future versions of libpng will provide this macro: */
+#ifndef png_jmpbuf
+#  define png_jmpbuf(png_ptr)   ((png_ptr)->jmpbuf)
+#endif
+
+
+static png_structp png_ptr = NULL;
+static png_infop info_ptr = NULL;
+
+png_uint_32  width, height;
+int  bit_depth, color_type;
+uch  *image_data = NULL;
+
+
+void readpng_version_info(void)
+{
+    fprintf(stderr, "   Compiled with libpng %s; using libpng %s.\n",
+      PNG_LIBPNG_VER_STRING, png_libpng_ver);
+    fprintf(stderr, "   Compiled with zlib %s; using zlib %s.\n",
+      ZLIB_VERSION, zlib_version);
+}
+
+
+/* return value = 0 for success, 1 for bad sig, 2 for bad IHDR, 4 for no mem */
+
+int readpng_init(FILE *infile, ulg *pWidth, ulg *pHeight)
+{
+    uch sig[8];
+
+
+    /* first do a quick check that the file really is a PNG image; could
+     * have used slightly more general png_sig_cmp() function instead */
+
+    fread(sig, 1, 8, infile);
+    if (!png_check_sig(sig, 8))
+        return 1;   /* bad signature */
+
+
+    /* could pass pointers to user-defined error handlers instead of NULLs: */
+
+    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+    if (!png_ptr)
+        return 4;   /* out of memory */
+
+    info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr) {
+        png_destroy_read_struct(&png_ptr, NULL, NULL);
+        return 4;   /* out of memory */
+    }
+
+
+    /* we could create a second info struct here (end_info), but it's only
+     * useful if we want to keep pre- and post-IDAT chunk info separated
+     * (mainly for PNG-aware image editors and converters) */
+
+
+    /* setjmp() must be called in every function that calls a PNG-reading
+     * libpng function */
+
+    if (setjmp(png_jmpbuf(png_ptr))) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        return 2;
+    }
+
+
+    png_init_io(png_ptr, infile);
+    png_set_sig_bytes(png_ptr, 8);  /* we already read the 8 signature bytes */
+
+    png_read_info(png_ptr, info_ptr);  /* read all PNG info up to image data */
+
+
+    /* alternatively, could make separate calls to png_get_image_width(),
+     * etc., but want bit_depth and color_type for later [don't care about
+     * compression_type and filter_type => NULLs] */
+
+    png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
+      NULL, NULL, NULL);
+    *pWidth = width;
+    *pHeight = height;
+
+
+    /* OK, that's all we need for now; return happy */
+
+    return 0;
+}
+
+
+
+
+/* returns 0 if succeeds, 1 if fails due to no bKGD chunk, 2 if libpng error;
+ * scales values to 8-bit if necessary */
+
+int readpng_get_bgcolor(uch *red, uch *green, uch *blue)
+{
+    png_color_16p pBackground;
+
+
+    /* setjmp() must be called in every function that calls a PNG-reading
+     * libpng function */
+
+    if (setjmp(png_jmpbuf(png_ptr))) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        return 2;
+    }
+
+
+    if (!png_get_valid(png_ptr, info_ptr, PNG_INFO_bKGD))
+        return 1;
+
+    /* it is not obvious from the libpng documentation, but this function
+     * takes a pointer to a pointer, and it always returns valid red, green
+     * and blue values, regardless of color_type: */
+
+    png_get_bKGD(png_ptr, info_ptr, &pBackground);
+
+
+    /* however, it always returns the raw bKGD data, regardless of any
+     * bit-depth transformations, so check depth and adjust if necessary */
+
+    if (bit_depth == 16) {
+        *red   = pBackground->red   >> 8;
+        *green = pBackground->green >> 8;
+        *blue  = pBackground->blue  >> 8;
+    } else if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) {
+        if (bit_depth == 1)
+            *red = *green = *blue = pBackground->gray? 255 : 0;
+        else if (bit_depth == 2)
+            *red = *green = *blue = (255/3) * pBackground->gray;
+        else /* bit_depth == 4 */
+            *red = *green = *blue = (255/15) * pBackground->gray;
+    } else {
+        *red   = (uch)pBackground->red;
+        *green = (uch)pBackground->green;
+        *blue  = (uch)pBackground->blue;
+    }
+
+    return 0;
+}
+
+
+
+
+/* display_exponent == LUT_exponent * CRT_exponent */
+
+uch *readpng_get_image(double display_exponent, int *pChannels, ulg *pRowbytes)
+{
+    double  gamma;
+    png_uint_32  i, rowbytes;
+    png_bytepp  row_pointers = NULL;
+
+
+    /* setjmp() must be called in every function that calls a PNG-reading
+     * libpng function */
+
+    if (setjmp(png_jmpbuf(png_ptr))) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        return NULL;
+    }
+
+
+    /* expand palette images to RGB, low-bit-depth grayscale images to 8 bits,
+     * transparency chunks to full alpha channel; strip 16-bit-per-sample
+     * images to 8 bits per sample; and convert grayscale to RGB[A] */
+
+    if (color_type == PNG_COLOR_TYPE_PALETTE)
+        png_set_expand(png_ptr);
+    if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
+        png_set_expand(png_ptr);
+    if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
+        png_set_expand(png_ptr);
+    if (bit_depth == 16)
+        png_set_strip_16(png_ptr);
+    if (color_type == PNG_COLOR_TYPE_GRAY ||
+        color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+        png_set_gray_to_rgb(png_ptr);
+
+
+    /* unlike the example in the libpng documentation, we have *no* idea where
+     * this file may have come from--so if it doesn't have a file gamma, don't
+     * do any correction ("do no harm") */
+
+    if (png_get_gAMA(png_ptr, info_ptr, &gamma))
+        png_set_gamma(png_ptr, display_exponent, gamma);
+
+
+    /* all transformations have been registered; now update info_ptr data,
+     * get rowbytes and channels, and allocate image memory */
+
+    png_read_update_info(png_ptr, info_ptr);
+
+    *pRowbytes = rowbytes = png_get_rowbytes(png_ptr, info_ptr);
+    *pChannels = (int)png_get_channels(png_ptr, info_ptr);
+
+    if ((image_data = (uch *)malloc(rowbytes*height)) == NULL) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        return NULL;
+    }
+    if ((row_pointers = (png_bytepp)malloc(height*sizeof(png_bytep))) == NULL) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        free(image_data);
+        image_data = NULL;
+        return NULL;
+    }
+
+    Trace((stderr, "readpng_get_image:  rowbytes = %ld, height = %ld\n", rowbytes, height));
+
+
+    /* set the individual row_pointers to point at the correct offsets */
+
+    for (i = 0;  i < height;  ++i)
+        row_pointers[i] = image_data + i*rowbytes;
+
+
+    /* now we can go ahead and just read the whole image */
+
+    png_read_image(png_ptr, row_pointers);
+
+
+    /* and we're done!  (png_read_end() can be omitted if no processing of
+     * post-IDAT text/time/etc. is desired) */
+
+    free(row_pointers);
+    row_pointers = NULL;
+
+    png_read_end(png_ptr, NULL);
+
+    return image_data;
+}
+
+
+void readpng_cleanup(int free_image_data)
+{
+    if (free_image_data && image_data) {
+        free(image_data);
+        image_data = NULL;
+    }
+
+    if (png_ptr && info_ptr) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        png_ptr = NULL;
+        info_ptr = NULL;
+    }
+}

contrib/gregbook/readpng.h

@@ -0,0 +1,64 @@
+/*---------------------------------------------------------------------------
+
+   rpng - simple PNG display program                              readpng.h
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2000 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+  ---------------------------------------------------------------------------*/
+
+#ifndef TRUE
+#  define TRUE 1
+#  define FALSE 0
+#endif
+
+#ifndef MAX
+#  define MAX(a,b)  ((a) > (b)? (a) : (b))
+#  define MIN(a,b)  ((a) < (b)? (a) : (b))
+#endif
+
+#ifdef DEBUG
+#  define Trace(x)  {fprintf x ; fflush(stderr); fflush(stdout);}
+#else
+#  define Trace(x)  ;
+#endif
+
+typedef unsigned char   uch;
+typedef unsigned short  ush;
+typedef unsigned long   ulg;
+
+
+/* prototypes for public functions in readpng.c */
+
+void readpng_version_info(void);
+
+int readpng_init(FILE *infile, ulg *pWidth, ulg *pHeight);
+
+int readpng_get_bgcolor(uch *bg_red, uch *bg_green, uch *bg_blue);
+
+uch *readpng_get_image(double display_exponent, int *pChannels,
+                       ulg *pRowbytes);
+
+void readpng_cleanup(int free_image_data);

contrib/gregbook/readpng2.c

@@ -0,0 +1,424 @@
+/*---------------------------------------------------------------------------
+
+   rpng2 - progressive-model PNG display program                 readpng2.c
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2000 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+  ---------------------------------------------------------------------------*/
+
+
+#include <stdlib.h>     /* for exit() prototype */
+
+#include "png.h"        /* libpng header; includes zlib.h and setjmp.h */
+#include "readpng2.h"   /* typedefs, common macros, public prototypes */
+
+
+/* local prototypes */
+
+static void readpng2_info_callback(png_structp png_ptr, png_infop info_ptr);
+static void readpng2_row_callback(png_structp png_ptr, png_bytep new_row,
+                                 png_uint_32 row_num, int pass);
+static void readpng2_end_callback(png_structp png_ptr, png_infop info_ptr);
+static void readpng2_error_handler(png_structp png_ptr, png_const_charp msg);
+
+
+
+
+void readpng2_version_info(void)
+{
+    fprintf(stderr, "   Compiled with libpng %s; using libpng %s.\n",
+      PNG_LIBPNG_VER_STRING, png_libpng_ver);
+    fprintf(stderr, "   Compiled with zlib %s; using zlib %s.\n",
+      ZLIB_VERSION, zlib_version);
+}
+
+
+
+
+int readpng2_check_sig(uch *sig, int num)
+{
+    return png_check_sig(sig, num);
+}
+
+
+
+
+/* returns 0 for success, 2 for libpng problem, 4 for out of memory */
+
+int readpng2_init(mainprog_info *mainprog_ptr)
+{
+    png_structp  png_ptr;       /* note:  temporary variables! */
+    png_infop  info_ptr;
+
+
+    /* could also replace libpng warning-handler (final NULL), but no need: */
+
+    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, mainprog_ptr,
+      readpng2_error_handler, NULL);
+    if (!png_ptr)
+        return 4;   /* out of memory */
+
+    info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr) {
+        png_destroy_read_struct(&png_ptr, NULL, NULL);
+        return 4;   /* out of memory */
+    }
+
+
+    /* we could create a second info struct here (end_info), but it's only
+     * useful if we want to keep pre- and post-IDAT chunk info separated
+     * (mainly for PNG-aware image editors and converters) */
+
+
+    /* setjmp() must be called in every function that calls a PNG-reading
+     * libpng function, unless an alternate error handler was installed--
+     * but compatible error handlers must either use longjmp() themselves
+     * (as in this program) or exit immediately, so here we are: */
+
+    if (setjmp(mainprog_ptr->jmpbuf)) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        return 2;
+    }
+
+
+    /* instead of doing png_init_io() here, now we set up our callback
+     * functions for progressive decoding */
+
+    png_set_progressive_read_fn(png_ptr, mainprog_ptr,
+      readpng2_info_callback, readpng2_row_callback, readpng2_end_callback);
+
+
+    /* make sure we save our pointers for use in readpng2_decode_data() */
+
+    mainprog_ptr->png_ptr = png_ptr;
+    mainprog_ptr->info_ptr = info_ptr;
+
+
+    /* and that's all there is to initialization */
+
+    return 0;
+}
+
+
+
+
+/* returns 0 for success, 2 for libpng (longjmp) problem */
+
+int readpng2_decode_data(mainprog_info *mainprog_ptr, uch *rawbuf, ulg length)
+{
+    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
+    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
+
+
+    /* setjmp() must be called in every function that calls a PNG-reading
+     * libpng function */
+
+    if (setjmp(mainprog_ptr->jmpbuf)) {
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+        mainprog_ptr->png_ptr = NULL;
+        mainprog_ptr->info_ptr = NULL;
+        return 2;
+    }
+
+
+    /* hand off the next chunk of input data to libpng for decoding */
+
+    png_process_data(png_ptr, info_ptr, rawbuf, length);
+
+    return 0;
+}
+
+
+
+
+static void readpng2_info_callback(png_structp png_ptr, png_infop info_ptr)
+{
+    mainprog_info  *mainprog_ptr;
+    int  color_type, bit_depth;
+    double  gamma;
+
+
+    /* setjmp() doesn't make sense here, because we'd either have to exit(),
+     * longjmp() ourselves, or return control to libpng, which doesn't want
+     * to see us again.  By not doing anything here, libpng will instead jump
+     * to readpng2_decode_data(), which can return an error value to the main
+     * program. */
+
+
+    /* retrieve the pointer to our special-purpose struct, using the png_ptr
+     * that libpng passed back to us (i.e., not a global this time--there's
+     * no real difference for a single image, but for a multithreaded browser
+     * decoding several PNG images at the same time, one needs to avoid mixing
+     * up different images' structs) */
+
+    mainprog_ptr = png_get_progressive_ptr(png_ptr);
+
+    if (mainprog_ptr == NULL) {         /* we be hosed */
+        fprintf(stderr,
+          "readpng2 error:  main struct not recoverable in info_callback.\n");
+        fflush(stderr);
+        return;
+        /*
+         * Alternatively, we could call our error-handler just like libpng
+         * does, which would effectively terminate the program.  Since this
+         * can only happen if png_ptr gets redirected somewhere odd or the
+         * main PNG struct gets wiped, we're probably toast anyway.  (If
+         * png_ptr itself is NULL, we would not have been called.)
+         */
+    }
+
+
+    /* this is just like in the non-progressive case */
+
+    png_get_IHDR(png_ptr, info_ptr, &mainprog_ptr->width,
+      &mainprog_ptr->height, &bit_depth, &color_type, NULL, NULL, NULL);
+
+
+    /* since we know we've read all of the PNG file's "header" (i.e., up
+     * to IDAT), we can check for a background color here */
+
+    if (mainprog_ptr->need_bgcolor &&
+        png_get_valid(png_ptr, info_ptr, PNG_INFO_bKGD))
+    {
+        png_color_16p pBackground;
+
+        /* it is not obvious from the libpng documentation, but this function
+         * takes a pointer to a pointer, and it always returns valid red,
+         * green and blue values, regardless of color_type: */
+        png_get_bKGD(png_ptr, info_ptr, &pBackground);
+
+        /* however, it always returns the raw bKGD data, regardless of any
+         * bit-depth transformations, so check depth and adjust if necessary */
+        if (bit_depth == 16) {
+            mainprog_ptr->bg_red   = pBackground->red   >> 8;
+            mainprog_ptr->bg_green = pBackground->green >> 8;
+            mainprog_ptr->bg_blue  = pBackground->blue  >> 8;
+        } else if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) {
+            if (bit_depth == 1)
+                mainprog_ptr->bg_red = mainprog_ptr->bg_green =
+                  mainprog_ptr->bg_blue = pBackground->gray? 255 : 0;
+            else if (bit_depth == 2)
+                mainprog_ptr->bg_red = mainprog_ptr->bg_green =
+                  mainprog_ptr->bg_blue = (255/3) * pBackground->gray;
+            else /* bit_depth == 4 */
+                mainprog_ptr->bg_red = mainprog_ptr->bg_green =
+                  mainprog_ptr->bg_blue = (255/15) * pBackground->gray;
+        } else {
+            mainprog_ptr->bg_red   = (uch)pBackground->red;
+            mainprog_ptr->bg_green = (uch)pBackground->green;
+            mainprog_ptr->bg_blue  = (uch)pBackground->blue;
+        }
+    }
+
+
+    /* as before, let libpng expand palette images to RGB, low-bit-depth
+     * grayscale images to 8 bits, transparency chunks to full alpha channel;
+     * strip 16-bit-per-sample images to 8 bits per sample; and convert
+     * grayscale to RGB[A] */
+
+    if (color_type == PNG_COLOR_TYPE_PALETTE)
+        png_set_expand(png_ptr);
+    if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
+        png_set_expand(png_ptr);
+    if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
+        png_set_expand(png_ptr);
+    if (bit_depth == 16)
+        png_set_strip_16(png_ptr);
+    if (color_type == PNG_COLOR_TYPE_GRAY ||
+        color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+        png_set_gray_to_rgb(png_ptr);
+
+
+    /* Unlike the basic viewer, which was designed to operate on local files,
+     * this program is intended to simulate a web browser--even though we
+     * actually read from a local file, too.  But because we are pretending
+     * that most of the images originate on the Internet, we follow the recom-
+     * mendation of the sRGB proposal and treat unlabelled images (no gAMA
+     * chunk) as existing in the sRGB color space.  That is, we assume that
+     * such images have a file gamma of 0.45455, which corresponds to a PC-like
+     * display system.  This change in assumptions will have no effect on a
+     * PC-like system, but on a Mac, SGI, NeXT or other system with a non-
+     * identity lookup table, it will darken unlabelled images, which effec-
+     * tively favors images from PC-like systems over those originating on
+     * the local platform.  Note that mainprog_ptr->display_exponent is the
+     * "gamma" value for the entire display system, i.e., the product of
+     * LUT_exponent and CRT_exponent. */
+
+    if (png_get_gAMA(png_ptr, info_ptr, &gamma))
+        png_set_gamma(png_ptr, mainprog_ptr->display_exponent, gamma);
+    else
+        png_set_gamma(png_ptr, mainprog_ptr->display_exponent, 0.45455);
+
+
+    /* we'll let libpng expand interlaced images, too */
+
+    mainprog_ptr->passes = png_set_interlace_handling(png_ptr);
+
+
+    /* all transformations have been registered; now update info_ptr data and
+     * then get rowbytes and channels */
+
+    png_read_update_info(png_ptr, info_ptr);
+
+    mainprog_ptr->rowbytes = (int)png_get_rowbytes(png_ptr, info_ptr);
+    mainprog_ptr->channels = png_get_channels(png_ptr, info_ptr);
+
+
+    /* Call the main program to allocate memory for the image buffer and
+     * initialize windows and whatnot.  (The old-style function-pointer
+     * invocation is used for compatibility with a few supposedly ANSI
+     * compilers that nevertheless barf on "fn_ptr()"-style syntax.) */
+
+    (*mainprog_ptr->mainprog_init)();
+
+
+    /* and that takes care of initialization */
+
+    return;
+}
+
+
+
+
+
+static void readpng2_row_callback(png_structp png_ptr, png_bytep new_row,
+                                  png_uint_32 row_num, int pass)
+{
+    mainprog_info  *mainprog_ptr;
+
+
+    /* first check whether the row differs from the previous pass; if not,
+     * nothing to combine or display */
+
+    if (!new_row)
+        return;
+
+
+    /* retrieve the pointer to our special-purpose struct so we can access
+     * the old rows and image-display callback function */
+
+    mainprog_ptr = png_get_progressive_ptr(png_ptr);
+
+
+    /* save the pass number for optional use by the front end */
+
+    mainprog_ptr->pass = pass;
+
+
+    /* have libpng either combine the new row data with the existing row data
+     * from previous passes (if interlaced) or else just copy the new row
+     * into the main program's image buffer */
+
+    png_progressive_combine_row(png_ptr, mainprog_ptr->row_pointers[row_num],
+      new_row);
+
+
+    /* finally, call the display routine in the main program with the number
+     * of the row we just updated */
+
+    (*mainprog_ptr->mainprog_display_row)(row_num);
+
+
+    /* and we're ready for more */
+
+    return;
+}
+
+
+
+
+
+static void readpng2_end_callback(png_structp png_ptr, png_infop info_ptr)
+{
+    mainprog_info  *mainprog_ptr;
+
+
+    /* retrieve the pointer to our special-purpose struct */
+
+    mainprog_ptr = png_get_progressive_ptr(png_ptr);
+
+
+    /* let the main program know that it should flush any buffered image
+     * data to the display now and set a "done" flag or whatever, but note
+     * that it SHOULD NOT DESTROY THE PNG STRUCTS YET--in other words, do
+     * NOT call readpng2_cleanup() either here or in the finish_display()
+     * routine; wait until control returns to the main program via
+     * readpng2_decode_data() */
+
+    (*mainprog_ptr->mainprog_finish_display)();
+
+
+    /* all done */
+
+    return;
+}
+
+
+
+
+
+void readpng2_cleanup(mainprog_info *mainprog_ptr)
+{
+    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
+    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
+
+    if (png_ptr && info_ptr)
+        png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+
+    mainprog_ptr->png_ptr = NULL;
+    mainprog_ptr->info_ptr = NULL;
+}
+
+
+
+
+
+static void readpng2_error_handler(png_structp png_ptr, png_const_charp msg)
+{
+    mainprog_info  *mainprog_ptr;
+
+    /* This function, aside from the extra step of retrieving the "error
+     * pointer" (below) and the fact that it exists within the application
+     * rather than within libpng, is essentially identical to libpng's
+     * default error handler.  The second point is critical:  since both
+     * setjmp() and longjmp() are called from the same code, they are
+     * guaranteed to have compatible notions of how big a jmp_buf is,
+     * regardless of whether _BSD_SOURCE or anything else has (or has not)
+     * been defined. */
+
+    fprintf(stderr, "readpng2 libpng error: %s\n", msg);
+    fflush(stderr);
+
+    mainprog_ptr = png_get_error_ptr(png_ptr);
+    if (mainprog_ptr == NULL) {         /* we are completely hosed now */
+        fprintf(stderr,
+          "readpng2 severe error:  jmpbuf not recoverable; terminating.\n");
+        fflush(stderr);
+        exit(99);
+    }
+
+    longjmp(mainprog_ptr->jmpbuf, 1);
+}

contrib/gregbook/readpng2.h

@@ -0,0 +1,86 @@
+/*---------------------------------------------------------------------------
+
+   rpng2 - progressive-model PNG display program                 readpng2.h
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2000 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+  ---------------------------------------------------------------------------*/
+
+#ifndef TRUE
+#  define TRUE 1
+#  define FALSE 0
+#endif
+
+#ifndef MAX
+#  define MAX(a,b)  ((a) > (b)? (a) : (b))
+#  define MIN(a,b)  ((a) < (b)? (a) : (b))
+#endif
+
+#ifdef DEBUG
+#  define Trace(x)  {fprintf x ; fflush(stderr); fflush(stdout);}
+#else
+#  define Trace(x)  ;
+#endif
+
+typedef unsigned char   uch;
+typedef unsigned short  ush;
+typedef unsigned long   ulg;
+
+typedef struct _mainprog_info {
+    double display_exponent;
+    ulg width;
+    ulg height;
+    void *png_ptr;
+    void *info_ptr;
+    void (*mainprog_init)(void);
+    void (*mainprog_display_row)(ulg row_num);
+    void (*mainprog_finish_display)(void);
+    uch *image_data;
+    uch **row_pointers;
+    jmp_buf jmpbuf;
+    int passes;              /* not used */
+    int pass;
+    int rowbytes;
+    int channels;
+    int need_bgcolor;
+    int done;
+    uch bg_red;
+    uch bg_green;
+    uch bg_blue;
+} mainprog_info;
+
+
+/* prototypes for public functions in readpng2.c */
+
+void readpng2_version_info(void);
+
+int readpng2_check_sig(uch *sig, int num);
+
+int readpng2_init(mainprog_info *mainprog_ptr);
+
+int readpng2_decode_data(mainprog_info *mainprog_ptr, uch *rawbuf, ulg length);
+
+void readpng2_cleanup(mainprog_info *mainprog_ptr);

contrib/gregbook/rpng-win.c

@@ -0,0 +1,620 @@
+/*---------------------------------------------------------------------------
+
+   rpng - simple PNG display program                             rpng-win.c
+
+   This program decodes and displays PNG images, with gamma correction and
+   optionally with a user-specified background color (in case the image has
+   transparency).  It is very nearly the most basic PNG viewer possible.
+   This version is for 32-bit Windows; it may compile under 16-bit Windows
+   with a little tweaking (or maybe not).
+
+   to do:
+    - stdout/stderr don't work!  need message window (maybe scrollable?)
+    - handle quoted command-line args (especially filenames with spaces)
+    - have minimum window width:  oh well
+    - use %.1023s to simplify truncation of title-bar string?
+
+  ---------------------------------------------------------------------------
+
+   Changelog:
+    - 1.00:  initial public release
+    - 1.01:  modified to allow abbreviated options; fixed long/ulong mis-
+              match; switched to png_jmpbuf() macro
+    - 1.02:  added extra set of parentheses to png_jmpbuf() macro; fixed
+              command-line parsing bug
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2000 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+  ---------------------------------------------------------------------------*/
+
+#define PROGNAME  "rpng-win"
+#define LONGNAME  "Simple PNG Viewer for Windows"
+#define VERSION   "1.02 of 19 March 2000"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <windows.h>
+
+/* #define DEBUG  :  this enables the Trace() macros */
+
+#include "readpng.h"    /* typedefs, common macros, readpng prototypes */
+
+
+/* could just include png.h, but this macro is the only thing we need
+ * (name and typedefs changed to local versions); note that side effects
+ * only happen with alpha (which could easily be avoided with
+ * "ush acopy = (alpha);") */
+
+#define alpha_composite(composite, fg, alpha, bg) {               \
+    ush temp = ((ush)(fg)*(ush)(alpha) +                          \
+                (ush)(bg)*(ush)(255 - (ush)(alpha)) + (ush)128);  \
+    (composite) = (uch)((temp + (temp >> 8)) >> 8);               \
+}
+
+
+/* local prototypes */
+static int        rpng_win_create_window(HINSTANCE hInst, int showmode);
+static int        rpng_win_display_image(void);
+static void       rpng_win_cleanup(void);
+LRESULT CALLBACK  rpng_win_wndproc(HWND, UINT, WPARAM, LPARAM);
+
+
+static char titlebar[1024], *window_name = titlebar;
+static char *progname = PROGNAME;
+static char *appname = LONGNAME;
+static char *icon_name = PROGNAME;     /* GRR:  not (yet) used */
+static char *filename;
+static FILE *infile;
+
+static char *bgstr;
+static uch bg_red=0, bg_green=0, bg_blue=0;
+
+static double display_exponent;
+
+static ulg image_width, image_height, image_rowbytes;
+static int image_channels;
+static uch *image_data;
+
+/* Windows-specific variables */
+static ulg wimage_rowbytes;
+static uch *dib;
+static uch *wimage_data;
+static BITMAPINFOHEADER *bmih;
+
+static HWND global_hwnd;
+
+
+
+
+int WINAPI WinMain(HINSTANCE hInst, HINSTANCE hPrevInst, PSTR cmd, int showmode)
+{
+    char *args[1024];                 /* arbitrary limit, but should suffice */
+    char *p, *q, **argv = args;
+    int argc = 0;
+    int rc, alen, flen;
+    int error = 0;
+    int have_bg = FALSE;
+    double LUT_exponent;              /* just the lookup table */
+    double CRT_exponent = 2.2;        /* just the monitor */
+    double default_display_exponent;  /* whole display system */
+    MSG msg;
+
+
+    filename = (char *)NULL;
+
+
+    /* First set the default value for our display-system exponent, i.e.,
+     * the product of the CRT exponent and the exponent corresponding to
+     * the frame-buffer's lookup table (LUT), if any.  This is not an
+     * exhaustive list of LUT values (e.g., OpenStep has a lot of weird
+     * ones), but it should cover 99% of the current possibilities.  And
+     * yes, these ifdefs are completely wasted in a Windows program... */
+
+#if defined(NeXT)
+    LUT_exponent = 1.0 / 2.2;
+    /*
+    if (some_next_function_that_returns_gamma(&next_gamma))
+        LUT_exponent = 1.0 / next_gamma;
+     */
+#elif defined(sgi)
+    LUT_exponent = 1.0 / 1.7;
+    /* there doesn't seem to be any documented function to get the
+     * "gamma" value, so we do it the hard way */
+    infile = fopen("/etc/config/system.glGammaVal", "r");
+    if (infile) {
+        double sgi_gamma;
+
+        fgets(tmpline, 80, infile);
+        fclose(infile);
+        sgi_gamma = atof(tmpline);
+        if (sgi_gamma > 0.0)
+            LUT_exponent = 1.0 / sgi_gamma;
+    }
+#elif defined(Macintosh)
+    LUT_exponent = 1.8 / 2.61;
+    /*
+    if (some_mac_function_that_returns_gamma(&mac_gamma))
+        LUT_exponent = mac_gamma / 2.61;
+     */
+#else
+    LUT_exponent = 1.0;   /* assume no LUT:  most PCs */
+#endif
+
+    /* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */
+    default_display_exponent = LUT_exponent * CRT_exponent;
+
+
+    /* If the user has set the SCREEN_GAMMA environment variable as suggested
+     * (somewhat imprecisely) in the libpng documentation, use that; otherwise
+     * use the default value we just calculated.  Either way, the user may
+     * override this via a command-line option. */
+
+    if ((p = getenv("SCREEN_GAMMA")) != NULL)
+        display_exponent = atof(p);
+    else
+        display_exponent = default_display_exponent;
+
+
+    /* Windows really hates command lines, so we have to set up our own argv.
+     * Note that we do NOT bother with quoted arguments here, so don't use
+     * filenames with spaces in 'em! */
+
+    argv[argc++] = PROGNAME;
+    p = cmd;
+    for (;;) {
+        if (*p == ' ')
+            while (*++p == ' ')
+                ;
+        /* now p points at the first non-space after some spaces */
+        if (*p == '\0')
+            break;    /* nothing after the spaces:  done */
+        argv[argc++] = q = p;
+        while (*q && *q != ' ')
+            ++q;
+        /* now q points at a space or the end of the string */
+        if (*q == '\0')
+            break;    /* last argv already terminated; quit */
+        *q = '\0';    /* change space to terminator */
+        p = q + 1;
+    }
+    argv[argc] = NULL;   /* terminate the argv array itself */
+
+
+    /* Now parse the command line for options and the PNG filename. */
+
+    while (*++argv && !error) {
+        if (!strncmp(*argv, "-gamma", 2)) {
+            if (!*++argv)
+                ++error;
+            else {
+                display_exponent = atof(*argv);
+                if (display_exponent <= 0.0)
+                    ++error;
+            }
+        } else if (!strncmp(*argv, "-bgcolor", 2)) {
+            if (!*++argv)
+                ++error;
+            else {
+                bgstr = *argv;
+                if (strlen(bgstr) != 7 || bgstr[0] != '#')
+                    ++error;
+                else
+                    have_bg = TRUE;
+            }
+        } else {
+            if (**argv != '-') {
+                filename = *argv;
+                if (argv[1])   /* shouldn't be any more args after filename */
+                    ++error;
+            } else
+                ++error;   /* not expecting any other options */
+        }
+    }
+
+    if (!filename) {
+        ++error;
+    } else if (!(infile = fopen(filename, "rb"))) {
+        fprintf(stderr, PROGNAME ":  can't open PNG file [%s]\n", filename);
+        ++error;
+    } else {
+        if ((rc = readpng_init(infile, &image_width, &image_height)) != 0) {
+            switch (rc) {
+                case 1:
+                    fprintf(stderr, PROGNAME
+                      ":  [%s] is not a PNG file: incorrect signature\n",
+                      filename);
+                    break;
+                case 2:
+                    fprintf(stderr, PROGNAME
+                      ":  [%s] has bad IHDR (libpng longjmp)\n",
+                      filename);
+                    break;
+                case 4:
+                    fprintf(stderr, PROGNAME ":  insufficient memory\n");
+                    break;
+                default:
+                    fprintf(stderr, PROGNAME
+                      ":  unknown readpng_init() error\n");
+                    break;
+            }
+            ++error;
+        }
+        if (error)
+            fclose(infile);
+    }
+
+
+    /* usage screen */
+
+    if (error) {
+        fprintf(stderr, "\n%s %s:  %s\n", PROGNAME, VERSION, appname);
+        readpng_version_info();
+        fprintf(stderr, "\n"
+         "Usage:  %s [-gamma exp] [-bgcolor bg] file.png\n"
+         "    exp \ttransfer-function exponent (``gamma'') of the display\n"
+         "\t\t  system in floating-point format (e.g., ``%.1f''); equal\n"
+         "\t\t  to the product of the lookup-table exponent (varies)\n"
+         "\t\t  and the CRT exponent (usually 2.2); must be positive\n"
+         "    bg  \tdesired background color in 7-character hex RGB format\n"
+         "\t\t  (e.g., ``#ff7700'' for orange:  same as HTML colors);\n"
+         "\t\t  used with transparent images\n"
+         "\nPress Q, Esc or mouse button 1 after image is displayed to quit.\n"
+         "\n", PROGNAME, default_display_exponent);
+        exit(1);
+    }
+
+
+    /* set the title-bar string, but make sure buffer doesn't overflow */
+
+    alen = strlen(appname);
+    flen = strlen(filename);
+    if (alen + flen + 3 > 1023)
+        sprintf(titlebar, "%s:  ...%s", appname, filename+(alen+flen+6-1023));
+    else
+        sprintf(titlebar, "%s:  %s", appname, filename);
+
+
+    /* if the user didn't specify a background color on the command line,
+     * check for one in the PNG file--if not, the initialized values of 0
+     * (black) will be used */
+
+    if (have_bg)
+        sscanf(bgstr+1, "%2x%2x%2x", &bg_red, &bg_green, &bg_blue);
+    else if (readpng_get_bgcolor(&bg_red, &bg_green, &bg_blue) > 1) {
+        readpng_cleanup(TRUE);
+        fprintf(stderr, PROGNAME
+          ":  libpng error while checking for background color\n");
+        exit(2);
+    }
+
+
+    /* do the basic Windows initialization stuff, make the window and fill it
+     * with the background color */
+
+    if (rpng_win_create_window(hInst, showmode))
+        exit(2);
+
+
+    /* decode the image, all at once */
+
+    Trace((stderr, "calling readpng_get_image()\n"))
+    image_data = readpng_get_image(display_exponent, &image_channels,
+      &image_rowbytes);
+    Trace((stderr, "done with readpng_get_image()\n"))
+
+
+    /* done with PNG file, so clean up to minimize memory usage (but do NOT
+     * nuke image_data!) */
+
+    readpng_cleanup(FALSE);
+    fclose(infile);
+
+    if (!image_data) {
+        fprintf(stderr, PROGNAME ":  unable to decode PNG image\n");
+        exit(3);
+    }
+
+
+    /* display image (composite with background if requested) */
+
+    Trace((stderr, "calling rpng_win_display_image()\n"))
+    if (rpng_win_display_image()) {
+        free(image_data);
+        exit(4);
+    }
+    Trace((stderr, "done with rpng_win_display_image()\n"))
+
+
+    /* wait for the user to tell us when to quit */
+
+    printf(
+      "Done.  Press Q, Esc or mouse button 1 (within image window) to quit.\n");
+    fflush(stdout);
+
+    while (GetMessage(&msg, NULL, 0, 0)) {
+        TranslateMessage(&msg);
+        DispatchMessage(&msg);
+    }
+
+
+    /* OK, we're done:  clean up all image and Windows resources and go away */
+
+    rpng_win_cleanup();
+
+    return msg.wParam;
+}
+
+
+
+
+
+static int rpng_win_create_window(HINSTANCE hInst, int showmode)
+{
+    uch *dest;
+    int extra_width, extra_height;
+    ulg i, j;
+    WNDCLASSEX wndclass;
+
+
+/*---------------------------------------------------------------------------
+    Allocate memory for the display-specific version of the image (round up
+    to multiple of 4 for Windows DIB).
+  ---------------------------------------------------------------------------*/
+
+    wimage_rowbytes = ((3*image_width + 3L) >> 2) << 2;
+
+    if (!(dib = (uch *)malloc(sizeof(BITMAPINFOHEADER) +
+                              wimage_rowbytes*image_height)))
+    {
+        return 4;   /* fail */
+    }
+
+/*---------------------------------------------------------------------------
+    Initialize the DIB.  Negative height means to use top-down BMP ordering
+    (must be uncompressed, but that's what we want).  Bit count of 1, 4 or 8
+    implies a colormap of RGBX quads, but 24-bit BMPs just use B,G,R values
+    directly => wimage_data begins immediately after BMP header.
+  ---------------------------------------------------------------------------*/
+
+    memset(dib, 0, sizeof(BITMAPINFOHEADER));
+    bmih = (BITMAPINFOHEADER *)dib;
+    bmih->biSize = sizeof(BITMAPINFOHEADER);
+    bmih->biWidth = image_width;
+    bmih->biHeight = -((long)image_height);
+    bmih->biPlanes = 1;
+    bmih->biBitCount = 24;
+    bmih->biCompression = 0;
+    wimage_data = dib + sizeof(BITMAPINFOHEADER);
+
+/*---------------------------------------------------------------------------
+    Fill in background color (black by default); data are in BGR order.
+  ---------------------------------------------------------------------------*/
+
+    for (j = 0;  j < image_height;  ++j) {
+        dest = wimage_data + j*wimage_rowbytes;
+        for (i = image_width;  i > 0;  --i) {
+            *dest++ = bg_blue;
+            *dest++ = bg_green;
+            *dest++ = bg_red;
+        }
+    }
+
+/*---------------------------------------------------------------------------
+    Set the window parameters.
+  ---------------------------------------------------------------------------*/
+
+    memset(&wndclass, 0, sizeof(wndclass));
+
+    wndclass.cbSize = sizeof(wndclass);
+    wndclass.style = CS_HREDRAW | CS_VREDRAW;
+    wndclass.lpfnWndProc = rpng_win_wndproc;
+    wndclass.hInstance = hInst;
+    wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
+    wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
+    wndclass.hbrBackground = (HBRUSH)GetStockObject(DKGRAY_BRUSH);
+    wndclass.lpszMenuName = NULL;
+    wndclass.lpszClassName = progname;
+    wndclass.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
+
+    RegisterClassEx(&wndclass);
+
+/*---------------------------------------------------------------------------
+    Finally, create the window.
+  ---------------------------------------------------------------------------*/
+
+    extra_width  = 2*(GetSystemMetrics(SM_CXBORDER) +
+                      GetSystemMetrics(SM_CXDLGFRAME));
+    extra_height = 2*(GetSystemMetrics(SM_CYBORDER) +
+                      GetSystemMetrics(SM_CYDLGFRAME)) +
+                      GetSystemMetrics(SM_CYCAPTION);
+
+    global_hwnd = CreateWindow(progname, titlebar, WS_OVERLAPPEDWINDOW,
+      CW_USEDEFAULT, CW_USEDEFAULT, image_width+extra_width,
+      image_height+extra_height, NULL, NULL, hInst, NULL);
+
+    ShowWindow(global_hwnd, showmode);
+    UpdateWindow(global_hwnd);
+
+    return 0;
+
+} /* end function rpng_win_create_window() */
+
+
+
+
+
+static int rpng_win_display_image()
+{
+    uch *src, *dest;
+    uch r, g, b, a;
+    ulg i, row, lastrow;
+    RECT rect;
+
+
+    Trace((stderr, "beginning display loop (image_channels == %d)\n",
+      image_channels))
+    Trace((stderr, "(width = %ld, rowbytes = %ld, wimage_rowbytes = %d)\n",
+      image_width, image_rowbytes, wimage_rowbytes))
+
+
+/*---------------------------------------------------------------------------
+    Blast image data to buffer.  This whole routine takes place before the
+    message loop begins, so there's no real point in any pseudo-progressive
+    display...
+  ---------------------------------------------------------------------------*/
+
+    for (lastrow = row = 0;  row < image_height;  ++row) {
+        src = image_data + row*image_rowbytes;
+        dest = wimage_data + row*wimage_rowbytes;
+        if (image_channels == 3) {
+            for (i = image_width;  i > 0;  --i) {
+                r = *src++;
+                g = *src++;
+                b = *src++;
+                *dest++ = b;
+                *dest++ = g;   /* note reverse order */
+                *dest++ = r;
+            }
+        } else /* if (image_channels == 4) */ {
+            for (i = image_width;  i > 0;  --i) {
+                r = *src++;
+                g = *src++;
+                b = *src++;
+                a = *src++;
+                if (a == 255) {
+                    *dest++ = b;
+                    *dest++ = g;
+                    *dest++ = r;
+                } else if (a == 0) {
+                    *dest++ = bg_blue;
+                    *dest++ = bg_green;
+                    *dest++ = bg_red;
+                } else {
+                    /* this macro (copied from png.h) composites the
+                     * foreground and background values and puts the
+                     * result into the first argument; there are no
+                     * side effects with the first argument */
+                    alpha_composite(*dest++, b, a, bg_blue);
+                    alpha_composite(*dest++, g, a, bg_green);
+                    alpha_composite(*dest++, r, a, bg_red);
+                }
+            }
+        }
+        /* display after every 16 lines */
+        if (((row+1) & 0xf) == 0) {
+            rect.left = 0L;
+            rect.top = (LONG)lastrow;
+            rect.right = (LONG)image_width;      /* possibly off by one? */
+            rect.bottom = (LONG)lastrow + 16L;   /* possibly off by one? */
+            InvalidateRect(global_hwnd, &rect, FALSE);
+            UpdateWindow(global_hwnd);     /* similar to XFlush() */
+            lastrow = row + 1;
+        }
+    }
+
+    Trace((stderr, "calling final image-flush routine\n"))
+    if (lastrow < image_height) {
+        rect.left = 0L;
+        rect.top = (LONG)lastrow;
+        rect.right = (LONG)image_width;      /* possibly off by one? */
+        rect.bottom = (LONG)image_height;    /* possibly off by one? */
+        InvalidateRect(global_hwnd, &rect, FALSE);
+        UpdateWindow(global_hwnd);     /* similar to XFlush() */
+    }
+
+/*
+    last param determines whether or not background is wiped before paint
+    InvalidateRect(global_hwnd, NULL, TRUE);
+    UpdateWindow(global_hwnd);
+ */
+
+    return 0;
+}
+
+
+
+
+
+static void rpng_win_cleanup()
+{
+    if (image_data) {
+        free(image_data);
+        image_data = NULL;
+    }
+
+    if (dib) {
+        free(dib);
+        dib = NULL;
+    }
+}
+
+
+
+
+
+LRESULT CALLBACK rpng_win_wndproc(HWND hwnd, UINT iMsg, WPARAM wP, LPARAM lP)
+{
+    HDC         hdc;
+    PAINTSTRUCT ps;
+    int rc;
+
+    switch (iMsg) {
+        case WM_CREATE:
+            /* one-time processing here, if any */
+            return 0;
+
+        case WM_PAINT:
+            hdc = BeginPaint(hwnd, &ps);
+                    /*                    dest                          */
+            rc = StretchDIBits(hdc, 0, 0, image_width, image_height,
+                    /*                    source                        */
+                                    0, 0, image_width, image_height,
+                                    wimage_data, (BITMAPINFO *)bmih,
+                    /*              iUsage: no clue                     */
+                                    0, SRCCOPY);
+            EndPaint(hwnd, &ps);
+            return 0;
+
+        /* wait for the user to tell us when to quit */
+        case WM_CHAR:
+            switch (wP) {      /* only need one, so ignore repeat count */
+                case 'q':
+                case 'Q':
+                case 0x1B:     /* Esc key */
+                    PostQuitMessage(0);
+            }
+            return 0;
+
+        case WM_LBUTTONDOWN:   /* another way of quitting */
+        case WM_DESTROY:
+            PostQuitMessage(0);
+            return 0;
+    }
+
+    return DefWindowProc(hwnd, iMsg, wP, lP);
+}

contrib/gregbook/rpng-x.c

@@ -0,0 +1,843 @@
+/*---------------------------------------------------------------------------
+
+   rpng - simple PNG display program                               rpng-x.c
+
+   This program decodes and displays PNG images, with gamma correction and
+   optionally with a user-specified background color (in case the image has
+   transparency).  It is very nearly the most basic PNG viewer possible.
+   This version is for the X Window System (tested by author under Unix and
+   by Martin Zinser under OpenVMS; may work under OS/2 with some tweaking).
+
+   to do:
+    - 8-bit support
+    - use %.1023s to simplify truncation of title-bar string?
+
+  ---------------------------------------------------------------------------
+
+   Changelog:
+    - 1.01:  initial public release
+    - 1.02:  modified to allow abbreviated options; fixed long/ulong mis-
+              match; switched to png_jmpbuf() macro
+    - 1.10:  added support for non-default visuals; fixed X pixel-conversion
+    - 1.11:  added extra set of parentheses to png_jmpbuf() macro; fixed
+              command-line parsing bug
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2000 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+  ---------------------------------------------------------------------------*/
+
+#define PROGNAME  "rpng-x"
+#define LONGNAME  "Simple PNG Viewer for X"
+#define VERSION   "1.11 of 19 March 2000"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <X11/Xlib.h>
+#include <X11/Xutil.h>
+#include <X11/Xos.h>
+#include <X11/keysym.h>
+
+/* #define DEBUG  :  this enables the Trace() macros */
+
+#include "readpng.h"   /* typedefs, common macros, readpng prototypes */
+
+
+/* could just include png.h, but this macro is the only thing we need
+ * (name and typedefs changed to local versions); note that side effects
+ * only happen with alpha (which could easily be avoided with
+ * "ush acopy = (alpha);") */
+
+#define alpha_composite(composite, fg, alpha, bg) {               \
+    ush temp = ((ush)(fg)*(ush)(alpha) +                          \
+                (ush)(bg)*(ush)(255 - (ush)(alpha)) + (ush)128);  \
+    (composite) = (uch)((temp + (temp >> 8)) >> 8);               \
+}
+
+
+/* local prototypes */
+static int  rpng_x_create_window(void);
+static int  rpng_x_display_image(void);
+static void rpng_x_cleanup(void);
+static int  rpng_x_msb(ulg u32val);
+
+
+static char titlebar[1024], *window_name = titlebar;
+static char *appname = LONGNAME;
+static char *icon_name = PROGNAME;
+static char *filename;
+static FILE *infile;
+
+static char *bgstr;
+static uch bg_red=0, bg_green=0, bg_blue=0;
+
+static double display_exponent;
+
+static ulg image_width, image_height, image_rowbytes;
+static int image_channels;
+static uch *image_data;
+
+/* X-specific variables */
+static char *displayname;
+static XImage *ximage;
+static Display *display;
+static int depth;
+static Visual *visual;
+static XVisualInfo *visual_list;
+static int RShift, GShift, BShift;
+static ulg RMask, GMask, BMask;
+static Window window;
+static GC gc;
+static Colormap colormap;
+
+static int have_nondefault_visual = FALSE;
+static int have_colormap = FALSE;
+static int have_window = FALSE;
+/*
+ulg numcolors=0, pixels[256];
+ush reds[256], greens[256], blues[256];
+ */
+
+
+
+
+int main(int argc, char **argv)
+{
+#ifdef sgi
+    char tmpline[80];
+#endif
+    char *p;
+    int rc, alen, flen;
+    int error = 0;
+    int have_bg = FALSE;
+    double LUT_exponent;               /* just the lookup table */
+    double CRT_exponent = 2.2;         /* just the monitor */
+    double default_display_exponent;   /* whole display system */
+    XEvent e;
+    KeySym k;
+
+
+    displayname = (char *)NULL;
+    filename = (char *)NULL;
+
+
+    /* First set the default value for our display-system exponent, i.e.,
+     * the product of the CRT exponent and the exponent corresponding to
+     * the frame-buffer's lookup table (LUT), if any.  This is not an
+     * exhaustive list of LUT values (e.g., OpenStep has a lot of weird
+     * ones), but it should cover 99% of the current possibilities. */
+
+#if defined(NeXT)
+    LUT_exponent = 1.0 / 2.2;
+    /*
+    if (some_next_function_that_returns_gamma(&next_gamma))
+        LUT_exponent = 1.0 / next_gamma;
+     */
+#elif defined(sgi)
+    LUT_exponent = 1.0 / 1.7;
+    /* there doesn't seem to be any documented function to get the
+     * "gamma" value, so we do it the hard way */
+    infile = fopen("/etc/config/system.glGammaVal", "r");
+    if (infile) {
+        double sgi_gamma;
+
+        fgets(tmpline, 80, infile);
+        fclose(infile);
+        sgi_gamma = atof(tmpline);
+        if (sgi_gamma > 0.0)
+            LUT_exponent = 1.0 / sgi_gamma;
+    }
+#elif defined(Macintosh)
+    LUT_exponent = 1.8 / 2.61;
+    /*
+    if (some_mac_function_that_returns_gamma(&mac_gamma))
+        LUT_exponent = mac_gamma / 2.61;
+     */
+#else
+    LUT_exponent = 1.0;   /* assume no LUT:  most PCs */
+#endif
+
+    /* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */
+    default_display_exponent = LUT_exponent * CRT_exponent;
+
+
+    /* If the user has set the SCREEN_GAMMA environment variable as suggested
+     * (somewhat imprecisely) in the libpng documentation, use that; otherwise
+     * use the default value we just calculated.  Either way, the user may
+     * override this via a command-line option. */
+
+    if ((p = getenv("SCREEN_GAMMA")) != NULL)
+        display_exponent = atof(p);
+    else
+        display_exponent = default_display_exponent;
+
+
+    /* Now parse the command line for options and the PNG filename. */
+
+    while (*++argv && !error) {
+        if (!strncmp(*argv, "-display", 2)) {
+            if (!*++argv)
+                ++error;
+            else
+                displayname = *argv;
+        } else if (!strncmp(*argv, "-gamma", 2)) {
+            if (!*++argv)
+                ++error;
+            else {
+                display_exponent = atof(*argv);
+                if (display_exponent <= 0.0)
+                    ++error;
+            }
+        } else if (!strncmp(*argv, "-bgcolor", 2)) {
+            if (!*++argv)
+                ++error;
+            else {
+                bgstr = *argv;
+                if (strlen(bgstr) != 7 || bgstr[0] != '#')
+                    ++error; 
+                else 
+                    have_bg = TRUE;
+            }
+        } else {
+            if (**argv != '-') {
+                filename = *argv;
+                if (argv[1])   /* shouldn't be any more args after filename */
+                    ++error;
+            } else
+                ++error;   /* not expecting any other options */
+        }
+    }
+
+    if (!filename) {
+        ++error;
+    } else if (!(infile = fopen(filename, "rb"))) {
+        fprintf(stderr, PROGNAME ":  can't open PNG file [%s]\n", filename);
+        ++error;
+    } else {
+        if ((rc = readpng_init(infile, &image_width, &image_height)) != 0) {
+            switch (rc) {
+                case 1:
+                    fprintf(stderr, PROGNAME
+                      ":  [%s] is not a PNG file: incorrect signature\n",
+                      filename);
+                    break;
+                case 2:
+                    fprintf(stderr, PROGNAME
+                      ":  [%s] has bad IHDR (libpng longjmp)\n",
+                      filename);
+                    break;
+                case 4:
+                    fprintf(stderr, PROGNAME ":  insufficient memory\n");
+                    break;
+                default:
+                    fprintf(stderr, PROGNAME
+                      ":  unknown readpng_init() error\n");
+                    break;
+            }
+            ++error;
+        } else {
+            display = XOpenDisplay(displayname);
+            if (!display) {
+                readpng_cleanup(TRUE);
+                fprintf(stderr, PROGNAME ":  can't open X display [%s]\n",
+                  displayname? displayname : "default");
+                ++error;
+            }
+        }
+        if (error)
+            fclose(infile);
+    }
+
+
+    /* usage screen */
+
+    if (error) {
+        fprintf(stderr, "\n%s %s:  %s\n", PROGNAME, VERSION, appname);
+        readpng_version_info();
+        fprintf(stderr, "\n"
+          "Usage:  %s [-display xdpy] [-gamma exp] [-bgcolor bg] file.png\n"
+          "    xdpy\tname of the target X display (e.g., ``hostname:0'')\n"
+          "    exp \ttransfer-function exponent (``gamma'') of the display\n"
+          "\t\t  system in floating-point format (e.g., ``%.1f''); equal\n"
+          "\t\t  to the product of the lookup-table exponent (varies)\n"
+          "\t\t  and the CRT exponent (usually 2.2); must be positive\n"
+          "    bg  \tdesired background color in 7-character hex RGB format\n"
+          "\t\t  (e.g., ``#ff7700'' for orange:  same as HTML colors);\n"
+          "\t\t  used with transparent images\n"
+          "\nPress Q, Esc or mouse button 1 (within image window, after image\n"
+          "is displayed) to quit.\n"
+          "\n", PROGNAME, default_display_exponent);
+        exit(1);
+    }
+
+
+    /* set the title-bar string, but make sure buffer doesn't overflow */
+
+    alen = strlen(appname);
+    flen = strlen(filename);
+    if (alen + flen + 3 > 1023)
+        sprintf(titlebar, "%s:  ...%s", appname, filename+(alen+flen+6-1023));
+    else
+        sprintf(titlebar, "%s:  %s", appname, filename);
+
+
+    /* if the user didn't specify a background color on the command line,
+     * check for one in the PNG file--if not, the initialized values of 0
+     * (black) will be used */
+
+    if (have_bg) {
+        unsigned r, g, b;   /* this approach quiets compiler warnings */
+
+        sscanf(bgstr+1, "%2x%2x%2x", &r, &g, &b);
+        bg_red   = (uch)r;
+        bg_green = (uch)g;
+        bg_blue  = (uch)b;
+    } else if (readpng_get_bgcolor(&bg_red, &bg_green, &bg_blue) > 1) {
+        readpng_cleanup(TRUE);
+        fprintf(stderr, PROGNAME
+          ":  libpng error while checking for background color\n");
+        exit(2);
+    }
+
+
+    /* do the basic X initialization stuff, make the window and fill it
+     * with the background color */
+
+    if (rpng_x_create_window())
+        exit(2);
+
+
+    /* decode the image, all at once */
+
+    Trace((stderr, "calling readpng_get_image()\n"))
+    image_data = readpng_get_image(display_exponent, &image_channels,
+      &image_rowbytes);
+    Trace((stderr, "done with readpng_get_image()\n"))
+
+
+    /* done with PNG file, so clean up to minimize memory usage (but do NOT
+     * nuke image_data!) */
+
+    readpng_cleanup(FALSE);
+    fclose(infile);
+
+    if (!image_data) {
+        fprintf(stderr, PROGNAME ":  unable to decode PNG image\n");
+        exit(3);
+    }
+
+
+    /* display image (composite with background if requested) */
+
+    Trace((stderr, "calling rpng_x_display_image()\n"))
+    if (rpng_x_display_image()) {
+        free(image_data);
+        exit(4);
+    }
+    Trace((stderr, "done with rpng_x_display_image()\n"))
+
+
+    /* wait for the user to tell us when to quit */
+
+    printf(
+      "Done.  Press Q, Esc or mouse button 1 (within image window) to quit.\n");
+    fflush(stdout);
+
+    do
+        XNextEvent(display, &e);
+    while (!(e.type == ButtonPress && e.xbutton.button == Button1) &&
+           !(e.type == KeyPress &&    /*  v--- or 1 for shifted keys */
+             ((k = XLookupKeysym(&e.xkey, 0)) == XK_q || k == XK_Escape) ));
+
+
+    /* OK, we're done:  clean up all image and X resources and go away */
+
+    rpng_x_cleanup();
+
+    return 0;
+}
+
+
+
+
+
+static int rpng_x_create_window(void)
+{
+    uch *xdata;
+    int need_colormap = FALSE;
+    int screen, pad;
+    ulg bg_pixel = 0L;
+    ulg attrmask;
+    Window root;
+    XEvent e;
+    XGCValues gcvalues;
+    XSetWindowAttributes attr;
+    XSizeHints *size_hints;
+    XTextProperty windowName, *pWindowName = &windowName;
+    XTextProperty iconName, *pIconName = &iconName;
+    XVisualInfo visual_info;
+    XWMHints *wm_hints;
+
+
+    screen = DefaultScreen(display);
+    depth = DisplayPlanes(display, screen);
+    root = RootWindow(display, screen);
+
+#ifdef DEBUG
+    XSynchronize(display, True);
+#endif
+
+#if 0
+/* GRR:  add 8-bit support */
+    if (/* depth != 8 && */ depth != 16 && depth != 24 && depth != 32) {
+        fprintf(stderr,
+          "screen depth %d not supported (only 16-, 24- or 32-bit TrueColor)\n",
+          depth);
+        return 2;
+    }
+
+    XMatchVisualInfo(display, screen, depth,
+      (depth == 8)? PseudoColor : TrueColor, &visual_info);
+    visual = visual_info.visual;
+#else
+    if (depth != 16 && depth != 24 && depth != 32) {
+        int visuals_matched = 0;
+
+        Trace((stderr, "default depth is %d:  checking other visuals\n",
+          depth))
+
+        /* 24-bit first */
+        visual_info.screen = screen;
+        visual_info.depth = 24;
+        visual_list = XGetVisualInfo(display,
+          VisualScreenMask | VisualDepthMask, &visual_info, &visuals_matched);
+        if (visuals_matched == 0) {
+/* GRR:  add 15-, 16- and 32-bit TrueColor visuals (also DirectColor?) */
+            fprintf(stderr, "default screen depth %d not supported, and no"
+              " 24-bit visuals found\n", depth);
+            return 2;
+        }
+        Trace((stderr, "XGetVisualInfo() returned %d 24-bit visuals\n",
+          visuals_matched))
+        visual = visual_list[0].visual;
+        depth = visual_list[0].depth;
+/*
+        colormap_size = visual_list[0].colormap_size;
+        visual_class = visual->class;
+        visualID = XVisualIDFromVisual(visual);
+ */
+        have_nondefault_visual = TRUE;
+        need_colormap = TRUE;
+    } else {
+        XMatchVisualInfo(display, screen, depth, TrueColor, &visual_info);
+        visual = visual_info.visual;
+    }
+#endif
+
+    RMask = visual->red_mask;
+    GMask = visual->green_mask;
+    BMask = visual->blue_mask;
+
+/* GRR:  add/check 8-bit support */
+    if (depth == 8 || need_colormap) {
+        colormap = XCreateColormap(display, root, visual, AllocNone);
+        if (!colormap) {
+            fprintf(stderr, "XCreateColormap() failed\n");
+            return 2;
+        }
+        have_colormap = TRUE;
+    }
+    if (depth == 15 || depth == 16) {
+        RShift = 15 - rpng_x_msb(RMask);    /* these are right-shifts */
+        GShift = 15 - rpng_x_msb(GMask);
+        BShift = 15 - rpng_x_msb(BMask);
+    } else if (depth > 16) {
+#define NO_24BIT_MASKS
+#ifdef NO_24BIT_MASKS
+        RShift = rpng_x_msb(RMask) - 7;     /* these are left-shifts */
+        GShift = rpng_x_msb(GMask) - 7;
+        BShift = rpng_x_msb(BMask) - 7;
+#else
+        RShift = 7 - rpng_x_msb(RMask);     /* these are right-shifts, too */
+        GShift = 7 - rpng_x_msb(GMask);
+        BShift = 7 - rpng_x_msb(BMask);
+#endif
+    }
+    if (depth >= 15 && (RShift < 0 || GShift < 0 || BShift < 0)) {
+        fprintf(stderr, "rpng internal logic error:  negative X shift(s)!\n");
+        return 2;
+    }
+
+/*---------------------------------------------------------------------------
+    Finally, create the window.
+  ---------------------------------------------------------------------------*/
+
+    attr.backing_store = Always;
+    attr.event_mask = ExposureMask | KeyPressMask | ButtonPressMask;
+    attrmask = CWBackingStore | CWEventMask;
+    if (have_nondefault_visual) {
+        attr.colormap = colormap;
+        attr.background_pixel = 0;
+        attr.border_pixel = 1;
+        attrmask |= CWColormap | CWBackPixel | CWBorderPixel;
+    }
+
+    window = XCreateWindow(display, root, 0, 0, image_width, image_height, 0,
+      depth, InputOutput, visual, attrmask, &attr);
+
+    if (window == None) {
+        fprintf(stderr, "XCreateWindow() failed\n");
+        return 2;
+    } else
+        have_window = TRUE;
+
+    if (depth == 8)
+        XSetWindowColormap(display, window, colormap);
+
+    if (!XStringListToTextProperty(&window_name, 1, pWindowName))
+        pWindowName = NULL;
+    if (!XStringListToTextProperty(&icon_name, 1, pIconName))
+        pIconName = NULL;
+
+    /* OK if either hints allocation fails; XSetWMProperties() allows NULLs */
+
+    if ((size_hints = XAllocSizeHints()) != NULL) {
+        /* window will not be resizable */
+        size_hints->flags = PMinSize | PMaxSize;
+        size_hints->min_width = size_hints->max_width = (int)image_width;
+        size_hints->min_height = size_hints->max_height = (int)image_height;
+    }
+
+    if ((wm_hints = XAllocWMHints()) != NULL) {
+        wm_hints->initial_state = NormalState;
+        wm_hints->input = True;
+     /* wm_hints->icon_pixmap = icon_pixmap; */
+        wm_hints->flags = StateHint | InputHint  /* | IconPixmapHint */ ;
+    }
+
+    XSetWMProperties(display, window, pWindowName, pIconName, NULL, 0,
+      size_hints, wm_hints, NULL);
+
+    XMapWindow(display, window);
+
+    gc = XCreateGC(display, window, 0, &gcvalues);
+
+/*---------------------------------------------------------------------------
+    Fill window with the specified background color.
+  ---------------------------------------------------------------------------*/
+
+    if (depth == 24 || depth == 32) {
+        bg_pixel = ((ulg)bg_red   << RShift) |
+                   ((ulg)bg_green << GShift) |
+                   ((ulg)bg_blue  << BShift);
+    } else if (depth == 16) {
+        bg_pixel = ((((ulg)bg_red   << 8) >> RShift) & RMask) |
+                   ((((ulg)bg_green << 8) >> GShift) & GMask) |
+                   ((((ulg)bg_blue  << 8) >> BShift) & BMask);
+    } else /* depth == 8 */ {
+
+        /* GRR:  add 8-bit support */
+
+    }
+
+    XSetForeground(display, gc, bg_pixel);
+    XFillRectangle(display, window, gc, 0, 0, image_width, image_height);
+
+/*---------------------------------------------------------------------------
+    Wait for first Expose event to do any drawing, then flush.
+  ---------------------------------------------------------------------------*/
+
+    do
+        XNextEvent(display, &e);
+    while (e.type != Expose || e.xexpose.count);
+
+    XFlush(display);
+
+/*---------------------------------------------------------------------------
+    Allocate memory for the X- and display-specific version of the image.
+  ---------------------------------------------------------------------------*/
+
+    if (depth == 24 || depth == 32) {
+        xdata = (uch *)malloc(4*image_width*image_height);
+        pad = 32;
+    } else if (depth == 16) {
+        xdata = (uch *)malloc(2*image_width*image_height);
+        pad = 16;
+    } else /* depth == 8 */ {
+        xdata = (uch *)malloc(image_width*image_height);
+        pad = 8;
+    }
+
+    if (!xdata) {
+        fprintf(stderr, PROGNAME ":  unable to allocate image memory\n");
+        return 4;
+    }
+
+    ximage = XCreateImage(display, visual, depth, ZPixmap, 0,
+      (char *)xdata, image_width, image_height, pad, 0);
+
+    if (!ximage) {
+        fprintf(stderr, PROGNAME ":  XCreateImage() failed\n");
+        free(xdata);
+        return 3;
+    }
+
+    /* to avoid testing the byte order every pixel (or doubling the size of
+     * the drawing routine with a giant if-test), we arbitrarily set the byte
+     * order to MSBFirst and let Xlib worry about inverting things on little-
+     * endian machines (like Linux/x86, old VAXen, etc.)--this is not the most
+     * efficient approach (the giant if-test would be better), but in the
+     * interest of clarity, we take the easy way out... */
+
+    ximage->byte_order = MSBFirst;
+
+    return 0;
+
+} /* end function rpng_x_create_window() */
+
+
+
+
+
+static int rpng_x_display_image(void)
+{
+    uch *src;
+    char *dest;
+    uch r, g, b, a;
+    ulg i, row, lastrow = 0;
+    ulg pixel;
+    int ximage_rowbytes = ximage->bytes_per_line;
+/*  int bpp = ximage->bits_per_pixel;  */
+
+
+    Trace((stderr, "beginning display loop (image_channels == %d)\n",
+      image_channels))
+    Trace((stderr, "   (width = %ld, rowbytes = %ld, ximage_rowbytes = %d)\n",
+      image_width, image_rowbytes, ximage_rowbytes))
+    Trace((stderr, "   (bpp = %d)\n", ximage->bits_per_pixel))
+    Trace((stderr, "   (byte_order = %s)\n", ximage->byte_order == MSBFirst?
+      "MSBFirst" : (ximage->byte_order == LSBFirst? "LSBFirst" : "unknown")))
+
+    if (depth == 24 || depth == 32) {
+        ulg red, green, blue;
+
+        for (lastrow = row = 0;  row < image_height;  ++row) {
+            src = image_data + row*image_rowbytes;
+            dest = ximage->data + row*ximage_rowbytes;
+            if (image_channels == 3) {
+                for (i = image_width;  i > 0;  --i) {
+                    red   = *src++;
+                    green = *src++;
+                    blue  = *src++;
+#ifdef NO_24BIT_MASKS
+                    pixel = (red   << RShift) |
+                            (green << GShift) |
+                            (blue  << BShift);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    /* GRR BUG:  this assumes bpp == 32, but may be 24: */
+                    *dest++ = (char)((pixel >> 24) & 0xff);
+                    *dest++ = (char)((pixel >> 16) & 0xff);
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+#else
+                    red   = (RShift < 0)? red   << (-RShift) : red   >> RShift;
+                    green = (GShift < 0)? green << (-GShift) : green >> GShift;
+                    blue  = (BShift < 0)? blue  << (-BShift) : blue  >> BShift;
+                    pixel = (red & RMask) | (green & GMask) | (blue & BMask);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    *dest++ = (char)((pixel >> 24) & 0xff);
+                    *dest++ = (char)((pixel >> 16) & 0xff);
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+#endif
+                }
+            } else /* if (image_channels == 4) */ {
+                for (i = image_width;  i > 0;  --i) {
+                    r = *src++;
+                    g = *src++;
+                    b = *src++;
+                    a = *src++;
+                    if (a == 255) {
+                        red   = r;
+                        green = g;
+                        blue  = b;
+                    } else if (a == 0) {
+                        red   = bg_red;
+                        green = bg_green;
+                        blue  = bg_blue;
+                    } else {
+                        /* this macro (from png.h) composites the foreground
+                         * and background values and puts the result into the
+                         * first argument */
+                        alpha_composite(red,   r, a, bg_red);
+                        alpha_composite(green, g, a, bg_green);
+                        alpha_composite(blue,  b, a, bg_blue);
+                    }
+                    pixel = (red   << RShift) |
+                            (green << GShift) |
+                            (blue  << BShift);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    *dest++ = (char)((pixel >> 24) & 0xff);
+                    *dest++ = (char)((pixel >> 16) & 0xff);
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+                }
+            }
+            /* display after every 16 lines */
+            if (((row+1) & 0xf) == 0) {
+                XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
+                  (int)lastrow, image_width, 16);
+                XFlush(display);
+                lastrow = row + 1;
+            }
+        }
+
+    } else if (depth == 16) {
+        ush red, green, blue;
+
+        for (lastrow = row = 0;  row < image_height;  ++row) {
+            src = image_data + row*image_rowbytes;
+            dest = ximage->data + row*ximage_rowbytes;
+            if (image_channels == 3) {
+                for (i = image_width;  i > 0;  --i) {
+                    red   = ((ush)(*src) << 8);
+                    ++src;
+                    green = ((ush)(*src) << 8);
+                    ++src;
+                    blue  = ((ush)(*src) << 8);
+                    ++src;
+                    pixel = ((red   >> RShift) & RMask) |
+                            ((green >> GShift) & GMask) |
+                            ((blue  >> BShift) & BMask);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+                }
+            } else /* if (image_channels == 4) */ {
+                for (i = image_width;  i > 0;  --i) {
+                    r = *src++;
+                    g = *src++;
+                    b = *src++;
+                    a = *src++;
+                    if (a == 255) {
+                        red   = ((ush)r << 8);
+                        green = ((ush)g << 8);
+                        blue  = ((ush)b << 8);
+                    } else if (a == 0) {
+                        red   = ((ush)bg_red   << 8);
+                        green = ((ush)bg_green << 8);
+                        blue  = ((ush)bg_blue  << 8);
+                    } else {
+                        /* this macro (from png.h) composites the foreground
+                         * and background values and puts the result back into
+                         * the first argument (== fg byte here:  safe) */
+                        alpha_composite(r, r, a, bg_red);
+                        alpha_composite(g, g, a, bg_green);
+                        alpha_composite(b, b, a, bg_blue);
+                        red   = ((ush)r << 8);
+                        green = ((ush)g << 8);
+                        blue  = ((ush)b << 8);
+                    }
+                    pixel = ((red   >> RShift) & RMask) |
+                            ((green >> GShift) & GMask) |
+                            ((blue  >> BShift) & BMask);
+                    /* recall that we set ximage->byte_order = MSBFirst above */
+                    *dest++ = (char)((pixel >>  8) & 0xff);
+                    *dest++ = (char)( pixel        & 0xff);
+                }
+            }
+            /* display after every 16 lines */
+            if (((row+1) & 0xf) == 0) {
+                XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
+                  (int)lastrow, image_width, 16);
+                XFlush(display);
+                lastrow = row + 1;
+            }
+        }
+
+    } else /* depth == 8 */ {
+
+        /* GRR:  add 8-bit support */
+
+    }
+
+    Trace((stderr, "calling final XPutImage()\n"))
+    if (lastrow < image_height) {
+        XPutImage(display, window, gc, ximage, 0, (int)lastrow, 0,
+          (int)lastrow, image_width, image_height-lastrow);
+        XFlush(display);
+    }
+
+    return 0;
+}
+
+
+
+
+static void rpng_x_cleanup(void)
+{
+    if (image_data) {
+        free(image_data);
+        image_data = NULL;
+    }
+
+    if (ximage) {
+        if (ximage->data) {
+            free(ximage->data);           /* we allocated it, so we free it */
+            ximage->data = (char *)NULL;  /*  instead of XDestroyImage() */
+        }
+        XDestroyImage(ximage);
+        ximage = NULL;
+    }
+
+    XFreeGC(display, gc);
+
+    if (have_window)
+        XDestroyWindow(display, window);
+
+    if (have_colormap)
+        XFreeColormap(display, colormap);
+
+    if (have_nondefault_visual)
+        XFree(visual_list);
+}
+
+
+
+
+
+static int rpng_x_msb(ulg u32val)
+{
+    int i;
+
+    for (i = 31;  i >= 0;  --i) {
+        if (u32val & 0x80000000L)
+            break;
+        u32val <<= 1;
+    }
+    return i;
+}

contrib/gregbook/wpng.c

@@ -0,0 +1,816 @@
+/*---------------------------------------------------------------------------
+
+   wpng - simple PNG-writing program                                 wpng.c
+
+   This program converts certain NetPBM binary files (grayscale and RGB,
+   maxval = 255) to PNG.  Non-interlaced PNGs are written progressively;
+   interlaced PNGs are read and written in one memory-intensive blast.
+   Thanks to Jean-loup Gailly for providing the necessary trick to read
+   interactive text from the keyboard while stdin is redirected.
+
+   NOTE:  includes provisional support for PNM type "8" (portable alphamap)
+          images, presumed to be a 32-bit interleaved RGBA format; no pro-
+          vision for possible interleaved grayscale+alpha (16-bit) format.
+          THIS IS UNLIKELY TO BECOME AN OFFICIAL NETPBM ALPHA FORMAT!
+
+   to do:
+    - delete output file if quit before calling any writepng routines
+    - process backspace with -text option under DOS/Win? (currently get ^H)
+
+  ---------------------------------------------------------------------------
+
+   Changelog:
+    - 1.01:  initial public release
+    - 1.02:  modified to allow abbreviated options
+    - 1.03:  removed extraneous character from usage screen; fixed bug in
+              command-line parsing
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2000 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+  ---------------------------------------------------------------------------*/
+
+#define PROGNAME  "wpng"
+#define VERSION   "1.03 of 19 March 2000"
+#define APPNAME   "Simple PGM/PPM/PAM to PNG Converter"
+
+#if defined(__MSDOS__) || defined(__OS2__)
+#  define DOS_OS2_W32
+#elif defined(_WIN32) || defined(__WIN32__)
+#  define DOS_OS2_W32
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <setjmp.h>     /* for jmpbuf declaration in writepng.h */
+#include <time.h>
+
+#ifdef DOS_OS2_W32
+#  include <io.h>       /* for isatty(), setmode() prototypes */
+#  include <fcntl.h>    /* O_BINARY for fdopen() without text translation */
+#  ifdef __EMX__
+#    ifndef getch
+#      define getch() _read_kbd(0, 1, 0)    /* need getche() */
+#    endif
+#  else /* !__EMX__ */
+#    ifdef __GO32__
+#      include <pc.h>
+#      define getch() getkey()  /* GRR:  need getche() */
+#    else
+#      include <conio.h>        /* for getche() console input */
+#    endif
+#  endif /* ?__EMX__ */
+#  define FGETS(buf,len,stream)  dos_kbd_gets(buf,len)
+#else
+#  include <unistd.h>           /* for isatty() prototype */
+#  define FGETS fgets
+#endif
+
+/* #define DEBUG  :  this enables the Trace() macros */
+
+/* #define FORBID_LATIN1_CTRL  :  this requires the user to re-enter any
+   text that includes control characters discouraged by the PNG spec; text
+   that includes an escape character (27) must be re-entered regardless */
+
+#include "writepng.h"   /* typedefs, common macros, writepng prototypes */
+
+
+
+/* local prototypes */
+
+static int  wpng_isvalid_latin1(uch *p, int len);
+static void wpng_cleanup(void);
+
+#ifdef DOS_OS2_W32
+   static char *dos_kbd_gets(char *buf, int len);
+#endif
+
+
+
+static mainprog_info wpng_info;   /* lone global */
+
+
+
+int main(int argc, char **argv)
+{
+#ifndef DOS_OS2_W32
+    FILE *keybd;
+#endif
+#ifdef sgi
+    FILE *tmpfile;      /* or we could just use keybd, since no overlap */
+    char tmpline[80];
+#endif
+    char *inname = NULL, outname[256];
+    char *p, pnmchar, pnmline[256];
+    char *bgstr, *textbuf = NULL;
+    ulg rowbytes;
+    int rc, len = 0;
+    int error = 0;
+    int text = FALSE;
+    int maxval;
+    double LUT_exponent;                /* just the lookup table */
+    double CRT_exponent = 2.2;          /* just the monitor */
+    double default_display_exponent;    /* whole display system */
+    double default_gamma = 0.0;
+
+
+    wpng_info.infile = NULL;
+    wpng_info.outfile = NULL;
+    wpng_info.image_data = NULL;
+    wpng_info.row_pointers = NULL;
+    wpng_info.filter = FALSE;
+    wpng_info.interlaced = FALSE;
+    wpng_info.have_bg = FALSE;
+    wpng_info.have_time = FALSE;
+    wpng_info.have_text = 0;
+    wpng_info.gamma = 0.0;
+
+
+    /* First get the default value for our display-system exponent, i.e.,
+     * the product of the CRT exponent and the exponent corresponding to
+     * the frame-buffer's lookup table (LUT), if any.  If the PNM image
+     * looks correct on the user's display system, its file gamma is the
+     * inverse of this value.  (Note that this is not an exhaustive list
+     * of LUT values--e.g., OpenStep has a lot of weird ones--but it should
+     * cover 99% of the current possibilities.  This section must ensure
+     * that default_display_exponent is positive.) */
+
+#if defined(NeXT)
+    /* third-party utilities can modify the default LUT exponent */
+    LUT_exponent = 1.0 / 2.2;
+    /*
+    if (some_next_function_that_returns_gamma(&next_gamma))
+        LUT_exponent = 1.0 / next_gamma;
+     */
+#elif defined(sgi)
+    LUT_exponent = 1.0 / 1.7;
+    /* there doesn't seem to be any documented function to
+     * get the "gamma" value, so we do it the hard way */
+    tmpfile = fopen("/etc/config/system.glGammaVal", "r");
+    if (tmpfile) {
+        double sgi_gamma;
+
+        fgets(tmpline, 80, tmpfile);
+        fclose(tmpfile);
+        sgi_gamma = atof(tmpline);
+        if (sgi_gamma > 0.0)
+            LUT_exponent = 1.0 / sgi_gamma;
+    }
+#elif defined(Macintosh)
+    LUT_exponent = 1.8 / 2.61;
+    /*
+    if (some_mac_function_that_returns_gamma(&mac_gamma))
+        LUT_exponent = mac_gamma / 2.61;
+     */
+#else
+    LUT_exponent = 1.0;   /* assume no LUT:  most PCs */
+#endif
+
+    /* the defaults above give 1.0, 1.3, 1.5 and 2.2, respectively: */
+    default_display_exponent = LUT_exponent * CRT_exponent;
+
+
+    /* If the user has set the SCREEN_GAMMA environment variable as suggested
+     * (somewhat imprecisely) in the libpng documentation, use that; otherwise
+     * use the default value we just calculated.  Either way, the user may
+     * override this via a command-line option. */
+
+    if ((p = getenv("SCREEN_GAMMA")) != NULL) {
+        double exponent = atof(p);
+
+        if (exponent > 0.0)
+            default_gamma = 1.0 / exponent;
+    }
+
+    if (default_gamma == 0.0)
+        default_gamma = 1.0 / default_display_exponent;
+
+
+    /* Now parse the command line for options and the PNM filename. */
+
+    while (*++argv && !error) {
+        if (!strncmp(*argv, "-i", 2)) {
+            wpng_info.interlaced = TRUE;
+        } else if (!strncmp(*argv, "-time", 3)) {
+            wpng_info.modtime = time(NULL);
+            wpng_info.have_time = TRUE;
+        } else if (!strncmp(*argv, "-text", 3)) {
+            text = TRUE;
+        } else if (!strncmp(*argv, "-gamma", 2)) {
+            if (!*++argv)
+                ++error;
+            else {
+                wpng_info.gamma = atof(*argv);
+                if (wpng_info.gamma <= 0.0)
+                    ++error;
+                else if (wpng_info.gamma > 1.01)
+                    fprintf(stderr, PROGNAME
+                      " warning:  file gammas are usually less than 1.0\n");
+            }
+        } else if (!strncmp(*argv, "-bgcolor", 4)) {
+            if (!*++argv)
+                ++error;
+            else {
+                bgstr = *argv;
+                if (strlen(bgstr) != 7 || bgstr[0] != '#')
+                    ++error;
+                else {
+                    unsigned r, g, b;  /* this way quiets compiler warnings */
+
+                    sscanf(bgstr+1, "%2x%2x%2x", &r, &g, &b);
+                    wpng_info.bg_red   = (uch)r;
+                    wpng_info.bg_green = (uch)g;
+                    wpng_info.bg_blue  = (uch)b;
+                    wpng_info.have_bg = TRUE;
+                }
+            }
+        } else {
+            if (**argv != '-') {
+                inname = *argv;
+                if (argv[1])   /* shouldn't be any more args after filename */
+                    ++error;
+            } else
+                ++error;   /* not expecting any other options */
+        }
+    }
+
+
+    /* open the input and output files, or register an error and abort */
+
+    if (!inname) {
+        if (isatty(0)) {
+            fprintf(stderr, PROGNAME
+              ":  must give input filename or provide image data via stdin\n");
+            ++error;
+        } else {
+#ifdef DOS_OS2_W32
+            /* some buggy C libraries require BOTH setmode() and fdopen(bin) */
+            setmode(fileno(stdin), O_BINARY);
+            setmode(fileno(stdout), O_BINARY);
+#endif
+            if ((wpng_info.infile = fdopen(fileno(stdin), "rb")) == NULL) {
+                fprintf(stderr, PROGNAME
+                  ":  unable to reopen stdin in binary mode\n");
+                ++error;
+            } else
+            if ((wpng_info.outfile = fdopen(fileno(stdout), "wb")) == NULL) {
+                fprintf(stderr, PROGNAME
+                  ":  unable to reopen stdout in binary mode\n");
+                fclose(wpng_info.infile);
+                ++error;
+            } else
+                wpng_info.filter = TRUE;
+        }
+    } else if ((len = strlen(inname)) > 250) {
+        fprintf(stderr, PROGNAME ":  input filename is too long [%d chars]\n",
+          len);
+        ++error;
+    } else if (!(wpng_info.infile = fopen(inname, "rb"))) {
+        fprintf(stderr, PROGNAME ":  can't open input file [%s]\n", inname);
+        ++error;
+    }
+
+    if (!error) {
+        fgets(pnmline, 256, wpng_info.infile);
+        if (pnmline[0] != 'P' || ((pnmchar = pnmline[1]) != '5' &&
+            pnmchar != '6' && pnmchar != '8'))
+        {
+            fprintf(stderr, PROGNAME
+              ":  input file [%s] is not a binary PGM, PPM or PAM file\n",
+              inname);
+            ++error;
+        } else {
+            wpng_info.pnmtype = (int)(pnmchar - '0');
+            if (wpng_info.pnmtype != 8)
+                wpng_info.have_bg = FALSE;  /* no need for bg if opaque */
+            do {
+                fgets(pnmline, 256, wpng_info.infile);  /* lose any comments */
+            } while (pnmline[0] == '#');
+            sscanf(pnmline, "%ld %ld", &wpng_info.width, &wpng_info.height);
+            do {
+                fgets(pnmline, 256, wpng_info.infile);  /* more comment lines */
+            } while (pnmline[0] == '#');
+            sscanf(pnmline, "%d", &maxval);
+            if (wpng_info.width <= 0L || wpng_info.height <= 0L ||
+                maxval != 255)
+            {
+                fprintf(stderr, PROGNAME
+                  ":  only positive width/height, maxval == 255 allowed \n");
+                ++error;
+            }
+            wpng_info.sample_depth = 8;  /* <==> maxval 255 */
+
+            if (!wpng_info.filter) {
+                /* make outname from inname */
+                if ((p = strrchr(inname, '.')) == NULL ||
+                    (p - inname) != (len - 4))
+                {
+                    strcpy(outname, inname);
+                    strcpy(outname+len, ".png");
+                } else {
+                    len -= 4;
+                    strncpy(outname, inname, len);
+                    strcpy(outname+len, ".png");
+                }
+                /* check if outname already exists; if not, open */
+                if ((wpng_info.outfile = fopen(outname, "rb")) != NULL) {
+                    fprintf(stderr, PROGNAME ":  output file exists [%s]\n",
+                      outname);
+                    fclose(wpng_info.outfile);
+                    ++error;
+                } else if (!(wpng_info.outfile = fopen(outname, "wb"))) {
+                    fprintf(stderr, PROGNAME ":  can't open output file [%s]\n",
+                      outname);
+                    ++error;
+                }
+            }
+        }
+        if (error) {
+            fclose(wpng_info.infile);
+            wpng_info.infile = NULL;
+            if (wpng_info.filter) {
+                fclose(wpng_info.outfile);
+                wpng_info.outfile = NULL;
+            }
+        }
+    }
+
+
+    /* if we had any errors, print usage and die horrible death...arrr! */
+
+    if (error) {
+        fprintf(stderr, "\n%s %s:  %s\n", PROGNAME, VERSION, APPNAME);
+        writepng_version_info();
+        fprintf(stderr, "\n"
+"Usage:  %s [-gamma exp] [-bgcolor bg] [-text] [-time] [-interlace] pnmfile\n"
+"or: ... | %s [-gamma exp] [-bgcolor bg] [-text] [-time] [-interlace] | ...\n"
+         "    exp \ttransfer-function exponent (``gamma'') of the image in\n"
+         "\t\t  floating-point format (e.g., ``%.5f''); if image looks\n"
+         "\t\t  correct on given display system, image gamma is equal to\n"
+         "\t\t  inverse of display-system exponent, i.e., 1 / (LUT * CRT)\n"
+         "\t\t  (where LUT = lookup-table exponent and CRT = CRT exponent;\n"
+         "\t\t  first varies, second is usually 2.2, all are positive)\n"
+         "    bg  \tdesired background color for alpha-channel images, in\n"
+         "\t\t  7-character hex RGB format (e.g., ``#ff7700'' for orange:\n"
+         "\t\t  same as HTML colors)\n"
+         "    -text\tprompt interactively for text info (tEXt chunks)\n"
+         "    -time\tinclude a tIME chunk (last modification time)\n"
+         "    -interlace\twrite interlaced PNG image\n"
+         "\n"
+"pnmfile or stdin must be a binary PGM (`P5'), PPM (`P6') or (extremely\n"
+"unofficial and unsupported!) PAM (`P8') file.  Currently it is required\n"
+"to have maxval == 255 (i.e., no scaling).  If pnmfile is specified, it\n"
+"is converted to the corresponding PNG file with the same base name but a\n"
+"``.png'' extension; files read from stdin are converted and sent to stdout.\n"
+"The conversion is progressive (low memory usage) unless interlacing is\n"
+"requested; in that case the whole image will be buffered in memory and\n"
+"written in one call.\n"
+         "\n", PROGNAME, PROGNAME, default_gamma);
+        exit(1);
+    }
+
+
+    /* prepare the text buffers for libpng's use; note that even though
+     * PNG's png_text struct includes a length field, we don't have to fill
+     * it out */
+
+    if (text &&
+#ifndef DOS_OS2_W32
+        (keybd = fdopen(fileno(stderr), "r")) != NULL &&
+#endif
+        (textbuf = (char *)malloc((5 + 9)*75)) != NULL)
+    {
+        int i, valid, result;
+
+        fprintf(stderr,
+          "Enter text info (no more than 72 characters per line);\n");
+        fprintf(stderr, "to skip a field, hit the <Enter> key.\n");
+        /* note:  just <Enter> leaves len == 1 */
+
+        do {
+            valid = TRUE;
+            p = textbuf + TEXT_TITLE_OFFSET;
+            fprintf(stderr, "  Title: ");
+            fflush(stderr);
+            if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) {
+                if (p[len-1] == '\n')
+                    p[--len] = '\0';
+                wpng_info.title = p;
+                wpng_info.have_text |= TEXT_TITLE;
+                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
+                    fprintf(stderr, "    " PROGNAME " warning:  character code"
+                      " %u is %sdiscouraged by the PNG\n    specification "
+                      "[first occurrence was at character position #%d]\n",
+                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
+                      result+1);
+                    fflush(stderr);
+#ifdef FORBID_LATIN1_CTRL
+                    wpng_info.have_text &= ~TEXT_TITLE;
+                    valid = FALSE;
+#else
+                    if (p[result] == 27) {    /* escape character */
+                        wpng_info.have_text &= ~TEXT_TITLE;
+                        valid = FALSE;
+                    }
+#endif
+                }
+            }
+        } while (!valid);
+
+        do {
+            valid = TRUE;
+            p = textbuf + TEXT_AUTHOR_OFFSET;
+            fprintf(stderr, "  Author: ");
+            fflush(stderr);
+            if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) {
+                if (p[len-1] == '\n')
+                    p[--len] = '\0';
+                wpng_info.author = p;
+                wpng_info.have_text |= TEXT_AUTHOR;
+                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
+                    fprintf(stderr, "    " PROGNAME " warning:  character code"
+                      " %u is %sdiscouraged by the PNG\n    specification "
+                      "[first occurrence was at character position #%d]\n",
+                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
+                      result+1);
+                    fflush(stderr);
+#ifdef FORBID_LATIN1_CTRL
+                    wpng_info.have_text &= ~TEXT_AUTHOR;
+                    valid = FALSE;
+#else
+                    if (p[result] == 27) {    /* escape character */
+                        wpng_info.have_text &= ~TEXT_AUTHOR;
+                        valid = FALSE;
+                    }
+#endif
+                }
+            }
+        } while (!valid);
+
+        do {
+            valid = TRUE;
+            p = textbuf + TEXT_DESC_OFFSET;
+            fprintf(stderr, "  Description (up to 9 lines):\n");
+            for (i = 1;  i < 10;  ++i) {
+                fprintf(stderr, "    [%d] ", i);
+                fflush(stderr);
+                if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1)
+                    p += len;   /* now points at NULL; char before is newline */
+                else
+                    break;
+            }
+            if ((len = p - (textbuf + TEXT_DESC_OFFSET)) > 1) {
+                if (p[-1] == '\n') {
+                    p[-1] = '\0';
+                    --len;
+                }
+                wpng_info.desc = textbuf + TEXT_DESC_OFFSET;
+                wpng_info.have_text |= TEXT_DESC;
+                p = textbuf + TEXT_DESC_OFFSET;
+                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
+                    fprintf(stderr, "    " PROGNAME " warning:  character code"
+                      " %u is %sdiscouraged by the PNG\n    specification "
+                      "[first occurrence was at character position #%d]\n",
+                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
+                      result+1);
+                    fflush(stderr);
+#ifdef FORBID_LATIN1_CTRL
+                    wpng_info.have_text &= ~TEXT_DESC;
+                    valid = FALSE;
+#else
+                    if (p[result] == 27) {    /* escape character */
+                        wpng_info.have_text &= ~TEXT_DESC;
+                        valid = FALSE;
+                    }
+#endif
+                }
+            }
+        } while (!valid);
+
+        do {
+            valid = TRUE;
+            p = textbuf + TEXT_COPY_OFFSET;
+            fprintf(stderr, "  Copyright: ");
+            fflush(stderr);
+            if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) {
+                if (p[len-1] == '\n')
+                    p[--len] = '\0';
+                wpng_info.copyright = p;
+                wpng_info.have_text |= TEXT_COPY;
+                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
+                    fprintf(stderr, "    " PROGNAME " warning:  character code"
+                      " %u is %sdiscouraged by the PNG\n    specification "
+                      "[first occurrence was at character position #%d]\n",
+                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
+                      result+1);
+                    fflush(stderr);
+#ifdef FORBID_LATIN1_CTRL
+                    wpng_info.have_text &= ~TEXT_COPY;
+                    valid = FALSE;
+#else
+                    if (p[result] == 27) {    /* escape character */
+                        wpng_info.have_text &= ~TEXT_COPY;
+                        valid = FALSE;
+                    }
+#endif
+                }
+            }
+        } while (!valid);
+
+        do {
+            valid = TRUE;
+            p = textbuf + TEXT_EMAIL_OFFSET;
+            fprintf(stderr, "  E-mail: ");
+            fflush(stderr);
+            if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) {
+                if (p[len-1] == '\n')
+                    p[--len] = '\0';
+                wpng_info.email = p;
+                wpng_info.have_text |= TEXT_EMAIL;
+                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
+                    fprintf(stderr, "    " PROGNAME " warning:  character code"
+                      " %u is %sdiscouraged by the PNG\n    specification "
+                      "[first occurrence was at character position #%d]\n",
+                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
+                      result+1);
+                    fflush(stderr);
+#ifdef FORBID_LATIN1_CTRL
+                    wpng_info.have_text &= ~TEXT_EMAIL;
+                    valid = FALSE;
+#else
+                    if (p[result] == 27) {    /* escape character */
+                        wpng_info.have_text &= ~TEXT_EMAIL;
+                        valid = FALSE;
+                    }
+#endif
+                }
+            }
+        } while (!valid);
+
+        do {
+            valid = TRUE;
+            p = textbuf + TEXT_URL_OFFSET;
+            fprintf(stderr, "  URL: ");
+            fflush(stderr);
+            if (FGETS(p, 74, keybd) && (len = strlen(p)) > 1) {
+                if (p[len-1] == '\n')
+                    p[--len] = '\0';
+                wpng_info.url = p;
+                wpng_info.have_text |= TEXT_URL;
+                if ((result = wpng_isvalid_latin1((uch *)p, len)) >= 0) {
+                    fprintf(stderr, "    " PROGNAME " warning:  character code"
+                      " %u is %sdiscouraged by the PNG\n    specification "
+                      "[first occurrence was at character position #%d]\n",
+                      (unsigned)p[result], (p[result] == 27)? "strongly " : "",
+                      result+1);
+                    fflush(stderr);
+#ifdef FORBID_LATIN1_CTRL
+                    wpng_info.have_text &= ~TEXT_URL;
+                    valid = FALSE;
+#else
+                    if (p[result] == 27) {    /* escape character */
+                        wpng_info.have_text &= ~TEXT_URL;
+                        valid = FALSE;
+                    }
+#endif
+                }
+            }
+        } while (!valid);
+
+#ifndef DOS_OS2_W32
+        fclose(keybd);
+#endif
+
+    } else if (text) {
+        fprintf(stderr, PROGNAME ":  unable to allocate memory for text\n");
+        text = FALSE;
+        wpng_info.have_text = 0;
+    }
+
+
+    /* allocate libpng stuff, initialize transformations, write pre-IDAT data */
+
+    if ((rc = writepng_init(&wpng_info)) != 0) {
+        switch (rc) {
+            case 2:
+                fprintf(stderr, PROGNAME
+                  ":  libpng initialization problem (longjmp)\n");
+                break;
+            case 4:
+                fprintf(stderr, PROGNAME ":  insufficient memory\n");
+                break;
+            case 11:
+                fprintf(stderr, PROGNAME
+                  ":  internal logic error (unexpected PNM type)\n");
+                break;
+            default:
+                fprintf(stderr, PROGNAME
+                  ":  unknown writepng_init() error\n");
+                break;
+        }
+        exit(rc);
+    }
+
+
+    /* free textbuf, since it's a completely local variable and all text info
+     * has just been written to the PNG file */
+
+    if (text && textbuf) {
+        free(textbuf);
+        textbuf = NULL;
+    }
+
+
+    /* calculate rowbytes on basis of image type; note that this becomes much
+     * more complicated if we choose to support PBM type, ASCII PNM types, or
+     * 16-bit-per-sample binary data [currently not an official NetPBM type] */
+
+    if (wpng_info.pnmtype == 5)
+        rowbytes = wpng_info.width;
+    else if (wpng_info.pnmtype == 6)
+        rowbytes = wpng_info.width * 3;
+    else /* if (wpng_info.pnmtype == 8) */
+        rowbytes = wpng_info.width * 4;
+
+
+    /* read and write the image, either in its entirety (if writing interlaced
+     * PNG) or row by row (if non-interlaced) */
+
+    fprintf(stderr, "Encoding image data...\n");
+    fflush(stderr);
+
+    if (wpng_info.interlaced) {
+        long i;
+        ulg bytes;
+        ulg image_bytes = rowbytes * wpng_info.height;   /* overflow? */
+
+        wpng_info.image_data = (uch *)malloc(image_bytes);
+        wpng_info.row_pointers = (uch **)malloc(wpng_info.height*sizeof(uch *));
+        if (wpng_info.image_data == NULL || wpng_info.row_pointers == NULL) {
+            fprintf(stderr, PROGNAME ":  insufficient memory for image data\n");
+            writepng_cleanup(&wpng_info);
+            wpng_cleanup();
+            exit(5);
+        }
+        for (i = 0;  i < wpng_info.height;  ++i)
+            wpng_info.row_pointers[i] = wpng_info.image_data + i*rowbytes;
+        bytes = fread(wpng_info.image_data, 1, image_bytes, wpng_info.infile);
+        if (bytes != image_bytes) {
+            fprintf(stderr, PROGNAME ":  expected %lu bytes, got %lu bytes\n",
+              image_bytes, bytes);
+            fprintf(stderr, "  (continuing anyway)\n");
+        }
+        if (writepng_encode_image(&wpng_info) != 0) {
+            fprintf(stderr, PROGNAME
+              ":  libpng problem (longjmp) while writing image data\n");
+            writepng_cleanup(&wpng_info);
+            wpng_cleanup();
+            exit(2);
+        }
+
+    } else /* not interlaced:  write progressively (row by row) */ {
+        long j;
+        ulg bytes;
+
+        wpng_info.image_data = (uch *)malloc(rowbytes);
+        if (wpng_info.image_data == NULL) {
+            fprintf(stderr, PROGNAME ":  insufficient memory for row data\n");
+            writepng_cleanup(&wpng_info);
+            wpng_cleanup();
+            exit(5);
+        }
+        error = 0;
+        for (j = wpng_info.height;  j > 0L;  --j) {
+            bytes = fread(wpng_info.image_data, 1, rowbytes, wpng_info.infile);
+            if (bytes != rowbytes) {
+                fprintf(stderr, PROGNAME
+                  ":  expected %lu bytes, got %lu bytes (row %ld)\n", rowbytes,
+                  bytes, wpng_info.height-j);
+                ++error;
+                break;
+            }
+            if (writepng_encode_row(&wpng_info) != 0) {
+                fprintf(stderr, PROGNAME
+                  ":  libpng problem (longjmp) while writing row %ld\n",
+                  wpng_info.height-j);
+                ++error;
+                break;
+            }
+        }
+        if (error) {
+            writepng_cleanup(&wpng_info);
+            wpng_cleanup();
+            exit(2);
+        }
+        if (writepng_encode_finish(&wpng_info) != 0) {
+            fprintf(stderr, PROGNAME ":  error on final libpng call\n");
+            writepng_cleanup(&wpng_info);
+            wpng_cleanup();
+            exit(2);
+        }
+    }
+
+
+    /* OK, we're done (successfully):  clean up all resources and quit */
+
+    fprintf(stderr, "Done.\n");
+    fflush(stderr);
+
+    writepng_cleanup(&wpng_info);
+    wpng_cleanup();
+
+    return 0;
+}
+
+
+
+
+
+static int wpng_isvalid_latin1(uch *p, int len)
+{
+    int i, result = -1;
+
+    for (i = 0;  i < len;  ++i) {
+        if (p[i] == 10 || (p[i] > 31 && p[i] < 127) || p[i] > 160)
+            continue;           /* character is completely OK */
+        if (result < 0 || (p[result] != 27 && p[i] == 27))
+            result = i;         /* mark location of first questionable one */
+    }                           /*  or of first escape character (bad) */
+
+    return result;
+}
+
+
+
+
+
+static void wpng_cleanup(void)
+{
+    if (wpng_info.outfile) {
+        fclose(wpng_info.outfile);
+        wpng_info.outfile = NULL;
+    }
+
+    if (wpng_info.infile) {
+        fclose(wpng_info.infile);
+        wpng_info.infile = NULL;
+    }
+
+    if (wpng_info.image_data) {
+        free(wpng_info.image_data);
+        wpng_info.image_data = NULL;
+    }
+
+    if (wpng_info.row_pointers) {
+        free(wpng_info.row_pointers);
+        wpng_info.row_pointers = NULL;
+    }
+}
+
+
+
+
+#ifdef DOS_OS2_W32
+
+static char *dos_kbd_gets(char *buf, int len)
+{
+    int ch, count=0;
+
+    do {
+        buf[count++] = ch = getche();
+    } while (ch != '\r' && count < len-1);
+
+    buf[count--] = '\0';        /* terminate string */
+    if (buf[count] == '\r')     /* Enter key makes CR, so change to newline */
+        buf[count] = '\n';
+
+    fprintf(stderr, "\n");      /* Enter key does *not* cause a newline */
+    fflush(stderr);
+
+    return buf;
+}
+
+#endif /* DOS_OS2_W32 */

contrib/gregbook/writepng.c

@@ -0,0 +1,368 @@
+/*---------------------------------------------------------------------------
+
+   wpng - simple PNG-writing program                             writepng.c
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2000 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+  ---------------------------------------------------------------------------*/
+
+
+#include <stdlib.h>     /* for exit() prototype */
+
+#include "png.h"        /* libpng header; includes zlib.h and setjmp.h */
+#include "writepng.h"   /* typedefs, common macros, public prototypes */
+
+
+/* local prototype */
+
+static void writepng_error_handler(png_structp png_ptr, png_const_charp msg);
+
+
+
+void writepng_version_info(void)
+{
+  fprintf(stderr, "   Compiled with libpng %s; using libpng %s.\n",
+    PNG_LIBPNG_VER_STRING, png_libpng_ver);
+  fprintf(stderr, "   Compiled with zlib %s; using zlib %s.\n",
+    ZLIB_VERSION, zlib_version);
+}
+
+
+
+
+/* returns 0 for success, 2 for libpng problem, 4 for out of memory, 11 for
+ *  unexpected pnmtype; note that outfile might be stdout */
+
+int writepng_init(mainprog_info *mainprog_ptr)
+{
+    png_structp  png_ptr;       /* note:  temporary variables! */
+    png_infop  info_ptr;
+    int color_type, interlace_type;
+
+
+    /* could also replace libpng warning-handler (final NULL), but no need: */
+
+    png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, mainprog_ptr,
+      writepng_error_handler, NULL);
+    if (!png_ptr)
+        return 4;   /* out of memory */
+
+    info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr) {
+        png_destroy_write_struct(&png_ptr, NULL);
+        return 4;   /* out of memory */
+    }
+
+
+    /* setjmp() must be called in every function that calls a PNG-writing
+     * libpng function, unless an alternate error handler was installed--
+     * but compatible error handlers must either use longjmp() themselves
+     * (as in this program) or exit immediately, so here we go: */
+
+    if (setjmp(mainprog_ptr->jmpbuf)) {
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+        return 2;
+    }
+
+
+    /* make sure outfile is (re)opened in BINARY mode */
+
+    png_init_io(png_ptr, mainprog_ptr->outfile);
+
+
+    /* set the compression levels--in general, always want to leave filtering
+     * turned on (except for palette images) and allow all of the filters,
+     * which is the default; want 32K zlib window, unless entire image buffer
+     * is 16K or smaller (unknown here)--also the default; usually want max
+     * compression (NOT the default); and remaining compression flags should
+     * be left alone */
+
+    png_set_compression_level(png_ptr, Z_BEST_COMPRESSION);
+/*
+    >> this is default for no filtering; Z_FILTERED is default otherwise:
+    png_set_compression_strategy(png_ptr, Z_DEFAULT_STRATEGY);
+    >> these are all defaults:
+    png_set_compression_mem_level(png_ptr, 8);
+    png_set_compression_window_bits(png_ptr, 15);
+    png_set_compression_method(png_ptr, 8);
+ */
+
+
+    /* set the image parameters appropriately */
+
+    if (mainprog_ptr->pnmtype == 5)
+        color_type = PNG_COLOR_TYPE_GRAY;
+    else if (mainprog_ptr->pnmtype == 6)
+        color_type = PNG_COLOR_TYPE_RGB;
+    else if (mainprog_ptr->pnmtype == 8)
+        color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+    else {
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+        return 11;
+    }
+
+    interlace_type = mainprog_ptr->interlaced? PNG_INTERLACE_ADAM7 :
+                                               PNG_INTERLACE_NONE;
+
+    png_set_IHDR(png_ptr, info_ptr, mainprog_ptr->width, mainprog_ptr->height,
+      mainprog_ptr->sample_depth, color_type, interlace_type,
+      PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
+
+    if (mainprog_ptr->gamma > 0.0)
+        png_set_gAMA(png_ptr, info_ptr, mainprog_ptr->gamma);
+
+    if (mainprog_ptr->have_bg) {   /* we know it's RGBA, not gray+alpha */
+        png_color_16  background;
+
+        background.red = mainprog_ptr->bg_red;
+        background.green = mainprog_ptr->bg_green;
+        background.blue = mainprog_ptr->bg_blue;
+        png_set_bKGD(png_ptr, info_ptr, &background);
+    }
+
+    if (mainprog_ptr->have_time) {
+        png_time  modtime;
+
+        png_convert_from_time_t(&modtime, mainprog_ptr->modtime);
+        png_set_tIME(png_ptr, info_ptr, &modtime);
+    }
+
+    if (mainprog_ptr->have_text) {
+        png_text  text[6];
+        int  num_text = 0;
+
+        if (mainprog_ptr->have_text & TEXT_TITLE) {
+            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
+            text[num_text].key = "Title";
+            text[num_text].text = mainprog_ptr->title;
+            ++num_text;
+        }
+        if (mainprog_ptr->have_text & TEXT_AUTHOR) {
+            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
+            text[num_text].key = "Author";
+            text[num_text].text = mainprog_ptr->author;
+            ++num_text;
+        }
+        if (mainprog_ptr->have_text & TEXT_DESC) {
+            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
+            text[num_text].key = "Description";
+            text[num_text].text = mainprog_ptr->desc;
+            ++num_text;
+        }
+        if (mainprog_ptr->have_text & TEXT_COPY) {
+            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
+            text[num_text].key = "Copyright";
+            text[num_text].text = mainprog_ptr->copyright;
+            ++num_text;
+        }
+        if (mainprog_ptr->have_text & TEXT_EMAIL) {
+            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
+            text[num_text].key = "E-mail";
+            text[num_text].text = mainprog_ptr->email;
+            ++num_text;
+        }
+        if (mainprog_ptr->have_text & TEXT_URL) {
+            text[num_text].compression = PNG_TEXT_COMPRESSION_NONE;
+            text[num_text].key = "URL";
+            text[num_text].text = mainprog_ptr->url;
+            ++num_text;
+        }
+        png_set_text(png_ptr, info_ptr, text, num_text);
+    }
+
+
+    /* write all chunks up to (but not including) first IDAT */
+
+    png_write_info(png_ptr, info_ptr);
+
+
+    /* if we wanted to write any more text info *after* the image data, we
+     * would set up text struct(s) here and call png_set_text() again, with
+     * just the new data; png_set_tIME() could also go here, but it would
+     * have no effect since we already called it above (only one tIME chunk
+     * allowed) */
+
+
+    /* set up the transformations:  for now, just pack low-bit-depth pixels
+     * into bytes (one, two or four pixels per byte) */
+
+    png_set_packing(png_ptr);
+/*  png_set_shift(png_ptr, &sig_bit);  to scale low-bit-depth values */
+
+
+    /* make sure we save our pointers for use in writepng_encode_image() */
+
+    mainprog_ptr->png_ptr = png_ptr;
+    mainprog_ptr->info_ptr = info_ptr;
+
+
+    /* OK, that's all we need to do for now; return happy */
+
+    return 0;
+}
+
+
+
+
+
+/* returns 0 for success, 2 for libpng (longjmp) problem */
+
+int writepng_encode_image(mainprog_info *mainprog_ptr)
+{
+    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
+    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
+
+
+    /* as always, setjmp() must be called in every function that calls a
+     * PNG-writing libpng function */
+
+    if (setjmp(mainprog_ptr->jmpbuf)) {
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+        mainprog_ptr->png_ptr = NULL;
+        mainprog_ptr->info_ptr = NULL;
+        return 2;
+    }
+
+
+    /* and now we just write the whole image; libpng takes care of interlacing
+     * for us */
+
+    png_write_image(png_ptr, mainprog_ptr->row_pointers);
+
+
+    /* since that's it, we also close out the end of the PNG file now--if we
+     * had any text or time info to write after the IDATs, second argument
+     * would be info_ptr, but we optimize slightly by sending NULL pointer: */
+
+    png_write_end(png_ptr, NULL);
+
+    return 0;
+}
+
+
+
+
+
+/* returns 0 if succeeds, 2 if libpng problem */
+
+int writepng_encode_row(mainprog_info *mainprog_ptr)  /* NON-interlaced only! */
+{
+    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
+    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
+
+
+    /* as always, setjmp() must be called in every function that calls a
+     * PNG-writing libpng function */
+
+    if (setjmp(mainprog_ptr->jmpbuf)) {
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+        mainprog_ptr->png_ptr = NULL;
+        mainprog_ptr->info_ptr = NULL;
+        return 2;
+    }
+
+
+    /* image_data points at our one row of image data */
+
+    png_write_row(png_ptr, mainprog_ptr->image_data);
+
+    return 0;
+}
+
+
+
+
+
+/* returns 0 if succeeds, 2 if libpng problem */
+
+int writepng_encode_finish(mainprog_info *mainprog_ptr)   /* NON-interlaced! */
+{
+    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
+    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
+
+
+    /* as always, setjmp() must be called in every function that calls a
+     * PNG-writing libpng function */
+
+    if (setjmp(mainprog_ptr->jmpbuf)) {
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+        mainprog_ptr->png_ptr = NULL;
+        mainprog_ptr->info_ptr = NULL;
+        return 2;
+    }
+
+
+    /* close out PNG file; if we had any text or time info to write after
+     * the IDATs, second argument would be info_ptr: */
+
+    png_write_end(png_ptr, NULL);
+
+    return 0;
+}
+
+
+
+
+
+void writepng_cleanup(mainprog_info *mainprog_ptr)
+{
+    png_structp png_ptr = (png_structp)mainprog_ptr->png_ptr;
+    png_infop info_ptr = (png_infop)mainprog_ptr->info_ptr;
+
+    if (png_ptr && info_ptr)
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+}
+
+
+
+
+
+static void writepng_error_handler(png_structp png_ptr, png_const_charp msg)
+{
+    mainprog_info  *mainprog_ptr;
+
+    /* This function, aside from the extra step of retrieving the "error
+     * pointer" (below) and the fact that it exists within the application
+     * rather than within libpng, is essentially identical to libpng's
+     * default error handler.  The second point is critical:  since both
+     * setjmp() and longjmp() are called from the same code, they are
+     * guaranteed to have compatible notions of how big a jmp_buf is,
+     * regardless of whether _BSD_SOURCE or anything else has (or has not)
+     * been defined. */
+
+    fprintf(stderr, "writepng libpng error: %s\n", msg);
+    fflush(stderr);
+
+    mainprog_ptr = png_get_error_ptr(png_ptr);
+    if (mainprog_ptr == NULL) {         /* we are completely hosed now */
+        fprintf(stderr,
+          "writepng severe error:  jmpbuf not recoverable; terminating.\n");
+        fflush(stderr);
+        exit(99);
+    }
+
+    longjmp(mainprog_ptr->jmpbuf, 1);
+}

contrib/gregbook/writepng.h

@@ -0,0 +1,109 @@
+/*---------------------------------------------------------------------------
+
+   wpng - simple PNG-writing program                             writepng.h
+
+  ---------------------------------------------------------------------------
+
+      Copyright (c) 1998-2000 Greg Roelofs.  All rights reserved.
+
+      This software is provided "as is," without warranty of any kind,
+      express or implied.  In no event shall the author or contributors
+      be held liable for any damages arising in any way from the use of
+      this software.
+
+      Permission is granted to anyone to use this software for any purpose,
+      including commercial applications, and to alter it and redistribute
+      it freely, subject to the following restrictions:
+
+      1. Redistributions of source code must retain the above copyright
+         notice, disclaimer, and this list of conditions.
+      2. Redistributions in binary form must reproduce the above copyright
+         notice, disclaimer, and this list of conditions in the documenta-
+         tion and/or other materials provided with the distribution.
+      3. All advertising materials mentioning features or use of this
+         software must display the following acknowledgment:
+
+            This product includes software developed by Greg Roelofs
+            and contributors for the book, "PNG: The Definitive Guide,"
+            published by O'Reilly and Associates.
+
+  ---------------------------------------------------------------------------*/
+
+#ifndef TRUE
+#  define TRUE 1
+#  define FALSE 0
+#endif
+
+#ifndef MAX
+#  define MAX(a,b)  ((a) > (b)? (a) : (b))
+#  define MIN(a,b)  ((a) < (b)? (a) : (b))
+#endif
+
+#ifdef DEBUG
+#  define Trace(x)  {fprintf x ; fflush(stderr); fflush(stdout);}
+#else
+#  define Trace(x)  ;
+#endif
+
+#define TEXT_TITLE    0x01
+#define TEXT_AUTHOR   0x02
+#define TEXT_DESC     0x04
+#define TEXT_COPY     0x08
+#define TEXT_EMAIL    0x10
+#define TEXT_URL      0x20
+
+#define TEXT_TITLE_OFFSET        0
+#define TEXT_AUTHOR_OFFSET      72
+#define TEXT_COPY_OFFSET     (2*72)
+#define TEXT_EMAIL_OFFSET    (3*72)
+#define TEXT_URL_OFFSET      (4*72)
+#define TEXT_DESC_OFFSET     (5*72)
+
+typedef unsigned char   uch;
+typedef unsigned short  ush;
+typedef unsigned long   ulg;
+
+typedef struct _mainprog_info {
+    double gamma;
+    long width;
+    long height;
+    time_t modtime;
+    FILE *infile;
+    FILE *outfile;
+    void *png_ptr;
+    void *info_ptr;
+    uch *image_data;
+    uch **row_pointers;
+    char *title;
+    char *author;
+    char *desc;
+    char *copyright;
+    char *email;
+    char *url;
+    int filter;    /* command-line-filter flag, not PNG row filter! */
+    int pnmtype;
+    int sample_depth;
+    int interlaced;
+    int have_bg;
+    int have_time;
+    int have_text;
+    jmp_buf jmpbuf;
+    uch bg_red;
+    uch bg_green;
+    uch bg_blue;
+} mainprog_info;
+
+
+/* prototypes for public functions in writepng.c */
+
+void writepng_version_info(void);
+
+int writepng_init(mainprog_info *mainprog_ptr);
+
+int writepng_encode_image(mainprog_info *mainprog_ptr);
+
+int writepng_encode_row(mainprog_info *mainprog_ptr);
+
+int writepng_encode_finish(mainprog_info *mainprog_ptr);
+
+void writepng_cleanup(mainprog_info *mainprog_ptr);

contrib/pngminus/README

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

contrib/pngminus/makefile

@@ -0,0 +1,52 @@
+# Makefile for PngMinus (png2pnm and pnm2png)
+# Linux / Unix
+
+CC=cc -O -n32
+LD=cc -O -n32
+#CC=gcc -O
+#LD=gcc -O
+LB=ar
+RM=rm
+CP=cp
+
+PNGPATH = /usr/local
+PNGINC = $(PNGPATH)/include
+PNGLIB = $(PNGPATH)/lib -lpng
+# PNGLIB = $(PNGPATH)/libpng.a
+
+ZPATH = /usr/local
+ZINC = $(ZPATH)/include
+ZLIB = $(ZPATH)/lib -lz
+# ZLIB = $(ZPATH)/libz.a
+
+CCFLAGS=-I$(PNGINC) -I$(ZINC)
+LDFLAGS=-L$(PNGLIB) -L$(ZLIB) -lm
+C=.c
+O=.o
+L=.a
+E=
+
+# dependencies
+
+all: png2pnm$(E) pnm2png$(E)
+
+png2pnm$(O): png2pnm$(C)
+	$(CC) -c $(CCFLAGS) png2pnm$(C)
+
+png2pnm$(E): png2pnm$(O)
+	$(LD) -o png2pnm$(E) png2pnm$(O) $(LDFLAGS)
+
+pnm2png$(O): pnm2png$(C)
+	$(CC) -c $(CCFLAGS) pnm2png$(C)
+
+pnm2png$(E): pnm2png$(O)
+	$(LD) -o pnm2png$(E) pnm2png$(O) $(LDFLAGS)
+
+clean:
+	$(RM) png2pnm$(O)
+	$(RM) pnm2png$(O)
+	$(RM) png2pnm$(E)
+	$(RM) pnm2png$(E)
+
+# End of makefile for png2pnm / pnm2png
+

contrib/pngminus/makefile.std

@@ -0,0 +1,52 @@
+# Makefile for PngMinus (png2pnm and pnm2png)
+# Linux / Unix
+
+CC=cc -O
+LD=cc -O
+#CC=gcc -O
+#LD=gcc -O
+LB=ar
+RM=rm
+CP=cp
+
+PNGPATH = /usr/local
+PNGINC = $(PNGPATH)/include
+#PNGLIB = $(PNGPATH)/lib -lpng
+PNGLIB = $(PNGPATH)/lib/libpng.a
+
+ZPATH = /usr/local
+ZINC = $(ZPATH)/include
+#ZLIB = $(ZPATH)/lib -lz
+ZLIB = $(ZPATH)/lib/libz.a
+
+CCFLAGS=-I$(PNGINC) -I$(ZINC)
+LDFLAGS=-L$(PNGLIB) -L$(ZLIB)
+C=.c
+O=.o
+L=.a
+E=
+
+# dependencies
+
+all: png2pnm$(E) pnm2png$(E)
+
+png2pnm$(O): png2pnm$(C)
+	$(CC) -c $(CCFLAGS) png2pnm$(C)
+
+png2pnm$(E): png2pnm$(O)
+	$(LD) -o png2pnm$(E) png2pnm$(O) $(LDFLAGS) -lpng -lz -lm
+
+pnm2png$(O): pnm2png$(C)
+	$(CC) -c $(CCFLAGS) pnm2png$(C)
+
+pnm2png$(E): pnm2png$(O)
+	$(LD) -o pnm2png$(E) pnm2png$(O) $(LDFLAGS) -lpng -lz -lm
+
+clean:
+	$(RM) png2pnm$(O)
+	$(RM) pnm2png$(O)
+	$(RM) png2pnm$(E)
+	$(RM) pnm2png$(E)
+
+# End of makefile for png2pnm / pnm2png
+

contrib/pngminus/makefile.tc3

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

contrib/pngminus/makevms.com

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

contrib/pngminus/png2pnm.bat

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

contrib/pngminus/png2pnm.c

@@ -0,0 +1,425 @@
+/*
+ *  png2pnm.c --- conversion from PNG-file to PGM/PPM-file
+ *  copyright (C) 1999 by Willem van Schaik <willem@schaik.com>
+ *
+ *  version 1.0 - 1999.10.15 - First version.
+ *
+ *  Permission to use, copy, modify, and distribute this software and
+ *  its documentation for any purpose and without fee is hereby granted,
+ *  provided that the above copyright notice appear in all copies and
+ *  that both that copyright notice and this permission notice appear in
+ *  supporting documentation. This software is provided "as is" without
+ *  express or implied warranty.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#ifdef __TURBOC__
+#include <mem.h>
+#include <fcntl.h>
+#endif
+
+#ifndef BOOL
+#define BOOL unsigned char
+#endif
+#ifndef TRUE
+#define TRUE (BOOL) 1
+#endif
+#ifndef FALSE
+#define FALSE (BOOL) 0
+#endif
+
+#ifdef __TURBOC__
+#define STDIN  0
+#define STDOUT 1
+#define STDERR 2
+#endif
+
+/* to make png2pnm verbose so we can find problems (needs to be before png.h) */
+#ifndef PNG_DEBUG
+#define PNG_DEBUG 0
+#endif
+
+#include "png.h"
+
+/* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */
+#ifndef png_jmpbuf
+#  define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
+#endif
+
+/* function prototypes */
+
+int  main (int argc, char *argv[]);
+void usage ();
+BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL alpha);
+
+/*
+ *  main
+ */
+
+int main(int argc, char *argv[])
+{
+  FILE *fp_rd = stdin;
+  FILE *fp_wr = stdout;
+  FILE *fp_al = NULL;
+  BOOL raw = TRUE;
+  BOOL alpha = FALSE;
+  int argi;
+
+  for (argi = 1; argi < argc; argi++)
+  {
+    if (argv[argi][0] == '-')
+    {
+      switch (argv[argi][1])
+      {
+        case 'n':
+          raw = FALSE;
+          break;
+        case 'r':
+          raw = TRUE;
+          break;
+        case 'a':
+          alpha = TRUE;
+          argi++;
+          if ((fp_al = fopen (argv[argi], "wb")) == NULL)
+          {
+            fprintf (stderr, "PNM2PNG\n");
+            fprintf (stderr, "Error:  can not create alpha-channel file %s\n", argv[argi]);
+            exit (1);
+          }
+          break;
+        case 'h':
+        case '?':
+          usage();
+          exit(0);
+          break;
+        default:
+          fprintf (stderr, "PNG2PNM\n");
+          fprintf (stderr, "Error:  unknown option %s\n", argv[argi]);
+          usage();
+          exit(1);
+          break;
+      } /* end switch */
+    }
+    else if (fp_rd == stdin)
+    {
+      if ((fp_rd = fopen (argv[argi], "rb")) == NULL)
+      {
+             fprintf (stderr, "PNG2PNM\n");
+            fprintf (stderr, "Error:  file %s does not exist\n", argv[argi]);
+            exit (1);
+      }
+    }
+    else if (fp_wr == stdout)
+    {
+      if ((fp_wr = fopen (argv[argi], "wb")) == NULL)
+      {
+        fprintf (stderr, "PNG2PNM\n");
+        fprintf (stderr, "Error:  can not create file %s\n", argv[argi]);
+        exit (1);
+      }
+    }
+    else
+    {
+      fprintf (stderr, "PNG2PNM\n");
+      fprintf (stderr, "Error:  too many parameters\n");
+      usage();
+      exit(1);
+    }
+  } /* end for */
+
+#ifdef __TURBOC__
+  /* set stdin/stdout if required to binary */
+  if (fp_rd == stdin)
+  {
+    setmode (STDIN, O_BINARY);
+  }
+  if ((raw) && (fp_wr == stdout))
+  {
+    setmode (STDOUT, O_BINARY);
+  }
+#endif
+
+  /* call the conversion program itself */
+  if (png2pnm (fp_rd, fp_wr, fp_al, raw, alpha) == FALSE)
+  {
+    fprintf (stderr, "PNG2PNM\n");
+    fprintf (stderr, "Error:  unsuccessful convertion of PNG-image\n");
+    exit(1);
+  }
+
+  /* close input file */
+  fclose (fp_rd);
+  /* close output file */
+  fclose (fp_wr);
+  /* close alpha file */
+  if (alpha)
+    fclose (fp_al);
+
+  return 0;
+}
+
+/*
+ *  usage
+ */
+
+void usage()
+{
+  fprintf (stderr, "PNG2PNM\n");
+  fprintf (stderr, "   by Willem van Schaik, 1999\n");
+#ifdef __TURBOC__
+  fprintf (stderr, "   for Turbo-C and Borland-C compilers\n");
+#else
+  fprintf (stderr, "   for Linux (and Unix) compilers\n");
+#endif
+  fprintf (stderr, "Usage:  png2pnm [options] <file>.png [<file>.pnm]\n");
+  fprintf (stderr, "   or:  ... | png2pnm [options]\n");
+  fprintf (stderr, "Options:\n");
+  fprintf (stderr, "   -r[aw]   write pnm-file in binary format (P4/P5/P6) (default)\n");
+  fprintf (stderr, "   -n[oraw] write pnm-file in ascii format (P1/P2/P3)\n");
+  fprintf (stderr, "   -a[lpha] <file>.pgm write PNG alpha channel as pgm-file\n");
+  fprintf (stderr, "   -h | -?  print this help-information\n");
+}
+
+/*
+ *  png2pnm
+ */
+
+BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL alpha)
+{
+  png_struct    *png_ptr = NULL;
+  png_info	*info_ptr = NULL;
+  png_byte      buf[8];
+  png_byte      *png_pixels = NULL;
+  png_byte      **row_pointers = NULL;
+  png_byte      *pix_ptr = NULL;
+  png_uint_32   row_bytes;
+
+  png_uint_32   width;
+  png_uint_32   height;
+  int           bit_depth;
+  int           channels;
+  int           color_type;
+  int           alpha_present;
+  int           row, col;
+  int           ret;
+  int           i;
+
+  /* read and check signature in PNG file */
+  ret = fread (buf, 1, 8, png_file);
+  if (ret != 8)
+    return FALSE;
+
+  ret = png_check_sig (buf, 8);
+  if (!ret)
+    return FALSE;
+
+  /* create png and info structures */
+
+  png_ptr = png_create_read_struct (PNG_LIBPNG_VER_STRING,
+    NULL, NULL, NULL);
+  if (!png_ptr)
+    return FALSE;   /* out of memory */
+
+  info_ptr = png_create_info_struct (png_ptr);
+  if (!info_ptr)
+  {
+    png_destroy_read_struct (&png_ptr, NULL, NULL);
+    return FALSE;   /* out of memory */
+  }
+
+  if (setjmp (png_jmpbuf(png_ptr)))
+  {
+    png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
+    return FALSE;
+  }
+
+  /* set up the input control for C streams */
+  png_init_io (png_ptr, png_file);
+  png_set_sig_bytes (png_ptr, 8);  /* we already read the 8 signature bytes */
+
+  /* read the file information */
+  png_read_info (png_ptr, info_ptr);
+
+  /* get size and bit-depth of the PNG-image */
+  png_get_IHDR (png_ptr, info_ptr,
+    &width, &height, &bit_depth, &color_type,
+    NULL, NULL, NULL);
+
+  /* set-up the transformations */
+
+  /* transform paletted images into full-color rgb */
+  if (color_type == PNG_COLOR_TYPE_PALETTE)
+    png_set_expand (png_ptr);
+  /* expand images to bit-depth 8 (only applicable for grayscale images) */
+  if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
+    png_set_expand (png_ptr);
+  /* transform transparency maps into full alpha-channel */
+  if (png_get_valid (png_ptr, info_ptr, PNG_INFO_tRNS))
+    png_set_expand (png_ptr);
+
+#ifdef NJET
+  /* downgrade 16-bit images to 8 bit */
+  if (bit_depth == 16)
+    png_set_strip_16 (png_ptr);
+  /* transform grayscale images into full-color */
+  if (color_type == PNG_COLOR_TYPE_GRAY ||
+    color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+    png_set_gray_to_rgb (png_ptr);
+  /* only if file has a file gamma, we do a correction */
+  if (png_get_gAMA (png_ptr, info_ptr, &file_gamma))
+    png_set_gamma (png_ptr, (double) 2.2, file_gamma);
+#endif
+
+  /* all transformations have been registered; now update info_ptr data,
+   * get rowbytes and channels, and allocate image memory */
+
+  png_read_update_info (png_ptr, info_ptr);
+
+  /* get the new color-type and bit-depth (after expansion/stripping) */
+  png_get_IHDR (png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
+    NULL, NULL, NULL);
+
+  /* check for 16-bit files */
+  if (bit_depth == 16)
+  {
+    raw = FALSE;
+#ifdef __TURBOC__
+    pnm_file->flags &= ~((unsigned) _F_BIN);
+#endif
+  }
+
+  /* calculate new number of channels and store alpha-presence */
+  if (color_type == PNG_COLOR_TYPE_GRAY)
+    channels = 1;
+  else if (color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+    channels = 2;
+  else if (color_type == PNG_COLOR_TYPE_RGB)
+    channels = 3;
+  else if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+    channels = 4;
+  else
+    channels = 0; /* should never happen */
+  alpha_present = (channels - 1) % 2;
+
+  /* check if alpha is expected to be present in file */
+  if (alpha && !alpha_present)
+  {
+    fprintf (stderr, "PNG2PNM\n");
+    fprintf (stderr, "Error:  PNG-file doesn't contain alpha channel\n");
+    exit (1);
+  }
+
+  /* row_bytes is the width x number of channels x (bit-depth / 8) */
+  row_bytes = png_get_rowbytes (png_ptr, info_ptr);
+
+  if ((png_pixels = (png_byte *) malloc (row_bytes * height * sizeof (png_byte))) == NULL) {
+    png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
+    return FALSE;
+  }
+
+  if ((row_pointers = (png_byte **) malloc (height * sizeof (png_bytep))) == NULL)
+  {
+    png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
+    free (png_pixels);
+    png_pixels = NULL;
+    return FALSE;
+  }
+
+  /* set the individual row_pointers to point at the correct offsets */
+  for (i = 0; i < (height); i++)
+    row_pointers[i] = png_pixels + i * row_bytes;
+
+  /* now we can go ahead and just read the whole image */
+  png_read_image (png_ptr, row_pointers);
+
+  /* read rest of file, and get additional chunks in info_ptr - REQUIRED */
+  png_read_end (png_ptr, info_ptr);
+
+  /* clean up after the read, and free any memory allocated - REQUIRED */
+  png_destroy_read_struct (&png_ptr, &info_ptr, (png_infopp) NULL);
+
+  /* write header of PNM file */
+
+  if ((color_type == PNG_COLOR_TYPE_GRAY) ||
+      (color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
+  {
+    fprintf (pnm_file, "%s\n", (raw) ? "P5" : "P2");
+    fprintf (pnm_file, "%d %d\n", (int) width, (int) height);
+    fprintf (pnm_file, "%ld\n", ((1L << (int) bit_depth) - 1L));
+  }
+  else if ((color_type == PNG_COLOR_TYPE_RGB) ||
+           (color_type == PNG_COLOR_TYPE_RGB_ALPHA))
+  {
+    fprintf (pnm_file, "%s\n", (raw) ? "P6" : "P3");
+    fprintf (pnm_file, "%d %d\n", (int) width, (int) height);
+    fprintf (pnm_file, "%ld\n", ((1L << (int) bit_depth) - 1L));
+  }
+
+  /* write header of PGM file with alpha channel */
+
+  if ((alpha) &&
+      ((color_type == PNG_COLOR_TYPE_GRAY_ALPHA) ||
+       (color_type == PNG_COLOR_TYPE_RGB_ALPHA)))
+  {
+    fprintf (alpha_file, "%s\n", (raw) ? "P5" : "P2");
+    fprintf (alpha_file, "%d %d\n", (int) width, (int) height);
+    fprintf (alpha_file, "%ld\n", ((1L << (int) bit_depth) - 1L));
+  }
+
+  /* write data to PNM file */
+  pix_ptr = png_pixels;
+
+  for (row = 0; row < height; row++)
+  {
+    for (col = 0; col < width; col++)
+    {
+      for (i = 0; i < (channels - alpha_present); i++)
+      {
+        if (raw)
+          fputc ((int) *pix_ptr++ , pnm_file);
+        else
+          if (bit_depth == 16)
+            fprintf (pnm_file, "%ld ", ((long) *pix_ptr++ << 8) + (long) *pix_ptr++);
+          else
+            fprintf (pnm_file, "%ld ", (long) *pix_ptr++);
+      }
+      if (alpha_present)
+      {
+        if (!alpha)
+        {
+          pix_ptr++; /* alpha */
+          if (bit_depth == 16)
+            pix_ptr++;
+        }
+        else /* output alpha-channel as pgm file */
+        {
+          if (raw)
+            fputc ((int) *pix_ptr++ , alpha_file);
+          else
+            if (bit_depth == 16)
+              fprintf (alpha_file, "%ld ", ((long) *pix_ptr++ << 8) + (long) *pix_ptr++);
+            else
+              fprintf (alpha_file, "%ld ", (long) *pix_ptr++);
+        }
+      } /* if alpha_present */
+
+      if (!raw)
+        if (col % 4 == 3)
+          fprintf (pnm_file, "\n");
+    } /* end for col */
+
+    if (!raw)
+      if (col % 4 != 0)
+        fprintf (pnm_file, "\n");
+  } /* end for row */
+
+  if (row_pointers != (unsigned char**) NULL)
+    free (row_pointers);
+  if (png_pixels != (unsigned char*) NULL)
+    free (png_pixels);
+
+  return TRUE;
+
+} /* end of source */
+

contrib/pngminus/png2pnm.sh

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

contrib/pngminus/pngminus.bat

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

contrib/pngminus/pngminus.sh

@@ -0,0 +1,4 @@
+make -f makefile.std
+sh png2pnm.sh
+sh pnm2png.sh
+

contrib/pngminus/pnm2png.bat

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

contrib/pngminus/pnm2png.c

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

contrib/pngminus/pnm2png.sh

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

contrib/pngsuite/README

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

example.c

@@ -1,20 +1,33 @@
 
+#if 0 /* in case someone actually tries to compile this */
+
 /* example.c - an example of using libpng */
 
 /* This is an example of how to use libpng to read and write PNG files.
  * The file libpng.txt is much more verbose then this.  If you have not
  * read it, do so first.  This was designed to be a starting point of an
- * implementation.  This is not officially part of libpng, and therefore
- * does not require a copyright notice.
+ * implementation.  This is not officially part of libpng, is hereby placed
+ * in the public domain, and therefore does not require a copyright notice.
  *
  * This file does not currently compile, because it is missing certain
  * parts, like allocating memory to hold an image.  You will have to
  * supply these parts to get it to compile.  For an example of a minimal
- * working PNG reader/writer, see pngtest.c, included in this distribution.
+ * working PNG reader/writer, see pngtest.c, included in this distribution;
+ * see also the programs in the contrib directory.
  */
 
 #include "png.h"
 
+ /* The png_jmpbuf() macro, used in error handling, became available in
+  * libpng version 1.0.6.  If you want to be able to run your code with older
+  * versions of libpng, you must define the macro yourself (but only if it
+  * is not already defined by libpng!).
+  */
+
+#ifndef png_jmpbuf
+#  define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
+#endif
+
 /* Check to see if a file is a PNG file using png_sig_cmp().  png_sig_cmp()
  * returns zero if the image is a PNG and nonzero if it isn't a PNG.
  *
@@ -41,7 +54,7 @@ int check_if_png(char *file_name, FILE **fp)
    char buf[PNG_BYTES_TO_CHECK];
 
    /* Open the prospective PNG file. */
-   if ((*fp = fopen(file_name, "rb")) != NULL);
+   if ((*fp = fopen(file_name, "rb")) == NULL)
       return 0;
 
    /* Read in some of the signature bytes */
@@ -109,7 +122,8 @@ void read_png(FILE *fp, unsigned int sig_read)  /* file is already open */
     * the normal method of doing things with libpng).  REQUIRED unless you
     * set up your own error handlers in the png_create_read_struct() earlier.
     */
-   if (setjmp(png_ptr->jmpbuf))
+
+   if (setjmp(png_jmpbuf(png_ptr)))
    {
       /* Free all of the memory associated with the png_ptr and info_ptr */
       png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
@@ -134,6 +148,19 @@ void read_png(FILE *fp, unsigned int sig_read)  /* file is already open */
    /* If we have already read some of the signature */
    png_set_sig_bytes(png_ptr, sig_read);
 
+#ifdef hilevel
+   /*
+    * If you have enough memory to read in the entire image at once,
+    * and you need to specify only transforms that can be controlled
+    * with one of the PNG_TRANSFORM_* bits (this presently excludes
+    * dithering, filling, setting background, and doing gamma
+    * adjustment), then you can read the entire image (including
+    * pixels) into the info structure with this call:
+    */
+   png_read_png(png_ptr, info_ptr, png_transforms, NULL);
+#else
+   /* OK, you're doing it the hard way, with the lower-level functions */
+
    /* The call to png_read_info() gives us all of the information from the
     * PNG file before the first IDAT (image data chunk).  REQUIRED
     */
@@ -216,7 +243,7 @@ void read_png(FILE *fp, unsigned int sig_read)  /* file is already open */
       screen_gamma = 1.7 or 1.0;  /* A good guess for Mac systems */
    }
 
-   /* Tell libpng to handle the gamma conversion for you.  The second call
+   /* Tell libpng to handle the gamma conversion for you.  The final call
     * is a good guess for PC generated images, but it should be configurable
     * by the user at run time by the user.  It is strongly suggested that
     * your application support gamma correction.
@@ -225,7 +252,7 @@ void read_png(FILE *fp, unsigned int sig_read)  /* file is already open */
    int intent;
 
    if (png_get_sRGB(png_ptr, info_ptr, &intent))
-      png_set_sRGB(png_ptr, intent, 0);
+      png_set_gamma(png_ptr, screen_gamma, 0.45455);
    else
    {
       double image_gamma;
@@ -273,7 +300,7 @@ void read_png(FILE *fp, unsigned int sig_read)  /* file is already open */
     */
    if (png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT))
    {
-      png_color8p sig_bit;
+      png_color_8p sig_bit;
 
       png_get_sBIT(png_ptr, info_ptr, &sig_bit);
       png_set_shift(png_ptr, sig_bit);
@@ -348,6 +375,9 @@ void read_png(FILE *fp, unsigned int sig_read)  /* file is already open */
 
    /* read rest of file, and get additional chunks in info_ptr - REQUIRED */
    png_read_end(png_ptr, info_ptr);
+#endif hilevel
+
+   /* At this point you have read the entire image */
 
    /* clean up after the read, and free any memory allocated - REQUIRED */
    png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
@@ -387,7 +417,7 @@ initialize_png_reader(png_structp *png_ptr, png_infop *info_ptr)
       return ERROR;
    }
 
-   if (setjmp((*png_ptr)->jmpbuf))
+   if (setjmp(png_jmpbuf((*png_ptr))))
    {
       png_destroy_read_struct(png_ptr, info_ptr, (png_infopp)NULL);
       return ERROR;
@@ -415,7 +445,7 @@ int
 process_data(png_structp *png_ptr, png_infop *info_ptr,
    png_bytep buffer, png_uint_32 length)
 {
-   if (setjmp((*png_ptr)->jmpbuf))
+   if (setjmp(png_jmpbuf((*png_ptr))))
    {
       /* Free the png_ptr and info_ptr memory on error */
       png_destroy_read_struct(png_ptr, info_ptr, (png_infopp)NULL);
@@ -497,6 +527,7 @@ void write_png(char *file_name /* , ... other image information ... */)
    FILE *fp;
    png_structp png_ptr;
    png_infop info_ptr;
+   png_colorp palette;
 
    /* open the file */
    fp = fopen(file_name, "wb");
@@ -528,13 +559,13 @@ void write_png(char *file_name /* , ... other image information ... */)
    }
 
    /* Set error handling.  REQUIRED if you aren't supplying your own
-    * error hadnling functions in the png_create_write_struct() call.
+    * error handling functions in the png_create_write_struct() call.
     */
-   if (setjmp(png_ptr->jmpbuf))
+   if (setjmp(png_jmpbuf(png_ptr)))
    {
       /* If we get here, we had a problem reading the file */
       fclose(fp);
-      png_destroy_write_struct(&png_ptr,  (png_infopp)NULL);
+      png_destroy_write_struct(&png_ptr,  (png_infopp)info_ptr);
       return;
    }
 
@@ -550,6 +581,15 @@ void write_png(char *file_name /* , ... other image information ... */)
    /* where user_io_ptr is a structure you want available to the callbacks */
 #endif no_streams /* only use one initialization method */
 
+#ifdef hilevel
+   /* This is the easy way.  Use it if you already have all the
+    * image info living info in the structure.  You could "|" many
+    * PNG_TRANSFORM flags into the png_transforms integer here.
+    */
+   png_write_png(png_ptr, info_ptr, png_transforms, NULL);
+#else
+   /* This is the hard way */
+
    /* Set the image information here.  Width and height are up to 2^31,
     * bit_depth is one of 1, 2, 4, 8, or 16, but valid values also depend on
     * the color_type selected. color_type is one of PNG_COLOR_TYPE_GRAY,
@@ -565,6 +605,9 @@ void write_png(char *file_name /* , ... other image information ... */)
    palette = (png_colorp)png_malloc(png_ptr, 256 * sizeof (png_color));
    /* ... set palette colors ... */
    png_set_PLTE(png_ptr, info_ptr, palette, 256);
+   /* You must not free palette here, because png_set_PLTE only makes a link to
+      the palette that you malloced.  Wait until you are about to destroy
+      the png structure. */
 
    /* optional significant bit chunk */
    /* if we are dealing with a grayscale image then */
@@ -593,15 +636,31 @@ void write_png(char *file_name /* , ... other image information ... */)
    text_ptr[2].key = "Description";
    text_ptr[2].text = "<long text>";
    text_ptr[2].compression = PNG_TEXT_COMPRESSION_zTXt;
+#ifdef PNG_iTXt_SUPPORTED
+   text_ptr[0].lang = NULL;
+   text_ptr[1].lang = NULL;
+   text_ptr[2].lang = NULL;
+#endif
    png_set_text(png_ptr, info_ptr, text_ptr, 3);
 
    /* other optional chunks like cHRM, bKGD, tRNS, tIME, oFFs, pHYs, */
-   /* note that if sRGB is present the cHRM chunk must be ignored
+   /* note that if sRGB is present the gAMA and cHRM chunks must be ignored
     * on read and must be written in accordance with the sRGB profile */
 
    /* Write the file header information.  REQUIRED */
    png_write_info(png_ptr, info_ptr);
 
+   /* If you want, you can write the info in two steps, in case you need to
+    * write your private chunk ahead of PLTE:
+    *
+    *   png_write_info_before_PLTE(write_ptr, write_info_ptr);
+    *   write_my_chunk();
+    *   png_write_info(png_ptr, info_ptr);
+    *
+    * However, given the level of known- and unknown-chunk support in 1.1.0
+    * and up, this should no longer be necessary.
+    */
+
    /* Once we write out the header, the compression type on the text
     * chunks gets changed to PNG_TEXT_COMPRESSION_NONE_WR or
     * PNG_TEXT_COMPRESSION_zTXt_WR, so it doesn't get written out again
@@ -651,10 +710,10 @@ void write_png(char *file_name /* , ... other image information ... */)
     * use the first method if you aren't handling interlacing yourself.
     */
    png_uint_32 k, height, width;
-   png_byte image[height][width];
+   png_byte image[height][width*bytes_per_pixel];
    png_bytep row_pointers[height];
    for (k = 0; k < height; k++)
-     row_pointers[k] = image + k*width;
+     row_pointers[k] = image + k*width*bytes_per_pixel;
 
    /* One of the following output methods is REQUIRED */
 #ifdef entire /* write out the entire image data in one call */
@@ -680,19 +739,29 @@ void write_png(char *file_name /* , ... other image information ... */)
 #endif no_entire /* use only one output method */
 
    /* You can write optional chunks like tEXt, zTXt, and tIME at the end
-    * as well.
+    * as well.  Shouldn't be necessary in 1.1.0 and up as all the public
+    * chunks are supported and you can use png_set_unknown_chunks() to
+    * register unknown chunks into the info structure to be written out.
     */
 
    /* It is REQUIRED to call this to finish writing the rest of the file */
    png_write_end(png_ptr, info_ptr);
+#endif hilevel
 
-   /* if you malloced the palette, free it here */
-   free(info_ptr->palette);
+   /* If you png_malloced a palette, free it here (don't free info_ptr->palette,
+      as recommended in versions 1.0.5m and earlier of this example; if
+      libpng mallocs info_ptr->palette, libpng will free it).  If you
+      allocated it with malloc() instead of png_malloc(), use free() instead
+      of png_free(). */
+   png_free(png_ptr, palette);
 
-   /* if you allocated any text comments, free them here */
+   /* Similarly, if you png_malloced any data that you passed in with
+      png_set_something(), such as a hist or trans array, free it here,
+      when you can be sure that libpng is through with it. */
+   png_free(png_ptr, trans);
 
    /* clean up after the write, and free any memory allocated */
-   png_destroy_write_struct(&png_ptr, (png_infopp)NULL);
+   png_destroy_write_struct(&png_ptr, (png_infopp)info_ptr);
 
    /* close the file */
    fclose(fp);
@@ -701,3 +770,4 @@ void write_png(char *file_name /* , ... other image information ... */)
    return;
 }
 
+#endif /* if 0 */

libpngpf.3

@@ -1,6 +1,6 @@
-.TH LIBPNGPF 3 October 1, 1999
+.TH LIBPNGPF 3 April 7, 2000
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.0.4c - October 1, 1999
+libpng \- Portable Network Graphics (PNG) Reference Library 1.0.6d
 (private functions)
 .SH SYNOPSIS
 \fB#include <png.h>\fP
@@ -55,6 +55,10 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.0.4c - October 1,
 
 \fI\fB
 
+\fBpng_charp png_decompress_chunk (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIcomp_type\fP\fB, png_charp \fP\fIchunkdata\fP\fB, png_size_t \fP\fIchunklength\fP\fB, png_size_t \fP\fIprefix_length\fP\fB, png_size_t \fI*data_length\fP\fB);\fP
+
+\fI\fB
+
 \fBvoid png_destroy_struct (png_voidp \fIstruct_ptr\fP\fB);\fP
 
 \fI\fB
@@ -187,6 +191,10 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.0.4c - October 1,
 
 \fI\fB
 
+\fBint png_handle_as_unknown (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIchunk_name\fP\fB);\fP
+
+\fI\fB
+
 \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
 
 \fI\fB
@@ -211,6 +219,14 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.0.4c - October 1,
 
 \fI\fB
 
+\fBvoid png_handle_iCCP (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_iTXt (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_oFFs (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
 \fI\fB
@@ -231,6 +247,14 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.0.4c - October 1,
 
 \fI\fB
 
+\fBvoid png_handle_sCAL (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_sPLT (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_sRGB (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIlength\fP\fB);\fP
 
 \fI\fB
@@ -399,6 +423,10 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.0.4c - October 1,
 
 \fI\fB
 
+\fBvoid png_write_cHRM_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIwhite_x\fP\fB, png_uint_32 \fP\fIwhite_y\fP\fB, png_uint_32 \fP\fIred_x\fP\fB, png_uint_32 \fP\fIred_y\fP\fB, png_uint_32 \fP\fIgreen_x\fP\fB, png_uint_32 \fP\fIgreen_y\fP\fB, png_uint_32 \fP\fIblue_x\fP\fB, png_uint_32 \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
@@ -417,11 +445,15 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.0.4c - October 1,
 
 \fI\fB
 
+\fBvoid png_write_gAMA_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIint_file_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
+\fBvoid png_write_iCCP (png_structp \fP\fIpng_ptr\fP\fB, png_charp \fP\fIname\fP\fB, int \fP\fIcompression_type\fP\fB, png_charp \fP\fIprofile\fP\fB, int \fIproflen\fP\fB);\fP
 
 \fI\fB
 
@@ -437,6 +469,14 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.0.4c - October 1,
 
 \fI\fB
 
+\fBvoid png_write_init (png_structp \fIpng_ptr\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_iTXt (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIcompression\fP\fB, png_charp \fP\fIkey\fP\fB, png_charp \fP\fIlang\fP\fB, png_charp \fP\fItranslated_key\fP\fB, png_charp \fItext)\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
@@ -457,6 +497,14 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.0.4c - October 1,
 
 \fI\fB
 
+\fBvoid png_write_sCAL (png_structp \fP\fIpng_ptr\fP\fB, png_charp \fP\fIunit\fP\fB, double \fP\fIwidth\fP\fB, double \fIheight\fP\fB);\fP
+
+\fI\fB
+
+\fBvoid png_write_sCAL_s (png_structp \fP\fIpng_ptr\fP\fB, png_charp \fP\fIunit\fP\fB, png_charp \fP\fIwidth\fP\fB, png_charp \fIheight\fP\fB);\fP
+
+\fI\fB
+
 \fBvoid png_write_sig (png_structp \fIpng_ptr\fP\fB);\fP
 
 \fI\fB
@@ -465,6 +513,10 @@ libpng \- Portable Network Graphics (PNG) Reference Library 1.0.4c - October 1,
 
 \fI\fB
 
+\fBvoid png_write_sPLT (png_structp \fP\fIpng_ptr\fP\fB, png_spalette_p \fIpalette\fP\fB);\fP
+
+\fI\fB
+
 \fBvoid png_write_start_row (png_structp \fIpng_ptr\fP\fB);\fP
 
 \fI\fB

png.5

@@ -1,4 +1,4 @@
-.TH PNG 5 "October 1, 1999"
+.TH PNG 5 "April 7, 2000"
 .SH NAME
 png \- Portable Network Graphics (PNG) format
 .SH DESCRIPTION
@@ -20,10 +20,12 @@ platforms.
 .SH "SEE ALSO"
 .IR libpng(3), zlib(3), deflate(5), and zlib(5)
 .LP
-PNG 1.1 specification, January 1999:
+PNG 1.2 specification, July 1999:
 .IP
 .br
-http://www.cdrom.com/pub/png
+http://www.cdrom.com/pub/png (moving to http://www.libpng.org)
+.br
+or ftp://ftp.uu.net/graphics/png/documents
 .LP
 PNG 1.0 specification, October 1996:
 .IP

png.c

@@ -1,47 +1,54 @@
 
 /* png.c - location for general purpose libpng functions
  *
- * libpng version 1.0.4c - October 1, 1999
+ * libpng version 1.0.6d - April 7, 2000
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
- * 
+ * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson
+ *
  */
 
 #define PNG_INTERNAL
 #define PNG_NO_EXTERN
+#include <assert.h>
 #include "png.h"
 
+/* Generate a compiler error if there is an old png.h in the search path. */
+typedef version_1_0_6d Your_png_h_is_not_version_1_0_6d;
+
 /* Version information for C files.  This had better match the version
- * string defined in png.h.
- */
+ * string defined in png.h.  */
 
-char png_libpng_ver[12] = "1.0.4c";
+#ifdef PNG_USE_GLOBAL_ARRAYS
+/* png_libpng_ver was changed to a function in version 1.0.5c */
+char png_libpng_ver[12] = "1.0.6d";
 
+/* png_sig was changed to a function in version 1.0.5c */
 /* Place to hold the signature string for a PNG file. */
 png_byte FARDATA png_sig[8] = {137, 80, 78, 71, 13, 10, 26, 10};
 
-/* Constant strings for known chunk types.  If you need to add a chunk,
- * add a string holding the name here.  If you want to make the code
- * portable to EBCDIC machines, use ASCII numbers, not characters.
- */
-png_byte FARDATA png_IHDR[5] = { 73,  72,  68,  82, '\0'};
-png_byte FARDATA png_IDAT[5] = { 73,  68,  65,  84, '\0'};
-png_byte FARDATA png_IEND[5] = { 73,  69,  78,  68, '\0'};
-png_byte FARDATA png_PLTE[5] = { 80,  76,  84,  69, '\0'};
-png_byte FARDATA png_bKGD[5] = { 98,  75,  71,  68, '\0'};
-png_byte FARDATA png_cHRM[5] = { 99,  72,  82,  77, '\0'};
-png_byte FARDATA png_gAMA[5] = {103,  65,  77,  65, '\0'};
-png_byte FARDATA png_hIST[5] = {104,  73,  83,  84, '\0'};
-png_byte FARDATA png_oFFs[5] = {111,  70,  70, 115, '\0'};
-png_byte FARDATA png_pCAL[5] = {112,  67,  65,  76, '\0'};
-png_byte FARDATA png_pHYs[5] = {112,  72,  89, 115, '\0'};
-png_byte FARDATA png_sBIT[5] = {115,  66,  73,  84, '\0'};
-png_byte FARDATA png_sRGB[5] = {115,  82,  71,  66, '\0'};
-png_byte FARDATA png_tEXt[5] = {116,  69,  88, 116, '\0'};
-png_byte FARDATA png_tIME[5] = {116,  73,  77,  69, '\0'};
-png_byte FARDATA png_tRNS[5] = {116,  82,  78,  83, '\0'};
-png_byte FARDATA png_zTXt[5] = {122,  84,  88, 116, '\0'};
+/* Invoke global declarations for constant strings for known chunk types */
+PNG_IHDR;
+PNG_IDAT;
+PNG_IEND;
+PNG_PLTE;
+PNG_bKGD;
+PNG_cHRM;
+PNG_gAMA;
+PNG_hIST;
+PNG_iCCP;
+PNG_iTXt;
+PNG_oFFs;
+PNG_pCAL;
+PNG_sCAL;
+PNG_pHYs;
+PNG_sBIT;
+PNG_sPLT;
+PNG_sRGB;
+PNG_tEXt;
+PNG_tIME;
+PNG_tRNS;
+PNG_zTXt;
 
 /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
 
@@ -57,10 +64,10 @@ int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
 /* offset to next interlace block in the y direction */
 int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
 
-/* Width of interlace block.  This is not currently used - if you need
- * it, uncomment it here and in png.h
+/* width of interlace block (used in assembler routines only) */
+#ifdef PNG_HAVE_ASSEMBLER_COMBINE_ROW
 int FARDATA png_pass_width[] = {8, 4, 4, 2, 2, 1, 1};
-*/
+#endif
 
 /* Height of interlace block.  This is not currently used - if you need
  * it, uncomment it here and in png.h
@@ -73,6 +80,8 @@ int FARDATA png_pass_mask[] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
 /* Mask to determine which pixels to overwrite while displaying */
 int FARDATA png_pass_dsp_mask[] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
 
+#endif
+
 /* Tells libpng that we have already handled the first "num_bytes" bytes
  * of the PNG file signature.  If the PNG data is embedded into another
  * stream we can set num_bytes = 8 so that libpng will not attempt to read
@@ -86,7 +95,7 @@ png_set_sig_bytes(png_structp png_ptr, int num_bytes)
    if (num_bytes > 8)
       png_error(png_ptr, "Too many bytes for PNG signature.");
 
-   png_ptr->sig_bytes = num_bytes < 0 ? 0 : num_bytes;
+   png_ptr->sig_bytes = (png_byte)(num_bytes < 0 ? 0 : num_bytes);
 }
 
 /* Checks whether the supplied bytes match the PNG signature.  We allow
@@ -100,6 +109,7 @@ png_set_sig_bytes(png_structp png_ptr, int num_bytes)
 int
 png_sig_cmp(png_bytep sig, png_size_t start, png_size_t num_to_check)
 {
+   png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
    if (num_to_check > 8)
       num_to_check = 8;
    else if (num_to_check < 1)
@@ -111,7 +121,7 @@ png_sig_cmp(png_bytep sig, png_size_t start, png_size_t num_to_check)
    if (start + num_to_check > 8)
       num_to_check = 8 - start;
 
-   return ((int)(png_memcmp(&sig[start], &png_sig[start], num_to_check)));
+   return ((int)(png_memcmp(&sig[start], &png_signature[start], num_to_check)));
 }
 
 /* (Obsolete) function to check signature bytes.  It does not allow one
@@ -251,6 +261,194 @@ png_info_init(png_infop info_ptr)
    png_memset(info_ptr, 0, sizeof (png_info));
 }
 
+void
+png_free_data(png_structp png_ptr, png_infop info_ptr, png_uint_32 mask, int num)
+{
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+#if defined(PNG_TEXT_SUPPORTED)
+/* free text item num or (if num == -1) all text items */
+if (mask & info_ptr->free_me & PNG_FREE_TEXT)
+{
+   if (num != -1)
+   {
+     if (info_ptr->text[num].key)
+     {
+         png_free(png_ptr, info_ptr->text[num].key);
+         info_ptr->text[num].key = NULL;
+     }
+   }
+   else if (info_ptr->text != NULL)
+   {
+     int i;
+     for (i = 0; i < info_ptr->num_text; i++)
+         png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, i);
+     png_free(png_ptr, info_ptr->text);
+     info_ptr->text = NULL;
+     info_ptr->num_text=0;
+   }
+}
+#endif
+
+#if defined(PNG_tRNS_SUPPORTED)
+/* free any tRNS entry */
+if (mask & PNG_FREE_TRNS)
+{
+   if (info_ptr->valid & PNG_INFO_tRNS)
+   {
+       if (info_ptr->free_me & PNG_FREE_TRNS)
+         png_free(png_ptr, info_ptr->trans);
+       info_ptr->valid &= ~PNG_INFO_tRNS;
+   }
+}
+#endif
+
+#if defined(PNG_sCAL_SUPPORTED)
+/* free any sCAL entry */
+if (mask & PNG_FREE_SCAL)
+{
+   if (info_ptr->valid & PNG_INFO_sCAL)
+   {
+#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
+       png_free(png_ptr, info_ptr->scal_s_width);
+       png_free(png_ptr, info_ptr->scal_s_height);
+#endif
+          info_ptr->valid &= ~PNG_INFO_sCAL;
+   }
+}
+#endif
+
+#if defined(PNG_pCAL_SUPPORTED)
+/* free any pCAL entry */
+if (mask & PNG_FREE_PCAL)
+{
+   if (info_ptr->valid & PNG_INFO_pCAL)
+   {
+       png_free(png_ptr, info_ptr->pcal_purpose);
+       png_free(png_ptr, info_ptr->pcal_units);
+       if (info_ptr->pcal_params != NULL)
+       {
+           int i;
+           for (i = 0; i < (int)info_ptr->pcal_nparams; i++)
+             {
+             png_free(png_ptr, info_ptr->pcal_params[i]);
+             }
+           png_free(png_ptr, info_ptr->pcal_params);
+       }
+       info_ptr->valid &= ~PNG_INFO_pCAL;
+   }
+}
+#endif
+
+#if defined(PNG_iCCP_SUPPORTED)
+/* free any iCCP entry */
+if (mask & PNG_FREE_ICCP)
+{
+   if (info_ptr->valid & PNG_INFO_iCCP)
+   {
+       if (info_ptr->free_me & PNG_FREE_ICCP)
+       {
+         png_free(png_ptr, info_ptr->iccp_name);
+         png_free(png_ptr, info_ptr->iccp_profile);
+       }
+       info_ptr->valid &= ~PNG_INFO_iCCP;
+   }
+}
+#endif
+
+#if defined(PNG_sPLT_SUPPORTED)
+/* free a given sPLT entry, or (if num == -1) all sPLT entries */
+if (mask & PNG_FREE_SPLT)
+{
+   if (num != -1)
+   {
+       png_free(png_ptr, info_ptr->splt_palettes[num].name);
+       png_free(png_ptr, info_ptr->splt_palettes[num].entries);
+       info_ptr->valid &= ~PNG_INFO_sPLT;
+   }
+   else
+   {
+       if(info_ptr->splt_palettes_num)
+       {
+         int i;
+         for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
+            png_free_data(png_ptr, info_ptr, PNG_FREE_SPLT, i);
+
+         png_free(png_ptr, info_ptr->splt_palettes);
+         info_ptr->splt_palettes_num = 0;
+       }
+   }
+}
+#endif
+
+#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+if (mask & PNG_FREE_UNKN)
+{
+   if (num != -1)
+   {
+       png_free(png_ptr, info_ptr->unknown_chunks[num].data);
+       info_ptr->unknown_chunks[num].data = NULL;
+   }
+   else
+   {
+       int i;
+
+       if(info_ptr->unknown_chunks_num)
+       {
+         for (i = 0; i < (int)info_ptr->unknown_chunks_num; i++)
+            png_free_data(png_ptr, info_ptr, PNG_FREE_UNKN, i);
+
+         png_free(png_ptr, info_ptr->unknown_chunks);
+         info_ptr->unknown_chunks_num = 0;
+       }
+   }
+}
+#endif
+
+#if defined(PNG_hIST_SUPPORTED)
+/* free any hIST entry */
+if (mask & PNG_FREE_HIST)
+{
+   if (info_ptr->valid & PNG_INFO_hIST)
+   {
+       if (info_ptr->free_me & PNG_FREE_HIST)
+         png_free(png_ptr, info_ptr->hist);
+       info_ptr->valid &= ~PNG_INFO_hIST;
+   }
+}
+#endif
+
+/* free any PLTE entry that was internally allocated */
+if (mask & PNG_FREE_PLTE)
+{
+   if (info_ptr->valid & PNG_INFO_PLTE)
+   {
+       if (info_ptr->free_me & PNG_FREE_PLTE)
+          png_zfree(png_ptr, info_ptr->palette);
+       info_ptr->valid &= ~(PNG_INFO_PLTE);
+       info_ptr->num_palette = 0;
+   }
+}
+
+#if defined(PNG_INFO_IMAGE_SUPPORTED)
+/* free any image bits attached to the info structure */
+if (mask & PNG_FREE_ROWS)
+{
+   if (info_ptr->free_me & PNG_FREE_ROWS)
+   {
+       int row;
+
+       for (row = 0; row < (int)info_ptr->height; row++)
+          png_free(png_ptr, info_ptr->row_pointers[row]);
+       png_free(png_ptr, info_ptr->row_pointers);
+   }
+}
+#endif
+   if(num == -1)
+     info_ptr->free_me &= ~mask;
+}
+
 /* This is an internal routine to free any memory that the info struct is
  * pointing to before re-using it or freeing the struct itself.  Recall
  * that png_free() checks for NULL pointers for us.
@@ -258,29 +456,15 @@ png_info_init(png_infop info_ptr)
 void
 png_info_destroy(png_structp png_ptr, png_infop info_ptr)
 {
-#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED)
    png_debug(1, "in png_info_destroy\n");
-   if (info_ptr->text != NULL)
+
+   png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
+    
+#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
+   if (png_ptr->num_chunk_list)
    {
-      int i;
-      for (i = 0; i < info_ptr->num_text; i++)
-      {
-         png_free(png_ptr, info_ptr->text[i].key);
-      }
-      png_free(png_ptr, info_ptr->text);
-   }
-#endif
-#if defined(PNG_READ_pCAL_SUPPORTED)
-   png_free(png_ptr, info_ptr->pcal_purpose);
-   png_free(png_ptr, info_ptr->pcal_units);
-   if (info_ptr->pcal_params != NULL)
-   {
-      int i;
-      for (i = 0; i < (int)info_ptr->pcal_nparams; i++)
-      {
-         png_free(png_ptr, info_ptr->pcal_params[i]);
-      }
-      png_free(png_ptr, info_ptr->pcal_params);
+       png_free(png_ptr, png_ptr->chunk_list);
+       png_ptr->num_chunk_list=0;
    }
 #endif
 
@@ -347,22 +531,72 @@ png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime)
 }
 #endif /* PNG_TIME_RFC1123_SUPPORTED */
 
+#if 0
+/* Signature string for a PNG file. */
+png_bytep
+png_sig_bytes(void)
+{
+   return ((png_bytep)"\211\120\116\107\015\012\032\012");
+}
+#endif
+
 png_charp
 png_get_copyright(png_structp png_ptr)
 {
-   if(png_ptr == NULL)
-     /* silence compiler warning about unused png_ptr */ ;
-   return("\n libpng version 1.0.4c - October 1, 1999\n\
+   if (png_ptr != NULL || png_ptr == NULL)  /* silence compiler warning */
+   return ("\n libpng version 1.0.6d - April 7, 2000\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");
+   Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson\n");
+   return ("");
 }
 
-/* Generate a compiler error if there is an old png.h in the search path. */
-void
-png_check_version
-   (version_1_0_4c png_h_is_not_version_1_0_4c)
+/* The following return the library version as a short string in the
+ * format 1.0.0 through 99.99.99zz.  To get the version of *.h files used
+ * with your application, print out PNG_LIBPNG_VER_STRING, which is defined
+ * in png.h.
+ */
+
+png_charp
+png_get_libpng_ver(png_structp png_ptr)
 {
-   if(png_h_is_not_version_1_0_4c == NULL)
-     /* silence compiler warning about unused parameter */ ;
+   /* Version of *.c files used when building libpng */
+   if(png_ptr != NULL) /* silence compiler warning about unused png_ptr */
+      return("1.0.6d");
+   return("1.0.6d");
 }
+
+png_charp
+png_get_header_ver(png_structp png_ptr)
+{
+   /* Version of *.h files used when building libpng */
+   if(png_ptr != NULL) /* silence compiler warning about unused png_ptr */
+      return(PNG_LIBPNG_VER_STRING);
+   return(PNG_LIBPNG_VER_STRING);
+}
+
+png_charp
+png_get_header_version(png_structp png_ptr)
+{
+   /* Returns longer string containing both version and date */
+   if(png_ptr != NULL) /* silence compiler warning about unused png_ptr */
+      return(PNG_HEADER_VERSION_STRING);
+   return(PNG_HEADER_VERSION_STRING);
+}
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+int
+png_handle_as_unknown(png_structp png_ptr, png_bytep chunk_name)
+{
+   /* check chunk_name and return "keep" value if it's on the list, else 0 */
+   int i;
+   png_bytep p;
+   if((png_ptr == NULL && chunk_name == NULL) || png_ptr->num_chunk_list<=0)
+      return 0;
+   p=png_ptr->chunk_list+png_ptr->num_chunk_list*5-5;
+   for (i = png_ptr->num_chunk_list; i; i--, p-=5)
+      if (!png_memcmp(chunk_name, p, 4))
+        return ((int)*(p+4));
+   return 0;
+}
+#endif

pngasmrd.h

@@ -1,32 +1,35 @@
 /* pngasmrd.h - assembler version of utilities to read a PNG file
  *
- * libpng 1.0.4c - October 1, 1999
+ * libpng 1.0.6d - April 7, 2000
  * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1999 Glenn Randers-Pehrson
+ * Copyright (c) 1999, 2000 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
+#ifdef PNG_USE_PNGVCRD
+#  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 1.0.4c).
+/* Set this in the makefile for gcc/as on Pentium, not in pngconf.h */
+/* Platform must be Pentium.  Makefile must assemble and load pnggccrd.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
+#ifdef PNG_USE_PNGGCCRD
+#  define PNG_HAVE_ASSEMBLER_COMBINE_ROW
+#  define PNG_HAVE_ASSEMBLER_READ_INTERLACE
+#  define PNG_HAVE_ASSEMBLER_READ_FILTER_ROW
 #endif
+/*
+    GRR notes:
+      - see pnggccrd.c for info about what is currently enabled
+ */
 
 #endif

pngconf.h

@@ -1,11 +1,11 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng 1.0.4c - October 1, 1999
+ * libpng 1.0.6d - April 7, 2000
  * 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, 1999 Glenn Randers-Pehrson
+ * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson
  */
 
 /* Any machine specific code is near the front of this file, so if you
@@ -17,7 +17,6 @@
 #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
@@ -112,29 +111,35 @@
 #include <sys/types.h>
 #endif
 
+#ifndef PNG_SETJMP_NOT_SUPPORTED
+#  define PNG_SETJMP_SUPPORTED
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
 /* This is an attempt to force a single setjmp behaviour on Linux.  If
  * the X config stuff didn't define _BSD_SOURCE we wouldn't need this.
  */
-#ifdef __linux__
-#ifdef _BSD_SOURCE
-#define _PNG_SAVE_BSD_SOURCE
-#undef _BSD_SOURCE
-#endif
-#ifdef _SETJMP_H
-__png.h__ already includes setjmp.h
-__dont__ include it again
-#endif
+#  ifdef __linux__
+#    ifdef _BSD_SOURCE
+#      define _PNG_SAVE_BSD_SOURCE
+#      undef _BSD_SOURCE
+#    endif
+#    ifdef _SETJMP_H
+      __png.h__ already includes setjmp.h
+      __dont__ include it again
+#    endif
 #endif /* __linux__ */
 
 /* include setjmp.h for error handling */
 #include <setjmp.h>
 
-#ifdef __linux__
-#ifdef _PNG_SAVE_BSD_SOURCE
-#define _BSD_SOURCE
-#undef _PNG_SAVE_BSD_SOURCE
-#endif
-#endif /* __linux__ */
+#  ifdef __linux__
+#    ifdef _PNG_SAVE_BSD_SOURCE
+#      define _BSD_SOURCE
+#      undef _PNG_SAVE_BSD_SOURCE
+#    endif
+#  endif /* __linux__ */
+#endif /* PNG_SETJMP_SUPPORTED */
 
 #ifdef BSD
 #include <strings.h>
@@ -159,6 +164,7 @@ __dont__ include it again
  * them inside an appropriate ifdef/endif pair for portability.
  */
 
+#if !defined(PNG_NO_FLOATING_POINT_SUPPORTED)
 #if defined(MACOS)
 /* We need to check that <math.h> hasn't already been included earlier
  * as it seems it doesn't agree with <fp.h>, yet we should really use
@@ -170,6 +176,7 @@ __dont__ include it again
 #else
 #include <math.h>
 #endif
+#endif
 
 /* Codewarrior on NT has linking problems without this. */
 #if (defined(__MWERKS__) && defined(WIN32)) || defined(__STDC__)
@@ -261,6 +268,7 @@ __dont__ include it again
  */
 
 
+
 #if !defined(PNG_READ_TRANSFORMS_NOT_SUPPORTED) && \
     !defined(PNG_NO_READ_TRANSFORMS)
 #define PNG_READ_TRANSFORMS_SUPPORTED
@@ -415,10 +423,34 @@ __dont__ include it again
 #define PNG_EASY_ACCESS_SUPPORTED
 #endif
 
-#ifndef PNG_NO_ASSEMBLER_CODE
+#if defined(PNG_USE_PNGVCRD) || defined(PNG_USE_PNGGCCRD) && \
+  !defined(PNG_NO_ASSEMBLER_CODE)
 #define PNG_ASSEMBLER_CODE_SUPPORTED
 #endif
 
+#ifndef PNG_NO_FLOATING_POINT_SUPPORTED
+#define PNG_FLOATING_POINT_SUPPORTED
+#endif
+
+#ifndef PNG_NO_FIXED_POINT_SUPPORTED
+#define PNG_FIXED_POINT_SUPPORTED
+#endif
+
+/* Do not use global arrays (helps with building DLL's)
+ * They are no longer used in libpng itself, since version 1.0.5c,
+ * but might be required for some pre-1.0.5c applications.
+ */
+#ifdef PNG_NO_GLOBAL_ARRAYS
+#  define PNG_USE_LOCAL_ARRAYS
+#else
+#  if defined(__GNUC__) && defined(WIN32)
+#    define PNG_NO_GLOBAL_ARRAYS
+#    define PNG_USE_LOCAL_ARRAYS
+#  else
+#    define PNG_USE_GLOBAL_ARRAYS
+#  endif
+#endif
+
 /* These are currently experimental features, define them if you want */
 
 /* very little testing */
@@ -455,95 +487,246 @@ __dont__ include it again
 #endif
 
 #ifdef PNG_READ_ANCILLARY_CHUNKS_SUPPORTED
+
+#ifdef PNG_NO_READ_TEXT
+#  define PNG_NO_READ_iTXt
+#  define PNG_NO_READ_tEXt
+#  define PNG_NO_READ_zTXt
+#endif
 #ifndef PNG_NO_READ_bKGD
-#define PNG_READ_bKGD_SUPPORTED
+#  define PNG_READ_bKGD_SUPPORTED
+#  define PNG_bKGD_SUPPORTED
 #endif
 #ifndef PNG_NO_READ_cHRM
-#define PNG_READ_cHRM_SUPPORTED
+#  define PNG_READ_cHRM_SUPPORTED
+#  define PNG_cHRM_SUPPORTED
 #endif
 #ifndef PNG_NO_READ_gAMA
-#define PNG_READ_gAMA_SUPPORTED
+#  define PNG_READ_gAMA_SUPPORTED
+#  define PNG_gAMA_SUPPORTED
 #endif
 #ifndef PNG_NO_READ_hIST
-#define PNG_READ_hIST_SUPPORTED
+#  define PNG_READ_hIST_SUPPORTED
+#  define PNG_hIST_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_iCCP
+#  define PNG_READ_iCCP_SUPPORTED
+#  define PNG_iCCP_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_iTXt
+#  define PNG_READ_iTXt_SUPPORTED
+#  define PNG_iTXt_SUPPORTED
 #endif
 #ifndef PNG_NO_READ_oFFs
-#define PNG_READ_oFFs_SUPPORTED
+#  define PNG_READ_oFFs_SUPPORTED
+#  define PNG_oFFs_SUPPORTED
 #endif
 #ifndef PNG_NO_READ_pCAL
-#define PNG_READ_pCAL_SUPPORTED
+#  define PNG_READ_pCAL_SUPPORTED
+#  define PNG_pCAL_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_sCAL
+#  define PNG_READ_sCAL_SUPPORTED
+#  define PNG_sCAL_SUPPORTED
 #endif
 #ifndef PNG_NO_READ_pHYs
-#define PNG_READ_pHYs_SUPPORTED
+#  define PNG_READ_pHYs_SUPPORTED
+#  define PNG_pHYs_SUPPORTED
 #endif
 #ifndef PNG_NO_READ_sBIT
-#define PNG_READ_sBIT_SUPPORTED
+#  define PNG_READ_sBIT_SUPPORTED
+#  define PNG_sBIT_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_sPLT
+#  define PNG_READ_sPLT_SUPPORTED
+#  define PNG_sPLT_SUPPORTED
 #endif
 #ifndef PNG_NO_READ_sRGB
-#define PNG_READ_sRGB_SUPPORTED
+#  define PNG_READ_sRGB_SUPPORTED
+#  define PNG_sRGB_SUPPORTED
 #endif
 #ifndef PNG_NO_READ_tEXt
-#define PNG_READ_tEXt_SUPPORTED
+#  define PNG_READ_tEXt_SUPPORTED
+#  define PNG_tEXt_SUPPORTED
 #endif
 #ifndef PNG_NO_READ_tIME
-#define PNG_READ_tIME_SUPPORTED
+#  define PNG_READ_tIME_SUPPORTED
+#  define PNG_tIME_SUPPORTED
 #endif
 #ifndef PNG_NO_READ_tRNS
-#define PNG_READ_tRNS_SUPPORTED
+#  define PNG_READ_tRNS_SUPPORTED
+#  define PNG_tRNS_SUPPORTED
 #endif
 #ifndef PNG_NO_READ_zTXt
-#define PNG_READ_zTXt_SUPPORTED
+#  define PNG_READ_zTXt_SUPPORTED
+#  define PNG_zTXt_SUPPORTED
+#endif
+#ifndef PNG_NO_READ_USER_CHUNKS
+#  define PNG_READ_USER_CHUNKS_SUPPORTED
+#  define PNG_USER_CHUNKS_SUPPORTED
+#  ifdef PNG_NO_READ_UNKNOWN_CHUNKS
+#    undef PNG_NO_READ_UNKNOWN_CHUNKS
+#  endif
+#  ifdef PNG_NO_HANDLE_AS_UNKNOWN
+#    undef PNG_NO_HANDLE_AS_UNKNOWN
+#  endif
+#endif
+#ifndef PNG_NO_READ_UNKNOWN_CHUNKS
+#  define PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
+#  define PNG_UNKNOWN_CHUNKS_SUPPORTED
+#  ifndef PNG_NO_HANDLE_AS_UNKNOWN
+#    define PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+#  endif
 #endif
 #ifndef PNG_NO_READ_OPT_PLTE
-#define PNG_READ_OPT_PLTE_SUPPORTED /* only affects support of the optional */
-#endif                              /* PLTE chunk in RGB and RGBA images */
+#  define PNG_READ_OPT_PLTE_SUPPORTED /* only affects support of the */
+#endif                      /* optional PLTE chunk in RGB and RGBA images */
+#if defined(PNG_READ_iTXt_SUPPORTED) || defined(PNG_READ_tEXt_SUPPORTED) || \
+  defined(PNG_READ_zTXt_SUPPORTED)
+#  define PNG_READ_TEXT_SUPPORTED
+#  define PNG_TEXT_SUPPORTED
+#endif
 #endif /* PNG_READ_ANCILLARY_CHUNKS_SUPPORTED */
 
 #ifdef PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED
+#ifdef PNG_NO_WRITE_TEXT
+#  define PNG_NO_WRITE_iTXt
+#  define PNG_NO_WRITE_tEXt
+#  define PNG_NO_WRITE_zTXt
+#endif
 #ifndef PNG_NO_WRITE_bKGD
-#define PNG_WRITE_bKGD_SUPPORTED
+#  define PNG_WRITE_bKGD_SUPPORTED
+#  ifndef PNG_bKGD_SUPPORTED
+#    define PNG_bKGD_SUPPORTED
+#  endif
 #endif
 #ifndef PNG_NO_WRITE_cHRM
-#define PNG_WRITE_cHRM_SUPPORTED
+#  define PNG_WRITE_cHRM_SUPPORTED
+#  ifndef PNG_cHRM_SUPPORTED
+#    define PNG_cHRM_SUPPORTED
+#  endif
 #endif
 #ifndef PNG_NO_WRITE_gAMA
-#define PNG_WRITE_gAMA_SUPPORTED
+#  define PNG_WRITE_gAMA_SUPPORTED
+#  ifndef PNG_gAMA_SUPPORTED
+#    define PNG_gAMA_SUPPORTED
+#  endif
 #endif
 #ifndef PNG_NO_WRITE_hIST
-#define PNG_WRITE_hIST_SUPPORTED
+#  define PNG_WRITE_hIST_SUPPORTED
+#  ifndef PNG_hIST_SUPPORTED
+#    define PNG_hIST_SUPPORTED
+#  endif
+#endif
+#ifndef PNG_NO_WRITE_iCCP
+#  define PNG_WRITE_iCCP_SUPPORTED
+#  ifndef PNG_iCCP_SUPPORTED
+#    define PNG_iCCP_SUPPORTED
+#  endif
+#endif
+#ifndef PNG_NO_WRITE_iTXt
+#  define PNG_WRITE_iTXt_SUPPORTED
+#  ifndef PNG_iTXt_SUPPORTED
+#    define PNG_iTXt_SUPPORTED
+#  endif
 #endif
 #ifndef PNG_NO_WRITE_oFFs
-#define PNG_WRITE_oFFs_SUPPORTED
+#  define PNG_WRITE_oFFs_SUPPORTED
+#  ifndef PNG_oFFs_SUPPORTED
+#    define PNG_oFFs_SUPPORTED
+#  endif
 #endif
 #ifndef PNG_NO_WRITE_pCAL
-#define PNG_WRITE_pCAL_SUPPORTED
+#  define PNG_WRITE_pCAL_SUPPORTED
+#  ifndef PNG_pCAL_SUPPORTED
+#    define PNG_pCAL_SUPPORTED
+#  endif
+#endif
+#ifndef PNG_NO_WRITE_sCAL
+#  define PNG_WRITE_sCAL_SUPPORTED
+#  ifndef PNG_sCAL_SUPPORTED
+#    define PNG_sCAL_SUPPORTED
+#  endif
 #endif
 #ifndef PNG_NO_WRITE_pHYs
-#define PNG_WRITE_pHYs_SUPPORTED
+#  define PNG_WRITE_pHYs_SUPPORTED
+#  ifndef PNG_pHYs_SUPPORTED
+#    define PNG_pHYs_SUPPORTED
+#  endif
 #endif
 #ifndef PNG_NO_WRITE_sBIT
-#define PNG_WRITE_sBIT_SUPPORTED
+#  define PNG_WRITE_sBIT_SUPPORTED
+#  ifndef PNG_sBIT_SUPPORTED
+#    define PNG_sBIT_SUPPORTED
+#  endif
+#endif
+#ifndef PNG_NO_WRITE_sPLT
+#  define PNG_WRITE_sPLT_SUPPORTED
+#  ifndef PNG_sPLT_SUPPORTED
+#    define PNG_sPLT_SUPPORTED
+#  endif
 #endif
 #ifndef PNG_NO_WRITE_sRGB
-#define PNG_WRITE_sRGB_SUPPORTED
+#  define PNG_WRITE_sRGB_SUPPORTED
+#  ifndef PNG_sRGB_SUPPORTED
+#    define PNG_sRGB_SUPPORTED
+#  endif
 #endif
 #ifndef PNG_NO_WRITE_tEXt
-#define PNG_WRITE_tEXt_SUPPORTED
+#  define PNG_WRITE_tEXt_SUPPORTED
+#  ifndef PNG_tEXt_SUPPORTED
+#    define PNG_tEXt_SUPPORTED
+#  endif
 #endif
 #ifndef PNG_NO_WRITE_tIME
-#define PNG_WRITE_tIME_SUPPORTED
+#  define PNG_WRITE_tIME_SUPPORTED
+#  ifndef PNG_tIME_SUPPORTED
+#    define PNG_tIME_SUPPORTED
+#  endif
 #endif
 #ifndef PNG_NO_WRITE_tRNS
-#define PNG_WRITE_tRNS_SUPPORTED
+#  define PNG_WRITE_tRNS_SUPPORTED
+#  ifndef PNG_tRNS_SUPPORTED
+#    define PNG_tRNS_SUPPORTED
+#  endif
 #endif
 #ifndef PNG_NO_WRITE_zTXt
-#define PNG_WRITE_zTXt_SUPPORTED
+#  define PNG_WRITE_zTXt_SUPPORTED
+#  ifndef PNG_zTXt_SUPPORTED
+#    define PNG_zTXt_SUPPORTED
+#  endif
+#endif
+#ifndef PNG_NO_WRITE_UNKNOWN_CHUNKS
+#  define PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
+#  ifndef PNG_UNKNOWN_CHUNKS_SUPPORTED
+#    define PNG_UNKNOWN_CHUNKS_SUPPORTED
+#  endif
+#  ifndef PNG_NO_HANDLE_AS_UNKNOWN
+#     ifndef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+#       define PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+#     endif
+#  endif
+#endif
+#if defined(PNG_WRITE_iTXt_SUPPORTED) || defined(PNG_WRITE_tEXt_SUPPORTED) || \
+  defined(PNG_WRITE_zTXt_SUPPORTED)
+#  define PNG_WRITE_TEXT_SUPPORTED
+#  ifndef PNG_TEXT_SUPPORTED
+#    define PNG_TEXT_SUPPORTED
+#  endif
 #endif
 #endif /* PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED */
 
+/* Turn this off to disable png_read_png() and
+ * png_write_png() and leave the row_pointers member
+ * out of the info structure.
+ */
+#ifndef PNG_NO_INFO_IMAGE
+#  define PNG_INFO_IMAGE_SUPPORTED
+#endif
+
 /* need the time information for reading tIME chunks */
-#if defined(PNG_READ_tIME_SUPPORTED) || defined(PNG_WRITE_tIME_SUPPORTED)
-#include <time.h>
+#if defined(PNG_tIME_SUPPORTED)
+#  include <time.h>
 #endif
 
 /* Some typedefs to get us started.  These should be safe on most of the
@@ -626,6 +809,10 @@ typedef size_t png_size_t;
 #define FARDATA
 #endif
 
+/* Typedef for floating-point numbers that are converted
+   to fixed-point with a multiple of 100,000, e.g., int_gamma */
+typedef png_int_32 png_fixed_point;
+
 /* Add typedefs for pointers */
 typedef void            FAR * png_voidp;
 typedef png_byte        FAR * png_bytep;
@@ -635,7 +822,10 @@ typedef png_uint_16     FAR * png_uint_16p;
 typedef png_int_16      FAR * png_int_16p;
 typedef PNG_CONST char  FAR * png_const_charp;
 typedef char            FAR * png_charp;
+typedef png_fixed_point FAR * png_fixed_point_p;
+#ifdef PNG_FLOATING_POINT_SUPPORTED
 typedef double          FAR * png_doublep;
+#endif
 
 /* Pointers to pointers; i.e. arrays */
 typedef png_byte        FAR * FAR * png_bytepp;
@@ -645,7 +835,10 @@ typedef png_uint_16     FAR * FAR * png_uint_16pp;
 typedef png_int_16      FAR * FAR * png_int_16pp;
 typedef PNG_CONST char  FAR * FAR * png_const_charpp;
 typedef char            FAR * FAR * png_charpp;
+typedef png_fixed_point FAR * FAR * png_fixed_point_pp;
+#ifdef PNG_FLOATING_POINT_SUPPORTED
 typedef double          FAR * FAR * png_doublepp;
+#endif
 
 /* Pointers to pointers to pointers; i.e. pointer to array */
 typedef char            FAR * FAR * FAR * png_charppp;
@@ -660,8 +853,13 @@ typedef z_stream FAR *  png_zstreamp;
 
 
 #ifndef PNG_EXPORT
-   /* allow for compilation as dll under MS Windows */
-#  ifdef __WIN32DLL__
+   /* GRR 20000206:  based on zconf.h and MSVC 5.0 docs */
+#  if defined(_MSC_VER) && defined(_DLL)
+#    define PNG_EXPORT(type,symbol)        type __declspec(dllexport) symbol
+#  endif
+
+   /* allow for compilation as a DLL under MS Windows */
+#  ifdef __WIN32DLL__	/* Borland? */
 #    define PNG_EXPORT(type,symbol) __declspec(dllexport) type symbol
 #  endif
 
@@ -670,7 +868,7 @@ typedef z_stream FAR *  png_zstreamp;
 #    define PNG_EXPORT(type,symbol) type __attribute__((dllexport)) symbol
 #  endif
 
-   /* allow for compilation as dll with Borland C++ 5.0 */
+   /* allow for compilation as a DLL with Borland C++ 5.0 */
 #  if defined(__BORLANDC__) && defined(_Windows) && defined(__DLL__)
 #    define PNG_EXPORT(type,symbol) type _export symbol
 #  endif
@@ -685,11 +883,47 @@ typedef z_stream FAR *  png_zstreamp;
 #  define PNG_EXPORT(type,symbol) type symbol
 #endif
 
+#if defined(__MINGW32__) || defined(__CYGWIN32__)
+#  define PNG_ATTR_DLLIMP
+#endif
+
+#ifndef PNG_EXPORT_VAR
+#  if defined(_MSC_VER) && defined(_DLL)	/* GRR 20000206 */
+#    define PNG_EXPORT_VAR(type) extern type __declspec(dllexport)
+#  endif
+#  ifdef PNG_DECL_DLLEXP
+#    define PNG_EXPORT_VAR(type) extern __declspec(dllexport) type
+#  endif
+#  ifdef PNG_ATTR_DLLEXP
+#    define PNG_EXPORT_VAR(type) extern type __attribute__((dllexport))
+#  endif
+#  ifdef PNG_DECL_DLLIMP
+#    define PNG_EXPORT_VAR(type) extern __declspec(dllimport) type
+#  endif
+#  ifdef PNG_ATTR_DLLIMP
+#    define PNG_EXPORT_VAR(type) extern type __attribute__((dllimport))
+#  endif
+#endif
+
+#ifndef PNG_EXPORT_VAR
+#    define PNG_EXPORT_VAR(type) extern type
+#endif
 
 /* User may want to use these so not in PNG_INTERNAL. Any library functions
  * that are passed far data must be model independent.
  */
 
+#ifndef PNG_ABORT
+#   define PNG_ABORT() abort()
+#endif
+
+#ifdef PNG_SETJMP_SUPPORTED
+#   define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
+#else
+#   define png_jmpbuf(png_ptr) \
+    (LIBPNG_WAS_COMPILED_WITH__PNG_SETJMP_NOT_SUPPORTED)
+#endif
+
 #if defined(USE_FAR_KEYWORD)  /* memory model independent fns */
 /* use this to make far-to-near assignments */
 #   define CHECK   1
@@ -712,7 +946,7 @@ typedef z_stream FAR *  png_zstreamp;
 #endif
 /* End of memory model independent support */
 
-/* Just a double check that someone hasn't tried to define something
+/* Just a little check that someone hasn't tried to define something
  * contradictory.
  */
 #if (PNG_ZBUF_SIZE > 65536) && defined(PNG_MAX_MALLOC_64K)

pngerror.c

@@ -1,11 +1,11 @@
 
 /* pngerror.c - stub functions for i/o and memory allocation
  *
- * libpng 1.0.4c - October 1, 1999
+ * libpng 1.0.6d - April 7, 2000
  * 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, 1999 Glenn Randers-Pehrson
+ * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson
  *
  * This file provides a location for all error handling.  Users who
  * need special error handling are expected to write replacement functions
@@ -67,21 +67,26 @@ png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp message
 {
    int iout = 0, iin = 0;
 
-   while (iin < 4) {
+   while (iin < 4)
+   {
       int c = png_ptr->chunk_name[iin++];
-      if (isnonalpha(c)) {
+      if (isnonalpha(c))
+      {
          buffer[iout++] = '[';
          buffer[iout++] = png_digit[(c & 0xf0) >> 4];
-         buffer[iout++] = png_digit[c & 0xf];
+         buffer[iout++] = png_digit[c & 0x0f];
          buffer[iout++] = ']';
-      } else {
-         buffer[iout++] = c;
+      }
+      else
+      {
+         buffer[iout++] = (png_byte)c;
       }
    }
 
    if (message == NULL)
       buffer[iout] = 0;
-   else {
+   else
+   {
       buffer[iout++] = ':';
       buffer[iout++] = ' ';
       png_memcpy(buffer+iout, message, 64);
@@ -117,14 +122,20 @@ png_default_error(png_structp png_ptr, png_const_charp message)
    fprintf(stderr, "libpng error: %s\n", message);
 #endif
 
-#ifdef USE_FAR_KEYWORD
+#ifdef PNG_SETJMP_SUPPORTED
+#  ifdef USE_FAR_KEYWORD
    {
       jmp_buf jmpbuf;
       png_memcpy(jmpbuf,png_ptr->jmpbuf,sizeof(jmp_buf));
       longjmp(jmpbuf, 1);
    }
-#else
+#  else
    longjmp(png_ptr->jmpbuf, 1);
+# endif
+#else
+   if (png_ptr == NULL)
+     /* make compiler happy */ ;
+   PNG_ABORT();
 #endif
 }
 

pngget.c

@@ -1,11 +1,11 @@
 
 /* pngget.c - retrieval of values from info struct
  *
- * libpng 1.0.4c - October 1, 1999
+ * libpng 1.0.6d - April 7, 2000
  * 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, 1999 Glenn Randers-Pehrson
+ * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson
  */
 
 #define PNG_INTERNAL
@@ -29,6 +29,17 @@ png_get_rowbytes(png_structp png_ptr, png_infop info_ptr)
       return(0);
 }
 
+#if defined(PNG_INFO_IMAGE_SUPPORTED)
+png_bytepp
+png_get_rows(png_structp png_ptr, png_infop info_ptr)
+{
+   if (png_ptr != NULL && info_ptr != NULL)
+      return(info_ptr->row_pointers);
+   else
+      return(0);
+}
+#endif
+
 #ifdef PNG_EASY_ACCESS_SUPPORTED
 /* easy access to info, added in libpng-0.99 */
 png_uint_32
@@ -104,7 +115,7 @@ png_get_compression_type(png_structp png_ptr, png_infop info_ptr)
 png_uint_32
 png_get_x_pixels_per_meter(png_structp png_ptr, png_infop info_ptr)
 {
-#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED)
+#if defined(PNG_pHYs_SUPPORTED)
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
    {
       png_debug1(1, "in %s retrieval function\n", "png_get_x_pixels_per_meter");
@@ -120,7 +131,7 @@ png_get_x_pixels_per_meter(png_structp png_ptr, png_infop info_ptr)
 png_uint_32
 png_get_y_pixels_per_meter(png_structp png_ptr, png_infop info_ptr)
 {
-#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED)
+#if defined(PNG_pHYs_SUPPORTED)
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
    {
       png_debug1(1, "in %s retrieval function\n", "png_get_y_pixels_per_meter");
@@ -136,7 +147,7 @@ png_get_y_pixels_per_meter(png_structp png_ptr, png_infop info_ptr)
 png_uint_32
 png_get_pixels_per_meter(png_structp png_ptr, png_infop info_ptr)
 {
-#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED)
+#if defined(PNG_pHYs_SUPPORTED)
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
    {
       png_debug1(1, "in %s retrieval function\n", "png_get_pixels_per_meter");
@@ -150,10 +161,11 @@ png_get_pixels_per_meter(png_structp png_ptr, png_infop info_ptr)
    return (0);
 }
 
+#ifdef PNG_FLOATING_POINT_SUPPORTED
 float
 png_get_pixel_aspect_ratio(png_structp png_ptr, png_infop info_ptr)
    {
-#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED)
+#if defined(PNG_pHYs_SUPPORTED)
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
    {
       png_debug1(1, "in %s retrieval function\n", "png_get_aspect_ratio");
@@ -167,11 +179,12 @@ png_get_pixel_aspect_ratio(png_structp png_ptr, png_infop info_ptr)
 #endif
       return ((float)0.0);
 }
+#endif
 
 png_uint_32
 png_get_x_offset_microns(png_structp png_ptr, png_infop info_ptr)
 {
-#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED)
+#if defined(PNG_oFFs_SUPPORTED)
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
    {
       png_debug1(1, "in %s retrieval function\n", "png_get_x_offset_microns");
@@ -187,7 +200,7 @@ png_get_x_offset_microns(png_structp png_ptr, png_infop info_ptr)
 png_uint_32
 png_get_y_offset_microns(png_structp png_ptr, png_infop info_ptr)
 {
-#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED)
+#if defined(PNG_oFFs_SUPPORTED)
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
    {
       png_debug1(1, "in %s retrieval function\n", "png_get_y_offset_microns");
@@ -203,7 +216,7 @@ png_get_y_offset_microns(png_structp png_ptr, png_infop info_ptr)
 png_uint_32
 png_get_x_offset_pixels(png_structp png_ptr, png_infop info_ptr)
 {
-#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED)
+#if defined(PNG_oFFs_SUPPORTED)
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
    {
       png_debug1(1, "in %s retrieval function\n", "png_get_x_offset_microns");
@@ -219,7 +232,7 @@ png_get_x_offset_pixels(png_structp png_ptr, png_infop info_ptr)
 png_uint_32
 png_get_y_offset_pixels(png_structp png_ptr, png_infop info_ptr)
 {
-#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED)
+#if defined(PNG_oFFs_SUPPORTED)
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs))
    {
       png_debug1(1, "in %s retrieval function\n", "png_get_y_offset_microns");
@@ -232,40 +245,40 @@ png_get_y_offset_pixels(png_structp png_ptr, png_infop info_ptr)
    return (0);
 }
 
-#ifdef PNG_INCH_CONVERSIONS
+#if defined(PNG_INCH_CONVERSIONS) && defined(PNG_FLOATING_POINT_SUPPORTED)
 png_uint_32
 png_get_pixels_per_inch(png_structp png_ptr, png_infop info_ptr)
 {
    return ((png_uint_32)((float)png_get_pixels_per_meter(png_ptr, info_ptr)
-     *.03937 +.5)
+     *.0254 +.5);
 }
 
 png_uint_32
 png_get_x_pixels_per_inch(png_structp png_ptr, png_infop info_ptr)
 {
    return ((png_uint_32)((float)png_get_x_pixels_per_meter(png_ptr, info_ptr)
-     *.03937 +.5)
+     *.0254 +.5);
 }
 
 png_uint_32
 png_get_y_pixels_per_inch(png_structp png_ptr, png_infop info_ptr)
 {
    return ((png_uint_32)((float)png_get_y_pixels_per_meter(png_ptr, info_ptr)
-     *.03937 +.5)
+     *.0254 +.5);
 }
 
 float
 png_get_x_offset_inches(png_structp png_ptr, png_infop info_ptr)
 {
    return ((float)png_get_x_offset_microns(png_ptr, info_ptr)
-     *.03937/1000000. +.5)
+     *.00003937);
 }
 
 float
 png_get_y_offset_inches(png_structp png_ptr, png_infop info_ptr)
 {
    return ((float)png_get_y_offset_microns(png_ptr, info_ptr)
-     *.03937/1000000. +.5)
+     *.00003937)
 }
 
 #if defined(PNG_READ_pHYs_SUPPORTED)
@@ -275,7 +288,7 @@ png_get_pHYs_dpi(png_structp png_ptr, png_infop info_ptr,
 {
    png_uint_32 retval = 0;
 
-   if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_pHYs)
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs))
    {
       png_debug1(1, "in %s retrieval function\n", "pHYs");
       if (res_x != NULL)
@@ -294,15 +307,15 @@ png_get_pHYs_dpi(png_structp png_ptr, png_infop info_ptr,
          retval |= PNG_INFO_pHYs;
          if(unit_type == 1)
          {
-            if (res_x != NULL) *res_x = (png_uint_32)(*res_x * 39.37 + .50);
-            if (res_y != NULL) *res_y = (png_uint_32)(*res_y * 39.37 + .50);
+            if (res_x != NULL) *res_x = (png_uint_32)(*res_x * .0254 + .50);
+            if (res_y != NULL) *res_y = (png_uint_32)(*res_y * .0254 + .50);
          }
       }
    }
    return (retval);
 }
 #endif /* PNG_READ_pHYs_SUPPORTED */
-#endif  /* PNG_INCH_CONVERSIONS */
+#endif  /* PNG_INCH_CONVERSIONS && PNG_FLOATING_POINT_SUPPORTED */
 
 /* png_get_channels really belongs in here, too, but it's been around longer */
 
@@ -343,6 +356,7 @@ png_get_bKGD(png_structp png_ptr, png_infop info_ptr,
 #endif
 
 #if defined(PNG_READ_cHRM_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
 png_uint_32
 png_get_cHRM(png_structp png_ptr, png_infop info_ptr,
    double *white_x, double *white_y, double *red_x, double *red_y,
@@ -372,8 +386,41 @@ png_get_cHRM(png_structp png_ptr, png_infop info_ptr,
    return (0);
 }
 #endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+png_uint_32
+png_get_cHRM_fixed(png_structp png_ptr, png_infop info_ptr,
+   png_fixed_point *white_x, png_fixed_point *white_y, png_fixed_point *red_x,
+   png_fixed_point *red_y, png_fixed_point *green_x, png_fixed_point *green_y,
+   png_fixed_point *blue_x, png_fixed_point *blue_y)
+{
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM))
+   {
+      png_debug1(1, "in %s retrieval function\n", "cHRM");
+      if (white_x != NULL)
+         *white_x = info_ptr->int_x_white;
+      if (white_y != NULL)
+         *white_y = info_ptr->int_y_white;
+      if (red_x != NULL)
+         *red_x = info_ptr->int_x_red;
+      if (red_y != NULL)
+         *red_y = info_ptr->int_y_red;
+      if (green_x != NULL)
+         *green_x = info_ptr->int_x_green;
+      if (green_y != NULL)
+         *green_y = info_ptr->int_y_green;
+      if (blue_x != NULL)
+         *blue_x = info_ptr->int_x_blue;
+      if (blue_y != NULL)
+         *blue_y = info_ptr->int_y_blue;
+      return (PNG_INFO_cHRM);
+   }
+   return (0);
+}
+#endif
+#endif
 
 #if defined(PNG_READ_gAMA_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
 png_uint_32
 png_get_gAMA(png_structp png_ptr, png_infop info_ptr, double *file_gamma)
 {
@@ -387,6 +434,20 @@ png_get_gAMA(png_structp png_ptr, png_infop info_ptr, double *file_gamma)
    return (0);
 }
 #endif
+png_uint_32
+png_get_gAMA_fixed(png_structp png_ptr, png_infop info_ptr,
+    png_fixed_point *int_file_gamma)
+{
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA)
+      && int_file_gamma != NULL)
+   {
+      png_debug1(1, "in %s retrieval function\n", "gAMA");
+      *int_file_gamma = info_ptr->int_gamma;
+      return (PNG_INFO_gAMA);
+   }
+   return (0);
+}
+#endif
 
 #if defined(PNG_READ_sRGB_SUPPORTED)
 png_uint_32
@@ -403,6 +464,39 @@ png_get_sRGB(png_structp png_ptr, png_infop info_ptr, int *file_srgb_intent)
 }
 #endif
 
+#if defined(PNG_READ_iCCP_SUPPORTED)
+png_uint_32
+png_get_iCCP(png_structp png_ptr, png_infop info_ptr,
+             png_charpp name, int *compression_type,
+             png_charpp profile, png_uint_32 *proflen)
+{
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_iCCP)
+      && name != NULL && profile != NULL && proflen != NULL)
+   {
+      png_debug1(1, "in %s retrieval function\n", "iCCP");
+      *name = info_ptr->iccp_name;
+      *profile = info_ptr->iccp_profile;
+      /* compression_type is a dummy so the API won't have to change
+         if we introduce multiple compression types later. */
+      *proflen = (int)info_ptr->iccp_proflen;
+      *compression_type = (int)info_ptr->iccp_compression;
+      return (PNG_INFO_iCCP);
+   }
+   return (0);
+}
+#endif
+
+#if defined(PNG_READ_sPLT_SUPPORTED)
+png_uint_32
+png_get_sPLT(png_structp png_ptr, png_infop info_ptr,
+             png_sPLT_tpp spalettes)
+{
+   if (png_ptr != NULL && info_ptr != NULL && spalettes != NULL)
+     *spalettes = info_ptr->splt_palettes;
+   return ((png_uint_32)info_ptr->splt_palettes_num);
+}
+#endif
+
 #if defined(PNG_READ_hIST_SUPPORTED)
 png_uint_32
 png_get_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_16p *hist)
@@ -467,7 +561,7 @@ png_get_IHDR(png_structp png_ptr, png_infop info_ptr,
 #if defined(PNG_READ_oFFs_SUPPORTED)
 png_uint_32
 png_get_oFFs(png_structp png_ptr, png_infop info_ptr,
-   png_uint_32 *offset_x, png_uint_32 *offset_y, int *unit_type)
+   png_int_32 *offset_x, png_int_32 *offset_y, int *unit_type)
 {
    if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)
       && offset_x != NULL && offset_y != NULL && unit_type != NULL)
@@ -488,8 +582,8 @@ png_get_pCAL(png_structp png_ptr, png_infop info_ptr,
    png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type, int *nparams,
    png_charp *units, png_charpp *params)
 {
-   if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_pCAL &&
-      purpose != NULL && X0 != NULL && X1 != NULL && type != NULL &&
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL)
+      && purpose != NULL && X0 != NULL && X1 != NULL && type != NULL &&
       nparams != NULL && units != NULL && params != NULL)
    {
       png_debug1(1, "in %s retrieval function\n", "pCAL");
@@ -506,6 +600,42 @@ png_get_pCAL(png_structp png_ptr, png_infop info_ptr,
 }
 #endif
 
+#if defined(PNG_READ_sCAL_SUPPORTED) || defined(PNG_WRITE_sCAL_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+png_uint_32
+png_get_sCAL(png_structp png_ptr, png_infop info_ptr,
+             int *unit, double *width, double *height)
+{
+    if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_sCAL))
+    {
+        *unit = info_ptr->scal_unit;
+        *width = info_ptr->scal_pixel_width;
+        *height = info_ptr->scal_pixel_height;
+        return (PNG_INFO_sCAL);
+    }
+    return(0);
+}
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+png_uint_32
+png_get_sCAL_s(png_structp png_ptr, png_infop info_ptr,
+             int *unit, png_charpp width, png_charpp height)
+{
+    if (png_ptr != NULL && info_ptr != NULL &&
+       (info_ptr->valid & PNG_INFO_sCAL))
+    {
+        *unit = info_ptr->scal_unit;
+        *width = info_ptr->scal_s_width;
+        *height = info_ptr->scal_s_height;
+        return (PNG_INFO_sCAL);
+    }
+    return(0);
+}
+#endif
+#endif
+#endif
+
 #if defined(PNG_READ_pHYs_SUPPORTED)
 png_uint_32
 png_get_pHYs(png_structp png_ptr, png_infop info_ptr,
@@ -513,7 +643,8 @@ png_get_pHYs(png_structp png_ptr, png_infop info_ptr,
 {
    png_uint_32 retval = 0;
 
-   if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_pHYs)
+   if (png_ptr != NULL && info_ptr != NULL &&
+      (info_ptr->valid & PNG_INFO_pHYs))
    {
       png_debug1(1, "in %s retrieval function\n", "pHYs");
       if (res_x != NULL)
@@ -540,8 +671,8 @@ png_uint_32
 png_get_PLTE(png_structp png_ptr, png_infop info_ptr, png_colorp *palette,
    int *num_palette)
 {
-   if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_PLTE &&
-       palette != NULL)
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_PLTE)
+       && palette != NULL)
    {
       png_debug1(1, "in %s retrieval function\n", "PLTE");
       *palette = info_ptr->palette;
@@ -556,8 +687,8 @@ png_get_PLTE(png_structp png_ptr, png_infop info_ptr, png_colorp *palette,
 png_uint_32
 png_get_sBIT(png_structp png_ptr, png_infop info_ptr, png_color_8p *sig_bit)
 {
-   if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_sBIT &&
-       sig_bit != NULL)
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT)
+      && sig_bit != NULL)
    {
       png_debug1(1, "in %s retrieval function\n", "sBIT");
       *sig_bit = &(info_ptr->sig_bit);
@@ -567,7 +698,7 @@ png_get_sBIT(png_structp png_ptr, png_infop info_ptr, png_color_8p *sig_bit)
 }
 #endif
 
-#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED)
+#if defined(PNG_READ_TEXT_SUPPORTED)
 png_uint_32
 png_get_text(png_structp png_ptr, png_infop info_ptr, png_textp *text_ptr,
    int *num_text)
@@ -583,6 +714,8 @@ png_get_text(png_structp png_ptr, png_infop info_ptr, png_textp *text_ptr,
          *num_text = info_ptr->num_text;
       return ((png_uint_32)info_ptr->num_text);
    }
+   if (num_text != NULL)
+     *num_text = 0;
    return(0);
 }
 #endif
@@ -591,8 +724,8 @@ png_get_text(png_structp png_ptr, png_infop info_ptr, png_textp *text_ptr,
 png_uint_32
 png_get_tIME(png_structp png_ptr, png_infop info_ptr, png_timep *mod_time)
 {
-   if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_tIME &&
-       mod_time != NULL)
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME)
+       && mod_time != NULL)
    {
       png_debug1(1, "in %s retrieval function\n", "tIME");
       *mod_time = &(info_ptr->mod_time);
@@ -608,7 +741,7 @@ png_get_tRNS(png_structp png_ptr, png_infop info_ptr,
    png_bytep *trans, int *num_trans, png_color_16p *trans_values)
 {
    png_uint_32 retval = 0;
-   if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_tRNS)
+   if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS))
    {
       png_debug1(1, "in %s retrieval function\n", "tRNS");
       if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
@@ -641,6 +774,17 @@ png_get_tRNS(png_structp png_ptr, png_infop info_ptr,
 }
 #endif
 
+#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
+png_uint_32
+png_get_unknown_chunks(png_structp png_ptr, png_infop info_ptr,
+             png_unknown_chunkpp unknowns)
+{
+   if (png_ptr != NULL && info_ptr != NULL && unknowns != NULL)
+     *unknowns = info_ptr->unknown_chunks;
+   return ((png_uint_32)info_ptr->unknown_chunks_num);
+}
+#endif
+
 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
 png_byte
 png_get_rgb_to_gray_status (png_structp png_ptr)
@@ -648,3 +792,12 @@ png_get_rgb_to_gray_status (png_structp png_ptr)
    return png_ptr->rgb_to_gray_status;
 }
 #endif
+
+#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
+png_voidp
+png_get_user_chunk_ptr(png_structp png_ptr)
+{
+   return (png_ptr->user_chunk_ptr);
+}
+#endif
+

pngmem.c

@@ -1,11 +1,11 @@
 
 /* pngmem.c - stub functions for memory allocation
  *
- * libpng 1.0.4c - October 1, 1999
+ * libpng 1.0.6d - April 7, 2000
  * 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, 1999 Glenn Randers-Pehrson
+ * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson
  *
  * This file provides a location for all memory allocation.  Users who
  * need special memory handling are expected to supply replacement
@@ -82,12 +82,10 @@ png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn)
          png_struct dummy_struct;
          png_structp png_ptr = &dummy_struct;
          (*(free_fn))(png_ptr, struct_ptr);
-         struct_ptr = NULL;
          return;
       }
 #endif /* PNG_USER_MEM_SUPPORTED */
       farfree (struct_ptr);
-      struct_ptr = NULL;
    }
 }
 
@@ -236,7 +234,6 @@ png_free(png_structp png_ptr, png_voidp ptr)
    if (png_ptr->free_fn != NULL)
    {
       (*(png_ptr->free_fn))(png_ptr, ptr);
-      ptr = NULL;
       return;
    }
    else png_free_default(png_ptr, ptr);
@@ -272,7 +269,6 @@ png_free_default(png_structp png_ptr, png_voidp ptr)
    if (ptr != NULL)
    {
       farfree(ptr);
-      ptr = NULL;
    }
 }
 
@@ -352,20 +348,16 @@ png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn)
          png_struct dummy_struct;
          png_structp png_ptr = &dummy_struct;
          (*(free_fn))(png_ptr, struct_ptr);
-         struct_ptr = NULL;
          return;
       }
 #endif /* PNG_USER_MEM_SUPPORTED */
 #if defined(__TURBOC__) && !defined(__FLAT__)
       farfree(struct_ptr);
-      struct_ptr = NULL;
 #else
 # if defined(_MSC_VER) && defined(MAXSEG_64K)
       hfree(struct_ptr);
-      struct_ptr = NULL;
 # else
       free(struct_ptr);
-      struct_ptr = NULL;
 # endif
 #endif
    }
@@ -434,7 +426,6 @@ png_free(png_structp png_ptr, png_voidp ptr)
    if (png_ptr->free_fn != NULL)
    {
       (*(png_ptr->free_fn))(png_ptr, ptr);
-      ptr = NULL;
       return;
    }
    else png_free_default(png_ptr, ptr);
@@ -442,18 +433,18 @@ png_free(png_structp png_ptr, png_voidp ptr)
 void
 png_free_default(png_structp png_ptr, png_voidp ptr)
 {
+   if (png_ptr == NULL || ptr == NULL)
+      return;
+
 #endif /* PNG_USER_MEM_SUPPORTED */
 
 #if defined(__TURBOC__) && !defined(__FLAT__)
    farfree(ptr);
-   ptr = NULL;
 #else
 # if defined(_MSC_VER) && defined(MAXSEG_64K)
    hfree(ptr);
-   ptr = NULL;
 # else
    free(ptr);
-   ptr = NULL;
 # endif
 #endif
 }

pngpread.c

@@ -1,11 +1,11 @@
 
 /* pngpread.c - read a png file in push mode
  *
- * libpng 1.0.4c - October 1, 1999
+ * libpng 1.0.6d - April 7, 2000
  * 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, 1999 Glenn Randers-Pehrson
+ * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson
  */
 
 #define PNG_INTERNAL
@@ -13,6 +13,17 @@
 
 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
 
+/* push model modes */
+#define PNG_READ_SIG_MODE   0
+#define PNG_READ_CHUNK_MODE 1
+#define PNG_READ_IDAT_MODE  2
+#define PNG_SKIP_MODE       3
+#define PNG_READ_tEXt_MODE  4
+#define PNG_READ_zTXt_MODE  5
+#define PNG_READ_DONE_MODE  6
+#define PNG_READ_iTXt_MODE  7
+#define PNG_ERROR_MODE      8
+
 void
 png_process_data(png_structp png_ptr, png_infop info_ptr,
    png_bytep buffer, png_size_t buffer_size)
@@ -61,6 +72,13 @@ png_process_some_data(png_structp png_ptr, png_infop info_ptr)
          png_push_read_zTXt(png_ptr, info_ptr);
          break;
       }
+#endif
+#if defined(PNG_READ_iTXt_SUPPORTED)
+      case PNG_READ_iTXt_MODE:
+      {
+         png_push_read_iTXt(png_ptr, info_ptr);
+         break;
+      }
 #endif
       case PNG_SKIP_MODE:
       {
@@ -94,7 +112,7 @@ png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
 
    png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]),
       num_to_check);
-   png_ptr->sig_bytes += num_to_check;
+   png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes+num_to_check);
 
    if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
    {
@@ -116,13 +134,70 @@ png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
 void
 png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
 {
+#ifdef PNG_USE_LOCAL_ARRAYS
+      PNG_IHDR;
+      PNG_IDAT;
+      PNG_IEND;
+      PNG_PLTE;
+#if defined(PNG_READ_bKGD_SUPPORTED)
+      PNG_bKGD;
+#endif
+#if defined(PNG_READ_cHRM_SUPPORTED)
+      PNG_cHRM;
+#endif
+#if defined(PNG_READ_gAMA_SUPPORTED)
+      PNG_gAMA;
+#endif
+#if defined(PNG_READ_hIST_SUPPORTED)
+      PNG_hIST;
+#endif
+#if defined(PNG_READ_iCCP_SUPPORTED)
+      PNG_iCCP;
+#endif
+#if defined(PNG_READ_iTXt_SUPPORTED)
+      PNG_iTXt;
+#endif
+#if defined(PNG_READ_oFFs_SUPPORTED)
+      PNG_oFFs;
+#endif
+#if defined(PNG_READ_pCAL_SUPPORTED)
+      PNG_pCAL;
+#endif
+#if defined(PNG_READ_pHYs_SUPPORTED)
+      PNG_pHYs;
+#endif
+#if defined(PNG_READ_sBIT_SUPPORTED)
+      PNG_sBIT;
+#endif
+#if defined(PNG_READ_sCAL_SUPPORTED)
+      PNG_sCAL;
+#endif
+#if defined(PNG_READ_sRGB_SUPPORTED)
+      PNG_sRGB;
+#endif
+#if defined(PNG_READ_sPLT_SUPPORTED)
+      PNG_sPLT;
+#endif
+#if defined(PNG_READ_tEXt_SUPPORTED)
+      PNG_tEXt;
+#endif
+#if defined(PNG_READ_tIME_SUPPORTED)
+      PNG_tIME;
+#endif
+#if defined(PNG_READ_tRNS_SUPPORTED)
+      PNG_tRNS;
+#endif
+#if defined(PNG_READ_zTXt_SUPPORTED)
+      PNG_zTXt;
+#endif
+#endif /* PNG_USE_LOCAL_ARRAYS */
    /* First we make sure we have enough data for the 4 byte chunk name
     * and the 4 byte chunk length before proceeding with decoding the
     * chunk data.  To fully decode each of these chunks, we also make
     * sure we have enough data in the buffer for the 4 byte CRC at the
     * end of every chunk (except IDAT, which is handled separately).
     */
-   if (!(png_ptr->flags & PNG_FLAG_HAVE_CHUNK_HEADER))
+   if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
    {
       png_byte chunk_length[4];
 
@@ -136,7 +211,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
       png_ptr->push_length = png_get_uint_32(chunk_length);
       png_reset_crc(png_ptr);
       png_crc_read(png_ptr, png_ptr->chunk_name, 4);
-      png_ptr->flags |= PNG_FLAG_HAVE_CHUNK_HEADER;
+      png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
    }
 
    if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
@@ -159,7 +234,7 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
 
       png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
    }
-   else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+   else if (!png_memcmp(png_ptr->chunk_name, (png_bytep)png_IDAT, 4))
    {
       /* If we reach an IDAT chunk, this means we have read all of the
        * header chunks, and we can start reading the image (or if this
@@ -242,6 +317,30 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
       png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);
    }
 #endif
+#if defined(PNG_READ_iCCP_SUPPORTED)
+   else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
+   {
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+
+      png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
+   }
+#endif
+#if defined(PNG_READ_sPLT_SUPPORTED)
+   else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
+   {
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+
+      png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);
+   }
+#endif
 #if defined(PNG_READ_tRNS_SUPPORTED)
    else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
    {
@@ -314,6 +413,18 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
       png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);
    }
 #endif
+#if defined(PNG_READ_sCAL_SUPPORTED)
+   else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
+   {
+      if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+
+      png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);
+   }
+#endif
 #if defined(PNG_READ_tIME_SUPPORTED)
    else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
    {
@@ -337,13 +448,19 @@ png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
    {
       png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
    }
+#endif
+#if defined(PNG_READ_iTXt_SUPPORTED)
+   else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
+   {
+      png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
+   }
 #endif
    else
    {
       png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
    }
 
-   png_ptr->flags &= ~PNG_FLAG_HAVE_CHUNK_HEADER;
+   png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
 }
 
 void
@@ -496,7 +613,10 @@ png_push_restore_buffer(png_structp png_ptr, png_bytep buffer,
 void
 png_push_read_IDAT(png_structp png_ptr)
 {
-   if (!(png_ptr->flags & PNG_FLAG_HAVE_CHUNK_HEADER))
+#ifdef PNG_USE_LOCAL_ARRAYS
+   PNG_IDAT;
+#endif
+   if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
    {
       png_byte chunk_length[4];
 
@@ -511,9 +631,9 @@ png_push_read_IDAT(png_structp png_ptr)
 
       png_reset_crc(png_ptr);
       png_crc_read(png_ptr, png_ptr->chunk_name, 4);
-      png_ptr->flags |= PNG_FLAG_HAVE_CHUNK_HEADER;
+      png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
 
-      if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+      if (png_memcmp(png_ptr->chunk_name, (png_bytep)png_IDAT, 4))
       {
          png_ptr->process_mode = PNG_READ_CHUNK_MODE;
          if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
@@ -576,7 +696,7 @@ png_push_read_IDAT(png_structp png_ptr)
       }
 
       png_crc_finish(png_ptr, 0);
-      png_ptr->flags &= ~PNG_FLAG_HAVE_CHUNK_HEADER;
+      png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
    }
 }
 
@@ -767,6 +887,32 @@ png_push_process_row(png_structp png_ptr)
 void
 png_read_push_finish_row(png_structp png_ptr)
 {
+#ifdef PNG_USE_LOCAL_ARRAYS
+   /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+   /* start of interlace block */
+   const int png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
+
+   /* offset to next interlace block */
+   const int png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
+
+   /* start of interlace block in the y direction */
+   const int png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
+
+   /* offset to next interlace block in the y direction */
+   const int png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
+
+   /* Width of interlace block.  This is not currently used - if you need
+    * it, uncomment it here and in png.h
+   const int png_pass_width[] = {8, 4, 4, 2, 2, 1, 1};
+   */
+
+   /* Height of interlace block.  This is not currently used - if you need
+    * it, uncomment it here and in png.h
+   const int png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
+   */
+#endif
+
    png_ptr->row_number++;
    if (png_ptr->row_number < png_ptr->num_rows)
       return;
@@ -806,7 +952,7 @@ png_read_push_finish_row(png_structp png_ptr)
 void
 png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
-   if (png_ptr->mode == PNG_BEFORE_IHDR || png_ptr->mode & PNG_HAVE_IEND)
+   if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
       {
          png_error(png_ptr, "Out of place tEXt");
          /* to quiet some compiler warnings */
@@ -878,7 +1024,9 @@ png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr)
 
       text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text));
       text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
+      text_ptr->lang = (char *)NULL;
       text_ptr->key = key;
+      text_ptr->lang_key = (char *)NULL;
       text_ptr->text = text;
 
       png_set_text(png_ptr, info_ptr, text_ptr, 1);
@@ -892,7 +1040,7 @@ png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr)
 void
 png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
-   if (png_ptr->mode == PNG_BEFORE_IHDR || png_ptr->mode & PNG_HAVE_IEND)
+   if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
       {
          png_error(png_ptr, "Out of place zTXt");
          /* to quiet some compiler warnings */
@@ -1058,6 +1206,8 @@ png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr)
       text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text));
       text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt;
       text_ptr->key = key;
+      text_ptr->lang = (char *)NULL;
+      text_ptr->lang_key = (char *)NULL;
       text_ptr->text = text;
 
       png_set_text(png_ptr, info_ptr, text_ptr, 1);
@@ -1067,26 +1217,178 @@ png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr)
 }
 #endif
 
+#if defined(PNG_READ_iTXt_SUPPORTED)
+void
+png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
+{
+   if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
+      {
+         png_error(png_ptr, "Out of place iTXt");
+         /* to quiet some compiler warnings */
+         if(info_ptr == NULL) return;
+      }
+
+#ifdef PNG_MAX_MALLOC_64K
+   png_ptr->skip_length = 0;  /* This may not be necessary */
+
+   if (length > (png_uint_32)65535L) /* Can't hold the entire string in memory */
+   {
+      png_warning(png_ptr, "iTXt chunk too large to fit in memory");
+      png_ptr->skip_length = length - (png_uint_32)65535L;
+      length = (png_uint_32)65535L;
+   }
+#endif
+
+   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;
+   png_ptr->current_text_size = (png_size_t)length;
+   png_ptr->current_text_left = (png_size_t)length;
+   png_ptr->process_mode = PNG_READ_iTXt_MODE;
+}
+
+void
+png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr)
+{
+
+   if (png_ptr->buffer_size && png_ptr->current_text_left)
+   {
+      png_size_t text_size;
+
+      if (png_ptr->buffer_size < png_ptr->current_text_left)
+         text_size = png_ptr->buffer_size;
+      else
+         text_size = png_ptr->current_text_left;
+      png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
+      png_ptr->current_text_left -= text_size;
+      png_ptr->current_text_ptr += text_size;
+   }
+   if (!(png_ptr->current_text_left))
+   {
+      png_textp text_ptr;
+      png_charp key;
+      int comp_flag;
+      png_charp lang;
+      png_charp lang_key;
+      png_charp text;
+
+      if (png_ptr->buffer_size < 4)
+      {
+         png_push_save_buffer(png_ptr);
+         return;
+      }
+
+      png_push_crc_finish(png_ptr);
+
+#if defined(PNG_MAX_MALLOC_64K)
+      if (png_ptr->skip_length)
+         return;
+#endif
+
+      key = png_ptr->current_text;
+      png_ptr->current_text = 0;
+
+      for (lang = key; *lang; lang++)
+         /* empty loop */ ;
+
+      if (lang != key + png_ptr->current_text_size)
+         lang++;
+
+      comp_flag = *lang++;
+      lang++;     /* skip comp_type, always zero */
+
+      for (lang_key = lang; *lang_key; lang_key++)
+         /* empty loop */ ;
+      lang_key++;        /* skip NUL separator */
+
+      for (text = lang_key; *text; text++)
+         /* empty loop */ ;
+
+      if (text != key + png_ptr->current_text_size)
+         text++;
+
+      text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text));
+      text_ptr->compression = comp_flag + 2;
+      text_ptr->key = key;
+      text_ptr->lang = lang;
+      text_ptr->lang_key = lang_key;
+      text_ptr->text = text;
+      text_ptr->text_length = 0;
+      text_ptr->itxt_length = png_strlen(text);
+
+      png_set_text(png_ptr, info_ptr, text_ptr, 1);
+
+      png_free(png_ptr, text_ptr);
+   }
+}
+#endif
+
 /* This function is called when we haven't found a handler for this
- * chunk.  In the future we will have code here that can handle
- * user-defined callback functions for unknown chunks before they are
- * ignored or cause an error.  If there isn't a problem with the
- * chunk itself (ie a bad chunk name or a critical chunk), the chunk
- * is (currently) silently ignored.
+ * chunk.  If there isn't a problem with the chunk itself (ie a bad chunk
+ * name or a critical chunk), the chunk is (currently) silently ignored.
  */
 void
 png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 {
+   png_uint_32 skip=0;
    png_check_chunk_name(png_ptr, png_ptr->chunk_name);
 
    if (!(png_ptr->chunk_name[0] & 0x20))
    {
-      png_chunk_error(png_ptr, "unknown critical chunk");
-      /* to quiet some compiler warnings */
-      if(info_ptr == NULL) return;
+      if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
+           HANDLE_CHUNK_ALWAYS
+#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
+           && png_ptr->read_user_chunk_fn == (png_user_chunk_ptr)NULL
+#endif
+         )
+         png_chunk_error(png_ptr, "unknown critical chunk");
+
+      /* to quiet compiler warnings about unused info_ptr */
+      if (info_ptr == NULL)
+         return;
    }
 
-   png_push_crc_skip(png_ptr, length);
+#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
+   if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
+   {
+       png_unknown_chunk chunk;
+
+#ifdef PNG_MAX_MALLOC_64K
+       if (length > (png_uint_32)65535L)
+       {
+           png_warning(png_ptr, "unknown chunk too large to fit in memory");
+           skip = length - (png_uint_32)65535L;
+           length = (png_uint_32)65535L;
+       }
+#endif
+
+       strcpy((png_charp)chunk.name, (png_charp)png_ptr->chunk_name);
+       chunk.data = (png_bytep)png_malloc(png_ptr, length);
+       png_crc_read(png_ptr, chunk.data, length);
+       chunk.size = length;
+#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
+       if(png_ptr->read_user_chunk_fn != (png_user_chunk_ptr)NULL)
+       {
+          /* callback to user unknown chunk handler */
+          if ((*(png_ptr->read_user_chunk_fn)) (png_ptr, &chunk) <= 0)
+          {
+             if (!(png_ptr->chunk_name[0] & 0x20))
+                if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
+                     HANDLE_CHUNK_ALWAYS)
+                   png_chunk_error(png_ptr, "unknown critical chunk");
+          }
+             png_set_unknown_chunks(png_ptr, info_ptr, &chunk, 1);
+       }
+       else
+#endif
+          png_set_unknown_chunks(png_ptr, info_ptr, &chunk, 1);
+       png_free(png_ptr, chunk.data);
+   }
+   else
+#endif
+      skip=length;
+   png_push_crc_skip(png_ptr, skip);
 }
 
 void
@@ -1115,6 +1417,9 @@ void
 png_progressive_combine_row (png_structp png_ptr,
    png_bytep old_row, png_bytep new_row)
 {
+#ifdef PNG_USE_LOCAL_ARRAYS
+   const int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
+#endif
    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 1.0.4c - October 1, 1999
+ * libpng 1.0.6d - April 7, 2000
  * 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, 1999 Glenn Randers-Pehrson
+ * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson
  *
  * This file contains routines that an application calls directly to
  * read a PNG file or stream.
@@ -34,9 +34,13 @@ png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
 #endif /* PNG_USER_MEM_SUPPORTED */
 
    png_structp png_ptr;
+
+#ifdef PNG_SETJMP_SUPPORTED
 #ifdef USE_FAR_KEYWORD
    jmp_buf jmpbuf;
 #endif
+#endif
+
    png_debug(1, "in png_create_read_struct\n");
 #ifdef PNG_USER_MEM_SUPPORTED
    if ((png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
@@ -47,6 +51,8 @@ png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
    {
       return (png_structp)NULL;
    }
+
+#ifdef PNG_SETJMP_SUPPORTED
 #ifdef USE_FAR_KEYWORD
    if (setjmp(jmpbuf))
 #else
@@ -60,10 +66,11 @@ png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
 #ifdef USE_FAR_KEYWORD
    png_memcpy(png_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf));
 #endif
+#endif
 
 #ifdef PNG_USER_MEM_SUPPORTED
    png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
-#endif /* PNG_USER_MEM_SUPPORTED */
+#endif
 
    png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
 
@@ -110,17 +117,24 @@ png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
 void
 png_read_init(png_structp png_ptr)
 {
+#ifdef PNG_SETJMP_SUPPORTED
    jmp_buf tmp_jmp;  /* to save current jump buffer */
+#endif
 
    png_debug(1, "in png_read_init\n");
+
+#ifdef PNG_SETJMP_SUPPORTED
    /* save jump buffer and error functions */
    png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf));
+#endif
 
    /* reset all variables to 0 */
    png_memset(png_ptr, 0, sizeof (png_struct));
 
+#ifdef PNG_SETJMP_SUPPORTED
    /* restore jump buffer */
    png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf));
+#endif
 
    /* initialize zbuf - compression buffer */
    png_ptr->zbuf_size = PNG_ZBUF_SIZE;
@@ -179,6 +193,63 @@ png_read_info(png_structp png_ptr, png_infop info_ptr)
 
    for(;;)
    {
+#ifdef PNG_USE_LOCAL_ARRAYS
+      PNG_IHDR;
+      PNG_IDAT;
+      PNG_IEND;
+      PNG_PLTE;
+#if defined(PNG_READ_bKGD_SUPPORTED)
+      PNG_bKGD;
+#endif
+#if defined(PNG_READ_cHRM_SUPPORTED)
+      PNG_cHRM;
+#endif
+#if defined(PNG_READ_gAMA_SUPPORTED)
+      PNG_gAMA;
+#endif
+#if defined(PNG_READ_hIST_SUPPORTED)
+      PNG_hIST;
+#endif
+#if defined(PNG_READ_iCCP_SUPPORTED)
+      PNG_iCCP;
+#endif
+#if defined(PNG_READ_iTXt_SUPPORTED)
+      PNG_iTXt;
+#endif
+#if defined(PNG_READ_oFFs_SUPPORTED)
+      PNG_oFFs;
+#endif
+#if defined(PNG_READ_pCAL_SUPPORTED)
+      PNG_pCAL;
+#endif
+#if defined(PNG_READ_pHYs_SUPPORTED)
+      PNG_pHYs;
+#endif
+#if defined(PNG_READ_sBIT_SUPPORTED)
+      PNG_sBIT;
+#endif
+#if defined(PNG_READ_sCAL_SUPPORTED)
+      PNG_sCAL;
+#endif
+#if defined(PNG_READ_sPLT_SUPPORTED)
+      PNG_sPLT;
+#endif
+#if defined(PNG_READ_sRGB_SUPPORTED)
+      PNG_sRGB;
+#endif
+#if defined(PNG_READ_tEXt_SUPPORTED)
+      PNG_tEXt;
+#endif
+#if defined(PNG_READ_tIME_SUPPORTED)
+      PNG_tIME;
+#endif
+#if defined(PNG_READ_tRNS_SUPPORTED)
+      PNG_tRNS;
+#endif
+#if defined(PNG_READ_zTXt_SUPPORTED)
+      PNG_zTXt;
+#endif
+#endif /* PNG_GLOBAL_ARRAYS */
       png_byte chunk_length[4];
       png_uint_32 length;
 
@@ -196,10 +267,29 @@ png_read_info(png_structp png_ptr, png_infop info_ptr)
        */
       if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
          png_handle_IHDR(png_ptr, info_ptr, length);
-      else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
-         png_handle_PLTE(png_ptr, info_ptr, length);
       else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
          png_handle_IEND(png_ptr, info_ptr, length);
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+      else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
+      {
+         if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+            png_ptr->mode |= PNG_HAVE_IDAT;
+         png_handle_unknown(png_ptr, info_ptr, length);
+         if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
+            png_ptr->mode |= PNG_HAVE_PLTE;
+         else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+         {
+            if (!(png_ptr->mode & PNG_HAVE_IHDR))
+               png_error(png_ptr, "Missing IHDR before IDAT");
+            else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+                     !(png_ptr->mode & PNG_HAVE_PLTE))
+               png_error(png_ptr, "Missing PLTE before IDAT");
+            break;
+         }
+      }
+#endif
+      else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
+         png_handle_PLTE(png_ptr, info_ptr, length);
       else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
       {
          if (!(png_ptr->mode & PNG_HAVE_IHDR))
@@ -236,6 +326,10 @@ png_read_info(png_structp png_ptr, png_infop info_ptr)
       else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
          png_handle_pCAL(png_ptr, info_ptr, length);
 #endif
+#if defined(PNG_READ_sCAL_SUPPORTED)
+      else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
+         png_handle_sCAL(png_ptr, info_ptr, length);
+#endif
 #if defined(PNG_READ_pHYs_SUPPORTED)
       else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
          png_handle_pHYs(png_ptr, info_ptr, length);
@@ -248,6 +342,14 @@ png_read_info(png_structp png_ptr, png_infop info_ptr)
       else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
          png_handle_sRGB(png_ptr, info_ptr, length);
 #endif
+#if defined(PNG_READ_iCCP_SUPPORTED)
+      else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
+         png_handle_iCCP(png_ptr, info_ptr, length);
+#endif
+#if defined(PNG_READ_sPLT_SUPPORTED)
+      else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
+         png_handle_sPLT(png_ptr, info_ptr, length);
+#endif
 #if defined(PNG_READ_tEXt_SUPPORTED)
       else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
          png_handle_tEXt(png_ptr, info_ptr, length);
@@ -263,6 +365,10 @@ png_read_info(png_structp png_ptr, png_infop info_ptr)
 #if defined(PNG_READ_zTXt_SUPPORTED)
       else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
          png_handle_zTXt(png_ptr, info_ptr, length);
+#endif
+#if defined(PNG_READ_iTXt_SUPPORTED)
+      else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
+         png_handle_iTXt(png_ptr, info_ptr, length);
 #endif
       else
          png_handle_unknown(png_ptr, info_ptr, length);
@@ -297,6 +403,11 @@ png_start_read_image(png_structp png_ptr)
 void
 png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
 {
+#ifdef PNG_USE_LOCAL_ARRAYS
+   PNG_IDAT;
+   const int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
+   const int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
+#endif
    int ret;
    png_debug2(1, "in png_read_row (row %d, pass %d)\n",
       png_ptr->row_number, png_ptr->pass);
@@ -343,7 +454,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
       switch (png_ptr->pass)
       {
          case 0:
-            if (png_ptr->row_number & 7)
+            if (png_ptr->row_number & 0x07)
             {
                if (dsp_row != NULL)
                   png_combine_row(png_ptr, dsp_row,
@@ -353,7 +464,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
             }
             break;
          case 1:
-            if ((png_ptr->row_number & 7) || png_ptr->width < 5)
+            if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
             {
                if (dsp_row != NULL)
                   png_combine_row(png_ptr, dsp_row,
@@ -363,7 +474,7 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
             }
             break;
          case 2:
-            if ((png_ptr->row_number & 7) != 4)
+            if ((png_ptr->row_number & 0x07) != 4)
             {
                if (dsp_row != NULL && (png_ptr->row_number & 4))
                   png_combine_row(png_ptr, dsp_row,
@@ -465,11 +576,10 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
    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);
-   }
+   png_ptr->row_info.rowbytes = ((png_ptr->row_info.width *
+      (png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3);
 
+   if(png_ptr->row_buf[0])
    png_read_filter_row(png_ptr, &(png_ptr->row_info),
       png_ptr->row_buf + 1, png_ptr->prev_row + 1,
       (int)(png_ptr->row_buf[0]));
@@ -531,7 +641,7 @@ 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 1.0.4c.
+ * [*] png_handle_alpha() does not exist yet, as of libpng version 1.0.6d.
  */
 
 void
@@ -580,7 +690,7 @@ png_read_rows(png_structp png_ptr, png_bytepp row,
  * 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 1.0.4c.
+ * [*] png_handle_alpha() does not exist yet, as of libpng version 1.0.6d.
  */
 void
 png_read_image(png_structp png_ptr, png_bytepp image)
@@ -632,6 +742,64 @@ png_read_end(png_structp png_ptr, png_infop info_ptr)
 
    do
    {
+#ifdef PNG_USE_LOCAL_ARRAYS
+      PNG_IHDR;
+      PNG_IDAT;
+      PNG_IEND;
+      PNG_PLTE;
+#if defined(PNG_READ_bKGD_SUPPORTED)
+      PNG_bKGD;
+#endif
+#if defined(PNG_READ_cHRM_SUPPORTED)
+      PNG_cHRM;
+#endif
+#if defined(PNG_READ_gAMA_SUPPORTED)
+      PNG_gAMA;
+#endif
+#if defined(PNG_READ_hIST_SUPPORTED)
+      PNG_hIST;
+#endif
+#if defined(PNG_READ_iCCP_SUPPORTED)
+      PNG_iCCP;
+#endif
+#if defined(PNG_READ_iTXt_SUPPORTED)
+      PNG_iTXt;
+#endif
+#if defined(PNG_READ_oFFs_SUPPORTED)
+      PNG_oFFs;
+#endif
+#if defined(PNG_READ_pCAL_SUPPORTED)
+      PNG_pCAL;
+#endif
+#if defined(PNG_READ_pHYs_SUPPORTED)
+      PNG_pHYs;
+#endif
+#if defined(PNG_READ_sBIT_SUPPORTED)
+      PNG_sBIT;
+#endif
+#if defined(PNG_READ_sCAL_SUPPORTED)
+      PNG_sCAL;
+#endif
+#if defined(PNG_READ_sPLT_SUPPORTED)
+      PNG_sPLT;
+#endif
+#if defined(PNG_READ_sRGB_SUPPORTED)
+      PNG_sRGB;
+#endif
+#if defined(PNG_READ_tEXt_SUPPORTED)
+      PNG_tEXt;
+#endif
+#if defined(PNG_READ_tIME_SUPPORTED)
+      PNG_tIME;
+#endif
+#if defined(PNG_READ_tRNS_SUPPORTED)
+      PNG_tRNS;
+#endif
+#if defined(PNG_READ_zTXt_SUPPORTED)
+      PNG_zTXt;
+#endif
+#endif /* PNG_GLOBAL_ARRAYS */
+
       png_read_data(png_ptr, chunk_length, 4);
       length = png_get_uint_32(chunk_length);
 
@@ -642,6 +810,23 @@ png_read_end(png_structp png_ptr, png_infop info_ptr)
 
       if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
          png_handle_IHDR(png_ptr, info_ptr, length);
+      else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
+         png_handle_IEND(png_ptr, info_ptr, length);
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+      else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
+      {
+         if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+         {
+            if (length > 0 || png_ptr->mode & PNG_AFTER_IDAT)
+               png_error(png_ptr, "Too many IDAT's found");
+         }
+         else
+            png_ptr->mode |= PNG_AFTER_IDAT;
+         png_handle_unknown(png_ptr, info_ptr, length);
+         if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
+            png_ptr->mode |= PNG_HAVE_PLTE;
+      }
+#endif
       else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
       {
          /* Zero length IDATs are legal after the last IDAT has been
@@ -654,8 +839,6 @@ png_read_end(png_structp png_ptr, png_infop info_ptr)
       }
       else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
          png_handle_PLTE(png_ptr, info_ptr, length);
-      else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
-         png_handle_IEND(png_ptr, info_ptr, length);
 #if defined(PNG_READ_bKGD_SUPPORTED)
       else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
          png_handle_bKGD(png_ptr, info_ptr, length);
@@ -680,6 +863,10 @@ png_read_end(png_structp png_ptr, png_infop info_ptr)
       else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
          png_handle_pCAL(png_ptr, info_ptr, length);
 #endif
+#if defined(PNG_READ_sCAL_SUPPORTED)
+      else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
+         png_handle_sCAL(png_ptr, info_ptr, length);
+#endif
 #if defined(PNG_READ_pHYs_SUPPORTED)
       else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
          png_handle_pHYs(png_ptr, info_ptr, length);
@@ -692,6 +879,14 @@ png_read_end(png_structp png_ptr, png_infop info_ptr)
       else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
          png_handle_sRGB(png_ptr, info_ptr, length);
 #endif
+#if defined(PNG_READ_iCCP_SUPPORTED)
+      else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
+         png_handle_iCCP(png_ptr, info_ptr, length);
+#endif
+#if defined(PNG_READ_sPLT_SUPPORTED)
+      else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
+         png_handle_sPLT(png_ptr, info_ptr, length);
+#endif
 #if defined(PNG_READ_tEXt_SUPPORTED)
       else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
          png_handle_tEXt(png_ptr, info_ptr, length);
@@ -707,6 +902,10 @@ png_read_end(png_structp png_ptr, png_infop info_ptr)
 #if defined(PNG_READ_zTXt_SUPPORTED)
       else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
          png_handle_zTXt(png_ptr, info_ptr, length);
+#endif
+#if defined(PNG_READ_iTXt_SUPPORTED)
+      else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
+         png_handle_iTXt(png_ptr, info_ptr, length);
 #endif
       else
          png_handle_unknown(png_ptr, info_ptr, length);
@@ -722,7 +921,7 @@ png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
    png_infop info_ptr = NULL, end_info_ptr = NULL;
 #ifdef PNG_USER_MEM_SUPPORTED
    png_free_ptr free_fn = NULL;
-#endif /* PNG_USER_MEM_SUPPORTED */
+#endif
 
    png_debug(1, "in png_destroy_read_struct\n");
    /* save jump buffer and error functions */
@@ -743,8 +942,8 @@ png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
 
    if (info_ptr != NULL)
    {
-#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED)
-      png_free(png_ptr, info_ptr->text);
+#if defined(PNG_TEXT_SUPPORTED)
+      png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, -1);
 #endif
 
 #ifdef PNG_USER_MEM_SUPPORTED
@@ -757,8 +956,8 @@ png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
 
    if (end_info_ptr != NULL)
    {
-#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED)
-      png_free(png_ptr, end_info_ptr->text);
+#if defined(PNG_READ_TEXT_SUPPORTED)
+      png_free_data(png_ptr, end_info_ptr, PNG_FREE_TEXT, -1);
 #endif
 #ifdef PNG_USER_MEM_SUPPORTED
       png_destroy_struct_2((png_voidp)end_info_ptr, free_fn);
@@ -783,7 +982,9 @@ png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
 void
 png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr)
 {
+#ifdef PNG_SETJMP_SUPPORTED
    jmp_buf tmp_jmp;
+#endif
    png_error_ptr error_fn;
    png_error_ptr warning_fn;
    png_voidp error_ptr;
@@ -813,16 +1014,19 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
    png_free(png_ptr, png_ptr->gamma_from_1);
    png_free(png_ptr, png_ptr->gamma_to_1);
 #endif
-   if (png_ptr->flags & PNG_FLAG_FREE_PALETTE)
+   if (png_ptr->free_me & PNG_FREE_PLTE)
       png_zfree(png_ptr, png_ptr->palette);
-#if defined(PNG_READ_tRNS_SUPPORTED) || defined(PNG_WRITE_tRNS_SUPPORTED) || \
+   png_ptr->free_me &= ~PNG_FREE_PLTE;
+#if defined(PNG_tRNS_SUPPORTED) || \
     defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
-   if (png_ptr->flags & PNG_FLAG_FREE_TRANS)
+   if (png_ptr->free_me & PNG_FREE_TRNS)
       png_free(png_ptr, png_ptr->trans);
+   png_ptr->free_me &= ~PNG_FREE_TRNS;
 #endif
 #if defined(PNG_READ_hIST_SUPPORTED)
-   if (png_ptr->flags & PNG_FLAG_FREE_HIST)
+   if (png_ptr->free_me & PNG_FREE_HIST)
       png_free(png_ptr, png_ptr->hist);
+   png_ptr->free_me &= ~PNG_FREE_HIST;
 #endif
 #if defined(PNG_READ_GAMMA_SUPPORTED)
    if (png_ptr->gamma_16_table != NULL)
@@ -860,7 +1064,7 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
 #endif
 #if defined(PNG_TIME_RFC1123_SUPPORTED)
    png_free(png_ptr, png_ptr->time_buffer);
-#endif /* PNG_TIME_RFC1123_SUPPORTED */
+#endif
 
    inflateEnd(&png_ptr->zstream);
 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
@@ -870,7 +1074,9 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
    /* Save the important info out of the png_struct, in case it is
     * being used again.
     */
+#ifdef PNG_SETJMP_SUPPORTED
    png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf));
+#endif
 
    error_fn = png_ptr->error_fn;
    warning_fn = png_ptr->warning_fn;
@@ -888,7 +1094,10 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
    png_ptr->free_fn = free_fn;
 #endif
 
+#ifdef PNG_SETJMP_SUPPORTED
    png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf));
+#endif
+
 }
 
 void
@@ -896,3 +1105,138 @@ png_set_read_status_fn(png_structp png_ptr, png_read_status_ptr read_row_fn)
 {
    png_ptr->read_row_fn = read_row_fn;
 }
+
+#if defined(PNG_INFO_IMAGE_SUPPORTED)
+void png_read_png(png_structp png_ptr, png_infop info_ptr,
+                           int transforms,
+                           voidp params)
+{
+   int row;
+
+#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
+   /* invert the alpha channel from opacity to transparency */
+   if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
+       png_set_invert_alpha(png_ptr);
+#endif
+
+   /* The call to png_read_info() gives us all of the information from the
+    * PNG file before the first IDAT (image data chunk).
+    */
+   png_read_info(png_ptr, info_ptr);
+
+   /* -------------- image transformations start here ------------------- */
+
+#if defined(PNG_READ_16_TO_8_SUPPORTED)
+   /* tell libpng to strip 16 bit/color files down to 8 bits/color */
+   if (transforms & PNG_TRANSFORM_STRIP_16)
+       png_set_strip_16(png_ptr);
+#endif
+
+#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
+   /* Strip alpha bytes from the input data without combining with the
+    * background (not recommended).
+    */
+   if (transforms & PNG_TRANSFORM_STRIP_ALPHA)
+       png_set_strip_alpha(png_ptr);
+#endif
+
+#if defined(PNG_READ_PACK_SUPPORTED) && !defined(PNG_READ_EXPAND_SUPPORTED)
+   /* Extract multiple pixels with bit depths of 1, 2, and 4 from a single
+    * byte into separate bytes (useful for paletted and grayscale images).
+    */
+   if (transforms & PNG_TRANSFORM_PACKING)
+       png_set_packing(png_ptr);
+#endif
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+   /* Change the order of packed pixels to least significant bit first
+    * (not useful if you are using png_set_packing). */
+   if (transforms & PNG_TRANSFORM_PACKSWAP)
+       png_set_packswap(png_ptr);
+#endif
+
+#if defined(PNG_READ_EXPAND_SUPPORTED)
+   /* Expand paletted colors into true RGB triplets
+    * Expand grayscale images to full 8 bits from 1, 2, or 4 bits/pixel
+    * Expand paletted or RGB images with transparency to full alpha
+    * channels so the data will be available as RGBA quartets.
+    */
+   if (transforms & PNG_TRANSFORM_EXPAND)
+       if ((png_ptr->bit_depth < 8) ||
+           (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ||
+           (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)))
+         png_set_expand(png_ptr);
+#endif
+
+   /* We don't handle background color or gamma transformation or dithering. */
+
+#if defined(PNG_READ_INVERT_SUPPORTED)
+   /* invert monochrome files to have 0 as white and 1 as black */
+   if (transforms & PNG_TRANSFORM_INVERT_MONO)
+       png_set_invert_mono(png_ptr);
+#endif
+
+#if defined(PNG_READ_SHIFT_SUPPORTED)
+   /* If you want to shift the pixel values from the range [0,255] or
+    * [0,65535] to the original [0,7] or [0,31], or whatever range the
+    * colors were originally in:
+    */
+   if ((transforms & PNG_TRANSFORM_SHIFT)
+       && png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT))
+   {
+      png_color_8p sig_bit;
+
+      png_get_sBIT(png_ptr, info_ptr, &sig_bit);
+      png_set_shift(png_ptr, sig_bit);
+   }
+#endif
+
+#if defined(PNG_READ_BGR_SUPPORTED)
+   /* flip the RGB pixels to BGR (or RGBA to BGRA) */
+   if (transforms & PNG_TRANSFORM_BGR)
+       png_set_bgr(png_ptr);
+#endif
+
+#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
+   /* swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */
+   if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
+       png_set_swap_alpha(png_ptr);
+#endif
+
+#if defined(PNG_READ_SWAP_SUPPORTED)
+   /* swap bytes of 16 bit files to least significant byte first */
+   if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
+       png_set_swap(png_ptr);
+#endif
+
+   /* We don't handle adding filler bytes */
+
+   /* Optional call to gamma correct and add the background to the palette
+    * and update info structure.  REQUIRED if you are expecting libpng to
+    * update the palette for you (ie you selected such a transform above).
+    */
+   png_read_update_info(png_ptr, info_ptr);
+
+   /* -------------- image transformations end here ------------------- */
+
+   if(info_ptr->row_pointers == NULL)
+   {
+      info_ptr->row_pointers = (png_bytepp)png_malloc(png_ptr,
+                                         info_ptr->height * sizeof(png_bytep));
+      info_ptr->free_me |= PNG_FREE_ROWS;
+   }
+   for (row = 0; row < (int)info_ptr->height; row++)
+       info_ptr->row_pointers[row] = png_malloc(png_ptr,
+                                      png_get_rowbytes(png_ptr, info_ptr));
+
+   png_read_image(png_ptr, info_ptr->row_pointers);
+   info_ptr->valid |= PNG_INFO_IDAT;
+
+   /* read rest of file, and get additional chunks in info_ptr - REQUIRED */
+   png_read_end(png_ptr, info_ptr);
+
+   if(transforms == 0 || params == (voidp)NULL)
+      /* quiet compiler warnings */ return;
+
+}
+#endif

pngrio.c

@@ -1,11 +1,11 @@
 
 /* pngrio.c - functions for data input
  *
- * libpng 1.0.4c - October 1, 1999
+ * libpng 1.0.6d - April 7, 2000
  * 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, 1999 Glenn Randers-Pehrson
+ * Copyright (c) 1998, 1999, 2000 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
@@ -146,6 +146,6 @@ png_set_read_fn(png_structp png_ptr, png_voidp io_ptr,
 
 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
    png_ptr->output_flush_fn = NULL;
-#endif /* PNG_WRITE_FLUSH_SUPPORTED */
+#endif
 }
 

pngrtran.c

@@ -1,11 +1,11 @@
 
 /* pngrtran.c - transforms the data in a row for PNG readers
  *
- * libpng 1.0.4c - October 1, 1999
+ * libpng 1.0.6d - April 7, 2000
  * 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, 1999 Glenn Randers-Pehrson
+ * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson
  *
  * This file contains functions optionally called by an application
  * in order to tell libpng how to handle data when reading a PNG.
@@ -69,7 +69,8 @@ png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action)
    }
 }
 
-#if defined(PNG_READ_BACKGROUND_SUPPORTED)
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
+    defined(PNG_FLOATING_POINT_SUPPORTED)
 /* handle alpha and tRNS via a background color */
 void
 png_set_background(png_structp png_ptr,
@@ -92,13 +93,13 @@ png_set_background(png_structp png_ptr,
    /* Note:  if need_expand is set and color_type is either RGB or RGB_ALPHA
     * (in which case need_expand is superfluous anyway), the background color
     * might actually be gray yet not be flagged as such. This is not a problem
-    * for the current code, which uses PNG_FLAG_BACKGROUND_IS_GRAY only to
+    * for the current code, which uses PNG_BACKGROUND_IS_GRAY only to
     * decide when to do the png_do_gray_to_rgb() transformation.
     */
    if ((need_expand && !(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) ||
        (!need_expand && background_color->red == background_color->green &&
         background_color->red == background_color->blue))
-      png_ptr->flags |= PNG_FLAG_BACKGROUND_IS_GRAY;
+      png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
 }
 #endif
 
@@ -366,7 +367,7 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
                      {
                         int j, next_j;
 
-                        if (num_new_palette & 1)
+                        if (num_new_palette & 0x01)
                         {
                            j = p->left;
                            next_j = p->right;
@@ -504,7 +505,7 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
 }
 #endif
 
-#if defined(PNG_READ_GAMMA_SUPPORTED)
+#if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
 /* Transform the image from the file_gamma to the screen_gamma.  We
  * only do transformations on images where the file_gamma and screen_gamma
  * are not close reciprocals, otherwise it slows things down slightly, and
@@ -582,12 +583,24 @@ png_set_gray_to_rgb(png_structp png_ptr)
 #endif
 
 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+#if defined(PNG_FLOATING_POINT_SUPPORTED)
 /* 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 error_action, double red,
-  double green)
+   double green)
+{
+      int red_fixed = (int)((float)red*100000.0 + 0.5);
+      int green_fixed = (int)((float)green*100000.0 + 0.5);
+      png_set_rgb_to_gray_fixed(png_ptr, error_action, red_fixed, green_fixed);
+}
+#endif
+
+void
+png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action,
+   png_fixed_point red, png_fixed_point green)
 {
    png_debug(1, "in png_set_rgb_to_gray\n");
    switch(error_action)
@@ -608,22 +621,26 @@ png_set_rgb_to_gray(png_structp png_ptr, int error_action, double red,
    }
 #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)
+      png_uint_16 red_int, green_int;
+      if(red < 0 || green < 0)
       {
-         red_byte = 54;
-         green_byte = 183;
+         red_int   =  6968; /* .212671 * 32768 + .5 */
+         green_int = 23434; /* .715160 * 32768 + .5 */
       }
-      else if(red_byte + green_byte > 255)
+      else if(red + green < 100000L)
+      {
+        red_int = (png_uint_16)(((png_uint_32)red*32768L)/100000L);
+        green_int = (png_uint_16)(((png_uint_32)green*32768L)/100000L);
+      }
+      else
       {
          png_warning(png_ptr, "ignoring out of range rgb_to_gray coefficients");
-         red_byte = 54;
-         green_byte = 183;
+         red_int   =  6968;
+         green_int = 23434;
       }
-      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;
+      png_ptr->rgb_to_gray_red_coeff   = red_int;
+      png_ptr->rgb_to_gray_green_coeff = green_int;
+      png_ptr->rgb_to_gray_blue_coeff  = (png_uint_16)(32768-red_int-green_int);
    }
 }
 #endif
@@ -656,7 +673,8 @@ png_init_read_transformations(png_structp png_ptr)
 #endif
 
 #if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
-   if (png_ptr->transformations & PNG_BACKGROUND_EXPAND)
+   if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
+       (png_ptr->transformations & PNG_EXPAND))
    {
       if (!(color_type & PNG_COLOR_MASK_COLOR))  /* i.e., GRAY or GRAY_ALPHA */
       {
@@ -706,7 +724,7 @@ png_init_read_transformations(png_structp png_ptr)
               int i,istop;
               istop=(int)png_ptr->num_trans;
               for (i=0; i<istop; i++)
-                 png_ptr->trans[i] = 255 - png_ptr->trans[i];
+                 png_ptr->trans[i] = (png_byte)(255 - png_ptr->trans[i]);
            }
         }
 #endif
@@ -718,7 +736,7 @@ png_init_read_transformations(png_structp png_ptr)
 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
    png_ptr->background_1 = png_ptr->background;
 #endif
-#if defined(PNG_READ_GAMMA_SUPPORTED)
+#if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
    if (png_ptr->transformations & (PNG_GAMMA | PNG_RGB_TO_GRAY))
    {
       png_build_gamma_table(png_ptr);
@@ -731,7 +749,6 @@ png_init_read_transformations(png_structp png_ptr)
             png_colorp palette = png_ptr->palette;
             int num_palette = png_ptr->num_palette;
             int i;
-
             if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE)
             {
                back.red = png_ptr->gamma_table[png_ptr->background.red];
@@ -789,7 +806,6 @@ png_init_read_transformations(png_structp png_ptr)
                back_1.blue = (png_byte)(pow(
                   (double)png_ptr->background.blue/255, g) * 255.0 + .5);
             }
-
             for (i = 0; i < num_palette; i++)
             {
                if (i < (int)png_ptr->num_trans && png_ptr->trans[i] != 0xff)
@@ -897,8 +913,8 @@ png_init_read_transformations(png_structp png_ptr)
 #endif
 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
    /* No GAMMA transformation */
-   if (png_ptr->transformations & PNG_BACKGROUND &&
-       color_type == PNG_COLOR_TYPE_PALETTE)
+   if ((png_ptr->transformations & PNG_BACKGROUND) &&
+       (color_type == PNG_COLOR_TYPE_PALETTE))
    {
       int i;
       int istop = (int)png_ptr->num_trans;
@@ -931,7 +947,7 @@ png_init_read_transformations(png_structp png_ptr)
 
 #if defined(PNG_READ_SHIFT_SUPPORTED)
    if ((png_ptr->transformations & PNG_SHIFT) &&
-      color_type == PNG_COLOR_TYPE_PALETTE)
+      (color_type == PNG_COLOR_TYPE_PALETTE))
    {
       png_uint_16 i;
       png_uint_16 istop = png_ptr->num_palette;
@@ -998,11 +1014,18 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
 
 #if defined(PNG_READ_GAMMA_SUPPORTED)
    if (png_ptr->transformations & PNG_GAMMA)
+   {
+#ifdef PNG_FLOATING_POINT_SUPPORTED
       info_ptr->gamma = png_ptr->gamma;
 #endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+      info_ptr->int_gamma = png_ptr->int_gamma;
+#endif
+   }
+#endif
 
 #if defined(PNG_READ_16_TO_8_SUPPORTED)
-   if ((png_ptr->transformations & PNG_16_TO_8) && info_ptr->bit_depth == 16)
+   if ((png_ptr->transformations & PNG_16_TO_8) && (info_ptr->bit_depth == 16))
       info_ptr->bit_depth = 8;
 #endif
 
@@ -1019,7 +1042,7 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
 #endif
 
 #if defined(PNG_READ_PACK_SUPPORTED)
-   if ((png_ptr->transformations & PNG_PACK) && info_ptr->bit_depth < 8)
+   if ((png_ptr->transformations & PNG_PACK) && (info_ptr->bit_depth < 8))
       info_ptr->bit_depth = 8;
 #endif
 
@@ -1050,10 +1073,10 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
 
 #if defined(PNG_READ_FILLER_SUPPORTED)
    /* STRIP_ALPHA and FILLER allowed:  MASK_ALPHA bit stripped above */
-   if (png_ptr->transformations & PNG_FILLER &&
-       (info_ptr->color_type == PNG_COLOR_TYPE_RGB ||
-        info_ptr->color_type == PNG_COLOR_TYPE_GRAY))
-      ++info_ptr->channels;
+   if ((png_ptr->transformations & PNG_FILLER) &&
+       ((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||
+       (info_ptr->color_type == PNG_COLOR_TYPE_GRAY)))
+      info_ptr->channels++;
 #endif
 
 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
@@ -1170,8 +1193,8 @@ From Andreas Dilger e-mail to png-implement, 26 March 1998:
 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
    /* if gray -> RGB, do so now only if background is non-gray; else do later
     * for performance reasons */
-   if (png_ptr->transformations & PNG_GRAY_TO_RGB &&
-       !(png_ptr->flags & PNG_FLAG_BACKGROUND_IS_GRAY))
+   if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
+       !(png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
       png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1);
 #endif
 
@@ -1244,8 +1267,8 @@ From Andreas Dilger e-mail to png-implement, 26 March 1998:
 
 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
    /* if gray -> RGB, do so now only if we did not do so above */
-   if (png_ptr->transformations & PNG_GRAY_TO_RGB &&
-       png_ptr->flags & PNG_FLAG_BACKGROUND_IS_GRAY)
+   if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
+       (png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
       png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1);
 #endif
 
@@ -1290,7 +1313,7 @@ From Andreas Dilger e-mail to png-implement, 26 March 1998:
          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.rowbytes = (png_ptr->row_info.width *
          png_ptr->row_info.pixel_depth+7)>>3;
    }
 #endif
@@ -1323,10 +1346,10 @@ png_do_unpack(png_row_infop row_info, png_bytep row)
          {
             png_bytep sp = row + (png_size_t)((row_width - 1) >> 3);
             png_bytep dp = row + (png_size_t)row_width - 1;
-            png_uint_32 shift = 7 - (int)((row_width + 7) & 7);
+            png_uint_32 shift = 7 - (int)((row_width + 7) & 0x07);
             for (i = 0; i < row_width; i++)
             {
-               *dp = (png_byte)((*sp >> shift) & 0x1);
+               *dp = (png_byte)((*sp >> shift) & 0x01);
                if (shift == 7)
                {
                   shift = 0;
@@ -1344,10 +1367,10 @@ png_do_unpack(png_row_infop row_info, png_bytep row)
 
             png_bytep sp = row + (png_size_t)((row_width - 1) >> 2);
             png_bytep dp = row + (png_size_t)row_width - 1;
-            png_uint_32 shift = (int)((3 - ((row_width + 3) & 3)) << 1);
+            png_uint_32 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
             for (i = 0; i < row_width; i++)
             {
-               *dp = (png_byte)((*sp >> shift) & 0x3);
+               *dp = (png_byte)((*sp >> shift) & 0x03);
                if (shift == 6)
                {
                   shift = 0;
@@ -1364,10 +1387,10 @@ png_do_unpack(png_row_infop row_info, png_bytep row)
          {
             png_bytep sp = row + (png_size_t)((row_width - 1) >> 1);
             png_bytep dp = row + (png_size_t)row_width - 1;
-            png_uint_32 shift = (int)((1 - ((row_width + 1) & 1)) << 2);
+            png_uint_32 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
             for (i = 0; i < row_width; i++)
             {
-               *dp = (png_byte)((*sp >> shift) & 0xf);
+               *dp = (png_byte)((*sp >> shift) & 0x0f);
                if (shift == 4)
                {
                   shift = 0;
@@ -1456,8 +1479,8 @@ png_do_unshift(png_row_infop row_info, png_bytep row, png_color_8p sig_bits)
             png_bytep bp = row;
             png_uint_32 i;
             png_uint_32 istop = row_info->rowbytes;
-            png_byte mask = (png_byte)(((int)0xf0 >> shift[0]) & (int)0xf0) |
-               (png_byte)((int)0xf >> shift[0]);
+            png_byte mask = (png_byte)((((int)0xf0 >> shift[0]) & (int)0xf0) |
+               (png_byte)((int)0xf >> shift[0]));
 
             for (i = 0; i < istop; i++)
             {
@@ -1666,10 +1689,16 @@ png_do_read_invert_alpha(png_row_infop row_info, png_bytep row)
 
             for (i = 0; i < row_width; i++)
             {
-               *(--dp) = 255 - *(--sp);
+               *(--dp) = (png_byte)(255 - *(--sp));
+
+/*             This does nothing:
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
+               We can replace it with:
+*/
+               sp-=3;
+               dp=sp;
             }
          }
          /* This inverts the alpha channel in RRGGBBAA */
@@ -1681,14 +1710,20 @@ png_do_read_invert_alpha(png_row_infop row_info, png_bytep row)
 
             for (i = 0; i < row_width; i++)
             {
-               *(--dp) = 255 - *(--sp);
-               *(--dp) = 255 - *(--sp);
+               *(--dp) = (png_byte)(255 - *(--sp));
+               *(--dp) = (png_byte)(255 - *(--sp));
+
+/*             This does nothing:
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
+               We can replace it with:
+*/
+               sp-=6;
+               dp=sp;
             }
          }
       }
@@ -1703,7 +1738,7 @@ png_do_read_invert_alpha(png_row_infop row_info, png_bytep row)
 
             for (i = 0; i < row_width; i++)
             {
-               *(--dp) = 255 - *(--sp);
+               *(--dp) = (png_byte)(255 - *(--sp));
                *(--dp) = *(--sp);
             }
          }
@@ -1716,10 +1751,14 @@ png_do_read_invert_alpha(png_row_infop row_info, png_bytep row)
 
             for (i = 0; i < row_width; i++)
             {
-               *(--dp) = 255 - *(--sp);
-               *(--dp) = 255 - *(--sp);
+               *(--dp) = (png_byte)(255 - *(--sp));
+               *(--dp) = (png_byte)(255 - *(--sp));
+/*
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
+*/
+               sp-=2;
+               dp=sp;
             }
          }
       }
@@ -1988,7 +2027,7 @@ 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 
+/* 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
@@ -1996,12 +2035,12 @@ png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
  *     Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
  *
  *  We approximate this with
- * 
- *     Y = 0.211 * R    + 0.715 * G    + 0.074 * B
+ *
+ *     Y = 0.21268 * R    + 0.7151 * G    + 0.07217 * B
  *
  *  which can be expressed with integers as
  *
- *     Y = (54 * R + 183 * G + 19 * B)/256
+ *     Y = (6969 * R + 23434 * G + 2365 * B)/32768
  *
  *  The calculation is to be done in a linear colorspace.
  *
@@ -2023,9 +2062,9 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
 #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;
+      png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff;
+      png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff;
+      png_uint_32 bc = png_ptr->rgb_to_gray_blue_coeff;
 
       if (row_info->color_type == PNG_COLOR_TYPE_RGB)
       {
@@ -2046,7 +2085,7 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
                   {
                      rgb_error |= 1;
                      *(dp++) = png_ptr->gamma_from_1[
-                       (rc*red+gc*green+bc*blue)>>8];
+                       (rc*red+gc*green+bc*blue)>>15];
                   }
                   else
                      *(dp++) = *(sp-1);
@@ -2065,14 +2104,14 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
                   if(red != green || red != blue)
                   {
                      rgb_error |= 1;
-                     *(dp++) = (rc*red+gc*green+bc*blue)>>8;
+                     *(dp++) = (png_byte)((rc*red+gc*green+bc*blue)>>15);
                   }
                   else
                      *(dp++) = *(sp-1);
                }
             }
          }
- 
+
          else /* RGB bit_depth == 16 */
          {
 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
@@ -2085,9 +2124,9 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
                {
                   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;
+                  red   = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
+                  green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
+                  blue  = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
 
                   if(red == green && red == blue)
                      w = red;
@@ -2097,17 +2136,17 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
                                   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_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;
+                     png_uint_16 gray16  = (png_uint_16)((rc*red_1 + gc*green_1
+                                  + bc*blue_1)>>15);
                      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++) = (png_byte)((w>>8) & 0xff);
+                  *(dp++) = (png_byte)(w & 0xff);
                }
             }
             else
@@ -2119,15 +2158,15 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
                {
                   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;
+                  red   = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
+                  green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
+                  blue  = (png_uint_16)(((*(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;
+                  gray16  = (png_uint_16)((rc*red + gc*green + bc*blue)>>15);
+                  *(dp++) = (png_byte)((gray16>>8) & 0xff);
+                  *(dp++) = (png_byte)(gray16 & 0xff);
                }
             }
          }
@@ -2149,7 +2188,7 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
                   if(red != green || red != blue)
                      rgb_error |= 1;
                   *(dp++) =  png_ptr->gamma_from_1
-                             [(rc*red + gc*green + bc*blue)>>8];
+                             [(rc*red + gc*green + bc*blue)>>15];
                   *(dp++) = *(sp++);  /* alpha */
                }
             }
@@ -2165,7 +2204,7 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
                   png_byte blue  = *(sp++);
                   if(red != green || red != blue)
                      rgb_error |= 1;
-                  *(dp++) =  (gc*red + gc*green + bc*blue)>>8;
+                  *(dp++) =  (png_byte)((gc*red + gc*green + bc*blue)>>8);
                   *(dp++) = *(sp++);  /* alpha */
                }
             }
@@ -2182,9 +2221,9 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
                {
                   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;
+                  red   = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
+                  green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
+                  blue  = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
 
                   if(red == green && red == blue)
                      w = red;
@@ -2194,17 +2233,17 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
                                   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_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;
+                     png_uint_16 gray16  = (png_uint_16)((rc * red_1
+                                  + gc * green_1 + bc * blue_1)>>15);
                      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++) = (png_byte)((w>>8) & 0xff);
+                  *(dp++) = (png_byte)(w & 0xff);
                   *(dp++) = *(sp++);  /* alpha */
                   *(dp++) = *(sp++);
                }
@@ -2217,14 +2256,14 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep 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;
+                  red   = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2;
+                  green = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2;
+                  blue  = (png_uint_16)((*(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;
+                  gray16  = (png_uint_16)((rc*red + gc*green + bc*blue)>>15);
+                  *(dp++) = (png_byte)((gray16>>8) & 0xff);
+                  *(dp++) = (png_byte)(gray16 & 0xff);
                   *(dp++) = *(sp++);  /* alpha */
                   *(dp++) = *(sp++);
                }
@@ -2298,7 +2337,8 @@ png_correct_palette(png_structp png_ptr, png_colorp palette,
    int num_palette)
 {
    png_debug(1, "in png_correct_palette\n");
-#if defined(PNG_READ_BACKGROUND_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
+    defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
    if (png_ptr->transformations & (PNG_GAMMA | PNG_BACKGROUND))
    {
       png_color back, back_1;
@@ -2510,7 +2550,7 @@ png_do_background(png_row_infop row_info, png_bytep row,
                   shift = 7;
                   for (i = 0; i < row_width; i++)
                   {
-                     if ((png_uint_16)((*sp >> shift) & 0x1)
+                     if ((png_uint_16)((*sp >> shift) & 0x01)
                         == trans_values->gray)
                      {
                         *sp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);
@@ -2535,7 +2575,7 @@ png_do_background(png_row_infop row_info, png_bytep row,
                      shift = 6;
                      for (i = 0; i < row_width; i++)
                      {
-                        if ((png_uint_16)((*sp >> shift) & 0x3)
+                        if ((png_uint_16)((*sp >> shift) & 0x03)
                             == trans_values->gray)
                         {
                            *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
@@ -2543,9 +2583,9 @@ png_do_background(png_row_infop row_info, png_bytep row,
                         }
                         else
                         {
-                           png_byte p = (*sp >> shift) & 0x3;
-                           png_byte g = (gamma_table [p | (p << 2) | (p << 4) |
-                               (p << 6)] >> 6) & 0x3;
+                           png_byte p = (png_byte)((*sp >> shift) & 0x03);
+                           png_byte g = (png_byte)((gamma_table [p | (p << 2) |
+                               (p << 4) | (p << 6)] >> 6) & 0x03);
                            *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
                            *sp |= (png_byte)(g << shift);
                         }
@@ -2565,7 +2605,7 @@ png_do_background(png_row_infop row_info, png_bytep row,
                      shift = 6;
                      for (i = 0; i < row_width; i++)
                      {
-                        if ((png_uint_16)((*sp >> shift) & 0x3)
+                        if ((png_uint_16)((*sp >> shift) & 0x03)
                             == trans_values->gray)
                         {
                            *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
@@ -2591,7 +2631,7 @@ png_do_background(png_row_infop row_info, png_bytep row,
                      shift = 4;
                      for (i = 0; i < row_width; i++)
                      {
-                        if ((png_uint_16)((*sp >> shift) & 0xf)
+                        if ((png_uint_16)((*sp >> shift) & 0x0f)
                             == trans_values->gray)
                         {
                            *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
@@ -2599,8 +2639,9 @@ png_do_background(png_row_infop row_info, png_bytep row,
                         }
                         else
                         {
-                           png_byte p = (*sp >> shift) & 0xf;
-                           png_byte g = (gamma_table[p | (p << 4)] >> 4) & 0xf;
+                           png_byte p = (png_byte)((*sp >> shift) & 0x0f);
+                           png_byte g = (png_byte)((gamma_table[p |
+                             (p << 4)] >> 4) & 0x0f);
                            *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
                            *sp |= (png_byte)(g << shift);
                         }
@@ -2620,7 +2661,7 @@ png_do_background(png_row_infop row_info, png_bytep row,
                      shift = 4;
                      for (i = 0; i < row_width; i++)
                      {
-                        if ((png_uint_16)((*sp >> shift) & 0xf)
+                        if ((png_uint_16)((*sp >> shift) & 0x0f)
                             == trans_values->gray)
                         {
                            *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
@@ -2679,7 +2720,7 @@ png_do_background(png_row_infop row_info, png_bytep row,
                      {
                         png_uint_16 v;
 
-                        v = ((png_uint_16)(*sp) << 8) + *(sp + 1);
+                        v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
                         if (v == trans_values->gray)
                         {
                            /* background is already in screen gamma */
@@ -2702,7 +2743,7 @@ png_do_background(png_row_infop row_info, png_bytep row,
                      {
                         png_uint_16 v;
 
-                        v = ((png_uint_16)(*sp) << 8) + *(sp + 1);
+                        v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
                         if (v == trans_values->gray)
                         {
                            *sp = (png_byte)((background->gray >> 8) & 0xff);
@@ -2766,9 +2807,9 @@ png_do_background(png_row_infop row_info, png_bytep row,
                   sp = row;
                   for (i = 0; i < row_width; i++, sp += 6)
                   {
-                     png_uint_16 r = ((png_uint_16)(*sp) << 8) + *(sp + 1);
-                     png_uint_16 g = ((png_uint_16)(*(sp + 2)) << 8) + *(sp + 3);
-                     png_uint_16 b = ((png_uint_16)(*(sp + 4)) << 8) + *(sp + 5);
+                     png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+                     png_uint_16 g = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));
+                     png_uint_16 b = (png_uint_16)(((*(sp+4)) << 8) + *(sp+5));
                      if (r == trans_values->red && g == trans_values->green &&
                         b == trans_values->blue)
                      {
@@ -2800,9 +2841,9 @@ png_do_background(png_row_infop row_info, png_bytep row,
                   sp = row;
                   for (i = 0; i < row_width; i++, sp += 6)
                   {
-                     png_uint_16 r = ((png_uint_16)(*sp) << 8) + *(sp + 1);
-                     png_uint_16 g = ((png_uint_16)(*(sp + 2)) << 8) + *(sp + 3);
-                     png_uint_16 b = ((png_uint_16)(*(sp + 4)) << 8) + *(sp + 5);
+                     png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp+1));
+                     png_uint_16 g = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));
+                     png_uint_16 b = (png_uint_16)(((*(sp+4)) << 8) + *(sp+5));
 
                      if (r == trans_values->red && g == trans_values->green &&
                         b == trans_values->blue)
@@ -2886,7 +2927,7 @@ png_do_background(png_row_infop row_info, png_bytep row,
                   dp = row;
                   for (i = 0; i < row_width; i++, sp += 4, dp += 2)
                   {
-                     png_uint_16 a = ((png_uint_16)(*(sp + 2)) << 8) + *(sp + 3);
+                     png_uint_16 a = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));
 
                      if (a == (png_uint_16)0xffff)
                      {
@@ -2921,7 +2962,7 @@ png_do_background(png_row_infop row_info, png_bytep row,
                   dp = row;
                   for (i = 0; i < row_width; i++, sp += 4, dp += 2)
                   {
-                     png_uint_16 a = ((png_uint_16)(*(sp + 2)) << 8) + *(sp + 3);
+                     png_uint_16 a = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));
                      if (a == (png_uint_16)0xffff)
                      {
                         png_memcpy(dp, sp, 2);
@@ -2935,7 +2976,7 @@ png_do_background(png_row_infop row_info, png_bytep row,
                      {
                         png_uint_16 g, v;
 
-                        g = ((png_uint_16)(*sp) << 8) + *(sp + 1);
+                        g = (png_uint_16)(((*sp) << 8) + *(sp + 1));
                         png_composite_16(v, g, a, background_1->gray);
                         *dp = (png_byte)((v >> 8) & 0xff);
                         *(dp + 1) = (png_byte)(v & 0xff);
@@ -3104,11 +3145,11 @@ png_do_background(png_row_infop row_info, png_bytep row,
                      {
                         png_uint_16 v;
 
-                        png_uint_16 r = ((png_uint_16)(*sp) << 8) + *(sp + 1);
-                        png_uint_16 g = ((png_uint_16)(*(sp + 2)) << 8)
-                            + *(sp + 3);
-                        png_uint_16 b = ((png_uint_16)(*(sp + 4)) << 8)
-                            + *(sp + 5);
+                        png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+                        png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
+                            + *(sp + 3));
+                        png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
+                            + *(sp + 5));
 
                         png_composite_16(v, r, a, background->red);
                         *dp = (png_byte)((v >> 8) & 0xff);
@@ -3277,10 +3318,11 @@ png_do_gamma(png_row_infop row_info, png_bytep row,
                   int c = *sp & 0x0c;
                   int d = *sp & 0x03;
 
-                  *sp = ((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)])   ) & 0xc0)|
+                  *sp = (png_byte)(
+                        ((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)])   ) & 0xc0)|
                         ((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)|
                         ((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)|
-                        ((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6)       );
+                        ((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) ));
                   sp++;
                }
             }
@@ -3292,8 +3334,8 @@ png_do_gamma(png_row_infop row_info, png_bytep row,
                   int msb = *sp & 0xf0;
                   int lsb = *sp & 0x0f;
 
-                  *sp = (((int)gamma_table[msb | (msb >> 4)]) & 0xf0) |
-                        (((int)gamma_table[(lsb << 4) | lsb]) >> 4);
+                  *sp = (png_byte)((((int)gamma_table[msb | (msb >> 4)]) & 0xf0)
+                          | (((int)gamma_table[(lsb << 4) | lsb]) >> 4));
                   sp++;
                }
             }
@@ -3352,10 +3394,10 @@ png_do_expand_palette(png_row_infop row_info, png_bytep row,
             {
                sp = row + (png_size_t)((row_width - 1) >> 3);
                dp = row + (png_size_t)row_width - 1;
-               shift = 7 - (int)((row_width + 7) & 7);
+               shift = 7 - (int)((row_width + 7) & 0x07);
                for (i = 0; i < row_width; i++)
                {
-                  if ((*sp >> shift) & 0x1)
+                  if ((*sp >> shift) & 0x01)
                      *dp = 1;
                   else
                      *dp = 0;
@@ -3375,10 +3417,10 @@ png_do_expand_palette(png_row_infop row_info, png_bytep row,
             {
                sp = row + (png_size_t)((row_width - 1) >> 2);
                dp = row + (png_size_t)row_width - 1;
-               shift = (int)((3 - ((row_width + 3) & 3)) << 1);
+               shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
                for (i = 0; i < row_width; i++)
                {
-                  value = (*sp >> shift) & 0x3;
+                  value = (*sp >> shift) & 0x03;
                   *dp = (png_byte)value;
                   if (shift == 6)
                   {
@@ -3396,10 +3438,10 @@ png_do_expand_palette(png_row_infop row_info, png_bytep row,
             {
                sp = row + (png_size_t)((row_width - 1) >> 1);
                dp = row + (png_size_t)row_width - 1;
-               shift = (int)((row_width & 1) << 2);
+               shift = (int)((row_width & 0x01) << 2);
                for (i = 0; i < row_width; i++)
                {
-                  value = (*sp >> shift) & 0xf;
+                  value = (*sp >> shift) & 0x0f;
                   *dp = (png_byte)value;
                   if (shift == 4)
                   {
@@ -3487,7 +3529,7 @@ png_do_expand(png_row_infop row_info, png_bytep row,
    {
       if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
       {
-         png_uint_16 gray = trans_value ? trans_value->gray : 0;
+         png_uint_16 gray = (png_uint_16)(trans_value ? trans_value->gray : 0);
 
          if (row_info->bit_depth < 8)
          {
@@ -3495,13 +3537,13 @@ png_do_expand(png_row_infop row_info, png_bytep row,
             {
                case 1:
                {
-                  gray *= 0xff;
+                  gray = (png_uint_16)(gray*0xff);
                   sp = row + (png_size_t)((row_width - 1) >> 3);
                   dp = row + (png_size_t)row_width - 1;
-                  shift = 7 - (int)((row_width + 7) & 7);
+                  shift = 7 - (int)((row_width + 7) & 0x07);
                   for (i = 0; i < row_width; i++)
                   {
-                     if ((*sp >> shift) & 0x1)
+                     if ((*sp >> shift) & 0x01)
                         *dp = 0xff;
                      else
                         *dp = 0;
@@ -3519,13 +3561,13 @@ png_do_expand(png_row_infop row_info, png_bytep row,
                }
                case 2:
                {
-                  gray *= 0x55;
+                  gray = (png_uint_16)(gray*0x55);
                   sp = row + (png_size_t)((row_width - 1) >> 2);
                   dp = row + (png_size_t)row_width - 1;
-                  shift = (int)((3 - ((row_width + 3) & 3)) << 1);
+                  shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
                   for (i = 0; i < row_width; i++)
                   {
-                     value = (*sp >> shift) & 0x3;
+                     value = (*sp >> shift) & 0x03;
                      *dp = (png_byte)(value | (value << 2) | (value << 4) |
                         (value << 6));
                      if (shift == 6)
@@ -3542,13 +3584,13 @@ png_do_expand(png_row_infop row_info, png_bytep row,
                }
                case 4:
                {
-                  gray *= 0x11;
+                  gray = (png_uint_16)(gray*0x11);
                   sp = row + (png_size_t)((row_width - 1) >> 1);
                   dp = row + (png_size_t)row_width - 1;
-                  shift = (int)((1 - ((row_width + 1) & 1)) << 2);
+                  shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
                   for (i = 0; i < row_width; i++)
                   {
-                     value = (*sp >> shift) & 0xf;
+                     value = (*sp >> shift) & 0x0f;
                      *dp = (png_byte)(value | (value << 4));
                      if (shift == 4)
                      {
@@ -3762,6 +3804,7 @@ png_do_dither(png_row_infop row_info, png_bytep row,
 }
 #endif
 
+#ifdef PNG_FLOATING_POINT_SUPPORTED
 #if defined(PNG_READ_GAMMA_SUPPORTED)
 static int png_gamma_shift[] =
    {0x10, 0x21, 0x42, 0x84, 0x110, 0x248, 0x550, 0xff0};
@@ -3798,7 +3841,7 @@ png_build_gamma_table(png_structp png_ptr)
 
 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
     defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
-      if (png_ptr->transformations & (PNG_BACKGROUND | PNG_RGB_TO_GRAY))
+      if (png_ptr->transformations & ((PNG_BACKGROUND) | PNG_RGB_TO_GRAY))
       {
 
          g = 1.0 / (png_ptr->gamma);
@@ -3812,7 +3855,7 @@ png_build_gamma_table(png_structp png_ptr)
                g) * 255.0 + .5);
          }
 
-         
+
          png_ptr->gamma_from_1 = (png_bytep)png_malloc(png_ptr,
             (png_uint_32)256);
 
@@ -3981,4 +4024,6 @@ png_build_gamma_table(png_structp png_ptr)
  }
 }
 #endif
+/* To do: install integer version of png_build_gamma_table here */
+#endif
 

pngset.c

@@ -1,11 +1,11 @@
 
 /* pngset.c - storage of image information into info struct
  *
- * libpng 1.0.4c - October 1, 1999
+ * libpng 1.0.6d - April 7, 2000
  * 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, 1999 Glenn Randers-Pehrson
+ * Copyright (c) 1998, 1999, 2000 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
@@ -16,7 +16,7 @@
 #define PNG_INTERNAL
 #include "png.h"
 
-#if defined(PNG_READ_bKGD_SUPPORTED) || defined(PNG_WRITE_bKGD_SUPPORTED)
+#if defined(PNG_bKGD_SUPPORTED)
 void
 png_set_bKGD(png_structp png_ptr, png_infop info_ptr, png_color_16p background)
 {
@@ -29,7 +29,8 @@ png_set_bKGD(png_structp png_ptr, png_infop info_ptr, png_color_16p background)
 }
 #endif
 
-#if defined(PNG_READ_cHRM_SUPPORTED) || defined(PNG_WRITE_cHRM_SUPPORTED)
+#if defined(PNG_cHRM_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
 void
 png_set_cHRM(png_structp png_ptr, png_infop info_ptr,
    double white_x, double white_y, double red_x, double red_y,
@@ -47,11 +48,55 @@ png_set_cHRM(png_structp png_ptr, png_infop info_ptr,
    info_ptr->y_green = (float)green_y;
    info_ptr->x_blue  = (float)blue_x;
    info_ptr->y_blue  = (float)blue_y;
+#ifdef PNG_FIXED_POINT_SUPPORTED
+   info_ptr->int_x_white = (png_fixed_point)(white_x*100000.+0.5);
+   info_ptr->int_y_white = (png_fixed_point)(white_y*100000.+0.5);
+   info_ptr->int_x_red   = (png_fixed_point)(red_x*100000.+0.5);
+   info_ptr->int_y_red   = (png_fixed_point)(red_y*100000.+0.5);
+   info_ptr->int_x_green = (png_fixed_point)(green_x*100000.+0.5);
+   info_ptr->int_y_green = (png_fixed_point)(green_y*100000.+0.5);
+   info_ptr->int_x_blue  = (png_fixed_point)(blue_x*100000.+0.5);
+   info_ptr->int_y_blue  = (png_fixed_point)(blue_y*100000.+0.5);
+#endif
    info_ptr->valid |= PNG_INFO_cHRM;
 }
 #endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+void
+png_set_cHRM_fixed(png_structp png_ptr, png_infop info_ptr,
+   png_fixed_point white_x, png_fixed_point white_y, png_fixed_point red_x,
+   png_fixed_point red_y, png_fixed_point green_x, png_fixed_point green_y,
+   png_fixed_point blue_x, png_fixed_point blue_y)
+{
+   png_debug1(1, "in %s storage function\n", "cHRM");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
 
-#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_WRITE_gAMA_SUPPORTED)
+   info_ptr->int_x_white = white_x;
+   info_ptr->int_y_white = white_y;
+   info_ptr->int_x_red   = red_x;
+   info_ptr->int_y_red   = red_y;
+   info_ptr->int_x_green = green_x;
+   info_ptr->int_y_green = green_y;
+   info_ptr->int_x_blue  = blue_x;
+   info_ptr->int_y_blue  = blue_y;
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+   info_ptr->x_white = (float)(white_x/100000.);
+   info_ptr->y_white = (float)(white_y/100000.);
+   info_ptr->x_red   = (float)(red_x/100000.);
+   info_ptr->y_red   = (float)(red_y/100000.);
+   info_ptr->x_green = (float)(green_x/100000.);
+   info_ptr->y_green = (float)(green_y/100000.);
+   info_ptr->x_blue  = (float)(blue_x/100000.);
+   info_ptr->y_blue  = (float)(blue_y/100000.);
+#endif
+   info_ptr->valid |= PNG_INFO_cHRM;
+}
+#endif
+#endif
+
+#if defined(PNG_gAMA_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
 void
 png_set_gAMA(png_structp png_ptr, png_infop info_ptr, double file_gamma)
 {
@@ -60,11 +105,29 @@ png_set_gAMA(png_structp png_ptr, png_infop info_ptr, double file_gamma)
       return;
 
    info_ptr->gamma = (float)file_gamma;
+#ifdef PNG_FIXED_POINT_SUPPORTED
+   info_ptr->int_gamma = (int)(file_gamma*100000.+.5);
+#endif
    info_ptr->valid |= PNG_INFO_gAMA;
 }
 #endif
+#endif
+void
+png_set_gAMA_fixed(png_structp png_ptr, png_infop info_ptr, png_fixed_point
+   int_gamma)
+{
+   png_debug1(1, "in %s storage function\n", "gAMA");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
 
-#if defined(PNG_READ_hIST_SUPPORTED) || defined(PNG_WRITE_hIST_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+   info_ptr->gamma = (float)(int_gamma/100000.);
+#endif
+   info_ptr->int_gamma = int_gamma;
+   info_ptr->valid |= PNG_INFO_gAMA;
+}
+
+#if defined(PNG_hIST_SUPPORTED)
 void
 png_set_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_16p hist)
 {
@@ -117,10 +180,10 @@ png_set_IHDR(png_structp png_ptr, png_infop info_ptr,
       info_ptr->rowbytes = (info_ptr->width * info_ptr->pixel_depth + 7) >> 3;
 }
 
-#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED)
+#if defined(PNG_oFFs_SUPPORTED)
 void
 png_set_oFFs(png_structp png_ptr, png_infop info_ptr,
-   png_uint_32 offset_x, png_uint_32 offset_y, int unit_type)
+   png_int_32 offset_x, png_int_32 offset_y, int unit_type)
 {
    png_debug1(1, "in %s storage function\n", "oFFs");
    if (png_ptr == NULL || info_ptr == NULL)
@@ -133,7 +196,7 @@ png_set_oFFs(png_structp png_ptr, png_infop info_ptr,
 }
 #endif
 
-#if defined(PNG_READ_pCAL_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED)
+#if defined(PNG_pCAL_SUPPORTED)
 void
 png_set_pCAL(png_structp png_ptr, png_infop info_ptr,
    png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams,
@@ -178,7 +241,53 @@ png_set_pCAL(png_structp png_ptr, png_infop info_ptr,
 }
 #endif
 
-#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED)
+#if defined(PNG_READ_sCAL_SUPPORTED) || defined(PNG_WRITE_sCAL_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+void
+png_set_sCAL(png_structp png_ptr, png_infop info_ptr,
+             int unit, double width, double height)
+{
+   png_debug1(1, "in %s storage function\n", "sCAL");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   info_ptr->scal_unit = (png_byte)unit;
+   info_ptr->scal_pixel_width = width;
+   info_ptr->scal_pixel_height = height;
+
+   info_ptr->valid |= PNG_INFO_sCAL;
+}
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+void
+png_set_sCAL_s(png_structp png_ptr, png_infop info_ptr,
+             int unit, png_charp swidth, png_charp sheight)
+{
+   png_uint_32 length;
+
+   png_debug1(1, "in %s storage function\n", "sCAL");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   info_ptr->scal_unit = (png_byte)unit;
+
+   length = png_strlen(swidth) + 1;
+   png_debug1(3, "allocating unit for info (%d bytes)\n", length);
+   info_ptr->scal_s_width = (png_charp)png_malloc(png_ptr, length);
+   png_memcpy(info_ptr->scal_s_width, swidth, (png_size_t)length);
+
+   length = png_strlen(sheight) + 1;
+   png_debug1(3, "allocating unit for info (%d bytes)\n", length);
+   info_ptr->scal_s_width = (png_charp)png_malloc(png_ptr, length);
+   png_memcpy(info_ptr->scal_s_height, sheight, (png_size_t)length);
+
+   info_ptr->valid |= PNG_INFO_sCAL;
+}
+#endif
+#endif
+#endif
+
+#if defined(PNG_pHYs_SUPPORTED)
 void
 png_set_pHYs(png_structp png_ptr, png_infop info_ptr,
    png_uint_32 res_x, png_uint_32 res_y, int unit_type)
@@ -198,16 +307,18 @@ void
 png_set_PLTE(png_structp png_ptr, png_infop info_ptr,
    png_colorp palette, int num_palette)
 {
+
    png_debug1(1, "in %s storage function\n", "PLTE");
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
    info_ptr->palette = palette;
+
    info_ptr->num_palette = (png_uint_16)num_palette;
    info_ptr->valid |= PNG_INFO_PLTE;
 }
 
-#if defined(PNG_READ_sBIT_SUPPORTED) || defined(PNG_WRITE_sBIT_SUPPORTED)
+#if defined(PNG_sBIT_SUPPORTED)
 void
 png_set_sBIT(png_structp png_ptr, png_infop info_ptr,
    png_color_8p sig_bit)
@@ -221,7 +332,7 @@ png_set_sBIT(png_structp png_ptr, png_infop info_ptr,
 }
 #endif
 
-#if defined(PNG_READ_sRGB_SUPPORTED) || defined(PNG_WRITE_sRGB_SUPPORTED)
+#if defined(PNG_sRGB_SUPPORTED)
 void
 png_set_sRGB(png_structp png_ptr, png_infop info_ptr, int intent)
 {
@@ -232,15 +343,27 @@ png_set_sRGB(png_structp png_ptr, png_infop info_ptr, int intent)
    info_ptr->srgb_intent = (png_byte)intent;
    info_ptr->valid |= PNG_INFO_sRGB;
 }
+
 void
 png_set_sRGB_gAMA_and_cHRM(png_structp png_ptr, png_infop info_ptr,
    int intent)
 {
-#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_WRITE_gAMA_SUPPORTED)
+#if defined(PNG_gAMA_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
    float file_gamma;
 #endif
-#if defined(PNG_READ_cHRM_SUPPORTED) || defined(PNG_WRITE_cHRM_SUPPORTED)
+#ifdef PNG_FIXED_POINT_SUPPORTED
+   png_fixed_point int_file_gamma;
+#endif
+#endif
+#if defined(PNG_cHRM_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
    float white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y;
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+   png_fixed_point int_white_x, int_white_y, int_red_x, int_red_y, int_green_x,
+      int_green_y, int_blue_x, int_blue_y;
+#endif
 #endif
    png_debug1(1, "in %s storage function\n", "sRGB_gAMA_and_cHRM");
    if (png_ptr == NULL || info_ptr == NULL)
@@ -248,12 +371,33 @@ png_set_sRGB_gAMA_and_cHRM(png_structp png_ptr, png_infop info_ptr,
 
    png_set_sRGB(png_ptr, info_ptr, intent);
 
-#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_WRITE_gAMA_SUPPORTED)
-   file_gamma = (float).45;
+#if defined(PNG_gAMA_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+   file_gamma = (float).45455;
    png_set_gAMA(png_ptr, info_ptr, file_gamma);
 #endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+   int_file_gamma = 45455L;
+   png_set_gAMA_fixed(png_ptr, info_ptr, int_file_gamma);
+#endif
+#endif
 
-#if defined(PNG_READ_cHRM_SUPPORTED) || defined(PNG_WRITE_cHRM_SUPPORTED)
+#if defined(PNG_cHRM_SUPPORTED)
+#ifdef PNG_FIXED_POINT_SUPPORTED
+   int_white_x = 31270L;
+   int_white_y = 32900L;
+   int_red_x   = 64000L;
+   int_red_y   = 33000L;
+   int_green_x = 30000L;
+   int_green_y = 60000L;
+   int_blue_x  = 15000L;
+   int_blue_y  =  6000L;
+
+   png_set_cHRM_fixed(png_ptr, info_ptr,
+      int_white_x, int_white_y, int_red_x, int_red_y, int_green_x, int_green_y,
+      int_blue_x, int_blue_y);
+#endif
+#ifdef PNG_FLOATING_POINT_SUPPORTED
    white_x = (float).3127;
    white_y = (float).3290;
    red_x   = (float).64;
@@ -265,13 +409,36 @@ png_set_sRGB_gAMA_and_cHRM(png_structp png_ptr, png_infop info_ptr,
 
    png_set_cHRM(png_ptr, info_ptr,
       white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y);
-
+#endif
 #endif
 }
 #endif
 
-#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_WRITE_tEXt_SUPPORTED) || \
-    defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED)
+
+#if defined(PNG_iCCP_SUPPORTED)
+void
+png_set_iCCP(png_structp png_ptr, png_infop info_ptr,
+             png_charp name, int compression_type,
+             png_charp profile, png_uint_32 proflen)
+{
+   png_debug1(1, "in %s storage function\n", "iCCP");
+   if (png_ptr == NULL || info_ptr == NULL || name == NULL || profile == NULL)
+      return;
+
+   info_ptr->iccp_name = png_malloc(png_ptr, png_strlen(name)+1);
+   strcpy(info_ptr->iccp_name, name);
+   info_ptr->iccp_profile = png_malloc(png_ptr, proflen);
+   png_memcpy(info_ptr->iccp_profile, profile, (png_size_t)proflen);
+   info_ptr->iccp_proflen = proflen;
+   /* Compression is always zero but is here so the API and info structure
+    * does not have to change * if we introduce multiple compression types */
+   info_ptr->iccp_compression = (png_byte)compression_type;
+   info_ptr->free_me |= PNG_FREE_ICCP;
+   info_ptr->valid |= PNG_INFO_iCCP;
+}
+#endif
+
+#if defined(PNG_TEXT_SUPPORTED)
 void
 png_set_text(png_structp png_ptr, png_infop info_ptr, png_textp text_ptr,
    int num_text)
@@ -316,36 +483,100 @@ png_set_text(png_structp png_ptr, png_infop info_ptr, png_textp text_ptr,
 
    for (i = 0; i < num_text; i++)
    {
+      png_size_t text_length,key_len,lang_len,lang_key_len;
       png_textp textp = &(info_ptr->text[info_ptr->num_text]);
 
-      if (text_ptr[i].text == NULL)
-         text_ptr[i].text = (png_charp)"";
+      if (text_ptr[i].key == (png_charp)NULL)
+          continue;
 
-      if (text_ptr[i].text[0] == '\0')
+      key_len = png_strlen(text_ptr[i].key);
+
+      if(text_ptr[i].compression > 0)
       {
-         textp->text_length = 0;
-         textp->compression = PNG_TEXT_COMPRESSION_NONE;
+        /* set iTXt data */
+        lang_len = png_strlen(text_ptr[i].lang);
+        lang_key_len = png_strlen(text_ptr[i].lang_key);
       }
       else
       {
-         textp->text_length = png_strlen(text_ptr[i].text);
+        lang_len = 0;
+        lang_key_len = 0;
+      }
+
+      if (text_ptr[i].text[0] == '\0')
+      {
+         text_length = 0;
+         if(text_ptr[i].compression > 0)
+            textp->compression = PNG_ITXT_COMPRESSION_NONE;
+         else
+            textp->compression = PNG_TEXT_COMPRESSION_NONE;
+      }
+      else
+      {
+         text_length = png_strlen(text_ptr[i].text);
          textp->compression = text_ptr[i].compression;
       }
-      textp->text = text_ptr[i].text;
-      textp->key = text_ptr[i].key;
+
+      textp->key = (png_charp)png_malloc(png_ptr,
+         (png_uint_32)(key_len + lang_len + lang_key_len + text_length + 4));
+      png_debug2(2, "Allocated %d bytes at %x in png_set_text\n",
+         key_len + lang_len + lang_key_len + text_length + 4, textp->key);
+
+      png_memcpy(textp->key, text_ptr[i].key,
+         (png_size_t)(key_len));
+      *(textp->key+key_len) = '\0';
+      if (text_ptr[i].compression > 0)
+      {
+         textp->lang=textp->key + key_len + 1;
+         png_memcpy(textp->lang, text_ptr[i].lang, lang_len);
+         *(textp->lang+lang_len) = '\0';
+         textp->lang_key=textp->lang + lang_len + 1;
+         png_memcpy(textp->lang_key, text_ptr[i].lang_key, lang_key_len);
+         *(textp->lang_key+lang_key_len) = '\0';
+         textp->text=textp->lang_key + lang_key_len + 1;
+      }
+      else
+      {
+         textp->lang=NULL;
+         textp->lang_key=NULL;
+         textp->text=textp->key + key_len + 1;
+      }
+
+      if(text_length)
+      {
+         png_memcpy(textp->text, text_ptr[i].text,
+            (png_size_t)(text_length));
+         *(textp->text+text_length) = '\0';
+      }
+      else
+         textp->text--;
+
+      if(textp->compression > 0)
+      {
+         textp->text_length = 0;
+         textp->itxt_length = text_length;
+      }
+      else
+      {
+         textp->text_length = text_length;
+         textp->itxt_length = 0;
+      }
+
+      info_ptr->text[info_ptr->num_text]= *textp;
       info_ptr->num_text++;
+      info_ptr->free_me |= PNG_FREE_TEXT;
       png_debug1(3, "transferred text chunk %d\n", info_ptr->num_text);
    }
 }
 #endif
 
-#if defined(PNG_READ_tIME_SUPPORTED) || defined(PNG_WRITE_tIME_SUPPORTED)
+#if defined(PNG_tIME_SUPPORTED)
 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 ||
-       (png_ptr->flags & PNG_FLAG_WROTE_tIME))
+       (png_ptr->mode & PNG_WROTE_tIME))
       return;
 
    png_memcpy(&(info_ptr->mod_time), mod_time, sizeof (png_time));
@@ -353,7 +584,7 @@ png_set_tIME(png_structp png_ptr, png_infop info_ptr, png_timep mod_time)
 }
 #endif
 
-#if defined(PNG_READ_tRNS_SUPPORTED) || defined(PNG_WRITE_tRNS_SUPPORTED)
+#if defined(PNG_tRNS_SUPPORTED)
 void
 png_set_tRNS(png_structp png_ptr, png_infop info_ptr,
    png_bytep trans, int num_trans, png_color_16p trans_values)
@@ -363,9 +594,7 @@ png_set_tRNS(png_structp png_ptr, png_infop info_ptr,
       return;
 
    if (trans != NULL)
-   {
       info_ptr->trans = trans;
-   }
 
    if (trans_values != NULL)
    {
@@ -379,7 +608,85 @@ png_set_tRNS(png_structp png_ptr, png_infop info_ptr,
 }
 #endif
 
-#if defined(PNG_READ_EMPTY_PLTE_SUPPORTED)
+#if defined(PNG_sPLT_SUPPORTED)
+void
+png_set_sPLT(png_structp png_ptr,
+             png_infop info_ptr, png_sPLT_tp entries, int nentries)
+{
+    png_sPLT_tp np;
+    int i;
+
+    np = (png_sPLT_tp)png_malloc(png_ptr,
+        (info_ptr->splt_palettes_num + nentries) * sizeof(png_sPLT_t));
+
+    png_memcpy(np, info_ptr->splt_palettes,
+           info_ptr->splt_palettes_num * sizeof(png_sPLT_t));
+    png_free(png_ptr, info_ptr->splt_palettes);
+
+    for (i = 0; i < nentries; i++)
+    {
+        png_sPLT_tp to = np + info_ptr->splt_palettes_num + i;
+        png_sPLT_tp from = entries + i;
+
+        to->name = (png_charp)png_malloc(png_ptr,
+                                        png_strlen(from->name) + 1);
+        png_strcpy(to->name, from->name);
+        to->entries = (png_sPLT_entryp)png_malloc(png_ptr,
+                                 from->nentries * sizeof(png_sPLT_t));
+        png_memcpy(to->entries, from->entries,
+               from->nentries * sizeof(png_sPLT_t));
+        to->nentries = from->nentries;
+        to->depth = from->depth;
+    }
+
+    info_ptr->splt_palettes = np;
+    info_ptr->splt_palettes_num += nentries;
+    info_ptr->valid |= PNG_INFO_sPLT;
+    info_ptr->free_me |= PNG_FREE_SPLT;
+}
+#endif /* PNG_sPLT_SUPPORTED */
+
+#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
+void
+png_set_unknown_chunks(png_structp png_ptr,
+   png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns)
+{
+    png_unknown_chunkp np;
+    int i;
+
+    if (png_ptr == NULL || info_ptr == NULL || num_unknowns == 0)
+        return;
+
+    np = (png_unknown_chunkp)png_malloc(png_ptr,
+        (info_ptr->unknown_chunks_num + num_unknowns) *
+        sizeof(png_unknown_chunk));
+
+    png_memcpy(np, info_ptr->unknown_chunks,
+           info_ptr->unknown_chunks_num * sizeof(png_unknown_chunk));
+    png_free(png_ptr, info_ptr->unknown_chunks);
+
+    for (i = 0; i < num_unknowns; i++)
+    {
+        png_unknown_chunkp to = np + info_ptr->unknown_chunks_num + i;
+        png_unknown_chunkp from = unknowns + i;
+
+        png_strcpy((png_charp)to->name, (png_charp)from->name);
+        to->data = (png_bytep)png_malloc(png_ptr, from->size);
+        png_memcpy(to->data, from->data, from->size);
+        to->size = from->size;
+
+        /* note our location in the read or write sequence */
+        to->location = (png_byte)(png_ptr->mode & 0xff);
+    }
+
+    info_ptr->unknown_chunks = np;
+    info_ptr->unknown_chunks_num += num_unknowns;
+    info_ptr->free_me |= PNG_FREE_UNKN;
+}
+#endif
+
+#if defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
+    defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
 void
 png_permit_empty_plte (png_structp png_ptr, int empty_plte_permitted)
 {
@@ -389,3 +696,66 @@ png_permit_empty_plte (png_structp png_ptr, int empty_plte_permitted)
    png_ptr->empty_plte_permitted=(png_byte)empty_plte_permitted;
 }
 #endif
+
+#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+void
+png_set_keep_unknown_chunks(png_structp png_ptr, int keep, png_bytep
+   chunk_list, int num_chunks)
+{
+    png_bytep new_list, p;
+    int i, old_num_chunks;
+    if (num_chunks == 0)
+    {
+      if(keep == HANDLE_CHUNK_ALWAYS || keep == HANDLE_CHUNK_IF_SAFE)
+        png_ptr->flags |= PNG_FLAG_KEEP_UNKNOWN_CHUNKS;
+      else
+        png_ptr->flags &= ~PNG_FLAG_KEEP_UNKNOWN_CHUNKS;
+
+      if(keep == HANDLE_CHUNK_ALWAYS)
+        png_ptr->flags |= PNG_FLAG_KEEP_UNSAFE_CHUNKS;
+      else
+        png_ptr->flags &= ~PNG_FLAG_KEEP_UNSAFE_CHUNKS;
+      return;
+    }
+    if (chunk_list == NULL)
+      return;
+    old_num_chunks=png_ptr->num_chunk_list;
+    new_list=png_malloc(png_ptr,5*(num_chunks+old_num_chunks));
+    if(png_ptr->chunk_list != (png_bytep)NULL)
+    {
+       png_memcpy(new_list, png_ptr->chunk_list, 5*old_num_chunks);
+       png_free(png_ptr, png_ptr->chunk_list);
+    }
+    png_memcpy(new_list+5*old_num_chunks, chunk_list, 5*num_chunks);
+    for (p=new_list+5*old_num_chunks+4, i=0; i<num_chunks; i++, p+=5)
+       *p=(png_byte)keep;
+    png_ptr->num_chunk_list=old_num_chunks+num_chunks;
+    png_ptr->chunk_list=new_list;
+    png_ptr->free_me |= PNG_FREE_LIST;
+}
+#endif
+
+#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
+void
+png_set_read_user_chunk_fn(png_structp png_ptr, png_voidp user_chunk_ptr,
+   png_user_chunk_ptr read_user_chunk_fn)
+{
+   png_debug(1, "in png_set_read_user_chunk_fn\n");
+   png_ptr->read_user_chunk_fn = read_user_chunk_fn;
+   png_ptr->user_chunk_ptr = user_chunk_ptr;
+}
+#endif
+
+#if defined(PNG_INFO_IMAGE_SUPPORTED)
+void
+png_set_rows(png_structp png_ptr, png_infop info_ptr, png_bytepp row_pointers)
+{
+   png_debug1(1, "in %s storage function\n", "rows");
+   if (png_ptr == NULL || info_ptr == NULL)
+      return;
+
+   info_ptr->row_pointers = row_pointers;
+   info_ptr->free_me |= PNG_FREE_ROWS;
+}
+#endif
+

pngtest.c

@@ -1,11 +1,11 @@
 
 /* pngtest.c - a simple test program to test libpng
  *
- * libpng 1.0.4c - October 1, 1999
+ * libpng 1.0.6d - April 7, 2000
  * 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, 1999 Glenn Randers-Pehrson
+ * Copyright (c) 1998, 1999, 2000 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
@@ -15,11 +15,11 @@
  *
  * 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.
+ * 2) when the maximum IDAT size (PNG_ZBUF_SIZE in pngconf.h) is not 8192.
  * 3) unknown ancillary chunks exist in the input file.
  * 4) others not listed here...
  * In these cases, it is best to check with another tool such as "pngcheck"
- * to see what the differences between the two images are.
+ * to see what the differences between the two files are.
  *
  * If a filename is given on the command-line, then this file is used
  * for the input, rather than the default "pngtest.png".  This allows
@@ -29,6 +29,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <assert.h>
 
 /* Makes pngtest verbose so we can find problems (needs to be before png.h) */
 #ifndef PNG_DEBUG
@@ -39,6 +40,10 @@
 #define PNGTEST_TIMING
 */
 
+#ifdef PNG_NO_FLOATING_POINT_SUPPORTED
+#undef PNGTEST_TIMING
+#endif
+
 #ifdef PNGTEST_TIMING
 static float t_start, t_stop, t_decode, t_encode, t_misc;
 #include <time.h>
@@ -46,9 +51,14 @@ static float t_start, t_stop, t_decode, t_encode, t_misc;
 
 #include "png.h"
 
+/* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */
+#ifndef png_jmpbuf
+#  define png_jmpbuf(png_ptr) png_ptr->jmpbuf
+#endif
+
 #ifdef PNGTEST_TIMING
 static float t_start, t_stop, t_decode, t_encode, t_misc;
-#if !defined(PNG_READ_tIME_SUPPORTED) && !defined(PNG_WRITE_tIME_SUPPORTED)
+#if !defined(PNG_tIME_SUPPORTED)
 #include <time.h>
 #endif
 #endif
@@ -56,7 +66,7 @@ static float t_start, t_stop, t_decode, t_encode, t_misc;
 #if defined(PNG_TIME_RFC1123_SUPPORTED)
 static int tIME_chunk_present=0;
 static char tIME_string[30] = "no tIME chunk present in file";
-#endif /* PNG_TIME_RFC1123_SUPPORTED */
+#endif
 
 static int verbose = 0;
 
@@ -147,7 +157,7 @@ count_zero_samples(png_structp png_ptr, png_row_infop row_info, png_bytep data)
        {
           if(row_info->bit_depth == 1)
           {
-             if(((*dp << pos++ )& 0x80) == 0) zero_samples++;
+             if(((*dp << pos++ ) & 0x80) == 0) zero_samples++;
              if(pos == 8)
              {
                 pos = 0;
@@ -156,7 +166,7 @@ count_zero_samples(png_structp png_ptr, png_row_infop row_info, png_bytep data)
           }
           if(row_info->bit_depth == 2)
           {
-             if(((*dp << (pos+=2))& 0xc0) == 0) zero_samples++;
+             if(((*dp << (pos+=2)) & 0xc0) == 0) zero_samples++;
              if(pos == 8)
              {
                 pos = 0;
@@ -165,7 +175,7 @@ count_zero_samples(png_structp png_ptr, png_row_infop row_info, png_bytep data)
           }
           if(row_info->bit_depth == 4)
           {
-             if(((*dp << (pos+=4))& 0xf0) == 0) zero_samples++;
+             if(((*dp << (pos+=4)) & 0xf0) == 0) zero_samples++;
              if(pos == 8)
              {
                 pos = 0;
@@ -405,7 +415,8 @@ png_default_error(png_structp png_ptr, png_const_charp message)
 
    This piece of code can be compiled to validate max 64K allocations
    by setting MAXSEG_64K in zlib zconf.h *or* PNG_MAX_MALLOC_64K. */
-typedef struct memory_information {
+typedef struct memory_information
+{
    png_uint_32                    size;
    png_voidp                 pointer;
    struct memory_information FAR *next;
@@ -422,7 +433,8 @@ extern PNG_EXPORT(void,png_debug_free) PNGARG((png_structp png_ptr,
    png_voidp ptr));
 
 png_voidp
-png_debug_malloc(png_structp png_ptr, png_uint_32 size) {
+png_debug_malloc(png_structp png_ptr, png_uint_32 size)
+{
 
    /* png_malloc has already tested for NULL; png_create_struct calls
       png_debug_malloc directly, with png_ptr == NULL which is OK */
@@ -443,6 +455,11 @@ png_debug_malloc(png_structp png_ptr, png_uint_32 size) {
       pinformation = pinfo;
       /* Make sure the caller isn't assuming zeroed memory. */
       png_memset(pinfo->pointer, 0xdd, pinfo->size);
+#if PNG_DEBUG
+      if(verbose)
+         printf("png_malloc %d bytes at %x\n",size,pinfo->pointer);
+#endif
+      assert(pinfo->size != 12345);
       return (png_voidp)(pinfo->pointer);
    }
 }
@@ -453,7 +470,8 @@ png_debug_free(png_structp png_ptr, png_voidp ptr)
 {
    if (png_ptr == NULL)
       fprintf(STDERR, "NULL pointer to png_debug_free.\n");
-   if (ptr == 0) {
+   if (ptr == 0)
+   {
 #if 0 /* This happens all the time. */
       fprintf(STDERR, "WARNING: freeing NULL pointer\n");
 #endif
@@ -463,9 +481,11 @@ png_debug_free(png_structp png_ptr, png_voidp ptr)
    /* Unlink the element from the list. */
    {
       memory_infop FAR *ppinfo = &pinformation;
-      for (;;) {
+      for (;;)
+      {
          memory_infop pinfo = *ppinfo;
-         if (pinfo->pointer == ptr) {
+         if (pinfo->pointer == ptr)
+         {
             *ppinfo = pinfo->next;
             current_allocation -= pinfo->size;
             if (current_allocation < 0)
@@ -476,7 +496,8 @@ png_debug_free(png_structp png_ptr, png_voidp ptr)
             png_free_default(png_ptr, pinfo);
             break;
          }
-         if (pinfo->next == NULL) {
+         if (pinfo->next == NULL)
+         {
             fprintf(STDERR, "Pointer %x not found\n", ptr);
             break;
          }
@@ -485,6 +506,10 @@ png_debug_free(png_structp png_ptr, png_voidp ptr)
    }
 
    /* Finally free the data. */
+#if PNG_DEBUG
+   if(verbose)
+      printf("Freeing %x\n",ptr);
+#endif
    png_free_default(png_ptr, ptr);
 }
 #endif /* PNG_USER_MEM_SUPPORTED */
@@ -496,15 +521,17 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 {
    static FILE *fpin, *fpout;  /* "static" prevents setjmp corruption */
    png_structp read_ptr, write_ptr;
-   png_infop read_info_ptr, write_info_ptr, end_info_ptr;
+   png_infop read_info_ptr, write_info_ptr, end_info_ptr, write_end_info_ptr;
    png_bytep row_buf;
    png_uint_32 y;
    png_uint_32 width, height;
    int num_pass, pass;
    int bit_depth, color_type;
+#ifdef PNG_SETJMP_SUPPORTED
 #ifdef USE_FAR_KEYWORD
    jmp_buf jmpbuf;
-#endif   
+#endif
+#endif
 
    char inbuf[256], outbuf[256];
 
@@ -552,43 +579,48 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    read_info_ptr = png_create_info_struct(read_ptr);
    write_info_ptr = png_create_info_struct(write_ptr);
    end_info_ptr = png_create_info_struct(read_ptr);
+   write_end_info_ptr = png_create_info_struct(write_ptr);
 #ifdef PNG_USER_MEM_SUPPORTED
 #endif
 
+#ifdef PNG_SETJMP_SUPPORTED
    png_debug(0, "Setting jmpbuf for read struct\n");
 #ifdef USE_FAR_KEYWORD
    if (setjmp(jmpbuf))
 #else
-   if (setjmp(read_ptr->jmpbuf))
+   if (setjmp(png_jmpbuf(read_ptr)))
 #endif
    {
       fprintf(STDERR, "%s -> %s: libpng read error\n", inname, outname);
       png_destroy_read_struct(&read_ptr, &read_info_ptr, &end_info_ptr);
+      png_destroy_info_struct(write_ptr, &write_end_info_ptr);
       png_destroy_write_struct(&write_ptr, &write_info_ptr);
       fclose(fpin);
       fclose(fpout);
       return (1);
    }
 #ifdef USE_FAR_KEYWORD
-   png_memcpy(read_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf));
+   png_memcpy(png_jmpbuf(read_ptr),jmpbuf,sizeof(jmp_buf));
 #endif
 
    png_debug(0, "Setting jmpbuf for write struct\n");
 #ifdef USE_FAR_KEYWORD
    if (setjmp(jmpbuf))
 #else
-   if (setjmp(write_ptr->jmpbuf))
+   if (setjmp(png_jmpbuf(write_ptr)))
 #endif
    {
       fprintf(STDERR, "%s -> %s: libpng write error\n", inname, outname);
       png_destroy_read_struct(&read_ptr, &read_info_ptr, &end_info_ptr);
+      png_destroy_info_struct(write_ptr, &write_end_info_ptr);
       png_destroy_write_struct(&write_ptr, &write_info_ptr);
       fclose(fpin);
       fclose(fpout);
       return (1);
    }
 #ifdef USE_FAR_KEYWORD
-   png_memcpy(write_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf));
+   png_memcpy(png_jmpbuf(write_ptr),jmpbuf,sizeof(jmp_buf));
+#endif
 #endif
 
    png_debug(0, "Initializing input and output streams\n");
@@ -628,6 +660,15 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    png_set_write_user_transform_fn(write_ptr, count_zero_samples);
 #endif
 
+#define HANDLE_CHUNK_IF_SAFE      2
+#define HANDLE_CHUNK_ALWAYS       3
+#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
+   png_set_keep_unknown_chunks(read_ptr, HANDLE_CHUNK_ALWAYS, NULL, 0);
+#endif
+#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
+   png_set_keep_unknown_chunks(write_ptr, HANDLE_CHUNK_IF_SAFE, NULL, 0);
+#endif
+
    png_debug(0, "Reading info struct\n");
    png_read_info(read_ptr, read_info_ptr);
 
@@ -646,39 +687,45 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 #endif
       }
    }
-#if defined(PNG_READ_bKGD_SUPPORTED) && defined(PNG_WRITE_bKGD_SUPPORTED)
+#if defined(PNG_cHRM_SUPPORTED)
    {
-      png_color_16p background;
+      png_fixed_point white_x, white_y, red_x, red_y, green_x, green_y, blue_x,
+         blue_y;
 
-      if (png_get_bKGD(read_ptr, read_info_ptr, &background))
-      {
-         png_set_bKGD(write_ptr, write_info_ptr, background);
-      }
-   }
-#endif
-#if defined(PNG_READ_cHRM_SUPPORTED) && defined(PNG_WRITE_cHRM_SUPPORTED)
-   {
-      double white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y;
-
-      if (png_get_cHRM(read_ptr, read_info_ptr, &white_x, &white_y, &red_x,
+      if (png_get_cHRM_fixed(read_ptr, read_info_ptr, &white_x, &white_y, &red_x,
          &red_y, &green_x, &green_y, &blue_x, &blue_y))
       {
-         png_set_cHRM(write_ptr, write_info_ptr, white_x, white_y, red_x,
+         png_set_cHRM_fixed(write_ptr, write_info_ptr, white_x, white_y, red_x,
             red_y, green_x, green_y, blue_x, blue_y);
       }
    }
 #endif
-#if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_WRITE_gAMA_SUPPORTED)
+#if defined(PNG_gAMA_SUPPORTED)
    {
-      double gamma;
+      png_fixed_point gamma;
 
-      if (png_get_gAMA(read_ptr, read_info_ptr, &gamma))
+      if (png_get_gAMA_fixed(read_ptr, read_info_ptr, &gamma))
       {
-         png_set_gAMA(write_ptr, write_info_ptr, gamma);
+         png_set_gAMA_fixed(write_ptr, write_info_ptr, gamma);
       }
    }
 #endif
-#if defined(PNG_READ_sRGB_SUPPORTED) && defined(PNG_WRITE_sRGB_SUPPORTED)
+#if defined(PNG_iCCP_SUPPORTED)
+   {
+      png_charp name;
+      png_charp profile;
+      png_uint_32 proflen;
+      int compression_type;
+
+      if (png_get_iCCP(read_ptr, read_info_ptr, &name, &compression_type,
+                      &profile, &proflen))
+      {
+         png_set_iCCP(write_ptr, write_info_ptr, name, compression_type,
+                      profile, proflen);
+      }
+   }
+#endif
+#if defined(PNG_sRGB_SUPPORTED)
    {
       int intent;
 
@@ -688,7 +735,26 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       }
    }
 #endif
-#if defined(PNG_READ_hIST_SUPPORTED) && defined(PNG_WRITE_hIST_SUPPORTED)
+   {
+      png_colorp palette;
+      int num_palette;
+
+      if (png_get_PLTE(read_ptr, read_info_ptr, &palette, &num_palette))
+      {
+         png_set_PLTE(write_ptr, write_info_ptr, palette, num_palette);
+      }
+   }
+#if defined(PNG_bKGD_SUPPORTED)
+   {
+      png_color_16p background;
+
+      if (png_get_bKGD(read_ptr, read_info_ptr, &background))
+      {
+         png_set_bKGD(write_ptr, write_info_ptr, background);
+      }
+   }
+#endif
+#if defined(PNG_hIST_SUPPORTED)
    {
       png_uint_16p hist;
 
@@ -698,9 +764,9 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       }
    }
 #endif
-#if defined(PNG_READ_oFFs_SUPPORTED) && defined(PNG_WRITE_oFFs_SUPPORTED)
+#if defined(PNG_oFFs_SUPPORTED)
    {
-      png_uint_32 offset_x, offset_y;
+      png_int_32 offset_x, offset_y;
       int unit_type;
 
       if (png_get_oFFs(read_ptr, read_info_ptr,&offset_x,&offset_y,&unit_type))
@@ -709,7 +775,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       }
    }
 #endif
-#if defined(PNG_READ_pCAL_SUPPORTED) && defined(PNG_WRITE_pCAL_SUPPORTED)
+#if defined(PNG_pCAL_SUPPORTED)
    {
       png_charp purpose, units;
       png_charpp params;
@@ -724,7 +790,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       }
    }
 #endif
-#if defined(PNG_READ_pHYs_SUPPORTED) && defined(PNG_WRITE_pHYs_SUPPORTED)
+#if defined(PNG_pHYs_SUPPORTED)
    {
       png_uint_32 res_x, res_y;
       int unit_type;
@@ -735,16 +801,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       }
    }
 #endif
-   {
-      png_colorp palette;
-      int num_palette;
-
-      if (png_get_PLTE(read_ptr, read_info_ptr, &palette, &num_palette))
-      {
-         png_set_PLTE(write_ptr, write_info_ptr, palette, num_palette);
-      }
-   }
-#if defined(PNG_READ_sBIT_SUPPORTED) && defined(PNG_WRITE_sBIT_SUPPORTED)
+#if defined(PNG_sBIT_SUPPORTED)
    {
       png_color_8p sig_bit;
 
@@ -754,20 +811,44 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       }
    }
 #endif
-#if (defined(PNG_READ_tEXt_SUPPORTED) && defined(PNG_WRITE_tEXt_SUPPORTED)) || \
-    (defined(PNG_READ_zTXt_SUPPORTED) && defined(PNG_WRITE_zTXt_SUPPORTED))
+#if defined(PNG_sCAL_SUPPORTED)
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+   {
+      int unit;
+      double width, height;
+
+      if (png_get_sCAL(read_ptr, read_info_ptr, &unit, &width, &height))
+      {
+         png_set_sCAL(write_ptr, write_info_ptr, unit, width, height);
+      }
+   }
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+   {
+      int unit;
+      png_charp width, height;
+
+      if (png_get_sCAL_s(read_ptr, read_info_ptr, &unit, &width, &height))
+      {
+         png_set_sCAL_s(write_ptr, write_info_ptr, unit, width, height);
+      }
+   }
+#endif
+#endif
+#endif
+#if defined(PNG_TEXT_SUPPORTED)
    {
       png_textp text_ptr;
       int num_text;
 
       if (png_get_text(read_ptr, read_info_ptr, &text_ptr, &num_text) > 0)
       {
-         png_debug1(0, "Handling %d tEXt/zTXt chunks\n", num_text);
+         png_debug1(0, "Handling %d iTXt/tEXt/zTXt chunks\n", num_text);
          png_set_text(write_ptr, write_info_ptr, text_ptr, num_text);
       }
    }
 #endif
-#if defined(PNG_READ_tIME_SUPPORTED) && defined(PNG_WRITE_tIME_SUPPORTED)
+#if defined(PNG_tIME_SUPPORTED)
    {
       png_timep mod_time;
 
@@ -784,7 +865,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       }
    }
 #endif
-#if defined(PNG_READ_tRNS_SUPPORTED) && defined(PNG_WRITE_tRNS_SUPPORTED)
+#if defined(PNG_tRNS_SUPPORTED)
    {
       png_bytep trans;
       int num_trans;
@@ -798,8 +879,30 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       }
    }
 #endif
+#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
+   {
+      png_unknown_chunkp unknowns;
+      int num_unknowns = (int)png_get_unknown_chunks(read_ptr, read_info_ptr,
+         &unknowns);
+      if (num_unknowns)
+      {
+         png_size_t i;
+         png_set_unknown_chunks(write_ptr, write_info_ptr, unknowns,
+           num_unknowns);
+         /* copy the locations from the read_info_ptr.  The automatically
+            generated locations in write_info_ptr are wrong because we
+            haven't written anything yet */
+         for (i = 0; i < (png_size_t)num_unknowns; i++)
+           write_info_ptr->unknown_chunks[i].location = unknowns[i].location;
+      }
+   }
+#endif
 
    png_debug(0, "\nWriting info struct\n");
+
+/* If we wanted, we could write info in two steps:
+   png_write_info_before_PLTE(write_ptr, write_info_ptr);
+ */
    png_write_info(write_ptr, write_info_ptr);
 
    png_debug(0, "\nAllocating row buffer \n");
@@ -809,6 +912,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    {
       fprintf(STDERR, "No memory to allocate row buffer\n");
       png_destroy_read_struct(&read_ptr, &read_info_ptr, (png_infopp)NULL);
+      png_destroy_info_struct(write_ptr, &write_end_info_ptr);
       png_destroy_write_struct(&write_ptr, &write_info_ptr);
       fclose(fpin);
       fclose(fpout);
@@ -849,9 +953,66 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       }
    }
 
+#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
+   png_free_data(read_ptr, read_info_ptr, PNG_FREE_UNKN, -1);
+#endif
+#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
+   png_free_data(write_ptr, write_info_ptr, PNG_FREE_UNKN, -1);
+#endif
+
    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);
+#if defined(PNG_TEXT_SUPPORTED)
+   {
+      png_textp text_ptr;
+      int num_text;
+
+      if (png_get_text(read_ptr, end_info_ptr, &text_ptr, &num_text) > 0)
+      {
+         png_debug1(0, "Handling %d iTXt/tEXt/zTXt chunks\n", num_text);
+         png_set_text(write_ptr, write_end_info_ptr, text_ptr, num_text);
+      }
+   }
+#endif
+#if defined(PNG_tIME_SUPPORTED)
+   {
+      png_timep mod_time;
+
+      if (png_get_tIME(read_ptr, end_info_ptr, &mod_time))
+      {
+         png_set_tIME(write_ptr, write_end_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_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
+   {
+      png_unknown_chunkp unknowns;
+      int num_unknowns;
+      num_unknowns = (int)png_get_unknown_chunks(read_ptr, end_info_ptr,
+         &unknowns);
+      if (num_unknowns)
+      {
+         png_size_t i;
+         png_set_unknown_chunks(write_ptr, write_end_info_ptr, unknowns,
+           num_unknowns);
+         /* copy the locations from the read_info_ptr.  The automatically
+            generated locations in write_end_info_ptr are wrong because we
+            haven't written the end_info yet */
+         for (i = 0; i < (png_size_t)num_unknowns; i++)
+           write_end_info_ptr->unknown_chunks[i].location =
+              unknowns[i].location;
+      }
+   }
+#endif
+   png_write_end(write_ptr, write_end_info_ptr);
 
 #ifdef PNG_EASY_ACCESS_SUPPORTED
    if(verbose)
@@ -867,6 +1028,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    png_debug(0, "Destroying data structs\n");
    png_free(read_ptr, row_buf);
    png_destroy_read_struct(&read_ptr, &read_info_ptr, &end_info_ptr);
+   png_destroy_info_struct(write_ptr, &write_end_info_ptr);
    png_destroy_write_struct(&write_ptr, &write_info_ptr);
 
    fclose(fpin);
@@ -895,16 +1057,17 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 
       if (num_in != num_out)
       {
-         fprintf(STDERR, "Files %s and %s are of a different size\n",
+         fprintf(STDERR, "\nFiles %s and %s are of a different size\n",
                  inname, outname);
          if(wrote_question == 0)
          {
             fprintf(STDERR,
-              "   Was %s written with the same chunk size (8k),",inname);
+         "   Was %s written with the same maximum IDAT chunk size (%d bytes),",
+              inname,PNG_ZBUF_SIZE);
             fprintf(STDERR,
-              " filtering\n   heuristic (libpng default), compression");
+              "\n   filtering heuristic (libpng default), compression");
             fprintf(STDERR,
-              " level (zlib default)\n   and zlib version (%s)?\n\n",
+              " level (zlib default),\n   and zlib version (%s)?\n\n",
               ZLIB_VERSION);
             wrote_question=1;
          }
@@ -922,11 +1085,12 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
          if(wrote_question == 0)
          {
             fprintf(STDERR,
-              "   Was %s written with the same chunk size (8k),",inname);
+         "   Was %s written with the same maximum IDAT chunk size (%d bytes),",
+                 inname,PNG_ZBUF_SIZE);
             fprintf(STDERR,
-              " filtering\n   heuristic (libpng default), compression");
+              "\n   filtering heuristic (libpng default), compression");
             fprintf(STDERR,
-              " level (zlib default)\n   and zlib version (%s)?\n\n",
+              " level (zlib default),\n   and zlib version (%s)?\n\n",
               ZLIB_VERSION);
             wrote_question=1;
          }
@@ -960,6 +1124,10 @@ 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));
+   /* Show the version of libpng used in building the library */
+   fprintf(STDERR," library:%s",png_get_header_version(NULL));
+   /* Show the version of libpng used in building the application */
+   fprintf(STDERR," pngtest:%s",PNG_HEADER_VERSION_STRING);
 
    /* 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
@@ -1038,7 +1206,7 @@ main(int argc, char *argv[])
          if (kerror == 0)
          {
 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
-            fprintf(STDERR, " PASS (%lu zero samples)\n",zero_samples);
+            fprintf(STDERR, "\n PASS (%lu zero samples)\n",zero_samples);
 #else
             fprintf(STDERR, " PASS\n");
 #endif
@@ -1063,15 +1231,17 @@ main(int argc, char *argv[])
          if (allocation_now != current_allocation)
             fprintf(STDERR, "MEMORY ERROR: %d bytes lost\n",
                current_allocation-allocation_now);
-         if (current_allocation != 0) {
+         if (current_allocation != 0)
+         {
             memory_infop pinfo = pinformation;
 
             fprintf(STDERR, "MEMORY ERROR: %d bytes still allocated\n",
                current_allocation);
-            while (pinfo != NULL) {
+            while (pinfo != NULL)
+            {
                fprintf(STDERR, " %d bytes at %x\n", pinfo->size, pinfo->pointer);
                pinfo = pinfo->next;
-               }
+            }
          }
 #endif
       }
@@ -1085,7 +1255,8 @@ main(int argc, char *argv[])
    else
    {
       int i;
-      for (i=0; i<3; ++i) {
+      for (i=0; i<3; ++i)
+      {
          int kerror;
 #ifdef PNG_USER_MEM_SUPPORTED
          int allocation_now = current_allocation;
@@ -1101,7 +1272,7 @@ main(int argc, char *argv[])
             {
                 int k;
 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
-                fprintf(STDERR, " PASS (%lu zero samples)\n",zero_samples);
+                fprintf(STDERR, "\n PASS (%lu zero samples)\n",zero_samples);
 #else
                 fprintf(STDERR, " PASS\n");
 #endif
@@ -1128,13 +1299,16 @@ main(int argc, char *argv[])
          if (allocation_now != current_allocation)
              fprintf(STDERR, "MEMORY ERROR: %d bytes lost\n",
                current_allocation-allocation_now);
-         if (current_allocation != 0) {
+         if (current_allocation != 0)
+         {
              memory_infop pinfo = pinformation;
 
              fprintf(STDERR, "MEMORY ERROR: %d bytes still allocated\n",
                 current_allocation);
-             while (pinfo != NULL) {
-                fprintf(STDERR, " %d bytes at %x\n", pinfo->size, pinfo->pointer);
+             while (pinfo != NULL)
+             {
+                fprintf(STDERR," %d bytes at %x\n",
+                   pinfo->size, pinfo->pointer);
                 pinfo = pinfo->next;
              }
           }
@@ -1170,9 +1344,4 @@ main(int argc, char *argv[])
 }
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-void
-png_check_pngtest_version
-   (version_1_0_4c png_h_is_not_version_1_0_4c)
-{
-   if(png_h_is_not_version_1_0_4c == NULL) return;
-}
+typedef version_1_0_6d your_png_h_is_not_version_1_0_6d;

pngtrans.c

@@ -1,11 +1,11 @@
 
 /* pngtrans.c - transforms the data in a row (used by both readers and writers)
  *
- * libpng 1.0.4c - October 1, 1999
+ * libpng 1.0.6d - April 7, 2000
  * 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, 1999 Glenn Randers-Pehrson
+ * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson
  */
 
 #define PNG_INTERNAL
@@ -578,8 +578,8 @@ png_set_user_transform_info(png_structp png_ptr, png_voidp
 {
    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;
+   png_ptr->user_transform_depth = (png_byte)user_transform_depth;
+   png_ptr->user_transform_channels = (png_byte)user_transform_channels;
 }
 
 /* This function returns a pointer to the user_transform_ptr associated with

pngvcrd.c

@@ -2,10 +2,10 @@
  *
  * For Intel x86 CPU and Microsoft Visual C++ compiler
  *
- * libpng 1.0.4c - October 1, 1999
+ * libpng 1.0.6d - April 7, 2000
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1998, Intel Corporation
- * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
+ * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson
  *
  * Contributed by Nirav Chhatrapati, Intel Corporation, 1998
  * Interface to libpng contributed by Gilles Vollant, 1999
@@ -17,6 +17,12 @@
 
 #if defined(PNG_ASSEMBLER_CODE_SUPPORTED) && defined(PNG_USE_PNGVCRD)
 
+/*
+   One of these might need to be defined.
+#define DISABLE_PNGVCRD_COMBINE
+#define DISABLE_PNGVCRD_INTERLACE
+*/
+
 static int mmx_supported=2;
 
 void
@@ -26,8 +32,10 @@ png_read_filter_row_c(png_structp png_ptr, png_row_infop row_info,
 static int mmxsupport()
 {
   int mmx_supported_local = 0;
-
   _asm {
+    push ebx          //CPUID will trash these
+    push ecx
+    push edx
     pushfd            //Save Eflag to stack
     pop eax           //Get Eflag from stack into eax
     mov ecx, eax      //Make another copy of Eflag in ecx
@@ -65,7 +73,9 @@ static int mmxsupport()
 
 NOT_SUPPORTED:
     mov  eax, mmx_supported_local  //move return value to eax
-
+    pop edx          //CPUID trashed these
+    pop ecx
+    pop ebx
   }
 
   //mmx_supported_local=0; // test code for force don't support MMX
@@ -80,8 +90,8 @@ NOT_SUPPORTED:
    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,
-   a zero indicates the pixel is to be skipped.  This is in addition
+   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.  */
 
@@ -91,20 +101,30 @@ NOT_SUPPORTED:
 void
 png_combine_row(png_structp png_ptr, png_bytep row, int mask)
 {
+#ifdef PNG_USE_LOCAL_ARRAYS
+   const int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+#endif
+#ifdef DISABLE_PNGVCRD_COMBINE
    int save_mmx_supported = mmx_supported;
+#endif
+
    png_debug(1,"in png_combine_row_asm\n");
 
+#ifdef DISABLE_PNGVCRD_COMBINE
    if ((png_ptr->transformations & PNG_INTERLACE) && png_ptr->pass != 6)
        mmx_supported = 0;
    else
-      if (mmx_supported == 2)
-          mmx_supported = mmxsupport();
+#endif
+       if (mmx_supported == 2)
+           mmx_supported = mmxsupport();
 
    if (mask == 0xff)
    {
       png_memcpy(row, png_ptr->row_buf + 1,
        (png_size_t)((png_ptr->width * png_ptr->row_info.pixel_depth + 7) >> 3));
    }
+   /* GRR:  add "else if (mask == 0)" case?
+    *       or does png_combine_row() not even get called in that case? */
    else
    {
       switch (png_ptr->row_info.pixel_depth)
@@ -220,6 +240,7 @@ png_combine_row(png_structp png_ptr, png_bytep row, int mask)
             }
             break;
          }
+
          case 4:
          {
             png_bytep sp;
@@ -273,6 +294,7 @@ png_combine_row(png_structp png_ptr, png_bytep row, int mask)
             }
             break;
          }
+
          case 8:
          {
             png_bytep srcptr;
@@ -305,7 +327,7 @@ png_combine_row(png_structp png_ptr, png_bytep row, int mask)
                   pand       mm0,mm7       //nonzero if keep byte
                   pcmpeqb    mm0,mm6       //zeros->1s, v versa
 
-                  mov        ecx,len       //load length of line
+                  mov        ecx,len       //load length of line (pixels)
                   mov        esi,srcptr    //load source
                   mov        ebx,dstptr    //load dest
                   cmp        ecx,0         //lcr
@@ -353,9 +375,9 @@ end8:
                register unsigned int incr1, initial_val, final_val;
                png_size_t pixel_bytes;
                png_uint_32 i;
-               //if ((mask != 0x0f) && (mask != 0x33))
                register int disp = png_pass_inc[png_ptr->pass];
                int offset_table[7] = {0, 4, 0, 2, 0, 1, 0};
+
                pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
                srcptr = png_ptr->row_buf + 1 + offset_table[png_ptr->pass]*
                   pixel_bytes;
@@ -372,7 +394,7 @@ end8:
             } /* end of else */
 
             break;
-         }       //end 8bpp
+         }       // end 8 bpp
 
          case 16:
          {
@@ -483,7 +505,7 @@ end16:
             } /* end of else */
 
             break;
-         }
+         }       // end 16 bpp
 
          case 24:
          {
@@ -596,6 +618,7 @@ end24:
                png_uint_32 i;
                register int disp = png_pass_inc[png_ptr->pass];
                int offset_table[7] = {0, 4, 0, 2, 0, 1, 0};
+
                pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
                srcptr = png_ptr->row_buf + 1 + offset_table[png_ptr->pass]*
                   pixel_bytes;
@@ -612,7 +635,7 @@ end24:
             } /* end of else */
 
             break;
-         }       //end 24bpp
+         }       // end 24 bpp
 
          case 32:
          {
@@ -734,6 +757,7 @@ end32:
                png_uint_32 i;
                register int disp = png_pass_inc[png_ptr->pass];
                int offset_table[7] = {0, 4, 0, 2, 0, 1, 0};
+
                pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
                srcptr = png_ptr->row_buf + 1 + offset_table[png_ptr->pass]*
                   pixel_bytes;
@@ -750,7 +774,7 @@ end32:
             } /* end of else */
 
             break;
-         }       //end 32bpp
+         }       // end 32 bpp
 
          case 48:
          {
@@ -890,6 +914,7 @@ end48:
                png_uint_32 i;
                register int disp = png_pass_inc[png_ptr->pass];
                int offset_table[7] = {0, 4, 0, 2, 0, 1, 0};
+
                pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
                srcptr = png_ptr->row_buf + 1 + offset_table[png_ptr->pass]*
                   pixel_bytes;
@@ -904,8 +929,9 @@ end48:
                   dstptr += incr1;
                }
             } /* end of else */
-            break;  // end 48 bpp
-         }
+
+            break;
+         }       // end 48 bpp
 
          default:
          {
@@ -916,6 +942,7 @@ end48:
             unsigned int i;
             register int disp = png_pass_inc[png_ptr->pass];  // get the offset
             register unsigned int incr1, initial_val, final_val;
+
             pixel_bytes = (png_ptr->row_info.pixel_depth >> 3);
             sptr = png_ptr->row_buf + 1 + offset_table[png_ptr->pass]*
                pixel_bytes;
@@ -932,8 +959,11 @@ end48:
             break;
          }
       } /* end switch (png_ptr->row_info.pixel_depth) */
-   }
+   } /* end if (non-trivial mask) */
+
+#ifdef DISABLE_PNGVCRD_COMBINE
    mmx_supported = save_mmx_supported;
+#endif
 
 } /* end png_combine_row() */
 
@@ -944,12 +974,30 @@ void
 png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
    png_uint_32 transformations)
 {
-
+#ifdef PNG_USE_LOCAL_ARRAYS
+   const int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
+#endif
+#ifdef DISABLE_PNGVCRD_INTERLACE
    int save_mmx_supported = mmx_supported;
+#endif
+
    png_debug(1,"in png_do_read_interlace\n");
 
-   // mmx_supported = mmxsupport();  // doesn't work
-   mmx_supported = 0;
+#ifdef DISABLE_PNGVCRD_INTERLACE
+   /* In libpng versions 1.0.3a through 1.0.4d,
+    * a sign error in the post-MMX cleanup code for each pixel_depth resulted
+    * in bad pixels at the beginning of some rows of some images, and also
+    * (due to out-of-range memory reads and writes) caused heap corruption
+    * when compiled with MSVC 6.0.  The error was fixed in version 1.0.4e,
+    * and the code appears to work completely correctly, so it is enabled
+    * by default.
+    */
+   if (1)  /* all passes caused a heap problem in the old code */
+      mmx_supported = 0;
+   else
+#endif
+       if (mmx_supported == 2)
+           mmx_supported = mmxsupport();
 
    if (row != NULL && row_info != NULL)
    {
@@ -1132,27 +1180,26 @@ png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
          default:         // This is the place where the routine is modified
          {
             __int64 const4 = 0x0000000000FFFFFF;
-            __int64 const5 = 0x000000FFFFFF0000;
+            // __int64 const5 = 0x000000FFFFFF0000;  // unused...
             __int64 const6 = 0x00000000000000FF;
-            //int mmx_supported = 1;
-
             png_bytep sptr, dp;
             png_uint_32 i;
             png_size_t pixel_bytes;
-
             int width = row_info->width;
 
             pixel_bytes = (row_info->pixel_depth >> 3);
 
-            sptr = row + (row_info->width - 1) * pixel_bytes;
+            sptr = row + (width - 1) * pixel_bytes;
             dp = row + (final_width - 1) * pixel_bytes;
             // New code by Nirav Chhatrapati - Intel Corporation
+            // sign fix by GRR
+            // NOTE:  there is NO MMX code for 48-bit and 64-bit images
 
             if (mmx_supported) // use MMX routine if machine supports it
             {
                if (pixel_bytes == 3)
                {
-                  if ((pass == 0) || (pass == 1))
+                  if (((pass == 0) || (pass == 1)) && width)
                   {
                      _asm
                      {
@@ -1187,7 +1234,7 @@ loop_pass0:
                         EMMS
                      }
                   }
-                  else if ((pass == 2) || (pass == 3))
+                  else if (((pass == 2) || (pass == 3)) && width)
                   {
                      _asm
                      {
@@ -1215,10 +1262,12 @@ loop_pass2:
                         EMMS
                      }
                   }
-                  else /* if ((pass == 4) || (pass == 5)) */
+                  else if (width) /* && ((pass == 4) || (pass == 5)) */
                   {
                      int width_mmx = ((width >> 1) << 1) - 8;
-                     width -= width_mmx;
+                     if (width_mmx < 0)
+                         width_mmx = 0;
+                     width -= width_mmx;        // 8 or 9 pix, 24 or 27 bytes
                      if (width_mmx)
                      {
                         _asm
@@ -1258,20 +1307,20 @@ loop_pass4:
                         png_byte v[8];
                         int j;
 
-                        png_memcpy(v, sptr, pixel_bytes);
+                        png_memcpy(v, sptr, 3);
                         for (j = 0; j < png_pass_inc[pass]; j++)
                         {
-                           png_memcpy(dp, v, pixel_bytes);
-                           dp -= pixel_bytes;
+                           png_memcpy(dp, v, 3);
+                           dp -= 3;
                         }
-                        sptr -= pixel_bytes;
+                        sptr -= 3;
                      }
                   }
                } /* end of pixel_bytes == 3 */
 
                else if (pixel_bytes == 1)
                {
-                  if ((pass == 0) || (pass == 1))
+                  if (((pass == 0) || (pass == 1)) && width)
                   {
                      int width_mmx = ((width >> 2) << 2);
                      width -= width_mmx;
@@ -1313,19 +1362,32 @@ loop1_pass0:
                      dp -= width_mmx*8;
                      for (i = width; i; i--)
                      {
-                        png_byte v[8];
                         int j;
 
-                        png_memcpy(v, sptr, pixel_bytes);
+                       /* I simplified this part in version 1.0.4e
+                        * here and in several other instances where
+                        * pixel_bytes == 1  -- GR-P
+                        *
+                        * Original code:
+                        *
+                        * png_byte v[8];
+                        * png_memcpy(v, sptr, pixel_bytes);
+                        * for (j = 0; j < png_pass_inc[pass]; j++)
+                        * {
+                        *    png_memcpy(dp, v, pixel_bytes);
+                        *    dp -= pixel_bytes;
+                        * }
+                        * sptr -= pixel_bytes;
+                        *
+                        * Replacement code is in the next three lines:
+                        */
+
                         for (j = 0; j < png_pass_inc[pass]; j++)
-                        {
-                           png_memcpy(dp, v, pixel_bytes);
-                           dp -= pixel_bytes;
-                        }
-                        sptr -= pixel_bytes;
+                           *dp-- = *sptr;
+                        sptr--;
                      }
                   }
-                  else if ((pass == 2) || (pass == 3))
+                  else if (((pass == 2) || (pass == 3)) && width)
                   {
                      int width_mmx = ((width >> 2) << 2);
                      width -= width_mmx;
@@ -1358,19 +1420,16 @@ loop1_pass2:
                      dp -= width_mmx*4;
                      for (i = width; i; i--)
                      {
-                        png_byte v[8];
                         int j;
 
-                        png_memcpy(v, sptr, pixel_bytes);
                         for (j = 0; j < png_pass_inc[pass]; j++)
                         {
-                           png_memcpy(dp, v, pixel_bytes);
-                           dp -= pixel_bytes;
+                           *dp-- = *sptr;
                         }
-                        sptr -= pixel_bytes;
+                        sptr --;
                      }
                   }
-                  else //if ((pass == 4) || (pass == 5))
+                  else if (width) /* && ((pass == 4) || (pass == 5))) */
                   {
                      int width_mmx = ((width >> 3) << 3);
                      width -= width_mmx;
@@ -1404,23 +1463,20 @@ loop1_pass4:
                      dp -= width_mmx*2;
                      for (i = width; i; i--)
                      {
-                        png_byte v[8];
                         int j;
 
-                        png_memcpy(v, sptr, pixel_bytes);
                         for (j = 0; j < png_pass_inc[pass]; j++)
                         {
-                           png_memcpy(dp, v, pixel_bytes);
-                           dp -= pixel_bytes;
+                           *dp-- = *sptr;
                         }
-                        sptr -= pixel_bytes;
+                        sptr --;
                      }
                   }
                } /* end of pixel_bytes == 1 */
 
                else if (pixel_bytes == 2)
                {
-                  if ((pass == 0) || (pass == 1))
+                  if (((pass == 0) || (pass == 1)) && width)
                   {
                      int width_mmx = ((width >> 1) << 1);
                      width -= width_mmx;
@@ -1451,25 +1507,22 @@ loop2_pass0:
                         }
                      }
 
-                     sptr -= (width_mmx*2 + 2);
-                     dp -= (width_mmx*16 + 2);
+                     sptr -= (width_mmx*2 - 2);            // sign fixed
+                     dp -= (width_mmx*16 - 2);            // sign fixed
                      for (i = width; i; i--)
                      {
                         png_byte v[8];
                         int j;
-                        sptr -= pixel_bytes;
-                        png_memcpy(v, sptr, pixel_bytes);
+                        sptr -= 2;
+                        png_memcpy(v, sptr, 2);
                         for (j = 0; j < png_pass_inc[pass]; j++)
                         {
-                           dp -= pixel_bytes;
-                           png_memcpy(dp, v, pixel_bytes);
-                           //dp -= pixel_bytes;
+                           dp -= 2;
+                           png_memcpy(dp, v, 2);
                         }
-                        //sptr -= pixel_bytes;
                      }
                   }
-
-                  else if ((pass == 2) || (pass == 3))
+                  else if (((pass == 2) || (pass == 3)) && width)
                   {
                      int width_mmx = ((width >> 1) << 1) ;
                      width -= width_mmx;
@@ -1499,25 +1552,22 @@ loop2_pass2:
                         }
                      }
 
-                     sptr -= (width_mmx*2 + 2);
-                     dp -= (width_mmx*8 + 2);
+                     sptr -= (width_mmx*2 - 2);            // sign fixed
+                     dp -= (width_mmx*8 - 2);            // sign fixed
                      for (i = width; i; i--)
                      {
                         png_byte v[8];
                         int j;
-                        sptr -= pixel_bytes;
-                        png_memcpy(v, sptr, pixel_bytes);
+                        sptr -= 2;
+                        png_memcpy(v, sptr, 2);
                         for (j = 0; j < png_pass_inc[pass]; j++)
                         {
-                           dp -= pixel_bytes;
-                           png_memcpy(dp, v, pixel_bytes);
-                           //dp -= pixel_bytes;
+                           dp -= 2;
+                           png_memcpy(dp, v, 2);
                         }
-                        //sptr -= pixel_bytes;
                      }
                   }
-
-                  else // pass == 4 or 5
+                  else if (width)  // pass == 4 or 5
                   {
                      int width_mmx = ((width >> 1) << 1) ;
                      width -= width_mmx;
@@ -1542,28 +1592,26 @@ loop2_pass4:
                         }
                      }
 
-                     sptr -= (width_mmx*2 + 2);
-                     dp -= (width_mmx*4 + 2);
+                     sptr -= (width_mmx*2 - 2);            // sign fixed
+                     dp -= (width_mmx*4 - 2);            // sign fixed
                      for (i = width; i; i--)
                      {
                         png_byte v[8];
                         int j;
-                        sptr -= pixel_bytes;
-                        png_memcpy(v, sptr, pixel_bytes);
+                        sptr -= 2;
+                        png_memcpy(v, sptr, 2);
                         for (j = 0; j < png_pass_inc[pass]; j++)
                         {
-                           dp -= pixel_bytes;
-                           png_memcpy(dp, v, pixel_bytes);
-                           //dp -= pixel_bytes;
+                           dp -= 2;
+                           png_memcpy(dp, v, 2);
                         }
-                        //sptr -= pixel_bytes;
                      }
                   }
                } /* end of pixel_bytes == 2 */
 
                else if (pixel_bytes == 4)
                {
-                  if ((pass == 0) || (pass == 1))
+                  if (((pass == 0) || (pass == 1)) && width)
                   {
                      int width_mmx = ((width >> 1) << 1) ;
                      width -= width_mmx;
@@ -1597,25 +1645,22 @@ loop4_pass0:
                         }
                      }
 
-                     sptr -= (width_mmx*4 + 4);
-                     dp -= (width_mmx*32 + 4);
+                     sptr -= (width_mmx*4 - 4);            // sign fixed
+                     dp -= (width_mmx*32 - 4);            // sign fixed
                      for (i = width; i; i--)
                      {
                         png_byte v[8];
                         int j;
-                        sptr -= pixel_bytes;
-                        png_memcpy(v, sptr, pixel_bytes);
+                        sptr -= 4;
+                        png_memcpy(v, sptr, 4);
                         for (j = 0; j < png_pass_inc[pass]; j++)
                         {
-                           dp -= pixel_bytes;
-                           png_memcpy(dp, v, pixel_bytes);
-                           //dp -= pixel_bytes;
+                           dp -= 4;
+                           png_memcpy(dp, v, 4);
                         }
-                        //sptr -= pixel_bytes;
                      }
                   }
-
-                  else if ((pass == 2) || (pass == 3))
+                  else if (((pass == 2) || (pass == 3)) && width)
                   {
                      int width_mmx = ((width >> 1) << 1) ;
                      width -= width_mmx;
@@ -1645,25 +1690,22 @@ loop4_pass2:
                         }
                      }
 
-                     sptr -= (width_mmx*4 + 4);
-                     dp -= (width_mmx*16 + 4);
+                     sptr -= (width_mmx*4 - 4);            // sign fixed
+                     dp -= (width_mmx*16 - 4);            // sign fixed
                      for (i = width; i; i--)
                      {
                         png_byte v[8];
                         int j;
-                        sptr -= pixel_bytes;
-                        png_memcpy(v, sptr, pixel_bytes);
+                        sptr -= 4;
+                        png_memcpy(v, sptr, 4);
                         for (j = 0; j < png_pass_inc[pass]; j++)
                         {
-                           dp -= pixel_bytes;
-                           png_memcpy(dp, v, pixel_bytes);
-                           //dp -= pixel_bytes;
+                           dp -= 4;
+                           png_memcpy(dp, v, 4);
                         }
-                        //sptr -= pixel_bytes;
                      }
                   }
-
-                  else // pass == 4 or 5
+                  else if (width)  // pass == 4 or 5
                   {
                      int width_mmx = ((width >> 1) << 1) ;
                      width -= width_mmx;
@@ -1691,21 +1733,19 @@ loop4_pass4:
                         }
                      }
 
-                     sptr -= (width_mmx*4 + 4);
-                     dp -= (width_mmx*8 + 4);
+                     sptr -= (width_mmx*4 - 4);          // sign fixed
+                     dp -= (width_mmx*8 - 4);            // sign fixed
                      for (i = width; i; i--)
                      {
                         png_byte v[8];
                         int j;
-                        sptr -= pixel_bytes;
-                        png_memcpy(v, sptr, pixel_bytes);
+                        sptr -= 4;
+                        png_memcpy(v, sptr, 4);
                         for (j = 0; j < png_pass_inc[pass]; j++)
                         {
-                           dp -= pixel_bytes;
-                           png_memcpy(dp, v, pixel_bytes);
-                           //dp -= pixel_bytes;
+                           dp -= 4;
+                           png_memcpy(dp, v, 4);
                         }
-                        //sptr -= pixel_bytes;
                      }
                   }
 
@@ -1713,23 +1753,23 @@ loop4_pass4:
 
                else if (pixel_bytes == 6)
                {
-                  for (i = row_info->width; i; i--)
+                  for (i = width; i; i--)
                   {
                      png_byte v[8];
                      int j;
-                     png_memcpy(v, sptr, pixel_bytes);
+                     png_memcpy(v, sptr, 6);
                      for (j = 0; j < png_pass_inc[pass]; j++)
                      {
-                        png_memcpy(dp, v, pixel_bytes);
-                        dp -= pixel_bytes;
+                        png_memcpy(dp, v, 6);
+                        dp -= 6;
                      }
-                     sptr -= pixel_bytes;
+                     sptr -= 6;
                   }
                } /* end of pixel_bytes == 6 */
 
                else
                {
-                  for (i = row_info->width; i; i--)
+                  for (i = width; i; i--)
                   {
                      png_byte v[8];
                      int j;
@@ -1749,23 +1789,17 @@ loop4_pass4:
             {
                if (pixel_bytes == 1)
                {
-                  for (i = row_info->width; i; i--)
+                  for (i = width; i; i--)
                   {
-                     png_byte v[8];
                      int j;
-
-                     png_memcpy(v, sptr, pixel_bytes);
                      for (j = 0; j < png_pass_inc[pass]; j++)
-                     {
-                        png_memcpy(dp, v, pixel_bytes);
-                        dp -= pixel_bytes;
-                     }
-                     sptr -= pixel_bytes;
+                        *dp-- = *sptr;
+                     sptr--;
                   }
                }
                else if (pixel_bytes == 3)
                {
-                  for (i = row_info->width; i; i--)
+                  for (i = width; i; i--)
                   {
                      png_byte v[8];
                      int j;
@@ -1780,7 +1814,7 @@ loop4_pass4:
                }
                else if (pixel_bytes == 2)
                {
-                  for (i = row_info->width; i; i--)
+                  for (i = width; i; i--)
                   {
                      png_byte v[8];
                      int j;
@@ -1795,7 +1829,7 @@ loop4_pass4:
                }
                else if (pixel_bytes == 4)
                {
-                  for (i = row_info->width; i; i--)
+                  for (i = width; i; i--)
                   {
                      png_byte v[8];
                      int j;
@@ -1810,7 +1844,7 @@ loop4_pass4:
                }
                else if (pixel_bytes == 6)
                {
-                  for (i = row_info->width; i; i--)
+                  for (i = width; i; i--)
                   {
                      png_byte v[8];
                      int j;
@@ -1825,7 +1859,7 @@ loop4_pass4:
                }
                else
                {
-                  for (i = row_info->width; i; i--)
+                  for (i = width; i; i--)
                   {
                      png_byte v[8];
                      int j;
@@ -1848,7 +1882,10 @@ loop4_pass4:
       row_info->rowbytes = ((final_width *
          (png_uint_32)row_info->pixel_depth + 7) >> 3);
    }
+
+#ifdef DISABLE_PNGVCRD_INTERLACE
    mmx_supported = save_mmx_supported;
+#endif
 }
 
 #endif /* PNG_READ_INTERLACING_SUPPORTED */
@@ -3621,7 +3658,7 @@ png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep
 #ifdef PNG_DEBUG
    char filnm[6];
 #endif
-   #define UseMMX (1)
+#define UseMMX 1
 
    if (mmx_supported == 2)
        mmx_supported = mmxsupport();
@@ -3634,7 +3671,11 @@ png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep
 
 #ifdef PNG_DEBUG
    png_debug(1, "in png_read_filter_row\n");
-   png_debug1(0,"%s, ", (UseMMX?"MMX":"x86"));
+#if (UseMMX == 1)
+   png_debug1(0,"%s, ", "MMX");
+#else
+   png_debug1(0,"%s, ", "x86");
+#endif
    switch (filter)
    {
       case 0: sprintf(filnm, "None ");
@@ -3662,12 +3703,14 @@ png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep
          break;
       case PNG_FILTER_VALUE_SUB:
       {
-         if ( UseMMX && (row_info->pixel_depth > 8) &&
+#if (UseMMX == 1)
+         if ((row_info->pixel_depth > 8) &&
             (row_info->rowbytes >= 128) )
          {
             png_read_filter_row_mmx_sub(row_info, row);
-         }  //end if UseMMX
+         }
          else
+#endif
          {
             png_uint_32 i;
             png_uint_32 istop = row_info->rowbytes;
@@ -3685,12 +3728,14 @@ png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep
       }
       case PNG_FILTER_VALUE_UP:
       {
-         if ( UseMMX && (row_info->pixel_depth > 8) &&
+#if (UseMMX == 1)
+         if ((row_info->pixel_depth > 8) &&
              (row_info->rowbytes >= 128) )
          {
             png_read_filter_row_mmx_up(row_info, row, prev_row);
          }  //end if UseMMX
          else
+#endif
          {
             png_bytep rp;
             png_bytep pp;
@@ -3705,12 +3750,14 @@ png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep
       }
       case PNG_FILTER_VALUE_AVG:
       {
-         if ( UseMMX && (row_info->pixel_depth > 8) &&
+#if (UseMMX == 1)
+         if ((row_info->pixel_depth > 8) &&
              (row_info->rowbytes >= 128) )
          {
             png_read_filter_row_mmx_avg(row_info, row, prev_row);
          }  //end if UseMMX
          else
+#endif
          {
             png_uint_32 i;
             png_bytep rp = row;
@@ -3737,12 +3784,14 @@ png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep
       }
       case PNG_FILTER_VALUE_PAETH:
       {
-         if ( UseMMX && (row_info->pixel_depth > 8) &&
+#if (UseMMX == 1)
+         if ((row_info->pixel_depth > 8) &&
              (row_info->rowbytes >= 128) )
          {
             png_read_filter_row_mmx_paeth(row_info, row, prev_row);
          }  //end if UseMMX
          else
+#endif
          {
             png_uint_32 i;
             png_bytep rp = row;
@@ -3769,7 +3818,7 @@ png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep
                p = b - c;
                pc = a - c;
 
-#ifdef    PNG_USE_ABS
+#ifdef PNG_USE_ABS
                pa = abs(p);
                pb = abs(pc);
                pc = abs(p + pc);

pngwio.c

@@ -1,11 +1,11 @@
 
 /* pngwio.c - functions for data output
  *
- * libpng 1.0.4c - October 1, 1999
+ * libpng 1.0.6d - April 7, 2000
  * 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, 1999 Glenn Randers-Pehrson
+ * Copyright (c) 1998, 1999, 2000 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

pngwrite.c

@@ -1,11 +1,11 @@
 
 /* pngwrite.c - general routines to write a PNG file
  *
- * libpng 1.0.4c - October 1, 1999
+ * libpng 1.0.6d - April 7, 2000
  * 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, 1999 Glenn Randers-Pehrson
+ * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson
  */
 
 /* get internal access to png.h */
@@ -22,13 +22,11 @@
  * them in png_write_end(), and compressing them.
  */
 void
-png_write_info(png_structp png_ptr, png_infop info_ptr)
+png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr)
 {
-#if defined(PNG_WRITE_tEXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED)
-   int i;
-#endif
-
-   png_debug(1, "in png_write_info\n");
+   png_debug(1, "in png_write_info_before_PLTE\n");
+   if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
+   {
    png_write_sig(png_ptr); /* write PNG signature */
    /* write IHDR information. */
    png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,
@@ -43,24 +41,86 @@ png_write_info(png_structp png_ptr, png_infop info_ptr)
       flag set, and if it does, writes the chunk. */
 #if defined(PNG_WRITE_gAMA_SUPPORTED)
    if (info_ptr->valid & PNG_INFO_gAMA)
+   {
+#  ifdef PNG_FLOATING_POINT_SUPPORTED
       png_write_gAMA(png_ptr, info_ptr->gamma);
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+      png_write_gAMA_fixed(png_ptr, info_ptr->int_gamma);
+#  endif
+#endif
+   }
 #endif
 #if defined(PNG_WRITE_sRGB_SUPPORTED)
    if (info_ptr->valid & PNG_INFO_sRGB)
       png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent);
 #endif
+#if defined(PNG_WRITE_iCCP_SUPPORTED)
+   if (info_ptr->valid & PNG_INFO_iCCP)
+      png_write_iCCP(png_ptr, info_ptr->iccp_name, PNG_TEXT_COMPRESSION_NONE,
+                     info_ptr->iccp_profile, (int)info_ptr->iccp_proflen);
+#endif
 #if defined(PNG_WRITE_sBIT_SUPPORTED)
    if (info_ptr->valid & PNG_INFO_sBIT)
       png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
 #endif
 #if defined(PNG_WRITE_cHRM_SUPPORTED)
    if (info_ptr->valid & PNG_INFO_cHRM)
+   {
+#ifdef PNG_FLOATING_POINT_SUPPORTED
       png_write_cHRM(png_ptr,
          info_ptr->x_white, info_ptr->y_white,
          info_ptr->x_red, info_ptr->y_red,
          info_ptr->x_green, info_ptr->y_green,
          info_ptr->x_blue, info_ptr->y_blue);
+#else
+#  ifdef PNG_FIXED_POINT_SUPPORTED
+      png_write_cHRM_fixed(png_ptr,
+         info_ptr->int_x_white, info_ptr->int_y_white,
+         info_ptr->int_x_red, info_ptr->int_y_red,
+         info_ptr->int_x_green, info_ptr->int_y_green,
+         info_ptr->int_x_blue, info_ptr->int_y_blue);
+#  endif
 #endif
+   }
+#endif
+#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
+   if (info_ptr->unknown_chunks_num)
+   {
+       png_unknown_chunk *up;
+
+       png_debug(5, "writing extra chunks\n");
+
+       for (up = info_ptr->unknown_chunks;
+            up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
+            up++)
+       {
+         int keep=png_handle_as_unknown(png_ptr, up->name);
+         if (keep != HANDLE_CHUNK_NEVER &&
+            up->location && (!(up->location & PNG_HAVE_PLTE)) &&
+            ((up->name[3] & 0x20) || keep == HANDLE_CHUNK_ALWAYS ||
+            (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
+         {
+            png_write_chunk(png_ptr, up->name, up->data, up->size);
+         }
+       }
+   }
+#endif
+      png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;
+   }
+}
+
+void
+png_write_info(png_structp png_ptr, png_infop info_ptr)
+{
+#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
+   int i;
+#endif
+
+   png_debug(1, "in png_write_info\n");
+
+   png_write_info_before_PLTE(png_ptr, info_ptr);
+
    if (info_ptr->valid & PNG_INFO_PLTE)
       png_write_PLTE(png_ptr, info_ptr->palette,
          (png_uint_32)info_ptr->num_palette);
@@ -72,12 +132,12 @@ png_write_info(png_structp png_ptr, png_infop info_ptr)
       {
 #if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
          /* invert the alpha channel (in tRNS) */
-         if (png_ptr->transformations & PNG_INVERT_ALPHA &&
+         if ((png_ptr->transformations & PNG_INVERT_ALPHA) &&
             info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
          {
             int j;
             for (j=0; j<(int)info_ptr->num_trans; j++)
-               info_ptr->trans[j] = 255 - info_ptr->trans[j];
+               info_ptr->trans[j] = (png_byte)(255 - info_ptr->trans[j]);
          }
 #endif
       png_write_tRNS(png_ptr, info_ptr->trans, &(info_ptr->trans_values),
@@ -103,6 +163,21 @@ png_write_info(png_structp png_ptr, png_infop info_ptr)
          info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams,
          info_ptr->pcal_units, info_ptr->pcal_params);
 #endif
+#if defined(PNG_WRITE_sCAL_SUPPORTED)
+   if (info_ptr->valid & PNG_INFO_sCAL)
+#if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
+      png_write_sCAL(png_ptr, (int)info_ptr->scal_unit,
+          info_ptr->scal_pixel_width, info_ptr->scal_pixel_height);
+#else
+#ifdef PNG_FIXED_POINT_SUPPORTED
+      png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,
+          info_ptr->scal_s_width, info_ptr->scal_s_height);
+#else
+      png_warning(png_ptr,
+          "png_write_sCAL not supported; sCAL chunk not written.\n");
+#endif
+#endif
+#endif
 #if defined(PNG_WRITE_pHYs_SUPPORTED)
    if (info_ptr->valid & PNG_INFO_pHYs)
       png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,
@@ -112,22 +187,44 @@ png_write_info(png_structp png_ptr, png_infop info_ptr)
    if (info_ptr->valid & PNG_INFO_tIME)
    {
       png_write_tIME(png_ptr, &(info_ptr->mod_time));
-      png_ptr->flags |= PNG_FLAG_WROTE_tIME;
+      png_ptr->mode |= PNG_WROTE_tIME;
    }
 #endif
-#if defined(PNG_WRITE_tEXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED)
+#if defined(PNG_WRITE_sPLT_SUPPORTED)
+   if (info_ptr->valid & PNG_INFO_sPLT)
+     for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
+       png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);
+#endif
+#if defined(PNG_WRITE_TEXT_SUPPORTED)
    /* Check to see if we need to write text chunks */
    for (i = 0; i < info_ptr->num_text; i++)
    {
       png_debug2(2, "Writing header text chunk %d, type %d\n", i,
          info_ptr->text[i].compression);
+      /* an internationalized chunk? */
+      if (info_ptr->text[i].compression > 0)
+      {
+#if defined(PNG_WRITE_iTXt_SUPPORTED)
+          /* write international chunk */
+          png_write_iTXt(png_ptr,
+                         info_ptr->text[i].compression,
+                         info_ptr->text[i].key,
+                         info_ptr->text[i].lang,
+                         info_ptr->text[i].lang_key,
+                         info_ptr->text[i].text);
+#else
+          png_warning(png_ptr, "Unable to write international text\n");
+#endif
+          /* Mark this chunk as written */
+          info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+      }
       /* If we want a compressed text chunk */
-      if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
+      else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
       {
 #if defined(PNG_WRITE_zTXt_SUPPORTED)
          /* write compressed chunk */
          png_write_zTXt(png_ptr, info_ptr->text[i].key,
-            info_ptr->text[i].text, info_ptr->text[i].text_length,
+            info_ptr->text[i].text, 0,
             info_ptr->text[i].compression);
 #else
          png_warning(png_ptr, "Unable to write compressed text\n");
@@ -140,7 +237,8 @@ png_write_info(png_structp png_ptr, png_infop info_ptr)
 #if defined(PNG_WRITE_tEXt_SUPPORTED)
          /* write uncompressed chunk */
          png_write_tEXt(png_ptr, info_ptr->text[i].key,
-            info_ptr->text[i].text, info_ptr->text[i].text_length);
+                         info_ptr->text[i].text,
+                         0);
 #else
          png_warning(png_ptr, "Unable to write uncompressed text\n");
 #endif
@@ -149,6 +247,29 @@ png_write_info(png_structp png_ptr, png_infop info_ptr)
       }
    }
 #endif
+#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
+   if (info_ptr->unknown_chunks_num)
+   {
+       png_unknown_chunk *up;
+
+       png_debug(5, "writing extra chunks\n");
+
+       for (up = info_ptr->unknown_chunks;
+            up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
+            up++)
+       {
+         int keep=png_handle_as_unknown(png_ptr, up->name);
+         if (keep != HANDLE_CHUNK_NEVER &&
+            up->location && (up->location & PNG_HAVE_PLTE) &&
+            !(up->location & PNG_HAVE_IDAT) &&
+            ((up->name[3] & 0x20) || keep == HANDLE_CHUNK_ALWAYS ||
+            (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
+         {
+            png_write_chunk(png_ptr, up->name, up->data, up->size);
+         }
+       }
+   }
+#endif
 }
 
 /* Writes the end of the PNG file.  If you don't want to write comments or
@@ -166,27 +287,44 @@ png_write_end(png_structp png_ptr, png_infop info_ptr)
    /* see if user wants us to write information chunks */
    if (info_ptr != NULL)
    {
-#if defined(PNG_WRITE_tEXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED)
+#if defined(PNG_WRITE_TEXT_SUPPORTED)
       int i; /* local index variable */
 #endif
 #if defined(PNG_WRITE_tIME_SUPPORTED)
       /* check to see if user has supplied a time chunk */
-      if (info_ptr->valid & PNG_INFO_tIME &&
-         !(png_ptr->flags & PNG_FLAG_WROTE_tIME))
+      if ((info_ptr->valid & PNG_INFO_tIME) &&
+         !(png_ptr->mode & PNG_WROTE_tIME))
          png_write_tIME(png_ptr, &(info_ptr->mod_time));
 #endif
-#if defined(PNG_WRITE_tEXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED)
+#if defined(PNG_WRITE_TEXT_SUPPORTED)
       /* loop through comment chunks */
       for (i = 0; i < info_ptr->num_text; i++)
       {
          png_debug2(2, "Writing trailer text chunk %d, type %d\n", i,
             info_ptr->text[i].compression);
-         if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
+         /* an internationalized chunk? */
+         if (info_ptr->text[i].compression > 0)
+         {
+#if defined(PNG_WRITE_iTXt_SUPPORTED)
+             /* write international chunk */
+             png_write_iTXt(png_ptr,
+                         info_ptr->text[i].compression,
+                         info_ptr->text[i].key,
+                         info_ptr->text[i].lang,
+                         info_ptr->text[i].lang_key,
+                         info_ptr->text[i].text);
+#else
+             png_warning(png_ptr, "Unable to write international text\n");
+#endif
+             /* Mark this chunk as written */
+             info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
+         }
+         else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
          {
 #if defined(PNG_WRITE_zTXt_SUPPORTED)
             /* write compressed chunk */
             png_write_zTXt(png_ptr, info_ptr->text[i].key,
-               info_ptr->text[i].text, info_ptr->text[i].text_length,
+               info_ptr->text[i].text, 0,
                info_ptr->text[i].compression);
 #else
             png_warning(png_ptr, "Unable to write compressed text\n");
@@ -199,7 +337,7 @@ png_write_end(png_structp png_ptr, png_infop info_ptr)
 #if defined(PNG_WRITE_tEXt_SUPPORTED)
             /* write uncompressed chunk */
             png_write_tEXt(png_ptr, info_ptr->text[i].key,
-               info_ptr->text[i].text, info_ptr->text[i].text_length);
+               info_ptr->text[i].text, 0);
 #else
             png_warning(png_ptr, "Unable to write uncompressed text\n");
 #endif
@@ -208,6 +346,28 @@ png_write_end(png_structp png_ptr, png_infop info_ptr)
             info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
          }
       }
+#endif
+#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
+   if (info_ptr->unknown_chunks_num)
+   {
+       png_unknown_chunk *up;
+
+       png_debug(5, "writing extra chunks\n");
+
+       for (up = info_ptr->unknown_chunks;
+            up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
+            up++)
+       {
+         int keep=png_handle_as_unknown(png_ptr, up->name);
+         if (keep != HANDLE_CHUNK_NEVER &&
+            up->location && (up->location & PNG_AFTER_IDAT) &&
+            ((up->name[3] & 0x20) || keep == HANDLE_CHUNK_ALWAYS ||
+            (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
+         {
+            png_write_chunk(png_ptr, up->name, up->data, up->size);
+         }
+       }
+   }
 #endif
    }
 
@@ -259,8 +419,10 @@ png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
 {
 #endif /* PNG_USER_MEM_SUPPORTED */
    png_structp png_ptr;
+#ifdef PNG_SETJMP_SUPPORTED
 #ifdef USE_FAR_KEYWORD
    jmp_buf jmpbuf;
+#endif
 #endif
    png_debug(1, "in png_create_write_struct\n");
 #ifdef PNG_USER_MEM_SUPPORTED
@@ -272,6 +434,8 @@ png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
    {
       return ((png_structp)NULL);
    }
+
+#ifdef PNG_SETJMP_SUPPORTED
 #ifdef USE_FAR_KEYWORD
    if (setjmp(jmpbuf))
 #else
@@ -285,6 +449,8 @@ png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
 #ifdef USE_FAR_KEYWORD
    png_memcpy(png_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf));
 #endif
+#endif
+
 #ifdef PNG_USER_MEM_SUPPORTED
    png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
 #endif /* PNG_USER_MEM_SUPPORTED */
@@ -321,17 +487,23 @@ png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
 void
 png_write_init(png_structp png_ptr)
 {
+#ifdef PNG_SETJMP_SUPPORTED
    jmp_buf tmp_jmp; /* to save current jump buffer */
+#endif
 
    png_debug(1, "in png_write_init\n");
+#ifdef PNG_SETJMP_SUPPORTED
    /* save jump buffer and error functions */
    png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf));
+#endif
 
    /* reset all variables to 0 */
    png_memset(png_ptr, 0, sizeof (png_struct));
 
+#ifdef PNG_SETJMP_SUPPORTED
    /* restore jump buffer */
    png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf));
+#endif
 
    /* initialize zbuf - compression buffer */
    png_ptr->zbuf_size = PNG_ZBUF_SIZE;
@@ -443,49 +615,49 @@ png_write_row(png_structp png_ptr, png_bytep row)
       switch (png_ptr->pass)
       {
          case 0:
-            if (png_ptr->row_number & 7)
+            if (png_ptr->row_number & 0x07)
             {
                png_write_finish_row(png_ptr);
                return;
             }
             break;
          case 1:
-            if ((png_ptr->row_number & 7) || png_ptr->width < 5)
+            if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
             {
                png_write_finish_row(png_ptr);
                return;
             }
             break;
          case 2:
-            if ((png_ptr->row_number & 7) != 4)
+            if ((png_ptr->row_number & 0x07) != 4)
             {
                png_write_finish_row(png_ptr);
                return;
             }
             break;
          case 3:
-            if ((png_ptr->row_number & 3) || png_ptr->width < 3)
+            if ((png_ptr->row_number & 0x03) || png_ptr->width < 3)
             {
                png_write_finish_row(png_ptr);
                return;
             }
             break;
          case 4:
-            if ((png_ptr->row_number & 3) != 2)
+            if ((png_ptr->row_number & 0x03) != 2)
             {
                png_write_finish_row(png_ptr);
                return;
             }
             break;
          case 5:
-            if ((png_ptr->row_number & 1) || png_ptr->width < 2)
+            if ((png_ptr->row_number & 0x01) || png_ptr->width < 2)
             {
                png_write_finish_row(png_ptr);
                return;
             }
             break;
          case 6:
-            if (!(png_ptr->row_number & 1))
+            if (!(png_ptr->row_number & 0x01))
             {
                png_write_finish_row(png_ptr);
                return;
@@ -630,22 +802,14 @@ png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
 
    if (info_ptr != NULL)
    {
-#ifdef PNG_WRITE_tEXt_SUPPORTED
-      png_free(png_ptr, info_ptr->text);
-#endif
-#if defined(PNG_READ_pCAL_SUPPORTED)
-      png_free(png_ptr, info_ptr->pcal_purpose);
-      png_free(png_ptr, info_ptr->pcal_units);
-      if (info_ptr->pcal_params != NULL)
+      png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
+
+      if (png_ptr->num_chunk_list)
       {
-         int i;
-         for (i = 0; i < (int)info_ptr->pcal_nparams; i++)
-         {
-            png_free(png_ptr, info_ptr->pcal_params[i]);
-         }
-         png_free(png_ptr, info_ptr->pcal_params);
+         png_free(png_ptr, png_ptr->chunk_list);
+         png_ptr->num_chunk_list=0;
       }
-#endif
+
 #ifdef PNG_USER_MEM_SUPPORTED
       png_destroy_struct_2((png_voidp)info_ptr, free_fn);
 #else
@@ -671,7 +835,9 @@ png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
 void
 png_write_destroy(png_structp png_ptr)
 {
+#ifdef PNG_SETJMP_SUPPORTED
    jmp_buf tmp_jmp; /* save jump buffer */
+#endif
    png_error_ptr error_fn;
    png_error_ptr warning_fn;
    png_voidp error_ptr;
@@ -691,19 +857,23 @@ png_write_destroy(png_structp png_ptr)
    png_free(png_ptr, png_ptr->up_row);
    png_free(png_ptr, png_ptr->avg_row);
    png_free(png_ptr, png_ptr->paeth_row);
+
 #if defined(PNG_TIME_RFC1123_SUPPORTED)
    png_free(png_ptr, png_ptr->time_buffer);
-#endif /* PNG_TIME_RFC1123_SUPPORTED */
+#endif
+
 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
    png_free(png_ptr, png_ptr->prev_filters);
    png_free(png_ptr, png_ptr->filter_weights);
    png_free(png_ptr, png_ptr->inv_filter_weights);
    png_free(png_ptr, png_ptr->filter_costs);
    png_free(png_ptr, png_ptr->inv_filter_costs);
-#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
+#endif
 
+#ifdef PNG_SETJMP_SUPPORTED
    /* reset structure */
    png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf));
+#endif
 
    error_fn = png_ptr->error_fn;
    warning_fn = png_ptr->warning_fn;
@@ -721,7 +891,9 @@ png_write_destroy(png_structp png_ptr)
    png_ptr->free_fn = free_fn;
 #endif
 
+#ifdef PNG_SETJMP_SUPPORTED
    png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf));
+#endif
 }
 
 /* Allow the application to select one or more row filters to use. */
@@ -756,14 +928,14 @@ png_set_filter(png_structp png_ptr, int method, int filters)
        */
       if (png_ptr->row_buf != NULL)
       {
-         if (png_ptr->do_filter & PNG_FILTER_SUB && png_ptr->sub_row == NULL)
+         if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL)
          {
             png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
               (png_ptr->rowbytes + 1));
             png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
          }
 
-         if (png_ptr->do_filter & PNG_FILTER_UP && png_ptr->up_row == NULL)
+         if ((png_ptr->do_filter & PNG_FILTER_UP) && png_ptr->up_row == NULL)
          {
             if (png_ptr->prev_row == NULL)
             {
@@ -778,7 +950,7 @@ png_set_filter(png_structp png_ptr, int method, int filters)
             }
          }
 
-         if (png_ptr->do_filter & PNG_FILTER_AVG && png_ptr->avg_row == NULL)
+         if ((png_ptr->do_filter & PNG_FILTER_AVG) && png_ptr->avg_row == NULL)
          {
             if (png_ptr->prev_row == NULL)
             {
@@ -793,13 +965,13 @@ png_set_filter(png_structp png_ptr, int method, int filters)
             }
          }
 
-         if (png_ptr->do_filter & PNG_FILTER_PAETH &&
+         if ((png_ptr->do_filter & PNG_FILTER_PAETH) &&
              png_ptr->paeth_row == NULL)
          {
             if (png_ptr->prev_row == NULL)
             {
                png_warning(png_ptr, "Can't add Paeth filter after starting");
-               png_ptr->do_filter &= ~PNG_FILTER_PAETH;
+               png_ptr->do_filter &= (png_byte)(~PNG_FILTER_PAETH);
             }
             else
             {
@@ -850,8 +1022,8 @@ png_set_filter_heuristics(png_structp png_ptr, int heuristic_method,
       num_weights = 0;
    }
 
-   png_ptr->num_prev_filters = num_weights;
-   png_ptr->heuristic_method = heuristic_method;
+   png_ptr->num_prev_filters = (png_byte)num_weights;
+   png_ptr->heuristic_method = (png_byte)heuristic_method;
 
    if (num_weights > 0)
    {
@@ -973,6 +1145,14 @@ png_set_compression_window_bits(png_structp png_ptr, int window_bits)
       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");
+#ifndef WBITS_8_OK
+   /* avoid libpng bug with 256-byte windows */
+   if (window_bits == 8)
+     {
+       png_warning(png_ptr, "Compression window is being reset to 512");
+       window_bits=9;
+     }
+#endif
    png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS;
    png_ptr->zlib_window_bits = window_bits;
 }
@@ -1003,3 +1183,87 @@ 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
+
+
+#if defined(PNG_INFO_IMAGE_SUPPORTED)
+void png_write_png(png_structp png_ptr, png_infop info_ptr,
+                           int transforms,
+                           voidp params)
+{
+#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
+   /* invert the alpha channel from opacity to transparency */
+   if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
+       png_set_invert_alpha(png_ptr);
+#endif
+
+   /* Write the file header information. */
+   png_write_info(png_ptr, info_ptr);
+
+   /* ------ these transformations don't touch the info structure ------- */
+
+#if defined(PNG_WRITE_INVERT_SUPPORTED)
+   /* invert monochrome pixels */
+   if (transforms & PNG_TRANSFORM_INVERT_MONO)
+       png_set_invert_mono(png_ptr);
+#endif
+
+#if defined(PNG_WRITE_SHIFT_SUPPORTED)
+   /* Shift the pixels up to a legal bit depth and fill in
+    * as appropriate to correctly scale the image.
+    */
+   if ((transforms & PNG_TRANSFORM_SHIFT)
+               && (info_ptr->valid & PNG_INFO_sBIT))
+       png_set_shift(png_ptr, &info_ptr->sig_bit);
+#endif
+
+#if defined(PNG_WRITE_PACK_SUPPORTED)
+   /* pack pixels into bytes */
+   if (transforms & PNG_TRANSFORM_PACKING)
+       png_set_packing(png_ptr);
+#endif
+
+#if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
+   /* swap location of alpha bytes from ARGB to RGBA */
+   if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
+       png_set_swap_alpha(png_ptr);
+#endif
+
+#if defined(PNG_WRITE_FILLER_SUPPORTED)
+   /* Get rid of filler (OR ALPHA) bytes, pack XRGB/RGBX/ARGB/RGBA into
+    * RGB (4 channels -> 3 channels). The second parameter is not used.
+    */
+   if (transforms & PNG_TRANSFORM_STRIP_FILLER)
+       png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
+#endif
+
+#if defined(PNG_WRITE_BGR_SUPPORTED)
+   /* flip BGR pixels to RGB */
+   if (transforms & PNG_TRANSFORM_BGR)
+       png_set_bgr(png_ptr);
+#endif
+
+#if defined(PNG_WRITE_SWAP_SUPPORTED)
+   /* swap bytes of 16-bit files to most significant byte first */
+   if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
+       png_set_swap(png_ptr);
+#endif
+
+#if defined(PNG_WRITE_PACKSWAP_SUPPORTED)
+   /* swap bits of 1, 2, 4 bit packed pixel formats */
+   if (transforms & PNG_TRANSFORM_PACKSWAP)
+       png_set_packswap(png_ptr);
+#endif
+
+   /* ----------------------- end of transformations ------------------- */
+
+   /* write the bits */
+   if (info_ptr->valid & PNG_INFO_IDAT)
+       png_write_image(png_ptr, info_ptr->row_pointers);
+
+   /* It is REQUIRED to call this to finish writing the rest of the file */
+   png_write_end(png_ptr, info_ptr);
+
+   if(transforms == 0 || params == (voidp)NULL)
+      /* quiet compiler warnings */ return;
+}
+#endif

pngwtran.c

@@ -1,11 +1,11 @@
 
 /* pngwtran.c - transforms the data in a row for PNG writers
  *
- * libpng 1.0.4c - October 1, 1999
+ * libpng 1.0.6d - April 7, 2000
  * 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, 1999 Glenn Randers-Pehrson
+ * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson
  */
 
 #define PNG_INTERNAL
@@ -19,6 +19,9 @@ png_do_write_transformations(png_structp png_ptr)
 {
    png_debug(1, "in png_do_write_transformations\n");
 
+   if (png_ptr == NULL)
+      return;
+
 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
    if (png_ptr->transformations & PNG_USER_TRANSFORM)
       if(png_ptr->write_user_transform_fn != NULL)
@@ -137,7 +140,7 @@ png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
             {
                png_byte value;
 
-               value = (png_byte)(*sp & 0x3);
+               value = (png_byte)(*sp & 0x03);
                v |= (value << shift);
                if (shift == 0)
                {
@@ -169,7 +172,7 @@ png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
             {
                png_byte value;
 
-               value = (png_byte)(*sp & 0xf);
+               value = (png_byte)(*sp & 0x0f);
                v |= (value << shift);
 
                if (shift == 0)
@@ -311,7 +314,7 @@ png_do_shift(png_row_infop row_info, png_bytep row, png_color_8p bit_depth)
             png_uint_16 value, v;
             int j;
 
-            v = ((png_uint_16)(*bp) << 8) + *(bp + 1);
+            v = (png_uint_16)(((png_uint_16)(*bp) << 8) + *(bp + 1));
             value = 0;
             for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
             {
@@ -438,7 +441,7 @@ png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
                *(dp++) = *(sp++);
                *(dp++) = *(sp++);
                *(dp++) = *(sp++);
-               *(dp++) = 255 - *(sp++);
+               *(dp++) = (png_byte)(255 - *(sp++));
             }
          }
          /* This inverts the alpha channel in RRGGBBAA */
@@ -456,8 +459,8 @@ png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
                *(dp++) = *(sp++);
                *(dp++) = *(sp++);
                *(dp++) = *(sp++);
-               *(dp++) = 255 - *(sp++);
-               *(dp++) = 255 - *(sp++);
+               *(dp++) = (png_byte)(255 - *(sp++));
+               *(dp++) = (png_byte)(255 - *(sp++));
             }
          }
       }
@@ -473,7 +476,7 @@ png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
             for (i = 0, sp = dp = row; i < row_width; i++)
             {
                *(dp++) = *(sp++);
-               *(dp++) = 255 - *(sp++);
+               *(dp++) = (png_byte)(255 - *(sp++));
             }
          }
          /* This inverts the alpha channel in GGAA */
@@ -487,8 +490,8 @@ png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
             {
                *(dp++) = *(sp++);
                *(dp++) = *(sp++);
-               *(dp++) = 255 - *(sp++);
-               *(dp++) = 255 - *(sp++);
+               *(dp++) = (png_byte)(255 - *(sp++));
+               *(dp++) = (png_byte)(255 - *(sp++));
             }
          }
       }

scripts/build.bat

@@ -1,2 +0,0 @@
-make -fmakefile.bor -B -DMODEL=m %1 %2 %3 libpng >buildm.out
-make -fmakefile.bor -B -DMODEL=l %1 %2 %3 libpng >buildl.out

scripts/libpng.icc

@@ -0,0 +1,43 @@
+// Project file for libpng (static)
+// IBM VisualAge/C++ version 4.0 or later
+// Copyright (C) 2000 Cosmin Truta
+// Notes:
+//   All modules are compiled in C mode
+//   Tested with IBM VAC++ 4.0 under Win32
+//   Expected to work with IBM VAC++ 4.0 or later under OS/2 and Win32
+//   Can be easily adapted for IBM VAC++ 4.0 or later under AIX
+// For conditions of distribution and use, see copyright notice in png.h
+
+option incl(searchpath, "../zlib"), opt(level, "2"),
+ link(libsearchpath, "../zlib")
+{
+   target type(lib) "libpng.lib"
+   {
+      source type(c) "png.c"
+      source type(c) "pngerror.c"
+      source type(c) "pngget.c"
+      source type(c) "pngmem.c"
+      source type(c) "pngpread.c"
+      source type(c) "pngread.c"
+      source type(c) "pngrio.c"
+      source type(c) "pngrtran.c"
+      source type(c) "pngrutil.c"
+      source type(c) "pngset.c"
+      source type(c) "pngtrans.c"
+      source type(c) "pngwio.c"
+      source type(c) "pngwrite.c"
+      source type(c) "pngwtran.c"
+      source type(c) "pngwutil.c"
+   }
+}
+
+option incl(searchpath, "../zlib"), opt(level, "2"),
+ link(libsearchpath, "../zlib")
+{
+   target type(exe) "pngtest.exe"
+   {
+      source type(c) "pngtest.c"
+      source type(lib) "libpng.lib"
+      source type(lib) "zlib.lib"
+   }
+}

scripts/makefile.bc32

@@ -0,0 +1,151 @@
+# Makefile for libpng
+# 32-bit Borland C++ (Note: All modules are compiled in C mode)
+# To build the library, do:
+#       "make -fmakefile.bc32"
+#
+# ---------- 32-bit Borland C++ ----------
+
+### Absolutely necessary for this makefile to work
+.AUTODEPEND
+
+## Where zlib.h, zconf.h and zlib.lib are
+ZLIB_DIR=..\zlib
+
+
+## Compiler, linker and lib stuff
+CC=bcc32
+LD=bcc32
+LIB=tlib
+
+#TARGET_CPU=6
+# 3 = 386, 4 = 486, 5 = Pentium etc.
+!ifndef TARGET_CPU
+TARGET_CPU=5
+!endif
+
+# Use this if you don't want Borland's fancy exception handling
+NOEHLIB=noeh32.lib
+
+!ifdef DEBUG
+CDEBUG=-v
+LDEBUG=-v
+!else
+CDEBUG=
+LDEBUG=
+!endif
+
+# STACKOFLOW=1
+!ifdef STACKOFLOW
+CDEBUG=$(CDEBUG) -N
+LDEBUG=$(LDEBUG) -N
+!endif
+
+# -X- turn on dependency generation in the object file
+# -w  set all warnings on
+# -O2 optimize for speed
+# -Z  global optimization
+CFLAGS=-O2 -Z -X- -w -I$(ZLIB_DIR) -$(TARGET_CPU) $(CDEBUG)
+
+# -M  generate map file
+LDFLAGS=-M -L$(ZLIB_DIR) $(LDEBUG)
+
+
+## Variables
+OBJS = \
+	png.obj \
+	pngerror.obj \
+	pngget.obj \
+	pngmem.obj \
+	pngpread.obj \
+	pngread.obj \
+	pngrio.obj \
+	pngrtran.obj \
+	pngrutil.obj \
+	pngset.obj \
+	pngtrans.obj \
+	pngwio.obj \
+	pngwrite.obj \
+	pngwtran.obj \
+	pngwutil.obj
+
+LIBOBJS = \
+	+png.obj \
+	+pngerror.obj \
+	+pngget.obj \
+	+pngmem.obj \
+	+pngpread.obj \
+	+pngread.obj \
+	+pngrio.obj \
+	+pngrtran.obj \
+	+pngrutil.obj \
+	+pngset.obj \
+	+pngtrans.obj \
+	+pngwio.obj \
+	+pngwrite.obj \
+	+pngwtran.obj \
+	+pngwutil.obj
+
+LIBNAME=libpng.lib
+
+
+## Implicit rules
+# Braces let make "batch" calls to the compiler,
+# 2 calls instead of 12; space is important.
+.c.obj:
+	$(CC) $(CFLAGS) -c {$*.c }
+
+.c.exe:
+	$(CC) $(CFLAGS) $(LDFLAGS) $*.c $(LIBNAME) zlib.lib $(NOEHLIB)
+
+.obj.exe:
+	$(LD) $(LDFLAGS) $*.obj $(LIBNAME) zlib.lib $(NOEHLIB)
+
+
+## Major targets
+all: libpng pngtest
+
+libpng: $(LIBNAME)
+
+pngtest: pngtest.exe
+
+test: pngtest.exe
+	pngtest
+
+
+## Minor Targets
+
+png.obj: png.c
+pngerror.obj: pngerror.c
+pngget.obj: pngget.c
+pngmem.obj: pngmem.c
+pngpread.obj: pngpread.c
+pngread.obj: pngread.c
+pngrio.obj: pngrio.c
+pngrtran.obj: pngrtran.c
+pngrutil.obj: pngrutil.c
+pngset.obj: pngset.c
+pngtrans.obj: pngtrans.c
+pngwio.obj: pngwio.c
+pngwrite.obj: pngwrite.c
+pngwtran.obj: pngwtran.c
+pngwutil.obj: pngwutil.c
+
+
+$(LIBNAME): $(OBJS)
+	-del $(LIBNAME)
+	$(LIB) $(LIBNAME) @&&|
+$(LIBOBJS), libpng
+|
+
+
+# Clean up anything else you want
+clean:
+	-del *.obj
+	-del *.exe
+	-del *.lib
+	-del *.lst
+	-del *.map
+	-del *.tds
+
+
+# End of makefile for libpng

scripts/makefile.bd32

@@ -1,5 +1,5 @@
 # Makefile for png32bd.dll
-# ------------- Borland C++ 4.5 -------------
+# ------------- 32-bit Borland C++ -------------
 
 # This makefile expects to find zlib.h and zlib32bd.lib in the
 # $(ZLIBDIR) directory.
@@ -12,42 +12,65 @@
 # compress and uncompress functions, nor any of the gz... functions,
 # since libpng does not call them.
 
-ZLIBDIR=..\zlib112
+.AUTODEPEND
+
+ZLIBDIR=..\zlib
 ZLIB=zlib32bd.lib
 PNGDLL=png32bd.dll
+PNGLIB=png32bd.lib
 
-CFLAGS= -ps -O2 -C -K -N- -k- -d -3 -r- -w-par -w-aus -WDE -I$(ZLIBDIR)
-CC=f:\bc45\bin\bcc32
-LINKFLAGS= -Tpd -aa -c
-LINK=f:\bc45\bin\tlink32
-LIBDIR=f:\bc45\lib
-IMPLIB=f:\bc45\bin\implib
+CC=bcc32
+CFLAGS= -ps -O2 -N- -k- -d -r- -w-par -w-aus -I$(ZLIBDIR) \
+  -DPNG_NO_GLOBAL_ARRAYS #-DPNG_DEBUG=5
+#LINK=tlink32
+#LINK=ilink32
+LINK=bcc32
+#LINKFLAGS= -Tpd -aa -c
+LINKFLAGS= -WDE
+IMPLIB=implib
+
+# Use this if you don't want Borland's fancy exception handling
+NOEHLIB=noeh32.lib
 
-.autodepend
 .c.obj:
-        $(CC) -c $(CFLAGS) $<
- 
-OBJ1=png.obj pngerror.obj pngget.obj pngmem.obj pngpread.obj 
-OBJ2=pngread.obj pngrio.obj pngrtran.obj pngrutil.obj pngset.obj 
+	$(CC) -c $(CFLAGS) $<
+
+.c.exe:
+	$(CC) $(CFLAGS) $< $(PNGLIB) $(NOEHLIB)
+
+
+OBJ1=png.obj pngerror.obj pngget.obj pngmem.obj pngpread.obj
+OBJ2=pngread.obj pngrio.obj pngrtran.obj pngrutil.obj pngset.obj
 OBJ3=pngtrans.obj pngwio.obj pngwrite.obj pngwtran.obj pngwutil.obj
 
 all: $(PNGDLL)
 
+test: pngtest.exe
+	pngtest
+
+
 $(PNGDLL): $(OBJ1) $(OBJ2) $(OBJ3) $(ZLIBDIR)\$(ZLIB)
-        $(LINK) @&&|
-$(LINKFLAGS) $(LIBDIR)\c0d32 +
-$(OBJ1) +
-$(OBJ2) +
+	$(LINK) @&&|
+$(LINKFLAGS)
+-e$(PNGDLL)
+$(OBJ1)
+$(OBJ2)
 $(OBJ3)
-$@
--x
-$(ZLIBDIR)\$(ZLIB) $(LIBDIR)\import32 $(LIBDIR)\cw32
-|,&&|
-LIBRARY $(@B)
-EXETYPE WINDOWS
-CODE PRELOAD MOVEABLE DISCARDABLE
-DATA PRELOAD MOVEABLE MULTIPLE
+$(ZLIBDIR)\$(ZLIB)
+$(NOEHLIB)
 |
-        $(IMPLIB) -c $(@R).lib $@
+	$(IMPLIB) -c $(@R).lib $@
+
+
+# Clean up anything else you want
+clean:
+	-del *.obj
+	-del *.dll
+	-del *.exe
+	-del *.lib
+	-del *.lst
+	-del *.map
+	-del *.tds
+
 
 # End of makefile for png32bd.dll

scripts/makefile.beos

@@ -31,7 +31,7 @@ RANLIB=ranlib
 # read libpng.txt or png.h to see why PNGMAJ is 2.  You should not
 # have to change it.
 PNGMAJ = 2
-PNGMIN = 1.0.4c
+PNGMIN = 1.0.6d
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
 # where make install puts libpng.a, libpng.so*, and png.h

scripts/makefile.bor

@@ -1,39 +1,38 @@
 # Makefile for libpng
-# Borland C++ 4.5 (Note: All modules are compiled in C mode)
-# Will work with C++ 4.02 also
-# To build the library, do: 
-#       "make -fmakefile.borland -DMODEL=m"
-# or:   "make -fmakefile.borland -DMODEL=l"
+# 16-bit Borland C++ (Note: All modules are compiled in C mode)
+# To build the library, do:
+#       "make -fmakefile.bor -DMODEL=c"
+# or:   "make -fmakefile.bor -DMODEL=l"
 #
-# ------------- Borland C++ 4.5 -------------
+# ------------ Borland C++ ------------
 
 ### Absolutely necessary for this makefile to work
 .AUTODEPEND
 
-## Useful user options
+## Where zlib.h, zconf.h and zlib_MODEL.lib are
+ZLIB_DIR=..\zlib
 
-# Usually defined in builtins.mak or the environment
-# Currently unused.
-!ifndef BCROOT
-BCROOT=N:\BC45
-!endif
 
-# Where zlib.h and zconf.h and zlib.lib are
-ZLIB_PATH=..\zlib
+## Compiler, linker and lib stuff
+CC=bcc
+LD=bcc
+LIB=tlib
 
 !ifndef MODEL
 MODEL=l
 !endif
 
+MODEL_ARG=-m$(MODEL)
+
 #TARGET_CPU=3
 # 2 = 286, 3 = 386, etc.
 !ifndef TARGET_CPU
 TARGET_CPU=2
 !endif
 
-
-# Use this if you don't want Borland's fancy exception handling.
-NOEHLIB=noeh$(MODEL).lib
+# Use this if you don't want Borland's fancy exception handling
+# (for Borland C++ 4.0 or later)
+#NOEHLIB=noeh$(MODEL).lib
 
 !ifdef DEBUG
 CDEBUG=-v
@@ -49,59 +48,50 @@ CDEBUG=$(CDEBUG) -N
 LDEBUG=$(LDEBUG) -N
 !endif
 
-
-## Compiler, linker, and lib stuff
-CC=bcc
-LD=bcc
-LIB=tlib
-
-MODELARG=-m$(MODEL)
-
-# -X- turns on dependency generation in the object file
-# -w  sets all warnings on
+# -X- turn on dependency generation in the object file
+# -w  set all warnings on
 # -O2 optimize for speed
 # -Z  global optimization
-CFLAGS=-O2 -Z -X- -w -I$(ZLIB_PATH) -$(TARGET_CPU) $(MODELARG) $(CDEBUG)
+CFLAGS=-O2 -Z -X- -w -I$(ZLIB_DIR) -$(TARGET_CPU) $(MODEL_ARG) $(CDEBUG)
 
 # -M  generate map file
-LDFLAGS=-M $(LDEBUG)
+LDFLAGS=-M -L$(ZLIB_DIR) $(MODEL_ARG) $(LDEBUG)
 
-O=obj
 
-## variables
+## 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.obj \
+	pngerror.obj \
+	pngget.obj \
+	pngmem.obj \
+	pngpread.obj \
+	pngread.obj \
+	pngrio.obj \
+	pngrtran.obj \
+	pngrutil.obj \
+	pngset.obj \
+	pngtrans.obj \
+	pngwio.obj \
+	pngwrite.obj \
+	pngwtran.obj \
+	pngwutil.obj
 
 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.obj \
+	+pngerror.obj \
+	+pngget.obj \
+	+pngmem.obj \
+	+pngpread.obj \
+	+pngread.obj \
+	+pngrio.obj \
+	+pngrtran.obj \
+	+pngrutil.obj \
+	+pngset.obj \
+	+pngtrans.obj \
+	+pngwio.obj \
+	+pngwrite.obj \
+	+pngwtran.obj \
+	+pngwutil.obj
 
 LIBNAME=libpng$(MODEL).lib
 
@@ -113,10 +103,12 @@ LIBNAME=libpng$(MODEL).lib
 	$(CC) $(CFLAGS) -c {$*.c }
 
 .c.exe:
-	$(CC) $(CFLAGS) $(LDFLAGS) $*.c
+	$(CC) $(CFLAGS) $(LDFLAGS) $*.c $(LIBNAME) zlib_$(MODEL).lib $(NOEHLIB)
 
 
 ## Major targets
+all: libpng pngtest
+
 libpng: $(LIBNAME)
 
 pngtest: pngtest$(MODEL).exe
@@ -128,17 +120,17 @@ test: pngtest$(MODEL).exe
 ## Minor Targets
 
 png.obj: png.c
-pngset.obj: pngset.c
+pngerror.obj: pngerror.c
 pngget.obj: pngget.c
-pngread.obj: pngread.c
+pngmem.obj: pngmem.c
 pngpread.obj: pngpread.c
+pngread.obj: pngread.c
+pngrio.obj: pngrio.c
 pngrtran.obj: pngrtran.c
 pngrutil.obj: pngrutil.c
-pngerror.obj: pngerror.c
-pngmem.obj: pngmem.c
-pngrio.obj: pngrio.c
-pngwio.obj: pngwio.c
+pngset.obj: pngset.c
 pngtrans.obj: pngtrans.c
+pngwio.obj: pngwio.c
 pngwrite.obj: pngwrite.c
 pngwtran.obj: pngwtran.c
 pngwutil.obj: pngwutil.c
@@ -155,14 +147,16 @@ pngtest$(MODEL).obj: pngtest.c
 	$(CC) $(CFLAGS) -opngtest$(MODEL) -c pngtest.c
 
 pngtest$(MODEL).exe: pngtest$(MODEL).obj
-	$(CC) $(MODELARG) $(LDFLAGS) -L$(ZLIB_PATH) pngtest$(MODEL).obj $(LIBNAME) zlib$(MODEL).lib $(NOEHLIB)
+	$(LD) $(LDFLAGS) pngtest$(MODEL).obj $(LIBNAME) zlib_$(MODEL).lib $(NOEHLIB)
 
 
 # Clean up anything else you want
 clean:
 	-del *.obj
+	-del *.exe
 	-del *.lib
 	-del *.lst
+	-del *.map
 
 
 # End of makefile for libpng

scripts/makefile.dec

@@ -14,7 +14,7 @@ ZLIBINC=../zlib
 # read libpng.txt or png.h to see why PNGMAJ is 2.  You should not
 # have to change it.
 PNGMAJ = 2
-PNGMIN = 1.0.4c
+PNGMIN = 1.0.6d
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
 CC=cc

scripts/makefile.gcc

@@ -0,0 +1,66 @@
+# makefile for libpng using gcc (generic, static library)
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
+# Copyright (C) 2000 Cosmin Truta
+# For conditions of distribution and use, see copyright notice in png.h
+
+# Location of the zlib library and include files
+ZLIBINC = ../zlib
+ZLIBLIB = ../zlib
+
+# Compiler, linker, lib and other tools
+CC = gcc
+LD = $(CC)
+AR = ar rcs
+RANLIB = ranlib
+RM = rm -f
+
+CDEBUG = -g -DPNG_DEBUG=5
+LDDEBUG =
+CRELEASE = -O2
+LDRELEASE = -s
+CFLAGS = -I$(ZLIBINC) -Wall $(CRELEASE)
+LDFLAGS = -L. -L$(ZLIBLIB) -lpng -lz -lm $(LDRELEASE)
+
+# File extensions
+O=.o
+A=.a
+E=
+
+# Variables
+OBJS = png$(O) pngerror$(O) pngget$(O) pngmem$(O) pngpread$(O) \
+	pngread$(O) pngrio$(O) pngrtran$(O) pngrutil$(O) pngset$(O) \
+	pngtrans$(O) pngwio$(O) pngwrite$(O) pngwtran$(O) pngwutil$(O)
+
+# Targets
+all: libpng$(A) pngtest$(E)
+
+libpng$(A): $(OBJS)
+	$(AR) $@ $(OBJS)
+	$(RANLIB) $@
+
+test: pngtest$(E)
+	./pngtest$(E)
+
+pngtest$(E): pngtest$(O) libpng$(A)
+	$(LD) -o $@ pngtest$(O) $(LDFLAGS)
+
+clean:
+	$(RM) *$(O) libpng$(A) pngtest$(E) pngout.png
+
+png$(O): png.h pngconf.h
+pngerror$(O): png.h pngconf.h
+pngget$(O): png.h pngconf.h
+pngmem$(O): png.h pngconf.h
+pngpread$(O): png.h pngconf.h
+pngread$(O): png.h pngconf.h
+pngrio$(O): png.h pngconf.h
+pngrtran$(O): png.h pngconf.h
+pngrutil$(O): png.h pngconf.h
+pngset$(O): png.h pngconf.h
+pngtest$(O): png.h pngconf.h
+pngtrans$(O): png.h pngconf.h
+pngwio$(O): png.h pngconf.h
+pngwrite$(O): png.h pngconf.h
+pngwtran$(O): png.h pngconf.h
+pngwutil$(O): png.h pngconf.h
+

scripts/makefile.gcmmx

@@ -0,0 +1,126 @@
+# makefile for libpng on Linux ELF with gcc using MMX assembler code
+# Copyright (C) 1996, 1997 Andreas Dilger
+# Copyright (C) 1998-2000 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
+ZLIBLIB=../zlib
+ZLIBINC=../zlib
+
+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
+
+# for pgcc version 2.95.1, -O3 is buggy; don't use it.
+
+CFLAGS=-DPNG_USE_PNGGCCRD -I$(ZLIBINC) -Wall -O3 $(ALIGN) -funroll-loops \
+        -fomit-frame-pointer  # $(WARNMORE) -g -DPNG_DEBUG=5
+LDFLAGS=-L. -Wl,-rpath,. -L$(ZLIBLIB) -Wl,-rpath,$(ZLIBLIB) -lpng -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 = 1.0.6d
+PNGVER = $(PNGMAJ).$(PNGMIN)
+
+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 pnggccrd.o
+
+OBJSDLL = $(OBJS:.o=.pic.o)
+
+.SUFFIXES:      .c .o .pic.o
+
+.c.pic.o:
+	$(CC) -c $(CFLAGS) -fPIC -o $@ $*.c
+
+all: libpng.a libpng.so pngtest
+
+pnggccrd.o:	png.h pngconf.h pngasmrd.h
+	@echo ""
+	@echo '    You can ignore the single "control reaches end of non-void function"'
+	@echo '    warning and multiple "<variable> defined but not used" warnings:'
+	@echo ""
+	$(CC) -c $(CFLAGS) -o $@ $*.c
+
+pnggccrd.pic.o:	png.h pngconf.h pngasmrd.h
+	@echo ""
+	@echo '    You can ignore the single "control reaches end of non-void function"'
+	@echo '    warning and multiple "<variable> defined but not used" warnings:'
+	@echo ""
+	$(CC) -c $(CFLAGS) -fPIC -o $@ pnggccrd.c
+
+libpng.a: $(OBJS)
+	ar rc $@ $(OBJS)
+	$(RANLIB) $@
+
+libpng.so: libpng.so.$(PNGMAJ)
+	ln -sf libpng.so.$(PNGMAJ) libpng.so
+
+libpng.so.$(PNGMAJ): libpng.so.$(PNGVER)
+	ln -sf libpng.so.$(PNGVER) libpng.so.$(PNGMAJ)
+
+libpng.so.$(PNGVER): $(OBJSDLL)
+	$(CC) -shared -Wl,-soname,libpng.so.$(PNGMAJ) -o libpng.so.$(PNGVER) \
+	 $(OBJSDLL) -L$(ZLIBLIB) -lz -lm -lc
+
+pngtest: pngtest.o libpng.so
+	$(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
+
+test: pngtest
+	./pngtest
+
+install: libpng.a libpng.so.$(PNGVER)
+	-@if [ ! -d $(INCPATH)  ]; then mkdir $(INCPATH); fi
+	-@if [ ! -d $(LIBPATH) ]; then mkdir $(LIBPATH); fi
+	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
+
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+writelock:
+	chmod a-w *.[ch35] $(DOCS) scripts/*
+
+# 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.hpux

@@ -47,6 +47,10 @@ install: libpng.a
 clean:
 	rm -f *.o libpng.a pngtest pngout.png
 
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+writelock:
+	chmod a-w *.[ch35] $(DOCS) scripts/*
+
 # DO NOT DELETE THIS LINE -- make depend depends on it.
 
 png.o: png.h pngconf.h

scripts/makefile.ibmc

@@ -0,0 +1,71 @@
+# Makefile for libpng (static)
+# IBM C version 3.x for Win32 and OS/2
+# Copyright (C) 2000 Cosmin Truta
+# Notes:
+#   Derived from makefile.std
+#   All modules are compiled in C mode
+#   Tested with IBM C 3.6.5 under Win32, expected to work under OS/2 too
+#   Can be easily adapted for IBM VisualAge/C++ for AIX
+# For conditions of distribution and use, see copyright notice in png.h
+
+# Location of the zlib library and include files
+ZLIBINC = ../zlib
+ZLIBLIB = ../zlib
+
+# Compiler, linker, lib and other tools
+CC = icc
+LD = ilink
+AR = ilib
+RM = del
+
+CFLAGS = -I$(ZLIBINC) -O2 -W3
+LDFLAGS =
+
+# File extensions
+O=.obj
+A=.lib
+E=.exe
+
+# Variables
+OBJS = png$(O) pngerror$(O) pngget$(O) pngmem$(O) pngpread$(O) \
+	pngread$(O) pngrio$(O) pngrtran$(O) pngrutil$(O) pngset$(O) \
+	pngtrans$(O) pngwio$(O) pngwrite$(O) pngwtran$(O) pngwutil$(O)
+
+LIBS = libpng$(A) $(ZLIBLIB)/zlib$(A)
+
+# Targets
+all: libpng$(A) pngtest$(E)
+
+libpng$(A): $(OBJS)
+	$(AR) -out:$@ $(OBJS)
+
+test: pngtest$(E)
+	pngtest$(E)
+
+pngtest: pngtest$(E)
+
+pngtest$(E): pngtest$(O) libpng$(A)
+	$(LD) $(LDFLAGS) pngtest$(O) $(LIBS)
+
+clean:
+	$(RM) *$(O)
+	$(RM) libpng$(A)
+	$(RM) pngtest$(E)
+	$(RM) pngout.png
+
+png$(O): png.h pngconf.h
+pngerror$(O): png.h pngconf.h
+pngget$(O): png.h pngconf.h
+pngmem$(O): png.h pngconf.h
+pngpread$(O): png.h pngconf.h
+pngread$(O): png.h pngconf.h
+pngrio$(O): png.h pngconf.h
+pngrtran$(O): png.h pngconf.h
+pngrutil$(O): png.h pngconf.h
+pngset$(O): png.h pngconf.h
+pngtest$(O): png.h pngconf.h
+pngtrans$(O): png.h pngconf.h
+pngwio$(O): png.h pngconf.h
+pngwrite$(O): png.h pngconf.h
+pngwtran$(O): png.h pngconf.h
+pngwutil$(O): png.h pngconf.h

scripts/makefile.knr

@@ -2,7 +2,7 @@
 # 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
+# This makefile requires the 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.
@@ -58,6 +58,10 @@ install: libpng.a
 clean:
 	rm -f *.o libpng.a pngtest pngout.png ansi2knr
 
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+writelock:
+	chmod a-w *.[ch35] $(DOCS) scripts/*
+
 # DO NOT DELETE THIS LINE -- make depend depends on it.
 
 png.o: png.h pngconf.h

scripts/makefile.linux

@@ -22,7 +22,7 @@ WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
 	-Wmissing-declarations -Wtraditional -Wcast-align \
 	-Wstrict-prototypes -Wmissing-prototypes #-Wconversion
 
-# for pgcc version 2.95.1, -O3 is buggy; don't us it.
+# for pgcc version 2.95.1, -O3 is buggy; don't use it.
 
 CFLAGS=-I$(ZLIBINC) -Wall -O3 -funroll-loops \
 	$(ALIGN) # $(WARNMORE) -g -DPNG_DEBUG=5
@@ -34,7 +34,7 @@ RANLIB=ranlib
 # read libpng.txt or png.h to see why PNGMAJ is 2.  You should not
 # have to change it.
 PNGMAJ = 2
-PNGMIN = 1.0.4c
+PNGMIN = 1.0.6d
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
 INCPATH=$(prefix)/include
@@ -74,7 +74,8 @@ test: pngtest
 	./pngtest
 
 install: libpng.a libpng.so.$(PNGVER)
-	-@mkdir $(INCPATH) $(LIBPATH)
+	-@if [ ! -d $(INCPATH)  ]; then mkdir $(INCPATH); fi
+	-@if [ ! -d $(LIBPATH) ]; then mkdir $(LIBPATH); fi
 	cp png.h pngconf.h $(INCPATH)
 	chmod 644 $(INCPATH)/png.h $(INCPATH)/pngconf.h
 	cp libpng.a libpng.so.$(PNGVER) $(LIBPATH)
@@ -86,6 +87,10 @@ install: libpng.a libpng.so.$(PNGVER)
 clean:
 	/bin/rm -f *.o libpng.a libpng.so* pngtest pngout.png
 
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+writelock:
+	chmod a-w *.[ch35] $(DOCS) scripts/*
+
 # DO NOT DELETE THIS LINE -- make depend depends on it.
 
 png.o png.pic.o: png.h pngconf.h

scripts/makefile.mips

@@ -42,6 +42,10 @@ install: libpng.a
 clean:
 	rm -f *.o libpng.a pngtest pngout.png
 
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+writelock:
+	chmod a-w *.[ch35] $(DOCS) scripts/*
+
 # DO NOT DELETE THIS LINE -- make depend depends on it.
 
 png.o: png.h pngconf.h

scripts/makefile.msc

@@ -4,8 +4,8 @@
 # Assumes that zlib.lib, zconf.h, and zlib.h have been copied to ..\zlib
 
 # -------- Microsoft C 5.1 and later, does not use assembler code -----
-MODEL=-AL
-CFLAGS=-Oait -Gs -nologo -W3 $(MODEL) -I..\zlib
+MODEL=L
+CFLAGS=-Oait -Gs -nologo -W3 -A$(MODEL) -I..\zlib
 #-Ox generates bad code with MSC 5.1
 CC=cl
 LD=link

scripts/makefile.sco

@@ -25,7 +25,7 @@ RANLIB=echo
 # read libpng.txt or png.h to see why PNGMAJ is 2.  You should not
 # have to change it.
 PNGMAJ = 2
-PNGMIN = 1.0.4c
+PNGMIN = 1.0.6d
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
 INCPATH=$(prefix)/include
@@ -77,6 +77,10 @@ install: libpng.a libpng.so.$(PNGVER)
 clean:
 	/bin/rm -f *.o libpng.a libpng.so* pngtest pngout.png
 
+DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
+writelock:
+	chmod a-w *.[ch35] $(DOCS) scripts/*
+
 # DO NOT DELETE THIS LINE -- make depend depends on it.
 
 png.o png.pic.o: png.h pngconf.h

scripts/makefile.sggcc

@@ -0,0 +1,90 @@
+# makefile for libpng, SGI IRIX with gcc
+# 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/lib32
+ZLIBINC=/usr/local/include
+#ZLIBLIB=../zlib
+#ZLIBINC=../zlib
+
+CC=gcc
+
+WARNMORE=
+CFLAGS=-I$(ZLIBINC) -O2 $(WARNMORE) -fPIC -mabi=n32 # -g -DPNG_DEBUG=5
+# zlib must also be compiled with n32
+LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm
+LDSHARED=gcc -shared
+
+VER=1.0.6d
+LIBS=libpng.so.1.0.6d
+SHAREDLIB=libpng.so
+libdir=$(prefix)/lib32
+
+RANLIB=echo
+#RANLIB=ranlib
+
+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 $(SHAREDLIB).$(VER) pngtest
+
+libpng.a: $(OBJS)
+	ar rc $@  $(OBJS)
+	$(RANLIB) $@
+
+$(SHAREDLIB).$(VER): $(OBJS)
+	$(LDSHARED) -o $@ $(OBJS)
+	rm -f $(SHAREDLIB) $(SHAREDLIB).1
+	ln -s $@ $(SHAREDLIB)
+	ln -s $@ $(SHAREDLIB).1
+
+pngtest: pngtest.o libpng.a
+	$(CC) -o pngtest $(CFLAGS) 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
+	cp $(SHAREDLIB).$(VER) $(libdir); chmod 755 $(SHAREDLIB).$(VER)
+	cd $(libdir); if test -f $(SHAREDLIB).$(VER); then \
+	rm -f $(SHAREDLIB) $(SHAREDLIB).1; \
+	ln -s $(SHAREDLIB).$(VER) $(SHAREDLIB); \
+	ln -s $(SHAREDLIB).$(VER) $(SHAREDLIB).1; \
+	(ldconfig || true)  >/dev/null 2>&1; \
+	fi
+
+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
+