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1 /* png.h - header file for PNG reference library
2  *
3  * libpng version 1.2.44 - June 26, 2010
4  * Copyright (c) 1998-2010 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 1.2.44 - June 26, 2010: 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  *    1.2.41beta01-18         13    10241  12.so.0.41[.0]
249  *    1.0.51rc01              10    10051  10.so.0.51[.0]
250  *    1.2.41rc01-03           13    10241  12.so.0.41[.0]
251  *    1.0.51                  10    10051  10.so.0.51[.0]
252  *    1.2.41                  13    10241  12.so.0.41[.0]
253  *    1.2.42beta01-02         13    10242  12.so.0.42[.0]
254  *    1.2.42rc01-05           13    10242  12.so.0.42[.0]
255  *    1.0.52                  10    10052  10.so.0.52[.0]
256  *    1.2.42                  13    10242  12.so.0.42[.0]
257  *    1.2.43beta01-05         13    10243  12.so.0.43[.0]
258  *    1.0.53rc01-02           10    10053  10.so.0.53[.0]
259  *    1.2.43rc01-02           13    10243  12.so.0.43[.0]
260  *    1.0.53                  10    10053  10.so.0.53[.0]
261  *    1.2.43                  13    10243  12.so.0.43[.0]
262  *    1.2.44beta01-03         13    10244  12.so.0.44[.0]
263  *    1.2.44rc01-03           13    10244  12.so.0.44[.0]
264  *    1.2.44                  13    10244  12.so.0.44[.0]
265  *
266  *    Henceforth the source version will match the shared-library major
267  *    and minor numbers; the shared-library major version number will be
268  *    used for changes in backward compatibility, as it is intended.  The
269  *    PNG_LIBPNG_VER macro, which is not used within libpng but is available
270  *    for applications, is an unsigned integer of the form xyyzz corresponding
271  *    to the source version x.y.z (leading zeros in y and z).  Beta versions
272  *    were given the previous public release number plus a letter, until
273  *    version 1.0.6j; from then on they were given the upcoming public
274  *    release number plus "betaNN" or "rcNN".
275  *
276  *    Binary incompatibility exists only when applications make direct access
277  *    to the info_ptr or png_ptr members through png.h, and the compiled
278  *    application is loaded with a different version of the library.
279  *
280  *    DLLNUM will change each time there are forward or backward changes
281  *    in binary compatibility (e.g., when a new feature is added).
282  *
283  * See libpng.txt or libpng.3 for more information.  The PNG specification
284  * is available as a W3C Recommendation and as an ISO Specification,
285  * <http://www.w3.org/TR/2003/REC-PNG-20031110/
286  */
287 
288 /*
289  * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
290  *
291  * If you modify libpng you may insert additional notices immediately following
292  * this sentence.
293  *
294  * This code is released under the libpng license.
295  *
296  * libpng versions 1.2.6, August 15, 2004, through 1.2.44, June 26, 2010, are
297  * Copyright (c) 2004, 2006-2010 Glenn Randers-Pehrson, and are
298  * distributed according to the same disclaimer and license as libpng-1.2.5
299  * with the following individual added to the list of Contributing Authors:
300  *
301  *    Cosmin Truta
302  *
303  * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
304  * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
305  * distributed according to the same disclaimer and license as libpng-1.0.6
306  * with the following individuals added to the list of Contributing Authors:
307  *
308  *    Simon-Pierre Cadieux
309  *    Eric S. Raymond
310  *    Gilles Vollant
311  *
312  * and with the following additions to the disclaimer:
313  *
314  *    There is no warranty against interference with your enjoyment of the
315  *    library or against infringement.  There is no warranty that our
316  *    efforts or the library will fulfill any of your particular purposes
317  *    or needs.  This library is provided with all faults, and the entire
318  *    risk of satisfactory quality, performance, accuracy, and effort is with
319  *    the user.
320  *
321  * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
322  * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are
323  * distributed according to the same disclaimer and license as libpng-0.96,
324  * with the following individuals added to the list of Contributing Authors:
325  *
326  *    Tom Lane
327  *    Glenn Randers-Pehrson
328  *    Willem van Schaik
329  *
330  * libpng versions 0.89, June 1996, through 0.96, May 1997, are
331  * Copyright (c) 1996, 1997 Andreas Dilger
332  * Distributed according to the same disclaimer and license as libpng-0.88,
333  * with the following individuals added to the list of Contributing Authors:
334  *
335  *    John Bowler
336  *    Kevin Bracey
337  *    Sam Bushell
338  *    Magnus Holmgren
339  *    Greg Roelofs
340  *    Tom Tanner
341  *
342  * libpng versions 0.5, May 1995, through 0.88, January 1996, are
343  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
344  *
345  * For the purposes of this copyright and license, "Contributing Authors"
346  * is defined as the following set of individuals:
347  *
348  *    Andreas Dilger
349  *    Dave Martindale
350  *    Guy Eric Schalnat
351  *    Paul Schmidt
352  *    Tim Wegner
353  *
354  * The PNG Reference Library is supplied "AS IS".  The Contributing Authors
355  * and Group 42, Inc. disclaim all warranties, expressed or implied,
356  * including, without limitation, the warranties of merchantability and of
357  * fitness for any purpose.  The Contributing Authors and Group 42, Inc.
358  * assume no liability for direct, indirect, incidental, special, exemplary,
359  * or consequential damages, which may result from the use of the PNG
360  * Reference Library, even if advised of the possibility of such damage.
361  *
362  * Permission is hereby granted to use, copy, modify, and distribute this
363  * source code, or portions hereof, for any purpose, without fee, subject
364  * to the following restrictions:
365  *
366  * 1. The origin of this source code must not be misrepresented.
367  *
368  * 2. Altered versions must be plainly marked as such and
369  * must not be misrepresented as being the original source.
370  *
371  * 3. This Copyright notice may not be removed or altered from
372  *    any source or altered source distribution.
373  *
374  * The Contributing Authors and Group 42, Inc. specifically permit, without
375  * fee, and encourage the use of this source code as a component to
376  * supporting the PNG file format in commercial products.  If you use this
377  * source code in a product, acknowledgment is not required but would be
378  * appreciated.
379  */
380 
381 /*
382  * A "png_get_copyright" function is available, for convenient use in "about"
383  * boxes and the like:
384  *
385  * printf("%s",png_get_copyright(NULL));
386  *
387  * Also, the PNG logo (in PNG format, of course) is supplied in the
388  * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
389  */
390 
391 /*
392  * Libpng is OSI Certified Open Source Software.  OSI Certified is a
393  * certification mark of the Open Source Initiative.
394  */
395 
396 /*
397  * The contributing authors would like to thank all those who helped
398  * with testing, bug fixes, and patience.  This wouldn't have been
399  * possible without all of you.
400  *
401  * Thanks to Frank J. T. Wojcik for helping with the documentation.
402  */
403 
404 /*
405  * Y2K compliance in libpng:
406  * =========================
407  *
408  *    June 26, 2010
409  *
410  *    Since the PNG Development group is an ad-hoc body, we can't make
411  *    an official declaration.
412  *
413  *    This is your unofficial assurance that libpng from version 0.71 and
414  *    upward through 1.2.44 are Y2K compliant.  It is my belief that earlier
415  *    versions were also Y2K compliant.
416  *
417  *    Libpng only has three year fields.  One is a 2-byte unsigned integer
418  *    that will hold years up to 65535.  The other two hold the date in text
419  *    format, and will hold years up to 9999.
420  *
421  *    The integer is
422  *        "png_uint_16 year" in png_time_struct.
423  *
424  *    The strings are
425  *        "png_charp time_buffer" in png_struct and
426  *        "near_time_buffer", which is a local character string in png.c.
427  *
428  *    There are seven time-related functions:
429  *        png.c: png_convert_to_rfc_1123() in png.c
430  *          (formerly png_convert_to_rfc_1152() in error)
431  *        png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
432  *        png_convert_from_time_t() in pngwrite.c
433  *        png_get_tIME() in pngget.c
434  *        png_handle_tIME() in pngrutil.c, called in pngread.c
435  *        png_set_tIME() in pngset.c
436  *        png_write_tIME() in pngwutil.c, called in pngwrite.c
437  *
438  *    All handle dates properly in a Y2K environment.  The
439  *    png_convert_from_time_t() function calls gmtime() to convert from system
440  *    clock time, which returns (year - 1900), which we properly convert to
441  *    the full 4-digit year.  There is a possibility that applications using
442  *    libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
443  *    function, or that they are incorrectly passing only a 2-digit year
444  *    instead of "year - 1900" into the png_convert_from_struct_tm() function,
445  *    but this is not under our control.  The libpng documentation has always
446  *    stated that it works with 4-digit years, and the APIs have been
447  *    documented as such.
448  *
449  *    The tIME chunk itself is also Y2K compliant.  It uses a 2-byte unsigned
450  *    integer to hold the year, and can hold years as large as 65535.
451  *
452  *    zlib, upon which libpng depends, is also Y2K compliant.  It contains
453  *    no date-related code.
454  *
455  *       Glenn Randers-Pehrson
456  *       libpng maintainer
457  *       PNG Development Group
458  */
459 
460 #ifndef PNG_H
461 #define PNG_H
462 
463 /* This is not the place to learn how to use libpng.  The file libpng.txt
464  * describes how to use libpng, and the file example.c summarizes it
465  * with some code on which to build.  This file is useful for looking
466  * at the actual function definitions and structure components.
467  */
468 
469 /* Version information for png.h - this should match the version in png.c */
470 #define PNG_LIBPNG_VER_STRING "1.2.44"
471 #define PNG_HEADER_VERSION_STRING \
472    " libpng version 1.2.44 - June 26, 2010\n"
473 
474 #define PNG_LIBPNG_VER_SONUM   0
475 #define PNG_LIBPNG_VER_DLLNUM  13
476 
477 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
478 #define PNG_LIBPNG_VER_MAJOR   1
479 #define PNG_LIBPNG_VER_MINOR   2
480 #define PNG_LIBPNG_VER_RELEASE 44
481 /* This should match the numeric part of the final component of
482  * PNG_LIBPNG_VER_STRING, omitting any leading zero:
483  */
484 
485 #define PNG_LIBPNG_VER_BUILD  0
486 
487 /* Release Status */
488 #define PNG_LIBPNG_BUILD_ALPHA    1
489 #define PNG_LIBPNG_BUILD_BETA     2
490 #define PNG_LIBPNG_BUILD_RC       3
491 #define PNG_LIBPNG_BUILD_STABLE   4
492 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
493 
494 /* Release-Specific Flags */
495 #define PNG_LIBPNG_BUILD_PATCH    8 /* Can be OR'ed with
496                                        PNG_LIBPNG_BUILD_STABLE only */
497 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
498                                        PNG_LIBPNG_BUILD_SPECIAL */
499 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
500                                        PNG_LIBPNG_BUILD_PRIVATE */
501 
502 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
503 
504 /* Careful here.  At one time, Guy wanted to use 082, but that would be octal.
505  * We must not include leading zeros.
506  * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
507  * version 1.0.0 was mis-numbered 100 instead of 10000).  From
508  * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=release
509  */
510 #define PNG_LIBPNG_VER 10244 /* 1.2.44 */
511 
512 #ifndef PNG_VERSION_INFO_ONLY
513 /* Include the compression library's header */
514 #include "zlib.h"
515 #endif
516 
517 /* Include all user configurable info, including optional assembler routines */
518 #include "pngconf.h"
519 
520 /*
521  * Added at libpng-1.2.8 */
522 /* Ref MSDN: Private as priority over Special
523  * VS_FF_PRIVATEBUILD File *was not* built using standard release
524  * procedures. If this value is given, the StringFileInfo block must
525  * contain a PrivateBuild string.
526  *
527  * VS_FF_SPECIALBUILD File *was* built by the original company using
528  * standard release procedures but is a variation of the standard
529  * file of the same version number. If this value is given, the
530  * StringFileInfo block must contain a SpecialBuild string.
531  */
532 
533 #ifdef PNG_USER_PRIVATEBUILD
534 #  define PNG_LIBPNG_BUILD_TYPE \
535           (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
536 #else
537 #  ifdef PNG_LIBPNG_SPECIALBUILD
538 #    define PNG_LIBPNG_BUILD_TYPE \
539             (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
540 #  else
541 #    define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
542 #  endif
543 #endif
544 
545 #ifndef PNG_VERSION_INFO_ONLY
546 
547 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
548 #ifdef __cplusplus
549 extern "C" {
550 #endif /* __cplusplus */
551 
552 /* This file is arranged in several sections.  The first section contains
553  * structure and type definitions.  The second section contains the external
554  * library functions, while the third has the internal library functions,
555  * which applications aren't expected to use directly.
556  */
557 
558 #ifndef PNG_NO_TYPECAST_NULL
559 #define int_p_NULL                (int *)NULL
560 #define png_bytep_NULL            (png_bytep)NULL
561 #define png_bytepp_NULL           (png_bytepp)NULL
562 #define png_doublep_NULL          (png_doublep)NULL
563 #define png_error_ptr_NULL        (png_error_ptr)NULL
564 #define png_flush_ptr_NULL        (png_flush_ptr)NULL
565 #define png_free_ptr_NULL         (png_free_ptr)NULL
566 #define png_infopp_NULL           (png_infopp)NULL
567 #define png_malloc_ptr_NULL       (png_malloc_ptr)NULL
568 #define png_read_status_ptr_NULL  (png_read_status_ptr)NULL
569 #define png_rw_ptr_NULL           (png_rw_ptr)NULL
570 #define png_structp_NULL          (png_structp)NULL
571 #define png_uint_16p_NULL         (png_uint_16p)NULL
572 #define png_voidp_NULL            (png_voidp)NULL
573 #define png_write_status_ptr_NULL (png_write_status_ptr)NULL
574 #else
575 #define int_p_NULL                NULL
576 #define png_bytep_NULL            NULL
577 #define png_bytepp_NULL           NULL
578 #define png_doublep_NULL          NULL
579 #define png_error_ptr_NULL        NULL
580 #define png_flush_ptr_NULL        NULL
581 #define png_free_ptr_NULL         NULL
582 #define png_infopp_NULL           NULL
583 #define png_malloc_ptr_NULL       NULL
584 #define png_read_status_ptr_NULL  NULL
585 #define png_rw_ptr_NULL           NULL
586 #define png_structp_NULL          NULL
587 #define png_uint_16p_NULL         NULL
588 #define png_voidp_NULL            NULL
589 #define png_write_status_ptr_NULL NULL
590 #endif
591 
592 /* Variables declared in png.c - only it needs to define PNG_NO_EXTERN */
593 #if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
594 /* Version information for C files, stored in png.c.  This had better match
595  * the version above.
596  */
597 #ifdef PNG_USE_GLOBAL_ARRAYS
598 PNG_EXPORT_VAR (PNG_CONST char) png_libpng_ver[18];
599   /* Need room for 99.99.99beta99z */
600 #else
601 #define png_libpng_ver png_get_header_ver(NULL)
602 #endif
603 
604 #ifdef PNG_USE_GLOBAL_ARRAYS
605 /* This was removed in version 1.0.5c */
606 /* Structures to facilitate easy interlacing.  See png.c for more details */
607 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_start[7];
608 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_inc[7];
609 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_ystart[7];
610 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_yinc[7];
611 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_mask[7];
612 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_dsp_mask[7];
613 /* This isn't currently used.  If you need it, see png.c for more details.
614 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_height[7];
615 */
616 #endif
617 
618 #endif /* PNG_NO_EXTERN */
619 
620 /* Three color definitions.  The order of the red, green, and blue, (and the
621  * exact size) is not important, although the size of the fields need to
622  * be png_byte or png_uint_16 (as defined below).
623  */
624 typedef struct png_color_struct
625 {
626    png_byte red;
627    png_byte green;
628    png_byte blue;
629 } png_color;
630 typedef png_color FAR * png_colorp;
631 typedef png_color FAR * FAR * png_colorpp;
632 
633 typedef struct png_color_16_struct
634 {
635    png_byte index;    /* used for palette files */
636    png_uint_16 red;   /* for use in red green blue files */
637    png_uint_16 green;
638    png_uint_16 blue;
639    png_uint_16 gray;  /* for use in grayscale files */
640 } png_color_16;
641 typedef png_color_16 FAR * png_color_16p;
642 typedef png_color_16 FAR * FAR * png_color_16pp;
643 
644 typedef struct png_color_8_struct
645 {
646    png_byte red;   /* for use in red green blue files */
647    png_byte green;
648    png_byte blue;
649    png_byte gray;  /* for use in grayscale files */
650    png_byte alpha; /* for alpha channel files */
651 } png_color_8;
652 typedef png_color_8 FAR * png_color_8p;
653 typedef png_color_8 FAR * FAR * png_color_8pp;
654 
655 /*
656  * The following two structures are used for the in-core representation
657  * of sPLT chunks.
658  */
659 typedef struct png_sPLT_entry_struct
660 {
661    png_uint_16 red;
662    png_uint_16 green;
663    png_uint_16 blue;
664    png_uint_16 alpha;
665    png_uint_16 frequency;
666 } png_sPLT_entry;
667 typedef png_sPLT_entry FAR * png_sPLT_entryp;
668 typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;
669 
670 /*  When the depth of the sPLT palette is 8 bits, the color and alpha samples
671  *  occupy the LSB of their respective members, and the MSB of each member
672  *  is zero-filled.  The frequency member always occupies the full 16 bits.
673  */
674 
675 typedef struct png_sPLT_struct
676 {
677    png_charp name;           /* palette name */
678    png_byte depth;           /* depth of palette samples */
679    png_sPLT_entryp entries;  /* palette entries */
680    png_int_32 nentries;      /* number of palette entries */
681 } png_sPLT_t;
682 typedef png_sPLT_t FAR * png_sPLT_tp;
683 typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
684 
685 #ifdef PNG_TEXT_SUPPORTED
686 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
687  * and whether that contents is compressed or not.  The "key" field
688  * points to a regular zero-terminated C string.  The "text", "lang", and
689  * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
690  * However, the * structure returned by png_get_text() will always contain
691  * regular zero-terminated C strings (possibly empty), never NULL pointers,
692  * so they can be safely used in printf() and other string-handling functions.
693  */
694 typedef struct png_text_struct
695 {
696    int  compression;       /* compression value:
697                              -1: tEXt, none
698                               0: zTXt, deflate
699                               1: iTXt, none
700                               2: iTXt, deflate  */
701    png_charp key;          /* keyword, 1-79 character description of "text" */
702    png_charp text;         /* comment, may be an empty string (ie "")
703                               or a NULL pointer */
704    png_size_t text_length; /* length of the text string */
705 #ifdef PNG_iTXt_SUPPORTED
706    png_size_t itxt_length; /* length of the itxt string */
707    png_charp lang;         /* language code, 0-79 characters
708                               or a NULL pointer */
709    png_charp lang_key;     /* keyword translated UTF-8 string, 0 or more
710                               chars or a NULL pointer */
711 #endif
712 } png_text;
713 typedef png_text FAR * png_textp;
714 typedef png_text FAR * FAR * png_textpp;
715 #endif
716 
717 /* Supported compression types for text in PNG files (tEXt, and zTXt).
718  * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed.
719  */
720 #define PNG_TEXT_COMPRESSION_NONE_WR -3
721 #define PNG_TEXT_COMPRESSION_zTXt_WR -2
722 #define PNG_TEXT_COMPRESSION_NONE    -1
723 #define PNG_TEXT_COMPRESSION_zTXt     0
724 #define PNG_ITXT_COMPRESSION_NONE     1
725 #define PNG_ITXT_COMPRESSION_zTXt     2
726 #define PNG_TEXT_COMPRESSION_LAST     3  /* Not a valid value */
727 
728 /* png_time is a way to hold the time in an machine independent way.
729  * Two conversions are provided, both from time_t and struct tm.  There
730  * is no portable way to convert to either of these structures, as far
731  * as I know.  If you know of a portable way, send it to me.  As a side
732  * note - PNG has always been Year 2000 compliant!
733  */
734 typedef struct png_time_struct
735 {
736    png_uint_16 year; /* full year, as in, 1995 */
737    png_byte month;   /* month of year, 1 - 12 */
738    png_byte day;     /* day of month, 1 - 31 */
739    png_byte hour;    /* hour of day, 0 - 23 */
740    png_byte minute;  /* minute of hour, 0 - 59 */
741    png_byte second;  /* second of minute, 0 - 60 (for leap seconds) */
742 } png_time;
743 typedef png_time FAR * png_timep;
744 typedef png_time FAR * FAR * png_timepp;
745 
746 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
747  defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
748 /* png_unknown_chunk is a structure to hold queued chunks for which there is
749  * no specific support.  The idea is that we can use this to queue
750  * up private chunks for output even though the library doesn't actually
751  * know about their semantics.
752  */
753 #define PNG_CHUNK_NAME_LENGTH 5
754 typedef struct png_unknown_chunk_t
755 {
756     png_byte name[PNG_CHUNK_NAME_LENGTH];
757     png_byte *data;
758     png_size_t size;
759 
760     /* libpng-using applications should NOT directly modify this byte. */
761     png_byte location; /* mode of operation at read time */
762 }
763 png_unknown_chunk;
764 typedef png_unknown_chunk FAR * png_unknown_chunkp;
765 typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
766 #endif
767 
768 /* png_info is a structure that holds the information in a PNG file so
769  * that the application can find out the characteristics of the image.
770  * If you are reading the file, this structure will tell you what is
771  * in the PNG file.  If you are writing the file, fill in the information
772  * you want to put into the PNG file, then call png_write_info().
773  * The names chosen should be very close to the PNG specification, so
774  * consult that document for information about the meaning of each field.
775  *
776  * With libpng < 0.95, it was only possible to directly set and read the
777  * the values in the png_info_struct, which meant that the contents and
778  * order of the values had to remain fixed.  With libpng 0.95 and later,
779  * however, there are now functions that abstract the contents of
780  * png_info_struct from the application, so this makes it easier to use
781  * libpng with dynamic libraries, and even makes it possible to use
782  * libraries that don't have all of the libpng ancillary chunk-handing
783  * functionality.
784  *
785  * In any case, the order of the parameters in png_info_struct should NOT
786  * be changed for as long as possible to keep compatibility with applications
787  * that use the old direct-access method with png_info_struct.
788  *
789  * The following members may have allocated storage attached that should be
790  * cleaned up before the structure is discarded: palette, trans, text,
791  * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
792  * splt_palettes, scal_unit, row_pointers, and unknowns.   By default, these
793  * are automatically freed when the info structure is deallocated, if they were
794  * allocated internally by libpng.  This behavior can be changed by means
795  * of the png_data_freer() function.
796  *
797  * More allocation details: all the chunk-reading functions that
798  * change these members go through the corresponding png_set_*
799  * functions.  A function to clear these members is available: see
800  * png_free_data().  The png_set_* functions do not depend on being
801  * able to point info structure members to any of the storage they are
802  * passed (they make their own copies), EXCEPT that the png_set_text
803  * functions use the same storage passed to them in the text_ptr or
804  * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
805  * functions do not make their own copies.
806  */
807 typedef struct png_info_struct
808 {
809    /* The following are necessary for every PNG file */
810    png_uint_32 width PNG_DEPSTRUCT;       /* width of image in pixels (from IHDR) */
811    png_uint_32 height PNG_DEPSTRUCT;      /* height of image in pixels (from IHDR) */
812    png_uint_32 valid PNG_DEPSTRUCT;       /* valid chunk data (see PNG_INFO_ below) */
813    png_uint_32 rowbytes PNG_DEPSTRUCT;    /* bytes needed to hold an untransformed row */
814    png_colorp palette PNG_DEPSTRUCT;      /* array of color values (valid & PNG_INFO_PLTE) */
815    png_uint_16 num_palette PNG_DEPSTRUCT; /* number of color entries in "palette" (PLTE) */
816    png_uint_16 num_trans PNG_DEPSTRUCT;   /* number of transparent palette color (tRNS) */
817    png_byte bit_depth PNG_DEPSTRUCT;      /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */
818    png_byte color_type PNG_DEPSTRUCT;     /* see PNG_COLOR_TYPE_ below (from IHDR) */
819    /* The following three should have been named *_method not *_type */
820    png_byte compression_type PNG_DEPSTRUCT; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */
821    png_byte filter_type PNG_DEPSTRUCT;    /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
822    png_byte interlace_type PNG_DEPSTRUCT; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
823 
824    /* The following is informational only on read, and not used on writes. */
825    png_byte channels PNG_DEPSTRUCT;       /* number of data channels per pixel (1, 2, 3, 4) */
826    png_byte pixel_depth PNG_DEPSTRUCT;    /* number of bits per pixel */
827    png_byte spare_byte PNG_DEPSTRUCT;     /* to align the data, and for future use */
828    png_byte signature[8] PNG_DEPSTRUCT;   /* magic bytes read by libpng from start of file */
829 
830    /* The rest of the data is optional.  If you are reading, check the
831     * valid field to see if the information in these are valid.  If you
832     * are writing, set the valid field to those chunks you want written,
833     * and initialize the appropriate fields below.
834     */
835 
836 #if defined(PNG_gAMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
837    /* The gAMA chunk describes the gamma characteristics of the system
838     * on which the image was created, normally in the range [1.0, 2.5].
839     * Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
840     */
841    float gamma PNG_DEPSTRUCT; /* gamma value of image, if (valid & PNG_INFO_gAMA) */
842 #endif
843 
844 #ifdef PNG_sRGB_SUPPORTED
845     /* GR-P, 0.96a */
846     /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
847    png_byte srgb_intent PNG_DEPSTRUCT; /* sRGB rendering intent [0, 1, 2, or 3] */
848 #endif
849 
850 #ifdef PNG_TEXT_SUPPORTED
851    /* The tEXt, and zTXt chunks contain human-readable textual data in
852     * uncompressed, compressed, and optionally compressed forms, respectively.
853     * The data in "text" is an array of pointers to uncompressed,
854     * null-terminated C strings. Each chunk has a keyword that describes the
855     * textual data contained in that chunk.  Keywords are not required to be
856     * unique, and the text string may be empty.  Any number of text chunks may
857     * be in an image.
858     */
859    int num_text PNG_DEPSTRUCT; /* number of comments read/to write */
860    int max_text PNG_DEPSTRUCT; /* current size of text array */
861    png_textp text PNG_DEPSTRUCT; /* array of comments read/to write */
862 #endif /* PNG_TEXT_SUPPORTED */
863 
864 #ifdef PNG_tIME_SUPPORTED
865    /* The tIME chunk holds the last time the displayed image data was
866     * modified.  See the png_time struct for the contents of this struct.
867     */
868    png_time mod_time PNG_DEPSTRUCT;
869 #endif
870 
871 #ifdef PNG_sBIT_SUPPORTED
872    /* The sBIT chunk specifies the number of significant high-order bits
873     * in the pixel data.  Values are in the range [1, bit_depth], and are
874     * only specified for the channels in the pixel data.  The contents of
875     * the low-order bits is not specified.  Data is valid if
876     * (valid & PNG_INFO_sBIT) is non-zero.
877     */
878    png_color_8 sig_bit PNG_DEPSTRUCT; /* significant bits in color channels */
879 #endif
880 
881 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
882 defined(PNG_READ_BACKGROUND_SUPPORTED)
883    /* The tRNS chunk supplies transparency data for paletted images and
884     * other image types that don't need a full alpha channel.  There are
885     * "num_trans" transparency values for a paletted image, stored in the
886     * same order as the palette colors, starting from index 0.  Values
887     * for the data are in the range [0, 255], ranging from fully transparent
888     * to fully opaque, respectively.  For non-paletted images, there is a
889     * single color specified that should be treated as fully transparent.
890     * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
891     */
892    png_bytep trans PNG_DEPSTRUCT; /* transparent values for paletted image */
893    png_color_16 trans_values PNG_DEPSTRUCT; /* transparent color for non-palette image */
894 #endif
895 
896 #if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
897    /* The bKGD chunk gives the suggested image background color if the
898     * display program does not have its own background color and the image
899     * is needs to composited onto a background before display.  The colors
900     * in "background" are normally in the same color space/depth as the
901     * pixel data.  Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
902     */
903    png_color_16 background PNG_DEPSTRUCT;
904 #endif
905 
906 #ifdef PNG_oFFs_SUPPORTED
907    /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
908     * and downwards from the top-left corner of the display, page, or other
909     * application-specific co-ordinate space.  See the PNG_OFFSET_ defines
910     * below for the unit types.  Valid if (valid & PNG_INFO_oFFs) non-zero.
911     */
912    png_int_32 x_offset PNG_DEPSTRUCT; /* x offset on page */
913    png_int_32 y_offset PNG_DEPSTRUCT; /* y offset on page */
914    png_byte offset_unit_type PNG_DEPSTRUCT; /* offset units type */
915 #endif
916 
917 #ifdef PNG_pHYs_SUPPORTED
918    /* The pHYs chunk gives the physical pixel density of the image for
919     * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
920     * defines below).  Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
921     */
922    png_uint_32 x_pixels_per_unit PNG_DEPSTRUCT; /* horizontal pixel density */
923    png_uint_32 y_pixels_per_unit PNG_DEPSTRUCT; /* vertical pixel density */
924    png_byte phys_unit_type PNG_DEPSTRUCT; /* resolution type (see PNG_RESOLUTION_ below) */
925 #endif
926 
927 #ifdef PNG_hIST_SUPPORTED
928    /* The hIST chunk contains the relative frequency or importance of the
929     * various palette entries, so that a viewer can intelligently select a
930     * reduced-color palette, if required.  Data is an array of "num_palette"
931     * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
932     * is non-zero.
933     */
934    png_uint_16p hist PNG_DEPSTRUCT;
935 #endif
936 
937 #ifdef PNG_cHRM_SUPPORTED
938    /* The cHRM chunk describes the CIE color characteristics of the monitor
939     * on which the PNG was created.  This data allows the viewer to do gamut
940     * mapping of the input image to ensure that the viewer sees the same
941     * colors in the image as the creator.  Values are in the range
942     * [0.0, 0.8].  Data valid if (valid & PNG_INFO_cHRM) non-zero.
943     */
944 #ifdef PNG_FLOATING_POINT_SUPPORTED
945    float x_white PNG_DEPSTRUCT;
946    float y_white PNG_DEPSTRUCT;
947    float x_red PNG_DEPSTRUCT;
948    float y_red PNG_DEPSTRUCT;
949    float x_green PNG_DEPSTRUCT;
950    float y_green PNG_DEPSTRUCT;
951    float x_blue PNG_DEPSTRUCT;
952    float y_blue PNG_DEPSTRUCT;
953 #endif
954 #endif
955 
956 #ifdef PNG_pCAL_SUPPORTED
957    /* The pCAL chunk describes a transformation between the stored pixel
958     * values and original physical data values used to create the image.
959     * The integer range [0, 2^bit_depth - 1] maps to the floating-point
960     * range given by [pcal_X0, pcal_X1], and are further transformed by a
961     * (possibly non-linear) transformation function given by "pcal_type"
962     * and "pcal_params" into "pcal_units".  Please see the PNG_EQUATION_
963     * defines below, and the PNG-Group's PNG extensions document for a
964     * complete description of the transformations and how they should be
965     * implemented, and for a description of the ASCII parameter strings.
966     * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
967     */
968    png_charp pcal_purpose PNG_DEPSTRUCT;  /* pCAL chunk description string */
969    png_int_32 pcal_X0 PNG_DEPSTRUCT;      /* minimum value */
970    png_int_32 pcal_X1 PNG_DEPSTRUCT;      /* maximum value */
971    png_charp pcal_units PNG_DEPSTRUCT;    /* Latin-1 string giving physical units */
972    png_charpp pcal_params PNG_DEPSTRUCT;  /* ASCII strings containing parameter values */
973    png_byte pcal_type PNG_DEPSTRUCT;      /* equation type (see PNG_EQUATION_ below) */
974    png_byte pcal_nparams PNG_DEPSTRUCT;   /* number of parameters given in pcal_params */
975 #endif
976 
977 /* New members added in libpng-1.0.6 */
978 #ifdef PNG_FREE_ME_SUPPORTED
979    png_uint_32 free_me PNG_DEPSTRUCT;     /* flags items libpng is responsible for freeing */
980 #endif
981 
982 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
983  defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
984    /* Storage for unknown chunks that the library doesn't recognize. */
985    png_unknown_chunkp unknown_chunks PNG_DEPSTRUCT;
986    png_size_t unknown_chunks_num PNG_DEPSTRUCT;
987 #endif
988 
989 #ifdef PNG_iCCP_SUPPORTED
990    /* iCCP chunk data. */
991    png_charp iccp_name PNG_DEPSTRUCT;     /* profile name */
992    png_charp iccp_profile PNG_DEPSTRUCT;  /* International Color Consortium profile data */
993                             /* Note to maintainer: should be png_bytep */
994    png_uint_32 iccp_proflen PNG_DEPSTRUCT;  /* ICC profile data length */
995    png_byte iccp_compression PNG_DEPSTRUCT; /* Always zero */
996 #endif
997 
998 #ifdef PNG_sPLT_SUPPORTED
999    /* Data on sPLT chunks (there may be more than one). */
1000    png_sPLT_tp splt_palettes PNG_DEPSTRUCT;
1001    png_uint_32 splt_palettes_num PNG_DEPSTRUCT;
1002 #endif
1003 
1004 #ifdef PNG_sCAL_SUPPORTED
1005    /* The sCAL chunk describes the actual physical dimensions of the
1006     * subject matter of the graphic.  The chunk contains a unit specification
1007     * a byte value, and two ASCII strings representing floating-point
1008     * values.  The values are width and height corresponsing to one pixel
1009     * in the image.  This external representation is converted to double
1010     * here.  Data values are valid if (valid & PNG_INFO_sCAL) is non-zero.
1011     */
1012    png_byte scal_unit PNG_DEPSTRUCT;         /* unit of physical scale */
1013 #ifdef PNG_FLOATING_POINT_SUPPORTED
1014    double scal_pixel_width PNG_DEPSTRUCT;    /* width of one pixel */
1015    double scal_pixel_height PNG_DEPSTRUCT;   /* height of one pixel */
1016 #endif
1017 #ifdef PNG_FIXED_POINT_SUPPORTED
1018    png_charp scal_s_width PNG_DEPSTRUCT;     /* string containing height */
1019    png_charp scal_s_height PNG_DEPSTRUCT;    /* string containing width */
1020 #endif
1021 #endif
1022 
1023 #ifdef PNG_INFO_IMAGE_SUPPORTED
1024    /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS) non-zero */
1025    /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
1026    png_bytepp row_pointers PNG_DEPSTRUCT;        /* the image bits */
1027 #endif
1028 
1029 #if defined(PNG_FIXED_POINT_SUPPORTED) && defined(PNG_gAMA_SUPPORTED)
1030    png_fixed_point int_gamma PNG_DEPSTRUCT; /* gamma of image, if (valid & PNG_INFO_gAMA) */
1031 #endif
1032 
1033 #if defined(PNG_cHRM_SUPPORTED) && defined(PNG_FIXED_POINT_SUPPORTED)
1034    png_fixed_point int_x_white PNG_DEPSTRUCT;
1035    png_fixed_point int_y_white PNG_DEPSTRUCT;
1036    png_fixed_point int_x_red PNG_DEPSTRUCT;
1037    png_fixed_point int_y_red PNG_DEPSTRUCT;
1038    png_fixed_point int_x_green PNG_DEPSTRUCT;
1039    png_fixed_point int_y_green PNG_DEPSTRUCT;
1040    png_fixed_point int_x_blue PNG_DEPSTRUCT;
1041    png_fixed_point int_y_blue PNG_DEPSTRUCT;
1042 #endif
1043 
1044 } png_info;
1045 
1046 typedef png_info FAR * png_infop;
1047 typedef png_info FAR * FAR * png_infopp;
1048 
1049 /* Maximum positive integer used in PNG is (2^31)-1 */
1050 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
1051 #define PNG_UINT_32_MAX ((png_uint_32)(-1))
1052 #define PNG_SIZE_MAX ((png_size_t)(-1))
1053 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1054 /* PNG_MAX_UINT is deprecated; use PNG_UINT_31_MAX instead. */
1055 #define PNG_MAX_UINT PNG_UINT_31_MAX
1056 #endif
1057 
1058 /* These describe the color_type field in png_info. */
1059 /* color type masks */
1060 #define PNG_COLOR_MASK_PALETTE    1
1061 #define PNG_COLOR_MASK_COLOR      2
1062 #define PNG_COLOR_MASK_ALPHA      4
1063 
1064 /* color types.  Note that not all combinations are legal */
1065 #define PNG_COLOR_TYPE_GRAY 0
1066 #define PNG_COLOR_TYPE_PALETTE  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
1067 #define PNG_COLOR_TYPE_RGB        (PNG_COLOR_MASK_COLOR)
1068 #define PNG_COLOR_TYPE_RGB_ALPHA  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
1069 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
1070 /* aliases */
1071 #define PNG_COLOR_TYPE_RGBA  PNG_COLOR_TYPE_RGB_ALPHA
1072 #define PNG_COLOR_TYPE_GA  PNG_COLOR_TYPE_GRAY_ALPHA
1073 
1074 /* This is for compression type. PNG 1.0-1.2 only define the single type. */
1075 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
1076 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
1077 
1078 /* This is for filter type. PNG 1.0-1.2 only define the single type. */
1079 #define PNG_FILTER_TYPE_BASE      0 /* Single row per-byte filtering */
1080 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
1081 #define PNG_FILTER_TYPE_DEFAULT   PNG_FILTER_TYPE_BASE
1082 
1083 /* These are for the interlacing type.  These values should NOT be changed. */
1084 #define PNG_INTERLACE_NONE        0 /* Non-interlaced image */
1085 #define PNG_INTERLACE_ADAM7       1 /* Adam7 interlacing */
1086 #define PNG_INTERLACE_LAST        2 /* Not a valid value */
1087 
1088 /* These are for the oFFs chunk.  These values should NOT be changed. */
1089 #define PNG_OFFSET_PIXEL          0 /* Offset in pixels */
1090 #define PNG_OFFSET_MICROMETER     1 /* Offset in micrometers (1/10^6 meter) */
1091 #define PNG_OFFSET_LAST           2 /* Not a valid value */
1092 
1093 /* These are for the pCAL chunk.  These values should NOT be changed. */
1094 #define PNG_EQUATION_LINEAR       0 /* Linear transformation */
1095 #define PNG_EQUATION_BASE_E       1 /* Exponential base e transform */
1096 #define PNG_EQUATION_ARBITRARY    2 /* Arbitrary base exponential transform */
1097 #define PNG_EQUATION_HYPERBOLIC   3 /* Hyperbolic sine transformation */
1098 #define PNG_EQUATION_LAST         4 /* Not a valid value */
1099 
1100 /* These are for the sCAL chunk.  These values should NOT be changed. */
1101 #define PNG_SCALE_UNKNOWN         0 /* unknown unit (image scale) */
1102 #define PNG_SCALE_METER           1 /* meters per pixel */
1103 #define PNG_SCALE_RADIAN          2 /* radians per pixel */
1104 #define PNG_SCALE_LAST            3 /* Not a valid value */
1105 
1106 /* These are for the pHYs chunk.  These values should NOT be changed. */
1107 #define PNG_RESOLUTION_UNKNOWN    0 /* pixels/unknown unit (aspect ratio) */
1108 #define PNG_RESOLUTION_METER      1 /* pixels/meter */
1109 #define PNG_RESOLUTION_LAST       2 /* Not a valid value */
1110 
1111 /* These are for the sRGB chunk.  These values should NOT be changed. */
1112 #define PNG_sRGB_INTENT_PERCEPTUAL 0
1113 #define PNG_sRGB_INTENT_RELATIVE   1
1114 #define PNG_sRGB_INTENT_SATURATION 2
1115 #define PNG_sRGB_INTENT_ABSOLUTE   3
1116 #define PNG_sRGB_INTENT_LAST       4 /* Not a valid value */
1117 
1118 /* This is for text chunks */
1119 #define PNG_KEYWORD_MAX_LENGTH     79
1120 
1121 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */
1122 #define PNG_MAX_PALETTE_LENGTH    256
1123 
1124 /* These determine if an ancillary chunk's data has been successfully read
1125  * from the PNG header, or if the application has filled in the corresponding
1126  * data in the info_struct to be written into the output file.  The values
1127  * of the PNG_INFO_<chunk> defines should NOT be changed.
1128  */
1129 #define PNG_INFO_gAMA 0x0001
1130 #define PNG_INFO_sBIT 0x0002
1131 #define PNG_INFO_cHRM 0x0004
1132 #define PNG_INFO_PLTE 0x0008
1133 #define PNG_INFO_tRNS 0x0010
1134 #define PNG_INFO_bKGD 0x0020
1135 #define PNG_INFO_hIST 0x0040
1136 #define PNG_INFO_pHYs 0x0080
1137 #define PNG_INFO_oFFs 0x0100
1138 #define PNG_INFO_tIME 0x0200
1139 #define PNG_INFO_pCAL 0x0400
1140 #define PNG_INFO_sRGB 0x0800   /* GR-P, 0.96a */
1141 #define PNG_INFO_iCCP 0x1000   /* ESR, 1.0.6 */
1142 #define PNG_INFO_sPLT 0x2000   /* ESR, 1.0.6 */
1143 #define PNG_INFO_sCAL 0x4000   /* ESR, 1.0.6 */
1144 #define PNG_INFO_IDAT 0x8000L  /* ESR, 1.0.6 */
1145 
1146 /* This is used for the transformation routines, as some of them
1147  * change these values for the row.  It also should enable using
1148  * the routines for other purposes.
1149  */
1150 typedef struct png_row_info_struct
1151 {
1152    png_uint_32 width; /* width of row */
1153    png_uint_32 rowbytes; /* number of bytes in row */
1154    png_byte color_type; /* color type of row */
1155    png_byte bit_depth; /* bit depth of row */
1156    png_byte channels; /* number of channels (1, 2, 3, or 4) */
1157    png_byte pixel_depth; /* bits per pixel (depth * channels) */
1158 } png_row_info;
1159 
1160 typedef png_row_info FAR * png_row_infop;
1161 typedef png_row_info FAR * FAR * png_row_infopp;
1162 
1163 /* These are the function types for the I/O functions and for the functions
1164  * that allow the user to override the default I/O functions with his or her
1165  * own.  The png_error_ptr type should match that of user-supplied warning
1166  * and error functions, while the png_rw_ptr type should match that of the
1167  * user read/write data functions.
1168  */
1169 typedef struct png_struct_def png_struct;
1170 typedef png_struct FAR * png_structp;
1171 
1172 typedef void (PNGAPI *png_error_ptr) PNGARG((png_structp, png_const_charp));
1173 typedef void (PNGAPI *png_rw_ptr) PNGARG((png_structp, png_bytep, png_size_t));
1174 typedef void (PNGAPI *png_flush_ptr) PNGARG((png_structp));
1175 typedef void (PNGAPI *png_read_status_ptr) PNGARG((png_structp, png_uint_32,
1176    int));
1177 typedef void (PNGAPI *png_write_status_ptr) PNGARG((png_structp, png_uint_32,
1178    int));
1179 
1180 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1181 typedef void (PNGAPI *png_progressive_info_ptr) PNGARG((png_structp, png_infop));
1182 typedef void (PNGAPI *png_progressive_end_ptr) PNGARG((png_structp, png_infop));
1183 typedef void (PNGAPI *png_progressive_row_ptr) PNGARG((png_structp, png_bytep,
1184    png_uint_32, int));
1185 #endif
1186 
1187 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1188     defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
1189     defined(PNG_LEGACY_SUPPORTED)
1190 typedef void (PNGAPI *png_user_transform_ptr) PNGARG((png_structp,
1191     png_row_infop, png_bytep));
1192 #endif
1193 
1194 #ifdef PNG_USER_CHUNKS_SUPPORTED
1195 typedef int (PNGAPI *png_user_chunk_ptr) PNGARG((png_structp, png_unknown_chunkp));
1196 #endif
1197 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
1198 typedef void (PNGAPI *png_unknown_chunk_ptr) PNGARG((png_structp));
1199 #endif
1200 
1201 /* Transform masks for the high-level interface */
1202 #define PNG_TRANSFORM_IDENTITY       0x0000    /* read and write */
1203 #define PNG_TRANSFORM_STRIP_16       0x0001    /* read only */
1204 #define PNG_TRANSFORM_STRIP_ALPHA    0x0002    /* read only */
1205 #define PNG_TRANSFORM_PACKING        0x0004    /* read and write */
1206 #define PNG_TRANSFORM_PACKSWAP       0x0008    /* read and write */
1207 #define PNG_TRANSFORM_EXPAND         0x0010    /* read only */
1208 #define PNG_TRANSFORM_INVERT_MONO    0x0020    /* read and write */
1209 #define PNG_TRANSFORM_SHIFT          0x0040    /* read and write */
1210 #define PNG_TRANSFORM_BGR            0x0080    /* read and write */
1211 #define PNG_TRANSFORM_SWAP_ALPHA     0x0100    /* read and write */
1212 #define PNG_TRANSFORM_SWAP_ENDIAN    0x0200    /* read and write */
1213 #define PNG_TRANSFORM_INVERT_ALPHA   0x0400    /* read and write */
1214 #define PNG_TRANSFORM_STRIP_FILLER   0x0800    /* write only, deprecated */
1215 /* Added to libpng-1.2.34 */
1216 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE 0x0800  /* write only */
1217 #define PNG_TRANSFORM_STRIP_FILLER_AFTER  0x1000  /* write only */
1218 /* Added to libpng-1.2.41 */
1219 #define PNG_TRANSFORM_GRAY_TO_RGB   0x2000      /* read only */
1220 
1221 /* Flags for MNG supported features */
1222 #define PNG_FLAG_MNG_EMPTY_PLTE     0x01
1223 #define PNG_FLAG_MNG_FILTER_64      0x04
1224 #define PNG_ALL_MNG_FEATURES        0x05
1225 
1226 typedef png_voidp (*png_malloc_ptr) PNGARG((png_structp, png_size_t));
1227 typedef void (*png_free_ptr) PNGARG((png_structp, png_voidp));
1228 
1229 /* The structure that holds the information to read and write PNG files.
1230  * The only people who need to care about what is inside of this are the
1231  * people who will be modifying the library for their own special needs.
1232  * It should NOT be accessed directly by an application, except to store
1233  * the jmp_buf.
1234  */
1235 
1236 struct png_struct_def
1237 {
1238 #ifdef PNG_SETJMP_SUPPORTED
1239    jmp_buf jmpbuf;            /* used in png_error */
1240 #endif
1241    png_error_ptr error_fn PNG_DEPSTRUCT;    /* function for printing errors and aborting */
1242    png_error_ptr warning_fn PNG_DEPSTRUCT;  /* function for printing warnings */
1243    png_voidp error_ptr PNG_DEPSTRUCT;       /* user supplied struct for error functions */
1244    png_rw_ptr write_data_fn PNG_DEPSTRUCT;  /* function for writing output data */
1245    png_rw_ptr read_data_fn PNG_DEPSTRUCT;   /* function for reading input data */
1246    png_voidp io_ptr PNG_DEPSTRUCT;          /* ptr to application struct for I/O functions */
1247 
1248 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
1249    png_user_transform_ptr read_user_transform_fn PNG_DEPSTRUCT; /* user read transform */
1250 #endif
1251 
1252 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1253    png_user_transform_ptr write_user_transform_fn PNG_DEPSTRUCT; /* user write transform */
1254 #endif
1255 
1256 /* These were added in libpng-1.0.2 */
1257 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
1258 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1259     defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1260    png_voidp user_transform_ptr PNG_DEPSTRUCT; /* user supplied struct for user transform */
1261    png_byte user_transform_depth PNG_DEPSTRUCT;    /* bit depth of user transformed pixels */
1262    png_byte user_transform_channels PNG_DEPSTRUCT; /* channels in user transformed pixels */
1263 #endif
1264 #endif
1265 
1266    png_uint_32 mode PNG_DEPSTRUCT;          /* tells us where we are in the PNG file */
1267    png_uint_32 flags PNG_DEPSTRUCT;         /* flags indicating various things to libpng */
1268    png_uint_32 transformations PNG_DEPSTRUCT; /* which transformations to perform */
1269 
1270    z_stream zstream PNG_DEPSTRUCT;          /* pointer to decompression structure (below) */
1271    png_bytep zbuf PNG_DEPSTRUCT;            /* buffer for zlib */
1272    png_size_t zbuf_size PNG_DEPSTRUCT;      /* size of zbuf */
1273    int zlib_level PNG_DEPSTRUCT;            /* holds zlib compression level */
1274    int zlib_method PNG_DEPSTRUCT;           /* holds zlib compression method */
1275    int zlib_window_bits PNG_DEPSTRUCT;      /* holds zlib compression window bits */
1276    int zlib_mem_level PNG_DEPSTRUCT;        /* holds zlib compression memory level */
1277    int zlib_strategy PNG_DEPSTRUCT;         /* holds zlib compression strategy */
1278 
1279    png_uint_32 width PNG_DEPSTRUCT;         /* width of image in pixels */
1280    png_uint_32 height PNG_DEPSTRUCT;        /* height of image in pixels */
1281    png_uint_32 num_rows PNG_DEPSTRUCT;      /* number of rows in current pass */
1282    png_uint_32 usr_width PNG_DEPSTRUCT;     /* width of row at start of write */
1283    png_uint_32 rowbytes PNG_DEPSTRUCT;      /* size of row in bytes */
1284 #if 0 /* Replaced with the following in libpng-1.2.43 */
1285    png_size_t irowbytes PNG_DEPSTRUCT;
1286 #endif
1287 /* Added in libpng-1.2.43 */
1288 #ifdef PNG_USER_LIMITS_SUPPORTED
1289    /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown
1290     * chunks that can be stored (0 means unlimited).
1291     */
1292    png_uint_32 user_chunk_cache_max PNG_DEPSTRUCT;
1293 #endif
1294    png_uint_32 iwidth PNG_DEPSTRUCT;        /* width of current interlaced row in pixels */
1295    png_uint_32 row_number PNG_DEPSTRUCT;    /* current row in interlace pass */
1296    png_bytep prev_row PNG_DEPSTRUCT;        /* buffer to save previous (unfiltered) row */
1297    png_bytep row_buf PNG_DEPSTRUCT;         /* buffer to save current (unfiltered) row */
1298 #ifndef PNG_NO_WRITE_FILTER
1299    png_bytep sub_row PNG_DEPSTRUCT;         /* buffer to save "sub" row when filtering */
1300    png_bytep up_row PNG_DEPSTRUCT;          /* buffer to save "up" row when filtering */
1301    png_bytep avg_row PNG_DEPSTRUCT;         /* buffer to save "avg" row when filtering */
1302    png_bytep paeth_row PNG_DEPSTRUCT;       /* buffer to save "Paeth" row when filtering */
1303 #endif
1304    png_row_info row_info PNG_DEPSTRUCT;     /* used for transformation routines */
1305 
1306    png_uint_32 idat_size PNG_DEPSTRUCT;     /* current IDAT size for read */
1307    png_uint_32 crc PNG_DEPSTRUCT;           /* current chunk CRC value */
1308    png_colorp palette PNG_DEPSTRUCT;        /* palette from the input file */
1309    png_uint_16 num_palette PNG_DEPSTRUCT;   /* number of color entries in palette */
1310    png_uint_16 num_trans PNG_DEPSTRUCT;     /* number of transparency values */
1311    png_byte chunk_name[5] PNG_DEPSTRUCT;    /* null-terminated name of current chunk */
1312    png_byte compression PNG_DEPSTRUCT;      /* file compression type (always 0) */
1313    png_byte filter PNG_DEPSTRUCT;           /* file filter type (always 0) */
1314    png_byte interlaced PNG_DEPSTRUCT;       /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
1315    png_byte pass PNG_DEPSTRUCT;             /* current interlace pass (0 - 6) */
1316    png_byte do_filter PNG_DEPSTRUCT;        /* row filter flags (see PNG_FILTER_ below ) */
1317    png_byte color_type PNG_DEPSTRUCT;       /* color type of file */
1318    png_byte bit_depth PNG_DEPSTRUCT;        /* bit depth of file */
1319    png_byte usr_bit_depth PNG_DEPSTRUCT;    /* bit depth of users row */
1320    png_byte pixel_depth PNG_DEPSTRUCT;      /* number of bits per pixel */
1321    png_byte channels PNG_DEPSTRUCT;         /* number of channels in file */
1322    png_byte usr_channels PNG_DEPSTRUCT;     /* channels at start of write */
1323    png_byte sig_bytes PNG_DEPSTRUCT;        /* magic bytes read/written from start of file */
1324 
1325 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1326 #ifdef PNG_LEGACY_SUPPORTED
1327    png_byte filler PNG_DEPSTRUCT;           /* filler byte for pixel expansion */
1328 #else
1329    png_uint_16 filler PNG_DEPSTRUCT;           /* filler bytes for pixel expansion */
1330 #endif
1331 #endif
1332 
1333 #ifdef PNG_bKGD_SUPPORTED
1334    png_byte background_gamma_type PNG_DEPSTRUCT;
1335 #  ifdef PNG_FLOATING_POINT_SUPPORTED
1336    float background_gamma PNG_DEPSTRUCT;
1337 #  endif
1338    png_color_16 background PNG_DEPSTRUCT;   /* background color in screen gamma space */
1339 #ifdef PNG_READ_GAMMA_SUPPORTED
1340    png_color_16 background_1 PNG_DEPSTRUCT; /* background normalized to gamma 1.0 */
1341 #endif
1342 #endif /* PNG_bKGD_SUPPORTED */
1343 
1344 #ifdef PNG_WRITE_FLUSH_SUPPORTED
1345    png_flush_ptr output_flush_fn PNG_DEPSTRUCT; /* Function for flushing output */
1346    png_uint_32 flush_dist PNG_DEPSTRUCT;    /* how many rows apart to flush, 0 - no flush */
1347    png_uint_32 flush_rows PNG_DEPSTRUCT;    /* number of rows written since last flush */
1348 #endif
1349 
1350 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1351    int gamma_shift PNG_DEPSTRUCT;      /* number of "insignificant" bits 16-bit gamma */
1352 #ifdef PNG_FLOATING_POINT_SUPPORTED
1353    float gamma PNG_DEPSTRUCT;          /* file gamma value */
1354    float screen_gamma PNG_DEPSTRUCT;   /* screen gamma value (display_exponent) */
1355 #endif
1356 #endif
1357 
1358 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1359    png_bytep gamma_table PNG_DEPSTRUCT;     /* gamma table for 8-bit depth files */
1360    png_bytep gamma_from_1 PNG_DEPSTRUCT;    /* converts from 1.0 to screen */
1361    png_bytep gamma_to_1 PNG_DEPSTRUCT;      /* converts from file to 1.0 */
1362    png_uint_16pp gamma_16_table PNG_DEPSTRUCT; /* gamma table for 16-bit depth files */
1363    png_uint_16pp gamma_16_from_1 PNG_DEPSTRUCT; /* converts from 1.0 to screen */
1364    png_uint_16pp gamma_16_to_1 PNG_DEPSTRUCT; /* converts from file to 1.0 */
1365 #endif
1366 
1367 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
1368    png_color_8 sig_bit PNG_DEPSTRUCT;       /* significant bits in each available channel */
1369 #endif
1370 
1371 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1372    png_color_8 shift PNG_DEPSTRUCT;         /* shift for significant bit tranformation */
1373 #endif
1374 
1375 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
1376  || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1377    png_bytep trans PNG_DEPSTRUCT;           /* transparency values for paletted files */
1378    png_color_16 trans_values PNG_DEPSTRUCT; /* transparency values for non-paletted files */
1379 #endif
1380 
1381    png_read_status_ptr read_row_fn PNG_DEPSTRUCT;   /* called after each row is decoded */
1382    png_write_status_ptr write_row_fn PNG_DEPSTRUCT; /* called after each row is encoded */
1383 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1384    png_progressive_info_ptr info_fn PNG_DEPSTRUCT; /* called after header data fully read */
1385    png_progressive_row_ptr row_fn PNG_DEPSTRUCT;   /* called after each prog. row is decoded */
1386    png_progressive_end_ptr end_fn PNG_DEPSTRUCT;   /* called after image is complete */
1387    png_bytep save_buffer_ptr PNG_DEPSTRUCT;        /* current location in save_buffer */
1388    png_bytep save_buffer PNG_DEPSTRUCT;            /* buffer for previously read data */
1389    png_bytep current_buffer_ptr PNG_DEPSTRUCT;     /* current location in current_buffer */
1390    png_bytep current_buffer PNG_DEPSTRUCT;         /* buffer for recently used data */
1391    png_uint_32 push_length PNG_DEPSTRUCT;          /* size of current input chunk */
1392    png_uint_32 skip_length PNG_DEPSTRUCT;          /* bytes to skip in input data */
1393    png_size_t save_buffer_size PNG_DEPSTRUCT;      /* amount of data now in save_buffer */
1394    png_size_t save_buffer_max PNG_DEPSTRUCT;       /* total size of save_buffer */
1395    png_size_t buffer_size PNG_DEPSTRUCT;           /* total amount of available input data */
1396    png_size_t current_buffer_size PNG_DEPSTRUCT;   /* amount of data now in current_buffer */
1397    int process_mode PNG_DEPSTRUCT;                 /* what push library is currently doing */
1398    int cur_palette PNG_DEPSTRUCT;                  /* current push library palette index */
1399 
1400 #  ifdef PNG_TEXT_SUPPORTED
1401      png_size_t current_text_size PNG_DEPSTRUCT;   /* current size of text input data */
1402      png_size_t current_text_left PNG_DEPSTRUCT;   /* how much text left to read in input */
1403      png_charp current_text PNG_DEPSTRUCT;         /* current text chunk buffer */
1404      png_charp current_text_ptr PNG_DEPSTRUCT;     /* current location in current_text */
1405 #  endif /* PNG_TEXT_SUPPORTED */
1406 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1407 
1408 #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
1409 /* for the Borland special 64K segment handler */
1410    png_bytepp offset_table_ptr PNG_DEPSTRUCT;
1411    png_bytep offset_table PNG_DEPSTRUCT;
1412    png_uint_16 offset_table_number PNG_DEPSTRUCT;
1413    png_uint_16 offset_table_count PNG_DEPSTRUCT;
1414    png_uint_16 offset_table_count_free PNG_DEPSTRUCT;
1415 #endif
1416 
1417 #ifdef PNG_READ_DITHER_SUPPORTED
1418    png_bytep palette_lookup PNG_DEPSTRUCT;         /* lookup table for dithering */
1419    png_bytep dither_index PNG_DEPSTRUCT;           /* index translation for palette files */
1420 #endif
1421 
1422 #if defined(PNG_READ_DITHER_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
1423    png_uint_16p hist PNG_DEPSTRUCT;                /* histogram */
1424 #endif
1425 
1426 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
1427    png_byte heuristic_method PNG_DEPSTRUCT;        /* heuristic for row filter selection */
1428    png_byte num_prev_filters PNG_DEPSTRUCT;        /* number of weights for previous rows */
1429    png_bytep prev_filters PNG_DEPSTRUCT;           /* filter type(s) of previous row(s) */
1430    png_uint_16p filter_weights PNG_DEPSTRUCT;      /* weight(s) for previous line(s) */
1431    png_uint_16p inv_filter_weights PNG_DEPSTRUCT;  /* 1/weight(s) for previous line(s) */
1432    png_uint_16p filter_costs PNG_DEPSTRUCT;        /* relative filter calculation cost */
1433    png_uint_16p inv_filter_costs PNG_DEPSTRUCT;    /* 1/relative filter calculation cost */
1434 #endif
1435 
1436 #ifdef PNG_TIME_RFC1123_SUPPORTED
1437    png_charp time_buffer PNG_DEPSTRUCT;            /* String to hold RFC 1123 time text */
1438 #endif
1439 
1440 /* New members added in libpng-1.0.6 */
1441 
1442 #ifdef PNG_FREE_ME_SUPPORTED
1443    png_uint_32 free_me PNG_DEPSTRUCT;   /* flags items libpng is responsible for freeing */
1444 #endif
1445 
1446 #ifdef PNG_USER_CHUNKS_SUPPORTED
1447    png_voidp user_chunk_ptr PNG_DEPSTRUCT;
1448    png_user_chunk_ptr read_user_chunk_fn PNG_DEPSTRUCT; /* user read chunk handler */
1449 #endif
1450 
1451 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
1452    int num_chunk_list PNG_DEPSTRUCT;
1453    png_bytep chunk_list PNG_DEPSTRUCT;
1454 #endif
1455 
1456 /* New members added in libpng-1.0.3 */
1457 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1458    png_byte rgb_to_gray_status PNG_DEPSTRUCT;
1459    /* These were changed from png_byte in libpng-1.0.6 */
1460    png_uint_16 rgb_to_gray_red_coeff PNG_DEPSTRUCT;
1461    png_uint_16 rgb_to_gray_green_coeff PNG_DEPSTRUCT;
1462    png_uint_16 rgb_to_gray_blue_coeff PNG_DEPSTRUCT;
1463 #endif
1464 
1465 /* New member added in libpng-1.0.4 (renamed in 1.0.9) */
1466 #if defined(PNG_MNG_FEATURES_SUPPORTED) || \
1467     defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1468     defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1469 /* Changed from png_byte to png_uint_32 at version 1.2.0 */
1470 #ifdef PNG_1_0_X
1471    png_byte mng_features_permitted PNG_DEPSTRUCT;
1472 #else
1473    png_uint_32 mng_features_permitted PNG_DEPSTRUCT;
1474 #endif /* PNG_1_0_X */
1475 #endif
1476 
1477 /* New member added in libpng-1.0.7 */
1478 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1479    png_fixed_point int_gamma PNG_DEPSTRUCT;
1480 #endif
1481 
1482 /* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
1483 #ifdef PNG_MNG_FEATURES_SUPPORTED
1484    png_byte filter_type PNG_DEPSTRUCT;
1485 #endif
1486 
1487 #ifdef PNG_1_0_X
1488 /* New member added in libpng-1.0.10, ifdef'ed out in 1.2.0 */
1489    png_uint_32 row_buf_size PNG_DEPSTRUCT;
1490 #endif
1491 
1492 /* New members added in libpng-1.2.0 */
1493 #ifdef PNG_ASSEMBLER_CODE_SUPPORTED
1494 #  ifndef PNG_1_0_X
1495 #    ifdef PNG_MMX_CODE_SUPPORTED
1496    png_byte     mmx_bitdepth_threshold PNG_DEPSTRUCT;
1497    png_uint_32  mmx_rowbytes_threshold PNG_DEPSTRUCT;
1498 #    endif
1499    png_uint_32  asm_flags PNG_DEPSTRUCT;
1500 #  endif
1501 #endif
1502 
1503 /* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
1504 #ifdef PNG_USER_MEM_SUPPORTED
1505    png_voidp mem_ptr PNG_DEPSTRUCT;            /* user supplied struct for mem functions */
1506    png_malloc_ptr malloc_fn PNG_DEPSTRUCT;     /* function for allocating memory */
1507    png_free_ptr free_fn PNG_DEPSTRUCT;         /* function for freeing memory */
1508 #endif
1509 
1510 /* New member added in libpng-1.0.13 and 1.2.0 */
1511    png_bytep big_row_buf PNG_DEPSTRUCT;        /* buffer to save current (unfiltered) row */
1512 
1513 #ifdef PNG_READ_DITHER_SUPPORTED
1514 /* The following three members were added at version 1.0.14 and 1.2.4 */
1515    png_bytep dither_sort PNG_DEPSTRUCT;        /* working sort array */
1516    png_bytep index_to_palette PNG_DEPSTRUCT;   /* where the original index currently is */
1517                                  /* in the palette */
1518    png_bytep palette_to_index PNG_DEPSTRUCT;   /* which original index points to this */
1519                                  /* palette color */
1520 #endif
1521 
1522 /* New members added in libpng-1.0.16 and 1.2.6 */
1523    png_byte compression_type PNG_DEPSTRUCT;
1524 
1525 #ifdef PNG_USER_LIMITS_SUPPORTED
1526    png_uint_32 user_width_max PNG_DEPSTRUCT;
1527    png_uint_32 user_height_max PNG_DEPSTRUCT;
1528 #endif
1529 
1530 /* New member added in libpng-1.0.25 and 1.2.17 */
1531 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
1532    /* Storage for unknown chunk that the library doesn't recognize. */
1533    png_unknown_chunk unknown_chunk PNG_DEPSTRUCT;
1534 #endif
1535 
1536 /* New members added in libpng-1.2.26 */
1537   png_uint_32 old_big_row_buf_size PNG_DEPSTRUCT;
1538   png_uint_32 old_prev_row_size PNG_DEPSTRUCT;
1539 
1540 /* New member added in libpng-1.2.30 */
1541   png_charp chunkdata PNG_DEPSTRUCT;  /* buffer for reading chunk data */
1542 
1543 
1544 };
1545 
1546 
1547 /* This triggers a compiler error in png.c, if png.c and png.h
1548  * do not agree upon the version number.
1549  */
1550 typedef png_structp version_1_2_44;
1551 
1552 typedef png_struct FAR * FAR * png_structpp;
1553 
1554 /* Here are the function definitions most commonly used.  This is not
1555  * the place to find out how to use libpng.  See libpng.txt for the
1556  * full explanation, see example.c for the summary.  This just provides
1557  * a simple one line description of the use of each function.
1558  */
1559 
1560 /* Returns the version number of the library */
1561 extern PNG_EXPORT(png_uint_32,png_access_version_number) PNGARG((void));
1562 
1563 /* Tell lib we have already handled the first <num_bytes> magic bytes.
1564  * Handling more than 8 bytes from the beginning of the file is an error.
1565  */
1566 extern PNG_EXPORT(void,png_set_sig_bytes) PNGARG((png_structp png_ptr,
1567    int num_bytes));
1568 
1569 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
1570  * PNG file.  Returns zero if the supplied bytes match the 8-byte PNG
1571  * signature, and non-zero otherwise.  Having num_to_check == 0 or
1572  * start > 7 will always fail (ie return non-zero).
1573  */
1574 extern PNG_EXPORT(int,png_sig_cmp) PNGARG((png_bytep sig, png_size_t start,
1575    png_size_t num_to_check));
1576 
1577 /* Simple signature checking function.  This is the same as calling
1578  * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
1579  */
1580 extern PNG_EXPORT(int,png_check_sig) PNGARG((png_bytep sig, int num)) PNG_DEPRECATED;
1581 
1582 /* Allocate and initialize png_ptr struct for reading, and any other memory. */
1583 extern PNG_EXPORT(png_structp,png_create_read_struct)
1584    PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1585    png_error_ptr error_fn, png_error_ptr warn_fn)) PNG_ALLOCATED;
1586 
1587 /* Allocate and initialize png_ptr struct for writing, and any other memory */
1588 extern PNG_EXPORT(png_structp,png_create_write_struct)
1589    PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1590    png_error_ptr error_fn, png_error_ptr warn_fn)) PNG_ALLOCATED;
1591 
1592 #ifdef PNG_WRITE_SUPPORTED
1593 extern PNG_EXPORT(png_uint_32,png_get_compression_buffer_size)
1594    PNGARG((png_structp png_ptr));
1595 #endif
1596 
1597 #ifdef PNG_WRITE_SUPPORTED
1598 extern PNG_EXPORT(void,png_set_compression_buffer_size)
1599    PNGARG((png_structp png_ptr, png_uint_32 size));
1600 #endif
1601 
1602 /* Reset the compression stream */
1603 extern PNG_EXPORT(int,png_reset_zstream) PNGARG((png_structp png_ptr));
1604 
1605 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
1606 #ifdef PNG_USER_MEM_SUPPORTED
1607 extern PNG_EXPORT(png_structp,png_create_read_struct_2)
1608    PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1609    png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1610    png_malloc_ptr malloc_fn, png_free_ptr free_fn)) PNG_ALLOCATED;
1611 extern PNG_EXPORT(png_structp,png_create_write_struct_2)
1612    PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1613    png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1614    png_malloc_ptr malloc_fn, png_free_ptr free_fn)) PNG_ALLOCATED;
1615 #endif
1616 
1617 /* Write a PNG chunk - size, type, (optional) data, CRC. */
1618 extern PNG_EXPORT(void,png_write_chunk) PNGARG((png_structp png_ptr,
1619    png_bytep chunk_name, png_bytep data, png_size_t length));
1620 
1621 /* Write the start of a PNG chunk - length and chunk name. */
1622 extern PNG_EXPORT(void,png_write_chunk_start) PNGARG((png_structp png_ptr,
1623    png_bytep chunk_name, png_uint_32 length));
1624 
1625 /* Write the data of a PNG chunk started with png_write_chunk_start(). */
1626 extern PNG_EXPORT(void,png_write_chunk_data) PNGARG((png_structp png_ptr,
1627    png_bytep data, png_size_t length));
1628 
1629 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1630 extern PNG_EXPORT(void,png_write_chunk_end) PNGARG((png_structp png_ptr));
1631 
1632 /* Allocate and initialize the info structure */
1633 extern PNG_EXPORT(png_infop,png_create_info_struct)
1634    PNGARG((png_structp png_ptr)) PNG_ALLOCATED;
1635 
1636 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1637 /* Initialize the info structure (old interface - DEPRECATED) */
1638 extern PNG_EXPORT(void,png_info_init) PNGARG((png_infop info_ptr))
1639     PNG_DEPRECATED;
1640 #undef png_info_init
1641 #define png_info_init(info_ptr) png_info_init_3(&info_ptr,\
1642     png_sizeof(png_info));
1643 #endif
1644 
1645 extern PNG_EXPORT(void,png_info_init_3) PNGARG((png_infopp info_ptr,
1646     png_size_t png_info_struct_size));
1647 
1648 /* Writes all the PNG information before the image. */
1649 extern PNG_EXPORT(void,png_write_info_before_PLTE) PNGARG((png_structp png_ptr,
1650    png_infop info_ptr));
1651 extern PNG_EXPORT(void,png_write_info) PNGARG((png_structp png_ptr,
1652    png_infop info_ptr));
1653 
1654 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1655 /* Read the information before the actual image data. */
1656 extern PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr,
1657    png_infop info_ptr));
1658 #endif
1659 
1660 #ifdef PNG_TIME_RFC1123_SUPPORTED
1661 extern PNG_EXPORT(png_charp,png_convert_to_rfc1123)
1662    PNGARG((png_structp png_ptr, png_timep ptime));
1663 #endif
1664 
1665 #ifdef PNG_CONVERT_tIME_SUPPORTED
1666 /* Convert from a struct tm to png_time */
1667 extern PNG_EXPORT(void,png_convert_from_struct_tm) PNGARG((png_timep ptime,
1668    struct tm FAR * ttime));
1669 
1670 /* Convert from time_t to png_time.  Uses gmtime() */
1671 extern PNG_EXPORT(void,png_convert_from_time_t) PNGARG((png_timep ptime,
1672    time_t ttime));
1673 #endif /* PNG_CONVERT_tIME_SUPPORTED */
1674 
1675 #ifdef PNG_READ_EXPAND_SUPPORTED
1676 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1677 extern PNG_EXPORT(void,png_set_expand) PNGARG((png_structp png_ptr));
1678 #ifndef PNG_1_0_X
1679 extern PNG_EXPORT(void,png_set_expand_gray_1_2_4_to_8) PNGARG((png_structp
1680   png_ptr));
1681 #endif
1682 extern PNG_EXPORT(void,png_set_palette_to_rgb) PNGARG((png_structp png_ptr));
1683 extern PNG_EXPORT(void,png_set_tRNS_to_alpha) PNGARG((png_structp png_ptr));
1684 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1685 /* Deprecated */
1686 extern PNG_EXPORT(void,png_set_gray_1_2_4_to_8) PNGARG((png_structp
1687     png_ptr)) PNG_DEPRECATED;
1688 #endif
1689 #endif
1690 
1691 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1692 /* Use blue, green, red order for pixels. */
1693 extern PNG_EXPORT(void,png_set_bgr) PNGARG((png_structp png_ptr));
1694 #endif
1695 
1696 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1697 /* Expand the grayscale to 24-bit RGB if necessary. */
1698 extern PNG_EXPORT(void,png_set_gray_to_rgb) PNGARG((png_structp png_ptr));
1699 #endif
1700 
1701 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1702 /* Reduce RGB to grayscale. */
1703 #ifdef PNG_FLOATING_POINT_SUPPORTED
1704 extern PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr,
1705    int error_action, double red, double green ));
1706 #endif
1707 extern PNG_EXPORT(void,png_set_rgb_to_gray_fixed) PNGARG((png_structp png_ptr,
1708    int error_action, png_fixed_point red, png_fixed_point green ));
1709 extern PNG_EXPORT(png_byte,png_get_rgb_to_gray_status) PNGARG((png_structp
1710    png_ptr));
1711 #endif
1712 
1713 extern PNG_EXPORT(void,png_build_grayscale_palette) PNGARG((int bit_depth,
1714    png_colorp palette));
1715 
1716 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1717 extern PNG_EXPORT(void,png_set_strip_alpha) PNGARG((png_structp png_ptr));
1718 #endif
1719 
1720 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1721     defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1722 extern PNG_EXPORT(void,png_set_swap_alpha) PNGARG((png_structp png_ptr));
1723 #endif
1724 
1725 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1726     defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1727 extern PNG_EXPORT(void,png_set_invert_alpha) PNGARG((png_structp png_ptr));
1728 #endif
1729 
1730 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1731 /* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
1732 extern PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr,
1733    png_uint_32 filler, int flags));
1734 /* The values of the PNG_FILLER_ defines should NOT be changed */
1735 #define PNG_FILLER_BEFORE 0
1736 #define PNG_FILLER_AFTER 1
1737 /* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
1738 #ifndef PNG_1_0_X
1739 extern PNG_EXPORT(void,png_set_add_alpha) PNGARG((png_structp png_ptr,
1740    png_uint_32 filler, int flags));
1741 #endif
1742 #endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
1743 
1744 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1745 /* Swap bytes in 16-bit depth files. */
1746 extern PNG_EXPORT(void,png_set_swap) PNGARG((png_structp png_ptr));
1747 #endif
1748 
1749 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1750 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1751 extern PNG_EXPORT(void,png_set_packing) PNGARG((png_structp png_ptr));
1752 #endif
1753 
1754 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1755 /* Swap packing order of pixels in bytes. */
1756 extern PNG_EXPORT(void,png_set_packswap) PNGARG((png_structp png_ptr));
1757 #endif
1758 
1759 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1760 /* Converts files to legal bit depths. */
1761 extern PNG_EXPORT(void,png_set_shift) PNGARG((png_structp png_ptr,
1762    png_color_8p true_bits));
1763 #endif
1764 
1765 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1766     defined(PNG_WRITE_INTERLACING_SUPPORTED)
1767 /* Have the code handle the interlacing.  Returns the number of passes. */
1768 extern PNG_EXPORT(int,png_set_interlace_handling) PNGARG((png_structp png_ptr));
1769 #endif
1770 
1771 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1772 /* Invert monochrome files */
1773 extern PNG_EXPORT(void,png_set_invert_mono) PNGARG((png_structp png_ptr));
1774 #endif
1775 
1776 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1777 /* Handle alpha and tRNS by replacing with a background color. */
1778 #ifdef PNG_FLOATING_POINT_SUPPORTED
1779 extern PNG_EXPORT(void,png_set_background) PNGARG((png_structp png_ptr,
1780    png_color_16p background_color, int background_gamma_code,
1781    int need_expand, double background_gamma));
1782 #endif
1783 #define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1784 #define PNG_BACKGROUND_GAMMA_SCREEN  1
1785 #define PNG_BACKGROUND_GAMMA_FILE    2
1786 #define PNG_BACKGROUND_GAMMA_UNIQUE  3
1787 #endif
1788 
1789 #ifdef PNG_READ_16_TO_8_SUPPORTED
1790 /* Strip the second byte of information from a 16-bit depth file. */
1791 extern PNG_EXPORT(void,png_set_strip_16) PNGARG((png_structp png_ptr));
1792 #endif
1793 
1794 #ifdef PNG_READ_DITHER_SUPPORTED
1795 /* Turn on dithering, and reduce the palette to the number of colors available. */
1796 extern PNG_EXPORT(void,png_set_dither) PNGARG((png_structp png_ptr,
1797    png_colorp palette, int num_palette, int maximum_colors,
1798    png_uint_16p histogram, int full_dither));
1799 #endif
1800 
1801 #ifdef PNG_READ_GAMMA_SUPPORTED
1802 /* Handle gamma correction. Screen_gamma=(display_exponent) */
1803 #ifdef PNG_FLOATING_POINT_SUPPORTED
1804 extern PNG_EXPORT(void,png_set_gamma) PNGARG((png_structp png_ptr,
1805    double screen_gamma, double default_file_gamma));
1806 #endif
1807 #endif
1808 
1809 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1810 #if defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1811     defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1812 /* Permit or disallow empty PLTE (0: not permitted, 1: permitted) */
1813 /* Deprecated and will be removed.  Use png_permit_mng_features() instead. */
1814 extern PNG_EXPORT(void,png_permit_empty_plte) PNGARG((png_structp png_ptr,
1815    int empty_plte_permitted)) PNG_DEPRECATED;
1816 #endif
1817 #endif
1818 
1819 #ifdef PNG_WRITE_FLUSH_SUPPORTED
1820 /* Set how many lines between output flushes - 0 for no flushing */
1821 extern PNG_EXPORT(void,png_set_flush) PNGARG((png_structp png_ptr, int nrows));
1822 /* Flush the current PNG output buffer */
1823 extern PNG_EXPORT(void,png_write_flush) PNGARG((png_structp png_ptr));
1824 #endif
1825 
1826 /* Optional update palette with requested transformations */
1827 extern PNG_EXPORT(void,png_start_read_image) PNGARG((png_structp png_ptr));
1828 
1829 /* Optional call to update the users info structure */
1830 extern PNG_EXPORT(void,png_read_update_info) PNGARG((png_structp png_ptr,
1831    png_infop info_ptr));
1832 
1833 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1834 /* Read one or more rows of image data. */
1835 extern PNG_EXPORT(void,png_read_rows) PNGARG((png_structp png_ptr,
1836    png_bytepp row, png_bytepp display_row, png_uint_32 num_rows));
1837 #endif
1838 
1839 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1840 /* Read a row of data. */
1841 extern PNG_EXPORT(void,png_read_row) PNGARG((png_structp png_ptr,
1842    png_bytep row,
1843    png_bytep display_row));
1844 #endif
1845 
1846 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1847 /* Read the whole image into memory at once. */
1848 extern PNG_EXPORT(void,png_read_image) PNGARG((png_structp png_ptr,
1849    png_bytepp image));
1850 #endif
1851 
1852 /* Write a row of image data */
1853 extern PNG_EXPORT(void,png_write_row) PNGARG((png_structp png_ptr,
1854    png_bytep row));
1855 
1856 /* Write a few rows of image data */
1857 extern PNG_EXPORT(void,png_write_rows) PNGARG((png_structp png_ptr,
1858    png_bytepp row, png_uint_32 num_rows));
1859 
1860 /* Write the image data */
1861 extern PNG_EXPORT(void,png_write_image) PNGARG((png_structp png_ptr,
1862    png_bytepp image));
1863 
1864 /* Writes the end of the PNG file. */
1865 extern PNG_EXPORT(void,png_write_end) PNGARG((png_structp png_ptr,
1866    png_infop info_ptr));
1867 
1868 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1869 /* Read the end of the PNG file. */
1870 extern PNG_EXPORT(void,png_read_end) PNGARG((png_structp png_ptr,
1871    png_infop info_ptr));
1872 #endif
1873 
1874 /* Free any memory associated with the png_info_struct */
1875 extern PNG_EXPORT(void,png_destroy_info_struct) PNGARG((png_structp png_ptr,
1876    png_infopp info_ptr_ptr));
1877 
1878 /* Free any memory associated with the png_struct and the png_info_structs */
1879 extern PNG_EXPORT(void,png_destroy_read_struct) PNGARG((png_structpp
1880    png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1881 
1882 /* Free all memory used by the read (old method - NOT DLL EXPORTED) */
1883 extern void png_read_destroy PNGARG((png_structp png_ptr, png_infop info_ptr,
1884    png_infop end_info_ptr)) PNG_DEPRECATED;
1885 
1886 /* Free any memory associated with the png_struct and the png_info_structs */
1887 extern PNG_EXPORT(void,png_destroy_write_struct)
1888    PNGARG((png_structpp png_ptr_ptr, png_infopp info_ptr_ptr));
1889 
1890 /* Free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */
1891 extern void png_write_destroy PNGARG((png_structp png_ptr)) PNG_DEPRECATED;
1892 
1893 /* Set the libpng method of handling chunk CRC errors */
1894 extern PNG_EXPORT(void,png_set_crc_action) PNGARG((png_structp png_ptr,
1895    int crit_action, int ancil_action));
1896 
1897 /* Values for png_set_crc_action() to say how to handle CRC errors in
1898  * ancillary and critical chunks, and whether to use the data contained
1899  * therein.  Note that it is impossible to "discard" data in a critical
1900  * chunk.  For versions prior to 0.90, the action was always error/quit,
1901  * whereas in version 0.90 and later, the action for CRC errors in ancillary
1902  * chunks is warn/discard.  These values should NOT be changed.
1903  *
1904  *      value                       action:critical     action:ancillary
1905  */
1906 #define PNG_CRC_DEFAULT       0  /* error/quit          warn/discard data */
1907 #define PNG_CRC_ERROR_QUIT    1  /* error/quit          error/quit        */
1908 #define PNG_CRC_WARN_DISCARD  2  /* (INVALID)           warn/discard data */
1909 #define PNG_CRC_WARN_USE      3  /* warn/use data       warn/use data     */
1910 #define PNG_CRC_QUIET_USE     4  /* quiet/use data      quiet/use data    */
1911 #define PNG_CRC_NO_CHANGE     5  /* use current value   use current value */
1912 
1913 /* These functions give the user control over the scan-line filtering in
1914  * libpng and the compression methods used by zlib.  These functions are
1915  * mainly useful for testing, as the defaults should work with most users.
1916  * Those users who are tight on memory or want faster performance at the
1917  * expense of compression can modify them.  See the compression library
1918  * header file (zlib.h) for an explination of the compression functions.
1919  */
1920 
1921 /* Set the filtering method(s) used by libpng.  Currently, the only valid
1922  * value for "method" is 0.
1923  */
1924 extern PNG_EXPORT(void,png_set_filter) PNGARG((png_structp png_ptr, int method,
1925    int filters));
1926 
1927 /* Flags for png_set_filter() to say which filters to use.  The flags
1928  * are chosen so that they don't conflict with real filter types
1929  * below, in case they are supplied instead of the #defined constants.
1930  * These values should NOT be changed.
1931  */
1932 #define PNG_NO_FILTERS     0x00
1933 #define PNG_FILTER_NONE    0x08
1934 #define PNG_FILTER_SUB     0x10
1935 #define PNG_FILTER_UP      0x20
1936 #define PNG_FILTER_AVG     0x40
1937 #define PNG_FILTER_PAETH   0x80
1938 #define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
1939                          PNG_FILTER_AVG | PNG_FILTER_PAETH)
1940 
1941 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1942  * These defines should NOT be changed.
1943  */
1944 #define PNG_FILTER_VALUE_NONE  0
1945 #define PNG_FILTER_VALUE_SUB   1
1946 #define PNG_FILTER_VALUE_UP    2
1947 #define PNG_FILTER_VALUE_AVG   3
1948 #define PNG_FILTER_VALUE_PAETH 4
1949 #define PNG_FILTER_VALUE_LAST  5
1950 
1951 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* EXPERIMENTAL */
1952 /* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
1953  * defines, either the default (minimum-sum-of-absolute-differences), or
1954  * the experimental method (weighted-minimum-sum-of-absolute-differences).
1955  *
1956  * Weights are factors >= 1.0, indicating how important it is to keep the
1957  * filter type consistent between rows.  Larger numbers mean the current
1958  * filter is that many times as likely to be the same as the "num_weights"
1959  * previous filters.  This is cumulative for each previous row with a weight.
1960  * There needs to be "num_weights" values in "filter_weights", or it can be
1961  * NULL if the weights aren't being specified.  Weights have no influence on
1962  * the selection of the first row filter.  Well chosen weights can (in theory)
1963  * improve the compression for a given image.
1964  *
1965  * Costs are factors >= 1.0 indicating the relative decoding costs of a
1966  * filter type.  Higher costs indicate more decoding expense, and are
1967  * therefore less likely to be selected over a filter with lower computational
1968  * costs.  There needs to be a value in "filter_costs" for each valid filter
1969  * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
1970  * setting the costs.  Costs try to improve the speed of decompression without
1971  * unduly increasing the compressed image size.
1972  *
1973  * A negative weight or cost indicates the default value is to be used, and
1974  * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
1975  * The default values for both weights and costs are currently 1.0, but may
1976  * change if good general weighting/cost heuristics can be found.  If both
1977  * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
1978  * to the UNWEIGHTED method, but with added encoding time/computation.
1979  */
1980 #ifdef PNG_FLOATING_POINT_SUPPORTED
1981 extern PNG_EXPORT(void,png_set_filter_heuristics) PNGARG((png_structp png_ptr,
1982    int heuristic_method, int num_weights, png_doublep filter_weights,
1983    png_doublep filter_costs));
1984 #endif
1985 #endif /*  PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1986 
1987 /* Heuristic used for row filter selection.  These defines should NOT be
1988  * changed.
1989  */
1990 #define PNG_FILTER_HEURISTIC_DEFAULT    0  /* Currently "UNWEIGHTED" */
1991 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1  /* Used by libpng < 0.95 */
1992 #define PNG_FILTER_HEURISTIC_WEIGHTED   2  /* Experimental feature */
1993 #define PNG_FILTER_HEURISTIC_LAST       3  /* Not a valid value */
1994 
1995 /* Set the library compression level.  Currently, valid values range from
1996  * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1997  * (0 - no compression, 9 - "maximal" compression).  Note that tests have
1998  * shown that zlib compression levels 3-6 usually perform as well as level 9
1999  * for PNG images, and do considerably fewer caclulations.  In the future,
2000  * these values may not correspond directly to the zlib compression levels.
2001  */
2002 extern PNG_EXPORT(void,png_set_compression_level) PNGARG((png_structp png_ptr,
2003    int level));
2004 
2005 extern PNG_EXPORT(void,png_set_compression_mem_level)
2006    PNGARG((png_structp png_ptr, int mem_level));
2007 
2008 extern PNG_EXPORT(void,png_set_compression_strategy)
2009    PNGARG((png_structp png_ptr, int strategy));
2010 
2011 extern PNG_EXPORT(void,png_set_compression_window_bits)
2012    PNGARG((png_structp png_ptr, int window_bits));
2013 
2014 extern PNG_EXPORT(void,png_set_compression_method) PNGARG((png_structp png_ptr,
2015    int method));
2016 
2017 /* These next functions are called for input/output, memory, and error
2018  * handling.  They are in the file pngrio.c, pngwio.c, and pngerror.c,
2019  * and call standard C I/O routines such as fread(), fwrite(), and
2020  * fprintf().  These functions can be made to use other I/O routines
2021  * at run time for those applications that need to handle I/O in a
2022  * different manner by calling png_set_???_fn().  See libpng.txt for
2023  * more information.
2024  */
2025 
2026 #ifdef PNG_STDIO_SUPPORTED
2027 /* Initialize the input/output for the PNG file to the default functions. */
2028 extern PNG_EXPORT(void,png_init_io) PNGARG((png_structp png_ptr, png_FILE_p fp));
2029 #endif
2030 
2031 /* Replace the (error and abort), and warning functions with user
2032  * supplied functions.  If no messages are to be printed you must still
2033  * write and use replacement functions. The replacement error_fn should
2034  * still do a longjmp to the last setjmp location if you are using this
2035  * method of error handling.  If error_fn or warning_fn is NULL, the
2036  * default function will be used.
2037  */
2038 
2039 extern PNG_EXPORT(void,png_set_error_fn) PNGARG((png_structp png_ptr,
2040    png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
2041 
2042 /* Return the user pointer associated with the error functions */
2043 extern PNG_EXPORT(png_voidp,png_get_error_ptr) PNGARG((png_structp png_ptr));
2044 
2045 /* Replace the default data output functions with a user supplied one(s).
2046  * If buffered output is not used, then output_flush_fn can be set to NULL.
2047  * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
2048  * output_flush_fn will be ignored (and thus can be NULL).
2049  * It is probably a mistake to use NULL for output_flush_fn if
2050  * write_data_fn is not also NULL unless you have built libpng with
2051  * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
2052  * default flush function, which uses the standard *FILE structure, will
2053  * be used.
2054  */
2055 extern PNG_EXPORT(void,png_set_write_fn) PNGARG((png_structp png_ptr,
2056    png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
2057 
2058 /* Replace the default data input function with a user supplied one. */
2059 extern PNG_EXPORT(void,png_set_read_fn) PNGARG((png_structp png_ptr,
2060    png_voidp io_ptr, png_rw_ptr read_data_fn));
2061 
2062 /* Return the user pointer associated with the I/O functions */
2063 extern PNG_EXPORT(png_voidp,png_get_io_ptr) PNGARG((png_structp png_ptr));
2064 
2065 extern PNG_EXPORT(void,png_set_read_status_fn) PNGARG((png_structp png_ptr,
2066    png_read_status_ptr read_row_fn));
2067 
2068 extern PNG_EXPORT(void,png_set_write_status_fn) PNGARG((png_structp png_ptr,
2069    png_write_status_ptr write_row_fn));
2070 
2071 #ifdef PNG_USER_MEM_SUPPORTED
2072 /* Replace the default memory allocation functions with user supplied one(s). */
2073 extern PNG_EXPORT(void,png_set_mem_fn) PNGARG((png_structp png_ptr,
2074    png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn));
2075 /* Return the user pointer associated with the memory functions */
2076 extern PNG_EXPORT(png_voidp,png_get_mem_ptr) PNGARG((png_structp png_ptr));
2077 #endif
2078 
2079 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
2080     defined(PNG_LEGACY_SUPPORTED)
2081 extern PNG_EXPORT(void,png_set_read_user_transform_fn) PNGARG((png_structp
2082    png_ptr, png_user_transform_ptr read_user_transform_fn));
2083 #endif
2084 
2085 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
2086     defined(PNG_LEGACY_SUPPORTED)
2087 extern PNG_EXPORT(void,png_set_write_user_transform_fn) PNGARG((png_structp
2088    png_ptr, png_user_transform_ptr write_user_transform_fn));
2089 #endif
2090 
2091 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
2092     defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
2093     defined(PNG_LEGACY_SUPPORTED)
2094 extern PNG_EXPORT(void,png_set_user_transform_info) PNGARG((png_structp
2095    png_ptr, png_voidp user_transform_ptr, int user_transform_depth,
2096    int user_transform_channels));
2097 /* Return the user pointer associated with the user transform functions */
2098 extern PNG_EXPORT(png_voidp,png_get_user_transform_ptr)
2099    PNGARG((png_structp png_ptr));
2100 #endif
2101 
2102 #ifdef PNG_USER_CHUNKS_SUPPORTED
2103 extern PNG_EXPORT(void,png_set_read_user_chunk_fn) PNGARG((png_structp png_ptr,
2104    png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
2105 extern PNG_EXPORT(png_voidp,png_get_user_chunk_ptr) PNGARG((png_structp
2106    png_ptr));
2107 #endif
2108 
2109 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
2110 /* Sets the function callbacks for the push reader, and a pointer to a
2111  * user-defined structure available to the callback functions.
2112  */
2113 extern PNG_EXPORT(void,png_set_progressive_read_fn) PNGARG((png_structp png_ptr,
2114    png_voidp progressive_ptr,
2115    png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
2116    png_progressive_end_ptr end_fn));
2117 
2118 /* Returns the user pointer associated with the push read functions */
2119 extern PNG_EXPORT(png_voidp,png_get_progressive_ptr)
2120    PNGARG((png_structp png_ptr));
2121 
2122 /* Function to be called when data becomes available */
2123 extern PNG_EXPORT(void,png_process_data) PNGARG((png_structp png_ptr,
2124    png_infop info_ptr, png_bytep buffer, png_size_t buffer_size));
2125 
2126 /* Function that combines rows.  Not very much different than the
2127  * png_combine_row() call.  Is this even used?????
2128  */
2129 extern PNG_EXPORT(void,png_progressive_combine_row) PNGARG((png_structp png_ptr,
2130    png_bytep old_row, png_bytep new_row));
2131 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
2132 
2133 extern PNG_EXPORT(png_voidp,png_malloc) PNGARG((png_structp png_ptr,
2134    png_uint_32 size)) PNG_ALLOCATED;
2135 
2136 #ifdef PNG_1_0_X
2137 #  define png_malloc_warn png_malloc
2138 #else
2139 /* Added at libpng version 1.2.4 */
2140 extern PNG_EXPORT(png_voidp,png_malloc_warn) PNGARG((png_structp png_ptr,
2141    png_uint_32 size)) PNG_ALLOCATED;
2142 #endif
2143 
2144 /* Frees a pointer allocated by png_malloc() */
2145 extern PNG_EXPORT(void,png_free) PNGARG((png_structp png_ptr, png_voidp ptr));
2146 
2147 #ifdef PNG_1_0_X
2148 /* Function to allocate memory for zlib. */
2149 extern PNG_EXPORT(voidpf,png_zalloc) PNGARG((voidpf png_ptr, uInt items,
2150    uInt size));
2151 
2152 /* Function to free memory for zlib */
2153 extern PNG_EXPORT(void,png_zfree) PNGARG((voidpf png_ptr, voidpf ptr));
2154 #endif
2155 
2156 /* Free data that was allocated internally */
2157 extern PNG_EXPORT(void,png_free_data) PNGARG((png_structp png_ptr,
2158    png_infop info_ptr, png_uint_32 free_me, int num));
2159 #ifdef PNG_FREE_ME_SUPPORTED
2160 /* Reassign responsibility for freeing existing data, whether allocated
2161  * by libpng or by the application
2162  */
2163 extern PNG_EXPORT(void,png_data_freer) PNGARG((png_structp png_ptr,
2164    png_infop info_ptr, int freer, png_uint_32 mask));
2165 #endif
2166 /* Assignments for png_data_freer */
2167 #define PNG_DESTROY_WILL_FREE_DATA 1
2168 #define PNG_SET_WILL_FREE_DATA 1
2169 #define PNG_USER_WILL_FREE_DATA 2
2170 /* Flags for png_ptr->free_me and info_ptr->free_me */
2171 #define PNG_FREE_HIST 0x0008
2172 #define PNG_FREE_ICCP 0x0010
2173 #define PNG_FREE_SPLT 0x0020
2174 #define PNG_FREE_ROWS 0x0040
2175 #define PNG_FREE_PCAL 0x0080
2176 #define PNG_FREE_SCAL 0x0100
2177 #define PNG_FREE_UNKN 0x0200
2178 #define PNG_FREE_LIST 0x0400
2179 #define PNG_FREE_PLTE 0x1000
2180 #define PNG_FREE_TRNS 0x2000
2181 #define PNG_FREE_TEXT 0x4000
2182 #define PNG_FREE_ALL  0x7fff
2183 #define PNG_FREE_MUL  0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
2184 
2185 #ifdef PNG_USER_MEM_SUPPORTED
2186 extern PNG_EXPORT(png_voidp,png_malloc_default) PNGARG((png_structp png_ptr,
2187    png_uint_32 size)) PNG_ALLOCATED;
2188 extern PNG_EXPORT(void,png_free_default) PNGARG((png_structp png_ptr,
2189    png_voidp ptr));
2190 #endif
2191 
2192 extern PNG_EXPORT(png_voidp,png_memcpy_check) PNGARG((png_structp png_ptr,
2193    png_voidp s1, png_voidp s2, png_uint_32 size)) PNG_DEPRECATED;
2194 
2195 extern PNG_EXPORT(png_voidp,png_memset_check) PNGARG((png_structp png_ptr,
2196    png_voidp s1, int value, png_uint_32 size)) PNG_DEPRECATED;
2197 
2198 #if defined(USE_FAR_KEYWORD)  /* memory model conversion function */
2199 extern void *png_far_to_near PNGARG((png_structp png_ptr,png_voidp ptr,
2200    int check));
2201 #endif /* USE_FAR_KEYWORD */
2202 
2203 #ifndef PNG_NO_ERROR_TEXT
2204 /* Fatal error in PNG image of libpng - can't continue */
2205 extern PNG_EXPORT(void,png_error) PNGARG((png_structp png_ptr,
2206    png_const_charp error_message)) PNG_NORETURN;
2207 
2208 /* The same, but the chunk name is prepended to the error string. */
2209 extern PNG_EXPORT(void,png_chunk_error) PNGARG((png_structp png_ptr,
2210    png_const_charp error_message)) PNG_NORETURN;
2211 #else
2212 /* Fatal error in PNG image of libpng - can't continue */
2213 extern PNG_EXPORT(void,png_err) PNGARG((png_structp png_ptr)) PNG_NORETURN;
2214 #endif
2215 
2216 #ifndef PNG_NO_WARNINGS
2217 /* Non-fatal error in libpng.  Can continue, but may have a problem. */
2218 extern PNG_EXPORT(void,png_warning) PNGARG((png_structp png_ptr,
2219    png_const_charp warning_message));
2220 
2221 #ifdef PNG_READ_SUPPORTED
2222 /* Non-fatal error in libpng, chunk name is prepended to message. */
2223 extern PNG_EXPORT(void,png_chunk_warning) PNGARG((png_structp png_ptr,
2224    png_const_charp warning_message));
2225 #endif /* PNG_READ_SUPPORTED */
2226 #endif /* PNG_NO_WARNINGS */
2227 
2228 /* The png_set_<chunk> functions are for storing values in the png_info_struct.
2229  * Similarly, the png_get_<chunk> calls are used to read values from the
2230  * png_info_struct, either storing the parameters in the passed variables, or
2231  * setting pointers into the png_info_struct where the data is stored.  The
2232  * png_get_<chunk> functions return a non-zero value if the data was available
2233  * in info_ptr, or return zero and do not change any of the parameters if the
2234  * data was not available.
2235  *
2236  * These functions should be used instead of directly accessing png_info
2237  * to avoid problems with future changes in the size and internal layout of
2238  * png_info_struct.
2239  */
2240 /* Returns "flag" if chunk data is valid in info_ptr. */
2241 extern PNG_EXPORT(png_uint_32,png_get_valid) PNGARG((png_structp png_ptr,
2242 png_infop info_ptr, png_uint_32 flag));
2243 
2244 /* Returns number of bytes needed to hold a transformed row. */
2245 extern PNG_EXPORT(png_uint_32,png_get_rowbytes) PNGARG((png_structp png_ptr,
2246 png_infop info_ptr));
2247 
2248 #ifdef PNG_INFO_IMAGE_SUPPORTED
2249 /* Returns row_pointers, which is an array of pointers to scanlines that was
2250  * returned from png_read_png().
2251  */
2252 extern PNG_EXPORT(png_bytepp,png_get_rows) PNGARG((png_structp png_ptr,
2253 png_infop info_ptr));
2254 /* Set row_pointers, which is an array of pointers to scanlines for use
2255  * by png_write_png().
2256  */
2257 extern PNG_EXPORT(void,png_set_rows) PNGARG((png_structp png_ptr,
2258    png_infop info_ptr, png_bytepp row_pointers));
2259 #endif
2260 
2261 /* Returns number of color channels in image. */
2262 extern PNG_EXPORT(png_byte,png_get_channels) PNGARG((png_structp png_ptr,
2263 png_infop info_ptr));
2264 
2265 #ifdef PNG_EASY_ACCESS_SUPPORTED
2266 /* Returns image width in pixels. */
2267 extern PNG_EXPORT(png_uint_32, png_get_image_width) PNGARG((png_structp
2268 png_ptr, png_infop info_ptr));
2269 
2270 /* Returns image height in pixels. */
2271 extern PNG_EXPORT(png_uint_32, png_get_image_height) PNGARG((png_structp
2272 png_ptr, png_infop info_ptr));
2273 
2274 /* Returns image bit_depth. */
2275 extern PNG_EXPORT(png_byte, png_get_bit_depth) PNGARG((png_structp
2276 png_ptr, png_infop info_ptr));
2277 
2278 /* Returns image color_type. */
2279 extern PNG_EXPORT(png_byte, png_get_color_type) PNGARG((png_structp
2280 png_ptr, png_infop info_ptr));
2281 
2282 /* Returns image filter_type. */
2283 extern PNG_EXPORT(png_byte, png_get_filter_type) PNGARG((png_structp
2284 png_ptr, png_infop info_ptr));
2285 
2286 /* Returns image interlace_type. */
2287 extern PNG_EXPORT(png_byte, png_get_interlace_type) PNGARG((png_structp
2288 png_ptr, png_infop info_ptr));
2289 
2290 /* Returns image compression_type. */
2291 extern PNG_EXPORT(png_byte, png_get_compression_type) PNGARG((png_structp
2292 png_ptr, png_infop info_ptr));
2293 
2294 /* Returns image resolution in pixels per meter, from pHYs chunk data. */
2295 extern PNG_EXPORT(png_uint_32, png_get_pixels_per_meter) PNGARG((png_structp
2296 png_ptr, png_infop info_ptr));
2297 extern PNG_EXPORT(png_uint_32, png_get_x_pixels_per_meter) PNGARG((png_structp
2298 png_ptr, png_infop info_ptr));
2299 extern PNG_EXPORT(png_uint_32, png_get_y_pixels_per_meter) PNGARG((png_structp
2300 png_ptr, png_infop info_ptr));
2301 
2302 /* Returns pixel aspect ratio, computed from pHYs chunk data.  */
2303 #ifdef PNG_FLOATING_POINT_SUPPORTED
2304 extern PNG_EXPORT(float, png_get_pixel_aspect_ratio) PNGARG((png_structp
2305 png_ptr, png_infop info_ptr));
2306 #endif
2307 
2308 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
2309 extern PNG_EXPORT(png_int_32, png_get_x_offset_pixels) PNGARG((png_structp
2310 png_ptr, png_infop info_ptr));
2311 extern PNG_EXPORT(png_int_32, png_get_y_offset_pixels) PNGARG((png_structp
2312 png_ptr, png_infop info_ptr));
2313 extern PNG_EXPORT(png_int_32, png_get_x_offset_microns) PNGARG((png_structp
2314 png_ptr, png_infop info_ptr));
2315 extern PNG_EXPORT(png_int_32, png_get_y_offset_microns) PNGARG((png_structp
2316 png_ptr, png_infop info_ptr));
2317 
2318 #endif /* PNG_EASY_ACCESS_SUPPORTED */
2319 
2320 /* Returns pointer to signature string read from PNG header */
2321 extern PNG_EXPORT(png_bytep,png_get_signature) PNGARG((png_structp png_ptr,
2322 png_infop info_ptr));
2323 
2324 #ifdef PNG_bKGD_SUPPORTED
2325 extern PNG_EXPORT(png_uint_32,png_get_bKGD) PNGARG((png_structp png_ptr,
2326    png_infop info_ptr, png_color_16p *background));
2327 #endif
2328 
2329 #ifdef PNG_bKGD_SUPPORTED
2330 extern PNG_EXPORT(void,png_set_bKGD) PNGARG((png_structp png_ptr,
2331    png_infop info_ptr, png_color_16p background));
2332 #endif
2333 
2334 #ifdef PNG_cHRM_SUPPORTED
2335 #ifdef PNG_FLOATING_POINT_SUPPORTED
2336 extern PNG_EXPORT(png_uint_32,png_get_cHRM) PNGARG((png_structp png_ptr,
2337    png_infop info_ptr, double *white_x, double *white_y, double *red_x,
2338    double *red_y, double *green_x, double *green_y, double *blue_x,
2339    double *blue_y));
2340 #endif
2341 #ifdef PNG_FIXED_POINT_SUPPORTED
2342 extern PNG_EXPORT(png_uint_32,png_get_cHRM_fixed) PNGARG((png_structp png_ptr,
2343    png_infop info_ptr, png_fixed_point *int_white_x, png_fixed_point
2344    *int_white_y, png_fixed_point *int_red_x, png_fixed_point *int_red_y,
2345    png_fixed_point *int_green_x, png_fixed_point *int_green_y, png_fixed_point
2346    *int_blue_x, png_fixed_point *int_blue_y));
2347 #endif
2348 #endif
2349 
2350 #ifdef PNG_cHRM_SUPPORTED
2351 #ifdef PNG_FLOATING_POINT_SUPPORTED
2352 extern PNG_EXPORT(void,png_set_cHRM) PNGARG((png_structp png_ptr,
2353    png_infop info_ptr, double white_x, double white_y, double red_x,
2354    double red_y, double green_x, double green_y, double blue_x, double blue_y));
2355 #endif
2356 #ifdef PNG_FIXED_POINT_SUPPORTED
2357 extern PNG_EXPORT(void,png_set_cHRM_fixed) PNGARG((png_structp png_ptr,
2358    png_infop info_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y,
2359    png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
2360    int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
2361    png_fixed_point int_blue_y));
2362 #endif
2363 #endif
2364 
2365 #ifdef PNG_gAMA_SUPPORTED
2366 #ifdef PNG_FLOATING_POINT_SUPPORTED
2367 extern PNG_EXPORT(png_uint_32,png_get_gAMA) PNGARG((png_structp png_ptr,
2368    png_infop info_ptr, double *file_gamma));
2369 #endif
2370 extern PNG_EXPORT(png_uint_32,png_get_gAMA_fixed) PNGARG((png_structp png_ptr,
2371    png_infop info_ptr, png_fixed_point *int_file_gamma));
2372 #endif
2373 
2374 #ifdef PNG_gAMA_SUPPORTED
2375 #ifdef PNG_FLOATING_POINT_SUPPORTED
2376 extern PNG_EXPORT(void,png_set_gAMA) PNGARG((png_structp png_ptr,
2377    png_infop info_ptr, double file_gamma));
2378 #endif
2379 extern PNG_EXPORT(void,png_set_gAMA_fixed) PNGARG((png_structp png_ptr,
2380    png_infop info_ptr, png_fixed_point int_file_gamma));
2381 #endif
2382 
2383 #ifdef PNG_hIST_SUPPORTED
2384 extern PNG_EXPORT(png_uint_32,png_get_hIST) PNGARG((png_structp png_ptr,
2385    png_infop info_ptr, png_uint_16p *hist));
2386 #endif
2387 
2388 #ifdef PNG_hIST_SUPPORTED
2389 extern PNG_EXPORT(void,png_set_hIST) PNGARG((png_structp png_ptr,
2390    png_infop info_ptr, png_uint_16p hist));
2391 #endif
2392 
2393 extern PNG_EXPORT(png_uint_32,png_get_IHDR) PNGARG((png_structp png_ptr,
2394    png_infop info_ptr, png_uint_32 *width, png_uint_32 *height,
2395    int *bit_depth, int *color_type, int *interlace_method,
2396    int *compression_method, int *filter_method));
2397 
2398 extern PNG_EXPORT(void,png_set_IHDR) PNGARG((png_structp png_ptr,
2399    png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
2400    int color_type, int interlace_method, int compression_method,
2401    int filter_method));
2402 
2403 #ifdef PNG_oFFs_SUPPORTED
2404 extern PNG_EXPORT(png_uint_32,png_get_oFFs) PNGARG((png_structp png_ptr,
2405    png_infop info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
2406    int *unit_type));
2407 #endif
2408 
2409 #ifdef PNG_oFFs_SUPPORTED
2410 extern PNG_EXPORT(void,png_set_oFFs) PNGARG((png_structp png_ptr,
2411    png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2412    int unit_type));
2413 #endif
2414 
2415 #ifdef PNG_pCAL_SUPPORTED
2416 extern PNG_EXPORT(png_uint_32,png_get_pCAL) PNGARG((png_structp png_ptr,
2417    png_infop info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1,
2418    int *type, int *nparams, png_charp *units, png_charpp *params));
2419 #endif
2420 
2421 #ifdef PNG_pCAL_SUPPORTED
2422 extern PNG_EXPORT(void,png_set_pCAL) PNGARG((png_structp png_ptr,
2423    png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1,
2424    int type, int nparams, png_charp units, png_charpp params));
2425 #endif
2426 
2427 #ifdef PNG_pHYs_SUPPORTED
2428 extern PNG_EXPORT(png_uint_32,png_get_pHYs) PNGARG((png_structp png_ptr,
2429    png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
2430 #endif
2431 
2432 #ifdef PNG_pHYs_SUPPORTED
2433 extern PNG_EXPORT(void,png_set_pHYs) PNGARG((png_structp png_ptr,
2434    png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2435 #endif
2436 
2437 extern PNG_EXPORT(png_uint_32,png_get_PLTE) PNGARG((png_structp png_ptr,
2438    png_infop info_ptr, png_colorp *palette, int *num_palette));
2439 
2440 extern PNG_EXPORT(void,png_set_PLTE) PNGARG((png_structp png_ptr,
2441    png_infop info_ptr, png_colorp palette, int num_palette));
2442 
2443 #ifdef PNG_sBIT_SUPPORTED
2444 extern PNG_EXPORT(png_uint_32,png_get_sBIT) PNGARG((png_structp png_ptr,
2445    png_infop info_ptr, png_color_8p *sig_bit));
2446 #endif
2447 
2448 #ifdef PNG_sBIT_SUPPORTED
2449 extern PNG_EXPORT(void,png_set_sBIT) PNGARG((png_structp png_ptr,
2450    png_infop info_ptr, png_color_8p sig_bit));
2451 #endif
2452 
2453 #ifdef PNG_sRGB_SUPPORTED
2454 extern PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr,
2455    png_infop info_ptr, int *intent));
2456 #endif
2457 
2458 #ifdef PNG_sRGB_SUPPORTED
2459 extern PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr,
2460    png_infop info_ptr, int intent));
2461 extern PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr,
2462    png_infop info_ptr, int intent));
2463 #endif
2464 
2465 #ifdef PNG_iCCP_SUPPORTED
2466 extern PNG_EXPORT(png_uint_32,png_get_iCCP) PNGARG((png_structp png_ptr,
2467    png_infop info_ptr, png_charpp name, int *compression_type,
2468    png_charpp profile, png_uint_32 *proflen));
2469    /* Note to maintainer: profile should be png_bytepp */
2470 #endif
2471 
2472 #ifdef PNG_iCCP_SUPPORTED
2473 extern PNG_EXPORT(void,png_set_iCCP) PNGARG((png_structp png_ptr,
2474    png_infop info_ptr, png_charp name, int compression_type,
2475    png_charp profile, png_uint_32 proflen));
2476    /* Note to maintainer: profile should be png_bytep */
2477 #endif
2478 
2479 #ifdef PNG_sPLT_SUPPORTED
2480 extern PNG_EXPORT(png_uint_32,png_get_sPLT) PNGARG((png_structp png_ptr,
2481    png_infop info_ptr, png_sPLT_tpp entries));
2482 #endif
2483 
2484 #ifdef PNG_sPLT_SUPPORTED
2485 extern PNG_EXPORT(void,png_set_sPLT) PNGARG((png_structp png_ptr,
2486    png_infop info_ptr, png_sPLT_tp entries, int nentries));
2487 #endif
2488 
2489 #ifdef PNG_TEXT_SUPPORTED
2490 /* png_get_text also returns the number of text chunks in *num_text */
2491 extern PNG_EXPORT(png_uint_32,png_get_text) PNGARG((png_structp png_ptr,
2492    png_infop info_ptr, png_textp *text_ptr, int *num_text));
2493 #endif
2494 
2495 /*
2496  *  Note while png_set_text() will accept a structure whose text,
2497  *  language, and  translated keywords are NULL pointers, the structure
2498  *  returned by png_get_text will always contain regular
2499  *  zero-terminated C strings.  They might be empty strings but
2500  *  they will never be NULL pointers.
2501  */
2502 
2503 #ifdef PNG_TEXT_SUPPORTED
2504 extern PNG_EXPORT(void,png_set_text) PNGARG((png_structp png_ptr,
2505    png_infop info_ptr, png_textp text_ptr, int num_text));
2506 #endif
2507 
2508 #ifdef PNG_tIME_SUPPORTED
2509 extern PNG_EXPORT(png_uint_32,png_get_tIME) PNGARG((png_structp png_ptr,
2510    png_infop info_ptr, png_timep *mod_time));
2511 #endif
2512 
2513 #ifdef PNG_tIME_SUPPORTED
2514 extern PNG_EXPORT(void,png_set_tIME) PNGARG((png_structp png_ptr,
2515    png_infop info_ptr, png_timep mod_time));
2516 #endif
2517 
2518 #ifdef PNG_tRNS_SUPPORTED
2519 extern PNG_EXPORT(png_uint_32,png_get_tRNS) PNGARG((png_structp png_ptr,
2520    png_infop info_ptr, png_bytep *trans, int *num_trans,
2521    png_color_16p *trans_values));
2522 #endif
2523 
2524 #ifdef PNG_tRNS_SUPPORTED
2525 extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
2526    png_infop info_ptr, png_bytep trans, int num_trans,
2527    png_color_16p trans_values));
2528 #endif
2529 
2530 #ifdef PNG_tRNS_SUPPORTED
2531 #endif
2532 
2533 #ifdef PNG_sCAL_SUPPORTED
2534 #ifdef PNG_FLOATING_POINT_SUPPORTED
2535 extern PNG_EXPORT(png_uint_32,png_get_sCAL) PNGARG((png_structp png_ptr,
2536    png_infop info_ptr, int *unit, double *width, double *height));
2537 #else
2538 #ifdef PNG_FIXED_POINT_SUPPORTED
2539 extern PNG_EXPORT(png_uint_32,png_get_sCAL_s) PNGARG((png_structp png_ptr,
2540    png_infop info_ptr, int *unit, png_charpp swidth, png_charpp sheight));
2541 #endif
2542 #endif
2543 #endif /* PNG_sCAL_SUPPORTED */
2544 
2545 #ifdef PNG_sCAL_SUPPORTED
2546 #ifdef PNG_FLOATING_POINT_SUPPORTED
2547 extern PNG_EXPORT(void,png_set_sCAL) PNGARG((png_structp png_ptr,
2548    png_infop info_ptr, int unit, double width, double height));
2549 #else
2550 #ifdef PNG_FIXED_POINT_SUPPORTED
2551 extern PNG_EXPORT(void,png_set_sCAL_s) PNGARG((png_structp png_ptr,
2552    png_infop info_ptr, int unit, png_charp swidth, png_charp sheight));
2553 #endif
2554 #endif
2555 #endif /* PNG_sCAL_SUPPORTED || PNG_WRITE_sCAL_SUPPORTED */
2556 
2557 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2558 /* Provide a list of chunks and how they are to be handled, if the built-in
2559    handling or default unknown chunk handling is not desired.  Any chunks not
2560    listed will be handled in the default manner.  The IHDR and IEND chunks
2561    must not be listed.
2562       keep = 0: follow default behaviour
2563            = 1: do not keep
2564            = 2: keep only if safe-to-copy
2565            = 3: keep even if unsafe-to-copy
2566 */
2567 extern PNG_EXPORT(void, png_set_keep_unknown_chunks) PNGARG((png_structp
2568    png_ptr, int keep, png_bytep chunk_list, int num_chunks));
2569 PNG_EXPORT(int,png_handle_as_unknown) PNGARG((png_structp png_ptr, png_bytep
2570    chunk_name));
2571 #endif
2572 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
2573 extern PNG_EXPORT(void, png_set_unknown_chunks) PNGARG((png_structp png_ptr,
2574    png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns));
2575 extern PNG_EXPORT(void, png_set_unknown_chunk_location)
2576    PNGARG((png_structp png_ptr, png_infop info_ptr, int chunk, int location));
2577 extern PNG_EXPORT(png_uint_32,png_get_unknown_chunks) PNGARG((png_structp
2578    png_ptr, png_infop info_ptr, png_unknown_chunkpp entries));
2579 #endif
2580 
2581 /* Png_free_data() will turn off the "valid" flag for anything it frees.
2582  * If you need to turn it off for a chunk that your application has freed,
2583  * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
2584  */
2585 extern PNG_EXPORT(void, png_set_invalid) PNGARG((png_structp png_ptr,
2586    png_infop info_ptr, int mask));
2587 
2588 #ifdef PNG_INFO_IMAGE_SUPPORTED
2589 /* The "params" pointer is currently not used and is for future expansion. */
2590 extern PNG_EXPORT(void, png_read_png) PNGARG((png_structp png_ptr,
2591                         png_infop info_ptr,
2592                         int transforms,
2593                         png_voidp params));
2594 extern PNG_EXPORT(void, png_write_png) PNGARG((png_structp png_ptr,
2595                         png_infop info_ptr,
2596                         int transforms,
2597                         png_voidp params));
2598 #endif
2599 
2600 /* Define PNG_DEBUG at compile time for debugging information.  Higher
2601  * numbers for PNG_DEBUG mean more debugging information.  This has
2602  * only been added since version 0.95 so it is not implemented throughout
2603  * libpng yet, but more support will be added as needed.
2604  */
2605 #ifdef PNG_DEBUG
2606 #if (PNG_DEBUG > 0)
2607 #if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER)
2608 #include <crtdbg.h>
2609 #if (PNG_DEBUG > 1)
2610 #ifndef _DEBUG
2611 #  define _DEBUG
2612 #endif
2613 #ifndef png_debug
2614 #define png_debug(l,m)  _RPT0(_CRT_WARN,m PNG_STRING_NEWLINE)
2615 #endif
2616 #ifndef png_debug1
2617 #define png_debug1(l,m,p1)  _RPT1(_CRT_WARN,m PNG_STRING_NEWLINE,p1)
2618 #endif
2619 #ifndef png_debug2
2620 #define png_debug2(l,m,p1,p2) _RPT2(_CRT_WARN,m PNG_STRING_NEWLINE,p1,p2)
2621 #endif
2622 #endif
2623 #else /* PNG_DEBUG_FILE || !_MSC_VER */
2624 #ifndef PNG_DEBUG_FILE
2625 #define PNG_DEBUG_FILE stderr
2626 #endif /* PNG_DEBUG_FILE */
2627 
2628 #if (PNG_DEBUG > 1)
2629 /* Note: ["%s"m PNG_STRING_NEWLINE] probably does not work on non-ISO
2630  * compilers.
2631  */
2632 #  ifdef __STDC__
2633 #    ifndef png_debug
2634 #      define png_debug(l,m) \
2635        { \
2636        int num_tabs=l; \
2637        fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
2638          (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":"")))); \
2639        }
2640 #    endif
2641 #    ifndef png_debug1
2642 #      define png_debug1(l,m,p1) \
2643        { \
2644        int num_tabs=l; \
2645        fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
2646          (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1); \
2647        }
2648 #    endif
2649 #    ifndef png_debug2
2650 #      define png_debug2(l,m,p1,p2) \
2651        { \
2652        int num_tabs=l; \
2653        fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
2654          (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1,p2); \
2655        }
2656 #    endif
2657 #  else /* __STDC __ */
2658 #    ifndef png_debug
2659 #      define png_debug(l,m) \
2660        { \
2661        int num_tabs=l; \
2662        char format[256]; \
2663        snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
2664          (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
2665          m,PNG_STRING_NEWLINE); \
2666        fprintf(PNG_DEBUG_FILE,format); \
2667        }
2668 #    endif
2669 #    ifndef png_debug1
2670 #      define png_debug1(l,m,p1) \
2671        { \
2672        int num_tabs=l; \
2673        char format[256]; \
2674        snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
2675          (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
2676          m,PNG_STRING_NEWLINE); \
2677        fprintf(PNG_DEBUG_FILE,format,p1); \
2678        }
2679 #    endif
2680 #    ifndef png_debug2
2681 #      define png_debug2(l,m,p1,p2) \
2682        { \
2683        int num_tabs=l; \
2684        char format[256]; \
2685        snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
2686          (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
2687          m,PNG_STRING_NEWLINE); \
2688        fprintf(PNG_DEBUG_FILE,format,p1,p2); \
2689        }
2690 #    endif
2691 #  endif /* __STDC __ */
2692 #endif /* (PNG_DEBUG > 1) */
2693 
2694 #endif /* _MSC_VER */
2695 #endif /* (PNG_DEBUG > 0) */
2696 #endif /* PNG_DEBUG */
2697 #ifndef png_debug
2698 #define png_debug(l, m)
2699 #endif
2700 #ifndef png_debug1
2701 #define png_debug1(l, m, p1)
2702 #endif
2703 #ifndef png_debug2
2704 #define png_debug2(l, m, p1, p2)
2705 #endif
2706 
2707 extern PNG_EXPORT(png_charp,png_get_copyright) PNGARG((png_structp png_ptr));
2708 extern PNG_EXPORT(png_charp,png_get_header_ver) PNGARG((png_structp png_ptr));
2709 extern PNG_EXPORT(png_charp,png_get_header_version) PNGARG((png_structp png_ptr));
2710 extern PNG_EXPORT(png_charp,png_get_libpng_ver) PNGARG((png_structp png_ptr));
2711 
2712 #ifdef PNG_MNG_FEATURES_SUPPORTED
2713 extern PNG_EXPORT(png_uint_32,png_permit_mng_features) PNGARG((png_structp
2714    png_ptr, png_uint_32 mng_features_permitted));
2715 #endif
2716 
2717 /* For use in png_set_keep_unknown, added to version 1.2.6 */
2718 #define PNG_HANDLE_CHUNK_AS_DEFAULT   0
2719 #define PNG_HANDLE_CHUNK_NEVER        1
2720 #define PNG_HANDLE_CHUNK_IF_SAFE      2
2721 #define PNG_HANDLE_CHUNK_ALWAYS       3
2722 
2723 /* Added to version 1.2.0 */
2724 #ifdef PNG_ASSEMBLER_CODE_SUPPORTED
2725 #ifdef PNG_MMX_CODE_SUPPORTED
2726 #define PNG_ASM_FLAG_MMX_SUPPORT_COMPILED  0x01  /* not user-settable */
2727 #define PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU    0x02  /* not user-settable */
2728 #define PNG_ASM_FLAG_MMX_READ_COMBINE_ROW  0x04
2729 #define PNG_ASM_FLAG_MMX_READ_INTERLACE    0x08
2730 #define PNG_ASM_FLAG_MMX_READ_FILTER_SUB   0x10
2731 #define PNG_ASM_FLAG_MMX_READ_FILTER_UP    0x20
2732 #define PNG_ASM_FLAG_MMX_READ_FILTER_AVG   0x40
2733 #define PNG_ASM_FLAG_MMX_READ_FILTER_PAETH 0x80
2734 #define PNG_ASM_FLAGS_INITIALIZED          0x80000000  /* not user-settable */
2735 
2736 #define PNG_MMX_READ_FLAGS ( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW  \
2737                            | PNG_ASM_FLAG_MMX_READ_INTERLACE    \
2738                            | PNG_ASM_FLAG_MMX_READ_FILTER_SUB   \
2739                            | PNG_ASM_FLAG_MMX_READ_FILTER_UP    \
2740                            | PNG_ASM_FLAG_MMX_READ_FILTER_AVG   \
2741                            | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH )
2742 #define PNG_MMX_WRITE_FLAGS ( 0 )
2743 
2744 #define PNG_MMX_FLAGS ( PNG_ASM_FLAG_MMX_SUPPORT_COMPILED \
2745                       | PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU   \
2746                       | PNG_MMX_READ_FLAGS                \
2747                       | PNG_MMX_WRITE_FLAGS )
2748 
2749 #define PNG_SELECT_READ   1
2750 #define PNG_SELECT_WRITE  2
2751 #endif /* PNG_MMX_CODE_SUPPORTED */
2752 
2753 #ifndef PNG_1_0_X
2754 /* pngget.c */
2755 extern PNG_EXPORT(png_uint_32,png_get_mmx_flagmask)
2756    PNGARG((int flag_select, int *compilerID));
2757 
2758 /* pngget.c */
2759 extern PNG_EXPORT(png_uint_32,png_get_asm_flagmask)
2760    PNGARG((int flag_select));
2761 
2762 /* pngget.c */
2763 extern PNG_EXPORT(png_uint_32,png_get_asm_flags)
2764    PNGARG((png_structp png_ptr));
2765 
2766 /* pngget.c */
2767 extern PNG_EXPORT(png_byte,png_get_mmx_bitdepth_threshold)
2768    PNGARG((png_structp png_ptr));
2769 
2770 /* pngget.c */
2771 extern PNG_EXPORT(png_uint_32,png_get_mmx_rowbytes_threshold)
2772    PNGARG((png_structp png_ptr));
2773 
2774 /* pngset.c */
2775 extern PNG_EXPORT(void,png_set_asm_flags)
2776    PNGARG((png_structp png_ptr, png_uint_32 asm_flags));
2777 
2778 /* pngset.c */
2779 extern PNG_EXPORT(void,png_set_mmx_thresholds)
2780    PNGARG((png_structp png_ptr, png_byte mmx_bitdepth_threshold,
2781    png_uint_32 mmx_rowbytes_threshold));
2782 
2783 #endif /* PNG_1_0_X */
2784 
2785 #ifndef PNG_1_0_X
2786 /* png.c, pnggccrd.c, or pngvcrd.c */
2787 extern PNG_EXPORT(int,png_mmx_support) PNGARG((void));
2788 #endif /* PNG_1_0_X */
2789 #endif /* PNG_ASSEMBLER_CODE_SUPPORTED */
2790 
2791 /* Strip the prepended error numbers ("#nnn ") from error and warning
2792  * messages before passing them to the error or warning handler.
2793  */
2794 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
2795 extern PNG_EXPORT(void,png_set_strip_error_numbers) PNGARG((png_structp
2796    png_ptr, png_uint_32 strip_mode));
2797 #endif
2798 
2799 /* Added at libpng-1.2.6 */
2800 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
2801 extern PNG_EXPORT(void,png_set_user_limits) PNGARG((png_structp
2802    png_ptr, png_uint_32 user_width_max, png_uint_32 user_height_max));
2803 extern PNG_EXPORT(png_uint_32,png_get_user_width_max) PNGARG((png_structp
2804    png_ptr));
2805 extern PNG_EXPORT(png_uint_32,png_get_user_height_max) PNGARG((png_structp
2806    png_ptr));
2807 #endif
2808 /* Maintainer: Put new public prototypes here ^, in libpng.3, and in
2809  * project defs
2810  */
2811 
2812 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2813 /* With these routines we avoid an integer divide, which will be slower on
2814  * most machines.  However, it does take more operations than the corresponding
2815  * divide method, so it may be slower on a few RISC systems.  There are two
2816  * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2817  *
2818  * Note that the rounding factors are NOT supposed to be the same!  128 and
2819  * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2820  * standard method.
2821  *
2822  * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2823  */
2824 
2825  /* fg and bg should be in `gamma 1.0' space; alpha is the opacity          */
2826 
2827 #  define png_composite(composite, fg, alpha, bg)                            \
2828      { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) * (png_uint_16)(alpha) \
2829                         +        (png_uint_16)(bg)*(png_uint_16)(255 -       \
2830                         (png_uint_16)(alpha)) + (png_uint_16)128);           \
2831        (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
2832 
2833 #  define png_composite_16(composite, fg, alpha, bg)                         \
2834      { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) * (png_uint_32)(alpha) \
2835                         + (png_uint_32)(bg)*(png_uint_32)(65535L -           \
2836                         (png_uint_32)(alpha)) + (png_uint_32)32768L);        \
2837        (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
2838 
2839 #else  /* Standard method using integer division */
2840 
2841 #  define png_composite(composite, fg, alpha, bg)                            \
2842      (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) +    \
2843        (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) +       \
2844        (png_uint_16)127) / 255)
2845 
2846 #  define png_composite_16(composite, fg, alpha, bg)                         \
2847      (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2848        (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) +      \
2849        (png_uint_32)32767) / (png_uint_32)65535L)
2850 
2851 #endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
2852 
2853 /* Inline macros to do direct reads of bytes from the input buffer.  These
2854  * require that you are using an architecture that uses PNG byte ordering
2855  * (MSB first) and supports unaligned data storage.  I think that PowerPC
2856  * in big-endian mode and 680x0 are the only ones that will support this.
2857  * The x86 line of processors definitely do not.  The png_get_int_32()
2858  * routine also assumes we are using two's complement format for negative
2859  * values, which is almost certainly true.
2860  */
2861 #ifdef PNG_READ_BIG_ENDIAN_SUPPORTED
2862 #  define png_get_uint_32(buf) ( *((png_uint_32p) (buf)))
2863 #  define png_get_uint_16(buf) ( *((png_uint_16p) (buf)))
2864 #  define png_get_int_32(buf)  ( *((png_int_32p)  (buf)))
2865 #else
2866 extern PNG_EXPORT(png_uint_32,png_get_uint_32) PNGARG((png_bytep buf));
2867 extern PNG_EXPORT(png_uint_16,png_get_uint_16) PNGARG((png_bytep buf));
2868 extern PNG_EXPORT(png_int_32,png_get_int_32) PNGARG((png_bytep buf));
2869 #endif /* !PNG_READ_BIG_ENDIAN_SUPPORTED */
2870 extern PNG_EXPORT(png_uint_32,png_get_uint_31)
2871   PNGARG((png_structp png_ptr, png_bytep buf));
2872 /* No png_get_int_16 -- may be added if there's a real need for it. */
2873 
2874 /* Place a 32-bit number into a buffer in PNG byte order (big-endian).
2875  */
2876 extern PNG_EXPORT(void,png_save_uint_32)
2877    PNGARG((png_bytep buf, png_uint_32 i));
2878 extern PNG_EXPORT(void,png_save_int_32)
2879    PNGARG((png_bytep buf, png_int_32 i));
2880 
2881 /* Place a 16-bit number into a buffer in PNG byte order.
2882  * The parameter is declared unsigned int, not png_uint_16,
2883  * just to avoid potential problems on pre-ANSI C compilers.
2884  */
2885 extern PNG_EXPORT(void,png_save_uint_16)
2886    PNGARG((png_bytep buf, unsigned int i));
2887 /* No png_save_int_16 -- may be added if there's a real need for it. */
2888 
2889 /* ************************************************************************* */
2890 
2891 /* These next functions are used internally in the code.  They generally
2892  * shouldn't be used unless you are writing code to add or replace some
2893  * functionality in libpng.  More information about most functions can
2894  * be found in the files where the functions are located.
2895  */
2896 
2897 
2898 /* Various modes of operation, that are visible to applications because
2899  * they are used for unknown chunk location.
2900  */
2901 #define PNG_HAVE_IHDR               0x01
2902 #define PNG_HAVE_PLTE               0x02
2903 #define PNG_HAVE_IDAT               0x04
2904 #define PNG_AFTER_IDAT              0x08 /* Have complete zlib datastream */
2905 #define PNG_HAVE_IEND               0x10
2906 
2907 #ifdef PNG_INTERNAL
2908 
2909 /* More modes of operation.  Note that after an init, mode is set to
2910  * zero automatically when the structure is created.
2911  */
2912 #define PNG_HAVE_gAMA               0x20
2913 #define PNG_HAVE_cHRM               0x40
2914 #define PNG_HAVE_sRGB               0x80
2915 #define PNG_HAVE_CHUNK_HEADER      0x100
2916 #define PNG_WROTE_tIME             0x200
2917 #define PNG_WROTE_INFO_BEFORE_PLTE 0x400
2918 #define PNG_BACKGROUND_IS_GRAY     0x800
2919 #define PNG_HAVE_PNG_SIGNATURE    0x1000
2920 #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
2921 
2922 /* Flags for the transformations the PNG library does on the image data */
2923 #define PNG_BGR                0x0001
2924 #define PNG_INTERLACE          0x0002
2925 #define PNG_PACK               0x0004
2926 #define PNG_SHIFT              0x0008
2927 #define PNG_SWAP_BYTES         0x0010
2928 #define PNG_INVERT_MONO        0x0020
2929 #define PNG_DITHER             0x0040
2930 #define PNG_BACKGROUND         0x0080
2931 #define PNG_BACKGROUND_EXPAND  0x0100
2932                           /*   0x0200 unused */
2933 #define PNG_16_TO_8            0x0400
2934 #define PNG_RGBA               0x0800
2935 #define PNG_EXPAND             0x1000
2936 #define PNG_GAMMA              0x2000
2937 #define PNG_GRAY_TO_RGB        0x4000
2938 #define PNG_FILLER             0x8000L
2939 #define PNG_PACKSWAP          0x10000L
2940 #define PNG_SWAP_ALPHA        0x20000L
2941 #define PNG_STRIP_ALPHA       0x40000L
2942 #define PNG_INVERT_ALPHA      0x80000L
2943 #define PNG_USER_TRANSFORM   0x100000L
2944 #define PNG_RGB_TO_GRAY_ERR  0x200000L
2945 #define PNG_RGB_TO_GRAY_WARN 0x400000L
2946 #define PNG_RGB_TO_GRAY      0x600000L  /* two bits, RGB_TO_GRAY_ERR|WARN */
2947                        /*    0x800000L     Unused */
2948 #define PNG_ADD_ALPHA       0x1000000L  /* Added to libpng-1.2.7 */
2949 #define PNG_EXPAND_tRNS     0x2000000L  /* Added to libpng-1.2.9 */
2950 #define PNG_PREMULTIPLY_ALPHA 0x4000000L  /* Added to libpng-1.2.41 */
2951                                           /* by volker */
2952                        /*   0x8000000L  unused */
2953                        /*  0x10000000L  unused */
2954                        /*  0x20000000L  unused */
2955                        /*  0x40000000L  unused */
2956 
2957 /* Flags for png_create_struct */
2958 #define PNG_STRUCT_PNG   0x0001
2959 #define PNG_STRUCT_INFO  0x0002
2960 
2961 /* Scaling factor for filter heuristic weighting calculations */
2962 #define PNG_WEIGHT_SHIFT 8
2963 #define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
2964 #define PNG_COST_SHIFT 3
2965 #define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
2966 
2967 /* Flags for the png_ptr->flags rather than declaring a byte for each one */
2968 #define PNG_FLAG_ZLIB_CUSTOM_STRATEGY     0x0001
2969 #define PNG_FLAG_ZLIB_CUSTOM_LEVEL        0x0002
2970 #define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL    0x0004
2971 #define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS  0x0008
2972 #define PNG_FLAG_ZLIB_CUSTOM_METHOD       0x0010
2973 #define PNG_FLAG_ZLIB_FINISHED            0x0020
2974 #define PNG_FLAG_ROW_INIT                 0x0040
2975 #define PNG_FLAG_FILLER_AFTER             0x0080
2976 #define PNG_FLAG_CRC_ANCILLARY_USE        0x0100
2977 #define PNG_FLAG_CRC_ANCILLARY_NOWARN     0x0200
2978 #define PNG_FLAG_CRC_CRITICAL_USE         0x0400
2979 #define PNG_FLAG_CRC_CRITICAL_IGNORE      0x0800
2980 #define PNG_FLAG_FREE_PLTE                0x1000
2981 #define PNG_FLAG_FREE_TRNS                0x2000
2982 #define PNG_FLAG_FREE_HIST                0x4000
2983 #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS      0x8000L
2984 #define PNG_FLAG_KEEP_UNSAFE_CHUNKS       0x10000L
2985 #define PNG_FLAG_LIBRARY_MISMATCH         0x20000L
2986 #define PNG_FLAG_STRIP_ERROR_NUMBERS      0x40000L
2987 #define PNG_FLAG_STRIP_ERROR_TEXT         0x80000L
2988 #define PNG_FLAG_MALLOC_NULL_MEM_OK       0x100000L
2989 #define PNG_FLAG_ADD_ALPHA                0x200000L  /* Added to libpng-1.2.8 */
2990 #define PNG_FLAG_STRIP_ALPHA              0x400000L  /* Added to libpng-1.2.8 */
2991                                   /*      0x800000L  unused */
2992                                   /*     0x1000000L  unused */
2993                                   /*     0x2000000L  unused */
2994                                   /*     0x4000000L  unused */
2995                                   /*     0x8000000L  unused */
2996                                   /*    0x10000000L  unused */
2997                                   /*    0x20000000L  unused */
2998                                   /*    0x40000000L  unused */
2999 
3000 #define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
3001                                      PNG_FLAG_CRC_ANCILLARY_NOWARN)
3002 
3003 #define PNG_FLAG_CRC_CRITICAL_MASK  (PNG_FLAG_CRC_CRITICAL_USE | \
3004                                      PNG_FLAG_CRC_CRITICAL_IGNORE)
3005 
3006 #define PNG_FLAG_CRC_MASK           (PNG_FLAG_CRC_ANCILLARY_MASK | \
3007                                      PNG_FLAG_CRC_CRITICAL_MASK)
3008 
3009 /* Save typing and make code easier to understand */
3010 
3011 #define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
3012    abs((int)((c1).green) - (int)((c2).green)) + \
3013    abs((int)((c1).blue) - (int)((c2).blue)))
3014 
3015 /* Added to libpng-1.2.6 JB */
3016 #define PNG_ROWBYTES(pixel_bits, width) \
3017     ((pixel_bits) >= 8 ? \
3018     ((width) * (((png_uint_32)(pixel_bits)) >> 3)) : \
3019     (( ((width) * ((png_uint_32)(pixel_bits))) + 7) >> 3) )
3020 
3021 /* PNG_OUT_OF_RANGE returns true if value is outside the range
3022  * ideal-delta..ideal+delta.  Each argument is evaluated twice.
3023  * "ideal" and "delta" should be constants, normally simple
3024  * integers, "value" a variable. Added to libpng-1.2.6 JB
3025  */
3026 #define PNG_OUT_OF_RANGE(value, ideal, delta) \
3027         ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
3028 
3029 /* Variables declared in png.c - only it needs to define PNG_NO_EXTERN */
3030 #if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
3031 /* Place to hold the signature string for a PNG file. */
3032 #ifdef PNG_USE_GLOBAL_ARRAYS
3033    PNG_EXPORT_VAR (PNG_CONST png_byte FARDATA) png_sig[8];
3034 #else
3035 #endif
3036 #endif /* PNG_NO_EXTERN */
3037 
3038 /* Constant strings for known chunk types.  If you need to add a chunk,
3039  * define the name here, and add an invocation of the macro in png.c and
3040  * wherever it's needed.
3041  */
3042 #define PNG_IHDR png_byte png_IHDR[5] = { 73,  72,  68,  82, '\0'}
3043 #define PNG_IDAT png_byte png_IDAT[5] = { 73,  68,  65,  84, '\0'}
3044 #define PNG_IEND png_byte png_IEND[5] = { 73,  69,  78,  68, '\0'}
3045 #define PNG_PLTE png_byte png_PLTE[5] = { 80,  76,  84,  69, '\0'}
3046 #define PNG_bKGD png_byte png_bKGD[5] = { 98,  75,  71,  68, '\0'}
3047 #define PNG_cHRM png_byte png_cHRM[5] = { 99,  72,  82,  77, '\0'}
3048 #define PNG_gAMA png_byte png_gAMA[5] = {103,  65,  77,  65, '\0'}
3049 #define PNG_hIST png_byte png_hIST[5] = {104,  73,  83,  84, '\0'}
3050 #define PNG_iCCP png_byte png_iCCP[5] = {105,  67,  67,  80, '\0'}
3051 #define PNG_iTXt png_byte png_iTXt[5] = {105,  84,  88, 116, '\0'}
3052 #define PNG_oFFs png_byte png_oFFs[5] = {111,  70,  70, 115, '\0'}
3053 #define PNG_pCAL png_byte png_pCAL[5] = {112,  67,  65,  76, '\0'}
3054 #define PNG_sCAL png_byte png_sCAL[5] = {115,  67,  65,  76, '\0'}
3055 #define PNG_pHYs png_byte png_pHYs[5] = {112,  72,  89, 115, '\0'}
3056 #define PNG_sBIT png_byte png_sBIT[5] = {115,  66,  73,  84, '\0'}
3057 #define PNG_sPLT png_byte png_sPLT[5] = {115,  80,  76,  84, '\0'}
3058 #define PNG_sRGB png_byte png_sRGB[5] = {115,  82,  71,  66, '\0'}
3059 #define PNG_tEXt png_byte png_tEXt[5] = {116,  69,  88, 116, '\0'}
3060 #define PNG_tIME png_byte png_tIME[5] = {116,  73,  77,  69, '\0'}
3061 #define PNG_tRNS png_byte png_tRNS[5] = {116,  82,  78,  83, '\0'}
3062 #define PNG_zTXt png_byte png_zTXt[5] = {122,  84,  88, 116, '\0'}
3063 
3064 #ifdef PNG_USE_GLOBAL_ARRAYS
3065 PNG_EXPORT_VAR (png_byte FARDATA) png_IHDR[5];
3066 PNG_EXPORT_VAR (png_byte FARDATA) png_IDAT[5];
3067 PNG_EXPORT_VAR (png_byte FARDATA) png_IEND[5];
3068 PNG_EXPORT_VAR (png_byte FARDATA) png_PLTE[5];
3069 PNG_EXPORT_VAR (png_byte FARDATA) png_bKGD[5];
3070 PNG_EXPORT_VAR (png_byte FARDATA) png_cHRM[5];
3071 PNG_EXPORT_VAR (png_byte FARDATA) png_gAMA[5];
3072 PNG_EXPORT_VAR (png_byte FARDATA) png_hIST[5];
3073 PNG_EXPORT_VAR (png_byte FARDATA) png_iCCP[5];
3074 PNG_EXPORT_VAR (png_byte FARDATA) png_iTXt[5];
3075 PNG_EXPORT_VAR (png_byte FARDATA) png_oFFs[5];
3076 PNG_EXPORT_VAR (png_byte FARDATA) png_pCAL[5];
3077 PNG_EXPORT_VAR (png_byte FARDATA) png_sCAL[5];
3078 PNG_EXPORT_VAR (png_byte FARDATA) png_pHYs[5];
3079 PNG_EXPORT_VAR (png_byte FARDATA) png_sBIT[5];
3080 PNG_EXPORT_VAR (png_byte FARDATA) png_sPLT[5];
3081 PNG_EXPORT_VAR (png_byte FARDATA) png_sRGB[5];
3082 PNG_EXPORT_VAR (png_byte FARDATA) png_tEXt[5];
3083 PNG_EXPORT_VAR (png_byte FARDATA) png_tIME[5];
3084 PNG_EXPORT_VAR (png_byte FARDATA) png_tRNS[5];
3085 PNG_EXPORT_VAR (png_byte FARDATA) png_zTXt[5];
3086 #endif /* PNG_USE_GLOBAL_ARRAYS */
3087 
3088 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
3089 /* Initialize png_ptr struct for reading, and allocate any other memory.
3090  * (old interface - DEPRECATED - use png_create_read_struct instead).
3091  */
3092 extern PNG_EXPORT(void,png_read_init) PNGARG((png_structp png_ptr))
3093     PNG_DEPRECATED;
3094 #undef png_read_init
3095 #define png_read_init(png_ptr) png_read_init_3(&png_ptr, \
3096     PNG_LIBPNG_VER_STRING,  png_sizeof(png_struct));
3097 #endif
3098 
3099 extern PNG_EXPORT(void,png_read_init_3) PNGARG((png_structpp ptr_ptr,
3100     png_const_charp user_png_ver, png_size_t png_struct_size));
3101 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
3102 extern PNG_EXPORT(void,png_read_init_2) PNGARG((png_structp png_ptr,
3103     png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
3104     png_info_size));
3105 #endif
3106 
3107 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
3108 /* Initialize png_ptr struct for writing, and allocate any other memory.
3109  * (old interface - DEPRECATED - use png_create_write_struct instead).
3110  */
3111 extern PNG_EXPORT(void,png_write_init) PNGARG((png_structp png_ptr))
3112     PNG_DEPRECATED;
3113 #undef png_write_init
3114 #define png_write_init(png_ptr) png_write_init_3(&png_ptr, \
3115     PNG_LIBPNG_VER_STRING, png_sizeof(png_struct));
3116 #endif
3117 
3118 extern PNG_EXPORT(void,png_write_init_3) PNGARG((png_structpp ptr_ptr,
3119     png_const_charp user_png_ver, png_size_t png_struct_size));
3120 extern PNG_EXPORT(void,png_write_init_2) PNGARG((png_structp png_ptr,
3121     png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
3122     png_info_size));
3123 
3124 /* Allocate memory for an internal libpng struct */
3125 PNG_EXTERN png_voidp png_create_struct PNGARG((int type)) PNG_PRIVATE;
3126 
3127 /* Free memory from internal libpng struct */
3128 PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr)) PNG_PRIVATE;
3129 
3130 PNG_EXTERN png_voidp png_create_struct_2 PNGARG((int type, png_malloc_ptr
3131   malloc_fn, png_voidp mem_ptr)) PNG_PRIVATE;
3132 PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr,
3133    png_free_ptr free_fn, png_voidp mem_ptr)) PNG_PRIVATE;
3134 
3135 /* Free any memory that info_ptr points to and reset struct. */
3136 PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr,
3137    png_infop info_ptr)) PNG_PRIVATE;
3138 
3139 #ifndef PNG_1_0_X
3140 /* Function to allocate memory for zlib. */
3141 PNG_EXTERN voidpf png_zalloc PNGARG((voidpf png_ptr, uInt items,
3142    uInt size)) PNG_PRIVATE;
3143 
3144 /* Function to free memory for zlib */
3145 PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr)) PNG_PRIVATE;
3146 
3147 #ifdef PNG_SIZE_T
3148 /* Function to convert a sizeof an item to png_sizeof item */
3149    PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size))
3150       PNG_PRIVATE;
3151 #endif
3152 
3153 /* Next four functions are used internally as callbacks.  PNGAPI is required
3154  * but not PNG_EXPORT.  PNGAPI added at libpng version 1.2.3.
3155  */
3156 
3157 PNG_EXTERN void PNGAPI png_default_read_data PNGARG((png_structp png_ptr,
3158    png_bytep data, png_size_t length)) PNG_PRIVATE;
3159 
3160 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3161 PNG_EXTERN void PNGAPI png_push_fill_buffer PNGARG((png_structp png_ptr,
3162    png_bytep buffer, png_size_t length)) PNG_PRIVATE;
3163 #endif
3164 
3165 PNG_EXTERN void PNGAPI png_default_write_data PNGARG((png_structp png_ptr,
3166    png_bytep data, png_size_t length)) PNG_PRIVATE;
3167 
3168 #ifdef PNG_WRITE_FLUSH_SUPPORTED
3169 #ifdef PNG_STDIO_SUPPORTED
3170 PNG_EXTERN void PNGAPI png_default_flush PNGARG((png_structp png_ptr))
3171    PNG_PRIVATE;
3172 #endif
3173 #endif
3174 #else /* PNG_1_0_X */
3175 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3176 PNG_EXTERN void png_push_fill_buffer PNGARG((png_structp png_ptr,
3177    png_bytep buffer, png_size_t length)) PNG_PRIVATE;
3178 #endif
3179 #endif /* PNG_1_0_X */
3180 
3181 /* Reset the CRC variable */
3182 PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3183 
3184 /* Write the "data" buffer to whatever output you are using. */
3185 PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr, png_bytep data,
3186    png_size_t length)) PNG_PRIVATE;
3187 
3188 /* Read data from whatever input you are using into the "data" buffer */
3189 PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data,
3190    png_size_t length)) PNG_PRIVATE;
3191 
3192 /* Read bytes into buf, and update png_ptr->crc */
3193 PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
3194    png_size_t length)) PNG_PRIVATE;
3195 
3196 /* Decompress data in a chunk that uses compression */
3197 #if defined(PNG_zTXt_SUPPORTED) || defined(PNG_iTXt_SUPPORTED) || \
3198     defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED)
3199 PNG_EXTERN void png_decompress_chunk PNGARG((png_structp png_ptr,
3200    int comp_type, png_size_t chunklength,
3201    png_size_t prefix_length, png_size_t *data_length)) PNG_PRIVATE;
3202 #endif
3203 
3204 /* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
3205 PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip)
3206    PNG_PRIVATE);
3207 
3208 /* Read the CRC from the file and compare it to the libpng calculated CRC */
3209 PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3210 
3211 /* Calculate the CRC over a section of data.  Note that we are only
3212  * passing a maximum of 64K on systems that have this as a memory limit,
3213  * since this is the maximum buffer size we can specify.
3214  */
3215 PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr, png_bytep ptr,
3216    png_size_t length)) PNG_PRIVATE;
3217 
3218 #ifdef PNG_WRITE_FLUSH_SUPPORTED
3219 PNG_EXTERN void png_flush PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3220 #endif
3221 
3222 /* Simple function to write the signature */
3223 PNG_EXTERN void png_write_sig PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3224 
3225 /* Write various chunks */
3226 
3227 /* Write the IHDR chunk, and update the png_struct with the necessary
3228  * information.
3229  */
3230 PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width,
3231    png_uint_32 height,
3232    int bit_depth, int color_type, int compression_method, int filter_method,
3233    int interlace_method)) PNG_PRIVATE;
3234 
3235 PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr, png_colorp palette,
3236    png_uint_32 num_pal)) PNG_PRIVATE;
3237 
3238 PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data,
3239    png_size_t length)) PNG_PRIVATE;
3240 
3241 PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3242 
3243 #ifdef PNG_WRITE_gAMA_SUPPORTED
3244 #ifdef PNG_FLOATING_POINT_SUPPORTED
3245 PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma))
3246     PNG_PRIVATE;
3247 #endif
3248 #ifdef PNG_FIXED_POINT_SUPPORTED
3249 PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr,
3250     png_fixed_point file_gamma)) PNG_PRIVATE;
3251 #endif
3252 #endif
3253 
3254 #ifdef PNG_WRITE_sBIT_SUPPORTED
3255 PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr, png_color_8p sbit,
3256    int color_type)) PNG_PRIVATE;
3257 #endif
3258 
3259 #ifdef PNG_WRITE_cHRM_SUPPORTED
3260 #ifdef PNG_FLOATING_POINT_SUPPORTED
3261 PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr,
3262    double white_x, double white_y,
3263    double red_x, double red_y, double green_x, double green_y,
3264    double blue_x, double blue_y)) PNG_PRIVATE;
3265 #endif
3266 #ifdef PNG_FIXED_POINT_SUPPORTED
3267 PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr,
3268    png_fixed_point int_white_x, png_fixed_point int_white_y,
3269    png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
3270    int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
3271    png_fixed_point int_blue_y)) PNG_PRIVATE;
3272 #endif
3273 #endif
3274 
3275 #ifdef PNG_WRITE_sRGB_SUPPORTED
3276 PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
3277    int intent)) PNG_PRIVATE;
3278 #endif
3279 
3280 #ifdef PNG_WRITE_iCCP_SUPPORTED
3281 PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr,
3282    png_charp name, int compression_type,
3283    png_charp profile, int proflen)) PNG_PRIVATE;
3284    /* Note to maintainer: profile should be png_bytep */
3285 #endif
3286 
3287 #ifdef PNG_WRITE_sPLT_SUPPORTED
3288 PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr,
3289    png_sPLT_tp palette)) PNG_PRIVATE;
3290 #endif
3291 
3292 #ifdef PNG_WRITE_tRNS_SUPPORTED
3293 PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr, png_bytep trans,
3294    png_color_16p values, int number, int color_type)) PNG_PRIVATE;
3295 #endif
3296 
3297 #ifdef PNG_WRITE_bKGD_SUPPORTED
3298 PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr,
3299    png_color_16p values, int color_type)) PNG_PRIVATE;
3300 #endif
3301 
3302 #ifdef PNG_WRITE_hIST_SUPPORTED
3303 PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, png_uint_16p hist,
3304    int num_hist)) PNG_PRIVATE;
3305 #endif
3306 
3307 #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
3308     defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
3309 PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
3310    png_charp key, png_charpp new_key)) PNG_PRIVATE;
3311 #endif
3312 
3313 #ifdef PNG_WRITE_tEXt_SUPPORTED
3314 PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_charp key,
3315    png_charp text, png_size_t text_len)) PNG_PRIVATE;
3316 #endif
3317 
3318 #ifdef PNG_WRITE_zTXt_SUPPORTED
3319 PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_charp key,
3320    png_charp text, png_size_t text_len, int compression)) PNG_PRIVATE;
3321 #endif
3322 
3323 #ifdef PNG_WRITE_iTXt_SUPPORTED
3324 PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr,
3325    int compression, png_charp key, png_charp lang, png_charp lang_key,
3326    png_charp text)) PNG_PRIVATE;
3327 #endif
3328 
3329 #ifdef PNG_TEXT_SUPPORTED  /* Added at version 1.0.14 and 1.2.4 */
3330 PNG_EXTERN int png_set_text_2 PNGARG((png_structp png_ptr,
3331    png_infop info_ptr, png_textp text_ptr, int num_text)) PNG_PRIVATE;
3332 #endif
3333 
3334 #ifdef PNG_WRITE_oFFs_SUPPORTED
3335 PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr,
3336    png_int_32 x_offset, png_int_32 y_offset, int unit_type)) PNG_PRIVATE;
3337 #endif
3338 
3339 #ifdef PNG_WRITE_pCAL_SUPPORTED
3340 PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose,
3341    png_int_32 X0, png_int_32 X1, int type, int nparams,
3342    png_charp units, png_charpp params)) PNG_PRIVATE;
3343 #endif
3344 
3345 #ifdef PNG_WRITE_pHYs_SUPPORTED
3346 PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr,
3347    png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
3348    int unit_type)) PNG_PRIVATE;
3349 #endif
3350 
3351 #ifdef PNG_WRITE_tIME_SUPPORTED
3352 PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr,
3353    png_timep mod_time)) PNG_PRIVATE;
3354 #endif
3355 
3356 #ifdef PNG_WRITE_sCAL_SUPPORTED
3357 #if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
3358 PNG_EXTERN void png_write_sCAL PNGARG((png_structp png_ptr,
3359    int unit, double width, double height)) PNG_PRIVATE;
3360 #else
3361 #ifdef PNG_FIXED_POINT_SUPPORTED
3362 PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr,
3363    int unit, png_charp width, png_charp height)) PNG_PRIVATE;
3364 #endif
3365 #endif
3366 #endif
3367 
3368 /* Called when finished processing a row of data */
3369 PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3370 
3371 /* Internal use only.   Called before first row of data */
3372 PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3373 
3374 #ifdef PNG_READ_GAMMA_SUPPORTED
3375 PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3376 #endif
3377 
3378 /* Combine a row of data, dealing with alpha, etc. if requested */
3379 PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row,
3380    int mask)) PNG_PRIVATE;
3381 
3382 #ifdef PNG_READ_INTERLACING_SUPPORTED
3383 /* Expand an interlaced row */
3384 /* OLD pre-1.0.9 interface:
3385 PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info,
3386    png_bytep row, int pass, png_uint_32 transformations)) PNG_PRIVATE;
3387  */
3388 PNG_EXTERN void png_do_read_interlace PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3389 #endif
3390 
3391 /* GRR TO DO (2.0 or whenever):  simplify other internal calling interfaces */
3392 
3393 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
3394 /* Grab pixels out of a row for an interlaced pass */
3395 PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info,
3396    png_bytep row, int pass)) PNG_PRIVATE;
3397 #endif
3398 
3399 /* Unfilter a row */
3400 PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr,
3401    png_row_infop row_info, png_bytep row, png_bytep prev_row,
3402    int filter)) PNG_PRIVATE;
3403 
3404 /* Choose the best filter to use and filter the row data */
3405 PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
3406    png_row_infop row_info)) PNG_PRIVATE;
3407 
3408 /* Write out the filtered row. */
3409 PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr,
3410    png_bytep filtered_row)) PNG_PRIVATE;
3411 /* Finish a row while reading, dealing with interlacing passes, etc. */
3412 PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
3413 
3414 /* Initialize the row buffers, etc. */
3415 PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3416 /* Optional call to update the users info structure */
3417 PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
3418    png_infop info_ptr)) PNG_PRIVATE;
3419 
3420 /* These are the functions that do the transformations */
3421 #ifdef PNG_READ_FILLER_SUPPORTED
3422 PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info,
3423    png_bytep row, png_uint_32 filler, png_uint_32 flags)) PNG_PRIVATE;
3424 #endif
3425 
3426 #ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
3427 PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info,
3428    png_bytep row)) PNG_PRIVATE;
3429 #endif
3430 
3431 #ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
3432 PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info,
3433    png_bytep row)) PNG_PRIVATE;
3434 #endif
3435 
3436 #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
3437 PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info,
3438    png_bytep row)) PNG_PRIVATE;
3439 #endif
3440 
3441 #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
3442 PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info,
3443    png_bytep row)) PNG_PRIVATE;
3444 #endif
3445 
3446 #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
3447     defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
3448 PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info,
3449    png_bytep row, png_uint_32 flags)) PNG_PRIVATE;
3450 #endif
3451 
3452 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
3453 PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info,
3454     png_bytep row)) PNG_PRIVATE;
3455 #endif
3456 
3457 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
3458 PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info,
3459     png_bytep row)) PNG_PRIVATE;
3460 #endif
3461 
3462 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
3463 PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr, png_row_infop
3464    row_info, png_bytep row)) PNG_PRIVATE;
3465 #endif
3466 
3467 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
3468 PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info,
3469    png_bytep row)) PNG_PRIVATE;
3470 #endif
3471 
3472 #ifdef PNG_READ_PACK_SUPPORTED
3473 PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info,
3474     png_bytep row)) PNG_PRIVATE;
3475 #endif
3476 
3477 #ifdef PNG_READ_SHIFT_SUPPORTED
3478 PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info, png_bytep row,
3479    png_color_8p sig_bits)) PNG_PRIVATE;
3480 #endif
3481 
3482 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
3483 PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info,
3484     png_bytep row)) PNG_PRIVATE;
3485 #endif
3486 
3487 #ifdef PNG_READ_16_TO_8_SUPPORTED
3488 PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info,
3489     png_bytep row)) PNG_PRIVATE;
3490 #endif
3491 
3492 #ifdef PNG_READ_DITHER_SUPPORTED
3493 PNG_EXTERN void png_do_dither PNGARG((png_row_infop row_info,
3494    png_bytep row, png_bytep palette_lookup,
3495     png_bytep dither_lookup)) PNG_PRIVATE;
3496 
3497 #  ifdef PNG_CORRECT_PALETTE_SUPPORTED
3498 PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr,
3499    png_colorp palette, int num_palette)) PNG_PRIVATE;
3500 #  endif
3501 #endif
3502 
3503 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
3504 PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info,
3505     png_bytep row)) PNG_PRIVATE;
3506 #endif
3507 
3508 #ifdef PNG_WRITE_PACK_SUPPORTED
3509 PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info,
3510    png_bytep row, png_uint_32 bit_depth)) PNG_PRIVATE;
3511 #endif
3512 
3513 #ifdef PNG_WRITE_SHIFT_SUPPORTED
3514 PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info, png_bytep row,
3515    png_color_8p bit_depth)) PNG_PRIVATE;
3516 #endif
3517 
3518 #ifdef PNG_READ_BACKGROUND_SUPPORTED
3519 #ifdef PNG_READ_GAMMA_SUPPORTED
3520 PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
3521    png_color_16p trans_values, png_color_16p background,
3522    png_color_16p background_1,
3523    png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,
3524    png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,
3525    png_uint_16pp gamma_16_to_1, int gamma_shift)) PNG_PRIVATE;
3526 #else
3527 PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
3528    png_color_16p trans_values, png_color_16p background)) PNG_PRIVATE;
3529 #endif
3530 #endif
3531 
3532 #ifdef PNG_READ_GAMMA_SUPPORTED
3533 PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info, png_bytep row,
3534    png_bytep gamma_table, png_uint_16pp gamma_16_table,
3535    int gamma_shift)) PNG_PRIVATE;
3536 #endif
3537 
3538 #ifdef PNG_READ_EXPAND_SUPPORTED
3539 PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info,
3540    png_bytep row, png_colorp palette, png_bytep trans,
3541    int num_trans)) PNG_PRIVATE;
3542 PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info,
3543    png_bytep row, png_color_16p trans_value)) PNG_PRIVATE;
3544 #endif
3545 
3546 /* The following decodes the appropriate chunks, and does error correction,
3547  * then calls the appropriate callback for the chunk if it is valid.
3548  */
3549 
3550 /* Decode the IHDR chunk */
3551 PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr,
3552    png_uint_32 length)) PNG_PRIVATE;
3553 PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr,
3554    png_uint_32 length));
3555 PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr,
3556    png_uint_32 length));
3557 
3558 #ifdef PNG_READ_bKGD_SUPPORTED
3559 PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr,
3560    png_uint_32 length)) PNG_PRIVATE;
3561 #endif
3562 
3563 #ifdef PNG_READ_cHRM_SUPPORTED
3564 PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr,
3565    png_uint_32 length)) PNG_PRIVATE;
3566 #endif
3567 
3568 #ifdef PNG_READ_gAMA_SUPPORTED
3569 PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr,
3570    png_uint_32 length)) PNG_PRIVATE;
3571 #endif
3572 
3573 #ifdef PNG_READ_hIST_SUPPORTED
3574 PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr,
3575    png_uint_32 length)) PNG_PRIVATE;
3576 #endif
3577 
3578 #ifdef PNG_READ_iCCP_SUPPORTED
3579 extern void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr,
3580    png_uint_32 length));
3581 #endif /* PNG_READ_iCCP_SUPPORTED */
3582 
3583 #ifdef PNG_READ_iTXt_SUPPORTED
3584 PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3585    png_uint_32 length)) PNG_PRIVATE;
3586 #endif
3587 
3588 #ifdef PNG_READ_oFFs_SUPPORTED
3589 PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr,
3590    png_uint_32 length)) PNG_PRIVATE;
3591 #endif
3592 
3593 #ifdef PNG_READ_pCAL_SUPPORTED
3594 PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
3595    png_uint_32 length)) PNG_PRIVATE;
3596 #endif
3597 
3598 #ifdef PNG_READ_pHYs_SUPPORTED
3599 PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr,
3600    png_uint_32 length)) PNG_PRIVATE;
3601 #endif
3602 
3603 #ifdef PNG_READ_sBIT_SUPPORTED
3604 PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr,
3605    png_uint_32 length)) PNG_PRIVATE;
3606 #endif
3607 
3608 #ifdef PNG_READ_sCAL_SUPPORTED
3609 PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
3610    png_uint_32 length)) PNG_PRIVATE;
3611 #endif
3612 
3613 #ifdef PNG_READ_sPLT_SUPPORTED
3614 extern void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr,
3615    png_uint_32 length)) PNG_PRIVATE;
3616 #endif /* PNG_READ_sPLT_SUPPORTED */
3617 
3618 #ifdef PNG_READ_sRGB_SUPPORTED
3619 PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr,
3620    png_uint_32 length)) PNG_PRIVATE;
3621 #endif
3622 
3623 #ifdef PNG_READ_tEXt_SUPPORTED
3624 PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3625    png_uint_32 length)) PNG_PRIVATE;
3626 #endif
3627 
3628 #ifdef PNG_READ_tIME_SUPPORTED
3629 PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr,
3630    png_uint_32 length)) PNG_PRIVATE;
3631 #endif
3632 
3633 #ifdef PNG_READ_tRNS_SUPPORTED
3634 PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr,
3635    png_uint_32 length)) PNG_PRIVATE;
3636 #endif
3637 
3638 #ifdef PNG_READ_zTXt_SUPPORTED
3639 PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3640    png_uint_32 length)) PNG_PRIVATE;
3641 #endif
3642 
3643 PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
3644    png_infop info_ptr, png_uint_32 length)) PNG_PRIVATE;
3645 
3646 PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
3647    png_bytep chunk_name)) PNG_PRIVATE;
3648 
3649 /* Handle the transformations for reading and writing */
3650 PNG_EXTERN void png_do_read_transformations
3651    PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3652 PNG_EXTERN void png_do_write_transformations
3653    PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3654 
3655 PNG_EXTERN void png_init_read_transformations
3656    PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3657 
3658 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3659 PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
3660    png_infop info_ptr)) PNG_PRIVATE;
3661 PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr,
3662    png_infop info_ptr)) PNG_PRIVATE;
3663 PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3664 PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr,
3665    png_uint_32 length)) PNG_PRIVATE;
3666 PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3667 PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3668 PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr,
3669    png_bytep buffer, png_size_t buffer_length)) PNG_PRIVATE;
3670 PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3671 PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr,
3672    png_bytep buffer, png_size_t buffer_length)) PNG_PRIVATE;
3673 PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3674 PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr,
3675    png_infop info_ptr, png_uint_32 length)) PNG_PRIVATE;
3676 PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr,
3677    png_infop info_ptr)) PNG_PRIVATE;
3678 PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr,
3679    png_infop info_ptr)) PNG_PRIVATE;
3680 PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr,
3681    png_bytep row)) PNG_PRIVATE;
3682 PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr,
3683    png_infop info_ptr)) PNG_PRIVATE;
3684 PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr,
3685    png_infop info_ptr)) PNG_PRIVATE;
3686 PNG_EXTERN void png_read_push_finish_row
3687    PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3688 #ifdef PNG_READ_tEXt_SUPPORTED
3689 PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr,
3690    png_infop info_ptr, png_uint_32 length)) PNG_PRIVATE;
3691 PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr,
3692    png_infop info_ptr)) PNG_PRIVATE;
3693 #endif
3694 #ifdef PNG_READ_zTXt_SUPPORTED
3695 PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr,
3696    png_infop info_ptr, png_uint_32 length)) PNG_PRIVATE;
3697 PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr,
3698    png_infop info_ptr)) PNG_PRIVATE;
3699 #endif
3700 #ifdef PNG_READ_iTXt_SUPPORTED
3701 PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr,
3702    png_infop info_ptr, png_uint_32 length)) PNG_PRIVATE;
3703 PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr,
3704    png_infop info_ptr)) PNG_PRIVATE;
3705 #endif
3706 
3707 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
3708 
3709 #ifdef PNG_MNG_FEATURES_SUPPORTED
3710 PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info,
3711    png_bytep row)) PNG_PRIVATE;
3712 PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info,
3713    png_bytep row)) PNG_PRIVATE;
3714 #endif
3715 
3716 #ifdef PNG_ASSEMBLER_CODE_SUPPORTED
3717 #ifdef PNG_MMX_CODE_SUPPORTED
3718 /* png.c */ /* PRIVATE */
3719 PNG_EXTERN void png_init_mmx_flags PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3720 #endif
3721 #endif
3722 
3723 
3724 /* The following six functions will be exported in libpng-1.4.0. */
3725 #if defined(PNG_INCH_CONVERSIONS) && defined(PNG_FLOATING_POINT_SUPPORTED)
3726 PNG_EXTERN png_uint_32 png_get_pixels_per_inch PNGARG((png_structp png_ptr,
3727 png_infop info_ptr));
3728 
3729 PNG_EXTERN png_uint_32 png_get_x_pixels_per_inch PNGARG((png_structp png_ptr,
3730 png_infop info_ptr));
3731 
3732 PNG_EXTERN png_uint_32 png_get_y_pixels_per_inch PNGARG((png_structp png_ptr,
3733 png_infop info_ptr));
3734 
3735 PNG_EXTERN float png_get_x_offset_inches PNGARG((png_structp png_ptr,
3736 png_infop info_ptr));
3737 
3738 PNG_EXTERN float png_get_y_offset_inches PNGARG((png_structp png_ptr,
3739 png_infop info_ptr));
3740 
3741 #ifdef PNG_pHYs_SUPPORTED
3742 PNG_EXTERN png_uint_32 png_get_pHYs_dpi PNGARG((png_structp png_ptr,
3743 png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
3744 #endif /* PNG_pHYs_SUPPORTED */
3745 #endif  /* PNG_INCH_CONVERSIONS && PNG_FLOATING_POINT_SUPPORTED */
3746 
3747 /* Read the chunk header (length + type name) */
3748 PNG_EXTERN png_uint_32 png_read_chunk_header
3749    PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3750 
3751 /* Added at libpng version 1.2.34 */
3752 #ifdef PNG_cHRM_SUPPORTED
3753 PNG_EXTERN int png_check_cHRM_fixed PNGARG((png_structp png_ptr,
3754    png_fixed_point int_white_x, png_fixed_point int_white_y,
3755    png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
3756    int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
3757    png_fixed_point int_blue_y)) PNG_PRIVATE;
3758 #endif
3759 
3760 #ifdef PNG_cHRM_SUPPORTED
3761 #ifdef PNG_CHECK_cHRM_SUPPORTED
3762 /* Added at libpng version 1.2.34 */
3763 PNG_EXTERN void png_64bit_product PNGARG((long v1, long v2,
3764    unsigned long *hi_product, unsigned long *lo_product)) PNG_PRIVATE;
3765 #endif
3766 #endif
3767 
3768 /* Added at libpng version 1.2.41 */
3769 PNG_EXTERN void png_check_IHDR PNGARG((png_structp png_ptr,
3770    png_uint_32 width, png_uint_32 height, int bit_depth,
3771    int color_type, int interlace_type, int compression_type,
3772    int filter_type)) PNG_PRIVATE;
3773 
3774 /* Added at libpng version 1.2.41 */
3775 PNG_EXTERN png_voidp png_calloc PNGARG((png_structp png_ptr,
3776    png_uint_32 size));
3777 
3778 /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
3779 
3780 #endif /* PNG_INTERNAL */
3781 
3782 #ifdef __cplusplus
3783 }
3784 #endif
3785 
3786 #endif /* PNG_VERSION_INFO_ONLY */
3787 /* Do not put anything past this line */
3788 #endif /* PNG_H */
3789