src/png/CHANGES

   1 CHANGES - changes for libpng
   2
   3 version 0.2
   4    added reader into png.h
   5    fixed small problems in stub file
   6 version 0.3
   7    added pull reader
   8    split up pngwrite.c to several files
   9    added pnglib.txt
  10    added example.c
  11    cleaned up writer, adding a few new tranformations
  12    fixed some bugs in writer
  13    interfaced with zlib 0.5
  14    added K&R support
  15    added check for 64 KB blocks for 16 bit machines
  16 version 0.4
  17    cleaned up code and commented code
  18    simplified time handling into png_time
  19    created png_color_16 and png_color_8 to handle color needs
  20    cleaned up color type defines
  21    fixed various bugs
  22    made various names more consistant
  23    interfaced with zlib 0.71
  24    cleaned up zTXt reader and writer (using zlib's Reset functions)
  25    split transformations into pngrtran.c and pngwtran.c
  26 version 0.5
  27    interfaced with zlib 0.8
  28    fixed many reading and writing bugs
  29    saved using 3 spaces instead of tabs
  30 version 0.6
  31    added png_large_malloc() and png_large_free()
  32    added png_size_t
  33    cleaned up some compiler warnings
  34    added png_start_read_image()
  35 version 0.7
  36    cleaned up lots of bugs
  37    finished dithering and other stuff
  38    added test program
  39    changed name from pnglib to libpng
  40 version 0.71 [June, 1995]
  41    changed pngtest.png for zlib 0.93
  42    fixed error in libpng.txt and example.c
  43 version 0.8
  44    cleaned up some bugs
  45    added png_set_filler()
  46    split up pngstub.c into pngmem.c, pngio.c, and pngerror.c
  47    added #define's to remove unwanted code
  48    moved png_info_init() to png.c
  49    added old_size into png_realloc()
  50    added functions to manually set filtering and compression info
  51    changed compression parameters based on image type
  52    optimized filter selection code
  53    added version info
  54    changed external functions passing floats to doubles (k&r problems?)
  55    put all the configurable stuff in pngconf.h
  56    enabled png_set_shift to work with paletted images on read
  57    added png_read_update_info() - updates info structure with
  58       transformations
  59 version 0.81 [August, 1995]
  60    incorporated Tim Wegner's medium model code (thanks, Tim)
  61 version 0.82 [September, 1995]
  62    [unspecified changes]
  63 version 0.85 [December, 1995]
  64    added more medium model code (almost everything's a far)
  65    added i/o, error, and memory callback functions
  66    fixed some bugs (16 bit, 4 bit interlaced, etc.)
  67    added first run progressive reader (barely tested)
  68 version 0.86 [January, 1996]
  69    fixed bugs
  70    improved documentation
  71 version 0.87 [January, 1996]
  72    fixed medium model bugs
  73    fixed other bugs introduced in 0.85 and 0.86
  74    added some minor documentation
  75 version 0.88 [January, 1996]
  76    fixed progressive bugs
  77    replaced tabs with spaces
  78    cleaned up documentation
  79    added callbacks for read/write and warning/error functions
  80 version 0.89 [July, 1996]
  81    added new initialization API to make libpng work better with shared libs
  82       we now have png_create_read_struct(), png_create_write_struct(),
  83       png_create_info_struct(), png_destroy_read_struct(), and
  84       png_destroy_write_struct() instead of the separate calls to
  85       malloc and png_read_init(), png_info_init(), and png_write_init()
  86    changed warning/error callback functions to fix bug - this means you
  87       should use the new initialization API if you were using the old
  88       png_set_message_fn() calls, and that the old API no longer exists
  89       so that people are aware that they need to change their code
  90    changed filter selection API to allow selection of multiple filters
  91       since it didn't work in previous versions of libpng anyways
  92    optimized filter selection code
  93    fixed png_set_background() to allow using an arbitrary RGB color for
  94       paletted images
  95    fixed gamma and background correction for paletted images, so
  96       png_correct_palette is not needed unless you are correcting an
  97       external palette (you will need to #define PNG_CORRECT_PALETTE_SUPPORTED
  98       in pngconf.h) - if nobody uses this, it may disappear in the future.
  99    fixed bug with Borland 64K memory allocation (Alexander Lehmann)
 100    fixed bug in interlace handling (Smarasderagd, I think)
 101    added more error checking for writing and image to reduce invalid files
 102    separated read and write functions so that they won't both be linked
 103       into a binary when only reading or writing functionality is used
 104    new pngtest image also has interlacing and zTXt
 105    updated documentation to reflect new API
 106 version 0.90 [January, 1997]
 107    made CRC errors/warnings on critical and ancillary chunks configurable
 108    libpng will use the zlib CRC routines by (compile-time) default
 109    changed DOS small/medium model memory support - needs zlib 1.04 (Tim Wegner)
 110    added external C++ wrapper statements to png.h (Gilles Dauphin)
 111    allow PNG file to be read when some or all of file signature has already
 112       been read from the beginning of the stream.  ****This affects the size
 113       of info_struct and invalidates all programs that use a shared libpng****
 114    fixed png_filler() declarations
 115    fixed? background color conversions
 116    fixed order of error function pointers to match documentation
 117    current chunk name is now available in png_struct to reduce the number
 118       of nearly identical error messages (will simplify multi-lingual
 119       support when available)
 120    try to get ready for unknown-chunk callback functions:
 121       - previously read critical chunks are flagged, so the chunk handling
 122         routines can determine if the chunk is in the right place
 123       - all chunk handling routines have the same prototypes, so we will
 124         be able to handle all chunks via a callback mechanism
 125    try to fix Linux "setjmp" buffer size problems
 126 version 0.95 [March, 1997]
 127    fixed bug in pngwutil.c allocating "up_row" twice and "avg_row" never
 128    fixed bug in PNG file signature compares when start != 0
 129    changed parameter type of png_set_filler(...filler...) from png_byte
 130       to png_uint_32
 131    added test for MACOS to ensure that both math.h and fp.h are not #included
 132    added macros for libpng to be compiled as a Windows DLL (Andreas Kupries)
 133    added "packswap" transformation, which changes the endianness of
 134       packed-pixel bytes (Kevin Bracey)
 135    added "strip_alpha" transformation, which removes the alpha channel of
 136       input images without using it (not neccesarily a good idea)
 137    added "swap_alpha" transformation, which puts the alpha channel in front
 138       of the color bytes instead of after
 139    removed all implicit variable tests which assume NULL == 0 (I think)
 140    changed several variables to "png_size_t" to show 16/32-bit limitations
 141    added new pCAL chunk read/write support
 142    added experimental filter selection weighting (Greg Roelofs)
 143    removed old png_set_rgbx() and png_set_xrgb() functions that have been
 144       obsolete for about 2 years now (use png_set_filler() instead)
 145    added macros to read 16- and 32-bit ints directly from buffer, to be
 146       used only on those systems that support it (namely PowerPC and 680x0)
 147       With some testing, this may become the default for MACOS/PPC systems.
 148    only calculate CRC on data if we are going to use it
 149    added macros for zTXt compression type PNG_zTXt_COMPRESSION_???
 150    added macros for simple libpng debugging output selectable at compile time
 151    removed PNG_READ_END_MODE in progressive reader (Smarasderagd)
 152    more description of info_struct in libpng.txt and png.h
 153    more instructions in example.c
 154    more chunk types tested in pngtest.c
 155    renamed pngrcb.c to pngset.c, and all png_read_<chunk> functions to be
 156       png_set_<chunk>.  We now have corresponding png_get_<chunk>
 157       functions in pngget.c to get infomation in info_ptr.  This isolates
 158       the application from the internal organization of png_info_struct
 159       (good for shared library implementations).
 160 version 0.96 [May, 1997]
 161    fixed serious bug with < 8bpp images introduced in 0.95
 162    fixed 256-color transparency bug (Greg Roelofs)
 163    fixed up documentation (Greg Roelofs, Laszlo Nyul)
 164    fixed "error" in pngconf.h for Linux setjmp() behaviour
 165    fixed DOS medium model support (Tim Wegner)
 166    fixed png_check_keyword() for case with error in static string text
 167    added read of CRC after IEND chunk for embedded PNGs (Laszlo Nyul)
 168    added typecasts to quiet compiler errors
 169    added more debugging info
 170 version 0.97 [January, 1998]
 171    removed PNG_USE_OWN_CRC capability
 172    relocated png_set_crc_action from pngrutil.c to pngrtran.c
 173    fixed typecasts of "new_key", etc. (Andreas Dilger)
 174    added RFC 1152 [sic] date support
 175    fixed bug in gamma handling of 4-bit grayscale
 176    added 2-bit grayscale gamma handling (Glenn R-P)
 177    added more typecasts. 65536L becomes (png_uint_32)65536L, etc. (Glenn R-P)
 178    minor corrections in libpng.txt
 179    added simple sRGB support (Glenn R-P)
 180    easier conditional compiling, e.g. define PNG_READ/WRITE_NOT_FULLY_SUPPORTED;
 181       all configurable options can be selected from command-line instead
 182       of having to edit pngconf.h (Glenn R-P)
 183    fixed memory leak in pngwrite.c (free info_ptr->text) (Glenn R-P)
 184    added more conditions for png_do_background, to avoid changing
 185       black pixels to background when a background is supplied and
 186       no pixels are transparent
 187    repaired PNG_NO_STDIO behaviour
 188    tested NODIV support and made it default behaviour (Greg Roelofs)
 189    added "-m" option and PNGTEST_DEBUG_MEMORY to pngtest (John Bowler)
 190    regularized version numbering scheme and bumped shared-library major
 191       version number to 2 to avoid problems with libpng 0.89 apps (Greg Roelofs)
 192 version 0.98 [January, 1998]
 193    cleaned up some typos in libpng.txt and in code documentation
 194    fixed memory leaks in pCAL chunk processing (Glenn R-P and John Bowler)
 195    cosmetic change "display_gamma" to "screen_gamma" in pngrtran.c
 196    changed recommendation about file_gamma for PC images to .51 from .45,
 197       in example.c and libpng.txt, added comments to distinguish between
 198       screen_gamma, viewing_gamma, and display_gamma.
 199    changed all references to RFC1152 to read RFC1123 and changed the
 200       PNG_TIME_RFC1152_SUPPORTED macro to PNG_TIME_RFC1123_SUPPORTED
 201    added png_invert_alpha capability (Glenn R-P -- suggestion by Jon Vincent)
 202    changed srgb_intent from png_byte to int to avoid compiler bugs
 203 version 0.99 [January 30, 1998]
 204    free info_ptr->text instead of end_info_ptr->text in pngread.c (John Bowler)
 205    fixed a longstanding "packswap" bug in pngtrans.c
 206    fixed some inconsistencies in pngconf.h that prevented compiling with
 207       PNG_READ_GAMMA_SUPPORTED and PNG_READ_hIST_SUPPORTED undefined
 208    fixed some typos and made other minor rearrangement of libpng.txt (Andreas)
 209    changed recommendation about file_gamma for PC images to .50 from .51 in
 210       example.c and libpng.txt, and changed file_gamma for sRGB images to .45
 211    added a number of functions to access information from the png structure
 212       png_get_image_height(), etc. (Glenn R-P, suggestion by Brad Pettit)
 213    added TARGET_MACOS similar to zlib-1.0.8
 214    define PNG_ALWAYS_EXTERN when __MWERKS__ && WIN32 are defined
 215    added type casting to all png_malloc() function calls
 216 version 0.99a [January 31, 1998]
 217    Added type casts and parentheses to all returns that return a value.(Tim W.)
 218 version 0.99b [February 4, 1998]
 219    Added type cast png_uint_32 on malloc function calls where needed.
 220    Changed type of num_hist from png_uint_32 to int (same as num_palette).
 221    Added checks for rowbytes overflow, in case png_size_t is less than 32 bits.
 222    Renamed makefile.elf to makefile.lnx.
 223 version 0.99c [February 7, 1998]
 224    More type casting.  Removed erroneous overflow test in pngmem.c.
 225    Added png_buffered_memcpy() and png_buffered_memset(), apply them to rowbytes.
 226    Added UNIX manual pages libpng.3 (incorporating libpng.txt) and  png.5.
 227 version 0.99d [February 11, 1998]
 228    Renamed "far_to_near()" "png_far_to_near()"
 229    Revised libpng.3
 230    Version 99c "buffered" operations didn't work as intended.  Replaced them
 231      with png_memcpy_check() and png_memset_check().
 232    Added many "if (png_ptr == NULL) return" to quell compiler warnings about
 233      unused png_ptr, mostly in pngget.c and pngset.c.
 234    Check for overlength tRNS chunk present when indexed-color PLTE is read.
 235    Cleaned up spelling errors in libpng.3/libpng.txt
 236    Corrected a problem with png_get_tRNS() which returned undefined trans array
 237 version 0.99e [February 28, 1998]
 238    Corrected png_get_tRNS() again.
 239    Add parentheses for easier reading of pngget.c, fixed "||" should be "&&".
 240    Touched up example.c to make more of it compileable, although the entire
 241      file still can't be compiled (Willem van Schaik)
 242    Fixed a bug in png_do_shift() (Bryan Tsai)
 243    Added a space in png.h prototype for png_write_chunk_start()
 244    Replaced pngtest.png with one created with zlib 1.1.1
 245    Changed pngtest to report PASS even when file size is different (Jean-loup G.)
 246    Corrected some logic errors in png_do_invert_alpha() (Chris Patterson)
 247 version 0.99f [March 5, 1998]
 248    Corrected a bug in pngpread() introduced in version 99c (Kevin Bracey)
 249    Moved makefiles into a "scripts" directory, and added INSTALL instruction file
 250    Added makefile.os2 and pngos2.def (A. Zabolotny) and makefile.s2x (W. Sebok)
 251    Added pointers to "note on libpng versions" in makefile.lnx and README
 252    Added row callback feature when reading and writing nonprogressive rows
 253       and added a test of this feature in pngtest.c
 254    Added user transform callbacks, with test of the feature in pngtest.c
 255 version 0.99g [March 6, 1998, morning]
 256    Minor changes to pngtest.c to suppress compiler warnings.
 257    Removed "beta" language from documentation.
 258 version 0.99h [March 6, 1998, evening]
 259    Minor changes to previous minor changes to pngtest.c
 260    Changed PNG_READ_NOT_FULLY_SUPPORTED to PNG_READ_TRANSFORMS_NOT_SUPPORTED
 261    and added PNG_PROGRESSIVE_READ_NOT_SUPPORTED macro
 262 version 1.00 [March 7, 1998]
 263    Changed several typedefs in pngrutil.c
 264    Added makefile.wat (Pawel Mrochen), updated makefile.tc3 (Willem van Schaik)
 265    replaced "while(1)" with "for(;;)"
 266    added PNGARG() to prototypes in pngtest.c and removed some prototypes
 267    updated some of the makefiles (Tom Lane)
 268    changed some typedefs (s_start, etc.) in pngrutil.c
 269    fixed dimensions of "short_months" array in pngwrite.c
 270    Replaced ansi2knr.c with the one from jpeg-v6
 271 version 1.0.0 [March 8, 1998]
 272    Changed name from 1.00 to 1.0.0 (Adam Costello)
 273    Added smakefile.ppc (with SCOPTIONS.ppc) for Amiga PPC (Andreas Kleinert)
 274 version 1.0.0a [March 9, 1998]
 275    Fixed three bugs in pngrtran.c to make gamma+background handling consistent
 276    (Greg Roelofs)
 277    Changed format of the PNG_LIBPNG_VER integer to xyyzz instead of xyz
 278    for major, minor, and bugfix releases.  This is 10001. (Adam Costello,
 279    Tom Lane)
 280    Make months range from 1-12 in png_convert_to_rfc1123
 281 version 1.0.0b [March 13, 1998]
 282    Quieted compiler complaints about two empty "for" loops in pngrutil.c
 283    Minor changes to makefile.s2x
 284    Removed #ifdef/#endif around a png_free() in pngread.c
 285 version 1.0.1 [March 14, 1998]
 286    Changes makefile.s2x to reduce security risk of using a relative pathname
 287    Fixed some typos in the documentation (Greg).
 288    Fixed a problem with value of "channels" returned by png_read_update_info()