Imported from libpng-1.0.3.tar

ANNOUNCE

@@ -1,62 +1,53 @@
 
-Libpng 1.0.1d May 21, 1998
+Libpng 1.0.3 - January 14, 1999
 
-This is not intended to be a public release.  It will be replaced
-within a few weeks by a public version or by another test version.
+This is a public release of libpng, intended for use in production codes.
 
-Changes since the last public release:
+Changes since the previous public release (1.0.2):
 
-version 1.0.1a [April 21, 1998]
-  Optimized Paeth calculations by replacing abs() function calls with intrinsics
-  plus other loop optimizations. Improves avg decoding speed by about 20%.
-  Commented out i386istic "align" compiler flags in makefile.lnx.
-  Reduced the default warning level in some makefiles, to make them consistent.
-  Removed references to IJG and JPEG in the ansi2knr.c copyright statement.
-  Fixed a bug in png_do_strip_filler with XXRRGGBB => RRGGBB transformation.
-  Added grayscale and 16-bit capability to png_do_read_filler().
-  Fixed a bug in pngset.c, introduced in version 0.99c, that sets rowbytes
-    too large when writing an image with bit_depth < 8 (Bob Dellaca).
-  Corrected some bugs in the experimental weighted filtering heuristics.
-  Moved a misplaced pngrutil code block that truncates tRNS if it has more
-    than num_palette entries -- test was done before num_palette was defined.
-  Fixed a png_convert_to_rfc1123() bug that converts day 31 to 0 (Steve Eddins).
-  Changed compiler flags in makefile.wat for better optimization (Pawel Mrochen).
-version 1.0.1b [May 2, 1998]
-  Relocated png_do_gray_to_rgb() within png_do_read_transformations() (Greg).
-  Relocated the png_composite macros from pngrtran.c to png.h (Greg).
-  Added makefile.sco (contributed by Mike Hopkirk).
-  Fixed two bugs (missing definitions of "istop") introduced in libpng-1.0.1a.
-  Fixed a bug in pngrtran.c that would set channels=5 under some circumstances.
-  More work on the Paeth-filtering, achieving imperceptible speedup (A Kleinert).
-  More work on loop optimization which may help when compiled with C++ compilers.
-  Added warnings when people try to use transforms they've defined out.
-  Collapsed 4 "i" and "c" loops into single "i" loops in pngrtran and pngwtran.
-  Revised paragraph about png_set_expand() in libpng.txt and libpng.3 (Greg)
-version 1.0.1c [May 11, 1998]
-  Fixed a bug in pngrtran.c (introduced in libpng-1.0.1a) where the masks for
-    filler bytes should have been 0xff instead of 0xf.
-  Added max_pixel_depth=32 in pngrutil.c when using FILLER with palette images.
-  Moved PNG_WRIGHT_WEIGHTED_FILTER_SUPPORTED and PNG_WRITE_FLUSH_SUPPORTED
-    out of the PNG_WRITE_TRANSFORMS_NOT_SUPPORTED block of pngconf.h
-  Added "PNG_NO_WRITE_TRANSFORMS" etc., as alternatives for *_NOT_SUPPORTED,
-    for consistency, in pngconf.h
-  Added individual "ifndef PNG_NO_CAPABILITY" for the capabilities in pngconf.h
-    to make it easier to remove unwanted capabilities via the compile line
-  Made some corrections to grammar (which, it's) in documentation (Greg).
-  Corrected example.c, use of row_pointers in png_write_image().
-version 1.0.1d [May 21, 1998]
-  Corrected several statements that some compilers interpret as illegal use
-    of side effects in pngrutil.c and pngtrans.c, that were introduced in
-    version 1.0.1b
-  Revised png_read_rows() to avoid repeated if-testing for NULL (A Kleinert)
-  More corrections to example.c, use of row_pointers in png_write_image()
-    and png_read_rows().
-  Added pngdll.mak and pngdef.pas to scripts directory, contributed by
-    Bob Dellaca, to make a png32bd.dll with Borland C++ 4.5
-  Fixed error in example.c with png_set_text: num_text is 3, not 2 (Guido V.)
-  Changed several loops from count-down to count-up, for consistency.
+libpng-1.0.3:
+
+  Replaced and extended code that was removed from png_set_filler() in 1.0.1a.
+  Fixed a bug in png_do_filler() that made it fail to write filler bytes in
+    the left-most pixel of each row (Kevin Bracey).
+  Changed "static pngcharp tIME_string" to "static char tIME_string[30]"
+    in pngtest.c (Duncan Simpson).
+  Fixed a bug in pngtest.c that caused pngtest to try to write a tIME chunk
+    even when no tIME chunk was present in the source file.
+  Fixed a problem in pngrutil.c: gray_to_rgb didn't always work with 16-bit.
+  Fixed a problem in png_read_push_finish_row(), which would not skip some
+    passes that it should skip, for images that are less than 3 pixels high.
+  Interchanged the order of calls to png_do_swap() and png_do_shift()
+    in pngwtran.c (John Cromer).
+  Added #ifdef PNG_DEBUG/#endif surrounding use of PNG_DEBUG in png.h .
+  Changed "bad adaptive filter type" from error to warning in pngrutil.c .
+  Fixed a documentation error about default filtering with 8-bit indexed-color.
+  Separated the PNG_NO_STDIO macro into PNG_NO_STDIO and PNG_NO_CONSOLE_IO
+    (L. Peter Deutsch).
+  Added png_set_rgb_to_gray() and png_get_rgb_to_gray_status() functions.
+  Added png_get_copyright() and png_get_header_version() functions.
+  Revised comments on png_set_progressive_read_fn() in libpng.txt and example.c
+  Added information about debugging in libpng.txt and libpng.3 .
+  Changed "ln -sf" to "ln -s -f" in makefile.s2x, makefile.lnx, and makefile.sco.
+  Removed lines after Dynamic Dependencies" in makefile.aco .
+  Revised makefile.dec to make a shared library (Jeremie Petit).
+  Removed trailing blanks from all files. 
+  Removed misplaced #endif and #ifdef PNG_NO_EXTERN near the end of png.h
+  Added "if" tests to silence complaints about unused png_ptr in png.h and png.c
+  Changed "check_if_png" function in example.c to return true (nonzero) if PNG.
+  Changed libpng.txt to demonstrate png_sig_cmp() instead of png_check_sig()
+    which is obsolete.
+  Added makefile.hux, for Hewlett Packard HPUX 10.20 and 11.00 (Jim Rice)
+  Added a statement of Y2K compliance in png.h, libpng.1, and Y2KINFO.
 
 Send comments/corrections/commendations to
 png-implement@dworkin.wustl.edu or to randeg@alumni.rpi.edu
 
 Glenn R-P
+
+Send comments/corrections/commendations to
+png-implement@dworkin.wustl.edu or to randeg@alumni.rpi.edu
+
+Glenn Randers-Pehrson
+libpng maintainer
+PNG Development Group

CHANGES

@@ -89,7 +89,7 @@ version 0.89 [July, 1996]
      so that people are aware that they need to change their code
   changed filter selection API to allow selection of multiple filters
      since it didn't work in previous versions of libpng anyways
-  optimized filter selection code    
+  optimized filter selection code
   fixed png_set_background() to allow using an arbitrary RGB color for
      paletted images
   fixed gamma and background correction for paletted images, so
@@ -256,7 +256,7 @@ version 0.99g [March 6, 1998, morning]
   Minor changes to pngtest.c to suppress compiler warnings.
   Removed "beta" language from documentation.
 version 0.99h [March 6, 1998, evening]
-  Minor changes to previous minor changes to pngtest.c 
+  Minor changes to previous minor changes to pngtest.c
   Changed PNG_READ_NOT_FULLY_SUPPORTED to PNG_READ_TRANSFORMS_NOT_SUPPORTED
   and added PNG_PROGRESSIVE_READ_NOT_SUPPORTED macro
 version 1.00 [March 7, 1998]
@@ -316,7 +316,7 @@ version 1.0.1c [May 11, 1998]
   Fixed a bug in pngrtran.c (introduced in libpng-1.0.1a) where the masks for
     filler bytes should have been 0xff instead of 0xf.
   Added max_pixel_depth=32 in pngrutil.c when using FILLER with palette images.
-  Moved PNG_WRIGHT_WEIGHTED_FILTER_SUPPORTED and PNG_WRITE_FLUSH_SUPPORTED
+  Moved PNG_WRITE_WEIGHTED_FILTER_SUPPORTED and PNG_WRITE_FLUSH_SUPPORTED
     out of the PNG_WRITE_TRANSFORMS_NOT_SUPPORTED block of pngconf.h
   Added "PNG_NO_WRITE_TRANSFORMS" etc., as alternatives for *_NOT_SUPPORTED,
     for consistency, in pngconf.h
@@ -324,10 +324,9 @@ version 1.0.1c [May 11, 1998]
     to remove unwanted capabilities via the compile line
   Made some corrections to grammar (which, it's) in documentation (Greg).
   Corrected example.c, use of row_pointers in png_write_image().
-version 1.0.1d [May 21, 1998]
-  Corrected several statements that some compilers interpret as illegal use
-    of side effects in pngrutil.c and pngtrans.c, that were introduced in
-    version 1.0.1b
+version 1.0.1d [May 24, 1998]
+  Corrected several statements that used side effects illegally in pngrutil.c
+    and pngtrans.c, that were introduced in version 1.0.1b
   Revised png_read_rows() to avoid repeated if-testing for NULL (A Kleinert)
   More corrections to example.c, use of row_pointers in png_write_image()
     and png_read_rows().
@@ -335,3 +334,56 @@ version 1.0.1d [May 21, 1998]
     Bob Dellaca, to make a png32bd.dll with Borland C++ 4.5
   Fixed error in example.c with png_set_text: num_text is 3, not 2 (Guido V.)
   Changed several loops from count-down to count-up, for consistency.
+version 1.0.1e [June 6, 1998]
+  Revised libpng.txt and libpng.3 description of png_set_read|write_fn(), and
+    added warnings when people try to set png_read_fn and png_write_fn in
+    the same structure.
+  Added a test such that png_do_gamma will be done when num_trans==0
+    for truecolor images that have defined a background.  This corrects an
+    error that was introduced in libpng-0.90 that can cause gamma processing
+    to be skipped.
+  Added tests in png.h to include "trans" and "trans_values" in structures
+    when PNG_READ_BACKGROUND_SUPPORTED or PNG_READ_EXPAND_SUPPORTED is defined.
+  Add png_free(png_ptr->time_buffer) in png_destroy_read_struct()
+  Moved png_convert_to_rfc_1123() from pngwrite.c to png.c
+  Added capability for user-provided malloc_fn() and free_fn() functions,
+    and revised pngtest.c to demonstrate their use, replacing the
+    PNGTEST_DEBUG_MEM feature.
+  Added makefile.w32, for Microsoft C++ 4.0 and later (Tim Wegner).
+version 1.0.2 [June 14, 1998]
+  Fixed two bugs in makefile.bor .
+version 1.0.2a [December 30, 1998]
+  Replaced and extended code that was removed from png_set_filler() in 1.0.1a.
+  Fixed a bug in png_do_filler() that made it fail to write filler bytes in
+    the left-most pixel of each row (Kevin Bracey).
+  Changed "static pngcharp tIME_string" to "static char tIME_string[30]"
+    in pngtest.c (Duncan Simpson).
+  Fixed a bug in pngtest.c that caused pngtest to try to write a tIME chunk
+    even when no tIME chunk was present in the source file.
+  Fixed a problem in pngrutil.c: gray_to_rgb didn't always work with 16-bit.
+  Fixed a problem in png_read_push_finish_row(), which would not skip some
+    passes that it should skip, for images that are less than 3 pixels high.
+  Interchanged the order of calls to png_do_swap() and png_do_shift()
+    in pngwtran.c (John Cromer).
+  Added #ifdef PNG_DEBUG/#endif surrounding use of PNG_DEBUG in png.h .
+  Changed "bad adaptive filter type" from error to warning in pngrutil.c .
+  Fixed a documentation error about default filtering with 8-bit indexed-color.
+  Separated the PNG_NO_STDIO macro into PNG_NO_STDIO and PNG_NO_CONSOLE_IO
+    (L. Peter Deutsch).
+  Added png_set_rgb_to_gray() and png_get_rgb_to_gray_status() functions.
+  Added png_get_copyright() and png_get_header_version() functions.
+  Revised comments on png_set_progressive_read_fn() in libpng.txt and example.c
+  Added information about debugging in libpng.txt and libpng.3 .
+  Changed "ln -sf" to "ln -s -f" in makefile.s2x, makefile.lnx, and makefile.sco.
+  Removed lines after Dynamic Dependencies" in makefile.aco .
+  Revised makefile.dec to make a shared library (Jeremie Petit).
+  Removed trailing blanks from all files. 
+version 1.0.2a [January 6, 1999]
+  Removed misplaced #endif and #ifdef PNG_NO_EXTERN near the end of png.h
+  Added "if" tests to silence complaints about unused png_ptr in png.h and png.c
+  Changed "check_if_png" function in example.c to return true (nonzero) if PNG.
+  Changed libpng.txt to demonstrate png_sig_cmp() instead of png_check_sig()
+    which is obsolete.
+version 1.0.3 [January 14, 1999]
+  Added makefile.hux, for Hewlett Packard HPUX 10.20 and 11.00 (Jim Rice)
+  Added a statement of Y2K compliance in png.h, libpng.1, and Y2KINFO.

INSTALL

@@ -1,17 +1,17 @@
 
-Installing libpng version %VER% %DATE%
+Installing libpng version 1.0.3 - January 14, 1999
 
 Before installing libpng, you must first install zlib.  zlib
 can usually be found wherever you got libpng.  zlib can be
 placed in another directory, at the same level as libpng.
 Note that your system might already have a preinstalled
-zlib, but you will still need to have access to the 
+zlib, but you will still need to have access to the
 zlib.h and zconf.h include files that correspond to the
 version of zlib that's installed.
 
 You can rename the directories that you downloaded (they
-might be called "libpng-%VER% or "lpng100" and "zlib-1.1.2"
-or "zlib112") so that you have directories called "zlib" and "libpng".
+might be called "libpng-1.0.3" or "lpng103" and "zlib-1.1.3"
+or "zlib113") so that you have directories called "zlib" and "libpng".
 
 Your directory structure should look like this:
 
@@ -42,6 +42,7 @@ include
       makefile.std  =>  Generic UNIX makefile
       makefile.knr  =>  Archaic UNIX Makefile that converts files with ansi2knr
       makefile.dec  =>  DEC Alpha UNIX makefile
+      makefile.hux  =>  HPUX (10.20 and 11.00) makefile
       makefile.sgi  =>  Silicon Graphics IRIX makefile
       makefile.sun  =>  Sun makefile
       makefile.s2x  =>  Solaris 2.X makefile (gcc, creates libpng.so.2.1.0)
@@ -56,6 +57,7 @@ include
       build.bat     =>  MS-DOS batch file for Borland compiler
       makefile.dj2  =>  DJGPP 2 makefile
       makefile.msc  =>  Microsoft C makefile
+      makefile.w32  =>  makefile for Microsoft Visual C++ 4.0 and later
       makefile.tc3  =>  Turbo C 3.0 makefile
       makefile.os2  =>  OS/2 Makefile (gcc and emx, requires pngos2.def)
       pngos2.def    =>  OS/2 module definition file used by makefile.os2

KNOWNBUG

@@ -1,186 +1,32 @@
 
-Known bugs and suggested enhancements in libpng-1.0.1
+Known bugs and suggested enhancements in libpng-1.0.3
 
-1. March 13, 1998 -- BUG -- pngtrans.c:
 
-   row_info->channels should be updated --
-   row_info->color_type should be updated --
-
-   STATUS: I think this is all fixed in libpng-1.0.1a but needs
-   to be tested.
-
-2. March 14, 1998 -- ENHANCEMENT -- Glenn
-
-   We should add the G>GA, G>GX, G>AG, and G>XG transformations
-   in png_do_read_filler()
-
-   STATUS:  Implemented in libpng-1.0.1a
-
-3. March 14, 1998 -- BUG? -- Greg Roelofs
-
-   pngrtran.c:  if-test for channels/FILLER may be incorrect
-
-   STATUS: Under investigation.  Appears to be working correctly
-   in libpng-1.0.1c.
-
-4. March 15, 1998 -- BUG -- Kevin Bracey
-
-   pngwtran.c:
-      line 306: loop should count to row_info->width, not to
-             row_info->width*row_info->channnels
-
-   STATUS: Fixed in libpng-1.0.1a
-
-5. March 15, 1998 -- OPTIMIZATION -- Kevin Bracey
+1. March 15, 1998 -- OPTIMIZATION -- Kevin Bracey
 
    Loops need to be optimized everywhere
 
-   a. Make them count down instead of up -- Kevin Bracey
-   
-      Optimizing compilers don't need this, and making
-      the change would be error prone -- Tom Lane, Glenn R-P
+   Make them count down instead of up -- Kevin Bracey
 
-      Question whether i-- or --i is better.
+   Optimizing compilers don't need this, and making
+   the change would be error prone -- Tom Lane, Glenn R-P
 
-      STATUS: Under investigation.  About 150 loops turned around
-      in libpng-1.0.1d, for testing.  Object files and executables
-      are about 20k smaller in SGI and gcc-compiled codes.  
+   Question whether i-- or --i is better.
 
-   b. Remove products and structure members from loop tests -- Glenn R-P
+   STATUS: Under investigation, postponed until after
+   libpng-1.0.3.  About 160 loops will be turned around
+   in libpng-1.0.Nn, for testing.
 
-      Can be accomplished without messing with loop guts.  This
-      was shown to be effective on optimized SGI compiler:
+2. July 4, 1998 -- ENHANCEMENT -- Glenn R-P
 
-              replace
-                  png_uint_32 i;
-                  for(i=0; i < s->a*s->b; i++)
-              with
-                  png_uint_32 i, istop;
-                  istop = s->a*s->b;
-                  for(i=0; i<istop; i++)
+   libpng-1.0.2 and earlier transform colors to gamma=1.0 space for
+   merging with background, and then back to the image's gamma.  The
+   bit_depth of the intermediate (gamma=1.0) representation is probably
+   not sufficient.  In the typical gamma=1/2.2 situation, the linear
+   pixels need about 4 more bits than the gamma-encoded ones, to avoid
+   loss of precision.  A similar situation exists with the rgb_to_gray
+   operation.
 
-      STATUS: Mostly done in libpng-1.0.1a, done for all important loops.
-              More done in libpng-1.0.1b.
+   STATUS: under development.
 
-   c. Replace abs() with intrinsic ternary operations in Paeth
-      filtering -- Glenn R-P
 
-      STATUS: Done in libpng-1.0.1a
-      (can be restored to original behavior with #define PNG_USE_ABS)
-
-   d. In pngwutil.c, make separate simple loops to use when filter 
-      heuristic sums aren't needed. -- Glenn R-P
-
-      STATUS: Done in libpng-1.0.1a
-
-6. April 6, 1998 -- BUG -- bug in pngset.c (rowbytes too large) -- Bob Dellaca
-
-   pngset.c has a bug, introduced in version 0.99c, that sets rowbytes
-     too large when writing an image with bit_depth < 8
-
-   STATUS: Fixed in libpng-1.0.1a
-              
-7. April 10, 1998 -- BUG -- pngwutil weighted filtering bugs -- Glenn R-P
-
-   pngwutil.c has some bugs in the experimental weighted filter
-   algorithm (PNG_FILTER_XXX should be PNG_FILTER_VALUE_XXX in
-   several places)
-
-   STATUS: Andreas concurs.  Fixed in libpng-1.0.1a
-
-8. April 10, 1998 -- ENHANCEMENT -- run-time selection of malloc function
-   -- Bob Dellaca
-
-   pngmem.c currently provides a compile-time option to replace
-   png_malloc() and png_free().  It's been requested that these
-   be made possible at run time, via calls to new png_set_malloc_fn()
-   and png_set_free_fn() functions.
-
-   STATUS: Under consideration
-
-9. April 11, 1998 -- BUG -- incorrect truncation of tRNS data in
-   illegal PNG file where tRNS precedes PLTE -- Larry Reeve
-
-   There is a misplaced pngrutil code block that truncates tRNS if it has
-   more than num_palette entries -- test was done before num_palette was
-   defined.  Although the PNG file is illegal, it shouldn't crash apps.
-   There is a simple fix; just moving the test to the point after
-   num_palette has been defined.
-
-   STATUS: Fixed in libpng-1.0.1a
-
-10. April 16, 1998 -- BUG -- incorrect operation of png_convert_to_rfc1123
-   with 31st day of the month -- Steve Eddins
-
-   The "ptime->date % 31" is wrong, should be "ptime->date % 32".
-
-   STATUS: Fixed in libpng-1.0.1a
-
-11. April 21, 1998 -- ENHANCEMENT -- relocation of composite macros
-
-   png_composite() and png_composite_16() relocated to png.h
-
-   STATUS: Done in libpng-1.0.1b
-
-12. April 22, 1998 -- ENHANCEMENT -- makefile.sco
-
-   Mike Hopkirk contributed a makefile for SCO osr5 and sco UW7
-
-   STATUS: Added to libpng-1.0.1b distribution
-
-13: April 30, 1998 -- ENHANCEMENT -- warnings
-
-   When people define out some of the read transformations and then
-   try to use them, the request is silently ignored.  It was suggested
-   that a warning be issued in such cases.
-
-   STATUS: Done in libpng-1.0.1b
-
-14. May 2, 1998 -- BUG -- incorrect mask for filler bytes
-
-   In pngrtran.c, png_do_filler(), the masks for hi_filler and low_filler
-   should be 0xff instead of 0xf
-
-   STATUS: Fixed in libpng-1.0.1c
-
-15. May 3, 1998 -- BUG -- buffer overflow in png_do_read_filler()
-
-   In pngrutil.c, max_pixel_depth needs to be set to 32 when using
-   png_do_read_filler with palette images.
-
-   STATUS: Fixed in libpng-1.0.1c (see also items 1 and 3 above).
-
-16. May 3, 1998 -- BUG -- type definitions wrong on error functions -- Tom Lane
-
-   In png_create_xxx_struct(), the error functions should have typedef
-   png_voidp instead of (void *).  Needs to be corrected in the functions,
-   the prototypes in png.h, the example.c file, and libpng.txt and libpng.3
-
-   
-   STATUS: Fixed in libpng-1.0.1c
-
-17. May 10, 1998 -- DOCUMENTATION -- Greg
-
-   There are a number of incorrect usages of "which" and "it's" in the
-   comments.
-
-   STATUS:
-
-   Fixed in libpng-1.0.1c
-
-18. May 20, 1998 -- BUG -- illegal use of side effects -- Magnus Holmgren
-
-   In libpng-1.0.1b several illegal uses of side effects were
-   introduced while tuning loops in pngrutil.c; also one in pngtrans.c.
-
-   STATUS:
-
-   Fixed in libpng-1.0.1d
-
-19. May 20, 1998 -- ENHANCEMENT --  script for making DLL -- Bob Dellaca
-
-   Bob Dellaca contributed script for making PNG DLL on Borland C++ 4.5
-
-   STATUS:
-
-   Added to distribution in libpng-1.0.1d 

README

@@ -1,4 +1,4 @@
-README for libpng %VER% (shared library 2.1)
+README for libpng 1.0.3 - January 14, 1999 (shared library 2.1)
 See the note about version numbers near the top of png.h
 
 See INSTALL for instructions on how to install libpng.
@@ -159,6 +159,7 @@ Files in this distribution:
         makefile.std  =>  Generic UNIX makefile
         makefile.knr  =>  Archaic UNIX Makefile that converts files with ansi2knr
         makefile.dec  =>  DEC Alpha UNIX makefile
+        makefile.hux  =>  HPUX (10.20 and 11.00) makefile
         makefile.sgi  =>  Silicon Graphics IRIX makefile
         makefile.sun  =>  Sun makefile
         makefile.s2x  =>  Solaris 2.X makefile (gcc, creates libpng.so.2.1.0)
@@ -173,6 +174,7 @@ Files in this distribution:
         build.bat     =>  MS-DOS batch file for Borland compiler
         makefile.dj2  =>  DJGPP 2 makefile
         makefile.msc  =>  Microsoft C makefile
+        makefile.w32  =>  makefile for Microsoft Visual C++ 4.0 and later
         makefile.tc3  =>  Turbo C 3.0 makefile
         makefile.os2  =>  OS/2 Makefile (gcc and emx, requires pngos2.def)
         makefile.wat  =>  Watcom 10a+ Makefile, 32-bit flat memory model

TODO

@@ -1,23 +1,24 @@
-TODO - list of things to do for libpng
+TODO - list of things to do for libpng:
 
-fix problem with C++ and EXTERN "C"
-add capability to set user malloc/free functions at run time
-add "grayscale->palette" transformation and "palette->grayscale" detection
-color to gray transformation
-improved dithering
-multi-lingual error and warning message support
-sPLT chunk handling
-cHRM transformation
-complete sRGB transformation (presently it simply uses gamma=0.45)
-man pages for function calls
-high-level API for reading images
-final bug fixes
-better documentation
-better filter selection
-   (counting huffman bits/precompression?  filter inertia?  filter costs?)
-optional palette creation
-histogram creation
-support for application-defined chunk handlers
-keep up with public chunks
-better C++ wrapper/full C++ implementation?
-text conversion between different code pages (Latin-1 -> Mac and DOS)
+Final bug fixes.
+Fix problem with C++ and EXTERN "C".
+Better C++ wrapper/full C++ implementation?
+Keep up with public chunks.
+sPLT chunk handling.
+cHRM transformation.
+Support for application-defined chunk handlers.
+Improve setjmp/longjmp usage or remove it in favor of returning error codes.
+High-level API for reading images.
+Add "grayscale->palette" transformation and "palette->grayscale" detection.
+Color to gray transformation.
+Improved dithering.
+Multi-lingual error and warning message support.
+Complete sRGB transformation (presently it simply uses gamma=0.45455).
+Man pages for function calls.
+Better documentation.
+Better filter selection
+   (counting huffman bits/precompression?  filter inertia?  filter costs?).
+Optional palette (sPLT) creation.
+Histogram creation.
+Text conversion between different code pages (Latin-1 -> Mac and DOS).
+Improve API by hiding the info_ptr.

Y2KINFO

@@ -0,0 +1,52 @@
+   Y2K compliance in libpng:
+   =========================
+      
+      January 13, 1999
+      
+      Since the PNG Development group is an ad-hoc body, we can't make
+      an official declaration.
+      
+      This is your unofficial assurance that libpng from version 0.81 and
+      upward are Y2K compliant.  It is my belief that earlier versions were
+      also Y2K compliant.
+      
+      Libpng only has three year fields.  One is a 2-byte unsigned integer
+      that will hold years up to 65535.  The other two hold the date in text
+      format, and will hold years up to 9999.
+      
+      The integer is
+          "png_uint_16 year" in png_time_struct.
+      
+      The strings are
+          "png_charp time_buffer" in png_struct and
+          "near_time_buffer", which is a local character string in png.c.
+      
+      There are seven time-related functions:
+
+          png_convert_to_rfc_1123() in png.c 
+            (formerly png_convert_to_rfc_1152() in error)
+          png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
+          png_convert_from_time_t() in pngwrite.c
+          png_get_tIME() in pngget.c
+          png_handle_tIME() in pngrutil.c, called in pngread.c
+          png_set_tIME() in pngset.c
+          png_write_tIME() in pngwutil.c, called in pngwrite.c
+      
+      All appear to handle dates properly in a Y2K environment.  The 
+      png_convert_from_time_t() function calls gmtime() to convert from system
+      clock time, which returns (year - 1900), which we properly convert to
+      the full 4-digit year.  There is a possibility that applications using
+      libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
+      function, or incorrectly passing only a 2-digit year instead of
+      "year - 1900" into the png_convert_from_struct_tm() function, but this
+      is not under our control.  The libpng documentation has always stated
+      that it works with 4-digit years, and the APIs have been documented as
+      such.
+      
+      The tIME chunk itself is also Y2K compliant.  It uses a 2-byte unsigned
+      integer to hold the year, and can hold years as large as 65535.
+      
+      
+         Glenn Randers-Pehrson
+         libpng maintainer
+         PNG Development Group

example.c

@@ -15,8 +15,11 @@
 
 #include "png.h"
 
-/* Check to see if a file is a PNG file using png_sig_cmp().  Returns
- * non-zero if the image is a PNG, and 0 if it isn't a PNG.
+/* Check to see if a file is a PNG file using png_sig_cmp().  png_sig_cmp()
+ * returns zero if the image is a PNG and nonzero if it isn't a PNG.
+ *
+ * The function check_if_png() shown here, but not used, returns nonzero (true)
+ * if the file can be opened and is a PNG, 0 (false) otherwise.
  *
  * If this call is successful, and you are going to keep the file open,
  * you should call png_set_sig_bytes(png_ptr, PNG_BYTES_TO_CHECK); once
@@ -41,12 +44,14 @@ int check_if_png(char *file_name, FILE **fp)
    if ((*fp = fopen(file_name, "rb")) != NULL);
       return 0;
 
-   /* Read in the signature bytes */
+   /* Read in some of the signature bytes */
    if (fread(buf, 1, PNG_BYTES_TO_CHECK, *fp) != PNG_BYTES_TO_CHECK)
       return 0;
 
-   /* Compare the first PNG_BYTES_TO_CHECK bytes of the signature. */
-   return(png_sig_cmp(buf, (png_size_t)0, PNG_BYTES_TO_CHECK));
+   /* Compare the first PNG_BYTES_TO_CHECK bytes of the signature.
+      Return nonzero (true) if they match */
+
+   return(!png_sig_cmp(buf, (png_size_t)0, PNG_BYTES_TO_CHECK));
 }
 
 /* Read a PNG file.  You may want to return an error code if the read
@@ -220,11 +225,14 @@ void read_png(FILE *fp, unsigned int sig_read)  /* file is already open */
 
    if (png_get_sRGB(png_ptr, info_ptr, &intent))
       png_set_sRGB(png_ptr, intent, 0);
-   else 
+   else
+   {
+      double image_gamma;
       if (png_get_gAMA(png_ptr, info_ptr, &image_gamma))
          png_set_gamma(png_ptr, screen_gamma, image_gamma);
       else
-         png_set_gamma(png_ptr, screen_gamma, 0.50);
+         png_set_gamma(png_ptr, screen_gamma, 0.45455);
+   }
 
    /* Dither RGB files down to 8 bit palette or reduce palettes
     * to the number of colors available on your screen.
@@ -324,13 +332,13 @@ void read_png(FILE *fp, unsigned int sig_read)  /* file is already open */
       {
 #ifdef sparkle /* Read the image using the "sparkle" effect. */
          png_read_rows(png_ptr, &row_pointers[y], NULL, number_of_rows);
-        
+
          png_read_rows(png_ptr, NULL, row_pointers[y], number_of_rows);
 #else no_sparkle /* Read the image using the "rectangle" effect */
          png_read_rows(png_ptr, NULL, &row_pointers[y], number_of_rows);
 #endif no_sparkle /* use only one of these two methods */
       }
-     
+
       /* if you want to display the image after every pass, do
          so here */
 #endif no_single /* use only one of these two methods */
@@ -384,8 +392,11 @@ initialize_png_reader(png_structp *png_ptr, png_infop *info_ptr)
       return ERROR;
    }
 
-   /* this one's new.  You will need to provide all three
+   /* This one's new.  You will need to provide all three
     * function callbacks, even if you aren't using them all.
+    * If you aren't using all functions, you can specify NULL
+    * parameters.  Even when all three functions are NULL,
+    * you need to call png_set_progressive_read_fn().
     * These functions shouldn't be dependent on global or
     * static variables if you are decoding several images
     * simultaneously.  You should store stream specific data
@@ -565,7 +576,7 @@ void write_png(char *file_name /* , ... other image information ... */)
    sig_bit.alpha = true_alpha_bit_depth;
    png_set_sBIT(png_ptr, info_ptr, sig_bit);
 
-  
+
    /* Optional gamma chunk is strongly suggested if you have any guess
     * as to the correct gamma of the image.
     */

libpng.3

@@ -1,6 +1,6 @@
-.TH LIBPNG 3 "May 21, 1998"
+.TH LIBPNG 3 "January 14, 1999"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library
+libpng \- Portable Network Graphics (PNG) Reference Library 1.0.3 - January 14, 1999
 .SH SYNOPSIS
 
 #include <png.h>
@@ -27,14 +27,25 @@ png_structp png_create_read_struct (png_const_charp
 user_png_ver, voidp error_ptr, png_error_ptr error_fn,
 png_error_ptr warn_fn);
 
+png_structp png_create_read_struct_2(png_const_charp user_png_ver,
+png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr
+warn_fn, png_voidp mem_ptr, png_malloc_ptr malloc_fn,
+png_free_ptr free_fn)
+
 png_structp png_create_write_struct (png_const_charp
 user_png_ver, voidp error_ptr, png_error_ptr error_fn,
 png_error_ptr warn_fn);
 
-void png_debug_free (png_structp png_ptr, png_voidp ptr);
+png_structp png_create_write_struct_2(png_const_charp
+user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
+png_error_ptr warn_fn, png_voidp mem_ptr,
+png_malloc_ptr malloc_fn, png_free_ptr free_fn)
 
-png_voidp png_debug_malloc (png_structp png_ptr, png_uint_32
-size);
+int png_debug(int level, png_const_charp message)
+
+int png_debug1(int level, png_const_charp message, p1)
+
+int png_debug2(int level, png_const_charp message, p1, p2)
 
 void png_destroy_info_struct (png_structp png_ptr, png_infopp
 info_ptr_ptr);
@@ -49,6 +60,8 @@ void png_error (png_structp png_ptr, png_const_charp error);
 
 void png_free (png_structp png_ptr, png_voidp ptr);
 
+void png_free_default(png_structp png_ptr, png_voidp ptr)
+
 png_byte png_get_bit_depth (png_structp png_ptr, png_infop
 info_ptr);
 
@@ -69,6 +82,8 @@ info_ptr);
 png_byte png_get_compression_type (png_structp png_ptr,
 png_infop info_ptr);
 
+png_byte png_get_copyright (png_structp png_ptr);
+
 png_voidp png_get_error_ptr (png_structp png_ptr);
 
 png_byte png_get_filter_type (png_structp png_ptr, png_infop
@@ -77,9 +92,16 @@ info_ptr);
 png_uint_32 png_get_gAMA (png_structp png_ptr, png_infop
 info_ptr, double *file_gamma);
 
+png_byte png_get_header_version (png_structp png_ptr);
+
 png_uint_32 png_get_hIST (png_structp png_ptr, png_infop
 info_ptr, png_uint_16p *hist);
 
+png_uint_32 png_get_IHDR (png_structp png_ptr, png_infop
+info_ptr, png_uint_32 *width, png_uint_32 *height, int
+*bit_depth, int *color_type, int *interlace_type, int
+*compression_type, int *filter_type);
+
 png_uint_32 png_get_image_height (png_structp png_ptr,
 png_infop info_ptr);
 
@@ -91,10 +113,7 @@ info_ptr);
 
 png_voidp png_get_io_ptr (png_structp png_ptr);
 
-png_uint_32 png_get_IHDR (png_structp png_ptr, png_infop
-info_ptr, png_uint_32 *width, png_uint_32 *height, int
-*bit_depth, int *color_type, int *interlace_type, int
-*compression_type, int *filter_type);
+png_voidp png_get_mem_ptr(png_structp png_ptr)
 
 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
@@ -119,6 +138,8 @@ png_voidp png_get_progressive_ptr (png_structp png_ptr);
 png_uint_32 png_get_PLTE (png_structp png_ptr, png_infop
 info_ptr, png_colorp *palette, int *num_palette);
 
+png_byte png_get_rgb_to_gray_status (png_structp png_ptr)
+
 png_uint_32 png_get_rowbytes (png_structp png_ptr, png_infop
 info_ptr);
 
@@ -168,6 +189,9 @@ void png_init_io (png_structp png_ptr, FILE *fp);
 
 png_voidp png_malloc (png_structp png_ptr, png_uint_32 size);
 
+png_voidp png_malloc_default(png_structp png_ptr,
+png_uint_32 size)
+
 voidp png_memcpy (png_voidp s1, png_voidp s2, png_size_t size);
 
 png_voidp png_memcpy_check (png_structp png_ptr, png_voidp s1,
@@ -276,6 +300,9 @@ png_uint_32 width, png_uint_32 height, int bit_depth, int
 color_type, int interlace_type, int compression_type, int
 filter_type);
 
+void png_set_mem_fn(png_structp png_ptr, png_voidp mem_ptr,
+png_malloc_ptr malloc_fn, png_free_ptr free_fn)
+
 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);
 
@@ -302,12 +329,12 @@ void png_set_read_fn (png_structp png_ptr, png_voidp io_ptr,
 png_rw_ptr read_data_fn);
 
 void png_set_read_status_fn (png_structp png_ptr, png_read_status_ptr
-   read_row_fn);
+read_row_fn);
 
 void png_set_read_user_transform_fn (png_structp png_ptr,
-   png_user_transform_ptr read_user_transform_fn);
+png_user_transform_ptr read_user_transform_fn);
 
-void png_set_rgb_to_gray (png_structp png_ptr);
+void png_set_rgb_to_gray (png_structp png_ptr, int error_action);
 
 void png_set_sBIT (png_structp png_ptr, png_infop info_ptr,
 png_color_8p sig_bit);
@@ -344,10 +371,10 @@ void png_set_write_fn (png_structp png_ptr, png_voidp io_ptr,
 png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn);
 
 void png_set_write_status_fn (png_structp png_ptr, png_write_status_ptr
-   write_row_fn);
+write_row_fn);
 
 void png_set_write_user_transform_fn (png_structp png_ptr,
-   png_user_transform_ptr write_user_transform_fn);
+png_user_transform_ptr write_user_transform_fn);
 
 int png_sig_cmp (png_bytep sig, png_size_t start, png_size_t
 num_to_check);
@@ -375,7 +402,7 @@ void png_write_destroy_info (png_infop info_ptr);
 void png_write_end (png_structp png_ptr, png_infop info_ptr);
 
 void png_write_flush (png_structp png_ptr);
- 
+
 void png_write_image (png_structp png_ptr, png_bytepp image);
 
 void png_write_info (png_structp png_ptr, png_infop info_ptr);
@@ -396,17 +423,17 @@ Following is a copy of the libpng.txt file that accompanies libpng.
 .SH LIBPNG.TXT
 libpng.txt - A description on how to use and modify libpng
 
- libpng version 1.0.1d May 21, 1998
+ libpng version 1.0.3 - January 14, 1999
  Updated and distributed by Glenn Randers-Pehrson
  <randeg@alumni.rpi.edu>
- Copyright (c) 1998, Glenn Randers-Pehrson
+ Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  For conditions of distribution and use, see copyright
  notice in png.h.
 
  based on:
 
  libpng 1.0 beta 6  version 0.96 May 28, 1997
- Updated and distributed by Andreas Dilger 
+ Updated and distributed by Andreas Dilger
  Copyright (c) 1996, 1997 Andreas Dilger
 
  libpng 1.0 beta 2 - version 0.88  January 26, 1996
@@ -436,7 +463,8 @@ as RFC 2083 <ftp://ftp.uu.net/graphics/png/documents/> and as a
 W3C Recommendation <http://www.w3.org/TR/REC.png.html>. Some
 additional chunks are described in the special-purpose public chunks
 documents at <ftp://ftp.uu.net/graphics/png/documents/>.  Other information
-about PNG can be found at the PNG home page, <http://www.cdrom.com/pub/png/>.
+about PNG, and the latest version of libpng, can be found at the PNG home
+page, <http://www.cdrom.com/pub/png/>.
 
 Most users will not have to modify the library significantly; advanced
 users may want to modify it more.  All attempts were made to make it as
@@ -453,6 +481,8 @@ work to be done (see the TODO file), libpng should cover the
 majority of the needs of its users.
 
 Libpng uses zlib for its compression and decompression of PNG files.
+Further information about zlib, and the latest version of zlib, can
+be found at the zlib home page, <http://www.cdrom.com/pub/infozip/zlib/>.
 The zlib compression utility is a general purpose utility that is
 useful for more than PNG files, and can be used without libpng.
 See the documentation delivered with zlib for more details.
@@ -522,7 +552,7 @@ Customizing libpng.
         return;
     }
     fread(header, 1, number, fp);
-    is_png = png_check_sig(header, 0, number);
+    is_png = !png_sig_cmp(header, 0, number);
     if (!is_png)
     {
         return;
@@ -560,12 +590,23 @@ on Changes to Libpng below regarding the old initialization functions.
         return;
     }
 
+If you want to use your own memory allocation routines,
+define PNG_USER_MEM_SUPPORTED and use
+png_create_read_struct_2() instead of png_create_read_struct():
 
-The error handling routines passed to png_create_read_struct() are only
-necessary if you are not using the libpng supplied error handling
-functions.  When libpng encounters an error, it expects to longjmp back
-to your routine.  Therefore, you will need to call setjmp and pass the
-jmpbuf field of your png_struct.  If you read the file from different
+    png_structp png_ptr = png_create_read_struct_2
+       (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+        user_error_fn, user_warning_fn, (png_voidp)
+        user_mem_ptr, user_malloc_fn, user_free_fn);
+
+The error handling routines passed to png_create_read_struct()
+and the memory alloc/free routines passed to png_create_struct_2()
+are only necessary if you are not using the libpng supplied error
+handling and memory alloc/free functions.
+
+When libpng encounters an error, it expects to longjmp back
+to your routine.  Therefore, you will need to call setjmp and pass
+your png_ptr->jmpbuf.  If you read the file from different
 routines, you will need to update the jmpbuf field every time you enter
 a new routine that will call a png_ function.
 
@@ -638,7 +679,7 @@ with
 You must supply the function
 
     void read_transform_fn(png_ptr ptr, row_info_ptr
-       row_info, png_bytep data) 
+       row_info, png_bytep data)
 
 See pngtest.c for a working example.  Your function will be called
 after all of the other transformations have been processed.
@@ -667,7 +708,7 @@ Functions are used to get the information from the info_ptr:
                          are present.
                      PNG_COLOR_TYPE_GRAY
                         (bit depths 1, 2, 4, 8, 16)
-                     PNG_COLOR_TYPE_GRAY_ALPHA  
+                     PNG_COLOR_TYPE_GRAY_ALPHA
                         (bit depths 8, 16)
                      PNG_COLOR_TYPE_PALETTE
                         (bit depths 1, 2, 4, 8)
@@ -973,6 +1014,63 @@ RGB.  This code will do that conversion:
         color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
           png_set_gray_to_rgb(png_ptr);
 
+Conversely, you can convert an RGB or RGBA image to grayscale or grayscale
+with alpha.  This is intended for conversion of images that really are
+gray (red == green == blue), so the function simply strips out the red
+and blue channels, leaving the green channel in the gray position.
+
+    if (color_type == PNG_COLOR_TYPE_RGB ||
+        color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+          png_set_rgb_to_gray(png_ptr, error_action,
+             float red_weight, float green_weight);
+
+    error_action = 1: silently do the conversion
+    error_action = 2: issue a warning if the original
+                      image has any pixel where
+                      red != green or red != blue
+    error_action = 3: issue an error and abort the
+                      conversion if the original
+                      image has any pixel where
+                      red != green or red != blue
+
+    red_weight:       weight of red component
+                      (NULL -> default 54/256)
+    green_weight:     weight of green component
+                      (NULL -> default 183/256)
+
+If you have set error_action = 1 or 2, you can
+later check whether the image really was gray, after processing
+the image rows, with the png_get_rgb_to_gray_status(png_ptr) function.
+It will return a png_byte that is zero if the image was gray or
+1 if there were any non-gray pixels.  bKGD and sBIT data
+will be silently converted to grayscale, using the green channel
+data, regardless of the error_action setting.
+
+With 0.0<=red_weight+green_weight<=1.0,
+the normalized graylevel is computed:
+
+    int rw = red_weight * 256;
+    int gw = green_weight * 256;
+    int bw = 256 - (rw + gw);
+    gray = (rw*red + gw*green + bw*blue)/256;
+
+The default values approximate those recommended in the Charles
+Poynton's Color FAQ, <http://www.inforamp.net/~poynton/>
+Copyright (c) 1998-01-04 Charles Poynton poynton@inforamp.net
+
+    Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
+
+Libpng approximates this with
+
+    Y = 0.211 * R    + 0.715 * G    + 0.074 * B
+
+which can be expressed with integers as
+
+    Y = (54 * R + 183 * G + 19 * B)/256
+
+The calculation is done in a linear colorspace, if the image gamma
+is known.
+
 If you have a grayscale and you are using png_set_expand() to change to
 a higher bit-depth, you must either supply the background color as a gray
 value at the original file bit-depth (need_expand = 1) or else supply the
@@ -1032,7 +1130,7 @@ compensation other than the display_gamma is needed (viewing_gamma=1.0).
 The png_set_gamma() function handles gamma transformations of the data.
 Pass both the file gamma and the current screen_gamma.  If the file does
 not have a gamma value, you can pass one anyway if you have an idea what
-it is (usually 0.50 is a good guess for GIF images on PCs).  Note
+it is (usually 0.45455 is a good guess for GIF images on PCs).  Note
 that file gammas are inverted from screen gammas.  See the discussions
 on gamma in the PNG specification for an excellent description of what
 gamma is, and why all applications should support it.  It is strongly
@@ -1041,7 +1139,7 @@ recommended that PNG viewers support gamma correction.
    if (png_get_gAMA(png_ptr, info_ptr, &gamma))
       png_set_gamma(png_ptr, screen_gamma, gamma);
    else
-      png_set_gamma(png_ptr, screen_gamma, 0.50);
+      png_set_gamma(png_ptr, screen_gamma, 0.45455);
 
 If you need to reduce an RGB file to a paletted file, or if a paletted
 file has more entries then will fit on your screen, png_set_dither()
@@ -1292,7 +1390,9 @@ png_infop info_ptr;
        to be called when the header info is valid,
        when each row is completed, and when the image
        is finished.  If you aren't using all functions,
-       you can specify a NULL parameter.  You can use
+       you can specify NULL parameters.  Even when all
+       three functions are NULL, you need to call
+       png_set_progressive_read_fn().  You can use
        any struct as the user_ptr (cast to a void pointer
        for the function call), and retrieve the pointer
        from inside the callbacks using the function
@@ -1324,21 +1424,21 @@ png_infop info_ptr;
        of data from the file stream (in order, of
        course).  On machines with segmented memory
        models machines, don't give it any more than
-       64K.  The library seems to run fine with sizes 
+       64K.  The library seems to run fine with sizes
        of 4K. Although you can give it much less if
        necessary (I assume you can give it chunks of
        1 byte, I haven't tried less then 256 bytes
        yet).  When this function returns, you may
        want to display any rows that were generated
        in the row callback if you don't already do
-       so there. 
+       so there.
      */
     png_process_data(png_ptr, info_ptr, buffer, length);
     return 0;
  }
 
  /* This function is called (as set by
-    png_set_progressive_fn() above) when enough data
+    png_set_progressive_read_fn() above) when enough data
     has been supplied so all of the header has been
     read.
  */
@@ -1388,14 +1488,14 @@ png_infop info_ptr;
           new_row);
 
     /* where old_row is what was displayed for
-       previous rows.  Note that the first pass
-       (pass == 0, really) will completely cover
+       previously for the row.  Note that the first
+       pass (pass == 0, really) will completely cover
        the old row, so the rows do not have to be
        initialized.  After the first pass (and only
        for interlaced images), you will have to pass
        the current row, and the function will combine
        the old row and the new row.
-    */  
+    */
  }
 
  void
@@ -1425,7 +1525,7 @@ You will want to do the I/O initialization before you get into libpng,
 so if it doesn't work, you don't have anything to undo. If you are not
 using the standard I/O functions, you will need to replace them with
 custom writing functions.  See the discussion under Customizing libpng.
-    
+
     FILE *fp = fopen(file_name, "wb");
     if (!fp)
     {
@@ -1454,23 +1554,34 @@ both "png_ptr"; you can call them anything you like, such as
        return;
     }
 
+If you want to use your own memory allocation routines,
+define PNG_USER_MEM_SUPPORTED and use
+png_create_write_struct_2() instead of png_create_read_struct():
+
+    png_structp png_ptr = png_create_write_struct_2
+       (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+        user_error_fn, user_warning_fn, (png_voidp)
+        user_mem_ptr, user_malloc_fn, user_free_fn);
+
 After you have these structures, you will need to set up the
 error handling.  When libpng encounters an error, it expects to
 longjmp() back to your routine.  Therefore, you will need to call
-setjmp and pass the jmpbuf field of your png_struct.  If you
+setjmp() and pass the png_ptr->jmpbuf.  If you
 write the file from different routines, you will need to update
 the jmpbuf field every time you enter a new routine that will
 call a png_ function.  See your documentation of setjmp/longjmp
 for your compiler for more information on setjmp/longjmp.  See
 the discussion on libpng error handling in the Customizing Libpng
 section below for more information on the libpng error handling.
-    
+
     if (setjmp(png_ptr->jmpbuf))
-    {    
+    {
         png_destroy_write_struct(&png_ptr, &info_ptr);
         fclose(fp);
         return;
     }
+    ...
+    return;
 
 Now you need to set up the output code.  The default for libpng is to
 use the C function fwrite().  If you use this, you will need to pass a
@@ -1511,7 +1622,7 @@ flag that indicates which filter type(s) are to be tested for each
 scanline.  See the Compression Library for details on the specific filter
 types.
 
-    
+
     /* turn on or off filtering, and/or choose
        specific filters */
     png_set_filter(png_ptr, 0,
@@ -1610,7 +1721,7 @@ Some of the more important parts of the png_info are:
                      PNG_SRGB_INTENT_PERCEPTUAL,
                      PNG_SRGB_INTENT_ABSOLUTE, or
                      PNG_SRGB_INTENT_RELATIVE.
-                        
+
 
     png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr,
        srgb_intent);
@@ -1701,7 +1812,7 @@ png_text structure holds a keyword-text value, and a compression type.
 The compression types have the same valid numbers as the compression
 types of the image data.  Currently, the only valid number is zero.
 However, you can store text either compressed or uncompressed, unlike
-images which always have to be compressed.  So if you don't want the
+images, which always have to be compressed.  So if you don't want the
 text compressed, set the compression type to PNG_TEXT_COMPRESSION_NONE.
 Until text gets around 1000 bytes, it is not worth compressing it.
 After the text has been written out to the file, the compression type
@@ -1761,7 +1872,7 @@ depending on whether you mean the PNG file, the time the image was
 created in a non-PNG format, a still photo from which the image was
 scanned, or possibly the subject matter itself.  In order to facilitate
 machine-readable dates, it is recommended that the "Creation Time"
-tEXt chunk use RFC 1123 format dates (e.g. 22 May 1997 18:07:10 GMT"),
+tEXt chunk use RFC 1123 format dates (e.g. "22 May 1997 18:07:10 GMT"),
 although this isn't a requirement.  Unlike the tIME chunk, the
 "Creation Time" tEXt chunk is not expected to be automatically changed
 by the software.  To facilitate the use of RFC 1123 dates, a function
@@ -1803,7 +1914,7 @@ correctly pack the pixels into a single byte:
 PNG files reduce possible bit depths to 1, 2, 4, 8, and 16.  If your
 data is of another bit depth, you can write an sBIT chunk into the
 file so that decoders can get the original data if desired.
-    
+
     /* Set the true bit depth of the image data */
     if (color_type & PNG_COLOR_MASK_COLOR)
     {
@@ -1864,7 +1975,7 @@ with
 You must supply the function
 
     void write_transform_fn(png_ptr ptr, row_info_ptr
-       row_info, png_bytep data) 
+       row_info, png_bytep data)
 
 See pngtest.c for a working example.  Your function will be called
 before any of the other transformations have been processed.
@@ -1979,7 +2090,7 @@ The second deals with more complicated things like adding new chunks,
 adding new transformations, and generally changing how libpng works.
 
 All of the memory allocation, input/output, and error handling in libpng
-goes through callbacks which are user settable.  The default routines are
+goes through callbacks that are user settable.  The default routines are
 in pngmem.c, pngrio.c, pngwio.c, and pngerror.c respectively.  To change
 these functions, call the appropriate png_set_???_fn() function.
 
@@ -2001,14 +2112,15 @@ time, instead of calling the png_init_io() function.  These functions
 also provide a void pointer that can be retrieved via the function
 png_get_io_ptr().  For example:
 
-    png_set_read_fn(png_structp png_ptr,
-        voidp io_ptr, png_rw_ptr read_data_fn)
+    png_set_read_fn(png_structp read_ptr,
+        voidp read_io_ptr, png_rw_ptr read_data_fn)
 
-    png_set_write_fn(png_structp png_ptr,
-        voidp io_ptr, png_rw_ptr write_data_fn,
+    png_set_write_fn(png_structp write_ptr,
+        voidp write_io_ptr, png_rw_ptr write_data_fn,
         png_flush_ptr output_flush_fn);
 
-    voidp io_ptr = png_get_io_ptr(png_ptr);
+    voidp read_io_ptr = png_get_io_ptr(read_ptr);
+    voidp write_io_ptr = png_get_io_ptr(write_ptr);
 
 The replacement I/O functions should have prototypes as follows:
 
@@ -2087,7 +2199,7 @@ won't be accessible.  So limit zlib and libpng to 64K by defining MAXSEG_64K.
 
 Configuring for DOS:
 
-For DOS users which only have access to the lower 640K, you will
+For DOS users who only have access to the lower 640K, you will
 have to limit zlib's memory usage via a png_set_compression_mem_level()
 call.  See zlib.h or zconf.h in the zlib library for more information.
 
@@ -2099,7 +2211,7 @@ defined, and FAR gets defined to far in pngconf.h, and you should be
 all set.  Everything in the library (except for zlib's structure) is
 expecting far data.  You must use the typedefs with the p or pp on
 the end for pointers (or at least look at them and be careful).  Make
-note that the row's of data are defined as png_bytepp which is a
+note that the row's of data are defined as png_bytepp, which is an
 unsigned char far * far *.
 
 Configuring for gui/windowing platforms:
@@ -2159,8 +2271,8 @@ can call one of these functions.  The selection and configuration
 of row filters can have a significant impact on the size and
 encoding speed and a somewhat lesser impact on the decoding speed
 of an image.  Filtering is enabled by default for RGB and grayscale
-images (with and without alpha), and for 8-bit paletted images, but
-not for paletted images with bit depths less than 8 bits/pixel.
+images (with and without alpha), but not for paletted images nor
+for any images with bit depths less than 8 bits/pixel.
 
 The 'method' parameter sets the main filtering method, which is
 currently only '0' in the PNG 1.0 specification.  The 'filters'
@@ -2195,10 +2307,10 @@ by telling it the relative computational costs of the filters.
        PNG_FILTER_SELECTION_WEIGHTED, 3,
        weights, costs);
 
-The weights are multiplying factors which indicate to libpng that row
-should be the same for successive rows unless another row filter is that
-many times better than the previous filter.  In the above example, if
-the previous 3 filters were SUB, SUB, NONE, the SUB filter could have a
+The weights are multiplying factors that indicate to libpng that the
+row filter should be the same for successive rows unless another row filter
+is that many times better than the previous filter.  In the above example,
+if the previous 3 filters were SUB, SUB, NONE, the SUB filter could have a
 "sum of absolute differences" 1.5 x 1.3 times higher than other filters
 and still be chosen, while the NONE filter could have a sum 1.1 times
 higher than other filters and still be chosen.  Unspecified weights are
@@ -2253,10 +2365,46 @@ or DLL file), you should not remove or disable any parts of the library,
 as this will cause applications linked with different versions of the
 library to fail if they call functions not available in your library.
 The size of the library itself should not be an issue, because only
-those sections which are actually used will be loaded into memory.
+those sections that are actually used will be loaded into memory.
 
+Requesting debug printout:
 
-Changes to Libpng from version 0.88
+The macro definition PNG_DEBUG can be used to request debugging
+printout.  Set it to an integer value in the range 0 to 3.  Higher
+numbers result in increasing amounts of debugging information.  The
+information is printed to the "stderr" file, unless another file
+name is specified in the PNG_DEBUG_FILE macro definition.
+
+When PNG_DEBUG > 0, the following functions (macros) become available:
+
+   png_debug(level, message)
+   png_debug1(level, message, p1)
+   png_debug2(level, message, p1, p2)
+
+in which "level" is compared to PNG_DEBUG to decide whether to print
+the message, "message" is the formatted string to be printed,
+and p1 and p2 are parameters that are to be embedded in the string
+according to printf-style formatting directives.  For example,
+
+   png_debug1(2, "foo=%d\n", foo);
+
+is expanded to
+
+   if(PNG_DEBUG > 2)
+     fprintf(PNG_DEBUG_FILE, "foo=%d\n", foo);
+
+When PNG_DEBUG is defined but is zero, the macros aren't defined, but you
+can still use PNG_DEBUG to control your own debugging:
+
+   #ifdef PNG_DEBUG
+       fprintf(stderr, ...
+   #endif
+
+When PNG_DEBUG = 1, the macros are defined, but only png_debug statements
+having level = 0 will be printed.  There aren't any such statements in
+this version of libpng, but if you insert some they will be printed.
+
+.SH VI.  Changes to Libpng from version 0.88
 
 It should be noted that versions of libpng later than 0.96 are not
 distributed by the original libpng author, Guy Schalnat, nor by
@@ -2282,13 +2430,65 @@ allocating and freeing the png_struct for each image read.
 
 Setting the error callbacks via png_set_message_fn() before
 png_read_init() as was suggested in libpng-0.88 is no longer supported
-because this caused applications which do not use custom error functions
+because this caused applications that do not use custom error functions
 to fail if the png_ptr was not initialized to zero.  It is still possible
 to set the error callbacks AFTER png_read_init(), or to change them with
 png_set_error_fn(), which is essentially the same function, but with a
 new name to force compilation errors with applications that try to use
 the old method.
 
+.SH VII. Y2K Compliance in libpng
+
+January 13, 1999
+
+Since the PNG Development group is an ad-hoc body, we can't make
+an official declaration.
+
+This is your unofficial assurance that libpng from version 0.81 and
+upward are Y2K compliant.  It is my belief that earlier versions were
+also Y2K compliant.
+
+Libpng only has three year fields.  One is a 2-byte unsigned integer that
+will hold years up to 65535.  The other two hold the date in text
+format, and will hold years up to 9999.
+
+The integer is
+    "png_uint_16 year" in png_time_struct.
+
+The strings are
+    "png_charp time_buffer" in png_struct and
+    "near_time_buffer", which is a local character string in png.c.
+
+There are seven time-related functions:
+
+    png_convert_to_rfc_1123() in png.c 
+      (formerly png_convert_to_rfc_1152() in error)
+    png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
+    png_convert_from_time_t() in pngwrite.c
+    png_get_tIME() in pngget.c
+    png_handle_tIME() in pngrutil.c, called in pngread.c
+    png_set_tIME() in pngset.c
+    png_write_tIME() in pngwutil.c, called in pngwrite.c
+
+All appear to handle dates properly in a Y2K environment.  The 
+png_convert_from_time_t() function calls gmtime() to convert from system
+clock time, which returns (year - 1900), which we properly convert to
+the full 4-digit year.  There is a possibility that applications using
+libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
+function, or incorrectly passing only a 2-digit year instead of
+"year - 1900" into the png_convert_from_struct_tm() function, but this
+is not under our control.  The libpng documentation has always stated
+that it works with 4-digit years, and the APIs have been documented as
+such.
+
+The tIME chunk itself is also Y2K compliant.  It uses a 2-byte unsigned
+integer to hold the year, and can hold years as large as 65535.
+
+
+   Glenn Randers-Pehrson
+   libpng maintainer
+   PNG Development Group
+
 .SH NOTE
 
 Note about libpng version numbers:
@@ -2374,7 +2574,7 @@ possible without all of you.
 
 Thanks to Frank J. T. Wojcik for helping with the documentation.
   
-Libpng version 1.0.1d May 21, 1998:
+Libpng version 1.0.3 - January 14, 1999:
 Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
 Currently maintained by Glenn Randers-Pehrson (randeg@alumni.rpi.edu).
 
@@ -2384,6 +2584,10 @@ Supported by the PNG development group
 
 .SH COPYRIGHT NOTICE:
 
+Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
+Copyright (c) 1996, 1997 Andreas Dilger
+Copyright (c) 1998, 1999 Glenn Randers-Pehrson
+
 The PNG Reference Library (libpng) is supplied "AS IS".  The Contributing
 Authors and Group 42, Inc. disclaim all warranties, expressed or implied,
 including, without limitation, the warranties of merchantability and of

libpng.txt

@@ -1,16 +1,16 @@
 libpng.txt - A description on how to use and modify libpng
 
- libpng version 1.0.1d May 21, 1998
+ libpng version 1.0.3 - January 14, 1999
  Updated and distributed by Glenn Randers-Pehrson
  <randeg@alumni.rpi.edu>
- Copyright (c) 1998, Glenn Randers-Pehrson
+ Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  For conditions of distribution and use, see copyright
  notice in png.h.
 
  based on:
 
  libpng 1.0 beta 6  version 0.96 May 28, 1997
- Updated and distributed by Andreas Dilger 
+ Updated and distributed by Andreas Dilger
  Copyright (c) 1996, 1997 Andreas Dilger
 
  libpng 1.0 beta 2 - version 0.88  January 26, 1996
@@ -40,7 +40,8 @@ as RFC 2083 <ftp://ftp.uu.net/graphics/png/documents/> and as a
 W3C Recommendation <http://www.w3.org/TR/REC.png.html>. Some
 additional chunks are described in the special-purpose public chunks
 documents at <ftp://ftp.uu.net/graphics/png/documents/>.  Other information
-about PNG can be found at the PNG home page, <http://www.cdrom.com/pub/png/>.
+about PNG, and the latest version of libpng, can be found at the PNG home
+page, <http://www.cdrom.com/pub/png/>.
 
 Most users will not have to modify the library significantly; advanced
 users may want to modify it more.  All attempts were made to make it as
@@ -57,6 +58,8 @@ work to be done (see the TODO file), libpng should cover the
 majority of the needs of its users.
 
 Libpng uses zlib for its compression and decompression of PNG files.
+Further information about zlib, and the latest version of zlib, can
+be found at the zlib home page, <http://www.cdrom.com/pub/infozip/zlib/>.
 The zlib compression utility is a general purpose utility that is
 useful for more than PNG files, and can be used without libpng.
 See the documentation delivered with zlib for more details.
@@ -126,7 +129,7 @@ Customizing libpng.
         return;
     }
     fread(header, 1, number, fp);
-    is_png = png_check_sig(header, 0, number);
+    is_png = !png_sig_cmp(header, 0, number);
     if (!is_png)
     {
         return;
@@ -164,12 +167,23 @@ on Changes to Libpng below regarding the old initialization functions.
         return;
     }
 
+If you want to use your own memory allocation routines,
+define PNG_USER_MEM_SUPPORTED and use
+png_create_read_struct_2() instead of png_create_read_struct():
 
-The error handling routines passed to png_create_read_struct() are only
-necessary if you are not using the libpng supplied error handling
-functions.  When libpng encounters an error, it expects to longjmp back
-to your routine.  Therefore, you will need to call setjmp and pass the
-jmpbuf field of your png_struct.  If you read the file from different
+    png_structp png_ptr = png_create_read_struct_2
+       (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+        user_error_fn, user_warning_fn, (png_voidp)
+        user_mem_ptr, user_malloc_fn, user_free_fn);
+
+The error handling routines passed to png_create_read_struct()
+and the memory alloc/free routines passed to png_create_struct_2()
+are only necessary if you are not using the libpng supplied error
+handling and memory alloc/free functions.
+
+When libpng encounters an error, it expects to longjmp back
+to your routine.  Therefore, you will need to call setjmp and pass
+your png_ptr->jmpbuf.  If you read the file from different
 routines, you will need to update the jmpbuf field every time you enter
 a new routine that will call a png_ function.
 
@@ -242,7 +256,7 @@ with
 You must supply the function
 
     void read_transform_fn(png_ptr ptr, row_info_ptr
-       row_info, png_bytep data) 
+       row_info, png_bytep data)
 
 See pngtest.c for a working example.  Your function will be called
 after all of the other transformations have been processed.
@@ -271,7 +285,7 @@ Functions are used to get the information from the info_ptr:
                          are present.
                      PNG_COLOR_TYPE_GRAY
                         (bit depths 1, 2, 4, 8, 16)
-                     PNG_COLOR_TYPE_GRAY_ALPHA  
+                     PNG_COLOR_TYPE_GRAY_ALPHA
                         (bit depths 8, 16)
                      PNG_COLOR_TYPE_PALETTE
                         (bit depths 1, 2, 4, 8)
@@ -577,6 +591,63 @@ RGB.  This code will do that conversion:
         color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
           png_set_gray_to_rgb(png_ptr);
 
+Conversely, you can convert an RGB or RGBA image to grayscale or grayscale
+with alpha.  This is intended for conversion of images that really are
+gray (red == green == blue), so the function simply strips out the red
+and blue channels, leaving the green channel in the gray position.
+
+    if (color_type == PNG_COLOR_TYPE_RGB ||
+        color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+          png_set_rgb_to_gray(png_ptr, error_action,
+             float red_weight, float green_weight);
+
+    error_action = 1: silently do the conversion
+    error_action = 2: issue a warning if the original
+                      image has any pixel where
+                      red != green or red != blue
+    error_action = 3: issue an error and abort the
+                      conversion if the original
+                      image has any pixel where
+                      red != green or red != blue
+
+    red_weight:       weight of red component
+                      (NULL -> default 54/256)
+    green_weight:     weight of green component
+                      (NULL -> default 183/256)
+
+If you have set error_action = 1 or 2, you can
+later check whether the image really was gray, after processing
+the image rows, with the png_get_rgb_to_gray_status(png_ptr) function.
+It will return a png_byte that is zero if the image was gray or
+1 if there were any non-gray pixels.  bKGD and sBIT data
+will be silently converted to grayscale, using the green channel
+data, regardless of the error_action setting.
+
+With 0.0<=red_weight+green_weight<=1.0,
+the normalized graylevel is computed:
+
+    int rw = red_weight * 256;
+    int gw = green_weight * 256;
+    int bw = 256 - (rw + gw);
+    gray = (rw*red + gw*green + bw*blue)/256;
+
+The default values approximate those recommended in the Charles
+Poynton's Color FAQ, <http://www.inforamp.net/~poynton/>
+Copyright (c) 1998-01-04 Charles Poynton poynton@inforamp.net
+
+    Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
+
+Libpng approximates this with
+
+    Y = 0.211 * R    + 0.715 * G    + 0.074 * B
+
+which can be expressed with integers as
+
+    Y = (54 * R + 183 * G + 19 * B)/256
+
+The calculation is done in a linear colorspace, if the image gamma
+is known.
+
 If you have a grayscale and you are using png_set_expand() to change to
 a higher bit-depth, you must either supply the background color as a gray
 value at the original file bit-depth (need_expand = 1) or else supply the
@@ -636,7 +707,7 @@ compensation other than the display_gamma is needed (viewing_gamma=1.0).
 The png_set_gamma() function handles gamma transformations of the data.
 Pass both the file gamma and the current screen_gamma.  If the file does
 not have a gamma value, you can pass one anyway if you have an idea what
-it is (usually 0.50 is a good guess for GIF images on PCs).  Note
+it is (usually 0.45455 is a good guess for GIF images on PCs).  Note
 that file gammas are inverted from screen gammas.  See the discussions
 on gamma in the PNG specification for an excellent description of what
 gamma is, and why all applications should support it.  It is strongly
@@ -645,7 +716,7 @@ recommended that PNG viewers support gamma correction.
    if (png_get_gAMA(png_ptr, info_ptr, &gamma))
       png_set_gamma(png_ptr, screen_gamma, gamma);
    else
-      png_set_gamma(png_ptr, screen_gamma, 0.50);
+      png_set_gamma(png_ptr, screen_gamma, 0.45455);
 
 If you need to reduce an RGB file to a paletted file, or if a paletted
 file has more entries then will fit on your screen, png_set_dither()
@@ -896,7 +967,9 @@ png_infop info_ptr;
        to be called when the header info is valid,
        when each row is completed, and when the image
        is finished.  If you aren't using all functions,
-       you can specify a NULL parameter.  You can use
+       you can specify NULL parameters.  Even when all
+       three functions are NULL, you need to call
+       png_set_progressive_read_fn().  You can use
        any struct as the user_ptr (cast to a void pointer
        for the function call), and retrieve the pointer
        from inside the callbacks using the function
@@ -928,21 +1001,21 @@ png_infop info_ptr;
        of data from the file stream (in order, of
        course).  On machines with segmented memory
        models machines, don't give it any more than
-       64K.  The library seems to run fine with sizes 
+       64K.  The library seems to run fine with sizes
        of 4K. Although you can give it much less if
        necessary (I assume you can give it chunks of
        1 byte, I haven't tried less then 256 bytes
        yet).  When this function returns, you may
        want to display any rows that were generated
        in the row callback if you don't already do
-       so there. 
+       so there.
      */
     png_process_data(png_ptr, info_ptr, buffer, length);
     return 0;
  }
 
  /* This function is called (as set by
-    png_set_progressive_fn() above) when enough data
+    png_set_progressive_read_fn() above) when enough data
     has been supplied so all of the header has been
     read.
  */
@@ -992,14 +1065,14 @@ png_infop info_ptr;
           new_row);
 
     /* where old_row is what was displayed for
-       previous rows.  Note that the first pass
-       (pass == 0, really) will completely cover
+       previously for the row.  Note that the first
+       pass (pass == 0, really) will completely cover
        the old row, so the rows do not have to be
        initialized.  After the first pass (and only
        for interlaced images), you will have to pass
        the current row, and the function will combine
        the old row and the new row.
-    */  
+    */
  }
 
  void
@@ -1029,7 +1102,7 @@ You will want to do the I/O initialization before you get into libpng,
 so if it doesn't work, you don't have anything to undo. If you are not
 using the standard I/O functions, you will need to replace them with
 custom writing functions.  See the discussion under Customizing libpng.
-    
+
     FILE *fp = fopen(file_name, "wb");
     if (!fp)
     {
@@ -1058,23 +1131,34 @@ both "png_ptr"; you can call them anything you like, such as
        return;
     }
 
+If you want to use your own memory allocation routines,
+define PNG_USER_MEM_SUPPORTED and use
+png_create_write_struct_2() instead of png_create_read_struct():
+
+    png_structp png_ptr = png_create_write_struct_2
+       (PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
+        user_error_fn, user_warning_fn, (png_voidp)
+        user_mem_ptr, user_malloc_fn, user_free_fn);
+
 After you have these structures, you will need to set up the
 error handling.  When libpng encounters an error, it expects to
 longjmp() back to your routine.  Therefore, you will need to call
-setjmp and pass the jmpbuf field of your png_struct.  If you
+setjmp() and pass the png_ptr->jmpbuf.  If you
 write the file from different routines, you will need to update
 the jmpbuf field every time you enter a new routine that will
 call a png_ function.  See your documentation of setjmp/longjmp
 for your compiler for more information on setjmp/longjmp.  See
 the discussion on libpng error handling in the Customizing Libpng
 section below for more information on the libpng error handling.
-    
+
     if (setjmp(png_ptr->jmpbuf))
-    {    
+    {
         png_destroy_write_struct(&png_ptr, &info_ptr);
         fclose(fp);
         return;
     }
+    ...
+    return;
 
 Now you need to set up the output code.  The default for libpng is to
 use the C function fwrite().  If you use this, you will need to pass a
@@ -1115,7 +1199,7 @@ flag that indicates which filter type(s) are to be tested for each
 scanline.  See the Compression Library for details on the specific filter
 types.
 
-    
+
     /* turn on or off filtering, and/or choose
        specific filters */
     png_set_filter(png_ptr, 0,
@@ -1214,7 +1298,7 @@ Some of the more important parts of the png_info are:
                      PNG_SRGB_INTENT_PERCEPTUAL,
                      PNG_SRGB_INTENT_ABSOLUTE, or
                      PNG_SRGB_INTENT_RELATIVE.
-                        
+
 
     png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr,
        srgb_intent);
@@ -1305,7 +1389,7 @@ png_text structure holds a keyword-text value, and a compression type.
 The compression types have the same valid numbers as the compression
 types of the image data.  Currently, the only valid number is zero.
 However, you can store text either compressed or uncompressed, unlike
-images which always have to be compressed.  So if you don't want the
+images, which always have to be compressed.  So if you don't want the
 text compressed, set the compression type to PNG_TEXT_COMPRESSION_NONE.
 Until text gets around 1000 bytes, it is not worth compressing it.
 After the text has been written out to the file, the compression type
@@ -1365,7 +1449,7 @@ depending on whether you mean the PNG file, the time the image was
 created in a non-PNG format, a still photo from which the image was
 scanned, or possibly the subject matter itself.  In order to facilitate
 machine-readable dates, it is recommended that the "Creation Time"
-tEXt chunk use RFC 1123 format dates (e.g. 22 May 1997 18:07:10 GMT"),
+tEXt chunk use RFC 1123 format dates (e.g. "22 May 1997 18:07:10 GMT"),
 although this isn't a requirement.  Unlike the tIME chunk, the
 "Creation Time" tEXt chunk is not expected to be automatically changed
 by the software.  To facilitate the use of RFC 1123 dates, a function
@@ -1407,7 +1491,7 @@ correctly pack the pixels into a single byte:
 PNG files reduce possible bit depths to 1, 2, 4, 8, and 16.  If your
 data is of another bit depth, you can write an sBIT chunk into the
 file so that decoders can get the original data if desired.
-    
+
     /* Set the true bit depth of the image data */
     if (color_type & PNG_COLOR_MASK_COLOR)
     {
@@ -1468,7 +1552,7 @@ with
 You must supply the function
 
     void write_transform_fn(png_ptr ptr, row_info_ptr
-       row_info, png_bytep data) 
+       row_info, png_bytep data)
 
 See pngtest.c for a working example.  Your function will be called
 before any of the other transformations have been processed.
@@ -1583,7 +1667,7 @@ The second deals with more complicated things like adding new chunks,
 adding new transformations, and generally changing how libpng works.
 
 All of the memory allocation, input/output, and error handling in libpng
-goes through callbacks which are user settable.  The default routines are
+goes through callbacks that are user settable.  The default routines are
 in pngmem.c, pngrio.c, pngwio.c, and pngerror.c respectively.  To change
 these functions, call the appropriate png_set_???_fn() function.
 
@@ -1605,14 +1689,15 @@ time, instead of calling the png_init_io() function.  These functions
 also provide a void pointer that can be retrieved via the function
 png_get_io_ptr().  For example:
 
-    png_set_read_fn(png_structp png_ptr,
-        voidp io_ptr, png_rw_ptr read_data_fn)
+    png_set_read_fn(png_structp read_ptr,
+        voidp read_io_ptr, png_rw_ptr read_data_fn)
 
-    png_set_write_fn(png_structp png_ptr,
-        voidp io_ptr, png_rw_ptr write_data_fn,
+    png_set_write_fn(png_structp write_ptr,
+        voidp write_io_ptr, png_rw_ptr write_data_fn,
         png_flush_ptr output_flush_fn);
 
-    voidp io_ptr = png_get_io_ptr(png_ptr);
+    voidp read_io_ptr = png_get_io_ptr(read_ptr);
+    voidp write_io_ptr = png_get_io_ptr(write_ptr);
 
 The replacement I/O functions should have prototypes as follows:
 
@@ -1691,7 +1776,7 @@ won't be accessible.  So limit zlib and libpng to 64K by defining MAXSEG_64K.
 
 Configuring for DOS:
 
-For DOS users which only have access to the lower 640K, you will
+For DOS users who only have access to the lower 640K, you will
 have to limit zlib's memory usage via a png_set_compression_mem_level()
 call.  See zlib.h or zconf.h in the zlib library for more information.
 
@@ -1703,7 +1788,7 @@ defined, and FAR gets defined to far in pngconf.h, and you should be
 all set.  Everything in the library (except for zlib's structure) is
 expecting far data.  You must use the typedefs with the p or pp on
 the end for pointers (or at least look at them and be careful).  Make
-note that the row's of data are defined as png_bytepp which is a
+note that the row's of data are defined as png_bytepp, which is an
 unsigned char far * far *.
 
 Configuring for gui/windowing platforms:
@@ -1763,8 +1848,8 @@ can call one of these functions.  The selection and configuration
 of row filters can have a significant impact on the size and
 encoding speed and a somewhat lesser impact on the decoding speed
 of an image.  Filtering is enabled by default for RGB and grayscale
-images (with and without alpha), and for 8-bit paletted images, but
-not for paletted images with bit depths less than 8 bits/pixel.
+images (with and without alpha), but not for paletted images nor
+for any images with bit depths less than 8 bits/pixel.
 
 The 'method' parameter sets the main filtering method, which is
 currently only '0' in the PNG 1.0 specification.  The 'filters'
@@ -1799,10 +1884,10 @@ by telling it the relative computational costs of the filters.
        PNG_FILTER_SELECTION_WEIGHTED, 3,
        weights, costs);
 
-The weights are multiplying factors which indicate to libpng that row
-should be the same for successive rows unless another row filter is that
-many times better than the previous filter.  In the above example, if
-the previous 3 filters were SUB, SUB, NONE, the SUB filter could have a
+The weights are multiplying factors that indicate to libpng that the
+row filter should be the same for successive rows unless another row filter
+is that many times better than the previous filter.  In the above example,
+if the previous 3 filters were SUB, SUB, NONE, the SUB filter could have a
 "sum of absolute differences" 1.5 x 1.3 times higher than other filters
 and still be chosen, while the NONE filter could have a sum 1.1 times
 higher than other filters and still be chosen.  Unspecified weights are
@@ -1857,10 +1942,46 @@ or DLL file), you should not remove or disable any parts of the library,
 as this will cause applications linked with different versions of the
 library to fail if they call functions not available in your library.
 The size of the library itself should not be an issue, because only
-those sections which are actually used will be loaded into memory.
+those sections that are actually used will be loaded into memory.
 
+Requesting debug printout:
 
-Changes to Libpng from version 0.88
+The macro definition PNG_DEBUG can be used to request debugging
+printout.  Set it to an integer value in the range 0 to 3.  Higher
+numbers result in increasing amounts of debugging information.  The
+information is printed to the "stderr" file, unless another file
+name is specified in the PNG_DEBUG_FILE macro definition.
+
+When PNG_DEBUG > 0, the following functions (macros) become available:
+
+   png_debug(level, message)
+   png_debug1(level, message, p1)
+   png_debug2(level, message, p1, p2)
+
+in which "level" is compared to PNG_DEBUG to decide whether to print
+the message, "message" is the formatted string to be printed,
+and p1 and p2 are parameters that are to be embedded in the string
+according to printf-style formatting directives.  For example,
+
+   png_debug1(2, "foo=%d\n", foo);
+
+is expanded to
+
+   if(PNG_DEBUG > 2)
+     fprintf(PNG_DEBUG_FILE, "foo=%d\n", foo);
+
+When PNG_DEBUG is defined but is zero, the macros aren't defined, but you
+can still use PNG_DEBUG to control your own debugging:
+
+   #ifdef PNG_DEBUG
+       fprintf(stderr, ...
+   #endif
+
+When PNG_DEBUG = 1, the macros are defined, but only png_debug statements
+having level = 0 will be printed.  There aren't any such statements in
+this version of libpng, but if you insert some they will be printed.
+
+VI.  Changes to Libpng from version 0.88
 
 It should be noted that versions of libpng later than 0.96 are not
 distributed by the original libpng author, Guy Schalnat, nor by
@@ -1886,9 +2007,61 @@ allocating and freeing the png_struct for each image read.
 
 Setting the error callbacks via png_set_message_fn() before
 png_read_init() as was suggested in libpng-0.88 is no longer supported
-because this caused applications which do not use custom error functions
+because this caused applications that do not use custom error functions
 to fail if the png_ptr was not initialized to zero.  It is still possible
 to set the error callbacks AFTER png_read_init(), or to change them with
 png_set_error_fn(), which is essentially the same function, but with a
 new name to force compilation errors with applications that try to use
 the old method.
+
+VII. Y2K Compliance in libpng
+
+January 13, 1999
+
+Since the PNG Development group is an ad-hoc body, we can't make
+an official declaration.
+
+This is your unofficial assurance that libpng from version 0.81 and
+upward are Y2K compliant.  It is my belief that earlier versions were
+also Y2K compliant.
+
+Libpng only has three year fields.  One is a 2-byte unsigned integer that
+will hold years up to 65535.  The other two hold the date in text
+format, and will hold years up to 9999.
+
+The integer is
+    "png_uint_16 year" in png_time_struct.
+
+The strings are
+    "png_charp time_buffer" in png_struct and
+    "near_time_buffer", which is a local character string in png.c.
+
+There are seven time-related functions:
+
+    png_convert_to_rfc_1123() in png.c 
+      (formerly png_convert_to_rfc_1152() in error)
+    png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
+    png_convert_from_time_t() in pngwrite.c
+    png_get_tIME() in pngget.c
+    png_handle_tIME() in pngrutil.c, called in pngread.c
+    png_set_tIME() in pngset.c
+    png_write_tIME() in pngwutil.c, called in pngwrite.c
+
+All appear to handle dates properly in a Y2K environment.  The 
+png_convert_from_time_t() function calls gmtime() to convert from system
+clock time, which returns (year - 1900), which we properly convert to
+the full 4-digit year.  There is a possibility that applications using
+libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
+function, or incorrectly passing only a 2-digit year instead of
+"year - 1900" into the png_convert_from_struct_tm() function, but this
+is not under our control.  The libpng documentation has always stated
+that it works with 4-digit years, and the APIs have been documented as
+such.
+
+The tIME chunk itself is also Y2K compliant.  It uses a 2-byte unsigned
+integer to hold the year, and can hold years as large as 65535.
+
+
+   Glenn Randers-Pehrson
+   libpng maintainer
+   PNG Development Group

libpngpf.3

@@ -1,6 +1,6 @@
-.TH LIBPNGPF 3 "May 21, 1998"
+.TH LIBPNGPF 3 "January 14, 1999"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library
+libpng \- Portable Network Graphics (PNG) Reference Library 1.0.3 - January 14, 1999
 (private functions)
 .SH SYNOPSIS
 #include <png.h>
@@ -31,10 +31,15 @@ int png_crc_finish (png_structp png_ptr, png_uint_32 skip);
 void png_crc_read (png_structp png_ptr, png_bytep buf,
 png_size_t length);
 
-png_voidp png_create_struct (int type);
+png_voidp png_create_struct (int type, png_malloc_ptr malloc_fn);
+
+png_voidp png_create_struct_2 (int type);
 
 void png_destroy_struct (png_voidp struct_ptr);
 
+void png_destroy_struct_2 (png_voidp struct_ptr, png_free_ptr
+free_fn);
+
 void png_do_background (png_row_infop row_info, png_bytep row,
 png_color_16p trans_values, png_color_16p background,
 png_color_16p background_1, png_bytep gamma_table, png_bytep
@@ -83,7 +88,7 @@ row);
 
 void png_do_read_transformations (png_structp png_ptr);
 
-void png_do_rgb_to_gray (png_row_infop row_info, png_bytep
+int png_do_rgb_to_gray (png_row_infop row_info, png_bytep
 row);
 
 void png_do_shift (png_row_infop row_info, png_bytep row,

png.5

@@ -1,4 +1,4 @@
-.TH PNG 5 "May 21, 1998"
+.TH PNG 5 "January 14, 1999"
 .SH NAME
 png \- Portable Network Graphics (PNG) format
 .SH DESCRIPTION
@@ -7,7 +7,7 @@ lossless, portable, well-compressed storage of raster images. PNG provides
 a patent-free replacement for GIF and can also replace many
 common uses of TIFF. Indexed-color, grayscale, and truecolor images are
 supported, plus an optional alpha channel. Sample depths range from
-1 to 16 bits. 
+1 to 16 bits.
 .br
 
 PNG is designed to work well in online viewing applications, such as the
@@ -15,7 +15,7 @@ World Wide Web, so it is fully streamable with a progressive display
 option. PNG is robust, providing both full file integrity checking and
 fast, simple detection of common transmission errors. Also, PNG can store
 gamma and chromaticity data for improved color matching on heterogeneous
-platforms. 
+platforms.
 
 .SH "SEE ALSO"
 .IR libpng(3), zlib(3), deflate(5), and zlib(5)

png.c

@@ -1,12 +1,11 @@
 
 /* png.c - location for general purpose libpng functions
  *
- * libpng 1.0.1d
- * For conditions of distribution and use, see copyright notice in png.h
+ * libpng version 1.0.3 - January 14, 1999
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
- * May 21, 1998
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
+ * 
  */
 
 #define PNG_INTERNAL
@@ -16,7 +15,8 @@
 /* Version information for C files.  This had better match the version
  * string defined in png.h.
  */
-char png_libpng_ver[12] = "1.0.1d";
+
+char png_libpng_ver[12] = "1.0.3";
 
 /* Place to hold the signature string for a PNG file. */
 png_byte FARDATA png_sig[8] = {137, 80, 78, 71, 13, 10, 26, 10};
@@ -115,8 +115,8 @@ png_sig_cmp(png_bytep sig, png_size_t start, png_size_t num_to_check)
 }
 
 /* (Obsolete) function to check signature bytes.  It does not allow one
- * to check a partial signature.  This function will be removed in the
- * future - use png_sig_cmp().
+ * to check a partial signature.  This function might be removed in the
+ * future - use png_sig_cmp().  Returns true (nonzero) if the file is a PNG.
  */
 int
 png_check_sig(png_bytep sig, int num)
@@ -128,12 +128,10 @@ png_check_sig(png_bytep sig, int num)
 voidpf
 png_zalloc(voidpf png_ptr, uInt items, uInt size)
 {
-   png_voidp ptr;
-   png_uint_32 num_bytes;
+   png_uint_32 num_bytes = (png_uint_32)items * size;
+   png_voidp ptr = (png_voidp)png_malloc((png_structp)png_ptr, num_bytes);
 
-   num_bytes = (png_uint_32)items * size;
-   ptr = (png_voidp)png_malloc((png_structp)png_ptr, num_bytes);
-   if (num_bytes > (png_uint_32)0x8000)
+   if (num_bytes > (png_uint_32)0x8000L)
    {
       png_memset(ptr, 0, (png_size_t)0x8000L);
       png_memset((png_bytep)ptr + (png_size_t)0x8000L, 0,
@@ -201,7 +199,12 @@ png_create_info_struct(png_structp png_ptr)
 
    png_debug(1, "in png_create_info_struct\n");
    if(png_ptr == NULL) return (NULL);
+#ifdef PNG_USER_MEM_SUPPORTED
+   if ((info_ptr = (png_infop)png_create_struct_2(PNG_STRUCT_INFO,
+      png_ptr->malloc_fn)) != NULL)
+#else
    if ((info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO)) != NULL)
+#endif
    {
       png_info_init(info_ptr);
    }
@@ -227,7 +230,11 @@ png_destroy_info_struct(png_structp png_ptr, png_infopp info_ptr_ptr)
    {
       png_info_destroy(png_ptr, info_ptr);
 
+#ifdef PNG_USER_MEM_SUPPORTED
+      png_destroy_struct_2((png_voidp)info_ptr, png_ptr->free_fn);
+#else
       png_destroy_struct((png_voidp)info_ptr);
+#endif
       *info_ptr_ptr = (png_infop)NULL;
    }
 }
@@ -252,11 +259,10 @@ void
 png_info_destroy(png_structp png_ptr, png_infop info_ptr)
 {
 #if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED)
-   int i;
-
    png_debug(1, "in png_info_destroy\n");
    if (info_ptr->text != NULL)
    {
+      int i;
       for (i = 0; i < info_ptr->num_text; i++)
       {
          png_free(png_ptr, info_ptr->text[i].key);
@@ -269,6 +275,7 @@ png_info_destroy(png_structp png_ptr, png_infop info_ptr)
    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]);
@@ -302,3 +309,51 @@ png_init_io(png_structp png_ptr, FILE *fp)
    png_ptr->io_ptr = (png_voidp)fp;
 }
 #endif
+
+#if defined(PNG_TIME_RFC1123_SUPPORTED)
+/* Convert the supplied time into an RFC 1123 string suitable for use in
+ * a "Creation Time" or other text-based time string.
+ */
+png_charp
+png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime)
+{
+   static PNG_CONST char short_months[12][4] =
+        {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
+         "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
+
+   if (png_ptr->time_buffer == NULL)
+   {
+      png_ptr->time_buffer = (png_charp)png_malloc(png_ptr, (png_uint_32)(29*
+         sizeof(char)));
+   }
+
+#ifdef USE_FAR_KEYWORD
+   {
+      char near_time_buf[29];
+      sprintf(near_time_buf, "%d %s %d %02d:%02d:%02d +0000",
+               ptime->day % 32, short_months[(ptime->month - 1) % 12],
+               ptime->year, ptime->hour % 24, ptime->minute % 60,
+               ptime->second % 61);
+      png_memcpy(png_ptr->time_buffer, near_time_buf,
+      29*sizeof(char));
+   }
+#else
+   sprintf(png_ptr->time_buffer, "%d %s %d %02d:%02d:%02d +0000",
+               ptime->day % 32, short_months[(ptime->month - 1) % 12],
+               ptime->year, ptime->hour % 24, ptime->minute % 60,
+               ptime->second % 61);
+#endif
+   return ((png_charp)png_ptr->time_buffer);
+}
+#endif /* PNG_TIME_RFC1123_SUPPORTED */
+
+png_charp
+png_get_copyright(png_structp png_ptr)
+{
+   if(png_ptr == NULL)
+     /* silence compiler warning about unused png_ptr */ ;
+   return("\n libpng version 1.0.3 - January 14, 1999\n\
+   Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.\n\
+   Copyright (c) 1996, 1997 Andreas Dilger\n\
+   Copyright (c) 1998, 1999, Glenn Randers-Pehrson\n");
+}

png.h

@@ -1,39 +1,90 @@
 
 /* png.h - header file for PNG reference library
  *
- * libpng 1.0.1d
- * For conditions of distribution and use, see the COPYRIGHT NOTICE below.
+ * libpng version 1.0.3 - January 14, 1999
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998 Glenn Randers-Pehrson
- * May 21, 1998
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  *
+ * Y2K compliance in libpng:
+ * =========================
+ *    
+ *    January 13, 1999
+ *    
+ *    Since the PNG Development group is an ad-hoc body, we can't make
+ *    an official declaration.
+ *    
+ *    This is your unofficial assurance that libpng from version 0.81 and
+ *    upward are Y2K compliant.  It is my belief that earlier versions were
+ *    also Y2K compliant.
+ *    
+ *    Libpng only has three year fields.  One is a 2-byte unsigned integer
+ *    that will hold years up to 65535.  The other two hold the date in text
+ *    format, and will hold years up to 9999.
+ *    
+ *    The integer is
+ *        "png_uint_16 year" in png_time_struct.
+ *    
+ *    The strings are
+ *        "png_charp time_buffer" in png_struct and
+ *        "near_time_buffer", which is a local character string in png.c.
+ *    
+ *    There are seven time-related functions:
+ *        png.c: png_convert_to_rfc_1123() in png.c 
+ *          (formerly png_convert_to_rfc_1152() in error)
+ *        png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
+ *        png_convert_from_time_t() in pngwrite.c
+ *        png_get_tIME() in pngget.c
+ *        png_handle_tIME() in pngrutil.c, called in pngread.c
+ *        png_set_tIME() in pngset.c
+ *        png_write_tIME() in pngwutil.c, called in pngwrite.c
+ *    
+ *    All handle dates properly in a Y2K environment.  The 
+ *    png_convert_from_time_t() function calls gmtime() to convert from system
+ *    clock time, which returns (year - 1900), which we properly convert to
+ *    the full 4-digit year.  There is a possibility that applications using
+ *    libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
+ *    function, or incorrectly passing only a 2-digit year instead of
+ *    "year - 1900" into the png_convert_from_struct_tm() function, but this
+ *    is not under our control.  The libpng documentation has always stated
+ *    that it works with 4-digit years, and the APIs have been documented as
+ *    such.
+ *    
+ *    The tIME chunk itself is also Y2K compliant.  It uses a 2-byte unsigned
+ *    integer to hold the year, and can hold years as large as 65535.
+ *    
+ *    
+ *       Glenn Randers-Pehrson
+ *       libpng maintainer
+ *       PNG Development Group
+ * 
  * Note about libpng version numbers:
- *
+ * 
  *    Due to various miscommunications, unforeseen code incompatibilities
  *    and occasional factors outside the authors' control, version numbering
  *    on the library has not always been consistent and straightforward.
  *    The following table summarizes matters since version 0.89c, which was
  *    the first widely used release:
  *
- *      source                    png.h   png.h   shared-lib
- *      version                   string    int   version
- *      -------                   ------  -----  ----------
- *      0.89c ("1.0 beta 3")      0.89       89  1.0.89
- *      0.90  ("1.0 beta 4")      0.90       90  0.90  [should have been 2.0.90]
- *      0.95  ("1.0 beta 5")      0.95       95  0.95  [should have been 2.0.95]
- *      0.96  ("1.0 beta 6")      0.96       96  0.96  [should have been 2.0.96]
- *      0.97b ("1.00.97 beta 7")  1.00.97    97  1.0.1 [should have been 2.0.97]
- *      0.97c                     0.97       97  2.0.97
- *      0.98                      0.98       98  2.0.98
- *      0.99                      0.99       98  2.0.99
- *      0.99a-m                   0.99       99  2.0.99
- *      1.00                      1.00      100  2.1.0 [int should be 10000]
- *      1.0.0                     1.0.0     100  2.1.0 [int should be 10000]
- *      1.0.1                     1.0.1   10001  2.1.0
- *      1.0.1a                    1.0.1a  10002  2.1.0.1a
- *      1.0.1b                    1.0.1b  10002  2.1.0.1b
- *      1.0.1c                    1.0.1c  10002  2.1.0.1c
+ *    source                    png.h    png.h   shared-lib
+ *    version                   string     int   version
+ *    -------                   ------   -----  ----------
+ *    0.89c ("1.0 beta 3")      0.89        89  1.0.89
+ *    0.90  ("1.0 beta 4")      0.90        90  0.90  [should have been 2.0.90]
+ *    0.95  ("1.0 beta 5")      0.95        95  0.95  [should have been 2.0.95]
+ *    0.96  ("1.0 beta 6")      0.96        96  0.96  [should have been 2.0.96]
+ *    0.97b ("1.00.97 beta 7")  1.00.97     97  1.0.1 [should have been 2.0.97]
+ *    0.97c                     0.97        97  2.0.97
+ *    0.98                      0.98        98  2.0.98
+ *    0.99                      0.99        98  2.0.99
+ *    0.99a-m                   0.99        99  2.0.99
+ *    1.00                      1.00       100  2.1.0 [int should be 10000]
+ *    1.0.0                     1.0.0      100  2.1.0 [int should be 10000]
+ *    1.0.1                     1.0.1    10001  2.1.0
+ *    1.0.1a-e                  1.0.1a-e 10002  2.1.0.1a-e
+ *    1.0.2                     1.0.2    10002  2.1.0.2
+ *    1.0.2a-c                  1.0.2a   10003  2.1.0.2a-c
+ *    1.0.3                     1.0.3    10003  2.1.0.3
  *
  *    Henceforth the source version will match the shared-library minor
  *    and patch numbers; the shared-library major version number will be
@@ -94,6 +145,7 @@
  * appreciated.
  */
 
+
 #ifndef _PNG_H
 #define _PNG_H
 
@@ -120,14 +172,14 @@ extern "C" {
  */
 
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.0.1d"
+#define PNG_LIBPNG_VER_STRING "1.0.3"
 
 /* Careful here.  At one time, Guy wanted to use 082, but that would be octal.
  * We must not include leading zeros.
  * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
  * version 1.0.0 was mis-numbered 100 instead of 10000).  From
  * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=bugfix */
-#define PNG_LIBPNG_VER    10002  /* 1.0.2 */
+#define PNG_LIBPNG_VER    10003  /* 1.0.3 */
 
 /* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
 #if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
@@ -147,6 +199,7 @@ extern int FARDATA png_pass_dsp_mask[7];
 extern int FARDATA png_pass_width[7];
 extern int FARDATA png_pass_height[7];
 */
+
 #endif /* PNG_NO_EXTERN */
 
 /* Three color definitions.  The order of the red, green, and blue, (and the
@@ -314,7 +367,8 @@ typedef struct png_info_struct
     */
    png_color_8 sig_bit; /* significant bits in color channels */
 #endif /* PNG_READ_sBIT_SUPPORTED || PNG_WRITE_sBIT_SUPPORTED */
-#if defined(PNG_READ_tRNS_SUPPORTED) || defined(PNG_WRITE_tRNS_SUPPORTED)
+#if defined(PNG_READ_tRNS_SUPPORTED) || defined(PNG_WRITE_tRNS_SUPPORTED) || \
+    defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
    /* The tRNS chunk supplies transparency data for paletted images and
     * other image types that don't need a full alpha channel.  There are
     * "num_trans" transparency values for a paletted image, stored in the
@@ -455,7 +509,7 @@ typedef png_info FAR * FAR * png_infopp;
 #define PNG_sRGB_INTENT_ABSOLUTE   2
 #define PNG_sRGB_INTENT_RELATIVE   3
 #define PNG_sRGB_INTENT_LAST       4 /* Not a valid value */
-                        
+
 
 
 /* These determine if an ancillary chunk's data has been successfully read
@@ -520,6 +574,9 @@ typedef void (*png_user_transform_ptr) PNGARG((png_structp,
     png_row_infop, png_bytep));
 #endif /* PNG_READ|WRITE_USER_TRANSFORM_SUPPORTED */
 
+typedef png_voidp (*png_malloc_ptr) PNGARG((png_structp, png_size_t));
+typedef void (*png_free_ptr) PNGARG((png_structp, png_structp));
+
 /* The structure that holds the information to read and write PNG files.
  * The only people who need to care about what is inside of this are the
  * people who will be modifying the library for their own special needs.
@@ -607,7 +664,7 @@ struct png_struct_def
    png_uint_32 flush_dist;    /* how many rows apart to flush, 0 - no flush */
    png_uint_32 flush_rows;    /* number of rows written since last flush */
 #endif /* PNG_WRITE_FLUSH_SUPPORTED */
-#if defined(PNG_READ_GAMMA_SUPPORTED)
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
    int gamma_shift;      /* number of "insignificant" bits 16-bit gamma */
    float gamma;          /* file gamma value */
    float screen_gamma;   /* screen gamma value (display_gamma/viewing_gamma */
@@ -626,10 +683,11 @@ struct png_struct_def
 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
    png_color_8 shift;         /* shift for significant bit tranformation */
 #endif /* PNG_READ_SHIFT_SUPPORTED || PNG_WRITE_SHIFT_SUPPORTED */
-#if defined(PNG_READ_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+#if defined(PNG_READ_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
+ || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
    png_bytep trans;           /* transparency values for paletted files */
    png_color_16 trans_values; /* transparency values for non-paletted files */
-#endif /* PNG_READ_tRNS_SUPPORTED || PNG_READ_BACKGROUND_SUPPORTED */
+#endif /* PNG_READ|WRITE_tRNS_SUPPORTED||PNG_READ_EXPAND|BACKGROUND_SUPPORTED */
    png_read_status_ptr read_row_fn;   /* called after each row is decoded */
    png_write_status_ptr write_row_fn; /* called after each row is encoded */
 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
@@ -682,6 +740,17 @@ struct png_struct_def
 #if defined(PNG_TIME_RFC1123_SUPPORTED)
    png_charp time_buffer;            /* String to hold RFC 1123 time text */
 #endif /* PNG_TIME_RFC1123_SUPPORTED */
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_voidp mem_ptr;                /* user supplied struct for mem functions */
+   png_malloc_ptr malloc_fn;         /* function for allocating memory */
+   png_free_ptr free_fn;             /* function for freeing memory */
+#endif /* PNG_USER_MEM_SUPPORTED */
+#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+   png_byte rgb_to_gray_status;
+   png_byte rgb_to_gray_red_coeff;
+   png_byte rgb_to_gray_green_coeff;
+   png_byte rgb_to_gray_blue_coeff;
+#endif
 };
 
 typedef png_struct FAR * FAR * png_structpp;
@@ -716,11 +785,22 @@ extern PNG_EXPORT(png_structp,png_create_read_struct)
    PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
    png_error_ptr error_fn, png_error_ptr warn_fn));
 
-/* Allocate and initialize png_ptr struct for reading, and any other memory */
+/* Allocate and initialize png_ptr struct for writing, and any other memory */
 extern PNG_EXPORT(png_structp,png_create_write_struct)
    PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
    png_error_ptr error_fn, png_error_ptr warn_fn));
 
+#ifdef PNG_USER_MEM_SUPPORTED
+extern PNG_EXPORT(png_structp,png_create_read_struct_2)
+   PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
+   png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
+   png_malloc_ptr malloc_fn, png_free_ptr free_fn));
+extern PNG_EXPORT(png_structp,png_create_write_struct_2)
+   PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
+   png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
+   png_malloc_ptr malloc_fn, png_free_ptr free_fn));
+#endif
+
 /* Write a PNG chunk - size, type, (optional) data, CRC. */
 extern PNG_EXPORT(void,png_write_chunk) PNGARG((png_structp png_ptr,
    png_bytep chunk_name, png_bytep data, png_size_t length));
@@ -782,8 +862,11 @@ extern PNG_EXPORT(void,png_set_gray_to_rgb) PNGARG((png_structp png_ptr));
 #endif /* PNG_READ_GRAY_TO_RGB_SUPPORTED */
 
 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
-/* Reduce RGB to grayscale. (Not yet implemented) */
-extern PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr));
+/* Reduce RGB to grayscale. */
+extern PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr,
+   int error_action, float red, float green ));
+extern PNG_EXPORT(png_byte,png_get_rgb_to_gray_status) PNGARG((png_structp
+   png_ptr));
 #endif /* PNG_READ_RGB_TO_GRAY_SUPPORTED */
 
 extern PNG_EXPORT(void,png_build_grayscale_palette) PNGARG((int bit_depth,
@@ -1087,6 +1170,7 @@ extern PNG_EXPORT(void,png_init_io) PNGARG((png_structp png_ptr, FILE *fp));
  * method of error handling.  If error_fn or warning_fn is NULL, the
  * default function will be used.
  */
+
 extern PNG_EXPORT(void,png_set_error_fn) PNGARG((png_structp png_ptr,
    png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
 
@@ -1114,6 +1198,15 @@ extern PNG_EXPORT(void,png_set_read_status_fn) PNGARG((png_structp png_ptr,
 extern PNG_EXPORT(void,png_set_write_status_fn) PNGARG((png_structp png_ptr,
    png_write_status_ptr write_row_fn));
 
+#ifdef PNG_USER_MEM_SUPPORTED
+/* Replace the default memory allocation functions with user supplied one(s). */
+extern PNG_EXPORT(void,png_set_mem_fn) PNGARG((png_structp png_ptr,
+   png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn));
+
+/* Return the user pointer associated with the memory functions */
+extern PNG_EXPORT(png_voidp,png_get_mem_ptr) PNGARG((png_structp png_ptr));
+#endif /* PNG_USER_MEM_SUPPORTED */
+
 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
 extern PNG_EXPORT(void,png_set_read_user_transform_fn) PNGARG((png_structp
    png_ptr, png_user_transform_ptr read_user_transform_fn));
@@ -1154,19 +1247,19 @@ extern PNG_EXPORT(png_voidp,png_malloc) PNGARG((png_structp png_ptr,
 /* frees a pointer allocated by png_malloc() */
 extern PNG_EXPORT(void,png_free) PNGARG((png_structp png_ptr, png_voidp ptr));
 
+#ifdef PNG_USER_MEM_SUPPORTED
+extern PNG_EXPORT(png_voidp,png_malloc_default) PNGARG((png_structp png_ptr,
+   png_uint_32 size));
+extern PNG_EXPORT(void,png_free_default) PNGARG((png_structp png_ptr,
+   png_voidp ptr));
+#endif /* PNG_USER_MEM_SUPPORTED */
+
 extern PNG_EXPORT(png_voidp,png_memcpy_check) PNGARG((png_structp png_ptr,
    png_voidp s1, png_voidp s2, png_uint_32 size));
 
 extern PNG_EXPORT(png_voidp,png_memset_check) PNGARG((png_structp png_ptr,
    png_voidp s1, int value, png_uint_32 size));
 
-#ifdef PNGTEST_MEMORY_DEBUG
-/* debugging versions of png_malloc() and png_free() */
-extern PNG_EXPORT(png_voidp,png_debug_malloc) PNGARG((png_structp png_ptr,
-   png_uint_32 size));
-extern PNG_EXPORT(void,png_debug_free) PNGARG((png_structp png_ptr,
-   png_voidp ptr));
-#endif
 #if defined(USE_FAR_KEYWORD)  /* memory model conversion function */
 extern void *png_far_to_near PNGARG((png_structp png_ptr,png_voidp ptr,
    int check));
@@ -1316,7 +1409,7 @@ extern PNG_EXPORT(png_uint_32,png_get_IHDR) PNGARG((png_structp png_ptr,
    png_infop info_ptr, png_uint_32 *width, png_uint_32 *height,
    int *bit_depth, int *color_type, int *interlace_type,
    int *compression_type, int *filter_type));
-  
+
 extern PNG_EXPORT(void,png_set_IHDR) PNGARG((png_structp png_ptr,
    png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
    int color_type, int interlace_type, int compression_type, int filter_type));
@@ -1422,28 +1515,46 @@ extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
  * only been added since version 0.95 so it is not implemented throughout
  * libpng yet, but more support will be added as needed.
  */
+#ifdef PNG_DEBUG
 #if (PNG_DEBUG > 0)
-#ifdef PNG_NO_STDIO
-#include <stdio.h>
-#endif
 #ifndef PNG_DEBUG_FILE
 #define PNG_DEBUG_FILE stderr
 #endif /* PNG_DEBUG_FILE */
 
 #define png_debug(l,m)        if (PNG_DEBUG > l) \
                                  fprintf(PNG_DEBUG_FILE,"%s"m,(l==1 ? "\t" : \
-                                    (l==2 ? "\t\t":(l==3 ? "\t\t\t":""))))
+                                    (l==2 ? "\t\t":(l>2 ? "\t\t\t":""))))
 #define png_debug1(l,m,p1)    if (PNG_DEBUG > l) \
                                  fprintf(PNG_DEBUG_FILE,"%s"m,(l==1 ? "\t" : \
-                                    (l==2 ? "\t\t":(l==3 ? "\t\t\t":""))),p1)
+                                    (l==2 ? "\t\t":(l>2 ? "\t\t\t":""))),p1)
 #define png_debug2(l,m,p1,p2) if (PNG_DEBUG > l) \
                                  fprintf(PNG_DEBUG_FILE,"%s"m,(l==1 ? "\t" : \
-                                    (l==2 ? "\t\t":(l==3 ? "\t\t\t":""))),p1,p2)
-#else
-#define png_debug(l, m)
-#define png_debug1(l, m, p1)
-#define png_debug2(l, m, p1, p2)
+                                    (l==2 ? "\t\t":(l>2 ? "\t\t\t":""))),p1,p2)
 #endif /* (PNG_DEBUG > 0) */
+#endif /* PNG_DEBUG */
+#ifndef png_debug
+#define png_debug(l, m)
+#endif
+#ifndef png_debug1
+#define png_debug1(l, m, p1)
+#endif
+#ifndef png_debug2
+#define png_debug2(l, m, p1, p2)
+#endif
+
+extern PNG_EXPORT(png_charp,png_get_copyright) PNGARG((png_structp png_ptr));
+extern PNG_EXPORT(png_charp,png_get_header_version) PNGARG((png_structp png_ptr));
+
+#ifdef PNG_NO_EXTERN
+/* this only gets included in png.c */
+png_charp
+png_get_header_version(png_structp png_ptr)
+{
+   if(png_ptr == NULL)
+     /* silence compiler warning about unused png_ptr */ ;
+   return("\n libpng version 1.0.3 - January 14, 1999 (header)\n");
+}
+#endif
 
 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
 /* With these routines we avoid an integer divide, which will be slower on
@@ -1458,28 +1569,30 @@ extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
  * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
  */
 
-   /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
-#  define png_composite(composite, fg, alpha, bg) \
-     { png_uint_16 temp = ((png_uint_16)(fg) * (png_uint_16)(alpha) + \
-                        (png_uint_16)(bg)*(png_uint_16)(255 - \
-                        (png_uint_16)(alpha)) + (png_uint_16)128); \
+ /* fg and bg should be in `gamma 1.0' space; alpha is the opacity          */
+
+#  define png_composite(composite, fg, alpha, bg)                            \
+     { png_uint_16 temp = ((png_uint_16)(fg) * (png_uint_16)(alpha) +        \
+                        (png_uint_16)(bg)*(png_uint_16)(255 -                \
+                        (png_uint_16)(alpha)) + (png_uint_16)128);           \
        (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
-#  define png_composite_16(composite, fg, alpha, bg) \
-     { png_uint_32 temp = ((png_uint_32)(fg) * (png_uint_32)(alpha) + \
-                        (png_uint_32)(bg)*(png_uint_32)(65535L - \
-                        (png_uint_32)(alpha)) + (png_uint_32)32768L); \
+
+#  define png_composite_16(composite, fg, alpha, bg)                         \
+     { png_uint_32 temp = ((png_uint_32)(fg) * (png_uint_32)(alpha) +        \
+                        (png_uint_32)(bg)*(png_uint_32)(65535L -             \
+                        (png_uint_32)(alpha)) + (png_uint_32)32768L);        \
        (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
 
 #else  /* standard method using integer division */
 
-   /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
-#  define png_composite(composite, fg, alpha, bg) \
-     (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \
-       (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
+#  define png_composite(composite, fg, alpha, bg)                            \
+     (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) +    \
+       (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) +       \
        (png_uint_16)127) / 255)
-#  define png_composite_16(composite, fg, alpha, bg) \
+
+#  define png_composite_16(composite, fg, alpha, bg)                         \
      (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
-       (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) + \
+       (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) +      \
        (png_uint_32)32767) / (png_uint_32)65535L)
 
 #endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
@@ -1525,7 +1638,7 @@ extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
 #define PNG_DITHER             0x0040
 #define PNG_BACKGROUND         0x0080
 #define PNG_BACKGROUND_EXPAND  0x0100
-#define PNG_RGB_TO_GRAY        0x0200 /* Not currently implemented */
+                          /*   0x0200 unused */
 #define PNG_16_TO_8            0x0400
 #define PNG_RGBA               0x0800
 #define PNG_EXPAND             0x1000
@@ -1537,6 +1650,9 @@ extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
 #define PNG_STRIP_ALPHA       0x40000L
 #define PNG_INVERT_ALPHA      0x80000L
 #define PNG_USER_TRANSFORM   0x100000L
+#define PNG_RGB_TO_GRAY_ERR  0x200000L
+#define PNG_RGB_TO_GRAY_WARN 0x400000L
+#define PNG_RGB_TO_GRAY      0x600000L  /* two bits, RGB_TO_GRAY_ERR|WARN */
 
 /* flags for png_create_struct */
 #define PNG_STRUCT_PNG   0x0001
@@ -1650,6 +1766,11 @@ PNG_EXTERN png_voidp png_create_struct PNGARG((int type));
 /* free memory from internal libpng struct */
 PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr));
 
+PNG_EXTERN png_voidp png_create_struct_2 PNGARG((int type, png_malloc_ptr
+  malloc_fn));
+PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr,
+   png_free_ptr free_fn));
+
 /* free any memory that info_ptr points to and reset struct. */
 PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr,
    png_infop info_ptr));
@@ -1693,8 +1814,8 @@ PNG_EXTERN void png_flush PNGARG((png_structp png_ptr));
 #endif
 
 /* Place a 32-bit number into a buffer in PNG byte order (big-endian).
- * The only currently known PNG chunk that uses signed numbers is
- * the ancillary extension chunk, pCAL.
+ * The only currently known PNG chunks that use signed numbers are
+ * the ancillary extension chunks, oFFs and pCAL.
  */
 PNG_EXTERN void png_save_uint_32 PNGARG((png_bytep buf, png_uint_32 i));
 
@@ -1765,7 +1886,8 @@ PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, png_uint_16p hist,
    int num_hist));
 #endif
 
-#if defined(PNG_WRITE_tEXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED)
+#if defined(PNG_WRITE_tEXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED) || \
+    defined(PNG_WRITE_pCAL_SUPPORTED)
 PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
    png_charp key, png_charpp new_key));
 #endif
@@ -1889,8 +2011,8 @@ PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info, png_bytep row));
 #endif
 
 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
-PNG_EXTERN void png_do_rgb_to_gray PNGARG((png_row_infop row_info,
-   png_bytep row));
+PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr, png_row_infop
+   row_info, png_bytep row));
 #endif
 
 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)

pngconf.h

@@ -1,12 +1,11 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng 1.0.1d
+ * libpng 1.0.3 - January 14, 1999
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
- * May 21, 1998
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  */
 
 /* Any machine specific code is near the front of this file, so if you
@@ -18,6 +17,7 @@
 #ifndef PNGCONF_H
 #define PNGCONF_H
 
+
 /* This is the size of the compression buffer, and thus the size of
  * an IDAT chunk.  Make this whatever size you feel is best for your
  * machine.  One of these will be allocated per png_struct.  When this
@@ -50,13 +50,28 @@
 /* This protects us against compilers that run on a windowing system
  * and thus don't have or would rather us not use the stdio types:
  * stdin, stdout, and stderr.  The only one currently used is stderr
- * in png_error() and png_warning().  #defining PNG_NO_STDIO will
- * prevent these from being compiled and used.
+ * in png_error() and png_warning().  #defining PNG_NO_CONSOLE_IO will
+ * prevent these from being compiled and used. #defining PNG_NO_STDIO
+ * will also prevent these, plus will prevent the entire set of stdio
+ * macros and functions (FILE *, printf, etc.) from being compiled and used,
+ * unless PNG_DEBUG has been #defined.
+ *
+ * #define PNG_NO_CONSOLE_IO
  * #define PNG_NO_STDIO
  */
 
-#ifndef PNG_NO_STDIO 
-#include <stdio.h>
+#ifdef PNG_DEBUG
+#  if (PNG_DEBUG > 0)
+#    include <stdio.h>
+#  endif
+#else
+#  ifdef PNG_NO_STDIO
+#    ifndef PNG_NO_CONSOLE_IO
+#      define PNG_NO_CONSOLE_IO
+#    endif
+#  else
+#    include <stdio.h>
+#  endif
 #endif
 
 /* This macro protects us against machines that don't have function
@@ -308,11 +323,9 @@ __dont__ include it again
 #ifndef PNG_NO_READ_USER_TRANSFORM
 #define PNG_READ_USER_TRANSFORM_SUPPORTED
 #endif
-/* the following aren't implemented yet
 #ifndef PNG_NO_READ_RGB_TO_GRAY
 #define PNG_READ_RGB_TO_GRAY_SUPPORTED
 #endif
- */
 #endif /* PNG_READ_TRANSFORMS_SUPPORTED */
 
 #if !defined(PNG_NO_PROGRESSIVE_READ) && \
@@ -400,6 +413,7 @@ __dont__ include it again
 /* very little testing */
 /*
 #define PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
+#define PNG_USER_MEM_SUPPORTED
 */
 
 /* This is only for PowerPC big-endian and 680x0 systems */
@@ -631,7 +645,7 @@ typedef char            FAR * FAR * FAR * png_charppp;
  */
 typedef charf *         png_zcharp;
 typedef charf * FAR *   png_zcharpp;
-typedef z_stream FAR *  png_zstreamp; 
+typedef z_stream FAR *  png_zstreamp;
 
 /* allow for compilation as dll under MS Windows */
 #ifdef __WIN32DLL__
@@ -663,6 +677,7 @@ typedef z_stream FAR *  png_zstreamp;
 #   define NOCHECK 0
 #   define CVT_PTR(ptr) (png_far_to_near(png_ptr,ptr,CHECK))
 #   define CVT_PTR_NOCHECK(ptr) (png_far_to_near(png_ptr,ptr,NOCHECK))
+#   define png_strcpy _fstrcpy
 #   define png_strlen _fstrlen
 #   define png_memcmp _fmemcmp      /* SJT: added */
 #   define png_memcpy _fmemcpy
@@ -670,6 +685,7 @@ typedef z_stream FAR *  png_zstreamp;
 #else /* use the usual functions */
 #   define CVT_PTR(ptr)         (ptr)
 #   define CVT_PTR_NOCHECK(ptr) (ptr)
+#   define png_strcpy strcpy
 #   define png_strlen strlen
 #   define png_memcmp memcmp     /* SJT: added */
 #   define png_memcpy memcpy
@@ -678,7 +694,7 @@ typedef z_stream FAR *  png_zstreamp;
 /* End of memory model independent support */
 
 /* Just a double check that someone hasn't tried to define something
- * contradictory. 
+ * contradictory.
  */
 #if (PNG_ZBUF_SIZE > 65536) && defined(PNG_MAX_MALLOC_64K)
 #undef PNG_ZBUF_SIZE

pngerror.c

@@ -1,12 +1,11 @@
 
 /* pngerror.c - stub functions for i/o and memory allocation
  *
- * libpng 1.0.1d
+ * libpng 1.0.3 - January 14, 1999
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
- * May 21, 1998
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  *
  * This file provides a location for all error handling.  Users who
  * need special error handling are expected to write replacement functions
@@ -114,7 +113,7 @@ png_chunk_warning(png_structp png_ptr, png_const_charp message)
 static void
 png_default_error(png_structp png_ptr, png_const_charp message)
 {
-#ifndef PNG_NO_STDIO
+#ifndef PNG_NO_CONSOLE_IO
    fprintf(stderr, "libpng error: %s\n", message);
 #endif
 
@@ -131,18 +130,17 @@ png_default_error(png_structp png_ptr, png_const_charp message)
 
 /* This function is called when there is a warning, but the library thinks
  * it can continue anyway.  Replacement functions don't have to do anything
- * here if you don't want to.  In the default configuration, png_ptr is
+ * here if you don't want them to.  In the default configuration, png_ptr is
  * not used, but it is passed in case it may be useful.
  */
 static void
 png_default_warning(png_structp png_ptr, png_const_charp message)
 {
-   if (png_ptr == NULL)
-      return;
-
-#ifndef PNG_NO_STDIO
+#ifndef PNG_NO_CONSOLE_IO
    fprintf(stderr, "libpng warning: %s\n", message);
 #endif
+   if (png_ptr == NULL)
+      return;
 }
 
 /* This function is called when the application wants to use another method

pngget.c

@@ -1,12 +1,11 @@
 
 /* pngget.c - retrieval of values from info struct
  *
- * libpng 1.0.1d
+ * libpng 1.0.3 - January 14, 1999
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
- * May 21, 1998
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  */
 
 #define PNG_INTERNAL
@@ -302,11 +301,11 @@ png_get_pHYs_dpi(png_structp png_ptr, png_infop info_ptr,
    }
    return (retval);
 }
-#endif
-
+#endif /* PNG_READ_pHYs_SUPPORTED */
 #endif  /* PNG_INCH_CONVERSIONS */
 
 /* png_get_channels really belongs in here, too, but it's been around longer */
+
 #endif  /* PNG_EASY_ACCESS_SUPPORTED */
 
 png_byte
@@ -424,7 +423,7 @@ png_get_IHDR(png_structp png_ptr, png_infop info_ptr,
    png_uint_32 *width, png_uint_32 *height, int *bit_depth,
    int *color_type, int *interlace_type, int *compression_type,
    int *filter_type)
-   
+
 {
    if (png_ptr != NULL && info_ptr != NULL && width != NULL && height != NULL &&
       bit_depth != NULL && color_type != NULL)
@@ -642,3 +641,10 @@ png_get_tRNS(png_structp png_ptr, png_infop info_ptr,
 }
 #endif
 
+#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+png_byte
+png_get_rgb_to_gray_status (png_structp png_ptr)
+{
+   return png_ptr->rgb_to_gray_status;
+}
+#endif

pngmem.c

@@ -1,31 +1,22 @@
 
 /* pngmem.c - stub functions for memory allocation
  *
- * libpng 1.0.1d
+ * libpng 1.0.3 - January 14, 1999
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
- * May 21, 1998
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  *
  * This file provides a location for all memory allocation.  Users who
- * need special memory handling are expected to modify the code in this file
- * to meet their needs.  See the instructions at each function.
+ * need special memory handling are expected to supply replacement
+ * functions for png_malloc() and png_free(), and to use
+ * png_create_read_struct_2() and png_create_write_struct_2() to
+ * identify the replacement functions.
  */
 
 #define PNG_INTERNAL
 #include "png.h"
 
-/* The following "hides" PNG_MALLOC and PNG_FREE thus allowing the pngtest
-   application to put a wrapper on top of them. */
-#ifdef PNGTEST_MEMORY_DEBUG
-#define PNG_MALLOC png_debug_malloc
-#define PNG_FREE   png_debug_free
-#else
-#define PNG_MALLOC png_malloc
-#define PNG_FREE   png_free
-#endif
-
 /* Borland DOS special memory handler */
 #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
 /* if you change this, be sure to change the one in png.h also */
@@ -35,6 +26,15 @@
 png_voidp
 png_create_struct(int type)
 {
+#ifdef PNG_USER_MEM_SUPPORTED
+   return (png_create_struct_2(type, NULL));
+}
+
+/* Alternate version of png_create_struct, for use with user-defined malloc. */
+png_voidp
+png_create_struct_2(int type, png_malloc_ptr malloc_fn)
+{
+#endif /* PNG_USER_MEM_SUPPORTED */
    png_size_t size;
    png_voidp struct_ptr;
 
@@ -45,11 +45,18 @@ png_create_struct(int type)
    else
      return ((png_voidp)NULL);
 
+#ifdef PNG_USER_MEM_SUPPORTED
+   if(malloc_fn != NULL)
+   {
+      if ((struct_ptr = (*(malloc_fn))(NULL, size)) != NULL)
+         png_memset(struct_ptr, 0, size);
+         return (struct_ptr);
+   }
+#endif /* PNG_USER_MEM_SUPPORTED */
    if ((struct_ptr = (png_voidp)farmalloc(size)) != NULL)
    {
       png_memset(struct_ptr, 0, size);
    }
-
    return (struct_ptr);
 }
 
@@ -58,8 +65,27 @@ png_create_struct(int type)
 void
 png_destroy_struct(png_voidp struct_ptr)
 {
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_destroy_struct_2(struct_ptr, (png_free_ptr)NULL);
+}
+
+/* Free memory allocated by a png_create_struct() call */
+void
+png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn)
+{
+#endif
    if (struct_ptr != NULL)
    {
+#ifdef PNG_USER_MEM_SUPPORTED
+      if(free_fn != NULL)
+      {
+         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;
    }
@@ -85,12 +111,27 @@ png_destroy_struct(png_voidp struct_ptr)
  * (which should cause a fatal error) and introducing major problems.
  */
 png_voidp
-PNG_MALLOC(png_structp png_ptr, png_uint_32 size)
+png_malloc(png_structp png_ptr, png_uint_32 size)
 {
+#ifndef PNG_USER_MEM_SUPPORTED
    png_voidp ret;
+#endif
    if (png_ptr == NULL || size == 0)
       return ((png_voidp)NULL);
 
+#ifdef PNG_USER_MEM_SUPPORTED
+   if(png_ptr->malloc_fn != NULL)
+       return ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, size));
+   else
+       return png_malloc_default(png_ptr, size);
+}
+
+png_voidp
+png_malloc_default(png_structp png_ptr, png_uint_32 size)
+{
+   png_voidp ret;
+#endif /* PNG_USER_MEM_SUPPORTED */
+
 #ifdef PNG_MAX_MALLOC_64K
    if (size > (png_uint_32)65536L)
       png_error(png_ptr, "Cannot Allocate > 64K");
@@ -181,15 +222,30 @@ PNG_MALLOC(png_structp png_ptr, png_uint_32 size)
    return (ret);
 }
 
-/* free a pointer allocated by PNG_MALLOC().  In the default
+/* free a pointer allocated by png_malloc().  In the default
    configuration, png_ptr is not used, but is passed in case it
    is needed.  If ptr is NULL, return without taking any action. */
 void
-PNG_FREE(png_structp png_ptr, png_voidp ptr)
+png_free(png_structp png_ptr, png_voidp ptr)
 {
    if (png_ptr == NULL || ptr == NULL)
       return;
 
+#ifdef PNG_USER_MEM_SUPPORTED
+   if (png_ptr->free_fn != NULL)
+   {
+      (*(png_ptr->free_fn))(png_ptr, ptr);
+      ptr = NULL;
+      return;
+   }
+   else png_free_default(png_ptr, ptr);
+}
+
+void
+png_free_default(png_structp png_ptr, png_voidp ptr)
+{
+#endif /* PNG_USER_MEM_SUPPORTED */
+
    if (png_ptr->offset_table != NULL)
    {
       int i;
@@ -227,6 +283,17 @@ PNG_FREE(png_structp png_ptr, png_voidp ptr)
 png_voidp
 png_create_struct(int type)
 {
+#ifdef PNG_USER_MEM_SUPPORTED
+   return (png_create_struct_2(type, NULL));
+}
+
+/* Allocate memory for a png_struct or a png_info.  The malloc and
+   memset can be replaced by a single call to calloc() if this is thought
+   to improve performance noticably.*/
+png_voidp
+png_create_struct_2(int type, png_malloc_ptr malloc_fn)
+{
+#endif /* PNG_USER_MEM_SUPPORTED */
    png_size_t size;
    png_voidp struct_ptr;
 
@@ -237,6 +304,15 @@ png_create_struct(int type)
    else
       return ((png_voidp)NULL);
 
+#ifdef PNG_USER_MEM_SUPPORTED
+   if(malloc_fn != NULL)
+   {
+      if ((struct_ptr = (*(malloc_fn))(NULL, size)) != NULL)
+         png_memset(struct_ptr, 0, size);
+      return (struct_ptr);
+   }
+#endif /* PNG_USER_MEM_SUPPORTED */
+
 #if defined(__TURBOC__) && !defined(__FLAT__)
    if ((struct_ptr = (png_voidp)farmalloc(size)) != NULL)
 #else
@@ -258,15 +334,37 @@ png_create_struct(int type)
 void
 png_destroy_struct(png_voidp struct_ptr)
 {
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_destroy_struct_2(struct_ptr, (png_free_ptr)NULL);
+}
+
+/* Free memory allocated by a png_create_struct() call */
+void
+png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn)
+{
+#endif /* PNG_USER_MEM_SUPPORTED */
    if (struct_ptr != NULL)
    {
+#ifdef PNG_USER_MEM_SUPPORTED
+      if(free_fn != NULL)
+      {
+         png_struct dummy_struct;
+         png_structp png_ptr = &dummy_struct;
+         (*(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
    }
@@ -280,13 +378,26 @@ png_destroy_struct(png_voidp struct_ptr)
    have the ability to do that. */
 
 png_voidp
-PNG_MALLOC(png_structp png_ptr, png_uint_32 size)
+png_malloc(png_structp png_ptr, png_uint_32 size)
 {
+#ifndef PNG_USER_MEM_SUPPORTED
    png_voidp ret;
-
+#endif
    if (png_ptr == NULL || size == 0)
       return ((png_voidp)NULL);
 
+#ifdef PNG_USER_MEM_SUPPORTED
+   if(png_ptr->malloc_fn != NULL)
+       return ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, size));
+   else
+       return (png_malloc_default(png_ptr, size));
+}
+png_voidp
+png_malloc_default(png_structp png_ptr, png_uint_32 size)
+{
+   png_voidp ret;
+#endif /* PNG_USER_MEM_SUPPORTED */
+
 #ifdef PNG_MAX_MALLOC_64K
    if (size > (png_uint_32)65536L)
       png_error(png_ptr, "Cannot Allocate > 64K");
@@ -310,22 +421,38 @@ PNG_MALLOC(png_structp png_ptr, png_uint_32 size)
    return (ret);
 }
 
-/* Free a pointer allocated by PNG_MALLOC().  In the default
-  configuration, png_ptr is not used, but is passed in case it
-  is needed.  If ptr is NULL, return without taking any action. */
+/* Free a pointer allocated by png_malloc().  If ptr is NULL, return
+   without taking any action. */
 void
-PNG_FREE(png_structp png_ptr, png_voidp ptr)
+png_free(png_structp png_ptr, png_voidp ptr)
 {
    if (png_ptr == NULL || ptr == NULL)
       return;
 
+#ifdef PNG_USER_MEM_SUPPORTED
+   if (png_ptr->free_fn != NULL)
+   {
+      (*(png_ptr->free_fn))(png_ptr, ptr);
+      ptr = NULL;
+      return;
+   }
+   else png_free_default(png_ptr, ptr);
+}
+void
+png_free_default(png_structp png_ptr, png_voidp ptr)
+{
+#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
 }
@@ -341,7 +468,7 @@ png_memcpy_check (png_structp png_ptr, png_voidp s1, png_voidp s2,
    size = (png_size_t)length;
    if ((png_uint_32)size != length)
       png_error(png_ptr,"Overflow in png_memcpy_check.");
-  
+
    return(png_memcpy (s1, s2, size));
 }
 
@@ -358,3 +485,27 @@ png_memset_check (png_structp png_ptr, png_voidp s1, int value,
    return (png_memset (s1, value, size));
 
 }
+
+#ifdef PNG_USER_MEM_SUPPORTED
+/* This function is called when the application wants to use another method
+ * of allocating and freeing memory.
+ */
+void
+png_set_mem_fn(png_structp png_ptr, png_voidp mem_ptr, png_malloc_ptr
+  malloc_fn, png_free_ptr free_fn)
+{
+   png_ptr->mem_ptr = mem_ptr;
+   png_ptr->malloc_fn = malloc_fn;
+   png_ptr->free_fn = free_fn;
+}
+
+/* This function returns a pointer to the mem_ptr associated with the user
+ * functions.  The application should free any memory associated with this
+ * pointer before png_write_destroy and png_read_destroy are called.
+ */
+png_voidp
+png_get_mem_ptr(png_structp png_ptr)
+{
+   return ((png_voidp)png_ptr->mem_ptr);
+}
+#endif /* PNG_USER_MEM_SUPPORTED */

pngpread.c

@@ -1,12 +1,11 @@
 
 /* pngpread.c - read a png file in push mode
  *
- * 1.0.1d
+ * libpng 1.0.3 - January 14, 1999
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
- * May 21, 1998
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  */
 
 #define PNG_INTERNAL
@@ -78,8 +77,9 @@ png_process_some_data(png_structp png_ptr, png_infop info_ptr)
 
 /* Read any remaining signature bytes from the stream and compare them with
  * the correct PNG signature.  It is possible that this routine is called
- * with bytes already read from the signature, whether because they have been
- * checked by the calling application, or from multiple calls to this routine.
+ * with bytes already read from the signature, either because they have been
+ * checked by the calling application, or because of multiple calls to this
+ * routine.
  */
 void
 png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
@@ -92,7 +92,7 @@ png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
       num_to_check = png_ptr->buffer_size;
    }
 
-   png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]), 
+   png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]),
       num_to_check);
    png_ptr->sig_bytes += num_to_check;
 
@@ -466,7 +466,7 @@ png_push_save_buffer(png_structp png_ptr)
 
       new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256;
       old_buffer = png_ptr->save_buffer;
-      png_ptr->save_buffer = (png_bytep)png_malloc(png_ptr, 
+      png_ptr->save_buffer = (png_bytep)png_malloc(png_ptr,
          (png_uint_32)new_max);
       png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
       png_free(png_ptr, old_buffer);
@@ -630,7 +630,7 @@ png_push_process_row(png_structp png_ptr)
    png_ptr->row_info.channels = png_ptr->channels;
    png_ptr->row_info.bit_depth = png_ptr->bit_depth;
    png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
-   
+
    png_ptr->row_info.rowbytes = ((png_ptr->row_info.width *
       (png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3);
 
@@ -781,6 +781,7 @@ png_read_push_finish_row(png_structp png_ptr)
          png_ptr->pass++;
          if (png_ptr->pass >= 7)
             break;
+
          png_ptr->iwidth = (png_ptr->width +
             png_pass_inc[png_ptr->pass] - 1 -
             png_pass_start[png_ptr->pass]) /
@@ -789,18 +790,15 @@ png_read_push_finish_row(png_structp png_ptr)
          png_ptr->irowbytes = ((png_ptr->iwidth *
             png_ptr->pixel_depth + 7) >> 3) + 1;
 
-         if (!(png_ptr->transformations & PNG_INTERLACE))
-         {
-            png_ptr->num_rows = (png_ptr->height +
-               png_pass_yinc[png_ptr->pass] - 1 -
-               png_pass_ystart[png_ptr->pass]) /
-               png_pass_yinc[png_ptr->pass];
-            if (!(png_ptr->num_rows))
-               continue;
-         }
          if (png_ptr->transformations & PNG_INTERLACE)
             break;
-      } while (png_ptr->iwidth == 0);
+
+         png_ptr->num_rows = (png_ptr->height +
+            png_pass_yinc[png_ptr->pass] - 1 -
+            png_pass_ystart[png_ptr->pass]) /
+            png_pass_yinc[png_ptr->pass];
+
+      } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
    }
 }
 
@@ -826,7 +824,7 @@ png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length
    }
 #endif
 
-   png_ptr->current_text = (png_charp)png_malloc(png_ptr, 
+   png_ptr->current_text = (png_charp)png_malloc(png_ptr,
          (png_uint_32)(length+1));
    png_ptr->current_text[length] = '\0';
    png_ptr->current_text_ptr = png_ptr->current_text;
@@ -1117,7 +1115,7 @@ void
 png_progressive_combine_row (png_structp png_ptr,
    png_bytep old_row, png_bytep new_row)
 {
-   if (new_row != NULL)
+   if (new_row != NULL)    /* new_row must == png_ptr->row_buf here. */
       png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]);
 }
 

pngread.c

@@ -1,12 +1,11 @@
 
 /* pngread.c - read a PNG file
  *
- * 1.0.1d
+ * libpng 1.0.3 - January 14, 1999
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
- * May 21, 1998
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  *
  * This file contains routines that an application calls directly to
  * read a PNG file or stream.
@@ -20,12 +19,31 @@ png_structp
 png_create_read_struct(png_const_charp user_png_ver, png_voidp error_ptr,
    png_error_ptr error_fn, png_error_ptr warn_fn)
 {
+
+#ifdef PNG_USER_MEM_SUPPORTED
+   return (png_create_read_struct_2(user_png_ver, error_ptr, error_fn,
+      warn_fn, NULL, NULL, NULL));
+}
+
+/* Alternate create PNG structure for reading, and allocate any memory needed. */
+png_structp
+png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
+   png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
+   png_malloc_ptr malloc_fn, png_free_ptr free_fn)
+{
+#endif /* PNG_USER_MEM_SUPPORTED */
+
    png_structp png_ptr;
 #ifdef USE_FAR_KEYWORD
    jmp_buf jmpbuf;
 #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,
+      (png_malloc_ptr)malloc_fn)) == NULL)
+#else
    if ((png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG)) == NULL)
+#endif
    {
       return (png_structp)NULL;
    }
@@ -42,6 +60,11 @@ png_create_read_struct(png_const_charp user_png_ver, png_voidp error_ptr,
 #ifdef USE_FAR_KEYWORD
    png_memcpy(png_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf));
 #endif
+
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
+#endif /* PNG_USER_MEM_SUPPORTED */
+
    png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
 
    /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
@@ -258,7 +281,7 @@ png_read_update_info(png_structp png_ptr, png_infop info_ptr)
 
 /* Initialize palette, background, etc, after transformations
  * are set, but before any reading takes place.  This allows
- * the user to obtail a gamma corrected palette, for example.
+ * the user to obtain a gamma-corrected palette, for example.
  * If the user doesn't call this, we will do it ourselves.
  */
 void
@@ -489,10 +512,10 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
 /* Read one or more rows of image data.  If the image is interlaced,
  * and png_set_interlace_handling() has been called, the rows need to
  * contain the contents of the rows from the previous pass.  If the
- * image has alpha or transparency, and png_handle_alpha() has been
+ * image has alpha or transparency, and png_handle_alpha()[*] has been
  * called, the rows contents must be initialized to the contents of the
  * screen.
- * 
+ *
  * "row" holds the actual image, and pixels are placed in it
  * as they arrive.  If the image is displayed after each pass, it will
  * appear to "sparkle" in.  "display_row" can be used to display a
@@ -506,6 +529,8 @@ png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
  * also, but you may.  If the image is not interlaced, or if you have
  * 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 1.0.3.
  */
 
 void
@@ -525,7 +550,7 @@ png_read_rows(png_structp png_ptr, png_bytepp row,
       {
          png_bytep rptr = *rp++;
          png_bytep dptr = *dp++;
-   
+
          png_read_row(png_ptr, rptr, dptr);
       }
    else if(rp != NULL)
@@ -545,7 +570,7 @@ png_read_rows(png_structp png_ptr, png_bytepp row,
 }
 
 /* Read the entire image.  If the image has an alpha channel or a tRNS
- * chunk, and you have called png_handle_alpha(), you will need to
+ * chunk, and you have called png_handle_alpha()[*], you will need to
  * initialize the image to the current image that PNG will be overlaying.
  * We set the num_rows again here, in case it was incorrectly set in
  * png_read_start_row() by a call to png_read_update_info() or
@@ -553,6 +578,8 @@ png_read_rows(png_structp png_ptr, png_bytepp row,
  * prior to either of these functions like it should have been.  You can
  * only call this function once.  If you desire to have an image for
  * each pass of a interlaced image, use png_read_rows() instead.
+ *
+ * [*] png_handle_alpha() does not exist yet, as of libpng version 1.0.3.
  */
 void
 png_read_image(png_structp png_ptr, png_bytepp image)
@@ -683,6 +710,9 @@ png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
 {
    png_structp png_ptr = NULL;
    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 */
 
    png_debug(1, "in png_destroy_read_struct\n");
    /* save jump buffer and error functions */
@@ -695,6 +725,10 @@ png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
    if (end_info_ptr_ptr != NULL)
       end_info_ptr = *end_info_ptr_ptr;
 
+#ifdef PNG_USER_MEM_SUPPORTED
+   free_fn = png_ptr->free_fn;
+#endif
+
    png_read_destroy(png_ptr, info_ptr, end_info_ptr);
 
    if (info_ptr != NULL)
@@ -702,7 +736,12 @@ png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
 #if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED)
       png_free(png_ptr, info_ptr->text);
 #endif
+
+#ifdef PNG_USER_MEM_SUPPORTED
+      png_destroy_struct_2((png_voidp)info_ptr, free_fn);
+#else
       png_destroy_struct((png_voidp)info_ptr);
+#endif
       *info_ptr_ptr = (png_infop)NULL;
    }
 
@@ -711,13 +750,21 @@ png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
 #if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED)
       png_free(png_ptr, end_info_ptr->text);
 #endif
+#ifdef PNG_USER_MEM_SUPPORTED
+      png_destroy_struct_2((png_voidp)end_info_ptr, free_fn);
+#else
       png_destroy_struct((png_voidp)end_info_ptr);
+#endif
       *end_info_ptr_ptr = (png_infop)NULL;
    }
 
    if (png_ptr != NULL)
    {
+#ifdef PNG_USER_MEM_SUPPORTED
+      png_destroy_struct_2((png_voidp)png_ptr, free_fn);
+#else
       png_destroy_struct((png_voidp)png_ptr);
+#endif
       *png_ptr_ptr = (png_structp)NULL;
    }
 }
@@ -730,6 +777,9 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
    png_error_ptr error_fn;
    png_error_ptr warning_fn;
    png_voidp error_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_free_ptr free_fn;
+#endif
 
    png_debug(1, "in png_read_destroy\n");
    /* save jump buffer and error functions */
@@ -770,10 +820,9 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
       {
          png_free(png_ptr, png_ptr->gamma_16_table[i]);
       }
-   }
-#endif
-#if defined(PNG_READ_BACKGROUND_SUPPORTED)
    png_free(png_ptr, png_ptr->gamma_16_table);
+   }
+#if defined(PNG_READ_BACKGROUND_SUPPORTED)
    if (png_ptr->gamma_16_from_1 != NULL)
    {
       int i;
@@ -782,8 +831,8 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
       {
          png_free(png_ptr, png_ptr->gamma_16_from_1[i]);
       }
-   }
    png_free(png_ptr, png_ptr->gamma_16_from_1);
+   }
    if (png_ptr->gamma_16_to_1 != NULL)
    {
       int i;
@@ -792,9 +841,13 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
       {
          png_free(png_ptr, png_ptr->gamma_16_to_1[i]);
       }
-   }
    png_free(png_ptr, png_ptr->gamma_16_to_1);
+   }
 #endif
+#endif
+#if defined(PNG_TIME_RFC1123_SUPPORTED)
+   png_free(png_ptr, png_ptr->time_buffer);
+#endif /* PNG_TIME_RFC1123_SUPPORTED */
 
    inflateEnd(&png_ptr->zstream);
 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
@@ -809,12 +862,18 @@ png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr
    error_fn = png_ptr->error_fn;
    warning_fn = png_ptr->warning_fn;
    error_ptr = png_ptr->error_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+   free_fn = png_ptr->free_fn;
+#endif
 
    png_memset(png_ptr, 0, sizeof (png_struct));
 
    png_ptr->error_fn = error_fn;
    png_ptr->warning_fn = warning_fn;
    png_ptr->error_ptr = error_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_ptr->free_fn = free_fn;
+#endif
 
    png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf));
 }

pngrio.c

@@ -1,12 +1,11 @@
 
 /* pngrio.c - functions for data input
  *
- * libpng 1.0.1d
+ * libpng 1.0.3 - January 14, 1999
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
- * May 21, 1998
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  *
  * This file provides a location for all input.  Users who need
  * special handling are expected to write a function that has the same
@@ -61,10 +60,10 @@ png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
    can't handle far buffers in the medium and small models, we have to copy
    the data.
 */
- 
+
 #define NEAR_BUF_SIZE 1024
 #define MIN(a,b) (a <= b ? a : b)
- 
+
 static void
 png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
 {
@@ -136,7 +135,14 @@ png_set_read_fn(png_structp png_ptr, png_voidp io_ptr,
 #endif
 
    /* It is an error to write to a read device */
-   png_ptr->write_data_fn = NULL;
+   if (png_ptr->write_data_fn != NULL)
+   {
+      png_ptr->write_data_fn = NULL;
+      png_warning(png_ptr,
+         "It's an error to set both read_data_fn and write_data_fn in the ");
+      png_warning(png_ptr,
+         "same structure.  Resetting write_data_fn to NULL.");
+   }
 
 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
    png_ptr->output_flush_fn = NULL;

pngrtran.c

@@ -1,14 +1,13 @@
 
 /* pngrtran.c - transforms the data in a row for PNG readers
  *
- * 1.0.1d
+ * libpng 1.0.3 - January 14, 1999
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
- * May 21, 1998
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  *
- * This file contains functions optionally called by an application 
+ * This file contains functions optionally called by an application
  * in order to tell libpng how to handle data when reading a PNG.
  * Transformations that are used in both reading and writing are
  * in pngtrans.c.
@@ -285,8 +284,8 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
             don't always behave themselves with only a few colors
             as input.  So we will just find the closest two colors,
             and throw out one of them (chosen somewhat randomly).
-            [I don't understand this at all, so if someone wants to
-             work on improving it, be my guest - AED]
+            [We don't understand this at all, so if someone wants to
+             work on improving it, be our guest - AED, GRP]
             */
          int i;
          int max_d;
@@ -310,7 +309,7 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
             palette_to_index[i] = (png_byte)i;
          }
 
-         hash = (png_dsortpp)png_malloc(png_ptr, (png_uint_32)(769 * 
+         hash = (png_dsortpp)png_malloc(png_ptr, (png_uint_32)(769 *
             sizeof (png_dsortp)));
          for (i = 0; i < 769; i++)
             hash[i] = NULL;
@@ -524,7 +523,7 @@ png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma)
 
 #if defined(PNG_READ_EXPAND_SUPPORTED)
 /* Expand paletted images to rgb, expand grayscale images of
- * less then 8 bit depth to 8 bit depth, and expand tRNS chunks
+ * less than 8 bit depth to 8 bit depth, and expand tRNS chunks
  * to alpha channels.
  */
 void
@@ -545,17 +544,49 @@ png_set_gray_to_rgb(png_structp png_ptr)
 #endif
 
 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
-/* Convert a RGB image to a grayscale of the given width.  This would
- * allow us, for example, to convert a 24 bpp RGB image into an 8 or
- * 16 bpp grayscale image. (Not yet implemented.)
+/* Convert a RGB image to a grayscale of the same width.  This allows us,
+ * for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image.
  */
 void
-png_set_rgb_to_gray(png_structp png_ptr, int gray_bits)
+png_set_rgb_to_gray(png_structp png_ptr, int error_action, float red,
+  float green)
 {
    png_debug(1, "in png_set_rgb_to_gray\n");
-   png_ptr->transformations |= PNG_RGB_TO_GRAY;
-   /* Need to do something with gray_bits here. */
-   png_warning(png_ptr, "RGB to GRAY transformation is not yet implemented.");
+   switch(error_action)
+   {
+      case 1: png_ptr->transformations |= PNG_RGB_TO_GRAY;
+              break;
+      case 2: png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN;
+              break;
+      case 3: png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR;
+   }
+   if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+#if defined(PNG_READ_EXPAND_SUPPORTED)
+      png_ptr->transformations |= PNG_EXPAND;
+#else
+   {
+      png_warning(png_ptr, "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED.");
+      png_ptr->transformations &= ~PNG_RGB_TO_GRAY;
+   }
+#endif
+   {
+      png_byte red_byte = (png_byte)(red*255.0 + 0.5);
+      png_byte green_byte = (png_byte)(green*255.0 + 0.5);
+      if(red < 0.0 || green < 0.0)
+      {
+         red_byte = 54;
+         green_byte = 183;
+      }
+      else if(red_byte + green_byte > 255)
+      {
+         png_warning(png_ptr, "ignoring out of range rgb_to_gray coefficients");
+         red_byte = 54;
+         green_byte = 183;
+      }
+      png_ptr->rgb_to_gray_red_coeff   = red_byte;
+      png_ptr->rgb_to_gray_green_coeff = green_byte;
+      png_ptr->rgb_to_gray_blue_coeff  = 255 - red_byte - green_byte;
+   }
 }
 #endif
 
@@ -632,7 +663,7 @@ png_init_read_transformations(png_structp png_ptr)
            if (!(png_ptr->transformations & PNG_EXPAND))
 #endif
            {
-           /* invert the alpha channel (in tRNS) unless the pixels are 
+           /* invert the alpha channel (in tRNS) unless the pixels are
               going to be expanded, in which case leave it for later */
               int i,istop;
               istop=(int)png_ptr->num_trans;
@@ -650,7 +681,7 @@ png_init_read_transformations(png_structp png_ptr)
    png_ptr->background_1 = png_ptr->background;
 #endif
 #if defined(PNG_READ_GAMMA_SUPPORTED)
-   if (png_ptr->transformations & PNG_GAMMA)
+   if (png_ptr->transformations & (PNG_GAMMA | PNG_RGB_TO_GRAY))
    {
       png_build_gamma_table(png_ptr);
 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
@@ -927,6 +958,11 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
    }
 #endif
 
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+   if (png_ptr->transformations & PNG_GAMMA)
+      info_ptr->gamma = png_ptr->gamma;
+#endif
+
 #if defined(PNG_READ_16_TO_8_SUPPORTED)
    if ((png_ptr->transformations & PNG_16_TO_8) && info_ptr->bit_depth == 16)
       info_ptr->bit_depth = 8;
@@ -954,6 +990,11 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
       info_ptr->color_type |= PNG_COLOR_MASK_COLOR;
 #endif
 
+#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+   if (png_ptr->transformations & PNG_RGB_TO_GRAY)
+      info_ptr->color_type &= ~PNG_COLOR_MASK_COLOR;
+#endif
+
    if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
       info_ptr->channels = 1;
    else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR)
@@ -1013,7 +1054,7 @@ png_do_read_transformations(png_structp png_ptr)
          png_do_expand_palette(&(png_ptr->row_info), png_ptr->row_buf + 1,
             png_ptr->palette, png_ptr->trans, png_ptr->num_trans);
       }
-      else if (png_ptr->transformations & PNG_EXPAND)
+      else
       {
          if (png_ptr->num_trans)
             png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1,
@@ -1031,12 +1072,28 @@ png_do_read_transformations(png_structp png_ptr)
          PNG_FLAG_FILLER_AFTER);
 #endif
 
+#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+   if (png_ptr->transformations & PNG_RGB_TO_GRAY)
+   {
+      int rgb_error =
+         png_do_rgb_to_gray(png_ptr, &(png_ptr->row_info), png_ptr->row_buf + 1);
+      if(rgb_error)
+      {
+         png_ptr->rgb_to_gray_status=1;
+         if(png_ptr->transformations == PNG_RGB_TO_GRAY_WARN)
+            png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel");
+         if(png_ptr->transformations == PNG_RGB_TO_GRAY_ERR)
+            png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel");
+      }
+   }
+#endif
+
 /*
 From Andreas Dilger e-mail to png-implement, 26 March 1998:
 
   In most cases, the "simple transparency" should be done prior to doing
   gray-to-RGB, or you will have to test 3x as many bytes to check if a
-  pixel is transparent.  You would also need to make sure that the 
+  pixel is transparent.  You would also need to make sure that the
   transparency information is upgraded to RGB.
 
   To summarize, the current flow is:
@@ -1084,18 +1141,17 @@ From Andreas Dilger e-mail to png-implement, 26 March 1998:
 
 #if defined(PNG_READ_GAMMA_SUPPORTED)
    if ((png_ptr->transformations & PNG_GAMMA) &&
-      !(png_ptr->transformations & PNG_BACKGROUND) &&
+#if defined(PNG_READ_BACKGROUND_SUPPORTED)
+      !((png_ptr->transformations & PNG_BACKGROUND) &&
+      ((png_ptr->num_trans != 0) ||
+      (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) &&
+#endif
       (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE))
       png_do_gamma(&(png_ptr->row_info), png_ptr->row_buf + 1,
          png_ptr->gamma_table, png_ptr->gamma_16_table,
          png_ptr->gamma_shift);
 #endif
 
-#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
-   if (png_ptr->transformations & PNG_RGB_TO_GRAY)
-      png_do_rgb_to_gray(&(png_ptr->row_info), png_ptr->row_buf + 1);
-#endif
-
 #if defined(PNG_READ_16_TO_8_SUPPORTED)
    if (png_ptr->transformations & PNG_16_TO_8)
       png_do_chop(&(png_ptr->row_info), png_ptr->row_buf + 1);
@@ -1351,7 +1407,6 @@ png_do_unshift(png_row_infop row_info, png_bytep row, png_color_8p sig_bits)
             }
             break;
          }
-#ifndef PNG_SLOW_SHIFT
          case 8:
          {
             png_bytep bp = row;
@@ -1379,43 +1434,6 @@ png_do_unshift(png_row_infop row_info, png_bytep row, png_color_8p sig_bits)
             }
             break;
          }
-#else
-         case 8:
-         {
-            png_bytep bp;
-            png_uint_32 i;
-            int cstop;
-
-            cstop=(int)row_info->channels;
-            for (bp = row, i = 0; i < row_width; i++)
-            {
-               for (c = 0; c < cstop; c++, bp++)
-               {
-                  *bp >>= shift[c];
-               }
-            }
-            break;
-         }
-         case 16:
-         {
-            png_bytep bp;
-            png_size_t i;
-            int cstop;
-
-            cstop=(int)row_info->channels;
-            for (bp = row, i = 0; i < row_width; i++)
-            {
-               for (c = 0; c < cstop; c++, bp += 2)
-               {
-                  value = (png_uint_16)((*bp << 8) + *(bp + 1));
-                  value >>= shift[c];
-                  *bp = (png_byte)(value >> 8);
-                  *(bp + 1) = (png_byte)(value & 0xff);
-               }
-            }
-            break;
-         }
-#endif
       }
    }
 }
@@ -1660,7 +1678,7 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
    png_uint_32 row_width = row_info->width;
 
    png_byte hi_filler = (png_byte)((filler>>8) & 0xff);
-   png_byte low_filler = (png_byte)(filler & 0xff);
+   png_byte lo_filler = (png_byte)(filler & 0xff);
 
    png_debug(1, "in png_do_read_filler\n");
    if (
@@ -1678,9 +1696,10 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
             png_bytep dp =  sp + (png_size_t)row_width;
             for (i = 1; i < row_width; i++)
             {
-               *(--dp) = low_filler;
+               *(--dp) = lo_filler;
                *(--dp) = *(--sp);
             }
+            *(--dp) = lo_filler;
             row_info->channels = 2;
             row_info->pixel_depth = 16;
             row_info->rowbytes = row_width * 2;
@@ -1693,7 +1712,7 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
             for (i = 0; i < row_width; i++)
             {
                *(--dp) = *(--sp);
-               *(--dp) = low_filler;
+               *(--dp) = lo_filler;
             }
             row_info->channels = 2;
             row_info->pixel_depth = 16;
@@ -1710,10 +1729,12 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
             for (i = 1; i < row_width; i++)
             {
                *(--dp) = hi_filler;
-               *(--dp) = low_filler;
+               *(--dp) = lo_filler;
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
             }
+            *(--dp) = hi_filler;
+            *(--dp) = lo_filler;
             row_info->channels = 2;
             row_info->pixel_depth = 32;
             row_info->rowbytes = row_width * 2;
@@ -1728,7 +1749,7 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
                *(--dp) = hi_filler;
-               *(--dp) = low_filler;
+               *(--dp) = lo_filler;
             }
             row_info->channels = 2;
             row_info->pixel_depth = 16;
@@ -1747,11 +1768,12 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
             png_bytep dp = sp  + (png_size_t)row_width;
             for (i = 1; i < row_width; i++)
             {
-               *(--dp) = low_filler;
+               *(--dp) = lo_filler;
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
             }
+            *(--dp) = lo_filler;
             row_info->channels = 4;
             row_info->pixel_depth = 32;
             row_info->rowbytes = row_width * 4;
@@ -1766,7 +1788,7 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
-               *(--dp) = low_filler;
+               *(--dp) = lo_filler;
             }
             row_info->channels = 4;
             row_info->pixel_depth = 32;
@@ -1783,7 +1805,7 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
             for (i = 1; i < row_width; i++)
             {
                *(--dp) = hi_filler;
-               *(--dp) = low_filler;
+               *(--dp) = lo_filler;
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
@@ -1791,6 +1813,8 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
             }
+            *(--dp) = hi_filler;
+            *(--dp) = lo_filler;
             row_info->channels = 4;
             row_info->pixel_depth = 64;
             row_info->rowbytes = row_width * 4;
@@ -1809,7 +1833,7 @@ png_do_read_filler(png_row_infop row_info, png_bytep row,
                *(--dp) = *(--sp);
                *(--dp) = *(--sp);
                *(--dp) = hi_filler;
-               *(--dp) = low_filler;
+               *(--dp) = lo_filler;
             }
             row_info->channels = 4;
             row_info->pixel_depth = 64;
@@ -1910,6 +1934,261 @@ png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
 }
 #endif
 
+#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+/* reduce RGB files to grayscale, with or without alpha 
+ * using the equation given in Poynton's ColorFAQ at
+ * <http://www.inforamp.net/~poynton/>
+ * Copyright (c) 1998-01-04 Charles Poynton poynton@inforamp.net
+ *
+ *     Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
+ *
+ *  We approximate this with
+ * 
+ *     Y = 0.211 * R    + 0.715 * G    + 0.074 * B
+ *
+ *  which can be expressed with integers as
+ *
+ *     Y = (54 * R + 183 * G + 19 * B)/256
+ *
+ *  The calculation is to be done in a linear colorspace.
+ *
+ *  Other integer coefficents can be used via png_set_rgb_to_gray().
+ */
+int
+png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
+
+{
+   png_uint_32 i;
+
+   png_uint_32 row_width = row_info->width;
+   int rgb_error = 0;
+
+   png_debug(1, "in png_do_rgb_to_gray\n");
+   if (
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+       row != NULL && row_info != NULL &&
+#endif
+      (row_info->color_type & PNG_COLOR_MASK_COLOR))
+   {
+      png_byte rc = png_ptr->rgb_to_gray_red_coeff;
+      png_byte gc = png_ptr->rgb_to_gray_green_coeff;
+      png_byte bc = png_ptr->rgb_to_gray_blue_coeff;
+
+      if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+      {
+         if (row_info->bit_depth == 8)
+         {
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+            if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL)
+            {
+               png_bytep sp = row;
+               png_bytep dp = row;
+
+               for (i = 0; i < row_width; i++)
+               {
+                  png_byte red   = png_ptr->gamma_to_1[*(sp++)];
+                  png_byte green = png_ptr->gamma_to_1[*(sp++)];
+                  png_byte blue  = png_ptr->gamma_to_1[*(sp++)];
+                  if(red != green || red != blue)
+                  {
+                     rgb_error |= 1;
+                     *(dp++) = png_ptr->gamma_from_1[
+                       (rc*red+gc*green+bc*blue)>>8];
+                  }
+                  else
+                     *(dp++) = *(sp-1);
+               }
+            }
+            else
+#endif
+            {
+               png_bytep sp = row;
+               png_bytep dp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  png_byte red   = *(sp++);
+                  png_byte green = *(sp++);
+                  png_byte blue  = *(sp++);
+                  if(red != green || red != blue)
+                  {
+                     rgb_error |= 1;
+                     *(dp++) = (rc*red+gc*green+bc*blue)>>8;
+                  }
+                  else
+                     *(dp++) = *(sp-1);
+               }
+            }
+         }
+ 
+         else /* RGB bit_depth == 16 */
+         {
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+            if (png_ptr->gamma_16_to_1 != NULL &&
+                png_ptr->gamma_16_from_1 != NULL)
+            {
+               png_bytep sp = row;
+               png_bytep dp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  png_uint_16 red, green, blue, w;
+
+                  red   = ((*(sp))<<8) | *(sp+1); sp+=2;
+                  green = ((*(sp))<<8) | *(sp+1); sp+=2;
+                  blue  = ((*(sp))<<8) | *(sp+1); sp+=2;
+
+                  if(red == green && red == blue)
+                     w = red;
+                  else
+                  {
+                     png_uint_16 red_1   = png_ptr->gamma_16_to_1[(red&0xff) >>
+                                  png_ptr->gamma_shift][red>>8];
+                     png_uint_16 green_1 = png_ptr->gamma_16_to_1[(green&0xff) >>
+                                  png_ptr->gamma_shift][green>>8];
+                     png_uint_16 blue_1  = png_ptr->gamma_16_to_1[(blue&0xff) >> 
+                                  png_ptr->gamma_shift][blue>>8];
+                     png_uint_16 gray16  =  (rc * red_1 + gc * green_1
+                                  + bc * blue_1)>>8;
+                     w = png_ptr->gamma_16_from_1[(gray16&0xff) >>
+                         png_ptr->gamma_shift][gray16 >> 8];
+                     rgb_error |= 1;
+                  }
+                  
+                  *(dp++) = (w>>8) & 0xff;
+                  *(dp++) = w & 0xff;
+               }
+            }
+            else
+#endif
+            {
+               png_bytep sp = row;
+               png_bytep dp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  png_uint_16 red, green, blue, gray16;
+
+                  red   = ((*(sp))<<8) | *(sp+1); sp+=2;
+                  green = ((*(sp))<<8) | *(sp+1); sp+=2;
+                  blue  = ((*(sp))<<8) | *(sp+1); sp+=2;
+
+                  if(red != green || red != blue)
+                     rgb_error |= 1;
+                  gray16  =  (rc * red + gc * green + bc * blue)>>8;
+                  *(dp++) = (gray16>>8) & 0xff;
+                  *(dp++) = gray16 & 0xff;
+               }
+            }
+         }
+      }
+      if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+      {
+         if (row_info->bit_depth == 8)
+         {
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+            if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL)
+            {
+               png_bytep sp = row;
+               png_bytep dp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  png_byte red   = png_ptr->gamma_to_1[*(sp++)];
+                  png_byte green = png_ptr->gamma_to_1[*(sp++)];
+                  png_byte blue  = png_ptr->gamma_to_1[*(sp++)];
+                  if(red != green || red != blue)
+                     rgb_error |= 1;
+                  *(dp++) =  png_ptr->gamma_from_1
+                             [(rc*red + gc*green + bc*blue)>>8];
+                  *(dp++) = *(sp++);  /* alpha */
+               }
+            }
+            else
+#endif
+            {
+               png_bytep sp = row;
+               png_bytep dp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  png_byte red   = *(sp++);
+                  png_byte green = *(sp++);
+                  png_byte blue  = *(sp++);
+                  if(red != green || red != blue)
+                     rgb_error |= 1;
+                  *(dp++) =  (gc*red + gc*green + bc*blue)>>8;
+                  *(dp++) = *(sp++);  /* alpha */
+               }
+            }
+         }
+         else /* RGBA bit_depth == 16 */
+         {
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+            if (png_ptr->gamma_16_to_1 != NULL &&
+                png_ptr->gamma_16_from_1 != NULL)
+            {
+               png_bytep sp = row;
+               png_bytep dp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  png_uint_16 red, green, blue, w;
+
+                  red   = ((*(sp))<<8) | *(sp+1); sp+=2;
+                  green = ((*(sp))<<8) | *(sp+1); sp+=2;
+                  blue  = ((*(sp))<<8) | *(sp+1); sp+=2;
+
+                  if(red == green && red == blue)
+                     w = red;
+                  else
+                  {
+                     png_uint_16 red_1   = png_ptr->gamma_16_to_1[(red&0xff) >>
+                                  png_ptr->gamma_shift][red>>8];
+                     png_uint_16 green_1 = png_ptr->gamma_16_to_1[(green&0xff) >>
+                                  png_ptr->gamma_shift][green>>8];
+                     png_uint_16 blue_1  = png_ptr->gamma_16_to_1[(blue&0xff) >> 
+                                  png_ptr->gamma_shift][blue>>8];
+                     png_uint_16 gray16  =  (rc * red_1 + gc * green_1
+                                  + bc * blue_1)>>8;
+                     w = png_ptr->gamma_16_from_1[(gray16&0xff) >>
+                         png_ptr->gamma_shift][gray16 >> 8];
+                     rgb_error |= 1;
+                  }
+                  
+                  *(dp++) = (w>>8) & 0xff;
+                  *(dp++) = w & 0xff;
+                  *(dp++) = *(sp++);  /* alpha */
+                  *(dp++) = *(sp++);
+               }
+            }
+            else
+#endif
+            {
+               png_bytep sp = row;
+               png_bytep dp = row;
+               for (i = 0; i < row_width; i++)
+               {
+                  png_uint_16 red, green, blue, gray16;
+                  red   = (*(sp)<<8) | *(sp+1); sp+=2;
+                  green = (*(sp)<<8) | *(sp+1); sp+=2;
+                  blue  = (*(sp)<<8) | *(sp+1); sp+=2;
+                  if(red != green || red != blue)
+                     rgb_error |= 1;
+                  gray16  =  (rc * red + gc * green + bc * blue)>>8;
+                  *(dp++) = (gray16>>8) & 0xff;
+                  *(dp++) = gray16 & 0xff;
+                  *(dp++) = *(sp++);  /* alpha */
+                  *(dp++) = *(sp++);
+               }
+            }
+         }
+      }
+   row_info->channels -= (png_byte)2;
+      row_info->color_type &= ~PNG_COLOR_MASK_COLOR;
+      row_info->pixel_depth = (png_byte)(row_info->channels *
+         row_info->bit_depth);
+      row_info->rowbytes = ((row_width *
+         row_info->pixel_depth + 7) >> 3);
+   }
+   return rgb_error;
+}
+#endif
+
 /* Build a grayscale palette.  Palette is assumed to be 1 << bit_depth
  * large of png_color.  This lets grayscale images be treated as
  * paletted.  Most useful for gamma correction and simplification
@@ -1967,8 +2246,7 @@ png_correct_palette(png_structp png_ptr, png_colorp palette,
 {
    png_debug(1, "in png_correct_palette\n");
 #if defined(PNG_READ_BACKGROUND_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
-   if ((png_ptr->transformations & (PNG_GAMMA)) &&
-      (png_ptr->transformations & (PNG_BACKGROUND)))
+   if (png_ptr->transformations & (PNG_GAMMA | PNG_BACKGROUND))
    {
       png_color back, back_1;
 
@@ -2197,45 +2475,112 @@ png_do_background(png_row_infop row_info, png_bytep row,
                }
                case 2:
                {
-                  sp = row;
-                  shift = 6;
-                  for (i = 0; i < row_width; i++)
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+                  if (gamma_table != NULL)
                   {
-                     if ((png_uint_16)((*sp >> shift) & 0x3)
-                         == trans_values->gray)
+                     sp = row;
+                     shift = 6;
+                     for (i = 0; i < row_width; i++)
                      {
-                        *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
-                        *sp |= (png_byte)(background->gray << shift);
+                        if ((png_uint_16)((*sp >> shift) & 0x3)
+                            == trans_values->gray)
+                        {
+                           *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
+                           *sp |= (png_byte)(background->gray << shift);
+                        }
+                        else
+                        {
+                           png_byte p = (*sp >> shift) & 0x3;
+                           png_byte g = (gamma_table [p | (p << 2) | (p << 4) |
+                               (p << 6)] >> 6) & 0x3;
+                           *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
+                           *sp |= (png_byte)(g << shift);
+                        }
+                        if (!shift)
+                        {
+                           shift = 6;
+                           sp++;
+                        }
+                        else
+                           shift -= 2;
                      }
-                     if (!shift)
+                  }
+                  else
+#endif
+                  {
+                     sp = row;
+                     shift = 6;
+                     for (i = 0; i < row_width; i++)
                      {
-                        shift = 6;
-                        sp++;
+                        if ((png_uint_16)((*sp >> shift) & 0x3)
+                            == trans_values->gray)
+                        {
+                           *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
+                           *sp |= (png_byte)(background->gray << shift);
+                        }
+                        if (!shift)
+                        {
+                           shift = 6;
+                           sp++;
+                        }
+                        else
+                           shift -= 2;
                      }
-                     else
-                        shift -= 2;
                   }
                   break;
                }
                case 4:
                {
-                  sp = row;
-                  shift = 4;
-                  for (i = 0; i < row_width; i++)
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+                  if (gamma_table != NULL)
                   {
-                     if ((png_uint_16)((*sp >> shift) & 0xf)
-                         == trans_values->gray)
+                     sp = row;
+                     shift = 4;
+                     for (i = 0; i < row_width; i++)
                      {
-                        *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
-                        *sp |= (png_byte)(background->gray << shift);
+                        if ((png_uint_16)((*sp >> shift) & 0xf)
+                            == trans_values->gray)
+                        {
+                           *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
+                           *sp |= (png_byte)(background->gray << shift);
+                        }
+                        else
+                        {
+                           png_byte p = (*sp >> shift) & 0xf;
+                           png_byte g = (gamma_table[p | (p << 4)] >> 4) & 0xf;
+                           *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
+                           *sp |= (png_byte)(g << shift);
+                        }
+                        if (!shift)
+                        {
+                           shift = 4;
+                           sp++;
+                        }
+                        else
+                           shift -= 4;
                      }
-                     if (!shift)
+                  }
+                  else
+#endif
+                  {
+                     sp = row;
+                     shift = 4;
+                     for (i = 0; i < row_width; i++)
                      {
-                        shift = 4;
-                        sp++;
+                        if ((png_uint_16)((*sp >> shift) & 0xf)
+                            == trans_values->gray)
+                        {
+                           *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
+                           *sp |= (png_byte)(background->gray << shift);
+                        }
+                        if (!shift)
+                        {
+                           shift = 4;
+                           sp++;
+                        }
+                        else
+                           shift -= 4;
                      }
-                     else
-                        shift -= 4;
                   }
                   break;
                }
@@ -2744,7 +3089,7 @@ png_do_background(png_row_infop row_info, png_bytep row,
 
 #if defined(PNG_READ_GAMMA_SUPPORTED)
 /* Gamma correct the image, avoiding the alpha channel.  Make sure
- * you do this after you deal with the trasparency issue on grayscale
+ * you do this after you deal with the transparency issue on grayscale
  * or rgb images. If your bit depth is 8, use gamma_table, if it
  * is 16, use gamma_16_table and gamma_shift.  Build these with
  * build_gamma_table().
@@ -3376,13 +3721,18 @@ static int png_gamma_shift[] =
 void
 png_build_gamma_table(png_structp png_ptr)
 {
-   png_debug(1, "in png_build_gamma_table\n");
+  png_debug(1, "in png_build_gamma_table\n");
+  if(png_ptr->gamma != 0.0)
+  {
    if (png_ptr->bit_depth <= 8)
    {
       int i;
       double g;
 
-      g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
+      if (png_ptr->screen_gamma > .000001)
+         g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
+      else
+         g = 1.0;
 
       png_ptr->gamma_table = (png_bytep)png_malloc(png_ptr,
          (png_uint_32)256);
@@ -3393,9 +3743,11 @@ png_build_gamma_table(png_structp png_ptr)
             g) * 255.0 + .5);
       }
 
-#if defined(PNG_READ_BACKGROUND_SUPPORTED)
-      if (png_ptr->transformations & PNG_BACKGROUND)
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+    defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+      if (png_ptr->transformations & (PNG_BACKGROUND | PNG_RGB_TO_GRAY))
       {
+
          g = 1.0 / (png_ptr->gamma);
 
          png_ptr->gamma_to_1 = (png_bytep)png_malloc(png_ptr,
@@ -3407,18 +3759,23 @@ png_build_gamma_table(png_structp png_ptr)
                g) * 255.0 + .5);
          }
 
-         g = 1.0 / (png_ptr->screen_gamma);
-
+         
          png_ptr->gamma_from_1 = (png_bytep)png_malloc(png_ptr,
             (png_uint_32)256);
 
+         if(png_ptr->screen_gamma > 0.000001)
+            g = 1.0 / png_ptr->screen_gamma;
+         else
+            g = png_ptr->gamma;   /* probably doing rgb_to_gray */
+
          for (i = 0; i < 256; i++)
          {
             png_ptr->gamma_from_1[i] = (png_byte)(pow((double)i / 255.0,
                g) * 255.0 + .5);
+
          }
       }
-#endif /* PNG_BACKGROUND_SUPPORTED */
+#endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */
    }
    else
    {
@@ -3460,13 +3817,15 @@ png_build_gamma_table(png_structp png_ptr)
 
       num = (1 << (8 - shift));
 
-      g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
+      if (png_ptr->screen_gamma > .000001)
+         g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
+      else
+         g = 1.0;
 
       png_ptr->gamma_16_table = (png_uint_16pp)png_malloc(png_ptr,
          (png_uint_32)(num * sizeof (png_uint_16p)));
 
-      if ((png_ptr->transformations & PNG_16_TO_8) &&
-         !(png_ptr->transformations & PNG_BACKGROUND))
+      if (png_ptr->transformations & (PNG_16_TO_8 | PNG_BACKGROUND))
       {
          double fin, fout;
          png_uint_32 last, max;
@@ -3516,9 +3875,11 @@ png_build_gamma_table(png_structp png_ptr)
          }
       }
 
-#if defined(PNG_READ_BACKGROUND_SUPPORTED)
-      if (png_ptr->transformations & PNG_BACKGROUND)
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+    defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+      if (png_ptr->transformations & (PNG_BACKGROUND | PNG_RGB_TO_GRAY))
       {
+
          g = 1.0 / (png_ptr->gamma);
 
          png_ptr->gamma_16_to_1 = (png_uint_16pp)png_malloc(png_ptr,
@@ -3538,7 +3899,11 @@ png_build_gamma_table(png_structp png_ptr)
                      65535.0, g) * 65535.0 + .5);
             }
          }
-         g = 1.0 / (png_ptr->screen_gamma);
+
+         if(png_ptr->screen_gamma > 0.000001)
+            g = 1.0 / png_ptr->screen_gamma;
+         else
+            g = png_ptr->gamma;   /* probably doing rgb_to_gray */
 
          png_ptr->gamma_16_from_1 = (png_uint_16pp)png_malloc(png_ptr,
             (png_uint_32)(num * sizeof (png_uint_16p)));
@@ -3558,8 +3923,9 @@ png_build_gamma_table(png_structp png_ptr)
             }
          }
       }
-#endif /* PNG_BACKGROUND_SUPPORTED */
+#endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */
    }
+ }
 }
 #endif
 

pngrutil.c

@@ -1,12 +1,11 @@
 
 /* pngrutil.c - utilities to read a PNG file
  *
- * 1.0.1d
+ * libpng 1.0.3 - January 14, 1999
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
- * May 21, 1998
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  *
  * This file contains routines that are only called from within
  * libpng itself during the course of reading an image.
@@ -425,7 +424,7 @@ png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       {
          png_warning(png_ptr,
            "Ignoring incorrect gAMA value when sRGB is also present");
-#ifndef PNG_NO_STDIO
+#ifndef PNG_NO_CONSOLE_IO
          fprintf(stderr, "igamma = %lu\n", igamma);
 #endif
          return;
@@ -497,6 +496,9 @@ png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
    else
    {
       png_ptr->sig_bit.gray = buf[0];
+      png_ptr->sig_bit.red = buf[0];
+      png_ptr->sig_bit.green = buf[0];
+      png_ptr->sig_bit.blue = buf[0];
       png_ptr->sig_bit.alpha = buf[1];
    }
    png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit));
@@ -625,7 +627,7 @@ png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
 
             png_warning(png_ptr,
               "Ignoring incorrect cHRM value when sRGB is also present");
-#ifndef PNG_NO_STDIO
+#ifndef PNG_NO_CONSOLE_IO
             fprintf(stderr,"wx=%f, wy=%f, rx=%f, ry=%f\n",
                white_x, white_y, red_x, red_y);
             fprintf(stderr,"gx=%f, gy=%f, bx=%f, by=%f\n",
@@ -694,7 +696,7 @@ png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
       {
          png_warning(png_ptr,
            "Ignoring incorrect gAMA value when sRGB is also present");
-#ifndef PNG_NO_STDIO
+#ifndef PNG_NO_CONSOLE_IO
            fprintf(stderr,"gamma=%f\n",png_ptr->gamma);
 #endif
       }
@@ -1467,13 +1469,13 @@ png_check_chunk_name(png_structp png_ptr, png_bytep chunk_name)
    }
 }
 
-/* Combines the row recently read in with the previous row.
-   This routine takes care of alpha and transparency if requested.
+/* Combines the row recently read in with the existing pixels in the
+   row.  This routine takes care of alpha and transparency if requested.
    This routine also handles the two methods of progressive display
    of interlaced images, depending on the mask value.
    The mask value describes which pixels are to be combined with
    the row.  The pattern always repeats every 8 pixels, so just 8
-   bits are needed.  A one indicates the pixels is to be combined,
+   bits are needed.  A one indicates the pixel is to be combined,
    a zero indicates the pixel is to be skipped.  This is in addition
    to any alpha or transparency value associated with the pixel.  If
    you want all pixels to be combined, pass 0xff (255) in mask.  */
@@ -1891,7 +1893,6 @@ png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
 }
 #endif
 
-#ifndef PNG_READ_SLOW_FILTERING
 void
 png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row,
    png_bytep prev_row, int filter)
@@ -1948,7 +1949,7 @@ png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row,
                ((int)(*pp++) / 2)) & 0xff);
             rp++;
          }
-        
+
          for (i = 0; i < istop; i++)
          {
             *rp = (png_byte)(((int)(*rp) +
@@ -2011,118 +2012,11 @@ png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row,
          break;
       }
       default:
-         png_error(png_ptr, "Bad adaptive filter type");
+         png_warning(png_ptr, "Ignoring bad adaptive filter type");
+         *row=0;
          break;
    }
 }
-#else /* PNG_READ_SLOW_FILTERING */
-void
-png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row,
-   png_bytep prev_row, int filter)
-{
-   png_debug(1, "in png_read_filter_row\n");
-   png_debug2(2,"row = %d, filter = %d\n", png_ptr->row_number, filter);
-
-
-   switch (filter)
-   {
-      case PNG_FILTER_VALUE_NONE:
-         break;
-      case PNG_FILTER_VALUE_SUB:
-      {
-         png_uint_32 i;
-         int bpp = (row_info->pixel_depth + 7) / 8;
-         png_bytep rp;
-         png_bytep lp;
-
-         for (i = (png_uint_32)bpp, rp = row + bpp, lp = row;
-            i < row_info->rowbytes; i++, rp++, lp++)
-         {
-            *rp = (png_byte)(((int)(*rp) + (int)(*lp)) & 0xff);
-         }
-         break;
-      }
-      case PNG_FILTER_VALUE_UP:
-      {
-         png_uint_32 i;
-         png_bytep rp;
-         png_bytep pp;
-
-         for (i = 0, rp = row, pp = prev_row;
-            i < row_info->rowbytes; i++, rp++, pp++)
-         {
-            *rp = (png_byte)(((int)(*rp) + (int)(*pp)) & 0xff);
-         }
-         break;
-      }
-      case PNG_FILTER_VALUE_AVG:
-      {
-         png_uint_32 i;
-         int bpp = (row_info->pixel_depth + 7) / 8;
-         png_bytep rp;
-         png_bytep pp;
-         png_bytep lp;
-
-         for (i = 0, rp = row, pp = prev_row;
-            i < (png_uint_32)bpp; i++, rp++, pp++)
-         {
-            *rp = (png_byte)(((int)(*rp) +
-               ((int)(*pp) / 2)) & 0xff);
-         }
-         for (lp = row; i < row_info->rowbytes; i++, rp++, lp++, pp++)
-         {
-            *rp = (png_byte)(((int)(*rp) +
-               (int)(*pp + *lp) / 2) & 0xff);
-         }
-         break;
-      }
-      case PNG_FILTER_VALUE_PAETH:
-      {
-         int bpp = (row_info->pixel_depth + 7) / 8;
-         png_uint_32 i;
-         png_bytep rp;
-         png_bytep pp;
-         png_bytep lp;
-         png_bytep cp;
-
-         for (i = 0, rp = row, pp = prev_row,
-            lp = row - bpp, cp = prev_row - bpp;
-            i < row_info->rowbytes; i++, rp++, pp++, lp++, cp++)
-         {
-            int a, b, c, pa, pb, pc, p;
-
-            b = *pp;
-            if (i >= (png_uint_32)bpp)
-            {
-               c = *cp;
-               a = *lp;
-            }
-            else
-            {
-               a = c = 0;
-            }
-            p = a + b - c;
-            pa = abs(p - a);
-            pb = abs(p - b);
-            pc = abs(p - c);
-
-            if (pa <= pb && pa <= pc)
-               p = a;
-            else if (pb <= pc)
-               p = b;
-            else
-               p = c;
-
-            *rp = (png_byte)(((int)(*rp) + p) & 0xff);
-         }
-         break;
-      }
-      default:
-         png_error(png_ptr, "Bad adaptive filter type");
-         break;
-   }
-}
-#endif /* PNG_READ_SLOW_FILTERING */
 
 void
 png_read_finish_row(png_structp png_ptr)
@@ -2157,7 +2051,7 @@ png_read_finish_row(png_structp png_ptr)
             if (!(png_ptr->num_rows))
                continue;
          }
-         if (png_ptr->transformations & PNG_INTERLACE)
+         else  /* if (png_ptr->transformations & PNG_INTERLACE) */
             break;
       } while (png_ptr->iwidth == 0);
 
@@ -2321,19 +2215,25 @@ png_read_start_row(png_structp png_ptr)
 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
    if (png_ptr->transformations & PNG_GRAY_TO_RGB)
    {
-      if ((png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) ||
-         png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+      if (
+#if defined(PNG_READ_EXPAND_SUPPORTED)
+        (png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) ||
+#endif
+#if defined(PNG_READ_FILLER_SUPPORTED)
+        (png_ptr->transformations & (PNG_FILLER)) ||
+#endif
+        png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
       {
          if (max_pixel_depth <= 16)
             max_pixel_depth = 32;
-         else if (max_pixel_depth <= 32)
+         else
             max_pixel_depth = 64;
       }
       else
       {
          if (max_pixel_depth <= 8)
             max_pixel_depth = 24;
-         else if (max_pixel_depth <= 16)
+         else
             max_pixel_depth = 48;
       }
    }

pngset.c

@@ -1,12 +1,11 @@
 
 /* pngset.c - storage of image information into info struct
  *
- * 1.0.1d
+ * libpng 1.0.3 - January 14, 1999
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
- * May 21, 1998
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  *
  * The functions here are used during reads to store data from the file
  * into the info struct, and during writes to store application data

pngtest.c

@@ -1,12 +1,11 @@
 
 /* pngtest.c - a simple test program to test libpng
  *
- * libpng 1.0.1d
+ * libpng 1.0.3 -January 14, 1999
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
- * May 21, 1998
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  *
  * This program reads in a PNG image, writes it out again, and then
  * compares the two files.  If the files are identical, this shows that
@@ -14,9 +13,9 @@
  * properly.  It does not currently test all of the transforms, although
  * it probably should.
  *
- * The program will fail in certain legitimate cases:
+ * The program will report "FAIL" in certain legitimate cases:
  * 1) when the compression level or filter selection method is changed.
- * 2) when the chunk size is smaller than 8K.
+ * 2) when the chunk size is not 8K.
  * 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"
@@ -24,7 +23,8 @@
  *
  * 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
- * testing a wide variety of files easily.
+ * testing a wide variety of files easily.  You can also test a number
+ * of files at once by typing "pngtest -m file1.png file2.png ..."
  */
 
 #include <stdio.h>
@@ -37,6 +37,11 @@
 
 #include "png.h"
 
+#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 */
+
 int test_one_file PNGARG((PNG_CONST char *inname, PNG_CONST char *outname));
 
 #ifdef __TURBOC__
@@ -89,7 +94,7 @@ void
 count_zero_samples(png_structp png_ptr, png_row_infop row_info, png_bytep data)
 {
    png_bytep dp = data;
-   if(png_ptr == NULL)return; 
+   if(png_ptr == NULL)return;
 
    /* contents of row_info:
     *  png_uint_32 width      width of row
@@ -206,10 +211,10 @@ png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
    can't handle far buffers in the medium and small models, we have to copy
    the data.
 */
- 
+
 #define NEAR_BUF_SIZE 1024
 #define MIN(a,b) (a <= b ? a : b)
- 
+
 static void
 png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
 {
@@ -359,11 +364,7 @@ png_default_error(png_structp png_ptr, png_const_charp message)
 /* END of code to validate stdio-free compilation */
 
 /* START of code to validate memory allocation and deallocation */
-#ifdef PNGTEST_MEMORY_DEBUG
-/* Borland DOS special memory handler */
-#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
-ERROR - memory debugging is not supported on this platform
-#else
+#ifdef PNG_USER_MEM_SUPPORTED
 
 /* Allocate memory.  For reasonable files, size should never exceed
    64K.  However, zlib may allocate more then 64K if you don't tell
@@ -375,7 +376,7 @@ ERROR - memory debugging is not supported on this platform
    by setting MAXSEG_64K in zlib zconf.h *or* PNG_MAX_MALLOC_64K. */
 typedef struct memory_information {
    png_uint_32                    size;
-   png_voidp                      pointer;
+   png_voidp                 pointer;
    struct memory_information FAR *next;
 } memory_information;
 typedef memory_information FAR *memory_infop;
@@ -390,23 +391,23 @@ extern PNG_EXPORT(void,png_debug_free) PNGARG((png_structp png_ptr,
    png_voidp ptr));
 
 png_voidp
-png_malloc(png_structp png_ptr, png_uint_32 size) {
-   if (png_ptr == NULL) {
-      fprintf(STDERR, "NULL pointer to memory allocator\n");
-      return (NULL);
-   }
+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 */
+
    if (size == 0)
       return (png_voidp)(NULL);
 
    /* This calls the library allocator twice, once to get the requested
       buffer and once to get a new free list entry. */
    {
-      memory_infop pinfo = png_debug_malloc(png_ptr, sizeof *pinfo);
+      memory_infop pinfo = png_malloc_default(png_ptr, sizeof *pinfo);
       pinfo->size = size;
       current_allocation += size;
       if (current_allocation > maximum_allocation)
          maximum_allocation = current_allocation;
-      pinfo->pointer = png_debug_malloc(png_ptr, size);
+      pinfo->pointer = png_malloc_default(png_ptr, size);
       pinfo->next = pinformation;
       pinformation = pinfo;
       /* Make sure the caller isn't assuming zeroed memory. */
@@ -417,10 +418,10 @@ png_malloc(png_structp png_ptr, png_uint_32 size) {
 
 /* Free a pointer.  It is removed from the list at the same time. */
 void
-png_free(png_structp png_ptr, png_voidp ptr)
+png_debug_free(png_structp png_ptr, png_voidp ptr)
 {
    if (png_ptr == NULL)
-      fprintf(STDERR, "NULL pointer to memory allocator\n");
+      fprintf(STDERR, "NULL pointer to png_debug_free.\n");
    if (ptr == 0) {
 #if 0 /* This happens all the time. */
       fprintf(STDERR, "WARNING: freeing NULL pointer\n");
@@ -441,7 +442,7 @@ png_free(png_structp png_ptr, png_voidp ptr)
             /* We must free the list element too, but first kill
                the memory that is to be freed. */
             memset(ptr, 0x55, pinfo->size);
-            png_debug_free(png_ptr, pinfo);
+            png_free_default(png_ptr, pinfo);
             break;
          }
          if (pinfo->next == NULL) {
@@ -453,10 +454,9 @@ png_free(png_structp png_ptr, png_voidp ptr)
    }
 
    /* Finally free the data. */
-   png_debug_free(png_ptr, ptr);
+   png_free_default(png_ptr, ptr);
 }
-#endif /* Not Borland DOS special memory handler */
-#endif
+#endif /* PNG_USER_MEM_SUPPORTED */
 /* END of code to test memory allocation/deallocation */
 
 /* Test one file */
@@ -474,7 +474,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
 #ifdef USE_FAR_KEYWORD
    jmp_buf jmpbuf;
 #endif   
-   
+
    char inbuf[256], outbuf[256];
 
    row_buf = (png_bytep)NULL;
@@ -493,14 +493,26 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    }
 
    png_debug(0, "Allocating read and write structures\n");
+#ifdef PNG_USER_MEM_SUPPORTED
+   read_ptr = png_create_read_struct_2(PNG_LIBPNG_VER_STRING, (png_voidp)NULL,
+      (png_error_ptr)NULL, (png_error_ptr)NULL, (png_voidp)NULL,
+      (png_malloc_ptr)png_debug_malloc, (png_free_ptr)png_debug_free);
+#else
    read_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, (png_voidp)NULL,
       (png_error_ptr)NULL, (png_error_ptr)NULL);
+#endif
 #if defined(PNG_NO_STDIO)
    png_set_error_fn(read_ptr, (png_voidp)inname, png_default_error,
        png_default_warning);
 #endif
+#ifdef PNG_USER_MEM_SUPPORTED
+   write_ptr = png_create_write_struct_2(PNG_LIBPNG_VER_STRING, (png_voidp)NULL,
+      (png_error_ptr)NULL, (png_error_ptr)NULL, (png_voidp)NULL,
+      (png_malloc_ptr)png_debug_malloc, (png_free_ptr)png_debug_free);
+#else
    write_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, (png_voidp)NULL,
       (png_error_ptr)NULL, (png_error_ptr)NULL);
+#endif
 #if defined(PNG_NO_STDIO)
    png_set_error_fn(write_ptr, (png_voidp)inname, png_default_error,
        png_default_warning);
@@ -509,6 +521,8 @@ 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);
+#ifdef PNG_USER_MEM_SUPPORTED
+#endif
 
    png_debug(0, "Setting jmpbuf for read struct\n");
 #ifdef USE_FAR_KEYWORD
@@ -524,10 +538,12 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       fclose(fpout);
       return (1);
    }
+#ifdef USE_FAR_KEYWORD
+   png_memcpy(read_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf));
+#endif
 
    png_debug(0, "Setting jmpbuf for write struct\n");
 #ifdef USE_FAR_KEYWORD
-   png_memcpy(read_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf));
    if (setjmp(jmpbuf))
 #else
    if (setjmp(write_ptr->jmpbuf))
@@ -540,10 +556,10 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       fclose(fpout);
       return (1);
    }
-
 #ifdef USE_FAR_KEYWORD
    png_memcpy(write_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf));
 #endif
+
    png_debug(0, "Initializing input and output streams\n");
 #if !defined(PNG_NO_STDIO)
    png_init_io(read_ptr, fpin);
@@ -719,6 +735,13 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
       if (png_get_tIME(read_ptr, read_info_ptr, &mod_time))
       {
          png_set_tIME(write_ptr, write_info_ptr, mod_time);
+#if defined(PNG_TIME_RFC1123_SUPPORTED)
+         /* we have to use png_strcpy instead of "=" because the string
+            pointed to by png_convert_to_rfc1123() gets free'ed before
+            we use it */
+         png_strcpy(tIME_string,png_convert_to_rfc1123(read_ptr, mod_time));
+         tIME_chunk_present++;
+#endif /* PNG_TIME_RFC1123_SUPPORTED */
       }
    }
 #endif
@@ -741,7 +764,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    png_write_info(write_ptr, write_info_ptr);
 
    png_debug(0, "\nAllocating row buffer \n");
-   row_buf = (png_bytep)png_malloc(read_ptr, 
+   row_buf = (png_bytep)png_malloc(read_ptr,
       png_get_rowbytes(read_ptr, read_info_ptr));
    if (row_buf == NULL)
    {
@@ -770,7 +793,7 @@ test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
    png_debug(0, "Reading and writing end_info data\n");
    png_read_end(read_ptr, end_info_ptr);
    png_write_end(write_ptr, end_info_ptr);
- 
+
 #ifdef PNG_EASY_ACCESS_SUPPORTED
    if(verbose)
    {
@@ -877,6 +900,7 @@ main(int argc, char *argv[])
 
    fprintf(STDERR, "Testing libpng version %s\n", PNG_LIBPNG_VER_STRING);
    fprintf(STDERR, "   with zlib   version %s\n", ZLIB_VERSION);
+   fprintf(STDERR,"%s",png_get_copyright(NULL));
 
    /* Do some consistency checking on the memory allocation settings, I'm
       not sure this matters, but it is nice to know, the first of these
@@ -944,7 +968,7 @@ main(int argc, char *argv[])
    if (multiple)
    {
       int i;
-#ifdef PNGTEST_MEMORY_DEBUG
+#ifdef PNG_USER_MEM_SUPPORTED
       int allocation_now = current_allocation;
 #endif
       for (i=2; i<argc; ++i)
@@ -952,17 +976,25 @@ main(int argc, char *argv[])
          int kerror;
          fprintf(STDERR, "Testing %s:",argv[i]);
          kerror = test_one_file(argv[i], outname);
-         if (kerror == 0) 
+         if (kerror == 0)
+         {
 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
             fprintf(STDERR, " PASS (%lu zero samples)\n",zero_samples);
 #else
             fprintf(STDERR, " PASS\n");
 #endif
-         else {
+#if defined(PNG_TIME_RFC1123_SUPPORTED)
+         if(tIME_chunk_present != 0)
+            fprintf(STDERR, " tIME = %s\n",tIME_string);
+         tIME_chunk_present = 0;
+#endif /* PNG_TIME_RFC1123_SUPPORTED */
+         }
+         else
+         {
             fprintf(STDERR, " FAIL\n");
             ierror += kerror;
-            }
-#ifdef PNGTEST_MEMORY_DEBUG
+         }
+#ifdef PNG_USER_MEM_SUPPORTED
          if (allocation_now != current_allocation)
             fprintf(STDERR, "MEMORY ERROR: %d bytes lost\n",
                current_allocation-allocation_now);
@@ -978,7 +1010,7 @@ main(int argc, char *argv[])
          }
 #endif
       }
-#ifdef PNGTEST_MEMORY_DEBUG
+#ifdef PNG_USER_MEM_SUPPORTED
          fprintf(STDERR, "Maximum memory allocation: %d bytes\n",
             maximum_allocation);
 #endif
@@ -988,7 +1020,7 @@ main(int argc, char *argv[])
       int i;
       for (i=0; i<3; ++i) {
          int kerror;
-#ifdef PNGTEST_MEMORY_DEBUG
+#ifdef PNG_USER_MEM_SUPPORTED
          int allocation_now = current_allocation;
 #endif
          if (i == 1) status_dots_requested = 1;
@@ -999,11 +1031,17 @@ main(int argc, char *argv[])
          if(kerror == 0)
          {
             if(verbose == 1 || i == 2)
+            {
 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
                 fprintf(STDERR, " PASS (%lu zero samples)\n",zero_samples);
 #else
                 fprintf(STDERR, " PASS\n");
 #endif
+#if defined(PNG_TIME_RFC1123_SUPPORTED)
+         if(tIME_chunk_present != 0)
+            fprintf(STDERR, " tIME = %s\n",tIME_string);
+#endif /* PNG_TIME_RFC1123_SUPPORTED */
+            }
          }
          else
          {
@@ -1012,13 +1050,13 @@ main(int argc, char *argv[])
             fprintf(STDERR, " FAIL\n");
             ierror += kerror;
          }
-#ifdef PNGTEST_MEMORY_DEBUG
+#ifdef PNG_USER_MEM_SUPPORTED
          if (allocation_now != current_allocation)
              fprintf(STDERR, "MEMORY ERROR: %d bytes lost\n",
                current_allocation-allocation_now);
          if (current_allocation != 0) {
              memory_infop pinfo = pinformation;
-   
+
              fprintf(STDERR, "MEMORY ERROR: %d bytes still allocated\n",
                 current_allocation);
              while (pinfo != NULL) {
@@ -1028,7 +1066,7 @@ main(int argc, char *argv[])
           }
 #endif
        }
-#ifdef PNGTEST_MEMORY_DEBUG
+#ifdef PNG_USER_MEM_SUPPORTED
        fprintf(STDERR, "Maximum memory allocation: %d bytes\n",
           maximum_allocation);
 #endif
@@ -1040,3 +1078,4 @@ main(int argc, char *argv[])
       fprintf(STDERR, "libpng FAILS test\n");
    return (int)(ierror != 0);
 }
+

pngtrans.c

@@ -1,12 +1,11 @@
 
 /* pngtrans.c - transforms the data in a row (used by both readers and writers)
  *
- * 1.0.1d
+ * libpng 1.0.3 - January 14, 1999
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
- * May 21, 1998
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  */
 
 #define PNG_INTERNAL
@@ -100,6 +99,24 @@ png_set_filler(png_structp png_ptr, png_uint_32 filler, int filler_loc)
       png_ptr->flags |= PNG_FLAG_FILLER_AFTER;
    else
       png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER;
+
+   /* This should probably go in the "do_filler" routine.
+    * I attempted to do that in libpng-1.0.1a but that caused problems
+    * so I restored it in libpng-1.0.2a
+   */
+
+   if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
+   {
+      png_ptr->usr_channels = 4;
+   }
+
+   /* Also I added this in libpng-1.0.2a (what happens when we expand
+    * a less-than-8-bit grayscale to GA? */
+
+   if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY && png_ptr->bit_depth >= 8)
+   {
+      png_ptr->usr_channels = 2;
+   }
 }
 #endif
 
@@ -131,7 +148,7 @@ png_set_invert_mono(png_structp png_ptr)
    png_ptr->transformations |= PNG_INVERT_MONO;
 }
 
-/* invert monocrome grayscale data */
+/* invert monochrome grayscale data */
 void
 png_do_invert(png_row_infop row_info, png_bytep row)
 {

pngwio.c

@@ -1,12 +1,11 @@
 
 /* pngwio.c - functions for data output
  *
- * libpng 1.0.1d
+ * libpng 1.0.3 - January 14, 1999
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
- * May 21, 1998
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  *
  * This file provides a location for all output.  Users who need
  * special handling are expected to write functions that have the same
@@ -23,7 +22,7 @@
    writes to a file pointer.  Note that this routine sometimes gets called
    with very small lengths, so you should implement some kind of simple
    buffering if you are using unbuffered writes.  This should never be asked
-   to write more then 64K on a 16 bit machine.  */
+   to write more than 64K on a 16 bit machine.  */
 
 void
 png_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
@@ -175,14 +174,21 @@ png_set_write_fn(png_structp png_ptr, png_voidp io_ptr,
 #endif /* PNG_WRITE_FLUSH_SUPPORTED */
 
    /* It is an error to read while writing a png file */
-   png_ptr->read_data_fn = NULL;
+   if (png_ptr->read_data_fn != NULL)
+   {
+      png_ptr->read_data_fn = NULL;
+      png_warning(png_ptr,
+         "Attempted to set both read_data_fn and write_data_fn in");
+      png_warning(png_ptr,
+         "the same structure.  Resetting read_data_fn to NULL.");
+   }
 }
 
-#if defined(USE_FAR_KEYWORD) 
-#if defined(_MSC_VER)   
+#if defined(USE_FAR_KEYWORD)
+#if defined(_MSC_VER)
 void *png_far_to_near(png_structp png_ptr,png_voidp ptr, int check)
 {
-   void *near_ptr;   
+   void *near_ptr;
    void FAR *far_ptr;
    FP_OFF(near_ptr) = FP_OFF(ptr);
    far_ptr = (void FAR *)near_ptr;
@@ -194,7 +200,7 @@ void *png_far_to_near(png_structp png_ptr,png_voidp ptr, int check)
 #  else
 void *png_far_to_near(png_structp png_ptr,png_voidp ptr, int check)
 {
-   void *near_ptr;   
+   void *near_ptr;
    void FAR *far_ptr;
    near_ptr = (void FAR *)ptr;
    far_ptr = (void FAR *)near_ptr;

pngwrite.c

@@ -1,12 +1,11 @@
-   
+
 /* pngwrite.c - general routines to write a PNG file
  *
- * 1.0.1d
+ * libpng 1.0.3 - January 14, 1999
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
- * May 21, 1998
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  */
 
 /* get internal access to png.h */
@@ -16,7 +15,7 @@
 /* Writes all the PNG information.  This is the suggested way to use the
  * library.  If you have a new chunk to add, make a function to write it,
  * and put it in the correct location here.  If you want the chunk written
- * after the image data, put it in png_write_end().  I strongly encurage
+ * after the image data, put it in png_write_end().  I strongly encourage
  * you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing
  * the chunk, as that will keep the code from breaking if you want to just
  * write a plain PNG file.  If you have long comments, I suggest writing
@@ -218,43 +217,6 @@ png_write_end(png_structp png_ptr, png_infop info_ptr)
    png_write_IEND(png_ptr);
 }
 
-#if defined(PNG_TIME_RFC1123_SUPPORTED)
-/* Convert the supplied time into an RFC 1123 string suitable for use in
- * a "Creation Time" or other text-based time string.
- */
-png_charp
-png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime)
-{
-   static PNG_CONST char short_months[12][4] =
-	{"Jan", "Feb", "Mar", "Apr", "May", "Jun",
-	 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
-
-   if (png_ptr->time_buffer == NULL)
-   {
-      png_ptr->time_buffer = (png_charp)png_malloc(png_ptr, (png_uint_32)(29*
-         sizeof(char)));
-   }
-
-#ifdef USE_FAR_KEYWORD
-   {
-      char near_time_buf[29];
-      sprintf(near_time_buf, "%d %s %d %02d:%02d:%02d +0000",
-               ptime->day % 32, short_months[(ptime->month - 1) % 12],
-               ptime->year, ptime->hour % 24, ptime->minute % 60,
-               ptime->second % 61);
-      png_memcpy(png_ptr->time_buffer, near_time_buf,
-      29*sizeof(char));
-   }
-#else
-   sprintf(png_ptr->time_buffer, "%d %s %d %02d:%02d:%02d +0000",
-               ptime->day % 32, short_months[(ptime->month - 1) % 12],
-               ptime->year, ptime->hour % 24, ptime->minute % 60,
-               ptime->second % 61);
-#endif
-   return ((png_charp)png_ptr->time_buffer);
-}
-#endif /* PNG_TIME_RFC1123_SUPPORTED */
-
 #if defined(PNG_WRITE_tIME_SUPPORTED)
 void
 png_convert_from_struct_tm(png_timep ptime, struct tm FAR * ttime)
@@ -284,12 +246,29 @@ png_structp
 png_create_write_struct(png_const_charp user_png_ver, png_voidp error_ptr,
    png_error_ptr error_fn, png_error_ptr warn_fn)
 {
+#ifdef PNG_USER_MEM_SUPPORTED
+   return (png_create_write_struct_2(user_png_ver, error_ptr, error_fn,
+      warn_fn, NULL, NULL, NULL));
+}
+
+/* Alternate initialize png_ptr structure, and allocate any memory needed */
+png_structp
+png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
+   png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
+   png_malloc_ptr malloc_fn, png_free_ptr free_fn)
+{
+#endif /* PNG_USER_MEM_SUPPORTED */
    png_structp png_ptr;
 #ifdef USE_FAR_KEYWORD
    jmp_buf jmpbuf;
 #endif
    png_debug(1, "in png_create_write_struct\n");
+#ifdef PNG_USER_MEM_SUPPORTED
+   if ((png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
+      (png_malloc_ptr)malloc_fn)) == NULL)
+#else
    if ((png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG)) == NULL)
+#endif /* PNG_USER_MEM_SUPPORTED */
    {
       return ((png_structp)NULL);
    }
@@ -306,6 +285,9 @@ png_create_write_struct(png_const_charp user_png_ver, png_voidp error_ptr,
 #ifdef USE_FAR_KEYWORD
    png_memcpy(png_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf));
 #endif
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
+#endif /* PNG_USER_MEM_SUPPORTED */
    png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
 
    /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
@@ -335,7 +317,6 @@ png_create_write_struct(png_const_charp user_png_ver, png_voidp error_ptr,
    return ((png_structp)png_ptr);
 }
 
-
 /* Initialize png_ptr structure, and allocate any memory needed */
 void
 png_write_init(png_structp png_ptr)
@@ -631,10 +612,18 @@ png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
 {
    png_structp png_ptr = NULL;
    png_infop info_ptr = NULL;
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_free_ptr free_fn = NULL;
+#endif
 
    png_debug(1, "in png_destroy_write_struct\n");
    if (png_ptr_ptr != NULL)
+   {
       png_ptr = *png_ptr_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+      free_fn = png_ptr->free_fn;
+#endif
+   }
 
    if (info_ptr_ptr != NULL)
       info_ptr = *info_ptr_ptr;
@@ -657,14 +646,22 @@ png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
          png_free(png_ptr, info_ptr->pcal_params);
       }
 #endif
+#ifdef PNG_USER_MEM_SUPPORTED
+      png_destroy_struct_2((png_voidp)info_ptr, free_fn);
+#else
       png_destroy_struct((png_voidp)info_ptr);
+#endif
       *info_ptr_ptr = (png_infop)NULL;
    }
 
    if (png_ptr != NULL)
    {
       png_write_destroy(png_ptr);
+#ifdef PNG_USER_MEM_SUPPORTED
+      png_destroy_struct_2((png_voidp)png_ptr, free_fn);
+#else
       png_destroy_struct((png_voidp)png_ptr);
+#endif
       *png_ptr_ptr = (png_structp)NULL;
    }
 }
@@ -678,6 +675,9 @@ png_write_destroy(png_structp png_ptr)
    png_error_ptr error_fn;
    png_error_ptr warning_fn;
    png_voidp error_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_free_ptr free_fn;
+#endif
 
    png_debug(1, "in png_write_destroy\n");
    /* free any memory zlib uses */
@@ -708,12 +708,18 @@ png_write_destroy(png_structp png_ptr)
    error_fn = png_ptr->error_fn;
    warning_fn = png_ptr->warning_fn;
    error_ptr = png_ptr->error_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+   free_fn = png_ptr->free_fn;
+#endif
 
    png_memset(png_ptr, 0, sizeof (png_struct));
 
    png_ptr->error_fn = error_fn;
    png_ptr->warning_fn = warning_fn;
    png_ptr->error_ptr = error_ptr;
+#ifdef PNG_USER_MEM_SUPPORTED
+   png_ptr->free_fn = free_fn;
+#endif
 
    png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf));
 }

pngwtran.c

@@ -1,18 +1,17 @@
 
 /* pngwtran.c - transforms the data in a row for PNG writers
  *
- * 1.0.1d
+ * libpng 1.0.3 - January 14, 1999
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
- * May 21, 1998
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  */
 
 #define PNG_INTERNAL
 #include "png.h"
 
-/* Transform the data according to the users wishes.  The order of
+/* Transform the data according to the user's wishes.  The order of
  * transformations is significant.
  */
 void
@@ -48,15 +47,15 @@ png_do_write_transformations(png_structp png_ptr)
       png_do_pack(&(png_ptr->row_info), png_ptr->row_buf + 1,
          (png_uint_32)png_ptr->bit_depth);
 #endif
+#if defined(PNG_WRITE_SWAP_SUPPORTED)
+   if (png_ptr->transformations & PNG_SWAP_BYTES)
+      png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
 #if defined(PNG_WRITE_SHIFT_SUPPORTED)
    if (png_ptr->transformations & PNG_SHIFT)
       png_do_shift(&(png_ptr->row_info), png_ptr->row_buf + 1,
          &(png_ptr->shift));
 #endif
-#if defined(PNG_WRITE_SWAP_SUPPORTED)
-   if (png_ptr->transformations & PNG_SWAP_BYTES)
-      png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1);
-#endif
 #if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
    if (png_ptr->transformations & PNG_INVERT_ALPHA)
       png_do_write_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
@@ -103,7 +102,7 @@ png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
             dp = row;
             mask = 0x80;
             v = 0;
-           
+
             for (i = 0; i < row_width; i++)
             {
                if (*sp != 0)

pngwutil.c

@@ -1,12 +1,11 @@
 
 /* pngwutil.c - utilities to write a PNG file
  *
- * 1.0.1d
+ * libpng 1.0.3 - January 14, 1999
  * For conditions of distribution and use, see copyright notice in png.h
  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, Glenn Randers-Pehrson
- * May 21, 1998
+ * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
  */
 
 #define PNG_INTERNAL
@@ -274,7 +273,7 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
 }
 
 /* write the palette.  We are careful not to trust png_color to be in the
- * correct order for PNG, so people can redefine it to any convient
+ * correct order for PNG, so people can redefine it to any convenient
  * structure.
  */
 void
@@ -377,9 +376,9 @@ png_write_sBIT(png_structp png_ptr, png_color_8p sbit, int color_type)
    {
       png_byte maxbits;
 
-      maxbits = color_type==PNG_COLOR_TYPE_PALETTE ? 8:png_ptr->usr_bit_depth;
-      if (sbit->red == 0 || sbit->red > maxbits || 
-          sbit->green == 0 || sbit->green > maxbits || 
+      maxbits = color_type==PNG_COLOR_TYPE_PALETTE ? 8 : png_ptr->usr_bit_depth;
+      if (sbit->red == 0 || sbit->red > maxbits ||
+          sbit->green == 0 || sbit->green > maxbits ||
           sbit->blue == 0 || sbit->blue > maxbits)
       {
          png_warning(png_ptr, "Invalid sBIT depth specified");
@@ -575,7 +574,8 @@ png_write_hIST(png_structp png_ptr, png_uint_16p hist, int num_hist)
 }
 #endif
 
-#if defined(PNG_WRITE_tEXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED)
+#if defined(PNG_WRITE_tEXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED) || \
+    defined(PNG_WRITE_pCAL_SUPPORTED)
 /* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,
  * and if invalid, correct the keyword rather than discarding the entire
  * chunk.  The PNG 1.0 specification requires keywords 1-79 characters in
@@ -835,7 +835,7 @@ png_write_zTXt(png_structp png_ptr, png_charp key, png_charp text,
          png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
          png_ptr->zstream.next_out = png_ptr->zbuf;
       }
-   /* continue until we don't have anymore to compress */
+   /* continue until we don't have any more to compress */
    } while (png_ptr->zstream.avail_in);
 
    /* finish the compression */
@@ -952,7 +952,7 @@ void
 png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0,
    png_int_32 X1, int type, int nparams, png_charp units, png_charpp params)
 {
-   png_size_t purpose_len, units_len, total_len; 
+   png_size_t purpose_len, units_len, total_len;
    png_uint_32p params_len;
    png_byte buf[10];
    png_charp new_purpose;
@@ -1180,7 +1180,7 @@ png_write_finish_row(png_structp png_ptr)
       if (png_ptr->pass < 7)
       {
          if (png_ptr->prev_row != NULL)
-            png_memset(png_ptr->prev_row, 0, 
+            png_memset(png_ptr->prev_row, 0,
                (png_size_t) (((png_uint_32)png_ptr->usr_channels *
                (png_uint_32)png_ptr->usr_bit_depth *
                png_ptr->width + 7) >> 3) + 1);
@@ -1416,10 +1416,19 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
     * as the "minimum sum of absolute differences" heuristic.  Other
     * heuristics are the "weighted minimum sum of absolute differences"
     * (experimental and can in theory improve compression), and the "zlib
-    * predictive" method (not implemented in libpng 0.95), which does test
-    * compressions of lines using different filter methods, and then chooses
-    * the (series of) filter(s) which give minimum compressed data size (VERY
+    * predictive" method (not implemented yet), which does test compressions
+    * of lines using different filter methods, and then chooses the
+    * (series of) filter(s) that give minimum compressed data size (VERY
     * computationally expensive).
+    *
+    * GRR 980525:  consider also
+    *   (1) minimum sum of absolute differences from running average (i.e.,
+    *       keep running sum of non-absolute differences & count of bytes)
+    *       [track dispersion, too?  restart average if dispersion too large?]
+    *  (1b) minimum sum of absolute differences from sliding average, probably
+    *       with window size <= deflate window (usually 32K)
+    *   (2) minimum sum of squared differences from zero or running average
+    *       (i.e., ~ root-mean-square approach)
     */
 
 
@@ -1763,7 +1772,7 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
       }
       for (lp = row_buf + 1; i < row_bytes; i++)
       {
-         v = *dp++ = 
+         v = *dp++ =
           (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff);
 
          sum += (v < 128) ? v : 256 - v;

scripts/makefile.aco

@@ -49,173 +49,3 @@ Test: @.pngtest
 
 
 # Dynamic dependencies:
-o.pngtest:	c.pngtest
-o.pngtest:	h.png
-o.pngtest:	Zlib:h.zlib
-o.pngtest:	Zlib:h.zconf
-o.pngtest:	h.pngconf
-mm.png:		LibPng:c.png
-mm.png:		LibPng:h.png
-mm.png:		Zlib:h.zlib
-mm.png:		Zlib:h.zconf
-mm.png:		LibPng:h.pngconf
-mm.png:		MemCheck:ANSI.h.stdio
-mm.pngerror:	LibPng:c.pngerror
-mm.pngerror:	LibPng:h.png
-mm.pngerror:	Zlib:h.zlib
-mm.pngerror:	Zlib:h.zconf
-mm.pngerror:	LibPng:h.pngconf
-mm.pngerror:	MemCheck:ANSI.h.stdio
-mm.pngrio:	LibPng:c.pngrio
-mm.pngrio:	LibPng:h.png
-mm.pngrio:	Zlib:h.zlib
-mm.pngrio:	Zlib:h.zconf
-mm.pngrio:	LibPng:h.pngconf
-mm.pngrio:	MemCheck:ANSI.h.stdio
-mm.pngwio:	LibPng:c.pngwio
-mm.pngwio:	LibPng:h.png
-mm.pngwio:	Zlib:h.zlib
-mm.pngwio:	Zlib:h.zconf
-mm.pngwio:	LibPng:h.pngconf
-mm.pngwio:	MemCheck:ANSI.h.stdio
-mm.pngmem:	LibPng:c.pngmem
-mm.pngmem:	LibPng:h.png
-mm.pngmem:	Zlib:h.zlib
-mm.pngmem:	Zlib:h.zconf
-mm.pngmem:	LibPng:h.pngconf
-mm.pngmem:	MemCheck:ANSI.h.stdio
-mm.pngpread:	LibPng:c.pngpread
-mm.pngpread:	LibPng:h.png
-mm.pngpread:	Zlib:h.zlib
-mm.pngpread:	Zlib:h.zconf
-mm.pngpread:	LibPng:h.pngconf
-mm.pngpread:	MemCheck:ANSI.h.stdio
-mm.pngset:	LibPng:c.pngset
-mm.pngset:	LibPng:h.png
-mm.pngset:	Zlib:h.zlib
-mm.pngset:	Zlib:h.zconf
-mm.pngset:	LibPng:h.pngconf
-mm.pngset:	MemCheck:ANSI.h.stdio
-mm.pngget:	LibPng:c.pngget
-mm.pngget:	LibPng:h.png
-mm.pngget:	Zlib:h.zlib
-mm.pngget:	Zlib:h.zconf
-mm.pngget:	LibPng:h.pngconf
-mm.pngget:	MemCheck:ANSI.h.stdio
-mm.pngread:	LibPng:c.pngread
-mm.pngread:	LibPng:h.png
-mm.pngread:	Zlib:h.zlib
-mm.pngread:	Zlib:h.zconf
-mm.pngread:	LibPng:h.pngconf
-mm.pngread:	MemCheck:ANSI.h.stdio
-mm.pngrtran:	LibPng:c.pngrtran
-mm.pngrtran:	LibPng:h.png
-mm.pngrtran:	Zlib:h.zlib
-mm.pngrtran:	Zlib:h.zconf
-mm.pngrtran:	LibPng:h.pngconf
-mm.pngrtran:	MemCheck:ANSI.h.stdio
-mm.pngrutil:	LibPng:c.pngrutil
-mm.pngrutil:	LibPng:h.png
-mm.pngrutil:	Zlib:h.zlib
-mm.pngrutil:	Zlib:h.zconf
-mm.pngrutil:	LibPng:h.pngconf
-mm.pngrutil:	MemCheck:ANSI.h.stdio
-mm.pngtrans:	LibPng:c.pngtrans
-mm.pngtrans:	LibPng:h.png
-mm.pngtrans:	Zlib:h.zlib
-mm.pngtrans:	Zlib:h.zconf
-mm.pngtrans:	LibPng:h.pngconf
-mm.pngtrans:	MemCheck:ANSI.h.stdio
-mm.pngwrite:	LibPng:c.pngwrite
-mm.pngwrite:	LibPng:h.png
-mm.pngwrite:	Zlib:h.zlib
-mm.pngwrite:	Zlib:h.zconf
-mm.pngwrite:	LibPng:h.pngconf
-mm.pngwrite:	MemCheck:ANSI.h.stdio
-mm.pngwtran:	LibPng:c.pngwtran
-mm.pngwtran:	LibPng:h.png
-mm.pngwtran:	Zlib:h.zlib
-mm.pngwtran:	Zlib:h.zconf
-mm.pngwtran:	LibPng:h.pngconf
-mm.pngwtran:	MemCheck:ANSI.h.stdio
-mm.pngwutil:	LibPng:c.pngwutil
-mm.pngwutil:	LibPng:h.png
-mm.pngwutil:	Zlib:h.zlib
-mm.pngwutil:	Zlib:h.zconf
-mm.pngwutil:	LibPng:h.pngconf
-mm.pngwutil:	MemCheck:ANSI.h.stdio
-o.png:		c.png
-o.png:		h.png
-o.png:		Zlib:h.zlib
-o.png:		Zlib:h.zconf
-o.png:		h.pngconf
-o.pngerror:	c.pngerror
-o.pngerror:	h.png
-o.pngerror:	Zlib:h.zlib
-o.pngerror:	Zlib:h.zconf
-o.pngerror:	h.pngconf
-o.pngrio:	c.pngrio
-o.pngrio:	h.png
-o.pngrio:	Zlib:h.zlib
-o.pngrio:	Zlib:h.zconf
-o.pngrio:	h.pngconf
-o.pngwio:	c.pngwio
-o.pngwio:	h.png
-o.pngwio:	Zlib:h.zlib
-o.pngwio:	Zlib:h.zconf
-o.pngwio:	h.pngconf
-o.pngmem:	c.pngmem
-o.pngmem:	h.png
-o.pngmem:	Zlib:h.zlib
-o.pngmem:	Zlib:h.zconf
-o.pngmem:	h.pngconf
-o.pngpread:	c.pngpread
-o.pngpread:	h.png
-o.pngpread:	Zlib:h.zlib
-o.pngpread:	Zlib:h.zconf
-o.pngpread:	h.pngconf
-o.pngset:	c.pngset
-o.pngset:	h.png
-o.pngset:	Zlib:h.zlib
-o.pngset:	Zlib:h.zconf
-o.pngset:	h.pngconf
-o.pngget:	c.pngget
-o.pngget:	h.png
-o.pngget:	Zlib:h.zlib
-o.pngget:	Zlib:h.zconf
-o.pngget:	h.pngconf
-o.pngread:	c.pngread
-o.pngread:	h.png
-o.pngread:	Zlib:h.zlib
-o.pngread:	Zlib:h.zconf
-o.pngread:	h.pngconf
-o.pngrtran:	c.pngrtran
-o.pngrtran:	h.png
-o.pngrtran:	Zlib:h.zlib
-o.pngrtran:	Zlib:h.zconf
-o.pngrtran:	h.pngconf
-o.pngrutil:	c.pngrutil
-o.pngrutil:	h.png
-o.pngrutil:	Zlib:h.zlib
-o.pngrutil:	Zlib:h.zconf
-o.pngrutil:	h.pngconf
-o.pngtrans:	c.pngtrans
-o.pngtrans:	h.png
-o.pngtrans:	Zlib:h.zlib
-o.pngtrans:	Zlib:h.zconf
-o.pngtrans:	h.pngconf
-o.pngwrite:	c.pngwrite
-o.pngwrite:	h.png
-o.pngwrite:	Zlib:h.zlib
-o.pngwrite:	Zlib:h.zconf
-o.pngwrite:	h.pngconf
-o.pngwtran:	c.pngwtran
-o.pngwtran:	h.png
-o.pngwtran:	Zlib:h.zlib
-o.pngwtran:	Zlib:h.zconf
-o.pngwtran:	h.pngconf
-o.pngwutil:	c.pngwutil
-o.pngwutil:	h.png
-o.pngwutil:	Zlib:h.zlib
-o.pngwutil:	Zlib:h.zconf
-o.pngwutil:	h.pngconf

scripts/makefile.atr

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

scripts/makefile.bor

@@ -100,7 +100,7 @@ LIBOBJS = \
  +pngtrans.$(O) \
  +pngwrite.$(O) \
  +pngwtran.$(O) \
- +pngwio.$(O)
+ +pngwio.$(O) \
  +pngwutil.$(O)
 
 LIBNAME=libpng$(MODEL).lib
@@ -121,7 +121,7 @@ libpng: $(LIBNAME)
 
 pngtest: pngtest$(MODEL).exe
 
-test:
+test: pngtest$(MODEL).exe
 	pngtest$(MODEL)
 
 

scripts/makefile.dec

@@ -2,12 +2,21 @@
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
 # For conditions of distribution and use, see copyright notice in png.h
 
+# where make install puts libpng.a and png.h
+prefix=/usr/local
+
 # Where the zlib library and include files are located
 #ZLIBLIB=/usr/local/lib
 #ZLIBINC=/usr/local/include
 ZLIBLIB=../zlib
 ZLIBINC=../zlib
 
+# read libpng.txt or png.h to see why PNGMAJ is 2.  You should not
+# have to change it.
+PNGMAJ = 2
+PNGMIN = 1.0.3
+PNGVER = $(PNGMAJ).$(PNGMIN)
+
 CC=cc
 CFLAGS=-std -w1 -I$(ZLIBINC) -O # -g -DPNG_DEBUG=1
 LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm
@@ -15,26 +24,33 @@ LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm
 #RANLIB=echo
 RANLIB=ranlib
 
-# where make install puts libpng.a and png.h
-prefix=/usr/local
 
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o
 
-all: libpng.a pngtest
+all: libpng.so libpng.a pngtest
 
 libpng.a: $(OBJS)
 	ar rc $@  $(OBJS)
 	$(RANLIB) $@
 
+libpng.so: libpng.so.$(PNGMAJ)
+	ln -s -f libpng.so.$(PNGMAJ) libpng.so
+
+libpng.so.$(PNGMAJ): libpng.so.$(PNGVER)
+	ln -s -f libpng.so.$(PNGVER) libpng.so.$(PNGMAJ)
+
+libpng.so.$(PNGVER): $(OBJS)
+	$(CC) -shared -o $@ $(OBJS) -L$(ZLIBLIB) -lz -lm
+
 pngtest: pngtest.o libpng.a
 	$(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
 
 test: pngtest
 	./pngtest
 
-install: libpng.a
+install: libpng.a libpng.so.$(PNGVER)
 	-@mkdir $(prefix)/include
 	-@mkdir $(prefix)/lib
 	cp png.h $(prefix)/include
@@ -42,10 +58,15 @@ install: libpng.a
 	chmod 644 $(prefix)/include/png.h
 	chmod 644 $(prefix)/include/pngconf.h
 	cp libpng.a $(prefix)/lib
+	cp libpng.so.$(PNGVER) $(prefix)/lib
 	chmod 644 $(prefix)/lib/libpng.a
+	chmod 644 $(prefix)/lib/libpng.so.$(PNGVER)
+	-@/bin/rm -f $(LIBPATH)/libpng.so.$(PNGMAJ) $(LIBPATH)/libpng.so
+	(cd $(LIBPATH); ln -s -f libpng.so.$(PNGVER) libpng.so.$(PNGMAJ); \
+	 ln -s -f libpng.so.$(PNGMAJ) libpng.so)
 
 clean:
-	rm -f *.o libpng.a pngtest pngout.png
+	rm -f *.o libpng.a pngtest pngout.png libpng.so*
 
 # DO NOT DELETE THIS LINE -- make depend depends on it.
 

scripts/makefile.dj2

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

scripts/makefile.hux

@@ -0,0 +1,68 @@
+===========================================================================
+# makefile for libpng, HPUX (10.20 and 11.00)
+# Copyright (C) 1995 Guy Eric Schalnat, Group 42
+# Copyright (C) 1999 Glenn Randers-Pehrson
+# contributed by Jim Rice, Hewlett Packard
+# For conditions of distribution and use, see copyright notice in png.h
+
+# Where the zlib library and include files are located
+ZLIBLIB=/opt/zlib/lib
+ZLIBINC=/opt/zlib/include
+
+CC=cc
+CFLAGS=-I$(ZLIBINC) -O -Ae +DA1.1 +DS2.0
+CCFLAGS=-I$(ZLIBINC) -O -Ae +DA1.1 +DS2.0
+LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm
+
+RANLIB=ranlib
+
+# where make install puts libpng.a and png.h
+prefix=/opt/libpng/
+
+OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
+        pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
+        pngwtran.o pngmem.o pngerror.o pngpread.o
+
+all: libpng.a pngtest
+
+libpng.a: $(OBJS)
+        ar rc $@  $(OBJS)
+        $(RANLIB) $@
+
+pngtest: pngtest.o libpng.a
+        $(CC) -o pngtest $(CCFLAGS) pngtest.o $(LDFLAGS)
+
+test: pngtest
+        ./pngtest
+
+install: libpng.a
+        -@mkdir $(prefix)/include
+        -@mkdir $(prefix)/lib
+        cp png.h $(prefix)/include
+        cp pngconf.h $(prefix)/include
+        chmod 644 $(prefix)/include/png.h
+        chmod 644 $(prefix)/include/pngconf.h
+        cp libpng.a $(prefix)/lib
+        chmod 644 $(prefix)/lib/libpng.a
+
+clean:
+        rm -f *.o libpng.a pngtest pngout.png
+
+# DO NOT DELETE THIS LINE -- make depend depends on it.
+
+png.o: png.h pngconf.h
+pngerror.o: png.h pngconf.h
+pngrio.o: png.h pngconf.h
+pngwio.o: png.h pngconf.h
+pngmem.o: png.h pngconf.h
+pngset.o: png.h pngconf.h
+pngget.o: png.h pngconf.h
+pngread.o: png.h pngconf.h
+pngrtran.o: png.h pngconf.h
+pngrutil.o: png.h pngconf.h
+pngtest.o: png.h pngconf.h
+pngtrans.o: png.h pngconf.h
+pngwrite.o: png.h pngconf.h
+pngwtran.o: png.h pngconf.h
+pngwutil.o: png.h pngconf.h
+pngpread.o: png.h pngconf.h

scripts/makefile.knr

@@ -2,6 +2,9 @@
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
 # For conditions of distribution and use, see copyright notice in png.h
 
+# where make install puts libpng.a and png.h
+prefix=/usr/local
+
 CC=cc
 CFLAGS=-I../zlib -O
 LDFLAGS=-L. -L../zlib/ -lpng -lz -lm
@@ -11,9 +14,6 @@ ANSI2KNRFLAGS=
 RANLIB=ranlib
 #RANLIB=echo
 
-# where make install puts libpng.a and png.h
-prefix=/usr/local
-
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o

scripts/makefile.lnx

@@ -5,6 +5,9 @@
 
 CC=gcc
 
+# where make install puts libpng.a, libpng.so*, and png.h
+prefix=/usr/local
+
 # Where the zlib library and include files are located
 #ZLIBLIB=/usr/local/lib
 #ZLIBINC=/usr/local/include
@@ -29,11 +32,9 @@ RANLIB=ranlib
 # read libpng.txt or png.h to see why PNGMAJ is 2.  You should not
 # have to change it.
 PNGMAJ = 2
-PNGMIN = 1.0.1d
+PNGMIN = 1.0.3
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
-# where make install puts libpng.a, libpng.so*, and png.h
-prefix=/usr/local
 INCPATH=$(prefix)/include
 LIBPATH=$(prefix)/lib
 
@@ -55,14 +56,14 @@ libpng.a: $(OBJS)
 	$(RANLIB) $@
 
 libpng.so: libpng.so.$(PNGMAJ)
-	ln -sf libpng.so.$(PNGMAJ) libpng.so
+	ln -s -f libpng.so.$(PNGMAJ) libpng.so
 
 libpng.so.$(PNGMAJ): libpng.so.$(PNGVER)
-	ln -sf libpng.so.$(PNGVER) libpng.so.$(PNGMAJ)
+	ln -s -f libpng.so.$(PNGVER) libpng.so.$(PNGMAJ)
 
 libpng.so.$(PNGVER): $(OBJSDLL)
 	$(CC) -shared -Wl,-soname,libpng.so.$(PNGMAJ) -o libpng.so.$(PNGVER) \
-	 $(OBJSDLL)
+	 $(OBJSDLL) -L$(ZLIBLIB) -lz -lm -lc
 
 pngtest: pngtest.o libpng.so
 	$(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
@@ -77,8 +78,8 @@ install: libpng.a libpng.so.$(PNGVER)
 	cp libpng.a libpng.so.$(PNGVER) $(LIBPATH)
 	chmod 755 $(LIBPATH)/libpng.so.$(PNGVER)
 	-@/bin/rm -f $(LIBPATH)/libpng.so.$(PNGMAJ) $(LIBPATH)/libpng.so
-	(cd $(LIBPATH); ln -sf libpng.so.$(PNGVER) libpng.so.$(PNGMAJ); \
-	 ln -sf libpng.so.$(PNGMAJ) libpng.so)
+	(cd $(LIBPATH); ln -s -f libpng.so.$(PNGVER) libpng.so.$(PNGMAJ); \
+	 ln -s -f libpng.so.$(PNGMAJ) libpng.so)
 
 clean:
 	/bin/rm -f *.o libpng.a libpng.so* pngtest pngout.png

scripts/makefile.mip

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

scripts/makefile.s2x

@@ -6,6 +6,9 @@
 
 CC=gcc
 
+# where make install puts libpng.a, libpng.so*, and png.h
+prefix=/usr/local
+
 # Where the zlib library and include files are located
 # Changing these to ../zlib poses a security risk.  If you want
 # to have zlib in an adjacent directory, specify the full path instead of "..".
@@ -15,7 +18,6 @@ CC=gcc
 ZLIBLIB=/usr/local/lib
 ZLIBINC=/usr/local/include
 
-
 WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
          -Wmissing-declarations -Wtraditional -Wcast-align \
          -Wstrict-prototypes -Wmissing-prototypes #-Wconversion
@@ -29,11 +31,9 @@ RANLIB=echo
 # read libpng.txt or png.h to see why PNGMAJ is 2.  You should not
 # have to change it.
 PNGMAJ = 2
-PNGMIN = 1.0.1d
+PNGMIN = 1.0.3
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
-# where make install puts libpng.a, libpng.so*, and png.h
-prefix=/usr/local
 INCPATH=$(prefix)/include
 LIBPATH=$(prefix)/lib
 
@@ -55,10 +55,10 @@ libpng.a: $(OBJS)
 	$(RANLIB) $@
 
 libpng.so: libpng.so.$(PNGMAJ)
-	ln -sf libpng.so.$(PNGMAJ) libpng.so
+	ln -s -f libpng.so.$(PNGMAJ) libpng.so
 
 libpng.so.$(PNGMAJ): libpng.so.$(PNGVER)
-	ln -sf libpng.so.$(PNGVER) libpng.so.$(PNGMAJ)
+	ln -s -f libpng.so.$(PNGVER) libpng.so.$(PNGMAJ)
 
 libpng.so.$(PNGVER): $(OBJSDLL)
 	$(LD) -G -L$(ZLIBLIB) -R$(ZLIBLIB) -h libpng.so.$(PNGMAJ) \
@@ -77,8 +77,8 @@ install: libpng.a libpng.so.$(PNGVER)
 	cp libpng.a libpng.so.$(PNGVER) $(LIBPATH)
 	chmod 755 $(LIBPATH)/libpng.so.$(PNGVER)
 	-@/bin/rm -f $(LIBPATH)/libpng.so.$(PNGMAJ) $(LIBPATH)/libpng.so
-	(cd $(LIBPATH); ln -sf libpng.so.$(PNGVER) libpng.so.$(PNGMAJ); \
-	 ln -sf libpng.so.$(PNGMAJ) libpng.so)
+	(cd $(LIBPATH); ln -s -f libpng.so.$(PNGVER) libpng.so.$(PNGMAJ); \
+	 ln -s -f libpng.so.$(PNGMAJ) libpng.so)
 
 clean:
 	/bin/rm -f *.o libpng.a libpng.so* pngtest pngout.png

scripts/makefile.sco

@@ -7,6 +7,9 @@
 
 CC=cc
 
+# where make install puts libpng.a, libpng.so*, and png.h
+prefix=/usr/local
+
 # Where the zlib library and include files are located
 #ZLIBLIB=/usr/local/lib
 #ZLIBINC=/usr/local/include
@@ -22,11 +25,9 @@ RANLIB=echo
 # read libpng.txt or png.h to see why PNGMAJ is 2.  You should not
 # have to change it.
 PNGMAJ = 2
-PNGMIN = 1.0.1d
+PNGMIN = 1.0.3
 PNGVER = $(PNGMAJ).$(PNGMIN)
 
-# where make install puts libpng.a, libpng.so*, and png.h
-prefix=/usr/local
 INCPATH=$(prefix)/include
 LIBPATH=$(prefix)/lib
 
@@ -48,10 +49,10 @@ libpng.a: $(OBJS)
 	$(RANLIB) $@
 
 libpng.so: libpng.so.$(PNGMAJ)
-	ln -sf libpng.so.$(PNGMAJ) libpng.so
+	ln -s -f libpng.so.$(PNGMAJ) libpng.so
 
 libpng.so.$(PNGMAJ): libpng.so.$(PNGVER)
-	ln -sf libpng.so.$(PNGVER) libpng.so.$(PNGMAJ)
+	ln -s -f libpng.so.$(PNGVER) libpng.so.$(PNGMAJ)
 
 libpng.so.$(PNGVER): $(OBJSDLL)
 	$(CC) -G  -Wl,-h,libpng.so.$(PNGMAJ) -o libpng.so.$(PNGVER) \
@@ -70,8 +71,8 @@ install: libpng.a libpng.so.$(PNGVER)
 	cp libpng.a libpng.so.$(PNGVER) $(LIBPATH)
 	chmod 755 $(LIBPATH)/libpng.so.$(PNGVER)
 	-@/bin/rm -f $(LIBPATH)/libpng.so.$(PNGMAJ) $(LIBPATH)/libpng.so
-	(cd $(LIBPATH); ln -sf libpng.so.$(PNGVER) libpng.so.$(PNGMAJ); \
-	 ln -sf libpng.so.$(PNGMAJ) libpng.so)
+	(cd $(LIBPATH); ln -s -f libpng.so.$(PNGVER) libpng.so.$(PNGMAJ); \
+	 ln -s -f libpng.so.$(PNGMAJ) libpng.so)
 
 clean:
 	/bin/rm -f *.o libpng.a libpng.so* pngtest pngout.png

scripts/makefile.sgi

@@ -2,6 +2,9 @@
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
 # For conditions of distribution and use, see copyright notice in png.h
 
+# where make install puts libpng.a and png.h
+prefix=/usr/local
+
 # Where the zlib library and include files are located
 #ZLIBLIB=/usr/local/lib
 #ZLIBINC=/usr/local/include
@@ -17,9 +20,6 @@ LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm
 RANLIB=echo
 #RANLIB=ranlib
 
-# where make install puts libpng.a and png.h
-prefix=/usr/local
-
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o

scripts/makefile.std

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

scripts/makefile.sun

@@ -2,6 +2,9 @@
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
 # For conditions of distribution and use, see copyright notice in png.h
 
+# where make install puts libpng.a and png.h
+prefix=/usr/local
+
 # Where the zlib library and include files are located
 #ZLIBLIB=/usr/local/lib
 #ZLIBINC=/usr/local/include
@@ -19,9 +22,6 @@ LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm
 RANLIB=ranlib
 #RANLIB=echo
 
-# where make install puts libpng.a and png.h
-prefix=/usr/local
-
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o

scripts/makefile.w32

@@ -0,0 +1,85 @@
+# makefile for libpng
+# Copyright (C) 1998 Tim Wegner
+# For conditions of distribution and use, see copyright notice in png.h
+# Assumes that zlib.lib, zconf.h, and zlib.h have been copied to ..\zlib
+# To use, do "nmake /f scripts\makefile.w32"
+
+# ------------- Microsoft Visual C++ 4.0 and later -------------
+MODEL=- 
+CFLAGS=-Ox -GA3s -nologo -W3 -I..\zlib
+
+CC=cl
+LD=link
+LDFLAGS= 
+O=.obj
+
+#uncomment next to put error messages in a file
+#ERRFILE= >> pngerrs
+
+# variables
+OBJS1 = png$(O) pngset$(O) pngget$(O) pngrutil$(O) pngtrans$(O) pngwutil$(O)
+OBJS2 = pngmem$(O) pngpread$(O) pngread$(O) pngerror$(O) pngwrite$(O)
+OBJS3 = pngrtran$(O) pngwtran$(O) pngrio$(O) pngwio$(O)
+
+all: libpng.lib
+
+png$(O): png.h pngconf.h
+		  $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngset$(O): png.h pngconf.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngget$(O): png.h pngconf.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngread$(O): png.h pngconf.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngpread$(O): png.h pngconf.h
+		  $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngrtran$(O): png.h pngconf.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngrutil$(O): png.h pngconf.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngerror$(O): png.h pngconf.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngmem$(O): png.h pngconf.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngrio$(O): png.h pngconf.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngwio$(O): png.h pngconf.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngtest$(O): png.h pngconf.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngtrans$(O): png.h pngconf.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngwrite$(O): png.h pngconf.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngwtran$(O): png.h pngconf.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+pngwutil$(O): png.h pngconf.h
+        $(CC) -c $(CFLAGS) $*.c $(ERRFILE)
+
+libpng.lib: $(OBJS1) $(OBJS2) $(OBJS3)
+        del libpng.lib
+	lib /OUT:libpng.lib $(OBJS1) $(OBJS2) $(OBJS3)
+
+pngtest.exe: pngtest.obj libpng.lib 
+	$(LD) $(LDFLAGS) pngtest.obj libpng.lib ..\zlib\zlib.lib /OUT:pngtest.exe /SUBSYSTEM:CONSOLE
+
+test: pngtest.exe
+	pngtest
+
+# End of makefile for libpng
+

scripts/pngdef.pas

@@ -3,7 +3,7 @@ unit pngdef;
 interface
 
 const
-  PNG_LIBPNG_VER_STRING = '1.0.1d';
+  PNG_LIBPNG_VER_STRING = '1.0.3';
   PNG_LIBPNG_VER        =  10001;
 
 type
@@ -259,6 +259,10 @@ function png_create_read_struct(user_png_ver: png_charp;
              error_ptr: user_error_ptr; error_fn: png_error_ptr;
              warn_fn: png_error_ptr): png_structp;
              stdcall;
+function png_get_copyright(png_ptr: png_structp): png_charp;
+             stdcall;
+function png_get_header_version(png_ptr: png_structp): png_charp;
+             stdcall;
 function png_create_write_struct(user_png_ver: png_charp;
              error_ptr: user_error_ptr; error_fn: png_error_ptr;
              warn_fn: png_error_ptr): png_structp;
@@ -343,6 +347,8 @@ function png_get_pixels_per_meter(png_ptr: png_structp;
              stdcall;
 function png_get_progressive_ptr(png_ptr: png_structp): png_voidp;
              stdcall;
+function png_get_rgb_to_gray_status(png_ptr: png_structp);
+             stdcall;
 function png_get_rowbytes(png_ptr: png_structp; info_ptr: png_infop):
              png_uint_32;
              stdcall;
@@ -510,6 +516,8 @@ procedure png_set_read_status_fn(png_ptr: png_structp;
 procedure png_set_read_user_transform_fn(png_ptr: png_structp;
              read_user_transform_fn: png_user_transform_ptr);
              stdcall;
+procedure png_set_rgb_to_gray(png_ptr: png_structp; int: error_action);
+             stdcall;
 procedure png_set_sBIT(png_ptr: png_structp; info_ptr: png_infop;
              sig_bits: png_color_8p);
              stdcall;

scripts/pngos2.def

@@ -12,7 +12,9 @@ EXPORTS
   png_sig_cmp
   png_check_sig
   png_create_read_struct
+; png_create_read_struct_2
   png_create_write_struct
+; png_create_write_struct_2
   png_write_chunk
   png_write_chunk_start
   png_write_chunk_data
@@ -27,7 +29,7 @@ EXPORTS
   png_set_expand
   png_set_bgr
   png_set_gray_to_rgb
-; png_set_rgb_to_gray
+  png_set_rgb_to_gray
   png_build_grayscale_palette
   png_set_strip_alpha
   png_set_swap_alpha
@@ -70,8 +72,12 @@ EXPORTS
   png_set_compression_window_bits
   png_set_compression_method
   png_init_io
+  png_get_copyright
   png_set_error_fn
   png_get_error_ptr
+  png_get_header_version
+; png_get_mem_fn
+; png_set_mem_fn
   png_set_write_fn
   png_set_read_fn
   png_set_write_status_fn
@@ -89,8 +95,8 @@ EXPORTS
   png_free
   png_memcpy_check
   png_memset_check
-; png_debug_malloc
-; png_debug_free
+; png_malloc_default
+; png_free_default
 ; png_far_to_near
   png_error
   png_chunk_error
@@ -108,6 +114,7 @@ EXPORTS
   png_get_compression_type
   png_get_pixels_per_meter
   png_get_pixel_aspect_ratio
+  png_get_rgb_to_gray_status
   png_get_x_offset_pixels
   png_get_y_offset_pixels
   png_get_x_offset_microns
@@ -198,7 +205,7 @@ EXPORTS
   png_do_strip_filler
   png_do_swap
   png_do_packswap
-; png_do_rgb_to_gray
+  png_do_rgb_to_gray
   png_do_gray_to_rgb
   png_do_unpack
   png_do_unshift