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 {
651 typedef png_color FAR *png_colorp;
652 typedef png_color FAR *FAR *png_colorpp;
654 typedef struct png_color_16_struct {
655 png_byte index; /* used for palette files */
656 png_uint_16 red; /* for use in red green blue files */
659 png_uint_16 gray; /* for use in grayscale files */
661 typedef png_color_16 FAR *png_color_16p;
662 typedef png_color_16 FAR *FAR *png_color_16pp;
664 typedef struct png_color_8_struct {
665 png_byte red; /* for use in red green blue files */
668 png_byte gray; /* for use in grayscale files */
669 png_byte alpha; /* for alpha channel files */
671 typedef png_color_8 FAR *png_color_8p;
672 typedef png_color_8 FAR *FAR *png_color_8pp;
675 * The following two structures are used for the in-core representation
678 typedef struct png_sPLT_entry_struct {
683 png_uint_16 frequency;
685 typedef png_sPLT_entry FAR *png_sPLT_entryp;
686 typedef png_sPLT_entry FAR *FAR *png_sPLT_entrypp;
688 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples
689 * occupy the LSB of their respective members, and the MSB of each member
690 * is zero-filled. The frequency member always occupies the full 16 bits.
693 typedef struct png_sPLT_struct {
694 png_charp name; /* palette name */
695 png_byte depth; /* depth of palette samples */
696 png_sPLT_entryp entries; /* palette entries */
697 png_int_32 nentries; /* number of palette entries */
699 typedef png_sPLT_t FAR *png_sPLT_tp;
700 typedef png_sPLT_t FAR *FAR *png_sPLT_tpp;
702 #ifdef PNG_TEXT_SUPPORTED
703 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
704 * and whether that contents is compressed or not. The "key" field
705 * points to a regular zero-terminated C string. The "text", "lang", and
706 * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
707 * However, the * structure returned by png_get_text() will always contain
708 * regular zero-terminated C strings (possibly empty), never NULL pointers,
709 * so they can be safely used in printf() and other string-handling functions.
711 typedef struct png_text_struct {
712 int compression; /* compression value:
717 png_charp key; /* keyword, 1-79 character description of "text" */
718 png_charp text; /* comment, may be an empty string (ie "")
720 png_size_t text_length; /* length of the text string */
721 #ifdef PNG_iTXt_SUPPORTED
722 png_size_t itxt_length; /* length of the itxt string */
723 png_charp lang; /* language code, 0-79 characters
725 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
726 chars or a NULL pointer */
729 typedef png_text FAR *png_textp;
730 typedef png_text FAR *FAR *png_textpp;
733 /* Supported compression types for text in PNG files (tEXt, and zTXt).
734 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed.
736 #define PNG_TEXT_COMPRESSION_NONE_WR -3
737 #define PNG_TEXT_COMPRESSION_zTXt_WR -2
738 #define PNG_TEXT_COMPRESSION_NONE -1
739 #define PNG_TEXT_COMPRESSION_zTXt 0
740 #define PNG_ITXT_COMPRESSION_NONE 1
741 #define PNG_ITXT_COMPRESSION_zTXt 2
742 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
744 /* png_time is a way to hold the time in an machine independent way.
745 * Two conversions are provided, both from time_t and struct tm. There
746 * is no portable way to convert to either of these structures, as far
747 * as I know. If you know of a portable way, send it to me. As a side
748 * note - PNG has always been Year 2000 compliant!
750 typedef struct png_time_struct {
751 png_uint_16 year; /* full year, as in, 1995 */
752 png_byte month; /* month of year, 1 - 12 */
753 png_byte day; /* day of month, 1 - 31 */
754 png_byte hour; /* hour of day, 0 - 23 */
755 png_byte minute; /* minute of hour, 0 - 59 */
756 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
758 typedef png_time FAR *png_timep;
759 typedef png_time FAR *FAR *png_timepp;
761 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
762 defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
763 /* png_unknown_chunk is a structure to hold queued chunks for which there is
764 * no specific support. The idea is that we can use this to queue
765 * up private chunks for output even though the library doesn't actually
766 * know about their semantics.
768 #define PNG_CHUNK_NAME_LENGTH 5
769 typedef struct png_unknown_chunk_t {
770 png_byte name[PNG_CHUNK_NAME_LENGTH];
774 /* libpng-using applications should NOT directly modify this byte. */
775 png_byte location; /* mode of operation at read time */
778 typedef png_unknown_chunk FAR *png_unknown_chunkp;
779 typedef png_unknown_chunk FAR *FAR *png_unknown_chunkpp;
782 /* png_info is a structure that holds the information in a PNG file so
783 * that the application can find out the characteristics of the image.
784 * If you are reading the file, this structure will tell you what is
785 * in the PNG file. If you are writing the file, fill in the information
786 * you want to put into the PNG file, then call png_write_info().
787 * The names chosen should be very close to the PNG specification, so
788 * consult that document for information about the meaning of each field.
790 * With libpng < 0.95, it was only possible to directly set and read the
791 * the values in the png_info_struct, which meant that the contents and
792 * order of the values had to remain fixed. With libpng 0.95 and later,
793 * however, there are now functions that abstract the contents of
794 * png_info_struct from the application, so this makes it easier to use
795 * libpng with dynamic libraries, and even makes it possible to use
796 * libraries that don't have all of the libpng ancillary chunk-handing
799 * In any case, the order of the parameters in png_info_struct should NOT
800 * be changed for as long as possible to keep compatibility with applications
801 * that use the old direct-access method with png_info_struct.
803 * The following members may have allocated storage attached that should be
804 * cleaned up before the structure is discarded: palette, trans, text,
805 * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
806 * splt_palettes, scal_unit, row_pointers, and unknowns. By default, these
807 * are automatically freed when the info structure is deallocated, if they were
808 * allocated internally by libpng. This behavior can be changed by means
809 * of the png_data_freer() function.
811 * More allocation details: all the chunk-reading functions that
812 * change these members go through the corresponding png_set_*
813 * functions. A function to clear these members is available: see
814 * png_free_data(). The png_set_* functions do not depend on being
815 * able to point info structure members to any of the storage they are
816 * passed (they make their own copies), EXCEPT that the png_set_text
817 * functions use the same storage passed to them in the text_ptr or
818 * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
819 * functions do not make their own copies.
821 typedef struct png_info_struct {
822 /* The following are necessary for every PNG file */
824 PNG_DEPSTRUCT; /* width of image in pixels (from IHDR) */
826 PNG_DEPSTRUCT; /* height of image in pixels (from IHDR) */
828 PNG_DEPSTRUCT; /* valid chunk data (see PNG_INFO_ below) */
830 PNG_DEPSTRUCT; /* bytes needed to hold an untransformed row */
832 PNG_DEPSTRUCT; /* array of color values (valid & PNG_INFO_PLTE) */
833 png_uint_16 num_palette
834 PNG_DEPSTRUCT; /* number of color entries in "palette" (PLTE) */
835 png_uint_16 num_trans
836 PNG_DEPSTRUCT; /* number of transparent palette color (tRNS) */
838 PNG_DEPSTRUCT; /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */
840 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
843 PNG_DEPSTRUCT; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */
845 PNG_DEPSTRUCT; /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
846 png_byte interlace_type
847 PNG_DEPSTRUCT; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
849 /* The following is informational only on read, and not used on writes. */
851 PNG_DEPSTRUCT; /* number of data channels per pixel (1, 2, 3, 4) */
852 png_byte pixel_depth PNG_DEPSTRUCT; /* number of bits per pixel */
854 PNG_DEPSTRUCT; /* to align the data, and for future use */
855 png_byte signature[8]
856 PNG_DEPSTRUCT; /* magic bytes read by libpng from start of file */
858 /* The rest of the data is optional. If you are reading, check the
859 * valid field to see if the information in these are valid. If you
860 * are writing, set the valid field to those chunks you want written,
861 * and initialize the appropriate fields below.
864 #if defined(PNG_gAMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
865 /* The gAMA chunk describes the gamma characteristics of the system
866 * on which the image was created, normally in the range [1.0, 2.5].
867 * Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
870 PNG_DEPSTRUCT; /* gamma value of image, if (valid & PNG_INFO_gAMA) */
873 #ifdef PNG_sRGB_SUPPORTED
875 /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
876 png_byte srgb_intent PNG_DEPSTRUCT; /* sRGB rendering intent [0, 1, 2, or 3] */
879 #ifdef PNG_TEXT_SUPPORTED
880 /* The tEXt, and zTXt chunks contain human-readable textual data in
881 * uncompressed, compressed, and optionally compressed forms, respectively.
882 * The data in "text" is an array of pointers to uncompressed,
883 * null-terminated C strings. Each chunk has a keyword that describes the
884 * textual data contained in that chunk. Keywords are not required to be
885 * unique, and the text string may be empty. Any number of text chunks may
888 int num_text PNG_DEPSTRUCT; /* number of comments read/to write */
889 int max_text PNG_DEPSTRUCT; /* current size of text array */
890 png_textp text PNG_DEPSTRUCT; /* array of comments read/to write */
891 #endif /* PNG_TEXT_SUPPORTED */
893 #ifdef PNG_tIME_SUPPORTED
894 /* The tIME chunk holds the last time the displayed image data was
895 * modified. See the png_time struct for the contents of this struct.
897 png_time mod_time PNG_DEPSTRUCT;
900 #ifdef PNG_sBIT_SUPPORTED
901 /* The sBIT chunk specifies the number of significant high-order bits
902 * in the pixel data. Values are in the range [1, bit_depth], and are
903 * only specified for the channels in the pixel data. The contents of
904 * the low-order bits is not specified. Data is valid if
905 * (valid & PNG_INFO_sBIT) is non-zero.
907 png_color_8 sig_bit PNG_DEPSTRUCT; /* significant bits in color channels */
910 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
911 defined(PNG_READ_BACKGROUND_SUPPORTED)
912 /* The tRNS chunk supplies transparency data for paletted images and
913 * other image types that don't need a full alpha channel. There are
914 * "num_trans" transparency values for a paletted image, stored in the
915 * same order as the palette colors, starting from index 0. Values
916 * for the data are in the range [0, 255], ranging from fully transparent
917 * to fully opaque, respectively. For non-paletted images, there is a
918 * single color specified that should be treated as fully transparent.
919 * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
921 png_bytep trans PNG_DEPSTRUCT; /* transparent values for paletted image */
922 png_color_16 trans_values
923 PNG_DEPSTRUCT; /* transparent color for non-palette image */
926 #if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
927 /* The bKGD chunk gives the suggested image background color if the
928 * display program does not have its own background color and the image
929 * is needs to composited onto a background before display. The colors
930 * in "background" are normally in the same color space/depth as the
931 * pixel data. Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
933 png_color_16 background PNG_DEPSTRUCT;
936 #ifdef PNG_oFFs_SUPPORTED
937 /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
938 * and downwards from the top-left corner of the display, page, or other
939 * application-specific co-ordinate space. See the PNG_OFFSET_ defines
940 * below for the unit types. Valid if (valid & PNG_INFO_oFFs) non-zero.
942 png_int_32 x_offset PNG_DEPSTRUCT; /* x offset on page */
943 png_int_32 y_offset PNG_DEPSTRUCT; /* y offset on page */
944 png_byte offset_unit_type PNG_DEPSTRUCT; /* offset units type */
947 #ifdef PNG_pHYs_SUPPORTED
948 /* The pHYs chunk gives the physical pixel density of the image for
949 * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
950 * defines below). Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
952 png_uint_32 x_pixels_per_unit PNG_DEPSTRUCT; /* horizontal pixel density */
953 png_uint_32 y_pixels_per_unit PNG_DEPSTRUCT; /* vertical pixel density */
954 png_byte phys_unit_type
955 PNG_DEPSTRUCT; /* resolution type (see PNG_RESOLUTION_ below) */
958 #ifdef PNG_hIST_SUPPORTED
959 /* The hIST chunk contains the relative frequency or importance of the
960 * various palette entries, so that a viewer can intelligently select a
961 * reduced-color palette, if required. Data is an array of "num_palette"
962 * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
965 png_uint_16p hist PNG_DEPSTRUCT;
968 #ifdef PNG_cHRM_SUPPORTED
969 /* The cHRM chunk describes the CIE color characteristics of the monitor
970 * on which the PNG was created. This data allows the viewer to do gamut
971 * mapping of the input image to ensure that the viewer sees the same
972 * colors in the image as the creator. Values are in the range
973 * [0.0, 0.8]. Data valid if (valid & PNG_INFO_cHRM) non-zero.
975 #ifdef PNG_FLOATING_POINT_SUPPORTED
976 float x_white PNG_DEPSTRUCT;
977 float y_white PNG_DEPSTRUCT;
978 float x_red PNG_DEPSTRUCT;
979 float y_red PNG_DEPSTRUCT;
980 float x_green PNG_DEPSTRUCT;
981 float y_green PNG_DEPSTRUCT;
982 float x_blue PNG_DEPSTRUCT;
983 float y_blue PNG_DEPSTRUCT;
987 #ifdef PNG_pCAL_SUPPORTED
988 /* The pCAL chunk describes a transformation between the stored pixel
989 * values and original physical data values used to create the image.
990 * The integer range [0, 2^bit_depth - 1] maps to the floating-point
991 * range given by [pcal_X0, pcal_X1], and are further transformed by a
992 * (possibly non-linear) transformation function given by "pcal_type"
993 * and "pcal_params" into "pcal_units". Please see the PNG_EQUATION_
994 * defines below, and the PNG-Group's PNG extensions document for a
995 * complete description of the transformations and how they should be
996 * implemented, and for a description of the ASCII parameter strings.
997 * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
999 png_charp pcal_purpose PNG_DEPSTRUCT; /* pCAL chunk description string */
1000 png_int_32 pcal_X0 PNG_DEPSTRUCT; /* minimum value */
1001 png_int_32 pcal_X1 PNG_DEPSTRUCT; /* maximum value */
1002 png_charp pcal_units
1003 PNG_DEPSTRUCT; /* Latin-1 string giving physical units */
1004 png_charpp pcal_params
1005 PNG_DEPSTRUCT; /* ASCII strings containing parameter values */
1007 PNG_DEPSTRUCT; /* equation type (see PNG_EQUATION_ below) */
1008 png_byte pcal_nparams
1009 PNG_DEPSTRUCT; /* number of parameters given in pcal_params */
1012 /* New members added in libpng-1.0.6 */
1013 #ifdef PNG_FREE_ME_SUPPORTED
1015 PNG_DEPSTRUCT; /* flags items libpng is responsible for freeing */
1018 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
1019 defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
1020 /* Storage for unknown chunks that the library doesn't recognize. */
1021 png_unknown_chunkp unknown_chunks PNG_DEPSTRUCT;
1022 png_size_t unknown_chunks_num PNG_DEPSTRUCT;
1025 #ifdef PNG_iCCP_SUPPORTED
1026 /* iCCP chunk data. */
1027 png_charp iccp_name PNG_DEPSTRUCT; /* profile name */
1028 png_charp iccp_profile
1029 PNG_DEPSTRUCT; /* International Color Consortium profile data */
1030 /* Note to maintainer: should be png_bytep */
1031 png_uint_32 iccp_proflen PNG_DEPSTRUCT; /* ICC profile data length */
1032 png_byte iccp_compression PNG_DEPSTRUCT; /* Always zero */
1035 #ifdef PNG_sPLT_SUPPORTED
1036 /* Data on sPLT chunks (there may be more than one). */
1037 png_sPLT_tp splt_palettes PNG_DEPSTRUCT;
1038 png_uint_32 splt_palettes_num PNG_DEPSTRUCT;
1041 #ifdef PNG_sCAL_SUPPORTED
1042 /* The sCAL chunk describes the actual physical dimensions of the
1043 * subject matter of the graphic. The chunk contains a unit specification
1044 * a byte value, and two ASCII strings representing floating-point
1045 * values. The values are width and height corresponsing to one pixel
1046 * in the image. This external representation is converted to double
1047 * here. Data values are valid if (valid & PNG_INFO_sCAL) is non-zero.
1049 png_byte scal_unit PNG_DEPSTRUCT; /* unit of physical scale */
1050 #ifdef PNG_FLOATING_POINT_SUPPORTED
1051 double scal_pixel_width PNG_DEPSTRUCT; /* width of one pixel */
1052 double scal_pixel_height PNG_DEPSTRUCT; /* height of one pixel */
1054 #ifdef PNG_FIXED_POINT_SUPPORTED
1055 png_charp scal_s_width PNG_DEPSTRUCT; /* string containing height */
1056 png_charp scal_s_height PNG_DEPSTRUCT; /* string containing width */
1060 #ifdef PNG_INFO_IMAGE_SUPPORTED
1061 /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS) non-zero */
1062 /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
1063 png_bytepp row_pointers PNG_DEPSTRUCT; /* the image bits */
1066 #if defined(PNG_FIXED_POINT_SUPPORTED) && defined(PNG_gAMA_SUPPORTED)
1067 png_fixed_point int_gamma
1068 PNG_DEPSTRUCT; /* gamma of image, if (valid & PNG_INFO_gAMA) */
1071 #if defined(PNG_cHRM_SUPPORTED) && defined(PNG_FIXED_POINT_SUPPORTED)
1072 png_fixed_point int_x_white PNG_DEPSTRUCT;
1073 png_fixed_point int_y_white PNG_DEPSTRUCT;
1074 png_fixed_point int_x_red PNG_DEPSTRUCT;
1075 png_fixed_point int_y_red PNG_DEPSTRUCT;
1076 png_fixed_point int_x_green PNG_DEPSTRUCT;
1077 png_fixed_point int_y_green PNG_DEPSTRUCT;
1078 png_fixed_point int_x_blue PNG_DEPSTRUCT;
1079 png_fixed_point int_y_blue PNG_DEPSTRUCT;
1084 typedef png_info FAR *png_infop;
1085 typedef png_info FAR *FAR *png_infopp;
1087 /* Maximum positive integer used in PNG is (2^31)-1 */
1088 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
1089 #define PNG_UINT_32_MAX ((png_uint_32)(-1))
1090 #define PNG_SIZE_MAX ((png_size_t)(-1))
1091 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1092 /* PNG_MAX_UINT is deprecated; use PNG_UINT_31_MAX instead. */
1093 #define PNG_MAX_UINT PNG_UINT_31_MAX
1096 /* These describe the color_type field in png_info. */
1097 /* color type masks */
1098 #define PNG_COLOR_MASK_PALETTE 1
1099 #define PNG_COLOR_MASK_COLOR 2
1100 #define PNG_COLOR_MASK_ALPHA 4
1102 /* color types. Note that not all combinations are legal */
1103 #define PNG_COLOR_TYPE_GRAY 0
1104 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
1105 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
1106 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
1107 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
1109 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
1110 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
1112 /* This is for compression type. PNG 1.0-1.2 only define the single type. */
1113 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
1114 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
1116 /* This is for filter type. PNG 1.0-1.2 only define the single type. */
1117 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
1118 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
1119 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
1121 /* These are for the interlacing type. These values should NOT be changed. */
1122 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
1123 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
1124 #define PNG_INTERLACE_LAST 2 /* Not a valid value */
1126 /* These are for the oFFs chunk. These values should NOT be changed. */
1127 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
1128 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
1129 #define PNG_OFFSET_LAST 2 /* Not a valid value */
1131 /* These are for the pCAL chunk. These values should NOT be changed. */
1132 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */
1133 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
1134 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
1135 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
1136 #define PNG_EQUATION_LAST 4 /* Not a valid value */
1138 /* These are for the sCAL chunk. These values should NOT be changed. */
1139 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
1140 #define PNG_SCALE_METER 1 /* meters per pixel */
1141 #define PNG_SCALE_RADIAN 2 /* radians per pixel */
1142 #define PNG_SCALE_LAST 3 /* Not a valid value */
1144 /* These are for the pHYs chunk. These values should NOT be changed. */
1145 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
1146 #define PNG_RESOLUTION_METER 1 /* pixels/meter */
1147 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */
1149 /* These are for the sRGB chunk. These values should NOT be changed. */
1150 #define PNG_sRGB_INTENT_PERCEPTUAL 0
1151 #define PNG_sRGB_INTENT_RELATIVE 1
1152 #define PNG_sRGB_INTENT_SATURATION 2
1153 #define PNG_sRGB_INTENT_ABSOLUTE 3
1154 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
1156 /* This is for text chunks */
1157 #define PNG_KEYWORD_MAX_LENGTH 79
1159 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */
1160 #define PNG_MAX_PALETTE_LENGTH 256
1162 /* These determine if an ancillary chunk's data has been successfully read
1163 * from the PNG header, or if the application has filled in the corresponding
1164 * data in the info_struct to be written into the output file. The values
1165 * of the PNG_INFO_<chunk> defines should NOT be changed.
1167 #define PNG_INFO_gAMA 0x0001
1168 #define PNG_INFO_sBIT 0x0002
1169 #define PNG_INFO_cHRM 0x0004
1170 #define PNG_INFO_PLTE 0x0008
1171 #define PNG_INFO_tRNS 0x0010
1172 #define PNG_INFO_bKGD 0x0020
1173 #define PNG_INFO_hIST 0x0040
1174 #define PNG_INFO_pHYs 0x0080
1175 #define PNG_INFO_oFFs 0x0100
1176 #define PNG_INFO_tIME 0x0200
1177 #define PNG_INFO_pCAL 0x0400
1178 #define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */
1179 #define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */
1180 #define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */
1181 #define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */
1182 #define PNG_INFO_IDAT 0x8000L /* ESR, 1.0.6 */
1184 /* This is used for the transformation routines, as some of them
1185 * change these values for the row. It also should enable using
1186 * the routines for other purposes.
1188 typedef struct png_row_info_struct {
1189 png_uint_32 width; /* width of row */
1190 png_uint_32 rowbytes; /* number of bytes in row */
1191 png_byte color_type; /* color type of row */
1192 png_byte bit_depth; /* bit depth of row */
1193 png_byte channels; /* number of channels (1, 2, 3, or 4) */
1194 png_byte pixel_depth; /* bits per pixel (depth * channels) */
1197 typedef png_row_info FAR *png_row_infop;
1198 typedef png_row_info FAR *FAR *png_row_infopp;
1200 /* These are the function types for the I/O functions and for the functions
1201 * that allow the user to override the default I/O functions with his or her
1202 * own. The png_error_ptr type should match that of user-supplied warning
1203 * and error functions, while the png_rw_ptr type should match that of the
1204 * user read/write data functions.
1206 typedef struct png_struct_def png_struct;
1207 typedef png_struct FAR *png_structp;
1209 typedef void (PNGAPI *png_error_ptr) PNGARG((png_structp, png_const_charp));
1210 typedef void (PNGAPI *png_rw_ptr) PNGARG((png_structp, png_bytep, png_size_t));
1211 typedef void (PNGAPI *png_flush_ptr) PNGARG((png_structp));
1212 typedef void (PNGAPI *png_read_status_ptr) PNGARG((png_structp, png_uint_32,
1214 typedef void (PNGAPI *png_write_status_ptr) PNGARG((png_structp, png_uint_32,
1217 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1218 typedef void (PNGAPI *png_progressive_info_ptr) PNGARG((png_structp,
1220 typedef void (PNGAPI *png_progressive_end_ptr) PNGARG((png_structp, png_infop));
1221 typedef void (PNGAPI *png_progressive_row_ptr) PNGARG((png_structp, png_bytep,
1225 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1226 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
1227 defined(PNG_LEGACY_SUPPORTED)
1228 typedef void (PNGAPI *png_user_transform_ptr) PNGARG((png_structp,
1229 png_row_infop, png_bytep));
1232 #ifdef PNG_USER_CHUNKS_SUPPORTED
1233 typedef int (PNGAPI *png_user_chunk_ptr) PNGARG((png_structp,
1234 png_unknown_chunkp));
1236 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
1237 typedef void (PNGAPI *png_unknown_chunk_ptr) PNGARG((png_structp));
1240 /* Transform masks for the high-level interface */
1241 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
1242 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
1243 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
1244 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
1245 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
1246 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
1247 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
1248 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
1249 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */
1250 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
1251 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
1252 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
1253 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only, deprecated */
1254 /* Added to libpng-1.2.34 */
1255 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE 0x0800 /* write only */
1256 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
1257 /* Added to libpng-1.2.41 */
1258 #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
1260 /* Flags for MNG supported features */
1261 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01
1262 #define PNG_FLAG_MNG_FILTER_64 0x04
1263 #define PNG_ALL_MNG_FEATURES 0x05
1265 typedef png_voidp (*png_malloc_ptr) PNGARG((png_structp, png_size_t));
1266 typedef void (*png_free_ptr) PNGARG((png_structp, png_voidp));
1268 /* The structure that holds the information to read and write PNG files.
1269 * The only people who need to care about what is inside of this are the
1270 * people who will be modifying the library for their own special needs.
1271 * It should NOT be accessed directly by an application, except to store
1275 struct png_struct_def {
1276 #ifdef PNG_SETJMP_SUPPORTED
1277 jmp_buf jmpbuf; /* used in png_error */
1279 png_error_ptr error_fn
1280 PNG_DEPSTRUCT; /* function for printing errors and aborting */
1281 png_error_ptr warning_fn PNG_DEPSTRUCT; /* function for printing warnings */
1283 PNG_DEPSTRUCT; /* user supplied struct for error functions */
1284 png_rw_ptr write_data_fn PNG_DEPSTRUCT; /* function for writing output data */
1285 png_rw_ptr read_data_fn PNG_DEPSTRUCT; /* function for reading input data */
1287 PNG_DEPSTRUCT; /* ptr to application struct for I/O functions */
1289 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
1290 png_user_transform_ptr read_user_transform_fn
1291 PNG_DEPSTRUCT; /* user read transform */
1294 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1295 png_user_transform_ptr write_user_transform_fn
1296 PNG_DEPSTRUCT; /* user write transform */
1299 /* These were added in libpng-1.0.2 */
1300 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
1301 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1302 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1303 png_voidp user_transform_ptr
1304 PNG_DEPSTRUCT; /* user supplied struct for user transform */
1305 png_byte user_transform_depth
1306 PNG_DEPSTRUCT; /* bit depth of user transformed pixels */
1307 png_byte user_transform_channels
1308 PNG_DEPSTRUCT; /* channels in user transformed pixels */
1313 PNG_DEPSTRUCT; /* tells us where we are in the PNG file */
1315 PNG_DEPSTRUCT; /* flags indicating various things to libpng */
1316 png_uint_32 transformations
1317 PNG_DEPSTRUCT; /* which transformations to perform */
1320 PNG_DEPSTRUCT; /* pointer to decompression structure (below) */
1321 png_bytep zbuf PNG_DEPSTRUCT; /* buffer for zlib */
1322 png_size_t zbuf_size PNG_DEPSTRUCT; /* size of zbuf */
1323 int zlib_level PNG_DEPSTRUCT; /* holds zlib compression level */
1324 int zlib_method PNG_DEPSTRUCT; /* holds zlib compression method */
1325 int zlib_window_bits
1326 PNG_DEPSTRUCT; /* holds zlib compression window bits */
1328 PNG_DEPSTRUCT; /* holds zlib compression memory level */
1329 int zlib_strategy PNG_DEPSTRUCT; /* holds zlib compression strategy */
1331 png_uint_32 width PNG_DEPSTRUCT; /* width of image in pixels */
1332 png_uint_32 height PNG_DEPSTRUCT; /* height of image in pixels */
1333 png_uint_32 num_rows PNG_DEPSTRUCT; /* number of rows in current pass */
1334 png_uint_32 usr_width PNG_DEPSTRUCT; /* width of row at start of write */
1335 png_uint_32 rowbytes PNG_DEPSTRUCT; /* size of row in bytes */
1336 #if 0 /* Replaced with the following in libpng-1.2.43 */
1337 png_size_t irowbytes PNG_DEPSTRUCT;
1339 /* Added in libpng-1.2.43 */
1340 #ifdef PNG_USER_LIMITS_SUPPORTED
1341 /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown
1342 * chunks that can be stored (0 means unlimited).
1344 png_uint_32 user_chunk_cache_max PNG_DEPSTRUCT;
1347 PNG_DEPSTRUCT; /* width of current interlaced row in pixels */
1348 png_uint_32 row_number PNG_DEPSTRUCT; /* current row in interlace pass */
1350 PNG_DEPSTRUCT; /* buffer to save previous (unfiltered) row */
1352 PNG_DEPSTRUCT; /* buffer to save current (unfiltered) row */
1353 #ifndef PNG_NO_WRITE_FILTER
1355 PNG_DEPSTRUCT; /* buffer to save "sub" row when filtering */
1357 PNG_DEPSTRUCT; /* buffer to save "up" row when filtering */
1359 PNG_DEPSTRUCT; /* buffer to save "avg" row when filtering */
1361 PNG_DEPSTRUCT; /* buffer to save "Paeth" row when filtering */
1363 png_row_info row_info PNG_DEPSTRUCT; /* used for transformation routines */
1365 png_uint_32 idat_size PNG_DEPSTRUCT; /* current IDAT size for read */
1366 png_uint_32 crc PNG_DEPSTRUCT; /* current chunk CRC value */
1367 png_colorp palette PNG_DEPSTRUCT; /* palette from the input file */
1368 png_uint_16 num_palette
1369 PNG_DEPSTRUCT; /* number of color entries in palette */
1370 png_uint_16 num_trans PNG_DEPSTRUCT; /* number of transparency values */
1371 png_byte chunk_name[5]
1372 PNG_DEPSTRUCT; /* null-terminated name of current chunk */
1373 png_byte compression PNG_DEPSTRUCT; /* file compression type (always 0) */
1374 png_byte filter PNG_DEPSTRUCT; /* file filter type (always 0) */
1376 PNG_DEPSTRUCT; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
1377 png_byte pass PNG_DEPSTRUCT; /* current interlace pass (0 - 6) */
1379 PNG_DEPSTRUCT; /* row filter flags (see PNG_FILTER_ below ) */
1380 png_byte color_type PNG_DEPSTRUCT; /* color type of file */
1381 png_byte bit_depth PNG_DEPSTRUCT; /* bit depth of file */
1382 png_byte usr_bit_depth PNG_DEPSTRUCT; /* bit depth of users row */
1383 png_byte pixel_depth PNG_DEPSTRUCT; /* number of bits per pixel */
1384 png_byte channels PNG_DEPSTRUCT; /* number of channels in file */
1385 png_byte usr_channels PNG_DEPSTRUCT; /* channels at start of write */
1387 PNG_DEPSTRUCT; /* magic bytes read/written from start of file */
1389 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1390 #ifdef PNG_LEGACY_SUPPORTED
1391 png_byte filler PNG_DEPSTRUCT; /* filler byte for pixel expansion */
1394 PNG_DEPSTRUCT; /* filler bytes for pixel expansion */
1398 #ifdef PNG_bKGD_SUPPORTED
1399 png_byte background_gamma_type PNG_DEPSTRUCT;
1400 # ifdef PNG_FLOATING_POINT_SUPPORTED
1401 float background_gamma PNG_DEPSTRUCT;
1403 png_color_16 background
1404 PNG_DEPSTRUCT; /* background color in screen gamma space */
1405 #ifdef PNG_READ_GAMMA_SUPPORTED
1406 png_color_16 background_1
1407 PNG_DEPSTRUCT; /* background normalized to gamma 1.0 */
1409 #endif /* PNG_bKGD_SUPPORTED */
1411 #ifdef PNG_WRITE_FLUSH_SUPPORTED
1412 png_flush_ptr output_flush_fn PNG_DEPSTRUCT; /* Function for flushing output */
1413 png_uint_32 flush_dist
1414 PNG_DEPSTRUCT; /* how many rows apart to flush, 0 - no flush */
1415 png_uint_32 flush_rows
1416 PNG_DEPSTRUCT; /* number of rows written since last flush */
1419 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1421 PNG_DEPSTRUCT; /* number of "insignificant" bits 16-bit gamma */
1422 #ifdef PNG_FLOATING_POINT_SUPPORTED
1423 float gamma PNG_DEPSTRUCT; /* file gamma value */
1424 float screen_gamma PNG_DEPSTRUCT; /* screen gamma value (display_exponent) */
1428 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1429 png_bytep gamma_table PNG_DEPSTRUCT; /* gamma table for 8-bit depth files */
1430 png_bytep gamma_from_1 PNG_DEPSTRUCT; /* converts from 1.0 to screen */
1431 png_bytep gamma_to_1 PNG_DEPSTRUCT; /* converts from file to 1.0 */
1432 png_uint_16pp gamma_16_table
1433 PNG_DEPSTRUCT; /* gamma table for 16-bit depth files */
1434 png_uint_16pp gamma_16_from_1 PNG_DEPSTRUCT; /* converts from 1.0 to screen */
1435 png_uint_16pp gamma_16_to_1 PNG_DEPSTRUCT; /* converts from file to 1.0 */
1438 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
1440 PNG_DEPSTRUCT; /* significant bits in each available channel */
1443 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1445 PNG_DEPSTRUCT; /* shift for significant bit tranformation */
1448 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
1449 || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1451 PNG_DEPSTRUCT; /* transparency values for paletted files */
1452 png_color_16 trans_values
1453 PNG_DEPSTRUCT; /* transparency values for non-paletted files */
1456 png_read_status_ptr read_row_fn
1457 PNG_DEPSTRUCT; /* called after each row is decoded */
1458 png_write_status_ptr write_row_fn
1459 PNG_DEPSTRUCT; /* called after each row is encoded */
1460 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1461 png_progressive_info_ptr info_fn
1462 PNG_DEPSTRUCT; /* called after header data fully read */
1463 png_progressive_row_ptr row_fn
1464 PNG_DEPSTRUCT; /* called after each prog. row is decoded */
1465 png_progressive_end_ptr end_fn
1466 PNG_DEPSTRUCT; /* called after image is complete */
1467 png_bytep save_buffer_ptr
1468 PNG_DEPSTRUCT; /* current location in save_buffer */
1469 png_bytep save_buffer
1470 PNG_DEPSTRUCT; /* buffer for previously read data */
1471 png_bytep current_buffer_ptr
1472 PNG_DEPSTRUCT; /* current location in current_buffer */
1473 png_bytep current_buffer
1474 PNG_DEPSTRUCT; /* buffer for recently used data */
1475 png_uint_32 push_length
1476 PNG_DEPSTRUCT; /* size of current input chunk */
1477 png_uint_32 skip_length
1478 PNG_DEPSTRUCT; /* bytes to skip in input data */
1479 png_size_t save_buffer_size
1480 PNG_DEPSTRUCT; /* amount of data now in save_buffer */
1481 png_size_t save_buffer_max PNG_DEPSTRUCT; /* total size of save_buffer */
1482 png_size_t buffer_size
1483 PNG_DEPSTRUCT; /* total amount of available input data */
1484 png_size_t current_buffer_size
1485 PNG_DEPSTRUCT; /* amount of data now in current_buffer */
1487 PNG_DEPSTRUCT; /* what push library is currently doing */
1489 PNG_DEPSTRUCT; /* current push library palette index */
1491 # ifdef PNG_TEXT_SUPPORTED
1492 png_size_t current_text_size
1493 PNG_DEPSTRUCT; /* current size of text input data */
1494 png_size_t current_text_left
1495 PNG_DEPSTRUCT; /* how much text left to read in input */
1496 png_charp current_text PNG_DEPSTRUCT; /* current text chunk buffer */
1497 png_charp current_text_ptr
1498 PNG_DEPSTRUCT; /* current location in current_text */
1499 # endif /* PNG_TEXT_SUPPORTED */
1500 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1502 #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
1503 /* for the Borland special 64K segment handler */
1504 png_bytepp offset_table_ptr PNG_DEPSTRUCT;
1505 png_bytep offset_table PNG_DEPSTRUCT;
1506 png_uint_16 offset_table_number PNG_DEPSTRUCT;
1507 png_uint_16 offset_table_count PNG_DEPSTRUCT;
1508 png_uint_16 offset_table_count_free PNG_DEPSTRUCT;
1511 #ifdef PNG_READ_DITHER_SUPPORTED
1512 png_bytep palette_lookup PNG_DEPSTRUCT; /* lookup table for dithering */
1513 png_bytep dither_index
1514 PNG_DEPSTRUCT; /* index translation for palette files */
1517 #if defined(PNG_READ_DITHER_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
1518 png_uint_16p hist PNG_DEPSTRUCT; /* histogram */
1521 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
1522 png_byte heuristic_method
1523 PNG_DEPSTRUCT; /* heuristic for row filter selection */
1524 png_byte num_prev_filters
1525 PNG_DEPSTRUCT; /* number of weights for previous rows */
1526 png_bytep prev_filters
1527 PNG_DEPSTRUCT; /* filter type(s) of previous row(s) */
1528 png_uint_16p filter_weights
1529 PNG_DEPSTRUCT; /* weight(s) for previous line(s) */
1530 png_uint_16p inv_filter_weights
1531 PNG_DEPSTRUCT; /* 1/weight(s) for previous line(s) */
1532 png_uint_16p filter_costs
1533 PNG_DEPSTRUCT; /* relative filter calculation cost */
1534 png_uint_16p inv_filter_costs
1535 PNG_DEPSTRUCT; /* 1/relative filter calculation cost */
1538 #ifdef PNG_TIME_RFC1123_SUPPORTED
1539 png_charp time_buffer
1540 PNG_DEPSTRUCT; /* String to hold RFC 1123 time text */
1543 /* New members added in libpng-1.0.6 */
1545 #ifdef PNG_FREE_ME_SUPPORTED
1547 PNG_DEPSTRUCT; /* flags items libpng is responsible for freeing */
1550 #ifdef PNG_USER_CHUNKS_SUPPORTED
1551 png_voidp user_chunk_ptr PNG_DEPSTRUCT;
1552 png_user_chunk_ptr read_user_chunk_fn
1553 PNG_DEPSTRUCT; /* user read chunk handler */
1556 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
1557 int num_chunk_list PNG_DEPSTRUCT;
1558 png_bytep chunk_list PNG_DEPSTRUCT;
1561 /* New members added in libpng-1.0.3 */
1562 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1563 png_byte rgb_to_gray_status PNG_DEPSTRUCT;
1564 /* These were changed from png_byte in libpng-1.0.6 */
1565 png_uint_16 rgb_to_gray_red_coeff PNG_DEPSTRUCT;
1566 png_uint_16 rgb_to_gray_green_coeff PNG_DEPSTRUCT;
1567 png_uint_16 rgb_to_gray_blue_coeff PNG_DEPSTRUCT;
1570 /* New member added in libpng-1.0.4 (renamed in 1.0.9) */
1571 #if defined(PNG_MNG_FEATURES_SUPPORTED) || \
1572 defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1573 defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1574 /* Changed from png_byte to png_uint_32 at version 1.2.0 */
1576 png_byte mng_features_permitted PNG_DEPSTRUCT;
1578 png_uint_32 mng_features_permitted PNG_DEPSTRUCT;
1579 #endif /* PNG_1_0_X */
1582 /* New member added in libpng-1.0.7 */
1583 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1584 png_fixed_point int_gamma PNG_DEPSTRUCT;
1587 /* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
1588 #ifdef PNG_MNG_FEATURES_SUPPORTED
1589 png_byte filter_type PNG_DEPSTRUCT;
1593 /* New member added in libpng-1.0.10, ifdef'ed out in 1.2.0 */
1594 png_uint_32 row_buf_size PNG_DEPSTRUCT;
1597 /* New members added in libpng-1.2.0 */
1598 #ifdef PNG_ASSEMBLER_CODE_SUPPORTED
1600 # ifdef PNG_MMX_CODE_SUPPORTED
1601 png_byte mmx_bitdepth_threshold PNG_DEPSTRUCT;
1602 png_uint_32 mmx_rowbytes_threshold PNG_DEPSTRUCT;
1604 png_uint_32 asm_flags PNG_DEPSTRUCT;
1608 /* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
1609 #ifdef PNG_USER_MEM_SUPPORTED
1611 PNG_DEPSTRUCT; /* user supplied struct for mem functions */
1612 png_malloc_ptr malloc_fn PNG_DEPSTRUCT; /* function for allocating memory */
1613 png_free_ptr free_fn PNG_DEPSTRUCT; /* function for freeing memory */
1616 /* New member added in libpng-1.0.13 and 1.2.0 */
1617 png_bytep big_row_buf
1618 PNG_DEPSTRUCT; /* buffer to save current (unfiltered) row */
1620 #ifdef PNG_READ_DITHER_SUPPORTED
1621 /* The following three members were added at version 1.0.14 and 1.2.4 */
1622 png_bytep dither_sort PNG_DEPSTRUCT; /* working sort array */
1623 png_bytep index_to_palette
1624 PNG_DEPSTRUCT; /* where the original index currently is */
1625 /* in the palette */
1626 png_bytep palette_to_index
1627 PNG_DEPSTRUCT; /* which original index points to this */
1631 /* New members added in libpng-1.0.16 and 1.2.6 */
1632 png_byte compression_type PNG_DEPSTRUCT;
1634 #ifdef PNG_USER_LIMITS_SUPPORTED
1635 png_uint_32 user_width_max PNG_DEPSTRUCT;
1636 png_uint_32 user_height_max PNG_DEPSTRUCT;
1639 /* New member added in libpng-1.0.25 and 1.2.17 */
1640 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
1641 /* Storage for unknown chunk that the library doesn't recognize. */
1642 png_unknown_chunk unknown_chunk PNG_DEPSTRUCT;
1645 /* New members added in libpng-1.2.26 */
1646 png_uint_32 old_big_row_buf_size PNG_DEPSTRUCT;
1647 png_uint_32 old_prev_row_size PNG_DEPSTRUCT;
1649 /* New member added in libpng-1.2.30 */
1650 png_charp chunkdata PNG_DEPSTRUCT; /* buffer for reading chunk data */
1656 /* This triggers a compiler error in png.c, if png.c and png.h
1657 * do not agree upon the version number.
1659 typedef png_structp version_1_2_50;
1661 typedef png_struct FAR *FAR *png_structpp;
1663 /* Here are the function definitions most commonly used. This is not
1664 * the place to find out how to use libpng. See libpng.txt for the
1665 * full explanation, see example.c for the summary. This just provides
1666 * a simple one line description of the use of each function.
1669 /* Returns the version number of the library */
1670 extern PNG_EXPORT(png_uint_32, png_access_version_number) PNGARG((void));
1672 /* Tell lib we have already handled the first <num_bytes> magic bytes.
1673 * Handling more than 8 bytes from the beginning of the file is an error.
1675 extern PNG_EXPORT(void, png_set_sig_bytes) PNGARG((png_structp png_ptr,
1678 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
1679 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
1680 * signature, and non-zero otherwise. Having num_to_check == 0 or
1681 * start > 7 will always fail (ie return non-zero).
1683 extern PNG_EXPORT(int, png_sig_cmp) PNGARG((png_bytep sig, png_size_t start,
1684 png_size_t num_to_check));
1686 /* Simple signature checking function. This is the same as calling
1687 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
1689 extern PNG_EXPORT(int, png_check_sig) PNGARG((png_bytep sig,
1690 int num)) PNG_DEPRECATED;
1692 /* Allocate and initialize png_ptr struct for reading, and any other memory. */
1693 extern PNG_EXPORT(png_structp, png_create_read_struct)
1694 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1695 png_error_ptr error_fn, png_error_ptr warn_fn)) PNG_ALLOCATED;
1697 /* Allocate and initialize png_ptr struct for writing, and any other memory */
1698 extern PNG_EXPORT(png_structp, png_create_write_struct)
1699 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1700 png_error_ptr error_fn, png_error_ptr warn_fn)) PNG_ALLOCATED;
1702 #ifdef PNG_WRITE_SUPPORTED
1703 extern PNG_EXPORT(png_uint_32, png_get_compression_buffer_size)
1704 PNGARG((png_structp png_ptr));
1707 #ifdef PNG_WRITE_SUPPORTED
1708 extern PNG_EXPORT(void, png_set_compression_buffer_size)
1709 PNGARG((png_structp png_ptr, png_uint_32 size));
1712 /* Reset the compression stream */
1713 extern PNG_EXPORT(int, png_reset_zstream) PNGARG((png_structp png_ptr));
1715 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
1716 #ifdef PNG_USER_MEM_SUPPORTED
1717 extern PNG_EXPORT(png_structp, png_create_read_struct_2)
1718 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1719 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1720 png_malloc_ptr malloc_fn, png_free_ptr free_fn)) PNG_ALLOCATED;
1721 extern PNG_EXPORT(png_structp, png_create_write_struct_2)
1722 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1723 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1724 png_malloc_ptr malloc_fn, png_free_ptr free_fn)) PNG_ALLOCATED;
1727 /* Write a PNG chunk - size, type, (optional) data, CRC. */
1728 extern PNG_EXPORT(void, png_write_chunk) PNGARG((png_structp png_ptr,
1729 png_bytep chunk_name, png_bytep data, png_size_t length));
1731 /* Write the start of a PNG chunk - length and chunk name. */
1732 extern PNG_EXPORT(void, png_write_chunk_start) PNGARG((png_structp png_ptr,
1733 png_bytep chunk_name, png_uint_32 length));
1735 /* Write the data of a PNG chunk started with png_write_chunk_start(). */
1736 extern PNG_EXPORT(void, png_write_chunk_data) PNGARG((png_structp png_ptr,
1737 png_bytep data, png_size_t length));
1739 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1740 extern PNG_EXPORT(void, png_write_chunk_end) PNGARG((png_structp png_ptr));
1742 /* Allocate and initialize the info structure */
1743 extern PNG_EXPORT(png_infop, png_create_info_struct)
1744 PNGARG((png_structp png_ptr)) PNG_ALLOCATED;
1746 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1747 /* Initialize the info structure (old interface - DEPRECATED) */
1748 extern PNG_EXPORT(void, png_info_init) PNGARG((png_infop info_ptr))
1750 #undef png_info_init
1751 #define png_info_init(info_ptr) png_info_init_3(&info_ptr,\
1752 png_sizeof(png_info));
1755 extern PNG_EXPORT(void, png_info_init_3) PNGARG((png_infopp info_ptr,
1756 png_size_t png_info_struct_size));
1758 /* Writes all the PNG information before the image. */
1759 extern PNG_EXPORT(void, png_write_info_before_PLTE) PNGARG((png_structp png_ptr,
1760 png_infop info_ptr));
1761 extern PNG_EXPORT(void, png_write_info) PNGARG((png_structp png_ptr,
1762 png_infop info_ptr));
1764 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1765 /* Read the information before the actual image data. */
1766 extern PNG_EXPORT(void, png_read_info) PNGARG((png_structp png_ptr,
1767 png_infop info_ptr));
1770 #ifdef PNG_TIME_RFC1123_SUPPORTED
1771 extern PNG_EXPORT(png_charp, png_convert_to_rfc1123)
1772 PNGARG((png_structp png_ptr, png_timep ptime));
1775 #ifdef PNG_CONVERT_tIME_SUPPORTED
1776 /* Convert from a struct tm to png_time */
1777 extern PNG_EXPORT(void, png_convert_from_struct_tm) PNGARG((png_timep ptime,
1778 struct tm FAR *ttime));
1780 /* Convert from time_t to png_time. Uses gmtime() */
1781 extern PNG_EXPORT(void, png_convert_from_time_t) PNGARG((png_timep ptime,
1783 #endif /* PNG_CONVERT_tIME_SUPPORTED */
1785 #ifdef PNG_READ_EXPAND_SUPPORTED
1786 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1787 extern PNG_EXPORT(void, png_set_expand) PNGARG((png_structp png_ptr));
1789 extern PNG_EXPORT(void, png_set_expand_gray_1_2_4_to_8) PNGARG((png_structp
1792 extern PNG_EXPORT(void, png_set_palette_to_rgb) PNGARG((png_structp png_ptr));
1793 extern PNG_EXPORT(void, png_set_tRNS_to_alpha) PNGARG((png_structp png_ptr));
1794 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1796 extern PNG_EXPORT(void, png_set_gray_1_2_4_to_8) PNGARG((png_structp
1797 png_ptr)) PNG_DEPRECATED;
1801 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1802 /* Use blue, green, red order for pixels. */
1803 extern PNG_EXPORT(void, png_set_bgr) PNGARG((png_structp png_ptr));
1806 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1807 /* Expand the grayscale to 24-bit RGB if necessary. */
1808 extern PNG_EXPORT(void, png_set_gray_to_rgb) PNGARG((png_structp png_ptr));
1811 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1812 /* Reduce RGB to grayscale. */
1813 #ifdef PNG_FLOATING_POINT_SUPPORTED
1814 extern PNG_EXPORT(void, png_set_rgb_to_gray) PNGARG((png_structp png_ptr,
1815 int error_action, double red, double green ));
1817 extern PNG_EXPORT(void, png_set_rgb_to_gray_fixed) PNGARG((png_structp png_ptr,
1818 int error_action, png_fixed_point red, png_fixed_point green ));
1819 extern PNG_EXPORT(png_byte, png_get_rgb_to_gray_status) PNGARG((png_structp
1823 extern PNG_EXPORT(void, png_build_grayscale_palette) PNGARG((int bit_depth,
1824 png_colorp palette));
1826 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1827 extern PNG_EXPORT(void, png_set_strip_alpha) PNGARG((png_structp png_ptr));
1830 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1831 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1832 extern PNG_EXPORT(void, png_set_swap_alpha) PNGARG((png_structp png_ptr));
1835 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1836 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1837 extern PNG_EXPORT(void, png_set_invert_alpha) PNGARG((png_structp png_ptr));
1840 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1841 /* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
1842 extern PNG_EXPORT(void, png_set_filler) PNGARG((png_structp png_ptr,
1843 png_uint_32 filler, int flags));
1844 /* The values of the PNG_FILLER_ defines should NOT be changed */
1845 #define PNG_FILLER_BEFORE 0
1846 #define PNG_FILLER_AFTER 1
1847 /* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
1849 extern PNG_EXPORT(void, png_set_add_alpha) PNGARG((png_structp png_ptr,
1850 png_uint_32 filler, int flags));
1852 #endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
1854 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1855 /* Swap bytes in 16-bit depth files. */
1856 extern PNG_EXPORT(void, png_set_swap) PNGARG((png_structp png_ptr));
1859 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1860 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1861 extern PNG_EXPORT(void, png_set_packing) PNGARG((png_structp png_ptr));
1864 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1865 /* Swap packing order of pixels in bytes. */
1866 extern PNG_EXPORT(void, png_set_packswap) PNGARG((png_structp png_ptr));
1869 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1870 /* Converts files to legal bit depths. */
1871 extern PNG_EXPORT(void, png_set_shift) PNGARG((png_structp png_ptr,
1872 png_color_8p true_bits));
1875 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1876 defined(PNG_WRITE_INTERLACING_SUPPORTED)
1877 /* Have the code handle the interlacing. Returns the number of passes. */
1878 extern PNG_EXPORT(int, png_set_interlace_handling) PNGARG((
1879 png_structp png_ptr));
1882 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1883 /* Invert monochrome files */
1884 extern PNG_EXPORT(void, png_set_invert_mono) PNGARG((png_structp png_ptr));
1887 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1888 /* Handle alpha and tRNS by replacing with a background color. */
1889 #ifdef PNG_FLOATING_POINT_SUPPORTED
1890 extern PNG_EXPORT(void, png_set_background) PNGARG((png_structp png_ptr,
1891 png_color_16p background_color, int background_gamma_code,
1892 int need_expand, double background_gamma));
1894 #define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1895 #define PNG_BACKGROUND_GAMMA_SCREEN 1
1896 #define PNG_BACKGROUND_GAMMA_FILE 2
1897 #define PNG_BACKGROUND_GAMMA_UNIQUE 3
1900 #ifdef PNG_READ_16_TO_8_SUPPORTED
1901 /* Strip the second byte of information from a 16-bit depth file. */
1902 extern PNG_EXPORT(void, png_set_strip_16) PNGARG((png_structp png_ptr));
1905 #ifdef PNG_READ_DITHER_SUPPORTED
1906 /* Turn on dithering, and reduce the palette to the number of colors available. */
1907 extern PNG_EXPORT(void, png_set_dither) PNGARG((png_structp png_ptr,
1908 png_colorp palette, int num_palette, int maximum_colors,
1909 png_uint_16p histogram, int full_dither));
1912 #ifdef PNG_READ_GAMMA_SUPPORTED
1913 /* Handle gamma correction. Screen_gamma=(display_exponent) */
1914 #ifdef PNG_FLOATING_POINT_SUPPORTED
1915 extern PNG_EXPORT(void, png_set_gamma) PNGARG((png_structp png_ptr,
1916 double screen_gamma, double default_file_gamma));
1920 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1921 #if defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1922 defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1923 /* Permit or disallow empty PLTE (0: not permitted, 1: permitted) */
1924 /* Deprecated and will be removed. Use png_permit_mng_features() instead. */
1925 extern PNG_EXPORT(void, png_permit_empty_plte) PNGARG((png_structp png_ptr,
1926 int empty_plte_permitted)) PNG_DEPRECATED;
1930 #ifdef PNG_WRITE_FLUSH_SUPPORTED
1931 /* Set how many lines between output flushes - 0 for no flushing */
1932 extern PNG_EXPORT(void, png_set_flush) PNGARG((png_structp png_ptr, int nrows));
1933 /* Flush the current PNG output buffer */
1934 extern PNG_EXPORT(void, png_write_flush) PNGARG((png_structp png_ptr));
1937 /* Optional update palette with requested transformations */
1938 extern PNG_EXPORT(void, png_start_read_image) PNGARG((png_structp png_ptr));
1940 /* Optional call to update the users info structure */
1941 extern PNG_EXPORT(void, png_read_update_info) PNGARG((png_structp png_ptr,
1942 png_infop info_ptr));
1944 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1945 /* Read one or more rows of image data. */
1946 extern PNG_EXPORT(void, png_read_rows) PNGARG((png_structp png_ptr,
1947 png_bytepp row, png_bytepp display_row, png_uint_32 num_rows));
1950 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1951 /* Read a row of data. */
1952 extern PNG_EXPORT(void, png_read_row) PNGARG((png_structp png_ptr,
1954 png_bytep display_row));
1957 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1958 /* Read the whole image into memory at once. */
1959 extern PNG_EXPORT(void, png_read_image) PNGARG((png_structp png_ptr,
1963 /* Write a row of image data */
1964 extern PNG_EXPORT(void, png_write_row) PNGARG((png_structp png_ptr,
1967 /* Write a few rows of image data */
1968 extern PNG_EXPORT(void, png_write_rows) PNGARG((png_structp png_ptr,
1969 png_bytepp row, png_uint_32 num_rows));
1971 /* Write the image data */
1972 extern PNG_EXPORT(void, png_write_image) PNGARG((png_structp png_ptr,
1975 /* Writes the end of the PNG file. */
1976 extern PNG_EXPORT(void, png_write_end) PNGARG((png_structp png_ptr,
1977 png_infop info_ptr));
1979 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1980 /* Read the end of the PNG file. */
1981 extern PNG_EXPORT(void, png_read_end) PNGARG((png_structp png_ptr,
1982 png_infop info_ptr));
1985 /* Free any memory associated with the png_info_struct */
1986 extern PNG_EXPORT(void, png_destroy_info_struct) PNGARG((png_structp png_ptr,
1987 png_infopp info_ptr_ptr));
1989 /* Free any memory associated with the png_struct and the png_info_structs */
1990 extern PNG_EXPORT(void, png_destroy_read_struct) PNGARG((png_structpp
1991 png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1993 /* Free all memory used by the read (old method - NOT DLL EXPORTED) */
1994 extern void png_read_destroy PNGARG((png_structp png_ptr, png_infop info_ptr,
1995 png_infop end_info_ptr)) PNG_DEPRECATED;
1997 /* Free any memory associated with the png_struct and the png_info_structs */
1998 extern PNG_EXPORT(void, png_destroy_write_struct)
1999 PNGARG((png_structpp png_ptr_ptr, png_infopp info_ptr_ptr));
2001 /* Free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */
2002 extern void png_write_destroy PNGARG((png_structp png_ptr)) PNG_DEPRECATED;
2004 /* Set the libpng method of handling chunk CRC errors */
2005 extern PNG_EXPORT(void, png_set_crc_action) PNGARG((png_structp png_ptr,
2006 int crit_action, int ancil_action));
2008 /* Values for png_set_crc_action() to say how to handle CRC errors in
2009 * ancillary and critical chunks, and whether to use the data contained
2010 * therein. Note that it is impossible to "discard" data in a critical
2011 * chunk. For versions prior to 0.90, the action was always error/quit,
2012 * whereas in version 0.90 and later, the action for CRC errors in ancillary
2013 * chunks is warn/discard. These values should NOT be changed.
2015 * value action:critical action:ancillary
2017 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
2018 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
2019 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
2020 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
2021 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
2022 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
2024 /* These functions give the user control over the scan-line filtering in
2025 * libpng and the compression methods used by zlib. These functions are
2026 * mainly useful for testing, as the defaults should work with most users.
2027 * Those users who are tight on memory or want faster performance at the
2028 * expense of compression can modify them. See the compression library
2029 * header file (zlib.h) for an explination of the compression functions.
2032 /* Set the filtering method(s) used by libpng. Currently, the only valid
2033 * value for "method" is 0.
2035 extern PNG_EXPORT(void, png_set_filter) PNGARG((png_structp png_ptr, int method,
2038 /* Flags for png_set_filter() to say which filters to use. The flags
2039 * are chosen so that they don't conflict with real filter types
2040 * below, in case they are supplied instead of the #defined constants.
2041 * These values should NOT be changed.
2043 #define PNG_NO_FILTERS 0x00
2044 #define PNG_FILTER_NONE 0x08
2045 #define PNG_FILTER_SUB 0x10
2046 #define PNG_FILTER_UP 0x20
2047 #define PNG_FILTER_AVG 0x40
2048 #define PNG_FILTER_PAETH 0x80
2049 #define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
2050 PNG_FILTER_AVG | PNG_FILTER_PAETH)
2052 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
2053 * These defines should NOT be changed.
2055 #define PNG_FILTER_VALUE_NONE 0
2056 #define PNG_FILTER_VALUE_SUB 1
2057 #define PNG_FILTER_VALUE_UP 2
2058 #define PNG_FILTER_VALUE_AVG 3
2059 #define PNG_FILTER_VALUE_PAETH 4
2060 #define PNG_FILTER_VALUE_LAST 5
2062 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* EXPERIMENTAL */
2063 /* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
2064 * defines, either the default (minimum-sum-of-absolute-differences), or
2065 * the experimental method (weighted-minimum-sum-of-absolute-differences).
2067 * Weights are factors >= 1.0, indicating how important it is to keep the
2068 * filter type consistent between rows. Larger numbers mean the current
2069 * filter is that many times as likely to be the same as the "num_weights"
2070 * previous filters. This is cumulative for each previous row with a weight.
2071 * There needs to be "num_weights" values in "filter_weights", or it can be
2072 * NULL if the weights aren't being specified. Weights have no influence on
2073 * the selection of the first row filter. Well chosen weights can (in theory)
2074 * improve the compression for a given image.
2076 * Costs are factors >= 1.0 indicating the relative decoding costs of a
2077 * filter type. Higher costs indicate more decoding expense, and are
2078 * therefore less likely to be selected over a filter with lower computational
2079 * costs. There needs to be a value in "filter_costs" for each valid filter
2080 * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
2081 * setting the costs. Costs try to improve the speed of decompression without
2082 * unduly increasing the compressed image size.
2084 * A negative weight or cost indicates the default value is to be used, and
2085 * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
2086 * The default values for both weights and costs are currently 1.0, but may
2087 * change if good general weighting/cost heuristics can be found. If both
2088 * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
2089 * to the UNWEIGHTED method, but with added encoding time/computation.
2091 #ifdef PNG_FLOATING_POINT_SUPPORTED
2092 extern PNG_EXPORT(void, png_set_filter_heuristics) PNGARG((png_structp png_ptr,
2093 int heuristic_method, int num_weights, png_doublep filter_weights,
2094 png_doublep filter_costs));
2096 #endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
2098 /* Heuristic used for row filter selection. These defines should NOT be
2101 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
2102 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
2103 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
2104 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
2106 /* Set the library compression level. Currently, valid values range from
2107 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
2108 * (0 - no compression, 9 - "maximal" compression). Note that tests have
2109 * shown that zlib compression levels 3-6 usually perform as well as level 9
2110 * for PNG images, and do considerably fewer caclulations. In the future,
2111 * these values may not correspond directly to the zlib compression levels.
2113 extern PNG_EXPORT(void, png_set_compression_level) PNGARG((png_structp png_ptr,
2116 extern PNG_EXPORT(void, png_set_compression_mem_level)
2117 PNGARG((png_structp png_ptr, int mem_level));
2119 extern PNG_EXPORT(void, png_set_compression_strategy)
2120 PNGARG((png_structp png_ptr, int strategy));
2122 extern PNG_EXPORT(void, png_set_compression_window_bits)
2123 PNGARG((png_structp png_ptr, int window_bits));
2125 extern PNG_EXPORT(void, png_set_compression_method) PNGARG((png_structp png_ptr,
2128 /* These next functions are called for input/output, memory, and error
2129 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
2130 * and call standard C I/O routines such as fread(), fwrite(), and
2131 * fprintf(). These functions can be made to use other I/O routines
2132 * at run time for those applications that need to handle I/O in a
2133 * different manner by calling png_set_???_fn(). See libpng.txt for
2137 #ifdef PNG_STDIO_SUPPORTED
2138 /* Initialize the input/output for the PNG file to the default functions. */
2139 extern PNG_EXPORT(void, png_init_io) PNGARG((png_structp png_ptr,
2143 /* Replace the (error and abort), and warning functions with user
2144 * supplied functions. If no messages are to be printed you must still
2145 * write and use replacement functions. The replacement error_fn should
2146 * still do a longjmp to the last setjmp location if you are using this
2147 * method of error handling. If error_fn or warning_fn is NULL, the
2148 * default function will be used.
2151 extern PNG_EXPORT(void, png_set_error_fn) PNGARG((png_structp png_ptr,
2152 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
2154 /* Return the user pointer associated with the error functions */
2155 extern PNG_EXPORT(png_voidp, png_get_error_ptr) PNGARG((png_structp png_ptr));
2157 /* Replace the default data output functions with a user supplied one(s).
2158 * If buffered output is not used, then output_flush_fn can be set to NULL.
2159 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
2160 * output_flush_fn will be ignored (and thus can be NULL).
2161 * It is probably a mistake to use NULL for output_flush_fn if
2162 * write_data_fn is not also NULL unless you have built libpng with
2163 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
2164 * default flush function, which uses the standard *FILE structure, will
2167 extern PNG_EXPORT(void, png_set_write_fn) PNGARG((png_structp png_ptr,
2168 png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
2170 /* Replace the default data input function with a user supplied one. */
2171 extern PNG_EXPORT(void, png_set_read_fn) PNGARG((png_structp png_ptr,
2172 png_voidp io_ptr, png_rw_ptr read_data_fn));
2174 /* Return the user pointer associated with the I/O functions */
2175 extern PNG_EXPORT(png_voidp, png_get_io_ptr) PNGARG((png_structp png_ptr));
2177 extern PNG_EXPORT(void, png_set_read_status_fn) PNGARG((png_structp png_ptr,
2178 png_read_status_ptr read_row_fn));
2180 extern PNG_EXPORT(void, png_set_write_status_fn) PNGARG((png_structp png_ptr,
2181 png_write_status_ptr write_row_fn));
2183 #ifdef PNG_USER_MEM_SUPPORTED
2184 /* Replace the default memory allocation functions with user supplied one(s). */
2185 extern PNG_EXPORT(void, png_set_mem_fn) PNGARG((png_structp png_ptr,
2186 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn));
2187 /* Return the user pointer associated with the memory functions */
2188 extern PNG_EXPORT(png_voidp, png_get_mem_ptr) PNGARG((png_structp png_ptr));
2191 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
2192 defined(PNG_LEGACY_SUPPORTED)
2193 extern PNG_EXPORT(void, png_set_read_user_transform_fn) PNGARG((png_structp
2194 png_ptr, png_user_transform_ptr read_user_transform_fn));
2197 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
2198 defined(PNG_LEGACY_SUPPORTED)
2199 extern PNG_EXPORT(void, png_set_write_user_transform_fn) PNGARG((png_structp
2200 png_ptr, png_user_transform_ptr write_user_transform_fn));
2203 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
2204 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
2205 defined(PNG_LEGACY_SUPPORTED)
2206 extern PNG_EXPORT(void, png_set_user_transform_info) PNGARG((png_structp
2207 png_ptr, png_voidp user_transform_ptr, int user_transform_depth,
2208 int user_transform_channels));
2209 /* Return the user pointer associated with the user transform functions */
2210 extern PNG_EXPORT(png_voidp, png_get_user_transform_ptr)
2211 PNGARG((png_structp png_ptr));
2214 #ifdef PNG_USER_CHUNKS_SUPPORTED
2215 extern PNG_EXPORT(void, png_set_read_user_chunk_fn) PNGARG((png_structp png_ptr,
2216 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
2217 extern PNG_EXPORT(png_voidp, png_get_user_chunk_ptr) PNGARG((png_structp
2221 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
2222 /* Sets the function callbacks for the push reader, and a pointer to a
2223 * user-defined structure available to the callback functions.
2225 extern PNG_EXPORT(void, png_set_progressive_read_fn) PNGARG((
2226 png_structp png_ptr,
2227 png_voidp progressive_ptr,
2228 png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
2229 png_progressive_end_ptr end_fn));
2231 /* Returns the user pointer associated with the push read functions */
2232 extern PNG_EXPORT(png_voidp, png_get_progressive_ptr)
2233 PNGARG((png_structp png_ptr));
2235 /* Function to be called when data becomes available */
2236 extern PNG_EXPORT(void, png_process_data) PNGARG((png_structp png_ptr,
2237 png_infop info_ptr, png_bytep buffer, png_size_t buffer_size));
2239 /* Function that combines rows. Not very much different than the
2240 * png_combine_row() call. Is this even used?????
2242 extern PNG_EXPORT(void, png_progressive_combine_row) PNGARG((
2243 png_structp png_ptr,
2244 png_bytep old_row, png_bytep new_row));
2245 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
2247 extern PNG_EXPORT(png_voidp, png_malloc) PNGARG((png_structp png_ptr,
2248 png_uint_32 size)) PNG_ALLOCATED;
2251 # define png_malloc_warn png_malloc
2253 /* Added at libpng version 1.2.4 */
2254 extern PNG_EXPORT(png_voidp, png_malloc_warn) PNGARG((png_structp png_ptr,
2255 png_uint_32 size)) PNG_ALLOCATED;
2258 /* Frees a pointer allocated by png_malloc() */
2259 extern PNG_EXPORT(void, png_free) PNGARG((png_structp png_ptr, png_voidp ptr));
2262 /* Function to allocate memory for zlib. */
2263 extern PNG_EXPORT(voidpf, png_zalloc) PNGARG((voidpf png_ptr, uInt items,
2266 /* Function to free memory for zlib */
2267 extern PNG_EXPORT(void, png_zfree) PNGARG((voidpf png_ptr, voidpf ptr));
2270 /* Free data that was allocated internally */
2271 extern PNG_EXPORT(void, png_free_data) PNGARG((png_structp png_ptr,
2272 png_infop info_ptr, png_uint_32 free_me, int num));
2273 #ifdef PNG_FREE_ME_SUPPORTED
2274 /* Reassign responsibility for freeing existing data, whether allocated
2275 * by libpng or by the application
2277 extern PNG_EXPORT(void, png_data_freer) PNGARG((png_structp png_ptr,
2278 png_infop info_ptr, int freer, png_uint_32 mask));
2280 /* Assignments for png_data_freer */
2281 #define PNG_DESTROY_WILL_FREE_DATA 1
2282 #define PNG_SET_WILL_FREE_DATA 1
2283 #define PNG_USER_WILL_FREE_DATA 2
2284 /* Flags for png_ptr->free_me and info_ptr->free_me */
2285 #define PNG_FREE_HIST 0x0008
2286 #define PNG_FREE_ICCP 0x0010
2287 #define PNG_FREE_SPLT 0x0020
2288 #define PNG_FREE_ROWS 0x0040
2289 #define PNG_FREE_PCAL 0x0080
2290 #define PNG_FREE_SCAL 0x0100
2291 #define PNG_FREE_UNKN 0x0200
2292 #define PNG_FREE_LIST 0x0400
2293 #define PNG_FREE_PLTE 0x1000
2294 #define PNG_FREE_TRNS 0x2000
2295 #define PNG_FREE_TEXT 0x4000
2296 #define PNG_FREE_ALL 0x7fff
2297 #define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
2299 #ifdef PNG_USER_MEM_SUPPORTED
2300 extern PNG_EXPORT(png_voidp, png_malloc_default) PNGARG((png_structp png_ptr,
2301 png_uint_32 size)) PNG_ALLOCATED;
2302 extern PNG_EXPORT(void, png_free_default) PNGARG((png_structp png_ptr,
2306 extern PNG_EXPORT(png_voidp, png_memcpy_check) PNGARG((png_structp png_ptr,
2307 png_voidp s1, png_voidp s2, png_uint_32 size)) PNG_DEPRECATED;
2309 extern PNG_EXPORT(png_voidp, png_memset_check) PNGARG((png_structp png_ptr,
2310 png_voidp s1, int value, png_uint_32 size)) PNG_DEPRECATED;
2312 #if defined(USE_FAR_KEYWORD) /* memory model conversion function */
2313 extern void *png_far_to_near PNGARG((png_structp png_ptr, png_voidp ptr,
2315 #endif /* USE_FAR_KEYWORD */
2317 #ifndef PNG_NO_ERROR_TEXT
2318 /* Fatal error in PNG image of libpng - can't continue */
2319 extern PNG_EXPORT(void, png_error) PNGARG((png_structp png_ptr,
2320 png_const_charp error_message)) PNG_NORETURN;
2322 /* The same, but the chunk name is prepended to the error string. */
2323 extern PNG_EXPORT(void, png_chunk_error) PNGARG((png_structp png_ptr,
2324 png_const_charp error_message)) PNG_NORETURN;
2326 /* Fatal error in PNG image of libpng - can't continue */
2327 extern PNG_EXPORT(void, png_err) PNGARG((png_structp png_ptr)) PNG_NORETURN;
2330 #ifndef PNG_NO_WARNINGS
2331 /* Non-fatal error in libpng. Can continue, but may have a problem. */
2332 extern PNG_EXPORT(void, png_warning) PNGARG((png_structp png_ptr,
2333 png_const_charp warning_message));
2335 #ifdef PNG_READ_SUPPORTED
2336 /* Non-fatal error in libpng, chunk name is prepended to message. */
2337 extern PNG_EXPORT(void, png_chunk_warning) PNGARG((png_structp png_ptr,
2338 png_const_charp warning_message));
2339 #endif /* PNG_READ_SUPPORTED */
2340 #endif /* PNG_NO_WARNINGS */
2342 /* The png_set_<chunk> functions are for storing values in the png_info_struct.
2343 * Similarly, the png_get_<chunk> calls are used to read values from the
2344 * png_info_struct, either storing the parameters in the passed variables, or
2345 * setting pointers into the png_info_struct where the data is stored. The
2346 * png_get_<chunk> functions return a non-zero value if the data was available
2347 * in info_ptr, or return zero and do not change any of the parameters if the
2348 * data was not available.
2350 * These functions should be used instead of directly accessing png_info
2351 * to avoid problems with future changes in the size and internal layout of
2354 /* Returns "flag" if chunk data is valid in info_ptr. */
2355 extern PNG_EXPORT(png_uint_32, png_get_valid) PNGARG((png_structp png_ptr,
2356 png_infop info_ptr, png_uint_32 flag));
2358 /* Returns number of bytes needed to hold a transformed row. */
2359 extern PNG_EXPORT(png_uint_32, png_get_rowbytes) PNGARG((png_structp png_ptr,
2360 png_infop info_ptr));
2362 #ifdef PNG_INFO_IMAGE_SUPPORTED
2363 /* Returns row_pointers, which is an array of pointers to scanlines that was
2364 * returned from png_read_png().
2366 extern PNG_EXPORT(png_bytepp, png_get_rows) PNGARG((png_structp png_ptr,
2367 png_infop info_ptr));
2368 /* Set row_pointers, which is an array of pointers to scanlines for use
2369 * by png_write_png().
2371 extern PNG_EXPORT(void, png_set_rows) PNGARG((png_structp png_ptr,
2372 png_infop info_ptr, png_bytepp row_pointers));
2375 /* Returns number of color channels in image. */
2376 extern PNG_EXPORT(png_byte, png_get_channels) PNGARG((png_structp png_ptr,
2377 png_infop info_ptr));
2379 #ifdef PNG_EASY_ACCESS_SUPPORTED
2380 /* Returns image width in pixels. */
2381 extern PNG_EXPORT(png_uint_32, png_get_image_width) PNGARG((png_structp
2382 png_ptr, png_infop info_ptr));
2384 /* Returns image height in pixels. */
2385 extern PNG_EXPORT(png_uint_32, png_get_image_height) PNGARG((png_structp
2386 png_ptr, png_infop info_ptr));
2388 /* Returns image bit_depth. */
2389 extern PNG_EXPORT(png_byte, png_get_bit_depth) PNGARG((png_structp
2390 png_ptr, png_infop info_ptr));
2392 /* Returns image color_type. */
2393 extern PNG_EXPORT(png_byte, png_get_color_type) PNGARG((png_structp
2394 png_ptr, png_infop info_ptr));
2396 /* Returns image filter_type. */
2397 extern PNG_EXPORT(png_byte, png_get_filter_type) PNGARG((png_structp
2398 png_ptr, png_infop info_ptr));
2400 /* Returns image interlace_type. */
2401 extern PNG_EXPORT(png_byte, png_get_interlace_type) PNGARG((png_structp
2402 png_ptr, png_infop info_ptr));
2404 /* Returns image compression_type. */
2405 extern PNG_EXPORT(png_byte, png_get_compression_type) PNGARG((png_structp
2406 png_ptr, png_infop info_ptr));
2408 /* Returns image resolution in pixels per meter, from pHYs chunk data. */
2409 extern PNG_EXPORT(png_uint_32, png_get_pixels_per_meter) PNGARG((png_structp
2410 png_ptr, png_infop info_ptr));
2411 extern PNG_EXPORT(png_uint_32, png_get_x_pixels_per_meter) PNGARG((png_structp
2412 png_ptr, png_infop info_ptr));
2413 extern PNG_EXPORT(png_uint_32, png_get_y_pixels_per_meter) PNGARG((png_structp
2414 png_ptr, png_infop info_ptr));
2416 /* Returns pixel aspect ratio, computed from pHYs chunk data. */
2417 #ifdef PNG_FLOATING_POINT_SUPPORTED
2418 extern PNG_EXPORT(float, png_get_pixel_aspect_ratio) PNGARG((png_structp
2419 png_ptr, png_infop info_ptr));
2422 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
2423 extern PNG_EXPORT(png_int_32, png_get_x_offset_pixels) PNGARG((png_structp
2424 png_ptr, png_infop info_ptr));
2425 extern PNG_EXPORT(png_int_32, png_get_y_offset_pixels) PNGARG((png_structp
2426 png_ptr, png_infop info_ptr));
2427 extern PNG_EXPORT(png_int_32, png_get_x_offset_microns) PNGARG((png_structp
2428 png_ptr, png_infop info_ptr));
2429 extern PNG_EXPORT(png_int_32, png_get_y_offset_microns) PNGARG((png_structp
2430 png_ptr, png_infop info_ptr));
2432 #endif /* PNG_EASY_ACCESS_SUPPORTED */
2434 /* Returns pointer to signature string read from PNG header */
2435 extern PNG_EXPORT(png_bytep, png_get_signature) PNGARG((png_structp png_ptr,
2436 png_infop info_ptr));
2438 #ifdef PNG_bKGD_SUPPORTED
2439 extern PNG_EXPORT(png_uint_32, png_get_bKGD) PNGARG((png_structp png_ptr,
2440 png_infop info_ptr, png_color_16p *background));
2443 #ifdef PNG_bKGD_SUPPORTED
2444 extern PNG_EXPORT(void, png_set_bKGD) PNGARG((png_structp png_ptr,
2445 png_infop info_ptr, png_color_16p background));
2448 #ifdef PNG_cHRM_SUPPORTED
2449 #ifdef PNG_FLOATING_POINT_SUPPORTED
2450 extern PNG_EXPORT(png_uint_32, png_get_cHRM) PNGARG((png_structp png_ptr,
2451 png_infop info_ptr, double *white_x, double *white_y, double *red_x,
2452 double *red_y, double *green_x, double *green_y, double *blue_x,
2455 #ifdef PNG_FIXED_POINT_SUPPORTED
2456 extern PNG_EXPORT(png_uint_32, png_get_cHRM_fixed) PNGARG((png_structp png_ptr,
2457 png_infop info_ptr, png_fixed_point *int_white_x, png_fixed_point
2458 *int_white_y, png_fixed_point *int_red_x, png_fixed_point *int_red_y,
2459 png_fixed_point *int_green_x, png_fixed_point *int_green_y, png_fixed_point
2460 *int_blue_x, png_fixed_point *int_blue_y));
2464 #ifdef PNG_cHRM_SUPPORTED
2465 #ifdef PNG_FLOATING_POINT_SUPPORTED
2466 extern PNG_EXPORT(void, png_set_cHRM) PNGARG((png_structp png_ptr,
2467 png_infop info_ptr, double white_x, double white_y, double red_x,
2468 double red_y, double green_x, double green_y, double blue_x, double blue_y));
2470 #ifdef PNG_FIXED_POINT_SUPPORTED
2471 extern PNG_EXPORT(void, png_set_cHRM_fixed) PNGARG((png_structp png_ptr,
2472 png_infop info_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y,
2473 png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
2474 int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
2475 png_fixed_point int_blue_y));
2479 #ifdef PNG_gAMA_SUPPORTED
2480 #ifdef PNG_FLOATING_POINT_SUPPORTED
2481 extern PNG_EXPORT(png_uint_32, png_get_gAMA) PNGARG((png_structp png_ptr,
2482 png_infop info_ptr, double *file_gamma));
2484 extern PNG_EXPORT(png_uint_32, png_get_gAMA_fixed) PNGARG((png_structp png_ptr,
2485 png_infop info_ptr, png_fixed_point *int_file_gamma));
2488 #ifdef PNG_gAMA_SUPPORTED
2489 #ifdef PNG_FLOATING_POINT_SUPPORTED
2490 extern PNG_EXPORT(void, png_set_gAMA) PNGARG((png_structp png_ptr,
2491 png_infop info_ptr, double file_gamma));
2493 extern PNG_EXPORT(void, png_set_gAMA_fixed) PNGARG((png_structp png_ptr,
2494 png_infop info_ptr, png_fixed_point int_file_gamma));
2497 #ifdef PNG_hIST_SUPPORTED
2498 extern PNG_EXPORT(png_uint_32, png_get_hIST) PNGARG((png_structp png_ptr,
2499 png_infop info_ptr, png_uint_16p *hist));
2502 #ifdef PNG_hIST_SUPPORTED
2503 extern PNG_EXPORT(void, png_set_hIST) PNGARG((png_structp png_ptr,
2504 png_infop info_ptr, png_uint_16p hist));
2507 extern PNG_EXPORT(png_uint_32, png_get_IHDR) PNGARG((png_structp png_ptr,
2508 png_infop info_ptr, png_uint_32 *width, png_uint_32 *height,
2509 int *bit_depth, int *color_type, int *interlace_method,
2510 int *compression_method, int *filter_method));
2512 extern PNG_EXPORT(void, png_set_IHDR) PNGARG((png_structp png_ptr,
2513 png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
2514 int color_type, int interlace_method, int compression_method,
2515 int filter_method));
2517 #ifdef PNG_oFFs_SUPPORTED
2518 extern PNG_EXPORT(png_uint_32, png_get_oFFs) PNGARG((png_structp png_ptr,
2519 png_infop info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
2523 #ifdef PNG_oFFs_SUPPORTED
2524 extern PNG_EXPORT(void, png_set_oFFs) PNGARG((png_structp png_ptr,
2525 png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2529 #ifdef PNG_pCAL_SUPPORTED
2530 extern PNG_EXPORT(png_uint_32, png_get_pCAL) PNGARG((png_structp png_ptr,
2531 png_infop info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1,
2532 int *type, int *nparams, png_charp *units, png_charpp *params));
2535 #ifdef PNG_pCAL_SUPPORTED
2536 extern PNG_EXPORT(void, png_set_pCAL) PNGARG((png_structp png_ptr,
2537 png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1,
2538 int type, int nparams, png_charp units, png_charpp params));
2541 #ifdef PNG_pHYs_SUPPORTED
2542 extern PNG_EXPORT(png_uint_32, png_get_pHYs) PNGARG((png_structp png_ptr,
2543 png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
2546 #ifdef PNG_pHYs_SUPPORTED
2547 extern PNG_EXPORT(void, png_set_pHYs) PNGARG((png_structp png_ptr,
2548 png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2551 extern PNG_EXPORT(png_uint_32, png_get_PLTE) PNGARG((png_structp png_ptr,
2552 png_infop info_ptr, png_colorp *palette, int *num_palette));
2554 extern PNG_EXPORT(void, png_set_PLTE) PNGARG((png_structp png_ptr,
2555 png_infop info_ptr, png_colorp palette, int num_palette));
2557 #ifdef PNG_sBIT_SUPPORTED
2558 extern PNG_EXPORT(png_uint_32, png_get_sBIT) PNGARG((png_structp png_ptr,
2559 png_infop info_ptr, png_color_8p *sig_bit));
2562 #ifdef PNG_sBIT_SUPPORTED
2563 extern PNG_EXPORT(void, png_set_sBIT) PNGARG((png_structp png_ptr,
2564 png_infop info_ptr, png_color_8p sig_bit));
2567 #ifdef PNG_sRGB_SUPPORTED
2568 extern PNG_EXPORT(png_uint_32, png_get_sRGB) PNGARG((png_structp png_ptr,
2569 png_infop info_ptr, int *intent));
2572 #ifdef PNG_sRGB_SUPPORTED
2573 extern PNG_EXPORT(void, png_set_sRGB) PNGARG((png_structp png_ptr,
2574 png_infop info_ptr, int intent));
2575 extern PNG_EXPORT(void, png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr,
2576 png_infop info_ptr, int intent));
2579 #ifdef PNG_iCCP_SUPPORTED
2580 extern PNG_EXPORT(png_uint_32, png_get_iCCP) PNGARG((png_structp png_ptr,
2581 png_infop info_ptr, png_charpp name, int *compression_type,
2582 png_charpp profile, png_uint_32 *proflen));
2583 /* Note to maintainer: profile should be png_bytepp */
2586 #ifdef PNG_iCCP_SUPPORTED
2587 extern PNG_EXPORT(void, png_set_iCCP) PNGARG((png_structp png_ptr,
2588 png_infop info_ptr, png_charp name, int compression_type,
2589 png_charp profile, png_uint_32 proflen));
2590 /* Note to maintainer: profile should be png_bytep */
2593 #ifdef PNG_sPLT_SUPPORTED
2594 extern PNG_EXPORT(png_uint_32, png_get_sPLT) PNGARG((png_structp png_ptr,
2595 png_infop info_ptr, png_sPLT_tpp entries));
2598 #ifdef PNG_sPLT_SUPPORTED
2599 extern PNG_EXPORT(void, png_set_sPLT) PNGARG((png_structp png_ptr,
2600 png_infop info_ptr, png_sPLT_tp entries, int nentries));
2603 #ifdef PNG_TEXT_SUPPORTED
2604 /* png_get_text also returns the number of text chunks in *num_text */
2605 extern PNG_EXPORT(png_uint_32, png_get_text) PNGARG((png_structp png_ptr,
2606 png_infop info_ptr, png_textp *text_ptr, int *num_text));
2610 * Note while png_set_text() will accept a structure whose text,
2611 * language, and translated keywords are NULL pointers, the structure
2612 * returned by png_get_text will always contain regular
2613 * zero-terminated C strings. They might be empty strings but
2614 * they will never be NULL pointers.
2617 #ifdef PNG_TEXT_SUPPORTED
2618 extern PNG_EXPORT(void, png_set_text) PNGARG((png_structp png_ptr,
2619 png_infop info_ptr, png_textp text_ptr, int num_text));
2622 #ifdef PNG_tIME_SUPPORTED
2623 extern PNG_EXPORT(png_uint_32, png_get_tIME) PNGARG((png_structp png_ptr,
2624 png_infop info_ptr, png_timep *mod_time));
2627 #ifdef PNG_tIME_SUPPORTED
2628 extern PNG_EXPORT(void, png_set_tIME) PNGARG((png_structp png_ptr,
2629 png_infop info_ptr, png_timep mod_time));
2632 #ifdef PNG_tRNS_SUPPORTED
2633 extern PNG_EXPORT(png_uint_32, png_get_tRNS) PNGARG((png_structp png_ptr,
2634 png_infop info_ptr, png_bytep *trans, int *num_trans,
2635 png_color_16p *trans_values));
2638 #ifdef PNG_tRNS_SUPPORTED
2639 extern PNG_EXPORT(void, png_set_tRNS) PNGARG((png_structp png_ptr,
2640 png_infop info_ptr, png_bytep trans, int num_trans,
2641 png_color_16p trans_values));
2644 #ifdef PNG_tRNS_SUPPORTED
2647 #ifdef PNG_sCAL_SUPPORTED
2648 #ifdef PNG_FLOATING_POINT_SUPPORTED
2649 extern PNG_EXPORT(png_uint_32, png_get_sCAL) PNGARG((png_structp png_ptr,
2650 png_infop info_ptr, int *unit, double *width, double *height));
2652 #ifdef PNG_FIXED_POINT_SUPPORTED
2653 extern PNG_EXPORT(png_uint_32, png_get_sCAL_s) PNGARG((png_structp png_ptr,
2654 png_infop info_ptr, int *unit, png_charpp swidth, png_charpp sheight));
2657 #endif /* PNG_sCAL_SUPPORTED */
2659 #ifdef PNG_sCAL_SUPPORTED
2660 #ifdef PNG_FLOATING_POINT_SUPPORTED
2661 extern PNG_EXPORT(void, png_set_sCAL) PNGARG((png_structp png_ptr,
2662 png_infop info_ptr, int unit, double width, double height));
2664 #ifdef PNG_FIXED_POINT_SUPPORTED
2665 extern PNG_EXPORT(void, png_set_sCAL_s) PNGARG((png_structp png_ptr,
2666 png_infop info_ptr, int unit, png_charp swidth, png_charp sheight));
2669 #endif /* PNG_sCAL_SUPPORTED || PNG_WRITE_sCAL_SUPPORTED */
2671 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2672 /* Provide a list of chunks and how they are to be handled, if the built-in
2673 handling or default unknown chunk handling is not desired. Any chunks not
2674 listed will be handled in the default manner. The IHDR and IEND chunks
2676 keep = 0: follow default behaviour
2678 = 2: keep only if safe-to-copy
2679 = 3: keep even if unsafe-to-copy
2681 extern PNG_EXPORT(void, png_set_keep_unknown_chunks) PNGARG((png_structp
2682 png_ptr, int keep, png_bytep chunk_list, int num_chunks));
2683 PNG_EXPORT(int, png_handle_as_unknown) PNGARG((png_structp png_ptr, png_bytep
2686 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
2687 extern PNG_EXPORT(void, png_set_unknown_chunks) PNGARG((png_structp png_ptr,
2688 png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns));
2689 extern PNG_EXPORT(void, png_set_unknown_chunk_location)
2690 PNGARG((png_structp png_ptr, png_infop info_ptr, int chunk, int location));
2691 extern PNG_EXPORT(png_uint_32, png_get_unknown_chunks) PNGARG((png_structp
2692 png_ptr, png_infop info_ptr, png_unknown_chunkpp entries));
2695 /* Png_free_data() will turn off the "valid" flag for anything it frees.
2696 * If you need to turn it off for a chunk that your application has freed,
2697 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
2699 extern PNG_EXPORT(void, png_set_invalid) PNGARG((png_structp png_ptr,
2700 png_infop info_ptr, int mask));
2702 #ifdef PNG_INFO_IMAGE_SUPPORTED
2703 /* The "params" pointer is currently not used and is for future expansion. */
2704 extern PNG_EXPORT(void, png_read_png) PNGARG((png_structp png_ptr,
2708 extern PNG_EXPORT(void, png_write_png) PNGARG((png_structp png_ptr,
2714 /* Define PNG_DEBUG at compile time for debugging information. Higher
2715 * numbers for PNG_DEBUG mean more debugging information. This has
2716 * only been added since version 0.95 so it is not implemented throughout
2717 * libpng yet, but more support will be added as needed.
2721 #if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER)
2728 #define png_debug(l,m) _RPT0(_CRT_WARN,m PNG_STRING_NEWLINE)
2731 #define png_debug1(l,m,p1) _RPT1(_CRT_WARN,m PNG_STRING_NEWLINE,p1)
2734 #define png_debug2(l,m,p1,p2) _RPT2(_CRT_WARN,m PNG_STRING_NEWLINE,p1,p2)
2737 #else /* PNG_DEBUG_FILE || !_MSC_VER */
2738 #ifndef PNG_DEBUG_FILE
2739 #define PNG_DEBUG_FILE stderr
2740 #endif /* PNG_DEBUG_FILE */
2743 /* Note: ["%s"m PNG_STRING_NEWLINE] probably does not work on non-ISO
2748 # define png_debug(l,m) \
2751 fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
2752 (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":"")))); \
2756 # define png_debug1(l,m,p1) \
2759 fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
2760 (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1); \
2764 # define png_debug2(l,m,p1,p2) \
2767 fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
2768 (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1,p2); \
2771 # else /* __STDC __ */
2773 # define png_debug(l,m) \
2777 snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
2778 (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
2779 m,PNG_STRING_NEWLINE); \
2780 fprintf(PNG_DEBUG_FILE,format); \
2784 # define png_debug1(l,m,p1) \
2788 snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
2789 (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
2790 m,PNG_STRING_NEWLINE); \
2791 fprintf(PNG_DEBUG_FILE,format,p1); \
2795 # define png_debug2(l,m,p1,p2) \
2799 snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
2800 (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
2801 m,PNG_STRING_NEWLINE); \
2802 fprintf(PNG_DEBUG_FILE,format,p1,p2); \
2805 # endif /* __STDC __ */
2806 #endif /* (PNG_DEBUG > 1) */
2808 #endif /* _MSC_VER */
2809 #endif /* (PNG_DEBUG > 0) */
2810 #endif /* PNG_DEBUG */
2812 #define png_debug(l, m)
2815 #define png_debug1(l, m, p1)
2818 #define png_debug2(l, m, p1, p2)
2821 extern PNG_EXPORT(png_charp, png_get_copyright) PNGARG((png_structp png_ptr));
2822 extern PNG_EXPORT(png_charp, png_get_header_ver) PNGARG((png_structp png_ptr));
2823 extern PNG_EXPORT(png_charp,
2824 png_get_header_version) PNGARG((png_structp png_ptr));
2825 extern PNG_EXPORT(png_charp, png_get_libpng_ver) PNGARG((png_structp png_ptr));
2827 #ifdef PNG_MNG_FEATURES_SUPPORTED
2828 extern PNG_EXPORT(png_uint_32, png_permit_mng_features) PNGARG((png_structp
2829 png_ptr, png_uint_32 mng_features_permitted));
2832 /* For use in png_set_keep_unknown, added to version 1.2.6 */
2833 #define PNG_HANDLE_CHUNK_AS_DEFAULT 0
2834 #define PNG_HANDLE_CHUNK_NEVER 1
2835 #define PNG_HANDLE_CHUNK_IF_SAFE 2
2836 #define PNG_HANDLE_CHUNK_ALWAYS 3
2838 /* Added to version 1.2.0 */
2839 #ifdef PNG_ASSEMBLER_CODE_SUPPORTED
2840 #ifdef PNG_MMX_CODE_SUPPORTED
2841 #define PNG_ASM_FLAG_MMX_SUPPORT_COMPILED 0x01 /* not user-settable */
2842 #define PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU 0x02 /* not user-settable */
2843 #define PNG_ASM_FLAG_MMX_READ_COMBINE_ROW 0x04
2844 #define PNG_ASM_FLAG_MMX_READ_INTERLACE 0x08
2845 #define PNG_ASM_FLAG_MMX_READ_FILTER_SUB 0x10
2846 #define PNG_ASM_FLAG_MMX_READ_FILTER_UP 0x20
2847 #define PNG_ASM_FLAG_MMX_READ_FILTER_AVG 0x40
2848 #define PNG_ASM_FLAG_MMX_READ_FILTER_PAETH 0x80
2849 #define PNG_ASM_FLAGS_INITIALIZED 0x80000000 /* not user-settable */
2851 #define PNG_MMX_READ_FLAGS ( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW \
2852 | PNG_ASM_FLAG_MMX_READ_INTERLACE \
2853 | PNG_ASM_FLAG_MMX_READ_FILTER_SUB \
2854 | PNG_ASM_FLAG_MMX_READ_FILTER_UP \
2855 | PNG_ASM_FLAG_MMX_READ_FILTER_AVG \
2856 | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH )
2857 #define PNG_MMX_WRITE_FLAGS ( 0 )
2859 #define PNG_MMX_FLAGS ( PNG_ASM_FLAG_MMX_SUPPORT_COMPILED \
2860 | PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU \
2861 | PNG_MMX_READ_FLAGS \
2862 | PNG_MMX_WRITE_FLAGS )
2864 #define PNG_SELECT_READ 1
2865 #define PNG_SELECT_WRITE 2
2866 #endif /* PNG_MMX_CODE_SUPPORTED */
2870 extern PNG_EXPORT(png_uint_32, png_get_mmx_flagmask)
2871 PNGARG((int flag_select, int *compilerID));
2874 extern PNG_EXPORT(png_uint_32, png_get_asm_flagmask)
2875 PNGARG((int flag_select));
2878 extern PNG_EXPORT(png_uint_32, png_get_asm_flags)
2879 PNGARG((png_structp png_ptr));
2882 extern PNG_EXPORT(png_byte, png_get_mmx_bitdepth_threshold)
2883 PNGARG((png_structp png_ptr));
2886 extern PNG_EXPORT(png_uint_32, png_get_mmx_rowbytes_threshold)
2887 PNGARG((png_structp png_ptr));
2890 extern PNG_EXPORT(void, png_set_asm_flags)
2891 PNGARG((png_structp png_ptr, png_uint_32 asm_flags));
2894 extern PNG_EXPORT(void, png_set_mmx_thresholds)
2895 PNGARG((png_structp png_ptr, png_byte mmx_bitdepth_threshold,
2896 png_uint_32 mmx_rowbytes_threshold));
2898 #endif /* PNG_1_0_X */
2901 /* png.c, pnggccrd.c, or pngvcrd.c */
2902 extern PNG_EXPORT(int, png_mmx_support) PNGARG((void));
2903 #endif /* PNG_1_0_X */
2904 #endif /* PNG_ASSEMBLER_CODE_SUPPORTED */
2906 /* Strip the prepended error numbers ("#nnn ") from error and warning
2907 * messages before passing them to the error or warning handler.
2909 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
2910 extern PNG_EXPORT(void, png_set_strip_error_numbers) PNGARG((png_structp
2911 png_ptr, png_uint_32 strip_mode));
2914 /* Added at libpng-1.2.6 */
2915 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
2916 extern PNG_EXPORT(void, png_set_user_limits) PNGARG((png_structp
2917 png_ptr, png_uint_32 user_width_max, png_uint_32 user_height_max));
2918 extern PNG_EXPORT(png_uint_32, png_get_user_width_max) PNGARG((png_structp
2920 extern PNG_EXPORT(png_uint_32, png_get_user_height_max) PNGARG((png_structp
2923 /* Maintainer: Put new public prototypes here ^, in libpng.3, and in
2927 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2928 /* With these routines we avoid an integer divide, which will be slower on
2929 * most machines. However, it does take more operations than the corresponding
2930 * divide method, so it may be slower on a few RISC systems. There are two
2931 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2933 * Note that the rounding factors are NOT supposed to be the same! 128 and
2934 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2937 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2940 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2942 # define png_composite(composite, fg, alpha, bg) \
2943 { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) * (png_uint_16)(alpha) \
2944 + (png_uint_16)(bg)*(png_uint_16)(255 - \
2945 (png_uint_16)(alpha)) + (png_uint_16)128); \
2946 (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
2948 # define png_composite_16(composite, fg, alpha, bg) \
2949 { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) * (png_uint_32)(alpha) \
2950 + (png_uint_32)(bg)*(png_uint_32)(65535L - \
2951 (png_uint_32)(alpha)) + (png_uint_32)32768L); \
2952 (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
2954 #else /* Standard method using integer division */
2956 # define png_composite(composite, fg, alpha, bg) \
2957 (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2958 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2959 (png_uint_16)127) / 255)
2961 # define png_composite_16(composite, fg, alpha, bg) \
2962 (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2963 (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) + \
2964 (png_uint_32)32767) / (png_uint_32)65535L)
2966 #endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
2968 /* Inline macros to do direct reads of bytes from the input buffer. These
2969 * require that you are using an architecture that uses PNG byte ordering
2970 * (MSB first) and supports unaligned data storage. I think that PowerPC
2971 * in big-endian mode and 680x0 are the only ones that will support this.
2972 * The x86 line of processors definitely do not. The png_get_int_32()
2973 * routine also assumes we are using two's complement format for negative
2974 * values, which is almost certainly true.
2976 #ifdef PNG_READ_BIG_ENDIAN_SUPPORTED
2977 # define png_get_uint_32(buf) ( *((png_uint_32p) (buf)))
2978 # define png_get_uint_16(buf) ( *((png_uint_16p) (buf)))
2979 # define png_get_int_32(buf) ( *((png_int_32p) (buf)))
2981 extern PNG_EXPORT(png_uint_32, png_get_uint_32) PNGARG((png_bytep buf));
2982 extern PNG_EXPORT(png_uint_16, png_get_uint_16) PNGARG((png_bytep buf));
2983 extern PNG_EXPORT(png_int_32, png_get_int_32) PNGARG((png_bytep buf));
2984 #endif /* !PNG_READ_BIG_ENDIAN_SUPPORTED */
2985 extern PNG_EXPORT(png_uint_32, png_get_uint_31)
2986 PNGARG((png_structp png_ptr, png_bytep buf));
2987 /* No png_get_int_16 -- may be added if there's a real need for it. */
2989 /* Place a 32-bit number into a buffer in PNG byte order (big-endian).
2991 extern PNG_EXPORT(void, png_save_uint_32)
2992 PNGARG((png_bytep buf, png_uint_32 i));
2993 extern PNG_EXPORT(void, png_save_int_32)
2994 PNGARG((png_bytep buf, png_int_32 i));
2996 /* Place a 16-bit number into a buffer in PNG byte order.
2997 * The parameter is declared unsigned int, not png_uint_16,
2998 * just to avoid potential problems on pre-ANSI C compilers.
3000 extern PNG_EXPORT(void, png_save_uint_16)
3001 PNGARG((png_bytep buf, unsigned int i));
3002 /* No png_save_int_16 -- may be added if there's a real need for it. */
3004 /* ************************************************************************* */
3006 /* These next functions are used internally in the code. They generally
3007 * shouldn't be used unless you are writing code to add or replace some
3008 * functionality in libpng. More information about most functions can
3009 * be found in the files where the functions are located.
3013 /* Various modes of operation, that are visible to applications because
3014 * they are used for unknown chunk location.
3016 #define PNG_HAVE_IHDR 0x01
3017 #define PNG_HAVE_PLTE 0x02
3018 #define PNG_HAVE_IDAT 0x04
3019 #define PNG_AFTER_IDAT 0x08 /* Have complete zlib datastream */
3020 #define PNG_HAVE_IEND 0x10
3024 /* More modes of operation. Note that after an init, mode is set to
3025 * zero automatically when the structure is created.
3027 #define PNG_HAVE_gAMA 0x20
3028 #define PNG_HAVE_cHRM 0x40
3029 #define PNG_HAVE_sRGB 0x80
3030 #define PNG_HAVE_CHUNK_HEADER 0x100
3031 #define PNG_WROTE_tIME 0x200
3032 #define PNG_WROTE_INFO_BEFORE_PLTE 0x400
3033 #define PNG_BACKGROUND_IS_GRAY 0x800
3034 #define PNG_HAVE_PNG_SIGNATURE 0x1000
3035 #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
3037 /* Flags for the transformations the PNG library does on the image data */
3038 #define PNG_BGR 0x0001
3039 #define PNG_INTERLACE 0x0002
3040 #define PNG_PACK 0x0004
3041 #define PNG_SHIFT 0x0008
3042 #define PNG_SWAP_BYTES 0x0010
3043 #define PNG_INVERT_MONO 0x0020
3044 #define PNG_DITHER 0x0040
3045 #define PNG_BACKGROUND 0x0080
3046 #define PNG_BACKGROUND_EXPAND 0x0100
3048 #define PNG_16_TO_8 0x0400
3049 #define PNG_RGBA 0x0800
3050 #define PNG_EXPAND 0x1000
3051 #define PNG_GAMMA 0x2000
3052 #define PNG_GRAY_TO_RGB 0x4000
3053 #define PNG_FILLER 0x8000L
3054 #define PNG_PACKSWAP 0x10000L
3055 #define PNG_SWAP_ALPHA 0x20000L
3056 #define PNG_STRIP_ALPHA 0x40000L
3057 #define PNG_INVERT_ALPHA 0x80000L
3058 #define PNG_USER_TRANSFORM 0x100000L
3059 #define PNG_RGB_TO_GRAY_ERR 0x200000L
3060 #define PNG_RGB_TO_GRAY_WARN 0x400000L
3061 #define PNG_RGB_TO_GRAY 0x600000L /* two bits, RGB_TO_GRAY_ERR|WARN */
3062 /* 0x800000L Unused */
3063 #define PNG_ADD_ALPHA 0x1000000L /* Added to libpng-1.2.7 */
3064 #define PNG_EXPAND_tRNS 0x2000000L /* Added to libpng-1.2.9 */
3065 #define PNG_PREMULTIPLY_ALPHA 0x4000000L /* Added to libpng-1.2.41 */
3067 /* 0x8000000L unused */
3068 /* 0x10000000L unused */
3069 /* 0x20000000L unused */
3070 /* 0x40000000L unused */
3072 /* Flags for png_create_struct */
3073 #define PNG_STRUCT_PNG 0x0001
3074 #define PNG_STRUCT_INFO 0x0002
3076 /* Scaling factor for filter heuristic weighting calculations */
3077 #define PNG_WEIGHT_SHIFT 8
3078 #define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
3079 #define PNG_COST_SHIFT 3
3080 #define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
3082 /* Flags for the png_ptr->flags rather than declaring a byte for each one */
3083 #define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001
3084 #define PNG_FLAG_ZLIB_CUSTOM_LEVEL 0x0002
3085 #define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL 0x0004
3086 #define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS 0x0008
3087 #define PNG_FLAG_ZLIB_CUSTOM_METHOD 0x0010
3088 #define PNG_FLAG_ZLIB_FINISHED 0x0020
3089 #define PNG_FLAG_ROW_INIT 0x0040
3090 #define PNG_FLAG_FILLER_AFTER 0x0080
3091 #define PNG_FLAG_CRC_ANCILLARY_USE 0x0100
3092 #define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200
3093 #define PNG_FLAG_CRC_CRITICAL_USE 0x0400
3094 #define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800
3095 #define PNG_FLAG_FREE_PLTE 0x1000
3096 #define PNG_FLAG_FREE_TRNS 0x2000
3097 #define PNG_FLAG_FREE_HIST 0x4000
3098 #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000L
3099 #define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000L
3100 #define PNG_FLAG_LIBRARY_MISMATCH 0x20000L
3101 #define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000L
3102 #define PNG_FLAG_STRIP_ERROR_TEXT 0x80000L
3103 #define PNG_FLAG_MALLOC_NULL_MEM_OK 0x100000L
3104 #define PNG_FLAG_ADD_ALPHA 0x200000L /* Added to libpng-1.2.8 */
3105 #define PNG_FLAG_STRIP_ALPHA 0x400000L /* Added to libpng-1.2.8 */
3106 /* 0x800000L unused */
3107 /* 0x1000000L unused */
3108 /* 0x2000000L unused */
3109 /* 0x4000000L unused */
3110 /* 0x8000000L unused */
3111 /* 0x10000000L unused */
3112 /* 0x20000000L unused */
3113 /* 0x40000000L unused */
3115 #define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
3116 PNG_FLAG_CRC_ANCILLARY_NOWARN)
3118 #define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE | \
3119 PNG_FLAG_CRC_CRITICAL_IGNORE)
3121 #define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK | \
3122 PNG_FLAG_CRC_CRITICAL_MASK)
3124 /* Save typing and make code easier to understand */
3126 #define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
3127 abs((int)((c1).green) - (int)((c2).green)) + \
3128 abs((int)((c1).blue) - (int)((c2).blue)))
3130 /* Added to libpng-1.2.6 JB */
3131 #define PNG_ROWBYTES(pixel_bits, width) \
3132 ((pixel_bits) >= 8 ? \
3133 ((width) * (((png_uint_32)(pixel_bits)) >> 3)) : \
3134 (( ((width) * ((png_uint_32)(pixel_bits))) + 7) >> 3) )
3136 /* PNG_OUT_OF_RANGE returns true if value is outside the range
3137 * ideal-delta..ideal+delta. Each argument is evaluated twice.
3138 * "ideal" and "delta" should be constants, normally simple
3139 * integers, "value" a variable. Added to libpng-1.2.6 JB
3141 #define PNG_OUT_OF_RANGE(value, ideal, delta) \
3142 ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
3144 /* Variables declared in png.c - only it needs to define PNG_NO_EXTERN */
3145 #if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
3146 /* Place to hold the signature string for a PNG file. */
3147 #ifdef PNG_USE_GLOBAL_ARRAYS
3148 PNG_EXPORT_VAR (PNG_CONST png_byte FARDATA) png_sig[8];
3151 #endif /* PNG_NO_EXTERN */
3153 /* Constant strings for known chunk types. If you need to add a chunk,
3154 * define the name here, and add an invocation of the macro in png.c and
3155 * wherever it's needed.
3157 #define PNG_IHDR png_byte png_IHDR[5] = { 73, 72, 68, 82, '\0'}
3158 #define PNG_IDAT png_byte png_IDAT[5] = { 73, 68, 65, 84, '\0'}
3159 #define PNG_IEND png_byte png_IEND[5] = { 73, 69, 78, 68, '\0'}
3160 #define PNG_PLTE png_byte png_PLTE[5] = { 80, 76, 84, 69, '\0'}
3161 #define PNG_bKGD png_byte png_bKGD[5] = { 98, 75, 71, 68, '\0'}
3162 #define PNG_cHRM png_byte png_cHRM[5] = { 99, 72, 82, 77, '\0'}
3163 #define PNG_gAMA png_byte png_gAMA[5] = {103, 65, 77, 65, '\0'}
3164 #define PNG_hIST png_byte png_hIST[5] = {104, 73, 83, 84, '\0'}
3165 #define PNG_iCCP png_byte png_iCCP[5] = {105, 67, 67, 80, '\0'}
3166 #define PNG_iTXt png_byte png_iTXt[5] = {105, 84, 88, 116, '\0'}
3167 #define PNG_oFFs png_byte png_oFFs[5] = {111, 70, 70, 115, '\0'}
3168 #define PNG_pCAL png_byte png_pCAL[5] = {112, 67, 65, 76, '\0'}
3169 #define PNG_sCAL png_byte png_sCAL[5] = {115, 67, 65, 76, '\0'}
3170 #define PNG_pHYs png_byte png_pHYs[5] = {112, 72, 89, 115, '\0'}
3171 #define PNG_sBIT png_byte png_sBIT[5] = {115, 66, 73, 84, '\0'}
3172 #define PNG_sPLT png_byte png_sPLT[5] = {115, 80, 76, 84, '\0'}
3173 #define PNG_sRGB png_byte png_sRGB[5] = {115, 82, 71, 66, '\0'}
3174 #define PNG_tEXt png_byte png_tEXt[5] = {116, 69, 88, 116, '\0'}
3175 #define PNG_tIME png_byte png_tIME[5] = {116, 73, 77, 69, '\0'}
3176 #define PNG_tRNS png_byte png_tRNS[5] = {116, 82, 78, 83, '\0'}
3177 #define PNG_zTXt png_byte png_zTXt[5] = {122, 84, 88, 116, '\0'}
3179 #ifdef PNG_USE_GLOBAL_ARRAYS
3180 PNG_EXPORT_VAR (png_byte FARDATA) png_IHDR[5];
3181 PNG_EXPORT_VAR (png_byte FARDATA) png_IDAT[5];
3182 PNG_EXPORT_VAR (png_byte FARDATA) png_IEND[5];
3183 PNG_EXPORT_VAR (png_byte FARDATA) png_PLTE[5];
3184 PNG_EXPORT_VAR (png_byte FARDATA) png_bKGD[5];
3185 PNG_EXPORT_VAR (png_byte FARDATA) png_cHRM[5];
3186 PNG_EXPORT_VAR (png_byte FARDATA) png_gAMA[5];
3187 PNG_EXPORT_VAR (png_byte FARDATA) png_hIST[5];
3188 PNG_EXPORT_VAR (png_byte FARDATA) png_iCCP[5];
3189 PNG_EXPORT_VAR (png_byte FARDATA) png_iTXt[5];
3190 PNG_EXPORT_VAR (png_byte FARDATA) png_oFFs[5];
3191 PNG_EXPORT_VAR (png_byte FARDATA) png_pCAL[5];
3192 PNG_EXPORT_VAR (png_byte FARDATA) png_sCAL[5];
3193 PNG_EXPORT_VAR (png_byte FARDATA) png_pHYs[5];
3194 PNG_EXPORT_VAR (png_byte FARDATA) png_sBIT[5];
3195 PNG_EXPORT_VAR (png_byte FARDATA) png_sPLT[5];
3196 PNG_EXPORT_VAR (png_byte FARDATA) png_sRGB[5];
3197 PNG_EXPORT_VAR (png_byte FARDATA) png_tEXt[5];
3198 PNG_EXPORT_VAR (png_byte FARDATA) png_tIME[5];
3199 PNG_EXPORT_VAR (png_byte FARDATA) png_tRNS[5];
3200 PNG_EXPORT_VAR (png_byte FARDATA) png_zTXt[5];
3201 #endif /* PNG_USE_GLOBAL_ARRAYS */
3203 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
3204 /* Initialize png_ptr struct for reading, and allocate any other memory.
3205 * (old interface - DEPRECATED - use png_create_read_struct instead).
3207 extern PNG_EXPORT(void, png_read_init) PNGARG((png_structp png_ptr))
3209 #undef png_read_init
3210 #define png_read_init(png_ptr) png_read_init_3(&png_ptr, \
3211 PNG_LIBPNG_VER_STRING, png_sizeof(png_struct));
3214 extern PNG_EXPORT(void, png_read_init_3) PNGARG((png_structpp ptr_ptr,
3215 png_const_charp user_png_ver, png_size_t png_struct_size));
3216 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
3217 extern PNG_EXPORT(void, png_read_init_2) PNGARG((png_structp png_ptr,
3218 png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
3222 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
3223 /* Initialize png_ptr struct for writing, and allocate any other memory.
3224 * (old interface - DEPRECATED - use png_create_write_struct instead).
3226 extern PNG_EXPORT(void, png_write_init) PNGARG((png_structp png_ptr))
3228 #undef png_write_init
3229 #define png_write_init(png_ptr) png_write_init_3(&png_ptr, \
3230 PNG_LIBPNG_VER_STRING, png_sizeof(png_struct));
3233 extern PNG_EXPORT(void, png_write_init_3) PNGARG((png_structpp ptr_ptr,
3234 png_const_charp user_png_ver, png_size_t png_struct_size));
3235 extern PNG_EXPORT(void, png_write_init_2) PNGARG((png_structp png_ptr,
3236 png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
3239 /* Allocate memory for an internal libpng struct */
3240 PNG_EXTERN png_voidp png_create_struct PNGARG((int type)) PNG_PRIVATE;
3242 /* Free memory from internal libpng struct */
3243 PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr)) PNG_PRIVATE;
3245 PNG_EXTERN png_voidp png_create_struct_2 PNGARG((int type, png_malloc_ptr
3246 malloc_fn, png_voidp mem_ptr)) PNG_PRIVATE;
3247 PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr,
3248 png_free_ptr free_fn, png_voidp mem_ptr)) PNG_PRIVATE;
3250 /* Free any memory that info_ptr points to and reset struct. */
3251 PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr,
3252 png_infop info_ptr)) PNG_PRIVATE;
3255 /* Function to allocate memory for zlib. */
3256 PNG_EXTERN voidpf png_zalloc PNGARG((voidpf png_ptr, uInt items,
3257 uInt size)) PNG_PRIVATE;
3259 /* Function to free memory for zlib */
3260 PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr)) PNG_PRIVATE;
3263 /* Function to convert a sizeof an item to png_sizeof item */
3264 PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size))
3268 /* Next four functions are used internally as callbacks. PNGAPI is required
3269 * but not PNG_EXPORT. PNGAPI added at libpng version 1.2.3.
3272 PNG_EXTERN void PNGAPI png_default_read_data PNGARG((png_structp png_ptr,
3273 png_bytep data, png_size_t length)) PNG_PRIVATE;
3275 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3276 PNG_EXTERN void PNGAPI png_push_fill_buffer PNGARG((png_structp png_ptr,
3277 png_bytep buffer, png_size_t length)) PNG_PRIVATE;
3280 PNG_EXTERN void PNGAPI png_default_write_data PNGARG((png_structp png_ptr,
3281 png_bytep data, png_size_t length)) PNG_PRIVATE;
3283 #ifdef PNG_WRITE_FLUSH_SUPPORTED
3284 #ifdef PNG_STDIO_SUPPORTED
3285 PNG_EXTERN void PNGAPI png_default_flush PNGARG((png_structp png_ptr))
3289 #else /* PNG_1_0_X */
3290 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3291 PNG_EXTERN void png_push_fill_buffer PNGARG((png_structp png_ptr,
3292 png_bytep buffer, png_size_t length)) PNG_PRIVATE;
3294 #endif /* PNG_1_0_X */
3296 /* Reset the CRC variable */
3297 PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3299 /* Write the "data" buffer to whatever output you are using. */
3300 PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr, png_bytep data,
3301 png_size_t length)) PNG_PRIVATE;
3303 /* Read data from whatever input you are using into the "data" buffer */
3304 PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data,
3305 png_size_t length)) PNG_PRIVATE;
3307 /* Read bytes into buf, and update png_ptr->crc */
3308 PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
3309 png_size_t length)) PNG_PRIVATE;
3311 /* Decompress data in a chunk that uses compression */
3312 #if defined(PNG_zTXt_SUPPORTED) || defined(PNG_iTXt_SUPPORTED) || \
3313 defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED)
3314 PNG_EXTERN void png_decompress_chunk PNGARG((png_structp png_ptr,
3315 int comp_type, png_size_t chunklength,
3316 png_size_t prefix_length, png_size_t *data_length)) PNG_PRIVATE;
3319 /* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
3320 PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip)
3323 /* Read the CRC from the file and compare it to the libpng calculated CRC */
3324 PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3326 /* Calculate the CRC over a section of data. Note that we are only
3327 * passing a maximum of 64K on systems that have this as a memory limit,
3328 * since this is the maximum buffer size we can specify.
3330 PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr, png_bytep ptr,
3331 png_size_t length)) PNG_PRIVATE;
3333 #ifdef PNG_WRITE_FLUSH_SUPPORTED
3334 PNG_EXTERN void png_flush PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3337 /* Simple function to write the signature */
3338 PNG_EXTERN void png_write_sig PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3340 /* Write various chunks */
3342 /* Write the IHDR chunk, and update the png_struct with the necessary
3345 PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width,
3347 int bit_depth, int color_type, int compression_method, int filter_method,
3348 int interlace_method)) PNG_PRIVATE;
3350 PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr, png_colorp palette,
3351 png_uint_32 num_pal)) PNG_PRIVATE;
3353 PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data,
3354 png_size_t length)) PNG_PRIVATE;
3356 PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3358 #ifdef PNG_WRITE_gAMA_SUPPORTED
3359 #ifdef PNG_FLOATING_POINT_SUPPORTED
3360 PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma))
3363 #ifdef PNG_FIXED_POINT_SUPPORTED
3364 PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr,
3365 png_fixed_point file_gamma)) PNG_PRIVATE;
3369 #ifdef PNG_WRITE_sBIT_SUPPORTED
3370 PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr, png_color_8p sbit,
3371 int color_type)) PNG_PRIVATE;
3374 #ifdef PNG_WRITE_cHRM_SUPPORTED
3375 #ifdef PNG_FLOATING_POINT_SUPPORTED
3376 PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr,
3377 double white_x, double white_y,
3378 double red_x, double red_y, double green_x, double green_y,
3379 double blue_x, double blue_y)) PNG_PRIVATE;
3381 #ifdef PNG_FIXED_POINT_SUPPORTED
3382 PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr,
3383 png_fixed_point int_white_x, png_fixed_point int_white_y,
3384 png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
3385 int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
3386 png_fixed_point int_blue_y)) PNG_PRIVATE;
3390 #ifdef PNG_WRITE_sRGB_SUPPORTED
3391 PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
3392 int intent)) PNG_PRIVATE;
3395 #ifdef PNG_WRITE_iCCP_SUPPORTED
3396 PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr,
3397 png_charp name, int compression_type,
3398 png_charp profile, int proflen)) PNG_PRIVATE;
3399 /* Note to maintainer: profile should be png_bytep */
3402 #ifdef PNG_WRITE_sPLT_SUPPORTED
3403 PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr,
3404 png_sPLT_tp palette)) PNG_PRIVATE;
3407 #ifdef PNG_WRITE_tRNS_SUPPORTED
3408 PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr, png_bytep trans,
3409 png_color_16p values, int number, int color_type)) PNG_PRIVATE;
3412 #ifdef PNG_WRITE_bKGD_SUPPORTED
3413 PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr,
3414 png_color_16p values, int color_type)) PNG_PRIVATE;
3417 #ifdef PNG_WRITE_hIST_SUPPORTED
3418 PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, png_uint_16p hist,
3419 int num_hist)) PNG_PRIVATE;
3422 #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
3423 defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
3424 PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
3425 png_charp key, png_charpp new_key)) PNG_PRIVATE;
3428 #ifdef PNG_WRITE_tEXt_SUPPORTED
3429 PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_charp key,
3430 png_charp text, png_size_t text_len)) PNG_PRIVATE;
3433 #ifdef PNG_WRITE_zTXt_SUPPORTED
3434 PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_charp key,
3435 png_charp text, png_size_t text_len, int compression)) PNG_PRIVATE;
3438 #ifdef PNG_WRITE_iTXt_SUPPORTED
3439 PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr,
3440 int compression, png_charp key, png_charp lang, png_charp lang_key,
3441 png_charp text)) PNG_PRIVATE;
3444 #ifdef PNG_TEXT_SUPPORTED /* Added at version 1.0.14 and 1.2.4 */
3445 PNG_EXTERN int png_set_text_2 PNGARG((png_structp png_ptr,
3446 png_infop info_ptr, png_textp text_ptr, int num_text)) PNG_PRIVATE;
3449 #ifdef PNG_WRITE_oFFs_SUPPORTED
3450 PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr,
3451 png_int_32 x_offset, png_int_32 y_offset, int unit_type)) PNG_PRIVATE;
3454 #ifdef PNG_WRITE_pCAL_SUPPORTED
3455 PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose,
3456 png_int_32 X0, png_int_32 X1, int type, int nparams,
3457 png_charp units, png_charpp params)) PNG_PRIVATE;
3460 #ifdef PNG_WRITE_pHYs_SUPPORTED
3461 PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr,
3462 png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
3463 int unit_type)) PNG_PRIVATE;
3466 #ifdef PNG_WRITE_tIME_SUPPORTED
3467 PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr,
3468 png_timep mod_time)) PNG_PRIVATE;
3471 #ifdef PNG_WRITE_sCAL_SUPPORTED
3472 #if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
3473 PNG_EXTERN void png_write_sCAL PNGARG((png_structp png_ptr,
3474 int unit, double width, double height)) PNG_PRIVATE;
3476 #ifdef PNG_FIXED_POINT_SUPPORTED
3477 PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr,
3478 int unit, png_charp width, png_charp height)) PNG_PRIVATE;
3483 /* Called when finished processing a row of data */
3484 PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3486 /* Internal use only. Called before first row of data */
3487 PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3489 #ifdef PNG_READ_GAMMA_SUPPORTED
3490 PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3493 /* Combine a row of data, dealing with alpha, etc. if requested */
3494 PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row,
3495 int mask)) PNG_PRIVATE;
3497 #ifdef PNG_READ_INTERLACING_SUPPORTED
3498 /* Expand an interlaced row */
3499 /* OLD pre-1.0.9 interface:
3500 PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info,
3501 png_bytep row, int pass, png_uint_32 transformations)) PNG_PRIVATE;
3503 PNG_EXTERN void png_do_read_interlace PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3506 /* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */
3508 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
3509 /* Grab pixels out of a row for an interlaced pass */
3510 PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info,
3511 png_bytep row, int pass)) PNG_PRIVATE;
3514 /* Unfilter a row */
3515 PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr,
3516 png_row_infop row_info, png_bytep row, png_bytep prev_row,
3517 int filter)) PNG_PRIVATE;
3519 /* Choose the best filter to use and filter the row data */
3520 PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
3521 png_row_infop row_info)) PNG_PRIVATE;
3523 /* Write out the filtered row. */
3524 PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr,
3525 png_bytep filtered_row)) PNG_PRIVATE;
3526 /* Finish a row while reading, dealing with interlacing passes, etc. */
3527 PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
3529 /* Initialize the row buffers, etc. */
3530 PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3531 /* Optional call to update the users info structure */
3532 PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
3533 png_infop info_ptr)) PNG_PRIVATE;
3535 /* These are the functions that do the transformations */
3536 #ifdef PNG_READ_FILLER_SUPPORTED
3537 PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info,
3538 png_bytep row, png_uint_32 filler, png_uint_32 flags)) PNG_PRIVATE;
3541 #ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
3542 PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info,
3543 png_bytep row)) PNG_PRIVATE;
3546 #ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
3547 PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info,
3548 png_bytep row)) PNG_PRIVATE;
3551 #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
3552 PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info,
3553 png_bytep row)) PNG_PRIVATE;
3556 #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
3557 PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info,
3558 png_bytep row)) PNG_PRIVATE;
3561 #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
3562 defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
3563 PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info,
3564 png_bytep row, png_uint_32 flags)) PNG_PRIVATE;
3567 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
3568 PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info,
3569 png_bytep row)) PNG_PRIVATE;
3572 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
3573 PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info,
3574 png_bytep row)) PNG_PRIVATE;
3577 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
3578 PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr, png_row_infop
3579 row_info, png_bytep row)) PNG_PRIVATE;
3582 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
3583 PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info,
3584 png_bytep row)) PNG_PRIVATE;
3587 #ifdef PNG_READ_PACK_SUPPORTED
3588 PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info,
3589 png_bytep row)) PNG_PRIVATE;
3592 #ifdef PNG_READ_SHIFT_SUPPORTED
3593 PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info, png_bytep row,
3594 png_color_8p sig_bits)) PNG_PRIVATE;
3597 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
3598 PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info,
3599 png_bytep row)) PNG_PRIVATE;
3602 #ifdef PNG_READ_16_TO_8_SUPPORTED
3603 PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info,
3604 png_bytep row)) PNG_PRIVATE;
3607 #ifdef PNG_READ_DITHER_SUPPORTED
3608 PNG_EXTERN void png_do_dither PNGARG((png_row_infop row_info,
3609 png_bytep row, png_bytep palette_lookup,
3610 png_bytep dither_lookup)) PNG_PRIVATE;
3612 # ifdef PNG_CORRECT_PALETTE_SUPPORTED
3613 PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr,
3614 png_colorp palette, int num_palette)) PNG_PRIVATE;
3618 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
3619 PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info,
3620 png_bytep row)) PNG_PRIVATE;
3623 #ifdef PNG_WRITE_PACK_SUPPORTED
3624 PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info,
3625 png_bytep row, png_uint_32 bit_depth)) PNG_PRIVATE;
3628 #ifdef PNG_WRITE_SHIFT_SUPPORTED
3629 PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info, png_bytep row,
3630 png_color_8p bit_depth)) PNG_PRIVATE;
3633 #ifdef PNG_READ_BACKGROUND_SUPPORTED
3634 #ifdef PNG_READ_GAMMA_SUPPORTED
3635 PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
3636 png_color_16p trans_values, png_color_16p background,
3637 png_color_16p background_1,
3638 png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,
3639 png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,
3640 png_uint_16pp gamma_16_to_1, int gamma_shift)) PNG_PRIVATE;
3642 PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
3643 png_color_16p trans_values, png_color_16p background)) PNG_PRIVATE;
3647 #ifdef PNG_READ_GAMMA_SUPPORTED
3648 PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info, png_bytep row,
3649 png_bytep gamma_table, png_uint_16pp gamma_16_table,
3650 int gamma_shift)) PNG_PRIVATE;
3653 #ifdef PNG_READ_EXPAND_SUPPORTED
3654 PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info,
3655 png_bytep row, png_colorp palette, png_bytep trans,
3656 int num_trans)) PNG_PRIVATE;
3657 PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info,
3658 png_bytep row, png_color_16p trans_value)) PNG_PRIVATE;
3661 /* The following decodes the appropriate chunks, and does error correction,
3662 * then calls the appropriate callback for the chunk if it is valid.
3665 /* Decode the IHDR chunk */
3666 PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr,
3667 png_uint_32 length)) PNG_PRIVATE;
3668 PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr,
3669 png_uint_32 length));
3670 PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr,
3671 png_uint_32 length));
3673 #ifdef PNG_READ_bKGD_SUPPORTED
3674 PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr,
3675 png_uint_32 length)) PNG_PRIVATE;
3678 #ifdef PNG_READ_cHRM_SUPPORTED
3679 PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr,
3680 png_uint_32 length)) PNG_PRIVATE;
3683 #ifdef PNG_READ_gAMA_SUPPORTED
3684 PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr,
3685 png_uint_32 length)) PNG_PRIVATE;
3688 #ifdef PNG_READ_hIST_SUPPORTED
3689 PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr,
3690 png_uint_32 length)) PNG_PRIVATE;
3693 #ifdef PNG_READ_iCCP_SUPPORTED
3694 extern void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr,
3695 png_uint_32 length));
3696 #endif /* PNG_READ_iCCP_SUPPORTED */
3698 #ifdef PNG_READ_iTXt_SUPPORTED
3699 PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3700 png_uint_32 length)) PNG_PRIVATE;
3703 #ifdef PNG_READ_oFFs_SUPPORTED
3704 PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr,
3705 png_uint_32 length)) PNG_PRIVATE;
3708 #ifdef PNG_READ_pCAL_SUPPORTED
3709 PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
3710 png_uint_32 length)) PNG_PRIVATE;
3713 #ifdef PNG_READ_pHYs_SUPPORTED
3714 PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr,
3715 png_uint_32 length)) PNG_PRIVATE;
3718 #ifdef PNG_READ_sBIT_SUPPORTED
3719 PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr,
3720 png_uint_32 length)) PNG_PRIVATE;
3723 #ifdef PNG_READ_sCAL_SUPPORTED
3724 PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
3725 png_uint_32 length)) PNG_PRIVATE;
3728 #ifdef PNG_READ_sPLT_SUPPORTED
3729 extern void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr,
3730 png_uint_32 length)) PNG_PRIVATE;
3731 #endif /* PNG_READ_sPLT_SUPPORTED */
3733 #ifdef PNG_READ_sRGB_SUPPORTED
3734 PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr,
3735 png_uint_32 length)) PNG_PRIVATE;
3738 #ifdef PNG_READ_tEXt_SUPPORTED
3739 PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3740 png_uint_32 length)) PNG_PRIVATE;
3743 #ifdef PNG_READ_tIME_SUPPORTED
3744 PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr,
3745 png_uint_32 length)) PNG_PRIVATE;
3748 #ifdef PNG_READ_tRNS_SUPPORTED
3749 PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr,
3750 png_uint_32 length)) PNG_PRIVATE;
3753 #ifdef PNG_READ_zTXt_SUPPORTED
3754 PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3755 png_uint_32 length)) PNG_PRIVATE;
3758 PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
3759 png_infop info_ptr, png_uint_32 length)) PNG_PRIVATE;
3761 PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
3762 png_bytep chunk_name)) PNG_PRIVATE;
3764 /* Handle the transformations for reading and writing */
3765 PNG_EXTERN void png_do_read_transformations
3766 PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3767 PNG_EXTERN void png_do_write_transformations
3768 PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3770 PNG_EXTERN void png_init_read_transformations
3771 PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3773 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3774 PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
3775 png_infop info_ptr)) PNG_PRIVATE;
3776 PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr,
3777 png_infop info_ptr)) PNG_PRIVATE;
3778 PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3779 PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr,
3780 png_uint_32 length)) PNG_PRIVATE;
3781 PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3782 PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3783 PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr,
3784 png_bytep buffer, png_size_t buffer_length)) PNG_PRIVATE;
3785 PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3786 PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr,
3787 png_bytep buffer, png_size_t buffer_length)) PNG_PRIVATE;
3788 PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3789 PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr,
3790 png_infop info_ptr, png_uint_32 length)) PNG_PRIVATE;
3791 PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr,
3792 png_infop info_ptr)) PNG_PRIVATE;
3793 PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr,
3794 png_infop info_ptr)) PNG_PRIVATE;
3795 PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr,
3796 png_bytep row)) PNG_PRIVATE;
3797 PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr,
3798 png_infop info_ptr)) PNG_PRIVATE;
3799 PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr,
3800 png_infop info_ptr)) PNG_PRIVATE;
3801 PNG_EXTERN void png_read_push_finish_row
3802 PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3803 #ifdef PNG_READ_tEXt_SUPPORTED
3804 PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr,
3805 png_infop info_ptr, png_uint_32 length)) PNG_PRIVATE;
3806 PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr,
3807 png_infop info_ptr)) PNG_PRIVATE;
3809 #ifdef PNG_READ_zTXt_SUPPORTED
3810 PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr,
3811 png_infop info_ptr, png_uint_32 length)) PNG_PRIVATE;
3812 PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr,
3813 png_infop info_ptr)) PNG_PRIVATE;
3815 #ifdef PNG_READ_iTXt_SUPPORTED
3816 PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr,
3817 png_infop info_ptr, png_uint_32 length)) PNG_PRIVATE;
3818 PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr,
3819 png_infop info_ptr)) PNG_PRIVATE;
3822 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
3824 #ifdef PNG_MNG_FEATURES_SUPPORTED
3825 PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info,
3826 png_bytep row)) PNG_PRIVATE;
3827 PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info,
3828 png_bytep row)) PNG_PRIVATE;
3831 #ifdef PNG_ASSEMBLER_CODE_SUPPORTED
3832 #ifdef PNG_MMX_CODE_SUPPORTED
3833 /* png.c */ /* PRIVATE */
3834 PNG_EXTERN void png_init_mmx_flags PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3839 /* The following six functions will be exported in libpng-1.4.0. */
3840 #if defined(PNG_INCH_CONVERSIONS) && defined(PNG_FLOATING_POINT_SUPPORTED)
3841 PNG_EXTERN png_uint_32 png_get_pixels_per_inch PNGARG((png_structp png_ptr,
3842 png_infop info_ptr));
3844 PNG_EXTERN png_uint_32 png_get_x_pixels_per_inch PNGARG((png_structp png_ptr,
3845 png_infop info_ptr));
3847 PNG_EXTERN png_uint_32 png_get_y_pixels_per_inch PNGARG((png_structp png_ptr,
3848 png_infop info_ptr));
3850 PNG_EXTERN float png_get_x_offset_inches PNGARG((png_structp png_ptr,
3851 png_infop info_ptr));
3853 PNG_EXTERN float png_get_y_offset_inches PNGARG((png_structp png_ptr,
3854 png_infop info_ptr));
3856 #ifdef PNG_pHYs_SUPPORTED
3857 PNG_EXTERN png_uint_32 png_get_pHYs_dpi PNGARG((png_structp png_ptr,
3858 png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
3859 #endif /* PNG_pHYs_SUPPORTED */
3860 #endif /* PNG_INCH_CONVERSIONS && PNG_FLOATING_POINT_SUPPORTED */
3862 /* Read the chunk header (length + type name) */
3863 PNG_EXTERN png_uint_32 png_read_chunk_header
3864 PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3866 /* Added at libpng version 1.2.34 */
3867 #ifdef PNG_cHRM_SUPPORTED
3868 PNG_EXTERN int png_check_cHRM_fixed PNGARG((png_structp png_ptr,
3869 png_fixed_point int_white_x, png_fixed_point int_white_y,
3870 png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
3871 int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
3872 png_fixed_point int_blue_y)) PNG_PRIVATE;
3875 #ifdef PNG_cHRM_SUPPORTED
3876 #ifdef PNG_CHECK_cHRM_SUPPORTED
3877 /* Added at libpng version 1.2.34 */
3878 PNG_EXTERN void png_64bit_product PNGARG((long v1, long v2,
3879 unsigned long *hi_product, unsigned long *lo_product)) PNG_PRIVATE;
3883 /* Added at libpng version 1.2.41 */
3884 PNG_EXTERN void png_check_IHDR PNGARG((png_structp png_ptr,
3885 png_uint_32 width, png_uint_32 height, int bit_depth,
3886 int color_type, int interlace_type, int compression_type,
3887 int filter_type)) PNG_PRIVATE;
3889 /* Added at libpng version 1.2.41 */
3890 PNG_EXTERN png_voidp png_calloc PNGARG((png_structp png_ptr,
3893 /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
3895 #endif /* PNG_INTERNAL */
3901 #endif /* PNG_VERSION_INFO_ONLY */
3902 /* Do not put anything past this line */
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