libpng/CHANGES
2009-04-06 16:04:56 -05:00

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CHANGES - changes for libpng
version 0.2
added reader into png.h
fixed small problems in stub file
version 0.3
added pull reader
split up pngwrite.c to several files
added pnglib.txt
added example.c
cleaned up writer, adding a few new tranformations
fixed some bugs in writer
interfaced with zlib 0.5
added K&R support
added check for 64 KB blocks for 16 bit machines
version 0.4
cleaned up code and commented code
simplified time handling into png_time
created png_color_16 and png_color_8 to handle color needs
cleaned up color type defines
fixed various bugs
made various names more consistant
interfaced with zlib 0.71
cleaned up zTXt reader and writer (using zlib's Reset functions)
split transformations into pngrtran.c and pngwtran.c
version 0.5
interfaced with zlib 0.8
fixed many reading and writing bugs
saved using 3 spaces instead of tabs
version 0.6
added png_large_malloc() and png_large_free()
added png_size_t
cleaned up some compiler warnings
added png_start_read_image()
version 0.7
cleaned up lots of bugs
finished dithering and other stuff
added test program
changed name from pnglib to libpng
version 0.71 [June, 1995]
changed pngtest.png for zlib 0.93
fixed error in libpng.txt and example.c
version 0.8
cleaned up some bugs
added png_set_filler()
split up pngstub.c into pngmem.c, pngio.c, and pngerror.c
added #define's to remove unwanted code
moved png_info_init() to png.c
added old_size into png_realloc()
added functions to manually set filtering and compression info
changed compression parameters based on image type
optimized filter selection code
added version info
changed external functions passing floats to doubles (k&r problems?)
put all the configurable stuff in pngconf.h
enabled png_set_shift to work with paletted images on read
added png_read_update_info() - updates info structure with
transformations
version 0.81 [August, 1995]
incorporated Tim Wegner's medium model code (thanks, Tim)
version 0.82 [September, 1995]
[unspecified changes]
version 0.85 [December, 1995]
added more medium model code (almost everything's a far)
added i/o, error, and memory callback functions
fixed some bugs (16 bit, 4 bit interlaced, etc.)
added first run progressive reader (barely tested)
version 0.86 [January, 1996]
fixed bugs
improved documentation
version 0.87 [January, 1996]
fixed medium model bugs
fixed other bugs introduced in 0.85 and 0.86
added some minor documentation
version 0.88 [January, 1996]
fixed progressive bugs
replaced tabs with spaces
cleaned up documentation
added callbacks for read/write and warning/error functions
version 0.89 [July, 1996]
added new initialization API to make libpng work better with shared libs
we now have png_create_read_struct(), png_create_write_struct(),
png_create_info_struct(), png_destroy_read_struct(), and
png_destroy_write_struct() instead of the separate calls to
malloc and png_read_init(), png_info_init(), and png_write_init()
changed warning/error callback functions to fix bug - this means you
should use the new initialization API if you were using the old
png_set_message_fn() calls, and that the old API no longer exists
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
fixed png_set_background() to allow using an arbitrary RGB color for
paletted images
fixed gamma and background correction for paletted images, so
png_correct_palette is not needed unless you are correcting an
external palette (you will need to #define PNG_CORRECT_PALETTE_SUPPORTED
in pngconf.h) - if nobody uses this, it may disappear in the future.
fixed bug with Borland 64K memory allocation (Alexander Lehmann)
fixed bug in interlace handling (Smarasderagd, I think)
added more error checking for writing and image to reduce invalid files
separated read and write functions so that they won't both be linked
into a binary when only reading or writing functionality is used
new pngtest image also has interlacing and zTXt
updated documentation to reflect new API
version 0.90 [January, 1997]
made CRC errors/warnings on critical and ancillary chunks configurable
libpng will use the zlib CRC routines by (compile-time) default
changed DOS small/medium model memory support - needs zlib 1.04 (Tim Wegner)
added external C++ wrapper statements to png.h (Gilles Dauphin)
allow PNG file to be read when some or all of file signature has already
been read from the beginning of the stream. ****This affects the size
of info_struct and invalidates all programs that use a shared libpng****
fixed png_filler() declarations
fixed? background color conversions
fixed order of error function pointers to match documentation
current chunk name is now available in png_struct to reduce the number
of nearly identical error messages (will simplify multi-lingual
support when available)
try to get ready for unknown-chunk callback functions:
- previously read critical chunks are flagged, so the chunk handling
routines can determine if the chunk is in the right place
- all chunk handling routines have the same prototypes, so we will
be able to handle all chunks via a callback mechanism
try to fix Linux "setjmp" buffer size problems
version 0.95 [March, 1997]
fixed bug in pngwutil.c allocating "up_row" twice and "avg_row" never
fixed bug in PNG file signature compares when start != 0
changed parameter type of png_set_filler(...filler...) from png_byte
to png_uint_32
added test for MACOS to ensure that both math.h and fp.h are not #included
added macros for libpng to be compiled as a Windows DLL (Andreas Kupries)
added "packswap" transformation, which changes the endianness of
packed-pixel bytes (Kevin Bracey)
added "strip_alpha" transformation, which removes the alpha channel of
input images without using it (not neccesarily a good idea)
added "swap_alpha" transformation, which puts the alpha channel in front
of the color bytes instead of after
removed all implicit variable tests which assume NULL == 0 (I think)
changed several variables to "png_size_t" to show 16/32-bit limitations
added new pCAL chunk read/write support
added experimental filter selection weighting (Greg Roelofs)
removed old png_set_rgbx() and png_set_xrgb() functions that have been
obsolete for about 2 years now (use png_set_filler() instead)
added macros to read 16- and 32-bit ints directly from buffer, to be
used only on those systems that support it (namely PowerPC and 680x0)
With some testing, this may become the default for MACOS/PPC systems.
only calculate CRC on data if we are going to use it
added macros for zTXt compression type PNG_zTXt_COMPRESSION_???
added macros for simple libpng debugging output selectable at compile time
removed PNG_READ_END_MODE in progressive reader (Smarasderagd)
more description of info_struct in libpng.txt and png.h
more instructions in example.c
more chunk types tested in pngtest.c
renamed pngrcb.c to pngset.c, and all png_read_<chunk> functions to be
png_set_<chunk>. We now have corresponding png_get_<chunk>
functions in pngget.c to get infomation in info_ptr. This isolates
the application from the internal organization of png_info_struct
(good for shared library implementations).
version 0.96 [May, 1997]
fixed serious bug with < 8bpp images introduced in 0.95
fixed 256-color transparency bug (Greg Roelofs)
fixed up documentation (Greg Roelofs, Laszlo Nyul)
fixed "error" in pngconf.h for Linux setjmp() behaviour
fixed DOS medium model support (Tim Wegner)
fixed png_check_keyword() for case with error in static string text
added read of CRC after IEND chunk for embedded PNGs (Laszlo Nyul)
added typecasts to quiet compiler errors
added more debugging info
version 0.97 [January, 1998]
removed PNG_USE_OWN_CRC capability
relocated png_set_crc_action from pngrutil.c to pngrtran.c
fixed typecasts of "new_key", etc. (Andreas Dilger)
added RFC 1152 [sic] date support
fixed bug in gamma handling of 4-bit grayscale
added 2-bit grayscale gamma handling (Glenn R-P)
added more typecasts. 65536L becomes (png_uint_32)65536L, etc. (Glenn R-P)
minor corrections in libpng.txt
added simple sRGB support (Glenn R-P)
easier conditional compiling, e.g. define PNG_READ/WRITE_NOT_FULLY_SUPPORTED;
all configurable options can be selected from command-line instead
of having to edit pngconf.h (Glenn R-P)
fixed memory leak in pngwrite.c (free info_ptr->text) (Glenn R-P)
added more conditions for png_do_background, to avoid changing
black pixels to background when a background is supplied and
no pixels are transparent
repaired PNG_NO_STDIO behaviour
tested NODIV support and made it default behaviour (Greg Roelofs)
added "-m" option and PNGTEST_DEBUG_MEMORY to pngtest (John Bowler)
regularized version numbering scheme and bumped shared-library major
version number to 2 to avoid problems with libpng 0.89 apps (Greg Roelofs)
version 0.98 [January, 1998]
cleaned up some typos in libpng.txt and in code documentation
fixed memory leaks in pCAL chunk processing (Glenn R-P and John Bowler)
cosmetic change "display_gamma" to "screen_gamma" in pngrtran.c
changed recommendation about file_gamma for PC images to .51 from .45,
in example.c and libpng.txt, added comments to distinguish between
screen_gamma, viewing_gamma, and display_gamma.
changed all references to RFC1152 to read RFC1123 and changed the
PNG_TIME_RFC1152_SUPPORTED macro to PNG_TIME_RFC1123_SUPPORTED
added png_invert_alpha capability (Glenn R-P -- suggestion by Jon Vincent)
changed srgb_intent from png_byte to int to avoid compiler bugs
version 0.99 [January 30, 1998]
free info_ptr->text instead of end_info_ptr->text in pngread.c (John Bowler)
fixed a longstanding "packswap" bug in pngtrans.c
fixed some inconsistencies in pngconf.h that prevented compiling with
PNG_READ_GAMMA_SUPPORTED and PNG_READ_hIST_SUPPORTED undefined
fixed some typos and made other minor rearrangement of libpng.txt (Andreas)
changed recommendation about file_gamma for PC images to .50 from .51 in
example.c and libpng.txt, and changed file_gamma for sRGB images to .45
added a number of functions to access information from the png structure
png_get_image_height(), etc. (Glenn R-P, suggestion by Brad Pettit)
added TARGET_MACOS similar to zlib-1.0.8
define PNG_ALWAYS_EXTERN when __MWERKS__ && WIN32 are defined
added type casting to all png_malloc() function calls
version 0.99a [January 31, 1998]
Added type casts and parentheses to all returns that return a value.(Tim W.)
version 0.99b [February 4, 1998]
Added type cast png_uint_32 on malloc function calls where needed.
Changed type of num_hist from png_uint_32 to int (same as num_palette).
Added checks for rowbytes overflow, in case png_size_t is less than 32 bits.
Renamed makefile.elf to makefile.lnx.
version 0.99c [February 7, 1998]
More type casting. Removed erroneous overflow test in pngmem.c.
Added png_buffered_memcpy() and png_buffered_memset(), apply them to rowbytes.
Added UNIX manual pages libpng.3 (incorporating libpng.txt) and png.5.
version 0.99d [February 11, 1998]
Renamed "far_to_near()" "png_far_to_near()"
Revised libpng.3
Version 99c "buffered" operations didn't work as intended. Replaced them
with png_memcpy_check() and png_memset_check().
Added many "if (png_ptr == NULL) return" to quell compiler warnings about
unused png_ptr, mostly in pngget.c and pngset.c.
Check for overlength tRNS chunk present when indexed-color PLTE is read.
Cleaned up spelling errors in libpng.3/libpng.txt
Corrected a problem with png_get_tRNS() which returned undefined trans array
version 0.99e [February 28, 1998]
Corrected png_get_tRNS() again.
Add parentheses for easier reading of pngget.c, fixed "||" should be "&&".
Touched up example.c to make more of it compileable, although the entire
file still can't be compiled (Willem van Schaik)
Fixed a bug in png_do_shift() (Bryan Tsai)
Added a space in png.h prototype for png_write_chunk_start()
Replaced pngtest.png with one created with zlib 1.1.1
Changed pngtest to report PASS even when file size is different (Jean-loup G.)
Corrected some logic errors in png_do_invert_alpha() (Chris Patterson)
version 0.99f [March 5, 1998]
Corrected a bug in pngpread() introduced in version 99c (Kevin Bracey)
Moved makefiles into a "scripts" directory, and added INSTALL instruction file
Added makefile.os2 and pngos2.def (A. Zabolotny) and makefile.s2x (W. Sebok)
Added pointers to "note on libpng versions" in makefile.lnx and README
Added row callback feature when reading and writing nonprogressive rows
and added a test of this feature in pngtest.c
Added user transform callbacks, with test of the feature in pngtest.c
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
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]
Changed several typedefs in pngrutil.c
Added makefile.wat (Pawel Mrochen), updated makefile.tc3 (Willem van Schaik)
replaced "while(1)" with "for(;;)"
added PNGARG() to prototypes in pngtest.c and removed some prototypes
updated some of the makefiles (Tom Lane)
changed some typedefs (s_start, etc.) in pngrutil.c
fixed dimensions of "short_months" array in pngwrite.c
Replaced ansi2knr.c with the one from jpeg-v6
version 1.0.0 [March 8, 1998]
Changed name from 1.00 to 1.0.0 (Adam Costello)
Added smakefile.ppc (with SCOPTIONS.ppc) for Amiga PPC (Andreas Kleinert)
version 1.0.0a [March 9, 1998]
Fixed three bugs in pngrtran.c to make gamma+background handling consistent
(Greg Roelofs)
Changed format of the PNG_LIBPNG_VER integer to xyyzz instead of xyz
for major, minor, and bugfix releases. This is 10001. (Adam Costello,
Tom Lane)
Make months range from 1-12 in png_convert_to_rfc1123
version 1.0.0b [March 13, 1998]
Quieted compiler complaints about two empty "for" loops in pngrutil.c
Minor changes to makefile.s2x
Removed #ifdef/#endif around a png_free() in pngread.c
version 1.0.1 [March 14, 1998]
Changed makefile.s2x to reduce security risk of using a relative pathname
Fixed some typos in the documentation (Greg).
Fixed a problem with value of "channels" returned by png_read_update_info()
version 1.0.1a [April 21, 1998]
Optimized Paeth calculations by replacing abs() function calls with intrinsics
plus other loop optimizations. Improves avg decoding speed by about 20%.
Commented out i386istic "align" compiler flags in makefile.lnx.
Reduced the default warning level in some makefiles, to make them consistent.
Removed references to IJG and JPEG in the ansi2knr.c copyright statement.
Fixed a bug in png_do_strip_filler with XXRRGGBB => RRGGBB transformation.
Added grayscale and 16-bit capability to png_do_read_filler().
Fixed a bug in pngset.c, introduced in version 0.99c, that sets rowbytes
too large when writing an image with bit_depth < 8 (Bob Dellaca).
Corrected some bugs in the experimental weighted filtering heuristics.
Moved a misplaced pngrutil code block that truncates tRNS if it has more
than num_palette entries -- test was done before num_palette was defined.
Fixed a png_convert_to_rfc1123() bug that converts day 31 to 0 (Steve Eddins).
Changed compiler flags in makefile.wat for better optimization (Pawel Mrochen).
version 1.0.1b [May 2, 1998]
Relocated png_do_gray_to_rgb() within png_do_read_transformations() (Greg).
Relocated the png_composite macros from pngrtran.c to png.h (Greg).
Added makefile.sco (contributed by Mike Hopkirk).
Fixed two bugs (missing definitions of "istop") introduced in libpng-1.0.1a.
Fixed a bug in pngrtran.c that would set channels=5 under some circumstances.
More work on the Paeth-filtering, achieving imperceptible speedup (A Kleinert).
More work on loop optimization which may help when compiled with C++ compilers.
Added warnings when people try to use transforms they've defined out.
Collapsed 4 "i" and "c" loops into single "i" loops in pngrtran and pngwtran.
Revised paragraph about png_set_expand() in libpng.txt and libpng.3 (Greg)
version 1.0.1c [May 11, 1998]
Fixed a bug in pngrtran.c (introduced in libpng-1.0.1a) where the masks for
filler bytes should have been 0xff instead of 0xf.
Added max_pixel_depth=32 in pngrutil.c when using FILLER with palette images.
Moved PNG_WRITE_WEIGHTED_FILTER_SUPPORTED and PNG_WRITE_FLUSH_SUPPORTED
out of the PNG_WRITE_TRANSFORMS_NOT_SUPPORTED block of pngconf.h
Added "PNG_NO_WRITE_TRANSFORMS" etc., as alternatives for *_NOT_SUPPORTED,
for consistency, in pngconf.h
Added individual "ifndef PNG_NO_[CAPABILITY]" in pngconf.h to make it easier
to remove unwanted capabilities via the compile line
Made some corrections to grammar (which, it's) in documentation (Greg).
Corrected example.c, use of row_pointers in png_write_image().
version 1.0.1d [May 24, 1998]
Corrected several statements that used side effects illegally in pngrutil.c
and pngtrans.c, that were introduced in version 1.0.1b
Revised png_read_rows() to avoid repeated if-testing for NULL (A Kleinert)
More corrections to example.c, use of row_pointers in png_write_image()
and png_read_rows().
Added pngdll.mak and pngdef.pas to scripts directory, contributed by
Bob Dellaca, to make a png32bd.dll with Borland C++ 4.5
Fixed error in example.c with png_set_text: num_text is 3, not 2 (Guido V.)
Changed several loops from count-down to count-up, for consistency.
version 1.0.1e [June 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.3, and Y2KINFO.
version 1.0.3a [August 12, 1999]
Added check for PNG_READ_INTERLACE_SUPPORTED in pngread.c; issue a warning
if an attempt is made to read an interlaced image when it's not supported.
Added check if png_ptr->trans is defined before free'ing it in pngread.c
Modified the Y2K statement to include versions back to version 0.71
Fixed a bug in the check for valid IHDR bit_depth/color_types in pngrutil.c
Modified makefile.wat (added -zp8 flag, ".symbolic", changed some comments)
Replaced leading blanks with tab characters in makefile.hux
Changed "dworkin.wustl.edu" to "ccrc.wustl.edu" in various documents.
Changed (float)red and (float)green to (double)red, (double)green
in png_set_rgb_to_gray() to avoid "promotion" problems in AIX.
Fixed a bug in pngconf.h that omitted <stdio.h> when PNG_DEBUG==0 (K Bracey).
Reformatted libpng.3 and libpngpf.3 with proper fonts (script by J. vanZandt).
Updated documentation to refer to the PNG-1.2 specification.
Removed ansi2knr.c and left pointers to the latest source for ansi2knr.c
in makefile.knr, INSTALL, and README (L. Peter Deutsch)
Fixed bugs in calculation of the length of rowbytes when adding alpha
channels to 16-bit images, in pngrtran.c (Chris Nokleberg)
Added function png_set_user_transform_info() to store user_transform_ptr,
user_depth, and user_channels into the png_struct, and a function
png_get_user_transform_ptr() to retrieve the pointer (Chris Nokleberg)
Added function png_set_empty_plte_permitted() to make libpng useable
in MNG applications.
Corrected the typedef for png_free_ptr in png.h (Jesse Jones).
Correct gamma with srgb is 45455 instead of 45000 in pngrutil.c, to be
consistent with PNG-1.2, and allow variance of 500 before complaining.
Added assembler code contributed by Intel in file pngvcrd.c and modified
makefile.w32 to use it (Nirav Chhatrapati, INTEL Corporation, Gilles Vollant)
Changed "ln -s -f" to "ln -f -s" in the makefiles to make Solaris happy.
Added some aliases for png_set_expand() in pngrtran.c, namely
png_set_expand_PLTE(), png_set_expand_depth(), and png_set_expand_tRNS()
(Greg Roelofs, in "PNG: The Definitive Guide").
Added makefile.beo for BEOS on X86, contributed by Sander Stok.
version 1.0.3b [August 26, 1999]
Replaced 2147483647L several places with PNG_MAX_UINT macro, defined in png.h
Changed leading blanks to tabs in all makefiles.
Define PNG_USE_PNGVCRD in makefile.w32, to get MMX assembler code.
Made alternate versions of png_set_expand() in pngrtran.c, namely
png_set_gray_1_2_4_to_8, png_set_palette_to_rgb, and png_set_tRNS_to_alpha
(Greg Roelofs, in "PNG: The Definitive Guide"). Deleted the 1.0.3a aliases.
Relocated start of 'extern "C"' block in png.h so it doesn't include pngconf.h
Revised calculation of num_blocks in pngmem.c to avoid a potentially
negative shift distance, whose results are undefined in the C language.
Added a check in pngset.c to prevent writing multiple tIME chunks.
Added a check in pngwrite.c to detect invalid small window_bits sizes.
version 1.0.3d [September 4, 1999]
Fixed type casting of igamma in pngrutil.c
Added new png_expand functions to scripts/pngdef.pas and pngos2.def
Added a demo read_user_transform_fn that examines the row filters in pngtest.c
version 1.0.4 [September 24, 1999]
Define PNG_ALWAYS_EXTERN in pngconf.h if __STDC__ is defined
Delete #define PNG_INTERNAL and include "png.h" from pngasmrd.h
Made several minor corrections to pngtest.c
Renamed the makefiles with longer but more user friendly extensions.
Copied the PNG copyright and license to a separate LICENSE file.
Revised documentation, png.h, and example.c to remove reference to
"viewing_gamma" which no longer appears in the PNG specification.
Revised pngvcrd.c to use MMX code for interlacing only on the final pass.
Updated pngvcrd.c to use the faster C filter algorithms from libpng-1.0.1a
Split makefile.win32vc into two versions, makefile.vcawin32 (uses MMX
assembler code) and makefile.vcwin32 (doesn't).
Added a CPU timing report to pngtest.c (enabled by defining PNGTEST_TIMING)
Added a copy of pngnow.png to the distribution.
version 1.0.4a [September 25, 1999]
Increase max_pixel_depth in pngrutil.c if a user transform needs it.
Changed several division operations to right-shifts in pngvcrd.c
version 1.0.4b [September 30, 1999]
Added parentheses in line 3732 of pngvcrd.c
Added a comment in makefile.linux warning about buggy -O3 in pgcc 2.95.1
version 1.0.4c [October 1, 1999]
Added a "png_check_version" function in png.c and pngtest.c that will generate
a helpful compiler error if an old png.h is found in the search path.
Changed type of png_user_transform_depth|channels from int to png_byte.
version 1.0.4d [October 6, 1999]
Changed 0.45 to 0.45455 in png_set_sRGB()
Removed unused PLTE entries from pngnow.png
Re-enabled some parts of pngvcrd.c (png_combine_row) that work properly.
version 1.0.4e [October 10, 1999]
Fixed sign error in pngvcrd.c (Greg Roelofs)
Replaced some instances of memcpy with simple assignments in pngvcrd (GR-P)
version 1.0.4f [October 15, 1999]
Surrounded example.c code with #if 0 .. #endif to prevent people from
inadvertently trying to compile it.
Changed png_get_header_version() from a function to a macro in png.h
Added type casting mostly in pngrtran.c and pngwtran.c
Removed some pointless "ptr = NULL" in pngmem.c
Added a "contrib" directory containing the source code from Greg's book.
version 1.0.5 [October 15, 1999]
Minor editing of the INSTALL and README files.
version 1.0.5a [October 23, 1999]
Added contrib/pngsuite and contrib/pngminus (Willem van Schaik)
Fixed a typo in the png_set_sRGB() function call in example.c (Jan Nijtmans)
Further optimization and bugfix of pngvcrd.c
Revised pngset.c so that it does not allocate or free memory in the user's
text_ptr structure. Instead, it makes its own copy.
Created separate write_end_info_struct in pngtest.c for a more severe test.
Added code in pngwrite.c to free info_ptr->text[i].key to stop a memory leak.
version 1.0.5b [November 23, 1999]
Moved PNG_FLAG_HAVE_CHUNK_HEADER, PNG_FLAG_BACKGROUND_IS_GRAY and
PNG_FLAG_WROTE_tIME from flags to mode.
Added png_write_info_before_PLTE() function.
Fixed some typecasting in contrib/gregbook/*.c
Updated scripts/makevms.com and added makevms.com to contrib/gregbook
and contrib/pngminus (Martin Zinser)
version 1.0.5c [November 26, 1999]
Moved png_get_header_version from png.h to png.c, to accomodate ansi2knr.
Removed all global arrays (according to PNG_NO_GLOBAL_ARRAYS macro), to
accomodate making DLL's: Moved usr_png_ver from global variable to function
png_get_header_ver() in png.c. Moved png_sig to png_sig_bytes in png.c and
eliminated use of png_sig in pngwutil.c. Moved the various png_CHNK arrays
into pngtypes.h. Eliminated use of global png_pass arrays. Declared the
png_CHNK and png_pass arrays to be "const". Made the global arrays
available to applications (although none are used in libpng itself) when
PNG_NO_GLOBAL_ARRAYS is not defined or when PNG_GLOBAL_ARRAYS is defined.
Removed some extraneous "-I" from contrib/pngminus/makefile.std
Changed the PNG_sRGB_INTENT macros in png.h to be consistent with PNG-1.2.
Change PNG_SRGB_INTENT to PNG_sRGB_INTENT in libpng.txt and libpng.3
version 1.0.5d [November 29, 1999]
Add type cast (png_const_charp) two places in png.c
Eliminated pngtypes.h; use macros instead to declare PNG_CHNK arrays.
Renamed "PNG_GLOBAL_ARRAYS" to "PNG_USE_GLOBAL_ARRAYS" and made available
to applications a macro "PNG_USE_LOCAL_ARRAYS".
#ifdef out all the new declarations when PNG_USE_GLOBAL_ARRAYS is defined.
Added PNG_EXPORT_VAR macro to accommodate making DLL's.
version 1.0.5e [November 30, 1999]
Added iCCP, iTXt, and sPLT support; added "lang" member to the png_text
structure; refactored the inflate/deflate support to make adding new chunks
with trailing compressed parts easier in the future, and added new functions
png_free_iCCP, png_free_pCAL, png_free_sPLT, png_free_text, png_get_iCCP,
png_get_spalettes, png_set_iCCP, png_set_spalettes (Eric S. Raymond).
NOTE: Applications that write text chunks MUST define png_text->lang
before calling png_set_text(). It must be set to NULL if you want to
write tEXt or zTXt chunks. If you want your application to be able to
run with older versions of libpng, use
#ifdef PNG_iTXt_SUPPORTED
png_text[i].lang = NULL;
#endif
Changed png_get_oFFs() and png_set_oFFs() to use signed rather than unsigned
offsets (Eric S. Raymond).
Combined PNG_READ_cHNK_SUPPORTED and PNG_WRITE_cHNK_SUPPORTED macros into
PNG_cHNK_SUPPORTED and combined the three types of PNG_text_SUPPORTED
macros, leaving the separate macros also available.
Removed comments on #endifs at the end of many short, non-nested #if-blocks.
version 1.0.5f [December 6, 1999]
Changed makefile.solaris to issue a warning about potential problems when
the ucb "ld" is in the path ahead of the ccs "ld".
Removed "- [date]" from the "synopsis" line in libpng.3 and libpngpf.3.
Added sCAL chunk support (Eric S. Raymond).
version 1.0.5g [December 7, 1999]
Fixed "png_free_spallettes" typo in png.h
Added code to handle new chunks in pngpread.c
Moved PNG_CHNK string macro definitions outside of PNG_NO_EXTERN block
Added "translated_key" to png_text structure and png_write_iTXt().
Added code in pngwrite.c to work around a newly discovered zlib bug.
version 1.0.5h [December 10, 1999]
NOTE: regarding the note for version 1.0.5e, the following must also
be included in your code:
png_text[i].translated_key = NULL;
Unknown chunk handling is now supported.
Option to eliminate all floating point support was added. Some new
fixed-point functions such as png_set_gAMA_fixed() were added.
Expanded tabs and removed trailing blanks in source files.
version 1.0.5i [December 13, 1999]
Added some type casts to silence compiler warnings.
Renamed "png_free_spalette" to "png_free_spalettes" for consistency.
Removed leading blanks from a #define in pngvcrd.c
Added some parameters to the new png_set_keep_unknown_chunks() function.
Added a test for up->location != 0 in the first instance of writing
unknown chunks in pngwrite.c
Changed "num" to "i" in png_free_spalettes() and png_free_unknowns() to
prevent recursion.
Added png_free_hIST() function.
Various patches to fix bugs in the sCAL and integer cHRM processing,
and to add some convenience macros for use with sCAL.
version 1.0.5j [December 21, 1999]
Changed "unit" parameter of png_write_sCAL from png_byte to int, to work
around buggy compilers.
Added new type "png_fixed_point" for integers that hold float*100000 values
Restored backward compatibility of tEXt/zTXt chunk processing:
Restored the first four members of png_text to the same order as v.1.0.5d.
Added members "lang_key" and "itxt_length" to png_text struct. Set
text_length=0 when "text" contains iTXt data. Use the "compression"
member to distinguish among tEXt/zTXt/iTXt types. Added
PNG_ITXT_COMPRESSION_NONE (1) and PNG_ITXT_COMPRESSION_zTXt(2) macros.
The "Note" above, about backward incompatibility of libpng-1.0.5e, no
longer applies.
Fixed png_read|write_iTXt() to read|write parameters in the right order,
and to write the iTXt chunk after IDAT if it appears in the end_ptr.
Added pnggccrd.c, version of pngvcrd.c Intel assembler for gcc (Greg Roelofs)
Reversed the order of trying to write floating-point and fixed-point gAMA.
version 1.0.5k [December 27, 1999]
Added many parentheses, e.g., "if (a && b & c)" becomes "if (a && (b & c))"
Added png_handle_as_unknown() function (Glenn)
Added png_free_chunk_list() function and chunk_list and num_chunk_list members
of png_ptr.
Eliminated erroneous warnings about multiple sPLT chunks and sPLT-after-PLTE.
Fixed a libpng-1.0.5h bug in pngrutil.c that was issuing erroneous warnings
about ignoring incorrect gAMA with sRGB (gAMA was in fact not ignored)
Added png_free_tRNS(); png_set_tRNS() now malloc's its own trans array (ESR).
Define png_get_int_32 when oFFs chunk is supported as well as when pCAL is.
Changed type of proflen from png_int_32 to png_uint_32 in png_get_iCCP().
version 1.0.5l [January 1, 2000]
Added functions png_set_read_user_chunk_fn() and png_get_user_chunk_ptr()
for setting a callback function to handle unknown chunks and for
retrieving the associated user pointer (Glenn).
version 1.0.5m [January 7, 2000]
Added high-level functions png_read_png(), png_write_png(), png_free_pixels().
version 1.0.5n [January 9, 2000]
Added png_free_PLTE() function, and modified png_set_PLTE() to malloc its
own memory for info_ptr->palette. This makes it safe for the calling
application to free its copy of the palette any time after it calls
png_set_PLTE().
version 1.0.5o [January 20, 2000]
Cosmetic changes only (removed some trailing blanks and TABs)
version 1.0.5p [January 31, 2000]
Renamed pngdll.mak to makefile.bd32
Cosmetic changes in pngtest.c
version 1.0.5q [February 5, 2000]
Relocated the makefile.solaris warning about PATH problems.
Fixed pngvcrd.c bug by pushing/popping registers in mmxsupport (Bruce Oberg)
Revised makefile.gcmmx
Added PNG_SETJMP_SUPPORTED, PNG_SETJMP_NOT_SUPPORTED, and PNG_ABORT() macros
version 1.0.5r [February 7, 2000]
Removed superfluous prototype for png_get_itxt from png.h
Fixed a bug in pngrtran.c that improperly expanded the background color.
Return *num_text=0 from png_get_text() when appropriate, and fix documentation
of png_get_text() in libpng.txt/libpng.3.
version 1.0.5s [February 18, 2000]
Added "png_jmp_env()" macro to pngconf.h, to help people migrate to the
new error handler that's planned for the next libpng release, and changed
example.c, pngtest.c, and contrib programs to use this macro.
Revised some of the DLL-export macros in pngconf.h (Greg Roelofs)
Fixed a bug in png_read_png() that caused it to fail to expand some images
that it should have expanded.
Fixed some mistakes in the unused and undocumented INCH_CONVERSIONS functions
in pngget.c
Changed the allocation of palette, history, and trans arrays back to
the version 1.0.5 method (linking instead of copying) which restores
backward compatibility with version 1.0.5. Added some remarks about
that in example.c. Added "free_me" member to info_ptr and png_ptr
and added png_free_data() function.
Updated makefile.linux and makefile.gccmmx to make directories conditionally.
Made cosmetic changes to pngasmrd.h
Added png_set_rows() and png_get_rows(), for use with png_read|write_png().
Modified png_read_png() to allocate info_ptr->row_pointers only if it
hasn't already been allocated.
version 1.0.5t [March 4, 2000]
Changed png_jmp_env() migration aiding macro to png_jmpbuf().
Fixed "interlace" typo (should be "interlaced") in contrib/gregbook/read2-x.c
Fixed bug with use of PNG_BEFORE_IHDR bit in png_ptr->mode, introduced when
PNG_FLAG_HAVE_CHUNK_HEADER was moved into png_ptr->mode in version 1.0.5b
Files in contrib/gregbook were revised to use png_jmpbuf() and to select
a 24-bit visual if one is available, and to allow abbreviated options.
Files in contrib/pngminus were revised to use the png_jmpbuf() macro.
Removed spaces in makefile.linux and makefile.gcmmx, introduced in 1.0.5s
version 1.0.5u [March 5, 2000]
Simplified the code that detects old png.h in png.c and pngtest.c
Renamed png_spalette (_p, _pp) to png_sPLT_t (_tp, _tpp)
Increased precision of rgb_to_gray calculations from 8 to 15 bits and
added png_set_rgb_to_gray_fixed() function.
Added makefile.bc32 (32-bit Borland C++, C mode)
version 1.0.5v [March 11, 2000]
Added some parentheses to the png_jmpbuf macro definition.
Updated references to the zlib home page, which has moved to freesoftware.com.
Corrected bugs in documentation regarding png_read_row() and png_write_row().
Updated documentation of png_rgb_to_gray calculations in libpng.3/libpng.txt.
Renamed makefile.borland,turboc3 back to makefile.bor,tc3 as in version 1.0.3,
revised borland makefiles; added makefile.ibmvac3 and makefile.gcc (Cosmin)
version 1.0.6 [March 20, 2000]
Minor revisions of makefile.bor, libpng.txt, and gregbook/rpng2-win.c
Added makefile.sggcc (SGI IRIX with gcc)
version 1.0.6d [April 7, 2000]
Changed sprintf() to strcpy() in png_write_sCAL_s() to work without STDIO
Added data_length parameter to png_decompress_chunk() function
Revised documentation to remove reference to abandoned png_free_chnk functions
Fixed an error in png_rgb_to_gray_fixed()
Revised example.c, usage of png_destroy_write_struct().
Renamed makefile.ibmvac3 to makefile.ibmc, added libpng.icc IBM project file
Added a check for info_ptr->free_me&PNG_FREE_TEXT when free'ing text in png.c
Simplify png_sig_bytes() function to remove use of non-ISO-C strdup().
version 1.0.6e [April 10, 2000]
Added png_data_freer() function.
In the code that checks for over-length tRNS chunks, added check of
info_ptr->num_trans as well as png_ptr->num_trans (Matthias Benckmann)
Minor revisions of libpng.txt/libpng.3.
Check for existing data and free it if the free_me flag is set, in png_set_*()
and png_handle_*().
Only define PNG_WEIGHTED_FILTERS_SUPPORTED when PNG_FLOATING_POINT_SUPPORTED
is defined.
Changed several instances of PNG_NO_CONSOLE_ID to PNG_NO_STDIO in pngrutil.c
and mentioned the purposes of the two macros in libpng.txt/libpng.3.
Send comments/corrections/commendations to
png-implement@ccrc.wustl.edu or to randeg@alum.rpi.edu
Glenn R-P