1 /* png.h - header file for PNG reference library
3 * libpng version 1.2.50 - July 10, 2012
4 * Copyright (c) 1998-2012 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.)
8 * This code is released under the libpng license (See LICENSE, below)
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 1.2.50 - July 10, 2012: Glenn
14 * See also "Contributing Authors", below.
16 * Note about libpng version numbers:
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:
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
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.
46 * 1.0.5 (+ 2 patches) 10005
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)
53 * 1.0.6h 10007 10.6h (testing xy.z so-numbering)
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 10 10055 10.so.0.55[.0]
267 * 1.2.45rc01 13 10245 12.so.0.45[.0]
268 * 1.0.55 10 10055 10.so.0.55[.0]
269 * 1.2.45 13 10245 12.so.0.45[.0]
270 * 1.2.46rc01-02 13 10246 12.so.0.46[.0]
271 * 1.0.56 10 10056 10.so.0.56[.0]
272 * 1.2.46 13 10246 12.so.0.46[.0]
273 * 1.2.47beta01 13 10247 12.so.0.47[.0]
274 * 1.2.47rc01 13 10247 12.so.0.47[.0]
275 * 1.0.57rc01 10 10057 10.so.0.57[.0]
276 * 1.2.47 13 10247 12.so.0.47[.0]
277 * 1.0.57 10 10057 10.so.0.57[.0]
278 * 1.2.48beta01 13 10248 12.so.0.48[.0]
279 * 1.2.48rc01-02 13 10248 12.so.0.48[.0]
280 * 1.0.58 10 10058 10.so.0.58[.0]
281 * 1.2.48 13 10248 12.so.0.48[.0]
282 * 1.2.49rc01 13 10249 12.so.0.49[.0]
283 * 1.0.59 10 10059 10.so.0.59[.0]
284 * 1.2.49 13 10249 12.so.0.49[.0]
285 * 1.0.60 10 10060 10.so.0.60[.0]
286 * 1.2.50 13 10250 12.so.0.50[.0]
288 * Henceforth the source version will match the shared-library major
289 * and minor numbers; the shared-library major version number will be
290 * used for changes in backward compatibility, as it is intended. The
291 * PNG_LIBPNG_VER macro, which is not used within libpng but is available
292 * for applications, is an unsigned integer of the form xyyzz corresponding
293 * to the source version x.y.z (leading zeros in y and z). Beta versions
294 * were given the previous public release number plus a letter, until
295 * version 1.0.6j; from then on they were given the upcoming public
296 * release number plus "betaNN" or "rcNN".
298 * Binary incompatibility exists only when applications make direct access
299 * to the info_ptr or png_ptr members through png.h, and the compiled
300 * application is loaded with a different version of the library.
302 * DLLNUM will change each time there are forward or backward changes
303 * in binary compatibility (e.g., when a new feature is added).
305 * See libpng.txt or libpng.3 for more information. The PNG specification
306 * is available as a W3C Recommendation and as an ISO Specification,
307 * <http://www.w3.org/TR/2003/REC-PNG-20031110/
311 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
313 * If you modify libpng you may insert additional notices immediately following
316 * This code is released under the libpng license.
318 * libpng versions 1.2.6, August 15, 2004, through 1.2.50, July 10, 2012, are
319 * Copyright (c) 2004, 2006-2011 Glenn Randers-Pehrson, and are
320 * distributed according to the same disclaimer and license as libpng-1.2.5
321 * with the following individual added to the list of Contributing Authors:
325 * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
326 * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
327 * distributed according to the same disclaimer and license as libpng-1.0.6
328 * with the following individuals added to the list of Contributing Authors:
330 * Simon-Pierre Cadieux
334 * and with the following additions to the disclaimer:
336 * There is no warranty against interference with your enjoyment of the
337 * library or against infringement. There is no warranty that our
338 * efforts or the library will fulfill any of your particular purposes
339 * or needs. This library is provided with all faults, and the entire
340 * risk of satisfactory quality, performance, accuracy, and effort is with
343 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
344 * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are
345 * distributed according to the same disclaimer and license as libpng-0.96,
346 * with the following individuals added to the list of Contributing Authors:
349 * Glenn Randers-Pehrson
352 * libpng versions 0.89, June 1996, through 0.96, May 1997, are
353 * Copyright (c) 1996, 1997 Andreas Dilger
354 * Distributed according to the same disclaimer and license as libpng-0.88,
355 * with the following individuals added to the list of Contributing Authors:
364 * libpng versions 0.5, May 1995, through 0.88, January 1996, are
365 * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
367 * For the purposes of this copyright and license, "Contributing Authors"
368 * is defined as the following set of individuals:
376 * The PNG Reference Library is supplied "AS IS". The Contributing Authors
377 * and Group 42, Inc. disclaim all warranties, expressed or implied,
378 * including, without limitation, the warranties of merchantability and of
379 * fitness for any purpose. The Contributing Authors and Group 42, Inc.
380 * assume no liability for direct, indirect, incidental, special, exemplary,
381 * or consequential damages, which may result from the use of the PNG
382 * Reference Library, even if advised of the possibility of such damage.
384 * Permission is hereby granted to use, copy, modify, and distribute this
385 * source code, or portions hereof, for any purpose, without fee, subject
386 * to the following restrictions:
388 * 1. The origin of this source code must not be misrepresented.
390 * 2. Altered versions must be plainly marked as such and
391 * must not be misrepresented as being the original source.
393 * 3. This Copyright notice may not be removed or altered from
394 * any source or altered source distribution.
396 * The Contributing Authors and Group 42, Inc. specifically permit, without
397 * fee, and encourage the use of this source code as a component to
398 * supporting the PNG file format in commercial products. If you use this
399 * source code in a product, acknowledgment is not required but would be
404 * A "png_get_copyright" function is available, for convenient use in "about"
405 * boxes and the like:
407 * printf("%s",png_get_copyright(NULL));
409 * Also, the PNG logo (in PNG format, of course) is supplied in the
410 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
414 * Libpng is OSI Certified Open Source Software. OSI Certified is a
415 * certification mark of the Open Source Initiative.
419 * The contributing authors would like to thank all those who helped
420 * with testing, bug fixes, and patience. This wouldn't have been
421 * possible without all of you.
423 * Thanks to Frank J. T. Wojcik for helping with the documentation.
427 * Y2K compliance in libpng:
428 * =========================
432 * Since the PNG Development group is an ad-hoc body, we can't make
433 * an official declaration.
435 * This is your unofficial assurance that libpng from version 0.71 and
436 * upward through 1.2.50 are Y2K compliant. It is my belief that earlier
437 * versions were also Y2K compliant.
439 * Libpng only has three year fields. One is a 2-byte unsigned integer
440 * that will hold years up to 65535. The other two hold the date in text
441 * format, and will hold years up to 9999.
444 * "png_uint_16 year" in png_time_struct.
447 * "png_charp time_buffer" in png_struct and
448 * "near_time_buffer", which is a local character string in png.c.
450 * There are seven time-related functions:
451 * png.c: png_convert_to_rfc_1123() in png.c
452 * (formerly png_convert_to_rfc_1152() in error)
453 * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
454 * png_convert_from_time_t() in pngwrite.c
455 * png_get_tIME() in pngget.c
456 * png_handle_tIME() in pngrutil.c, called in pngread.c
457 * png_set_tIME() in pngset.c
458 * png_write_tIME() in pngwutil.c, called in pngwrite.c
460 * All handle dates properly in a Y2K environment. The
461 * png_convert_from_time_t() function calls gmtime() to convert from system
462 * clock time, which returns (year - 1900), which we properly convert to
463 * the full 4-digit year. There is a possibility that applications using
464 * libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
465 * function, or that they are incorrectly passing only a 2-digit year
466 * instead of "year - 1900" into the png_convert_from_struct_tm() function,
467 * but this is not under our control. The libpng documentation has always
468 * stated that it works with 4-digit years, and the APIs have been
469 * documented as such.
471 * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
472 * integer to hold the year, and can hold years as large as 65535.
474 * zlib, upon which libpng depends, is also Y2K compliant. It contains
475 * no date-related code.
477 * Glenn Randers-Pehrson
479 * PNG Development Group
485 /* This is not the place to learn how to use libpng. The file libpng.txt
486 * describes how to use libpng, and the file example.c summarizes it
487 * with some code on which to build. This file is useful for looking
488 * at the actual function definitions and structure components.
491 /* Version information for png.h - this should match the version in png.c */
492 #define PNG_LIBPNG_VER_STRING "1.2.50"
493 #define PNG_HEADER_VERSION_STRING \
494 " libpng version 1.2.50 - July 10, 2012\n"
496 #define PNG_LIBPNG_VER_SONUM 0
497 #define PNG_LIBPNG_VER_DLLNUM 13
499 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
500 #define PNG_LIBPNG_VER_MAJOR 1
501 #define PNG_LIBPNG_VER_MINOR 2
502 #define PNG_LIBPNG_VER_RELEASE 50
503 /* This should match the numeric part of the final component of
504 * PNG_LIBPNG_VER_STRING, omitting any leading zero:
507 #define PNG_LIBPNG_VER_BUILD 0
510 #define PNG_LIBPNG_BUILD_ALPHA 1
511 #define PNG_LIBPNG_BUILD_BETA 2
512 #define PNG_LIBPNG_BUILD_RC 3
513 #define PNG_LIBPNG_BUILD_STABLE 4
514 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
516 /* Release-Specific Flags */
517 #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
518 PNG_LIBPNG_BUILD_STABLE only */
519 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
520 PNG_LIBPNG_BUILD_SPECIAL */
521 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
522 PNG_LIBPNG_BUILD_PRIVATE */
524 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
526 /* Careful here. At one time, Guy wanted to use 082, but that would be octal.
527 * We must not include leading zeros.
528 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
529 * version 1.0.0 was mis-numbered 100 instead of 10000). From
530 * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release
532 #define PNG_LIBPNG_VER 10250 /* 1.2.50 */
534 #ifndef PNG_VERSION_INFO_ONLY
535 /* Include the compression library's header */
539 /* Include all user configurable info, including optional assembler routines */
543 * Added at libpng-1.2.8 */
544 /* Ref MSDN: Private as priority over Special
545 * VS_FF_PRIVATEBUILD File *was not* built using standard release
546 * procedures. If this value is given, the StringFileInfo block must
547 * contain a PrivateBuild string.
549 * VS_FF_SPECIALBUILD File *was* built by the original company using
550 * standard release procedures but is a variation of the standard
551 * file of the same version number. If this value is given, the
552 * StringFileInfo block must contain a SpecialBuild string.
555 #ifdef PNG_USER_PRIVATEBUILD
556 # define PNG_LIBPNG_BUILD_TYPE \
557 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
559 # ifdef PNG_LIBPNG_SPECIALBUILD
560 # define PNG_LIBPNG_BUILD_TYPE \
561 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
563 # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
567 #ifndef PNG_VERSION_INFO_ONLY
569 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
572 #endif /* __cplusplus */
574 /* This file is arranged in several sections. The first section contains
575 * structure and type definitions. The second section contains the external
576 * library functions, while the third has the internal library functions,
577 * which applications aren't expected to use directly.
580 #ifndef PNG_NO_TYPECAST_NULL
581 #define int_p_NULL (int *)NULL
582 #define png_bytep_NULL (png_bytep)NULL
583 #define png_bytepp_NULL (png_bytepp)NULL
584 #define png_doublep_NULL (png_doublep)NULL
585 #define png_error_ptr_NULL (png_error_ptr)NULL
586 #define png_flush_ptr_NULL (png_flush_ptr)NULL
587 #define png_free_ptr_NULL (png_free_ptr)NULL
588 #define png_infopp_NULL (png_infopp)NULL
589 #define png_malloc_ptr_NULL (png_malloc_ptr)NULL
590 #define png_read_status_ptr_NULL (png_read_status_ptr)NULL
591 #define png_rw_ptr_NULL (png_rw_ptr)NULL
592 #define png_structp_NULL (png_structp)NULL
593 #define png_uint_16p_NULL (png_uint_16p)NULL
594 #define png_voidp_NULL (png_voidp)NULL
595 #define png_write_status_ptr_NULL (png_write_status_ptr)NULL
597 #define int_p_NULL NULL
598 #define png_bytep_NULL NULL
599 #define png_bytepp_NULL NULL
600 #define png_doublep_NULL NULL
601 #define png_error_ptr_NULL NULL
602 #define png_flush_ptr_NULL NULL
603 #define png_free_ptr_NULL NULL
604 #define png_infopp_NULL NULL
605 #define png_malloc_ptr_NULL NULL
606 #define png_read_status_ptr_NULL NULL
607 #define png_rw_ptr_NULL NULL
608 #define png_structp_NULL NULL
609 #define png_uint_16p_NULL NULL
610 #define png_voidp_NULL NULL
611 #define png_write_status_ptr_NULL NULL
614 /* Variables declared in png.c - only it needs to define PNG_NO_EXTERN */
615 #if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
616 /* Version information for C files, stored in png.c. This had better match
619 #ifdef PNG_USE_GLOBAL_ARRAYS
620 PNG_EXPORT_VAR (PNG_CONST char) png_libpng_ver[18];
621 /* Need room for 99.99.99beta99z */
623 #define png_libpng_ver png_get_header_ver(NULL)
626 #ifdef PNG_USE_GLOBAL_ARRAYS
627 /* This was removed in version 1.0.5c */
628 /* Structures to facilitate easy interlacing. See png.c for more details */
629 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_start[7];
630 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_inc[7];
631 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_ystart[7];
632 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_yinc[7];
633 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_mask[7];
634 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_dsp_mask[7];
635 /* This isn't currently used. If you need it, see png.c for more details.
636 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_height[7];
640 #endif /* PNG_NO_EXTERN */
642 /* Three color definitions. The order of the red, green, and blue, (and the
643 * exact size) is not important, although the size of the fields need to
644 * be png_byte or png_uint_16 (as defined below).
646 typedef struct png_color_struct
652 typedef png_color FAR * png_colorp;
653 typedef png_color FAR * FAR * png_colorpp;
655 typedef struct png_color_16_struct
657 png_byte index; /* used for palette files */
658 png_uint_16 red; /* for use in red green blue files */
661 png_uint_16 gray; /* for use in grayscale files */
663 typedef png_color_16 FAR * png_color_16p;
664 typedef png_color_16 FAR * FAR * png_color_16pp;
666 typedef struct png_color_8_struct
668 png_byte red; /* for use in red green blue files */
671 png_byte gray; /* for use in grayscale files */
672 png_byte alpha; /* for alpha channel files */
674 typedef png_color_8 FAR * png_color_8p;
675 typedef png_color_8 FAR * FAR * png_color_8pp;
678 * The following two structures are used for the in-core representation
681 typedef struct png_sPLT_entry_struct
687 png_uint_16 frequency;
689 typedef png_sPLT_entry FAR * png_sPLT_entryp;
690 typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;
692 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples
693 * occupy the LSB of their respective members, and the MSB of each member
694 * is zero-filled. The frequency member always occupies the full 16 bits.
697 typedef struct png_sPLT_struct
699 png_charp name; /* palette name */
700 png_byte depth; /* depth of palette samples */
701 png_sPLT_entryp entries; /* palette entries */
702 png_int_32 nentries; /* number of palette entries */
704 typedef png_sPLT_t FAR * png_sPLT_tp;
705 typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
707 #ifdef PNG_TEXT_SUPPORTED
708 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
709 * and whether that contents is compressed or not. The "key" field
710 * points to a regular zero-terminated C string. The "text", "lang", and
711 * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
712 * However, the * structure returned by png_get_text() will always contain
713 * regular zero-terminated C strings (possibly empty), never NULL pointers,
714 * so they can be safely used in printf() and other string-handling functions.
716 typedef struct png_text_struct
718 int compression; /* compression value:
723 png_charp key; /* keyword, 1-79 character description of "text" */
724 png_charp text; /* comment, may be an empty string (ie "")
726 png_size_t text_length; /* length of the text string */
727 #ifdef PNG_iTXt_SUPPORTED
728 png_size_t itxt_length; /* length of the itxt string */
729 png_charp lang; /* language code, 0-79 characters
731 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
732 chars or a NULL pointer */
735 typedef png_text FAR * png_textp;
736 typedef png_text FAR * FAR * png_textpp;
739 /* Supported compression types for text in PNG files (tEXt, and zTXt).
740 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed.
742 #define PNG_TEXT_COMPRESSION_NONE_WR -3
743 #define PNG_TEXT_COMPRESSION_zTXt_WR -2
744 #define PNG_TEXT_COMPRESSION_NONE -1
745 #define PNG_TEXT_COMPRESSION_zTXt 0
746 #define PNG_ITXT_COMPRESSION_NONE 1
747 #define PNG_ITXT_COMPRESSION_zTXt 2
748 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
750 /* png_time is a way to hold the time in an machine independent way.
751 * Two conversions are provided, both from time_t and struct tm. There
752 * is no portable way to convert to either of these structures, as far
753 * as I know. If you know of a portable way, send it to me. As a side
754 * note - PNG has always been Year 2000 compliant!
756 typedef struct png_time_struct
758 png_uint_16 year; /* full year, as in, 1995 */
759 png_byte month; /* month of year, 1 - 12 */
760 png_byte day; /* day of month, 1 - 31 */
761 png_byte hour; /* hour of day, 0 - 23 */
762 png_byte minute; /* minute of hour, 0 - 59 */
763 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
765 typedef png_time FAR * png_timep;
766 typedef png_time FAR * FAR * png_timepp;
768 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
769 defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
770 /* png_unknown_chunk is a structure to hold queued chunks for which there is
771 * no specific support. The idea is that we can use this to queue
772 * up private chunks for output even though the library doesn't actually
773 * know about their semantics.
775 #define PNG_CHUNK_NAME_LENGTH 5
776 typedef struct png_unknown_chunk_t
778 png_byte name[PNG_CHUNK_NAME_LENGTH];
782 /* libpng-using applications should NOT directly modify this byte. */
783 png_byte location; /* mode of operation at read time */
786 typedef png_unknown_chunk FAR * png_unknown_chunkp;
787 typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
790 /* png_info is a structure that holds the information in a PNG file so
791 * that the application can find out the characteristics of the image.
792 * If you are reading the file, this structure will tell you what is
793 * in the PNG file. If you are writing the file, fill in the information
794 * you want to put into the PNG file, then call png_write_info().
795 * The names chosen should be very close to the PNG specification, so
796 * consult that document for information about the meaning of each field.
798 * With libpng < 0.95, it was only possible to directly set and read the
799 * the values in the png_info_struct, which meant that the contents and
800 * order of the values had to remain fixed. With libpng 0.95 and later,
801 * however, there are now functions that abstract the contents of
802 * png_info_struct from the application, so this makes it easier to use
803 * libpng with dynamic libraries, and even makes it possible to use
804 * libraries that don't have all of the libpng ancillary chunk-handing
807 * In any case, the order of the parameters in png_info_struct should NOT
808 * be changed for as long as possible to keep compatibility with applications
809 * that use the old direct-access method with png_info_struct.
811 * The following members may have allocated storage attached that should be
812 * cleaned up before the structure is discarded: palette, trans, text,
813 * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
814 * splt_palettes, scal_unit, row_pointers, and unknowns. By default, these
815 * are automatically freed when the info structure is deallocated, if they were
816 * allocated internally by libpng. This behavior can be changed by means
817 * of the png_data_freer() function.
819 * More allocation details: all the chunk-reading functions that
820 * change these members go through the corresponding png_set_*
821 * functions. A function to clear these members is available: see
822 * png_free_data(). The png_set_* functions do not depend on being
823 * able to point info structure members to any of the storage they are
824 * passed (they make their own copies), EXCEPT that the png_set_text
825 * functions use the same storage passed to them in the text_ptr or
826 * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
827 * functions do not make their own copies.
829 typedef struct png_info_struct
831 /* The following are necessary for every PNG file */
832 png_uint_32 width PNG_DEPSTRUCT; /* width of image in pixels (from IHDR) */
833 png_uint_32 height PNG_DEPSTRUCT; /* height of image in pixels (from IHDR) */
834 png_uint_32 valid PNG_DEPSTRUCT; /* valid chunk data (see PNG_INFO_ below) */
835 png_uint_32 rowbytes PNG_DEPSTRUCT; /* bytes needed to hold an untransformed row */
836 png_colorp palette PNG_DEPSTRUCT; /* array of color values (valid & PNG_INFO_PLTE) */
837 png_uint_16 num_palette PNG_DEPSTRUCT; /* number of color entries in "palette" (PLTE) */
838 png_uint_16 num_trans PNG_DEPSTRUCT; /* number of transparent palette color (tRNS) */
839 png_byte bit_depth PNG_DEPSTRUCT; /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */
840 png_byte color_type PNG_DEPSTRUCT; /* see PNG_COLOR_TYPE_ below (from IHDR) */
841 /* The following three should have been named *_method not *_type */
842 png_byte compression_type PNG_DEPSTRUCT; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */
843 png_byte filter_type PNG_DEPSTRUCT; /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
844 png_byte interlace_type PNG_DEPSTRUCT; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
846 /* The following is informational only on read, and not used on writes. */
847 png_byte channels PNG_DEPSTRUCT; /* number of data channels per pixel (1, 2, 3, 4) */
848 png_byte pixel_depth PNG_DEPSTRUCT; /* number of bits per pixel */
849 png_byte spare_byte PNG_DEPSTRUCT; /* to align the data, and for future use */
850 png_byte signature[8] PNG_DEPSTRUCT; /* magic bytes read by libpng from start of file */
852 /* The rest of the data is optional. If you are reading, check the
853 * valid field to see if the information in these are valid. If you
854 * are writing, set the valid field to those chunks you want written,
855 * and initialize the appropriate fields below.
858 #if defined(PNG_gAMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
859 /* The gAMA chunk describes the gamma characteristics of the system
860 * on which the image was created, normally in the range [1.0, 2.5].
861 * Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
863 float gamma PNG_DEPSTRUCT; /* gamma value of image, if (valid & PNG_INFO_gAMA) */
866 #ifdef PNG_sRGB_SUPPORTED
868 /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
869 png_byte srgb_intent PNG_DEPSTRUCT; /* sRGB rendering intent [0, 1, 2, or 3] */
872 #ifdef PNG_TEXT_SUPPORTED
873 /* The tEXt, and zTXt chunks contain human-readable textual data in
874 * uncompressed, compressed, and optionally compressed forms, respectively.
875 * The data in "text" is an array of pointers to uncompressed,
876 * null-terminated C strings. Each chunk has a keyword that describes the
877 * textual data contained in that chunk. Keywords are not required to be
878 * unique, and the text string may be empty. Any number of text chunks may
881 int num_text PNG_DEPSTRUCT; /* number of comments read/to write */
882 int max_text PNG_DEPSTRUCT; /* current size of text array */
883 png_textp text PNG_DEPSTRUCT; /* array of comments read/to write */
884 #endif /* PNG_TEXT_SUPPORTED */
886 #ifdef PNG_tIME_SUPPORTED
887 /* The tIME chunk holds the last time the displayed image data was
888 * modified. See the png_time struct for the contents of this struct.
890 png_time mod_time PNG_DEPSTRUCT;
893 #ifdef PNG_sBIT_SUPPORTED
894 /* The sBIT chunk specifies the number of significant high-order bits
895 * in the pixel data. Values are in the range [1, bit_depth], and are
896 * only specified for the channels in the pixel data. The contents of
897 * the low-order bits is not specified. Data is valid if
898 * (valid & PNG_INFO_sBIT) is non-zero.
900 png_color_8 sig_bit PNG_DEPSTRUCT; /* significant bits in color channels */
903 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
904 defined(PNG_READ_BACKGROUND_SUPPORTED)
905 /* The tRNS chunk supplies transparency data for paletted images and
906 * other image types that don't need a full alpha channel. There are
907 * "num_trans" transparency values for a paletted image, stored in the
908 * same order as the palette colors, starting from index 0. Values
909 * for the data are in the range [0, 255], ranging from fully transparent
910 * to fully opaque, respectively. For non-paletted images, there is a
911 * single color specified that should be treated as fully transparent.
912 * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
914 png_bytep trans PNG_DEPSTRUCT; /* transparent values for paletted image */
915 png_color_16 trans_values PNG_DEPSTRUCT; /* transparent color for non-palette image */
918 #if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
919 /* The bKGD chunk gives the suggested image background color if the
920 * display program does not have its own background color and the image
921 * is needs to composited onto a background before display. The colors
922 * in "background" are normally in the same color space/depth as the
923 * pixel data. Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
925 png_color_16 background PNG_DEPSTRUCT;
928 #ifdef PNG_oFFs_SUPPORTED
929 /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
930 * and downwards from the top-left corner of the display, page, or other
931 * application-specific co-ordinate space. See the PNG_OFFSET_ defines
932 * below for the unit types. Valid if (valid & PNG_INFO_oFFs) non-zero.
934 png_int_32 x_offset PNG_DEPSTRUCT; /* x offset on page */
935 png_int_32 y_offset PNG_DEPSTRUCT; /* y offset on page */
936 png_byte offset_unit_type PNG_DEPSTRUCT; /* offset units type */
939 #ifdef PNG_pHYs_SUPPORTED
940 /* The pHYs chunk gives the physical pixel density of the image for
941 * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
942 * defines below). Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
944 png_uint_32 x_pixels_per_unit PNG_DEPSTRUCT; /* horizontal pixel density */
945 png_uint_32 y_pixels_per_unit PNG_DEPSTRUCT; /* vertical pixel density */
946 png_byte phys_unit_type PNG_DEPSTRUCT; /* resolution type (see PNG_RESOLUTION_ below) */
949 #ifdef PNG_hIST_SUPPORTED
950 /* The hIST chunk contains the relative frequency or importance of the
951 * various palette entries, so that a viewer can intelligently select a
952 * reduced-color palette, if required. Data is an array of "num_palette"
953 * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
956 png_uint_16p hist PNG_DEPSTRUCT;
959 #ifdef PNG_cHRM_SUPPORTED
960 /* The cHRM chunk describes the CIE color characteristics of the monitor
961 * on which the PNG was created. This data allows the viewer to do gamut
962 * mapping of the input image to ensure that the viewer sees the same
963 * colors in the image as the creator. Values are in the range
964 * [0.0, 0.8]. Data valid if (valid & PNG_INFO_cHRM) non-zero.
966 #ifdef PNG_FLOATING_POINT_SUPPORTED
967 float x_white PNG_DEPSTRUCT;
968 float y_white PNG_DEPSTRUCT;
969 float x_red PNG_DEPSTRUCT;
970 float y_red PNG_DEPSTRUCT;
971 float x_green PNG_DEPSTRUCT;
972 float y_green PNG_DEPSTRUCT;
973 float x_blue PNG_DEPSTRUCT;
974 float y_blue PNG_DEPSTRUCT;
978 #ifdef PNG_pCAL_SUPPORTED
979 /* The pCAL chunk describes a transformation between the stored pixel
980 * values and original physical data values used to create the image.
981 * The integer range [0, 2^bit_depth - 1] maps to the floating-point
982 * range given by [pcal_X0, pcal_X1], and are further transformed by a
983 * (possibly non-linear) transformation function given by "pcal_type"
984 * and "pcal_params" into "pcal_units". Please see the PNG_EQUATION_
985 * defines below, and the PNG-Group's PNG extensions document for a
986 * complete description of the transformations and how they should be
987 * implemented, and for a description of the ASCII parameter strings.
988 * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
990 png_charp pcal_purpose PNG_DEPSTRUCT; /* pCAL chunk description string */
991 png_int_32 pcal_X0 PNG_DEPSTRUCT; /* minimum value */
992 png_int_32 pcal_X1 PNG_DEPSTRUCT; /* maximum value */
993 png_charp pcal_units PNG_DEPSTRUCT; /* Latin-1 string giving physical units */
994 png_charpp pcal_params PNG_DEPSTRUCT; /* ASCII strings containing parameter values */
995 png_byte pcal_type PNG_DEPSTRUCT; /* equation type (see PNG_EQUATION_ below) */
996 png_byte pcal_nparams PNG_DEPSTRUCT; /* number of parameters given in pcal_params */
999 /* New members added in libpng-1.0.6 */
1000 #ifdef PNG_FREE_ME_SUPPORTED
1001 png_uint_32 free_me PNG_DEPSTRUCT; /* flags items libpng is responsible for freeing */
1004 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
1005 defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
1006 /* Storage for unknown chunks that the library doesn't recognize. */
1007 png_unknown_chunkp unknown_chunks PNG_DEPSTRUCT;
1008 png_size_t unknown_chunks_num PNG_DEPSTRUCT;
1011 #ifdef PNG_iCCP_SUPPORTED
1012 /* iCCP chunk data. */
1013 png_charp iccp_name PNG_DEPSTRUCT; /* profile name */
1014 png_charp iccp_profile PNG_DEPSTRUCT; /* International Color Consortium profile data */
1015 /* Note to maintainer: should be png_bytep */
1016 png_uint_32 iccp_proflen PNG_DEPSTRUCT; /* ICC profile data length */
1017 png_byte iccp_compression PNG_DEPSTRUCT; /* Always zero */
1020 #ifdef PNG_sPLT_SUPPORTED
1021 /* Data on sPLT chunks (there may be more than one). */
1022 png_sPLT_tp splt_palettes PNG_DEPSTRUCT;
1023 png_uint_32 splt_palettes_num PNG_DEPSTRUCT;
1026 #ifdef PNG_sCAL_SUPPORTED
1027 /* The sCAL chunk describes the actual physical dimensions of the
1028 * subject matter of the graphic. The chunk contains a unit specification
1029 * a byte value, and two ASCII strings representing floating-point
1030 * values. The values are width and height corresponsing to one pixel
1031 * in the image. This external representation is converted to double
1032 * here. Data values are valid if (valid & PNG_INFO_sCAL) is non-zero.
1034 png_byte scal_unit PNG_DEPSTRUCT; /* unit of physical scale */
1035 #ifdef PNG_FLOATING_POINT_SUPPORTED
1036 double scal_pixel_width PNG_DEPSTRUCT; /* width of one pixel */
1037 double scal_pixel_height PNG_DEPSTRUCT; /* height of one pixel */
1039 #ifdef PNG_FIXED_POINT_SUPPORTED
1040 png_charp scal_s_width PNG_DEPSTRUCT; /* string containing height */
1041 png_charp scal_s_height PNG_DEPSTRUCT; /* string containing width */
1045 #ifdef PNG_INFO_IMAGE_SUPPORTED
1046 /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS) non-zero */
1047 /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
1048 png_bytepp row_pointers PNG_DEPSTRUCT; /* the image bits */
1051 #if defined(PNG_FIXED_POINT_SUPPORTED) && defined(PNG_gAMA_SUPPORTED)
1052 png_fixed_point int_gamma PNG_DEPSTRUCT; /* gamma of image, if (valid & PNG_INFO_gAMA) */
1055 #if defined(PNG_cHRM_SUPPORTED) && defined(PNG_FIXED_POINT_SUPPORTED)
1056 png_fixed_point int_x_white PNG_DEPSTRUCT;
1057 png_fixed_point int_y_white PNG_DEPSTRUCT;
1058 png_fixed_point int_x_red PNG_DEPSTRUCT;
1059 png_fixed_point int_y_red PNG_DEPSTRUCT;
1060 png_fixed_point int_x_green PNG_DEPSTRUCT;
1061 png_fixed_point int_y_green PNG_DEPSTRUCT;
1062 png_fixed_point int_x_blue PNG_DEPSTRUCT;
1063 png_fixed_point int_y_blue PNG_DEPSTRUCT;
1068 typedef png_info FAR * png_infop;
1069 typedef png_info FAR * FAR * png_infopp;
1071 /* Maximum positive integer used in PNG is (2^31)-1 */
1072 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
1073 #define PNG_UINT_32_MAX ((png_uint_32)(-1))
1074 #define PNG_SIZE_MAX ((png_size_t)(-1))
1075 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1076 /* PNG_MAX_UINT is deprecated; use PNG_UINT_31_MAX instead. */
1077 #define PNG_MAX_UINT PNG_UINT_31_MAX
1080 /* These describe the color_type field in png_info. */
1081 /* color type masks */
1082 #define PNG_COLOR_MASK_PALETTE 1
1083 #define PNG_COLOR_MASK_COLOR 2
1084 #define PNG_COLOR_MASK_ALPHA 4
1086 /* color types. Note that not all combinations are legal */
1087 #define PNG_COLOR_TYPE_GRAY 0
1088 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
1089 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
1090 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
1091 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
1093 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
1094 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
1096 /* This is for compression type. PNG 1.0-1.2 only define the single type. */
1097 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
1098 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
1100 /* This is for filter type. PNG 1.0-1.2 only define the single type. */
1101 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
1102 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
1103 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
1105 /* These are for the interlacing type. These values should NOT be changed. */
1106 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
1107 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
1108 #define PNG_INTERLACE_LAST 2 /* Not a valid value */
1110 /* These are for the oFFs chunk. These values should NOT be changed. */
1111 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
1112 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
1113 #define PNG_OFFSET_LAST 2 /* Not a valid value */
1115 /* These are for the pCAL chunk. These values should NOT be changed. */
1116 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */
1117 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
1118 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
1119 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
1120 #define PNG_EQUATION_LAST 4 /* Not a valid value */
1122 /* These are for the sCAL chunk. These values should NOT be changed. */
1123 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
1124 #define PNG_SCALE_METER 1 /* meters per pixel */
1125 #define PNG_SCALE_RADIAN 2 /* radians per pixel */
1126 #define PNG_SCALE_LAST 3 /* Not a valid value */
1128 /* These are for the pHYs chunk. These values should NOT be changed. */
1129 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
1130 #define PNG_RESOLUTION_METER 1 /* pixels/meter */
1131 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */
1133 /* These are for the sRGB chunk. These values should NOT be changed. */
1134 #define PNG_sRGB_INTENT_PERCEPTUAL 0
1135 #define PNG_sRGB_INTENT_RELATIVE 1
1136 #define PNG_sRGB_INTENT_SATURATION 2
1137 #define PNG_sRGB_INTENT_ABSOLUTE 3
1138 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
1140 /* This is for text chunks */
1141 #define PNG_KEYWORD_MAX_LENGTH 79
1143 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */
1144 #define PNG_MAX_PALETTE_LENGTH 256
1146 /* These determine if an ancillary chunk's data has been successfully read
1147 * from the PNG header, or if the application has filled in the corresponding
1148 * data in the info_struct to be written into the output file. The values
1149 * of the PNG_INFO_<chunk> defines should NOT be changed.
1151 #define PNG_INFO_gAMA 0x0001
1152 #define PNG_INFO_sBIT 0x0002
1153 #define PNG_INFO_cHRM 0x0004
1154 #define PNG_INFO_PLTE 0x0008
1155 #define PNG_INFO_tRNS 0x0010
1156 #define PNG_INFO_bKGD 0x0020
1157 #define PNG_INFO_hIST 0x0040
1158 #define PNG_INFO_pHYs 0x0080
1159 #define PNG_INFO_oFFs 0x0100
1160 #define PNG_INFO_tIME 0x0200
1161 #define PNG_INFO_pCAL 0x0400
1162 #define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */
1163 #define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */
1164 #define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */
1165 #define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */
1166 #define PNG_INFO_IDAT 0x8000L /* ESR, 1.0.6 */
1168 /* This is used for the transformation routines, as some of them
1169 * change these values for the row. It also should enable using
1170 * the routines for other purposes.
1172 typedef struct png_row_info_struct
1174 png_uint_32 width; /* width of row */
1175 png_uint_32 rowbytes; /* number of bytes in row */
1176 png_byte color_type; /* color type of row */
1177 png_byte bit_depth; /* bit depth of row */
1178 png_byte channels; /* number of channels (1, 2, 3, or 4) */
1179 png_byte pixel_depth; /* bits per pixel (depth * channels) */
1182 typedef png_row_info FAR * png_row_infop;
1183 typedef png_row_info FAR * FAR * png_row_infopp;
1185 /* These are the function types for the I/O functions and for the functions
1186 * that allow the user to override the default I/O functions with his or her
1187 * own. The png_error_ptr type should match that of user-supplied warning
1188 * and error functions, while the png_rw_ptr type should match that of the
1189 * user read/write data functions.
1191 typedef struct png_struct_def png_struct;
1192 typedef png_struct FAR * png_structp;
1194 typedef void (PNGAPI *png_error_ptr) PNGARG((png_structp, png_const_charp));
1195 typedef void (PNGAPI *png_rw_ptr) PNGARG((png_structp, png_bytep, png_size_t));
1196 typedef void (PNGAPI *png_flush_ptr) PNGARG((png_structp));
1197 typedef void (PNGAPI *png_read_status_ptr) PNGARG((png_structp, png_uint_32,
1199 typedef void (PNGAPI *png_write_status_ptr) PNGARG((png_structp, png_uint_32,
1202 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1203 typedef void (PNGAPI *png_progressive_info_ptr) PNGARG((png_structp, png_infop));
1204 typedef void (PNGAPI *png_progressive_end_ptr) PNGARG((png_structp, png_infop));
1205 typedef void (PNGAPI *png_progressive_row_ptr) PNGARG((png_structp, png_bytep,
1209 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1210 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
1211 defined(PNG_LEGACY_SUPPORTED)
1212 typedef void (PNGAPI *png_user_transform_ptr) PNGARG((png_structp,
1213 png_row_infop, png_bytep));
1216 #ifdef PNG_USER_CHUNKS_SUPPORTED
1217 typedef int (PNGAPI *png_user_chunk_ptr) PNGARG((png_structp, png_unknown_chunkp));
1219 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
1220 typedef void (PNGAPI *png_unknown_chunk_ptr) PNGARG((png_structp));
1223 /* Transform masks for the high-level interface */
1224 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
1225 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
1226 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
1227 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
1228 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
1229 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
1230 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
1231 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
1232 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */
1233 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
1234 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
1235 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
1236 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only, deprecated */
1237 /* Added to libpng-1.2.34 */
1238 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE 0x0800 /* write only */
1239 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
1240 /* Added to libpng-1.2.41 */
1241 #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
1243 /* Flags for MNG supported features */
1244 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01
1245 #define PNG_FLAG_MNG_FILTER_64 0x04
1246 #define PNG_ALL_MNG_FEATURES 0x05
1248 typedef png_voidp (*png_malloc_ptr) PNGARG((png_structp, png_size_t));
1249 typedef void (*png_free_ptr) PNGARG((png_structp, png_voidp));
1251 /* The structure that holds the information to read and write PNG files.
1252 * The only people who need to care about what is inside of this are the
1253 * people who will be modifying the library for their own special needs.
1254 * It should NOT be accessed directly by an application, except to store
1258 struct png_struct_def
1260 #ifdef PNG_SETJMP_SUPPORTED
1261 jmp_buf jmpbuf; /* used in png_error */
1263 png_error_ptr error_fn PNG_DEPSTRUCT; /* function for printing errors and aborting */
1264 png_error_ptr warning_fn PNG_DEPSTRUCT; /* function for printing warnings */
1265 png_voidp error_ptr PNG_DEPSTRUCT; /* user supplied struct for error functions */
1266 png_rw_ptr write_data_fn PNG_DEPSTRUCT; /* function for writing output data */
1267 png_rw_ptr read_data_fn PNG_DEPSTRUCT; /* function for reading input data */
1268 png_voidp io_ptr PNG_DEPSTRUCT; /* ptr to application struct for I/O functions */
1270 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
1271 png_user_transform_ptr read_user_transform_fn PNG_DEPSTRUCT; /* user read transform */
1274 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1275 png_user_transform_ptr write_user_transform_fn PNG_DEPSTRUCT; /* user write transform */
1278 /* These were added in libpng-1.0.2 */
1279 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
1280 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1281 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1282 png_voidp user_transform_ptr PNG_DEPSTRUCT; /* user supplied struct for user transform */
1283 png_byte user_transform_depth PNG_DEPSTRUCT; /* bit depth of user transformed pixels */
1284 png_byte user_transform_channels PNG_DEPSTRUCT; /* channels in user transformed pixels */
1288 png_uint_32 mode PNG_DEPSTRUCT; /* tells us where we are in the PNG file */
1289 png_uint_32 flags PNG_DEPSTRUCT; /* flags indicating various things to libpng */
1290 png_uint_32 transformations PNG_DEPSTRUCT; /* which transformations to perform */
1292 z_stream zstream PNG_DEPSTRUCT; /* pointer to decompression structure (below) */
1293 png_bytep zbuf PNG_DEPSTRUCT; /* buffer for zlib */
1294 png_size_t zbuf_size PNG_DEPSTRUCT; /* size of zbuf */
1295 int zlib_level PNG_DEPSTRUCT; /* holds zlib compression level */
1296 int zlib_method PNG_DEPSTRUCT; /* holds zlib compression method */
1297 int zlib_window_bits PNG_DEPSTRUCT; /* holds zlib compression window bits */
1298 int zlib_mem_level PNG_DEPSTRUCT; /* holds zlib compression memory level */
1299 int zlib_strategy PNG_DEPSTRUCT; /* holds zlib compression strategy */
1301 png_uint_32 width PNG_DEPSTRUCT; /* width of image in pixels */
1302 png_uint_32 height PNG_DEPSTRUCT; /* height of image in pixels */
1303 png_uint_32 num_rows PNG_DEPSTRUCT; /* number of rows in current pass */
1304 png_uint_32 usr_width PNG_DEPSTRUCT; /* width of row at start of write */
1305 png_uint_32 rowbytes PNG_DEPSTRUCT; /* size of row in bytes */
1306 #if 0 /* Replaced with the following in libpng-1.2.43 */
1307 png_size_t irowbytes PNG_DEPSTRUCT;
1309 /* Added in libpng-1.2.43 */
1310 #ifdef PNG_USER_LIMITS_SUPPORTED
1311 /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown
1312 * chunks that can be stored (0 means unlimited).
1314 png_uint_32 user_chunk_cache_max PNG_DEPSTRUCT;
1316 png_uint_32 iwidth PNG_DEPSTRUCT; /* width of current interlaced row in pixels */
1317 png_uint_32 row_number PNG_DEPSTRUCT; /* current row in interlace pass */
1318 png_bytep prev_row PNG_DEPSTRUCT; /* buffer to save previous (unfiltered) row */
1319 png_bytep row_buf PNG_DEPSTRUCT; /* buffer to save current (unfiltered) row */
1320 #ifndef PNG_NO_WRITE_FILTER
1321 png_bytep sub_row PNG_DEPSTRUCT; /* buffer to save "sub" row when filtering */
1322 png_bytep up_row PNG_DEPSTRUCT; /* buffer to save "up" row when filtering */
1323 png_bytep avg_row PNG_DEPSTRUCT; /* buffer to save "avg" row when filtering */
1324 png_bytep paeth_row PNG_DEPSTRUCT; /* buffer to save "Paeth" row when filtering */
1326 png_row_info row_info PNG_DEPSTRUCT; /* used for transformation routines */
1328 png_uint_32 idat_size PNG_DEPSTRUCT; /* current IDAT size for read */
1329 png_uint_32 crc PNG_DEPSTRUCT; /* current chunk CRC value */
1330 png_colorp palette PNG_DEPSTRUCT; /* palette from the input file */
1331 png_uint_16 num_palette PNG_DEPSTRUCT; /* number of color entries in palette */
1332 png_uint_16 num_trans PNG_DEPSTRUCT; /* number of transparency values */
1333 png_byte chunk_name[5] PNG_DEPSTRUCT; /* null-terminated name of current chunk */
1334 png_byte compression PNG_DEPSTRUCT; /* file compression type (always 0) */
1335 png_byte filter PNG_DEPSTRUCT; /* file filter type (always 0) */
1336 png_byte interlaced PNG_DEPSTRUCT; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
1337 png_byte pass PNG_DEPSTRUCT; /* current interlace pass (0 - 6) */
1338 png_byte do_filter PNG_DEPSTRUCT; /* row filter flags (see PNG_FILTER_ below ) */
1339 png_byte color_type PNG_DEPSTRUCT; /* color type of file */
1340 png_byte bit_depth PNG_DEPSTRUCT; /* bit depth of file */
1341 png_byte usr_bit_depth PNG_DEPSTRUCT; /* bit depth of users row */
1342 png_byte pixel_depth PNG_DEPSTRUCT; /* number of bits per pixel */
1343 png_byte channels PNG_DEPSTRUCT; /* number of channels in file */
1344 png_byte usr_channels PNG_DEPSTRUCT; /* channels at start of write */
1345 png_byte sig_bytes PNG_DEPSTRUCT; /* magic bytes read/written from start of file */
1347 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1348 #ifdef PNG_LEGACY_SUPPORTED
1349 png_byte filler PNG_DEPSTRUCT; /* filler byte for pixel expansion */
1351 png_uint_16 filler PNG_DEPSTRUCT; /* filler bytes for pixel expansion */
1355 #ifdef PNG_bKGD_SUPPORTED
1356 png_byte background_gamma_type PNG_DEPSTRUCT;
1357 # ifdef PNG_FLOATING_POINT_SUPPORTED
1358 float background_gamma PNG_DEPSTRUCT;
1360 png_color_16 background PNG_DEPSTRUCT; /* background color in screen gamma space */
1361 #ifdef PNG_READ_GAMMA_SUPPORTED
1362 png_color_16 background_1 PNG_DEPSTRUCT; /* background normalized to gamma 1.0 */
1364 #endif /* PNG_bKGD_SUPPORTED */
1366 #ifdef PNG_WRITE_FLUSH_SUPPORTED
1367 png_flush_ptr output_flush_fn PNG_DEPSTRUCT; /* Function for flushing output */
1368 png_uint_32 flush_dist PNG_DEPSTRUCT; /* how many rows apart to flush, 0 - no flush */
1369 png_uint_32 flush_rows PNG_DEPSTRUCT; /* number of rows written since last flush */
1372 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1373 int gamma_shift PNG_DEPSTRUCT; /* number of "insignificant" bits 16-bit gamma */
1374 #ifdef PNG_FLOATING_POINT_SUPPORTED
1375 float gamma PNG_DEPSTRUCT; /* file gamma value */
1376 float screen_gamma PNG_DEPSTRUCT; /* screen gamma value (display_exponent) */
1380 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1381 png_bytep gamma_table PNG_DEPSTRUCT; /* gamma table for 8-bit depth files */
1382 png_bytep gamma_from_1 PNG_DEPSTRUCT; /* converts from 1.0 to screen */
1383 png_bytep gamma_to_1 PNG_DEPSTRUCT; /* converts from file to 1.0 */
1384 png_uint_16pp gamma_16_table PNG_DEPSTRUCT; /* gamma table for 16-bit depth files */
1385 png_uint_16pp gamma_16_from_1 PNG_DEPSTRUCT; /* converts from 1.0 to screen */
1386 png_uint_16pp gamma_16_to_1 PNG_DEPSTRUCT; /* converts from file to 1.0 */
1389 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
1390 png_color_8 sig_bit PNG_DEPSTRUCT; /* significant bits in each available channel */
1393 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1394 png_color_8 shift PNG_DEPSTRUCT; /* shift for significant bit tranformation */
1397 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
1398 || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1399 png_bytep trans PNG_DEPSTRUCT; /* transparency values for paletted files */
1400 png_color_16 trans_values PNG_DEPSTRUCT; /* transparency values for non-paletted files */
1403 png_read_status_ptr read_row_fn PNG_DEPSTRUCT; /* called after each row is decoded */
1404 png_write_status_ptr write_row_fn PNG_DEPSTRUCT; /* called after each row is encoded */
1405 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1406 png_progressive_info_ptr info_fn PNG_DEPSTRUCT; /* called after header data fully read */
1407 png_progressive_row_ptr row_fn PNG_DEPSTRUCT; /* called after each prog. row is decoded */
1408 png_progressive_end_ptr end_fn PNG_DEPSTRUCT; /* called after image is complete */
1409 png_bytep save_buffer_ptr PNG_DEPSTRUCT; /* current location in save_buffer */
1410 png_bytep save_buffer PNG_DEPSTRUCT; /* buffer for previously read data */
1411 png_bytep current_buffer_ptr PNG_DEPSTRUCT; /* current location in current_buffer */
1412 png_bytep current_buffer PNG_DEPSTRUCT; /* buffer for recently used data */
1413 png_uint_32 push_length PNG_DEPSTRUCT; /* size of current input chunk */
1414 png_uint_32 skip_length PNG_DEPSTRUCT; /* bytes to skip in input data */
1415 png_size_t save_buffer_size PNG_DEPSTRUCT; /* amount of data now in save_buffer */
1416 png_size_t save_buffer_max PNG_DEPSTRUCT; /* total size of save_buffer */
1417 png_size_t buffer_size PNG_DEPSTRUCT; /* total amount of available input data */
1418 png_size_t current_buffer_size PNG_DEPSTRUCT; /* amount of data now in current_buffer */
1419 int process_mode PNG_DEPSTRUCT; /* what push library is currently doing */
1420 int cur_palette PNG_DEPSTRUCT; /* current push library palette index */
1422 # ifdef PNG_TEXT_SUPPORTED
1423 png_size_t current_text_size PNG_DEPSTRUCT; /* current size of text input data */
1424 png_size_t current_text_left PNG_DEPSTRUCT; /* how much text left to read in input */
1425 png_charp current_text PNG_DEPSTRUCT; /* current text chunk buffer */
1426 png_charp current_text_ptr PNG_DEPSTRUCT; /* current location in current_text */
1427 # endif /* PNG_TEXT_SUPPORTED */
1428 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1430 #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
1431 /* for the Borland special 64K segment handler */
1432 png_bytepp offset_table_ptr PNG_DEPSTRUCT;
1433 png_bytep offset_table PNG_DEPSTRUCT;
1434 png_uint_16 offset_table_number PNG_DEPSTRUCT;
1435 png_uint_16 offset_table_count PNG_DEPSTRUCT;
1436 png_uint_16 offset_table_count_free PNG_DEPSTRUCT;
1439 #ifdef PNG_READ_DITHER_SUPPORTED
1440 png_bytep palette_lookup PNG_DEPSTRUCT; /* lookup table for dithering */
1441 png_bytep dither_index PNG_DEPSTRUCT; /* index translation for palette files */
1444 #if defined(PNG_READ_DITHER_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
1445 png_uint_16p hist PNG_DEPSTRUCT; /* histogram */
1448 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
1449 png_byte heuristic_method PNG_DEPSTRUCT; /* heuristic for row filter selection */
1450 png_byte num_prev_filters PNG_DEPSTRUCT; /* number of weights for previous rows */
1451 png_bytep prev_filters PNG_DEPSTRUCT; /* filter type(s) of previous row(s) */
1452 png_uint_16p filter_weights PNG_DEPSTRUCT; /* weight(s) for previous line(s) */
1453 png_uint_16p inv_filter_weights PNG_DEPSTRUCT; /* 1/weight(s) for previous line(s) */
1454 png_uint_16p filter_costs PNG_DEPSTRUCT; /* relative filter calculation cost */
1455 png_uint_16p inv_filter_costs PNG_DEPSTRUCT; /* 1/relative filter calculation cost */
1458 #ifdef PNG_TIME_RFC1123_SUPPORTED
1459 png_charp time_buffer PNG_DEPSTRUCT; /* String to hold RFC 1123 time text */
1462 /* New members added in libpng-1.0.6 */
1464 #ifdef PNG_FREE_ME_SUPPORTED
1465 png_uint_32 free_me PNG_DEPSTRUCT; /* flags items libpng is responsible for freeing */
1468 #ifdef PNG_USER_CHUNKS_SUPPORTED
1469 png_voidp user_chunk_ptr PNG_DEPSTRUCT;
1470 png_user_chunk_ptr read_user_chunk_fn PNG_DEPSTRUCT; /* user read chunk handler */
1473 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
1474 int num_chunk_list PNG_DEPSTRUCT;
1475 png_bytep chunk_list PNG_DEPSTRUCT;
1478 /* New members added in libpng-1.0.3 */
1479 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1480 png_byte rgb_to_gray_status PNG_DEPSTRUCT;
1481 /* These were changed from png_byte in libpng-1.0.6 */
1482 png_uint_16 rgb_to_gray_red_coeff PNG_DEPSTRUCT;
1483 png_uint_16 rgb_to_gray_green_coeff PNG_DEPSTRUCT;
1484 png_uint_16 rgb_to_gray_blue_coeff PNG_DEPSTRUCT;
1487 /* New member added in libpng-1.0.4 (renamed in 1.0.9) */
1488 #if defined(PNG_MNG_FEATURES_SUPPORTED) || \
1489 defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1490 defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1491 /* Changed from png_byte to png_uint_32 at version 1.2.0 */
1493 png_byte mng_features_permitted PNG_DEPSTRUCT;
1495 png_uint_32 mng_features_permitted PNG_DEPSTRUCT;
1496 #endif /* PNG_1_0_X */
1499 /* New member added in libpng-1.0.7 */
1500 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1501 png_fixed_point int_gamma PNG_DEPSTRUCT;
1504 /* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
1505 #ifdef PNG_MNG_FEATURES_SUPPORTED
1506 png_byte filter_type PNG_DEPSTRUCT;
1510 /* New member added in libpng-1.0.10, ifdef'ed out in 1.2.0 */
1511 png_uint_32 row_buf_size PNG_DEPSTRUCT;
1514 /* New members added in libpng-1.2.0 */
1515 #ifdef PNG_ASSEMBLER_CODE_SUPPORTED
1517 # ifdef PNG_MMX_CODE_SUPPORTED
1518 png_byte mmx_bitdepth_threshold PNG_DEPSTRUCT;
1519 png_uint_32 mmx_rowbytes_threshold PNG_DEPSTRUCT;
1521 png_uint_32 asm_flags PNG_DEPSTRUCT;
1525 /* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
1526 #ifdef PNG_USER_MEM_SUPPORTED
1527 png_voidp mem_ptr PNG_DEPSTRUCT; /* user supplied struct for mem functions */
1528 png_malloc_ptr malloc_fn PNG_DEPSTRUCT; /* function for allocating memory */
1529 png_free_ptr free_fn PNG_DEPSTRUCT; /* function for freeing memory */
1532 /* New member added in libpng-1.0.13 and 1.2.0 */
1533 png_bytep big_row_buf PNG_DEPSTRUCT; /* buffer to save current (unfiltered) row */
1535 #ifdef PNG_READ_DITHER_SUPPORTED
1536 /* The following three members were added at version 1.0.14 and 1.2.4 */
1537 png_bytep dither_sort PNG_DEPSTRUCT; /* working sort array */
1538 png_bytep index_to_palette PNG_DEPSTRUCT; /* where the original index currently is */
1539 /* in the palette */
1540 png_bytep palette_to_index PNG_DEPSTRUCT; /* which original index points to this */
1544 /* New members added in libpng-1.0.16 and 1.2.6 */
1545 png_byte compression_type PNG_DEPSTRUCT;
1547 #ifdef PNG_USER_LIMITS_SUPPORTED
1548 png_uint_32 user_width_max PNG_DEPSTRUCT;
1549 png_uint_32 user_height_max PNG_DEPSTRUCT;
1552 /* New member added in libpng-1.0.25 and 1.2.17 */
1553 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
1554 /* Storage for unknown chunk that the library doesn't recognize. */
1555 png_unknown_chunk unknown_chunk PNG_DEPSTRUCT;
1558 /* New members added in libpng-1.2.26 */
1559 png_uint_32 old_big_row_buf_size PNG_DEPSTRUCT;
1560 png_uint_32 old_prev_row_size PNG_DEPSTRUCT;
1562 /* New member added in libpng-1.2.30 */
1563 png_charp chunkdata PNG_DEPSTRUCT; /* buffer for reading chunk data */
1569 /* This triggers a compiler error in png.c, if png.c and png.h
1570 * do not agree upon the version number.
1572 typedef png_structp version_1_2_50;
1574 typedef png_struct FAR * FAR * png_structpp;
1576 /* Here are the function definitions most commonly used. This is not
1577 * the place to find out how to use libpng. See libpng.txt for the
1578 * full explanation, see example.c for the summary. This just provides
1579 * a simple one line description of the use of each function.
1582 /* Returns the version number of the library */
1583 extern PNG_EXPORT(png_uint_32,png_access_version_number) PNGARG((void));
1585 /* Tell lib we have already handled the first <num_bytes> magic bytes.
1586 * Handling more than 8 bytes from the beginning of the file is an error.
1588 extern PNG_EXPORT(void,png_set_sig_bytes) PNGARG((png_structp png_ptr,
1591 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
1592 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
1593 * signature, and non-zero otherwise. Having num_to_check == 0 or
1594 * start > 7 will always fail (ie return non-zero).
1596 extern PNG_EXPORT(int,png_sig_cmp) PNGARG((png_bytep sig, png_size_t start,
1597 png_size_t num_to_check));
1599 /* Simple signature checking function. This is the same as calling
1600 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
1602 extern PNG_EXPORT(int,png_check_sig) PNGARG((png_bytep sig, int num)) PNG_DEPRECATED;
1604 /* Allocate and initialize png_ptr struct for reading, and any other memory. */
1605 extern PNG_EXPORT(png_structp,png_create_read_struct)
1606 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1607 png_error_ptr error_fn, png_error_ptr warn_fn)) PNG_ALLOCATED;
1609 /* Allocate and initialize png_ptr struct for writing, and any other memory */
1610 extern PNG_EXPORT(png_structp,png_create_write_struct)
1611 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1612 png_error_ptr error_fn, png_error_ptr warn_fn)) PNG_ALLOCATED;
1614 #ifdef PNG_WRITE_SUPPORTED
1615 extern PNG_EXPORT(png_uint_32,png_get_compression_buffer_size)
1616 PNGARG((png_structp png_ptr));
1619 #ifdef PNG_WRITE_SUPPORTED
1620 extern PNG_EXPORT(void,png_set_compression_buffer_size)
1621 PNGARG((png_structp png_ptr, png_uint_32 size));
1624 /* Reset the compression stream */
1625 extern PNG_EXPORT(int,png_reset_zstream) PNGARG((png_structp png_ptr));
1627 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
1628 #ifdef PNG_USER_MEM_SUPPORTED
1629 extern PNG_EXPORT(png_structp,png_create_read_struct_2)
1630 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1631 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1632 png_malloc_ptr malloc_fn, png_free_ptr free_fn)) PNG_ALLOCATED;
1633 extern PNG_EXPORT(png_structp,png_create_write_struct_2)
1634 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1635 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1636 png_malloc_ptr malloc_fn, png_free_ptr free_fn)) PNG_ALLOCATED;
1639 /* Write a PNG chunk - size, type, (optional) data, CRC. */
1640 extern PNG_EXPORT(void,png_write_chunk) PNGARG((png_structp png_ptr,
1641 png_bytep chunk_name, png_bytep data, png_size_t length));
1643 /* Write the start of a PNG chunk - length and chunk name. */
1644 extern PNG_EXPORT(void,png_write_chunk_start) PNGARG((png_structp png_ptr,
1645 png_bytep chunk_name, png_uint_32 length));
1647 /* Write the data of a PNG chunk started with png_write_chunk_start(). */
1648 extern PNG_EXPORT(void,png_write_chunk_data) PNGARG((png_structp png_ptr,
1649 png_bytep data, png_size_t length));
1651 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1652 extern PNG_EXPORT(void,png_write_chunk_end) PNGARG((png_structp png_ptr));
1654 /* Allocate and initialize the info structure */
1655 extern PNG_EXPORT(png_infop,png_create_info_struct)
1656 PNGARG((png_structp png_ptr)) PNG_ALLOCATED;
1658 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1659 /* Initialize the info structure (old interface - DEPRECATED) */
1660 extern PNG_EXPORT(void,png_info_init) PNGARG((png_infop info_ptr))
1662 #undef png_info_init
1663 #define png_info_init(info_ptr) png_info_init_3(&info_ptr,\
1664 png_sizeof(png_info));
1667 extern PNG_EXPORT(void,png_info_init_3) PNGARG((png_infopp info_ptr,
1668 png_size_t png_info_struct_size));
1670 /* Writes all the PNG information before the image. */
1671 extern PNG_EXPORT(void,png_write_info_before_PLTE) PNGARG((png_structp png_ptr,
1672 png_infop info_ptr));
1673 extern PNG_EXPORT(void,png_write_info) PNGARG((png_structp png_ptr,
1674 png_infop info_ptr));
1676 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1677 /* Read the information before the actual image data. */
1678 extern PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr,
1679 png_infop info_ptr));
1682 #ifdef PNG_TIME_RFC1123_SUPPORTED
1683 extern PNG_EXPORT(png_charp,png_convert_to_rfc1123)
1684 PNGARG((png_structp png_ptr, png_timep ptime));
1687 #ifdef PNG_CONVERT_tIME_SUPPORTED
1688 /* Convert from a struct tm to png_time */
1689 extern PNG_EXPORT(void,png_convert_from_struct_tm) PNGARG((png_timep ptime,
1690 struct tm FAR * ttime));
1692 /* Convert from time_t to png_time. Uses gmtime() */
1693 extern PNG_EXPORT(void,png_convert_from_time_t) PNGARG((png_timep ptime,
1695 #endif /* PNG_CONVERT_tIME_SUPPORTED */
1697 #ifdef PNG_READ_EXPAND_SUPPORTED
1698 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1699 extern PNG_EXPORT(void,png_set_expand) PNGARG((png_structp png_ptr));
1701 extern PNG_EXPORT(void,png_set_expand_gray_1_2_4_to_8) PNGARG((png_structp
1704 extern PNG_EXPORT(void,png_set_palette_to_rgb) PNGARG((png_structp png_ptr));
1705 extern PNG_EXPORT(void,png_set_tRNS_to_alpha) PNGARG((png_structp png_ptr));
1706 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1708 extern PNG_EXPORT(void,png_set_gray_1_2_4_to_8) PNGARG((png_structp
1709 png_ptr)) PNG_DEPRECATED;
1713 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1714 /* Use blue, green, red order for pixels. */
1715 extern PNG_EXPORT(void,png_set_bgr) PNGARG((png_structp png_ptr));
1718 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1719 /* Expand the grayscale to 24-bit RGB if necessary. */
1720 extern PNG_EXPORT(void,png_set_gray_to_rgb) PNGARG((png_structp png_ptr));
1723 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1724 /* Reduce RGB to grayscale. */
1725 #ifdef PNG_FLOATING_POINT_SUPPORTED
1726 extern PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr,
1727 int error_action, double red, double green ));
1729 extern PNG_EXPORT(void,png_set_rgb_to_gray_fixed) PNGARG((png_structp png_ptr,
1730 int error_action, png_fixed_point red, png_fixed_point green ));
1731 extern PNG_EXPORT(png_byte,png_get_rgb_to_gray_status) PNGARG((png_structp
1735 extern PNG_EXPORT(void,png_build_grayscale_palette) PNGARG((int bit_depth,
1736 png_colorp palette));
1738 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1739 extern PNG_EXPORT(void,png_set_strip_alpha) PNGARG((png_structp png_ptr));
1742 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1743 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1744 extern PNG_EXPORT(void,png_set_swap_alpha) PNGARG((png_structp png_ptr));
1747 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1748 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1749 extern PNG_EXPORT(void,png_set_invert_alpha) PNGARG((png_structp png_ptr));
1752 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1753 /* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
1754 extern PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr,
1755 png_uint_32 filler, int flags));
1756 /* The values of the PNG_FILLER_ defines should NOT be changed */
1757 #define PNG_FILLER_BEFORE 0
1758 #define PNG_FILLER_AFTER 1
1759 /* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
1761 extern PNG_EXPORT(void,png_set_add_alpha) PNGARG((png_structp png_ptr,
1762 png_uint_32 filler, int flags));
1764 #endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
1766 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1767 /* Swap bytes in 16-bit depth files. */
1768 extern PNG_EXPORT(void,png_set_swap) PNGARG((png_structp png_ptr));
1771 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1772 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1773 extern PNG_EXPORT(void,png_set_packing) PNGARG((png_structp png_ptr));
1776 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1777 /* Swap packing order of pixels in bytes. */
1778 extern PNG_EXPORT(void,png_set_packswap) PNGARG((png_structp png_ptr));
1781 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1782 /* Converts files to legal bit depths. */
1783 extern PNG_EXPORT(void,png_set_shift) PNGARG((png_structp png_ptr,
1784 png_color_8p true_bits));
1787 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1788 defined(PNG_WRITE_INTERLACING_SUPPORTED)
1789 /* Have the code handle the interlacing. Returns the number of passes. */
1790 extern PNG_EXPORT(int,png_set_interlace_handling) PNGARG((png_structp png_ptr));
1793 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1794 /* Invert monochrome files */
1795 extern PNG_EXPORT(void,png_set_invert_mono) PNGARG((png_structp png_ptr));
1798 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1799 /* Handle alpha and tRNS by replacing with a background color. */
1800 #ifdef PNG_FLOATING_POINT_SUPPORTED
1801 extern PNG_EXPORT(void,png_set_background) PNGARG((png_structp png_ptr,
1802 png_color_16p background_color, int background_gamma_code,
1803 int need_expand, double background_gamma));
1805 #define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1806 #define PNG_BACKGROUND_GAMMA_SCREEN 1
1807 #define PNG_BACKGROUND_GAMMA_FILE 2
1808 #define PNG_BACKGROUND_GAMMA_UNIQUE 3
1811 #ifdef PNG_READ_16_TO_8_SUPPORTED
1812 /* Strip the second byte of information from a 16-bit depth file. */
1813 extern PNG_EXPORT(void,png_set_strip_16) PNGARG((png_structp png_ptr));
1816 #ifdef PNG_READ_DITHER_SUPPORTED
1817 /* Turn on dithering, and reduce the palette to the number of colors available. */
1818 extern PNG_EXPORT(void,png_set_dither) PNGARG((png_structp png_ptr,
1819 png_colorp palette, int num_palette, int maximum_colors,
1820 png_uint_16p histogram, int full_dither));
1823 #ifdef PNG_READ_GAMMA_SUPPORTED
1824 /* Handle gamma correction. Screen_gamma=(display_exponent) */
1825 #ifdef PNG_FLOATING_POINT_SUPPORTED
1826 extern PNG_EXPORT(void,png_set_gamma) PNGARG((png_structp png_ptr,
1827 double screen_gamma, double default_file_gamma));
1831 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1832 #if defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1833 defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1834 /* Permit or disallow empty PLTE (0: not permitted, 1: permitted) */
1835 /* Deprecated and will be removed. Use png_permit_mng_features() instead. */
1836 extern PNG_EXPORT(void,png_permit_empty_plte) PNGARG((png_structp png_ptr,
1837 int empty_plte_permitted)) PNG_DEPRECATED;
1841 #ifdef PNG_WRITE_FLUSH_SUPPORTED
1842 /* Set how many lines between output flushes - 0 for no flushing */
1843 extern PNG_EXPORT(void,png_set_flush) PNGARG((png_structp png_ptr, int nrows));
1844 /* Flush the current PNG output buffer */
1845 extern PNG_EXPORT(void,png_write_flush) PNGARG((png_structp png_ptr));
1848 /* Optional update palette with requested transformations */
1849 extern PNG_EXPORT(void,png_start_read_image) PNGARG((png_structp png_ptr));
1851 /* Optional call to update the users info structure */
1852 extern PNG_EXPORT(void,png_read_update_info) PNGARG((png_structp png_ptr,
1853 png_infop info_ptr));
1855 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1856 /* Read one or more rows of image data. */
1857 extern PNG_EXPORT(void,png_read_rows) PNGARG((png_structp png_ptr,
1858 png_bytepp row, png_bytepp display_row, png_uint_32 num_rows));
1861 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1862 /* Read a row of data. */
1863 extern PNG_EXPORT(void,png_read_row) PNGARG((png_structp png_ptr,
1865 png_bytep display_row));
1868 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1869 /* Read the whole image into memory at once. */
1870 extern PNG_EXPORT(void,png_read_image) PNGARG((png_structp png_ptr,
1874 /* Write a row of image data */
1875 extern PNG_EXPORT(void,png_write_row) PNGARG((png_structp png_ptr,
1878 /* Write a few rows of image data */
1879 extern PNG_EXPORT(void,png_write_rows) PNGARG((png_structp png_ptr,
1880 png_bytepp row, png_uint_32 num_rows));
1882 /* Write the image data */
1883 extern PNG_EXPORT(void,png_write_image) PNGARG((png_structp png_ptr,
1886 /* Writes the end of the PNG file. */
1887 extern PNG_EXPORT(void,png_write_end) PNGARG((png_structp png_ptr,
1888 png_infop info_ptr));
1890 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1891 /* Read the end of the PNG file. */
1892 extern PNG_EXPORT(void,png_read_end) PNGARG((png_structp png_ptr,
1893 png_infop info_ptr));
1896 /* Free any memory associated with the png_info_struct */
1897 extern PNG_EXPORT(void,png_destroy_info_struct) PNGARG((png_structp png_ptr,
1898 png_infopp info_ptr_ptr));
1900 /* Free any memory associated with the png_struct and the png_info_structs */
1901 extern PNG_EXPORT(void,png_destroy_read_struct) PNGARG((png_structpp
1902 png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1904 /* Free all memory used by the read (old method - NOT DLL EXPORTED) */
1905 extern void png_read_destroy PNGARG((png_structp png_ptr, png_infop info_ptr,
1906 png_infop end_info_ptr)) PNG_DEPRECATED;
1908 /* Free any memory associated with the png_struct and the png_info_structs */
1909 extern PNG_EXPORT(void,png_destroy_write_struct)
1910 PNGARG((png_structpp png_ptr_ptr, png_infopp info_ptr_ptr));
1912 /* Free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */
1913 extern void png_write_destroy PNGARG((png_structp png_ptr)) PNG_DEPRECATED;
1915 /* Set the libpng method of handling chunk CRC errors */
1916 extern PNG_EXPORT(void,png_set_crc_action) PNGARG((png_structp png_ptr,
1917 int crit_action, int ancil_action));
1919 /* Values for png_set_crc_action() to say how to handle CRC errors in
1920 * ancillary and critical chunks, and whether to use the data contained
1921 * therein. Note that it is impossible to "discard" data in a critical
1922 * chunk. For versions prior to 0.90, the action was always error/quit,
1923 * whereas in version 0.90 and later, the action for CRC errors in ancillary
1924 * chunks is warn/discard. These values should NOT be changed.
1926 * value action:critical action:ancillary
1928 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1929 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1930 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1931 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1932 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1933 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1935 /* These functions give the user control over the scan-line filtering in
1936 * libpng and the compression methods used by zlib. These functions are
1937 * mainly useful for testing, as the defaults should work with most users.
1938 * Those users who are tight on memory or want faster performance at the
1939 * expense of compression can modify them. See the compression library
1940 * header file (zlib.h) for an explination of the compression functions.
1943 /* Set the filtering method(s) used by libpng. Currently, the only valid
1944 * value for "method" is 0.
1946 extern PNG_EXPORT(void,png_set_filter) PNGARG((png_structp png_ptr, int method,
1949 /* Flags for png_set_filter() to say which filters to use. The flags
1950 * are chosen so that they don't conflict with real filter types
1951 * below, in case they are supplied instead of the #defined constants.
1952 * These values should NOT be changed.
1954 #define PNG_NO_FILTERS 0x00
1955 #define PNG_FILTER_NONE 0x08
1956 #define PNG_FILTER_SUB 0x10
1957 #define PNG_FILTER_UP 0x20
1958 #define PNG_FILTER_AVG 0x40
1959 #define PNG_FILTER_PAETH 0x80
1960 #define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
1961 PNG_FILTER_AVG | PNG_FILTER_PAETH)
1963 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1964 * These defines should NOT be changed.
1966 #define PNG_FILTER_VALUE_NONE 0
1967 #define PNG_FILTER_VALUE_SUB 1
1968 #define PNG_FILTER_VALUE_UP 2
1969 #define PNG_FILTER_VALUE_AVG 3
1970 #define PNG_FILTER_VALUE_PAETH 4
1971 #define PNG_FILTER_VALUE_LAST 5
1973 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* EXPERIMENTAL */
1974 /* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
1975 * defines, either the default (minimum-sum-of-absolute-differences), or
1976 * the experimental method (weighted-minimum-sum-of-absolute-differences).
1978 * Weights are factors >= 1.0, indicating how important it is to keep the
1979 * filter type consistent between rows. Larger numbers mean the current
1980 * filter is that many times as likely to be the same as the "num_weights"
1981 * previous filters. This is cumulative for each previous row with a weight.
1982 * There needs to be "num_weights" values in "filter_weights", or it can be
1983 * NULL if the weights aren't being specified. Weights have no influence on
1984 * the selection of the first row filter. Well chosen weights can (in theory)
1985 * improve the compression for a given image.
1987 * Costs are factors >= 1.0 indicating the relative decoding costs of a
1988 * filter type. Higher costs indicate more decoding expense, and are
1989 * therefore less likely to be selected over a filter with lower computational
1990 * costs. There needs to be a value in "filter_costs" for each valid filter
1991 * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
1992 * setting the costs. Costs try to improve the speed of decompression without
1993 * unduly increasing the compressed image size.
1995 * A negative weight or cost indicates the default value is to be used, and
1996 * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
1997 * The default values for both weights and costs are currently 1.0, but may
1998 * change if good general weighting/cost heuristics can be found. If both
1999 * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
2000 * to the UNWEIGHTED method, but with added encoding time/computation.
2002 #ifdef PNG_FLOATING_POINT_SUPPORTED
2003 extern PNG_EXPORT(void,png_set_filter_heuristics) PNGARG((png_structp png_ptr,
2004 int heuristic_method, int num_weights, png_doublep filter_weights,
2005 png_doublep filter_costs));
2007 #endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
2009 /* Heuristic used for row filter selection. These defines should NOT be
2012 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
2013 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
2014 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
2015 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
2017 /* Set the library compression level. Currently, valid values range from
2018 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
2019 * (0 - no compression, 9 - "maximal" compression). Note that tests have
2020 * shown that zlib compression levels 3-6 usually perform as well as level 9
2021 * for PNG images, and do considerably fewer caclulations. In the future,
2022 * these values may not correspond directly to the zlib compression levels.
2024 extern PNG_EXPORT(void,png_set_compression_level) PNGARG((png_structp png_ptr,
2027 extern PNG_EXPORT(void,png_set_compression_mem_level)
2028 PNGARG((png_structp png_ptr, int mem_level));
2030 extern PNG_EXPORT(void,png_set_compression_strategy)
2031 PNGARG((png_structp png_ptr, int strategy));
2033 extern PNG_EXPORT(void,png_set_compression_window_bits)
2034 PNGARG((png_structp png_ptr, int window_bits));
2036 extern PNG_EXPORT(void,png_set_compression_method) PNGARG((png_structp png_ptr,
2039 /* These next functions are called for input/output, memory, and error
2040 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
2041 * and call standard C I/O routines such as fread(), fwrite(), and
2042 * fprintf(). These functions can be made to use other I/O routines
2043 * at run time for those applications that need to handle I/O in a
2044 * different manner by calling png_set_???_fn(). See libpng.txt for
2048 #ifdef PNG_STDIO_SUPPORTED
2049 /* Initialize the input/output for the PNG file to the default functions. */
2050 extern PNG_EXPORT(void,png_init_io) PNGARG((png_structp png_ptr, png_FILE_p fp));
2053 /* Replace the (error and abort), and warning functions with user
2054 * supplied functions. If no messages are to be printed you must still
2055 * write and use replacement functions. The replacement error_fn should
2056 * still do a longjmp to the last setjmp location if you are using this
2057 * method of error handling. If error_fn or warning_fn is NULL, the
2058 * default function will be used.
2061 extern PNG_EXPORT(void,png_set_error_fn) PNGARG((png_structp png_ptr,
2062 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
2064 /* Return the user pointer associated with the error functions */
2065 extern PNG_EXPORT(png_voidp,png_get_error_ptr) PNGARG((png_structp png_ptr));
2067 /* Replace the default data output functions with a user supplied one(s).
2068 * If buffered output is not used, then output_flush_fn can be set to NULL.
2069 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
2070 * output_flush_fn will be ignored (and thus can be NULL).
2071 * It is probably a mistake to use NULL for output_flush_fn if
2072 * write_data_fn is not also NULL unless you have built libpng with
2073 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
2074 * default flush function, which uses the standard *FILE structure, will
2077 extern PNG_EXPORT(void,png_set_write_fn) PNGARG((png_structp png_ptr,
2078 png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
2080 /* Replace the default data input function with a user supplied one. */
2081 extern PNG_EXPORT(void,png_set_read_fn) PNGARG((png_structp png_ptr,
2082 png_voidp io_ptr, png_rw_ptr read_data_fn));
2084 /* Return the user pointer associated with the I/O functions */
2085 extern PNG_EXPORT(png_voidp,png_get_io_ptr) PNGARG((png_structp png_ptr));
2087 extern PNG_EXPORT(void,png_set_read_status_fn) PNGARG((png_structp png_ptr,
2088 png_read_status_ptr read_row_fn));
2090 extern PNG_EXPORT(void,png_set_write_status_fn) PNGARG((png_structp png_ptr,
2091 png_write_status_ptr write_row_fn));
2093 #ifdef PNG_USER_MEM_SUPPORTED
2094 /* Replace the default memory allocation functions with user supplied one(s). */
2095 extern PNG_EXPORT(void,png_set_mem_fn) PNGARG((png_structp png_ptr,
2096 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn));
2097 /* Return the user pointer associated with the memory functions */
2098 extern PNG_EXPORT(png_voidp,png_get_mem_ptr) PNGARG((png_structp png_ptr));
2101 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
2102 defined(PNG_LEGACY_SUPPORTED)
2103 extern PNG_EXPORT(void,png_set_read_user_transform_fn) PNGARG((png_structp
2104 png_ptr, png_user_transform_ptr read_user_transform_fn));
2107 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
2108 defined(PNG_LEGACY_SUPPORTED)
2109 extern PNG_EXPORT(void,png_set_write_user_transform_fn) PNGARG((png_structp
2110 png_ptr, png_user_transform_ptr write_user_transform_fn));
2113 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
2114 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
2115 defined(PNG_LEGACY_SUPPORTED)
2116 extern PNG_EXPORT(void,png_set_user_transform_info) PNGARG((png_structp
2117 png_ptr, png_voidp user_transform_ptr, int user_transform_depth,
2118 int user_transform_channels));
2119 /* Return the user pointer associated with the user transform functions */
2120 extern PNG_EXPORT(png_voidp,png_get_user_transform_ptr)
2121 PNGARG((png_structp png_ptr));
2124 #ifdef PNG_USER_CHUNKS_SUPPORTED
2125 extern PNG_EXPORT(void,png_set_read_user_chunk_fn) PNGARG((png_structp png_ptr,
2126 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
2127 extern PNG_EXPORT(png_voidp,png_get_user_chunk_ptr) PNGARG((png_structp
2131 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
2132 /* Sets the function callbacks for the push reader, and a pointer to a
2133 * user-defined structure available to the callback functions.
2135 extern PNG_EXPORT(void,png_set_progressive_read_fn) PNGARG((png_structp png_ptr,
2136 png_voidp progressive_ptr,
2137 png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
2138 png_progressive_end_ptr end_fn));
2140 /* Returns the user pointer associated with the push read functions */
2141 extern PNG_EXPORT(png_voidp,png_get_progressive_ptr)
2142 PNGARG((png_structp png_ptr));
2144 /* Function to be called when data becomes available */
2145 extern PNG_EXPORT(void,png_process_data) PNGARG((png_structp png_ptr,
2146 png_infop info_ptr, png_bytep buffer, png_size_t buffer_size));
2148 /* Function that combines rows. Not very much different than the
2149 * png_combine_row() call. Is this even used?????
2151 extern PNG_EXPORT(void,png_progressive_combine_row) PNGARG((png_structp png_ptr,
2152 png_bytep old_row, png_bytep new_row));
2153 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
2155 extern PNG_EXPORT(png_voidp,png_malloc) PNGARG((png_structp png_ptr,
2156 png_uint_32 size)) PNG_ALLOCATED;
2159 # define png_malloc_warn png_malloc
2161 /* Added at libpng version 1.2.4 */
2162 extern PNG_EXPORT(png_voidp,png_malloc_warn) PNGARG((png_structp png_ptr,
2163 png_uint_32 size)) PNG_ALLOCATED;
2166 /* Frees a pointer allocated by png_malloc() */
2167 extern PNG_EXPORT(void,png_free) PNGARG((png_structp png_ptr, png_voidp ptr));
2170 /* Function to allocate memory for zlib. */
2171 extern PNG_EXPORT(voidpf,png_zalloc) PNGARG((voidpf png_ptr, uInt items,
2174 /* Function to free memory for zlib */
2175 extern PNG_EXPORT(void,png_zfree) PNGARG((voidpf png_ptr, voidpf ptr));
2178 /* Free data that was allocated internally */
2179 extern PNG_EXPORT(void,png_free_data) PNGARG((png_structp png_ptr,
2180 png_infop info_ptr, png_uint_32 free_me, int num));
2181 #ifdef PNG_FREE_ME_SUPPORTED
2182 /* Reassign responsibility for freeing existing data, whether allocated
2183 * by libpng or by the application
2185 extern PNG_EXPORT(void,png_data_freer) PNGARG((png_structp png_ptr,
2186 png_infop info_ptr, int freer, png_uint_32 mask));
2188 /* Assignments for png_data_freer */
2189 #define PNG_DESTROY_WILL_FREE_DATA 1
2190 #define PNG_SET_WILL_FREE_DATA 1
2191 #define PNG_USER_WILL_FREE_DATA 2
2192 /* Flags for png_ptr->free_me and info_ptr->free_me */
2193 #define PNG_FREE_HIST 0x0008
2194 #define PNG_FREE_ICCP 0x0010
2195 #define PNG_FREE_SPLT 0x0020
2196 #define PNG_FREE_ROWS 0x0040
2197 #define PNG_FREE_PCAL 0x0080
2198 #define PNG_FREE_SCAL 0x0100
2199 #define PNG_FREE_UNKN 0x0200
2200 #define PNG_FREE_LIST 0x0400
2201 #define PNG_FREE_PLTE 0x1000
2202 #define PNG_FREE_TRNS 0x2000
2203 #define PNG_FREE_TEXT 0x4000
2204 #define PNG_FREE_ALL 0x7fff
2205 #define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
2207 #ifdef PNG_USER_MEM_SUPPORTED
2208 extern PNG_EXPORT(png_voidp,png_malloc_default) PNGARG((png_structp png_ptr,
2209 png_uint_32 size)) PNG_ALLOCATED;
2210 extern PNG_EXPORT(void,png_free_default) PNGARG((png_structp png_ptr,
2214 extern PNG_EXPORT(png_voidp,png_memcpy_check) PNGARG((png_structp png_ptr,
2215 png_voidp s1, png_voidp s2, png_uint_32 size)) PNG_DEPRECATED;
2217 extern PNG_EXPORT(png_voidp,png_memset_check) PNGARG((png_structp png_ptr,
2218 png_voidp s1, int value, png_uint_32 size)) PNG_DEPRECATED;
2220 #if defined(USE_FAR_KEYWORD) /* memory model conversion function */
2221 extern void *png_far_to_near PNGARG((png_structp png_ptr,png_voidp ptr,
2223 #endif /* USE_FAR_KEYWORD */
2225 #ifndef PNG_NO_ERROR_TEXT
2226 /* Fatal error in PNG image of libpng - can't continue */
2227 extern PNG_EXPORT(void,png_error) PNGARG((png_structp png_ptr,
2228 png_const_charp error_message)) PNG_NORETURN;
2230 /* The same, but the chunk name is prepended to the error string. */
2231 extern PNG_EXPORT(void,png_chunk_error) PNGARG((png_structp png_ptr,
2232 png_const_charp error_message)) PNG_NORETURN;
2234 /* Fatal error in PNG image of libpng - can't continue */
2235 extern PNG_EXPORT(void,png_err) PNGARG((png_structp png_ptr)) PNG_NORETURN;
2238 #ifndef PNG_NO_WARNINGS
2239 /* Non-fatal error in libpng. Can continue, but may have a problem. */
2240 extern PNG_EXPORT(void,png_warning) PNGARG((png_structp png_ptr,
2241 png_const_charp warning_message));
2243 #ifdef PNG_READ_SUPPORTED
2244 /* Non-fatal error in libpng, chunk name is prepended to message. */
2245 extern PNG_EXPORT(void,png_chunk_warning) PNGARG((png_structp png_ptr,
2246 png_const_charp warning_message));
2247 #endif /* PNG_READ_SUPPORTED */
2248 #endif /* PNG_NO_WARNINGS */
2250 /* The png_set_<chunk> functions are for storing values in the png_info_struct.
2251 * Similarly, the png_get_<chunk> calls are used to read values from the
2252 * png_info_struct, either storing the parameters in the passed variables, or
2253 * setting pointers into the png_info_struct where the data is stored. The
2254 * png_get_<chunk> functions return a non-zero value if the data was available
2255 * in info_ptr, or return zero and do not change any of the parameters if the
2256 * data was not available.
2258 * These functions should be used instead of directly accessing png_info
2259 * to avoid problems with future changes in the size and internal layout of
2262 /* Returns "flag" if chunk data is valid in info_ptr. */
2263 extern PNG_EXPORT(png_uint_32,png_get_valid) PNGARG((png_structp png_ptr,
2264 png_infop info_ptr, png_uint_32 flag));
2266 /* Returns number of bytes needed to hold a transformed row. */
2267 extern PNG_EXPORT(png_uint_32,png_get_rowbytes) PNGARG((png_structp png_ptr,
2268 png_infop info_ptr));
2270 #ifdef PNG_INFO_IMAGE_SUPPORTED
2271 /* Returns row_pointers, which is an array of pointers to scanlines that was
2272 * returned from png_read_png().
2274 extern PNG_EXPORT(png_bytepp,png_get_rows) PNGARG((png_structp png_ptr,
2275 png_infop info_ptr));
2276 /* Set row_pointers, which is an array of pointers to scanlines for use
2277 * by png_write_png().
2279 extern PNG_EXPORT(void,png_set_rows) PNGARG((png_structp png_ptr,
2280 png_infop info_ptr, png_bytepp row_pointers));
2283 /* Returns number of color channels in image. */
2284 extern PNG_EXPORT(png_byte,png_get_channels) PNGARG((png_structp png_ptr,
2285 png_infop info_ptr));
2287 #ifdef PNG_EASY_ACCESS_SUPPORTED
2288 /* Returns image width in pixels. */
2289 extern PNG_EXPORT(png_uint_32, png_get_image_width) PNGARG((png_structp
2290 png_ptr, png_infop info_ptr));
2292 /* Returns image height in pixels. */
2293 extern PNG_EXPORT(png_uint_32, png_get_image_height) PNGARG((png_structp
2294 png_ptr, png_infop info_ptr));
2296 /* Returns image bit_depth. */
2297 extern PNG_EXPORT(png_byte, png_get_bit_depth) PNGARG((png_structp
2298 png_ptr, png_infop info_ptr));
2300 /* Returns image color_type. */
2301 extern PNG_EXPORT(png_byte, png_get_color_type) PNGARG((png_structp
2302 png_ptr, png_infop info_ptr));
2304 /* Returns image filter_type. */
2305 extern PNG_EXPORT(png_byte, png_get_filter_type) PNGARG((png_structp
2306 png_ptr, png_infop info_ptr));
2308 /* Returns image interlace_type. */
2309 extern PNG_EXPORT(png_byte, png_get_interlace_type) PNGARG((png_structp
2310 png_ptr, png_infop info_ptr));
2312 /* Returns image compression_type. */
2313 extern PNG_EXPORT(png_byte, png_get_compression_type) PNGARG((png_structp
2314 png_ptr, png_infop info_ptr));
2316 /* Returns image resolution in pixels per meter, from pHYs chunk data. */
2317 extern PNG_EXPORT(png_uint_32, png_get_pixels_per_meter) PNGARG((png_structp
2318 png_ptr, png_infop info_ptr));
2319 extern PNG_EXPORT(png_uint_32, png_get_x_pixels_per_meter) PNGARG((png_structp
2320 png_ptr, png_infop info_ptr));
2321 extern PNG_EXPORT(png_uint_32, png_get_y_pixels_per_meter) PNGARG((png_structp
2322 png_ptr, png_infop info_ptr));
2324 /* Returns pixel aspect ratio, computed from pHYs chunk data. */
2325 #ifdef PNG_FLOATING_POINT_SUPPORTED
2326 extern PNG_EXPORT(float, png_get_pixel_aspect_ratio) PNGARG((png_structp
2327 png_ptr, png_infop info_ptr));
2330 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
2331 extern PNG_EXPORT(png_int_32, png_get_x_offset_pixels) PNGARG((png_structp
2332 png_ptr, png_infop info_ptr));
2333 extern PNG_EXPORT(png_int_32, png_get_y_offset_pixels) PNGARG((png_structp
2334 png_ptr, png_infop info_ptr));
2335 extern PNG_EXPORT(png_int_32, png_get_x_offset_microns) PNGARG((png_structp
2336 png_ptr, png_infop info_ptr));
2337 extern PNG_EXPORT(png_int_32, png_get_y_offset_microns) PNGARG((png_structp
2338 png_ptr, png_infop info_ptr));
2340 #endif /* PNG_EASY_ACCESS_SUPPORTED */
2342 /* Returns pointer to signature string read from PNG header */
2343 extern PNG_EXPORT(png_bytep,png_get_signature) PNGARG((png_structp png_ptr,
2344 png_infop info_ptr));
2346 #ifdef PNG_bKGD_SUPPORTED
2347 extern PNG_EXPORT(png_uint_32,png_get_bKGD) PNGARG((png_structp png_ptr,
2348 png_infop info_ptr, png_color_16p *background));
2351 #ifdef PNG_bKGD_SUPPORTED
2352 extern PNG_EXPORT(void,png_set_bKGD) PNGARG((png_structp png_ptr,
2353 png_infop info_ptr, png_color_16p background));
2356 #ifdef PNG_cHRM_SUPPORTED
2357 #ifdef PNG_FLOATING_POINT_SUPPORTED
2358 extern PNG_EXPORT(png_uint_32,png_get_cHRM) PNGARG((png_structp png_ptr,
2359 png_infop info_ptr, double *white_x, double *white_y, double *red_x,
2360 double *red_y, double *green_x, double *green_y, double *blue_x,
2363 #ifdef PNG_FIXED_POINT_SUPPORTED
2364 extern PNG_EXPORT(png_uint_32,png_get_cHRM_fixed) PNGARG((png_structp png_ptr,
2365 png_infop info_ptr, png_fixed_point *int_white_x, png_fixed_point
2366 *int_white_y, png_fixed_point *int_red_x, png_fixed_point *int_red_y,
2367 png_fixed_point *int_green_x, png_fixed_point *int_green_y, png_fixed_point
2368 *int_blue_x, png_fixed_point *int_blue_y));
2372 #ifdef PNG_cHRM_SUPPORTED
2373 #ifdef PNG_FLOATING_POINT_SUPPORTED
2374 extern PNG_EXPORT(void,png_set_cHRM) PNGARG((png_structp png_ptr,
2375 png_infop info_ptr, double white_x, double white_y, double red_x,
2376 double red_y, double green_x, double green_y, double blue_x, double blue_y));
2378 #ifdef PNG_FIXED_POINT_SUPPORTED
2379 extern PNG_EXPORT(void,png_set_cHRM_fixed) PNGARG((png_structp png_ptr,
2380 png_infop info_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y,
2381 png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
2382 int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
2383 png_fixed_point int_blue_y));
2387 #ifdef PNG_gAMA_SUPPORTED
2388 #ifdef PNG_FLOATING_POINT_SUPPORTED
2389 extern PNG_EXPORT(png_uint_32,png_get_gAMA) PNGARG((png_structp png_ptr,
2390 png_infop info_ptr, double *file_gamma));
2392 extern PNG_EXPORT(png_uint_32,png_get_gAMA_fixed) PNGARG((png_structp png_ptr,
2393 png_infop info_ptr, png_fixed_point *int_file_gamma));
2396 #ifdef PNG_gAMA_SUPPORTED
2397 #ifdef PNG_FLOATING_POINT_SUPPORTED
2398 extern PNG_EXPORT(void,png_set_gAMA) PNGARG((png_structp png_ptr,
2399 png_infop info_ptr, double file_gamma));
2401 extern PNG_EXPORT(void,png_set_gAMA_fixed) PNGARG((png_structp png_ptr,
2402 png_infop info_ptr, png_fixed_point int_file_gamma));
2405 #ifdef PNG_hIST_SUPPORTED
2406 extern PNG_EXPORT(png_uint_32,png_get_hIST) PNGARG((png_structp png_ptr,
2407 png_infop info_ptr, png_uint_16p *hist));
2410 #ifdef PNG_hIST_SUPPORTED
2411 extern PNG_EXPORT(void,png_set_hIST) PNGARG((png_structp png_ptr,
2412 png_infop info_ptr, png_uint_16p hist));
2415 extern PNG_EXPORT(png_uint_32,png_get_IHDR) PNGARG((png_structp png_ptr,
2416 png_infop info_ptr, png_uint_32 *width, png_uint_32 *height,
2417 int *bit_depth, int *color_type, int *interlace_method,
2418 int *compression_method, int *filter_method));
2420 extern PNG_EXPORT(void,png_set_IHDR) PNGARG((png_structp png_ptr,
2421 png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
2422 int color_type, int interlace_method, int compression_method,
2423 int filter_method));
2425 #ifdef PNG_oFFs_SUPPORTED
2426 extern PNG_EXPORT(png_uint_32,png_get_oFFs) PNGARG((png_structp png_ptr,
2427 png_infop info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
2431 #ifdef PNG_oFFs_SUPPORTED
2432 extern PNG_EXPORT(void,png_set_oFFs) PNGARG((png_structp png_ptr,
2433 png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2437 #ifdef PNG_pCAL_SUPPORTED
2438 extern PNG_EXPORT(png_uint_32,png_get_pCAL) PNGARG((png_structp png_ptr,
2439 png_infop info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1,
2440 int *type, int *nparams, png_charp *units, png_charpp *params));
2443 #ifdef PNG_pCAL_SUPPORTED
2444 extern PNG_EXPORT(void,png_set_pCAL) PNGARG((png_structp png_ptr,
2445 png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1,
2446 int type, int nparams, png_charp units, png_charpp params));
2449 #ifdef PNG_pHYs_SUPPORTED
2450 extern PNG_EXPORT(png_uint_32,png_get_pHYs) PNGARG((png_structp png_ptr,
2451 png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
2454 #ifdef PNG_pHYs_SUPPORTED
2455 extern PNG_EXPORT(void,png_set_pHYs) PNGARG((png_structp png_ptr,
2456 png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2459 extern PNG_EXPORT(png_uint_32,png_get_PLTE) PNGARG((png_structp png_ptr,
2460 png_infop info_ptr, png_colorp *palette, int *num_palette));
2462 extern PNG_EXPORT(void,png_set_PLTE) PNGARG((png_structp png_ptr,
2463 png_infop info_ptr, png_colorp palette, int num_palette));
2465 #ifdef PNG_sBIT_SUPPORTED
2466 extern PNG_EXPORT(png_uint_32,png_get_sBIT) PNGARG((png_structp png_ptr,
2467 png_infop info_ptr, png_color_8p *sig_bit));
2470 #ifdef PNG_sBIT_SUPPORTED
2471 extern PNG_EXPORT(void,png_set_sBIT) PNGARG((png_structp png_ptr,
2472 png_infop info_ptr, png_color_8p sig_bit));
2475 #ifdef PNG_sRGB_SUPPORTED
2476 extern PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr,
2477 png_infop info_ptr, int *intent));
2480 #ifdef PNG_sRGB_SUPPORTED
2481 extern PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr,
2482 png_infop info_ptr, int intent));
2483 extern PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr,
2484 png_infop info_ptr, int intent));
2487 #ifdef PNG_iCCP_SUPPORTED
2488 extern PNG_EXPORT(png_uint_32,png_get_iCCP) PNGARG((png_structp png_ptr,
2489 png_infop info_ptr, png_charpp name, int *compression_type,
2490 png_charpp profile, png_uint_32 *proflen));
2491 /* Note to maintainer: profile should be png_bytepp */
2494 #ifdef PNG_iCCP_SUPPORTED
2495 extern PNG_EXPORT(void,png_set_iCCP) PNGARG((png_structp png_ptr,
2496 png_infop info_ptr, png_charp name, int compression_type,
2497 png_charp profile, png_uint_32 proflen));
2498 /* Note to maintainer: profile should be png_bytep */
2501 #ifdef PNG_sPLT_SUPPORTED
2502 extern PNG_EXPORT(png_uint_32,png_get_sPLT) PNGARG((png_structp png_ptr,
2503 png_infop info_ptr, png_sPLT_tpp entries));
2506 #ifdef PNG_sPLT_SUPPORTED
2507 extern PNG_EXPORT(void,png_set_sPLT) PNGARG((png_structp png_ptr,
2508 png_infop info_ptr, png_sPLT_tp entries, int nentries));
2511 #ifdef PNG_TEXT_SUPPORTED
2512 /* png_get_text also returns the number of text chunks in *num_text */
2513 extern PNG_EXPORT(png_uint_32,png_get_text) PNGARG((png_structp png_ptr,
2514 png_infop info_ptr, png_textp *text_ptr, int *num_text));
2518 * Note while png_set_text() will accept a structure whose text,
2519 * language, and translated keywords are NULL pointers, the structure
2520 * returned by png_get_text will always contain regular
2521 * zero-terminated C strings. They might be empty strings but
2522 * they will never be NULL pointers.
2525 #ifdef PNG_TEXT_SUPPORTED
2526 extern PNG_EXPORT(void,png_set_text) PNGARG((png_structp png_ptr,
2527 png_infop info_ptr, png_textp text_ptr, int num_text));
2530 #ifdef PNG_tIME_SUPPORTED
2531 extern PNG_EXPORT(png_uint_32,png_get_tIME) PNGARG((png_structp png_ptr,
2532 png_infop info_ptr, png_timep *mod_time));
2535 #ifdef PNG_tIME_SUPPORTED
2536 extern PNG_EXPORT(void,png_set_tIME) PNGARG((png_structp png_ptr,
2537 png_infop info_ptr, png_timep mod_time));
2540 #ifdef PNG_tRNS_SUPPORTED
2541 extern PNG_EXPORT(png_uint_32,png_get_tRNS) PNGARG((png_structp png_ptr,
2542 png_infop info_ptr, png_bytep *trans, int *num_trans,
2543 png_color_16p *trans_values));
2546 #ifdef PNG_tRNS_SUPPORTED
2547 extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
2548 png_infop info_ptr, png_bytep trans, int num_trans,
2549 png_color_16p trans_values));
2552 #ifdef PNG_tRNS_SUPPORTED
2555 #ifdef PNG_sCAL_SUPPORTED
2556 #ifdef PNG_FLOATING_POINT_SUPPORTED
2557 extern PNG_EXPORT(png_uint_32,png_get_sCAL) PNGARG((png_structp png_ptr,
2558 png_infop info_ptr, int *unit, double *width, double *height));
2560 #ifdef PNG_FIXED_POINT_SUPPORTED
2561 extern PNG_EXPORT(png_uint_32,png_get_sCAL_s) PNGARG((png_structp png_ptr,
2562 png_infop info_ptr, int *unit, png_charpp swidth, png_charpp sheight));
2565 #endif /* PNG_sCAL_SUPPORTED */
2567 #ifdef PNG_sCAL_SUPPORTED
2568 #ifdef PNG_FLOATING_POINT_SUPPORTED
2569 extern PNG_EXPORT(void,png_set_sCAL) PNGARG((png_structp png_ptr,
2570 png_infop info_ptr, int unit, double width, double height));
2572 #ifdef PNG_FIXED_POINT_SUPPORTED
2573 extern PNG_EXPORT(void,png_set_sCAL_s) PNGARG((png_structp png_ptr,
2574 png_infop info_ptr, int unit, png_charp swidth, png_charp sheight));
2577 #endif /* PNG_sCAL_SUPPORTED || PNG_WRITE_sCAL_SUPPORTED */
2579 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2580 /* Provide a list of chunks and how they are to be handled, if the built-in
2581 handling or default unknown chunk handling is not desired. Any chunks not
2582 listed will be handled in the default manner. The IHDR and IEND chunks
2584 keep = 0: follow default behaviour
2586 = 2: keep only if safe-to-copy
2587 = 3: keep even if unsafe-to-copy
2589 extern PNG_EXPORT(void, png_set_keep_unknown_chunks) PNGARG((png_structp
2590 png_ptr, int keep, png_bytep chunk_list, int num_chunks));
2591 PNG_EXPORT(int,png_handle_as_unknown) PNGARG((png_structp png_ptr, png_bytep
2594 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
2595 extern PNG_EXPORT(void, png_set_unknown_chunks) PNGARG((png_structp png_ptr,
2596 png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns));
2597 extern PNG_EXPORT(void, png_set_unknown_chunk_location)
2598 PNGARG((png_structp png_ptr, png_infop info_ptr, int chunk, int location));
2599 extern PNG_EXPORT(png_uint_32,png_get_unknown_chunks) PNGARG((png_structp
2600 png_ptr, png_infop info_ptr, png_unknown_chunkpp entries));
2603 /* Png_free_data() will turn off the "valid" flag for anything it frees.
2604 * If you need to turn it off for a chunk that your application has freed,
2605 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
2607 extern PNG_EXPORT(void, png_set_invalid) PNGARG((png_structp png_ptr,
2608 png_infop info_ptr, int mask));
2610 #ifdef PNG_INFO_IMAGE_SUPPORTED
2611 /* The "params" pointer is currently not used and is for future expansion. */
2612 extern PNG_EXPORT(void, png_read_png) PNGARG((png_structp png_ptr,
2616 extern PNG_EXPORT(void, png_write_png) PNGARG((png_structp png_ptr,
2622 /* Define PNG_DEBUG at compile time for debugging information. Higher
2623 * numbers for PNG_DEBUG mean more debugging information. This has
2624 * only been added since version 0.95 so it is not implemented throughout
2625 * libpng yet, but more support will be added as needed.
2629 #if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER)
2636 #define png_debug(l,m) _RPT0(_CRT_WARN,m PNG_STRING_NEWLINE)
2639 #define png_debug1(l,m,p1) _RPT1(_CRT_WARN,m PNG_STRING_NEWLINE,p1)
2642 #define png_debug2(l,m,p1,p2) _RPT2(_CRT_WARN,m PNG_STRING_NEWLINE,p1,p2)
2645 #else /* PNG_DEBUG_FILE || !_MSC_VER */
2646 #ifndef PNG_DEBUG_FILE
2647 #define PNG_DEBUG_FILE stderr
2648 #endif /* PNG_DEBUG_FILE */
2651 /* Note: ["%s"m PNG_STRING_NEWLINE] probably does not work on non-ISO
2656 # define png_debug(l,m) \
2659 fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
2660 (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":"")))); \
2664 # define png_debug1(l,m,p1) \
2667 fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
2668 (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1); \
2672 # define png_debug2(l,m,p1,p2) \
2675 fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
2676 (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1,p2); \
2679 # else /* __STDC __ */
2681 # define png_debug(l,m) \
2685 snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
2686 (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
2687 m,PNG_STRING_NEWLINE); \
2688 fprintf(PNG_DEBUG_FILE,format); \
2692 # define png_debug1(l,m,p1) \
2696 snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
2697 (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
2698 m,PNG_STRING_NEWLINE); \
2699 fprintf(PNG_DEBUG_FILE,format,p1); \
2703 # define png_debug2(l,m,p1,p2) \
2707 snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
2708 (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
2709 m,PNG_STRING_NEWLINE); \
2710 fprintf(PNG_DEBUG_FILE,format,p1,p2); \
2713 # endif /* __STDC __ */
2714 #endif /* (PNG_DEBUG > 1) */
2716 #endif /* _MSC_VER */
2717 #endif /* (PNG_DEBUG > 0) */
2718 #endif /* PNG_DEBUG */
2720 #define png_debug(l, m)
2723 #define png_debug1(l, m, p1)
2726 #define png_debug2(l, m, p1, p2)
2729 extern PNG_EXPORT(png_charp,png_get_copyright) PNGARG((png_structp png_ptr));
2730 extern PNG_EXPORT(png_charp,png_get_header_ver) PNGARG((png_structp png_ptr));
2731 extern PNG_EXPORT(png_charp,png_get_header_version) PNGARG((png_structp png_ptr));
2732 extern PNG_EXPORT(png_charp,png_get_libpng_ver) PNGARG((png_structp png_ptr));
2734 #ifdef PNG_MNG_FEATURES_SUPPORTED
2735 extern PNG_EXPORT(png_uint_32,png_permit_mng_features) PNGARG((png_structp
2736 png_ptr, png_uint_32 mng_features_permitted));
2739 /* For use in png_set_keep_unknown, added to version 1.2.6 */
2740 #define PNG_HANDLE_CHUNK_AS_DEFAULT 0
2741 #define PNG_HANDLE_CHUNK_NEVER 1
2742 #define PNG_HANDLE_CHUNK_IF_SAFE 2
2743 #define PNG_HANDLE_CHUNK_ALWAYS 3
2745 /* Added to version 1.2.0 */
2746 #ifdef PNG_ASSEMBLER_CODE_SUPPORTED
2747 #ifdef PNG_MMX_CODE_SUPPORTED
2748 #define PNG_ASM_FLAG_MMX_SUPPORT_COMPILED 0x01 /* not user-settable */
2749 #define PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU 0x02 /* not user-settable */
2750 #define PNG_ASM_FLAG_MMX_READ_COMBINE_ROW 0x04
2751 #define PNG_ASM_FLAG_MMX_READ_INTERLACE 0x08
2752 #define PNG_ASM_FLAG_MMX_READ_FILTER_SUB 0x10
2753 #define PNG_ASM_FLAG_MMX_READ_FILTER_UP 0x20
2754 #define PNG_ASM_FLAG_MMX_READ_FILTER_AVG 0x40
2755 #define PNG_ASM_FLAG_MMX_READ_FILTER_PAETH 0x80
2756 #define PNG_ASM_FLAGS_INITIALIZED 0x80000000 /* not user-settable */
2758 #define PNG_MMX_READ_FLAGS ( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW \
2759 | PNG_ASM_FLAG_MMX_READ_INTERLACE \
2760 | PNG_ASM_FLAG_MMX_READ_FILTER_SUB \
2761 | PNG_ASM_FLAG_MMX_READ_FILTER_UP \
2762 | PNG_ASM_FLAG_MMX_READ_FILTER_AVG \
2763 | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH )
2764 #define PNG_MMX_WRITE_FLAGS ( 0 )
2766 #define PNG_MMX_FLAGS ( PNG_ASM_FLAG_MMX_SUPPORT_COMPILED \
2767 | PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU \
2768 | PNG_MMX_READ_FLAGS \
2769 | PNG_MMX_WRITE_FLAGS )
2771 #define PNG_SELECT_READ 1
2772 #define PNG_SELECT_WRITE 2
2773 #endif /* PNG_MMX_CODE_SUPPORTED */
2777 extern PNG_EXPORT(png_uint_32,png_get_mmx_flagmask)
2778 PNGARG((int flag_select, int *compilerID));
2781 extern PNG_EXPORT(png_uint_32,png_get_asm_flagmask)
2782 PNGARG((int flag_select));
2785 extern PNG_EXPORT(png_uint_32,png_get_asm_flags)
2786 PNGARG((png_structp png_ptr));
2789 extern PNG_EXPORT(png_byte,png_get_mmx_bitdepth_threshold)
2790 PNGARG((png_structp png_ptr));
2793 extern PNG_EXPORT(png_uint_32,png_get_mmx_rowbytes_threshold)
2794 PNGARG((png_structp png_ptr));
2797 extern PNG_EXPORT(void,png_set_asm_flags)
2798 PNGARG((png_structp png_ptr, png_uint_32 asm_flags));
2801 extern PNG_EXPORT(void,png_set_mmx_thresholds)
2802 PNGARG((png_structp png_ptr, png_byte mmx_bitdepth_threshold,
2803 png_uint_32 mmx_rowbytes_threshold));
2805 #endif /* PNG_1_0_X */
2808 /* png.c, pnggccrd.c, or pngvcrd.c */
2809 extern PNG_EXPORT(int,png_mmx_support) PNGARG((void));
2810 #endif /* PNG_1_0_X */
2811 #endif /* PNG_ASSEMBLER_CODE_SUPPORTED */
2813 /* Strip the prepended error numbers ("#nnn ") from error and warning
2814 * messages before passing them to the error or warning handler.
2816 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
2817 extern PNG_EXPORT(void,png_set_strip_error_numbers) PNGARG((png_structp
2818 png_ptr, png_uint_32 strip_mode));
2821 /* Added at libpng-1.2.6 */
2822 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
2823 extern PNG_EXPORT(void,png_set_user_limits) PNGARG((png_structp
2824 png_ptr, png_uint_32 user_width_max, png_uint_32 user_height_max));
2825 extern PNG_EXPORT(png_uint_32,png_get_user_width_max) PNGARG((png_structp
2827 extern PNG_EXPORT(png_uint_32,png_get_user_height_max) PNGARG((png_structp
2830 /* Maintainer: Put new public prototypes here ^, in libpng.3, and in
2834 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2835 /* With these routines we avoid an integer divide, which will be slower on
2836 * most machines. However, it does take more operations than the corresponding
2837 * divide method, so it may be slower on a few RISC systems. There are two
2838 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2840 * Note that the rounding factors are NOT supposed to be the same! 128 and
2841 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2844 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2847 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2849 # define png_composite(composite, fg, alpha, bg) \
2850 { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) * (png_uint_16)(alpha) \
2851 + (png_uint_16)(bg)*(png_uint_16)(255 - \
2852 (png_uint_16)(alpha)) + (png_uint_16)128); \
2853 (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
2855 # define png_composite_16(composite, fg, alpha, bg) \
2856 { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) * (png_uint_32)(alpha) \
2857 + (png_uint_32)(bg)*(png_uint_32)(65535L - \
2858 (png_uint_32)(alpha)) + (png_uint_32)32768L); \
2859 (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
2861 #else /* Standard method using integer division */
2863 # define png_composite(composite, fg, alpha, bg) \
2864 (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2865 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2866 (png_uint_16)127) / 255)
2868 # define png_composite_16(composite, fg, alpha, bg) \
2869 (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2870 (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) + \
2871 (png_uint_32)32767) / (png_uint_32)65535L)
2873 #endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
2875 /* Inline macros to do direct reads of bytes from the input buffer. These
2876 * require that you are using an architecture that uses PNG byte ordering
2877 * (MSB first) and supports unaligned data storage. I think that PowerPC
2878 * in big-endian mode and 680x0 are the only ones that will support this.
2879 * The x86 line of processors definitely do not. The png_get_int_32()
2880 * routine also assumes we are using two's complement format for negative
2881 * values, which is almost certainly true.
2883 #ifdef PNG_READ_BIG_ENDIAN_SUPPORTED
2884 # define png_get_uint_32(buf) ( *((png_uint_32p) (buf)))
2885 # define png_get_uint_16(buf) ( *((png_uint_16p) (buf)))
2886 # define png_get_int_32(buf) ( *((png_int_32p) (buf)))
2888 extern PNG_EXPORT(png_uint_32,png_get_uint_32) PNGARG((png_bytep buf));
2889 extern PNG_EXPORT(png_uint_16,png_get_uint_16) PNGARG((png_bytep buf));
2890 extern PNG_EXPORT(png_int_32,png_get_int_32) PNGARG((png_bytep buf));
2891 #endif /* !PNG_READ_BIG_ENDIAN_SUPPORTED */
2892 extern PNG_EXPORT(png_uint_32,png_get_uint_31)
2893 PNGARG((png_structp png_ptr, png_bytep buf));
2894 /* No png_get_int_16 -- may be added if there's a real need for it. */
2896 /* Place a 32-bit number into a buffer in PNG byte order (big-endian).
2898 extern PNG_EXPORT(void,png_save_uint_32)
2899 PNGARG((png_bytep buf, png_uint_32 i));
2900 extern PNG_EXPORT(void,png_save_int_32)
2901 PNGARG((png_bytep buf, png_int_32 i));
2903 /* Place a 16-bit number into a buffer in PNG byte order.
2904 * The parameter is declared unsigned int, not png_uint_16,
2905 * just to avoid potential problems on pre-ANSI C compilers.
2907 extern PNG_EXPORT(void,png_save_uint_16)
2908 PNGARG((png_bytep buf, unsigned int i));
2909 /* No png_save_int_16 -- may be added if there's a real need for it. */
2911 /* ************************************************************************* */
2913 /* These next functions are used internally in the code. They generally
2914 * shouldn't be used unless you are writing code to add or replace some
2915 * functionality in libpng. More information about most functions can
2916 * be found in the files where the functions are located.
2920 /* Various modes of operation, that are visible to applications because
2921 * they are used for unknown chunk location.
2923 #define PNG_HAVE_IHDR 0x01
2924 #define PNG_HAVE_PLTE 0x02
2925 #define PNG_HAVE_IDAT 0x04
2926 #define PNG_AFTER_IDAT 0x08 /* Have complete zlib datastream */
2927 #define PNG_HAVE_IEND 0x10
2931 /* More modes of operation. Note that after an init, mode is set to
2932 * zero automatically when the structure is created.
2934 #define PNG_HAVE_gAMA 0x20
2935 #define PNG_HAVE_cHRM 0x40
2936 #define PNG_HAVE_sRGB 0x80
2937 #define PNG_HAVE_CHUNK_HEADER 0x100
2938 #define PNG_WROTE_tIME 0x200
2939 #define PNG_WROTE_INFO_BEFORE_PLTE 0x400
2940 #define PNG_BACKGROUND_IS_GRAY 0x800
2941 #define PNG_HAVE_PNG_SIGNATURE 0x1000
2942 #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
2944 /* Flags for the transformations the PNG library does on the image data */
2945 #define PNG_BGR 0x0001
2946 #define PNG_INTERLACE 0x0002
2947 #define PNG_PACK 0x0004
2948 #define PNG_SHIFT 0x0008
2949 #define PNG_SWAP_BYTES 0x0010
2950 #define PNG_INVERT_MONO 0x0020
2951 #define PNG_DITHER 0x0040
2952 #define PNG_BACKGROUND 0x0080
2953 #define PNG_BACKGROUND_EXPAND 0x0100
2955 #define PNG_16_TO_8 0x0400
2956 #define PNG_RGBA 0x0800
2957 #define PNG_EXPAND 0x1000
2958 #define PNG_GAMMA 0x2000
2959 #define PNG_GRAY_TO_RGB 0x4000
2960 #define PNG_FILLER 0x8000L
2961 #define PNG_PACKSWAP 0x10000L
2962 #define PNG_SWAP_ALPHA 0x20000L
2963 #define PNG_STRIP_ALPHA 0x40000L
2964 #define PNG_INVERT_ALPHA 0x80000L
2965 #define PNG_USER_TRANSFORM 0x100000L
2966 #define PNG_RGB_TO_GRAY_ERR 0x200000L
2967 #define PNG_RGB_TO_GRAY_WARN 0x400000L
2968 #define PNG_RGB_TO_GRAY 0x600000L /* two bits, RGB_TO_GRAY_ERR|WARN */
2969 /* 0x800000L Unused */
2970 #define PNG_ADD_ALPHA 0x1000000L /* Added to libpng-1.2.7 */
2971 #define PNG_EXPAND_tRNS 0x2000000L /* Added to libpng-1.2.9 */
2972 #define PNG_PREMULTIPLY_ALPHA 0x4000000L /* Added to libpng-1.2.41 */
2974 /* 0x8000000L unused */
2975 /* 0x10000000L unused */
2976 /* 0x20000000L unused */
2977 /* 0x40000000L unused */
2979 /* Flags for png_create_struct */
2980 #define PNG_STRUCT_PNG 0x0001
2981 #define PNG_STRUCT_INFO 0x0002
2983 /* Scaling factor for filter heuristic weighting calculations */
2984 #define PNG_WEIGHT_SHIFT 8
2985 #define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
2986 #define PNG_COST_SHIFT 3
2987 #define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
2989 /* Flags for the png_ptr->flags rather than declaring a byte for each one */
2990 #define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001
2991 #define PNG_FLAG_ZLIB_CUSTOM_LEVEL 0x0002
2992 #define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL 0x0004
2993 #define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS 0x0008
2994 #define PNG_FLAG_ZLIB_CUSTOM_METHOD 0x0010
2995 #define PNG_FLAG_ZLIB_FINISHED 0x0020
2996 #define PNG_FLAG_ROW_INIT 0x0040
2997 #define PNG_FLAG_FILLER_AFTER 0x0080
2998 #define PNG_FLAG_CRC_ANCILLARY_USE 0x0100
2999 #define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200
3000 #define PNG_FLAG_CRC_CRITICAL_USE 0x0400
3001 #define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800
3002 #define PNG_FLAG_FREE_PLTE 0x1000
3003 #define PNG_FLAG_FREE_TRNS 0x2000
3004 #define PNG_FLAG_FREE_HIST 0x4000
3005 #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000L
3006 #define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000L
3007 #define PNG_FLAG_LIBRARY_MISMATCH 0x20000L
3008 #define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000L
3009 #define PNG_FLAG_STRIP_ERROR_TEXT 0x80000L
3010 #define PNG_FLAG_MALLOC_NULL_MEM_OK 0x100000L
3011 #define PNG_FLAG_ADD_ALPHA 0x200000L /* Added to libpng-1.2.8 */
3012 #define PNG_FLAG_STRIP_ALPHA 0x400000L /* Added to libpng-1.2.8 */
3013 /* 0x800000L unused */
3014 /* 0x1000000L unused */
3015 /* 0x2000000L unused */
3016 /* 0x4000000L unused */
3017 /* 0x8000000L unused */
3018 /* 0x10000000L unused */
3019 /* 0x20000000L unused */
3020 /* 0x40000000L unused */
3022 #define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
3023 PNG_FLAG_CRC_ANCILLARY_NOWARN)
3025 #define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE | \
3026 PNG_FLAG_CRC_CRITICAL_IGNORE)
3028 #define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK | \
3029 PNG_FLAG_CRC_CRITICAL_MASK)
3031 /* Save typing and make code easier to understand */
3033 #define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
3034 abs((int)((c1).green) - (int)((c2).green)) + \
3035 abs((int)((c1).blue) - (int)((c2).blue)))
3037 /* Added to libpng-1.2.6 JB */
3038 #define PNG_ROWBYTES(pixel_bits, width) \
3039 ((pixel_bits) >= 8 ? \
3040 ((width) * (((png_uint_32)(pixel_bits)) >> 3)) : \
3041 (( ((width) * ((png_uint_32)(pixel_bits))) + 7) >> 3) )
3043 /* PNG_OUT_OF_RANGE returns true if value is outside the range
3044 * ideal-delta..ideal+delta. Each argument is evaluated twice.
3045 * "ideal" and "delta" should be constants, normally simple
3046 * integers, "value" a variable. Added to libpng-1.2.6 JB
3048 #define PNG_OUT_OF_RANGE(value, ideal, delta) \
3049 ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
3051 /* Variables declared in png.c - only it needs to define PNG_NO_EXTERN */
3052 #if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
3053 /* Place to hold the signature string for a PNG file. */
3054 #ifdef PNG_USE_GLOBAL_ARRAYS
3055 PNG_EXPORT_VAR (PNG_CONST png_byte FARDATA) png_sig[8];
3058 #endif /* PNG_NO_EXTERN */
3060 /* Constant strings for known chunk types. If you need to add a chunk,
3061 * define the name here, and add an invocation of the macro in png.c and
3062 * wherever it's needed.
3064 #define PNG_IHDR png_byte png_IHDR[5] = { 73, 72, 68, 82, '\0'}
3065 #define PNG_IDAT png_byte png_IDAT[5] = { 73, 68, 65, 84, '\0'}
3066 #define PNG_IEND png_byte png_IEND[5] = { 73, 69, 78, 68, '\0'}
3067 #define PNG_PLTE png_byte png_PLTE[5] = { 80, 76, 84, 69, '\0'}
3068 #define PNG_bKGD png_byte png_bKGD[5] = { 98, 75, 71, 68, '\0'}
3069 #define PNG_cHRM png_byte png_cHRM[5] = { 99, 72, 82, 77, '\0'}
3070 #define PNG_gAMA png_byte png_gAMA[5] = {103, 65, 77, 65, '\0'}
3071 #define PNG_hIST png_byte png_hIST[5] = {104, 73, 83, 84, '\0'}
3072 #define PNG_iCCP png_byte png_iCCP[5] = {105, 67, 67, 80, '\0'}
3073 #define PNG_iTXt png_byte png_iTXt[5] = {105, 84, 88, 116, '\0'}
3074 #define PNG_oFFs png_byte png_oFFs[5] = {111, 70, 70, 115, '\0'}
3075 #define PNG_pCAL png_byte png_pCAL[5] = {112, 67, 65, 76, '\0'}
3076 #define PNG_sCAL png_byte png_sCAL[5] = {115, 67, 65, 76, '\0'}
3077 #define PNG_pHYs png_byte png_pHYs[5] = {112, 72, 89, 115, '\0'}
3078 #define PNG_sBIT png_byte png_sBIT[5] = {115, 66, 73, 84, '\0'}
3079 #define PNG_sPLT png_byte png_sPLT[5] = {115, 80, 76, 84, '\0'}
3080 #define PNG_sRGB png_byte png_sRGB[5] = {115, 82, 71, 66, '\0'}
3081 #define PNG_tEXt png_byte png_tEXt[5] = {116, 69, 88, 116, '\0'}
3082 #define PNG_tIME png_byte png_tIME[5] = {116, 73, 77, 69, '\0'}
3083 #define PNG_tRNS png_byte png_tRNS[5] = {116, 82, 78, 83, '\0'}
3084 #define PNG_zTXt png_byte png_zTXt[5] = {122, 84, 88, 116, '\0'}
3086 #ifdef PNG_USE_GLOBAL_ARRAYS
3087 PNG_EXPORT_VAR (png_byte FARDATA) png_IHDR[5];
3088 PNG_EXPORT_VAR (png_byte FARDATA) png_IDAT[5];
3089 PNG_EXPORT_VAR (png_byte FARDATA) png_IEND[5];
3090 PNG_EXPORT_VAR (png_byte FARDATA) png_PLTE[5];
3091 PNG_EXPORT_VAR (png_byte FARDATA) png_bKGD[5];
3092 PNG_EXPORT_VAR (png_byte FARDATA) png_cHRM[5];
3093 PNG_EXPORT_VAR (png_byte FARDATA) png_gAMA[5];
3094 PNG_EXPORT_VAR (png_byte FARDATA) png_hIST[5];
3095 PNG_EXPORT_VAR (png_byte FARDATA) png_iCCP[5];
3096 PNG_EXPORT_VAR (png_byte FARDATA) png_iTXt[5];
3097 PNG_EXPORT_VAR (png_byte FARDATA) png_oFFs[5];
3098 PNG_EXPORT_VAR (png_byte FARDATA) png_pCAL[5];
3099 PNG_EXPORT_VAR (png_byte FARDATA) png_sCAL[5];
3100 PNG_EXPORT_VAR (png_byte FARDATA) png_pHYs[5];
3101 PNG_EXPORT_VAR (png_byte FARDATA) png_sBIT[5];
3102 PNG_EXPORT_VAR (png_byte FARDATA) png_sPLT[5];
3103 PNG_EXPORT_VAR (png_byte FARDATA) png_sRGB[5];
3104 PNG_EXPORT_VAR (png_byte FARDATA) png_tEXt[5];
3105 PNG_EXPORT_VAR (png_byte FARDATA) png_tIME[5];
3106 PNG_EXPORT_VAR (png_byte FARDATA) png_tRNS[5];
3107 PNG_EXPORT_VAR (png_byte FARDATA) png_zTXt[5];
3108 #endif /* PNG_USE_GLOBAL_ARRAYS */
3110 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
3111 /* Initialize png_ptr struct for reading, and allocate any other memory.
3112 * (old interface - DEPRECATED - use png_create_read_struct instead).
3114 extern PNG_EXPORT(void,png_read_init) PNGARG((png_structp png_ptr))
3116 #undef png_read_init
3117 #define png_read_init(png_ptr) png_read_init_3(&png_ptr, \
3118 PNG_LIBPNG_VER_STRING, png_sizeof(png_struct));
3121 extern PNG_EXPORT(void,png_read_init_3) PNGARG((png_structpp ptr_ptr,
3122 png_const_charp user_png_ver, png_size_t png_struct_size));
3123 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
3124 extern PNG_EXPORT(void,png_read_init_2) PNGARG((png_structp png_ptr,
3125 png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
3129 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
3130 /* Initialize png_ptr struct for writing, and allocate any other memory.
3131 * (old interface - DEPRECATED - use png_create_write_struct instead).
3133 extern PNG_EXPORT(void,png_write_init) PNGARG((png_structp png_ptr))
3135 #undef png_write_init
3136 #define png_write_init(png_ptr) png_write_init_3(&png_ptr, \
3137 PNG_LIBPNG_VER_STRING, png_sizeof(png_struct));
3140 extern PNG_EXPORT(void,png_write_init_3) PNGARG((png_structpp ptr_ptr,
3141 png_const_charp user_png_ver, png_size_t png_struct_size));
3142 extern PNG_EXPORT(void,png_write_init_2) PNGARG((png_structp png_ptr,
3143 png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
3146 /* Allocate memory for an internal libpng struct */
3147 PNG_EXTERN png_voidp png_create_struct PNGARG((int type)) PNG_PRIVATE;
3149 /* Free memory from internal libpng struct */
3150 PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr)) PNG_PRIVATE;
3152 PNG_EXTERN png_voidp png_create_struct_2 PNGARG((int type, png_malloc_ptr
3153 malloc_fn, png_voidp mem_ptr)) PNG_PRIVATE;
3154 PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr,
3155 png_free_ptr free_fn, png_voidp mem_ptr)) PNG_PRIVATE;
3157 /* Free any memory that info_ptr points to and reset struct. */
3158 PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr,
3159 png_infop info_ptr)) PNG_PRIVATE;
3162 /* Function to allocate memory for zlib. */
3163 PNG_EXTERN voidpf png_zalloc PNGARG((voidpf png_ptr, uInt items,
3164 uInt size)) PNG_PRIVATE;
3166 /* Function to free memory for zlib */
3167 PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr)) PNG_PRIVATE;
3170 /* Function to convert a sizeof an item to png_sizeof item */
3171 PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size))
3175 /* Next four functions are used internally as callbacks. PNGAPI is required
3176 * but not PNG_EXPORT. PNGAPI added at libpng version 1.2.3.
3179 PNG_EXTERN void PNGAPI png_default_read_data PNGARG((png_structp png_ptr,
3180 png_bytep data, png_size_t length)) PNG_PRIVATE;
3182 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3183 PNG_EXTERN void PNGAPI png_push_fill_buffer PNGARG((png_structp png_ptr,
3184 png_bytep buffer, png_size_t length)) PNG_PRIVATE;
3187 PNG_EXTERN void PNGAPI png_default_write_data PNGARG((png_structp png_ptr,
3188 png_bytep data, png_size_t length)) PNG_PRIVATE;
3190 #ifdef PNG_WRITE_FLUSH_SUPPORTED
3191 #ifdef PNG_STDIO_SUPPORTED
3192 PNG_EXTERN void PNGAPI png_default_flush PNGARG((png_structp png_ptr))
3196 #else /* PNG_1_0_X */
3197 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3198 PNG_EXTERN void png_push_fill_buffer PNGARG((png_structp png_ptr,
3199 png_bytep buffer, png_size_t length)) PNG_PRIVATE;
3201 #endif /* PNG_1_0_X */
3203 /* Reset the CRC variable */
3204 PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3206 /* Write the "data" buffer to whatever output you are using. */
3207 PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr, png_bytep data,
3208 png_size_t length)) PNG_PRIVATE;
3210 /* Read data from whatever input you are using into the "data" buffer */
3211 PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data,
3212 png_size_t length)) PNG_PRIVATE;
3214 /* Read bytes into buf, and update png_ptr->crc */
3215 PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
3216 png_size_t length)) PNG_PRIVATE;
3218 /* Decompress data in a chunk that uses compression */
3219 #if defined(PNG_zTXt_SUPPORTED) || defined(PNG_iTXt_SUPPORTED) || \
3220 defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED)
3221 PNG_EXTERN void png_decompress_chunk PNGARG((png_structp png_ptr,
3222 int comp_type, png_size_t chunklength,
3223 png_size_t prefix_length, png_size_t *data_length)) PNG_PRIVATE;
3226 /* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
3227 PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip)
3230 /* Read the CRC from the file and compare it to the libpng calculated CRC */
3231 PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3233 /* Calculate the CRC over a section of data. Note that we are only
3234 * passing a maximum of 64K on systems that have this as a memory limit,
3235 * since this is the maximum buffer size we can specify.
3237 PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr, png_bytep ptr,
3238 png_size_t length)) PNG_PRIVATE;
3240 #ifdef PNG_WRITE_FLUSH_SUPPORTED
3241 PNG_EXTERN void png_flush PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3244 /* Simple function to write the signature */
3245 PNG_EXTERN void png_write_sig PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3247 /* Write various chunks */
3249 /* Write the IHDR chunk, and update the png_struct with the necessary
3252 PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width,
3254 int bit_depth, int color_type, int compression_method, int filter_method,
3255 int interlace_method)) PNG_PRIVATE;
3257 PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr, png_colorp palette,
3258 png_uint_32 num_pal)) PNG_PRIVATE;
3260 PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data,
3261 png_size_t length)) PNG_PRIVATE;
3263 PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3265 #ifdef PNG_WRITE_gAMA_SUPPORTED
3266 #ifdef PNG_FLOATING_POINT_SUPPORTED
3267 PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma))
3270 #ifdef PNG_FIXED_POINT_SUPPORTED
3271 PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr,
3272 png_fixed_point file_gamma)) PNG_PRIVATE;
3276 #ifdef PNG_WRITE_sBIT_SUPPORTED
3277 PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr, png_color_8p sbit,
3278 int color_type)) PNG_PRIVATE;
3281 #ifdef PNG_WRITE_cHRM_SUPPORTED
3282 #ifdef PNG_FLOATING_POINT_SUPPORTED
3283 PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr,
3284 double white_x, double white_y,
3285 double red_x, double red_y, double green_x, double green_y,
3286 double blue_x, double blue_y)) PNG_PRIVATE;
3288 #ifdef PNG_FIXED_POINT_SUPPORTED
3289 PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr,
3290 png_fixed_point int_white_x, png_fixed_point int_white_y,
3291 png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
3292 int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
3293 png_fixed_point int_blue_y)) PNG_PRIVATE;
3297 #ifdef PNG_WRITE_sRGB_SUPPORTED
3298 PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
3299 int intent)) PNG_PRIVATE;
3302 #ifdef PNG_WRITE_iCCP_SUPPORTED
3303 PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr,
3304 png_charp name, int compression_type,
3305 png_charp profile, int proflen)) PNG_PRIVATE;
3306 /* Note to maintainer: profile should be png_bytep */
3309 #ifdef PNG_WRITE_sPLT_SUPPORTED
3310 PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr,
3311 png_sPLT_tp palette)) PNG_PRIVATE;
3314 #ifdef PNG_WRITE_tRNS_SUPPORTED
3315 PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr, png_bytep trans,
3316 png_color_16p values, int number, int color_type)) PNG_PRIVATE;
3319 #ifdef PNG_WRITE_bKGD_SUPPORTED
3320 PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr,
3321 png_color_16p values, int color_type)) PNG_PRIVATE;
3324 #ifdef PNG_WRITE_hIST_SUPPORTED
3325 PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, png_uint_16p hist,
3326 int num_hist)) PNG_PRIVATE;
3329 #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
3330 defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
3331 PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
3332 png_charp key, png_charpp new_key)) PNG_PRIVATE;
3335 #ifdef PNG_WRITE_tEXt_SUPPORTED
3336 PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_charp key,
3337 png_charp text, png_size_t text_len)) PNG_PRIVATE;
3340 #ifdef PNG_WRITE_zTXt_SUPPORTED
3341 PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_charp key,
3342 png_charp text, png_size_t text_len, int compression)) PNG_PRIVATE;
3345 #ifdef PNG_WRITE_iTXt_SUPPORTED
3346 PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr,
3347 int compression, png_charp key, png_charp lang, png_charp lang_key,
3348 png_charp text)) PNG_PRIVATE;
3351 #ifdef PNG_TEXT_SUPPORTED /* Added at version 1.0.14 and 1.2.4 */
3352 PNG_EXTERN int png_set_text_2 PNGARG((png_structp png_ptr,
3353 png_infop info_ptr, png_textp text_ptr, int num_text)) PNG_PRIVATE;
3356 #ifdef PNG_WRITE_oFFs_SUPPORTED
3357 PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr,
3358 png_int_32 x_offset, png_int_32 y_offset, int unit_type)) PNG_PRIVATE;
3361 #ifdef PNG_WRITE_pCAL_SUPPORTED
3362 PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose,
3363 png_int_32 X0, png_int_32 X1, int type, int nparams,
3364 png_charp units, png_charpp params)) PNG_PRIVATE;
3367 #ifdef PNG_WRITE_pHYs_SUPPORTED
3368 PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr,
3369 png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
3370 int unit_type)) PNG_PRIVATE;
3373 #ifdef PNG_WRITE_tIME_SUPPORTED
3374 PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr,
3375 png_timep mod_time)) PNG_PRIVATE;
3378 #ifdef PNG_WRITE_sCAL_SUPPORTED
3379 #if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
3380 PNG_EXTERN void png_write_sCAL PNGARG((png_structp png_ptr,
3381 int unit, double width, double height)) PNG_PRIVATE;
3383 #ifdef PNG_FIXED_POINT_SUPPORTED
3384 PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr,
3385 int unit, png_charp width, png_charp height)) PNG_PRIVATE;
3390 /* Called when finished processing a row of data */
3391 PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3393 /* Internal use only. Called before first row of data */
3394 PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3396 #ifdef PNG_READ_GAMMA_SUPPORTED
3397 PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3400 /* Combine a row of data, dealing with alpha, etc. if requested */
3401 PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row,
3402 int mask)) PNG_PRIVATE;
3404 #ifdef PNG_READ_INTERLACING_SUPPORTED
3405 /* Expand an interlaced row */
3406 /* OLD pre-1.0.9 interface:
3407 PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info,
3408 png_bytep row, int pass, png_uint_32 transformations)) PNG_PRIVATE;
3410 PNG_EXTERN void png_do_read_interlace PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3413 /* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */
3415 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
3416 /* Grab pixels out of a row for an interlaced pass */
3417 PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info,
3418 png_bytep row, int pass)) PNG_PRIVATE;
3421 /* Unfilter a row */
3422 PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr,
3423 png_row_infop row_info, png_bytep row, png_bytep prev_row,
3424 int filter)) PNG_PRIVATE;
3426 /* Choose the best filter to use and filter the row data */
3427 PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
3428 png_row_infop row_info)) PNG_PRIVATE;
3430 /* Write out the filtered row. */
3431 PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr,
3432 png_bytep filtered_row)) PNG_PRIVATE;
3433 /* Finish a row while reading, dealing with interlacing passes, etc. */
3434 PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
3436 /* Initialize the row buffers, etc. */
3437 PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3438 /* Optional call to update the users info structure */
3439 PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
3440 png_infop info_ptr)) PNG_PRIVATE;
3442 /* These are the functions that do the transformations */
3443 #ifdef PNG_READ_FILLER_SUPPORTED
3444 PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info,
3445 png_bytep row, png_uint_32 filler, png_uint_32 flags)) PNG_PRIVATE;
3448 #ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
3449 PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info,
3450 png_bytep row)) PNG_PRIVATE;
3453 #ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
3454 PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info,
3455 png_bytep row)) PNG_PRIVATE;
3458 #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
3459 PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info,
3460 png_bytep row)) PNG_PRIVATE;
3463 #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
3464 PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info,
3465 png_bytep row)) PNG_PRIVATE;
3468 #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
3469 defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
3470 PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info,
3471 png_bytep row, png_uint_32 flags)) PNG_PRIVATE;
3474 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
3475 PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info,
3476 png_bytep row)) PNG_PRIVATE;
3479 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
3480 PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info,
3481 png_bytep row)) PNG_PRIVATE;
3484 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
3485 PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr, png_row_infop
3486 row_info, png_bytep row)) PNG_PRIVATE;
3489 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
3490 PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info,
3491 png_bytep row)) PNG_PRIVATE;
3494 #ifdef PNG_READ_PACK_SUPPORTED
3495 PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info,
3496 png_bytep row)) PNG_PRIVATE;
3499 #ifdef PNG_READ_SHIFT_SUPPORTED
3500 PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info, png_bytep row,
3501 png_color_8p sig_bits)) PNG_PRIVATE;
3504 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
3505 PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info,
3506 png_bytep row)) PNG_PRIVATE;
3509 #ifdef PNG_READ_16_TO_8_SUPPORTED
3510 PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info,
3511 png_bytep row)) PNG_PRIVATE;
3514 #ifdef PNG_READ_DITHER_SUPPORTED
3515 PNG_EXTERN void png_do_dither PNGARG((png_row_infop row_info,
3516 png_bytep row, png_bytep palette_lookup,
3517 png_bytep dither_lookup)) PNG_PRIVATE;
3519 # ifdef PNG_CORRECT_PALETTE_SUPPORTED
3520 PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr,
3521 png_colorp palette, int num_palette)) PNG_PRIVATE;
3525 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
3526 PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info,
3527 png_bytep row)) PNG_PRIVATE;
3530 #ifdef PNG_WRITE_PACK_SUPPORTED
3531 PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info,
3532 png_bytep row, png_uint_32 bit_depth)) PNG_PRIVATE;
3535 #ifdef PNG_WRITE_SHIFT_SUPPORTED
3536 PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info, png_bytep row,
3537 png_color_8p bit_depth)) PNG_PRIVATE;
3540 #ifdef PNG_READ_BACKGROUND_SUPPORTED
3541 #ifdef PNG_READ_GAMMA_SUPPORTED
3542 PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
3543 png_color_16p trans_values, png_color_16p background,
3544 png_color_16p background_1,
3545 png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,
3546 png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,
3547 png_uint_16pp gamma_16_to_1, int gamma_shift)) PNG_PRIVATE;
3549 PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
3550 png_color_16p trans_values, png_color_16p background)) PNG_PRIVATE;
3554 #ifdef PNG_READ_GAMMA_SUPPORTED
3555 PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info, png_bytep row,
3556 png_bytep gamma_table, png_uint_16pp gamma_16_table,
3557 int gamma_shift)) PNG_PRIVATE;
3560 #ifdef PNG_READ_EXPAND_SUPPORTED
3561 PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info,
3562 png_bytep row, png_colorp palette, png_bytep trans,
3563 int num_trans)) PNG_PRIVATE;
3564 PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info,
3565 png_bytep row, png_color_16p trans_value)) PNG_PRIVATE;
3568 /* The following decodes the appropriate chunks, and does error correction,
3569 * then calls the appropriate callback for the chunk if it is valid.
3572 /* Decode the IHDR chunk */
3573 PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr,
3574 png_uint_32 length)) PNG_PRIVATE;
3575 PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr,
3576 png_uint_32 length));
3577 PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr,
3578 png_uint_32 length));
3580 #ifdef PNG_READ_bKGD_SUPPORTED
3581 PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr,
3582 png_uint_32 length)) PNG_PRIVATE;
3585 #ifdef PNG_READ_cHRM_SUPPORTED
3586 PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr,
3587 png_uint_32 length)) PNG_PRIVATE;
3590 #ifdef PNG_READ_gAMA_SUPPORTED
3591 PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr,
3592 png_uint_32 length)) PNG_PRIVATE;
3595 #ifdef PNG_READ_hIST_SUPPORTED
3596 PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr,
3597 png_uint_32 length)) PNG_PRIVATE;
3600 #ifdef PNG_READ_iCCP_SUPPORTED
3601 extern void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr,
3602 png_uint_32 length));
3603 #endif /* PNG_READ_iCCP_SUPPORTED */
3605 #ifdef PNG_READ_iTXt_SUPPORTED
3606 PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3607 png_uint_32 length)) PNG_PRIVATE;
3610 #ifdef PNG_READ_oFFs_SUPPORTED
3611 PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr,
3612 png_uint_32 length)) PNG_PRIVATE;
3615 #ifdef PNG_READ_pCAL_SUPPORTED
3616 PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
3617 png_uint_32 length)) PNG_PRIVATE;
3620 #ifdef PNG_READ_pHYs_SUPPORTED
3621 PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr,
3622 png_uint_32 length)) PNG_PRIVATE;
3625 #ifdef PNG_READ_sBIT_SUPPORTED
3626 PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr,
3627 png_uint_32 length)) PNG_PRIVATE;
3630 #ifdef PNG_READ_sCAL_SUPPORTED
3631 PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
3632 png_uint_32 length)) PNG_PRIVATE;
3635 #ifdef PNG_READ_sPLT_SUPPORTED
3636 extern void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr,
3637 png_uint_32 length)) PNG_PRIVATE;
3638 #endif /* PNG_READ_sPLT_SUPPORTED */
3640 #ifdef PNG_READ_sRGB_SUPPORTED
3641 PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr,
3642 png_uint_32 length)) PNG_PRIVATE;
3645 #ifdef PNG_READ_tEXt_SUPPORTED
3646 PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3647 png_uint_32 length)) PNG_PRIVATE;
3650 #ifdef PNG_READ_tIME_SUPPORTED
3651 PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr,
3652 png_uint_32 length)) PNG_PRIVATE;
3655 #ifdef PNG_READ_tRNS_SUPPORTED
3656 PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr,
3657 png_uint_32 length)) PNG_PRIVATE;
3660 #ifdef PNG_READ_zTXt_SUPPORTED
3661 PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3662 png_uint_32 length)) PNG_PRIVATE;
3665 PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
3666 png_infop info_ptr, png_uint_32 length)) PNG_PRIVATE;
3668 PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
3669 png_bytep chunk_name)) PNG_PRIVATE;
3671 /* Handle the transformations for reading and writing */
3672 PNG_EXTERN void png_do_read_transformations
3673 PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3674 PNG_EXTERN void png_do_write_transformations
3675 PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3677 PNG_EXTERN void png_init_read_transformations
3678 PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3680 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3681 PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
3682 png_infop info_ptr)) PNG_PRIVATE;
3683 PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr,
3684 png_infop info_ptr)) PNG_PRIVATE;
3685 PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3686 PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr,
3687 png_uint_32 length)) PNG_PRIVATE;
3688 PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3689 PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3690 PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr,
3691 png_bytep buffer, png_size_t buffer_length)) PNG_PRIVATE;
3692 PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3693 PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr,
3694 png_bytep buffer, png_size_t buffer_length)) PNG_PRIVATE;
3695 PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3696 PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr,
3697 png_infop info_ptr, png_uint_32 length)) PNG_PRIVATE;
3698 PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr,
3699 png_infop info_ptr)) PNG_PRIVATE;
3700 PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr,
3701 png_infop info_ptr)) PNG_PRIVATE;
3702 PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr,
3703 png_bytep row)) PNG_PRIVATE;
3704 PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr,
3705 png_infop info_ptr)) PNG_PRIVATE;
3706 PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr,
3707 png_infop info_ptr)) PNG_PRIVATE;
3708 PNG_EXTERN void png_read_push_finish_row
3709 PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3710 #ifdef PNG_READ_tEXt_SUPPORTED
3711 PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr,
3712 png_infop info_ptr, png_uint_32 length)) PNG_PRIVATE;
3713 PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr,
3714 png_infop info_ptr)) PNG_PRIVATE;
3716 #ifdef PNG_READ_zTXt_SUPPORTED
3717 PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr,
3718 png_infop info_ptr, png_uint_32 length)) PNG_PRIVATE;
3719 PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr,
3720 png_infop info_ptr)) PNG_PRIVATE;
3722 #ifdef PNG_READ_iTXt_SUPPORTED
3723 PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr,
3724 png_infop info_ptr, png_uint_32 length)) PNG_PRIVATE;
3725 PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr,
3726 png_infop info_ptr)) PNG_PRIVATE;
3729 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
3731 #ifdef PNG_MNG_FEATURES_SUPPORTED
3732 PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info,
3733 png_bytep row)) PNG_PRIVATE;
3734 PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info,
3735 png_bytep row)) PNG_PRIVATE;
3738 #ifdef PNG_ASSEMBLER_CODE_SUPPORTED
3739 #ifdef PNG_MMX_CODE_SUPPORTED
3740 /* png.c */ /* PRIVATE */
3741 PNG_EXTERN void png_init_mmx_flags PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3746 /* The following six functions will be exported in libpng-1.4.0. */
3747 #if defined(PNG_INCH_CONVERSIONS) && defined(PNG_FLOATING_POINT_SUPPORTED)
3748 PNG_EXTERN png_uint_32 png_get_pixels_per_inch PNGARG((png_structp png_ptr,
3749 png_infop info_ptr));
3751 PNG_EXTERN png_uint_32 png_get_x_pixels_per_inch PNGARG((png_structp png_ptr,
3752 png_infop info_ptr));
3754 PNG_EXTERN png_uint_32 png_get_y_pixels_per_inch PNGARG((png_structp png_ptr,
3755 png_infop info_ptr));
3757 PNG_EXTERN float png_get_x_offset_inches PNGARG((png_structp png_ptr,
3758 png_infop info_ptr));
3760 PNG_EXTERN float png_get_y_offset_inches PNGARG((png_structp png_ptr,
3761 png_infop info_ptr));
3763 #ifdef PNG_pHYs_SUPPORTED
3764 PNG_EXTERN png_uint_32 png_get_pHYs_dpi PNGARG((png_structp png_ptr,
3765 png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
3766 #endif /* PNG_pHYs_SUPPORTED */
3767 #endif /* PNG_INCH_CONVERSIONS && PNG_FLOATING_POINT_SUPPORTED */
3769 /* Read the chunk header (length + type name) */
3770 PNG_EXTERN png_uint_32 png_read_chunk_header
3771 PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3773 /* Added at libpng version 1.2.34 */
3774 #ifdef PNG_cHRM_SUPPORTED
3775 PNG_EXTERN int png_check_cHRM_fixed PNGARG((png_structp png_ptr,
3776 png_fixed_point int_white_x, png_fixed_point int_white_y,
3777 png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
3778 int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
3779 png_fixed_point int_blue_y)) PNG_PRIVATE;
3782 #ifdef PNG_cHRM_SUPPORTED
3783 #ifdef PNG_CHECK_cHRM_SUPPORTED
3784 /* Added at libpng version 1.2.34 */
3785 PNG_EXTERN void png_64bit_product PNGARG((long v1, long v2,
3786 unsigned long *hi_product, unsigned long *lo_product)) PNG_PRIVATE;
3790 /* Added at libpng version 1.2.41 */
3791 PNG_EXTERN void png_check_IHDR PNGARG((png_structp png_ptr,
3792 png_uint_32 width, png_uint_32 height, int bit_depth,
3793 int color_type, int interlace_type, int compression_type,
3794 int filter_type)) PNG_PRIVATE;
3796 /* Added at libpng version 1.2.41 */
3797 PNG_EXTERN png_voidp png_calloc PNGARG((png_structp png_ptr,
3800 /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
3802 #endif /* PNG_INTERNAL */
3808 #endif /* PNG_VERSION_INFO_ONLY */
3809 /* Do not put anything past this line */