1/* png.h - header file for PNG reference library
2 *
3 * libpng version 1.2.45 - July 7, 2011
4 * Copyright (c) 1998-2011 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 1.2.45 - July 7, 2011: 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 *    1.0.45                  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 *    1.2.45beta01-03         13    10245  12.so.0.45[.0]
266 *    1.0.55rc01              13    10055  10.so.0.55[.0]
267 *    1.2.45rc01              13    10245  12.so.0.45[.0]
268 *    1.0.55                  13    10055  10.so.0.55[.0]
269 *    1.2.45                  13    10245  12.so.0.45[.0]
270 *
271 *    Henceforth the source version will match the shared-library major
272 *    and minor numbers; the shared-library major version number will be
273 *    used for changes in backward compatibility, as it is intended.  The
274 *    PNG_LIBPNG_VER macro, which is not used within libpng but is available
275 *    for applications, is an unsigned integer of the form xyyzz corresponding
276 *    to the source version x.y.z (leading zeros in y and z).  Beta versions
277 *    were given the previous public release number plus a letter, until
278 *    version 1.0.6j; from then on they were given the upcoming public
279 *    release number plus "betaNN" or "rcNN".
280 *
281 *    Binary incompatibility exists only when applications make direct access
282 *    to the info_ptr or png_ptr members through png.h, and the compiled
283 *    application is loaded with a different version of the library.
284 *
285 *    DLLNUM will change each time there are forward or backward changes
286 *    in binary compatibility (e.g., when a new feature is added).
287 *
288 * See libpng.txt or libpng.3 for more information.  The PNG specification
289 * is available as a W3C Recommendation and as an ISO Specification,
290 * <http://www.w3.org/TR/2003/REC-PNG-20031110/
291 */
292
293/*
294 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
295 *
296 * If you modify libpng you may insert additional notices immediately following
297 * this sentence.
298 *
299 * This code is released under the libpng license.
300 *
301 * libpng versions 1.2.6, August 15, 2004, through 1.2.45, July 7, 2011, are
302 * Copyright (c) 2004, 2006-2010 Glenn Randers-Pehrson, and are
303 * distributed according to the same disclaimer and license as libpng-1.2.5
304 * with the following individual added to the list of Contributing Authors:
305 *
306 *    Cosmin Truta
307 *
308 * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
309 * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
310 * distributed according to the same disclaimer and license as libpng-1.0.6
311 * with the following individuals added to the list of Contributing Authors:
312 *
313 *    Simon-Pierre Cadieux
314 *    Eric S. Raymond
315 *    Gilles Vollant
316 *
317 * and with the following additions to the disclaimer:
318 *
319 *    There is no warranty against interference with your enjoyment of the
320 *    library or against infringement.  There is no warranty that our
321 *    efforts or the library will fulfill any of your particular purposes
322 *    or needs.  This library is provided with all faults, and the entire
323 *    risk of satisfactory quality, performance, accuracy, and effort is with
324 *    the user.
325 *
326 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
327 * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are
328 * distributed according to the same disclaimer and license as libpng-0.96,
329 * with the following individuals added to the list of Contributing Authors:
330 *
331 *    Tom Lane
332 *    Glenn Randers-Pehrson
333 *    Willem van Schaik
334 *
335 * libpng versions 0.89, June 1996, through 0.96, May 1997, are
336 * Copyright (c) 1996, 1997 Andreas Dilger
337 * Distributed according to the same disclaimer and license as libpng-0.88,
338 * with the following individuals added to the list of Contributing Authors:
339 *
340 *    John Bowler
341 *    Kevin Bracey
342 *    Sam Bushell
343 *    Magnus Holmgren
344 *    Greg Roelofs
345 *    Tom Tanner
346 *
347 * libpng versions 0.5, May 1995, through 0.88, January 1996, are
348 * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
349 *
350 * For the purposes of this copyright and license, "Contributing Authors"
351 * is defined as the following set of individuals:
352 *
353 *    Andreas Dilger
354 *    Dave Martindale
355 *    Guy Eric Schalnat
356 *    Paul Schmidt
357 *    Tim Wegner
358 *
359 * The PNG Reference Library is supplied "AS IS".  The Contributing Authors
360 * and Group 42, Inc. disclaim all warranties, expressed or implied,
361 * including, without limitation, the warranties of merchantability and of
362 * fitness for any purpose.  The Contributing Authors and Group 42, Inc.
363 * assume no liability for direct, indirect, incidental, special, exemplary,
364 * or consequential damages, which may result from the use of the PNG
365 * Reference Library, even if advised of the possibility of such damage.
366 *
367 * Permission is hereby granted to use, copy, modify, and distribute this
368 * source code, or portions hereof, for any purpose, without fee, subject
369 * to the following restrictions:
370 *
371 * 1. The origin of this source code must not be misrepresented.
372 *
373 * 2. Altered versions must be plainly marked as such and
374 * must not be misrepresented as being the original source.
375 *
376 * 3. This Copyright notice may not be removed or altered from
377 *    any source or altered source distribution.
378 *
379 * The Contributing Authors and Group 42, Inc. specifically permit, without
380 * fee, and encourage the use of this source code as a component to
381 * supporting the PNG file format in commercial products.  If you use this
382 * source code in a product, acknowledgment is not required but would be
383 * appreciated.
384 */
385
386/*
387 * A "png_get_copyright" function is available, for convenient use in "about"
388 * boxes and the like:
389 *
390 * printf("%s",png_get_copyright(NULL));
391 *
392 * Also, the PNG logo (in PNG format, of course) is supplied in the
393 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
394 */
395
396/*
397 * Libpng is OSI Certified Open Source Software.  OSI Certified is a
398 * certification mark of the Open Source Initiative.
399 */
400
401/*
402 * The contributing authors would like to thank all those who helped
403 * with testing, bug fixes, and patience.  This wouldn't have been
404 * possible without all of you.
405 *
406 * Thanks to Frank J. T. Wojcik for helping with the documentation.
407 */
408
409/*
410 * Y2K compliance in libpng:
411 * =========================
412 *
413 *    July 7, 2011
414 *
415 *    Since the PNG Development group is an ad-hoc body, we can't make
416 *    an official declaration.
417 *
418 *    This is your unofficial assurance that libpng from version 0.71 and
419 *    upward through 1.2.45 are Y2K compliant.  It is my belief that earlier
420 *    versions were also Y2K compliant.
421 *
422 *    Libpng only has three year fields.  One is a 2-byte unsigned integer
423 *    that will hold years up to 65535.  The other two hold the date in text
424 *    format, and will hold years up to 9999.
425 *
426 *    The integer is
427 *        "png_uint_16 year" in png_time_struct.
428 *
429 *    The strings are
430 *        "png_charp time_buffer" in png_struct and
431 *        "near_time_buffer", which is a local character string in png.c.
432 *
433 *    There are seven time-related functions:
434 *        png.c: png_convert_to_rfc_1123() in png.c
435 *          (formerly png_convert_to_rfc_1152() in error)
436 *        png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
437 *        png_convert_from_time_t() in pngwrite.c
438 *        png_get_tIME() in pngget.c
439 *        png_handle_tIME() in pngrutil.c, called in pngread.c
440 *        png_set_tIME() in pngset.c
441 *        png_write_tIME() in pngwutil.c, called in pngwrite.c
442 *
443 *    All handle dates properly in a Y2K environment.  The
444 *    png_convert_from_time_t() function calls gmtime() to convert from system
445 *    clock time, which returns (year - 1900), which we properly convert to
446 *    the full 4-digit year.  There is a possibility that applications using
447 *    libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
448 *    function, or that they are incorrectly passing only a 2-digit year
449 *    instead of "year - 1900" into the png_convert_from_struct_tm() function,
450 *    but this is not under our control.  The libpng documentation has always
451 *    stated that it works with 4-digit years, and the APIs have been
452 *    documented as such.
453 *
454 *    The tIME chunk itself is also Y2K compliant.  It uses a 2-byte unsigned
455 *    integer to hold the year, and can hold years as large as 65535.
456 *
457 *    zlib, upon which libpng depends, is also Y2K compliant.  It contains
458 *    no date-related code.
459 *
460 *       Glenn Randers-Pehrson
461 *       libpng maintainer
462 *       PNG Development Group
463 */
464
465#ifndef PNG_H
466#define PNG_H
467
468/* This is not the place to learn how to use libpng.  The file libpng.txt
469 * describes how to use libpng, and the file example.c summarizes it
470 * with some code on which to build.  This file is useful for looking
471 * at the actual function definitions and structure components.
472 */
473
474/* Version information for png.h - this should match the version in png.c */
475#define PNG_LIBPNG_VER_STRING "1.2.45"
476#define PNG_HEADER_VERSION_STRING \
477   " libpng version 1.2.45 - July 7, 2011\n"
478
479#define PNG_LIBPNG_VER_SONUM   0
480#define PNG_LIBPNG_VER_DLLNUM  13
481
482/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
483#define PNG_LIBPNG_VER_MAJOR   1
484#define PNG_LIBPNG_VER_MINOR   2
485#define PNG_LIBPNG_VER_RELEASE 45
486/* This should match the numeric part of the final component of
487 * PNG_LIBPNG_VER_STRING, omitting any leading zero:
488 */
489
490#define PNG_LIBPNG_VER_BUILD  0
491
492/* Release Status */
493#define PNG_LIBPNG_BUILD_ALPHA    1
494#define PNG_LIBPNG_BUILD_BETA     2
495#define PNG_LIBPNG_BUILD_RC       3
496#define PNG_LIBPNG_BUILD_STABLE   4
497#define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
498
499/* Release-Specific Flags */
500#define PNG_LIBPNG_BUILD_PATCH    8 /* Can be OR'ed with
501                                       PNG_LIBPNG_BUILD_STABLE only */
502#define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
503                                       PNG_LIBPNG_BUILD_SPECIAL */
504#define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
505                                       PNG_LIBPNG_BUILD_PRIVATE */
506
507#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
508
509/* Careful here.  At one time, Guy wanted to use 082, but that would be octal.
510 * We must not include leading zeros.
511 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
512 * version 1.0.0 was mis-numbered 100 instead of 10000).  From
513 * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=release
514 */
515#define PNG_LIBPNG_VER 10245 /* 1.2.45 */
516
517#ifndef PNG_VERSION_INFO_ONLY
518/* Include the compression library's header */
519#include "zlib.h"
520#endif
521
522/* Include all user configurable info, including optional assembler routines */
523#include "pngconf.h"
524
525/*
526 * Added at libpng-1.2.8 */
527/* Ref MSDN: Private as priority over Special
528 * VS_FF_PRIVATEBUILD File *was not* built using standard release
529 * procedures. If this value is given, the StringFileInfo block must
530 * contain a PrivateBuild string.
531 *
532 * VS_FF_SPECIALBUILD File *was* built by the original company using
533 * standard release procedures but is a variation of the standard
534 * file of the same version number. If this value is given, the
535 * StringFileInfo block must contain a SpecialBuild string.
536 */
537
538#ifdef PNG_USER_PRIVATEBUILD
539#  define PNG_LIBPNG_BUILD_TYPE \
540          (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
541#else
542#  ifdef PNG_LIBPNG_SPECIALBUILD
543#    define PNG_LIBPNG_BUILD_TYPE \
544            (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
545#  else
546#    define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
547#  endif
548#endif
549
550#ifndef PNG_VERSION_INFO_ONLY
551
552/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
553#ifdef __cplusplus
554extern "C" {
555#endif /* __cplusplus */
556
557/* This file is arranged in several sections.  The first section contains
558 * structure and type definitions.  The second section contains the external
559 * library functions, while the third has the internal library functions,
560 * which applications aren't expected to use directly.
561 */
562
563#ifndef PNG_NO_TYPECAST_NULL
564#define int_p_NULL                (int *)NULL
565#define png_bytep_NULL            (png_bytep)NULL
566#define png_bytepp_NULL           (png_bytepp)NULL
567#define png_doublep_NULL          (png_doublep)NULL
568#define png_error_ptr_NULL        (png_error_ptr)NULL
569#define png_flush_ptr_NULL        (png_flush_ptr)NULL
570#define png_free_ptr_NULL         (png_free_ptr)NULL
571#define png_infopp_NULL           (png_infopp)NULL
572#define png_malloc_ptr_NULL       (png_malloc_ptr)NULL
573#define png_read_status_ptr_NULL  (png_read_status_ptr)NULL
574#define png_rw_ptr_NULL           (png_rw_ptr)NULL
575#define png_structp_NULL          (png_structp)NULL
576#define png_uint_16p_NULL         (png_uint_16p)NULL
577#define png_voidp_NULL            (png_voidp)NULL
578#define png_write_status_ptr_NULL (png_write_status_ptr)NULL
579#else
580#define int_p_NULL                NULL
581#define png_bytep_NULL            NULL
582#define png_bytepp_NULL           NULL
583#define png_doublep_NULL          NULL
584#define png_error_ptr_NULL        NULL
585#define png_flush_ptr_NULL        NULL
586#define png_free_ptr_NULL         NULL
587#define png_infopp_NULL           NULL
588#define png_malloc_ptr_NULL       NULL
589#define png_read_status_ptr_NULL  NULL
590#define png_rw_ptr_NULL           NULL
591#define png_structp_NULL          NULL
592#define png_uint_16p_NULL         NULL
593#define png_voidp_NULL            NULL
594#define png_write_status_ptr_NULL NULL
595#endif
596
597/* Variables declared in png.c - only it needs to define PNG_NO_EXTERN */
598#if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
599/* Version information for C files, stored in png.c.  This had better match
600 * the version above.
601 */
602#ifdef PNG_USE_GLOBAL_ARRAYS
603PNG_EXPORT_VAR (PNG_CONST char) png_libpng_ver[18];
604  /* Need room for 99.99.99beta99z */
605#else
606#define png_libpng_ver png_get_header_ver(NULL)
607#endif
608
609#ifdef PNG_USE_GLOBAL_ARRAYS
610/* This was removed in version 1.0.5c */
611/* Structures to facilitate easy interlacing.  See png.c for more details */
612PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_start[7];
613PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_inc[7];
614PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_ystart[7];
615PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_yinc[7];
616PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_mask[7];
617PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_dsp_mask[7];
618/* This isn't currently used.  If you need it, see png.c for more details.
619PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_height[7];
620*/
621#endif
622
623#endif /* PNG_NO_EXTERN */
624
625/* Three color definitions.  The order of the red, green, and blue, (and the
626 * exact size) is not important, although the size of the fields need to
627 * be png_byte or png_uint_16 (as defined below).
628 */
629typedef struct png_color_struct
630{
631   png_byte red;
632   png_byte green;
633   png_byte blue;
634} png_color;
635typedef png_color FAR * png_colorp;
636typedef png_color FAR * FAR * png_colorpp;
637
638typedef struct png_color_16_struct
639{
640   png_byte index;    /* used for palette files */
641   png_uint_16 red;   /* for use in red green blue files */
642   png_uint_16 green;
643   png_uint_16 blue;
644   png_uint_16 gray;  /* for use in grayscale files */
645} png_color_16;
646typedef png_color_16 FAR * png_color_16p;
647typedef png_color_16 FAR * FAR * png_color_16pp;
648
649typedef struct png_color_8_struct
650{
651   png_byte red;   /* for use in red green blue files */
652   png_byte green;
653   png_byte blue;
654   png_byte gray;  /* for use in grayscale files */
655   png_byte alpha; /* for alpha channel files */
656} png_color_8;
657typedef png_color_8 FAR * png_color_8p;
658typedef png_color_8 FAR * FAR * png_color_8pp;
659
660/*
661 * The following two structures are used for the in-core representation
662 * of sPLT chunks.
663 */
664typedef struct png_sPLT_entry_struct
665{
666   png_uint_16 red;
667   png_uint_16 green;
668   png_uint_16 blue;
669   png_uint_16 alpha;
670   png_uint_16 frequency;
671} png_sPLT_entry;
672typedef png_sPLT_entry FAR * png_sPLT_entryp;
673typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;
674
675/*  When the depth of the sPLT palette is 8 bits, the color and alpha samples
676 *  occupy the LSB of their respective members, and the MSB of each member
677 *  is zero-filled.  The frequency member always occupies the full 16 bits.
678 */
679
680typedef struct png_sPLT_struct
681{
682   png_charp name;           /* palette name */
683   png_byte depth;           /* depth of palette samples */
684   png_sPLT_entryp entries;  /* palette entries */
685   png_int_32 nentries;      /* number of palette entries */
686} png_sPLT_t;
687typedef png_sPLT_t FAR * png_sPLT_tp;
688typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
689
690#ifdef PNG_TEXT_SUPPORTED
691/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
692 * and whether that contents is compressed or not.  The "key" field
693 * points to a regular zero-terminated C string.  The "text", "lang", and
694 * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
695 * However, the * structure returned by png_get_text() will always contain
696 * regular zero-terminated C strings (possibly empty), never NULL pointers,
697 * so they can be safely used in printf() and other string-handling functions.
698 */
699typedef struct png_text_struct
700{
701   int  compression;       /* compression value:
702                             -1: tEXt, none
703                              0: zTXt, deflate
704                              1: iTXt, none
705                              2: iTXt, deflate  */
706   png_charp key;          /* keyword, 1-79 character description of "text" */
707   png_charp text;         /* comment, may be an empty string (ie "")
708                              or a NULL pointer */
709   png_size_t text_length; /* length of the text string */
710#ifdef PNG_iTXt_SUPPORTED
711   png_size_t itxt_length; /* length of the itxt string */
712   png_charp lang;         /* language code, 0-79 characters
713                              or a NULL pointer */
714   png_charp lang_key;     /* keyword translated UTF-8 string, 0 or more
715                              chars or a NULL pointer */
716#endif
717} png_text;
718typedef png_text FAR * png_textp;
719typedef png_text FAR * FAR * png_textpp;
720#endif
721
722/* Supported compression types for text in PNG files (tEXt, and zTXt).
723 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed.
724 */
725#define PNG_TEXT_COMPRESSION_NONE_WR -3
726#define PNG_TEXT_COMPRESSION_zTXt_WR -2
727#define PNG_TEXT_COMPRESSION_NONE    -1
728#define PNG_TEXT_COMPRESSION_zTXt     0
729#define PNG_ITXT_COMPRESSION_NONE     1
730#define PNG_ITXT_COMPRESSION_zTXt     2
731#define PNG_TEXT_COMPRESSION_LAST     3  /* Not a valid value */
732
733/* png_time is a way to hold the time in an machine independent way.
734 * Two conversions are provided, both from time_t and struct tm.  There
735 * is no portable way to convert to either of these structures, as far
736 * as I know.  If you know of a portable way, send it to me.  As a side
737 * note - PNG has always been Year 2000 compliant!
738 */
739typedef struct png_time_struct
740{
741   png_uint_16 year; /* full year, as in, 1995 */
742   png_byte month;   /* month of year, 1 - 12 */
743   png_byte day;     /* day of month, 1 - 31 */
744   png_byte hour;    /* hour of day, 0 - 23 */
745   png_byte minute;  /* minute of hour, 0 - 59 */
746   png_byte second;  /* second of minute, 0 - 60 (for leap seconds) */
747} png_time;
748typedef png_time FAR * png_timep;
749typedef png_time FAR * FAR * png_timepp;
750
751#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
752 defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
753/* png_unknown_chunk is a structure to hold queued chunks for which there is
754 * no specific support.  The idea is that we can use this to queue
755 * up private chunks for output even though the library doesn't actually
756 * know about their semantics.
757 */
758#define PNG_CHUNK_NAME_LENGTH 5
759typedef struct png_unknown_chunk_t
760{
761    png_byte name[PNG_CHUNK_NAME_LENGTH];
762    png_byte *data;
763    png_size_t size;
764
765    /* libpng-using applications should NOT directly modify this byte. */
766    png_byte location; /* mode of operation at read time */
767}
768png_unknown_chunk;
769typedef png_unknown_chunk FAR * png_unknown_chunkp;
770typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
771#endif
772
773/* png_info is a structure that holds the information in a PNG file so
774 * that the application can find out the characteristics of the image.
775 * If you are reading the file, this structure will tell you what is
776 * in the PNG file.  If you are writing the file, fill in the information
777 * you want to put into the PNG file, then call png_write_info().
778 * The names chosen should be very close to the PNG specification, so
779 * consult that document for information about the meaning of each field.
780 *
781 * With libpng < 0.95, it was only possible to directly set and read the
782 * the values in the png_info_struct, which meant that the contents and
783 * order of the values had to remain fixed.  With libpng 0.95 and later,
784 * however, there are now functions that abstract the contents of
785 * png_info_struct from the application, so this makes it easier to use
786 * libpng with dynamic libraries, and even makes it possible to use
787 * libraries that don't have all of the libpng ancillary chunk-handing
788 * functionality.
789 *
790 * In any case, the order of the parameters in png_info_struct should NOT
791 * be changed for as long as possible to keep compatibility with applications
792 * that use the old direct-access method with png_info_struct.
793 *
794 * The following members may have allocated storage attached that should be
795 * cleaned up before the structure is discarded: palette, trans, text,
796 * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
797 * splt_palettes, scal_unit, row_pointers, and unknowns.   By default, these
798 * are automatically freed when the info structure is deallocated, if they were
799 * allocated internally by libpng.  This behavior can be changed by means
800 * of the png_data_freer() function.
801 *
802 * More allocation details: all the chunk-reading functions that
803 * change these members go through the corresponding png_set_*
804 * functions.  A function to clear these members is available: see
805 * png_free_data().  The png_set_* functions do not depend on being
806 * able to point info structure members to any of the storage they are
807 * passed (they make their own copies), EXCEPT that the png_set_text
808 * functions use the same storage passed to them in the text_ptr or
809 * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
810 * functions do not make their own copies.
811 */
812typedef struct png_info_struct
813{
814   /* The following are necessary for every PNG file */
815   png_uint_32 width PNG_DEPSTRUCT;       /* width of image in pixels (from IHDR) */
816   png_uint_32 height PNG_DEPSTRUCT;      /* height of image in pixels (from IHDR) */
817   png_uint_32 valid PNG_DEPSTRUCT;       /* valid chunk data (see PNG_INFO_ below) */
818   png_uint_32 rowbytes PNG_DEPSTRUCT;    /* bytes needed to hold an untransformed row */
819   png_colorp palette PNG_DEPSTRUCT;      /* array of color values (valid & PNG_INFO_PLTE) */
820   png_uint_16 num_palette PNG_DEPSTRUCT; /* number of color entries in "palette" (PLTE) */
821   png_uint_16 num_trans PNG_DEPSTRUCT;   /* number of transparent palette color (tRNS) */
822   png_byte bit_depth PNG_DEPSTRUCT;      /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */
823   png_byte color_type PNG_DEPSTRUCT;     /* see PNG_COLOR_TYPE_ below (from IHDR) */
824   /* The following three should have been named *_method not *_type */
825   png_byte compression_type PNG_DEPSTRUCT; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */
826   png_byte filter_type PNG_DEPSTRUCT;    /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
827   png_byte interlace_type PNG_DEPSTRUCT; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
828
829   /* The following is informational only on read, and not used on writes. */
830   png_byte channels PNG_DEPSTRUCT;       /* number of data channels per pixel (1, 2, 3, 4) */
831   png_byte pixel_depth PNG_DEPSTRUCT;    /* number of bits per pixel */
832   png_byte spare_byte PNG_DEPSTRUCT;     /* to align the data, and for future use */
833   png_byte signature[8] PNG_DEPSTRUCT;   /* magic bytes read by libpng from start of file */
834
835   /* The rest of the data is optional.  If you are reading, check the
836    * valid field to see if the information in these are valid.  If you
837    * are writing, set the valid field to those chunks you want written,
838    * and initialize the appropriate fields below.
839    */
840
841#if defined(PNG_gAMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
842   /* The gAMA chunk describes the gamma characteristics of the system
843    * on which the image was created, normally in the range [1.0, 2.5].
844    * Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
845    */
846   float gamma PNG_DEPSTRUCT; /* gamma value of image, if (valid & PNG_INFO_gAMA) */
847#endif
848
849#ifdef PNG_sRGB_SUPPORTED
850    /* GR-P, 0.96a */
851    /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
852   png_byte srgb_intent PNG_DEPSTRUCT; /* sRGB rendering intent [0, 1, 2, or 3] */
853#endif
854
855#ifdef PNG_TEXT_SUPPORTED
856   /* The tEXt, and zTXt chunks contain human-readable textual data in
857    * uncompressed, compressed, and optionally compressed forms, respectively.
858    * The data in "text" is an array of pointers to uncompressed,
859    * null-terminated C strings. Each chunk has a keyword that describes the
860    * textual data contained in that chunk.  Keywords are not required to be
861    * unique, and the text string may be empty.  Any number of text chunks may
862    * be in an image.
863    */
864   int num_text PNG_DEPSTRUCT; /* number of comments read/to write */
865   int max_text PNG_DEPSTRUCT; /* current size of text array */
866   png_textp text PNG_DEPSTRUCT; /* array of comments read/to write */
867#endif /* PNG_TEXT_SUPPORTED */
868
869#ifdef PNG_tIME_SUPPORTED
870   /* The tIME chunk holds the last time the displayed image data was
871    * modified.  See the png_time struct for the contents of this struct.
872    */
873   png_time mod_time PNG_DEPSTRUCT;
874#endif
875
876#ifdef PNG_sBIT_SUPPORTED
877   /* The sBIT chunk specifies the number of significant high-order bits
878    * in the pixel data.  Values are in the range [1, bit_depth], and are
879    * only specified for the channels in the pixel data.  The contents of
880    * the low-order bits is not specified.  Data is valid if
881    * (valid & PNG_INFO_sBIT) is non-zero.
882    */
883   png_color_8 sig_bit PNG_DEPSTRUCT; /* significant bits in color channels */
884#endif
885
886#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
887defined(PNG_READ_BACKGROUND_SUPPORTED)
888   /* The tRNS chunk supplies transparency data for paletted images and
889    * other image types that don't need a full alpha channel.  There are
890    * "num_trans" transparency values for a paletted image, stored in the
891    * same order as the palette colors, starting from index 0.  Values
892    * for the data are in the range [0, 255], ranging from fully transparent
893    * to fully opaque, respectively.  For non-paletted images, there is a
894    * single color specified that should be treated as fully transparent.
895    * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
896    */
897   png_bytep trans PNG_DEPSTRUCT; /* transparent values for paletted image */
898   png_color_16 trans_values PNG_DEPSTRUCT; /* transparent color for non-palette image */
899#endif
900
901#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
902   /* The bKGD chunk gives the suggested image background color if the
903    * display program does not have its own background color and the image
904    * is needs to composited onto a background before display.  The colors
905    * in "background" are normally in the same color space/depth as the
906    * pixel data.  Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
907    */
908   png_color_16 background PNG_DEPSTRUCT;
909#endif
910
911#ifdef PNG_oFFs_SUPPORTED
912   /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
913    * and downwards from the top-left corner of the display, page, or other
914    * application-specific co-ordinate space.  See the PNG_OFFSET_ defines
915    * below for the unit types.  Valid if (valid & PNG_INFO_oFFs) non-zero.
916    */
917   png_int_32 x_offset PNG_DEPSTRUCT; /* x offset on page */
918   png_int_32 y_offset PNG_DEPSTRUCT; /* y offset on page */
919   png_byte offset_unit_type PNG_DEPSTRUCT; /* offset units type */
920#endif
921
922#ifdef PNG_pHYs_SUPPORTED
923   /* The pHYs chunk gives the physical pixel density of the image for
924    * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
925    * defines below).  Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
926    */
927   png_uint_32 x_pixels_per_unit PNG_DEPSTRUCT; /* horizontal pixel density */
928   png_uint_32 y_pixels_per_unit PNG_DEPSTRUCT; /* vertical pixel density */
929   png_byte phys_unit_type PNG_DEPSTRUCT; /* resolution type (see PNG_RESOLUTION_ below) */
930#endif
931
932#ifdef PNG_hIST_SUPPORTED
933   /* The hIST chunk contains the relative frequency or importance of the
934    * various palette entries, so that a viewer can intelligently select a
935    * reduced-color palette, if required.  Data is an array of "num_palette"
936    * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
937    * is non-zero.
938    */
939   png_uint_16p hist PNG_DEPSTRUCT;
940#endif
941
942#ifdef PNG_cHRM_SUPPORTED
943   /* The cHRM chunk describes the CIE color characteristics of the monitor
944    * on which the PNG was created.  This data allows the viewer to do gamut
945    * mapping of the input image to ensure that the viewer sees the same
946    * colors in the image as the creator.  Values are in the range
947    * [0.0, 0.8].  Data valid if (valid & PNG_INFO_cHRM) non-zero.
948    */
949#ifdef PNG_FLOATING_POINT_SUPPORTED
950   float x_white PNG_DEPSTRUCT;
951   float y_white PNG_DEPSTRUCT;
952   float x_red PNG_DEPSTRUCT;
953   float y_red PNG_DEPSTRUCT;
954   float x_green PNG_DEPSTRUCT;
955   float y_green PNG_DEPSTRUCT;
956   float x_blue PNG_DEPSTRUCT;
957   float y_blue PNG_DEPSTRUCT;
958#endif
959#endif
960
961#ifdef PNG_pCAL_SUPPORTED
962   /* The pCAL chunk describes a transformation between the stored pixel
963    * values and original physical data values used to create the image.
964    * The integer range [0, 2^bit_depth - 1] maps to the floating-point
965    * range given by [pcal_X0, pcal_X1], and are further transformed by a
966    * (possibly non-linear) transformation function given by "pcal_type"
967    * and "pcal_params" into "pcal_units".  Please see the PNG_EQUATION_
968    * defines below, and the PNG-Group's PNG extensions document for a
969    * complete description of the transformations and how they should be
970    * implemented, and for a description of the ASCII parameter strings.
971    * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
972    */
973   png_charp pcal_purpose PNG_DEPSTRUCT;  /* pCAL chunk description string */
974   png_int_32 pcal_X0 PNG_DEPSTRUCT;      /* minimum value */
975   png_int_32 pcal_X1 PNG_DEPSTRUCT;      /* maximum value */
976   png_charp pcal_units PNG_DEPSTRUCT;    /* Latin-1 string giving physical units */
977   png_charpp pcal_params PNG_DEPSTRUCT;  /* ASCII strings containing parameter values */
978   png_byte pcal_type PNG_DEPSTRUCT;      /* equation type (see PNG_EQUATION_ below) */
979   png_byte pcal_nparams PNG_DEPSTRUCT;   /* number of parameters given in pcal_params */
980#endif
981
982/* New members added in libpng-1.0.6 */
983#ifdef PNG_FREE_ME_SUPPORTED
984   png_uint_32 free_me PNG_DEPSTRUCT;     /* flags items libpng is responsible for freeing */
985#endif
986
987#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
988 defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
989   /* Storage for unknown chunks that the library doesn't recognize. */
990   png_unknown_chunkp unknown_chunks PNG_DEPSTRUCT;
991   png_size_t unknown_chunks_num PNG_DEPSTRUCT;
992#endif
993
994#ifdef PNG_iCCP_SUPPORTED
995   /* iCCP chunk data. */
996   png_charp iccp_name PNG_DEPSTRUCT;     /* profile name */
997   png_charp iccp_profile PNG_DEPSTRUCT;  /* International Color Consortium profile data */
998                            /* Note to maintainer: should be png_bytep */
999   png_uint_32 iccp_proflen PNG_DEPSTRUCT;  /* ICC profile data length */
1000   png_byte iccp_compression PNG_DEPSTRUCT; /* Always zero */
1001#endif
1002
1003#ifdef PNG_sPLT_SUPPORTED
1004   /* Data on sPLT chunks (there may be more than one). */
1005   png_sPLT_tp splt_palettes PNG_DEPSTRUCT;
1006   png_uint_32 splt_palettes_num PNG_DEPSTRUCT;
1007#endif
1008
1009#ifdef PNG_sCAL_SUPPORTED
1010   /* The sCAL chunk describes the actual physical dimensions of the
1011    * subject matter of the graphic.  The chunk contains a unit specification
1012    * a byte value, and two ASCII strings representing floating-point
1013    * values.  The values are width and height corresponsing to one pixel
1014    * in the image.  This external representation is converted to double
1015    * here.  Data values are valid if (valid & PNG_INFO_sCAL) is non-zero.
1016    */
1017   png_byte scal_unit PNG_DEPSTRUCT;         /* unit of physical scale */
1018#ifdef PNG_FLOATING_POINT_SUPPORTED
1019   double scal_pixel_width PNG_DEPSTRUCT;    /* width of one pixel */
1020   double scal_pixel_height PNG_DEPSTRUCT;   /* height of one pixel */
1021#endif
1022#ifdef PNG_FIXED_POINT_SUPPORTED
1023   png_charp scal_s_width PNG_DEPSTRUCT;     /* string containing height */
1024   png_charp scal_s_height PNG_DEPSTRUCT;    /* string containing width */
1025#endif
1026#endif
1027
1028#ifdef PNG_INFO_IMAGE_SUPPORTED
1029   /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS) non-zero */
1030   /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
1031   png_bytepp row_pointers PNG_DEPSTRUCT;        /* the image bits */
1032#endif
1033
1034#if defined(PNG_FIXED_POINT_SUPPORTED) && defined(PNG_gAMA_SUPPORTED)
1035   png_fixed_point int_gamma PNG_DEPSTRUCT; /* gamma of image, if (valid & PNG_INFO_gAMA) */
1036#endif
1037
1038#if defined(PNG_cHRM_SUPPORTED) && defined(PNG_FIXED_POINT_SUPPORTED)
1039   png_fixed_point int_x_white PNG_DEPSTRUCT;
1040   png_fixed_point int_y_white PNG_DEPSTRUCT;
1041   png_fixed_point int_x_red PNG_DEPSTRUCT;
1042   png_fixed_point int_y_red PNG_DEPSTRUCT;
1043   png_fixed_point int_x_green PNG_DEPSTRUCT;
1044   png_fixed_point int_y_green PNG_DEPSTRUCT;
1045   png_fixed_point int_x_blue PNG_DEPSTRUCT;
1046   png_fixed_point int_y_blue PNG_DEPSTRUCT;
1047#endif
1048
1049} png_info;
1050
1051typedef png_info FAR * png_infop;
1052typedef png_info FAR * FAR * png_infopp;
1053
1054/* Maximum positive integer used in PNG is (2^31)-1 */
1055#define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
1056#define PNG_UINT_32_MAX ((png_uint_32)(-1))
1057#define PNG_SIZE_MAX ((png_size_t)(-1))
1058#if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1059/* PNG_MAX_UINT is deprecated; use PNG_UINT_31_MAX instead. */
1060#define PNG_MAX_UINT PNG_UINT_31_MAX
1061#endif
1062
1063/* These describe the color_type field in png_info. */
1064/* color type masks */
1065#define PNG_COLOR_MASK_PALETTE    1
1066#define PNG_COLOR_MASK_COLOR      2
1067#define PNG_COLOR_MASK_ALPHA      4
1068
1069/* color types.  Note that not all combinations are legal */
1070#define PNG_COLOR_TYPE_GRAY 0
1071#define PNG_COLOR_TYPE_PALETTE  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
1072#define PNG_COLOR_TYPE_RGB        (PNG_COLOR_MASK_COLOR)
1073#define PNG_COLOR_TYPE_RGB_ALPHA  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
1074#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
1075/* aliases */
1076#define PNG_COLOR_TYPE_RGBA  PNG_COLOR_TYPE_RGB_ALPHA
1077#define PNG_COLOR_TYPE_GA  PNG_COLOR_TYPE_GRAY_ALPHA
1078
1079/* This is for compression type. PNG 1.0-1.2 only define the single type. */
1080#define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
1081#define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
1082
1083/* This is for filter type. PNG 1.0-1.2 only define the single type. */
1084#define PNG_FILTER_TYPE_BASE      0 /* Single row per-byte filtering */
1085#define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
1086#define PNG_FILTER_TYPE_DEFAULT   PNG_FILTER_TYPE_BASE
1087
1088/* These are for the interlacing type.  These values should NOT be changed. */
1089#define PNG_INTERLACE_NONE        0 /* Non-interlaced image */
1090#define PNG_INTERLACE_ADAM7       1 /* Adam7 interlacing */
1091#define PNG_INTERLACE_LAST        2 /* Not a valid value */
1092
1093/* These are for the oFFs chunk.  These values should NOT be changed. */
1094#define PNG_OFFSET_PIXEL          0 /* Offset in pixels */
1095#define PNG_OFFSET_MICROMETER     1 /* Offset in micrometers (1/10^6 meter) */
1096#define PNG_OFFSET_LAST           2 /* Not a valid value */
1097
1098/* These are for the pCAL chunk.  These values should NOT be changed. */
1099#define PNG_EQUATION_LINEAR       0 /* Linear transformation */
1100#define PNG_EQUATION_BASE_E       1 /* Exponential base e transform */
1101#define PNG_EQUATION_ARBITRARY    2 /* Arbitrary base exponential transform */
1102#define PNG_EQUATION_HYPERBOLIC   3 /* Hyperbolic sine transformation */
1103#define PNG_EQUATION_LAST         4 /* Not a valid value */
1104
1105/* These are for the sCAL chunk.  These values should NOT be changed. */
1106#define PNG_SCALE_UNKNOWN         0 /* unknown unit (image scale) */
1107#define PNG_SCALE_METER           1 /* meters per pixel */
1108#define PNG_SCALE_RADIAN          2 /* radians per pixel */
1109#define PNG_SCALE_LAST            3 /* Not a valid value */
1110
1111/* These are for the pHYs chunk.  These values should NOT be changed. */
1112#define PNG_RESOLUTION_UNKNOWN    0 /* pixels/unknown unit (aspect ratio) */
1113#define PNG_RESOLUTION_METER      1 /* pixels/meter */
1114#define PNG_RESOLUTION_LAST       2 /* Not a valid value */
1115
1116/* These are for the sRGB chunk.  These values should NOT be changed. */
1117#define PNG_sRGB_INTENT_PERCEPTUAL 0
1118#define PNG_sRGB_INTENT_RELATIVE   1
1119#define PNG_sRGB_INTENT_SATURATION 2
1120#define PNG_sRGB_INTENT_ABSOLUTE   3
1121#define PNG_sRGB_INTENT_LAST       4 /* Not a valid value */
1122
1123/* This is for text chunks */
1124#define PNG_KEYWORD_MAX_LENGTH     79
1125
1126/* Maximum number of entries in PLTE/sPLT/tRNS arrays */
1127#define PNG_MAX_PALETTE_LENGTH    256
1128
1129/* These determine if an ancillary chunk's data has been successfully read
1130 * from the PNG header, or if the application has filled in the corresponding
1131 * data in the info_struct to be written into the output file.  The values
1132 * of the PNG_INFO_<chunk> defines should NOT be changed.
1133 */
1134#define PNG_INFO_gAMA 0x0001
1135#define PNG_INFO_sBIT 0x0002
1136#define PNG_INFO_cHRM 0x0004
1137#define PNG_INFO_PLTE 0x0008
1138#define PNG_INFO_tRNS 0x0010
1139#define PNG_INFO_bKGD 0x0020
1140#define PNG_INFO_hIST 0x0040
1141#define PNG_INFO_pHYs 0x0080
1142#define PNG_INFO_oFFs 0x0100
1143#define PNG_INFO_tIME 0x0200
1144#define PNG_INFO_pCAL 0x0400
1145#define PNG_INFO_sRGB 0x0800   /* GR-P, 0.96a */
1146#define PNG_INFO_iCCP 0x1000   /* ESR, 1.0.6 */
1147#define PNG_INFO_sPLT 0x2000   /* ESR, 1.0.6 */
1148#define PNG_INFO_sCAL 0x4000   /* ESR, 1.0.6 */
1149#define PNG_INFO_IDAT 0x8000L  /* ESR, 1.0.6 */
1150
1151/* This is used for the transformation routines, as some of them
1152 * change these values for the row.  It also should enable using
1153 * the routines for other purposes.
1154 */
1155typedef struct png_row_info_struct
1156{
1157   png_uint_32 width; /* width of row */
1158   png_uint_32 rowbytes; /* number of bytes in row */
1159   png_byte color_type; /* color type of row */
1160   png_byte bit_depth; /* bit depth of row */
1161   png_byte channels; /* number of channels (1, 2, 3, or 4) */
1162   png_byte pixel_depth; /* bits per pixel (depth * channels) */
1163} png_row_info;
1164
1165typedef png_row_info FAR * png_row_infop;
1166typedef png_row_info FAR * FAR * png_row_infopp;
1167
1168/* These are the function types for the I/O functions and for the functions
1169 * that allow the user to override the default I/O functions with his or her
1170 * own.  The png_error_ptr type should match that of user-supplied warning
1171 * and error functions, while the png_rw_ptr type should match that of the
1172 * user read/write data functions.
1173 */
1174typedef struct png_struct_def png_struct;
1175typedef png_struct FAR * png_structp;
1176
1177typedef void (PNGAPI *png_error_ptr) PNGARG((png_structp, png_const_charp));
1178typedef void (PNGAPI *png_rw_ptr) PNGARG((png_structp, png_bytep, png_size_t));
1179typedef void (PNGAPI *png_flush_ptr) PNGARG((png_structp));
1180typedef void (PNGAPI *png_read_status_ptr) PNGARG((png_structp, png_uint_32,
1181   int));
1182typedef void (PNGAPI *png_write_status_ptr) PNGARG((png_structp, png_uint_32,
1183   int));
1184
1185#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1186typedef void (PNGAPI *png_progressive_info_ptr) PNGARG((png_structp, png_infop));
1187typedef void (PNGAPI *png_progressive_end_ptr) PNGARG((png_structp, png_infop));
1188typedef void (PNGAPI *png_progressive_row_ptr) PNGARG((png_structp, png_bytep,
1189   png_uint_32, int));
1190#endif
1191
1192#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1193    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
1194    defined(PNG_LEGACY_SUPPORTED)
1195typedef void (PNGAPI *png_user_transform_ptr) PNGARG((png_structp,
1196    png_row_infop, png_bytep));
1197#endif
1198
1199#ifdef PNG_USER_CHUNKS_SUPPORTED
1200typedef int (PNGAPI *png_user_chunk_ptr) PNGARG((png_structp, png_unknown_chunkp));
1201#endif
1202#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
1203typedef void (PNGAPI *png_unknown_chunk_ptr) PNGARG((png_structp));
1204#endif
1205
1206/* Transform masks for the high-level interface */
1207#define PNG_TRANSFORM_IDENTITY       0x0000    /* read and write */
1208#define PNG_TRANSFORM_STRIP_16       0x0001    /* read only */
1209#define PNG_TRANSFORM_STRIP_ALPHA    0x0002    /* read only */
1210#define PNG_TRANSFORM_PACKING        0x0004    /* read and write */
1211#define PNG_TRANSFORM_PACKSWAP       0x0008    /* read and write */
1212#define PNG_TRANSFORM_EXPAND         0x0010    /* read only */
1213#define PNG_TRANSFORM_INVERT_MONO    0x0020    /* read and write */
1214#define PNG_TRANSFORM_SHIFT          0x0040    /* read and write */
1215#define PNG_TRANSFORM_BGR            0x0080    /* read and write */
1216#define PNG_TRANSFORM_SWAP_ALPHA     0x0100    /* read and write */
1217#define PNG_TRANSFORM_SWAP_ENDIAN    0x0200    /* read and write */
1218#define PNG_TRANSFORM_INVERT_ALPHA   0x0400    /* read and write */
1219#define PNG_TRANSFORM_STRIP_FILLER   0x0800    /* write only, deprecated */
1220/* Added to libpng-1.2.34 */
1221#define PNG_TRANSFORM_STRIP_FILLER_BEFORE 0x0800  /* write only */
1222#define PNG_TRANSFORM_STRIP_FILLER_AFTER  0x1000  /* write only */
1223/* Added to libpng-1.2.41 */
1224#define PNG_TRANSFORM_GRAY_TO_RGB   0x2000      /* read only */
1225
1226/* Flags for MNG supported features */
1227#define PNG_FLAG_MNG_EMPTY_PLTE     0x01
1228#define PNG_FLAG_MNG_FILTER_64      0x04
1229#define PNG_ALL_MNG_FEATURES        0x05
1230
1231typedef png_voidp (*png_malloc_ptr) PNGARG((png_structp, png_size_t));
1232typedef void (*png_free_ptr) PNGARG((png_structp, png_voidp));
1233
1234/* The structure that holds the information to read and write PNG files.
1235 * The only people who need to care about what is inside of this are the
1236 * people who will be modifying the library for their own special needs.
1237 * It should NOT be accessed directly by an application, except to store
1238 * the jmp_buf.
1239 */
1240
1241struct png_struct_def
1242{
1243#ifdef PNG_SETJMP_SUPPORTED
1244   jmp_buf jmpbuf;            /* used in png_error */
1245#endif
1246   png_error_ptr error_fn PNG_DEPSTRUCT;    /* function for printing errors and aborting */
1247   png_error_ptr warning_fn PNG_DEPSTRUCT;  /* function for printing warnings */
1248   png_voidp error_ptr PNG_DEPSTRUCT;       /* user supplied struct for error functions */
1249   png_rw_ptr write_data_fn PNG_DEPSTRUCT;  /* function for writing output data */
1250   png_rw_ptr read_data_fn PNG_DEPSTRUCT;   /* function for reading input data */
1251   png_voidp io_ptr PNG_DEPSTRUCT;          /* ptr to application struct for I/O functions */
1252
1253#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
1254   png_user_transform_ptr read_user_transform_fn PNG_DEPSTRUCT; /* user read transform */
1255#endif
1256
1257#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1258   png_user_transform_ptr write_user_transform_fn PNG_DEPSTRUCT; /* user write transform */
1259#endif
1260
1261/* These were added in libpng-1.0.2 */
1262#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
1263#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1264    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1265   png_voidp user_transform_ptr PNG_DEPSTRUCT; /* user supplied struct for user transform */
1266   png_byte user_transform_depth PNG_DEPSTRUCT;    /* bit depth of user transformed pixels */
1267   png_byte user_transform_channels PNG_DEPSTRUCT; /* channels in user transformed pixels */
1268#endif
1269#endif
1270
1271   png_uint_32 mode PNG_DEPSTRUCT;          /* tells us where we are in the PNG file */
1272   png_uint_32 flags PNG_DEPSTRUCT;         /* flags indicating various things to libpng */
1273   png_uint_32 transformations PNG_DEPSTRUCT; /* which transformations to perform */
1274
1275   z_stream zstream PNG_DEPSTRUCT;          /* pointer to decompression structure (below) */
1276   png_bytep zbuf PNG_DEPSTRUCT;            /* buffer for zlib */
1277   png_size_t zbuf_size PNG_DEPSTRUCT;      /* size of zbuf */
1278   int zlib_level PNG_DEPSTRUCT;            /* holds zlib compression level */
1279   int zlib_method PNG_DEPSTRUCT;           /* holds zlib compression method */
1280   int zlib_window_bits PNG_DEPSTRUCT;      /* holds zlib compression window bits */
1281   int zlib_mem_level PNG_DEPSTRUCT;        /* holds zlib compression memory level */
1282   int zlib_strategy PNG_DEPSTRUCT;         /* holds zlib compression strategy */
1283
1284   png_uint_32 width PNG_DEPSTRUCT;         /* width of image in pixels */
1285   png_uint_32 height PNG_DEPSTRUCT;        /* height of image in pixels */
1286   png_uint_32 num_rows PNG_DEPSTRUCT;      /* number of rows in current pass */
1287   png_uint_32 usr_width PNG_DEPSTRUCT;     /* width of row at start of write */
1288   png_uint_32 rowbytes PNG_DEPSTRUCT;      /* size of row in bytes */
1289#if 0 /* Replaced with the following in libpng-1.2.43 */
1290   png_size_t irowbytes PNG_DEPSTRUCT;
1291#endif
1292/* Added in libpng-1.2.43 */
1293#ifdef PNG_USER_LIMITS_SUPPORTED
1294   /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown
1295    * chunks that can be stored (0 means unlimited).
1296    */
1297   png_uint_32 user_chunk_cache_max PNG_DEPSTRUCT;
1298#endif
1299   png_uint_32 iwidth PNG_DEPSTRUCT;        /* width of current interlaced row in pixels */
1300   png_uint_32 row_number PNG_DEPSTRUCT;    /* current row in interlace pass */
1301   png_bytep prev_row PNG_DEPSTRUCT;        /* buffer to save previous (unfiltered) row */
1302   png_bytep row_buf PNG_DEPSTRUCT;         /* buffer to save current (unfiltered) row */
1303#ifndef PNG_NO_WRITE_FILTER
1304   png_bytep sub_row PNG_DEPSTRUCT;         /* buffer to save "sub" row when filtering */
1305   png_bytep up_row PNG_DEPSTRUCT;          /* buffer to save "up" row when filtering */
1306   png_bytep avg_row PNG_DEPSTRUCT;         /* buffer to save "avg" row when filtering */
1307   png_bytep paeth_row PNG_DEPSTRUCT;       /* buffer to save "Paeth" row when filtering */
1308#endif
1309   png_row_info row_info PNG_DEPSTRUCT;     /* used for transformation routines */
1310
1311   png_uint_32 idat_size PNG_DEPSTRUCT;     /* current IDAT size for read */
1312   png_uint_32 crc PNG_DEPSTRUCT;           /* current chunk CRC value */
1313   png_colorp palette PNG_DEPSTRUCT;        /* palette from the input file */
1314   png_uint_16 num_palette PNG_DEPSTRUCT;   /* number of color entries in palette */
1315   png_uint_16 num_trans PNG_DEPSTRUCT;     /* number of transparency values */
1316   png_byte chunk_name[5] PNG_DEPSTRUCT;    /* null-terminated name of current chunk */
1317   png_byte compression PNG_DEPSTRUCT;      /* file compression type (always 0) */
1318   png_byte filter PNG_DEPSTRUCT;           /* file filter type (always 0) */
1319   png_byte interlaced PNG_DEPSTRUCT;       /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
1320   png_byte pass PNG_DEPSTRUCT;             /* current interlace pass (0 - 6) */
1321   png_byte do_filter PNG_DEPSTRUCT;        /* row filter flags (see PNG_FILTER_ below ) */
1322   png_byte color_type PNG_DEPSTRUCT;       /* color type of file */
1323   png_byte bit_depth PNG_DEPSTRUCT;        /* bit depth of file */
1324   png_byte usr_bit_depth PNG_DEPSTRUCT;    /* bit depth of users row */
1325   png_byte pixel_depth PNG_DEPSTRUCT;      /* number of bits per pixel */
1326   png_byte channels PNG_DEPSTRUCT;         /* number of channels in file */
1327   png_byte usr_channels PNG_DEPSTRUCT;     /* channels at start of write */
1328   png_byte sig_bytes PNG_DEPSTRUCT;        /* magic bytes read/written from start of file */
1329
1330#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1331#ifdef PNG_LEGACY_SUPPORTED
1332   png_byte filler PNG_DEPSTRUCT;           /* filler byte for pixel expansion */
1333#else
1334   png_uint_16 filler PNG_DEPSTRUCT;           /* filler bytes for pixel expansion */
1335#endif
1336#endif
1337
1338#ifdef PNG_bKGD_SUPPORTED
1339   png_byte background_gamma_type PNG_DEPSTRUCT;
1340#  ifdef PNG_FLOATING_POINT_SUPPORTED
1341   float background_gamma PNG_DEPSTRUCT;
1342#  endif
1343   png_color_16 background PNG_DEPSTRUCT;   /* background color in screen gamma space */
1344#ifdef PNG_READ_GAMMA_SUPPORTED
1345   png_color_16 background_1 PNG_DEPSTRUCT; /* background normalized to gamma 1.0 */
1346#endif
1347#endif /* PNG_bKGD_SUPPORTED */
1348
1349#ifdef PNG_WRITE_FLUSH_SUPPORTED
1350   png_flush_ptr output_flush_fn PNG_DEPSTRUCT; /* Function for flushing output */
1351   png_uint_32 flush_dist PNG_DEPSTRUCT;    /* how many rows apart to flush, 0 - no flush */
1352   png_uint_32 flush_rows PNG_DEPSTRUCT;    /* number of rows written since last flush */
1353#endif
1354
1355#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1356   int gamma_shift PNG_DEPSTRUCT;      /* number of "insignificant" bits 16-bit gamma */
1357#ifdef PNG_FLOATING_POINT_SUPPORTED
1358   float gamma PNG_DEPSTRUCT;          /* file gamma value */
1359   float screen_gamma PNG_DEPSTRUCT;   /* screen gamma value (display_exponent) */
1360#endif
1361#endif
1362
1363#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1364   png_bytep gamma_table PNG_DEPSTRUCT;     /* gamma table for 8-bit depth files */
1365   png_bytep gamma_from_1 PNG_DEPSTRUCT;    /* converts from 1.0 to screen */
1366   png_bytep gamma_to_1 PNG_DEPSTRUCT;      /* converts from file to 1.0 */
1367   png_uint_16pp gamma_16_table PNG_DEPSTRUCT; /* gamma table for 16-bit depth files */
1368   png_uint_16pp gamma_16_from_1 PNG_DEPSTRUCT; /* converts from 1.0 to screen */
1369   png_uint_16pp gamma_16_to_1 PNG_DEPSTRUCT; /* converts from file to 1.0 */
1370#endif
1371
1372#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
1373   png_color_8 sig_bit PNG_DEPSTRUCT;       /* significant bits in each available channel */
1374#endif
1375
1376#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1377   png_color_8 shift PNG_DEPSTRUCT;         /* shift for significant bit tranformation */
1378#endif
1379
1380#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
1381 || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1382   png_bytep trans PNG_DEPSTRUCT;           /* transparency values for paletted files */
1383   png_color_16 trans_values PNG_DEPSTRUCT; /* transparency values for non-paletted files */
1384#endif
1385
1386   png_read_status_ptr read_row_fn PNG_DEPSTRUCT;   /* called after each row is decoded */
1387   png_write_status_ptr write_row_fn PNG_DEPSTRUCT; /* called after each row is encoded */
1388#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1389   png_progressive_info_ptr info_fn PNG_DEPSTRUCT; /* called after header data fully read */
1390   png_progressive_row_ptr row_fn PNG_DEPSTRUCT;   /* called after each prog. row is decoded */
1391   png_progressive_end_ptr end_fn PNG_DEPSTRUCT;   /* called after image is complete */
1392   png_bytep save_buffer_ptr PNG_DEPSTRUCT;        /* current location in save_buffer */
1393   png_bytep save_buffer PNG_DEPSTRUCT;            /* buffer for previously read data */
1394   png_bytep current_buffer_ptr PNG_DEPSTRUCT;     /* current location in current_buffer */
1395   png_bytep current_buffer PNG_DEPSTRUCT;         /* buffer for recently used data */
1396   png_uint_32 push_length PNG_DEPSTRUCT;          /* size of current input chunk */
1397   png_uint_32 skip_length PNG_DEPSTRUCT;          /* bytes to skip in input data */
1398   png_size_t save_buffer_size PNG_DEPSTRUCT;      /* amount of data now in save_buffer */
1399   png_size_t save_buffer_max PNG_DEPSTRUCT;       /* total size of save_buffer */
1400   png_size_t buffer_size PNG_DEPSTRUCT;           /* total amount of available input data */
1401   png_size_t current_buffer_size PNG_DEPSTRUCT;   /* amount of data now in current_buffer */
1402   int process_mode PNG_DEPSTRUCT;                 /* what push library is currently doing */
1403   int cur_palette PNG_DEPSTRUCT;                  /* current push library palette index */
1404
1405#  ifdef PNG_TEXT_SUPPORTED
1406     png_size_t current_text_size PNG_DEPSTRUCT;   /* current size of text input data */
1407     png_size_t current_text_left PNG_DEPSTRUCT;   /* how much text left to read in input */
1408     png_charp current_text PNG_DEPSTRUCT;         /* current text chunk buffer */
1409     png_charp current_text_ptr PNG_DEPSTRUCT;     /* current location in current_text */
1410#  endif /* PNG_TEXT_SUPPORTED */
1411#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1412
1413#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
1414/* for the Borland special 64K segment handler */
1415   png_bytepp offset_table_ptr PNG_DEPSTRUCT;
1416   png_bytep offset_table PNG_DEPSTRUCT;
1417   png_uint_16 offset_table_number PNG_DEPSTRUCT;
1418   png_uint_16 offset_table_count PNG_DEPSTRUCT;
1419   png_uint_16 offset_table_count_free PNG_DEPSTRUCT;
1420#endif
1421
1422#ifdef PNG_READ_DITHER_SUPPORTED
1423   png_bytep palette_lookup PNG_DEPSTRUCT;         /* lookup table for dithering */
1424   png_bytep dither_index PNG_DEPSTRUCT;           /* index translation for palette files */
1425#endif
1426
1427#if defined(PNG_READ_DITHER_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
1428   png_uint_16p hist PNG_DEPSTRUCT;                /* histogram */
1429#endif
1430
1431#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
1432   png_byte heuristic_method PNG_DEPSTRUCT;        /* heuristic for row filter selection */
1433   png_byte num_prev_filters PNG_DEPSTRUCT;        /* number of weights for previous rows */
1434   png_bytep prev_filters PNG_DEPSTRUCT;           /* filter type(s) of previous row(s) */
1435   png_uint_16p filter_weights PNG_DEPSTRUCT;      /* weight(s) for previous line(s) */
1436   png_uint_16p inv_filter_weights PNG_DEPSTRUCT;  /* 1/weight(s) for previous line(s) */
1437   png_uint_16p filter_costs PNG_DEPSTRUCT;        /* relative filter calculation cost */
1438   png_uint_16p inv_filter_costs PNG_DEPSTRUCT;    /* 1/relative filter calculation cost */
1439#endif
1440
1441#ifdef PNG_TIME_RFC1123_SUPPORTED
1442   png_charp time_buffer PNG_DEPSTRUCT;            /* String to hold RFC 1123 time text */
1443#endif
1444
1445/* New members added in libpng-1.0.6 */
1446
1447#ifdef PNG_FREE_ME_SUPPORTED
1448   png_uint_32 free_me PNG_DEPSTRUCT;   /* flags items libpng is responsible for freeing */
1449#endif
1450
1451#ifdef PNG_USER_CHUNKS_SUPPORTED
1452   png_voidp user_chunk_ptr PNG_DEPSTRUCT;
1453   png_user_chunk_ptr read_user_chunk_fn PNG_DEPSTRUCT; /* user read chunk handler */
1454#endif
1455
1456#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
1457   int num_chunk_list PNG_DEPSTRUCT;
1458   png_bytep chunk_list PNG_DEPSTRUCT;
1459#endif
1460
1461/* New members added in libpng-1.0.3 */
1462#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1463   png_byte rgb_to_gray_status PNG_DEPSTRUCT;
1464   /* These were changed from png_byte in libpng-1.0.6 */
1465   png_uint_16 rgb_to_gray_red_coeff PNG_DEPSTRUCT;
1466   png_uint_16 rgb_to_gray_green_coeff PNG_DEPSTRUCT;
1467   png_uint_16 rgb_to_gray_blue_coeff PNG_DEPSTRUCT;
1468#endif
1469
1470/* New member added in libpng-1.0.4 (renamed in 1.0.9) */
1471#if defined(PNG_MNG_FEATURES_SUPPORTED) || \
1472    defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1473    defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1474/* Changed from png_byte to png_uint_32 at version 1.2.0 */
1475#ifdef PNG_1_0_X
1476   png_byte mng_features_permitted PNG_DEPSTRUCT;
1477#else
1478   png_uint_32 mng_features_permitted PNG_DEPSTRUCT;
1479#endif /* PNG_1_0_X */
1480#endif
1481
1482/* New member added in libpng-1.0.7 */
1483#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1484   png_fixed_point int_gamma PNG_DEPSTRUCT;
1485#endif
1486
1487/* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
1488#ifdef PNG_MNG_FEATURES_SUPPORTED
1489   png_byte filter_type PNG_DEPSTRUCT;
1490#endif
1491
1492#ifdef PNG_1_0_X
1493/* New member added in libpng-1.0.10, ifdef'ed out in 1.2.0 */
1494   png_uint_32 row_buf_size PNG_DEPSTRUCT;
1495#endif
1496
1497/* New members added in libpng-1.2.0 */
1498#ifdef PNG_ASSEMBLER_CODE_SUPPORTED
1499#  ifndef PNG_1_0_X
1500#    ifdef PNG_MMX_CODE_SUPPORTED
1501   png_byte     mmx_bitdepth_threshold PNG_DEPSTRUCT;
1502   png_uint_32  mmx_rowbytes_threshold PNG_DEPSTRUCT;
1503#    endif
1504   png_uint_32  asm_flags PNG_DEPSTRUCT;
1505#  endif
1506#endif
1507
1508/* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
1509#ifdef PNG_USER_MEM_SUPPORTED
1510   png_voidp mem_ptr PNG_DEPSTRUCT;            /* user supplied struct for mem functions */
1511   png_malloc_ptr malloc_fn PNG_DEPSTRUCT;     /* function for allocating memory */
1512   png_free_ptr free_fn PNG_DEPSTRUCT;         /* function for freeing memory */
1513#endif
1514
1515/* New member added in libpng-1.0.13 and 1.2.0 */
1516   png_bytep big_row_buf PNG_DEPSTRUCT;        /* buffer to save current (unfiltered) row */
1517
1518#ifdef PNG_READ_DITHER_SUPPORTED
1519/* The following three members were added at version 1.0.14 and 1.2.4 */
1520   png_bytep dither_sort PNG_DEPSTRUCT;        /* working sort array */
1521   png_bytep index_to_palette PNG_DEPSTRUCT;   /* where the original index currently is */
1522                                 /* in the palette */
1523   png_bytep palette_to_index PNG_DEPSTRUCT;   /* which original index points to this */
1524                                 /* palette color */
1525#endif
1526
1527/* New members added in libpng-1.0.16 and 1.2.6 */
1528   png_byte compression_type PNG_DEPSTRUCT;
1529
1530#ifdef PNG_USER_LIMITS_SUPPORTED
1531   png_uint_32 user_width_max PNG_DEPSTRUCT;
1532   png_uint_32 user_height_max PNG_DEPSTRUCT;
1533#endif
1534
1535/* New member added in libpng-1.0.25 and 1.2.17 */
1536#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
1537   /* Storage for unknown chunk that the library doesn't recognize. */
1538   png_unknown_chunk unknown_chunk PNG_DEPSTRUCT;
1539#endif
1540
1541/* New members added in libpng-1.2.26 */
1542  png_uint_32 old_big_row_buf_size PNG_DEPSTRUCT;
1543  png_uint_32 old_prev_row_size PNG_DEPSTRUCT;
1544
1545/* New member added in libpng-1.2.30 */
1546  png_charp chunkdata PNG_DEPSTRUCT;  /* buffer for reading chunk data */
1547
1548
1549};
1550
1551
1552/* This triggers a compiler error in png.c, if png.c and png.h
1553 * do not agree upon the version number.
1554 */
1555typedef png_structp version_1_2_45;
1556
1557typedef png_struct FAR * FAR * png_structpp;
1558
1559/* Here are the function definitions most commonly used.  This is not
1560 * the place to find out how to use libpng.  See libpng.txt for the
1561 * full explanation, see example.c for the summary.  This just provides
1562 * a simple one line description of the use of each function.
1563 */
1564
1565/* Returns the version number of the library */
1566extern PNG_EXPORT(png_uint_32,png_access_version_number) PNGARG((void));
1567
1568/* Tell lib we have already handled the first <num_bytes> magic bytes.
1569 * Handling more than 8 bytes from the beginning of the file is an error.
1570 */
1571extern PNG_EXPORT(void,png_set_sig_bytes) PNGARG((png_structp png_ptr,
1572   int num_bytes));
1573
1574/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
1575 * PNG file.  Returns zero if the supplied bytes match the 8-byte PNG
1576 * signature, and non-zero otherwise.  Having num_to_check == 0 or
1577 * start > 7 will always fail (ie return non-zero).
1578 */
1579extern PNG_EXPORT(int,png_sig_cmp) PNGARG((png_bytep sig, png_size_t start,
1580   png_size_t num_to_check));
1581
1582/* Simple signature checking function.  This is the same as calling
1583 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
1584 */
1585extern PNG_EXPORT(int,png_check_sig) PNGARG((png_bytep sig, int num)) PNG_DEPRECATED;
1586
1587/* Allocate and initialize png_ptr struct for reading, and any other memory. */
1588extern PNG_EXPORT(png_structp,png_create_read_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/* Allocate and initialize png_ptr struct for writing, and any other memory */
1593extern PNG_EXPORT(png_structp,png_create_write_struct)
1594   PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1595   png_error_ptr error_fn, png_error_ptr warn_fn)) PNG_ALLOCATED;
1596
1597#ifdef PNG_WRITE_SUPPORTED
1598extern PNG_EXPORT(png_uint_32,png_get_compression_buffer_size)
1599   PNGARG((png_structp png_ptr));
1600#endif
1601
1602#ifdef PNG_WRITE_SUPPORTED
1603extern PNG_EXPORT(void,png_set_compression_buffer_size)
1604   PNGARG((png_structp png_ptr, png_uint_32 size));
1605#endif
1606
1607/* Reset the compression stream */
1608extern PNG_EXPORT(int,png_reset_zstream) PNGARG((png_structp png_ptr));
1609
1610/* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
1611#ifdef PNG_USER_MEM_SUPPORTED
1612extern PNG_EXPORT(png_structp,png_create_read_struct_2)
1613   PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1614   png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1615   png_malloc_ptr malloc_fn, png_free_ptr free_fn)) PNG_ALLOCATED;
1616extern PNG_EXPORT(png_structp,png_create_write_struct_2)
1617   PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1618   png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1619   png_malloc_ptr malloc_fn, png_free_ptr free_fn)) PNG_ALLOCATED;
1620#endif
1621
1622/* Write a PNG chunk - size, type, (optional) data, CRC. */
1623extern PNG_EXPORT(void,png_write_chunk) PNGARG((png_structp png_ptr,
1624   png_bytep chunk_name, png_bytep data, png_size_t length));
1625
1626/* Write the start of a PNG chunk - length and chunk name. */
1627extern PNG_EXPORT(void,png_write_chunk_start) PNGARG((png_structp png_ptr,
1628   png_bytep chunk_name, png_uint_32 length));
1629
1630/* Write the data of a PNG chunk started with png_write_chunk_start(). */
1631extern PNG_EXPORT(void,png_write_chunk_data) PNGARG((png_structp png_ptr,
1632   png_bytep data, png_size_t length));
1633
1634/* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1635extern PNG_EXPORT(void,png_write_chunk_end) PNGARG((png_structp png_ptr));
1636
1637/* Allocate and initialize the info structure */
1638extern PNG_EXPORT(png_infop,png_create_info_struct)
1639   PNGARG((png_structp png_ptr)) PNG_ALLOCATED;
1640
1641#if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1642/* Initialize the info structure (old interface - DEPRECATED) */
1643extern PNG_EXPORT(void,png_info_init) PNGARG((png_infop info_ptr))
1644    PNG_DEPRECATED;
1645#undef png_info_init
1646#define png_info_init(info_ptr) png_info_init_3(&info_ptr,\
1647    png_sizeof(png_info));
1648#endif
1649
1650extern PNG_EXPORT(void,png_info_init_3) PNGARG((png_infopp info_ptr,
1651    png_size_t png_info_struct_size));
1652
1653/* Writes all the PNG information before the image. */
1654extern PNG_EXPORT(void,png_write_info_before_PLTE) PNGARG((png_structp png_ptr,
1655   png_infop info_ptr));
1656extern PNG_EXPORT(void,png_write_info) PNGARG((png_structp png_ptr,
1657   png_infop info_ptr));
1658
1659#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1660/* Read the information before the actual image data. */
1661extern PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr,
1662   png_infop info_ptr));
1663#endif
1664
1665#ifdef PNG_TIME_RFC1123_SUPPORTED
1666extern PNG_EXPORT(png_charp,png_convert_to_rfc1123)
1667   PNGARG((png_structp png_ptr, png_timep ptime));
1668#endif
1669
1670#ifdef PNG_CONVERT_tIME_SUPPORTED
1671/* Convert from a struct tm to png_time */
1672extern PNG_EXPORT(void,png_convert_from_struct_tm) PNGARG((png_timep ptime,
1673   struct tm FAR * ttime));
1674
1675/* Convert from time_t to png_time.  Uses gmtime() */
1676extern PNG_EXPORT(void,png_convert_from_time_t) PNGARG((png_timep ptime,
1677   time_t ttime));
1678#endif /* PNG_CONVERT_tIME_SUPPORTED */
1679
1680#ifdef PNG_READ_EXPAND_SUPPORTED
1681/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1682extern PNG_EXPORT(void,png_set_expand) PNGARG((png_structp png_ptr));
1683#ifndef PNG_1_0_X
1684extern PNG_EXPORT(void,png_set_expand_gray_1_2_4_to_8) PNGARG((png_structp
1685  png_ptr));
1686#endif
1687extern PNG_EXPORT(void,png_set_palette_to_rgb) PNGARG((png_structp png_ptr));
1688extern PNG_EXPORT(void,png_set_tRNS_to_alpha) PNGARG((png_structp png_ptr));
1689#if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1690/* Deprecated */
1691extern PNG_EXPORT(void,png_set_gray_1_2_4_to_8) PNGARG((png_structp
1692    png_ptr)) PNG_DEPRECATED;
1693#endif
1694#endif
1695
1696#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1697/* Use blue, green, red order for pixels. */
1698extern PNG_EXPORT(void,png_set_bgr) PNGARG((png_structp png_ptr));
1699#endif
1700
1701#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1702/* Expand the grayscale to 24-bit RGB if necessary. */
1703extern PNG_EXPORT(void,png_set_gray_to_rgb) PNGARG((png_structp png_ptr));
1704#endif
1705
1706#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1707/* Reduce RGB to grayscale. */
1708#ifdef PNG_FLOATING_POINT_SUPPORTED
1709extern PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr,
1710   int error_action, double red, double green ));
1711#endif
1712extern PNG_EXPORT(void,png_set_rgb_to_gray_fixed) PNGARG((png_structp png_ptr,
1713   int error_action, png_fixed_point red, png_fixed_point green ));
1714extern PNG_EXPORT(png_byte,png_get_rgb_to_gray_status) PNGARG((png_structp
1715   png_ptr));
1716#endif
1717
1718extern PNG_EXPORT(void,png_build_grayscale_palette) PNGARG((int bit_depth,
1719   png_colorp palette));
1720
1721#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1722extern PNG_EXPORT(void,png_set_strip_alpha) PNGARG((png_structp png_ptr));
1723#endif
1724
1725#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1726    defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1727extern PNG_EXPORT(void,png_set_swap_alpha) PNGARG((png_structp png_ptr));
1728#endif
1729
1730#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1731    defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1732extern PNG_EXPORT(void,png_set_invert_alpha) PNGARG((png_structp png_ptr));
1733#endif
1734
1735#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1736/* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
1737extern PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr,
1738   png_uint_32 filler, int flags));
1739/* The values of the PNG_FILLER_ defines should NOT be changed */
1740#define PNG_FILLER_BEFORE 0
1741#define PNG_FILLER_AFTER 1
1742/* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
1743#ifndef PNG_1_0_X
1744extern PNG_EXPORT(void,png_set_add_alpha) PNGARG((png_structp png_ptr,
1745   png_uint_32 filler, int flags));
1746#endif
1747#endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
1748
1749#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1750/* Swap bytes in 16-bit depth files. */
1751extern PNG_EXPORT(void,png_set_swap) PNGARG((png_structp png_ptr));
1752#endif
1753
1754#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1755/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1756extern PNG_EXPORT(void,png_set_packing) PNGARG((png_structp png_ptr));
1757#endif
1758
1759#if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1760/* Swap packing order of pixels in bytes. */
1761extern PNG_EXPORT(void,png_set_packswap) PNGARG((png_structp png_ptr));
1762#endif
1763
1764#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1765/* Converts files to legal bit depths. */
1766extern PNG_EXPORT(void,png_set_shift) PNGARG((png_structp png_ptr,
1767   png_color_8p true_bits));
1768#endif
1769
1770#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1771    defined(PNG_WRITE_INTERLACING_SUPPORTED)
1772/* Have the code handle the interlacing.  Returns the number of passes. */
1773extern PNG_EXPORT(int,png_set_interlace_handling) PNGARG((png_structp png_ptr));
1774#endif
1775
1776#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1777/* Invert monochrome files */
1778extern PNG_EXPORT(void,png_set_invert_mono) PNGARG((png_structp png_ptr));
1779#endif
1780
1781#ifdef PNG_READ_BACKGROUND_SUPPORTED
1782/* Handle alpha and tRNS by replacing with a background color. */
1783#ifdef PNG_FLOATING_POINT_SUPPORTED
1784extern PNG_EXPORT(void,png_set_background) PNGARG((png_structp png_ptr,
1785   png_color_16p background_color, int background_gamma_code,
1786   int need_expand, double background_gamma));
1787#endif
1788#define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1789#define PNG_BACKGROUND_GAMMA_SCREEN  1
1790#define PNG_BACKGROUND_GAMMA_FILE    2
1791#define PNG_BACKGROUND_GAMMA_UNIQUE  3
1792#endif
1793
1794#ifdef PNG_READ_16_TO_8_SUPPORTED
1795/* Strip the second byte of information from a 16-bit depth file. */
1796extern PNG_EXPORT(void,png_set_strip_16) PNGARG((png_structp png_ptr));
1797#endif
1798
1799#ifdef PNG_READ_DITHER_SUPPORTED
1800/* Turn on dithering, and reduce the palette to the number of colors available. */
1801extern PNG_EXPORT(void,png_set_dither) PNGARG((png_structp png_ptr,
1802   png_colorp palette, int num_palette, int maximum_colors,
1803   png_uint_16p histogram, int full_dither));
1804#endif
1805
1806#ifdef PNG_READ_GAMMA_SUPPORTED
1807/* Handle gamma correction. Screen_gamma=(display_exponent) */
1808#ifdef PNG_FLOATING_POINT_SUPPORTED
1809extern PNG_EXPORT(void,png_set_gamma) PNGARG((png_structp png_ptr,
1810   double screen_gamma, double default_file_gamma));
1811#endif
1812#endif
1813
1814#if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1815#if defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1816    defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1817/* Permit or disallow empty PLTE (0: not permitted, 1: permitted) */
1818/* Deprecated and will be removed.  Use png_permit_mng_features() instead. */
1819extern PNG_EXPORT(void,png_permit_empty_plte) PNGARG((png_structp png_ptr,
1820   int empty_plte_permitted)) PNG_DEPRECATED;
1821#endif
1822#endif
1823
1824#ifdef PNG_WRITE_FLUSH_SUPPORTED
1825/* Set how many lines between output flushes - 0 for no flushing */
1826extern PNG_EXPORT(void,png_set_flush) PNGARG((png_structp png_ptr, int nrows));
1827/* Flush the current PNG output buffer */
1828extern PNG_EXPORT(void,png_write_flush) PNGARG((png_structp png_ptr));
1829#endif
1830
1831/* Optional update palette with requested transformations */
1832extern PNG_EXPORT(void,png_start_read_image) PNGARG((png_structp png_ptr));
1833
1834/* Optional call to update the users info structure */
1835extern PNG_EXPORT(void,png_read_update_info) PNGARG((png_structp png_ptr,
1836   png_infop info_ptr));
1837
1838#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1839/* Read one or more rows of image data. */
1840extern PNG_EXPORT(void,png_read_rows) PNGARG((png_structp png_ptr,
1841   png_bytepp row, png_bytepp display_row, png_uint_32 num_rows));
1842#endif
1843
1844#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1845/* Read a row of data. */
1846extern PNG_EXPORT(void,png_read_row) PNGARG((png_structp png_ptr,
1847   png_bytep row,
1848   png_bytep display_row));
1849#endif
1850
1851#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1852/* Read the whole image into memory at once. */
1853extern PNG_EXPORT(void,png_read_image) PNGARG((png_structp png_ptr,
1854   png_bytepp image));
1855#endif
1856
1857/* Write a row of image data */
1858extern PNG_EXPORT(void,png_write_row) PNGARG((png_structp png_ptr,
1859   png_bytep row));
1860
1861/* Write a few rows of image data */
1862extern PNG_EXPORT(void,png_write_rows) PNGARG((png_structp png_ptr,
1863   png_bytepp row, png_uint_32 num_rows));
1864
1865/* Write the image data */
1866extern PNG_EXPORT(void,png_write_image) PNGARG((png_structp png_ptr,
1867   png_bytepp image));
1868
1869/* Writes the end of the PNG file. */
1870extern PNG_EXPORT(void,png_write_end) PNGARG((png_structp png_ptr,
1871   png_infop info_ptr));
1872
1873#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1874/* Read the end of the PNG file. */
1875extern PNG_EXPORT(void,png_read_end) PNGARG((png_structp png_ptr,
1876   png_infop info_ptr));
1877#endif
1878
1879/* Free any memory associated with the png_info_struct */
1880extern PNG_EXPORT(void,png_destroy_info_struct) PNGARG((png_structp png_ptr,
1881   png_infopp info_ptr_ptr));
1882
1883/* Free any memory associated with the png_struct and the png_info_structs */
1884extern PNG_EXPORT(void,png_destroy_read_struct) PNGARG((png_structpp
1885   png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1886
1887/* Free all memory used by the read (old method - NOT DLL EXPORTED) */
1888extern void png_read_destroy PNGARG((png_structp png_ptr, png_infop info_ptr,
1889   png_infop end_info_ptr)) PNG_DEPRECATED;
1890
1891/* Free any memory associated with the png_struct and the png_info_structs */
1892extern PNG_EXPORT(void,png_destroy_write_struct)
1893   PNGARG((png_structpp png_ptr_ptr, png_infopp info_ptr_ptr));
1894
1895/* Free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */
1896extern void png_write_destroy PNGARG((png_structp png_ptr)) PNG_DEPRECATED;
1897
1898/* Set the libpng method of handling chunk CRC errors */
1899extern PNG_EXPORT(void,png_set_crc_action) PNGARG((png_structp png_ptr,
1900   int crit_action, int ancil_action));
1901
1902/* Values for png_set_crc_action() to say how to handle CRC errors in
1903 * ancillary and critical chunks, and whether to use the data contained
1904 * therein.  Note that it is impossible to "discard" data in a critical
1905 * chunk.  For versions prior to 0.90, the action was always error/quit,
1906 * whereas in version 0.90 and later, the action for CRC errors in ancillary
1907 * chunks is warn/discard.  These values should NOT be changed.
1908 *
1909 *      value                       action:critical     action:ancillary
1910 */
1911#define PNG_CRC_DEFAULT       0  /* error/quit          warn/discard data */
1912#define PNG_CRC_ERROR_QUIT    1  /* error/quit          error/quit        */
1913#define PNG_CRC_WARN_DISCARD  2  /* (INVALID)           warn/discard data */
1914#define PNG_CRC_WARN_USE      3  /* warn/use data       warn/use data     */
1915#define PNG_CRC_QUIET_USE     4  /* quiet/use data      quiet/use data    */
1916#define PNG_CRC_NO_CHANGE     5  /* use current value   use current value */
1917
1918/* These functions give the user control over the scan-line filtering in
1919 * libpng and the compression methods used by zlib.  These functions are
1920 * mainly useful for testing, as the defaults should work with most users.
1921 * Those users who are tight on memory or want faster performance at the
1922 * expense of compression can modify them.  See the compression library
1923 * header file (zlib.h) for an explination of the compression functions.
1924 */
1925
1926/* Set the filtering method(s) used by libpng.  Currently, the only valid
1927 * value for "method" is 0.
1928 */
1929extern PNG_EXPORT(void,png_set_filter) PNGARG((png_structp png_ptr, int method,
1930   int filters));
1931
1932/* Flags for png_set_filter() to say which filters to use.  The flags
1933 * are chosen so that they don't conflict with real filter types
1934 * below, in case they are supplied instead of the #defined constants.
1935 * These values should NOT be changed.
1936 */
1937#define PNG_NO_FILTERS     0x00
1938#define PNG_FILTER_NONE    0x08
1939#define PNG_FILTER_SUB     0x10
1940#define PNG_FILTER_UP      0x20
1941#define PNG_FILTER_AVG     0x40
1942#define PNG_FILTER_PAETH   0x80
1943#define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
1944                         PNG_FILTER_AVG | PNG_FILTER_PAETH)
1945
1946/* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1947 * These defines should NOT be changed.
1948 */
1949#define PNG_FILTER_VALUE_NONE  0
1950#define PNG_FILTER_VALUE_SUB   1
1951#define PNG_FILTER_VALUE_UP    2
1952#define PNG_FILTER_VALUE_AVG   3
1953#define PNG_FILTER_VALUE_PAETH 4
1954#define PNG_FILTER_VALUE_LAST  5
1955
1956#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* EXPERIMENTAL */
1957/* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
1958 * defines, either the default (minimum-sum-of-absolute-differences), or
1959 * the experimental method (weighted-minimum-sum-of-absolute-differences).
1960 *
1961 * Weights are factors >= 1.0, indicating how important it is to keep the
1962 * filter type consistent between rows.  Larger numbers mean the current
1963 * filter is that many times as likely to be the same as the "num_weights"
1964 * previous filters.  This is cumulative for each previous row with a weight.
1965 * There needs to be "num_weights" values in "filter_weights", or it can be
1966 * NULL if the weights aren't being specified.  Weights have no influence on
1967 * the selection of the first row filter.  Well chosen weights can (in theory)
1968 * improve the compression for a given image.
1969 *
1970 * Costs are factors >= 1.0 indicating the relative decoding costs of a
1971 * filter type.  Higher costs indicate more decoding expense, and are
1972 * therefore less likely to be selected over a filter with lower computational
1973 * costs.  There needs to be a value in "filter_costs" for each valid filter
1974 * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
1975 * setting the costs.  Costs try to improve the speed of decompression without
1976 * unduly increasing the compressed image size.
1977 *
1978 * A negative weight or cost indicates the default value is to be used, and
1979 * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
1980 * The default values for both weights and costs are currently 1.0, but may
1981 * change if good general weighting/cost heuristics can be found.  If both
1982 * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
1983 * to the UNWEIGHTED method, but with added encoding time/computation.
1984 */
1985#ifdef PNG_FLOATING_POINT_SUPPORTED
1986extern PNG_EXPORT(void,png_set_filter_heuristics) PNGARG((png_structp png_ptr,
1987   int heuristic_method, int num_weights, png_doublep filter_weights,
1988   png_doublep filter_costs));
1989#endif
1990#endif /*  PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1991
1992/* Heuristic used for row filter selection.  These defines should NOT be
1993 * changed.
1994 */
1995#define PNG_FILTER_HEURISTIC_DEFAULT    0  /* Currently "UNWEIGHTED" */
1996#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1  /* Used by libpng < 0.95 */
1997#define PNG_FILTER_HEURISTIC_WEIGHTED   2  /* Experimental feature */
1998#define PNG_FILTER_HEURISTIC_LAST       3  /* Not a valid value */
1999
2000/* Set the library compression level.  Currently, valid values range from
2001 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
2002 * (0 - no compression, 9 - "maximal" compression).  Note that tests have
2003 * shown that zlib compression levels 3-6 usually perform as well as level 9
2004 * for PNG images, and do considerably fewer caclulations.  In the future,
2005 * these values may not correspond directly to the zlib compression levels.
2006 */
2007extern PNG_EXPORT(void,png_set_compression_level) PNGARG((png_structp png_ptr,
2008   int level));
2009
2010extern PNG_EXPORT(void,png_set_compression_mem_level)
2011   PNGARG((png_structp png_ptr, int mem_level));
2012
2013extern PNG_EXPORT(void,png_set_compression_strategy)
2014   PNGARG((png_structp png_ptr, int strategy));
2015
2016extern PNG_EXPORT(void,png_set_compression_window_bits)
2017   PNGARG((png_structp png_ptr, int window_bits));
2018
2019extern PNG_EXPORT(void,png_set_compression_method) PNGARG((png_structp png_ptr,
2020   int method));
2021
2022/* These next functions are called for input/output, memory, and error
2023 * handling.  They are in the file pngrio.c, pngwio.c, and pngerror.c,
2024 * and call standard C I/O routines such as fread(), fwrite(), and
2025 * fprintf().  These functions can be made to use other I/O routines
2026 * at run time for those applications that need to handle I/O in a
2027 * different manner by calling png_set_???_fn().  See libpng.txt for
2028 * more information.
2029 */
2030
2031#ifdef PNG_STDIO_SUPPORTED
2032/* Initialize the input/output for the PNG file to the default functions. */
2033extern PNG_EXPORT(void,png_init_io) PNGARG((png_structp png_ptr, png_FILE_p fp));
2034#endif
2035
2036/* Replace the (error and abort), and warning functions with user
2037 * supplied functions.  If no messages are to be printed you must still
2038 * write and use replacement functions. The replacement error_fn should
2039 * still do a longjmp to the last setjmp location if you are using this
2040 * method of error handling.  If error_fn or warning_fn is NULL, the
2041 * default function will be used.
2042 */
2043
2044extern PNG_EXPORT(void,png_set_error_fn) PNGARG((png_structp png_ptr,
2045   png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
2046
2047/* Return the user pointer associated with the error functions */
2048extern PNG_EXPORT(png_voidp,png_get_error_ptr) PNGARG((png_structp png_ptr));
2049
2050/* Replace the default data output functions with a user supplied one(s).
2051 * If buffered output is not used, then output_flush_fn can be set to NULL.
2052 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
2053 * output_flush_fn will be ignored (and thus can be NULL).
2054 * It is probably a mistake to use NULL for output_flush_fn if
2055 * write_data_fn is not also NULL unless you have built libpng with
2056 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
2057 * default flush function, which uses the standard *FILE structure, will
2058 * be used.
2059 */
2060extern PNG_EXPORT(void,png_set_write_fn) PNGARG((png_structp png_ptr,
2061   png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
2062
2063/* Replace the default data input function with a user supplied one. */
2064extern PNG_EXPORT(void,png_set_read_fn) PNGARG((png_structp png_ptr,
2065   png_voidp io_ptr, png_rw_ptr read_data_fn));
2066
2067/* Return the user pointer associated with the I/O functions */
2068extern PNG_EXPORT(png_voidp,png_get_io_ptr) PNGARG((png_structp png_ptr));
2069
2070extern PNG_EXPORT(void,png_set_read_status_fn) PNGARG((png_structp png_ptr,
2071   png_read_status_ptr read_row_fn));
2072
2073extern PNG_EXPORT(void,png_set_write_status_fn) PNGARG((png_structp png_ptr,
2074   png_write_status_ptr write_row_fn));
2075
2076#ifdef PNG_USER_MEM_SUPPORTED
2077/* Replace the default memory allocation functions with user supplied one(s). */
2078extern PNG_EXPORT(void,png_set_mem_fn) PNGARG((png_structp png_ptr,
2079   png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn));
2080/* Return the user pointer associated with the memory functions */
2081extern PNG_EXPORT(png_voidp,png_get_mem_ptr) PNGARG((png_structp png_ptr));
2082#endif
2083
2084#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
2085    defined(PNG_LEGACY_SUPPORTED)
2086extern PNG_EXPORT(void,png_set_read_user_transform_fn) PNGARG((png_structp
2087   png_ptr, png_user_transform_ptr read_user_transform_fn));
2088#endif
2089
2090#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
2091    defined(PNG_LEGACY_SUPPORTED)
2092extern PNG_EXPORT(void,png_set_write_user_transform_fn) PNGARG((png_structp
2093   png_ptr, png_user_transform_ptr write_user_transform_fn));
2094#endif
2095
2096#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
2097    defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
2098    defined(PNG_LEGACY_SUPPORTED)
2099extern PNG_EXPORT(void,png_set_user_transform_info) PNGARG((png_structp
2100   png_ptr, png_voidp user_transform_ptr, int user_transform_depth,
2101   int user_transform_channels));
2102/* Return the user pointer associated with the user transform functions */
2103extern PNG_EXPORT(png_voidp,png_get_user_transform_ptr)
2104   PNGARG((png_structp png_ptr));
2105#endif
2106
2107#ifdef PNG_USER_CHUNKS_SUPPORTED
2108extern PNG_EXPORT(void,png_set_read_user_chunk_fn) PNGARG((png_structp png_ptr,
2109   png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
2110extern PNG_EXPORT(png_voidp,png_get_user_chunk_ptr) PNGARG((png_structp
2111   png_ptr));
2112#endif
2113
2114#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
2115/* Sets the function callbacks for the push reader, and a pointer to a
2116 * user-defined structure available to the callback functions.
2117 */
2118extern PNG_EXPORT(void,png_set_progressive_read_fn) PNGARG((png_structp png_ptr,
2119   png_voidp progressive_ptr,
2120   png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
2121   png_progressive_end_ptr end_fn));
2122
2123/* Returns the user pointer associated with the push read functions */
2124extern PNG_EXPORT(png_voidp,png_get_progressive_ptr)
2125   PNGARG((png_structp png_ptr));
2126
2127/* Function to be called when data becomes available */
2128extern PNG_EXPORT(void,png_process_data) PNGARG((png_structp png_ptr,
2129   png_infop info_ptr, png_bytep buffer, png_size_t buffer_size));
2130
2131/* Function that combines rows.  Not very much different than the
2132 * png_combine_row() call.  Is this even used?????
2133 */
2134extern PNG_EXPORT(void,png_progressive_combine_row) PNGARG((png_structp png_ptr,
2135   png_bytep old_row, png_bytep new_row));
2136#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
2137
2138extern PNG_EXPORT(png_voidp,png_malloc) PNGARG((png_structp png_ptr,
2139   png_uint_32 size)) PNG_ALLOCATED;
2140
2141#ifdef PNG_1_0_X
2142#  define png_malloc_warn png_malloc
2143#else
2144/* Added at libpng version 1.2.4 */
2145extern PNG_EXPORT(png_voidp,png_malloc_warn) PNGARG((png_structp png_ptr,
2146   png_uint_32 size)) PNG_ALLOCATED;
2147#endif
2148
2149/* Frees a pointer allocated by png_malloc() */
2150extern PNG_EXPORT(void,png_free) PNGARG((png_structp png_ptr, png_voidp ptr));
2151
2152#ifdef PNG_1_0_X
2153/* Function to allocate memory for zlib. */
2154extern PNG_EXPORT(voidpf,png_zalloc) PNGARG((voidpf png_ptr, uInt items,
2155   uInt size));
2156
2157/* Function to free memory for zlib */
2158extern PNG_EXPORT(void,png_zfree) PNGARG((voidpf png_ptr, voidpf ptr));
2159#endif
2160
2161/* Free data that was allocated internally */
2162extern PNG_EXPORT(void,png_free_data) PNGARG((png_structp png_ptr,
2163   png_infop info_ptr, png_uint_32 free_me, int num));
2164#ifdef PNG_FREE_ME_SUPPORTED
2165/* Reassign responsibility for freeing existing data, whether allocated
2166 * by libpng or by the application
2167 */
2168extern PNG_EXPORT(void,png_data_freer) PNGARG((png_structp png_ptr,
2169   png_infop info_ptr, int freer, png_uint_32 mask));
2170#endif
2171/* Assignments for png_data_freer */
2172#define PNG_DESTROY_WILL_FREE_DATA 1
2173#define PNG_SET_WILL_FREE_DATA 1
2174#define PNG_USER_WILL_FREE_DATA 2
2175/* Flags for png_ptr->free_me and info_ptr->free_me */
2176#define PNG_FREE_HIST 0x0008
2177#define PNG_FREE_ICCP 0x0010
2178#define PNG_FREE_SPLT 0x0020
2179#define PNG_FREE_ROWS 0x0040
2180#define PNG_FREE_PCAL 0x0080
2181#define PNG_FREE_SCAL 0x0100
2182#define PNG_FREE_UNKN 0x0200
2183#define PNG_FREE_LIST 0x0400
2184#define PNG_FREE_PLTE 0x1000
2185#define PNG_FREE_TRNS 0x2000
2186#define PNG_FREE_TEXT 0x4000
2187#define PNG_FREE_ALL  0x7fff
2188#define PNG_FREE_MUL  0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
2189
2190#ifdef PNG_USER_MEM_SUPPORTED
2191extern PNG_EXPORT(png_voidp,png_malloc_default) PNGARG((png_structp png_ptr,
2192   png_uint_32 size)) PNG_ALLOCATED;
2193extern PNG_EXPORT(void,png_free_default) PNGARG((png_structp png_ptr,
2194   png_voidp ptr));
2195#endif
2196
2197extern PNG_EXPORT(png_voidp,png_memcpy_check) PNGARG((png_structp png_ptr,
2198   png_voidp s1, png_voidp s2, png_uint_32 size)) PNG_DEPRECATED;
2199
2200extern PNG_EXPORT(png_voidp,png_memset_check) PNGARG((png_structp png_ptr,
2201   png_voidp s1, int value, png_uint_32 size)) PNG_DEPRECATED;
2202
2203#if defined(USE_FAR_KEYWORD)  /* memory model conversion function */
2204extern void *png_far_to_near PNGARG((png_structp png_ptr,png_voidp ptr,
2205   int check));
2206#endif /* USE_FAR_KEYWORD */
2207
2208#ifndef PNG_NO_ERROR_TEXT
2209/* Fatal error in PNG image of libpng - can't continue */
2210extern PNG_EXPORT(void,png_error) PNGARG((png_structp png_ptr,
2211   png_const_charp error_message)) PNG_NORETURN;
2212
2213/* The same, but the chunk name is prepended to the error string. */
2214extern PNG_EXPORT(void,png_chunk_error) PNGARG((png_structp png_ptr,
2215   png_const_charp error_message)) PNG_NORETURN;
2216#else
2217/* Fatal error in PNG image of libpng - can't continue */
2218extern PNG_EXPORT(void,png_err) PNGARG((png_structp png_ptr)) PNG_NORETURN;
2219#endif
2220
2221#ifndef PNG_NO_WARNINGS
2222/* Non-fatal error in libpng.  Can continue, but may have a problem. */
2223extern PNG_EXPORT(void,png_warning) PNGARG((png_structp png_ptr,
2224   png_const_charp warning_message));
2225
2226#ifdef PNG_READ_SUPPORTED
2227/* Non-fatal error in libpng, chunk name is prepended to message. */
2228extern PNG_EXPORT(void,png_chunk_warning) PNGARG((png_structp png_ptr,
2229   png_const_charp warning_message));
2230#endif /* PNG_READ_SUPPORTED */
2231#endif /* PNG_NO_WARNINGS */
2232
2233/* The png_set_<chunk> functions are for storing values in the png_info_struct.
2234 * Similarly, the png_get_<chunk> calls are used to read values from the
2235 * png_info_struct, either storing the parameters in the passed variables, or
2236 * setting pointers into the png_info_struct where the data is stored.  The
2237 * png_get_<chunk> functions return a non-zero value if the data was available
2238 * in info_ptr, or return zero and do not change any of the parameters if the
2239 * data was not available.
2240 *
2241 * These functions should be used instead of directly accessing png_info
2242 * to avoid problems with future changes in the size and internal layout of
2243 * png_info_struct.
2244 */
2245/* Returns "flag" if chunk data is valid in info_ptr. */
2246extern PNG_EXPORT(png_uint_32,png_get_valid) PNGARG((png_structp png_ptr,
2247png_infop info_ptr, png_uint_32 flag));
2248
2249/* Returns number of bytes needed to hold a transformed row. */
2250extern PNG_EXPORT(png_uint_32,png_get_rowbytes) PNGARG((png_structp png_ptr,
2251png_infop info_ptr));
2252
2253#ifdef PNG_INFO_IMAGE_SUPPORTED
2254/* Returns row_pointers, which is an array of pointers to scanlines that was
2255 * returned from png_read_png().
2256 */
2257extern PNG_EXPORT(png_bytepp,png_get_rows) PNGARG((png_structp png_ptr,
2258png_infop info_ptr));
2259/* Set row_pointers, which is an array of pointers to scanlines for use
2260 * by png_write_png().
2261 */
2262extern PNG_EXPORT(void,png_set_rows) PNGARG((png_structp png_ptr,
2263   png_infop info_ptr, png_bytepp row_pointers));
2264#endif
2265
2266/* Returns number of color channels in image. */
2267extern PNG_EXPORT(png_byte,png_get_channels) PNGARG((png_structp png_ptr,
2268png_infop info_ptr));
2269
2270#ifdef PNG_EASY_ACCESS_SUPPORTED
2271/* Returns image width in pixels. */
2272extern PNG_EXPORT(png_uint_32, png_get_image_width) PNGARG((png_structp
2273png_ptr, png_infop info_ptr));
2274
2275/* Returns image height in pixels. */
2276extern PNG_EXPORT(png_uint_32, png_get_image_height) PNGARG((png_structp
2277png_ptr, png_infop info_ptr));
2278
2279/* Returns image bit_depth. */
2280extern PNG_EXPORT(png_byte, png_get_bit_depth) PNGARG((png_structp
2281png_ptr, png_infop info_ptr));
2282
2283/* Returns image color_type. */
2284extern PNG_EXPORT(png_byte, png_get_color_type) PNGARG((png_structp
2285png_ptr, png_infop info_ptr));
2286
2287/* Returns image filter_type. */
2288extern PNG_EXPORT(png_byte, png_get_filter_type) PNGARG((png_structp
2289png_ptr, png_infop info_ptr));
2290
2291/* Returns image interlace_type. */
2292extern PNG_EXPORT(png_byte, png_get_interlace_type) PNGARG((png_structp
2293png_ptr, png_infop info_ptr));
2294
2295/* Returns image compression_type. */
2296extern PNG_EXPORT(png_byte, png_get_compression_type) PNGARG((png_structp
2297png_ptr, png_infop info_ptr));
2298
2299/* Returns image resolution in pixels per meter, from pHYs chunk data. */
2300extern PNG_EXPORT(png_uint_32, png_get_pixels_per_meter) PNGARG((png_structp
2301png_ptr, png_infop info_ptr));
2302extern PNG_EXPORT(png_uint_32, png_get_x_pixels_per_meter) PNGARG((png_structp
2303png_ptr, png_infop info_ptr));
2304extern PNG_EXPORT(png_uint_32, png_get_y_pixels_per_meter) PNGARG((png_structp
2305png_ptr, png_infop info_ptr));
2306
2307/* Returns pixel aspect ratio, computed from pHYs chunk data.  */
2308#ifdef PNG_FLOATING_POINT_SUPPORTED
2309extern PNG_EXPORT(float, png_get_pixel_aspect_ratio) PNGARG((png_structp
2310png_ptr, png_infop info_ptr));
2311#endif
2312
2313/* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
2314extern PNG_EXPORT(png_int_32, png_get_x_offset_pixels) PNGARG((png_structp
2315png_ptr, png_infop info_ptr));
2316extern PNG_EXPORT(png_int_32, png_get_y_offset_pixels) PNGARG((png_structp
2317png_ptr, png_infop info_ptr));
2318extern PNG_EXPORT(png_int_32, png_get_x_offset_microns) PNGARG((png_structp
2319png_ptr, png_infop info_ptr));
2320extern PNG_EXPORT(png_int_32, png_get_y_offset_microns) PNGARG((png_structp
2321png_ptr, png_infop info_ptr));
2322
2323#endif /* PNG_EASY_ACCESS_SUPPORTED */
2324
2325/* Returns pointer to signature string read from PNG header */
2326extern PNG_EXPORT(png_bytep,png_get_signature) PNGARG((png_structp png_ptr,
2327png_infop info_ptr));
2328
2329#ifdef PNG_bKGD_SUPPORTED
2330extern PNG_EXPORT(png_uint_32,png_get_bKGD) PNGARG((png_structp png_ptr,
2331   png_infop info_ptr, png_color_16p *background));
2332#endif
2333
2334#ifdef PNG_bKGD_SUPPORTED
2335extern PNG_EXPORT(void,png_set_bKGD) PNGARG((png_structp png_ptr,
2336   png_infop info_ptr, png_color_16p background));
2337#endif
2338
2339#ifdef PNG_cHRM_SUPPORTED
2340#ifdef PNG_FLOATING_POINT_SUPPORTED
2341extern PNG_EXPORT(png_uint_32,png_get_cHRM) PNGARG((png_structp png_ptr,
2342   png_infop info_ptr, double *white_x, double *white_y, double *red_x,
2343   double *red_y, double *green_x, double *green_y, double *blue_x,
2344   double *blue_y));
2345#endif
2346#ifdef PNG_FIXED_POINT_SUPPORTED
2347extern PNG_EXPORT(png_uint_32,png_get_cHRM_fixed) PNGARG((png_structp png_ptr,
2348   png_infop info_ptr, png_fixed_point *int_white_x, png_fixed_point
2349   *int_white_y, png_fixed_point *int_red_x, png_fixed_point *int_red_y,
2350   png_fixed_point *int_green_x, png_fixed_point *int_green_y, png_fixed_point
2351   *int_blue_x, png_fixed_point *int_blue_y));
2352#endif
2353#endif
2354
2355#ifdef PNG_cHRM_SUPPORTED
2356#ifdef PNG_FLOATING_POINT_SUPPORTED
2357extern PNG_EXPORT(void,png_set_cHRM) PNGARG((png_structp png_ptr,
2358   png_infop info_ptr, double white_x, double white_y, double red_x,
2359   double red_y, double green_x, double green_y, double blue_x, double blue_y));
2360#endif
2361#ifdef PNG_FIXED_POINT_SUPPORTED
2362extern PNG_EXPORT(void,png_set_cHRM_fixed) PNGARG((png_structp png_ptr,
2363   png_infop info_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y,
2364   png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
2365   int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
2366   png_fixed_point int_blue_y));
2367#endif
2368#endif
2369
2370#ifdef PNG_gAMA_SUPPORTED
2371#ifdef PNG_FLOATING_POINT_SUPPORTED
2372extern PNG_EXPORT(png_uint_32,png_get_gAMA) PNGARG((png_structp png_ptr,
2373   png_infop info_ptr, double *file_gamma));
2374#endif
2375extern PNG_EXPORT(png_uint_32,png_get_gAMA_fixed) PNGARG((png_structp png_ptr,
2376   png_infop info_ptr, png_fixed_point *int_file_gamma));
2377#endif
2378
2379#ifdef PNG_gAMA_SUPPORTED
2380#ifdef PNG_FLOATING_POINT_SUPPORTED
2381extern PNG_EXPORT(void,png_set_gAMA) PNGARG((png_structp png_ptr,
2382   png_infop info_ptr, double file_gamma));
2383#endif
2384extern PNG_EXPORT(void,png_set_gAMA_fixed) PNGARG((png_structp png_ptr,
2385   png_infop info_ptr, png_fixed_point int_file_gamma));
2386#endif
2387
2388#ifdef PNG_hIST_SUPPORTED
2389extern PNG_EXPORT(png_uint_32,png_get_hIST) PNGARG((png_structp png_ptr,
2390   png_infop info_ptr, png_uint_16p *hist));
2391#endif
2392
2393#ifdef PNG_hIST_SUPPORTED
2394extern PNG_EXPORT(void,png_set_hIST) PNGARG((png_structp png_ptr,
2395   png_infop info_ptr, png_uint_16p hist));
2396#endif
2397
2398extern PNG_EXPORT(png_uint_32,png_get_IHDR) PNGARG((png_structp png_ptr,
2399   png_infop info_ptr, png_uint_32 *width, png_uint_32 *height,
2400   int *bit_depth, int *color_type, int *interlace_method,
2401   int *compression_method, int *filter_method));
2402
2403extern PNG_EXPORT(void,png_set_IHDR) PNGARG((png_structp png_ptr,
2404   png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
2405   int color_type, int interlace_method, int compression_method,
2406   int filter_method));
2407
2408#ifdef PNG_oFFs_SUPPORTED
2409extern PNG_EXPORT(png_uint_32,png_get_oFFs) PNGARG((png_structp png_ptr,
2410   png_infop info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
2411   int *unit_type));
2412#endif
2413
2414#ifdef PNG_oFFs_SUPPORTED
2415extern PNG_EXPORT(void,png_set_oFFs) PNGARG((png_structp png_ptr,
2416   png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2417   int unit_type));
2418#endif
2419
2420#ifdef PNG_pCAL_SUPPORTED
2421extern PNG_EXPORT(png_uint_32,png_get_pCAL) PNGARG((png_structp png_ptr,
2422   png_infop info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1,
2423   int *type, int *nparams, png_charp *units, png_charpp *params));
2424#endif
2425
2426#ifdef PNG_pCAL_SUPPORTED
2427extern PNG_EXPORT(void,png_set_pCAL) PNGARG((png_structp png_ptr,
2428   png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1,
2429   int type, int nparams, png_charp units, png_charpp params));
2430#endif
2431
2432#ifdef PNG_pHYs_SUPPORTED
2433extern PNG_EXPORT(png_uint_32,png_get_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#ifdef PNG_pHYs_SUPPORTED
2438extern PNG_EXPORT(void,png_set_pHYs) PNGARG((png_structp png_ptr,
2439   png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2440#endif
2441
2442extern PNG_EXPORT(png_uint_32,png_get_PLTE) PNGARG((png_structp png_ptr,
2443   png_infop info_ptr, png_colorp *palette, int *num_palette));
2444
2445extern PNG_EXPORT(void,png_set_PLTE) PNGARG((png_structp png_ptr,
2446   png_infop info_ptr, png_colorp palette, int num_palette));
2447
2448#ifdef PNG_sBIT_SUPPORTED
2449extern PNG_EXPORT(png_uint_32,png_get_sBIT) PNGARG((png_structp png_ptr,
2450   png_infop info_ptr, png_color_8p *sig_bit));
2451#endif
2452
2453#ifdef PNG_sBIT_SUPPORTED
2454extern PNG_EXPORT(void,png_set_sBIT) PNGARG((png_structp png_ptr,
2455   png_infop info_ptr, png_color_8p sig_bit));
2456#endif
2457
2458#ifdef PNG_sRGB_SUPPORTED
2459extern PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr,
2460   png_infop info_ptr, int *intent));
2461#endif
2462
2463#ifdef PNG_sRGB_SUPPORTED
2464extern PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr,
2465   png_infop info_ptr, int intent));
2466extern PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr,
2467   png_infop info_ptr, int intent));
2468#endif
2469
2470#ifdef PNG_iCCP_SUPPORTED
2471extern PNG_EXPORT(png_uint_32,png_get_iCCP) PNGARG((png_structp png_ptr,
2472   png_infop info_ptr, png_charpp name, int *compression_type,
2473   png_charpp profile, png_uint_32 *proflen));
2474   /* Note to maintainer: profile should be png_bytepp */
2475#endif
2476
2477#ifdef PNG_iCCP_SUPPORTED
2478extern PNG_EXPORT(void,png_set_iCCP) PNGARG((png_structp png_ptr,
2479   png_infop info_ptr, png_charp name, int compression_type,
2480   png_charp profile, png_uint_32 proflen));
2481   /* Note to maintainer: profile should be png_bytep */
2482#endif
2483
2484#ifdef PNG_sPLT_SUPPORTED
2485extern PNG_EXPORT(png_uint_32,png_get_sPLT) PNGARG((png_structp png_ptr,
2486   png_infop info_ptr, png_sPLT_tpp entries));
2487#endif
2488
2489#ifdef PNG_sPLT_SUPPORTED
2490extern PNG_EXPORT(void,png_set_sPLT) PNGARG((png_structp png_ptr,
2491   png_infop info_ptr, png_sPLT_tp entries, int nentries));
2492#endif
2493
2494#ifdef PNG_TEXT_SUPPORTED
2495/* png_get_text also returns the number of text chunks in *num_text */
2496extern PNG_EXPORT(png_uint_32,png_get_text) PNGARG((png_structp png_ptr,
2497   png_infop info_ptr, png_textp *text_ptr, int *num_text));
2498#endif
2499
2500/*
2501 *  Note while png_set_text() will accept a structure whose text,
2502 *  language, and  translated keywords are NULL pointers, the structure
2503 *  returned by png_get_text will always contain regular
2504 *  zero-terminated C strings.  They might be empty strings but
2505 *  they will never be NULL pointers.
2506 */
2507
2508#ifdef PNG_TEXT_SUPPORTED
2509extern PNG_EXPORT(void,png_set_text) PNGARG((png_structp png_ptr,
2510   png_infop info_ptr, png_textp text_ptr, int num_text));
2511#endif
2512
2513#ifdef PNG_tIME_SUPPORTED
2514extern PNG_EXPORT(png_uint_32,png_get_tIME) PNGARG((png_structp png_ptr,
2515   png_infop info_ptr, png_timep *mod_time));
2516#endif
2517
2518#ifdef PNG_tIME_SUPPORTED
2519extern PNG_EXPORT(void,png_set_tIME) PNGARG((png_structp png_ptr,
2520   png_infop info_ptr, png_timep mod_time));
2521#endif
2522
2523#ifdef PNG_tRNS_SUPPORTED
2524extern PNG_EXPORT(png_uint_32,png_get_tRNS) PNGARG((png_structp png_ptr,
2525   png_infop info_ptr, png_bytep *trans, int *num_trans,
2526   png_color_16p *trans_values));
2527#endif
2528
2529#ifdef PNG_tRNS_SUPPORTED
2530extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
2531   png_infop info_ptr, png_bytep trans, int num_trans,
2532   png_color_16p trans_values));
2533#endif
2534
2535#ifdef PNG_tRNS_SUPPORTED
2536#endif
2537
2538#ifdef PNG_sCAL_SUPPORTED
2539#ifdef PNG_FLOATING_POINT_SUPPORTED
2540extern PNG_EXPORT(png_uint_32,png_get_sCAL) PNGARG((png_structp png_ptr,
2541   png_infop info_ptr, int *unit, double *width, double *height));
2542#else
2543#ifdef PNG_FIXED_POINT_SUPPORTED
2544extern PNG_EXPORT(png_uint_32,png_get_sCAL_s) PNGARG((png_structp png_ptr,
2545   png_infop info_ptr, int *unit, png_charpp swidth, png_charpp sheight));
2546#endif
2547#endif
2548#endif /* PNG_sCAL_SUPPORTED */
2549
2550#ifdef PNG_sCAL_SUPPORTED
2551#ifdef PNG_FLOATING_POINT_SUPPORTED
2552extern PNG_EXPORT(void,png_set_sCAL) PNGARG((png_structp png_ptr,
2553   png_infop info_ptr, int unit, double width, double height));
2554#else
2555#ifdef PNG_FIXED_POINT_SUPPORTED
2556extern PNG_EXPORT(void,png_set_sCAL_s) PNGARG((png_structp png_ptr,
2557   png_infop info_ptr, int unit, png_charp swidth, png_charp sheight));
2558#endif
2559#endif
2560#endif /* PNG_sCAL_SUPPORTED || PNG_WRITE_sCAL_SUPPORTED */
2561
2562#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2563/* Provide a list of chunks and how they are to be handled, if the built-in
2564   handling or default unknown chunk handling is not desired.  Any chunks not
2565   listed will be handled in the default manner.  The IHDR and IEND chunks
2566   must not be listed.
2567      keep = 0: follow default behaviour
2568           = 1: do not keep
2569           = 2: keep only if safe-to-copy
2570           = 3: keep even if unsafe-to-copy
2571*/
2572extern PNG_EXPORT(void, png_set_keep_unknown_chunks) PNGARG((png_structp
2573   png_ptr, int keep, png_bytep chunk_list, int num_chunks));
2574PNG_EXPORT(int,png_handle_as_unknown) PNGARG((png_structp png_ptr, png_bytep
2575   chunk_name));
2576#endif
2577#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
2578extern PNG_EXPORT(void, png_set_unknown_chunks) PNGARG((png_structp png_ptr,
2579   png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns));
2580extern PNG_EXPORT(void, png_set_unknown_chunk_location)
2581   PNGARG((png_structp png_ptr, png_infop info_ptr, int chunk, int location));
2582extern PNG_EXPORT(png_uint_32,png_get_unknown_chunks) PNGARG((png_structp
2583   png_ptr, png_infop info_ptr, png_unknown_chunkpp entries));
2584#endif
2585
2586/* Png_free_data() will turn off the "valid" flag for anything it frees.
2587 * If you need to turn it off for a chunk that your application has freed,
2588 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
2589 */
2590extern PNG_EXPORT(void, png_set_invalid) PNGARG((png_structp png_ptr,
2591   png_infop info_ptr, int mask));
2592
2593#ifdef PNG_INFO_IMAGE_SUPPORTED
2594/* The "params" pointer is currently not used and is for future expansion. */
2595extern PNG_EXPORT(void, png_read_png) PNGARG((png_structp png_ptr,
2596                        png_infop info_ptr,
2597                        int transforms,
2598                        png_voidp params));
2599extern PNG_EXPORT(void, png_write_png) PNGARG((png_structp png_ptr,
2600                        png_infop info_ptr,
2601                        int transforms,
2602                        png_voidp params));
2603#endif
2604
2605/* Define PNG_DEBUG at compile time for debugging information.  Higher
2606 * numbers for PNG_DEBUG mean more debugging information.  This has
2607 * only been added since version 0.95 so it is not implemented throughout
2608 * libpng yet, but more support will be added as needed.
2609 */
2610#ifdef PNG_DEBUG
2611#if (PNG_DEBUG > 0)
2612#if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER)
2613#include <crtdbg.h>
2614#if (PNG_DEBUG > 1)
2615#ifndef _DEBUG
2616#  define _DEBUG
2617#endif
2618#ifndef png_debug
2619#define png_debug(l,m)  _RPT0(_CRT_WARN,m PNG_STRING_NEWLINE)
2620#endif
2621#ifndef png_debug1
2622#define png_debug1(l,m,p1)  _RPT1(_CRT_WARN,m PNG_STRING_NEWLINE,p1)
2623#endif
2624#ifndef png_debug2
2625#define png_debug2(l,m,p1,p2) _RPT2(_CRT_WARN,m PNG_STRING_NEWLINE,p1,p2)
2626#endif
2627#endif
2628#else /* PNG_DEBUG_FILE || !_MSC_VER */
2629#ifndef PNG_DEBUG_FILE
2630#define PNG_DEBUG_FILE stderr
2631#endif /* PNG_DEBUG_FILE */
2632
2633#if (PNG_DEBUG > 1)
2634/* Note: ["%s"m PNG_STRING_NEWLINE] probably does not work on non-ISO
2635 * compilers.
2636 */
2637#  ifdef __STDC__
2638#    ifndef png_debug
2639#      define png_debug(l,m) \
2640       { \
2641       int num_tabs=l; \
2642       fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
2643         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":"")))); \
2644       }
2645#    endif
2646#    ifndef png_debug1
2647#      define png_debug1(l,m,p1) \
2648       { \
2649       int num_tabs=l; \
2650       fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
2651         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1); \
2652       }
2653#    endif
2654#    ifndef png_debug2
2655#      define png_debug2(l,m,p1,p2) \
2656       { \
2657       int num_tabs=l; \
2658       fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
2659         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1,p2); \
2660       }
2661#    endif
2662#  else /* __STDC __ */
2663#    ifndef png_debug
2664#      define png_debug(l,m) \
2665       { \
2666       int num_tabs=l; \
2667       char format[256]; \
2668       snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
2669         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
2670         m,PNG_STRING_NEWLINE); \
2671       fprintf(PNG_DEBUG_FILE,format); \
2672       }
2673#    endif
2674#    ifndef png_debug1
2675#      define png_debug1(l,m,p1) \
2676       { \
2677       int num_tabs=l; \
2678       char format[256]; \
2679       snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
2680         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
2681         m,PNG_STRING_NEWLINE); \
2682       fprintf(PNG_DEBUG_FILE,format,p1); \
2683       }
2684#    endif
2685#    ifndef png_debug2
2686#      define png_debug2(l,m,p1,p2) \
2687       { \
2688       int num_tabs=l; \
2689       char format[256]; \
2690       snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
2691         (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
2692         m,PNG_STRING_NEWLINE); \
2693       fprintf(PNG_DEBUG_FILE,format,p1,p2); \
2694       }
2695#    endif
2696#  endif /* __STDC __ */
2697#endif /* (PNG_DEBUG > 1) */
2698
2699#endif /* _MSC_VER */
2700#endif /* (PNG_DEBUG > 0) */
2701#endif /* PNG_DEBUG */
2702#ifndef png_debug
2703#define png_debug(l, m)
2704#endif
2705#ifndef png_debug1
2706#define png_debug1(l, m, p1)
2707#endif
2708#ifndef png_debug2
2709#define png_debug2(l, m, p1, p2)
2710#endif
2711
2712extern PNG_EXPORT(png_charp,png_get_copyright) PNGARG((png_structp png_ptr));
2713extern PNG_EXPORT(png_charp,png_get_header_ver) PNGARG((png_structp png_ptr));
2714extern PNG_EXPORT(png_charp,png_get_header_version) PNGARG((png_structp png_ptr));
2715extern PNG_EXPORT(png_charp,png_get_libpng_ver) PNGARG((png_structp png_ptr));
2716
2717#ifdef PNG_MNG_FEATURES_SUPPORTED
2718extern PNG_EXPORT(png_uint_32,png_permit_mng_features) PNGARG((png_structp
2719   png_ptr, png_uint_32 mng_features_permitted));
2720#endif
2721
2722/* For use in png_set_keep_unknown, added to version 1.2.6 */
2723#define PNG_HANDLE_CHUNK_AS_DEFAULT   0
2724#define PNG_HANDLE_CHUNK_NEVER        1
2725#define PNG_HANDLE_CHUNK_IF_SAFE      2
2726#define PNG_HANDLE_CHUNK_ALWAYS       3
2727
2728/* Added to version 1.2.0 */
2729#ifdef PNG_ASSEMBLER_CODE_SUPPORTED
2730#ifdef PNG_MMX_CODE_SUPPORTED
2731#define PNG_ASM_FLAG_MMX_SUPPORT_COMPILED  0x01  /* not user-settable */
2732#define PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU    0x02  /* not user-settable */
2733#define PNG_ASM_FLAG_MMX_READ_COMBINE_ROW  0x04
2734#define PNG_ASM_FLAG_MMX_READ_INTERLACE    0x08
2735#define PNG_ASM_FLAG_MMX_READ_FILTER_SUB   0x10
2736#define PNG_ASM_FLAG_MMX_READ_FILTER_UP    0x20
2737#define PNG_ASM_FLAG_MMX_READ_FILTER_AVG   0x40
2738#define PNG_ASM_FLAG_MMX_READ_FILTER_PAETH 0x80
2739#define PNG_ASM_FLAGS_INITIALIZED          0x80000000  /* not user-settable */
2740
2741#define PNG_MMX_READ_FLAGS ( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW  \
2742                           | PNG_ASM_FLAG_MMX_READ_INTERLACE    \
2743                           | PNG_ASM_FLAG_MMX_READ_FILTER_SUB   \
2744                           | PNG_ASM_FLAG_MMX_READ_FILTER_UP    \
2745                           | PNG_ASM_FLAG_MMX_READ_FILTER_AVG   \
2746                           | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH )
2747#define PNG_MMX_WRITE_FLAGS ( 0 )
2748
2749#define PNG_MMX_FLAGS ( PNG_ASM_FLAG_MMX_SUPPORT_COMPILED \
2750                      | PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU   \
2751                      | PNG_MMX_READ_FLAGS                \
2752                      | PNG_MMX_WRITE_FLAGS )
2753
2754#define PNG_SELECT_READ   1
2755#define PNG_SELECT_WRITE  2
2756#endif /* PNG_MMX_CODE_SUPPORTED */
2757
2758#ifndef PNG_1_0_X
2759/* pngget.c */
2760extern PNG_EXPORT(png_uint_32,png_get_mmx_flagmask)
2761   PNGARG((int flag_select, int *compilerID));
2762
2763/* pngget.c */
2764extern PNG_EXPORT(png_uint_32,png_get_asm_flagmask)
2765   PNGARG((int flag_select));
2766
2767/* pngget.c */
2768extern PNG_EXPORT(png_uint_32,png_get_asm_flags)
2769   PNGARG((png_structp png_ptr));
2770
2771/* pngget.c */
2772extern PNG_EXPORT(png_byte,png_get_mmx_bitdepth_threshold)
2773   PNGARG((png_structp png_ptr));
2774
2775/* pngget.c */
2776extern PNG_EXPORT(png_uint_32,png_get_mmx_rowbytes_threshold)
2777   PNGARG((png_structp png_ptr));
2778
2779/* pngset.c */
2780extern PNG_EXPORT(void,png_set_asm_flags)
2781   PNGARG((png_structp png_ptr, png_uint_32 asm_flags));
2782
2783/* pngset.c */
2784extern PNG_EXPORT(void,png_set_mmx_thresholds)
2785   PNGARG((png_structp png_ptr, png_byte mmx_bitdepth_threshold,
2786   png_uint_32 mmx_rowbytes_threshold));
2787
2788#endif /* PNG_1_0_X */
2789
2790#ifndef PNG_1_0_X
2791/* png.c, pnggccrd.c, or pngvcrd.c */
2792extern PNG_EXPORT(int,png_mmx_support) PNGARG((void));
2793#endif /* PNG_1_0_X */
2794#endif /* PNG_ASSEMBLER_CODE_SUPPORTED */
2795
2796/* Strip the prepended error numbers ("#nnn ") from error and warning
2797 * messages before passing them to the error or warning handler.
2798 */
2799#ifdef PNG_ERROR_NUMBERS_SUPPORTED
2800extern PNG_EXPORT(void,png_set_strip_error_numbers) PNGARG((png_structp
2801   png_ptr, png_uint_32 strip_mode));
2802#endif
2803
2804/* Added at libpng-1.2.6 */
2805#ifdef PNG_SET_USER_LIMITS_SUPPORTED
2806extern PNG_EXPORT(void,png_set_user_limits) PNGARG((png_structp
2807   png_ptr, png_uint_32 user_width_max, png_uint_32 user_height_max));
2808extern PNG_EXPORT(png_uint_32,png_get_user_width_max) PNGARG((png_structp
2809   png_ptr));
2810extern PNG_EXPORT(png_uint_32,png_get_user_height_max) PNGARG((png_structp
2811   png_ptr));
2812#endif
2813/* Maintainer: Put new public prototypes here ^, in libpng.3, and in
2814 * project defs
2815 */
2816
2817#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2818/* With these routines we avoid an integer divide, which will be slower on
2819 * most machines.  However, it does take more operations than the corresponding
2820 * divide method, so it may be slower on a few RISC systems.  There are two
2821 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2822 *
2823 * Note that the rounding factors are NOT supposed to be the same!  128 and
2824 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2825 * standard method.
2826 *
2827 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2828 */
2829
2830 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity          */
2831
2832#  define png_composite(composite, fg, alpha, bg)                            \
2833     { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) * (png_uint_16)(alpha) \
2834                        +        (png_uint_16)(bg)*(png_uint_16)(255 -       \
2835                        (png_uint_16)(alpha)) + (png_uint_16)128);           \
2836       (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
2837
2838#  define png_composite_16(composite, fg, alpha, bg)                         \
2839     { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) * (png_uint_32)(alpha) \
2840                        + (png_uint_32)(bg)*(png_uint_32)(65535L -           \
2841                        (png_uint_32)(alpha)) + (png_uint_32)32768L);        \
2842       (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
2843
2844#else  /* Standard method using integer division */
2845
2846#  define png_composite(composite, fg, alpha, bg)                            \
2847     (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) +    \
2848       (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) +       \
2849       (png_uint_16)127) / 255)
2850
2851#  define png_composite_16(composite, fg, alpha, bg)                         \
2852     (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2853       (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) +      \
2854       (png_uint_32)32767) / (png_uint_32)65535L)
2855
2856#endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
2857
2858/* Inline macros to do direct reads of bytes from the input buffer.  These
2859 * require that you are using an architecture that uses PNG byte ordering
2860 * (MSB first) and supports unaligned data storage.  I think that PowerPC
2861 * in big-endian mode and 680x0 are the only ones that will support this.
2862 * The x86 line of processors definitely do not.  The png_get_int_32()
2863 * routine also assumes we are using two's complement format for negative
2864 * values, which is almost certainly true.
2865 */
2866#ifdef PNG_READ_BIG_ENDIAN_SUPPORTED
2867#  define png_get_uint_32(buf) ( *((png_uint_32p) (buf)))
2868#  define png_get_uint_16(buf) ( *((png_uint_16p) (buf)))
2869#  define png_get_int_32(buf)  ( *((png_int_32p)  (buf)))
2870#else
2871extern PNG_EXPORT(png_uint_32,png_get_uint_32) PNGARG((png_bytep buf));
2872extern PNG_EXPORT(png_uint_16,png_get_uint_16) PNGARG((png_bytep buf));
2873extern PNG_EXPORT(png_int_32,png_get_int_32) PNGARG((png_bytep buf));
2874#endif /* !PNG_READ_BIG_ENDIAN_SUPPORTED */
2875extern PNG_EXPORT(png_uint_32,png_get_uint_31)
2876  PNGARG((png_structp png_ptr, png_bytep buf));
2877/* No png_get_int_16 -- may be added if there's a real need for it. */
2878
2879/* Place a 32-bit number into a buffer in PNG byte order (big-endian).
2880 */
2881extern PNG_EXPORT(void,png_save_uint_32)
2882   PNGARG((png_bytep buf, png_uint_32 i));
2883extern PNG_EXPORT(void,png_save_int_32)
2884   PNGARG((png_bytep buf, png_int_32 i));
2885
2886/* Place a 16-bit number into a buffer in PNG byte order.
2887 * The parameter is declared unsigned int, not png_uint_16,
2888 * just to avoid potential problems on pre-ANSI C compilers.
2889 */
2890extern PNG_EXPORT(void,png_save_uint_16)
2891   PNGARG((png_bytep buf, unsigned int i));
2892/* No png_save_int_16 -- may be added if there's a real need for it. */
2893
2894/* ************************************************************************* */
2895
2896/* These next functions are used internally in the code.  They generally
2897 * shouldn't be used unless you are writing code to add or replace some
2898 * functionality in libpng.  More information about most functions can
2899 * be found in the files where the functions are located.
2900 */
2901
2902
2903/* Various modes of operation, that are visible to applications because
2904 * they are used for unknown chunk location.
2905 */
2906#define PNG_HAVE_IHDR               0x01
2907#define PNG_HAVE_PLTE               0x02
2908#define PNG_HAVE_IDAT               0x04
2909#define PNG_AFTER_IDAT              0x08 /* Have complete zlib datastream */
2910#define PNG_HAVE_IEND               0x10
2911
2912#ifdef PNG_INTERNAL
2913
2914/* More modes of operation.  Note that after an init, mode is set to
2915 * zero automatically when the structure is created.
2916 */
2917#define PNG_HAVE_gAMA               0x20
2918#define PNG_HAVE_cHRM               0x40
2919#define PNG_HAVE_sRGB               0x80
2920#define PNG_HAVE_CHUNK_HEADER      0x100
2921#define PNG_WROTE_tIME             0x200
2922#define PNG_WROTE_INFO_BEFORE_PLTE 0x400
2923#define PNG_BACKGROUND_IS_GRAY     0x800
2924#define PNG_HAVE_PNG_SIGNATURE    0x1000
2925#define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
2926
2927/* Flags for the transformations the PNG library does on the image data */
2928#define PNG_BGR                0x0001
2929#define PNG_INTERLACE          0x0002
2930#define PNG_PACK               0x0004
2931#define PNG_SHIFT              0x0008
2932#define PNG_SWAP_BYTES         0x0010
2933#define PNG_INVERT_MONO        0x0020
2934#define PNG_DITHER             0x0040
2935#define PNG_BACKGROUND         0x0080
2936#define PNG_BACKGROUND_EXPAND  0x0100
2937                          /*   0x0200 unused */
2938#define PNG_16_TO_8            0x0400
2939#define PNG_RGBA               0x0800
2940#define PNG_EXPAND             0x1000
2941#define PNG_GAMMA              0x2000
2942#define PNG_GRAY_TO_RGB        0x4000
2943#define PNG_FILLER             0x8000L
2944#define PNG_PACKSWAP          0x10000L
2945#define PNG_SWAP_ALPHA        0x20000L
2946#define PNG_STRIP_ALPHA       0x40000L
2947#define PNG_INVERT_ALPHA      0x80000L
2948#define PNG_USER_TRANSFORM   0x100000L
2949#define PNG_RGB_TO_GRAY_ERR  0x200000L
2950#define PNG_RGB_TO_GRAY_WARN 0x400000L
2951#define PNG_RGB_TO_GRAY      0x600000L  /* two bits, RGB_TO_GRAY_ERR|WARN */
2952                       /*    0x800000L     Unused */
2953#define PNG_ADD_ALPHA       0x1000000L  /* Added to libpng-1.2.7 */
2954#define PNG_EXPAND_tRNS     0x2000000L  /* Added to libpng-1.2.9 */
2955#define PNG_PREMULTIPLY_ALPHA 0x4000000L  /* Added to libpng-1.2.41 */
2956                                          /* by volker */
2957                       /*   0x8000000L  unused */
2958                       /*  0x10000000L  unused */
2959                       /*  0x20000000L  unused */
2960                       /*  0x40000000L  unused */
2961
2962/* Flags for png_create_struct */
2963#define PNG_STRUCT_PNG   0x0001
2964#define PNG_STRUCT_INFO  0x0002
2965
2966/* Scaling factor for filter heuristic weighting calculations */
2967#define PNG_WEIGHT_SHIFT 8
2968#define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
2969#define PNG_COST_SHIFT 3
2970#define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
2971
2972/* Flags for the png_ptr->flags rather than declaring a byte for each one */
2973#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY     0x0001
2974#define PNG_FLAG_ZLIB_CUSTOM_LEVEL        0x0002
2975#define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL    0x0004
2976#define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS  0x0008
2977#define PNG_FLAG_ZLIB_CUSTOM_METHOD       0x0010
2978#define PNG_FLAG_ZLIB_FINISHED            0x0020
2979#define PNG_FLAG_ROW_INIT                 0x0040
2980#define PNG_FLAG_FILLER_AFTER             0x0080
2981#define PNG_FLAG_CRC_ANCILLARY_USE        0x0100
2982#define PNG_FLAG_CRC_ANCILLARY_NOWARN     0x0200
2983#define PNG_FLAG_CRC_CRITICAL_USE         0x0400
2984#define PNG_FLAG_CRC_CRITICAL_IGNORE      0x0800
2985#define PNG_FLAG_FREE_PLTE                0x1000
2986#define PNG_FLAG_FREE_TRNS                0x2000
2987#define PNG_FLAG_FREE_HIST                0x4000
2988#define PNG_FLAG_KEEP_UNKNOWN_CHUNKS      0x8000L
2989#define PNG_FLAG_KEEP_UNSAFE_CHUNKS       0x10000L
2990#define PNG_FLAG_LIBRARY_MISMATCH         0x20000L
2991#define PNG_FLAG_STRIP_ERROR_NUMBERS      0x40000L
2992#define PNG_FLAG_STRIP_ERROR_TEXT         0x80000L
2993#define PNG_FLAG_MALLOC_NULL_MEM_OK       0x100000L
2994#define PNG_FLAG_ADD_ALPHA                0x200000L  /* Added to libpng-1.2.8 */
2995#define PNG_FLAG_STRIP_ALPHA              0x400000L  /* Added to libpng-1.2.8 */
2996                                  /*      0x800000L  unused */
2997                                  /*     0x1000000L  unused */
2998                                  /*     0x2000000L  unused */
2999                                  /*     0x4000000L  unused */
3000                                  /*     0x8000000L  unused */
3001                                  /*    0x10000000L  unused */
3002                                  /*    0x20000000L  unused */
3003                                  /*    0x40000000L  unused */
3004
3005#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
3006                                     PNG_FLAG_CRC_ANCILLARY_NOWARN)
3007
3008#define PNG_FLAG_CRC_CRITICAL_MASK  (PNG_FLAG_CRC_CRITICAL_USE | \
3009                                     PNG_FLAG_CRC_CRITICAL_IGNORE)
3010
3011#define PNG_FLAG_CRC_MASK           (PNG_FLAG_CRC_ANCILLARY_MASK | \
3012                                     PNG_FLAG_CRC_CRITICAL_MASK)
3013
3014/* Save typing and make code easier to understand */
3015
3016#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
3017   abs((int)((c1).green) - (int)((c2).green)) + \
3018   abs((int)((c1).blue) - (int)((c2).blue)))
3019
3020/* Added to libpng-1.2.6 JB */
3021#define PNG_ROWBYTES(pixel_bits, width) \
3022    ((pixel_bits) >= 8 ? \
3023    ((width) * (((png_uint_32)(pixel_bits)) >> 3)) : \
3024    (( ((width) * ((png_uint_32)(pixel_bits))) + 7) >> 3) )
3025
3026/* PNG_OUT_OF_RANGE returns true if value is outside the range
3027 * ideal-delta..ideal+delta.  Each argument is evaluated twice.
3028 * "ideal" and "delta" should be constants, normally simple
3029 * integers, "value" a variable. Added to libpng-1.2.6 JB
3030 */
3031#define PNG_OUT_OF_RANGE(value, ideal, delta) \
3032        ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
3033
3034/* Variables declared in png.c - only it needs to define PNG_NO_EXTERN */
3035#if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
3036/* Place to hold the signature string for a PNG file. */
3037#ifdef PNG_USE_GLOBAL_ARRAYS
3038   PNG_EXPORT_VAR (PNG_CONST png_byte FARDATA) png_sig[8];
3039#else
3040#endif
3041#endif /* PNG_NO_EXTERN */
3042
3043/* Constant strings for known chunk types.  If you need to add a chunk,
3044 * define the name here, and add an invocation of the macro in png.c and
3045 * wherever it's needed.
3046 */
3047#define PNG_IHDR png_byte png_IHDR[5] = { 73,  72,  68,  82, '\0'}
3048#define PNG_IDAT png_byte png_IDAT[5] = { 73,  68,  65,  84, '\0'}
3049#define PNG_IEND png_byte png_IEND[5] = { 73,  69,  78,  68, '\0'}
3050#define PNG_PLTE png_byte png_PLTE[5] = { 80,  76,  84,  69, '\0'}
3051#define PNG_bKGD png_byte png_bKGD[5] = { 98,  75,  71,  68, '\0'}
3052#define PNG_cHRM png_byte png_cHRM[5] = { 99,  72,  82,  77, '\0'}
3053#define PNG_gAMA png_byte png_gAMA[5] = {103,  65,  77,  65, '\0'}
3054#define PNG_hIST png_byte png_hIST[5] = {104,  73,  83,  84, '\0'}
3055#define PNG_iCCP png_byte png_iCCP[5] = {105,  67,  67,  80, '\0'}
3056#define PNG_iTXt png_byte png_iTXt[5] = {105,  84,  88, 116, '\0'}
3057#define PNG_oFFs png_byte png_oFFs[5] = {111,  70,  70, 115, '\0'}
3058#define PNG_pCAL png_byte png_pCAL[5] = {112,  67,  65,  76, '\0'}
3059#define PNG_sCAL png_byte png_sCAL[5] = {115,  67,  65,  76, '\0'}
3060#define PNG_pHYs png_byte png_pHYs[5] = {112,  72,  89, 115, '\0'}
3061#define PNG_sBIT png_byte png_sBIT[5] = {115,  66,  73,  84, '\0'}
3062#define PNG_sPLT png_byte png_sPLT[5] = {115,  80,  76,  84, '\0'}
3063#define PNG_sRGB png_byte png_sRGB[5] = {115,  82,  71,  66, '\0'}
3064#define PNG_tEXt png_byte png_tEXt[5] = {116,  69,  88, 116, '\0'}
3065#define PNG_tIME png_byte png_tIME[5] = {116,  73,  77,  69, '\0'}
3066#define PNG_tRNS png_byte png_tRNS[5] = {116,  82,  78,  83, '\0'}
3067#define PNG_zTXt png_byte png_zTXt[5] = {122,  84,  88, 116, '\0'}
3068
3069#ifdef PNG_USE_GLOBAL_ARRAYS
3070PNG_EXPORT_VAR (png_byte FARDATA) png_IHDR[5];
3071PNG_EXPORT_VAR (png_byte FARDATA) png_IDAT[5];
3072PNG_EXPORT_VAR (png_byte FARDATA) png_IEND[5];
3073PNG_EXPORT_VAR (png_byte FARDATA) png_PLTE[5];
3074PNG_EXPORT_VAR (png_byte FARDATA) png_bKGD[5];
3075PNG_EXPORT_VAR (png_byte FARDATA) png_cHRM[5];
3076PNG_EXPORT_VAR (png_byte FARDATA) png_gAMA[5];
3077PNG_EXPORT_VAR (png_byte FARDATA) png_hIST[5];
3078PNG_EXPORT_VAR (png_byte FARDATA) png_iCCP[5];
3079PNG_EXPORT_VAR (png_byte FARDATA) png_iTXt[5];
3080PNG_EXPORT_VAR (png_byte FARDATA) png_oFFs[5];
3081PNG_EXPORT_VAR (png_byte FARDATA) png_pCAL[5];
3082PNG_EXPORT_VAR (png_byte FARDATA) png_sCAL[5];
3083PNG_EXPORT_VAR (png_byte FARDATA) png_pHYs[5];
3084PNG_EXPORT_VAR (png_byte FARDATA) png_sBIT[5];
3085PNG_EXPORT_VAR (png_byte FARDATA) png_sPLT[5];
3086PNG_EXPORT_VAR (png_byte FARDATA) png_sRGB[5];
3087PNG_EXPORT_VAR (png_byte FARDATA) png_tEXt[5];
3088PNG_EXPORT_VAR (png_byte FARDATA) png_tIME[5];
3089PNG_EXPORT_VAR (png_byte FARDATA) png_tRNS[5];
3090PNG_EXPORT_VAR (png_byte FARDATA) png_zTXt[5];
3091#endif /* PNG_USE_GLOBAL_ARRAYS */
3092
3093#if defined(PNG_1_0_X) || defined (PNG_1_2_X)
3094/* Initialize png_ptr struct for reading, and allocate any other memory.
3095 * (old interface - DEPRECATED - use png_create_read_struct instead).
3096 */
3097extern PNG_EXPORT(void,png_read_init) PNGARG((png_structp png_ptr))
3098    PNG_DEPRECATED;
3099#undef png_read_init
3100#define png_read_init(png_ptr) png_read_init_3(&png_ptr, \
3101    PNG_LIBPNG_VER_STRING,  png_sizeof(png_struct));
3102#endif
3103
3104extern PNG_EXPORT(void,png_read_init_3) PNGARG((png_structpp ptr_ptr,
3105    png_const_charp user_png_ver, png_size_t png_struct_size));
3106#if defined(PNG_1_0_X) || defined (PNG_1_2_X)
3107extern PNG_EXPORT(void,png_read_init_2) PNGARG((png_structp png_ptr,
3108    png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
3109    png_info_size));
3110#endif
3111
3112#if defined(PNG_1_0_X) || defined (PNG_1_2_X)
3113/* Initialize png_ptr struct for writing, and allocate any other memory.
3114 * (old interface - DEPRECATED - use png_create_write_struct instead).
3115 */
3116extern PNG_EXPORT(void,png_write_init) PNGARG((png_structp png_ptr))
3117    PNG_DEPRECATED;
3118#undef png_write_init
3119#define png_write_init(png_ptr) png_write_init_3(&png_ptr, \
3120    PNG_LIBPNG_VER_STRING, png_sizeof(png_struct));
3121#endif
3122
3123extern PNG_EXPORT(void,png_write_init_3) PNGARG((png_structpp ptr_ptr,
3124    png_const_charp user_png_ver, png_size_t png_struct_size));
3125extern PNG_EXPORT(void,png_write_init_2) PNGARG((png_structp png_ptr,
3126    png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
3127    png_info_size));
3128
3129/* Allocate memory for an internal libpng struct */
3130PNG_EXTERN png_voidp png_create_struct PNGARG((int type)) PNG_PRIVATE;
3131
3132/* Free memory from internal libpng struct */
3133PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr)) PNG_PRIVATE;
3134
3135PNG_EXTERN png_voidp png_create_struct_2 PNGARG((int type, png_malloc_ptr
3136  malloc_fn, png_voidp mem_ptr)) PNG_PRIVATE;
3137PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr,
3138   png_free_ptr free_fn, png_voidp mem_ptr)) PNG_PRIVATE;
3139
3140/* Free any memory that info_ptr points to and reset struct. */
3141PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr,
3142   png_infop info_ptr)) PNG_PRIVATE;
3143
3144#ifndef PNG_1_0_X
3145/* Function to allocate memory for zlib. */
3146PNG_EXTERN voidpf png_zalloc PNGARG((voidpf png_ptr, uInt items,
3147   uInt size)) PNG_PRIVATE;
3148
3149/* Function to free memory for zlib */
3150PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr)) PNG_PRIVATE;
3151
3152#ifdef PNG_SIZE_T
3153/* Function to convert a sizeof an item to png_sizeof item */
3154   PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size))
3155      PNG_PRIVATE;
3156#endif
3157
3158/* Next four functions are used internally as callbacks.  PNGAPI is required
3159 * but not PNG_EXPORT.  PNGAPI added at libpng version 1.2.3.
3160 */
3161
3162PNG_EXTERN void PNGAPI png_default_read_data PNGARG((png_structp png_ptr,
3163   png_bytep data, png_size_t length)) PNG_PRIVATE;
3164
3165#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3166PNG_EXTERN void PNGAPI png_push_fill_buffer PNGARG((png_structp png_ptr,
3167   png_bytep buffer, png_size_t length)) PNG_PRIVATE;
3168#endif
3169
3170PNG_EXTERN void PNGAPI png_default_write_data PNGARG((png_structp png_ptr,
3171   png_bytep data, png_size_t length)) PNG_PRIVATE;
3172
3173#ifdef PNG_WRITE_FLUSH_SUPPORTED
3174#ifdef PNG_STDIO_SUPPORTED
3175PNG_EXTERN void PNGAPI png_default_flush PNGARG((png_structp png_ptr))
3176   PNG_PRIVATE;
3177#endif
3178#endif
3179#else /* PNG_1_0_X */
3180#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3181PNG_EXTERN void png_push_fill_buffer PNGARG((png_structp png_ptr,
3182   png_bytep buffer, png_size_t length)) PNG_PRIVATE;
3183#endif
3184#endif /* PNG_1_0_X */
3185
3186/* Reset the CRC variable */
3187PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3188
3189/* Write the "data" buffer to whatever output you are using. */
3190PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr, png_bytep data,
3191   png_size_t length)) PNG_PRIVATE;
3192
3193/* Read data from whatever input you are using into the "data" buffer */
3194PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data,
3195   png_size_t length)) PNG_PRIVATE;
3196
3197/* Read bytes into buf, and update png_ptr->crc */
3198PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
3199   png_size_t length)) PNG_PRIVATE;
3200
3201/* Decompress data in a chunk that uses compression */
3202#if defined(PNG_zTXt_SUPPORTED) || defined(PNG_iTXt_SUPPORTED) || \
3203    defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED)
3204PNG_EXTERN void png_decompress_chunk PNGARG((png_structp png_ptr,
3205   int comp_type, png_size_t chunklength,
3206   png_size_t prefix_length, png_size_t *data_length)) PNG_PRIVATE;
3207#endif
3208
3209/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
3210PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip)
3211   PNG_PRIVATE);
3212
3213/* Read the CRC from the file and compare it to the libpng calculated CRC */
3214PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3215
3216/* Calculate the CRC over a section of data.  Note that we are only
3217 * passing a maximum of 64K on systems that have this as a memory limit,
3218 * since this is the maximum buffer size we can specify.
3219 */
3220PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr, png_bytep ptr,
3221   png_size_t length)) PNG_PRIVATE;
3222
3223#ifdef PNG_WRITE_FLUSH_SUPPORTED
3224PNG_EXTERN void png_flush PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3225#endif
3226
3227/* Simple function to write the signature */
3228PNG_EXTERN void png_write_sig PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3229
3230/* Write various chunks */
3231
3232/* Write the IHDR chunk, and update the png_struct with the necessary
3233 * information.
3234 */
3235PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width,
3236   png_uint_32 height,
3237   int bit_depth, int color_type, int compression_method, int filter_method,
3238   int interlace_method)) PNG_PRIVATE;
3239
3240PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr, png_colorp palette,
3241   png_uint_32 num_pal)) PNG_PRIVATE;
3242
3243PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data,
3244   png_size_t length)) PNG_PRIVATE;
3245
3246PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3247
3248#ifdef PNG_WRITE_gAMA_SUPPORTED
3249#ifdef PNG_FLOATING_POINT_SUPPORTED
3250PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma))
3251    PNG_PRIVATE;
3252#endif
3253#ifdef PNG_FIXED_POINT_SUPPORTED
3254PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr,
3255    png_fixed_point file_gamma)) PNG_PRIVATE;
3256#endif
3257#endif
3258
3259#ifdef PNG_WRITE_sBIT_SUPPORTED
3260PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr, png_color_8p sbit,
3261   int color_type)) PNG_PRIVATE;
3262#endif
3263
3264#ifdef PNG_WRITE_cHRM_SUPPORTED
3265#ifdef PNG_FLOATING_POINT_SUPPORTED
3266PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr,
3267   double white_x, double white_y,
3268   double red_x, double red_y, double green_x, double green_y,
3269   double blue_x, double blue_y)) PNG_PRIVATE;
3270#endif
3271#ifdef PNG_FIXED_POINT_SUPPORTED
3272PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr,
3273   png_fixed_point int_white_x, png_fixed_point int_white_y,
3274   png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
3275   int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
3276   png_fixed_point int_blue_y)) PNG_PRIVATE;
3277#endif
3278#endif
3279
3280#ifdef PNG_WRITE_sRGB_SUPPORTED
3281PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
3282   int intent)) PNG_PRIVATE;
3283#endif
3284
3285#ifdef PNG_WRITE_iCCP_SUPPORTED
3286PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr,
3287   png_charp name, int compression_type,
3288   png_charp profile, int proflen)) PNG_PRIVATE;
3289   /* Note to maintainer: profile should be png_bytep */
3290#endif
3291
3292#ifdef PNG_WRITE_sPLT_SUPPORTED
3293PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr,
3294   png_sPLT_tp palette)) PNG_PRIVATE;
3295#endif
3296
3297#ifdef PNG_WRITE_tRNS_SUPPORTED
3298PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr, png_bytep trans,
3299   png_color_16p values, int number, int color_type)) PNG_PRIVATE;
3300#endif
3301
3302#ifdef PNG_WRITE_bKGD_SUPPORTED
3303PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr,
3304   png_color_16p values, int color_type)) PNG_PRIVATE;
3305#endif
3306
3307#ifdef PNG_WRITE_hIST_SUPPORTED
3308PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, png_uint_16p hist,
3309   int num_hist)) PNG_PRIVATE;
3310#endif
3311
3312#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
3313    defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
3314PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
3315   png_charp key, png_charpp new_key)) PNG_PRIVATE;
3316#endif
3317
3318#ifdef PNG_WRITE_tEXt_SUPPORTED
3319PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_charp key,
3320   png_charp text, png_size_t text_len)) PNG_PRIVATE;
3321#endif
3322
3323#ifdef PNG_WRITE_zTXt_SUPPORTED
3324PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_charp key,
3325   png_charp text, png_size_t text_len, int compression)) PNG_PRIVATE;
3326#endif
3327
3328#ifdef PNG_WRITE_iTXt_SUPPORTED
3329PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr,
3330   int compression, png_charp key, png_charp lang, png_charp lang_key,
3331   png_charp text)) PNG_PRIVATE;
3332#endif
3333
3334#ifdef PNG_TEXT_SUPPORTED  /* Added at version 1.0.14 and 1.2.4 */
3335PNG_EXTERN int png_set_text_2 PNGARG((png_structp png_ptr,
3336   png_infop info_ptr, png_textp text_ptr, int num_text)) PNG_PRIVATE;
3337#endif
3338
3339#ifdef PNG_WRITE_oFFs_SUPPORTED
3340PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr,
3341   png_int_32 x_offset, png_int_32 y_offset, int unit_type)) PNG_PRIVATE;
3342#endif
3343
3344#ifdef PNG_WRITE_pCAL_SUPPORTED
3345PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose,
3346   png_int_32 X0, png_int_32 X1, int type, int nparams,
3347   png_charp units, png_charpp params)) PNG_PRIVATE;
3348#endif
3349
3350#ifdef PNG_WRITE_pHYs_SUPPORTED
3351PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr,
3352   png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
3353   int unit_type)) PNG_PRIVATE;
3354#endif
3355
3356#ifdef PNG_WRITE_tIME_SUPPORTED
3357PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr,
3358   png_timep mod_time)) PNG_PRIVATE;
3359#endif
3360
3361#ifdef PNG_WRITE_sCAL_SUPPORTED
3362#if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
3363PNG_EXTERN void png_write_sCAL PNGARG((png_structp png_ptr,
3364   int unit, double width, double height)) PNG_PRIVATE;
3365#else
3366#ifdef PNG_FIXED_POINT_SUPPORTED
3367PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr,
3368   int unit, png_charp width, png_charp height)) PNG_PRIVATE;
3369#endif
3370#endif
3371#endif
3372
3373/* Called when finished processing a row of data */
3374PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3375
3376/* Internal use only.   Called before first row of data */
3377PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3378
3379#ifdef PNG_READ_GAMMA_SUPPORTED
3380PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3381#endif
3382
3383/* Combine a row of data, dealing with alpha, etc. if requested */
3384PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row,
3385   int mask)) PNG_PRIVATE;
3386
3387#ifdef PNG_READ_INTERLACING_SUPPORTED
3388/* Expand an interlaced row */
3389/* OLD pre-1.0.9 interface:
3390PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info,
3391   png_bytep row, int pass, png_uint_32 transformations)) PNG_PRIVATE;
3392 */
3393PNG_EXTERN void png_do_read_interlace PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3394#endif
3395
3396/* GRR TO DO (2.0 or whenever):  simplify other internal calling interfaces */
3397
3398#ifdef PNG_WRITE_INTERLACING_SUPPORTED
3399/* Grab pixels out of a row for an interlaced pass */
3400PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info,
3401   png_bytep row, int pass)) PNG_PRIVATE;
3402#endif
3403
3404/* Unfilter a row */
3405PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr,
3406   png_row_infop row_info, png_bytep row, png_bytep prev_row,
3407   int filter)) PNG_PRIVATE;
3408
3409/* Choose the best filter to use and filter the row data */
3410PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
3411   png_row_infop row_info)) PNG_PRIVATE;
3412
3413/* Write out the filtered row. */
3414PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr,
3415   png_bytep filtered_row)) PNG_PRIVATE;
3416/* Finish a row while reading, dealing with interlacing passes, etc. */
3417PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
3418
3419/* Initialize the row buffers, etc. */
3420PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3421/* Optional call to update the users info structure */
3422PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
3423   png_infop info_ptr)) PNG_PRIVATE;
3424
3425/* These are the functions that do the transformations */
3426#ifdef PNG_READ_FILLER_SUPPORTED
3427PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info,
3428   png_bytep row, png_uint_32 filler, png_uint_32 flags)) PNG_PRIVATE;
3429#endif
3430
3431#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
3432PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info,
3433   png_bytep row)) PNG_PRIVATE;
3434#endif
3435
3436#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
3437PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info,
3438   png_bytep row)) PNG_PRIVATE;
3439#endif
3440
3441#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
3442PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info,
3443   png_bytep row)) PNG_PRIVATE;
3444#endif
3445
3446#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
3447PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info,
3448   png_bytep row)) PNG_PRIVATE;
3449#endif
3450
3451#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
3452    defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
3453PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info,
3454   png_bytep row, png_uint_32 flags)) PNG_PRIVATE;
3455#endif
3456
3457#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
3458PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info,
3459    png_bytep row)) PNG_PRIVATE;
3460#endif
3461
3462#if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
3463PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info,
3464    png_bytep row)) PNG_PRIVATE;
3465#endif
3466
3467#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
3468PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr, png_row_infop
3469   row_info, png_bytep row)) PNG_PRIVATE;
3470#endif
3471
3472#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
3473PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info,
3474   png_bytep row)) PNG_PRIVATE;
3475#endif
3476
3477#ifdef PNG_READ_PACK_SUPPORTED
3478PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info,
3479    png_bytep row)) PNG_PRIVATE;
3480#endif
3481
3482#ifdef PNG_READ_SHIFT_SUPPORTED
3483PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info, png_bytep row,
3484   png_color_8p sig_bits)) PNG_PRIVATE;
3485#endif
3486
3487#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
3488PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info,
3489    png_bytep row)) PNG_PRIVATE;
3490#endif
3491
3492#ifdef PNG_READ_16_TO_8_SUPPORTED
3493PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info,
3494    png_bytep row)) PNG_PRIVATE;
3495#endif
3496
3497#ifdef PNG_READ_DITHER_SUPPORTED
3498PNG_EXTERN void png_do_dither PNGARG((png_row_infop row_info,
3499   png_bytep row, png_bytep palette_lookup,
3500    png_bytep dither_lookup)) PNG_PRIVATE;
3501
3502#  ifdef PNG_CORRECT_PALETTE_SUPPORTED
3503PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr,
3504   png_colorp palette, int num_palette)) PNG_PRIVATE;
3505#  endif
3506#endif
3507
3508#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
3509PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info,
3510    png_bytep row)) PNG_PRIVATE;
3511#endif
3512
3513#ifdef PNG_WRITE_PACK_SUPPORTED
3514PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info,
3515   png_bytep row, png_uint_32 bit_depth)) PNG_PRIVATE;
3516#endif
3517
3518#ifdef PNG_WRITE_SHIFT_SUPPORTED
3519PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info, png_bytep row,
3520   png_color_8p bit_depth)) PNG_PRIVATE;
3521#endif
3522
3523#ifdef PNG_READ_BACKGROUND_SUPPORTED
3524#ifdef PNG_READ_GAMMA_SUPPORTED
3525PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
3526   png_color_16p trans_values, png_color_16p background,
3527   png_color_16p background_1,
3528   png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,
3529   png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,
3530   png_uint_16pp gamma_16_to_1, int gamma_shift)) PNG_PRIVATE;
3531#else
3532PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
3533   png_color_16p trans_values, png_color_16p background)) PNG_PRIVATE;
3534#endif
3535#endif
3536
3537#ifdef PNG_READ_GAMMA_SUPPORTED
3538PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info, png_bytep row,
3539   png_bytep gamma_table, png_uint_16pp gamma_16_table,
3540   int gamma_shift)) PNG_PRIVATE;
3541#endif
3542
3543#ifdef PNG_READ_EXPAND_SUPPORTED
3544PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info,
3545   png_bytep row, png_colorp palette, png_bytep trans,
3546   int num_trans)) PNG_PRIVATE;
3547PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info,
3548   png_bytep row, png_color_16p trans_value)) PNG_PRIVATE;
3549#endif
3550
3551/* The following decodes the appropriate chunks, and does error correction,
3552 * then calls the appropriate callback for the chunk if it is valid.
3553 */
3554
3555/* Decode the IHDR chunk */
3556PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr,
3557   png_uint_32 length)) PNG_PRIVATE;
3558PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr,
3559   png_uint_32 length));
3560PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr,
3561   png_uint_32 length));
3562
3563#ifdef PNG_READ_bKGD_SUPPORTED
3564PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr,
3565   png_uint_32 length)) PNG_PRIVATE;
3566#endif
3567
3568#ifdef PNG_READ_cHRM_SUPPORTED
3569PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr,
3570   png_uint_32 length)) PNG_PRIVATE;
3571#endif
3572
3573#ifdef PNG_READ_gAMA_SUPPORTED
3574PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr,
3575   png_uint_32 length)) PNG_PRIVATE;
3576#endif
3577
3578#ifdef PNG_READ_hIST_SUPPORTED
3579PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr,
3580   png_uint_32 length)) PNG_PRIVATE;
3581#endif
3582
3583#ifdef PNG_READ_iCCP_SUPPORTED
3584extern void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr,
3585   png_uint_32 length));
3586#endif /* PNG_READ_iCCP_SUPPORTED */
3587
3588#ifdef PNG_READ_iTXt_SUPPORTED
3589PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3590   png_uint_32 length)) PNG_PRIVATE;
3591#endif
3592
3593#ifdef PNG_READ_oFFs_SUPPORTED
3594PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr,
3595   png_uint_32 length)) PNG_PRIVATE;
3596#endif
3597
3598#ifdef PNG_READ_pCAL_SUPPORTED
3599PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
3600   png_uint_32 length)) PNG_PRIVATE;
3601#endif
3602
3603#ifdef PNG_READ_pHYs_SUPPORTED
3604PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr,
3605   png_uint_32 length)) PNG_PRIVATE;
3606#endif
3607
3608#ifdef PNG_READ_sBIT_SUPPORTED
3609PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr,
3610   png_uint_32 length)) PNG_PRIVATE;
3611#endif
3612
3613#ifdef PNG_READ_sCAL_SUPPORTED
3614PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
3615   png_uint_32 length)) PNG_PRIVATE;
3616#endif
3617
3618#ifdef PNG_READ_sPLT_SUPPORTED
3619extern void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr,
3620   png_uint_32 length)) PNG_PRIVATE;
3621#endif /* PNG_READ_sPLT_SUPPORTED */
3622
3623#ifdef PNG_READ_sRGB_SUPPORTED
3624PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr,
3625   png_uint_32 length)) PNG_PRIVATE;
3626#endif
3627
3628#ifdef PNG_READ_tEXt_SUPPORTED
3629PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3630   png_uint_32 length)) PNG_PRIVATE;
3631#endif
3632
3633#ifdef PNG_READ_tIME_SUPPORTED
3634PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr,
3635   png_uint_32 length)) PNG_PRIVATE;
3636#endif
3637
3638#ifdef PNG_READ_tRNS_SUPPORTED
3639PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr,
3640   png_uint_32 length)) PNG_PRIVATE;
3641#endif
3642
3643#ifdef PNG_READ_zTXt_SUPPORTED
3644PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3645   png_uint_32 length)) PNG_PRIVATE;
3646#endif
3647
3648PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
3649   png_infop info_ptr, png_uint_32 length)) PNG_PRIVATE;
3650
3651PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
3652   png_bytep chunk_name)) PNG_PRIVATE;
3653
3654/* Handle the transformations for reading and writing */
3655PNG_EXTERN void png_do_read_transformations
3656   PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3657PNG_EXTERN void png_do_write_transformations
3658   PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3659
3660PNG_EXTERN void png_init_read_transformations
3661   PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3662
3663#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3664PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
3665   png_infop info_ptr)) PNG_PRIVATE;
3666PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr,
3667   png_infop info_ptr)) PNG_PRIVATE;
3668PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3669PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr,
3670   png_uint_32 length)) PNG_PRIVATE;
3671PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3672PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3673PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr,
3674   png_bytep buffer, png_size_t buffer_length)) PNG_PRIVATE;
3675PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3676PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr,
3677   png_bytep buffer, png_size_t buffer_length)) PNG_PRIVATE;
3678PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3679PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr,
3680   png_infop info_ptr, png_uint_32 length)) PNG_PRIVATE;
3681PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr,
3682   png_infop info_ptr)) PNG_PRIVATE;
3683PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr,
3684   png_infop info_ptr)) PNG_PRIVATE;
3685PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr,
3686   png_bytep row)) PNG_PRIVATE;
3687PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr,
3688   png_infop info_ptr)) PNG_PRIVATE;
3689PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr,
3690   png_infop info_ptr)) PNG_PRIVATE;
3691PNG_EXTERN void png_read_push_finish_row
3692   PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3693#ifdef PNG_READ_tEXt_SUPPORTED
3694PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr,
3695   png_infop info_ptr, png_uint_32 length)) PNG_PRIVATE;
3696PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr,
3697   png_infop info_ptr)) PNG_PRIVATE;
3698#endif
3699#ifdef PNG_READ_zTXt_SUPPORTED
3700PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr,
3701   png_infop info_ptr, png_uint_32 length)) PNG_PRIVATE;
3702PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr,
3703   png_infop info_ptr)) PNG_PRIVATE;
3704#endif
3705#ifdef PNG_READ_iTXt_SUPPORTED
3706PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr,
3707   png_infop info_ptr, png_uint_32 length)) PNG_PRIVATE;
3708PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr,
3709   png_infop info_ptr)) PNG_PRIVATE;
3710#endif
3711
3712#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
3713
3714#ifdef PNG_MNG_FEATURES_SUPPORTED
3715PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info,
3716   png_bytep row)) PNG_PRIVATE;
3717PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info,
3718   png_bytep row)) PNG_PRIVATE;
3719#endif
3720
3721#ifdef PNG_ASSEMBLER_CODE_SUPPORTED
3722#ifdef PNG_MMX_CODE_SUPPORTED
3723/* png.c */ /* PRIVATE */
3724PNG_EXTERN void png_init_mmx_flags PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3725#endif
3726#endif
3727
3728
3729/* The following six functions will be exported in libpng-1.4.0. */
3730#if defined(PNG_INCH_CONVERSIONS) && defined(PNG_FLOATING_POINT_SUPPORTED)
3731PNG_EXTERN png_uint_32 png_get_pixels_per_inch PNGARG((png_structp png_ptr,
3732png_infop info_ptr));
3733
3734PNG_EXTERN png_uint_32 png_get_x_pixels_per_inch PNGARG((png_structp png_ptr,
3735png_infop info_ptr));
3736
3737PNG_EXTERN png_uint_32 png_get_y_pixels_per_inch PNGARG((png_structp png_ptr,
3738png_infop info_ptr));
3739
3740PNG_EXTERN float png_get_x_offset_inches PNGARG((png_structp png_ptr,
3741png_infop info_ptr));
3742
3743PNG_EXTERN float png_get_y_offset_inches PNGARG((png_structp png_ptr,
3744png_infop info_ptr));
3745
3746#ifdef PNG_pHYs_SUPPORTED
3747PNG_EXTERN png_uint_32 png_get_pHYs_dpi PNGARG((png_structp png_ptr,
3748png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
3749#endif /* PNG_pHYs_SUPPORTED */
3750#endif  /* PNG_INCH_CONVERSIONS && PNG_FLOATING_POINT_SUPPORTED */
3751
3752/* Read the chunk header (length + type name) */
3753PNG_EXTERN png_uint_32 png_read_chunk_header
3754   PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3755
3756/* Added at libpng version 1.2.34 */
3757#ifdef PNG_cHRM_SUPPORTED
3758PNG_EXTERN int png_check_cHRM_fixed PNGARG((png_structp png_ptr,
3759   png_fixed_point int_white_x, png_fixed_point int_white_y,
3760   png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
3761   int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
3762   png_fixed_point int_blue_y)) PNG_PRIVATE;
3763#endif
3764
3765#ifdef PNG_cHRM_SUPPORTED
3766#ifdef PNG_CHECK_cHRM_SUPPORTED
3767/* Added at libpng version 1.2.34 */
3768PNG_EXTERN void png_64bit_product PNGARG((long v1, long v2,
3769   unsigned long *hi_product, unsigned long *lo_product)) PNG_PRIVATE;
3770#endif
3771#endif
3772
3773/* Added at libpng version 1.2.41 */
3774PNG_EXTERN void png_check_IHDR PNGARG((png_structp png_ptr,
3775   png_uint_32 width, png_uint_32 height, int bit_depth,
3776   int color_type, int interlace_type, int compression_type,
3777   int filter_type)) PNG_PRIVATE;
3778
3779/* Added at libpng version 1.2.41 */
3780PNG_EXTERN png_voidp png_calloc PNGARG((png_structp png_ptr,
3781   png_uint_32 size));
3782
3783/* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
3784
3785#endif /* PNG_INTERNAL */
3786
3787#ifdef __cplusplus
3788}
3789#endif
3790
3791#endif /* PNG_VERSION_INFO_ONLY */
3792/* Do not put anything past this line */
3793#endif /* PNG_H */
3794