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  1. /* png.h - header file for PNG reference library
  2.  *
  3.  * libpng version 1.2.37 - June 4, 2009
  4.  * Copyright (c) 1998-2009 Glenn Randers-Pehrson
  5.  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  6.  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  7.  *
  8.  * Authors and maintainers:
  9.  *  libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
  10.  *  libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
  11.  *  libpng versions 0.97, January 1998, through 1.2.37 - June 4, 2009: Glenn
  12.  *  See also "Contributing Authors", below.
  13.  *
  14.  * Note about libpng version numbers:
  15.  *
  16.  *    Due to various miscommunications, unforeseen code incompatibilities
  17.  *    and occasional factors outside the authors' control, version numbering
  18.  *    on the library has not always been consistent and straightforward.
  19.  *    The following table summarizes matters since version 0.89c, which was
  20.  *    the first widely used release:
  21.  *
  22.  *    source                 png.h  png.h  shared-lib
  23.  *    version                string   int  version
  24.  *    -------                ------ -----  ----------
  25.  *    0.89c "1.0 beta 3"     0.89      89  1.0.89
  26.  *    0.90  "1.0 beta 4"     0.90      90  0.90  [should have been 2.0.90]
  27.  *    0.95  "1.0 beta 5"     0.95      95  0.95  [should have been 2.0.95]
  28.  *    0.96  "1.0 beta 6"     0.96      96  0.96  [should have been 2.0.96]
  29.  *    0.97b "1.00.97 beta 7" 1.00.97   97  1.0.1 [should have been 2.0.97]
  30.  *    0.97c                  0.97      97  2.0.97
  31.  *    0.98                   0.98      98  2.0.98
  32.  *    0.99                   0.99      98  2.0.99
  33.  *    0.99a-m                0.99      99  2.0.99
  34.  *    1.00                   1.00     100  2.1.0 [100 should be 10000]
  35.  *    1.0.0      (from here on, the   100  2.1.0 [100 should be 10000]
  36.  *    1.0.1       png.h string is   10001  2.1.0
  37.  *    1.0.1a-e    identical to the  10002  from here on, the shared library
  38.  *    1.0.2       source version)   10002  is 2.V where V is the source code
  39.  *    1.0.2a-b                      10003  version, except as noted.
  40.  *    1.0.3                         10003
  41.  *    1.0.3a-d                      10004
  42.  *    1.0.4                         10004
  43.  *    1.0.4a-f                      10005
  44.  *    1.0.5 (+ 2 patches)           10005
  45.  *    1.0.5a-d                      10006
  46.  *    1.0.5e-r                      10100 (not source compatible)
  47.  *    1.0.5s-v                      10006 (not binary compatible)
  48.  *    1.0.6 (+ 3 patches)           10006 (still binary incompatible)
  49.  *    1.0.6d-f                      10007 (still binary incompatible)
  50.  *    1.0.6g                        10007
  51.  *    1.0.6h                        10007  10.6h (testing xy.z so-numbering)
  52.  *    1.0.6i                        10007  10.6i
  53.  *    1.0.6j                        10007  2.1.0.6j (incompatible with 1.0.0)
  54.  *    1.0.7beta11-14        DLLNUM  10007  2.1.0.7beta11-14 (binary compatible)
  55.  *    1.0.7beta15-18           1    10007  2.1.0.7beta15-18 (binary compatible)
  56.  *    1.0.7rc1-2               1    10007  2.1.0.7rc1-2 (binary compatible)
  57.  *    1.0.7                    1    10007  (still compatible)
  58.  *    1.0.8beta1-4             1    10008  2.1.0.8beta1-4
  59.  *    1.0.8rc1                 1    10008  2.1.0.8rc1
  60.  *    1.0.8                    1    10008  2.1.0.8
  61.  *    1.0.9beta1-6             1    10009  2.1.0.9beta1-6
  62.  *    1.0.9rc1                 1    10009  2.1.0.9rc1
  63.  *    1.0.9beta7-10            1    10009  2.1.0.9beta7-10
  64.  *    1.0.9rc2                 1    10009  2.1.0.9rc2
  65.  *    1.0.9                    1    10009  2.1.0.9
  66.  *    1.0.10beta1              1    10010  2.1.0.10beta1
  67.  *    1.0.10rc1                1    10010  2.1.0.10rc1
  68.  *    1.0.10                   1    10010  2.1.0.10
  69.  *    1.0.11beta1-3            1    10011  2.1.0.11beta1-3
  70.  *    1.0.11rc1                1    10011  2.1.0.11rc1
  71.  *    1.0.11                   1    10011  2.1.0.11
  72.  *    1.0.12beta1-2            2    10012  2.1.0.12beta1-2
  73.  *    1.0.12rc1                2    10012  2.1.0.12rc1
  74.  *    1.0.12                   2    10012  2.1.0.12
  75.  *    1.1.0a-f                 -    10100  2.1.1.0a-f (branch abandoned)
  76.  *    1.2.0beta1-2             2    10200  2.1.2.0beta1-2
  77.  *    1.2.0beta3-5             3    10200  3.1.2.0beta3-5
  78.  *    1.2.0rc1                 3    10200  3.1.2.0rc1
  79.  *    1.2.0                    3    10200  3.1.2.0
  80.  *    1.2.1beta1-4             3    10201  3.1.2.1beta1-4
  81.  *    1.2.1rc1-2               3    10201  3.1.2.1rc1-2
  82.  *    1.2.1                    3    10201  3.1.2.1
  83.  *    1.2.2beta1-6            12    10202  12.so.0.1.2.2beta1-6
  84.  *    1.0.13beta1             10    10013  10.so.0.1.0.13beta1
  85.  *    1.0.13rc1               10    10013  10.so.0.1.0.13rc1
  86.  *    1.2.2rc1                12    10202  12.so.0.1.2.2rc1
  87.  *    1.0.13                  10    10013  10.so.0.1.0.13
  88.  *    1.2.2                   12    10202  12.so.0.1.2.2
  89.  *    1.2.3rc1-6              12    10203  12.so.0.1.2.3rc1-6
  90.  *    1.2.3                   12    10203  12.so.0.1.2.3
  91.  *    1.2.4beta1-3            13    10204  12.so.0.1.2.4beta1-3
  92.  *    1.0.14rc1               13    10014  10.so.0.1.0.14rc1
  93.  *    1.2.4rc1                13    10204  12.so.0.1.2.4rc1
  94.  *    1.0.14                  10    10014  10.so.0.1.0.14
  95.  *    1.2.4                   13    10204  12.so.0.1.2.4
  96.  *    1.2.5beta1-2            13    10205  12.so.0.1.2.5beta1-2
  97.  *    1.0.15rc1-3             10    10015  10.so.0.1.0.15rc1-3
  98.  *    1.2.5rc1-3              13    10205  12.so.0.1.2.5rc1-3
  99.  *    1.0.15                  10    10015  10.so.0.1.0.15
  100.  *    1.2.5                   13    10205  12.so.0.1.2.5
  101.  *    1.2.6beta1-4            13    10206  12.so.0.1.2.6beta1-4
  102.  *    1.0.16                  10    10016  10.so.0.1.0.16
  103.  *    1.2.6                   13    10206  12.so.0.1.2.6
  104.  *    1.2.7beta1-2            13    10207  12.so.0.1.2.7beta1-2
  105.  *    1.0.17rc1               10    10017  10.so.0.1.0.17rc1
  106.  *    1.2.7rc1                13    10207  12.so.0.1.2.7rc1
  107.  *    1.0.17                  10    10017  10.so.0.1.0.17
  108.  *    1.2.7                   13    10207  12.so.0.1.2.7
  109.  *    1.2.8beta1-5            13    10208  12.so.0.1.2.8beta1-5
  110.  *    1.0.18rc1-5             10    10018  10.so.0.1.0.18rc1-5
  111.  *    1.2.8rc1-5              13    10208  12.so.0.1.2.8rc1-5
  112.  *    1.0.18                  10    10018  10.so.0.1.0.18
  113.  *    1.2.8                   13    10208  12.so.0.1.2.8
  114.  *    1.2.9beta1-3            13    10209  12.so.0.1.2.9beta1-3
  115.  *    1.2.9beta4-11           13    10209  12.so.0.9[.0]
  116.  *    1.2.9rc1                13    10209  12.so.0.9[.0]
  117.  *    1.2.9                   13    10209  12.so.0.9[.0]
  118.  *    1.2.10beta1-8           13    10210  12.so.0.10[.0]
  119.  *    1.2.10rc1-3             13    10210  12.so.0.10[.0]
  120.  *    1.2.10                  13    10210  12.so.0.10[.0]
  121.  *    1.2.11beta1-4           13    10211  12.so.0.11[.0]
  122.  *    1.0.19rc1-5             10    10019  10.so.0.19[.0]
  123.  *    1.2.11rc1-5             13    10211  12.so.0.11[.0]
  124.  *    1.0.19                  10    10019  10.so.0.19[.0]
  125.  *    1.2.11                  13    10211  12.so.0.11[.0]
  126.  *    1.0.20                  10    10020  10.so.0.20[.0]
  127.  *    1.2.12                  13    10212  12.so.0.12[.0]
  128.  *    1.2.13beta1             13    10213  12.so.0.13[.0]
  129.  *    1.0.21                  10    10021  10.so.0.21[.0]
  130.  *    1.2.13                  13    10213  12.so.0.13[.0]
  131.  *    1.2.14beta1-2           13    10214  12.so.0.14[.0]
  132.  *    1.0.22rc1               10    10022  10.so.0.22[.0]
  133.  *    1.2.14rc1               13    10214  12.so.0.14[.0]
  134.  *    1.0.22                  10    10022  10.so.0.22[.0]
  135.  *    1.2.14                  13    10214  12.so.0.14[.0]
  136.  *    1.2.15beta1-6           13    10215  12.so.0.15[.0]
  137.  *    1.0.23rc1-5             10    10023  10.so.0.23[.0]
  138.  *    1.2.15rc1-5             13    10215  12.so.0.15[.0]
  139.  *    1.0.23                  10    10023  10.so.0.23[.0]
  140.  *    1.2.15                  13    10215  12.so.0.15[.0]
  141.  *    1.2.16beta1-2           13    10216  12.so.0.16[.0]
  142.  *    1.2.16rc1               13    10216  12.so.0.16[.0]
  143.  *    1.0.24                  10    10024  10.so.0.24[.0]
  144.  *    1.2.16                  13    10216  12.so.0.16[.0]
  145.  *    1.2.17beta1-2           13    10217  12.so.0.17[.0]
  146.  *    1.0.25rc1               10    10025  10.so.0.25[.0]
  147.  *    1.2.17rc1-3             13    10217  12.so.0.17[.0]
  148.  *    1.0.25                  10    10025  10.so.0.25[.0]
  149.  *    1.2.17                  13    10217  12.so.0.17[.0]
  150.  *    1.0.26                  10    10026  10.so.0.26[.0]
  151.  *    1.2.18                  13    10218  12.so.0.18[.0]
  152.  *    1.2.19beta1-31          13    10219  12.so.0.19[.0]
  153.  *    1.0.27rc1-6             10    10027  10.so.0.27[.0]
  154.  *    1.2.19rc1-6             13    10219  12.so.0.19[.0]
  155.  *    1.0.27                  10    10027  10.so.0.27[.0]
  156.  *    1.2.19                  13    10219  12.so.0.19[.0]
  157.  *    1.2.20beta01-04         13    10220  12.so.0.20[.0]
  158.  *    1.0.28rc1-6             10    10028  10.so.0.28[.0]
  159.  *    1.2.20rc1-6             13    10220  12.so.0.20[.0]
  160.  *    1.0.28                  10    10028  10.so.0.28[.0]
  161.  *    1.2.20                  13    10220  12.so.0.20[.0]
  162.  *    1.2.21beta1-2           13    10221  12.so.0.21[.0]
  163.  *    1.2.21rc1-3             13    10221  12.so.0.21[.0]
  164.  *    1.0.29                  10    10029  10.so.0.29[.0]
  165.  *    1.2.21                  13    10221  12.so.0.21[.0]
  166.  *    1.2.22beta1-4           13    10222  12.so.0.22[.0]
  167.  *    1.0.30rc1               10    10030  10.so.0.30[.0]
  168.  *    1.2.22rc1               13    10222  12.so.0.22[.0]
  169.  *    1.0.30                  10    10030  10.so.0.30[.0]
  170.  *    1.2.22                  13    10222  12.so.0.22[.0]
  171.  *    1.2.23beta01-05         13    10223  12.so.0.23[.0]
  172.  *    1.2.23rc01              13    10223  12.so.0.23[.0]
  173.  *    1.2.23                  13    10223  12.so.0.23[.0]
  174.  *    1.2.24beta01-02         13    10224  12.so.0.24[.0]
  175.  *    1.2.24rc01              13    10224  12.so.0.24[.0]
  176.  *    1.2.24                  13    10224  12.so.0.24[.0]
  177.  *    1.2.25beta01-06         13    10225  12.so.0.25[.0]
  178.  *    1.2.25rc01-02           13    10225  12.so.0.25[.0]
  179.  *    1.0.31                  10    10031  10.so.0.31[.0]
  180.  *    1.2.25                  13    10225  12.so.0.25[.0]
  181.  *    1.2.26beta01-06         13    10226  12.so.0.26[.0]
  182.  *    1.2.26rc01              13    10226  12.so.0.26[.0]
  183.  *    1.2.26                  13    10226  12.so.0.26[.0]
  184.  *    1.0.32                  10    10032  10.so.0.32[.0]
  185.  *    1.2.27beta01-06         13    10227  12.so.0.27[.0]
  186.  *    1.2.27rc01              13    10227  12.so.0.27[.0]
  187.  *    1.0.33                  10    10033  10.so.0.33[.0]
  188.  *    1.2.27                  13    10227  12.so.0.27[.0]
  189.  *    1.0.34                  10    10034  10.so.0.34[.0]
  190.  *    1.2.28                  13    10228  12.so.0.28[.0]
  191.  *    1.2.29beta01-03         13    10229  12.so.0.29[.0]
  192.  *    1.2.29rc01              13    10229  12.so.0.29[.0]
  193.  *    1.0.35                  10    10035  10.so.0.35[.0]
  194.  *    1.2.29                  13    10229  12.so.0.29[.0]
  195.  *    1.0.37                  10    10037  10.so.0.37[.0]
  196.  *    1.2.30beta01-04         13    10230  12.so.0.30[.0]
  197.  *    1.0.38rc01-08           10    10038  10.so.0.38[.0]
  198.  *    1.2.30rc01-08           13    10230  12.so.0.30[.0]
  199.  *    1.0.38                  10    10038  10.so.0.38[.0]
  200.  *    1.2.30                  13    10230  12.so.0.30[.0]
  201.  *    1.0.39rc01-03           10    10039  10.so.0.39[.0]
  202.  *    1.2.31rc01-03           13    10231  12.so.0.31[.0]
  203.  *    1.0.39                  10    10039  10.so.0.39[.0]
  204.  *    1.2.31                  13    10231  12.so.0.31[.0]
  205.  *    1.2.32beta01-02         13    10232  12.so.0.32[.0]
  206.  *    1.0.40rc01              10    10040  10.so.0.40[.0]
  207.  *    1.2.32rc01              13    10232  12.so.0.32[.0]
  208.  *    1.0.40                  10    10040  10.so.0.40[.0]
  209.  *    1.2.32                  13    10232  12.so.0.32[.0]
  210.  *    1.2.33beta01-02         13    10233  12.so.0.33[.0]
  211.  *    1.2.33rc01-02           13    10233  12.so.0.33[.0]
  212.  *    1.0.41rc01              10    10041  10.so.0.41[.0]
  213.  *    1.2.33                  13    10233  12.so.0.33[.0]
  214.  *    1.0.41                  10    10041  10.so.0.41[.0]
  215.  *    1.2.34beta01-07         13    10234  12.so.0.34[.0]
  216.  *    1.0.42rc01              10    10042  10.so.0.42[.0]
  217.  *    1.2.34rc01              13    10234  12.so.0.34[.0]
  218.  *    1.0.42                  10    10042  10.so.0.42[.0]
  219.  *    1.2.34                  13    10234  12.so.0.34[.0]
  220.  *    1.2.35beta01-03         13    10235  12.so.0.35[.0]
  221.  *    1.0.43rc01-02           10    10043  10.so.0.43[.0]
  222.  *    1.2.35rc01-02           13    10235  12.so.0.35[.0]
  223.  *    1.0.43                  10    10043  10.so.0.43[.0]
  224.  *    1.2.35                  13    10235  12.so.0.35[.0]
  225.  *    1.2.36beta01-05         13    10236  12.so.0.36[.0]
  226.  *    1.2.36rc01              13    10236  12.so.0.36[.0]
  227.  *    1.0.44                  10    10044  10.so.0.44[.0]
  228.  *    1.2.36                  13    10236  12.so.0.36[.0]
  229.  *    1.2.37beta01-03         13    10237  12.so.0.37[.0]
  230.  *    1.2.37rc01              13    10237  12.so.0.37[.0]
  231.  *    1.2.37                  13    10237  12.so.0.37[.0]
  232.  *
  233.  *    Henceforth the source version will match the shared-library major
  234.  *    and minor numbers; the shared-library major version number will be
  235.  *    used for changes in backward compatibility, as it is intended.  The
  236.  *    PNG_LIBPNG_VER macro, which is not used within libpng but is available
  237.  *    for applications, is an unsigned integer of the form xyyzz corresponding
  238.  *    to the source version x.y.z (leading zeros in y and z).  Beta versions
  239.  *    were given the previous public release number plus a letter, until
  240.  *    version 1.0.6j; from then on they were given the upcoming public
  241.  *    release number plus "betaNN" or "rcNN".
  242.  *
  243.  *    Binary incompatibility exists only when applications make direct access
  244.  *    to the info_ptr or png_ptr members through png.h, and the compiled
  245.  *    application is loaded with a different version of the library.
  246.  *
  247.  *    DLLNUM will change each time there are forward or backward changes
  248.  *    in binary compatibility (e.g., when a new feature is added).
  249.  *
  250.  * See libpng.txt or libpng.3 for more information.  The PNG specification
  251.  * is available as a W3C Recommendation and as an ISO Specification,
  252.  * <http://www.w3.org/TR/2003/REC-PNG-20031110/
  253.  */
  254.  
  255. /*
  256.  * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
  257.  *
  258.  * If you modify libpng you may insert additional notices immediately following
  259.  * this sentence.
  260.  *
  261.  * libpng versions 1.2.6, August 15, 2004, through 1.2.37, June 4, 2009, are
  262.  * Copyright (c) 2004, 2006-2009 Glenn Randers-Pehrson, and are
  263.  * distributed according to the same disclaimer and license as libpng-1.2.5
  264.  * with the following individual added to the list of Contributing Authors:
  265.  *
  266.  *    Cosmin Truta
  267.  *
  268.  * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
  269.  * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
  270.  * distributed according to the same disclaimer and license as libpng-1.0.6
  271.  * with the following individuals added to the list of Contributing Authors:
  272.  *
  273.  *    Simon-Pierre Cadieux
  274.  *    Eric S. Raymond
  275.  *    Gilles Vollant
  276.  *
  277.  * and with the following additions to the disclaimer:
  278.  *
  279.  *    There is no warranty against interference with your enjoyment of the
  280.  *    library or against infringement.  There is no warranty that our
  281.  *    efforts or the library will fulfill any of your particular purposes
  282.  *    or needs.  This library is provided with all faults, and the entire
  283.  *    risk of satisfactory quality, performance, accuracy, and effort is with
  284.  *    the user.
  285.  *
  286.  * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
  287.  * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are
  288.  * distributed according to the same disclaimer and license as libpng-0.96,
  289.  * with the following individuals added to the list of Contributing Authors:
  290.  *
  291.  *    Tom Lane
  292.  *    Glenn Randers-Pehrson
  293.  *    Willem van Schaik
  294.  *
  295.  * libpng versions 0.89, June 1996, through 0.96, May 1997, are
  296.  * Copyright (c) 1996, 1997 Andreas Dilger
  297.  * Distributed according to the same disclaimer and license as libpng-0.88,
  298.  * with the following individuals added to the list of Contributing Authors:
  299.  *
  300.  *    John Bowler
  301.  *    Kevin Bracey
  302.  *    Sam Bushell
  303.  *    Magnus Holmgren
  304.  *    Greg Roelofs
  305.  *    Tom Tanner
  306.  *
  307.  * libpng versions 0.5, May 1995, through 0.88, January 1996, are
  308.  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
  309.  *
  310.  * For the purposes of this copyright and license, "Contributing Authors"
  311.  * is defined as the following set of individuals:
  312.  *
  313.  *    Andreas Dilger
  314.  *    Dave Martindale
  315.  *    Guy Eric Schalnat
  316.  *    Paul Schmidt
  317.  *    Tim Wegner
  318.  *
  319.  * The PNG Reference Library is supplied "AS IS".  The Contributing Authors
  320.  * and Group 42, Inc. disclaim all warranties, expressed or implied,
  321.  * including, without limitation, the warranties of merchantability and of
  322.  * fitness for any purpose.  The Contributing Authors and Group 42, Inc.
  323.  * assume no liability for direct, indirect, incidental, special, exemplary,
  324.  * or consequential damages, which may result from the use of the PNG
  325.  * Reference Library, even if advised of the possibility of such damage.
  326.  *
  327.  * Permission is hereby granted to use, copy, modify, and distribute this
  328.  * source code, or portions hereof, for any purpose, without fee, subject
  329.  * to the following restrictions:
  330.  *
  331.  * 1. The origin of this source code must not be misrepresented.
  332.  *
  333.  * 2. Altered versions must be plainly marked as such and
  334.  * must not be misrepresented as being the original source.
  335.  *
  336.  * 3. This Copyright notice may not be removed or altered from
  337.  *    any source or altered source distribution.
  338.  *
  339.  * The Contributing Authors and Group 42, Inc. specifically permit, without
  340.  * fee, and encourage the use of this source code as a component to
  341.  * supporting the PNG file format in commercial products.  If you use this
  342.  * source code in a product, acknowledgment is not required but would be
  343.  * appreciated.
  344.  */
  345.  
  346. /*
  347.  * A "png_get_copyright" function is available, for convenient use in "about"
  348.  * boxes and the like:
  349.  *
  350.  * printf("%s",png_get_copyright(NULL));
  351.  *
  352.  * Also, the PNG logo (in PNG format, of course) is supplied in the
  353.  * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
  354.  */
  355.  
  356. /*
  357.  * Libpng is OSI Certified Open Source Software.  OSI Certified is a
  358.  * certification mark of the Open Source Initiative.
  359.  */
  360.  
  361. /*
  362.  * The contributing authors would like to thank all those who helped
  363.  * with testing, bug fixes, and patience.  This wouldn't have been
  364.  * possible without all of you.
  365.  *
  366.  * Thanks to Frank J. T. Wojcik for helping with the documentation.
  367.  */
  368.  
  369. /*
  370.  * Y2K compliance in libpng:
  371.  * =========================
  372.  *
  373.  *    June 4, 2009
  374.  *
  375.  *    Since the PNG Development group is an ad-hoc body, we can't make
  376.  *    an official declaration.
  377.  *
  378.  *    This is your unofficial assurance that libpng from version 0.71 and
  379.  *    upward through 1.2.37 are Y2K compliant.  It is my belief that earlier
  380.  *    versions were also Y2K compliant.
  381.  *
  382.  *    Libpng only has three year fields.  One is a 2-byte unsigned integer
  383.  *    that will hold years up to 65535.  The other two hold the date in text
  384.  *    format, and will hold years up to 9999.
  385.  *
  386.  *    The integer is
  387.  *        "png_uint_16 year" in png_time_struct.
  388.  *
  389.  *    The strings are
  390.  *        "png_charp time_buffer" in png_struct and
  391.  *        "near_time_buffer", which is a local character string in png.c.
  392.  *
  393.  *    There are seven time-related functions:
  394.  *        png.c: png_convert_to_rfc_1123() in png.c
  395.  *          (formerly png_convert_to_rfc_1152() in error)
  396.  *        png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
  397.  *        png_convert_from_time_t() in pngwrite.c
  398.  *        png_get_tIME() in pngget.c
  399.  *        png_handle_tIME() in pngrutil.c, called in pngread.c
  400.  *        png_set_tIME() in pngset.c
  401.  *        png_write_tIME() in pngwutil.c, called in pngwrite.c
  402.  *
  403.  *    All handle dates properly in a Y2K environment.  The
  404.  *    png_convert_from_time_t() function calls gmtime() to convert from system
  405.  *    clock time, which returns (year - 1900), which we properly convert to
  406.  *    the full 4-digit year.  There is a possibility that applications using
  407.  *    libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
  408.  *    function, or that they are incorrectly passing only a 2-digit year
  409.  *    instead of "year - 1900" into the png_convert_from_struct_tm() function,
  410.  *    but this is not under our control.  The libpng documentation has always
  411.  *    stated that it works with 4-digit years, and the APIs have been
  412.  *    documented as such.
  413.  *
  414.  *    The tIME chunk itself is also Y2K compliant.  It uses a 2-byte unsigned
  415.  *    integer to hold the year, and can hold years as large as 65535.
  416.  *
  417.  *    zlib, upon which libpng depends, is also Y2K compliant.  It contains
  418.  *    no date-related code.
  419.  *
  420.  *       Glenn Randers-Pehrson
  421.  *       libpng maintainer
  422.  *       PNG Development Group
  423.  */
  424.  
  425. #ifndef PNG_H
  426. #define PNG_H
  427.  
  428. /* This is not the place to learn how to use libpng.  The file libpng.txt
  429.  * describes how to use libpng, and the file example.c summarizes it
  430.  * with some code on which to build.  This file is useful for looking
  431.  * at the actual function definitions and structure components.
  432.  */
  433.  
  434. /* Version information for png.h - this should match the version in png.c */
  435. #define PNG_LIBPNG_VER_STRING "1.2.37"
  436. #define PNG_HEADER_VERSION_STRING \
  437.    " libpng version 1.2.37 - June 4, 2009\n"
  438.  
  439. #define PNG_LIBPNG_VER_SONUM   0
  440. #define PNG_LIBPNG_VER_DLLNUM  13
  441.  
  442. /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
  443. #define PNG_LIBPNG_VER_MAJOR   1
  444. #define PNG_LIBPNG_VER_MINOR   2
  445. #define PNG_LIBPNG_VER_RELEASE 37
  446. /* This should match the numeric part of the final component of
  447.  * PNG_LIBPNG_VER_STRING, omitting any leading zero: */
  448.  
  449. #define PNG_LIBPNG_VER_BUILD  0
  450.  
  451. /* Release Status */
  452. #define PNG_LIBPNG_BUILD_ALPHA    1
  453. #define PNG_LIBPNG_BUILD_BETA     2
  454. #define PNG_LIBPNG_BUILD_RC       3
  455. #define PNG_LIBPNG_BUILD_STABLE   4
  456. #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
  457.  
  458. /* Release-Specific Flags */
  459. #define PNG_LIBPNG_BUILD_PATCH    8 /* Can be OR'ed with
  460.                                        PNG_LIBPNG_BUILD_STABLE only */
  461. #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
  462.                                        PNG_LIBPNG_BUILD_SPECIAL */
  463. #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
  464.                                        PNG_LIBPNG_BUILD_PRIVATE */
  465.  
  466. #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
  467.  
  468. /* Careful here.  At one time, Guy wanted to use 082, but that would be octal.
  469.  * We must not include leading zeros.
  470.  * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
  471.  * version 1.0.0 was mis-numbered 100 instead of 10000).  From
  472.  * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=release */
  473. #define PNG_LIBPNG_VER 10237 /* 1.2.37 */
  474.  
  475. #ifndef PNG_VERSION_INFO_ONLY
  476. /* include the compression library's header */
  477. #include "zlib.h"
  478. #endif
  479.  
  480. /* include all user configurable info, including optional assembler routines */
  481. #include "pngconf.h"
  482.  
  483. /*
  484.  * Added at libpng-1.2.8 */
  485. /* Ref MSDN: Private as priority over Special
  486.  * VS_FF_PRIVATEBUILD File *was not* built using standard release
  487.  * procedures. If this value is given, the StringFileInfo block must
  488.  * contain a PrivateBuild string.
  489.  *
  490.  * VS_FF_SPECIALBUILD File *was* built by the original company using
  491.  * standard release procedures but is a variation of the standard
  492.  * file of the same version number. If this value is given, the
  493.  * StringFileInfo block must contain a SpecialBuild string.
  494.  */
  495.  
  496. #if defined(PNG_USER_PRIVATEBUILD)
  497. #  define PNG_LIBPNG_BUILD_TYPE \
  498.           (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
  499. #else
  500. #  if defined(PNG_LIBPNG_SPECIALBUILD)
  501. #    define PNG_LIBPNG_BUILD_TYPE \
  502.             (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
  503. #  else
  504. #    define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
  505. #  endif
  506. #endif
  507.  
  508. #ifndef PNG_VERSION_INFO_ONLY
  509.  
  510. /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
  511. #ifdef __cplusplus
  512. extern "C" {
  513. #endif /* __cplusplus */
  514.  
  515. /* This file is arranged in several sections.  The first section contains
  516.  * structure and type definitions.  The second section contains the external
  517.  * library functions, while the third has the internal library functions,
  518.  * which applications aren't expected to use directly.
  519.  */
  520.  
  521. #ifndef PNG_NO_TYPECAST_NULL
  522. #define int_p_NULL                (int *)NULL
  523. #define png_bytep_NULL            (png_bytep)NULL
  524. #define png_bytepp_NULL           (png_bytepp)NULL
  525. #define png_doublep_NULL          (png_doublep)NULL
  526. #define png_error_ptr_NULL        (png_error_ptr)NULL
  527. #define png_flush_ptr_NULL        (png_flush_ptr)NULL
  528. #define png_free_ptr_NULL         (png_free_ptr)NULL
  529. #define png_infopp_NULL           (png_infopp)NULL
  530. #define png_malloc_ptr_NULL       (png_malloc_ptr)NULL
  531. #define png_read_status_ptr_NULL  (png_read_status_ptr)NULL
  532. #define png_rw_ptr_NULL           (png_rw_ptr)NULL
  533. #define png_structp_NULL          (png_structp)NULL
  534. #define png_uint_16p_NULL         (png_uint_16p)NULL
  535. #define png_voidp_NULL            (png_voidp)NULL
  536. #define png_write_status_ptr_NULL (png_write_status_ptr)NULL
  537. #else
  538. #define int_p_NULL                NULL
  539. #define png_bytep_NULL            NULL
  540. #define png_bytepp_NULL           NULL
  541. #define png_doublep_NULL          NULL
  542. #define png_error_ptr_NULL        NULL
  543. #define png_flush_ptr_NULL        NULL
  544. #define png_free_ptr_NULL         NULL
  545. #define png_infopp_NULL           NULL
  546. #define png_malloc_ptr_NULL       NULL
  547. #define png_read_status_ptr_NULL  NULL
  548. #define png_rw_ptr_NULL           NULL
  549. #define png_structp_NULL          NULL
  550. #define png_uint_16p_NULL         NULL
  551. #define png_voidp_NULL            NULL
  552. #define png_write_status_ptr_NULL NULL
  553. #endif
  554.  
  555. /* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
  556. #if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
  557. /* Version information for C files, stored in png.c.  This had better match
  558.  * the version above.
  559.  */
  560. #ifdef PNG_USE_GLOBAL_ARRAYS
  561. PNG_EXPORT_VAR (PNG_CONST char) png_libpng_ver[18];
  562.   /* need room for 99.99.99beta99z */
  563. #else
  564. #define png_libpng_ver png_get_header_ver(NULL)
  565. #endif
  566.  
  567. #ifdef PNG_USE_GLOBAL_ARRAYS
  568. /* This was removed in version 1.0.5c */
  569. /* Structures to facilitate easy interlacing.  See png.c for more details */
  570. PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_start[7];
  571. PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_inc[7];
  572. PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_ystart[7];
  573. PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_yinc[7];
  574. PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_mask[7];
  575. PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_dsp_mask[7];
  576. /* This isn't currently used.  If you need it, see png.c for more details.
  577. PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_height[7];
  578. */
  579. #endif
  580.  
  581. #endif /* PNG_NO_EXTERN */
  582.  
  583. /* Three color definitions.  The order of the red, green, and blue, (and the
  584.  * exact size) is not important, although the size of the fields need to
  585.  * be png_byte or png_uint_16 (as defined below).
  586.  */
  587. typedef struct png_color_struct
  588. {
  589.    png_byte red;
  590.    png_byte green;
  591.    png_byte blue;
  592. } png_color;
  593. typedef png_color FAR * png_colorp;
  594. typedef png_color FAR * FAR * png_colorpp;
  595.  
  596. typedef struct png_color_16_struct
  597. {
  598.    png_byte index;    /* used for palette files */
  599.    png_uint_16 red;   /* for use in red green blue files */
  600.    png_uint_16 green;
  601.    png_uint_16 blue;
  602.    png_uint_16 gray;  /* for use in grayscale files */
  603. } png_color_16;
  604. typedef png_color_16 FAR * png_color_16p;
  605. typedef png_color_16 FAR * FAR * png_color_16pp;
  606.  
  607. typedef struct png_color_8_struct
  608. {
  609.    png_byte red;   /* for use in red green blue files */
  610.    png_byte green;
  611.    png_byte blue;
  612.    png_byte gray;  /* for use in grayscale files */
  613.    png_byte alpha; /* for alpha channel files */
  614. } png_color_8;
  615. typedef png_color_8 FAR * png_color_8p;
  616. typedef png_color_8 FAR * FAR * png_color_8pp;
  617.  
  618. /*
  619.  * The following two structures are used for the in-core representation
  620.  * of sPLT chunks.
  621.  */
  622. typedef struct png_sPLT_entry_struct
  623. {
  624.    png_uint_16 red;
  625.    png_uint_16 green;
  626.    png_uint_16 blue;
  627.    png_uint_16 alpha;
  628.    png_uint_16 frequency;
  629. } png_sPLT_entry;
  630. typedef png_sPLT_entry FAR * png_sPLT_entryp;
  631. typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;
  632.  
  633. /*  When the depth of the sPLT palette is 8 bits, the color and alpha samples
  634.  *  occupy the LSB of their respective members, and the MSB of each member
  635.  *  is zero-filled.  The frequency member always occupies the full 16 bits.
  636.  */
  637.  
  638. typedef struct png_sPLT_struct
  639. {
  640.    png_charp name;           /* palette name */
  641.    png_byte depth;           /* depth of palette samples */
  642.    png_sPLT_entryp entries;  /* palette entries */
  643.    png_int_32 nentries;      /* number of palette entries */
  644. } png_sPLT_t;
  645. typedef png_sPLT_t FAR * png_sPLT_tp;
  646. typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
  647.  
  648. #ifdef PNG_TEXT_SUPPORTED
  649. /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
  650.  * and whether that contents is compressed or not.  The "key" field
  651.  * points to a regular zero-terminated C string.  The "text", "lang", and
  652.  * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
  653.  * However, the * structure returned by png_get_text() will always contain
  654.  * regular zero-terminated C strings (possibly empty), never NULL pointers,
  655.  * so they can be safely used in printf() and other string-handling functions.
  656.  */
  657. typedef struct png_text_struct
  658. {
  659.    int  compression;       /* compression value:
  660.                              -1: tEXt, none
  661.                               0: zTXt, deflate
  662.                               1: iTXt, none
  663.                               2: iTXt, deflate  */
  664.    png_charp key;          /* keyword, 1-79 character description of "text" */
  665.    png_charp text;         /* comment, may be an empty string (ie "")
  666.                               or a NULL pointer */
  667.    png_size_t text_length; /* length of the text string */
  668. #ifdef PNG_iTXt_SUPPORTED
  669.    png_size_t itxt_length; /* length of the itxt string */
  670.    png_charp lang;         /* language code, 0-79 characters
  671.                               or a NULL pointer */
  672.    png_charp lang_key;     /* keyword translated UTF-8 string, 0 or more
  673.                               chars or a NULL pointer */
  674. #endif
  675. } png_text;
  676. typedef png_text FAR * png_textp;
  677. typedef png_text FAR * FAR * png_textpp;
  678. #endif
  679.  
  680. /* Supported compression types for text in PNG files (tEXt, and zTXt).
  681.  * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
  682. #define PNG_TEXT_COMPRESSION_NONE_WR -3
  683. #define PNG_TEXT_COMPRESSION_zTXt_WR -2
  684. #define PNG_TEXT_COMPRESSION_NONE    -1
  685. #define PNG_TEXT_COMPRESSION_zTXt     0
  686. #define PNG_ITXT_COMPRESSION_NONE     1
  687. #define PNG_ITXT_COMPRESSION_zTXt     2
  688. #define PNG_TEXT_COMPRESSION_LAST     3  /* Not a valid value */
  689.  
  690. /* png_time is a way to hold the time in an machine independent way.
  691.  * Two conversions are provided, both from time_t and struct tm.  There
  692.  * is no portable way to convert to either of these structures, as far
  693.  * as I know.  If you know of a portable way, send it to me.  As a side
  694.  * note - PNG has always been Year 2000 compliant!
  695.  */
  696. typedef struct png_time_struct
  697. {
  698.    png_uint_16 year; /* full year, as in, 1995 */
  699.    png_byte month;   /* month of year, 1 - 12 */
  700.    png_byte day;     /* day of month, 1 - 31 */
  701.    png_byte hour;    /* hour of day, 0 - 23 */
  702.    png_byte minute;  /* minute of hour, 0 - 59 */
  703.    png_byte second;  /* second of minute, 0 - 60 (for leap seconds) */
  704. } png_time;
  705. typedef png_time FAR * png_timep;
  706. typedef png_time FAR * FAR * png_timepp;
  707.  
  708. #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
  709. /* png_unknown_chunk is a structure to hold queued chunks for which there is
  710.  * no specific support.  The idea is that we can use this to queue
  711.  * up private chunks for output even though the library doesn't actually
  712.  * know about their semantics.
  713.  */
  714. #define PNG_CHUNK_NAME_LENGTH 5
  715. typedef struct png_unknown_chunk_t
  716. {
  717.     png_byte name[PNG_CHUNK_NAME_LENGTH];
  718.     png_byte *data;
  719.     png_size_t size;
  720.  
  721.     /* libpng-using applications should NOT directly modify this byte. */
  722.     png_byte location; /* mode of operation at read time */
  723. }
  724. png_unknown_chunk;
  725. typedef png_unknown_chunk FAR * png_unknown_chunkp;
  726. typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
  727. #endif
  728.  
  729. /* png_info is a structure that holds the information in a PNG file so
  730.  * that the application can find out the characteristics of the image.
  731.  * If you are reading the file, this structure will tell you what is
  732.  * in the PNG file.  If you are writing the file, fill in the information
  733.  * you want to put into the PNG file, then call png_write_info().
  734.  * The names chosen should be very close to the PNG specification, so
  735.  * consult that document for information about the meaning of each field.
  736.  *
  737.  * With libpng < 0.95, it was only possible to directly set and read the
  738.  * the values in the png_info_struct, which meant that the contents and
  739.  * order of the values had to remain fixed.  With libpng 0.95 and later,
  740.  * however, there are now functions that abstract the contents of
  741.  * png_info_struct from the application, so this makes it easier to use
  742.  * libpng with dynamic libraries, and even makes it possible to use
  743.  * libraries that don't have all of the libpng ancillary chunk-handing
  744.  * functionality.
  745.  *
  746.  * In any case, the order of the parameters in png_info_struct should NOT
  747.  * be changed for as long as possible to keep compatibility with applications
  748.  * that use the old direct-access method with png_info_struct.
  749.  *
  750.  * The following members may have allocated storage attached that should be
  751.  * cleaned up before the structure is discarded: palette, trans, text,
  752.  * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
  753.  * splt_palettes, scal_unit, row_pointers, and unknowns.   By default, these
  754.  * are automatically freed when the info structure is deallocated, if they were
  755.  * allocated internally by libpng.  This behavior can be changed by means
  756.  * of the png_data_freer() function.
  757.  *
  758.  * More allocation details: all the chunk-reading functions that
  759.  * change these members go through the corresponding png_set_*
  760.  * functions.  A function to clear these members is available: see
  761.  * png_free_data().  The png_set_* functions do not depend on being
  762.  * able to point info structure members to any of the storage they are
  763.  * passed (they make their own copies), EXCEPT that the png_set_text
  764.  * functions use the same storage passed to them in the text_ptr or
  765.  * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
  766.  * functions do not make their own copies.
  767.  */
  768. typedef struct png_info_struct
  769. {
  770.    /* the following are necessary for every PNG file */
  771.    png_uint_32 width;       /* width of image in pixels (from IHDR) */
  772.    png_uint_32 height;      /* height of image in pixels (from IHDR) */
  773.    png_uint_32 valid;       /* valid chunk data (see PNG_INFO_ below) */
  774.    png_uint_32 rowbytes;    /* bytes needed to hold an untransformed row */
  775.    png_colorp palette;      /* array of color values (valid & PNG_INFO_PLTE) */
  776.    png_uint_16 num_palette; /* number of color entries in "palette" (PLTE) */
  777.    png_uint_16 num_trans;   /* number of transparent palette color (tRNS) */
  778.    png_byte bit_depth;      /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */
  779.    png_byte color_type;     /* see PNG_COLOR_TYPE_ below (from IHDR) */
  780.    /* The following three should have been named *_method not *_type */
  781.    png_byte compression_type; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */
  782.    png_byte filter_type;    /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
  783.    png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
  784.  
  785.    /* The following is informational only on read, and not used on writes. */
  786.    png_byte channels;       /* number of data channels per pixel (1, 2, 3, 4) */
  787.    png_byte pixel_depth;    /* number of bits per pixel */
  788.    png_byte spare_byte;     /* to align the data, and for future use */
  789.    png_byte signature[8];   /* magic bytes read by libpng from start of file */
  790.  
  791.    /* The rest of the data is optional.  If you are reading, check the
  792.     * valid field to see if the information in these are valid.  If you
  793.     * are writing, set the valid field to those chunks you want written,
  794.     * and initialize the appropriate fields below.
  795.     */
  796.  
  797. #if defined(PNG_gAMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
  798.    /* The gAMA chunk describes the gamma characteristics of the system
  799.     * on which the image was created, normally in the range [1.0, 2.5].
  800.     * Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
  801.     */
  802.    float gamma; /* gamma value of image, if (valid & PNG_INFO_gAMA) */
  803. #endif
  804.  
  805. #if defined(PNG_sRGB_SUPPORTED)
  806.     /* GR-P, 0.96a */
  807.     /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
  808.    png_byte srgb_intent; /* sRGB rendering intent [0, 1, 2, or 3] */
  809. #endif
  810.  
  811. #if defined(PNG_TEXT_SUPPORTED)
  812.    /* The tEXt, and zTXt chunks contain human-readable textual data in
  813.     * uncompressed, compressed, and optionally compressed forms, respectively.
  814.     * The data in "text" is an array of pointers to uncompressed,
  815.     * null-terminated C strings. Each chunk has a keyword that describes the
  816.     * textual data contained in that chunk.  Keywords are not required to be
  817.     * unique, and the text string may be empty.  Any number of text chunks may
  818.     * be in an image.
  819.     */
  820.    int num_text; /* number of comments read/to write */
  821.    int max_text; /* current size of text array */
  822.    png_textp text; /* array of comments read/to write */
  823. #endif /* PNG_TEXT_SUPPORTED */
  824.  
  825. #if defined(PNG_tIME_SUPPORTED)
  826.    /* The tIME chunk holds the last time the displayed image data was
  827.     * modified.  See the png_time struct for the contents of this struct.
  828.     */
  829.    png_time mod_time;
  830. #endif
  831.  
  832. #if defined(PNG_sBIT_SUPPORTED)
  833.    /* The sBIT chunk specifies the number of significant high-order bits
  834.     * in the pixel data.  Values are in the range [1, bit_depth], and are
  835.     * only specified for the channels in the pixel data.  The contents of
  836.     * the low-order bits is not specified.  Data is valid if
  837.     * (valid & PNG_INFO_sBIT) is non-zero.
  838.     */
  839.    png_color_8 sig_bit; /* significant bits in color channels */
  840. #endif
  841.  
  842. #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
  843. defined(PNG_READ_BACKGROUND_SUPPORTED)
  844.    /* The tRNS chunk supplies transparency data for paletted images and
  845.     * other image types that don't need a full alpha channel.  There are
  846.     * "num_trans" transparency values for a paletted image, stored in the
  847.     * same order as the palette colors, starting from index 0.  Values
  848.     * for the data are in the range [0, 255], ranging from fully transparent
  849.     * to fully opaque, respectively.  For non-paletted images, there is a
  850.     * single color specified that should be treated as fully transparent.
  851.     * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
  852.     */
  853.    png_bytep trans; /* transparent values for paletted image */
  854.    png_color_16 trans_values; /* transparent color for non-palette image */
  855. #endif
  856.  
  857. #if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
  858.    /* The bKGD chunk gives the suggested image background color if the
  859.     * display program does not have its own background color and the image
  860.     * is needs to composited onto a background before display.  The colors
  861.     * in "background" are normally in the same color space/depth as the
  862.     * pixel data.  Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
  863.     */
  864.    png_color_16 background;
  865. #endif
  866.  
  867. #if defined(PNG_oFFs_SUPPORTED)
  868.    /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
  869.     * and downwards from the top-left corner of the display, page, or other
  870.     * application-specific co-ordinate space.  See the PNG_OFFSET_ defines
  871.     * below for the unit types.  Valid if (valid & PNG_INFO_oFFs) non-zero.
  872.     */
  873.    png_int_32 x_offset; /* x offset on page */
  874.    png_int_32 y_offset; /* y offset on page */
  875.    png_byte offset_unit_type; /* offset units type */
  876. #endif
  877.  
  878. #if defined(PNG_pHYs_SUPPORTED)
  879.    /* The pHYs chunk gives the physical pixel density of the image for
  880.     * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
  881.     * defines below).  Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
  882.     */
  883.    png_uint_32 x_pixels_per_unit; /* horizontal pixel density */
  884.    png_uint_32 y_pixels_per_unit; /* vertical pixel density */
  885.    png_byte phys_unit_type; /* resolution type (see PNG_RESOLUTION_ below) */
  886. #endif
  887.  
  888. #if defined(PNG_hIST_SUPPORTED)
  889.    /* The hIST chunk contains the relative frequency or importance of the
  890.     * various palette entries, so that a viewer can intelligently select a
  891.     * reduced-color palette, if required.  Data is an array of "num_palette"
  892.     * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
  893.     * is non-zero.
  894.     */
  895.    png_uint_16p hist;
  896. #endif
  897.  
  898. #ifdef PNG_cHRM_SUPPORTED
  899.    /* The cHRM chunk describes the CIE color characteristics of the monitor
  900.     * on which the PNG was created.  This data allows the viewer to do gamut
  901.     * mapping of the input image to ensure that the viewer sees the same
  902.     * colors in the image as the creator.  Values are in the range
  903.     * [0.0, 0.8].  Data valid if (valid & PNG_INFO_cHRM) non-zero.
  904.     */
  905. #ifdef PNG_FLOATING_POINT_SUPPORTED
  906.    float x_white;
  907.    float y_white;
  908.    float x_red;
  909.    float y_red;
  910.    float x_green;
  911.    float y_green;
  912.    float x_blue;
  913.    float y_blue;
  914. #endif
  915. #endif
  916.  
  917. #if defined(PNG_pCAL_SUPPORTED)
  918.    /* The pCAL chunk describes a transformation between the stored pixel
  919.     * values and original physical data values used to create the image.
  920.     * The integer range [0, 2^bit_depth - 1] maps to the floating-point
  921.     * range given by [pcal_X0, pcal_X1], and are further transformed by a
  922.     * (possibly non-linear) transformation function given by "pcal_type"
  923.     * and "pcal_params" into "pcal_units".  Please see the PNG_EQUATION_
  924.     * defines below, and the PNG-Group's PNG extensions document for a
  925.     * complete description of the transformations and how they should be
  926.     * implemented, and for a description of the ASCII parameter strings.
  927.     * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
  928.     */
  929.    png_charp pcal_purpose;  /* pCAL chunk description string */
  930.    png_int_32 pcal_X0;      /* minimum value */
  931.    png_int_32 pcal_X1;      /* maximum value */
  932.    png_charp pcal_units;    /* Latin-1 string giving physical units */
  933.    png_charpp pcal_params;  /* ASCII strings containing parameter values */
  934.    png_byte pcal_type;      /* equation type (see PNG_EQUATION_ below) */
  935.    png_byte pcal_nparams;   /* number of parameters given in pcal_params */
  936. #endif
  937.  
  938. /* New members added in libpng-1.0.6 */
  939. #ifdef PNG_FREE_ME_SUPPORTED
  940.    png_uint_32 free_me;     /* flags items libpng is responsible for freeing */
  941. #endif
  942.  
  943. #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
  944.    /* storage for unknown chunks that the library doesn't recognize. */
  945.    png_unknown_chunkp unknown_chunks;
  946.    png_size_t unknown_chunks_num;
  947. #endif
  948.  
  949. #if defined(PNG_iCCP_SUPPORTED)
  950.    /* iCCP chunk data. */
  951.    png_charp iccp_name;     /* profile name */
  952.    png_charp iccp_profile;  /* International Color Consortium profile data */
  953.                             /* Note to maintainer: should be png_bytep */
  954.    png_uint_32 iccp_proflen;  /* ICC profile data length */
  955.    png_byte iccp_compression; /* Always zero */
  956. #endif
  957.  
  958. #if defined(PNG_sPLT_SUPPORTED)
  959.    /* data on sPLT chunks (there may be more than one). */
  960.    png_sPLT_tp splt_palettes;
  961.    png_uint_32 splt_palettes_num;
  962. #endif
  963.  
  964. #if defined(PNG_sCAL_SUPPORTED)
  965.    /* The sCAL chunk describes the actual physical dimensions of the
  966.     * subject matter of the graphic.  The chunk contains a unit specification
  967.     * a byte value, and two ASCII strings representing floating-point
  968.     * values.  The values are width and height corresponsing to one pixel
  969.     * in the image.  This external representation is converted to double
  970.     * here.  Data values are valid if (valid & PNG_INFO_sCAL) is non-zero.
  971.     */
  972.    png_byte scal_unit;         /* unit of physical scale */
  973. #ifdef PNG_FLOATING_POINT_SUPPORTED
  974.    double scal_pixel_width;    /* width of one pixel */
  975.    double scal_pixel_height;   /* height of one pixel */
  976. #endif
  977. #ifdef PNG_FIXED_POINT_SUPPORTED
  978.    png_charp scal_s_width;     /* string containing height */
  979.    png_charp scal_s_height;    /* string containing width */
  980. #endif
  981. #endif
  982.  
  983. #if defined(PNG_INFO_IMAGE_SUPPORTED)
  984.    /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS) non-zero */
  985.    /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
  986.    png_bytepp row_pointers;        /* the image bits */
  987. #endif
  988.  
  989. #if defined(PNG_FIXED_POINT_SUPPORTED) && defined(PNG_gAMA_SUPPORTED)
  990.    png_fixed_point int_gamma; /* gamma of image, if (valid & PNG_INFO_gAMA) */
  991. #endif
  992.  
  993. #if defined(PNG_cHRM_SUPPORTED) && defined(PNG_FIXED_POINT_SUPPORTED)
  994.    png_fixed_point int_x_white;
  995.    png_fixed_point int_y_white;
  996.    png_fixed_point int_x_red;
  997.    png_fixed_point int_y_red;
  998.    png_fixed_point int_x_green;
  999.    png_fixed_point int_y_green;
  1000.    png_fixed_point int_x_blue;
  1001.    png_fixed_point int_y_blue;
  1002. #endif
  1003.  
  1004. } png_info;
  1005.  
  1006. typedef png_info FAR * png_infop;
  1007. typedef png_info FAR * FAR * png_infopp;
  1008.  
  1009. /* Maximum positive integer used in PNG is (2^31)-1 */
  1010. #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
  1011. #define PNG_UINT_32_MAX ((png_uint_32)(-1))
  1012. #define PNG_SIZE_MAX ((png_size_t)(-1))
  1013. #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
  1014. /* PNG_MAX_UINT is deprecated; use PNG_UINT_31_MAX instead. */
  1015. #define PNG_MAX_UINT PNG_UINT_31_MAX
  1016. #endif
  1017.  
  1018. /* These describe the color_type field in png_info. */
  1019. /* color type masks */
  1020. #define PNG_COLOR_MASK_PALETTE    1
  1021. #define PNG_COLOR_MASK_COLOR      2
  1022. #define PNG_COLOR_MASK_ALPHA      4
  1023.  
  1024. /* color types.  Note that not all combinations are legal */
  1025. #define PNG_COLOR_TYPE_GRAY 0
  1026. #define PNG_COLOR_TYPE_PALETTE  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
  1027. #define PNG_COLOR_TYPE_RGB        (PNG_COLOR_MASK_COLOR)
  1028. #define PNG_COLOR_TYPE_RGB_ALPHA  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
  1029. #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
  1030. /* aliases */
  1031. #define PNG_COLOR_TYPE_RGBA  PNG_COLOR_TYPE_RGB_ALPHA
  1032. #define PNG_COLOR_TYPE_GA  PNG_COLOR_TYPE_GRAY_ALPHA
  1033.  
  1034. /* This is for compression type. PNG 1.0-1.2 only define the single type. */
  1035. #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
  1036. #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
  1037.  
  1038. /* This is for filter type. PNG 1.0-1.2 only define the single type. */
  1039. #define PNG_FILTER_TYPE_BASE      0 /* Single row per-byte filtering */
  1040. #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
  1041. #define PNG_FILTER_TYPE_DEFAULT   PNG_FILTER_TYPE_BASE
  1042.  
  1043. /* These are for the interlacing type.  These values should NOT be changed. */
  1044. #define PNG_INTERLACE_NONE        0 /* Non-interlaced image */
  1045. #define PNG_INTERLACE_ADAM7       1 /* Adam7 interlacing */
  1046. #define PNG_INTERLACE_LAST        2 /* Not a valid value */
  1047.  
  1048. /* These are for the oFFs chunk.  These values should NOT be changed. */
  1049. #define PNG_OFFSET_PIXEL          0 /* Offset in pixels */
  1050. #define PNG_OFFSET_MICROMETER     1 /* Offset in micrometers (1/10^6 meter) */
  1051. #define PNG_OFFSET_LAST           2 /* Not a valid value */
  1052.  
  1053. /* These are for the pCAL chunk.  These values should NOT be changed. */
  1054. #define PNG_EQUATION_LINEAR       0 /* Linear transformation */
  1055. #define PNG_EQUATION_BASE_E       1 /* Exponential base e transform */
  1056. #define PNG_EQUATION_ARBITRARY    2 /* Arbitrary base exponential transform */
  1057. #define PNG_EQUATION_HYPERBOLIC   3 /* Hyperbolic sine transformation */
  1058. #define PNG_EQUATION_LAST         4 /* Not a valid value */
  1059.  
  1060. /* These are for the sCAL chunk.  These values should NOT be changed. */
  1061. #define PNG_SCALE_UNKNOWN         0 /* unknown unit (image scale) */
  1062. #define PNG_SCALE_METER           1 /* meters per pixel */
  1063. #define PNG_SCALE_RADIAN          2 /* radians per pixel */
  1064. #define PNG_SCALE_LAST            3 /* Not a valid value */
  1065.  
  1066. /* These are for the pHYs chunk.  These values should NOT be changed. */
  1067. #define PNG_RESOLUTION_UNKNOWN    0 /* pixels/unknown unit (aspect ratio) */
  1068. #define PNG_RESOLUTION_METER      1 /* pixels/meter */
  1069. #define PNG_RESOLUTION_LAST       2 /* Not a valid value */
  1070.  
  1071. /* These are for the sRGB chunk.  These values should NOT be changed. */
  1072. #define PNG_sRGB_INTENT_PERCEPTUAL 0
  1073. #define PNG_sRGB_INTENT_RELATIVE   1
  1074. #define PNG_sRGB_INTENT_SATURATION 2
  1075. #define PNG_sRGB_INTENT_ABSOLUTE   3
  1076. #define PNG_sRGB_INTENT_LAST       4 /* Not a valid value */
  1077.  
  1078. /* This is for text chunks */
  1079. #define PNG_KEYWORD_MAX_LENGTH     79
  1080.  
  1081. /* Maximum number of entries in PLTE/sPLT/tRNS arrays */
  1082. #define PNG_MAX_PALETTE_LENGTH    256
  1083.  
  1084. /* These determine if an ancillary chunk's data has been successfully read
  1085.  * from the PNG header, or if the application has filled in the corresponding
  1086.  * data in the info_struct to be written into the output file.  The values
  1087.  * of the PNG_INFO_<chunk> defines should NOT be changed.
  1088.  */
  1089. #define PNG_INFO_gAMA 0x0001
  1090. #define PNG_INFO_sBIT 0x0002
  1091. #define PNG_INFO_cHRM 0x0004
  1092. #define PNG_INFO_PLTE 0x0008
  1093. #define PNG_INFO_tRNS 0x0010
  1094. #define PNG_INFO_bKGD 0x0020
  1095. #define PNG_INFO_hIST 0x0040
  1096. #define PNG_INFO_pHYs 0x0080
  1097. #define PNG_INFO_oFFs 0x0100
  1098. #define PNG_INFO_tIME 0x0200
  1099. #define PNG_INFO_pCAL 0x0400
  1100. #define PNG_INFO_sRGB 0x0800   /* GR-P, 0.96a */
  1101. #define PNG_INFO_iCCP 0x1000   /* ESR, 1.0.6 */
  1102. #define PNG_INFO_sPLT 0x2000   /* ESR, 1.0.6 */
  1103. #define PNG_INFO_sCAL 0x4000   /* ESR, 1.0.6 */
  1104. #define PNG_INFO_IDAT 0x8000L  /* ESR, 1.0.6 */
  1105.  
  1106. /* This is used for the transformation routines, as some of them
  1107.  * change these values for the row.  It also should enable using
  1108.  * the routines for other purposes.
  1109.  */
  1110. typedef struct png_row_info_struct
  1111. {
  1112.    png_uint_32 width; /* width of row */
  1113.    png_uint_32 rowbytes; /* number of bytes in row */
  1114.    png_byte color_type; /* color type of row */
  1115.    png_byte bit_depth; /* bit depth of row */
  1116.    png_byte channels; /* number of channels (1, 2, 3, or 4) */
  1117.    png_byte pixel_depth; /* bits per pixel (depth * channels) */
  1118. } png_row_info;
  1119.  
  1120. typedef png_row_info FAR * png_row_infop;
  1121. typedef png_row_info FAR * FAR * png_row_infopp;
  1122.  
  1123. /* These are the function types for the I/O functions and for the functions
  1124.  * that allow the user to override the default I/O functions with his or her
  1125.  * own.  The png_error_ptr type should match that of user-supplied warning
  1126.  * and error functions, while the png_rw_ptr type should match that of the
  1127.  * user read/write data functions.
  1128.  */
  1129. typedef struct png_struct_def png_struct;
  1130. typedef png_struct FAR * png_structp;
  1131.  
  1132. typedef void (PNGAPI *png_error_ptr) PNGARG((png_structp, png_const_charp));
  1133. typedef void (PNGAPI *png_rw_ptr) PNGARG((png_structp, png_bytep, png_size_t));
  1134. typedef void (PNGAPI *png_flush_ptr) PNGARG((png_structp));
  1135. typedef void (PNGAPI *png_read_status_ptr) PNGARG((png_structp, png_uint_32,
  1136.    int));
  1137. typedef void (PNGAPI *png_write_status_ptr) PNGARG((png_structp, png_uint_32,
  1138.    int));
  1139.  
  1140. #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
  1141. typedef void (PNGAPI *png_progressive_info_ptr) PNGARG((png_structp, png_infop));
  1142. typedef void (PNGAPI *png_progressive_end_ptr) PNGARG((png_structp, png_infop));
  1143. typedef void (PNGAPI *png_progressive_row_ptr) PNGARG((png_structp, png_bytep,
  1144.    png_uint_32, int));
  1145. #endif
  1146.  
  1147. #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
  1148.     defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
  1149.     defined(PNG_LEGACY_SUPPORTED)
  1150. typedef void (PNGAPI *png_user_transform_ptr) PNGARG((png_structp,
  1151.     png_row_infop, png_bytep));
  1152. #endif
  1153.  
  1154. #if defined(PNG_USER_CHUNKS_SUPPORTED)
  1155. typedef int (PNGAPI *png_user_chunk_ptr) PNGARG((png_structp, png_unknown_chunkp));
  1156. #endif
  1157. #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
  1158. typedef void (PNGAPI *png_unknown_chunk_ptr) PNGARG((png_structp));
  1159. #endif
  1160.  
  1161. /* Transform masks for the high-level interface */
  1162. #define PNG_TRANSFORM_IDENTITY       0x0000    /* read and write */
  1163. #define PNG_TRANSFORM_STRIP_16       0x0001    /* read only */
  1164. #define PNG_TRANSFORM_STRIP_ALPHA    0x0002    /* read only */
  1165. #define PNG_TRANSFORM_PACKING        0x0004    /* read and write */
  1166. #define PNG_TRANSFORM_PACKSWAP       0x0008    /* read and write */
  1167. #define PNG_TRANSFORM_EXPAND         0x0010    /* read only */
  1168. #define PNG_TRANSFORM_INVERT_MONO    0x0020    /* read and write */
  1169. #define PNG_TRANSFORM_SHIFT          0x0040    /* read and write */
  1170. #define PNG_TRANSFORM_BGR            0x0080    /* read and write */
  1171. #define PNG_TRANSFORM_SWAP_ALPHA     0x0100    /* read and write */
  1172. #define PNG_TRANSFORM_SWAP_ENDIAN    0x0200    /* read and write */
  1173. #define PNG_TRANSFORM_INVERT_ALPHA   0x0400    /* read and write */
  1174. #define PNG_TRANSFORM_STRIP_FILLER   0x0800    /* WRITE only, deprecated */
  1175. /* Added to libpng-1.2.34 */
  1176. #define PNG_TRANSFORM_STRIP_FILLER_BEFORE 0x0800  /* WRITE only */
  1177. #define PNG_TRANSFORM_STRIP_FILLER_AFTER  0x1000  /* WRITE only */
  1178.  
  1179. /* Flags for MNG supported features */
  1180. #define PNG_FLAG_MNG_EMPTY_PLTE     0x01
  1181. #define PNG_FLAG_MNG_FILTER_64      0x04
  1182. #define PNG_ALL_MNG_FEATURES        0x05
  1183.  
  1184. typedef png_voidp (*png_malloc_ptr) PNGARG((png_structp, png_size_t));
  1185. typedef void (*png_free_ptr) PNGARG((png_structp, png_voidp));
  1186.  
  1187. /* The structure that holds the information to read and write PNG files.
  1188.  * The only people who need to care about what is inside of this are the
  1189.  * people who will be modifying the library for their own special needs.
  1190.  * It should NOT be accessed directly by an application, except to store
  1191.  * the jmp_buf.
  1192.  */
  1193.  
  1194. struct png_struct_def
  1195. {
  1196. #ifdef PNG_SETJMP_SUPPORTED
  1197.    jmp_buf jmpbuf;            /* used in png_error */
  1198. #endif
  1199.    png_error_ptr error_fn;    /* function for printing errors and aborting */
  1200.    png_error_ptr warning_fn;  /* function for printing warnings */
  1201.    png_voidp error_ptr;       /* user supplied struct for error functions */
  1202.    png_rw_ptr write_data_fn;  /* function for writing output data */
  1203.    png_rw_ptr read_data_fn;   /* function for reading input data */
  1204.    png_voidp io_ptr;          /* ptr to application struct for I/O functions */
  1205.  
  1206. #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
  1207.    png_user_transform_ptr read_user_transform_fn; /* user read transform */
  1208. #endif
  1209.  
  1210. #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
  1211.    png_user_transform_ptr write_user_transform_fn; /* user write transform */
  1212. #endif
  1213.  
  1214. /* These were added in libpng-1.0.2 */
  1215. #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
  1216. #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
  1217.     defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
  1218.    png_voidp user_transform_ptr; /* user supplied struct for user transform */
  1219.    png_byte user_transform_depth;    /* bit depth of user transformed pixels */
  1220.    png_byte user_transform_channels; /* channels in user transformed pixels */
  1221. #endif
  1222. #endif
  1223.  
  1224.    png_uint_32 mode;          /* tells us where we are in the PNG file */
  1225.    png_uint_32 flags;         /* flags indicating various things to libpng */
  1226.    png_uint_32 transformations; /* which transformations to perform */
  1227.  
  1228.    z_stream zstream;          /* pointer to decompression structure (below) */
  1229.    png_bytep zbuf;            /* buffer for zlib */
  1230.    png_size_t zbuf_size;      /* size of zbuf */
  1231.    int zlib_level;            /* holds zlib compression level */
  1232.    int zlib_method;           /* holds zlib compression method */
  1233.    int zlib_window_bits;      /* holds zlib compression window bits */
  1234.    int zlib_mem_level;        /* holds zlib compression memory level */
  1235.    int zlib_strategy;         /* holds zlib compression strategy */
  1236.  
  1237.    png_uint_32 width;         /* width of image in pixels */
  1238.    png_uint_32 height;        /* height of image in pixels */
  1239.    png_uint_32 num_rows;      /* number of rows in current pass */
  1240.    png_uint_32 usr_width;     /* width of row at start of write */
  1241.    png_uint_32 rowbytes;      /* size of row in bytes */
  1242.    png_uint_32 irowbytes;     /* size of current interlaced row in bytes */
  1243.    png_uint_32 iwidth;        /* width of current interlaced row in pixels */
  1244.    png_uint_32 row_number;    /* current row in interlace pass */
  1245.    png_bytep prev_row;        /* buffer to save previous (unfiltered) row */
  1246.    png_bytep row_buf;         /* buffer to save current (unfiltered) row */
  1247. #ifndef PNG_NO_WRITE_FILTER
  1248.    png_bytep sub_row;         /* buffer to save "sub" row when filtering */
  1249.    png_bytep up_row;          /* buffer to save "up" row when filtering */
  1250.    png_bytep avg_row;         /* buffer to save "avg" row when filtering */
  1251.    png_bytep paeth_row;       /* buffer to save "Paeth" row when filtering */
  1252. #endif
  1253.    png_row_info row_info;     /* used for transformation routines */
  1254.  
  1255.    png_uint_32 idat_size;     /* current IDAT size for read */
  1256.    png_uint_32 crc;           /* current chunk CRC value */
  1257.    png_colorp palette;        /* palette from the input file */
  1258.    png_uint_16 num_palette;   /* number of color entries in palette */
  1259.    png_uint_16 num_trans;     /* number of transparency values */
  1260.    png_byte chunk_name[5];    /* null-terminated name of current chunk */
  1261.    png_byte compression;      /* file compression type (always 0) */
  1262.    png_byte filter;           /* file filter type (always 0) */
  1263.    png_byte interlaced;       /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
  1264.    png_byte pass;             /* current interlace pass (0 - 6) */
  1265.    png_byte do_filter;        /* row filter flags (see PNG_FILTER_ below ) */
  1266.    png_byte color_type;       /* color type of file */
  1267.    png_byte bit_depth;        /* bit depth of file */
  1268.    png_byte usr_bit_depth;    /* bit depth of users row */
  1269.    png_byte pixel_depth;      /* number of bits per pixel */
  1270.    png_byte channels;         /* number of channels in file */
  1271.    png_byte usr_channels;     /* channels at start of write */
  1272.    png_byte sig_bytes;        /* magic bytes read/written from start of file */
  1273.  
  1274. #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
  1275. #ifdef PNG_LEGACY_SUPPORTED
  1276.    png_byte filler;           /* filler byte for pixel expansion */
  1277. #else
  1278.    png_uint_16 filler;           /* filler bytes for pixel expansion */
  1279. #endif
  1280. #endif
  1281.  
  1282. #if defined(PNG_bKGD_SUPPORTED)
  1283.    png_byte background_gamma_type;
  1284. #  ifdef PNG_FLOATING_POINT_SUPPORTED
  1285.    float background_gamma;
  1286. #  endif
  1287.    png_color_16 background;   /* background color in screen gamma space */
  1288. #if defined(PNG_READ_GAMMA_SUPPORTED)
  1289.    png_color_16 background_1; /* background normalized to gamma 1.0 */
  1290. #endif
  1291. #endif /* PNG_bKGD_SUPPORTED */
  1292.  
  1293. #if defined(PNG_WRITE_FLUSH_SUPPORTED)
  1294.    png_flush_ptr output_flush_fn;/* Function for flushing output */
  1295.    png_uint_32 flush_dist;    /* how many rows apart to flush, 0 - no flush */
  1296.    png_uint_32 flush_rows;    /* number of rows written since last flush */
  1297. #endif
  1298.  
  1299. #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
  1300.    int gamma_shift;      /* number of "insignificant" bits 16-bit gamma */
  1301. #ifdef PNG_FLOATING_POINT_SUPPORTED
  1302.    float gamma;          /* file gamma value */
  1303.    float screen_gamma;   /* screen gamma value (display_exponent) */
  1304. #endif
  1305. #endif
  1306.  
  1307. #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
  1308.    png_bytep gamma_table;     /* gamma table for 8-bit depth files */
  1309.    png_bytep gamma_from_1;    /* converts from 1.0 to screen */
  1310.    png_bytep gamma_to_1;      /* converts from file to 1.0 */
  1311.    png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */
  1312.    png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */
  1313.    png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */
  1314. #endif
  1315.  
  1316. #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
  1317.    png_color_8 sig_bit;       /* significant bits in each available channel */
  1318. #endif
  1319.  
  1320. #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
  1321.    png_color_8 shift;         /* shift for significant bit tranformation */
  1322. #endif
  1323.  
  1324. #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
  1325.  || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
  1326.    png_bytep trans;           /* transparency values for paletted files */
  1327.    png_color_16 trans_values; /* transparency values for non-paletted files */
  1328. #endif
  1329.  
  1330.    png_read_status_ptr read_row_fn;   /* called after each row is decoded */
  1331.    png_write_status_ptr write_row_fn; /* called after each row is encoded */
  1332. #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
  1333.    png_progressive_info_ptr info_fn; /* called after header data fully read */
  1334.    png_progressive_row_ptr row_fn;   /* called after each prog. row is decoded */
  1335.    png_progressive_end_ptr end_fn;   /* called after image is complete */
  1336.    png_bytep save_buffer_ptr;        /* current location in save_buffer */
  1337.    png_bytep save_buffer;            /* buffer for previously read data */
  1338.    png_bytep current_buffer_ptr;     /* current location in current_buffer */
  1339.    png_bytep current_buffer;         /* buffer for recently used data */
  1340.    png_uint_32 push_length;          /* size of current input chunk */
  1341.    png_uint_32 skip_length;          /* bytes to skip in input data */
  1342.    png_size_t save_buffer_size;      /* amount of data now in save_buffer */
  1343.    png_size_t save_buffer_max;       /* total size of save_buffer */
  1344.    png_size_t buffer_size;           /* total amount of available input data */
  1345.    png_size_t current_buffer_size;   /* amount of data now in current_buffer */
  1346.    int process_mode;                 /* what push library is currently doing */
  1347.    int cur_palette;                  /* current push library palette index */
  1348.  
  1349. #  if defined(PNG_TEXT_SUPPORTED)
  1350.      png_size_t current_text_size;   /* current size of text input data */
  1351.      png_size_t current_text_left;   /* how much text left to read in input */
  1352.      png_charp current_text;         /* current text chunk buffer */
  1353.      png_charp current_text_ptr;     /* current location in current_text */
  1354. #  endif /* PNG_TEXT_SUPPORTED */
  1355. #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
  1356.  
  1357. #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
  1358. /* for the Borland special 64K segment handler */
  1359.    png_bytepp offset_table_ptr;
  1360.    png_bytep offset_table;
  1361.    png_uint_16 offset_table_number;
  1362.    png_uint_16 offset_table_count;
  1363.    png_uint_16 offset_table_count_free;
  1364. #endif
  1365.  
  1366. #if defined(PNG_READ_DITHER_SUPPORTED)
  1367.    png_bytep palette_lookup;         /* lookup table for dithering */
  1368.    png_bytep dither_index;           /* index translation for palette files */
  1369. #endif
  1370.  
  1371. #if defined(PNG_READ_DITHER_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
  1372.    png_uint_16p hist;                /* histogram */
  1373. #endif
  1374.  
  1375. #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
  1376.    png_byte heuristic_method;        /* heuristic for row filter selection */
  1377.    png_byte num_prev_filters;        /* number of weights for previous rows */
  1378.    png_bytep prev_filters;           /* filter type(s) of previous row(s) */
  1379.    png_uint_16p filter_weights;      /* weight(s) for previous line(s) */
  1380.    png_uint_16p inv_filter_weights;  /* 1/weight(s) for previous line(s) */
  1381.    png_uint_16p filter_costs;        /* relative filter calculation cost */
  1382.    png_uint_16p inv_filter_costs;    /* 1/relative filter calculation cost */
  1383. #endif
  1384.  
  1385. #if defined(PNG_TIME_RFC1123_SUPPORTED)
  1386.    png_charp time_buffer;            /* String to hold RFC 1123 time text */
  1387. #endif
  1388.  
  1389. /* New members added in libpng-1.0.6 */
  1390.  
  1391. #ifdef PNG_FREE_ME_SUPPORTED
  1392.    png_uint_32 free_me;       /* flags items libpng is responsible for freeing */
  1393. #endif
  1394.  
  1395. #if defined(PNG_USER_CHUNKS_SUPPORTED)
  1396.    png_voidp user_chunk_ptr;
  1397.    png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
  1398. #endif
  1399.  
  1400. #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
  1401.    int num_chunk_list;
  1402.    png_bytep chunk_list;
  1403. #endif
  1404.  
  1405. /* New members added in libpng-1.0.3 */
  1406. #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
  1407.    png_byte rgb_to_gray_status;
  1408.    /* These were changed from png_byte in libpng-1.0.6 */
  1409.    png_uint_16 rgb_to_gray_red_coeff;
  1410.    png_uint_16 rgb_to_gray_green_coeff;
  1411.    png_uint_16 rgb_to_gray_blue_coeff;
  1412. #endif
  1413.  
  1414. /* New member added in libpng-1.0.4 (renamed in 1.0.9) */
  1415. #if defined(PNG_MNG_FEATURES_SUPPORTED) || \
  1416.     defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
  1417.     defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
  1418. /* changed from png_byte to png_uint_32 at version 1.2.0 */
  1419. #ifdef PNG_1_0_X
  1420.    png_byte mng_features_permitted;
  1421. #else
  1422.    png_uint_32 mng_features_permitted;
  1423. #endif /* PNG_1_0_X */
  1424. #endif
  1425.  
  1426. /* New member added in libpng-1.0.7 */
  1427. #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
  1428.    png_fixed_point int_gamma;
  1429. #endif
  1430.  
  1431. /* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
  1432. #if defined(PNG_MNG_FEATURES_SUPPORTED)
  1433.    png_byte filter_type;
  1434. #endif
  1435.  
  1436. #if defined(PNG_1_0_X)
  1437. /* New member added in libpng-1.0.10, ifdef'ed out in 1.2.0 */
  1438.    png_uint_32 row_buf_size;
  1439. #endif
  1440.  
  1441. /* New members added in libpng-1.2.0 */
  1442. #if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
  1443. #  if !defined(PNG_1_0_X)
  1444. #    if defined(PNG_MMX_CODE_SUPPORTED)
  1445.    png_byte     mmx_bitdepth_threshold;
  1446.    png_uint_32  mmx_rowbytes_threshold;
  1447. #    endif
  1448.    png_uint_32  asm_flags;
  1449. #  endif
  1450. #endif
  1451.  
  1452. /* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
  1453. #ifdef PNG_USER_MEM_SUPPORTED
  1454.    png_voidp mem_ptr;                /* user supplied struct for mem functions */
  1455.    png_malloc_ptr malloc_fn;         /* function for allocating memory */
  1456.    png_free_ptr free_fn;             /* function for freeing memory */
  1457. #endif
  1458.  
  1459. /* New member added in libpng-1.0.13 and 1.2.0 */
  1460.    png_bytep big_row_buf;         /* buffer to save current (unfiltered) row */
  1461.  
  1462. #if defined(PNG_READ_DITHER_SUPPORTED)
  1463. /* The following three members were added at version 1.0.14 and 1.2.4 */
  1464.    png_bytep dither_sort;            /* working sort array */
  1465.    png_bytep index_to_palette;       /* where the original index currently is */
  1466.                                      /* in the palette */
  1467.    png_bytep palette_to_index;       /* which original index points to this */
  1468.                                      /* palette color */
  1469. #endif
  1470.  
  1471. /* New members added in libpng-1.0.16 and 1.2.6 */
  1472.    png_byte compression_type;
  1473.  
  1474. #ifdef PNG_SET_USER_LIMITS_SUPPORTED
  1475.    png_uint_32 user_width_max;
  1476.    png_uint_32 user_height_max;
  1477. #endif
  1478.  
  1479. /* New member added in libpng-1.0.25 and 1.2.17 */
  1480. #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
  1481.    /* storage for unknown chunk that the library doesn't recognize. */
  1482.    png_unknown_chunk unknown_chunk;
  1483. #endif
  1484.  
  1485. /* New members added in libpng-1.2.26 */
  1486.   png_uint_32 old_big_row_buf_size, old_prev_row_size;
  1487.  
  1488. /* New member added in libpng-1.2.30 */
  1489.   png_charp chunkdata;  /* buffer for reading chunk data */
  1490.  
  1491. };
  1492.  
  1493.  
  1494. /* This triggers a compiler error in png.c, if png.c and png.h
  1495.  * do not agree upon the version number.
  1496.  */
  1497. typedef png_structp version_1_2_37;
  1498.  
  1499. typedef png_struct FAR * FAR * png_structpp;
  1500.  
  1501. /* Here are the function definitions most commonly used.  This is not
  1502.  * the place to find out how to use libpng.  See libpng.txt for the
  1503.  * full explanation, see example.c for the summary.  This just provides
  1504.  * a simple one line description of the use of each function.
  1505.  */
  1506.  
  1507. /* Returns the version number of the library */
  1508. extern PNG_EXPORT(png_uint_32,png_access_version_number) PNGARG((void));
  1509.  
  1510. /* Tell lib we have already handled the first <num_bytes> magic bytes.
  1511.  * Handling more than 8 bytes from the beginning of the file is an error.
  1512.  */
  1513. extern PNG_EXPORT(void,png_set_sig_bytes) PNGARG((png_structp png_ptr,
  1514.    int num_bytes));
  1515.  
  1516. /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
  1517.  * PNG file.  Returns zero if the supplied bytes match the 8-byte PNG
  1518.  * signature, and non-zero otherwise.  Having num_to_check == 0 or
  1519.  * start > 7 will always fail (ie return non-zero).
  1520.  */
  1521. extern PNG_EXPORT(int,png_sig_cmp) PNGARG((png_bytep sig, png_size_t start,
  1522.    png_size_t num_to_check));
  1523.  
  1524. /* Simple signature checking function.  This is the same as calling
  1525.  * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
  1526.  */
  1527. extern PNG_EXPORT(int,png_check_sig) PNGARG((png_bytep sig, int num));
  1528.  
  1529. /* Allocate and initialize png_ptr struct for reading, and any other memory. */
  1530. extern PNG_EXPORT(png_structp,png_create_read_struct)
  1531.    PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
  1532.    png_error_ptr error_fn, png_error_ptr warn_fn));
  1533.  
  1534. /* Allocate and initialize png_ptr struct for writing, and any other memory */
  1535. extern PNG_EXPORT(png_structp,png_create_write_struct)
  1536.    PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
  1537.    png_error_ptr error_fn, png_error_ptr warn_fn));
  1538.  
  1539. #ifdef PNG_WRITE_SUPPORTED
  1540. extern PNG_EXPORT(png_uint_32,png_get_compression_buffer_size)
  1541.    PNGARG((png_structp png_ptr));
  1542. #endif
  1543.  
  1544. #ifdef PNG_WRITE_SUPPORTED
  1545. extern PNG_EXPORT(void,png_set_compression_buffer_size)
  1546.    PNGARG((png_structp png_ptr, png_uint_32 size));
  1547. #endif
  1548.  
  1549. /* Reset the compression stream */
  1550. extern PNG_EXPORT(int,png_reset_zstream) PNGARG((png_structp png_ptr));
  1551.  
  1552. /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
  1553. #ifdef PNG_USER_MEM_SUPPORTED
  1554. extern PNG_EXPORT(png_structp,png_create_read_struct_2)
  1555.    PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
  1556.    png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
  1557.    png_malloc_ptr malloc_fn, png_free_ptr free_fn));
  1558. extern PNG_EXPORT(png_structp,png_create_write_struct_2)
  1559.    PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
  1560.    png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
  1561.    png_malloc_ptr malloc_fn, png_free_ptr free_fn));
  1562. #endif
  1563.  
  1564. /* Write a PNG chunk - size, type, (optional) data, CRC. */
  1565. extern PNG_EXPORT(void,png_write_chunk) PNGARG((png_structp png_ptr,
  1566.    png_bytep chunk_name, png_bytep data, png_size_t length));
  1567.  
  1568. /* Write the start of a PNG chunk - length and chunk name. */
  1569. extern PNG_EXPORT(void,png_write_chunk_start) PNGARG((png_structp png_ptr,
  1570.    png_bytep chunk_name, png_uint_32 length));
  1571.  
  1572. /* Write the data of a PNG chunk started with png_write_chunk_start(). */
  1573. extern PNG_EXPORT(void,png_write_chunk_data) PNGARG((png_structp png_ptr,
  1574.    png_bytep data, png_size_t length));
  1575.  
  1576. /* Finish a chunk started with png_write_chunk_start() (includes CRC). */
  1577. extern PNG_EXPORT(void,png_write_chunk_end) PNGARG((png_structp png_ptr));
  1578.  
  1579. /* Allocate and initialize the info structure */
  1580. extern PNG_EXPORT(png_infop,png_create_info_struct)
  1581.    PNGARG((png_structp png_ptr));
  1582.  
  1583. #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
  1584. /* Initialize the info structure (old interface - DEPRECATED) */
  1585. extern PNG_EXPORT(void,png_info_init) PNGARG((png_infop info_ptr));
  1586. #undef png_info_init
  1587. #define png_info_init(info_ptr) png_info_init_3(&info_ptr,\
  1588.     png_sizeof(png_info));
  1589. #endif
  1590.  
  1591. extern PNG_EXPORT(void,png_info_init_3) PNGARG((png_infopp info_ptr,
  1592.     png_size_t png_info_struct_size));
  1593.  
  1594. /* Writes all the PNG information before the image. */
  1595. extern PNG_EXPORT(void,png_write_info_before_PLTE) PNGARG((png_structp png_ptr,
  1596.    png_infop info_ptr));
  1597. extern PNG_EXPORT(void,png_write_info) PNGARG((png_structp png_ptr,
  1598.    png_infop info_ptr));
  1599.  
  1600. #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
  1601. /* read the information before the actual image data. */
  1602. extern PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr,
  1603.    png_infop info_ptr));
  1604. #endif
  1605.  
  1606. #if defined(PNG_TIME_RFC1123_SUPPORTED)
  1607. extern PNG_EXPORT(png_charp,png_convert_to_rfc1123)
  1608.    PNGARG((png_structp png_ptr, png_timep ptime));
  1609. #endif
  1610.  
  1611. #if !defined(_WIN32_WCE)
  1612. /* "time.h" functions are not supported on WindowsCE */
  1613. #if defined(PNG_WRITE_tIME_SUPPORTED)
  1614. /* convert from a struct tm to png_time */
  1615. extern PNG_EXPORT(void,png_convert_from_struct_tm) PNGARG((png_timep ptime,
  1616.    struct tm FAR * ttime));
  1617.  
  1618. /* convert from time_t to png_time.  Uses gmtime() */
  1619. extern PNG_EXPORT(void,png_convert_from_time_t) PNGARG((png_timep ptime,
  1620.    time_t ttime));
  1621. #endif /* PNG_WRITE_tIME_SUPPORTED */
  1622. #endif /* _WIN32_WCE */
  1623.  
  1624. #if defined(PNG_READ_EXPAND_SUPPORTED)
  1625. /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
  1626. extern PNG_EXPORT(void,png_set_expand) PNGARG((png_structp png_ptr));
  1627. #if !defined(PNG_1_0_X)
  1628. extern PNG_EXPORT(void,png_set_expand_gray_1_2_4_to_8) PNGARG((png_structp
  1629.   png_ptr));
  1630. #endif
  1631. extern PNG_EXPORT(void,png_set_palette_to_rgb) PNGARG((png_structp png_ptr));
  1632. extern PNG_EXPORT(void,png_set_tRNS_to_alpha) PNGARG((png_structp png_ptr));
  1633. #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
  1634. /* Deprecated */
  1635. extern PNG_EXPORT(void,png_set_gray_1_2_4_to_8) PNGARG((png_structp png_ptr));
  1636. #endif
  1637. #endif
  1638.  
  1639. #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
  1640. /* Use blue, green, red order for pixels. */
  1641. extern PNG_EXPORT(void,png_set_bgr) PNGARG((png_structp png_ptr));
  1642. #endif
  1643.  
  1644. #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
  1645. /* Expand the grayscale to 24-bit RGB if necessary. */
  1646. extern PNG_EXPORT(void,png_set_gray_to_rgb) PNGARG((png_structp png_ptr));
  1647. #endif
  1648.  
  1649. #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
  1650. /* Reduce RGB to grayscale. */
  1651. #ifdef PNG_FLOATING_POINT_SUPPORTED
  1652. extern PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr,
  1653.    int error_action, double red, double green ));
  1654. #endif
  1655. extern PNG_EXPORT(void,png_set_rgb_to_gray_fixed) PNGARG((png_structp png_ptr,
  1656.    int error_action, png_fixed_point red, png_fixed_point green ));
  1657. extern PNG_EXPORT(png_byte,png_get_rgb_to_gray_status) PNGARG((png_structp
  1658.    png_ptr));
  1659. #endif
  1660.  
  1661. extern PNG_EXPORT(void,png_build_grayscale_palette) PNGARG((int bit_depth,
  1662.    png_colorp palette));
  1663.  
  1664. #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
  1665. extern PNG_EXPORT(void,png_set_strip_alpha) PNGARG((png_structp png_ptr));
  1666. #endif
  1667.  
  1668. #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
  1669.     defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
  1670. extern PNG_EXPORT(void,png_set_swap_alpha) PNGARG((png_structp png_ptr));
  1671. #endif
  1672.  
  1673. #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
  1674.     defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
  1675. extern PNG_EXPORT(void,png_set_invert_alpha) PNGARG((png_structp png_ptr));
  1676. #endif
  1677.  
  1678. #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
  1679. /* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
  1680. extern PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr,
  1681.    png_uint_32 filler, int flags));
  1682. /* The values of the PNG_FILLER_ defines should NOT be changed */
  1683. #define PNG_FILLER_BEFORE 0
  1684. #define PNG_FILLER_AFTER 1
  1685. /* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
  1686. #if !defined(PNG_1_0_X)
  1687. extern PNG_EXPORT(void,png_set_add_alpha) PNGARG((png_structp png_ptr,
  1688.    png_uint_32 filler, int flags));
  1689. #endif
  1690. #endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
  1691.  
  1692. #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
  1693. /* Swap bytes in 16-bit depth files. */
  1694. extern PNG_EXPORT(void,png_set_swap) PNGARG((png_structp png_ptr));
  1695. #endif
  1696.  
  1697. #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
  1698. /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
  1699. extern PNG_EXPORT(void,png_set_packing) PNGARG((png_structp png_ptr));
  1700. #endif
  1701.  
  1702. #if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
  1703. /* Swap packing order of pixels in bytes. */
  1704. extern PNG_EXPORT(void,png_set_packswap) PNGARG((png_structp png_ptr));
  1705. #endif
  1706.  
  1707. #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
  1708. /* Converts files to legal bit depths. */
  1709. extern PNG_EXPORT(void,png_set_shift) PNGARG((png_structp png_ptr,
  1710.    png_color_8p true_bits));
  1711. #endif
  1712.  
  1713. #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
  1714.     defined(PNG_WRITE_INTERLACING_SUPPORTED)
  1715. /* Have the code handle the interlacing.  Returns the number of passes. */
  1716. extern PNG_EXPORT(int,png_set_interlace_handling) PNGARG((png_structp png_ptr));
  1717. #endif
  1718.  
  1719. #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
  1720. /* Invert monochrome files */
  1721. extern PNG_EXPORT(void,png_set_invert_mono) PNGARG((png_structp png_ptr));
  1722. #endif
  1723.  
  1724. #if defined(PNG_READ_BACKGROUND_SUPPORTED)
  1725. /* Handle alpha and tRNS by replacing with a background color. */
  1726. #ifdef PNG_FLOATING_POINT_SUPPORTED
  1727. extern PNG_EXPORT(void,png_set_background) PNGARG((png_structp png_ptr,
  1728.    png_color_16p background_color, int background_gamma_code,
  1729.    int need_expand, double background_gamma));
  1730. #endif
  1731. #define PNG_BACKGROUND_GAMMA_UNKNOWN 0
  1732. #define PNG_BACKGROUND_GAMMA_SCREEN  1
  1733. #define PNG_BACKGROUND_GAMMA_FILE    2
  1734. #define PNG_BACKGROUND_GAMMA_UNIQUE  3
  1735. #endif
  1736.  
  1737. #if defined(PNG_READ_16_TO_8_SUPPORTED)
  1738. /* strip the second byte of information from a 16-bit depth file. */
  1739. extern PNG_EXPORT(void,png_set_strip_16) PNGARG((png_structp png_ptr));
  1740. #endif
  1741.  
  1742. #if defined(PNG_READ_DITHER_SUPPORTED)
  1743. /* Turn on dithering, and reduce the palette to the number of colors available. */
  1744. extern PNG_EXPORT(void,png_set_dither) PNGARG((png_structp png_ptr,
  1745.    png_colorp palette, int num_palette, int maximum_colors,
  1746.    png_uint_16p histogram, int full_dither));
  1747. #endif
  1748.  
  1749. #if defined(PNG_READ_GAMMA_SUPPORTED)
  1750. /* Handle gamma correction. Screen_gamma=(display_exponent) */
  1751. #ifdef PNG_FLOATING_POINT_SUPPORTED
  1752. extern PNG_EXPORT(void,png_set_gamma) PNGARG((png_structp png_ptr,
  1753.    double screen_gamma, double default_file_gamma));
  1754. #endif
  1755. #endif
  1756.  
  1757. #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
  1758. #if defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
  1759.     defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
  1760. /* Permit or disallow empty PLTE (0: not permitted, 1: permitted) */
  1761. /* Deprecated and will be removed.  Use png_permit_mng_features() instead. */
  1762. extern PNG_EXPORT(void,png_permit_empty_plte) PNGARG((png_structp png_ptr,
  1763.    int empty_plte_permitted));
  1764. #endif
  1765. #endif
  1766.  
  1767. #if defined(PNG_WRITE_FLUSH_SUPPORTED)
  1768. /* Set how many lines between output flushes - 0 for no flushing */
  1769. extern PNG_EXPORT(void,png_set_flush) PNGARG((png_structp png_ptr, int nrows));
  1770. /* Flush the current PNG output buffer */
  1771. extern PNG_EXPORT(void,png_write_flush) PNGARG((png_structp png_ptr));
  1772. #endif
  1773.  
  1774. /* optional update palette with requested transformations */
  1775. extern PNG_EXPORT(void,png_start_read_image) PNGARG((png_structp png_ptr));
  1776.  
  1777. /* optional call to update the users info structure */
  1778. extern PNG_EXPORT(void,png_read_update_info) PNGARG((png_structp png_ptr,
  1779.    png_infop info_ptr));
  1780.  
  1781. #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
  1782. /* read one or more rows of image data. */
  1783. extern PNG_EXPORT(void,png_read_rows) PNGARG((png_structp png_ptr,
  1784.    png_bytepp row, png_bytepp display_row, png_uint_32 num_rows));
  1785. #endif
  1786.  
  1787. #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
  1788. /* read a row of data. */
  1789. extern PNG_EXPORT(void,png_read_row) PNGARG((png_structp png_ptr,
  1790.    png_bytep row,
  1791.    png_bytep display_row));
  1792. #endif
  1793.  
  1794. #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
  1795. /* read the whole image into memory at once. */
  1796. extern PNG_EXPORT(void,png_read_image) PNGARG((png_structp png_ptr,
  1797.    png_bytepp image));
  1798. #endif
  1799.  
  1800. /* write a row of image data */
  1801. extern PNG_EXPORT(void,png_write_row) PNGARG((png_structp png_ptr,
  1802.    png_bytep row));
  1803.  
  1804. /* write a few rows of image data */
  1805. extern PNG_EXPORT(void,png_write_rows) PNGARG((png_structp png_ptr,
  1806.    png_bytepp row, png_uint_32 num_rows));
  1807.  
  1808. /* write the image data */
  1809. extern PNG_EXPORT(void,png_write_image) PNGARG((png_structp png_ptr,
  1810.    png_bytepp image));
  1811.  
  1812. /* writes the end of the PNG file. */
  1813. extern PNG_EXPORT(void,png_write_end) PNGARG((png_structp png_ptr,
  1814.    png_infop info_ptr));
  1815.  
  1816. #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
  1817. /* read the end of the PNG file. */
  1818. extern PNG_EXPORT(void,png_read_end) PNGARG((png_structp png_ptr,
  1819.    png_infop info_ptr));
  1820. #endif
  1821.  
  1822. /* free any memory associated with the png_info_struct */
  1823. extern PNG_EXPORT(void,png_destroy_info_struct) PNGARG((png_structp png_ptr,
  1824.    png_infopp info_ptr_ptr));
  1825.  
  1826. /* free any memory associated with the png_struct and the png_info_structs */
  1827. extern PNG_EXPORT(void,png_destroy_read_struct) PNGARG((png_structpp
  1828.    png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
  1829.  
  1830. /* free all memory used by the read (old method - NOT DLL EXPORTED) */
  1831. extern void png_read_destroy PNGARG((png_structp png_ptr, png_infop info_ptr,
  1832.    png_infop end_info_ptr));
  1833.  
  1834. /* free any memory associated with the png_struct and the png_info_structs */
  1835. extern PNG_EXPORT(void,png_destroy_write_struct)
  1836.    PNGARG((png_structpp png_ptr_ptr, png_infopp info_ptr_ptr));
  1837.  
  1838. /* free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */
  1839. extern void png_write_destroy PNGARG((png_structp png_ptr));
  1840.  
  1841. /* set the libpng method of handling chunk CRC errors */
  1842. extern PNG_EXPORT(void,png_set_crc_action) PNGARG((png_structp png_ptr,
  1843.    int crit_action, int ancil_action));
  1844.  
  1845. /* Values for png_set_crc_action() to say how to handle CRC errors in
  1846.  * ancillary and critical chunks, and whether to use the data contained
  1847.  * therein.  Note that it is impossible to "discard" data in a critical
  1848.  * chunk.  For versions prior to 0.90, the action was always error/quit,
  1849.  * whereas in version 0.90 and later, the action for CRC errors in ancillary
  1850.  * chunks is warn/discard.  These values should NOT be changed.
  1851.  *
  1852.  *      value                       action:critical     action:ancillary
  1853.  */
  1854. #define PNG_CRC_DEFAULT       0  /* error/quit          warn/discard data */
  1855. #define PNG_CRC_ERROR_QUIT    1  /* error/quit          error/quit        */
  1856. #define PNG_CRC_WARN_DISCARD  2  /* (INVALID)           warn/discard data */
  1857. #define PNG_CRC_WARN_USE      3  /* warn/use data       warn/use data     */
  1858. #define PNG_CRC_QUIET_USE     4  /* quiet/use data      quiet/use data    */
  1859. #define PNG_CRC_NO_CHANGE     5  /* use current value   use current value */
  1860.  
  1861. /* These functions give the user control over the scan-line filtering in
  1862.  * libpng and the compression methods used by zlib.  These functions are
  1863.  * mainly useful for testing, as the defaults should work with most users.
  1864.  * Those users who are tight on memory or want faster performance at the
  1865.  * expense of compression can modify them.  See the compression library
  1866.  * header file (zlib.h) for an explination of the compression functions.
  1867.  */
  1868.  
  1869. /* set the filtering method(s) used by libpng.  Currently, the only valid
  1870.  * value for "method" is 0.
  1871.  */
  1872. extern PNG_EXPORT(void,png_set_filter) PNGARG((png_structp png_ptr, int method,
  1873.    int filters));
  1874.  
  1875. /* Flags for png_set_filter() to say which filters to use.  The flags
  1876.  * are chosen so that they don't conflict with real filter types
  1877.  * below, in case they are supplied instead of the #defined constants.
  1878.  * These values should NOT be changed.
  1879.  */
  1880. #define PNG_NO_FILTERS     0x00
  1881. #define PNG_FILTER_NONE    0x08
  1882. #define PNG_FILTER_SUB     0x10
  1883. #define PNG_FILTER_UP      0x20
  1884. #define PNG_FILTER_AVG     0x40
  1885. #define PNG_FILTER_PAETH   0x80
  1886. #define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
  1887.                          PNG_FILTER_AVG | PNG_FILTER_PAETH)
  1888.  
  1889. /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
  1890.  * These defines should NOT be changed.
  1891.  */
  1892. #define PNG_FILTER_VALUE_NONE  0
  1893. #define PNG_FILTER_VALUE_SUB   1
  1894. #define PNG_FILTER_VALUE_UP    2
  1895. #define PNG_FILTER_VALUE_AVG   3
  1896. #define PNG_FILTER_VALUE_PAETH 4
  1897. #define PNG_FILTER_VALUE_LAST  5
  1898.  
  1899. #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* EXPERIMENTAL */
  1900. /* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
  1901.  * defines, either the default (minimum-sum-of-absolute-differences), or
  1902.  * the experimental method (weighted-minimum-sum-of-absolute-differences).
  1903.  *
  1904.  * Weights are factors >= 1.0, indicating how important it is to keep the
  1905.  * filter type consistent between rows.  Larger numbers mean the current
  1906.  * filter is that many times as likely to be the same as the "num_weights"
  1907.  * previous filters.  This is cumulative for each previous row with a weight.
  1908.  * There needs to be "num_weights" values in "filter_weights", or it can be
  1909.  * NULL if the weights aren't being specified.  Weights have no influence on
  1910.  * the selection of the first row filter.  Well chosen weights can (in theory)
  1911.  * improve the compression for a given image.
  1912.  *
  1913.  * Costs are factors >= 1.0 indicating the relative decoding costs of a
  1914.  * filter type.  Higher costs indicate more decoding expense, and are
  1915.  * therefore less likely to be selected over a filter with lower computational
  1916.  * costs.  There needs to be a value in "filter_costs" for each valid filter
  1917.  * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
  1918.  * setting the costs.  Costs try to improve the speed of decompression without
  1919.  * unduly increasing the compressed image size.
  1920.  *
  1921.  * A negative weight or cost indicates the default value is to be used, and
  1922.  * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
  1923.  * The default values for both weights and costs are currently 1.0, but may
  1924.  * change if good general weighting/cost heuristics can be found.  If both
  1925.  * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
  1926.  * to the UNWEIGHTED method, but with added encoding time/computation.
  1927.  */
  1928. #ifdef PNG_FLOATING_POINT_SUPPORTED
  1929. extern PNG_EXPORT(void,png_set_filter_heuristics) PNGARG((png_structp png_ptr,
  1930.    int heuristic_method, int num_weights, png_doublep filter_weights,
  1931.    png_doublep filter_costs));
  1932. #endif
  1933. #endif /*  PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
  1934.  
  1935. /* Heuristic used for row filter selection.  These defines should NOT be
  1936.  * changed.
  1937.  */
  1938. #define PNG_FILTER_HEURISTIC_DEFAULT    0  /* Currently "UNWEIGHTED" */
  1939. #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1  /* Used by libpng < 0.95 */
  1940. #define PNG_FILTER_HEURISTIC_WEIGHTED   2  /* Experimental feature */
  1941. #define PNG_FILTER_HEURISTIC_LAST       3  /* Not a valid value */
  1942.  
  1943. /* Set the library compression level.  Currently, valid values range from
  1944.  * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
  1945.  * (0 - no compression, 9 - "maximal" compression).  Note that tests have
  1946.  * shown that zlib compression levels 3-6 usually perform as well as level 9
  1947.  * for PNG images, and do considerably fewer caclulations.  In the future,
  1948.  * these values may not correspond directly to the zlib compression levels.
  1949.  */
  1950. extern PNG_EXPORT(void,png_set_compression_level) PNGARG((png_structp png_ptr,
  1951.    int level));
  1952.  
  1953. extern PNG_EXPORT(void,png_set_compression_mem_level)
  1954.    PNGARG((png_structp png_ptr, int mem_level));
  1955.  
  1956. extern PNG_EXPORT(void,png_set_compression_strategy)
  1957.    PNGARG((png_structp png_ptr, int strategy));
  1958.  
  1959. extern PNG_EXPORT(void,png_set_compression_window_bits)
  1960.    PNGARG((png_structp png_ptr, int window_bits));
  1961.  
  1962. extern PNG_EXPORT(void,png_set_compression_method) PNGARG((png_structp png_ptr,
  1963.    int method));
  1964.  
  1965. /* These next functions are called for input/output, memory, and error
  1966.  * handling.  They are in the file pngrio.c, pngwio.c, and pngerror.c,
  1967.  * and call standard C I/O routines such as fread(), fwrite(), and
  1968.  * fprintf().  These functions can be made to use other I/O routines
  1969.  * at run time for those applications that need to handle I/O in a
  1970.  * different manner by calling png_set_???_fn().  See libpng.txt for
  1971.  * more information.
  1972.  */
  1973.  
  1974. #if !defined(PNG_NO_STDIO)
  1975. /* Initialize the input/output for the PNG file to the default functions. */
  1976. extern PNG_EXPORT(void,png_init_io) PNGARG((png_structp png_ptr, png_FILE_p fp));
  1977. #endif
  1978.  
  1979. /* Replace the (error and abort), and warning functions with user
  1980.  * supplied functions.  If no messages are to be printed you must still
  1981.  * write and use replacement functions. The replacement error_fn should
  1982.  * still do a longjmp to the last setjmp location if you are using this
  1983.  * method of error handling.  If error_fn or warning_fn is NULL, the
  1984.  * default function will be used.
  1985.  */
  1986.  
  1987. extern PNG_EXPORT(void,png_set_error_fn) PNGARG((png_structp png_ptr,
  1988.    png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
  1989.  
  1990. /* Return the user pointer associated with the error functions */
  1991. extern PNG_EXPORT(png_voidp,png_get_error_ptr) PNGARG((png_structp png_ptr));
  1992.  
  1993. /* Replace the default data output functions with a user supplied one(s).
  1994.  * If buffered output is not used, then output_flush_fn can be set to NULL.
  1995.  * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
  1996.  * output_flush_fn will be ignored (and thus can be NULL).
  1997.  * It is probably a mistake to use NULL for output_flush_fn if
  1998.  * write_data_fn is not also NULL unless you have built libpng with
  1999.  * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
  2000.  * default flush function, which uses the standard *FILE structure, will
  2001.  * be used.
  2002.  */
  2003. extern PNG_EXPORT(void,png_set_write_fn) PNGARG((png_structp png_ptr,
  2004.    png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
  2005.  
  2006. /* Replace the default data input function with a user supplied one. */
  2007. extern PNG_EXPORT(void,png_set_read_fn) PNGARG((png_structp png_ptr,
  2008.    png_voidp io_ptr, png_rw_ptr read_data_fn));
  2009.  
  2010. /* Return the user pointer associated with the I/O functions */
  2011. extern PNG_EXPORT(png_voidp,png_get_io_ptr) PNGARG((png_structp png_ptr));
  2012.  
  2013. extern PNG_EXPORT(void,png_set_read_status_fn) PNGARG((png_structp png_ptr,
  2014.    png_read_status_ptr read_row_fn));
  2015.  
  2016. extern PNG_EXPORT(void,png_set_write_status_fn) PNGARG((png_structp png_ptr,
  2017.    png_write_status_ptr write_row_fn));
  2018.  
  2019. #ifdef PNG_USER_MEM_SUPPORTED
  2020. /* Replace the default memory allocation functions with user supplied one(s). */
  2021. extern PNG_EXPORT(void,png_set_mem_fn) PNGARG((png_structp png_ptr,
  2022.    png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn));
  2023. /* Return the user pointer associated with the memory functions */
  2024. extern PNG_EXPORT(png_voidp,png_get_mem_ptr) PNGARG((png_structp png_ptr));
  2025. #endif
  2026.  
  2027. #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
  2028.     defined(PNG_LEGACY_SUPPORTED)
  2029. extern PNG_EXPORT(void,png_set_read_user_transform_fn) PNGARG((png_structp
  2030.    png_ptr, png_user_transform_ptr read_user_transform_fn));
  2031. #endif
  2032.  
  2033. #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
  2034.     defined(PNG_LEGACY_SUPPORTED)
  2035. extern PNG_EXPORT(void,png_set_write_user_transform_fn) PNGARG((png_structp
  2036.    png_ptr, png_user_transform_ptr write_user_transform_fn));
  2037. #endif
  2038.  
  2039. #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
  2040.     defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
  2041.     defined(PNG_LEGACY_SUPPORTED)
  2042. extern PNG_EXPORT(void,png_set_user_transform_info) PNGARG((png_structp
  2043.    png_ptr, png_voidp user_transform_ptr, int user_transform_depth,
  2044.    int user_transform_channels));
  2045. /* Return the user pointer associated with the user transform functions */
  2046. extern PNG_EXPORT(png_voidp,png_get_user_transform_ptr)
  2047.    PNGARG((png_structp png_ptr));
  2048. #endif
  2049.  
  2050. #ifdef PNG_USER_CHUNKS_SUPPORTED
  2051. extern PNG_EXPORT(void,png_set_read_user_chunk_fn) PNGARG((png_structp png_ptr,
  2052.    png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
  2053. extern PNG_EXPORT(png_voidp,png_get_user_chunk_ptr) PNGARG((png_structp
  2054.    png_ptr));
  2055. #endif
  2056.  
  2057. #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
  2058. /* Sets the function callbacks for the push reader, and a pointer to a
  2059.  * user-defined structure available to the callback functions.
  2060.  */
  2061. extern PNG_EXPORT(void,png_set_progressive_read_fn) PNGARG((png_structp png_ptr,
  2062.    png_voidp progressive_ptr,
  2063.    png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
  2064.    png_progressive_end_ptr end_fn));
  2065.  
  2066. /* returns the user pointer associated with the push read functions */
  2067. extern PNG_EXPORT(png_voidp,png_get_progressive_ptr)
  2068.    PNGARG((png_structp png_ptr));
  2069.  
  2070. /* function to be called when data becomes available */
  2071. extern PNG_EXPORT(void,png_process_data) PNGARG((png_structp png_ptr,
  2072.    png_infop info_ptr, png_bytep buffer, png_size_t buffer_size));
  2073.  
  2074. /* function that combines rows.  Not very much different than the
  2075.  * png_combine_row() call.  Is this even used?????
  2076.  */
  2077. extern PNG_EXPORT(void,png_progressive_combine_row) PNGARG((png_structp png_ptr,
  2078.    png_bytep old_row, png_bytep new_row));
  2079. #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
  2080.  
  2081. extern PNG_EXPORT(png_voidp,png_malloc) PNGARG((png_structp png_ptr,
  2082.    png_uint_32 size));
  2083.  
  2084. #if defined(PNG_1_0_X)
  2085. #  define png_malloc_warn png_malloc
  2086. #else
  2087. /* Added at libpng version 1.2.4 */
  2088. extern PNG_EXPORT(png_voidp,png_malloc_warn) PNGARG((png_structp png_ptr,
  2089.    png_uint_32 size));
  2090. #endif
  2091.  
  2092. /* frees a pointer allocated by png_malloc() */
  2093. extern PNG_EXPORT(void,png_free) PNGARG((png_structp png_ptr, png_voidp ptr));
  2094.  
  2095. #if defined(PNG_1_0_X)
  2096. /* Function to allocate memory for zlib. */
  2097. extern PNG_EXPORT(voidpf,png_zalloc) PNGARG((voidpf png_ptr, uInt items,
  2098.    uInt size));
  2099.  
  2100. /* Function to free memory for zlib */
  2101. extern PNG_EXPORT(void,png_zfree) PNGARG((voidpf png_ptr, voidpf ptr));
  2102. #endif
  2103.  
  2104. /* Free data that was allocated internally */
  2105. extern PNG_EXPORT(void,png_free_data) PNGARG((png_structp png_ptr,
  2106.    png_infop info_ptr, png_uint_32 free_me, int num));
  2107. #ifdef PNG_FREE_ME_SUPPORTED
  2108. /* Reassign responsibility for freeing existing data, whether allocated
  2109.  * by libpng or by the application */
  2110. extern PNG_EXPORT(void,png_data_freer) PNGARG((png_structp png_ptr,
  2111.    png_infop info_ptr, int freer, png_uint_32 mask));
  2112. #endif
  2113. /* assignments for png_data_freer */
  2114. #define PNG_DESTROY_WILL_FREE_DATA 1
  2115. #define PNG_SET_WILL_FREE_DATA 1
  2116. #define PNG_USER_WILL_FREE_DATA 2
  2117. /* Flags for png_ptr->free_me and info_ptr->free_me */
  2118. #define PNG_FREE_HIST 0x0008
  2119. #define PNG_FREE_ICCP 0x0010
  2120. #define PNG_FREE_SPLT 0x0020
  2121. #define PNG_FREE_ROWS 0x0040
  2122. #define PNG_FREE_PCAL 0x0080
  2123. #define PNG_FREE_SCAL 0x0100
  2124. #define PNG_FREE_UNKN 0x0200
  2125. #define PNG_FREE_LIST 0x0400
  2126. #define PNG_FREE_PLTE 0x1000
  2127. #define PNG_FREE_TRNS 0x2000
  2128. #define PNG_FREE_TEXT 0x4000
  2129. #define PNG_FREE_ALL  0x7fff
  2130. #define PNG_FREE_MUL  0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
  2131.  
  2132. #ifdef PNG_USER_MEM_SUPPORTED
  2133. extern PNG_EXPORT(png_voidp,png_malloc_default) PNGARG((png_structp png_ptr,
  2134.    png_uint_32 size));
  2135. extern PNG_EXPORT(void,png_free_default) PNGARG((png_structp png_ptr,
  2136.    png_voidp ptr));
  2137. #endif
  2138.  
  2139. extern PNG_EXPORT(png_voidp,png_memcpy_check) PNGARG((png_structp png_ptr,
  2140.    png_voidp s1, png_voidp s2, png_uint_32 size));
  2141.  
  2142. extern PNG_EXPORT(png_voidp,png_memset_check) PNGARG((png_structp png_ptr,
  2143.    png_voidp s1, int value, png_uint_32 size));
  2144.  
  2145. #if defined(USE_FAR_KEYWORD)  /* memory model conversion function */
  2146. extern void *png_far_to_near PNGARG((png_structp png_ptr,png_voidp ptr,
  2147.    int check));
  2148. #endif /* USE_FAR_KEYWORD */
  2149.  
  2150. #ifndef PNG_NO_ERROR_TEXT
  2151. /* Fatal error in PNG image of libpng - can't continue */
  2152. extern PNG_EXPORT(void,png_error) PNGARG((png_structp png_ptr,
  2153.    png_const_charp error_message));
  2154.  
  2155. /* The same, but the chunk name is prepended to the error string. */
  2156. extern PNG_EXPORT(void,png_chunk_error) PNGARG((png_structp png_ptr,
  2157.    png_const_charp error_message));
  2158. #else
  2159. /* Fatal error in PNG image of libpng - can't continue */
  2160. extern PNG_EXPORT(void,png_err) PNGARG((png_structp png_ptr));
  2161. #endif
  2162.  
  2163. #ifndef PNG_NO_WARNINGS
  2164. /* Non-fatal error in libpng.  Can continue, but may have a problem. */
  2165. extern PNG_EXPORT(void,png_warning) PNGARG((png_structp png_ptr,
  2166.    png_const_charp warning_message));
  2167.  
  2168. #ifdef PNG_READ_SUPPORTED
  2169. /* Non-fatal error in libpng, chunk name is prepended to message. */
  2170. extern PNG_EXPORT(void,png_chunk_warning) PNGARG((png_structp png_ptr,
  2171.    png_const_charp warning_message));
  2172. #endif /* PNG_READ_SUPPORTED */
  2173. #endif /* PNG_NO_WARNINGS */
  2174.  
  2175. /* The png_set_<chunk> functions are for storing values in the png_info_struct.
  2176.  * Similarly, the png_get_<chunk> calls are used to read values from the
  2177.  * png_info_struct, either storing the parameters in the passed variables, or
  2178.  * setting pointers into the png_info_struct where the data is stored.  The
  2179.  * png_get_<chunk> functions return a non-zero value if the data was available
  2180.  * in info_ptr, or return zero and do not change any of the parameters if the
  2181.  * data was not available.
  2182.  *
  2183.  * These functions should be used instead of directly accessing png_info
  2184.  * to avoid problems with future changes in the size and internal layout of
  2185.  * png_info_struct.
  2186.  */
  2187. /* Returns "flag" if chunk data is valid in info_ptr. */
  2188. extern PNG_EXPORT(png_uint_32,png_get_valid) PNGARG((png_structp png_ptr,
  2189. png_infop info_ptr, png_uint_32 flag));
  2190.  
  2191. /* Returns number of bytes needed to hold a transformed row. */
  2192. extern PNG_EXPORT(png_uint_32,png_get_rowbytes) PNGARG((png_structp png_ptr,
  2193. png_infop info_ptr));
  2194.  
  2195. #if defined(PNG_INFO_IMAGE_SUPPORTED)
  2196. /* Returns row_pointers, which is an array of pointers to scanlines that was
  2197. returned from png_read_png(). */
  2198. extern PNG_EXPORT(png_bytepp,png_get_rows) PNGARG((png_structp png_ptr,
  2199. png_infop info_ptr));
  2200. /* Set row_pointers, which is an array of pointers to scanlines for use
  2201. by png_write_png(). */
  2202. extern PNG_EXPORT(void,png_set_rows) PNGARG((png_structp png_ptr,
  2203.    png_infop info_ptr, png_bytepp row_pointers));
  2204. #endif
  2205.  
  2206. /* Returns number of color channels in image. */
  2207. extern PNG_EXPORT(png_byte,png_get_channels) PNGARG((png_structp png_ptr,
  2208. png_infop info_ptr));
  2209.  
  2210. #ifdef PNG_EASY_ACCESS_SUPPORTED
  2211. /* Returns image width in pixels. */
  2212. extern PNG_EXPORT(png_uint_32, png_get_image_width) PNGARG((png_structp
  2213. png_ptr, png_infop info_ptr));
  2214.  
  2215. /* Returns image height in pixels. */
  2216. extern PNG_EXPORT(png_uint_32, png_get_image_height) PNGARG((png_structp
  2217. png_ptr, png_infop info_ptr));
  2218.  
  2219. /* Returns image bit_depth. */
  2220. extern PNG_EXPORT(png_byte, png_get_bit_depth) PNGARG((png_structp
  2221. png_ptr, png_infop info_ptr));
  2222.  
  2223. /* Returns image color_type. */
  2224. extern PNG_EXPORT(png_byte, png_get_color_type) PNGARG((png_structp
  2225. png_ptr, png_infop info_ptr));
  2226.  
  2227. /* Returns image filter_type. */
  2228. extern PNG_EXPORT(png_byte, png_get_filter_type) PNGARG((png_structp
  2229. png_ptr, png_infop info_ptr));
  2230.  
  2231. /* Returns image interlace_type. */
  2232. extern PNG_EXPORT(png_byte, png_get_interlace_type) PNGARG((png_structp
  2233. png_ptr, png_infop info_ptr));
  2234.  
  2235. /* Returns image compression_type. */
  2236. extern PNG_EXPORT(png_byte, png_get_compression_type) PNGARG((png_structp
  2237. png_ptr, png_infop info_ptr));
  2238.  
  2239. /* Returns image resolution in pixels per meter, from pHYs chunk data. */
  2240. extern PNG_EXPORT(png_uint_32, png_get_pixels_per_meter) PNGARG((png_structp
  2241. png_ptr, png_infop info_ptr));
  2242. extern PNG_EXPORT(png_uint_32, png_get_x_pixels_per_meter) PNGARG((png_structp
  2243. png_ptr, png_infop info_ptr));
  2244. extern PNG_EXPORT(png_uint_32, png_get_y_pixels_per_meter) PNGARG((png_structp
  2245. png_ptr, png_infop info_ptr));
  2246.  
  2247. /* Returns pixel aspect ratio, computed from pHYs chunk data.  */
  2248. #ifdef PNG_FLOATING_POINT_SUPPORTED
  2249. extern PNG_EXPORT(float, png_get_pixel_aspect_ratio) PNGARG((png_structp
  2250. png_ptr, png_infop info_ptr));
  2251. #endif
  2252.  
  2253. /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
  2254. extern PNG_EXPORT(png_int_32, png_get_x_offset_pixels) PNGARG((png_structp
  2255. png_ptr, png_infop info_ptr));
  2256. extern PNG_EXPORT(png_int_32, png_get_y_offset_pixels) PNGARG((png_structp
  2257. png_ptr, png_infop info_ptr));
  2258. extern PNG_EXPORT(png_int_32, png_get_x_offset_microns) PNGARG((png_structp
  2259. png_ptr, png_infop info_ptr));
  2260. extern PNG_EXPORT(png_int_32, png_get_y_offset_microns) PNGARG((png_structp
  2261. png_ptr, png_infop info_ptr));
  2262.  
  2263. #endif /* PNG_EASY_ACCESS_SUPPORTED */
  2264.  
  2265. /* Returns pointer to signature string read from PNG header */
  2266. extern PNG_EXPORT(png_bytep,png_get_signature) PNGARG((png_structp png_ptr,
  2267. png_infop info_ptr));
  2268.  
  2269. #if defined(PNG_bKGD_SUPPORTED)
  2270. extern PNG_EXPORT(png_uint_32,png_get_bKGD) PNGARG((png_structp png_ptr,
  2271.    png_infop info_ptr, png_color_16p *background));
  2272. #endif
  2273.  
  2274. #if defined(PNG_bKGD_SUPPORTED)
  2275. extern PNG_EXPORT(void,png_set_bKGD) PNGARG((png_structp png_ptr,
  2276.    png_infop info_ptr, png_color_16p background));
  2277. #endif
  2278.  
  2279. #if defined(PNG_cHRM_SUPPORTED)
  2280. #ifdef PNG_FLOATING_POINT_SUPPORTED
  2281. extern PNG_EXPORT(png_uint_32,png_get_cHRM) PNGARG((png_structp png_ptr,
  2282.    png_infop info_ptr, double *white_x, double *white_y, double *red_x,
  2283.    double *red_y, double *green_x, double *green_y, double *blue_x,
  2284.    double *blue_y));
  2285. #endif
  2286. #ifdef PNG_FIXED_POINT_SUPPORTED
  2287. extern PNG_EXPORT(png_uint_32,png_get_cHRM_fixed) PNGARG((png_structp png_ptr,
  2288.    png_infop info_ptr, png_fixed_point *int_white_x, png_fixed_point
  2289.    *int_white_y, png_fixed_point *int_red_x, png_fixed_point *int_red_y,
  2290.    png_fixed_point *int_green_x, png_fixed_point *int_green_y, png_fixed_point
  2291.    *int_blue_x, png_fixed_point *int_blue_y));
  2292. #endif
  2293. #endif
  2294.  
  2295. #if defined(PNG_cHRM_SUPPORTED)
  2296. #ifdef PNG_FLOATING_POINT_SUPPORTED
  2297. extern PNG_EXPORT(void,png_set_cHRM) PNGARG((png_structp png_ptr,
  2298.    png_infop info_ptr, double white_x, double white_y, double red_x,
  2299.    double red_y, double green_x, double green_y, double blue_x, double blue_y));
  2300. #endif
  2301. #ifdef PNG_FIXED_POINT_SUPPORTED
  2302. extern PNG_EXPORT(void,png_set_cHRM_fixed) PNGARG((png_structp png_ptr,
  2303.    png_infop info_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y,
  2304.    png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
  2305.    int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
  2306.    png_fixed_point int_blue_y));
  2307. #endif
  2308. #endif
  2309.  
  2310. #if defined(PNG_gAMA_SUPPORTED)
  2311. #ifdef PNG_FLOATING_POINT_SUPPORTED
  2312. extern PNG_EXPORT(png_uint_32,png_get_gAMA) PNGARG((png_structp png_ptr,
  2313.    png_infop info_ptr, double *file_gamma));
  2314. #endif
  2315. extern PNG_EXPORT(png_uint_32,png_get_gAMA_fixed) PNGARG((png_structp png_ptr,
  2316.    png_infop info_ptr, png_fixed_point *int_file_gamma));
  2317. #endif
  2318.  
  2319. #if defined(PNG_gAMA_SUPPORTED)
  2320. #ifdef PNG_FLOATING_POINT_SUPPORTED
  2321. extern PNG_EXPORT(void,png_set_gAMA) PNGARG((png_structp png_ptr,
  2322.    png_infop info_ptr, double file_gamma));
  2323. #endif
  2324. extern PNG_EXPORT(void,png_set_gAMA_fixed) PNGARG((png_structp png_ptr,
  2325.    png_infop info_ptr, png_fixed_point int_file_gamma));
  2326. #endif
  2327.  
  2328. #if defined(PNG_hIST_SUPPORTED)
  2329. extern PNG_EXPORT(png_uint_32,png_get_hIST) PNGARG((png_structp png_ptr,
  2330.    png_infop info_ptr, png_uint_16p *hist));
  2331. #endif
  2332.  
  2333. #if defined(PNG_hIST_SUPPORTED)
  2334. extern PNG_EXPORT(void,png_set_hIST) PNGARG((png_structp png_ptr,
  2335.    png_infop info_ptr, png_uint_16p hist));
  2336. #endif
  2337.  
  2338. extern PNG_EXPORT(png_uint_32,png_get_IHDR) PNGARG((png_structp png_ptr,
  2339.    png_infop info_ptr, png_uint_32 *width, png_uint_32 *height,
  2340.    int *bit_depth, int *color_type, int *interlace_method,
  2341.    int *compression_method, int *filter_method));
  2342.  
  2343. extern PNG_EXPORT(void,png_set_IHDR) PNGARG((png_structp png_ptr,
  2344.    png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
  2345.    int color_type, int interlace_method, int compression_method,
  2346.    int filter_method));
  2347.  
  2348. #if defined(PNG_oFFs_SUPPORTED)
  2349. extern PNG_EXPORT(png_uint_32,png_get_oFFs) PNGARG((png_structp png_ptr,
  2350.    png_infop info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
  2351.    int *unit_type));
  2352. #endif
  2353.  
  2354. #if defined(PNG_oFFs_SUPPORTED)
  2355. extern PNG_EXPORT(void,png_set_oFFs) PNGARG((png_structp png_ptr,
  2356.    png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y,
  2357.    int unit_type));
  2358. #endif
  2359.  
  2360. #if defined(PNG_pCAL_SUPPORTED)
  2361. extern PNG_EXPORT(png_uint_32,png_get_pCAL) PNGARG((png_structp png_ptr,
  2362.    png_infop info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1,
  2363.    int *type, int *nparams, png_charp *units, png_charpp *params));
  2364. #endif
  2365.  
  2366. #if defined(PNG_pCAL_SUPPORTED)
  2367. extern PNG_EXPORT(void,png_set_pCAL) PNGARG((png_structp png_ptr,
  2368.    png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1,
  2369.    int type, int nparams, png_charp units, png_charpp params));
  2370. #endif
  2371.  
  2372. #if defined(PNG_pHYs_SUPPORTED)
  2373. extern PNG_EXPORT(png_uint_32,png_get_pHYs) PNGARG((png_structp png_ptr,
  2374.    png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
  2375. #endif
  2376.  
  2377. #if defined(PNG_pHYs_SUPPORTED)
  2378. extern PNG_EXPORT(void,png_set_pHYs) PNGARG((png_structp png_ptr,
  2379.    png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
  2380. #endif
  2381.  
  2382. extern PNG_EXPORT(png_uint_32,png_get_PLTE) PNGARG((png_structp png_ptr,
  2383.    png_infop info_ptr, png_colorp *palette, int *num_palette));
  2384.  
  2385. extern PNG_EXPORT(void,png_set_PLTE) PNGARG((png_structp png_ptr,
  2386.    png_infop info_ptr, png_colorp palette, int num_palette));
  2387.  
  2388. #if defined(PNG_sBIT_SUPPORTED)
  2389. extern PNG_EXPORT(png_uint_32,png_get_sBIT) PNGARG((png_structp png_ptr,
  2390.    png_infop info_ptr, png_color_8p *sig_bit));
  2391. #endif
  2392.  
  2393. #if defined(PNG_sBIT_SUPPORTED)
  2394. extern PNG_EXPORT(void,png_set_sBIT) PNGARG((png_structp png_ptr,
  2395.    png_infop info_ptr, png_color_8p sig_bit));
  2396. #endif
  2397.  
  2398. #if defined(PNG_sRGB_SUPPORTED)
  2399. extern PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr,
  2400.    png_infop info_ptr, int *intent));
  2401. #endif
  2402.  
  2403. #if defined(PNG_sRGB_SUPPORTED)
  2404. extern PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr,
  2405.    png_infop info_ptr, int intent));
  2406. extern PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr,
  2407.    png_infop info_ptr, int intent));
  2408. #endif
  2409.  
  2410. #if defined(PNG_iCCP_SUPPORTED)
  2411. extern PNG_EXPORT(png_uint_32,png_get_iCCP) PNGARG((png_structp png_ptr,
  2412.    png_infop info_ptr, png_charpp name, int *compression_type,
  2413.    png_charpp profile, png_uint_32 *proflen));
  2414.    /* Note to maintainer: profile should be png_bytepp */
  2415. #endif
  2416.  
  2417. #if defined(PNG_iCCP_SUPPORTED)
  2418. extern PNG_EXPORT(void,png_set_iCCP) PNGARG((png_structp png_ptr,
  2419.    png_infop info_ptr, png_charp name, int compression_type,
  2420.    png_charp profile, png_uint_32 proflen));
  2421.    /* Note to maintainer: profile should be png_bytep */
  2422. #endif
  2423.  
  2424. #if defined(PNG_sPLT_SUPPORTED)
  2425. extern PNG_EXPORT(png_uint_32,png_get_sPLT) PNGARG((png_structp png_ptr,
  2426.    png_infop info_ptr, png_sPLT_tpp entries));
  2427. #endif
  2428.  
  2429. #if defined(PNG_sPLT_SUPPORTED)
  2430. extern PNG_EXPORT(void,png_set_sPLT) PNGARG((png_structp png_ptr,
  2431.    png_infop info_ptr, png_sPLT_tp entries, int nentries));
  2432. #endif
  2433.  
  2434. #if defined(PNG_TEXT_SUPPORTED)
  2435. /* png_get_text also returns the number of text chunks in *num_text */
  2436. extern PNG_EXPORT(png_uint_32,png_get_text) PNGARG((png_structp png_ptr,
  2437.    png_infop info_ptr, png_textp *text_ptr, int *num_text));
  2438. #endif
  2439.  
  2440. /*
  2441.  *  Note while png_set_text() will accept a structure whose text,
  2442.  *  language, and  translated keywords are NULL pointers, the structure
  2443.  *  returned by png_get_text will always contain regular
  2444.  *  zero-terminated C strings.  They might be empty strings but
  2445.  *  they will never be NULL pointers.
  2446.  */
  2447.  
  2448. #if defined(PNG_TEXT_SUPPORTED)
  2449. extern PNG_EXPORT(void,png_set_text) PNGARG((png_structp png_ptr,
  2450.    png_infop info_ptr, png_textp text_ptr, int num_text));
  2451. #endif
  2452.  
  2453. #if defined(PNG_tIME_SUPPORTED)
  2454. extern PNG_EXPORT(png_uint_32,png_get_tIME) PNGARG((png_structp png_ptr,
  2455.    png_infop info_ptr, png_timep *mod_time));
  2456. #endif
  2457.  
  2458. #if defined(PNG_tIME_SUPPORTED)
  2459. extern PNG_EXPORT(void,png_set_tIME) PNGARG((png_structp png_ptr,
  2460.    png_infop info_ptr, png_timep mod_time));
  2461. #endif
  2462.  
  2463. #if defined(PNG_tRNS_SUPPORTED)
  2464. extern PNG_EXPORT(png_uint_32,png_get_tRNS) PNGARG((png_structp png_ptr,
  2465.    png_infop info_ptr, png_bytep *trans, int *num_trans,
  2466.    png_color_16p *trans_values));
  2467. #endif
  2468.  
  2469. #if defined(PNG_tRNS_SUPPORTED)
  2470. extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
  2471.    png_infop info_ptr, png_bytep trans, int num_trans,
  2472.    png_color_16p trans_values));
  2473. #endif
  2474.  
  2475. #if defined(PNG_tRNS_SUPPORTED)
  2476. #endif
  2477.  
  2478. #if defined(PNG_sCAL_SUPPORTED)
  2479. #ifdef PNG_FLOATING_POINT_SUPPORTED
  2480. extern PNG_EXPORT(png_uint_32,png_get_sCAL) PNGARG((png_structp png_ptr,
  2481.    png_infop info_ptr, int *unit, double *width, double *height));
  2482. #else
  2483. #ifdef PNG_FIXED_POINT_SUPPORTED
  2484. extern PNG_EXPORT(png_uint_32,png_get_sCAL_s) PNGARG((png_structp png_ptr,
  2485.    png_infop info_ptr, int *unit, png_charpp swidth, png_charpp sheight));
  2486. #endif
  2487. #endif
  2488. #endif /* PNG_sCAL_SUPPORTED */
  2489.  
  2490. #if defined(PNG_sCAL_SUPPORTED)
  2491. #ifdef PNG_FLOATING_POINT_SUPPORTED
  2492. extern PNG_EXPORT(void,png_set_sCAL) PNGARG((png_structp png_ptr,
  2493.    png_infop info_ptr, int unit, double width, double height));
  2494. #else
  2495. #ifdef PNG_FIXED_POINT_SUPPORTED
  2496. extern PNG_EXPORT(void,png_set_sCAL_s) PNGARG((png_structp png_ptr,
  2497.    png_infop info_ptr, int unit, png_charp swidth, png_charp sheight));
  2498. #endif
  2499. #endif
  2500. #endif /* PNG_sCAL_SUPPORTED || PNG_WRITE_sCAL_SUPPORTED */
  2501.  
  2502. #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
  2503. /* provide a list of chunks and how they are to be handled, if the built-in
  2504.    handling or default unknown chunk handling is not desired.  Any chunks not
  2505.    listed will be handled in the default manner.  The IHDR and IEND chunks
  2506.    must not be listed.
  2507.       keep = 0: follow default behaviour
  2508.            = 1: do not keep
  2509.            = 2: keep only if safe-to-copy
  2510.            = 3: keep even if unsafe-to-copy
  2511. */
  2512. extern PNG_EXPORT(void, png_set_keep_unknown_chunks) PNGARG((png_structp
  2513.    png_ptr, int keep, png_bytep chunk_list, int num_chunks));
  2514. extern PNG_EXPORT(void, png_set_unknown_chunks) PNGARG((png_structp png_ptr,
  2515.    png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns));
  2516. extern PNG_EXPORT(void, png_set_unknown_chunk_location)
  2517.    PNGARG((png_structp png_ptr, png_infop info_ptr, int chunk, int location));
  2518. extern PNG_EXPORT(png_uint_32,png_get_unknown_chunks) PNGARG((png_structp
  2519.    png_ptr, png_infop info_ptr, png_unknown_chunkpp entries));
  2520. #endif
  2521. #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
  2522. PNG_EXPORT(int,png_handle_as_unknown) PNGARG((png_structp png_ptr, png_bytep
  2523.    chunk_name));
  2524. #endif
  2525.  
  2526. /* Png_free_data() will turn off the "valid" flag for anything it frees.
  2527.    If you need to turn it off for a chunk that your application has freed,
  2528.    you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); */
  2529. extern PNG_EXPORT(void, png_set_invalid) PNGARG((png_structp png_ptr,
  2530.    png_infop info_ptr, int mask));
  2531.  
  2532. #if defined(PNG_INFO_IMAGE_SUPPORTED)
  2533. /* The "params" pointer is currently not used and is for future expansion. */
  2534. extern PNG_EXPORT(void, png_read_png) PNGARG((png_structp png_ptr,
  2535.                         png_infop info_ptr,
  2536.                         int transforms,
  2537.                         png_voidp params));
  2538. extern PNG_EXPORT(void, png_write_png) PNGARG((png_structp png_ptr,
  2539.                         png_infop info_ptr,
  2540.                         int transforms,
  2541.                         png_voidp params));
  2542. #endif
  2543.  
  2544. /* Define PNG_DEBUG at compile time for debugging information.  Higher
  2545.  * numbers for PNG_DEBUG mean more debugging information.  This has
  2546.  * only been added since version 0.95 so it is not implemented throughout
  2547.  * libpng yet, but more support will be added as needed.
  2548.  */
  2549. #ifdef PNG_DEBUG
  2550. #if (PNG_DEBUG > 0)
  2551. #if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER)
  2552. #include <crtdbg.h>
  2553. #if (PNG_DEBUG > 1)
  2554. #ifndef _DEBUG
  2555. #  define _DEBUG
  2556. #endif
  2557. #ifndef png_debug
  2558. #define png_debug(l,m)  _RPT0(_CRT_WARN,m PNG_STRING_NEWLINE)
  2559. #endif
  2560. #ifndef png_debug1
  2561. #define png_debug1(l,m,p1)  _RPT1(_CRT_WARN,m PNG_STRING_NEWLINE,p1)
  2562. #endif
  2563. #ifndef png_debug2
  2564. #define png_debug2(l,m,p1,p2) _RPT2(_CRT_WARN,m PNG_STRING_NEWLINE,p1,p2)
  2565. #endif
  2566. #endif
  2567. #else /* PNG_DEBUG_FILE || !_MSC_VER */
  2568. #ifndef PNG_DEBUG_FILE
  2569. #define PNG_DEBUG_FILE stderr
  2570. #endif /* PNG_DEBUG_FILE */
  2571.  
  2572. #if (PNG_DEBUG > 1)
  2573. /* Note: ["%s"m PNG_STRING_NEWLINE] probably does not work on
  2574.  * non-ISO compilers */
  2575. #  ifdef __STDC__
  2576. #    ifndef png_debug
  2577. #      define png_debug(l,m) \
  2578.        { \
  2579.        int num_tabs=l; \
  2580.        fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
  2581.          (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":"")))); \
  2582.        }
  2583. #    endif
  2584. #    ifndef png_debug1
  2585. #      define png_debug1(l,m,p1) \
  2586.        { \
  2587.        int num_tabs=l; \
  2588.        fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
  2589.          (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1); \
  2590.        }
  2591. #    endif
  2592. #    ifndef png_debug2
  2593. #      define png_debug2(l,m,p1,p2) \
  2594.        { \
  2595.        int num_tabs=l; \
  2596.        fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
  2597.          (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1,p2); \
  2598.        }
  2599. #    endif
  2600. #  else /* __STDC __ */
  2601. #    ifndef png_debug
  2602. #      define png_debug(l,m) \
  2603.        { \
  2604.        int num_tabs=l; \
  2605.        char format[256]; \
  2606.        snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
  2607.          (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
  2608.          m,PNG_STRING_NEWLINE); \
  2609.        fprintf(PNG_DEBUG_FILE,format); \
  2610.        }
  2611. #    endif
  2612. #    ifndef png_debug1
  2613. #      define png_debug1(l,m,p1) \
  2614.        { \
  2615.        int num_tabs=l; \
  2616.        char format[256]; \
  2617.        snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
  2618.          (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
  2619.          m,PNG_STRING_NEWLINE); \
  2620.        fprintf(PNG_DEBUG_FILE,format,p1); \
  2621.        }
  2622. #    endif
  2623. #    ifndef png_debug2
  2624. #      define png_debug2(l,m,p1,p2) \
  2625.        { \
  2626.        int num_tabs=l; \
  2627.        char format[256]; \
  2628.        snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
  2629.          (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
  2630.          m,PNG_STRING_NEWLINE); \
  2631.        fprintf(PNG_DEBUG_FILE,format,p1,p2); \
  2632.        }
  2633. #    endif
  2634. #  endif /* __STDC __ */
  2635. #endif /* (PNG_DEBUG > 1) */
  2636.  
  2637. #endif /* _MSC_VER */
  2638. #endif /* (PNG_DEBUG > 0) */
  2639. #endif /* PNG_DEBUG */
  2640. #ifndef png_debug
  2641. #define png_debug(l, m)
  2642. #endif
  2643. #ifndef png_debug1
  2644. #define png_debug1(l, m, p1)
  2645. #endif
  2646. #ifndef png_debug2
  2647. #define png_debug2(l, m, p1, p2)
  2648. #endif
  2649.  
  2650. extern PNG_EXPORT(png_charp,png_get_copyright) PNGARG((png_structp png_ptr));
  2651. extern PNG_EXPORT(png_charp,png_get_header_ver) PNGARG((png_structp png_ptr));
  2652. extern PNG_EXPORT(png_charp,png_get_header_version) PNGARG((png_structp png_ptr));
  2653. extern PNG_EXPORT(png_charp,png_get_libpng_ver) PNGARG((png_structp png_ptr));
  2654.  
  2655. #ifdef PNG_MNG_FEATURES_SUPPORTED
  2656. extern PNG_EXPORT(png_uint_32,png_permit_mng_features) PNGARG((png_structp
  2657.    png_ptr, png_uint_32 mng_features_permitted));
  2658. #endif
  2659.  
  2660. /* For use in png_set_keep_unknown, added to version 1.2.6 */
  2661. #define PNG_HANDLE_CHUNK_AS_DEFAULT   0
  2662. #define PNG_HANDLE_CHUNK_NEVER        1
  2663. #define PNG_HANDLE_CHUNK_IF_SAFE      2
  2664. #define PNG_HANDLE_CHUNK_ALWAYS       3
  2665.  
  2666. /* Added to version 1.2.0 */
  2667. #if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
  2668. #if defined(PNG_MMX_CODE_SUPPORTED)
  2669. #define PNG_ASM_FLAG_MMX_SUPPORT_COMPILED  0x01  /* not user-settable */
  2670. #define PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU    0x02  /* not user-settable */
  2671. #define PNG_ASM_FLAG_MMX_READ_COMBINE_ROW  0x04
  2672. #define PNG_ASM_FLAG_MMX_READ_INTERLACE    0x08
  2673. #define PNG_ASM_FLAG_MMX_READ_FILTER_SUB   0x10
  2674. #define PNG_ASM_FLAG_MMX_READ_FILTER_UP    0x20
  2675. #define PNG_ASM_FLAG_MMX_READ_FILTER_AVG   0x40
  2676. #define PNG_ASM_FLAG_MMX_READ_FILTER_PAETH 0x80
  2677. #define PNG_ASM_FLAGS_INITIALIZED          0x80000000  /* not user-settable */
  2678.  
  2679. #define PNG_MMX_READ_FLAGS ( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW  \
  2680.                            | PNG_ASM_FLAG_MMX_READ_INTERLACE    \
  2681.                            | PNG_ASM_FLAG_MMX_READ_FILTER_SUB   \
  2682.                            | PNG_ASM_FLAG_MMX_READ_FILTER_UP    \
  2683.                            | PNG_ASM_FLAG_MMX_READ_FILTER_AVG   \
  2684.                            | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH )
  2685. #define PNG_MMX_WRITE_FLAGS ( 0 )
  2686.  
  2687. #define PNG_MMX_FLAGS ( PNG_ASM_FLAG_MMX_SUPPORT_COMPILED \
  2688.                       | PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU   \
  2689.                       | PNG_MMX_READ_FLAGS                \
  2690.                       | PNG_MMX_WRITE_FLAGS )
  2691.  
  2692. #define PNG_SELECT_READ   1
  2693. #define PNG_SELECT_WRITE  2
  2694. #endif /* PNG_MMX_CODE_SUPPORTED */
  2695.  
  2696. #if !defined(PNG_1_0_X)
  2697. /* pngget.c */
  2698. extern PNG_EXPORT(png_uint_32,png_get_mmx_flagmask)
  2699.    PNGARG((int flag_select, int *compilerID));
  2700.  
  2701. /* pngget.c */
  2702. extern PNG_EXPORT(png_uint_32,png_get_asm_flagmask)
  2703.    PNGARG((int flag_select));
  2704.  
  2705. /* pngget.c */
  2706. extern PNG_EXPORT(png_uint_32,png_get_asm_flags)
  2707.    PNGARG((png_structp png_ptr));
  2708.  
  2709. /* pngget.c */
  2710. extern PNG_EXPORT(png_byte,png_get_mmx_bitdepth_threshold)
  2711.    PNGARG((png_structp png_ptr));
  2712.  
  2713. /* pngget.c */
  2714. extern PNG_EXPORT(png_uint_32,png_get_mmx_rowbytes_threshold)
  2715.    PNGARG((png_structp png_ptr));
  2716.  
  2717. /* pngset.c */
  2718. extern PNG_EXPORT(void,png_set_asm_flags)
  2719.    PNGARG((png_structp png_ptr, png_uint_32 asm_flags));
  2720.  
  2721. /* pngset.c */
  2722. extern PNG_EXPORT(void,png_set_mmx_thresholds)
  2723.    PNGARG((png_structp png_ptr, png_byte mmx_bitdepth_threshold,
  2724.    png_uint_32 mmx_rowbytes_threshold));
  2725.  
  2726. #endif /* PNG_1_0_X */
  2727.  
  2728. #if !defined(PNG_1_0_X)
  2729. /* png.c, pnggccrd.c, or pngvcrd.c */
  2730. extern PNG_EXPORT(int,png_mmx_support) PNGARG((void));
  2731. #endif /* PNG_1_0_X */
  2732. #endif /* PNG_ASSEMBLER_CODE_SUPPORTED */
  2733.  
  2734. /* Strip the prepended error numbers ("#nnn ") from error and warning
  2735.  * messages before passing them to the error or warning handler. */
  2736. #ifdef PNG_ERROR_NUMBERS_SUPPORTED
  2737. extern PNG_EXPORT(void,png_set_strip_error_numbers) PNGARG((png_structp
  2738.    png_ptr, png_uint_32 strip_mode));
  2739. #endif
  2740.  
  2741. /* Added at libpng-1.2.6 */
  2742. #ifdef PNG_SET_USER_LIMITS_SUPPORTED
  2743. extern PNG_EXPORT(void,png_set_user_limits) PNGARG((png_structp
  2744.    png_ptr, png_uint_32 user_width_max, png_uint_32 user_height_max));
  2745. extern PNG_EXPORT(png_uint_32,png_get_user_width_max) PNGARG((png_structp
  2746.    png_ptr));
  2747. extern PNG_EXPORT(png_uint_32,png_get_user_height_max) PNGARG((png_structp
  2748.    png_ptr));
  2749. #endif
  2750.  
  2751.  
  2752. /* Maintainer: Put new public prototypes here ^, in libpng.3, and project defs */
  2753.  
  2754. #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
  2755. /* With these routines we avoid an integer divide, which will be slower on
  2756.  * most machines.  However, it does take more operations than the corresponding
  2757.  * divide method, so it may be slower on a few RISC systems.  There are two
  2758.  * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
  2759.  *
  2760.  * Note that the rounding factors are NOT supposed to be the same!  128 and
  2761.  * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
  2762.  * standard method.
  2763.  *
  2764.  * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
  2765.  */
  2766.  
  2767.  /* fg and bg should be in `gamma 1.0' space; alpha is the opacity          */
  2768.  
  2769. #  define png_composite(composite, fg, alpha, bg)                            \
  2770.      { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) * (png_uint_16)(alpha) \
  2771.                         +        (png_uint_16)(bg)*(png_uint_16)(255 -       \
  2772.                         (png_uint_16)(alpha)) + (png_uint_16)128);           \
  2773.        (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
  2774.  
  2775. #  define png_composite_16(composite, fg, alpha, bg)                         \
  2776.      { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) * (png_uint_32)(alpha) \
  2777.                         + (png_uint_32)(bg)*(png_uint_32)(65535L -           \
  2778.                         (png_uint_32)(alpha)) + (png_uint_32)32768L);        \
  2779.        (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
  2780.  
  2781. #else  /* standard method using integer division */
  2782.  
  2783. #  define png_composite(composite, fg, alpha, bg)                            \
  2784.      (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) +    \
  2785.        (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) +       \
  2786.        (png_uint_16)127) / 255)
  2787.  
  2788. #  define png_composite_16(composite, fg, alpha, bg)                         \
  2789.      (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
  2790.        (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) +      \
  2791.        (png_uint_32)32767) / (png_uint_32)65535L)
  2792.  
  2793. #endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
  2794.  
  2795. /* Inline macros to do direct reads of bytes from the input buffer.  These
  2796.  * require that you are using an architecture that uses PNG byte ordering
  2797.  * (MSB first) and supports unaligned data storage.  I think that PowerPC
  2798.  * in big-endian mode and 680x0 are the only ones that will support this.
  2799.  * The x86 line of processors definitely do not.  The png_get_int_32()
  2800.  * routine also assumes we are using two's complement format for negative
  2801.  * values, which is almost certainly true.
  2802.  */
  2803. #if defined(PNG_READ_BIG_ENDIAN_SUPPORTED)
  2804. #  define png_get_uint_32(buf) ( *((png_uint_32p) (buf)))
  2805. #  define png_get_uint_16(buf) ( *((png_uint_16p) (buf)))
  2806. #  define png_get_int_32(buf)  ( *((png_int_32p)  (buf)))
  2807. #else
  2808. extern PNG_EXPORT(png_uint_32,png_get_uint_32) PNGARG((png_bytep buf));
  2809. extern PNG_EXPORT(png_uint_16,png_get_uint_16) PNGARG((png_bytep buf));
  2810. extern PNG_EXPORT(png_int_32,png_get_int_32) PNGARG((png_bytep buf));
  2811. #endif /* !PNG_READ_BIG_ENDIAN_SUPPORTED */
  2812. extern PNG_EXPORT(png_uint_32,png_get_uint_31)
  2813.   PNGARG((png_structp png_ptr, png_bytep buf));
  2814. /* No png_get_int_16 -- may be added if there's a real need for it. */
  2815.  
  2816. /* Place a 32-bit number into a buffer in PNG byte order (big-endian).
  2817.  */
  2818. extern PNG_EXPORT(void,png_save_uint_32)
  2819.    PNGARG((png_bytep buf, png_uint_32 i));
  2820. extern PNG_EXPORT(void,png_save_int_32)
  2821.    PNGARG((png_bytep buf, png_int_32 i));
  2822.  
  2823. /* Place a 16-bit number into a buffer in PNG byte order.
  2824.  * The parameter is declared unsigned int, not png_uint_16,
  2825.  * just to avoid potential problems on pre-ANSI C compilers.
  2826.  */
  2827. extern PNG_EXPORT(void,png_save_uint_16)
  2828.    PNGARG((png_bytep buf, unsigned int i));
  2829. /* No png_save_int_16 -- may be added if there's a real need for it. */
  2830.  
  2831. /* ************************************************************************* */
  2832.  
  2833. /* These next functions are used internally in the code.  They generally
  2834.  * shouldn't be used unless you are writing code to add or replace some
  2835.  * functionality in libpng.  More information about most functions can
  2836.  * be found in the files where the functions are located.
  2837.  */
  2838.  
  2839.  
  2840. /* Various modes of operation, that are visible to applications because
  2841.  * they are used for unknown chunk location.
  2842.  */
  2843. #define PNG_HAVE_IHDR               0x01
  2844. #define PNG_HAVE_PLTE               0x02
  2845. #define PNG_HAVE_IDAT               0x04
  2846. #define PNG_AFTER_IDAT              0x08 /* Have complete zlib datastream */
  2847. #define PNG_HAVE_IEND               0x10
  2848.  
  2849. #if defined(PNG_INTERNAL)
  2850.  
  2851. /* More modes of operation.  Note that after an init, mode is set to
  2852.  * zero automatically when the structure is created.
  2853.  */
  2854. #define PNG_HAVE_gAMA               0x20
  2855. #define PNG_HAVE_cHRM               0x40
  2856. #define PNG_HAVE_sRGB               0x80
  2857. #define PNG_HAVE_CHUNK_HEADER      0x100
  2858. #define PNG_WROTE_tIME             0x200
  2859. #define PNG_WROTE_INFO_BEFORE_PLTE 0x400
  2860. #define PNG_BACKGROUND_IS_GRAY     0x800
  2861. #define PNG_HAVE_PNG_SIGNATURE    0x1000
  2862. #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
  2863.  
  2864. /* flags for the transformations the PNG library does on the image data */
  2865. #define PNG_BGR                0x0001
  2866. #define PNG_INTERLACE          0x0002
  2867. #define PNG_PACK               0x0004
  2868. #define PNG_SHIFT              0x0008
  2869. #define PNG_SWAP_BYTES         0x0010
  2870. #define PNG_INVERT_MONO        0x0020
  2871. #define PNG_DITHER             0x0040
  2872. #define PNG_BACKGROUND         0x0080
  2873. #define PNG_BACKGROUND_EXPAND  0x0100
  2874.                           /*   0x0200 unused */
  2875. #define PNG_16_TO_8            0x0400
  2876. #define PNG_RGBA               0x0800
  2877. #define PNG_EXPAND             0x1000
  2878. #define PNG_GAMMA              0x2000
  2879. #define PNG_GRAY_TO_RGB        0x4000
  2880. #define PNG_FILLER             0x8000L
  2881. #define PNG_PACKSWAP          0x10000L
  2882. #define PNG_SWAP_ALPHA        0x20000L
  2883. #define PNG_STRIP_ALPHA       0x40000L
  2884. #define PNG_INVERT_ALPHA      0x80000L
  2885. #define PNG_USER_TRANSFORM   0x100000L
  2886. #define PNG_RGB_TO_GRAY_ERR  0x200000L
  2887. #define PNG_RGB_TO_GRAY_WARN 0x400000L
  2888. #define PNG_RGB_TO_GRAY      0x600000L  /* two bits, RGB_TO_GRAY_ERR|WARN */
  2889.                        /*    0x800000L     Unused */
  2890. #define PNG_ADD_ALPHA       0x1000000L  /* Added to libpng-1.2.7 */
  2891. #define PNG_EXPAND_tRNS     0x2000000L  /* Added to libpng-1.2.9 */
  2892.                        /*   0x4000000L  unused */
  2893.                        /*   0x8000000L  unused */
  2894.                        /*  0x10000000L  unused */
  2895.                        /*  0x20000000L  unused */
  2896.                        /*  0x40000000L  unused */
  2897.  
  2898. /* flags for png_create_struct */
  2899. #define PNG_STRUCT_PNG   0x0001
  2900. #define PNG_STRUCT_INFO  0x0002
  2901.  
  2902. /* Scaling factor for filter heuristic weighting calculations */
  2903. #define PNG_WEIGHT_SHIFT 8
  2904. #define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
  2905. #define PNG_COST_SHIFT 3
  2906. #define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
  2907.  
  2908. /* flags for the png_ptr->flags rather than declaring a byte for each one */
  2909. #define PNG_FLAG_ZLIB_CUSTOM_STRATEGY     0x0001
  2910. #define PNG_FLAG_ZLIB_CUSTOM_LEVEL        0x0002
  2911. #define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL    0x0004
  2912. #define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS  0x0008
  2913. #define PNG_FLAG_ZLIB_CUSTOM_METHOD       0x0010
  2914. #define PNG_FLAG_ZLIB_FINISHED            0x0020
  2915. #define PNG_FLAG_ROW_INIT                 0x0040
  2916. #define PNG_FLAG_FILLER_AFTER             0x0080
  2917. #define PNG_FLAG_CRC_ANCILLARY_USE        0x0100
  2918. #define PNG_FLAG_CRC_ANCILLARY_NOWARN     0x0200
  2919. #define PNG_FLAG_CRC_CRITICAL_USE         0x0400
  2920. #define PNG_FLAG_CRC_CRITICAL_IGNORE      0x0800
  2921. #define PNG_FLAG_FREE_PLTE                0x1000
  2922. #define PNG_FLAG_FREE_TRNS                0x2000
  2923. #define PNG_FLAG_FREE_HIST                0x4000
  2924. #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS      0x8000L
  2925. #define PNG_FLAG_KEEP_UNSAFE_CHUNKS       0x10000L
  2926. #define PNG_FLAG_LIBRARY_MISMATCH         0x20000L
  2927. #define PNG_FLAG_STRIP_ERROR_NUMBERS      0x40000L
  2928. #define PNG_FLAG_STRIP_ERROR_TEXT         0x80000L
  2929. #define PNG_FLAG_MALLOC_NULL_MEM_OK       0x100000L
  2930. #define PNG_FLAG_ADD_ALPHA                0x200000L  /* Added to libpng-1.2.8 */
  2931. #define PNG_FLAG_STRIP_ALPHA              0x400000L  /* Added to libpng-1.2.8 */
  2932.                                   /*      0x800000L  unused */
  2933.                                   /*     0x1000000L  unused */
  2934.                                   /*     0x2000000L  unused */
  2935.                                   /*     0x4000000L  unused */
  2936.                                   /*     0x8000000L  unused */
  2937.                                   /*    0x10000000L  unused */
  2938.                                   /*    0x20000000L  unused */
  2939.                                   /*    0x40000000L  unused */
  2940.  
  2941. #define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
  2942.                                      PNG_FLAG_CRC_ANCILLARY_NOWARN)
  2943.  
  2944. #define PNG_FLAG_CRC_CRITICAL_MASK  (PNG_FLAG_CRC_CRITICAL_USE | \
  2945.                                      PNG_FLAG_CRC_CRITICAL_IGNORE)
  2946.  
  2947. #define PNG_FLAG_CRC_MASK           (PNG_FLAG_CRC_ANCILLARY_MASK | \
  2948.                                      PNG_FLAG_CRC_CRITICAL_MASK)
  2949.  
  2950. /* save typing and make code easier to understand */
  2951.  
  2952. #define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
  2953.    abs((int)((c1).green) - (int)((c2).green)) + \
  2954.    abs((int)((c1).blue) - (int)((c2).blue)))
  2955.  
  2956. /* Added to libpng-1.2.6 JB */
  2957. #define PNG_ROWBYTES(pixel_bits, width) \
  2958.     ((pixel_bits) >= 8 ? \
  2959.     ((width) * (((png_uint_32)(pixel_bits)) >> 3)) : \
  2960.     (( ((width) * ((png_uint_32)(pixel_bits))) + 7) >> 3) )
  2961.  
  2962. /* PNG_OUT_OF_RANGE returns true if value is outside the range
  2963.    ideal-delta..ideal+delta.  Each argument is evaluated twice.
  2964.    "ideal" and "delta" should be constants, normally simple
  2965.    integers, "value" a variable. Added to libpng-1.2.6 JB */
  2966. #define PNG_OUT_OF_RANGE(value, ideal, delta) \
  2967.         ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
  2968.  
  2969. /* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
  2970. #if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
  2971. /* place to hold the signature string for a PNG file. */
  2972. #ifdef PNG_USE_GLOBAL_ARRAYS
  2973.    PNG_EXPORT_VAR (PNG_CONST png_byte FARDATA) png_sig[8];
  2974. #else
  2975. #endif
  2976. #endif /* PNG_NO_EXTERN */
  2977.  
  2978. /* Constant strings for known chunk types.  If you need to add a chunk,
  2979.  * define the name here, and add an invocation of the macro in png.c and
  2980.  * wherever it's needed.
  2981.  */
  2982. #define PNG_IHDR png_byte png_IHDR[5] = { 73,  72,  68,  82, '\0'}
  2983. #define PNG_IDAT png_byte png_IDAT[5] = { 73,  68,  65,  84, '\0'}
  2984. #define PNG_IEND png_byte png_IEND[5] = { 73,  69,  78,  68, '\0'}
  2985. #define PNG_PLTE png_byte png_PLTE[5] = { 80,  76,  84,  69, '\0'}
  2986. #define PNG_bKGD png_byte png_bKGD[5] = { 98,  75,  71,  68, '\0'}
  2987. #define PNG_cHRM png_byte png_cHRM[5] = { 99,  72,  82,  77, '\0'}
  2988. #define PNG_gAMA png_byte png_gAMA[5] = {103,  65,  77,  65, '\0'}
  2989. #define PNG_hIST png_byte png_hIST[5] = {104,  73,  83,  84, '\0'}
  2990. #define PNG_iCCP png_byte png_iCCP[5] = {105,  67,  67,  80, '\0'}
  2991. #define PNG_iTXt png_byte png_iTXt[5] = {105,  84,  88, 116, '\0'}
  2992. #define PNG_oFFs png_byte png_oFFs[5] = {111,  70,  70, 115, '\0'}
  2993. #define PNG_pCAL png_byte png_pCAL[5] = {112,  67,  65,  76, '\0'}
  2994. #define PNG_sCAL png_byte png_sCAL[5] = {115,  67,  65,  76, '\0'}
  2995. #define PNG_pHYs png_byte png_pHYs[5] = {112,  72,  89, 115, '\0'}
  2996. #define PNG_sBIT png_byte png_sBIT[5] = {115,  66,  73,  84, '\0'}
  2997. #define PNG_sPLT png_byte png_sPLT[5] = {115,  80,  76,  84, '\0'}
  2998. #define PNG_sRGB png_byte png_sRGB[5] = {115,  82,  71,  66, '\0'}
  2999. #define PNG_tEXt png_byte png_tEXt[5] = {116,  69,  88, 116, '\0'}
  3000. #define PNG_tIME png_byte png_tIME[5] = {116,  73,  77,  69, '\0'}
  3001. #define PNG_tRNS png_byte png_tRNS[5] = {116,  82,  78,  83, '\0'}
  3002. #define PNG_zTXt png_byte png_zTXt[5] = {122,  84,  88, 116, '\0'}
  3003.  
  3004. #ifdef PNG_USE_GLOBAL_ARRAYS
  3005. PNG_EXPORT_VAR (png_byte FARDATA) png_IHDR[5];
  3006. PNG_EXPORT_VAR (png_byte FARDATA) png_IDAT[5];
  3007. PNG_EXPORT_VAR (png_byte FARDATA) png_IEND[5];
  3008. PNG_EXPORT_VAR (png_byte FARDATA) png_PLTE[5];
  3009. PNG_EXPORT_VAR (png_byte FARDATA) png_bKGD[5];
  3010. PNG_EXPORT_VAR (png_byte FARDATA) png_cHRM[5];
  3011. PNG_EXPORT_VAR (png_byte FARDATA) png_gAMA[5];
  3012. PNG_EXPORT_VAR (png_byte FARDATA) png_hIST[5];
  3013. PNG_EXPORT_VAR (png_byte FARDATA) png_iCCP[5];
  3014. PNG_EXPORT_VAR (png_byte FARDATA) png_iTXt[5];
  3015. PNG_EXPORT_VAR (png_byte FARDATA) png_oFFs[5];
  3016. PNG_EXPORT_VAR (png_byte FARDATA) png_pCAL[5];
  3017. PNG_EXPORT_VAR (png_byte FARDATA) png_sCAL[5];
  3018. PNG_EXPORT_VAR (png_byte FARDATA) png_pHYs[5];
  3019. PNG_EXPORT_VAR (png_byte FARDATA) png_sBIT[5];
  3020. PNG_EXPORT_VAR (png_byte FARDATA) png_sPLT[5];
  3021. PNG_EXPORT_VAR (png_byte FARDATA) png_sRGB[5];
  3022. PNG_EXPORT_VAR (png_byte FARDATA) png_tEXt[5];
  3023. PNG_EXPORT_VAR (png_byte FARDATA) png_tIME[5];
  3024. PNG_EXPORT_VAR (png_byte FARDATA) png_tRNS[5];
  3025. PNG_EXPORT_VAR (png_byte FARDATA) png_zTXt[5];
  3026. #endif /* PNG_USE_GLOBAL_ARRAYS */
  3027.  
  3028. #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
  3029. /* Initialize png_ptr struct for reading, and allocate any other memory.
  3030.  * (old interface - DEPRECATED - use png_create_read_struct instead).
  3031.  */
  3032. extern PNG_EXPORT(void,png_read_init) PNGARG((png_structp png_ptr));
  3033. #undef png_read_init
  3034. #define png_read_init(png_ptr) png_read_init_3(&png_ptr, \
  3035.     PNG_LIBPNG_VER_STRING,  png_sizeof(png_struct));
  3036. #endif
  3037.  
  3038. extern PNG_EXPORT(void,png_read_init_3) PNGARG((png_structpp ptr_ptr,
  3039.     png_const_charp user_png_ver, png_size_t png_struct_size));
  3040. #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
  3041. extern PNG_EXPORT(void,png_read_init_2) PNGARG((png_structp png_ptr,
  3042.     png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
  3043.     png_info_size));
  3044. #endif
  3045.  
  3046. #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
  3047. /* Initialize png_ptr struct for writing, and allocate any other memory.
  3048.  * (old interface - DEPRECATED - use png_create_write_struct instead).
  3049.  */
  3050. extern PNG_EXPORT(void,png_write_init) PNGARG((png_structp png_ptr));
  3051. #undef png_write_init
  3052. #define png_write_init(png_ptr) png_write_init_3(&png_ptr, \
  3053.     PNG_LIBPNG_VER_STRING, png_sizeof(png_struct));
  3054. #endif
  3055.  
  3056. extern PNG_EXPORT(void,png_write_init_3) PNGARG((png_structpp ptr_ptr,
  3057.     png_const_charp user_png_ver, png_size_t png_struct_size));
  3058. extern PNG_EXPORT(void,png_write_init_2) PNGARG((png_structp png_ptr,
  3059.     png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
  3060.     png_info_size));
  3061.  
  3062. /* Allocate memory for an internal libpng struct */
  3063. PNG_EXTERN png_voidp png_create_struct PNGARG((int type));
  3064.  
  3065. /* Free memory from internal libpng struct */
  3066. PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr));
  3067.  
  3068. PNG_EXTERN png_voidp png_create_struct_2 PNGARG((int type, png_malloc_ptr
  3069.   malloc_fn, png_voidp mem_ptr));
  3070. PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr,
  3071.    png_free_ptr free_fn, png_voidp mem_ptr));
  3072.  
  3073. /* Free any memory that info_ptr points to and reset struct. */
  3074. PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr,
  3075.    png_infop info_ptr));
  3076.  
  3077. #ifndef PNG_1_0_X
  3078. /* Function to allocate memory for zlib. */
  3079. PNG_EXTERN voidpf png_zalloc PNGARG((voidpf png_ptr, uInt items, uInt size));
  3080.  
  3081. /* Function to free memory for zlib */
  3082. PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr));
  3083.  
  3084. #ifdef PNG_SIZE_T
  3085. /* Function to convert a sizeof an item to png_sizeof item */
  3086.    PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size));
  3087. #endif
  3088.  
  3089. /* Next four functions are used internally as callbacks.  PNGAPI is required
  3090.  * but not PNG_EXPORT.  PNGAPI added at libpng version 1.2.3. */
  3091.  
  3092. PNG_EXTERN void PNGAPI png_default_read_data PNGARG((png_structp png_ptr,
  3093.    png_bytep data, png_size_t length));
  3094.  
  3095. #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
  3096. PNG_EXTERN void PNGAPI png_push_fill_buffer PNGARG((png_structp png_ptr,
  3097.    png_bytep buffer, png_size_t length));
  3098. #endif
  3099.  
  3100. PNG_EXTERN void PNGAPI png_default_write_data PNGARG((png_structp png_ptr,
  3101.    png_bytep data, png_size_t length));
  3102.  
  3103. #if defined(PNG_WRITE_FLUSH_SUPPORTED)
  3104. #if !defined(PNG_NO_STDIO)
  3105. PNG_EXTERN void PNGAPI png_default_flush PNGARG((png_structp png_ptr));
  3106. #endif
  3107. #endif
  3108. #else /* PNG_1_0_X */
  3109. #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
  3110. PNG_EXTERN void png_push_fill_buffer PNGARG((png_structp png_ptr,
  3111.    png_bytep buffer, png_size_t length));
  3112. #endif
  3113. #endif /* PNG_1_0_X */
  3114.  
  3115. /* Reset the CRC variable */
  3116. PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr));
  3117.  
  3118. /* Write the "data" buffer to whatever output you are using. */
  3119. PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr, png_bytep data,
  3120.    png_size_t length));
  3121.  
  3122. /* Read data from whatever input you are using into the "data" buffer */
  3123. PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data,
  3124.    png_size_t length));
  3125.  
  3126. /* Read bytes into buf, and update png_ptr->crc */
  3127. PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
  3128.    png_size_t length));
  3129.  
  3130. /* Decompress data in a chunk that uses compression */
  3131. #if defined(PNG_zTXt_SUPPORTED) || defined(PNG_iTXt_SUPPORTED) || \
  3132.     defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED)
  3133. PNG_EXTERN void png_decompress_chunk PNGARG((png_structp png_ptr,
  3134.    int comp_type, png_size_t chunklength,
  3135.    png_size_t prefix_length, png_size_t *data_length));
  3136. #endif
  3137.  
  3138. /* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
  3139. PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip));
  3140.  
  3141. /* Read the CRC from the file and compare it to the libpng calculated CRC */
  3142. PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr));
  3143.  
  3144. /* Calculate the CRC over a section of data.  Note that we are only
  3145.  * passing a maximum of 64K on systems that have this as a memory limit,
  3146.  * since this is the maximum buffer size we can specify.
  3147.  */
  3148. PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr, png_bytep ptr,
  3149.    png_size_t length));
  3150.  
  3151. #if defined(PNG_WRITE_FLUSH_SUPPORTED)
  3152. PNG_EXTERN void png_flush PNGARG((png_structp png_ptr));
  3153. #endif
  3154.  
  3155. /* simple function to write the signature */
  3156. PNG_EXTERN void png_write_sig PNGARG((png_structp png_ptr));
  3157.  
  3158. /* write various chunks */
  3159.  
  3160. /* Write the IHDR chunk, and update the png_struct with the necessary
  3161.  * information.
  3162.  */
  3163. PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width,
  3164.    png_uint_32 height,
  3165.    int bit_depth, int color_type, int compression_method, int filter_method,
  3166.    int interlace_method));
  3167.  
  3168. PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr, png_colorp palette,
  3169.    png_uint_32 num_pal));
  3170.  
  3171. PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data,
  3172.    png_size_t length));
  3173.  
  3174. PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr));
  3175.  
  3176. #if defined(PNG_WRITE_gAMA_SUPPORTED)
  3177. #ifdef PNG_FLOATING_POINT_SUPPORTED
  3178. PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma));
  3179. #endif
  3180. #ifdef PNG_FIXED_POINT_SUPPORTED
  3181. PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr, png_fixed_point
  3182.     file_gamma));
  3183. #endif
  3184. #endif
  3185.  
  3186. #if defined(PNG_WRITE_sBIT_SUPPORTED)
  3187. PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr, png_color_8p sbit,
  3188.    int color_type));
  3189. #endif
  3190.  
  3191. #if defined(PNG_WRITE_cHRM_SUPPORTED)
  3192. #ifdef PNG_FLOATING_POINT_SUPPORTED
  3193. PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr,
  3194.    double white_x, double white_y,
  3195.    double red_x, double red_y, double green_x, double green_y,
  3196.    double blue_x, double blue_y));
  3197. #endif
  3198. #ifdef PNG_FIXED_POINT_SUPPORTED
  3199. PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr,
  3200.    png_fixed_point int_white_x, png_fixed_point int_white_y,
  3201.    png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
  3202.    int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
  3203.    png_fixed_point int_blue_y));
  3204. #endif
  3205. #endif
  3206.  
  3207. #if defined(PNG_WRITE_sRGB_SUPPORTED)
  3208. PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
  3209.    int intent));
  3210. #endif
  3211.  
  3212. #if defined(PNG_WRITE_iCCP_SUPPORTED)
  3213. PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr,
  3214.    png_charp name, int compression_type,
  3215.    png_charp profile, int proflen));
  3216.    /* Note to maintainer: profile should be png_bytep */
  3217. #endif
  3218.  
  3219. #if defined(PNG_WRITE_sPLT_SUPPORTED)
  3220. PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr,
  3221.    png_sPLT_tp palette));
  3222. #endif
  3223.  
  3224. #if defined(PNG_WRITE_tRNS_SUPPORTED)
  3225. PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr, png_bytep trans,
  3226.    png_color_16p values, int number, int color_type));
  3227. #endif
  3228.  
  3229. #if defined(PNG_WRITE_bKGD_SUPPORTED)
  3230. PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr,
  3231.    png_color_16p values, int color_type));
  3232. #endif
  3233.  
  3234. #if defined(PNG_WRITE_hIST_SUPPORTED)
  3235. PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, png_uint_16p hist,
  3236.    int num_hist));
  3237. #endif
  3238.  
  3239. #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
  3240.     defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
  3241. PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
  3242.    png_charp key, png_charpp new_key));
  3243. #endif
  3244.  
  3245. #if defined(PNG_WRITE_tEXt_SUPPORTED)
  3246. PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_charp key,
  3247.    png_charp text, png_size_t text_len));
  3248. #endif
  3249.  
  3250. #if defined(PNG_WRITE_zTXt_SUPPORTED)
  3251. PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_charp key,
  3252.    png_charp text, png_size_t text_len, int compression));
  3253. #endif
  3254.  
  3255. #if defined(PNG_WRITE_iTXt_SUPPORTED)
  3256. PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr,
  3257.    int compression, png_charp key, png_charp lang, png_charp lang_key,
  3258.    png_charp text));
  3259. #endif
  3260.  
  3261. #if defined(PNG_TEXT_SUPPORTED)  /* Added at version 1.0.14 and 1.2.4 */
  3262. PNG_EXTERN int png_set_text_2 PNGARG((png_structp png_ptr,
  3263.    png_infop info_ptr, png_textp text_ptr, int num_text));
  3264. #endif
  3265.  
  3266. #if defined(PNG_WRITE_oFFs_SUPPORTED)
  3267. PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr,
  3268.    png_int_32 x_offset, png_int_32 y_offset, int unit_type));
  3269. #endif
  3270.  
  3271. #if defined(PNG_WRITE_pCAL_SUPPORTED)
  3272. PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose,
  3273.    png_int_32 X0, png_int_32 X1, int type, int nparams,
  3274.    png_charp units, png_charpp params));
  3275. #endif
  3276.  
  3277. #if defined(PNG_WRITE_pHYs_SUPPORTED)
  3278. PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr,
  3279.    png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
  3280.    int unit_type));
  3281. #endif
  3282.  
  3283. #if defined(PNG_WRITE_tIME_SUPPORTED)
  3284. PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr,
  3285.    png_timep mod_time));
  3286. #endif
  3287.  
  3288. #if defined(PNG_WRITE_sCAL_SUPPORTED)
  3289. #if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
  3290. PNG_EXTERN void png_write_sCAL PNGARG((png_structp png_ptr,
  3291.    int unit, double width, double height));
  3292. #else
  3293. #ifdef PNG_FIXED_POINT_SUPPORTED
  3294. PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr,
  3295.    int unit, png_charp width, png_charp height));
  3296. #endif
  3297. #endif
  3298. #endif
  3299.  
  3300. /* Called when finished processing a row of data */
  3301. PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr));
  3302.  
  3303. /* Internal use only.   Called before first row of data */
  3304. PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr));
  3305.  
  3306. #if defined(PNG_READ_GAMMA_SUPPORTED)
  3307. PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr));
  3308. #endif
  3309.  
  3310. /* combine a row of data, dealing with alpha, etc. if requested */
  3311. PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row,
  3312.    int mask));
  3313.  
  3314. #if defined(PNG_READ_INTERLACING_SUPPORTED)
  3315. /* expand an interlaced row */
  3316. /* OLD pre-1.0.9 interface:
  3317. PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info,
  3318.    png_bytep row, int pass, png_uint_32 transformations));
  3319.  */
  3320. PNG_EXTERN void png_do_read_interlace PNGARG((png_structp png_ptr));
  3321. #endif
  3322.  
  3323. /* GRR TO DO (2.0 or whenever):  simplify other internal calling interfaces */
  3324.  
  3325. #if defined(PNG_WRITE_INTERLACING_SUPPORTED)
  3326. /* grab pixels out of a row for an interlaced pass */
  3327. PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info,
  3328.    png_bytep row, int pass));
  3329. #endif
  3330.  
  3331. /* unfilter a row */
  3332. PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr,
  3333.    png_row_infop row_info, png_bytep row, png_bytep prev_row, int filter));
  3334.  
  3335. /* Choose the best filter to use and filter the row data */
  3336. PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
  3337.    png_row_infop row_info));
  3338.  
  3339. /* Write out the filtered row. */
  3340. PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr,
  3341.    png_bytep filtered_row));
  3342. /* finish a row while reading, dealing with interlacing passes, etc. */
  3343. PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
  3344.  
  3345. /* initialize the row buffers, etc. */
  3346. PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr));
  3347. /* optional call to update the users info structure */
  3348. PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
  3349.    png_infop info_ptr));
  3350.  
  3351. /* these are the functions that do the transformations */
  3352. #if defined(PNG_READ_FILLER_SUPPORTED)
  3353. PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info,
  3354.    png_bytep row, png_uint_32 filler, png_uint_32 flags));
  3355. #endif
  3356.  
  3357. #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
  3358. PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info,
  3359.    png_bytep row));
  3360. #endif
  3361.  
  3362. #if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
  3363. PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info,
  3364.    png_bytep row));
  3365. #endif
  3366.  
  3367. #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
  3368. PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info,
  3369.    png_bytep row));
  3370. #endif
  3371.  
  3372. #if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
  3373. PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info,
  3374.    png_bytep row));
  3375. #endif
  3376.  
  3377. #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
  3378.     defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
  3379. PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info,
  3380.    png_bytep row, png_uint_32 flags));
  3381. #endif
  3382.  
  3383. #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
  3384. PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info, png_bytep row));
  3385. #endif
  3386.  
  3387. #if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
  3388. PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info, png_bytep row));
  3389. #endif
  3390.  
  3391. #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
  3392. PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr, png_row_infop
  3393.    row_info, png_bytep row));
  3394. #endif
  3395.  
  3396. #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
  3397. PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info,
  3398.    png_bytep row));
  3399. #endif
  3400.  
  3401. #if defined(PNG_READ_PACK_SUPPORTED)
  3402. PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info, png_bytep row));
  3403. #endif
  3404.  
  3405. #if defined(PNG_READ_SHIFT_SUPPORTED)
  3406. PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info, png_bytep row,
  3407.    png_color_8p sig_bits));
  3408. #endif
  3409.  
  3410. #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
  3411. PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info, png_bytep row));
  3412. #endif
  3413.  
  3414. #if defined(PNG_READ_16_TO_8_SUPPORTED)
  3415. PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info, png_bytep row));
  3416. #endif
  3417.  
  3418. #if defined(PNG_READ_DITHER_SUPPORTED)
  3419. PNG_EXTERN void png_do_dither PNGARG((png_row_infop row_info,
  3420.    png_bytep row, png_bytep palette_lookup, png_bytep dither_lookup));
  3421.  
  3422. #  if defined(PNG_CORRECT_PALETTE_SUPPORTED)
  3423. PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr,
  3424.    png_colorp palette, int num_palette));
  3425. #  endif
  3426. #endif
  3427.  
  3428. #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
  3429. PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info, png_bytep row));
  3430. #endif
  3431.  
  3432. #if defined(PNG_WRITE_PACK_SUPPORTED)
  3433. PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info,
  3434.    png_bytep row, png_uint_32 bit_depth));
  3435. #endif
  3436.  
  3437. #if defined(PNG_WRITE_SHIFT_SUPPORTED)
  3438. PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info, png_bytep row,
  3439.    png_color_8p bit_depth));
  3440. #endif
  3441.  
  3442. #if defined(PNG_READ_BACKGROUND_SUPPORTED)
  3443. #if defined(PNG_READ_GAMMA_SUPPORTED)
  3444. PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
  3445.    png_color_16p trans_values, png_color_16p background,
  3446.    png_color_16p background_1,
  3447.    png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,
  3448.    png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,
  3449.    png_uint_16pp gamma_16_to_1, int gamma_shift));
  3450. #else
  3451. PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
  3452.    png_color_16p trans_values, png_color_16p background));
  3453. #endif
  3454. #endif
  3455.  
  3456. #if defined(PNG_READ_GAMMA_SUPPORTED)
  3457. PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info, png_bytep row,
  3458.    png_bytep gamma_table, png_uint_16pp gamma_16_table,
  3459.    int gamma_shift));
  3460. #endif
  3461.  
  3462. #if defined(PNG_READ_EXPAND_SUPPORTED)
  3463. PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info,
  3464.    png_bytep row, png_colorp palette, png_bytep trans, int num_trans));
  3465. PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info,
  3466.    png_bytep row, png_color_16p trans_value));
  3467. #endif
  3468.  
  3469. /* The following decodes the appropriate chunks, and does error correction,
  3470.  * then calls the appropriate callback for the chunk if it is valid.
  3471.  */
  3472.  
  3473. /* decode the IHDR chunk */
  3474. PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr,
  3475.    png_uint_32 length));
  3476. PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr,
  3477.    png_uint_32 length));
  3478. PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr,
  3479.    png_uint_32 length));
  3480.  
  3481. #if defined(PNG_READ_bKGD_SUPPORTED)
  3482. PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr,
  3483.    png_uint_32 length));
  3484. #endif
  3485.  
  3486. #if defined(PNG_READ_cHRM_SUPPORTED)
  3487. PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr,
  3488.    png_uint_32 length));
  3489. #endif
  3490.  
  3491. #if defined(PNG_READ_gAMA_SUPPORTED)
  3492. PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr,
  3493.    png_uint_32 length));
  3494. #endif
  3495.  
  3496. #if defined(PNG_READ_hIST_SUPPORTED)
  3497. PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr,
  3498.    png_uint_32 length));
  3499. #endif
  3500.  
  3501. #if defined(PNG_READ_iCCP_SUPPORTED)
  3502. extern void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr,
  3503.    png_uint_32 length));
  3504. #endif /* PNG_READ_iCCP_SUPPORTED */
  3505.  
  3506. #if defined(PNG_READ_iTXt_SUPPORTED)
  3507. PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
  3508.    png_uint_32 length));
  3509. #endif
  3510.  
  3511. #if defined(PNG_READ_oFFs_SUPPORTED)
  3512. PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr,
  3513.    png_uint_32 length));
  3514. #endif
  3515.  
  3516. #if defined(PNG_READ_pCAL_SUPPORTED)
  3517. PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
  3518.    png_uint_32 length));
  3519. #endif
  3520.  
  3521. #if defined(PNG_READ_pHYs_SUPPORTED)
  3522. PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr,
  3523.    png_uint_32 length));
  3524. #endif
  3525.  
  3526. #if defined(PNG_READ_sBIT_SUPPORTED)
  3527. PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr,
  3528.    png_uint_32 length));
  3529. #endif
  3530.  
  3531. #if defined(PNG_READ_sCAL_SUPPORTED)
  3532. PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
  3533.    png_uint_32 length));
  3534. #endif
  3535.  
  3536. #if defined(PNG_READ_sPLT_SUPPORTED)
  3537. extern void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr,
  3538.    png_uint_32 length));
  3539. #endif /* PNG_READ_sPLT_SUPPORTED */
  3540.  
  3541. #if defined(PNG_READ_sRGB_SUPPORTED)
  3542. PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr,
  3543.    png_uint_32 length));
  3544. #endif
  3545.  
  3546. #if defined(PNG_READ_tEXt_SUPPORTED)
  3547. PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr,
  3548.    png_uint_32 length));
  3549. #endif
  3550.  
  3551. #if defined(PNG_READ_tIME_SUPPORTED)
  3552. PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr,
  3553.    png_uint_32 length));
  3554. #endif
  3555.  
  3556. #if defined(PNG_READ_tRNS_SUPPORTED)
  3557. PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr,
  3558.    png_uint_32 length));
  3559. #endif
  3560.  
  3561. #if defined(PNG_READ_zTXt_SUPPORTED)
  3562. PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
  3563.    png_uint_32 length));
  3564. #endif
  3565.  
  3566. PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
  3567.    png_infop info_ptr, png_uint_32 length));
  3568.  
  3569. PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
  3570.    png_bytep chunk_name));
  3571.  
  3572. /* handle the transformations for reading and writing */
  3573. PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr));
  3574. PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr));
  3575.  
  3576. PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr));
  3577.  
  3578. #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
  3579. PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
  3580.    png_infop info_ptr));
  3581. PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr,
  3582.    png_infop info_ptr));
  3583. PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr));
  3584. PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr,
  3585.    png_uint_32 length));
  3586. PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr));
  3587. PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr));
  3588. PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr,
  3589.    png_bytep buffer, png_size_t buffer_length));
  3590. PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr));
  3591. PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr,
  3592.    png_bytep buffer, png_size_t buffer_length));
  3593. PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr));
  3594. PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr,
  3595.    png_infop info_ptr, png_uint_32 length));
  3596. PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr,
  3597.    png_infop info_ptr));
  3598. PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr,
  3599.    png_infop info_ptr));
  3600. PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr, png_bytep row));
  3601. PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr,
  3602.    png_infop info_ptr));
  3603. PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr,
  3604.    png_infop info_ptr));
  3605. PNG_EXTERN void png_read_push_finish_row PNGARG((png_structp png_ptr));
  3606. #if defined(PNG_READ_tEXt_SUPPORTED)
  3607. PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr,
  3608.    png_infop info_ptr, png_uint_32 length));
  3609. PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr,
  3610.    png_infop info_ptr));
  3611. #endif
  3612. #if defined(PNG_READ_zTXt_SUPPORTED)
  3613. PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr,
  3614.    png_infop info_ptr, png_uint_32 length));
  3615. PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr,
  3616.    png_infop info_ptr));
  3617. #endif
  3618. #if defined(PNG_READ_iTXt_SUPPORTED)
  3619. PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr,
  3620.    png_infop info_ptr, png_uint_32 length));
  3621. PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr,
  3622.    png_infop info_ptr));
  3623. #endif
  3624.  
  3625. #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
  3626.  
  3627. #ifdef PNG_MNG_FEATURES_SUPPORTED
  3628. PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info,
  3629.    png_bytep row));
  3630. PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info,
  3631.    png_bytep row));
  3632. #endif
  3633.  
  3634. #if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
  3635. #if defined(PNG_MMX_CODE_SUPPORTED)
  3636. /* png.c */ /* PRIVATE */
  3637. PNG_EXTERN void png_init_mmx_flags PNGARG((png_structp png_ptr));
  3638. #endif
  3639. #endif
  3640.  
  3641. #if defined(PNG_INCH_CONVERSIONS) && defined(PNG_FLOATING_POINT_SUPPORTED)
  3642. PNG_EXTERN png_uint_32 png_get_pixels_per_inch PNGARG((png_structp png_ptr,
  3643. png_infop info_ptr));
  3644.  
  3645. PNG_EXTERN png_uint_32 png_get_x_pixels_per_inch PNGARG((png_structp png_ptr,
  3646. png_infop info_ptr));
  3647.  
  3648. PNG_EXTERN png_uint_32 png_get_y_pixels_per_inch PNGARG((png_structp png_ptr,
  3649. png_infop info_ptr));
  3650.  
  3651. PNG_EXTERN float png_get_x_offset_inches PNGARG((png_structp png_ptr,
  3652. png_infop info_ptr));
  3653.  
  3654. PNG_EXTERN float png_get_y_offset_inches PNGARG((png_structp png_ptr,
  3655. png_infop info_ptr));
  3656.  
  3657. #if defined(PNG_pHYs_SUPPORTED)
  3658. PNG_EXTERN png_uint_32 png_get_pHYs_dpi PNGARG((png_structp png_ptr,
  3659. png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
  3660. #endif /* PNG_pHYs_SUPPORTED */
  3661. #endif  /* PNG_INCH_CONVERSIONS && PNG_FLOATING_POINT_SUPPORTED */
  3662.  
  3663. /* Read the chunk header (length + type name) */
  3664. PNG_EXTERN png_uint_32 png_read_chunk_header PNGARG((png_structp png_ptr));
  3665.  
  3666. /* Added at libpng version 1.2.34 */
  3667. #if defined(PNG_cHRM_SUPPORTED)
  3668. PNG_EXTERN int png_check_cHRM_fixed  PNGARG((png_structp png_ptr,
  3669.    png_fixed_point int_white_x, png_fixed_point int_white_y,
  3670.    png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
  3671.    int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
  3672.    png_fixed_point int_blue_y));
  3673. #endif
  3674.  
  3675. /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
  3676.  
  3677. #endif /* PNG_INTERNAL */
  3678.  
  3679. #ifdef __cplusplus
  3680. }
  3681. #endif
  3682.  
  3683. #endif /* PNG_VERSION_INFO_ONLY */
  3684. /* do not put anything past this line */
  3685. #endif /* PNG_H */
  3686.