src/3rdparty/libpng/png.h
changeset 0 1918ee327afb
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     1 /* png.h - header file for PNG reference library
       
     2  *
       
     3  * libpng version 1.2.40 - September 10, 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  * This code is released under the libpng license (See LICENSE, below)
       
     9  *
       
    10  * Authors and maintainers:
       
    11  *  libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
       
    12  *  libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
       
    13  *  libpng versions 0.97, January 1998, through 1.2.40 - September 10, 2009: Glenn
       
    14  *  See also "Contributing Authors", below.
       
    15  *
       
    16  * Note about libpng version numbers:
       
    17  *
       
    18  *    Due to various miscommunications, unforeseen code incompatibilities
       
    19  *    and occasional factors outside the authors' control, version numbering
       
    20  *    on the library has not always been consistent and straightforward.
       
    21  *    The following table summarizes matters since version 0.89c, which was
       
    22  *    the first widely used release:
       
    23  *
       
    24  *    source                 png.h  png.h  shared-lib
       
    25  *    version                string   int  version
       
    26  *    -------                ------ -----  ----------
       
    27  *    0.89c "1.0 beta 3"     0.89      89  1.0.89
       
    28  *    0.90  "1.0 beta 4"     0.90      90  0.90  [should have been 2.0.90]
       
    29  *    0.95  "1.0 beta 5"     0.95      95  0.95  [should have been 2.0.95]
       
    30  *    0.96  "1.0 beta 6"     0.96      96  0.96  [should have been 2.0.96]
       
    31  *    0.97b "1.00.97 beta 7" 1.00.97   97  1.0.1 [should have been 2.0.97]
       
    32  *    0.97c                  0.97      97  2.0.97
       
    33  *    0.98                   0.98      98  2.0.98
       
    34  *    0.99                   0.99      98  2.0.99
       
    35  *    0.99a-m                0.99      99  2.0.99
       
    36  *    1.00                   1.00     100  2.1.0 [100 should be 10000]
       
    37  *    1.0.0      (from here on, the   100  2.1.0 [100 should be 10000]
       
    38  *    1.0.1       png.h string is   10001  2.1.0
       
    39  *    1.0.1a-e    identical to the  10002  from here on, the shared library
       
    40  *    1.0.2       source version)   10002  is 2.V where V is the source code
       
    41  *    1.0.2a-b                      10003  version, except as noted.
       
    42  *    1.0.3                         10003
       
    43  *    1.0.3a-d                      10004
       
    44  *    1.0.4                         10004
       
    45  *    1.0.4a-f                      10005
       
    46  *    1.0.5 (+ 2 patches)           10005
       
    47  *    1.0.5a-d                      10006
       
    48  *    1.0.5e-r                      10100 (not source compatible)
       
    49  *    1.0.5s-v                      10006 (not binary compatible)
       
    50  *    1.0.6 (+ 3 patches)           10006 (still binary incompatible)
       
    51  *    1.0.6d-f                      10007 (still binary incompatible)
       
    52  *    1.0.6g                        10007
       
    53  *    1.0.6h                        10007  10.6h (testing xy.z so-numbering)
       
    54  *    1.0.6i                        10007  10.6i
       
    55  *    1.0.6j                        10007  2.1.0.6j (incompatible with 1.0.0)
       
    56  *    1.0.7beta11-14        DLLNUM  10007  2.1.0.7beta11-14 (binary compatible)
       
    57  *    1.0.7beta15-18           1    10007  2.1.0.7beta15-18 (binary compatible)
       
    58  *    1.0.7rc1-2               1    10007  2.1.0.7rc1-2 (binary compatible)
       
    59  *    1.0.7                    1    10007  (still compatible)
       
    60  *    1.0.8beta1-4             1    10008  2.1.0.8beta1-4
       
    61  *    1.0.8rc1                 1    10008  2.1.0.8rc1
       
    62  *    1.0.8                    1    10008  2.1.0.8
       
    63  *    1.0.9beta1-6             1    10009  2.1.0.9beta1-6
       
    64  *    1.0.9rc1                 1    10009  2.1.0.9rc1
       
    65  *    1.0.9beta7-10            1    10009  2.1.0.9beta7-10
       
    66  *    1.0.9rc2                 1    10009  2.1.0.9rc2
       
    67  *    1.0.9                    1    10009  2.1.0.9
       
    68  *    1.0.10beta1              1    10010  2.1.0.10beta1
       
    69  *    1.0.10rc1                1    10010  2.1.0.10rc1
       
    70  *    1.0.10                   1    10010  2.1.0.10
       
    71  *    1.0.11beta1-3            1    10011  2.1.0.11beta1-3
       
    72  *    1.0.11rc1                1    10011  2.1.0.11rc1
       
    73  *    1.0.11                   1    10011  2.1.0.11
       
    74  *    1.0.12beta1-2            2    10012  2.1.0.12beta1-2
       
    75  *    1.0.12rc1                2    10012  2.1.0.12rc1
       
    76  *    1.0.12                   2    10012  2.1.0.12
       
    77  *    1.1.0a-f                 -    10100  2.1.1.0a-f (branch abandoned)
       
    78  *    1.2.0beta1-2             2    10200  2.1.2.0beta1-2
       
    79  *    1.2.0beta3-5             3    10200  3.1.2.0beta3-5
       
    80  *    1.2.0rc1                 3    10200  3.1.2.0rc1
       
    81  *    1.2.0                    3    10200  3.1.2.0
       
    82  *    1.2.1beta1-4             3    10201  3.1.2.1beta1-4
       
    83  *    1.2.1rc1-2               3    10201  3.1.2.1rc1-2
       
    84  *    1.2.1                    3    10201  3.1.2.1
       
    85  *    1.2.2beta1-6            12    10202  12.so.0.1.2.2beta1-6
       
    86  *    1.0.13beta1             10    10013  10.so.0.1.0.13beta1
       
    87  *    1.0.13rc1               10    10013  10.so.0.1.0.13rc1
       
    88  *    1.2.2rc1                12    10202  12.so.0.1.2.2rc1
       
    89  *    1.0.13                  10    10013  10.so.0.1.0.13
       
    90  *    1.2.2                   12    10202  12.so.0.1.2.2
       
    91  *    1.2.3rc1-6              12    10203  12.so.0.1.2.3rc1-6
       
    92  *    1.2.3                   12    10203  12.so.0.1.2.3
       
    93  *    1.2.4beta1-3            13    10204  12.so.0.1.2.4beta1-3
       
    94  *    1.0.14rc1               13    10014  10.so.0.1.0.14rc1
       
    95  *    1.2.4rc1                13    10204  12.so.0.1.2.4rc1
       
    96  *    1.0.14                  10    10014  10.so.0.1.0.14
       
    97  *    1.2.4                   13    10204  12.so.0.1.2.4
       
    98  *    1.2.5beta1-2            13    10205  12.so.0.1.2.5beta1-2
       
    99  *    1.0.15rc1-3             10    10015  10.so.0.1.0.15rc1-3
       
   100  *    1.2.5rc1-3              13    10205  12.so.0.1.2.5rc1-3
       
   101  *    1.0.15                  10    10015  10.so.0.1.0.15
       
   102  *    1.2.5                   13    10205  12.so.0.1.2.5
       
   103  *    1.2.6beta1-4            13    10206  12.so.0.1.2.6beta1-4
       
   104  *    1.0.16                  10    10016  10.so.0.1.0.16
       
   105  *    1.2.6                   13    10206  12.so.0.1.2.6
       
   106  *    1.2.7beta1-2            13    10207  12.so.0.1.2.7beta1-2
       
   107  *    1.0.17rc1               10    10017  10.so.0.1.0.17rc1
       
   108  *    1.2.7rc1                13    10207  12.so.0.1.2.7rc1
       
   109  *    1.0.17                  10    10017  10.so.0.1.0.17
       
   110  *    1.2.7                   13    10207  12.so.0.1.2.7
       
   111  *    1.2.8beta1-5            13    10208  12.so.0.1.2.8beta1-5
       
   112  *    1.0.18rc1-5             10    10018  10.so.0.1.0.18rc1-5
       
   113  *    1.2.8rc1-5              13    10208  12.so.0.1.2.8rc1-5
       
   114  *    1.0.18                  10    10018  10.so.0.1.0.18
       
   115  *    1.2.8                   13    10208  12.so.0.1.2.8
       
   116  *    1.2.9beta1-3            13    10209  12.so.0.1.2.9beta1-3
       
   117  *    1.2.9beta4-11           13    10209  12.so.0.9[.0]
       
   118  *    1.2.9rc1                13    10209  12.so.0.9[.0]
       
   119  *    1.2.9                   13    10209  12.so.0.9[.0]
       
   120  *    1.2.10beta1-8           13    10210  12.so.0.10[.0]
       
   121  *    1.2.10rc1-3             13    10210  12.so.0.10[.0]
       
   122  *    1.2.10                  13    10210  12.so.0.10[.0]
       
   123  *    1.2.11beta1-4           13    10211  12.so.0.11[.0]
       
   124  *    1.0.19rc1-5             10    10019  10.so.0.19[.0]
       
   125  *    1.2.11rc1-5             13    10211  12.so.0.11[.0]
       
   126  *    1.0.19                  10    10019  10.so.0.19[.0]
       
   127  *    1.2.11                  13    10211  12.so.0.11[.0]
       
   128  *    1.0.20                  10    10020  10.so.0.20[.0]
       
   129  *    1.2.12                  13    10212  12.so.0.12[.0]
       
   130  *    1.2.13beta1             13    10213  12.so.0.13[.0]
       
   131  *    1.0.21                  10    10021  10.so.0.21[.0]
       
   132  *    1.2.13                  13    10213  12.so.0.13[.0]
       
   133  *    1.2.14beta1-2           13    10214  12.so.0.14[.0]
       
   134  *    1.0.22rc1               10    10022  10.so.0.22[.0]
       
   135  *    1.2.14rc1               13    10214  12.so.0.14[.0]
       
   136  *    1.0.22                  10    10022  10.so.0.22[.0]
       
   137  *    1.2.14                  13    10214  12.so.0.14[.0]
       
   138  *    1.2.15beta1-6           13    10215  12.so.0.15[.0]
       
   139  *    1.0.23rc1-5             10    10023  10.so.0.23[.0]
       
   140  *    1.2.15rc1-5             13    10215  12.so.0.15[.0]
       
   141  *    1.0.23                  10    10023  10.so.0.23[.0]
       
   142  *    1.2.15                  13    10215  12.so.0.15[.0]
       
   143  *    1.2.16beta1-2           13    10216  12.so.0.16[.0]
       
   144  *    1.2.16rc1               13    10216  12.so.0.16[.0]
       
   145  *    1.0.24                  10    10024  10.so.0.24[.0]
       
   146  *    1.2.16                  13    10216  12.so.0.16[.0]
       
   147  *    1.2.17beta1-2           13    10217  12.so.0.17[.0]
       
   148  *    1.0.25rc1               10    10025  10.so.0.25[.0]
       
   149  *    1.2.17rc1-3             13    10217  12.so.0.17[.0]
       
   150  *    1.0.25                  10    10025  10.so.0.25[.0]
       
   151  *    1.2.17                  13    10217  12.so.0.17[.0]
       
   152  *    1.0.26                  10    10026  10.so.0.26[.0]
       
   153  *    1.2.18                  13    10218  12.so.0.18[.0]
       
   154  *    1.2.19beta1-31          13    10219  12.so.0.19[.0]
       
   155  *    1.0.27rc1-6             10    10027  10.so.0.27[.0]
       
   156  *    1.2.19rc1-6             13    10219  12.so.0.19[.0]
       
   157  *    1.0.27                  10    10027  10.so.0.27[.0]
       
   158  *    1.2.19                  13    10219  12.so.0.19[.0]
       
   159  *    1.2.20beta01-04         13    10220  12.so.0.20[.0]
       
   160  *    1.0.28rc1-6             10    10028  10.so.0.28[.0]
       
   161  *    1.2.20rc1-6             13    10220  12.so.0.20[.0]
       
   162  *    1.0.28                  10    10028  10.so.0.28[.0]
       
   163  *    1.2.20                  13    10220  12.so.0.20[.0]
       
   164  *    1.2.21beta1-2           13    10221  12.so.0.21[.0]
       
   165  *    1.2.21rc1-3             13    10221  12.so.0.21[.0]
       
   166  *    1.0.29                  10    10029  10.so.0.29[.0]
       
   167  *    1.2.21                  13    10221  12.so.0.21[.0]
       
   168  *    1.2.22beta1-4           13    10222  12.so.0.22[.0]
       
   169  *    1.0.30rc1               10    10030  10.so.0.30[.0]
       
   170  *    1.2.22rc1               13    10222  12.so.0.22[.0]
       
   171  *    1.0.30                  10    10030  10.so.0.30[.0]
       
   172  *    1.2.22                  13    10222  12.so.0.22[.0]
       
   173  *    1.2.23beta01-05         13    10223  12.so.0.23[.0]
       
   174  *    1.2.23rc01              13    10223  12.so.0.23[.0]
       
   175  *    1.2.23                  13    10223  12.so.0.23[.0]
       
   176  *    1.2.24beta01-02         13    10224  12.so.0.24[.0]
       
   177  *    1.2.24rc01              13    10224  12.so.0.24[.0]
       
   178  *    1.2.24                  13    10224  12.so.0.24[.0]
       
   179  *    1.2.25beta01-06         13    10225  12.so.0.25[.0]
       
   180  *    1.2.25rc01-02           13    10225  12.so.0.25[.0]
       
   181  *    1.0.31                  10    10031  10.so.0.31[.0]
       
   182  *    1.2.25                  13    10225  12.so.0.25[.0]
       
   183  *    1.2.26beta01-06         13    10226  12.so.0.26[.0]
       
   184  *    1.2.26rc01              13    10226  12.so.0.26[.0]
       
   185  *    1.2.26                  13    10226  12.so.0.26[.0]
       
   186  *    1.0.32                  10    10032  10.so.0.32[.0]
       
   187  *    1.2.27beta01-06         13    10227  12.so.0.27[.0]
       
   188  *    1.2.27rc01              13    10227  12.so.0.27[.0]
       
   189  *    1.0.33                  10    10033  10.so.0.33[.0]
       
   190  *    1.2.27                  13    10227  12.so.0.27[.0]
       
   191  *    1.0.34                  10    10034  10.so.0.34[.0]
       
   192  *    1.2.28                  13    10228  12.so.0.28[.0]
       
   193  *    1.2.29beta01-03         13    10229  12.so.0.29[.0]
       
   194  *    1.2.29rc01              13    10229  12.so.0.29[.0]
       
   195  *    1.0.35                  10    10035  10.so.0.35[.0]
       
   196  *    1.2.29                  13    10229  12.so.0.29[.0]
       
   197  *    1.0.37                  10    10037  10.so.0.37[.0]
       
   198  *    1.2.30beta01-04         13    10230  12.so.0.30[.0]
       
   199  *    1.0.38rc01-08           10    10038  10.so.0.38[.0]
       
   200  *    1.2.30rc01-08           13    10230  12.so.0.30[.0]
       
   201  *    1.0.38                  10    10038  10.so.0.38[.0]
       
   202  *    1.2.30                  13    10230  12.so.0.30[.0]
       
   203  *    1.0.39rc01-03           10    10039  10.so.0.39[.0]
       
   204  *    1.2.31rc01-03           13    10231  12.so.0.31[.0]
       
   205  *    1.0.39                  10    10039  10.so.0.39[.0]
       
   206  *    1.2.31                  13    10231  12.so.0.31[.0]
       
   207  *    1.2.32beta01-02         13    10232  12.so.0.32[.0]
       
   208  *    1.0.40rc01              10    10040  10.so.0.40[.0]
       
   209  *    1.2.32rc01              13    10232  12.so.0.32[.0]
       
   210  *    1.0.40                  10    10040  10.so.0.40[.0]
       
   211  *    1.2.32                  13    10232  12.so.0.32[.0]
       
   212  *    1.2.33beta01-02         13    10233  12.so.0.33[.0]
       
   213  *    1.2.33rc01-02           13    10233  12.so.0.33[.0]
       
   214  *    1.0.41rc01              10    10041  10.so.0.41[.0]
       
   215  *    1.2.33                  13    10233  12.so.0.33[.0]
       
   216  *    1.0.41                  10    10041  10.so.0.41[.0]
       
   217  *    1.2.34beta01-07         13    10234  12.so.0.34[.0]
       
   218  *    1.0.42rc01              10    10042  10.so.0.42[.0]
       
   219  *    1.2.34rc01              13    10234  12.so.0.34[.0]
       
   220  *    1.0.42                  10    10042  10.so.0.42[.0]
       
   221  *    1.2.34                  13    10234  12.so.0.34[.0]
       
   222  *    1.2.35beta01-03         13    10235  12.so.0.35[.0]
       
   223  *    1.0.43rc01-02           10    10043  10.so.0.43[.0]
       
   224  *    1.2.35rc01-02           13    10235  12.so.0.35[.0]
       
   225  *    1.0.43                  10    10043  10.so.0.43[.0]
       
   226  *    1.2.35                  13    10235  12.so.0.35[.0]
       
   227  *    1.2.36beta01-05         13    10236  12.so.0.36[.0]
       
   228  *    1.2.36rc01              13    10236  12.so.0.36[.0]
       
   229  *    1.0.44                  10    10044  10.so.0.44[.0]
       
   230  *    1.2.36                  13    10236  12.so.0.36[.0]
       
   231  *    1.2.37beta01-03         13    10237  12.so.0.37[.0]
       
   232  *    1.2.37rc01              13    10237  12.so.0.37[.0]
       
   233  *    1.2.37                  13    10237  12.so.0.37[.0]
       
   234  *    1.2.45                  10    10045  12.so.0.45[.0]
       
   235  *    1.0.46                  10    10046  10.so.0.46[.0]
       
   236  *    1.2.38beta01            13    10238  12.so.0.38[.0]
       
   237  *    1.2.38rc01-03           13    10238  12.so.0.38[.0]
       
   238  *    1.0.47                  10    10047  10.so.0.47[.0]
       
   239  *    1.2.38                  13    10238  12.so.0.38[.0]
       
   240  *    1.2.39beta01-05         13    10239  12.so.0.39[.0]
       
   241  *    1.2.39rc01              13    10239  12.so.0.39[.0]
       
   242  *    1.0.48                  10    10048  10.so.0.48[.0]
       
   243  *    1.2.39                  13    10239  12.so.0.39[.0]
       
   244  *    1.2.40beta01            13    10240  12.so.0.40[.0]
       
   245  *    1.2.40rc01              13    10240  12.so.0.40[.0]
       
   246  *    1.0.49                  10    10049  10.so.0.49[.0]
       
   247  *    1.2.40                  13    10240  12.so.0.40[.0]
       
   248  *
       
   249  *    Henceforth the source version will match the shared-library major
       
   250  *    and minor numbers; the shared-library major version number will be
       
   251  *    used for changes in backward compatibility, as it is intended.  The
       
   252  *    PNG_LIBPNG_VER macro, which is not used within libpng but is available
       
   253  *    for applications, is an unsigned integer of the form xyyzz corresponding
       
   254  *    to the source version x.y.z (leading zeros in y and z).  Beta versions
       
   255  *    were given the previous public release number plus a letter, until
       
   256  *    version 1.0.6j; from then on they were given the upcoming public
       
   257  *    release number plus "betaNN" or "rcNN".
       
   258  *
       
   259  *    Binary incompatibility exists only when applications make direct access
       
   260  *    to the info_ptr or png_ptr members through png.h, and the compiled
       
   261  *    application is loaded with a different version of the library.
       
   262  *
       
   263  *    DLLNUM will change each time there are forward or backward changes
       
   264  *    in binary compatibility (e.g., when a new feature is added).
       
   265  *
       
   266  * See libpng.txt or libpng.3 for more information.  The PNG specification
       
   267  * is available as a W3C Recommendation and as an ISO Specification,
       
   268  * <http://www.w3.org/TR/2003/REC-PNG-20031110/
       
   269  */
       
   270 
       
   271 /*
       
   272  * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
       
   273  *
       
   274  * If you modify libpng you may insert additional notices immediately following
       
   275  * this sentence.
       
   276  *
       
   277  * This code is released under the libpng license.
       
   278  *
       
   279  * libpng versions 1.2.6, August 15, 2004, through 1.2.40, September 10, 2009, are
       
   280  * Copyright (c) 2004, 2006-2009 Glenn Randers-Pehrson, and are
       
   281  * distributed according to the same disclaimer and license as libpng-1.2.5
       
   282  * with the following individual added to the list of Contributing Authors:
       
   283  *
       
   284  *    Cosmin Truta
       
   285  *
       
   286  * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
       
   287  * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
       
   288  * distributed according to the same disclaimer and license as libpng-1.0.6
       
   289  * with the following individuals added to the list of Contributing Authors:
       
   290  *
       
   291  *    Simon-Pierre Cadieux
       
   292  *    Eric S. Raymond
       
   293  *    Gilles Vollant
       
   294  *
       
   295  * and with the following additions to the disclaimer:
       
   296  *
       
   297  *    There is no warranty against interference with your enjoyment of the
       
   298  *    library or against infringement.  There is no warranty that our
       
   299  *    efforts or the library will fulfill any of your particular purposes
       
   300  *    or needs.  This library is provided with all faults, and the entire
       
   301  *    risk of satisfactory quality, performance, accuracy, and effort is with
       
   302  *    the user.
       
   303  *
       
   304  * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
       
   305  * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are
       
   306  * distributed according to the same disclaimer and license as libpng-0.96,
       
   307  * with the following individuals added to the list of Contributing Authors:
       
   308  *
       
   309  *    Tom Lane
       
   310  *    Glenn Randers-Pehrson
       
   311  *    Willem van Schaik
       
   312  *
       
   313  * libpng versions 0.89, June 1996, through 0.96, May 1997, are
       
   314  * Copyright (c) 1996, 1997 Andreas Dilger
       
   315  * Distributed according to the same disclaimer and license as libpng-0.88,
       
   316  * with the following individuals added to the list of Contributing Authors:
       
   317  *
       
   318  *    John Bowler
       
   319  *    Kevin Bracey
       
   320  *    Sam Bushell
       
   321  *    Magnus Holmgren
       
   322  *    Greg Roelofs
       
   323  *    Tom Tanner
       
   324  *
       
   325  * libpng versions 0.5, May 1995, through 0.88, January 1996, are
       
   326  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
       
   327  *
       
   328  * For the purposes of this copyright and license, "Contributing Authors"
       
   329  * is defined as the following set of individuals:
       
   330  *
       
   331  *    Andreas Dilger
       
   332  *    Dave Martindale
       
   333  *    Guy Eric Schalnat
       
   334  *    Paul Schmidt
       
   335  *    Tim Wegner
       
   336  *
       
   337  * The PNG Reference Library is supplied "AS IS".  The Contributing Authors
       
   338  * and Group 42, Inc. disclaim all warranties, expressed or implied,
       
   339  * including, without limitation, the warranties of merchantability and of
       
   340  * fitness for any purpose.  The Contributing Authors and Group 42, Inc.
       
   341  * assume no liability for direct, indirect, incidental, special, exemplary,
       
   342  * or consequential damages, which may result from the use of the PNG
       
   343  * Reference Library, even if advised of the possibility of such damage.
       
   344  *
       
   345  * Permission is hereby granted to use, copy, modify, and distribute this
       
   346  * source code, or portions hereof, for any purpose, without fee, subject
       
   347  * to the following restrictions:
       
   348  *
       
   349  * 1. The origin of this source code must not be misrepresented.
       
   350  *
       
   351  * 2. Altered versions must be plainly marked as such and
       
   352  * must not be misrepresented as being the original source.
       
   353  *
       
   354  * 3. This Copyright notice may not be removed or altered from
       
   355  *    any source or altered source distribution.
       
   356  *
       
   357  * The Contributing Authors and Group 42, Inc. specifically permit, without
       
   358  * fee, and encourage the use of this source code as a component to
       
   359  * supporting the PNG file format in commercial products.  If you use this
       
   360  * source code in a product, acknowledgment is not required but would be
       
   361  * appreciated.
       
   362  */
       
   363 
       
   364 /*
       
   365  * A "png_get_copyright" function is available, for convenient use in "about"
       
   366  * boxes and the like:
       
   367  *
       
   368  * printf("%s",png_get_copyright(NULL));
       
   369  *
       
   370  * Also, the PNG logo (in PNG format, of course) is supplied in the
       
   371  * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
       
   372  */
       
   373 
       
   374 /*
       
   375  * Libpng is OSI Certified Open Source Software.  OSI Certified is a
       
   376  * certification mark of the Open Source Initiative.
       
   377  */
       
   378 
       
   379 /*
       
   380  * The contributing authors would like to thank all those who helped
       
   381  * with testing, bug fixes, and patience.  This wouldn't have been
       
   382  * possible without all of you.
       
   383  *
       
   384  * Thanks to Frank J. T. Wojcik for helping with the documentation.
       
   385  */
       
   386 
       
   387 /*
       
   388  * Y2K compliance in libpng:
       
   389  * =========================
       
   390  *
       
   391  *    September 10, 2009
       
   392  *
       
   393  *    Since the PNG Development group is an ad-hoc body, we can't make
       
   394  *    an official declaration.
       
   395  *
       
   396  *    This is your unofficial assurance that libpng from version 0.71 and
       
   397  *    upward through 1.2.40 are Y2K compliant.  It is my belief that earlier
       
   398  *    versions were also Y2K compliant.
       
   399  *
       
   400  *    Libpng only has three year fields.  One is a 2-byte unsigned integer
       
   401  *    that will hold years up to 65535.  The other two hold the date in text
       
   402  *    format, and will hold years up to 9999.
       
   403  *
       
   404  *    The integer is
       
   405  *        "png_uint_16 year" in png_time_struct.
       
   406  *
       
   407  *    The strings are
       
   408  *        "png_charp time_buffer" in png_struct and
       
   409  *        "near_time_buffer", which is a local character string in png.c.
       
   410  *
       
   411  *    There are seven time-related functions:
       
   412  *        png.c: png_convert_to_rfc_1123() in png.c
       
   413  *          (formerly png_convert_to_rfc_1152() in error)
       
   414  *        png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
       
   415  *        png_convert_from_time_t() in pngwrite.c
       
   416  *        png_get_tIME() in pngget.c
       
   417  *        png_handle_tIME() in pngrutil.c, called in pngread.c
       
   418  *        png_set_tIME() in pngset.c
       
   419  *        png_write_tIME() in pngwutil.c, called in pngwrite.c
       
   420  *
       
   421  *    All handle dates properly in a Y2K environment.  The
       
   422  *    png_convert_from_time_t() function calls gmtime() to convert from system
       
   423  *    clock time, which returns (year - 1900), which we properly convert to
       
   424  *    the full 4-digit year.  There is a possibility that applications using
       
   425  *    libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
       
   426  *    function, or that they are incorrectly passing only a 2-digit year
       
   427  *    instead of "year - 1900" into the png_convert_from_struct_tm() function,
       
   428  *    but this is not under our control.  The libpng documentation has always
       
   429  *    stated that it works with 4-digit years, and the APIs have been
       
   430  *    documented as such.
       
   431  *
       
   432  *    The tIME chunk itself is also Y2K compliant.  It uses a 2-byte unsigned
       
   433  *    integer to hold the year, and can hold years as large as 65535.
       
   434  *
       
   435  *    zlib, upon which libpng depends, is also Y2K compliant.  It contains
       
   436  *    no date-related code.
       
   437  *
       
   438  *       Glenn Randers-Pehrson
       
   439  *       libpng maintainer
       
   440  *       PNG Development Group
       
   441  */
       
   442 
       
   443 #ifndef PNG_H
       
   444 #define PNG_H
       
   445 
       
   446 /* This is not the place to learn how to use libpng.  The file libpng.txt
       
   447  * describes how to use libpng, and the file example.c summarizes it
       
   448  * with some code on which to build.  This file is useful for looking
       
   449  * at the actual function definitions and structure components.
       
   450  */
       
   451 
       
   452 /* Version information for png.h - this should match the version in png.c */
       
   453 #define PNG_LIBPNG_VER_STRING "1.2.40"
       
   454 #define PNG_HEADER_VERSION_STRING \
       
   455    " libpng version 1.2.40 - September 10, 2009\n"
       
   456 
       
   457 #define PNG_LIBPNG_VER_SONUM   0
       
   458 #define PNG_LIBPNG_VER_DLLNUM  13
       
   459 
       
   460 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
       
   461 #define PNG_LIBPNG_VER_MAJOR   1
       
   462 #define PNG_LIBPNG_VER_MINOR   2
       
   463 #define PNG_LIBPNG_VER_RELEASE 40
       
   464 /* This should match the numeric part of the final component of
       
   465  * PNG_LIBPNG_VER_STRING, omitting any leading zero:
       
   466  */
       
   467 
       
   468 #define PNG_LIBPNG_VER_BUILD  0
       
   469 
       
   470 /* Release Status */
       
   471 #define PNG_LIBPNG_BUILD_ALPHA    1
       
   472 #define PNG_LIBPNG_BUILD_BETA     2
       
   473 #define PNG_LIBPNG_BUILD_RC       3
       
   474 #define PNG_LIBPNG_BUILD_STABLE   4
       
   475 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
       
   476 
       
   477 /* Release-Specific Flags */
       
   478 #define PNG_LIBPNG_BUILD_PATCH    8 /* Can be OR'ed with
       
   479                                        PNG_LIBPNG_BUILD_STABLE only */
       
   480 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
       
   481                                        PNG_LIBPNG_BUILD_SPECIAL */
       
   482 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
       
   483                                        PNG_LIBPNG_BUILD_PRIVATE */
       
   484 
       
   485 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
       
   486 
       
   487 /* Careful here.  At one time, Guy wanted to use 082, but that would be octal.
       
   488  * We must not include leading zeros.
       
   489  * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
       
   490  * version 1.0.0 was mis-numbered 100 instead of 10000).  From
       
   491  * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=release
       
   492  */
       
   493 #define PNG_LIBPNG_VER 10240 /* 1.2.40 */
       
   494 
       
   495 #ifndef PNG_VERSION_INFO_ONLY
       
   496 /* Include the compression library's header */
       
   497 #include "zlib.h"
       
   498 #endif
       
   499 
       
   500 /* Include all user configurable info, including optional assembler routines */
       
   501 #include "pngconf.h"
       
   502 
       
   503 /*
       
   504  * Added at libpng-1.2.8 */
       
   505 /* Ref MSDN: Private as priority over Special
       
   506  * VS_FF_PRIVATEBUILD File *was not* built using standard release
       
   507  * procedures. If this value is given, the StringFileInfo block must
       
   508  * contain a PrivateBuild string.
       
   509  *
       
   510  * VS_FF_SPECIALBUILD File *was* built by the original company using
       
   511  * standard release procedures but is a variation of the standard
       
   512  * file of the same version number. If this value is given, the
       
   513  * StringFileInfo block must contain a SpecialBuild string.
       
   514  */
       
   515 
       
   516 #if defined(PNG_USER_PRIVATEBUILD)
       
   517 #  define PNG_LIBPNG_BUILD_TYPE \
       
   518           (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
       
   519 #else
       
   520 #  if defined(PNG_LIBPNG_SPECIALBUILD)
       
   521 #    define PNG_LIBPNG_BUILD_TYPE \
       
   522             (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
       
   523 #  else
       
   524 #    define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
       
   525 #  endif
       
   526 #endif
       
   527 
       
   528 #ifndef PNG_VERSION_INFO_ONLY
       
   529 
       
   530 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
       
   531 #ifdef __cplusplus
       
   532 extern "C" {
       
   533 #endif /* __cplusplus */
       
   534 
       
   535 /* This file is arranged in several sections.  The first section contains
       
   536  * structure and type definitions.  The second section contains the external
       
   537  * library functions, while the third has the internal library functions,
       
   538  * which applications aren't expected to use directly.
       
   539  */
       
   540 
       
   541 #ifndef PNG_NO_TYPECAST_NULL
       
   542 #define int_p_NULL                (int *)NULL
       
   543 #define png_bytep_NULL            (png_bytep)NULL
       
   544 #define png_bytepp_NULL           (png_bytepp)NULL
       
   545 #define png_doublep_NULL          (png_doublep)NULL
       
   546 #define png_error_ptr_NULL        (png_error_ptr)NULL
       
   547 #define png_flush_ptr_NULL        (png_flush_ptr)NULL
       
   548 #define png_free_ptr_NULL         (png_free_ptr)NULL
       
   549 #define png_infopp_NULL           (png_infopp)NULL
       
   550 #define png_malloc_ptr_NULL       (png_malloc_ptr)NULL
       
   551 #define png_read_status_ptr_NULL  (png_read_status_ptr)NULL
       
   552 #define png_rw_ptr_NULL           (png_rw_ptr)NULL
       
   553 #define png_structp_NULL          (png_structp)NULL
       
   554 #define png_uint_16p_NULL         (png_uint_16p)NULL
       
   555 #define png_voidp_NULL            (png_voidp)NULL
       
   556 #define png_write_status_ptr_NULL (png_write_status_ptr)NULL
       
   557 #else
       
   558 #define int_p_NULL                NULL
       
   559 #define png_bytep_NULL            NULL
       
   560 #define png_bytepp_NULL           NULL
       
   561 #define png_doublep_NULL          NULL
       
   562 #define png_error_ptr_NULL        NULL
       
   563 #define png_flush_ptr_NULL        NULL
       
   564 #define png_free_ptr_NULL         NULL
       
   565 #define png_infopp_NULL           NULL
       
   566 #define png_malloc_ptr_NULL       NULL
       
   567 #define png_read_status_ptr_NULL  NULL
       
   568 #define png_rw_ptr_NULL           NULL
       
   569 #define png_structp_NULL          NULL
       
   570 #define png_uint_16p_NULL         NULL
       
   571 #define png_voidp_NULL            NULL
       
   572 #define png_write_status_ptr_NULL NULL
       
   573 #endif
       
   574 
       
   575 /* Variables declared in png.c - only it needs to define PNG_NO_EXTERN */
       
   576 #if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
       
   577 /* Version information for C files, stored in png.c.  This had better match
       
   578  * the version above.
       
   579  */
       
   580 #ifdef PNG_USE_GLOBAL_ARRAYS
       
   581 PNG_EXPORT_VAR (PNG_CONST char) png_libpng_ver[18];
       
   582   /* Need room for 99.99.99beta99z */
       
   583 #else
       
   584 #define png_libpng_ver png_get_header_ver(NULL)
       
   585 #endif
       
   586 
       
   587 #ifdef PNG_USE_GLOBAL_ARRAYS
       
   588 /* This was removed in version 1.0.5c */
       
   589 /* Structures to facilitate easy interlacing.  See png.c for more details */
       
   590 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_start[7];
       
   591 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_inc[7];
       
   592 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_ystart[7];
       
   593 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_yinc[7];
       
   594 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_mask[7];
       
   595 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_dsp_mask[7];
       
   596 /* This isn't currently used.  If you need it, see png.c for more details.
       
   597 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_height[7];
       
   598 */
       
   599 #endif
       
   600 
       
   601 #endif /* PNG_NO_EXTERN */
       
   602 
       
   603 /* Three color definitions.  The order of the red, green, and blue, (and the
       
   604  * exact size) is not important, although the size of the fields need to
       
   605  * be png_byte or png_uint_16 (as defined below).
       
   606  */
       
   607 typedef struct png_color_struct
       
   608 {
       
   609    png_byte red;
       
   610    png_byte green;
       
   611    png_byte blue;
       
   612 } png_color;
       
   613 typedef png_color FAR * png_colorp;
       
   614 typedef png_color FAR * FAR * png_colorpp;
       
   615 
       
   616 typedef struct png_color_16_struct
       
   617 {
       
   618    png_byte index;    /* used for palette files */
       
   619    png_uint_16 red;   /* for use in red green blue files */
       
   620    png_uint_16 green;
       
   621    png_uint_16 blue;
       
   622    png_uint_16 gray;  /* for use in grayscale files */
       
   623 } png_color_16;
       
   624 typedef png_color_16 FAR * png_color_16p;
       
   625 typedef png_color_16 FAR * FAR * png_color_16pp;
       
   626 
       
   627 typedef struct png_color_8_struct
       
   628 {
       
   629    png_byte red;   /* for use in red green blue files */
       
   630    png_byte green;
       
   631    png_byte blue;
       
   632    png_byte gray;  /* for use in grayscale files */
       
   633    png_byte alpha; /* for alpha channel files */
       
   634 } png_color_8;
       
   635 typedef png_color_8 FAR * png_color_8p;
       
   636 typedef png_color_8 FAR * FAR * png_color_8pp;
       
   637 
       
   638 /*
       
   639  * The following two structures are used for the in-core representation
       
   640  * of sPLT chunks.
       
   641  */
       
   642 typedef struct png_sPLT_entry_struct
       
   643 {
       
   644    png_uint_16 red;
       
   645    png_uint_16 green;
       
   646    png_uint_16 blue;
       
   647    png_uint_16 alpha;
       
   648    png_uint_16 frequency;
       
   649 } png_sPLT_entry;
       
   650 typedef png_sPLT_entry FAR * png_sPLT_entryp;
       
   651 typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;
       
   652 
       
   653 /*  When the depth of the sPLT palette is 8 bits, the color and alpha samples
       
   654  *  occupy the LSB of their respective members, and the MSB of each member
       
   655  *  is zero-filled.  The frequency member always occupies the full 16 bits.
       
   656  */
       
   657 
       
   658 typedef struct png_sPLT_struct
       
   659 {
       
   660    png_charp name;           /* palette name */
       
   661    png_byte depth;           /* depth of palette samples */
       
   662    png_sPLT_entryp entries;  /* palette entries */
       
   663    png_int_32 nentries;      /* number of palette entries */
       
   664 } png_sPLT_t;
       
   665 typedef png_sPLT_t FAR * png_sPLT_tp;
       
   666 typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
       
   667 
       
   668 #ifdef PNG_TEXT_SUPPORTED
       
   669 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
       
   670  * and whether that contents is compressed or not.  The "key" field
       
   671  * points to a regular zero-terminated C string.  The "text", "lang", and
       
   672  * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
       
   673  * However, the * structure returned by png_get_text() will always contain
       
   674  * regular zero-terminated C strings (possibly empty), never NULL pointers,
       
   675  * so they can be safely used in printf() and other string-handling functions.
       
   676  */
       
   677 typedef struct png_text_struct
       
   678 {
       
   679    int  compression;       /* compression value:
       
   680                              -1: tEXt, none
       
   681                               0: zTXt, deflate
       
   682                               1: iTXt, none
       
   683                               2: iTXt, deflate  */
       
   684    png_charp key;          /* keyword, 1-79 character description of "text" */
       
   685    png_charp text;         /* comment, may be an empty string (ie "")
       
   686                               or a NULL pointer */
       
   687    png_size_t text_length; /* length of the text string */
       
   688 #ifdef PNG_iTXt_SUPPORTED
       
   689    png_size_t itxt_length; /* length of the itxt string */
       
   690    png_charp lang;         /* language code, 0-79 characters
       
   691                               or a NULL pointer */
       
   692    png_charp lang_key;     /* keyword translated UTF-8 string, 0 or more
       
   693                               chars or a NULL pointer */
       
   694 #endif
       
   695 } png_text;
       
   696 typedef png_text FAR * png_textp;
       
   697 typedef png_text FAR * FAR * png_textpp;
       
   698 #endif
       
   699 
       
   700 /* Supported compression types for text in PNG files (tEXt, and zTXt).
       
   701  * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed.
       
   702  */
       
   703 #define PNG_TEXT_COMPRESSION_NONE_WR -3
       
   704 #define PNG_TEXT_COMPRESSION_zTXt_WR -2
       
   705 #define PNG_TEXT_COMPRESSION_NONE    -1
       
   706 #define PNG_TEXT_COMPRESSION_zTXt     0
       
   707 #define PNG_ITXT_COMPRESSION_NONE     1
       
   708 #define PNG_ITXT_COMPRESSION_zTXt     2
       
   709 #define PNG_TEXT_COMPRESSION_LAST     3  /* Not a valid value */
       
   710 
       
   711 /* png_time is a way to hold the time in an machine independent way.
       
   712  * Two conversions are provided, both from time_t and struct tm.  There
       
   713  * is no portable way to convert to either of these structures, as far
       
   714  * as I know.  If you know of a portable way, send it to me.  As a side
       
   715  * note - PNG has always been Year 2000 compliant!
       
   716  */
       
   717 typedef struct png_time_struct
       
   718 {
       
   719    png_uint_16 year; /* full year, as in, 1995 */
       
   720    png_byte month;   /* month of year, 1 - 12 */
       
   721    png_byte day;     /* day of month, 1 - 31 */
       
   722    png_byte hour;    /* hour of day, 0 - 23 */
       
   723    png_byte minute;  /* minute of hour, 0 - 59 */
       
   724    png_byte second;  /* second of minute, 0 - 60 (for leap seconds) */
       
   725 } png_time;
       
   726 typedef png_time FAR * png_timep;
       
   727 typedef png_time FAR * FAR * png_timepp;
       
   728 
       
   729 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
       
   730  defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
       
   731 /* png_unknown_chunk is a structure to hold queued chunks for which there is
       
   732  * no specific support.  The idea is that we can use this to queue
       
   733  * up private chunks for output even though the library doesn't actually
       
   734  * know about their semantics.
       
   735  */
       
   736 #define PNG_CHUNK_NAME_LENGTH 5
       
   737 typedef struct png_unknown_chunk_t
       
   738 {
       
   739     png_byte name[PNG_CHUNK_NAME_LENGTH];
       
   740     png_byte *data;
       
   741     png_size_t size;
       
   742 
       
   743     /* libpng-using applications should NOT directly modify this byte. */
       
   744     png_byte location; /* mode of operation at read time */
       
   745 }
       
   746 png_unknown_chunk;
       
   747 typedef png_unknown_chunk FAR * png_unknown_chunkp;
       
   748 typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
       
   749 #endif
       
   750 
       
   751 /* png_info is a structure that holds the information in a PNG file so
       
   752  * that the application can find out the characteristics of the image.
       
   753  * If you are reading the file, this structure will tell you what is
       
   754  * in the PNG file.  If you are writing the file, fill in the information
       
   755  * you want to put into the PNG file, then call png_write_info().
       
   756  * The names chosen should be very close to the PNG specification, so
       
   757  * consult that document for information about the meaning of each field.
       
   758  *
       
   759  * With libpng < 0.95, it was only possible to directly set and read the
       
   760  * the values in the png_info_struct, which meant that the contents and
       
   761  * order of the values had to remain fixed.  With libpng 0.95 and later,
       
   762  * however, there are now functions that abstract the contents of
       
   763  * png_info_struct from the application, so this makes it easier to use
       
   764  * libpng with dynamic libraries, and even makes it possible to use
       
   765  * libraries that don't have all of the libpng ancillary chunk-handing
       
   766  * functionality.
       
   767  *
       
   768  * In any case, the order of the parameters in png_info_struct should NOT
       
   769  * be changed for as long as possible to keep compatibility with applications
       
   770  * that use the old direct-access method with png_info_struct.
       
   771  *
       
   772  * The following members may have allocated storage attached that should be
       
   773  * cleaned up before the structure is discarded: palette, trans, text,
       
   774  * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
       
   775  * splt_palettes, scal_unit, row_pointers, and unknowns.   By default, these
       
   776  * are automatically freed when the info structure is deallocated, if they were
       
   777  * allocated internally by libpng.  This behavior can be changed by means
       
   778  * of the png_data_freer() function.
       
   779  *
       
   780  * More allocation details: all the chunk-reading functions that
       
   781  * change these members go through the corresponding png_set_*
       
   782  * functions.  A function to clear these members is available: see
       
   783  * png_free_data().  The png_set_* functions do not depend on being
       
   784  * able to point info structure members to any of the storage they are
       
   785  * passed (they make their own copies), EXCEPT that the png_set_text
       
   786  * functions use the same storage passed to them in the text_ptr or
       
   787  * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
       
   788  * functions do not make their own copies.
       
   789  */
       
   790 typedef struct png_info_struct
       
   791 {
       
   792    /* The following are necessary for every PNG file */
       
   793    png_uint_32 width;       /* width of image in pixels (from IHDR) */
       
   794    png_uint_32 height;      /* height of image in pixels (from IHDR) */
       
   795    png_uint_32 valid;       /* valid chunk data (see PNG_INFO_ below) */
       
   796    png_uint_32 rowbytes;    /* bytes needed to hold an untransformed row */
       
   797    png_colorp palette;      /* array of color values (valid & PNG_INFO_PLTE) */
       
   798    png_uint_16 num_palette; /* number of color entries in "palette" (PLTE) */
       
   799    png_uint_16 num_trans;   /* number of transparent palette color (tRNS) */
       
   800    png_byte bit_depth;      /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */
       
   801    png_byte color_type;     /* see PNG_COLOR_TYPE_ below (from IHDR) */
       
   802    /* The following three should have been named *_method not *_type */
       
   803    png_byte compression_type; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */
       
   804    png_byte filter_type;    /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
       
   805    png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
       
   806 
       
   807    /* The following is informational only on read, and not used on writes. */
       
   808    png_byte channels;       /* number of data channels per pixel (1, 2, 3, 4) */
       
   809    png_byte pixel_depth;    /* number of bits per pixel */
       
   810    png_byte spare_byte;     /* to align the data, and for future use */
       
   811    png_byte signature[8];   /* magic bytes read by libpng from start of file */
       
   812 
       
   813    /* The rest of the data is optional.  If you are reading, check the
       
   814     * valid field to see if the information in these are valid.  If you
       
   815     * are writing, set the valid field to those chunks you want written,
       
   816     * and initialize the appropriate fields below.
       
   817     */
       
   818 
       
   819 #if defined(PNG_gAMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
       
   820    /* The gAMA chunk describes the gamma characteristics of the system
       
   821     * on which the image was created, normally in the range [1.0, 2.5].
       
   822     * Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
       
   823     */
       
   824    float gamma; /* gamma value of image, if (valid & PNG_INFO_gAMA) */
       
   825 #endif
       
   826 
       
   827 #if defined(PNG_sRGB_SUPPORTED)
       
   828     /* GR-P, 0.96a */
       
   829     /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
       
   830    png_byte srgb_intent; /* sRGB rendering intent [0, 1, 2, or 3] */
       
   831 #endif
       
   832 
       
   833 #if defined(PNG_TEXT_SUPPORTED)
       
   834    /* The tEXt, and zTXt chunks contain human-readable textual data in
       
   835     * uncompressed, compressed, and optionally compressed forms, respectively.
       
   836     * The data in "text" is an array of pointers to uncompressed,
       
   837     * null-terminated C strings. Each chunk has a keyword that describes the
       
   838     * textual data contained in that chunk.  Keywords are not required to be
       
   839     * unique, and the text string may be empty.  Any number of text chunks may
       
   840     * be in an image.
       
   841     */
       
   842    int num_text; /* number of comments read/to write */
       
   843    int max_text; /* current size of text array */
       
   844    png_textp text; /* array of comments read/to write */
       
   845 #endif /* PNG_TEXT_SUPPORTED */
       
   846 
       
   847 #if defined(PNG_tIME_SUPPORTED)
       
   848    /* The tIME chunk holds the last time the displayed image data was
       
   849     * modified.  See the png_time struct for the contents of this struct.
       
   850     */
       
   851    png_time mod_time;
       
   852 #endif
       
   853 
       
   854 #if defined(PNG_sBIT_SUPPORTED)
       
   855    /* The sBIT chunk specifies the number of significant high-order bits
       
   856     * in the pixel data.  Values are in the range [1, bit_depth], and are
       
   857     * only specified for the channels in the pixel data.  The contents of
       
   858     * the low-order bits is not specified.  Data is valid if
       
   859     * (valid & PNG_INFO_sBIT) is non-zero.
       
   860     */
       
   861    png_color_8 sig_bit; /* significant bits in color channels */
       
   862 #endif
       
   863 
       
   864 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
       
   865 defined(PNG_READ_BACKGROUND_SUPPORTED)
       
   866    /* The tRNS chunk supplies transparency data for paletted images and
       
   867     * other image types that don't need a full alpha channel.  There are
       
   868     * "num_trans" transparency values for a paletted image, stored in the
       
   869     * same order as the palette colors, starting from index 0.  Values
       
   870     * for the data are in the range [0, 255], ranging from fully transparent
       
   871     * to fully opaque, respectively.  For non-paletted images, there is a
       
   872     * single color specified that should be treated as fully transparent.
       
   873     * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
       
   874     */
       
   875    png_bytep trans; /* transparent values for paletted image */
       
   876    png_color_16 trans_values; /* transparent color for non-palette image */
       
   877 #endif
       
   878 
       
   879 #if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
       
   880    /* The bKGD chunk gives the suggested image background color if the
       
   881     * display program does not have its own background color and the image
       
   882     * is needs to composited onto a background before display.  The colors
       
   883     * in "background" are normally in the same color space/depth as the
       
   884     * pixel data.  Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
       
   885     */
       
   886    png_color_16 background;
       
   887 #endif
       
   888 
       
   889 #if defined(PNG_oFFs_SUPPORTED)
       
   890    /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
       
   891     * and downwards from the top-left corner of the display, page, or other
       
   892     * application-specific co-ordinate space.  See the PNG_OFFSET_ defines
       
   893     * below for the unit types.  Valid if (valid & PNG_INFO_oFFs) non-zero.
       
   894     */
       
   895    png_int_32 x_offset; /* x offset on page */
       
   896    png_int_32 y_offset; /* y offset on page */
       
   897    png_byte offset_unit_type; /* offset units type */
       
   898 #endif
       
   899 
       
   900 #if defined(PNG_pHYs_SUPPORTED)
       
   901    /* The pHYs chunk gives the physical pixel density of the image for
       
   902     * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
       
   903     * defines below).  Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
       
   904     */
       
   905    png_uint_32 x_pixels_per_unit; /* horizontal pixel density */
       
   906    png_uint_32 y_pixels_per_unit; /* vertical pixel density */
       
   907    png_byte phys_unit_type; /* resolution type (see PNG_RESOLUTION_ below) */
       
   908 #endif
       
   909 
       
   910 #if defined(PNG_hIST_SUPPORTED)
       
   911    /* The hIST chunk contains the relative frequency or importance of the
       
   912     * various palette entries, so that a viewer can intelligently select a
       
   913     * reduced-color palette, if required.  Data is an array of "num_palette"
       
   914     * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
       
   915     * is non-zero.
       
   916     */
       
   917    png_uint_16p hist;
       
   918 #endif
       
   919 
       
   920 #ifdef PNG_cHRM_SUPPORTED
       
   921    /* The cHRM chunk describes the CIE color characteristics of the monitor
       
   922     * on which the PNG was created.  This data allows the viewer to do gamut
       
   923     * mapping of the input image to ensure that the viewer sees the same
       
   924     * colors in the image as the creator.  Values are in the range
       
   925     * [0.0, 0.8].  Data valid if (valid & PNG_INFO_cHRM) non-zero.
       
   926     */
       
   927 #ifdef PNG_FLOATING_POINT_SUPPORTED
       
   928    float x_white;
       
   929    float y_white;
       
   930    float x_red;
       
   931    float y_red;
       
   932    float x_green;
       
   933    float y_green;
       
   934    float x_blue;
       
   935    float y_blue;
       
   936 #endif
       
   937 #endif
       
   938 
       
   939 #if defined(PNG_pCAL_SUPPORTED)
       
   940    /* The pCAL chunk describes a transformation between the stored pixel
       
   941     * values and original physical data values used to create the image.
       
   942     * The integer range [0, 2^bit_depth - 1] maps to the floating-point
       
   943     * range given by [pcal_X0, pcal_X1], and are further transformed by a
       
   944     * (possibly non-linear) transformation function given by "pcal_type"
       
   945     * and "pcal_params" into "pcal_units".  Please see the PNG_EQUATION_
       
   946     * defines below, and the PNG-Group's PNG extensions document for a
       
   947     * complete description of the transformations and how they should be
       
   948     * implemented, and for a description of the ASCII parameter strings.
       
   949     * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
       
   950     */
       
   951    png_charp pcal_purpose;  /* pCAL chunk description string */
       
   952    png_int_32 pcal_X0;      /* minimum value */
       
   953    png_int_32 pcal_X1;      /* maximum value */
       
   954    png_charp pcal_units;    /* Latin-1 string giving physical units */
       
   955    png_charpp pcal_params;  /* ASCII strings containing parameter values */
       
   956    png_byte pcal_type;      /* equation type (see PNG_EQUATION_ below) */
       
   957    png_byte pcal_nparams;   /* number of parameters given in pcal_params */
       
   958 #endif
       
   959 
       
   960 /* New members added in libpng-1.0.6 */
       
   961 #ifdef PNG_FREE_ME_SUPPORTED
       
   962    png_uint_32 free_me;     /* flags items libpng is responsible for freeing */
       
   963 #endif
       
   964 
       
   965 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
       
   966  defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
       
   967    /* Storage for unknown chunks that the library doesn't recognize. */
       
   968    png_unknown_chunkp unknown_chunks;
       
   969    png_size_t unknown_chunks_num;
       
   970 #endif
       
   971 
       
   972 #if defined(PNG_iCCP_SUPPORTED)
       
   973    /* iCCP chunk data. */
       
   974    png_charp iccp_name;     /* profile name */
       
   975    png_charp iccp_profile;  /* International Color Consortium profile data */
       
   976                             /* Note to maintainer: should be png_bytep */
       
   977    png_uint_32 iccp_proflen;  /* ICC profile data length */
       
   978    png_byte iccp_compression; /* Always zero */
       
   979 #endif
       
   980 
       
   981 #if defined(PNG_sPLT_SUPPORTED)
       
   982    /* Data on sPLT chunks (there may be more than one). */
       
   983    png_sPLT_tp splt_palettes;
       
   984    png_uint_32 splt_palettes_num;
       
   985 #endif
       
   986 
       
   987 #if defined(PNG_sCAL_SUPPORTED)
       
   988    /* The sCAL chunk describes the actual physical dimensions of the
       
   989     * subject matter of the graphic.  The chunk contains a unit specification
       
   990     * a byte value, and two ASCII strings representing floating-point
       
   991     * values.  The values are width and height corresponsing to one pixel
       
   992     * in the image.  This external representation is converted to double
       
   993     * here.  Data values are valid if (valid & PNG_INFO_sCAL) is non-zero.
       
   994     */
       
   995    png_byte scal_unit;         /* unit of physical scale */
       
   996 #ifdef PNG_FLOATING_POINT_SUPPORTED
       
   997    double scal_pixel_width;    /* width of one pixel */
       
   998    double scal_pixel_height;   /* height of one pixel */
       
   999 #endif
       
  1000 #ifdef PNG_FIXED_POINT_SUPPORTED
       
  1001    png_charp scal_s_width;     /* string containing height */
       
  1002    png_charp scal_s_height;    /* string containing width */
       
  1003 #endif
       
  1004 #endif
       
  1005 
       
  1006 #if defined(PNG_INFO_IMAGE_SUPPORTED)
       
  1007    /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS) non-zero */
       
  1008    /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
       
  1009    png_bytepp row_pointers;        /* the image bits */
       
  1010 #endif
       
  1011 
       
  1012 #if defined(PNG_FIXED_POINT_SUPPORTED) && defined(PNG_gAMA_SUPPORTED)
       
  1013    png_fixed_point int_gamma; /* gamma of image, if (valid & PNG_INFO_gAMA) */
       
  1014 #endif
       
  1015 
       
  1016 #if defined(PNG_cHRM_SUPPORTED) && defined(PNG_FIXED_POINT_SUPPORTED)
       
  1017    png_fixed_point int_x_white;
       
  1018    png_fixed_point int_y_white;
       
  1019    png_fixed_point int_x_red;
       
  1020    png_fixed_point int_y_red;
       
  1021    png_fixed_point int_x_green;
       
  1022    png_fixed_point int_y_green;
       
  1023    png_fixed_point int_x_blue;
       
  1024    png_fixed_point int_y_blue;
       
  1025 #endif
       
  1026 
       
  1027 } png_info;
       
  1028 
       
  1029 typedef png_info FAR * png_infop;
       
  1030 typedef png_info FAR * FAR * png_infopp;
       
  1031 
       
  1032 /* Maximum positive integer used in PNG is (2^31)-1 */
       
  1033 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
       
  1034 #define PNG_UINT_32_MAX ((png_uint_32)(-1))
       
  1035 #define PNG_SIZE_MAX ((png_size_t)(-1))
       
  1036 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
       
  1037 /* PNG_MAX_UINT is deprecated; use PNG_UINT_31_MAX instead. */
       
  1038 #define PNG_MAX_UINT PNG_UINT_31_MAX
       
  1039 #endif
       
  1040 
       
  1041 /* These describe the color_type field in png_info. */
       
  1042 /* color type masks */
       
  1043 #define PNG_COLOR_MASK_PALETTE    1
       
  1044 #define PNG_COLOR_MASK_COLOR      2
       
  1045 #define PNG_COLOR_MASK_ALPHA      4
       
  1046 
       
  1047 /* color types.  Note that not all combinations are legal */
       
  1048 #define PNG_COLOR_TYPE_GRAY 0
       
  1049 #define PNG_COLOR_TYPE_PALETTE  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
       
  1050 #define PNG_COLOR_TYPE_RGB        (PNG_COLOR_MASK_COLOR)
       
  1051 #define PNG_COLOR_TYPE_RGB_ALPHA  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
       
  1052 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
       
  1053 /* aliases */
       
  1054 #define PNG_COLOR_TYPE_RGBA  PNG_COLOR_TYPE_RGB_ALPHA
       
  1055 #define PNG_COLOR_TYPE_GA  PNG_COLOR_TYPE_GRAY_ALPHA
       
  1056 
       
  1057 /* This is for compression type. PNG 1.0-1.2 only define the single type. */
       
  1058 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
       
  1059 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
       
  1060 
       
  1061 /* This is for filter type. PNG 1.0-1.2 only define the single type. */
       
  1062 #define PNG_FILTER_TYPE_BASE      0 /* Single row per-byte filtering */
       
  1063 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
       
  1064 #define PNG_FILTER_TYPE_DEFAULT   PNG_FILTER_TYPE_BASE
       
  1065 
       
  1066 /* These are for the interlacing type.  These values should NOT be changed. */
       
  1067 #define PNG_INTERLACE_NONE        0 /* Non-interlaced image */
       
  1068 #define PNG_INTERLACE_ADAM7       1 /* Adam7 interlacing */
       
  1069 #define PNG_INTERLACE_LAST        2 /* Not a valid value */
       
  1070 
       
  1071 /* These are for the oFFs chunk.  These values should NOT be changed. */
       
  1072 #define PNG_OFFSET_PIXEL          0 /* Offset in pixels */
       
  1073 #define PNG_OFFSET_MICROMETER     1 /* Offset in micrometers (1/10^6 meter) */
       
  1074 #define PNG_OFFSET_LAST           2 /* Not a valid value */
       
  1075 
       
  1076 /* These are for the pCAL chunk.  These values should NOT be changed. */
       
  1077 #define PNG_EQUATION_LINEAR       0 /* Linear transformation */
       
  1078 #define PNG_EQUATION_BASE_E       1 /* Exponential base e transform */
       
  1079 #define PNG_EQUATION_ARBITRARY    2 /* Arbitrary base exponential transform */
       
  1080 #define PNG_EQUATION_HYPERBOLIC   3 /* Hyperbolic sine transformation */
       
  1081 #define PNG_EQUATION_LAST         4 /* Not a valid value */
       
  1082 
       
  1083 /* These are for the sCAL chunk.  These values should NOT be changed. */
       
  1084 #define PNG_SCALE_UNKNOWN         0 /* unknown unit (image scale) */
       
  1085 #define PNG_SCALE_METER           1 /* meters per pixel */
       
  1086 #define PNG_SCALE_RADIAN          2 /* radians per pixel */
       
  1087 #define PNG_SCALE_LAST            3 /* Not a valid value */
       
  1088 
       
  1089 /* These are for the pHYs chunk.  These values should NOT be changed. */
       
  1090 #define PNG_RESOLUTION_UNKNOWN    0 /* pixels/unknown unit (aspect ratio) */
       
  1091 #define PNG_RESOLUTION_METER      1 /* pixels/meter */
       
  1092 #define PNG_RESOLUTION_LAST       2 /* Not a valid value */
       
  1093 
       
  1094 /* These are for the sRGB chunk.  These values should NOT be changed. */
       
  1095 #define PNG_sRGB_INTENT_PERCEPTUAL 0
       
  1096 #define PNG_sRGB_INTENT_RELATIVE   1
       
  1097 #define PNG_sRGB_INTENT_SATURATION 2
       
  1098 #define PNG_sRGB_INTENT_ABSOLUTE   3
       
  1099 #define PNG_sRGB_INTENT_LAST       4 /* Not a valid value */
       
  1100 
       
  1101 /* This is for text chunks */
       
  1102 #define PNG_KEYWORD_MAX_LENGTH     79
       
  1103 
       
  1104 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */
       
  1105 #define PNG_MAX_PALETTE_LENGTH    256
       
  1106 
       
  1107 /* These determine if an ancillary chunk's data has been successfully read
       
  1108  * from the PNG header, or if the application has filled in the corresponding
       
  1109  * data in the info_struct to be written into the output file.  The values
       
  1110  * of the PNG_INFO_<chunk> defines should NOT be changed.
       
  1111  */
       
  1112 #define PNG_INFO_gAMA 0x0001
       
  1113 #define PNG_INFO_sBIT 0x0002
       
  1114 #define PNG_INFO_cHRM 0x0004
       
  1115 #define PNG_INFO_PLTE 0x0008
       
  1116 #define PNG_INFO_tRNS 0x0010
       
  1117 #define PNG_INFO_bKGD 0x0020
       
  1118 #define PNG_INFO_hIST 0x0040
       
  1119 #define PNG_INFO_pHYs 0x0080
       
  1120 #define PNG_INFO_oFFs 0x0100
       
  1121 #define PNG_INFO_tIME 0x0200
       
  1122 #define PNG_INFO_pCAL 0x0400
       
  1123 #define PNG_INFO_sRGB 0x0800   /* GR-P, 0.96a */
       
  1124 #define PNG_INFO_iCCP 0x1000   /* ESR, 1.0.6 */
       
  1125 #define PNG_INFO_sPLT 0x2000   /* ESR, 1.0.6 */
       
  1126 #define PNG_INFO_sCAL 0x4000   /* ESR, 1.0.6 */
       
  1127 #define PNG_INFO_IDAT 0x8000L  /* ESR, 1.0.6 */
       
  1128 
       
  1129 /* This is used for the transformation routines, as some of them
       
  1130  * change these values for the row.  It also should enable using
       
  1131  * the routines for other purposes.
       
  1132  */
       
  1133 typedef struct png_row_info_struct
       
  1134 {
       
  1135    png_uint_32 width; /* width of row */
       
  1136    png_uint_32 rowbytes; /* number of bytes in row */
       
  1137    png_byte color_type; /* color type of row */
       
  1138    png_byte bit_depth; /* bit depth of row */
       
  1139    png_byte channels; /* number of channels (1, 2, 3, or 4) */
       
  1140    png_byte pixel_depth; /* bits per pixel (depth * channels) */
       
  1141 } png_row_info;
       
  1142 
       
  1143 typedef png_row_info FAR * png_row_infop;
       
  1144 typedef png_row_info FAR * FAR * png_row_infopp;
       
  1145 
       
  1146 /* These are the function types for the I/O functions and for the functions
       
  1147  * that allow the user to override the default I/O functions with his or her
       
  1148  * own.  The png_error_ptr type should match that of user-supplied warning
       
  1149  * and error functions, while the png_rw_ptr type should match that of the
       
  1150  * user read/write data functions.
       
  1151  */
       
  1152 typedef struct png_struct_def png_struct;
       
  1153 typedef png_struct FAR * png_structp;
       
  1154 
       
  1155 typedef void (PNGAPI *png_error_ptr) PNGARG((png_structp, png_const_charp));
       
  1156 typedef void (PNGAPI *png_rw_ptr) PNGARG((png_structp, png_bytep, png_size_t));
       
  1157 typedef void (PNGAPI *png_flush_ptr) PNGARG((png_structp));
       
  1158 typedef void (PNGAPI *png_read_status_ptr) PNGARG((png_structp, png_uint_32,
       
  1159    int));
       
  1160 typedef void (PNGAPI *png_write_status_ptr) PNGARG((png_structp, png_uint_32,
       
  1161    int));
       
  1162 
       
  1163 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
       
  1164 typedef void (PNGAPI *png_progressive_info_ptr) PNGARG((png_structp, png_infop));
       
  1165 typedef void (PNGAPI *png_progressive_end_ptr) PNGARG((png_structp, png_infop));
       
  1166 typedef void (PNGAPI *png_progressive_row_ptr) PNGARG((png_structp, png_bytep,
       
  1167    png_uint_32, int));
       
  1168 #endif
       
  1169 
       
  1170 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
       
  1171     defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
       
  1172     defined(PNG_LEGACY_SUPPORTED)
       
  1173 typedef void (PNGAPI *png_user_transform_ptr) PNGARG((png_structp,
       
  1174     png_row_infop, png_bytep));
       
  1175 #endif
       
  1176 
       
  1177 #if defined(PNG_USER_CHUNKS_SUPPORTED)
       
  1178 typedef int (PNGAPI *png_user_chunk_ptr) PNGARG((png_structp, png_unknown_chunkp));
       
  1179 #endif
       
  1180 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
       
  1181 typedef void (PNGAPI *png_unknown_chunk_ptr) PNGARG((png_structp));
       
  1182 #endif
       
  1183 
       
  1184 /* Transform masks for the high-level interface */
       
  1185 #define PNG_TRANSFORM_IDENTITY       0x0000    /* read and write */
       
  1186 #define PNG_TRANSFORM_STRIP_16       0x0001    /* read only */
       
  1187 #define PNG_TRANSFORM_STRIP_ALPHA    0x0002    /* read only */
       
  1188 #define PNG_TRANSFORM_PACKING        0x0004    /* read and write */
       
  1189 #define PNG_TRANSFORM_PACKSWAP       0x0008    /* read and write */
       
  1190 #define PNG_TRANSFORM_EXPAND         0x0010    /* read only */
       
  1191 #define PNG_TRANSFORM_INVERT_MONO    0x0020    /* read and write */
       
  1192 #define PNG_TRANSFORM_SHIFT          0x0040    /* read and write */
       
  1193 #define PNG_TRANSFORM_BGR            0x0080    /* read and write */
       
  1194 #define PNG_TRANSFORM_SWAP_ALPHA     0x0100    /* read and write */
       
  1195 #define PNG_TRANSFORM_SWAP_ENDIAN    0x0200    /* read and write */
       
  1196 #define PNG_TRANSFORM_INVERT_ALPHA   0x0400    /* read and write */
       
  1197 #define PNG_TRANSFORM_STRIP_FILLER   0x0800    /* write only, deprecated */
       
  1198 /* Added to libpng-1.2.34 */
       
  1199 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE 0x0800  /* write only */
       
  1200 #define PNG_TRANSFORM_STRIP_FILLER_AFTER  0x1000  /* write only */
       
  1201 
       
  1202 /* Flags for MNG supported features */
       
  1203 #define PNG_FLAG_MNG_EMPTY_PLTE     0x01
       
  1204 #define PNG_FLAG_MNG_FILTER_64      0x04
       
  1205 #define PNG_ALL_MNG_FEATURES        0x05
       
  1206 
       
  1207 typedef png_voidp (*png_malloc_ptr) PNGARG((png_structp, png_size_t));
       
  1208 typedef void (*png_free_ptr) PNGARG((png_structp, png_voidp));
       
  1209 
       
  1210 /* The structure that holds the information to read and write PNG files.
       
  1211  * The only people who need to care about what is inside of this are the
       
  1212  * people who will be modifying the library for their own special needs.
       
  1213  * It should NOT be accessed directly by an application, except to store
       
  1214  * the jmp_buf.
       
  1215  */
       
  1216 
       
  1217 struct png_struct_def
       
  1218 {
       
  1219 #ifdef PNG_SETJMP_SUPPORTED
       
  1220    jmp_buf jmpbuf;            /* used in png_error */
       
  1221 #endif
       
  1222    png_error_ptr error_fn;    /* function for printing errors and aborting */
       
  1223    png_error_ptr warning_fn;  /* function for printing warnings */
       
  1224    png_voidp error_ptr;       /* user supplied struct for error functions */
       
  1225    png_rw_ptr write_data_fn;  /* function for writing output data */
       
  1226    png_rw_ptr read_data_fn;   /* function for reading input data */
       
  1227    png_voidp io_ptr;          /* ptr to application struct for I/O functions */
       
  1228 
       
  1229 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
       
  1230    png_user_transform_ptr read_user_transform_fn; /* user read transform */
       
  1231 #endif
       
  1232 
       
  1233 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
       
  1234    png_user_transform_ptr write_user_transform_fn; /* user write transform */
       
  1235 #endif
       
  1236 
       
  1237 /* These were added in libpng-1.0.2 */
       
  1238 #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
       
  1239 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
       
  1240     defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
       
  1241    png_voidp user_transform_ptr; /* user supplied struct for user transform */
       
  1242    png_byte user_transform_depth;    /* bit depth of user transformed pixels */
       
  1243    png_byte user_transform_channels; /* channels in user transformed pixels */
       
  1244 #endif
       
  1245 #endif
       
  1246 
       
  1247    png_uint_32 mode;          /* tells us where we are in the PNG file */
       
  1248    png_uint_32 flags;         /* flags indicating various things to libpng */
       
  1249    png_uint_32 transformations; /* which transformations to perform */
       
  1250 
       
  1251    z_stream zstream;          /* pointer to decompression structure (below) */
       
  1252    png_bytep zbuf;            /* buffer for zlib */
       
  1253    png_size_t zbuf_size;      /* size of zbuf */
       
  1254    int zlib_level;            /* holds zlib compression level */
       
  1255    int zlib_method;           /* holds zlib compression method */
       
  1256    int zlib_window_bits;      /* holds zlib compression window bits */
       
  1257    int zlib_mem_level;        /* holds zlib compression memory level */
       
  1258    int zlib_strategy;         /* holds zlib compression strategy */
       
  1259 
       
  1260    png_uint_32 width;         /* width of image in pixels */
       
  1261    png_uint_32 height;        /* height of image in pixels */
       
  1262    png_uint_32 num_rows;      /* number of rows in current pass */
       
  1263    png_uint_32 usr_width;     /* width of row at start of write */
       
  1264    png_uint_32 rowbytes;      /* size of row in bytes */
       
  1265    png_uint_32 irowbytes;     /* size of current interlaced row in bytes */
       
  1266    png_uint_32 iwidth;        /* width of current interlaced row in pixels */
       
  1267    png_uint_32 row_number;    /* current row in interlace pass */
       
  1268    png_bytep prev_row;        /* buffer to save previous (unfiltered) row */
       
  1269    png_bytep row_buf;         /* buffer to save current (unfiltered) row */
       
  1270 #ifndef PNG_NO_WRITE_FILTER
       
  1271    png_bytep sub_row;         /* buffer to save "sub" row when filtering */
       
  1272    png_bytep up_row;          /* buffer to save "up" row when filtering */
       
  1273    png_bytep avg_row;         /* buffer to save "avg" row when filtering */
       
  1274    png_bytep paeth_row;       /* buffer to save "Paeth" row when filtering */
       
  1275 #endif
       
  1276    png_row_info row_info;     /* used for transformation routines */
       
  1277 
       
  1278    png_uint_32 idat_size;     /* current IDAT size for read */
       
  1279    png_uint_32 crc;           /* current chunk CRC value */
       
  1280    png_colorp palette;        /* palette from the input file */
       
  1281    png_uint_16 num_palette;   /* number of color entries in palette */
       
  1282    png_uint_16 num_trans;     /* number of transparency values */
       
  1283    png_byte chunk_name[5];    /* null-terminated name of current chunk */
       
  1284    png_byte compression;      /* file compression type (always 0) */
       
  1285    png_byte filter;           /* file filter type (always 0) */
       
  1286    png_byte interlaced;       /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
       
  1287    png_byte pass;             /* current interlace pass (0 - 6) */
       
  1288    png_byte do_filter;        /* row filter flags (see PNG_FILTER_ below ) */
       
  1289    png_byte color_type;       /* color type of file */
       
  1290    png_byte bit_depth;        /* bit depth of file */
       
  1291    png_byte usr_bit_depth;    /* bit depth of users row */
       
  1292    png_byte pixel_depth;      /* number of bits per pixel */
       
  1293    png_byte channels;         /* number of channels in file */
       
  1294    png_byte usr_channels;     /* channels at start of write */
       
  1295    png_byte sig_bytes;        /* magic bytes read/written from start of file */
       
  1296 
       
  1297 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
       
  1298 #ifdef PNG_LEGACY_SUPPORTED
       
  1299    png_byte filler;           /* filler byte for pixel expansion */
       
  1300 #else
       
  1301    png_uint_16 filler;           /* filler bytes for pixel expansion */
       
  1302 #endif
       
  1303 #endif
       
  1304 
       
  1305 #if defined(PNG_bKGD_SUPPORTED)
       
  1306    png_byte background_gamma_type;
       
  1307 #  ifdef PNG_FLOATING_POINT_SUPPORTED
       
  1308    float background_gamma;
       
  1309 #  endif
       
  1310    png_color_16 background;   /* background color in screen gamma space */
       
  1311 #if defined(PNG_READ_GAMMA_SUPPORTED)
       
  1312    png_color_16 background_1; /* background normalized to gamma 1.0 */
       
  1313 #endif
       
  1314 #endif /* PNG_bKGD_SUPPORTED */
       
  1315 
       
  1316 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
       
  1317    png_flush_ptr output_flush_fn; /* Function for flushing output */
       
  1318    png_uint_32 flush_dist;    /* how many rows apart to flush, 0 - no flush */
       
  1319    png_uint_32 flush_rows;    /* number of rows written since last flush */
       
  1320 #endif
       
  1321 
       
  1322 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
       
  1323    int gamma_shift;      /* number of "insignificant" bits 16-bit gamma */
       
  1324 #ifdef PNG_FLOATING_POINT_SUPPORTED
       
  1325    float gamma;          /* file gamma value */
       
  1326    float screen_gamma;   /* screen gamma value (display_exponent) */
       
  1327 #endif
       
  1328 #endif
       
  1329 
       
  1330 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
       
  1331    png_bytep gamma_table;     /* gamma table for 8-bit depth files */
       
  1332    png_bytep gamma_from_1;    /* converts from 1.0 to screen */
       
  1333    png_bytep gamma_to_1;      /* converts from file to 1.0 */
       
  1334    png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */
       
  1335    png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */
       
  1336    png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */
       
  1337 #endif
       
  1338 
       
  1339 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
       
  1340    png_color_8 sig_bit;       /* significant bits in each available channel */
       
  1341 #endif
       
  1342 
       
  1343 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
       
  1344    png_color_8 shift;         /* shift for significant bit tranformation */
       
  1345 #endif
       
  1346 
       
  1347 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
       
  1348  || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
       
  1349    png_bytep trans;           /* transparency values for paletted files */
       
  1350    png_color_16 trans_values; /* transparency values for non-paletted files */
       
  1351 #endif
       
  1352 
       
  1353    png_read_status_ptr read_row_fn;   /* called after each row is decoded */
       
  1354    png_write_status_ptr write_row_fn; /* called after each row is encoded */
       
  1355 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
       
  1356    png_progressive_info_ptr info_fn; /* called after header data fully read */
       
  1357    png_progressive_row_ptr row_fn;   /* called after each prog. row is decoded */
       
  1358    png_progressive_end_ptr end_fn;   /* called after image is complete */
       
  1359    png_bytep save_buffer_ptr;        /* current location in save_buffer */
       
  1360    png_bytep save_buffer;            /* buffer for previously read data */
       
  1361    png_bytep current_buffer_ptr;     /* current location in current_buffer */
       
  1362    png_bytep current_buffer;         /* buffer for recently used data */
       
  1363    png_uint_32 push_length;          /* size of current input chunk */
       
  1364    png_uint_32 skip_length;          /* bytes to skip in input data */
       
  1365    png_size_t save_buffer_size;      /* amount of data now in save_buffer */
       
  1366    png_size_t save_buffer_max;       /* total size of save_buffer */
       
  1367    png_size_t buffer_size;           /* total amount of available input data */
       
  1368    png_size_t current_buffer_size;   /* amount of data now in current_buffer */
       
  1369    int process_mode;                 /* what push library is currently doing */
       
  1370    int cur_palette;                  /* current push library palette index */
       
  1371 
       
  1372 #  if defined(PNG_TEXT_SUPPORTED)
       
  1373      png_size_t current_text_size;   /* current size of text input data */
       
  1374      png_size_t current_text_left;   /* how much text left to read in input */
       
  1375      png_charp current_text;         /* current text chunk buffer */
       
  1376      png_charp current_text_ptr;     /* current location in current_text */
       
  1377 #  endif /* PNG_TEXT_SUPPORTED */
       
  1378 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
       
  1379 
       
  1380 #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
       
  1381 /* for the Borland special 64K segment handler */
       
  1382    png_bytepp offset_table_ptr;
       
  1383    png_bytep offset_table;
       
  1384    png_uint_16 offset_table_number;
       
  1385    png_uint_16 offset_table_count;
       
  1386    png_uint_16 offset_table_count_free;
       
  1387 #endif
       
  1388 
       
  1389 #if defined(PNG_READ_DITHER_SUPPORTED)
       
  1390    png_bytep palette_lookup;         /* lookup table for dithering */
       
  1391    png_bytep dither_index;           /* index translation for palette files */
       
  1392 #endif
       
  1393 
       
  1394 #if defined(PNG_READ_DITHER_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
       
  1395    png_uint_16p hist;                /* histogram */
       
  1396 #endif
       
  1397 
       
  1398 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
       
  1399    png_byte heuristic_method;        /* heuristic for row filter selection */
       
  1400    png_byte num_prev_filters;        /* number of weights for previous rows */
       
  1401    png_bytep prev_filters;           /* filter type(s) of previous row(s) */
       
  1402    png_uint_16p filter_weights;      /* weight(s) for previous line(s) */
       
  1403    png_uint_16p inv_filter_weights;  /* 1/weight(s) for previous line(s) */
       
  1404    png_uint_16p filter_costs;        /* relative filter calculation cost */
       
  1405    png_uint_16p inv_filter_costs;    /* 1/relative filter calculation cost */
       
  1406 #endif
       
  1407 
       
  1408 #if defined(PNG_TIME_RFC1123_SUPPORTED)
       
  1409    png_charp time_buffer;            /* String to hold RFC 1123 time text */
       
  1410 #endif
       
  1411 
       
  1412 /* New members added in libpng-1.0.6 */
       
  1413 
       
  1414 #ifdef PNG_FREE_ME_SUPPORTED
       
  1415    png_uint_32 free_me;   /* flags items libpng is responsible for freeing */
       
  1416 #endif
       
  1417 
       
  1418 #if defined(PNG_USER_CHUNKS_SUPPORTED)
       
  1419    png_voidp user_chunk_ptr;
       
  1420    png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
       
  1421 #endif
       
  1422 
       
  1423 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
       
  1424    int num_chunk_list;
       
  1425    png_bytep chunk_list;
       
  1426 #endif
       
  1427 
       
  1428 /* New members added in libpng-1.0.3 */
       
  1429 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
       
  1430    png_byte rgb_to_gray_status;
       
  1431    /* These were changed from png_byte in libpng-1.0.6 */
       
  1432    png_uint_16 rgb_to_gray_red_coeff;
       
  1433    png_uint_16 rgb_to_gray_green_coeff;
       
  1434    png_uint_16 rgb_to_gray_blue_coeff;
       
  1435 #endif
       
  1436 
       
  1437 /* New member added in libpng-1.0.4 (renamed in 1.0.9) */
       
  1438 #if defined(PNG_MNG_FEATURES_SUPPORTED) || \
       
  1439     defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
       
  1440     defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
       
  1441 /* Changed from png_byte to png_uint_32 at version 1.2.0 */
       
  1442 #ifdef PNG_1_0_X
       
  1443    png_byte mng_features_permitted;
       
  1444 #else
       
  1445    png_uint_32 mng_features_permitted;
       
  1446 #endif /* PNG_1_0_X */
       
  1447 #endif
       
  1448 
       
  1449 /* New member added in libpng-1.0.7 */
       
  1450 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
       
  1451    png_fixed_point int_gamma;
       
  1452 #endif
       
  1453 
       
  1454 /* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
       
  1455 #if defined(PNG_MNG_FEATURES_SUPPORTED)
       
  1456    png_byte filter_type;
       
  1457 #endif
       
  1458 
       
  1459 #if defined(PNG_1_0_X)
       
  1460 /* New member added in libpng-1.0.10, ifdef'ed out in 1.2.0 */
       
  1461    png_uint_32 row_buf_size;
       
  1462 #endif
       
  1463 
       
  1464 /* New members added in libpng-1.2.0 */
       
  1465 #if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
       
  1466 #  if !defined(PNG_1_0_X)
       
  1467 #    if defined(PNG_MMX_CODE_SUPPORTED)
       
  1468    png_byte     mmx_bitdepth_threshold;
       
  1469    png_uint_32  mmx_rowbytes_threshold;
       
  1470 #    endif
       
  1471    png_uint_32  asm_flags;
       
  1472 #  endif
       
  1473 #endif
       
  1474 
       
  1475 /* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
       
  1476 #ifdef PNG_USER_MEM_SUPPORTED
       
  1477    png_voidp mem_ptr;            /* user supplied struct for mem functions */
       
  1478    png_malloc_ptr malloc_fn;     /* function for allocating memory */
       
  1479    png_free_ptr free_fn;         /* function for freeing memory */
       
  1480 #endif
       
  1481 
       
  1482 /* New member added in libpng-1.0.13 and 1.2.0 */
       
  1483    png_bytep big_row_buf;        /* buffer to save current (unfiltered) row */
       
  1484 
       
  1485 #if defined(PNG_READ_DITHER_SUPPORTED)
       
  1486 /* The following three members were added at version 1.0.14 and 1.2.4 */
       
  1487    png_bytep dither_sort;        /* working sort array */
       
  1488    png_bytep index_to_palette;   /* where the original index currently is */
       
  1489                                  /* in the palette */
       
  1490    png_bytep palette_to_index;   /* which original index points to this */
       
  1491                                  /* palette color */
       
  1492 #endif
       
  1493 
       
  1494 /* New members added in libpng-1.0.16 and 1.2.6 */
       
  1495    png_byte compression_type;
       
  1496 
       
  1497 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
       
  1498    png_uint_32 user_width_max;
       
  1499    png_uint_32 user_height_max;
       
  1500 #endif
       
  1501 
       
  1502 /* New member added in libpng-1.0.25 and 1.2.17 */
       
  1503 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
       
  1504    /* Storage for unknown chunk that the library doesn't recognize. */
       
  1505    png_unknown_chunk unknown_chunk;
       
  1506 #endif
       
  1507 
       
  1508 /* New members added in libpng-1.2.26 */
       
  1509   png_uint_32 old_big_row_buf_size, old_prev_row_size;
       
  1510 
       
  1511 /* New member added in libpng-1.2.30 */
       
  1512   png_charp chunkdata;  /* buffer for reading chunk data */
       
  1513 
       
  1514 };
       
  1515 
       
  1516 
       
  1517 /* This triggers a compiler error in png.c, if png.c and png.h
       
  1518  * do not agree upon the version number.
       
  1519  */
       
  1520 typedef png_structp version_1_2_40;
       
  1521 
       
  1522 typedef png_struct FAR * FAR * png_structpp;
       
  1523 
       
  1524 /* Here are the function definitions most commonly used.  This is not
       
  1525  * the place to find out how to use libpng.  See libpng.txt for the
       
  1526  * full explanation, see example.c for the summary.  This just provides
       
  1527  * a simple one line description of the use of each function.
       
  1528  */
       
  1529 
       
  1530 /* Returns the version number of the library */
       
  1531 extern PNG_EXPORT(png_uint_32,png_access_version_number) PNGARG((void));
       
  1532 
       
  1533 /* Tell lib we have already handled the first <num_bytes> magic bytes.
       
  1534  * Handling more than 8 bytes from the beginning of the file is an error.
       
  1535  */
       
  1536 extern PNG_EXPORT(void,png_set_sig_bytes) PNGARG((png_structp png_ptr,
       
  1537    int num_bytes));
       
  1538 
       
  1539 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
       
  1540  * PNG file.  Returns zero if the supplied bytes match the 8-byte PNG
       
  1541  * signature, and non-zero otherwise.  Having num_to_check == 0 or
       
  1542  * start > 7 will always fail (ie return non-zero).
       
  1543  */
       
  1544 extern PNG_EXPORT(int,png_sig_cmp) PNGARG((png_bytep sig, png_size_t start,
       
  1545    png_size_t num_to_check));
       
  1546 
       
  1547 /* Simple signature checking function.  This is the same as calling
       
  1548  * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
       
  1549  */
       
  1550 extern PNG_EXPORT(int,png_check_sig) PNGARG((png_bytep sig, int num));
       
  1551 
       
  1552 /* Allocate and initialize png_ptr struct for reading, and any other memory. */
       
  1553 extern PNG_EXPORT(png_structp,png_create_read_struct)
       
  1554    PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
       
  1555    png_error_ptr error_fn, png_error_ptr warn_fn));
       
  1556 
       
  1557 /* Allocate and initialize png_ptr struct for writing, and any other memory */
       
  1558 extern PNG_EXPORT(png_structp,png_create_write_struct)
       
  1559    PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
       
  1560    png_error_ptr error_fn, png_error_ptr warn_fn));
       
  1561 
       
  1562 #ifdef PNG_WRITE_SUPPORTED
       
  1563 extern PNG_EXPORT(png_uint_32,png_get_compression_buffer_size)
       
  1564    PNGARG((png_structp png_ptr));
       
  1565 #endif
       
  1566 
       
  1567 #ifdef PNG_WRITE_SUPPORTED
       
  1568 extern PNG_EXPORT(void,png_set_compression_buffer_size)
       
  1569    PNGARG((png_structp png_ptr, png_uint_32 size));
       
  1570 #endif
       
  1571 
       
  1572 /* Reset the compression stream */
       
  1573 extern PNG_EXPORT(int,png_reset_zstream) PNGARG((png_structp png_ptr));
       
  1574 
       
  1575 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
       
  1576 #ifdef PNG_USER_MEM_SUPPORTED
       
  1577 extern PNG_EXPORT(png_structp,png_create_read_struct_2)
       
  1578    PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
       
  1579    png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
       
  1580    png_malloc_ptr malloc_fn, png_free_ptr free_fn));
       
  1581 extern PNG_EXPORT(png_structp,png_create_write_struct_2)
       
  1582    PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
       
  1583    png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
       
  1584    png_malloc_ptr malloc_fn, png_free_ptr free_fn));
       
  1585 #endif
       
  1586 
       
  1587 /* Write a PNG chunk - size, type, (optional) data, CRC. */
       
  1588 extern PNG_EXPORT(void,png_write_chunk) PNGARG((png_structp png_ptr,
       
  1589    png_bytep chunk_name, png_bytep data, png_size_t length));
       
  1590 
       
  1591 /* Write the start of a PNG chunk - length and chunk name. */
       
  1592 extern PNG_EXPORT(void,png_write_chunk_start) PNGARG((png_structp png_ptr,
       
  1593    png_bytep chunk_name, png_uint_32 length));
       
  1594 
       
  1595 /* Write the data of a PNG chunk started with png_write_chunk_start(). */
       
  1596 extern PNG_EXPORT(void,png_write_chunk_data) PNGARG((png_structp png_ptr,
       
  1597    png_bytep data, png_size_t length));
       
  1598 
       
  1599 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */
       
  1600 extern PNG_EXPORT(void,png_write_chunk_end) PNGARG((png_structp png_ptr));
       
  1601 
       
  1602 /* Allocate and initialize the info structure */
       
  1603 extern PNG_EXPORT(png_infop,png_create_info_struct)
       
  1604    PNGARG((png_structp png_ptr));
       
  1605 
       
  1606 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
       
  1607 /* Initialize the info structure (old interface - DEPRECATED) */
       
  1608 extern PNG_EXPORT(void,png_info_init) PNGARG((png_infop info_ptr));
       
  1609 #undef png_info_init
       
  1610 #define png_info_init(info_ptr) png_info_init_3(&info_ptr,\
       
  1611     png_sizeof(png_info));
       
  1612 #endif
       
  1613 
       
  1614 extern PNG_EXPORT(void,png_info_init_3) PNGARG((png_infopp info_ptr,
       
  1615     png_size_t png_info_struct_size));
       
  1616 
       
  1617 /* Writes all the PNG information before the image. */
       
  1618 extern PNG_EXPORT(void,png_write_info_before_PLTE) PNGARG((png_structp png_ptr,
       
  1619    png_infop info_ptr));
       
  1620 extern PNG_EXPORT(void,png_write_info) PNGARG((png_structp png_ptr,
       
  1621    png_infop info_ptr));
       
  1622 
       
  1623 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
       
  1624 /* Read the information before the actual image data. */
       
  1625 extern PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr,
       
  1626    png_infop info_ptr));
       
  1627 #endif
       
  1628 
       
  1629 #if defined(PNG_TIME_RFC1123_SUPPORTED)
       
  1630 extern PNG_EXPORT(png_charp,png_convert_to_rfc1123)
       
  1631    PNGARG((png_structp png_ptr, png_timep ptime));
       
  1632 #endif
       
  1633 
       
  1634 #if !defined(_WIN32_WCE)
       
  1635 /* "time.h" functions are not supported on WindowsCE */
       
  1636 #if defined(PNG_WRITE_tIME_SUPPORTED)
       
  1637 /* Convert from a struct tm to png_time */
       
  1638 extern PNG_EXPORT(void,png_convert_from_struct_tm) PNGARG((png_timep ptime,
       
  1639    struct tm FAR * ttime));
       
  1640 
       
  1641 /* Convert from time_t to png_time.  Uses gmtime() */
       
  1642 extern PNG_EXPORT(void,png_convert_from_time_t) PNGARG((png_timep ptime,
       
  1643    time_t ttime));
       
  1644 #endif /* PNG_WRITE_tIME_SUPPORTED */
       
  1645 #endif /* _WIN32_WCE */
       
  1646 
       
  1647 #if defined(PNG_READ_EXPAND_SUPPORTED)
       
  1648 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
       
  1649 extern PNG_EXPORT(void,png_set_expand) PNGARG((png_structp png_ptr));
       
  1650 #if !defined(PNG_1_0_X)
       
  1651 extern PNG_EXPORT(void,png_set_expand_gray_1_2_4_to_8) PNGARG((png_structp
       
  1652   png_ptr));
       
  1653 #endif
       
  1654 extern PNG_EXPORT(void,png_set_palette_to_rgb) PNGARG((png_structp png_ptr));
       
  1655 extern PNG_EXPORT(void,png_set_tRNS_to_alpha) PNGARG((png_structp png_ptr));
       
  1656 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
       
  1657 /* Deprecated */
       
  1658 extern PNG_EXPORT(void,png_set_gray_1_2_4_to_8) PNGARG((png_structp png_ptr));
       
  1659 #endif
       
  1660 #endif
       
  1661 
       
  1662 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
       
  1663 /* Use blue, green, red order for pixels. */
       
  1664 extern PNG_EXPORT(void,png_set_bgr) PNGARG((png_structp png_ptr));
       
  1665 #endif
       
  1666 
       
  1667 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
       
  1668 /* Expand the grayscale to 24-bit RGB if necessary. */
       
  1669 extern PNG_EXPORT(void,png_set_gray_to_rgb) PNGARG((png_structp png_ptr));
       
  1670 #endif
       
  1671 
       
  1672 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
       
  1673 /* Reduce RGB to grayscale. */
       
  1674 #ifdef PNG_FLOATING_POINT_SUPPORTED
       
  1675 extern PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr,
       
  1676    int error_action, double red, double green ));
       
  1677 #endif
       
  1678 extern PNG_EXPORT(void,png_set_rgb_to_gray_fixed) PNGARG((png_structp png_ptr,
       
  1679    int error_action, png_fixed_point red, png_fixed_point green ));
       
  1680 extern PNG_EXPORT(png_byte,png_get_rgb_to_gray_status) PNGARG((png_structp
       
  1681    png_ptr));
       
  1682 #endif
       
  1683 
       
  1684 extern PNG_EXPORT(void,png_build_grayscale_palette) PNGARG((int bit_depth,
       
  1685    png_colorp palette));
       
  1686 
       
  1687 #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
       
  1688 extern PNG_EXPORT(void,png_set_strip_alpha) PNGARG((png_structp png_ptr));
       
  1689 #endif
       
  1690 
       
  1691 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
       
  1692     defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
       
  1693 extern PNG_EXPORT(void,png_set_swap_alpha) PNGARG((png_structp png_ptr));
       
  1694 #endif
       
  1695 
       
  1696 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
       
  1697     defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
       
  1698 extern PNG_EXPORT(void,png_set_invert_alpha) PNGARG((png_structp png_ptr));
       
  1699 #endif
       
  1700 
       
  1701 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
       
  1702 /* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
       
  1703 extern PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr,
       
  1704    png_uint_32 filler, int flags));
       
  1705 /* The values of the PNG_FILLER_ defines should NOT be changed */
       
  1706 #define PNG_FILLER_BEFORE 0
       
  1707 #define PNG_FILLER_AFTER 1
       
  1708 /* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
       
  1709 #if !defined(PNG_1_0_X)
       
  1710 extern PNG_EXPORT(void,png_set_add_alpha) PNGARG((png_structp png_ptr,
       
  1711    png_uint_32 filler, int flags));
       
  1712 #endif
       
  1713 #endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
       
  1714 
       
  1715 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
       
  1716 /* Swap bytes in 16-bit depth files. */
       
  1717 extern PNG_EXPORT(void,png_set_swap) PNGARG((png_structp png_ptr));
       
  1718 #endif
       
  1719 
       
  1720 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
       
  1721 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
       
  1722 extern PNG_EXPORT(void,png_set_packing) PNGARG((png_structp png_ptr));
       
  1723 #endif
       
  1724 
       
  1725 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
       
  1726 /* Swap packing order of pixels in bytes. */
       
  1727 extern PNG_EXPORT(void,png_set_packswap) PNGARG((png_structp png_ptr));
       
  1728 #endif
       
  1729 
       
  1730 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
       
  1731 /* Converts files to legal bit depths. */
       
  1732 extern PNG_EXPORT(void,png_set_shift) PNGARG((png_structp png_ptr,
       
  1733    png_color_8p true_bits));
       
  1734 #endif
       
  1735 
       
  1736 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
       
  1737     defined(PNG_WRITE_INTERLACING_SUPPORTED)
       
  1738 /* Have the code handle the interlacing.  Returns the number of passes. */
       
  1739 extern PNG_EXPORT(int,png_set_interlace_handling) PNGARG((png_structp png_ptr));
       
  1740 #endif
       
  1741 
       
  1742 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
       
  1743 /* Invert monochrome files */
       
  1744 extern PNG_EXPORT(void,png_set_invert_mono) PNGARG((png_structp png_ptr));
       
  1745 #endif
       
  1746 
       
  1747 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
       
  1748 /* Handle alpha and tRNS by replacing with a background color. */
       
  1749 #ifdef PNG_FLOATING_POINT_SUPPORTED
       
  1750 extern PNG_EXPORT(void,png_set_background) PNGARG((png_structp png_ptr,
       
  1751    png_color_16p background_color, int background_gamma_code,
       
  1752    int need_expand, double background_gamma));
       
  1753 #endif
       
  1754 #define PNG_BACKGROUND_GAMMA_UNKNOWN 0
       
  1755 #define PNG_BACKGROUND_GAMMA_SCREEN  1
       
  1756 #define PNG_BACKGROUND_GAMMA_FILE    2
       
  1757 #define PNG_BACKGROUND_GAMMA_UNIQUE  3
       
  1758 #endif
       
  1759 
       
  1760 #if defined(PNG_READ_16_TO_8_SUPPORTED)
       
  1761 /* Strip the second byte of information from a 16-bit depth file. */
       
  1762 extern PNG_EXPORT(void,png_set_strip_16) PNGARG((png_structp png_ptr));
       
  1763 #endif
       
  1764 
       
  1765 #if defined(PNG_READ_DITHER_SUPPORTED)
       
  1766 /* Turn on dithering, and reduce the palette to the number of colors available. */
       
  1767 extern PNG_EXPORT(void,png_set_dither) PNGARG((png_structp png_ptr,
       
  1768    png_colorp palette, int num_palette, int maximum_colors,
       
  1769    png_uint_16p histogram, int full_dither));
       
  1770 #endif
       
  1771 
       
  1772 #if defined(PNG_READ_GAMMA_SUPPORTED)
       
  1773 /* Handle gamma correction. Screen_gamma=(display_exponent) */
       
  1774 #ifdef PNG_FLOATING_POINT_SUPPORTED
       
  1775 extern PNG_EXPORT(void,png_set_gamma) PNGARG((png_structp png_ptr,
       
  1776    double screen_gamma, double default_file_gamma));
       
  1777 #endif
       
  1778 #endif
       
  1779 
       
  1780 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
       
  1781 #if defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
       
  1782     defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
       
  1783 /* Permit or disallow empty PLTE (0: not permitted, 1: permitted) */
       
  1784 /* Deprecated and will be removed.  Use png_permit_mng_features() instead. */
       
  1785 extern PNG_EXPORT(void,png_permit_empty_plte) PNGARG((png_structp png_ptr,
       
  1786    int empty_plte_permitted));
       
  1787 #endif
       
  1788 #endif
       
  1789 
       
  1790 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
       
  1791 /* Set how many lines between output flushes - 0 for no flushing */
       
  1792 extern PNG_EXPORT(void,png_set_flush) PNGARG((png_structp png_ptr, int nrows));
       
  1793 /* Flush the current PNG output buffer */
       
  1794 extern PNG_EXPORT(void,png_write_flush) PNGARG((png_structp png_ptr));
       
  1795 #endif
       
  1796 
       
  1797 /* Optional update palette with requested transformations */
       
  1798 extern PNG_EXPORT(void,png_start_read_image) PNGARG((png_structp png_ptr));
       
  1799 
       
  1800 /* Optional call to update the users info structure */
       
  1801 extern PNG_EXPORT(void,png_read_update_info) PNGARG((png_structp png_ptr,
       
  1802    png_infop info_ptr));
       
  1803 
       
  1804 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
       
  1805 /* Read one or more rows of image data. */
       
  1806 extern PNG_EXPORT(void,png_read_rows) PNGARG((png_structp png_ptr,
       
  1807    png_bytepp row, png_bytepp display_row, png_uint_32 num_rows));
       
  1808 #endif
       
  1809 
       
  1810 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
       
  1811 /* Read a row of data. */
       
  1812 extern PNG_EXPORT(void,png_read_row) PNGARG((png_structp png_ptr,
       
  1813    png_bytep row,
       
  1814    png_bytep display_row));
       
  1815 #endif
       
  1816 
       
  1817 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
       
  1818 /* Read the whole image into memory at once. */
       
  1819 extern PNG_EXPORT(void,png_read_image) PNGARG((png_structp png_ptr,
       
  1820    png_bytepp image));
       
  1821 #endif
       
  1822 
       
  1823 /* Write a row of image data */
       
  1824 extern PNG_EXPORT(void,png_write_row) PNGARG((png_structp png_ptr,
       
  1825    png_bytep row));
       
  1826 
       
  1827 /* Write a few rows of image data */
       
  1828 extern PNG_EXPORT(void,png_write_rows) PNGARG((png_structp png_ptr,
       
  1829    png_bytepp row, png_uint_32 num_rows));
       
  1830 
       
  1831 /* Write the image data */
       
  1832 extern PNG_EXPORT(void,png_write_image) PNGARG((png_structp png_ptr,
       
  1833    png_bytepp image));
       
  1834 
       
  1835 /* Writes the end of the PNG file. */
       
  1836 extern PNG_EXPORT(void,png_write_end) PNGARG((png_structp png_ptr,
       
  1837    png_infop info_ptr));
       
  1838 
       
  1839 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
       
  1840 /* Read the end of the PNG file. */
       
  1841 extern PNG_EXPORT(void,png_read_end) PNGARG((png_structp png_ptr,
       
  1842    png_infop info_ptr));
       
  1843 #endif
       
  1844 
       
  1845 /* Free any memory associated with the png_info_struct */
       
  1846 extern PNG_EXPORT(void,png_destroy_info_struct) PNGARG((png_structp png_ptr,
       
  1847    png_infopp info_ptr_ptr));
       
  1848 
       
  1849 /* Free any memory associated with the png_struct and the png_info_structs */
       
  1850 extern PNG_EXPORT(void,png_destroy_read_struct) PNGARG((png_structpp
       
  1851    png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
       
  1852 
       
  1853 /* Free all memory used by the read (old method - NOT DLL EXPORTED) */
       
  1854 extern void png_read_destroy PNGARG((png_structp png_ptr, png_infop info_ptr,
       
  1855    png_infop end_info_ptr));
       
  1856 
       
  1857 /* Free any memory associated with the png_struct and the png_info_structs */
       
  1858 extern PNG_EXPORT(void,png_destroy_write_struct)
       
  1859    PNGARG((png_structpp png_ptr_ptr, png_infopp info_ptr_ptr));
       
  1860 
       
  1861 /* Free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */
       
  1862 extern void png_write_destroy PNGARG((png_structp png_ptr));
       
  1863 
       
  1864 /* Set the libpng method of handling chunk CRC errors */
       
  1865 extern PNG_EXPORT(void,png_set_crc_action) PNGARG((png_structp png_ptr,
       
  1866    int crit_action, int ancil_action));
       
  1867 
       
  1868 /* Values for png_set_crc_action() to say how to handle CRC errors in
       
  1869  * ancillary and critical chunks, and whether to use the data contained
       
  1870  * therein.  Note that it is impossible to "discard" data in a critical
       
  1871  * chunk.  For versions prior to 0.90, the action was always error/quit,
       
  1872  * whereas in version 0.90 and later, the action for CRC errors in ancillary
       
  1873  * chunks is warn/discard.  These values should NOT be changed.
       
  1874  *
       
  1875  *      value                       action:critical     action:ancillary
       
  1876  */
       
  1877 #define PNG_CRC_DEFAULT       0  /* error/quit          warn/discard data */
       
  1878 #define PNG_CRC_ERROR_QUIT    1  /* error/quit          error/quit        */
       
  1879 #define PNG_CRC_WARN_DISCARD  2  /* (INVALID)           warn/discard data */
       
  1880 #define PNG_CRC_WARN_USE      3  /* warn/use data       warn/use data     */
       
  1881 #define PNG_CRC_QUIET_USE     4  /* quiet/use data      quiet/use data    */
       
  1882 #define PNG_CRC_NO_CHANGE     5  /* use current value   use current value */
       
  1883 
       
  1884 /* These functions give the user control over the scan-line filtering in
       
  1885  * libpng and the compression methods used by zlib.  These functions are
       
  1886  * mainly useful for testing, as the defaults should work with most users.
       
  1887  * Those users who are tight on memory or want faster performance at the
       
  1888  * expense of compression can modify them.  See the compression library
       
  1889  * header file (zlib.h) for an explination of the compression functions.
       
  1890  */
       
  1891 
       
  1892 /* Set the filtering method(s) used by libpng.  Currently, the only valid
       
  1893  * value for "method" is 0.
       
  1894  */
       
  1895 extern PNG_EXPORT(void,png_set_filter) PNGARG((png_structp png_ptr, int method,
       
  1896    int filters));
       
  1897 
       
  1898 /* Flags for png_set_filter() to say which filters to use.  The flags
       
  1899  * are chosen so that they don't conflict with real filter types
       
  1900  * below, in case they are supplied instead of the #defined constants.
       
  1901  * These values should NOT be changed.
       
  1902  */
       
  1903 #define PNG_NO_FILTERS     0x00
       
  1904 #define PNG_FILTER_NONE    0x08
       
  1905 #define PNG_FILTER_SUB     0x10
       
  1906 #define PNG_FILTER_UP      0x20
       
  1907 #define PNG_FILTER_AVG     0x40
       
  1908 #define PNG_FILTER_PAETH   0x80
       
  1909 #define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
       
  1910                          PNG_FILTER_AVG | PNG_FILTER_PAETH)
       
  1911 
       
  1912 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
       
  1913  * These defines should NOT be changed.
       
  1914  */
       
  1915 #define PNG_FILTER_VALUE_NONE  0
       
  1916 #define PNG_FILTER_VALUE_SUB   1
       
  1917 #define PNG_FILTER_VALUE_UP    2
       
  1918 #define PNG_FILTER_VALUE_AVG   3
       
  1919 #define PNG_FILTER_VALUE_PAETH 4
       
  1920 #define PNG_FILTER_VALUE_LAST  5
       
  1921 
       
  1922 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* EXPERIMENTAL */
       
  1923 /* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
       
  1924  * defines, either the default (minimum-sum-of-absolute-differences), or
       
  1925  * the experimental method (weighted-minimum-sum-of-absolute-differences).
       
  1926  *
       
  1927  * Weights are factors >= 1.0, indicating how important it is to keep the
       
  1928  * filter type consistent between rows.  Larger numbers mean the current
       
  1929  * filter is that many times as likely to be the same as the "num_weights"
       
  1930  * previous filters.  This is cumulative for each previous row with a weight.
       
  1931  * There needs to be "num_weights" values in "filter_weights", or it can be
       
  1932  * NULL if the weights aren't being specified.  Weights have no influence on
       
  1933  * the selection of the first row filter.  Well chosen weights can (in theory)
       
  1934  * improve the compression for a given image.
       
  1935  *
       
  1936  * Costs are factors >= 1.0 indicating the relative decoding costs of a
       
  1937  * filter type.  Higher costs indicate more decoding expense, and are
       
  1938  * therefore less likely to be selected over a filter with lower computational
       
  1939  * costs.  There needs to be a value in "filter_costs" for each valid filter
       
  1940  * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
       
  1941  * setting the costs.  Costs try to improve the speed of decompression without
       
  1942  * unduly increasing the compressed image size.
       
  1943  *
       
  1944  * A negative weight or cost indicates the default value is to be used, and
       
  1945  * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
       
  1946  * The default values for both weights and costs are currently 1.0, but may
       
  1947  * change if good general weighting/cost heuristics can be found.  If both
       
  1948  * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
       
  1949  * to the UNWEIGHTED method, but with added encoding time/computation.
       
  1950  */
       
  1951 #ifdef PNG_FLOATING_POINT_SUPPORTED
       
  1952 extern PNG_EXPORT(void,png_set_filter_heuristics) PNGARG((png_structp png_ptr,
       
  1953    int heuristic_method, int num_weights, png_doublep filter_weights,
       
  1954    png_doublep filter_costs));
       
  1955 #endif
       
  1956 #endif /*  PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
       
  1957 
       
  1958 /* Heuristic used for row filter selection.  These defines should NOT be
       
  1959  * changed.
       
  1960  */
       
  1961 #define PNG_FILTER_HEURISTIC_DEFAULT    0  /* Currently "UNWEIGHTED" */
       
  1962 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1  /* Used by libpng < 0.95 */
       
  1963 #define PNG_FILTER_HEURISTIC_WEIGHTED   2  /* Experimental feature */
       
  1964 #define PNG_FILTER_HEURISTIC_LAST       3  /* Not a valid value */
       
  1965 
       
  1966 /* Set the library compression level.  Currently, valid values range from
       
  1967  * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
       
  1968  * (0 - no compression, 9 - "maximal" compression).  Note that tests have
       
  1969  * shown that zlib compression levels 3-6 usually perform as well as level 9
       
  1970  * for PNG images, and do considerably fewer caclulations.  In the future,
       
  1971  * these values may not correspond directly to the zlib compression levels.
       
  1972  */
       
  1973 extern PNG_EXPORT(void,png_set_compression_level) PNGARG((png_structp png_ptr,
       
  1974    int level));
       
  1975 
       
  1976 extern PNG_EXPORT(void,png_set_compression_mem_level)
       
  1977    PNGARG((png_structp png_ptr, int mem_level));
       
  1978 
       
  1979 extern PNG_EXPORT(void,png_set_compression_strategy)
       
  1980    PNGARG((png_structp png_ptr, int strategy));
       
  1981 
       
  1982 extern PNG_EXPORT(void,png_set_compression_window_bits)
       
  1983    PNGARG((png_structp png_ptr, int window_bits));
       
  1984 
       
  1985 extern PNG_EXPORT(void,png_set_compression_method) PNGARG((png_structp png_ptr,
       
  1986    int method));
       
  1987 
       
  1988 /* These next functions are called for input/output, memory, and error
       
  1989  * handling.  They are in the file pngrio.c, pngwio.c, and pngerror.c,
       
  1990  * and call standard C I/O routines such as fread(), fwrite(), and
       
  1991  * fprintf().  These functions can be made to use other I/O routines
       
  1992  * at run time for those applications that need to handle I/O in a
       
  1993  * different manner by calling png_set_???_fn().  See libpng.txt for
       
  1994  * more information.
       
  1995  */
       
  1996 
       
  1997 #if !defined(PNG_NO_STDIO)
       
  1998 /* Initialize the input/output for the PNG file to the default functions. */
       
  1999 extern PNG_EXPORT(void,png_init_io) PNGARG((png_structp png_ptr, png_FILE_p fp));
       
  2000 #endif
       
  2001 
       
  2002 /* Replace the (error and abort), and warning functions with user
       
  2003  * supplied functions.  If no messages are to be printed you must still
       
  2004  * write and use replacement functions. The replacement error_fn should
       
  2005  * still do a longjmp to the last setjmp location if you are using this
       
  2006  * method of error handling.  If error_fn or warning_fn is NULL, the
       
  2007  * default function will be used.
       
  2008  */
       
  2009 
       
  2010 extern PNG_EXPORT(void,png_set_error_fn) PNGARG((png_structp png_ptr,
       
  2011    png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
       
  2012 
       
  2013 /* Return the user pointer associated with the error functions */
       
  2014 extern PNG_EXPORT(png_voidp,png_get_error_ptr) PNGARG((png_structp png_ptr));
       
  2015 
       
  2016 /* Replace the default data output functions with a user supplied one(s).
       
  2017  * If buffered output is not used, then output_flush_fn can be set to NULL.
       
  2018  * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
       
  2019  * output_flush_fn will be ignored (and thus can be NULL).
       
  2020  * It is probably a mistake to use NULL for output_flush_fn if
       
  2021  * write_data_fn is not also NULL unless you have built libpng with
       
  2022  * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
       
  2023  * default flush function, which uses the standard *FILE structure, will
       
  2024  * be used.
       
  2025  */
       
  2026 extern PNG_EXPORT(void,png_set_write_fn) PNGARG((png_structp png_ptr,
       
  2027    png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
       
  2028 
       
  2029 /* Replace the default data input function with a user supplied one. */
       
  2030 extern PNG_EXPORT(void,png_set_read_fn) PNGARG((png_structp png_ptr,
       
  2031    png_voidp io_ptr, png_rw_ptr read_data_fn));
       
  2032 
       
  2033 /* Return the user pointer associated with the I/O functions */
       
  2034 extern PNG_EXPORT(png_voidp,png_get_io_ptr) PNGARG((png_structp png_ptr));
       
  2035 
       
  2036 extern PNG_EXPORT(void,png_set_read_status_fn) PNGARG((png_structp png_ptr,
       
  2037    png_read_status_ptr read_row_fn));
       
  2038 
       
  2039 extern PNG_EXPORT(void,png_set_write_status_fn) PNGARG((png_structp png_ptr,
       
  2040    png_write_status_ptr write_row_fn));
       
  2041 
       
  2042 #ifdef PNG_USER_MEM_SUPPORTED
       
  2043 /* Replace the default memory allocation functions with user supplied one(s). */
       
  2044 extern PNG_EXPORT(void,png_set_mem_fn) PNGARG((png_structp png_ptr,
       
  2045    png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn));
       
  2046 /* Return the user pointer associated with the memory functions */
       
  2047 extern PNG_EXPORT(png_voidp,png_get_mem_ptr) PNGARG((png_structp png_ptr));
       
  2048 #endif
       
  2049 
       
  2050 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
       
  2051     defined(PNG_LEGACY_SUPPORTED)
       
  2052 extern PNG_EXPORT(void,png_set_read_user_transform_fn) PNGARG((png_structp
       
  2053    png_ptr, png_user_transform_ptr read_user_transform_fn));
       
  2054 #endif
       
  2055 
       
  2056 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
       
  2057     defined(PNG_LEGACY_SUPPORTED)
       
  2058 extern PNG_EXPORT(void,png_set_write_user_transform_fn) PNGARG((png_structp
       
  2059    png_ptr, png_user_transform_ptr write_user_transform_fn));
       
  2060 #endif
       
  2061 
       
  2062 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
       
  2063     defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
       
  2064     defined(PNG_LEGACY_SUPPORTED)
       
  2065 extern PNG_EXPORT(void,png_set_user_transform_info) PNGARG((png_structp
       
  2066    png_ptr, png_voidp user_transform_ptr, int user_transform_depth,
       
  2067    int user_transform_channels));
       
  2068 /* Return the user pointer associated with the user transform functions */
       
  2069 extern PNG_EXPORT(png_voidp,png_get_user_transform_ptr)
       
  2070    PNGARG((png_structp png_ptr));
       
  2071 #endif
       
  2072 
       
  2073 #ifdef PNG_USER_CHUNKS_SUPPORTED
       
  2074 extern PNG_EXPORT(void,png_set_read_user_chunk_fn) PNGARG((png_structp png_ptr,
       
  2075    png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
       
  2076 extern PNG_EXPORT(png_voidp,png_get_user_chunk_ptr) PNGARG((png_structp
       
  2077    png_ptr));
       
  2078 #endif
       
  2079 
       
  2080 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
       
  2081 /* Sets the function callbacks for the push reader, and a pointer to a
       
  2082  * user-defined structure available to the callback functions.
       
  2083  */
       
  2084 extern PNG_EXPORT(void,png_set_progressive_read_fn) PNGARG((png_structp png_ptr,
       
  2085    png_voidp progressive_ptr,
       
  2086    png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
       
  2087    png_progressive_end_ptr end_fn));
       
  2088 
       
  2089 /* Returns the user pointer associated with the push read functions */
       
  2090 extern PNG_EXPORT(png_voidp,png_get_progressive_ptr)
       
  2091    PNGARG((png_structp png_ptr));
       
  2092 
       
  2093 /* Function to be called when data becomes available */
       
  2094 extern PNG_EXPORT(void,png_process_data) PNGARG((png_structp png_ptr,
       
  2095    png_infop info_ptr, png_bytep buffer, png_size_t buffer_size));
       
  2096 
       
  2097 /* Function that combines rows.  Not very much different than the
       
  2098  * png_combine_row() call.  Is this even used?????
       
  2099  */
       
  2100 extern PNG_EXPORT(void,png_progressive_combine_row) PNGARG((png_structp png_ptr,
       
  2101    png_bytep old_row, png_bytep new_row));
       
  2102 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
       
  2103 
       
  2104 extern PNG_EXPORT(png_voidp,png_malloc) PNGARG((png_structp png_ptr,
       
  2105    png_uint_32 size));
       
  2106 
       
  2107 #if defined(PNG_1_0_X)
       
  2108 #  define png_malloc_warn png_malloc
       
  2109 #else
       
  2110 /* Added at libpng version 1.2.4 */
       
  2111 extern PNG_EXPORT(png_voidp,png_malloc_warn) PNGARG((png_structp png_ptr,
       
  2112    png_uint_32 size));
       
  2113 #endif
       
  2114 
       
  2115 /* Frees a pointer allocated by png_malloc() */
       
  2116 extern PNG_EXPORT(void,png_free) PNGARG((png_structp png_ptr, png_voidp ptr));
       
  2117 
       
  2118 #if defined(PNG_1_0_X)
       
  2119 /* Function to allocate memory for zlib. */
       
  2120 extern PNG_EXPORT(voidpf,png_zalloc) PNGARG((voidpf png_ptr, uInt items,
       
  2121    uInt size));
       
  2122 
       
  2123 /* Function to free memory for zlib */
       
  2124 extern PNG_EXPORT(void,png_zfree) PNGARG((voidpf png_ptr, voidpf ptr));
       
  2125 #endif
       
  2126 
       
  2127 /* Free data that was allocated internally */
       
  2128 extern PNG_EXPORT(void,png_free_data) PNGARG((png_structp png_ptr,
       
  2129    png_infop info_ptr, png_uint_32 free_me, int num));
       
  2130 #ifdef PNG_FREE_ME_SUPPORTED
       
  2131 /* Reassign responsibility for freeing existing data, whether allocated
       
  2132  * by libpng or by the application
       
  2133  */
       
  2134 extern PNG_EXPORT(void,png_data_freer) PNGARG((png_structp png_ptr,
       
  2135    png_infop info_ptr, int freer, png_uint_32 mask));
       
  2136 #endif
       
  2137 /* Assignments for png_data_freer */
       
  2138 #define PNG_DESTROY_WILL_FREE_DATA 1
       
  2139 #define PNG_SET_WILL_FREE_DATA 1
       
  2140 #define PNG_USER_WILL_FREE_DATA 2
       
  2141 /* Flags for png_ptr->free_me and info_ptr->free_me */
       
  2142 #define PNG_FREE_HIST 0x0008
       
  2143 #define PNG_FREE_ICCP 0x0010
       
  2144 #define PNG_FREE_SPLT 0x0020
       
  2145 #define PNG_FREE_ROWS 0x0040
       
  2146 #define PNG_FREE_PCAL 0x0080
       
  2147 #define PNG_FREE_SCAL 0x0100
       
  2148 #define PNG_FREE_UNKN 0x0200
       
  2149 #define PNG_FREE_LIST 0x0400
       
  2150 #define PNG_FREE_PLTE 0x1000
       
  2151 #define PNG_FREE_TRNS 0x2000
       
  2152 #define PNG_FREE_TEXT 0x4000
       
  2153 #define PNG_FREE_ALL  0x7fff
       
  2154 #define PNG_FREE_MUL  0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
       
  2155 
       
  2156 #ifdef PNG_USER_MEM_SUPPORTED
       
  2157 extern PNG_EXPORT(png_voidp,png_malloc_default) PNGARG((png_structp png_ptr,
       
  2158    png_uint_32 size));
       
  2159 extern PNG_EXPORT(void,png_free_default) PNGARG((png_structp png_ptr,
       
  2160    png_voidp ptr));
       
  2161 #endif
       
  2162 
       
  2163 extern PNG_EXPORT(png_voidp,png_memcpy_check) PNGARG((png_structp png_ptr,
       
  2164    png_voidp s1, png_voidp s2, png_uint_32 size));
       
  2165 
       
  2166 extern PNG_EXPORT(png_voidp,png_memset_check) PNGARG((png_structp png_ptr,
       
  2167    png_voidp s1, int value, png_uint_32 size));
       
  2168 
       
  2169 #if defined(USE_FAR_KEYWORD)  /* memory model conversion function */
       
  2170 extern void *png_far_to_near PNGARG((png_structp png_ptr,png_voidp ptr,
       
  2171    int check));
       
  2172 #endif /* USE_FAR_KEYWORD */
       
  2173 
       
  2174 #ifndef PNG_NO_ERROR_TEXT
       
  2175 /* Fatal error in PNG image of libpng - can't continue */
       
  2176 extern PNG_EXPORT(void,png_error) PNGARG((png_structp png_ptr,
       
  2177    png_const_charp error_message));
       
  2178 
       
  2179 /* The same, but the chunk name is prepended to the error string. */
       
  2180 extern PNG_EXPORT(void,png_chunk_error) PNGARG((png_structp png_ptr,
       
  2181    png_const_charp error_message));
       
  2182 #else
       
  2183 /* Fatal error in PNG image of libpng - can't continue */
       
  2184 extern PNG_EXPORT(void,png_err) PNGARG((png_structp png_ptr));
       
  2185 #endif
       
  2186 
       
  2187 #ifndef PNG_NO_WARNINGS
       
  2188 /* Non-fatal error in libpng.  Can continue, but may have a problem. */
       
  2189 extern PNG_EXPORT(void,png_warning) PNGARG((png_structp png_ptr,
       
  2190    png_const_charp warning_message));
       
  2191 
       
  2192 #ifdef PNG_READ_SUPPORTED
       
  2193 /* Non-fatal error in libpng, chunk name is prepended to message. */
       
  2194 extern PNG_EXPORT(void,png_chunk_warning) PNGARG((png_structp png_ptr,
       
  2195    png_const_charp warning_message));
       
  2196 #endif /* PNG_READ_SUPPORTED */
       
  2197 #endif /* PNG_NO_WARNINGS */
       
  2198 
       
  2199 /* The png_set_<chunk> functions are for storing values in the png_info_struct.
       
  2200  * Similarly, the png_get_<chunk> calls are used to read values from the
       
  2201  * png_info_struct, either storing the parameters in the passed variables, or
       
  2202  * setting pointers into the png_info_struct where the data is stored.  The
       
  2203  * png_get_<chunk> functions return a non-zero value if the data was available
       
  2204  * in info_ptr, or return zero and do not change any of the parameters if the
       
  2205  * data was not available.
       
  2206  *
       
  2207  * These functions should be used instead of directly accessing png_info
       
  2208  * to avoid problems with future changes in the size and internal layout of
       
  2209  * png_info_struct.
       
  2210  */
       
  2211 /* Returns "flag" if chunk data is valid in info_ptr. */
       
  2212 extern PNG_EXPORT(png_uint_32,png_get_valid) PNGARG((png_structp png_ptr,
       
  2213 png_infop info_ptr, png_uint_32 flag));
       
  2214 
       
  2215 /* Returns number of bytes needed to hold a transformed row. */
       
  2216 extern PNG_EXPORT(png_uint_32,png_get_rowbytes) PNGARG((png_structp png_ptr,
       
  2217 png_infop info_ptr));
       
  2218 
       
  2219 #if defined(PNG_INFO_IMAGE_SUPPORTED)
       
  2220 /* Returns row_pointers, which is an array of pointers to scanlines that was
       
  2221  * returned from png_read_png().
       
  2222  */
       
  2223 extern PNG_EXPORT(png_bytepp,png_get_rows) PNGARG((png_structp png_ptr,
       
  2224 png_infop info_ptr));
       
  2225 /* Set row_pointers, which is an array of pointers to scanlines for use
       
  2226  * by png_write_png().
       
  2227  */
       
  2228 extern PNG_EXPORT(void,png_set_rows) PNGARG((png_structp png_ptr,
       
  2229    png_infop info_ptr, png_bytepp row_pointers));
       
  2230 #endif
       
  2231 
       
  2232 /* Returns number of color channels in image. */
       
  2233 extern PNG_EXPORT(png_byte,png_get_channels) PNGARG((png_structp png_ptr,
       
  2234 png_infop info_ptr));
       
  2235 
       
  2236 #ifdef PNG_EASY_ACCESS_SUPPORTED
       
  2237 /* Returns image width in pixels. */
       
  2238 extern PNG_EXPORT(png_uint_32, png_get_image_width) PNGARG((png_structp
       
  2239 png_ptr, png_infop info_ptr));
       
  2240 
       
  2241 /* Returns image height in pixels. */
       
  2242 extern PNG_EXPORT(png_uint_32, png_get_image_height) PNGARG((png_structp
       
  2243 png_ptr, png_infop info_ptr));
       
  2244 
       
  2245 /* Returns image bit_depth. */
       
  2246 extern PNG_EXPORT(png_byte, png_get_bit_depth) PNGARG((png_structp
       
  2247 png_ptr, png_infop info_ptr));
       
  2248 
       
  2249 /* Returns image color_type. */
       
  2250 extern PNG_EXPORT(png_byte, png_get_color_type) PNGARG((png_structp
       
  2251 png_ptr, png_infop info_ptr));
       
  2252 
       
  2253 /* Returns image filter_type. */
       
  2254 extern PNG_EXPORT(png_byte, png_get_filter_type) PNGARG((png_structp
       
  2255 png_ptr, png_infop info_ptr));
       
  2256 
       
  2257 /* Returns image interlace_type. */
       
  2258 extern PNG_EXPORT(png_byte, png_get_interlace_type) PNGARG((png_structp
       
  2259 png_ptr, png_infop info_ptr));
       
  2260 
       
  2261 /* Returns image compression_type. */
       
  2262 extern PNG_EXPORT(png_byte, png_get_compression_type) PNGARG((png_structp
       
  2263 png_ptr, png_infop info_ptr));
       
  2264 
       
  2265 /* Returns image resolution in pixels per meter, from pHYs chunk data. */
       
  2266 extern PNG_EXPORT(png_uint_32, png_get_pixels_per_meter) PNGARG((png_structp
       
  2267 png_ptr, png_infop info_ptr));
       
  2268 extern PNG_EXPORT(png_uint_32, png_get_x_pixels_per_meter) PNGARG((png_structp
       
  2269 png_ptr, png_infop info_ptr));
       
  2270 extern PNG_EXPORT(png_uint_32, png_get_y_pixels_per_meter) PNGARG((png_structp
       
  2271 png_ptr, png_infop info_ptr));
       
  2272 
       
  2273 /* Returns pixel aspect ratio, computed from pHYs chunk data.  */
       
  2274 #ifdef PNG_FLOATING_POINT_SUPPORTED
       
  2275 extern PNG_EXPORT(float, png_get_pixel_aspect_ratio) PNGARG((png_structp
       
  2276 png_ptr, png_infop info_ptr));
       
  2277 #endif
       
  2278 
       
  2279 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
       
  2280 extern PNG_EXPORT(png_int_32, png_get_x_offset_pixels) PNGARG((png_structp
       
  2281 png_ptr, png_infop info_ptr));
       
  2282 extern PNG_EXPORT(png_int_32, png_get_y_offset_pixels) PNGARG((png_structp
       
  2283 png_ptr, png_infop info_ptr));
       
  2284 extern PNG_EXPORT(png_int_32, png_get_x_offset_microns) PNGARG((png_structp
       
  2285 png_ptr, png_infop info_ptr));
       
  2286 extern PNG_EXPORT(png_int_32, png_get_y_offset_microns) PNGARG((png_structp
       
  2287 png_ptr, png_infop info_ptr));
       
  2288 
       
  2289 #endif /* PNG_EASY_ACCESS_SUPPORTED */
       
  2290 
       
  2291 /* Returns pointer to signature string read from PNG header */
       
  2292 extern PNG_EXPORT(png_bytep,png_get_signature) PNGARG((png_structp png_ptr,
       
  2293 png_infop info_ptr));
       
  2294 
       
  2295 #if defined(PNG_bKGD_SUPPORTED)
       
  2296 extern PNG_EXPORT(png_uint_32,png_get_bKGD) PNGARG((png_structp png_ptr,
       
  2297    png_infop info_ptr, png_color_16p *background));
       
  2298 #endif
       
  2299 
       
  2300 #if defined(PNG_bKGD_SUPPORTED)
       
  2301 extern PNG_EXPORT(void,png_set_bKGD) PNGARG((png_structp png_ptr,
       
  2302    png_infop info_ptr, png_color_16p background));
       
  2303 #endif
       
  2304 
       
  2305 #if defined(PNG_cHRM_SUPPORTED)
       
  2306 #ifdef PNG_FLOATING_POINT_SUPPORTED
       
  2307 extern PNG_EXPORT(png_uint_32,png_get_cHRM) PNGARG((png_structp png_ptr,
       
  2308    png_infop info_ptr, double *white_x, double *white_y, double *red_x,
       
  2309    double *red_y, double *green_x, double *green_y, double *blue_x,
       
  2310    double *blue_y));
       
  2311 #endif
       
  2312 #ifdef PNG_FIXED_POINT_SUPPORTED
       
  2313 extern PNG_EXPORT(png_uint_32,png_get_cHRM_fixed) PNGARG((png_structp png_ptr,
       
  2314    png_infop info_ptr, png_fixed_point *int_white_x, png_fixed_point
       
  2315    *int_white_y, png_fixed_point *int_red_x, png_fixed_point *int_red_y,
       
  2316    png_fixed_point *int_green_x, png_fixed_point *int_green_y, png_fixed_point
       
  2317    *int_blue_x, png_fixed_point *int_blue_y));
       
  2318 #endif
       
  2319 #endif
       
  2320 
       
  2321 #if defined(PNG_cHRM_SUPPORTED)
       
  2322 #ifdef PNG_FLOATING_POINT_SUPPORTED
       
  2323 extern PNG_EXPORT(void,png_set_cHRM) PNGARG((png_structp png_ptr,
       
  2324    png_infop info_ptr, double white_x, double white_y, double red_x,
       
  2325    double red_y, double green_x, double green_y, double blue_x, double blue_y));
       
  2326 #endif
       
  2327 #ifdef PNG_FIXED_POINT_SUPPORTED
       
  2328 extern PNG_EXPORT(void,png_set_cHRM_fixed) PNGARG((png_structp png_ptr,
       
  2329    png_infop info_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y,
       
  2330    png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
       
  2331    int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
       
  2332    png_fixed_point int_blue_y));
       
  2333 #endif
       
  2334 #endif
       
  2335 
       
  2336 #if defined(PNG_gAMA_SUPPORTED)
       
  2337 #ifdef PNG_FLOATING_POINT_SUPPORTED
       
  2338 extern PNG_EXPORT(png_uint_32,png_get_gAMA) PNGARG((png_structp png_ptr,
       
  2339    png_infop info_ptr, double *file_gamma));
       
  2340 #endif
       
  2341 extern PNG_EXPORT(png_uint_32,png_get_gAMA_fixed) PNGARG((png_structp png_ptr,
       
  2342    png_infop info_ptr, png_fixed_point *int_file_gamma));
       
  2343 #endif
       
  2344 
       
  2345 #if defined(PNG_gAMA_SUPPORTED)
       
  2346 #ifdef PNG_FLOATING_POINT_SUPPORTED
       
  2347 extern PNG_EXPORT(void,png_set_gAMA) PNGARG((png_structp png_ptr,
       
  2348    png_infop info_ptr, double file_gamma));
       
  2349 #endif
       
  2350 extern PNG_EXPORT(void,png_set_gAMA_fixed) PNGARG((png_structp png_ptr,
       
  2351    png_infop info_ptr, png_fixed_point int_file_gamma));
       
  2352 #endif
       
  2353 
       
  2354 #if defined(PNG_hIST_SUPPORTED)
       
  2355 extern PNG_EXPORT(png_uint_32,png_get_hIST) PNGARG((png_structp png_ptr,
       
  2356    png_infop info_ptr, png_uint_16p *hist));
       
  2357 #endif
       
  2358 
       
  2359 #if defined(PNG_hIST_SUPPORTED)
       
  2360 extern PNG_EXPORT(void,png_set_hIST) PNGARG((png_structp png_ptr,
       
  2361    png_infop info_ptr, png_uint_16p hist));
       
  2362 #endif
       
  2363 
       
  2364 extern PNG_EXPORT(png_uint_32,png_get_IHDR) PNGARG((png_structp png_ptr,
       
  2365    png_infop info_ptr, png_uint_32 *width, png_uint_32 *height,
       
  2366    int *bit_depth, int *color_type, int *interlace_method,
       
  2367    int *compression_method, int *filter_method));
       
  2368 
       
  2369 extern PNG_EXPORT(void,png_set_IHDR) PNGARG((png_structp png_ptr,
       
  2370    png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
       
  2371    int color_type, int interlace_method, int compression_method,
       
  2372    int filter_method));
       
  2373 
       
  2374 #if defined(PNG_oFFs_SUPPORTED)
       
  2375 extern PNG_EXPORT(png_uint_32,png_get_oFFs) PNGARG((png_structp png_ptr,
       
  2376    png_infop info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
       
  2377    int *unit_type));
       
  2378 #endif
       
  2379 
       
  2380 #if defined(PNG_oFFs_SUPPORTED)
       
  2381 extern PNG_EXPORT(void,png_set_oFFs) PNGARG((png_structp png_ptr,
       
  2382    png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y,
       
  2383    int unit_type));
       
  2384 #endif
       
  2385 
       
  2386 #if defined(PNG_pCAL_SUPPORTED)
       
  2387 extern PNG_EXPORT(png_uint_32,png_get_pCAL) PNGARG((png_structp png_ptr,
       
  2388    png_infop info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1,
       
  2389    int *type, int *nparams, png_charp *units, png_charpp *params));
       
  2390 #endif
       
  2391 
       
  2392 #if defined(PNG_pCAL_SUPPORTED)
       
  2393 extern PNG_EXPORT(void,png_set_pCAL) PNGARG((png_structp png_ptr,
       
  2394    png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1,
       
  2395    int type, int nparams, png_charp units, png_charpp params));
       
  2396 #endif
       
  2397 
       
  2398 #if defined(PNG_pHYs_SUPPORTED)
       
  2399 extern PNG_EXPORT(png_uint_32,png_get_pHYs) PNGARG((png_structp png_ptr,
       
  2400    png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
       
  2401 #endif
       
  2402 
       
  2403 #if defined(PNG_pHYs_SUPPORTED)
       
  2404 extern PNG_EXPORT(void,png_set_pHYs) PNGARG((png_structp png_ptr,
       
  2405    png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
       
  2406 #endif
       
  2407 
       
  2408 extern PNG_EXPORT(png_uint_32,png_get_PLTE) PNGARG((png_structp png_ptr,
       
  2409    png_infop info_ptr, png_colorp *palette, int *num_palette));
       
  2410 
       
  2411 extern PNG_EXPORT(void,png_set_PLTE) PNGARG((png_structp png_ptr,
       
  2412    png_infop info_ptr, png_colorp palette, int num_palette));
       
  2413 
       
  2414 #if defined(PNG_sBIT_SUPPORTED)
       
  2415 extern PNG_EXPORT(png_uint_32,png_get_sBIT) PNGARG((png_structp png_ptr,
       
  2416    png_infop info_ptr, png_color_8p *sig_bit));
       
  2417 #endif
       
  2418 
       
  2419 #if defined(PNG_sBIT_SUPPORTED)
       
  2420 extern PNG_EXPORT(void,png_set_sBIT) PNGARG((png_structp png_ptr,
       
  2421    png_infop info_ptr, png_color_8p sig_bit));
       
  2422 #endif
       
  2423 
       
  2424 #if defined(PNG_sRGB_SUPPORTED)
       
  2425 extern PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr,
       
  2426    png_infop info_ptr, int *intent));
       
  2427 #endif
       
  2428 
       
  2429 #if defined(PNG_sRGB_SUPPORTED)
       
  2430 extern PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr,
       
  2431    png_infop info_ptr, int intent));
       
  2432 extern PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr,
       
  2433    png_infop info_ptr, int intent));
       
  2434 #endif
       
  2435 
       
  2436 #if defined(PNG_iCCP_SUPPORTED)
       
  2437 extern PNG_EXPORT(png_uint_32,png_get_iCCP) PNGARG((png_structp png_ptr,
       
  2438    png_infop info_ptr, png_charpp name, int *compression_type,
       
  2439    png_charpp profile, png_uint_32 *proflen));
       
  2440    /* Note to maintainer: profile should be png_bytepp */
       
  2441 #endif
       
  2442 
       
  2443 #if defined(PNG_iCCP_SUPPORTED)
       
  2444 extern PNG_EXPORT(void,png_set_iCCP) PNGARG((png_structp png_ptr,
       
  2445    png_infop info_ptr, png_charp name, int compression_type,
       
  2446    png_charp profile, png_uint_32 proflen));
       
  2447    /* Note to maintainer: profile should be png_bytep */
       
  2448 #endif
       
  2449 
       
  2450 #if defined(PNG_sPLT_SUPPORTED)
       
  2451 extern PNG_EXPORT(png_uint_32,png_get_sPLT) PNGARG((png_structp png_ptr,
       
  2452    png_infop info_ptr, png_sPLT_tpp entries));
       
  2453 #endif
       
  2454 
       
  2455 #if defined(PNG_sPLT_SUPPORTED)
       
  2456 extern PNG_EXPORT(void,png_set_sPLT) PNGARG((png_structp png_ptr,
       
  2457    png_infop info_ptr, png_sPLT_tp entries, int nentries));
       
  2458 #endif
       
  2459 
       
  2460 #if defined(PNG_TEXT_SUPPORTED)
       
  2461 /* png_get_text also returns the number of text chunks in *num_text */
       
  2462 extern PNG_EXPORT(png_uint_32,png_get_text) PNGARG((png_structp png_ptr,
       
  2463    png_infop info_ptr, png_textp *text_ptr, int *num_text));
       
  2464 #endif
       
  2465 
       
  2466 /*
       
  2467  *  Note while png_set_text() will accept a structure whose text,
       
  2468  *  language, and  translated keywords are NULL pointers, the structure
       
  2469  *  returned by png_get_text will always contain regular
       
  2470  *  zero-terminated C strings.  They might be empty strings but
       
  2471  *  they will never be NULL pointers.
       
  2472  */
       
  2473 
       
  2474 #if defined(PNG_TEXT_SUPPORTED)
       
  2475 extern PNG_EXPORT(void,png_set_text) PNGARG((png_structp png_ptr,
       
  2476    png_infop info_ptr, png_textp text_ptr, int num_text));
       
  2477 #endif
       
  2478 
       
  2479 #if defined(PNG_tIME_SUPPORTED)
       
  2480 extern PNG_EXPORT(png_uint_32,png_get_tIME) PNGARG((png_structp png_ptr,
       
  2481    png_infop info_ptr, png_timep *mod_time));
       
  2482 #endif
       
  2483 
       
  2484 #if defined(PNG_tIME_SUPPORTED)
       
  2485 extern PNG_EXPORT(void,png_set_tIME) PNGARG((png_structp png_ptr,
       
  2486    png_infop info_ptr, png_timep mod_time));
       
  2487 #endif
       
  2488 
       
  2489 #if defined(PNG_tRNS_SUPPORTED)
       
  2490 extern PNG_EXPORT(png_uint_32,png_get_tRNS) PNGARG((png_structp png_ptr,
       
  2491    png_infop info_ptr, png_bytep *trans, int *num_trans,
       
  2492    png_color_16p *trans_values));
       
  2493 #endif
       
  2494 
       
  2495 #if defined(PNG_tRNS_SUPPORTED)
       
  2496 extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
       
  2497    png_infop info_ptr, png_bytep trans, int num_trans,
       
  2498    png_color_16p trans_values));
       
  2499 #endif
       
  2500 
       
  2501 #if defined(PNG_tRNS_SUPPORTED)
       
  2502 #endif
       
  2503 
       
  2504 #if defined(PNG_sCAL_SUPPORTED)
       
  2505 #ifdef PNG_FLOATING_POINT_SUPPORTED
       
  2506 extern PNG_EXPORT(png_uint_32,png_get_sCAL) PNGARG((png_structp png_ptr,
       
  2507    png_infop info_ptr, int *unit, double *width, double *height));
       
  2508 #else
       
  2509 #ifdef PNG_FIXED_POINT_SUPPORTED
       
  2510 extern PNG_EXPORT(png_uint_32,png_get_sCAL_s) PNGARG((png_structp png_ptr,
       
  2511    png_infop info_ptr, int *unit, png_charpp swidth, png_charpp sheight));
       
  2512 #endif
       
  2513 #endif
       
  2514 #endif /* PNG_sCAL_SUPPORTED */
       
  2515 
       
  2516 #if defined(PNG_sCAL_SUPPORTED)
       
  2517 #ifdef PNG_FLOATING_POINT_SUPPORTED
       
  2518 extern PNG_EXPORT(void,png_set_sCAL) PNGARG((png_structp png_ptr,
       
  2519    png_infop info_ptr, int unit, double width, double height));
       
  2520 #else
       
  2521 #ifdef PNG_FIXED_POINT_SUPPORTED
       
  2522 extern PNG_EXPORT(void,png_set_sCAL_s) PNGARG((png_structp png_ptr,
       
  2523    png_infop info_ptr, int unit, png_charp swidth, png_charp sheight));
       
  2524 #endif
       
  2525 #endif
       
  2526 #endif /* PNG_sCAL_SUPPORTED || PNG_WRITE_sCAL_SUPPORTED */
       
  2527 
       
  2528 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
       
  2529 /* Provide a list of chunks and how they are to be handled, if the built-in
       
  2530    handling or default unknown chunk handling is not desired.  Any chunks not
       
  2531    listed will be handled in the default manner.  The IHDR and IEND chunks
       
  2532    must not be listed.
       
  2533       keep = 0: follow default behaviour
       
  2534            = 1: do not keep
       
  2535            = 2: keep only if safe-to-copy
       
  2536            = 3: keep even if unsafe-to-copy
       
  2537 */
       
  2538 extern PNG_EXPORT(void, png_set_keep_unknown_chunks) PNGARG((png_structp
       
  2539    png_ptr, int keep, png_bytep chunk_list, int num_chunks));
       
  2540 PNG_EXPORT(int,png_handle_as_unknown) PNGARG((png_structp png_ptr, png_bytep
       
  2541    chunk_name));
       
  2542 #endif
       
  2543 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
       
  2544 extern PNG_EXPORT(void, png_set_unknown_chunks) PNGARG((png_structp png_ptr,
       
  2545    png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns));
       
  2546 extern PNG_EXPORT(void, png_set_unknown_chunk_location)
       
  2547    PNGARG((png_structp png_ptr, png_infop info_ptr, int chunk, int location));
       
  2548 extern PNG_EXPORT(png_uint_32,png_get_unknown_chunks) PNGARG((png_structp
       
  2549    png_ptr, png_infop info_ptr, png_unknown_chunkpp entries));
       
  2550 #endif
       
  2551 
       
  2552 /* Png_free_data() will turn off the "valid" flag for anything it frees.
       
  2553  * If you need to turn it off for a chunk that your application has freed,
       
  2554  * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
       
  2555  */
       
  2556 extern PNG_EXPORT(void, png_set_invalid) PNGARG((png_structp png_ptr,
       
  2557    png_infop info_ptr, int mask));
       
  2558 
       
  2559 #if defined(PNG_INFO_IMAGE_SUPPORTED)
       
  2560 /* The "params" pointer is currently not used and is for future expansion. */
       
  2561 extern PNG_EXPORT(void, png_read_png) PNGARG((png_structp png_ptr,
       
  2562                         png_infop info_ptr,
       
  2563                         int transforms,
       
  2564                         png_voidp params));
       
  2565 extern PNG_EXPORT(void, png_write_png) PNGARG((png_structp png_ptr,
       
  2566                         png_infop info_ptr,
       
  2567                         int transforms,
       
  2568                         png_voidp params));
       
  2569 #endif
       
  2570 
       
  2571 /* Define PNG_DEBUG at compile time for debugging information.  Higher
       
  2572  * numbers for PNG_DEBUG mean more debugging information.  This has
       
  2573  * only been added since version 0.95 so it is not implemented throughout
       
  2574  * libpng yet, but more support will be added as needed.
       
  2575  */
       
  2576 #ifdef PNG_DEBUG
       
  2577 #if (PNG_DEBUG > 0)
       
  2578 #if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER)
       
  2579 #include <crtdbg.h>
       
  2580 #if (PNG_DEBUG > 1)
       
  2581 #ifndef _DEBUG
       
  2582 #  define _DEBUG
       
  2583 #endif
       
  2584 #ifndef png_debug
       
  2585 #define png_debug(l,m)  _RPT0(_CRT_WARN,m PNG_STRING_NEWLINE)
       
  2586 #endif
       
  2587 #ifndef png_debug1
       
  2588 #define png_debug1(l,m,p1)  _RPT1(_CRT_WARN,m PNG_STRING_NEWLINE,p1)
       
  2589 #endif
       
  2590 #ifndef png_debug2
       
  2591 #define png_debug2(l,m,p1,p2) _RPT2(_CRT_WARN,m PNG_STRING_NEWLINE,p1,p2)
       
  2592 #endif
       
  2593 #endif
       
  2594 #else /* PNG_DEBUG_FILE || !_MSC_VER */
       
  2595 #ifndef PNG_DEBUG_FILE
       
  2596 #define PNG_DEBUG_FILE stderr
       
  2597 #endif /* PNG_DEBUG_FILE */
       
  2598 
       
  2599 #if (PNG_DEBUG > 1)
       
  2600 /* Note: ["%s"m PNG_STRING_NEWLINE] probably does not work on non-ISO
       
  2601  * compilers.
       
  2602  */
       
  2603 #  ifdef __STDC__
       
  2604 #    ifndef png_debug
       
  2605 #      define png_debug(l,m) \
       
  2606        { \
       
  2607        int num_tabs=l; \
       
  2608        fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
       
  2609          (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":"")))); \
       
  2610        }
       
  2611 #    endif
       
  2612 #    ifndef png_debug1
       
  2613 #      define png_debug1(l,m,p1) \
       
  2614        { \
       
  2615        int num_tabs=l; \
       
  2616        fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
       
  2617          (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1); \
       
  2618        }
       
  2619 #    endif
       
  2620 #    ifndef png_debug2
       
  2621 #      define png_debug2(l,m,p1,p2) \
       
  2622        { \
       
  2623        int num_tabs=l; \
       
  2624        fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
       
  2625          (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1,p2); \
       
  2626        }
       
  2627 #    endif
       
  2628 #  else /* __STDC __ */
       
  2629 #    ifndef png_debug
       
  2630 #      define png_debug(l,m) \
       
  2631        { \
       
  2632        int num_tabs=l; \
       
  2633        char format[256]; \
       
  2634        snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
       
  2635          (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
       
  2636          m,PNG_STRING_NEWLINE); \
       
  2637        fprintf(PNG_DEBUG_FILE,format); \
       
  2638        }
       
  2639 #    endif
       
  2640 #    ifndef png_debug1
       
  2641 #      define png_debug1(l,m,p1) \
       
  2642        { \
       
  2643        int num_tabs=l; \
       
  2644        char format[256]; \
       
  2645        snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
       
  2646          (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
       
  2647          m,PNG_STRING_NEWLINE); \
       
  2648        fprintf(PNG_DEBUG_FILE,format,p1); \
       
  2649        }
       
  2650 #    endif
       
  2651 #    ifndef png_debug2
       
  2652 #      define png_debug2(l,m,p1,p2) \
       
  2653        { \
       
  2654        int num_tabs=l; \
       
  2655        char format[256]; \
       
  2656        snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
       
  2657          (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
       
  2658          m,PNG_STRING_NEWLINE); \
       
  2659        fprintf(PNG_DEBUG_FILE,format,p1,p2); \
       
  2660        }
       
  2661 #    endif
       
  2662 #  endif /* __STDC __ */
       
  2663 #endif /* (PNG_DEBUG > 1) */
       
  2664 
       
  2665 #endif /* _MSC_VER */
       
  2666 #endif /* (PNG_DEBUG > 0) */
       
  2667 #endif /* PNG_DEBUG */
       
  2668 #ifndef png_debug
       
  2669 #define png_debug(l, m)
       
  2670 #endif
       
  2671 #ifndef png_debug1
       
  2672 #define png_debug1(l, m, p1)
       
  2673 #endif
       
  2674 #ifndef png_debug2
       
  2675 #define png_debug2(l, m, p1, p2)
       
  2676 #endif
       
  2677 
       
  2678 extern PNG_EXPORT(png_charp,png_get_copyright) PNGARG((png_structp png_ptr));
       
  2679 extern PNG_EXPORT(png_charp,png_get_header_ver) PNGARG((png_structp png_ptr));
       
  2680 extern PNG_EXPORT(png_charp,png_get_header_version) PNGARG((png_structp png_ptr));
       
  2681 extern PNG_EXPORT(png_charp,png_get_libpng_ver) PNGARG((png_structp png_ptr));
       
  2682 
       
  2683 #ifdef PNG_MNG_FEATURES_SUPPORTED
       
  2684 extern PNG_EXPORT(png_uint_32,png_permit_mng_features) PNGARG((png_structp
       
  2685    png_ptr, png_uint_32 mng_features_permitted));
       
  2686 #endif
       
  2687 
       
  2688 /* For use in png_set_keep_unknown, added to version 1.2.6 */
       
  2689 #define PNG_HANDLE_CHUNK_AS_DEFAULT   0
       
  2690 #define PNG_HANDLE_CHUNK_NEVER        1
       
  2691 #define PNG_HANDLE_CHUNK_IF_SAFE      2
       
  2692 #define PNG_HANDLE_CHUNK_ALWAYS       3
       
  2693 
       
  2694 /* Added to version 1.2.0 */
       
  2695 #if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
       
  2696 #if defined(PNG_MMX_CODE_SUPPORTED)
       
  2697 #define PNG_ASM_FLAG_MMX_SUPPORT_COMPILED  0x01  /* not user-settable */
       
  2698 #define PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU    0x02  /* not user-settable */
       
  2699 #define PNG_ASM_FLAG_MMX_READ_COMBINE_ROW  0x04
       
  2700 #define PNG_ASM_FLAG_MMX_READ_INTERLACE    0x08
       
  2701 #define PNG_ASM_FLAG_MMX_READ_FILTER_SUB   0x10
       
  2702 #define PNG_ASM_FLAG_MMX_READ_FILTER_UP    0x20
       
  2703 #define PNG_ASM_FLAG_MMX_READ_FILTER_AVG   0x40
       
  2704 #define PNG_ASM_FLAG_MMX_READ_FILTER_PAETH 0x80
       
  2705 #define PNG_ASM_FLAGS_INITIALIZED          0x80000000  /* not user-settable */
       
  2706 
       
  2707 #define PNG_MMX_READ_FLAGS ( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW  \
       
  2708                            | PNG_ASM_FLAG_MMX_READ_INTERLACE    \
       
  2709                            | PNG_ASM_FLAG_MMX_READ_FILTER_SUB   \
       
  2710                            | PNG_ASM_FLAG_MMX_READ_FILTER_UP    \
       
  2711                            | PNG_ASM_FLAG_MMX_READ_FILTER_AVG   \
       
  2712                            | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH )
       
  2713 #define PNG_MMX_WRITE_FLAGS ( 0 )
       
  2714 
       
  2715 #define PNG_MMX_FLAGS ( PNG_ASM_FLAG_MMX_SUPPORT_COMPILED \
       
  2716                       | PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU   \
       
  2717                       | PNG_MMX_READ_FLAGS                \
       
  2718                       | PNG_MMX_WRITE_FLAGS )
       
  2719 
       
  2720 #define PNG_SELECT_READ   1
       
  2721 #define PNG_SELECT_WRITE  2
       
  2722 #endif /* PNG_MMX_CODE_SUPPORTED */
       
  2723 
       
  2724 #if !defined(PNG_1_0_X)
       
  2725 /* pngget.c */
       
  2726 extern PNG_EXPORT(png_uint_32,png_get_mmx_flagmask)
       
  2727    PNGARG((int flag_select, int *compilerID));
       
  2728 
       
  2729 /* pngget.c */
       
  2730 extern PNG_EXPORT(png_uint_32,png_get_asm_flagmask)
       
  2731    PNGARG((int flag_select));
       
  2732 
       
  2733 /* pngget.c */
       
  2734 extern PNG_EXPORT(png_uint_32,png_get_asm_flags)
       
  2735    PNGARG((png_structp png_ptr));
       
  2736 
       
  2737 /* pngget.c */
       
  2738 extern PNG_EXPORT(png_byte,png_get_mmx_bitdepth_threshold)
       
  2739    PNGARG((png_structp png_ptr));
       
  2740 
       
  2741 /* pngget.c */
       
  2742 extern PNG_EXPORT(png_uint_32,png_get_mmx_rowbytes_threshold)
       
  2743    PNGARG((png_structp png_ptr));
       
  2744 
       
  2745 /* pngset.c */
       
  2746 extern PNG_EXPORT(void,png_set_asm_flags)
       
  2747    PNGARG((png_structp png_ptr, png_uint_32 asm_flags));
       
  2748 
       
  2749 /* pngset.c */
       
  2750 extern PNG_EXPORT(void,png_set_mmx_thresholds)
       
  2751    PNGARG((png_structp png_ptr, png_byte mmx_bitdepth_threshold,
       
  2752    png_uint_32 mmx_rowbytes_threshold));
       
  2753 
       
  2754 #endif /* PNG_1_0_X */
       
  2755 
       
  2756 #if !defined(PNG_1_0_X)
       
  2757 /* png.c, pnggccrd.c, or pngvcrd.c */
       
  2758 extern PNG_EXPORT(int,png_mmx_support) PNGARG((void));
       
  2759 #endif /* PNG_1_0_X */
       
  2760 #endif /* PNG_ASSEMBLER_CODE_SUPPORTED */
       
  2761 
       
  2762 /* Strip the prepended error numbers ("#nnn ") from error and warning
       
  2763  * messages before passing them to the error or warning handler.
       
  2764  */
       
  2765 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
       
  2766 extern PNG_EXPORT(void,png_set_strip_error_numbers) PNGARG((png_structp
       
  2767    png_ptr, png_uint_32 strip_mode));
       
  2768 #endif
       
  2769 
       
  2770 /* Added at libpng-1.2.6 */
       
  2771 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
       
  2772 extern PNG_EXPORT(void,png_set_user_limits) PNGARG((png_structp
       
  2773    png_ptr, png_uint_32 user_width_max, png_uint_32 user_height_max));
       
  2774 extern PNG_EXPORT(png_uint_32,png_get_user_width_max) PNGARG((png_structp
       
  2775    png_ptr));
       
  2776 extern PNG_EXPORT(png_uint_32,png_get_user_height_max) PNGARG((png_structp
       
  2777    png_ptr));
       
  2778 #endif
       
  2779 
       
  2780 
       
  2781 /* Maintainer: Put new public prototypes here ^, in libpng.3, and in
       
  2782  * project defs
       
  2783  */
       
  2784 
       
  2785 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
       
  2786 /* With these routines we avoid an integer divide, which will be slower on
       
  2787  * most machines.  However, it does take more operations than the corresponding
       
  2788  * divide method, so it may be slower on a few RISC systems.  There are two
       
  2789  * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
       
  2790  *
       
  2791  * Note that the rounding factors are NOT supposed to be the same!  128 and
       
  2792  * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
       
  2793  * standard method.
       
  2794  *
       
  2795  * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
       
  2796  */
       
  2797 
       
  2798  /* fg and bg should be in `gamma 1.0' space; alpha is the opacity          */
       
  2799 
       
  2800 #  define png_composite(composite, fg, alpha, bg)                            \
       
  2801      { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) * (png_uint_16)(alpha) \
       
  2802                         +        (png_uint_16)(bg)*(png_uint_16)(255 -       \
       
  2803                         (png_uint_16)(alpha)) + (png_uint_16)128);           \
       
  2804        (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
       
  2805 
       
  2806 #  define png_composite_16(composite, fg, alpha, bg)                         \
       
  2807      { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) * (png_uint_32)(alpha) \
       
  2808                         + (png_uint_32)(bg)*(png_uint_32)(65535L -           \
       
  2809                         (png_uint_32)(alpha)) + (png_uint_32)32768L);        \
       
  2810        (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
       
  2811 
       
  2812 #else  /* Standard method using integer division */
       
  2813 
       
  2814 #  define png_composite(composite, fg, alpha, bg)                            \
       
  2815      (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) +    \
       
  2816        (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) +       \
       
  2817        (png_uint_16)127) / 255)
       
  2818 
       
  2819 #  define png_composite_16(composite, fg, alpha, bg)                         \
       
  2820      (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
       
  2821        (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) +      \
       
  2822        (png_uint_32)32767) / (png_uint_32)65535L)
       
  2823 
       
  2824 #endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
       
  2825 
       
  2826 /* Inline macros to do direct reads of bytes from the input buffer.  These
       
  2827  * require that you are using an architecture that uses PNG byte ordering
       
  2828  * (MSB first) and supports unaligned data storage.  I think that PowerPC
       
  2829  * in big-endian mode and 680x0 are the only ones that will support this.
       
  2830  * The x86 line of processors definitely do not.  The png_get_int_32()
       
  2831  * routine also assumes we are using two's complement format for negative
       
  2832  * values, which is almost certainly true.
       
  2833  */
       
  2834 #if defined(PNG_READ_BIG_ENDIAN_SUPPORTED)
       
  2835 #  define png_get_uint_32(buf) ( *((png_uint_32p) (buf)))
       
  2836 #  define png_get_uint_16(buf) ( *((png_uint_16p) (buf)))
       
  2837 #  define png_get_int_32(buf)  ( *((png_int_32p)  (buf)))
       
  2838 #else
       
  2839 extern PNG_EXPORT(png_uint_32,png_get_uint_32) PNGARG((png_bytep buf));
       
  2840 extern PNG_EXPORT(png_uint_16,png_get_uint_16) PNGARG((png_bytep buf));
       
  2841 extern PNG_EXPORT(png_int_32,png_get_int_32) PNGARG((png_bytep buf));
       
  2842 #endif /* !PNG_READ_BIG_ENDIAN_SUPPORTED */
       
  2843 extern PNG_EXPORT(png_uint_32,png_get_uint_31)
       
  2844   PNGARG((png_structp png_ptr, png_bytep buf));
       
  2845 /* No png_get_int_16 -- may be added if there's a real need for it. */
       
  2846 
       
  2847 /* Place a 32-bit number into a buffer in PNG byte order (big-endian).
       
  2848  */
       
  2849 extern PNG_EXPORT(void,png_save_uint_32)
       
  2850    PNGARG((png_bytep buf, png_uint_32 i));
       
  2851 extern PNG_EXPORT(void,png_save_int_32)
       
  2852    PNGARG((png_bytep buf, png_int_32 i));
       
  2853 
       
  2854 /* Place a 16-bit number into a buffer in PNG byte order.
       
  2855  * The parameter is declared unsigned int, not png_uint_16,
       
  2856  * just to avoid potential problems on pre-ANSI C compilers.
       
  2857  */
       
  2858 extern PNG_EXPORT(void,png_save_uint_16)
       
  2859    PNGARG((png_bytep buf, unsigned int i));
       
  2860 /* No png_save_int_16 -- may be added if there's a real need for it. */
       
  2861 
       
  2862 /* ************************************************************************* */
       
  2863 
       
  2864 /* These next functions are used internally in the code.  They generally
       
  2865  * shouldn't be used unless you are writing code to add or replace some
       
  2866  * functionality in libpng.  More information about most functions can
       
  2867  * be found in the files where the functions are located.
       
  2868  */
       
  2869 
       
  2870 
       
  2871 /* Various modes of operation, that are visible to applications because
       
  2872  * they are used for unknown chunk location.
       
  2873  */
       
  2874 #define PNG_HAVE_IHDR               0x01
       
  2875 #define PNG_HAVE_PLTE               0x02
       
  2876 #define PNG_HAVE_IDAT               0x04
       
  2877 #define PNG_AFTER_IDAT              0x08 /* Have complete zlib datastream */
       
  2878 #define PNG_HAVE_IEND               0x10
       
  2879 
       
  2880 #if defined(PNG_INTERNAL)
       
  2881 
       
  2882 /* More modes of operation.  Note that after an init, mode is set to
       
  2883  * zero automatically when the structure is created.
       
  2884  */
       
  2885 #define PNG_HAVE_gAMA               0x20
       
  2886 #define PNG_HAVE_cHRM               0x40
       
  2887 #define PNG_HAVE_sRGB               0x80
       
  2888 #define PNG_HAVE_CHUNK_HEADER      0x100
       
  2889 #define PNG_WROTE_tIME             0x200
       
  2890 #define PNG_WROTE_INFO_BEFORE_PLTE 0x400
       
  2891 #define PNG_BACKGROUND_IS_GRAY     0x800
       
  2892 #define PNG_HAVE_PNG_SIGNATURE    0x1000
       
  2893 #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
       
  2894 
       
  2895 /* Flags for the transformations the PNG library does on the image data */
       
  2896 #define PNG_BGR                0x0001
       
  2897 #define PNG_INTERLACE          0x0002
       
  2898 #define PNG_PACK               0x0004
       
  2899 #define PNG_SHIFT              0x0008
       
  2900 #define PNG_SWAP_BYTES         0x0010
       
  2901 #define PNG_INVERT_MONO        0x0020
       
  2902 #define PNG_DITHER             0x0040
       
  2903 #define PNG_BACKGROUND         0x0080
       
  2904 #define PNG_BACKGROUND_EXPAND  0x0100
       
  2905                           /*   0x0200 unused */
       
  2906 #define PNG_16_TO_8            0x0400
       
  2907 #define PNG_RGBA               0x0800
       
  2908 #define PNG_EXPAND             0x1000
       
  2909 #define PNG_GAMMA              0x2000
       
  2910 #define PNG_GRAY_TO_RGB        0x4000
       
  2911 #define PNG_FILLER             0x8000L
       
  2912 #define PNG_PACKSWAP          0x10000L
       
  2913 #define PNG_SWAP_ALPHA        0x20000L
       
  2914 #define PNG_STRIP_ALPHA       0x40000L
       
  2915 #define PNG_INVERT_ALPHA      0x80000L
       
  2916 #define PNG_USER_TRANSFORM   0x100000L
       
  2917 #define PNG_RGB_TO_GRAY_ERR  0x200000L
       
  2918 #define PNG_RGB_TO_GRAY_WARN 0x400000L
       
  2919 #define PNG_RGB_TO_GRAY      0x600000L  /* two bits, RGB_TO_GRAY_ERR|WARN */
       
  2920                        /*    0x800000L     Unused */
       
  2921 #define PNG_ADD_ALPHA       0x1000000L  /* Added to libpng-1.2.7 */
       
  2922 #define PNG_EXPAND_tRNS     0x2000000L  /* Added to libpng-1.2.9 */
       
  2923                        /*   0x4000000L  unused */
       
  2924                        /*   0x8000000L  unused */
       
  2925                        /*  0x10000000L  unused */
       
  2926                        /*  0x20000000L  unused */
       
  2927                        /*  0x40000000L  unused */
       
  2928 
       
  2929 /* Flags for png_create_struct */
       
  2930 #define PNG_STRUCT_PNG   0x0001
       
  2931 #define PNG_STRUCT_INFO  0x0002
       
  2932 
       
  2933 /* Scaling factor for filter heuristic weighting calculations */
       
  2934 #define PNG_WEIGHT_SHIFT 8
       
  2935 #define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
       
  2936 #define PNG_COST_SHIFT 3
       
  2937 #define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
       
  2938 
       
  2939 /* Flags for the png_ptr->flags rather than declaring a byte for each one */
       
  2940 #define PNG_FLAG_ZLIB_CUSTOM_STRATEGY     0x0001
       
  2941 #define PNG_FLAG_ZLIB_CUSTOM_LEVEL        0x0002
       
  2942 #define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL    0x0004
       
  2943 #define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS  0x0008
       
  2944 #define PNG_FLAG_ZLIB_CUSTOM_METHOD       0x0010
       
  2945 #define PNG_FLAG_ZLIB_FINISHED            0x0020
       
  2946 #define PNG_FLAG_ROW_INIT                 0x0040
       
  2947 #define PNG_FLAG_FILLER_AFTER             0x0080
       
  2948 #define PNG_FLAG_CRC_ANCILLARY_USE        0x0100
       
  2949 #define PNG_FLAG_CRC_ANCILLARY_NOWARN     0x0200
       
  2950 #define PNG_FLAG_CRC_CRITICAL_USE         0x0400
       
  2951 #define PNG_FLAG_CRC_CRITICAL_IGNORE      0x0800
       
  2952 #define PNG_FLAG_FREE_PLTE                0x1000
       
  2953 #define PNG_FLAG_FREE_TRNS                0x2000
       
  2954 #define PNG_FLAG_FREE_HIST                0x4000
       
  2955 #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS      0x8000L
       
  2956 #define PNG_FLAG_KEEP_UNSAFE_CHUNKS       0x10000L
       
  2957 #define PNG_FLAG_LIBRARY_MISMATCH         0x20000L
       
  2958 #define PNG_FLAG_STRIP_ERROR_NUMBERS      0x40000L
       
  2959 #define PNG_FLAG_STRIP_ERROR_TEXT         0x80000L
       
  2960 #define PNG_FLAG_MALLOC_NULL_MEM_OK       0x100000L
       
  2961 #define PNG_FLAG_ADD_ALPHA                0x200000L  /* Added to libpng-1.2.8 */
       
  2962 #define PNG_FLAG_STRIP_ALPHA              0x400000L  /* Added to libpng-1.2.8 */
       
  2963                                   /*      0x800000L  unused */
       
  2964                                   /*     0x1000000L  unused */
       
  2965                                   /*     0x2000000L  unused */
       
  2966                                   /*     0x4000000L  unused */
       
  2967                                   /*     0x8000000L  unused */
       
  2968                                   /*    0x10000000L  unused */
       
  2969                                   /*    0x20000000L  unused */
       
  2970                                   /*    0x40000000L  unused */
       
  2971 
       
  2972 #define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
       
  2973                                      PNG_FLAG_CRC_ANCILLARY_NOWARN)
       
  2974 
       
  2975 #define PNG_FLAG_CRC_CRITICAL_MASK  (PNG_FLAG_CRC_CRITICAL_USE | \
       
  2976                                      PNG_FLAG_CRC_CRITICAL_IGNORE)
       
  2977 
       
  2978 #define PNG_FLAG_CRC_MASK           (PNG_FLAG_CRC_ANCILLARY_MASK | \
       
  2979                                      PNG_FLAG_CRC_CRITICAL_MASK)
       
  2980 
       
  2981 /* Save typing and make code easier to understand */
       
  2982 
       
  2983 #define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
       
  2984    abs((int)((c1).green) - (int)((c2).green)) + \
       
  2985    abs((int)((c1).blue) - (int)((c2).blue)))
       
  2986 
       
  2987 /* Added to libpng-1.2.6 JB */
       
  2988 #define PNG_ROWBYTES(pixel_bits, width) \
       
  2989     ((pixel_bits) >= 8 ? \
       
  2990     ((width) * (((png_uint_32)(pixel_bits)) >> 3)) : \
       
  2991     (( ((width) * ((png_uint_32)(pixel_bits))) + 7) >> 3) )
       
  2992 
       
  2993 /* PNG_OUT_OF_RANGE returns true if value is outside the range
       
  2994  * ideal-delta..ideal+delta.  Each argument is evaluated twice.
       
  2995  * "ideal" and "delta" should be constants, normally simple
       
  2996  * integers, "value" a variable. Added to libpng-1.2.6 JB
       
  2997  */
       
  2998 #define PNG_OUT_OF_RANGE(value, ideal, delta) \
       
  2999         ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
       
  3000 
       
  3001 /* Variables declared in png.c - only it needs to define PNG_NO_EXTERN */
       
  3002 #if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
       
  3003 /* Place to hold the signature string for a PNG file. */
       
  3004 #ifdef PNG_USE_GLOBAL_ARRAYS
       
  3005    PNG_EXPORT_VAR (PNG_CONST png_byte FARDATA) png_sig[8];
       
  3006 #else
       
  3007 #endif
       
  3008 #endif /* PNG_NO_EXTERN */
       
  3009 
       
  3010 /* Constant strings for known chunk types.  If you need to add a chunk,
       
  3011  * define the name here, and add an invocation of the macro in png.c and
       
  3012  * wherever it's needed.
       
  3013  */
       
  3014 #define PNG_IHDR png_byte png_IHDR[5] = { 73,  72,  68,  82, '\0'}
       
  3015 #define PNG_IDAT png_byte png_IDAT[5] = { 73,  68,  65,  84, '\0'}
       
  3016 #define PNG_IEND png_byte png_IEND[5] = { 73,  69,  78,  68, '\0'}
       
  3017 #define PNG_PLTE png_byte png_PLTE[5] = { 80,  76,  84,  69, '\0'}
       
  3018 #define PNG_bKGD png_byte png_bKGD[5] = { 98,  75,  71,  68, '\0'}
       
  3019 #define PNG_cHRM png_byte png_cHRM[5] = { 99,  72,  82,  77, '\0'}
       
  3020 #define PNG_gAMA png_byte png_gAMA[5] = {103,  65,  77,  65, '\0'}
       
  3021 #define PNG_hIST png_byte png_hIST[5] = {104,  73,  83,  84, '\0'}
       
  3022 #define PNG_iCCP png_byte png_iCCP[5] = {105,  67,  67,  80, '\0'}
       
  3023 #define PNG_iTXt png_byte png_iTXt[5] = {105,  84,  88, 116, '\0'}
       
  3024 #define PNG_oFFs png_byte png_oFFs[5] = {111,  70,  70, 115, '\0'}
       
  3025 #define PNG_pCAL png_byte png_pCAL[5] = {112,  67,  65,  76, '\0'}
       
  3026 #define PNG_sCAL png_byte png_sCAL[5] = {115,  67,  65,  76, '\0'}
       
  3027 #define PNG_pHYs png_byte png_pHYs[5] = {112,  72,  89, 115, '\0'}
       
  3028 #define PNG_sBIT png_byte png_sBIT[5] = {115,  66,  73,  84, '\0'}
       
  3029 #define PNG_sPLT png_byte png_sPLT[5] = {115,  80,  76,  84, '\0'}
       
  3030 #define PNG_sRGB png_byte png_sRGB[5] = {115,  82,  71,  66, '\0'}
       
  3031 #define PNG_tEXt png_byte png_tEXt[5] = {116,  69,  88, 116, '\0'}
       
  3032 #define PNG_tIME png_byte png_tIME[5] = {116,  73,  77,  69, '\0'}
       
  3033 #define PNG_tRNS png_byte png_tRNS[5] = {116,  82,  78,  83, '\0'}
       
  3034 #define PNG_zTXt png_byte png_zTXt[5] = {122,  84,  88, 116, '\0'}
       
  3035 
       
  3036 #ifdef PNG_USE_GLOBAL_ARRAYS
       
  3037 PNG_EXPORT_VAR (png_byte FARDATA) png_IHDR[5];
       
  3038 PNG_EXPORT_VAR (png_byte FARDATA) png_IDAT[5];
       
  3039 PNG_EXPORT_VAR (png_byte FARDATA) png_IEND[5];
       
  3040 PNG_EXPORT_VAR (png_byte FARDATA) png_PLTE[5];
       
  3041 PNG_EXPORT_VAR (png_byte FARDATA) png_bKGD[5];
       
  3042 PNG_EXPORT_VAR (png_byte FARDATA) png_cHRM[5];
       
  3043 PNG_EXPORT_VAR (png_byte FARDATA) png_gAMA[5];
       
  3044 PNG_EXPORT_VAR (png_byte FARDATA) png_hIST[5];
       
  3045 PNG_EXPORT_VAR (png_byte FARDATA) png_iCCP[5];
       
  3046 PNG_EXPORT_VAR (png_byte FARDATA) png_iTXt[5];
       
  3047 PNG_EXPORT_VAR (png_byte FARDATA) png_oFFs[5];
       
  3048 PNG_EXPORT_VAR (png_byte FARDATA) png_pCAL[5];
       
  3049 PNG_EXPORT_VAR (png_byte FARDATA) png_sCAL[5];
       
  3050 PNG_EXPORT_VAR (png_byte FARDATA) png_pHYs[5];
       
  3051 PNG_EXPORT_VAR (png_byte FARDATA) png_sBIT[5];
       
  3052 PNG_EXPORT_VAR (png_byte FARDATA) png_sPLT[5];
       
  3053 PNG_EXPORT_VAR (png_byte FARDATA) png_sRGB[5];
       
  3054 PNG_EXPORT_VAR (png_byte FARDATA) png_tEXt[5];
       
  3055 PNG_EXPORT_VAR (png_byte FARDATA) png_tIME[5];
       
  3056 PNG_EXPORT_VAR (png_byte FARDATA) png_tRNS[5];
       
  3057 PNG_EXPORT_VAR (png_byte FARDATA) png_zTXt[5];
       
  3058 #endif /* PNG_USE_GLOBAL_ARRAYS */
       
  3059 
       
  3060 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
       
  3061 /* Initialize png_ptr struct for reading, and allocate any other memory.
       
  3062  * (old interface - DEPRECATED - use png_create_read_struct instead).
       
  3063  */
       
  3064 extern PNG_EXPORT(void,png_read_init) PNGARG((png_structp png_ptr));
       
  3065 #undef png_read_init
       
  3066 #define png_read_init(png_ptr) png_read_init_3(&png_ptr, \
       
  3067     PNG_LIBPNG_VER_STRING,  png_sizeof(png_struct));
       
  3068 #endif
       
  3069 
       
  3070 extern PNG_EXPORT(void,png_read_init_3) PNGARG((png_structpp ptr_ptr,
       
  3071     png_const_charp user_png_ver, png_size_t png_struct_size));
       
  3072 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
       
  3073 extern PNG_EXPORT(void,png_read_init_2) PNGARG((png_structp png_ptr,
       
  3074     png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
       
  3075     png_info_size));
       
  3076 #endif
       
  3077 
       
  3078 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
       
  3079 /* Initialize png_ptr struct for writing, and allocate any other memory.
       
  3080  * (old interface - DEPRECATED - use png_create_write_struct instead).
       
  3081  */
       
  3082 extern PNG_EXPORT(void,png_write_init) PNGARG((png_structp png_ptr));
       
  3083 #undef png_write_init
       
  3084 #define png_write_init(png_ptr) png_write_init_3(&png_ptr, \
       
  3085     PNG_LIBPNG_VER_STRING, png_sizeof(png_struct));
       
  3086 #endif
       
  3087 
       
  3088 extern PNG_EXPORT(void,png_write_init_3) PNGARG((png_structpp ptr_ptr,
       
  3089     png_const_charp user_png_ver, png_size_t png_struct_size));
       
  3090 extern PNG_EXPORT(void,png_write_init_2) PNGARG((png_structp png_ptr,
       
  3091     png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
       
  3092     png_info_size));
       
  3093 
       
  3094 /* Allocate memory for an internal libpng struct */
       
  3095 PNG_EXTERN png_voidp png_create_struct PNGARG((int type));
       
  3096 
       
  3097 /* Free memory from internal libpng struct */
       
  3098 PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr));
       
  3099 
       
  3100 PNG_EXTERN png_voidp png_create_struct_2 PNGARG((int type, png_malloc_ptr
       
  3101   malloc_fn, png_voidp mem_ptr));
       
  3102 PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr,
       
  3103    png_free_ptr free_fn, png_voidp mem_ptr));
       
  3104 
       
  3105 /* Free any memory that info_ptr points to and reset struct. */
       
  3106 PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr,
       
  3107    png_infop info_ptr));
       
  3108 
       
  3109 #ifndef PNG_1_0_X
       
  3110 /* Function to allocate memory for zlib. */
       
  3111 PNG_EXTERN voidpf png_zalloc PNGARG((voidpf png_ptr, uInt items, uInt size));
       
  3112 
       
  3113 /* Function to free memory for zlib */
       
  3114 PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr));
       
  3115 
       
  3116 #ifdef PNG_SIZE_T
       
  3117 /* Function to convert a sizeof an item to png_sizeof item */
       
  3118    PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size));
       
  3119 #endif
       
  3120 
       
  3121 /* Next four functions are used internally as callbacks.  PNGAPI is required
       
  3122  * but not PNG_EXPORT.  PNGAPI added at libpng version 1.2.3.
       
  3123  */
       
  3124 
       
  3125 PNG_EXTERN void PNGAPI png_default_read_data PNGARG((png_structp png_ptr,
       
  3126    png_bytep data, png_size_t length));
       
  3127 
       
  3128 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
       
  3129 PNG_EXTERN void PNGAPI png_push_fill_buffer PNGARG((png_structp png_ptr,
       
  3130    png_bytep buffer, png_size_t length));
       
  3131 #endif
       
  3132 
       
  3133 PNG_EXTERN void PNGAPI png_default_write_data PNGARG((png_structp png_ptr,
       
  3134    png_bytep data, png_size_t length));
       
  3135 
       
  3136 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
       
  3137 #if !defined(PNG_NO_STDIO)
       
  3138 PNG_EXTERN void PNGAPI png_default_flush PNGARG((png_structp png_ptr));
       
  3139 #endif
       
  3140 #endif
       
  3141 #else /* PNG_1_0_X */
       
  3142 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
       
  3143 PNG_EXTERN void png_push_fill_buffer PNGARG((png_structp png_ptr,
       
  3144    png_bytep buffer, png_size_t length));
       
  3145 #endif
       
  3146 #endif /* PNG_1_0_X */
       
  3147 
       
  3148 /* Reset the CRC variable */
       
  3149 PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr));
       
  3150 
       
  3151 /* Write the "data" buffer to whatever output you are using. */
       
  3152 PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr, png_bytep data,
       
  3153    png_size_t length));
       
  3154 
       
  3155 /* Read data from whatever input you are using into the "data" buffer */
       
  3156 PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data,
       
  3157    png_size_t length));
       
  3158 
       
  3159 /* Read bytes into buf, and update png_ptr->crc */
       
  3160 PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
       
  3161    png_size_t length));
       
  3162 
       
  3163 /* Decompress data in a chunk that uses compression */
       
  3164 #if defined(PNG_zTXt_SUPPORTED) || defined(PNG_iTXt_SUPPORTED) || \
       
  3165     defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED)
       
  3166 PNG_EXTERN void png_decompress_chunk PNGARG((png_structp png_ptr,
       
  3167    int comp_type, png_size_t chunklength,
       
  3168    png_size_t prefix_length, png_size_t *data_length));
       
  3169 #endif
       
  3170 
       
  3171 /* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
       
  3172 PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip));
       
  3173 
       
  3174 /* Read the CRC from the file and compare it to the libpng calculated CRC */
       
  3175 PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr));
       
  3176 
       
  3177 /* Calculate the CRC over a section of data.  Note that we are only
       
  3178  * passing a maximum of 64K on systems that have this as a memory limit,
       
  3179  * since this is the maximum buffer size we can specify.
       
  3180  */
       
  3181 PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr, png_bytep ptr,
       
  3182    png_size_t length));
       
  3183 
       
  3184 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
       
  3185 PNG_EXTERN void png_flush PNGARG((png_structp png_ptr));
       
  3186 #endif
       
  3187 
       
  3188 /* Simple function to write the signature */
       
  3189 PNG_EXTERN void png_write_sig PNGARG((png_structp png_ptr));
       
  3190 
       
  3191 /* Write various chunks */
       
  3192 
       
  3193 /* Write the IHDR chunk, and update the png_struct with the necessary
       
  3194  * information.
       
  3195  */
       
  3196 PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width,
       
  3197    png_uint_32 height,
       
  3198    int bit_depth, int color_type, int compression_method, int filter_method,
       
  3199    int interlace_method));
       
  3200 
       
  3201 PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr, png_colorp palette,
       
  3202    png_uint_32 num_pal));
       
  3203 
       
  3204 PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data,
       
  3205    png_size_t length));
       
  3206 
       
  3207 PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr));
       
  3208 
       
  3209 #if defined(PNG_WRITE_gAMA_SUPPORTED)
       
  3210 #ifdef PNG_FLOATING_POINT_SUPPORTED
       
  3211 PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma));
       
  3212 #endif
       
  3213 #ifdef PNG_FIXED_POINT_SUPPORTED
       
  3214 PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr, png_fixed_point
       
  3215     file_gamma));
       
  3216 #endif
       
  3217 #endif
       
  3218 
       
  3219 #if defined(PNG_WRITE_sBIT_SUPPORTED)
       
  3220 PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr, png_color_8p sbit,
       
  3221    int color_type));
       
  3222 #endif
       
  3223 
       
  3224 #if defined(PNG_WRITE_cHRM_SUPPORTED)
       
  3225 #ifdef PNG_FLOATING_POINT_SUPPORTED
       
  3226 PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr,
       
  3227    double white_x, double white_y,
       
  3228    double red_x, double red_y, double green_x, double green_y,
       
  3229    double blue_x, double blue_y));
       
  3230 #endif
       
  3231 #ifdef PNG_FIXED_POINT_SUPPORTED
       
  3232 PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr,
       
  3233    png_fixed_point int_white_x, png_fixed_point int_white_y,
       
  3234    png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
       
  3235    int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
       
  3236    png_fixed_point int_blue_y));
       
  3237 #endif
       
  3238 #endif
       
  3239 
       
  3240 #if defined(PNG_WRITE_sRGB_SUPPORTED)
       
  3241 PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
       
  3242    int intent));
       
  3243 #endif
       
  3244 
       
  3245 #if defined(PNG_WRITE_iCCP_SUPPORTED)
       
  3246 PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr,
       
  3247    png_charp name, int compression_type,
       
  3248    png_charp profile, int proflen));
       
  3249    /* Note to maintainer: profile should be png_bytep */
       
  3250 #endif
       
  3251 
       
  3252 #if defined(PNG_WRITE_sPLT_SUPPORTED)
       
  3253 PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr,
       
  3254    png_sPLT_tp palette));
       
  3255 #endif
       
  3256 
       
  3257 #if defined(PNG_WRITE_tRNS_SUPPORTED)
       
  3258 PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr, png_bytep trans,
       
  3259    png_color_16p values, int number, int color_type));
       
  3260 #endif
       
  3261 
       
  3262 #if defined(PNG_WRITE_bKGD_SUPPORTED)
       
  3263 PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr,
       
  3264    png_color_16p values, int color_type));
       
  3265 #endif
       
  3266 
       
  3267 #if defined(PNG_WRITE_hIST_SUPPORTED)
       
  3268 PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, png_uint_16p hist,
       
  3269    int num_hist));
       
  3270 #endif
       
  3271 
       
  3272 #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
       
  3273     defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
       
  3274 PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
       
  3275    png_charp key, png_charpp new_key));
       
  3276 #endif
       
  3277 
       
  3278 #if defined(PNG_WRITE_tEXt_SUPPORTED)
       
  3279 PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_charp key,
       
  3280    png_charp text, png_size_t text_len));
       
  3281 #endif
       
  3282 
       
  3283 #if defined(PNG_WRITE_zTXt_SUPPORTED)
       
  3284 PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_charp key,
       
  3285    png_charp text, png_size_t text_len, int compression));
       
  3286 #endif
       
  3287 
       
  3288 #if defined(PNG_WRITE_iTXt_SUPPORTED)
       
  3289 PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr,
       
  3290    int compression, png_charp key, png_charp lang, png_charp lang_key,
       
  3291    png_charp text));
       
  3292 #endif
       
  3293 
       
  3294 #if defined(PNG_TEXT_SUPPORTED)  /* Added at version 1.0.14 and 1.2.4 */
       
  3295 PNG_EXTERN int png_set_text_2 PNGARG((png_structp png_ptr,
       
  3296    png_infop info_ptr, png_textp text_ptr, int num_text));
       
  3297 #endif
       
  3298 
       
  3299 #if defined(PNG_WRITE_oFFs_SUPPORTED)
       
  3300 PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr,
       
  3301    png_int_32 x_offset, png_int_32 y_offset, int unit_type));
       
  3302 #endif
       
  3303 
       
  3304 #if defined(PNG_WRITE_pCAL_SUPPORTED)
       
  3305 PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose,
       
  3306    png_int_32 X0, png_int_32 X1, int type, int nparams,
       
  3307    png_charp units, png_charpp params));
       
  3308 #endif
       
  3309 
       
  3310 #if defined(PNG_WRITE_pHYs_SUPPORTED)
       
  3311 PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr,
       
  3312    png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
       
  3313    int unit_type));
       
  3314 #endif
       
  3315 
       
  3316 #if defined(PNG_WRITE_tIME_SUPPORTED)
       
  3317 PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr,
       
  3318    png_timep mod_time));
       
  3319 #endif
       
  3320 
       
  3321 #if defined(PNG_WRITE_sCAL_SUPPORTED)
       
  3322 #if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
       
  3323 PNG_EXTERN void png_write_sCAL PNGARG((png_structp png_ptr,
       
  3324    int unit, double width, double height));
       
  3325 #else
       
  3326 #ifdef PNG_FIXED_POINT_SUPPORTED
       
  3327 PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr,
       
  3328    int unit, png_charp width, png_charp height));
       
  3329 #endif
       
  3330 #endif
       
  3331 #endif
       
  3332 
       
  3333 /* Called when finished processing a row of data */
       
  3334 PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr));
       
  3335 
       
  3336 /* Internal use only.   Called before first row of data */
       
  3337 PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr));
       
  3338 
       
  3339 #if defined(PNG_READ_GAMMA_SUPPORTED)
       
  3340 PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr));
       
  3341 #endif
       
  3342 
       
  3343 /* Combine a row of data, dealing with alpha, etc. if requested */
       
  3344 PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row,
       
  3345    int mask));
       
  3346 
       
  3347 #if defined(PNG_READ_INTERLACING_SUPPORTED)
       
  3348 /* Expand an interlaced row */
       
  3349 /* OLD pre-1.0.9 interface:
       
  3350 PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info,
       
  3351    png_bytep row, int pass, png_uint_32 transformations));
       
  3352  */
       
  3353 PNG_EXTERN void png_do_read_interlace PNGARG((png_structp png_ptr));
       
  3354 #endif
       
  3355 
       
  3356 /* GRR TO DO (2.0 or whenever):  simplify other internal calling interfaces */
       
  3357 
       
  3358 #if defined(PNG_WRITE_INTERLACING_SUPPORTED)
       
  3359 /* Grab pixels out of a row for an interlaced pass */
       
  3360 PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info,
       
  3361    png_bytep row, int pass));
       
  3362 #endif
       
  3363 
       
  3364 /* Unfilter a row */
       
  3365 PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr,
       
  3366    png_row_infop row_info, png_bytep row, png_bytep prev_row, int filter));
       
  3367 
       
  3368 /* Choose the best filter to use and filter the row data */
       
  3369 PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
       
  3370    png_row_infop row_info));
       
  3371 
       
  3372 /* Write out the filtered row. */
       
  3373 PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr,
       
  3374    png_bytep filtered_row));
       
  3375 /* Finish a row while reading, dealing with interlacing passes, etc. */
       
  3376 PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
       
  3377 
       
  3378 /* Initialize the row buffers, etc. */
       
  3379 PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr));
       
  3380 /* Optional call to update the users info structure */
       
  3381 PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
       
  3382    png_infop info_ptr));
       
  3383 
       
  3384 /* These are the functions that do the transformations */
       
  3385 #if defined(PNG_READ_FILLER_SUPPORTED)
       
  3386 PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info,
       
  3387    png_bytep row, png_uint_32 filler, png_uint_32 flags));
       
  3388 #endif
       
  3389 
       
  3390 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
       
  3391 PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info,
       
  3392    png_bytep row));
       
  3393 #endif
       
  3394 
       
  3395 #if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
       
  3396 PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info,
       
  3397    png_bytep row));
       
  3398 #endif
       
  3399 
       
  3400 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
       
  3401 PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info,
       
  3402    png_bytep row));
       
  3403 #endif
       
  3404 
       
  3405 #if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
       
  3406 PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info,
       
  3407    png_bytep row));
       
  3408 #endif
       
  3409 
       
  3410 #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
       
  3411     defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
       
  3412 PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info,
       
  3413    png_bytep row, png_uint_32 flags));
       
  3414 #endif
       
  3415 
       
  3416 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
       
  3417 PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info, png_bytep row));
       
  3418 #endif
       
  3419 
       
  3420 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
       
  3421 PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info, png_bytep row));
       
  3422 #endif
       
  3423 
       
  3424 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
       
  3425 PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr, png_row_infop
       
  3426    row_info, png_bytep row));
       
  3427 #endif
       
  3428 
       
  3429 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
       
  3430 PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info,
       
  3431    png_bytep row));
       
  3432 #endif
       
  3433 
       
  3434 #if defined(PNG_READ_PACK_SUPPORTED)
       
  3435 PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info, png_bytep row));
       
  3436 #endif
       
  3437 
       
  3438 #if defined(PNG_READ_SHIFT_SUPPORTED)
       
  3439 PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info, png_bytep row,
       
  3440    png_color_8p sig_bits));
       
  3441 #endif
       
  3442 
       
  3443 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
       
  3444 PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info, png_bytep row));
       
  3445 #endif
       
  3446 
       
  3447 #if defined(PNG_READ_16_TO_8_SUPPORTED)
       
  3448 PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info, png_bytep row));
       
  3449 #endif
       
  3450 
       
  3451 #if defined(PNG_READ_DITHER_SUPPORTED)
       
  3452 PNG_EXTERN void png_do_dither PNGARG((png_row_infop row_info,
       
  3453    png_bytep row, png_bytep palette_lookup, png_bytep dither_lookup));
       
  3454 
       
  3455 #  if defined(PNG_CORRECT_PALETTE_SUPPORTED)
       
  3456 PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr,
       
  3457    png_colorp palette, int num_palette));
       
  3458 #  endif
       
  3459 #endif
       
  3460 
       
  3461 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
       
  3462 PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info, png_bytep row));
       
  3463 #endif
       
  3464 
       
  3465 #if defined(PNG_WRITE_PACK_SUPPORTED)
       
  3466 PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info,
       
  3467    png_bytep row, png_uint_32 bit_depth));
       
  3468 #endif
       
  3469 
       
  3470 #if defined(PNG_WRITE_SHIFT_SUPPORTED)
       
  3471 PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info, png_bytep row,
       
  3472    png_color_8p bit_depth));
       
  3473 #endif
       
  3474 
       
  3475 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
       
  3476 #if defined(PNG_READ_GAMMA_SUPPORTED)
       
  3477 PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
       
  3478    png_color_16p trans_values, png_color_16p background,
       
  3479    png_color_16p background_1,
       
  3480    png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,
       
  3481    png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,
       
  3482    png_uint_16pp gamma_16_to_1, int gamma_shift));
       
  3483 #else
       
  3484 PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
       
  3485    png_color_16p trans_values, png_color_16p background));
       
  3486 #endif
       
  3487 #endif
       
  3488 
       
  3489 #if defined(PNG_READ_GAMMA_SUPPORTED)
       
  3490 PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info, png_bytep row,
       
  3491    png_bytep gamma_table, png_uint_16pp gamma_16_table,
       
  3492    int gamma_shift));
       
  3493 #endif
       
  3494 
       
  3495 #if defined(PNG_READ_EXPAND_SUPPORTED)
       
  3496 PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info,
       
  3497    png_bytep row, png_colorp palette, png_bytep trans, int num_trans));
       
  3498 PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info,
       
  3499    png_bytep row, png_color_16p trans_value));
       
  3500 #endif
       
  3501 
       
  3502 /* The following decodes the appropriate chunks, and does error correction,
       
  3503  * then calls the appropriate callback for the chunk if it is valid.
       
  3504  */
       
  3505 
       
  3506 /* Decode the IHDR chunk */
       
  3507 PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr,
       
  3508    png_uint_32 length));
       
  3509 PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr,
       
  3510    png_uint_32 length));
       
  3511 PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr,
       
  3512    png_uint_32 length));
       
  3513 
       
  3514 #if defined(PNG_READ_bKGD_SUPPORTED)
       
  3515 PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr,
       
  3516    png_uint_32 length));
       
  3517 #endif
       
  3518 
       
  3519 #if defined(PNG_READ_cHRM_SUPPORTED)
       
  3520 PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr,
       
  3521    png_uint_32 length));
       
  3522 #endif
       
  3523 
       
  3524 #if defined(PNG_READ_gAMA_SUPPORTED)
       
  3525 PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr,
       
  3526    png_uint_32 length));
       
  3527 #endif
       
  3528 
       
  3529 #if defined(PNG_READ_hIST_SUPPORTED)
       
  3530 PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr,
       
  3531    png_uint_32 length));
       
  3532 #endif
       
  3533 
       
  3534 #if defined(PNG_READ_iCCP_SUPPORTED)
       
  3535 extern void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr,
       
  3536    png_uint_32 length));
       
  3537 #endif /* PNG_READ_iCCP_SUPPORTED */
       
  3538 
       
  3539 #if defined(PNG_READ_iTXt_SUPPORTED)
       
  3540 PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
       
  3541    png_uint_32 length));
       
  3542 #endif
       
  3543 
       
  3544 #if defined(PNG_READ_oFFs_SUPPORTED)
       
  3545 PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr,
       
  3546    png_uint_32 length));
       
  3547 #endif
       
  3548 
       
  3549 #if defined(PNG_READ_pCAL_SUPPORTED)
       
  3550 PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
       
  3551    png_uint_32 length));
       
  3552 #endif
       
  3553 
       
  3554 #if defined(PNG_READ_pHYs_SUPPORTED)
       
  3555 PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr,
       
  3556    png_uint_32 length));
       
  3557 #endif
       
  3558 
       
  3559 #if defined(PNG_READ_sBIT_SUPPORTED)
       
  3560 PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr,
       
  3561    png_uint_32 length));
       
  3562 #endif
       
  3563 
       
  3564 #if defined(PNG_READ_sCAL_SUPPORTED)
       
  3565 PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
       
  3566    png_uint_32 length));
       
  3567 #endif
       
  3568 
       
  3569 #if defined(PNG_READ_sPLT_SUPPORTED)
       
  3570 extern void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr,
       
  3571    png_uint_32 length));
       
  3572 #endif /* PNG_READ_sPLT_SUPPORTED */
       
  3573 
       
  3574 #if defined(PNG_READ_sRGB_SUPPORTED)
       
  3575 PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr,
       
  3576    png_uint_32 length));
       
  3577 #endif
       
  3578 
       
  3579 #if defined(PNG_READ_tEXt_SUPPORTED)
       
  3580 PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr,
       
  3581    png_uint_32 length));
       
  3582 #endif
       
  3583 
       
  3584 #if defined(PNG_READ_tIME_SUPPORTED)
       
  3585 PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr,
       
  3586    png_uint_32 length));
       
  3587 #endif
       
  3588 
       
  3589 #if defined(PNG_READ_tRNS_SUPPORTED)
       
  3590 PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr,
       
  3591    png_uint_32 length));
       
  3592 #endif
       
  3593 
       
  3594 #if defined(PNG_READ_zTXt_SUPPORTED)
       
  3595 PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
       
  3596    png_uint_32 length));
       
  3597 #endif
       
  3598 
       
  3599 PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
       
  3600    png_infop info_ptr, png_uint_32 length));
       
  3601 
       
  3602 PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
       
  3603    png_bytep chunk_name));
       
  3604 
       
  3605 /* Handle the transformations for reading and writing */
       
  3606 PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr));
       
  3607 PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr));
       
  3608 
       
  3609 PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr));
       
  3610 
       
  3611 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
       
  3612 PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
       
  3613    png_infop info_ptr));
       
  3614 PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr,
       
  3615    png_infop info_ptr));
       
  3616 PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr));
       
  3617 PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr,
       
  3618    png_uint_32 length));
       
  3619 PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr));
       
  3620 PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr));
       
  3621 PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr,
       
  3622    png_bytep buffer, png_size_t buffer_length));
       
  3623 PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr));
       
  3624 PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr,
       
  3625    png_bytep buffer, png_size_t buffer_length));
       
  3626 PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr));
       
  3627 PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr,
       
  3628    png_infop info_ptr, png_uint_32 length));
       
  3629 PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr,
       
  3630    png_infop info_ptr));
       
  3631 PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr,
       
  3632    png_infop info_ptr));
       
  3633 PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr, png_bytep row));
       
  3634 PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr,
       
  3635    png_infop info_ptr));
       
  3636 PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr,
       
  3637    png_infop info_ptr));
       
  3638 PNG_EXTERN void png_read_push_finish_row PNGARG((png_structp png_ptr));
       
  3639 #if defined(PNG_READ_tEXt_SUPPORTED)
       
  3640 PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr,
       
  3641    png_infop info_ptr, png_uint_32 length));
       
  3642 PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr,
       
  3643    png_infop info_ptr));
       
  3644 #endif
       
  3645 #if defined(PNG_READ_zTXt_SUPPORTED)
       
  3646 PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr,
       
  3647    png_infop info_ptr, png_uint_32 length));
       
  3648 PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr,
       
  3649    png_infop info_ptr));
       
  3650 #endif
       
  3651 #if defined(PNG_READ_iTXt_SUPPORTED)
       
  3652 PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr,
       
  3653    png_infop info_ptr, png_uint_32 length));
       
  3654 PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr,
       
  3655    png_infop info_ptr));
       
  3656 #endif
       
  3657 
       
  3658 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
       
  3659 
       
  3660 #ifdef PNG_MNG_FEATURES_SUPPORTED
       
  3661 PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info,
       
  3662    png_bytep row));
       
  3663 PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info,
       
  3664    png_bytep row));
       
  3665 #endif
       
  3666 
       
  3667 #if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
       
  3668 #if defined(PNG_MMX_CODE_SUPPORTED)
       
  3669 /* png.c */ /* PRIVATE */
       
  3670 PNG_EXTERN void png_init_mmx_flags PNGARG((png_structp png_ptr));
       
  3671 #endif
       
  3672 #endif
       
  3673 
       
  3674 #if defined(PNG_INCH_CONVERSIONS) && defined(PNG_FLOATING_POINT_SUPPORTED)
       
  3675 PNG_EXTERN png_uint_32 png_get_pixels_per_inch PNGARG((png_structp png_ptr,
       
  3676 png_infop info_ptr));
       
  3677 
       
  3678 PNG_EXTERN png_uint_32 png_get_x_pixels_per_inch PNGARG((png_structp png_ptr,
       
  3679 png_infop info_ptr));
       
  3680 
       
  3681 PNG_EXTERN png_uint_32 png_get_y_pixels_per_inch PNGARG((png_structp png_ptr,
       
  3682 png_infop info_ptr));
       
  3683 
       
  3684 PNG_EXTERN float png_get_x_offset_inches PNGARG((png_structp png_ptr,
       
  3685 png_infop info_ptr));
       
  3686 
       
  3687 PNG_EXTERN float png_get_y_offset_inches PNGARG((png_structp png_ptr,
       
  3688 png_infop info_ptr));
       
  3689 
       
  3690 #if defined(PNG_pHYs_SUPPORTED)
       
  3691 PNG_EXTERN png_uint_32 png_get_pHYs_dpi PNGARG((png_structp png_ptr,
       
  3692 png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
       
  3693 #endif /* PNG_pHYs_SUPPORTED */
       
  3694 #endif  /* PNG_INCH_CONVERSIONS && PNG_FLOATING_POINT_SUPPORTED */
       
  3695 
       
  3696 /* Read the chunk header (length + type name) */
       
  3697 PNG_EXTERN png_uint_32 png_read_chunk_header PNGARG((png_structp png_ptr));
       
  3698 
       
  3699 /* Added at libpng version 1.2.34 */
       
  3700 #if defined(PNG_cHRM_SUPPORTED)
       
  3701 PNG_EXTERN int png_check_cHRM_fixed  PNGARG((png_structp png_ptr,
       
  3702    png_fixed_point int_white_x, png_fixed_point int_white_y,
       
  3703    png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
       
  3704    int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
       
  3705    png_fixed_point int_blue_y));
       
  3706 #endif
       
  3707 
       
  3708 #if defined(PNG_cHRM_SUPPORTED)
       
  3709 #if !defined(PNG_NO_CHECK_cHRM)
       
  3710 /* Added at libpng version 1.2.34 */
       
  3711 PNG_EXTERN void png_64bit_product (long v1, long v2, unsigned long *hi_product,
       
  3712    unsigned long *lo_product);
       
  3713 #endif
       
  3714 #endif
       
  3715 
       
  3716 /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
       
  3717 
       
  3718 #endif /* PNG_INTERNAL */
       
  3719 
       
  3720 #ifdef __cplusplus
       
  3721 }
       
  3722 #endif
       
  3723 
       
  3724 #endif /* PNG_VERSION_INFO_ONLY */
       
  3725 /* Do not put anything past this line */
       
  3726 #endif /* PNG_H */