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2/* png.h - header file for PNG reference library
3 *
4 * libpng version 1.5.7 - December 15, 2011
5 * Copyright (c) 1998-2011 Glenn Randers-Pehrson
6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
8 *
9 * This code is released under the libpng license (See LICENSE, below)
10 *
11 * Authors and maintainers:
12 * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
13 * libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
14 * libpng versions 0.97, January 1998, through 1.5.7 - December 15, 2011: Glenn
15 * See also "Contributing Authors", below.
16 *
17 * Note about libpng version numbers:
18 *
19 * Due to various miscommunications, unforeseen code incompatibilities
20 * and occasional factors outside the authors' control, version numbering
21 * on the library has not always been consistent and straightforward.
22 * The following table summarizes matters since version 0.89c, which was
23 * the first widely used release:
24 *
25 * source png.h png.h shared-lib
26 * version string int version
27 * ------- ------ ----- ----------
28 * 0.89c "1.0 beta 3" 0.89 89 1.0.89
29 * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]
30 * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]
31 * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]
32 * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]
33 * 0.97c 0.97 97 2.0.97
34 * 0.98 0.98 98 2.0.98
35 * 0.99 0.99 98 2.0.99
36 * 0.99a-m 0.99 99 2.0.99
37 * 1.00 1.00 100 2.1.0 [100 should be 10000]
38 * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]
39 * 1.0.1 png.h string is 10001 2.1.0
40 * 1.0.1a-e identical to the 10002 from here on, the shared library
41 * 1.0.2 source version) 10002 is 2.V where V is the source code
42 * 1.0.2a-b 10003 version, except as noted.
43 * 1.0.3 10003
44 * 1.0.3a-d 10004
45 * 1.0.4 10004
46 * 1.0.4a-f 10005
47 * 1.0.5 (+ 2 patches) 10005
48 * 1.0.5a-d 10006
49 * 1.0.5e-r 10100 (not source compatible)
50 * 1.0.5s-v 10006 (not binary compatible)
51 * 1.0.6 (+ 3 patches) 10006 (still binary incompatible)
52 * 1.0.6d-f 10007 (still binary incompatible)
53 * 1.0.6g 10007
54 * 1.0.6h 10007 10.6h (testing xy.z so-numbering)
55 * 1.0.6i 10007 10.6i
56 * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
57 * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)
58 * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
59 * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
60 * 1.0.7 1 10007 (still compatible)
61 * 1.0.8beta1-4 1 10008 2.1.0.8beta1-4
62 * 1.0.8rc1 1 10008 2.1.0.8rc1
63 * 1.0.8 1 10008 2.1.0.8
64 * 1.0.9beta1-6 1 10009 2.1.0.9beta1-6
65 * 1.0.9rc1 1 10009 2.1.0.9rc1
66 * 1.0.9beta7-10 1 10009 2.1.0.9beta7-10
67 * 1.0.9rc2 1 10009 2.1.0.9rc2
68 * 1.0.9 1 10009 2.1.0.9
69 * 1.0.10beta1 1 10010 2.1.0.10beta1
70 * 1.0.10rc1 1 10010 2.1.0.10rc1
71 * 1.0.10 1 10010 2.1.0.10
72 * 1.0.11beta1-3 1 10011 2.1.0.11beta1-3
73 * 1.0.11rc1 1 10011 2.1.0.11rc1
74 * 1.0.11 1 10011 2.1.0.11
75 * 1.0.12beta1-2 2 10012 2.1.0.12beta1-2
76 * 1.0.12rc1 2 10012 2.1.0.12rc1
77 * 1.0.12 2 10012 2.1.0.12
78 * 1.1.0a-f - 10100 2.1.1.0a-f (branch abandoned)
79 * 1.2.0beta1-2 2 10200 2.1.2.0beta1-2
80 * 1.2.0beta3-5 3 10200 3.1.2.0beta3-5
81 * 1.2.0rc1 3 10200 3.1.2.0rc1
82 * 1.2.0 3 10200 3.1.2.0
83 * 1.2.1beta1-4 3 10201 3.1.2.1beta1-4
84 * 1.2.1rc1-2 3 10201 3.1.2.1rc1-2
85 * 1.2.1 3 10201 3.1.2.1
86 * 1.2.2beta1-6 12 10202 12.so.0.1.2.2beta1-6
87 * 1.0.13beta1 10 10013 10.so.0.1.0.13beta1
88 * 1.0.13rc1 10 10013 10.so.0.1.0.13rc1
89 * 1.2.2rc1 12 10202 12.so.0.1.2.2rc1
90 * 1.0.13 10 10013 10.so.0.1.0.13
91 * 1.2.2 12 10202 12.so.0.1.2.2
92 * 1.2.3rc1-6 12 10203 12.so.0.1.2.3rc1-6
93 * 1.2.3 12 10203 12.so.0.1.2.3
94 * 1.2.4beta1-3 13 10204 12.so.0.1.2.4beta1-3
95 * 1.0.14rc1 13 10014 10.so.0.1.0.14rc1
96 * 1.2.4rc1 13 10204 12.so.0.1.2.4rc1
97 * 1.0.14 10 10014 10.so.0.1.0.14
98 * 1.2.4 13 10204 12.so.0.1.2.4
99 * 1.2.5beta1-2 13 10205 12.so.0.1.2.5beta1-2
100 * 1.0.15rc1-3 10 10015 10.so.0.1.0.15rc1-3
101 * 1.2.5rc1-3 13 10205 12.so.0.1.2.5rc1-3
102 * 1.0.15 10 10015 10.so.0.1.0.15
103 * 1.2.5 13 10205 12.so.0.1.2.5
104 * 1.2.6beta1-4 13 10206 12.so.0.1.2.6beta1-4
105 * 1.0.16 10 10016 10.so.0.1.0.16
106 * 1.2.6 13 10206 12.so.0.1.2.6
107 * 1.2.7beta1-2 13 10207 12.so.0.1.2.7beta1-2
108 * 1.0.17rc1 10 10017 12.so.0.1.0.17rc1
109 * 1.2.7rc1 13 10207 12.so.0.1.2.7rc1
110 * 1.0.17 10 10017 12.so.0.1.0.17
111 * 1.2.7 13 10207 12.so.0.1.2.7
112 * 1.2.8beta1-5 13 10208 12.so.0.1.2.8beta1-5
113 * 1.0.18rc1-5 10 10018 12.so.0.1.0.18rc1-5
114 * 1.2.8rc1-5 13 10208 12.so.0.1.2.8rc1-5
115 * 1.0.18 10 10018 12.so.0.1.0.18
116 * 1.2.8 13 10208 12.so.0.1.2.8
117 * 1.2.9beta1-3 13 10209 12.so.0.1.2.9beta1-3
118 * 1.2.9beta4-11 13 10209 12.so.0.9[.0]
119 * 1.2.9rc1 13 10209 12.so.0.9[.0]
120 * 1.2.9 13 10209 12.so.0.9[.0]
121 * 1.2.10beta1-7 13 10210 12.so.0.10[.0]
122 * 1.2.10rc1-2 13 10210 12.so.0.10[.0]
123 * 1.2.10 13 10210 12.so.0.10[.0]
124 * 1.4.0beta1-5 14 10400 14.so.0.0[.0]
125 * 1.2.11beta1-4 13 10211 12.so.0.11[.0]
126 * 1.4.0beta7-8 14 10400 14.so.0.0[.0]
127 * 1.2.11 13 10211 12.so.0.11[.0]
128 * 1.2.12 13 10212 12.so.0.12[.0]
129 * 1.4.0beta9-14 14 10400 14.so.0.0[.0]
130 * 1.2.13 13 10213 12.so.0.13[.0]
131 * 1.4.0beta15-36 14 10400 14.so.0.0[.0]
132 * 1.4.0beta37-87 14 10400 14.so.14.0[.0]
133 * 1.4.0rc01 14 10400 14.so.14.0[.0]
134 * 1.4.0beta88-109 14 10400 14.so.14.0[.0]
135 * 1.4.0rc02-08 14 10400 14.so.14.0[.0]
136 * 1.4.0 14 10400 14.so.14.0[.0]
137 * 1.4.1beta01-03 14 10401 14.so.14.1[.0]
138 * 1.4.1rc01 14 10401 14.so.14.1[.0]
139 * 1.4.1beta04-12 14 10401 14.so.14.1[.0]
140 * 1.4.1 14 10401 14.so.14.1[.0]
141 * 1.4.2 14 10402 14.so.14.2[.0]
142 * 1.4.3 14 10403 14.so.14.3[.0]
143 * 1.4.4 14 10404 14.so.14.4[.0]
144 * 1.5.0beta01-58 15 10500 15.so.15.0[.0]
145 * 1.5.0rc01-07 15 10500 15.so.15.0[.0]
146 * 1.5.0 15 10500 15.so.15.0[.0]
147 * 1.5.1beta01-11 15 10501 15.so.15.1[.0]
148 * 1.5.1rc01-02 15 10501 15.so.15.1[.0]
149 * 1.5.1 15 10501 15.so.15.1[.0]
150 * 1.5.2beta01-03 15 10502 15.so.15.2[.0]
151 * 1.5.2rc01-03 15 10502 15.so.15.2[.0]
152 * 1.5.2 15 10502 15.so.15.2[.0]
153 * 1.5.3beta01-10 15 10503 15.so.15.3[.0]
154 * 1.5.3rc01-02 15 10503 15.so.15.3[.0]
155 * 1.5.3beta11 15 10503 15.so.15.3[.0]
156 * 1.5.3 [omitted]
157 * 1.5.4beta01-08 15 10504 15.so.15.4[.0]
158 * 1.5.4rc01 15 10504 15.so.15.4[.0]
159 * 1.5.4 15 10504 15.so.15.4[.0]
160 * 1.5.5beta01-08 15 10505 15.so.15.5[.0]
161 * 1.5.5rc01 15 10505 15.so.15.5[.0]
162 * 1.5.5 15 10505 15.so.15.5[.0]
163 * 1.5.6beta01-07 15 10506 15.so.15.6[.0]
164 * 1.5.6rc01-03 15 10506 15.so.15.6[.0]
165 * 1.5.6 15 10506 15.so.15.6[.0]
166 * 1.5.7beta01-05 15 10507 15.so.15.7[.0]
167 * 1.5.7rc01-03 15 10507 15.so.15.7[.0]
168 * 1.5.7 15 10507 15.so.15.7[.0]
169 *
170 * Henceforth the source version will match the shared-library major
171 * and minor numbers; the shared-library major version number will be
172 * used for changes in backward compatibility, as it is intended. The
173 * PNG_LIBPNG_VER macro, which is not used within libpng but is available
174 * for applications, is an unsigned integer of the form xyyzz corresponding
175 * to the source version x.y.z (leading zeros in y and z). Beta versions
176 * were given the previous public release number plus a letter, until
177 * version 1.0.6j; from then on they were given the upcoming public
178 * release number plus "betaNN" or "rcN".
179 *
180 * Binary incompatibility exists only when applications make direct access
181 * to the info_ptr or png_ptr members through png.h, and the compiled
182 * application is loaded with a different version of the library.
183 *
184 * DLLNUM will change each time there are forward or backward changes
185 * in binary compatibility (e.g., when a new feature is added).
186 *
187 * See libpng-manual.txt or libpng.3 for more information. The PNG
188 * specification is available as a W3C Recommendation and as an ISO
189 * Specification, <http://www.w3.org/TR/2003/REC-PNG-20031110/
190 */
191
192/*
193 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
194 *
195 * If you modify libpng you may insert additional notices immediately following
196 * this sentence.
197 *
198 * This code is released under the libpng license.
199 *
200 * libpng versions 1.2.6, August 15, 2004, through 1.5.7, December 15, 2011, are
201 * Copyright (c) 2004, 2006-2011 Glenn Randers-Pehrson, and are
202 * distributed according to the same disclaimer and license as libpng-1.2.5
203 * with the following individual added to the list of Contributing Authors:
204 *
205 * Cosmin Truta
206 *
207 * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
208 * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
209 * distributed according to the same disclaimer and license as libpng-1.0.6
210 * with the following individuals added to the list of Contributing Authors:
211 *
212 * Simon-Pierre Cadieux
213 * Eric S. Raymond
214 * Gilles Vollant
215 *
216 * and with the following additions to the disclaimer:
217 *
218 * There is no warranty against interference with your enjoyment of the
219 * library or against infringement. There is no warranty that our
220 * efforts or the library will fulfill any of your particular purposes
221 * or needs. This library is provided with all faults, and the entire
222 * risk of satisfactory quality, performance, accuracy, and effort is with
223 * the user.
224 *
225 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
226 * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are
227 * distributed according to the same disclaimer and license as libpng-0.96,
228 * with the following individuals added to the list of Contributing Authors:
229 *
230 * Tom Lane
231 * Glenn Randers-Pehrson
232 * Willem van Schaik
233 *
234 * libpng versions 0.89, June 1996, through 0.96, May 1997, are
235 * Copyright (c) 1996, 1997 Andreas Dilger
236 * Distributed according to the same disclaimer and license as libpng-0.88,
237 * with the following individuals added to the list of Contributing Authors:
238 *
239 * John Bowler
240 * Kevin Bracey
241 * Sam Bushell
242 * Magnus Holmgren
243 * Greg Roelofs
244 * Tom Tanner
245 *
246 * libpng versions 0.5, May 1995, through 0.88, January 1996, are
247 * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
248 *
249 * For the purposes of this copyright and license, "Contributing Authors"
250 * is defined as the following set of individuals:
251 *
252 * Andreas Dilger
253 * Dave Martindale
254 * Guy Eric Schalnat
255 * Paul Schmidt
256 * Tim Wegner
257 *
258 * The PNG Reference Library is supplied "AS IS". The Contributing Authors
259 * and Group 42, Inc. disclaim all warranties, expressed or implied,
260 * including, without limitation, the warranties of merchantability and of
261 * fitness for any purpose. The Contributing Authors and Group 42, Inc.
262 * assume no liability for direct, indirect, incidental, special, exemplary,
263 * or consequential damages, which may result from the use of the PNG
264 * Reference Library, even if advised of the possibility of such damage.
265 *
266 * Permission is hereby granted to use, copy, modify, and distribute this
267 * source code, or portions hereof, for any purpose, without fee, subject
268 * to the following restrictions:
269 *
270 * 1. The origin of this source code must not be misrepresented.
271 *
272 * 2. Altered versions must be plainly marked as such and must not
273 * be misrepresented as being the original source.
274 *
275 * 3. This Copyright notice may not be removed or altered from
276 * any source or altered source distribution.
277 *
278 * The Contributing Authors and Group 42, Inc. specifically permit, without
279 * fee, and encourage the use of this source code as a component to
280 * supporting the PNG file format in commercial products. If you use this
281 * source code in a product, acknowledgment is not required but would be
282 * appreciated.
283 */
284
285/*
286 * A "png_get_copyright" function is available, for convenient use in "about"
287 * boxes and the like:
288 *
289 * printf("%s", png_get_copyright(NULL));
290 *
291 * Also, the PNG logo (in PNG format, of course) is supplied in the
292 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
293 */
294
295/*
296 * Libpng is OSI Certified Open Source Software. OSI Certified is a
297 * certification mark of the Open Source Initiative.
298 */
299
300/*
301 * The contributing authors would like to thank all those who helped
302 * with testing, bug fixes, and patience. This wouldn't have been
303 * possible without all of you.
304 *
305 * Thanks to Frank J. T. Wojcik for helping with the documentation.
306 */
307
308/*
309 * Y2K compliance in libpng:
310 * =========================
311 *
312 * December 15, 2011
313 *
314 * Since the PNG Development group is an ad-hoc body, we can't make
315 * an official declaration.
316 *
317 * This is your unofficial assurance that libpng from version 0.71 and
318 * upward through 1.5.7 are Y2K compliant. It is my belief that
319 * earlier versions were also Y2K compliant.
320 *
321 * Libpng only has two year fields. One is a 2-byte unsigned integer
322 * that will hold years up to 65535. The other holds the date in text
323 * format, and will hold years up to 9999.
324 *
325 * The integer is
326 * "png_uint_16 year" in png_time_struct.
327 *
328 * The string is
329 * "png_char time_buffer" in png_struct
330 *
331 * There are seven time-related functions:
332 * png.c: png_convert_to_rfc_1123() in png.c
333 * (formerly png_convert_to_rfc_1152() in error)
334 * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
335 * png_convert_from_time_t() in pngwrite.c
336 * png_get_tIME() in pngget.c
337 * png_handle_tIME() in pngrutil.c, called in pngread.c
338 * png_set_tIME() in pngset.c
339 * png_write_tIME() in pngwutil.c, called in pngwrite.c
340 *
341 * All handle dates properly in a Y2K environment. The
342 * png_convert_from_time_t() function calls gmtime() to convert from system
343 * clock time, which returns (year - 1900), which we properly convert to
344 * the full 4-digit year. There is a possibility that applications using
345 * libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
346 * function, or that they are incorrectly passing only a 2-digit year
347 * instead of "year - 1900" into the png_convert_from_struct_tm() function,
348 * but this is not under our control. The libpng documentation has always
349 * stated that it works with 4-digit years, and the APIs have been
350 * documented as such.
351 *
352 * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
353 * integer to hold the year, and can hold years as large as 65535.
354 *
355 * zlib, upon which libpng depends, is also Y2K compliant. It contains
356 * no date-related code.
357 *
358 * Glenn Randers-Pehrson
359 * libpng maintainer
360 * PNG Development Group
361 */
362
363#ifndef PNG_H
364#define PNG_H
365
366/* This is not the place to learn how to use libpng. The file libpng-manual.txt
367 * describes how to use libpng, and the file example.c summarizes it
368 * with some code on which to build. This file is useful for looking
369 * at the actual function definitions and structure components.
370 *
371 * If you just need to read a PNG file and don't want to read the documentation
372 * skip to the end of this file and read the section entitled 'simplified API'.
373 */
374
375/* Version information for png.h - this should match the version in png.c */
376#define PNG_LIBPNG_VER_STRING "1.5.7"
377#define PNG_HEADER_VERSION_STRING \
378 " libpng version 1.5.7 - December 15, 2011\n"
379
380#define PNG_LIBPNG_VER_SONUM 15
381#define PNG_LIBPNG_VER_DLLNUM 15
382
383/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
384#define PNG_LIBPNG_VER_MAJOR 1
385#define PNG_LIBPNG_VER_MINOR 5
386#define PNG_LIBPNG_VER_RELEASE 7
387
388/* This should match the numeric part of the final component of
389 * PNG_LIBPNG_VER_STRING, omitting any leading zero:
390 */
391
392#define PNG_LIBPNG_VER_BUILD 0
393
394/* Release Status */
395#define PNG_LIBPNG_BUILD_ALPHA 1
396#define PNG_LIBPNG_BUILD_BETA 2
397#define PNG_LIBPNG_BUILD_RC 3
398#define PNG_LIBPNG_BUILD_STABLE 4
399#define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
400
401/* Release-Specific Flags */
402#define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
403 PNG_LIBPNG_BUILD_STABLE only */
404#define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
405 PNG_LIBPNG_BUILD_SPECIAL */
406#define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
407 PNG_LIBPNG_BUILD_PRIVATE */
408
409#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_BETA
410
411/* Careful here. At one time, Guy wanted to use 082, but that would be octal.
412 * We must not include leading zeros.
413 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
414 * version 1.0.0 was mis-numbered 100 instead of 10000). From
415 * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release
416 */
417#define PNG_LIBPNG_VER 10507 /* 1.5.7 */
418
419/* Library configuration: these options cannot be changed after
420 * the library has been built.
421 */
422#ifndef PNGLCONF_H
423 /* If pnglibconf.h is missing, you can
424 * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h
425 */
426# include "pnglibconf.h"
427#endif
428
429#ifndef PNG_VERSION_INFO_ONLY
430# ifndef PNG_BUILDING_SYMBOL_TABLE
431 /*
432 * Standard header files (not needed for the version info or while
433 * building symbol table -- see scripts/pnglibconf.dfa)
434 */
435# ifdef PNG_SETJMP_SUPPORTED
436# include <setjmp.h>
437# endif
438
439 /* Need the time information for converting tIME chunks, it
440 * defines struct tm:
441 */
442# ifdef PNG_CONVERT_tIME_SUPPORTED
443 /* "time.h" functions are not supported on all operating systems */
444# include <time.h>
445# endif
446# endif
447
448/* Machine specific configuration. */
449# include "pngconf.h"
450#endif
451
452/*
453 * Added at libpng-1.2.8
454 *
455 * Ref MSDN: Private as priority over Special
456 * VS_FF_PRIVATEBUILD File *was not* built using standard release
457 * procedures. If this value is given, the StringFileInfo block must
458 * contain a PrivateBuild string.
459 *
460 * VS_FF_SPECIALBUILD File *was* built by the original company using
461 * standard release procedures but is a variation of the standard
462 * file of the same version number. If this value is given, the
463 * StringFileInfo block must contain a SpecialBuild string.
464 */
465
466#ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */
467# define PNG_LIBPNG_BUILD_TYPE \
468 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
469#else
470# ifdef PNG_LIBPNG_SPECIALBUILD
471# define PNG_LIBPNG_BUILD_TYPE \
472 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
473# else
474# define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
475# endif
476#endif
477
478#ifndef PNG_VERSION_INFO_ONLY
479
480/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
481#ifdef __cplusplus
482extern "C" {
483#endif /* __cplusplus */
484
485/* Version information for C files, stored in png.c. This had better match
486 * the version above.
487 */
488#define png_libpng_ver png_get_header_ver(NULL)
489
490/* This file is arranged in several sections:
491 *
492 * 1. Any configuration options that can be specified by for the application
493 * code when it is built. (Build time configuration is in pnglibconf.h)
494 * 2. Type definitions (base types are defined in pngconf.h), structure
495 * definitions.
496 * 3. Exported library functions.
497 *
498 * The library source code has additional files (principally pngpriv.h) that
499 * allow configuration of the library.
500 */
501/* Section 1: run time configuration
502 * See pnglibconf.h for build time configuration
503 *
504 * Run time configuration allows the application to choose between
505 * implementations of certain arithmetic APIs. The default is set
506 * at build time and recorded in pnglibconf.h, but it is safe to
507 * override these (and only these) settings. Note that this won't
508 * change what the library does, only application code, and the
509 * settings can (and probably should) be made on a per-file basis
510 * by setting the #defines before including png.h
511 *
512 * Use macros to read integers from PNG data or use the exported
513 * functions?
514 * PNG_USE_READ_MACROS: use the macros (see below) Note that
515 * the macros evaluate their argument multiple times.
516 * PNG_NO_USE_READ_MACROS: call the relevant library function.
517 *
518 * Use the alternative algorithm for compositing alpha samples that
519 * does not use division?
520 * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division'
521 * algorithm.
522 * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm.
523 *
524 * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is
525 * false?
526 * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error
527 * APIs to png_warning.
528 * Otherwise the calls are mapped to png_error.
529 */
530
531/* Section 2: type definitions, including structures and compile time
532 * constants.
533 * See pngconf.h for base types that vary by machine/system
534 */
535
536/* This triggers a compiler error in png.c, if png.c and png.h
537 * do not agree upon the version number.
538 */
539typedef char* png_libpng_version_1_5_7;
540
541/* Three color definitions. The order of the red, green, and blue, (and the
542 * exact size) is not important, although the size of the fields need to
543 * be png_byte or png_uint_16 (as defined below).
544 */
545typedef struct png_color_struct
546{
547 png_byte red;
548 png_byte green;
549 png_byte blue;
550} png_color;
551typedef png_color FAR * png_colorp;
552typedef PNG_CONST png_color FAR * png_const_colorp;
553typedef png_color FAR * FAR * png_colorpp;
554
555typedef struct png_color_16_struct
556{
557 png_byte index; /* used for palette files */
558 png_uint_16 red; /* for use in red green blue files */
559 png_uint_16 green;
560 png_uint_16 blue;
561 png_uint_16 gray; /* for use in grayscale files */
562} png_color_16;
563typedef png_color_16 FAR * png_color_16p;
564typedef PNG_CONST png_color_16 FAR * png_const_color_16p;
565typedef png_color_16 FAR * FAR * png_color_16pp;
566
567typedef struct png_color_8_struct
568{
569 png_byte red; /* for use in red green blue files */
570 png_byte green;
571 png_byte blue;
572 png_byte gray; /* for use in grayscale files */
573 png_byte alpha; /* for alpha channel files */
574} png_color_8;
575typedef png_color_8 FAR * png_color_8p;
576typedef PNG_CONST png_color_8 FAR * png_const_color_8p;
577typedef png_color_8 FAR * FAR * png_color_8pp;
578
579/*
580 * The following two structures are used for the in-core representation
581 * of sPLT chunks.
582 */
583typedef struct png_sPLT_entry_struct
584{
585 png_uint_16 red;
586 png_uint_16 green;
587 png_uint_16 blue;
588 png_uint_16 alpha;
589 png_uint_16 frequency;
590} png_sPLT_entry;
591typedef png_sPLT_entry FAR * png_sPLT_entryp;
592typedef PNG_CONST png_sPLT_entry FAR * png_const_sPLT_entryp;
593typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;
594
595/* When the depth of the sPLT palette is 8 bits, the color and alpha samples
596 * occupy the LSB of their respective members, and the MSB of each member
597 * is zero-filled. The frequency member always occupies the full 16 bits.
598 */
599
600typedef struct png_sPLT_struct
601{
602 png_charp name; /* palette name */
603 png_byte depth; /* depth of palette samples */
604 png_sPLT_entryp entries; /* palette entries */
605 png_int_32 nentries; /* number of palette entries */
606} png_sPLT_t;
607typedef png_sPLT_t FAR * png_sPLT_tp;
608typedef PNG_CONST png_sPLT_t FAR * png_const_sPLT_tp;
609typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
610
611#ifdef PNG_TEXT_SUPPORTED
612/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
613 * and whether that contents is compressed or not. The "key" field
614 * points to a regular zero-terminated C string. The "text" fields can be a
615 * regular C string, an empty string, or a NULL pointer.
616 * However, the structure returned by png_get_text() will always contain
617 * the "text" field as a regular zero-terminated C string (possibly
618 * empty), never a NULL pointer, so it can be safely used in printf() and
619 * other string-handling functions. Note that the "itxt_length", "lang", and
620 * "lang_key" members of the structure only exist when the library is built
621 * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by
622 * default without iTXt support. Also note that when iTXt *is* supported,
623 * the "lang" and "lang_key" fields contain NULL pointers when the
624 * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or
625 * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the
626 * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag"
627 * which is always 0 or 1, or its "compression method" which is always 0.
628 */
629typedef struct png_text_struct
630{
631 int compression; /* compression value:
632 -1: tEXt, none
633 0: zTXt, deflate
634 1: iTXt, none
635 2: iTXt, deflate */
636 png_charp key; /* keyword, 1-79 character description of "text" */
637 png_charp text; /* comment, may be an empty string (ie "")
638 or a NULL pointer */
639 png_size_t text_length; /* length of the text string */
640 png_size_t itxt_length; /* length of the itxt string */
641 png_charp lang; /* language code, 0-79 characters
642 or a NULL pointer */
643 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
644 chars or a NULL pointer */
645} png_text;
646typedef png_text FAR * png_textp;
647typedef PNG_CONST png_text FAR * png_const_textp;
648typedef png_text FAR * FAR * png_textpp;
649#endif
650
651/* Supported compression types for text in PNG files (tEXt, and zTXt).
652 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
653#define PNG_TEXT_COMPRESSION_NONE_WR -3
654#define PNG_TEXT_COMPRESSION_zTXt_WR -2
655#define PNG_TEXT_COMPRESSION_NONE -1
656#define PNG_TEXT_COMPRESSION_zTXt 0
657#define PNG_ITXT_COMPRESSION_NONE 1
658#define PNG_ITXT_COMPRESSION_zTXt 2
659#define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
660
661/* png_time is a way to hold the time in an machine independent way.
662 * Two conversions are provided, both from time_t and struct tm. There
663 * is no portable way to convert to either of these structures, as far
664 * as I know. If you know of a portable way, send it to me. As a side
665 * note - PNG has always been Year 2000 compliant!
666 */
667typedef struct png_time_struct
668{
669 png_uint_16 year; /* full year, as in, 1995 */
670 png_byte month; /* month of year, 1 - 12 */
671 png_byte day; /* day of month, 1 - 31 */
672 png_byte hour; /* hour of day, 0 - 23 */
673 png_byte minute; /* minute of hour, 0 - 59 */
674 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
675} png_time;
676typedef png_time FAR * png_timep;
677typedef PNG_CONST png_time FAR * png_const_timep;
678typedef png_time FAR * FAR * png_timepp;
679
680#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
681 defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
682/* png_unknown_chunk is a structure to hold queued chunks for which there is
683 * no specific support. The idea is that we can use this to queue
684 * up private chunks for output even though the library doesn't actually
685 * know about their semantics.
686 */
687typedef struct png_unknown_chunk_t
688{
689 png_byte name[5];
690 png_byte *data;
691 png_size_t size;
692
693 /* libpng-using applications should NOT directly modify this byte. */
694 png_byte location; /* mode of operation at read time */
695}
696
697
698png_unknown_chunk;
699typedef png_unknown_chunk FAR * png_unknown_chunkp;
700typedef PNG_CONST png_unknown_chunk FAR * png_const_unknown_chunkp;
701typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
702#endif
703
704/* Values for the unknown chunk location byte */
705
706#define PNG_HAVE_IHDR 0x01
707#define PNG_HAVE_PLTE 0x02
708#define PNG_AFTER_IDAT 0x08
709
710/* The complete definition of png_info has, as of libpng-1.5.0,
711 * been moved into a separate header file that is not accessible to
712 * applications. Read libpng-manual.txt or libpng.3 for more info.
713 */
714typedef struct png_info_def png_info;
715typedef png_info FAR * png_infop;
716typedef PNG_CONST png_info FAR * png_const_infop;
717typedef png_info FAR * FAR * png_infopp;
718
719/* Maximum positive integer used in PNG is (2^31)-1 */
720#define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
721#define PNG_UINT_32_MAX ((png_uint_32)(-1))
722#define PNG_SIZE_MAX ((png_size_t)(-1))
723
724/* These are constants for fixed point values encoded in the
725 * PNG specification manner (x100000)
726 */
727#define PNG_FP_1 100000
728#define PNG_FP_HALF 50000
729#define PNG_FP_MAX ((png_fixed_point)0x7fffffffL)
730#define PNG_FP_MIN (-PNG_FP_MAX)
731
732/* These describe the color_type field in png_info. */
733/* color type masks */
734#define PNG_COLOR_MASK_PALETTE 1
735#define PNG_COLOR_MASK_COLOR 2
736#define PNG_COLOR_MASK_ALPHA 4
737
738/* color types. Note that not all combinations are legal */
739#define PNG_COLOR_TYPE_GRAY 0
740#define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
741#define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
742#define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
743#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
744/* aliases */
745#define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
746#define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
747
748/* This is for compression type. PNG 1.0-1.2 only define the single type. */
749#define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
750#define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
751
752/* This is for filter type. PNG 1.0-1.2 only define the single type. */
753#define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
754#define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
755#define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
756
757/* These are for the interlacing type. These values should NOT be changed. */
758#define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
759#define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
760#define PNG_INTERLACE_LAST 2 /* Not a valid value */
761
762/* These are for the oFFs chunk. These values should NOT be changed. */
763#define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
764#define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
765#define PNG_OFFSET_LAST 2 /* Not a valid value */
766
767/* These are for the pCAL chunk. These values should NOT be changed. */
768#define PNG_EQUATION_LINEAR 0 /* Linear transformation */
769#define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
770#define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
771#define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
772#define PNG_EQUATION_LAST 4 /* Not a valid value */
773
774/* These are for the sCAL chunk. These values should NOT be changed. */
775#define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
776#define PNG_SCALE_METER 1 /* meters per pixel */
777#define PNG_SCALE_RADIAN 2 /* radians per pixel */
778#define PNG_SCALE_LAST 3 /* Not a valid value */
779
780/* These are for the pHYs chunk. These values should NOT be changed. */
781#define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
782#define PNG_RESOLUTION_METER 1 /* pixels/meter */
783#define PNG_RESOLUTION_LAST 2 /* Not a valid value */
784
785/* These are for the sRGB chunk. These values should NOT be changed. */
786#define PNG_sRGB_INTENT_PERCEPTUAL 0
787#define PNG_sRGB_INTENT_RELATIVE 1
788#define PNG_sRGB_INTENT_SATURATION 2
789#define PNG_sRGB_INTENT_ABSOLUTE 3
790#define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
791
792/* This is for text chunks */
793#define PNG_KEYWORD_MAX_LENGTH 79
794
795/* Maximum number of entries in PLTE/sPLT/tRNS arrays */
796#define PNG_MAX_PALETTE_LENGTH 256
797
798/* These determine if an ancillary chunk's data has been successfully read
799 * from the PNG header, or if the application has filled in the corresponding
800 * data in the info_struct to be written into the output file. The values
801 * of the PNG_INFO_<chunk> defines should NOT be changed.
802 */
803#define PNG_INFO_gAMA 0x0001
804#define PNG_INFO_sBIT 0x0002
805#define PNG_INFO_cHRM 0x0004
806#define PNG_INFO_PLTE 0x0008
807#define PNG_INFO_tRNS 0x0010
808#define PNG_INFO_bKGD 0x0020
809#define PNG_INFO_hIST 0x0040
810#define PNG_INFO_pHYs 0x0080
811#define PNG_INFO_oFFs 0x0100
812#define PNG_INFO_tIME 0x0200
813#define PNG_INFO_pCAL 0x0400
814#define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */
815#define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */
816#define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */
817#define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */
818#define PNG_INFO_IDAT 0x8000 /* ESR, 1.0.6 */
819
820/* This is used for the transformation routines, as some of them
821 * change these values for the row. It also should enable using
822 * the routines for other purposes.
823 */
824typedef struct png_row_info_struct
825{
826 png_uint_32 width; /* width of row */
827 png_size_t rowbytes; /* number of bytes in row */
828 png_byte color_type; /* color type of row */
829 png_byte bit_depth; /* bit depth of row */
830 png_byte channels; /* number of channels (1, 2, 3, or 4) */
831 png_byte pixel_depth; /* bits per pixel (depth * channels) */
832} png_row_info;
833
834typedef png_row_info FAR * png_row_infop;
835typedef png_row_info FAR * FAR * png_row_infopp;
836
837/* The complete definition of png_struct has, as of libpng-1.5.0,
838 * been moved into a separate header file that is not accessible to
839 * applications. Read libpng-manual.txt or libpng.3 for more info.
840 */
841typedef struct png_struct_def png_struct;
842typedef PNG_CONST png_struct FAR * png_const_structp;
843typedef png_struct FAR * png_structp;
844
845/* These are the function types for the I/O functions and for the functions
846 * that allow the user to override the default I/O functions with his or her
847 * own. The png_error_ptr type should match that of user-supplied warning
848 * and error functions, while the png_rw_ptr type should match that of the
849 * user read/write data functions. Note that the 'write' function must not
850 * modify the buffer it is passed. The 'read' function, on the other hand, is
851 * expected to return the read data in the buffer.
852 */
853typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp));
854typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, png_size_t));
855typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp));
856typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32,
857 int));
858typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32,
859 int));
860
861#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
862typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop));
863typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop));
864
865/* The following callback receives png_uint_32 row_number, int pass for the
866 * png_bytep data of the row. When transforming an interlaced image the
867 * row number is the row number within the sub-image of the interlace pass, so
868 * the value will increase to the height of the sub-image (not the full image)
869 * then reset to 0 for the next pass.
870 *
871 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
872 * find the output pixel (x,y) given an interlaced sub-image pixel
873 * (row,col,pass). (See below for these macros.)
874 */
875typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep,
876 png_uint_32, int));
877#endif
878
879#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
880 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
881typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop,
882 png_bytep));
883#endif
884
885#ifdef PNG_USER_CHUNKS_SUPPORTED
886typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp,
887 png_unknown_chunkp));
888#endif
889#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
890typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp));
891#endif
892
893#ifdef PNG_SETJMP_SUPPORTED
894/* This must match the function definition in <setjmp.h>, and the application
895 * must include this before png.h to obtain the definition of jmp_buf. The
896 * function is required to be PNG_NORETURN, but this is not checked. If the
897 * function does return the application will crash via an abort() or similar
898 * system level call.
899 *
900 * If you get a warning here while building the library you may need to make
901 * changes to ensure that pnglibconf.h records the calling convention used by
902 * your compiler. This may be very difficult - try using a different compiler
903 * to build the library!
904 */
905PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef);
906#endif
907
908/* Transform masks for the high-level interface */
909#define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
910#define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
911#define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
912#define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
913#define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
914#define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
915#define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
916#define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
917#define PNG_TRANSFORM_BGR 0x0080 /* read and write */
918#define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
919#define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
920#define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
921#define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */
922/* Added to libpng-1.2.34 */
923#define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
924#define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
925/* Added to libpng-1.4.0 */
926#define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
927/* Added to libpng-1.5.4 */
928#define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */
929#define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */
930
931/* Flags for MNG supported features */
932#define PNG_FLAG_MNG_EMPTY_PLTE 0x01
933#define PNG_FLAG_MNG_FILTER_64 0x04
934#define PNG_ALL_MNG_FEATURES 0x05
935
936/* NOTE: prior to 1.5 these functions had no 'API' style declaration,
937 * this allowed the zlib default functions to be used on Windows
938 * platforms. In 1.5 the zlib default malloc (which just calls malloc and
939 * ignores the first argument) should be completely compatible with the
940 * following.
941 */
942typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp,
943 png_alloc_size_t));
944typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp));
945
946typedef png_struct FAR * FAR * png_structpp;
947
948/* Section 3: exported functions
949 * Here are the function definitions most commonly used. This is not
950 * the place to find out how to use libpng. See libpng-manual.txt for the
951 * full explanation, see example.c for the summary. This just provides
952 * a simple one line description of the use of each function.
953 *
954 * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in
955 * pngconf.h and in the *.dfn files in the scripts directory.
956 *
957 * PNG_EXPORT(ordinal, type, name, (args));
958 *
959 * ordinal: ordinal that is used while building
960 * *.def files. The ordinal value is only
961 * relevant when preprocessing png.h with
962 * the *.dfn files for building symbol table
963 * entries, and are removed by pngconf.h.
964 * type: return type of the function
965 * name: function name
966 * args: function arguments, with types
967 *
968 * When we wish to append attributes to a function prototype we use
969 * the PNG_EXPORTA() macro instead.
970 *
971 * PNG_EXPORTA(ordinal, type, name, (args), attributes);
972 *
973 * ordinal, type, name, and args: same as in PNG_EXPORT().
974 * attributes: function attributes
975 */
976
977/* Returns the version number of the library */
978PNG_EXPORT(1, png_uint_32, png_access_version_number, (void));
979
980/* Tell lib we have already handled the first <num_bytes> magic bytes.
981 * Handling more than 8 bytes from the beginning of the file is an error.
982 */
983PNG_EXPORT(2, void, png_set_sig_bytes, (png_structp png_ptr, int num_bytes));
984
985/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
986 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
987 * signature, and non-zero otherwise. Having num_to_check == 0 or
988 * start > 7 will always fail (ie return non-zero).
989 */
990PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start,
991 png_size_t num_to_check));
992
993/* Simple signature checking function. This is the same as calling
994 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
995 */
996#define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n))
997
998/* Allocate and initialize png_ptr struct for reading, and any other memory. */
999PNG_EXPORTA(4, png_structp, png_create_read_struct,
1000 (png_const_charp user_png_ver, png_voidp error_ptr,
1001 png_error_ptr error_fn, png_error_ptr warn_fn),
1002 PNG_ALLOCATED);
1003
1004/* Allocate and initialize png_ptr struct for writing, and any other memory */
1005PNG_EXPORTA(5, png_structp, png_create_write_struct,
1006 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1007 png_error_ptr warn_fn),
1008 PNG_ALLOCATED);
1009
1010PNG_EXPORT(6, png_size_t, png_get_compression_buffer_size,
1011 (png_const_structp png_ptr));
1012
1013PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structp png_ptr,
1014 png_size_t size));
1015
1016/* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
1017 * match up.
1018 */
1019#ifdef PNG_SETJMP_SUPPORTED
1020/* This function returns the jmp_buf built in to *png_ptr. It must be
1021 * supplied with an appropriate 'longjmp' function to use on that jmp_buf
1022 * unless the default error function is overridden in which case NULL is
1023 * acceptable. The size of the jmp_buf is checked against the actual size
1024 * allocated by the library - the call will return NULL on a mismatch
1025 * indicating an ABI mismatch.
1026 */
1027PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structp png_ptr,
1028 png_longjmp_ptr longjmp_fn, size_t jmp_buf_size));
1029# define png_jmpbuf(png_ptr) \
1030 (*png_set_longjmp_fn((png_ptr), longjmp, sizeof (jmp_buf)))
1031#else
1032# define png_jmpbuf(png_ptr) \
1033 (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
1034#endif
1035/* This function should be used by libpng applications in place of
1036 * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it
1037 * will use it; otherwise it will call PNG_ABORT(). This function was
1038 * added in libpng-1.5.0.
1039 */
1040PNG_EXPORTA(9, void, png_longjmp, (png_structp png_ptr, int val),
1041 PNG_NORETURN);
1042
1043#ifdef PNG_READ_SUPPORTED
1044/* Reset the compression stream */
1045PNG_EXPORT(10, int, png_reset_zstream, (png_structp png_ptr));
1046#endif
1047
1048/* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
1049#ifdef PNG_USER_MEM_SUPPORTED
1050PNG_EXPORTA(11, png_structp, png_create_read_struct_2,
1051 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1052 png_error_ptr warn_fn,
1053 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
1054 PNG_ALLOCATED);
1055PNG_EXPORTA(12, png_structp, png_create_write_struct_2,
1056 (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1057 png_error_ptr warn_fn,
1058 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
1059 PNG_ALLOCATED);
1060#endif
1061
1062/* Write the PNG file signature. */
1063PNG_EXPORT(13, void, png_write_sig, (png_structp png_ptr));
1064
1065/* Write a PNG chunk - size, type, (optional) data, CRC. */
1066PNG_EXPORT(14, void, png_write_chunk, (png_structp png_ptr, png_const_bytep
1067 chunk_name, png_const_bytep data, png_size_t length));
1068
1069/* Write the start of a PNG chunk - length and chunk name. */
1070PNG_EXPORT(15, void, png_write_chunk_start, (png_structp png_ptr,
1071 png_const_bytep chunk_name, png_uint_32 length));
1072
1073/* Write the data of a PNG chunk started with png_write_chunk_start(). */
1074PNG_EXPORT(16, void, png_write_chunk_data, (png_structp png_ptr,
1075 png_const_bytep data, png_size_t length));
1076
1077/* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1078PNG_EXPORT(17, void, png_write_chunk_end, (png_structp png_ptr));
1079
1080/* Allocate and initialize the info structure */
1081PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_structp png_ptr),
1082 PNG_ALLOCATED);
1083
1084PNG_EXPORT(19, void, png_info_init_3, (png_infopp info_ptr,
1085 png_size_t png_info_struct_size));
1086
1087/* Writes all the PNG information before the image. */
1088PNG_EXPORT(20, void, png_write_info_before_PLTE,
1089 (png_structp png_ptr, png_infop info_ptr));
1090PNG_EXPORT(21, void, png_write_info,
1091 (png_structp png_ptr, png_infop info_ptr));
1092
1093#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1094/* Read the information before the actual image data. */
1095PNG_EXPORT(22, void, png_read_info,
1096 (png_structp png_ptr, png_infop info_ptr));
1097#endif
1098
1099#ifdef PNG_TIME_RFC1123_SUPPORTED
1100PNG_EXPORT(23, png_const_charp, png_convert_to_rfc1123,
1101 (png_structp png_ptr,
1102 png_const_timep ptime));
1103#endif
1104
1105#ifdef PNG_CONVERT_tIME_SUPPORTED
1106/* Convert from a struct tm to png_time */
1107PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime,
1108 PNG_CONST struct tm FAR * ttime));
1109
1110/* Convert from time_t to png_time. Uses gmtime() */
1111PNG_EXPORT(25, void, png_convert_from_time_t,
1112 (png_timep ptime, time_t ttime));
1113#endif /* PNG_CONVERT_tIME_SUPPORTED */
1114
1115#ifdef PNG_READ_EXPAND_SUPPORTED
1116/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1117PNG_EXPORT(26, void, png_set_expand, (png_structp png_ptr));
1118PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structp png_ptr));
1119PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structp png_ptr));
1120PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structp png_ptr));
1121#endif
1122
1123#ifdef PNG_READ_EXPAND_16_SUPPORTED
1124/* Expand to 16-bit channels, forces conversion of palette to RGB and expansion
1125 * of a tRNS chunk if present.
1126 */
1127PNG_EXPORT(221, void, png_set_expand_16, (png_structp png_ptr));
1128#endif
1129
1130#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1131/* Use blue, green, red order for pixels. */
1132PNG_EXPORT(30, void, png_set_bgr, (png_structp png_ptr));
1133#endif
1134
1135#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1136/* Expand the grayscale to 24-bit RGB if necessary. */
1137PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structp png_ptr));
1138#endif
1139
1140#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1141/* Reduce RGB to grayscale. */
1142#define PNG_ERROR_ACTION_NONE 1
1143#define PNG_ERROR_ACTION_WARN 2
1144#define PNG_ERROR_ACTION_ERROR 3
1145#define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/
1146
1147PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structp png_ptr,
1148 int error_action, double red, double green));
1149PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structp png_ptr,
1150 int error_action, png_fixed_point red, png_fixed_point green));
1151
1152PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structp
1153 png_ptr));
1154#endif
1155
1156#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
1157PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,
1158 png_colorp palette));
1159#endif
1160
1161#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
1162/* How the alpha channel is interpreted - this affects how the color channels of
1163 * a PNG file are returned when an alpha channel, or tRNS chunk in a palette
1164 * file, is present.
1165 *
1166 * This has no effect on the way pixels are written into a PNG output
1167 * datastream. The color samples in a PNG datastream are never premultiplied
1168 * with the alpha samples.
1169 *
1170 * The default is to return data according to the PNG specification: the alpha
1171 * channel is a linear measure of the contribution of the pixel to the
1172 * corresponding composited pixel. The gamma encoded color channels must be
1173 * scaled according to the contribution and to do this it is necessary to undo
1174 * the encoding, scale the color values, perform the composition and reencode
1175 * the values. This is the 'PNG' mode.
1176 *
1177 * The alternative is to 'associate' the alpha with the color information by
1178 * storing color channel values that have been scaled by the alpha. The
1179 * advantage is that the color channels can be resampled (the image can be
1180 * scaled) in this form. The disadvantage is that normal practice is to store
1181 * linear, not (gamma) encoded, values and this requires 16-bit channels for
1182 * still images rather than the 8-bit channels that are just about sufficient if
1183 * gamma encoding is used. In addition all non-transparent pixel values,
1184 * including completely opaque ones, must be gamma encoded to produce the final
1185 * image. This is the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' mode (the
1186 * latter being the two common names for associated alpha color channels.)
1187 *
1188 * Since it is not necessary to perform arithmetic on opaque color values so
1189 * long as they are not to be resampled and are in the final color space it is
1190 * possible to optimize the handling of alpha by storing the opaque pixels in
1191 * the PNG format (adjusted for the output color space) while storing partially
1192 * opaque pixels in the standard, linear, format. The accuracy required for
1193 * standard alpha composition is relatively low, because the pixels are
1194 * isolated, therefore typically the accuracy loss in storing 8-bit linear
1195 * values is acceptable. (This is not true if the alpha channel is used to
1196 * simulate transparency over large areas - use 16 bits or the PNG mode in
1197 * this case!) This is the 'OPTIMIZED' mode. For this mode a pixel is
1198 * treated as opaque only if the alpha value is equal to the maximum value.
1199 *
1200 * The final choice is to gamma encode the alpha channel as well. This is
1201 * broken because, in practice, no implementation that uses this choice
1202 * correctly undoes the encoding before handling alpha composition. Use this
1203 * choice only if other serious errors in the software or hardware you use
1204 * mandate it; the typical serious error is for dark halos to appear around
1205 * opaque areas of the composited PNG image because of arithmetic overflow.
1206 *
1207 * The API function png_set_alpha_mode specifies which of these choices to use
1208 * with an enumerated 'mode' value and the gamma of the required output:
1209 */
1210#define PNG_ALPHA_PNG 0 /* according to the PNG standard */
1211#define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */
1212#define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */
1213#define PNG_ALPHA_PREMULTIPLIED 1 /* as above */
1214#define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */
1215#define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */
1216
1217PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structp png_ptr, int mode,
1218 double output_gamma));
1219PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structp png_ptr,
1220 int mode, png_fixed_point output_gamma));
1221#endif
1222
1223#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)
1224/* The output_gamma value is a screen gamma in libpng terminology: it expresses
1225 * how to decode the output values, not how they are encoded. The values used
1226 * correspond to the normal numbers used to describe the overall gamma of a
1227 * computer display system; for example 2.2 for an sRGB conformant system. The
1228 * values are scaled by 100000 in the _fixed version of the API (so 220000 for
1229 * sRGB.)
1230 *
1231 * The inverse of the value is always used to provide a default for the PNG file
1232 * encoding if it has no gAMA chunk and if png_set_gamma() has not been called
1233 * to override the PNG gamma information.
1234 *
1235 * When the ALPHA_OPTIMIZED mode is selected the output gamma is used to encode
1236 * opaque pixels however pixels with lower alpha values are not encoded,
1237 * regardless of the output gamma setting.
1238 *
1239 * When the standard Porter Duff handling is requested with mode 1 the output
1240 * encoding is set to be linear and the output_gamma value is only relevant
1241 * as a default for input data that has no gamma information. The linear output
1242 * encoding will be overridden if png_set_gamma() is called - the results may be
1243 * highly unexpected!
1244 *
1245 * The following numbers are derived from the sRGB standard and the research
1246 * behind it. sRGB is defined to be approximated by a PNG gAMA chunk value of
1247 * 0.45455 (1/2.2) for PNG. The value implicitly includes any viewing
1248 * correction required to take account of any differences in the color
1249 * environment of the original scene and the intended display environment; the
1250 * value expresses how to *decode* the image for display, not how the original
1251 * data was *encoded*.
1252 *
1253 * sRGB provides a peg for the PNG standard by defining a viewing environment.
1254 * sRGB itself, and earlier TV standards, actually use a more complex transform
1255 * (a linear portion then a gamma 2.4 power law) than PNG can express. (PNG is
1256 * limited to simple power laws.) By saying that an image for direct display on
1257 * an sRGB conformant system should be stored with a gAMA chunk value of 45455
1258 * (11.3.3.2 and 11.3.3.5 of the ISO PNG specification) the PNG specification
1259 * makes it possible to derive values for other display systems and
1260 * environments.
1261 *
1262 * The Mac value is deduced from the sRGB based on an assumption that the actual
1263 * extra viewing correction used in early Mac display systems was implemented as
1264 * a power 1.45 lookup table.
1265 *
1266 * Any system where a programmable lookup table is used or where the behavior of
1267 * the final display device characteristics can be changed requires system
1268 * specific code to obtain the current characteristic. However this can be
1269 * difficult and most PNG gamma correction only requires an approximate value.
1270 *
1271 * By default, if png_set_alpha_mode() is not called, libpng assumes that all
1272 * values are unencoded, linear, values and that the output device also has a
1273 * linear characteristic. This is only very rarely correct - it is invariably
1274 * better to call png_set_alpha_mode() with PNG_DEFAULT_sRGB than rely on the
1275 * default if you don't know what the right answer is!
1276 *
1277 * The special value PNG_GAMMA_MAC_18 indicates an older Mac system (pre Mac OS
1278 * 10.6) which used a correction table to implement a somewhat lower gamma on an
1279 * otherwise sRGB system.
1280 *
1281 * Both these values are reserved (not simple gamma values) in order to allow
1282 * more precise correction internally in the future.
1283 *
1284 * NOTE: the following values can be passed to either the fixed or floating
1285 * point APIs, but the floating point API will also accept floating point
1286 * values.
1287 */
1288#define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */
1289#define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */
1290#define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */
1291#define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */
1292#endif
1293
1294/* The following are examples of calls to png_set_alpha_mode to achieve the
1295 * required overall gamma correction and, where necessary, alpha
1296 * premultiplication.
1297 *
1298 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
1299 * This is the default libpng handling of the alpha channel - it is not
1300 * pre-multiplied into the color components. In addition the call states
1301 * that the output is for a sRGB system and causes all PNG files without gAMA
1302 * chunks to be assumed to be encoded using sRGB.
1303 *
1304 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
1305 * In this case the output is assumed to be something like an sRGB conformant
1306 * display preceeded by a power-law lookup table of power 1.45. This is how
1307 * early Mac systems behaved.
1308 *
1309 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
1310 * This is the classic Jim Blinn approach and will work in academic
1311 * environments where everything is done by the book. It has the shortcoming
1312 * of assuming that input PNG data with no gamma information is linear - this
1313 * is unlikely to be correct unless the PNG files where generated locally.
1314 * Most of the time the output precision will be so low as to show
1315 * significant banding in dark areas of the image.
1316 *
1317 * png_set_expand_16(pp);
1318 * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
1319 * This is a somewhat more realistic Jim Blinn inspired approach. PNG files
1320 * are assumed to have the sRGB encoding if not marked with a gamma value and
1321 * the output is always 16 bits per component. This permits accurate scaling
1322 * and processing of the data. If you know that your input PNG files were
1323 * generated locally you might need to replace PNG_DEFAULT_sRGB with the
1324 * correct value for your system.
1325 *
1326 * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
1327 * If you just need to composite the PNG image onto an existing background
1328 * and if you control the code that does this you can use the optimization
1329 * setting. In this case you just copy completely opaque pixels to the
1330 * output. For pixels that are not completely transparent (you just skip
1331 * those) you do the composition math using png_composite or png_composite_16
1332 * below then encode the resultant 8-bit or 16-bit values to match the output
1333 * encoding.
1334 *
1335 * Other cases
1336 * If neither the PNG nor the standard linear encoding work for you because
1337 * of the software or hardware you use then you have a big problem. The PNG
1338 * case will probably result in halos around the image. The linear encoding
1339 * will probably result in a washed out, too bright, image (it's actually too
1340 * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably
1341 * substantially reduce the halos. Alternatively try:
1342 *
1343 * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);
1344 * This option will also reduce the halos, but there will be slight dark
1345 * halos round the opaque parts of the image where the background is light.
1346 * In the OPTIMIZED mode the halos will be light halos where the background
1347 * is dark. Take your pick - the halos are unavoidable unless you can get
1348 * your hardware/software fixed! (The OPTIMIZED approach is slightly
1349 * faster.)
1350 *
1351 * When the default gamma of PNG files doesn't match the output gamma.
1352 * If you have PNG files with no gamma information png_set_alpha_mode allows
1353 * you to provide a default gamma, but it also sets the ouput gamma to the
1354 * matching value. If you know your PNG files have a gamma that doesn't
1355 * match the output you can take advantage of the fact that
1356 * png_set_alpha_mode always sets the output gamma but only sets the PNG
1357 * default if it is not already set:
1358 *
1359 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
1360 * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
1361 * The first call sets both the default and the output gamma values, the
1362 * second call overrides the output gamma without changing the default. This
1363 * is easier than achieving the same effect with png_set_gamma. You must use
1364 * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will
1365 * fire if more than one call to png_set_alpha_mode and png_set_background is
1366 * made in the same read operation, however multiple calls with PNG_ALPHA_PNG
1367 * are ignored.
1368 */
1369
1370#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1371PNG_EXPORT(36, void, png_set_strip_alpha, (png_structp png_ptr));
1372#endif
1373
1374#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1375 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1376PNG_EXPORT(37, void, png_set_swap_alpha, (png_structp png_ptr));
1377#endif
1378
1379#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1380 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1381PNG_EXPORT(38, void, png_set_invert_alpha, (png_structp png_ptr));
1382#endif
1383
1384#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1385/* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
1386PNG_EXPORT(39, void, png_set_filler, (png_structp png_ptr, png_uint_32 filler,
1387 int flags));
1388/* The values of the PNG_FILLER_ defines should NOT be changed */
1389# define PNG_FILLER_BEFORE 0
1390# define PNG_FILLER_AFTER 1
1391/* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
1392PNG_EXPORT(40, void, png_set_add_alpha,
1393 (png_structp png_ptr, png_uint_32 filler,
1394 int flags));
1395#endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
1396
1397#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1398/* Swap bytes in 16-bit depth files. */
1399PNG_EXPORT(41, void, png_set_swap, (png_structp png_ptr));
1400#endif
1401
1402#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1403/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1404PNG_EXPORT(42, void, png_set_packing, (png_structp png_ptr));
1405#endif
1406
1407#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1408 defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1409/* Swap packing order of pixels in bytes. */
1410PNG_EXPORT(43, void, png_set_packswap, (png_structp png_ptr));
1411#endif
1412
1413#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1414/* Converts files to legal bit depths. */
1415PNG_EXPORT(44, void, png_set_shift, (png_structp png_ptr, png_const_color_8p
1416 true_bits));
1417#endif
1418
1419#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1420 defined(PNG_WRITE_INTERLACING_SUPPORTED)
1421/* Have the code handle the interlacing. Returns the number of passes.
1422 * MUST be called before png_read_update_info or png_start_read_image,
1423 * otherwise it will not have the desired effect. Note that it is still
1424 * necessary to call png_read_row or png_read_rows png_get_image_height
1425 * times for each pass.
1426*/
1427PNG_EXPORT(45, int, png_set_interlace_handling, (png_structp png_ptr));
1428#endif
1429
1430#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1431/* Invert monochrome files */
1432PNG_EXPORT(46, void, png_set_invert_mono, (png_structp png_ptr));
1433#endif
1434
1435#ifdef PNG_READ_BACKGROUND_SUPPORTED
1436/* Handle alpha and tRNS by replacing with a background color. Prior to
1437 * libpng-1.5.4 this API must not be called before the PNG file header has been
1438 * read. Doing so will result in unexpected behavior and possible warnings or
1439 * errors if the PNG file contains a bKGD chunk.
1440 */
1441PNG_FP_EXPORT(47, void, png_set_background, (png_structp png_ptr,
1442 png_const_color_16p background_color, int background_gamma_code,
1443 int need_expand, double background_gamma));
1444PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structp png_ptr,
1445 png_const_color_16p background_color, int background_gamma_code,
1446 int need_expand, png_fixed_point background_gamma));
1447#endif
1448#ifdef PNG_READ_BACKGROUND_SUPPORTED
1449# define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1450# define PNG_BACKGROUND_GAMMA_SCREEN 1
1451# define PNG_BACKGROUND_GAMMA_FILE 2
1452# define PNG_BACKGROUND_GAMMA_UNIQUE 3
1453#endif
1454
1455#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
1456/* Scale a 16-bit depth file down to 8-bit, accurately. */
1457PNG_EXPORT(229, void, png_set_scale_16, (png_structp png_ptr));
1458#endif
1459
1460#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
1461#define PNG_READ_16_TO_8 SUPPORTED /* Name prior to 1.5.4 */
1462/* Strip the second byte of information from a 16-bit depth file. */
1463PNG_EXPORT(48, void, png_set_strip_16, (png_structp png_ptr));
1464#endif
1465
1466#ifdef PNG_READ_QUANTIZE_SUPPORTED
1467/* Turn on quantizing, and reduce the palette to the number of colors
1468 * available.
1469 */
1470PNG_EXPORT(49, void, png_set_quantize,
1471 (png_structp png_ptr, png_colorp palette,
1472 int num_palette, int maximum_colors, png_const_uint_16p histogram,
1473 int full_quantize));
1474#endif
1475
1476#ifdef PNG_READ_GAMMA_SUPPORTED
1477/* The threshold on gamma processing is configurable but hard-wired into the
1478 * library. The following is the floating point variant.
1479 */
1480#define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001)
1481
1482/* Handle gamma correction. Screen_gamma=(display_exponent).
1483 * NOTE: this API simply sets the screen and file gamma values. It will
1484 * therefore override the value for gamma in a PNG file if it is called after
1485 * the file header has been read - use with care - call before reading the PNG
1486 * file for best results!
1487 *
1488 * These routines accept the same gamma values as png_set_alpha_mode (described
1489 * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either
1490 * API (floating point or fixed.) Notice, however, that the 'file_gamma' value
1491 * is the inverse of a 'screen gamma' value.
1492 */
1493PNG_FP_EXPORT(50, void, png_set_gamma,
1494 (png_structp png_ptr, double screen_gamma,
1495 double override_file_gamma));
1496PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structp png_ptr,
1497 png_fixed_point screen_gamma, png_fixed_point override_file_gamma));
1498#endif
1499
1500#ifdef PNG_WRITE_FLUSH_SUPPORTED
1501/* Set how many lines between output flushes - 0 for no flushing */
1502PNG_EXPORT(51, void, png_set_flush, (png_structp png_ptr, int nrows));
1503/* Flush the current PNG output buffer */
1504PNG_EXPORT(52, void, png_write_flush, (png_structp png_ptr));
1505#endif
1506
1507/* Optional update palette with requested transformations */
1508PNG_EXPORT(53, void, png_start_read_image, (png_structp png_ptr));
1509
1510/* Optional call to update the users info structure */
1511PNG_EXPORT(54, void, png_read_update_info,
1512 (png_structp png_ptr, png_infop info_ptr));
1513
1514#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1515/* Read one or more rows of image data. */
1516PNG_EXPORT(55, void, png_read_rows, (png_structp png_ptr, png_bytepp row,
1517 png_bytepp display_row, png_uint_32 num_rows));
1518#endif
1519
1520#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1521/* Read a row of data. */
1522PNG_EXPORT(56, void, png_read_row, (png_structp png_ptr, png_bytep row,
1523 png_bytep display_row));
1524#endif
1525
1526#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1527/* Read the whole image into memory at once. */
1528PNG_EXPORT(57, void, png_read_image, (png_structp png_ptr, png_bytepp image));
1529#endif
1530
1531/* Write a row of image data */
1532PNG_EXPORT(58, void, png_write_row,
1533 (png_structp png_ptr, png_const_bytep row));
1534
1535/* Write a few rows of image data: (*row) is not written; however, the type
1536 * is declared as writeable to maintain compatibility with previous versions
1537 * of libpng and to allow the 'display_row' array from read_rows to be passed
1538 * unchanged to write_rows.
1539 */
1540PNG_EXPORT(59, void, png_write_rows, (png_structp png_ptr, png_bytepp row,
1541 png_uint_32 num_rows));
1542
1543/* Write the image data */
1544PNG_EXPORT(60, void, png_write_image,
1545 (png_structp png_ptr, png_bytepp image));
1546
1547/* Write the end of the PNG file. */
1548PNG_EXPORT(61, void, png_write_end,
1549 (png_structp png_ptr, png_infop info_ptr));
1550
1551#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1552/* Read the end of the PNG file. */
1553PNG_EXPORT(62, void, png_read_end, (png_structp png_ptr, png_infop info_ptr));
1554#endif
1555
1556/* Free any memory associated with the png_info_struct */
1557PNG_EXPORT(63, void, png_destroy_info_struct, (png_structp png_ptr,
1558 png_infopp info_ptr_ptr));
1559
1560/* Free any memory associated with the png_struct and the png_info_structs */
1561PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr,
1562 png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1563
1564/* Free any memory associated with the png_struct and the png_info_structs */
1565PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr,
1566 png_infopp info_ptr_ptr));
1567
1568/* Set the libpng method of handling chunk CRC errors */
1569PNG_EXPORT(66, void, png_set_crc_action,
1570 (png_structp png_ptr, int crit_action, int ancil_action));
1571
1572/* Values for png_set_crc_action() say how to handle CRC errors in
1573 * ancillary and critical chunks, and whether to use the data contained
1574 * therein. Note that it is impossible to "discard" data in a critical
1575 * chunk. For versions prior to 0.90, the action was always error/quit,
1576 * whereas in version 0.90 and later, the action for CRC errors in ancillary
1577 * chunks is warn/discard. These values should NOT be changed.
1578 *
1579 * value action:critical action:ancillary
1580 */
1581#define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1582#define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1583#define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1584#define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1585#define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1586#define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1587
1588/* These functions give the user control over the scan-line filtering in
1589 * libpng and the compression methods used by zlib. These functions are
1590 * mainly useful for testing, as the defaults should work with most users.
1591 * Those users who are tight on memory or want faster performance at the
1592 * expense of compression can modify them. See the compression library
1593 * header file (zlib.h) for an explination of the compression functions.
1594 */
1595
1596/* Set the filtering method(s) used by libpng. Currently, the only valid
1597 * value for "method" is 0.
1598 */
1599PNG_EXPORT(67, void, png_set_filter,
1600 (png_structp png_ptr, int method, int filters));
1601
1602/* Flags for png_set_filter() to say which filters to use. The flags
1603 * are chosen so that they don't conflict with real filter types
1604 * below, in case they are supplied instead of the #defined constants.
1605 * These values should NOT be changed.
1606 */
1607#define PNG_NO_FILTERS 0x00
1608#define PNG_FILTER_NONE 0x08
1609#define PNG_FILTER_SUB 0x10
1610#define PNG_FILTER_UP 0x20
1611#define PNG_FILTER_AVG 0x40
1612#define PNG_FILTER_PAETH 0x80
1613#define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
1614 PNG_FILTER_AVG | PNG_FILTER_PAETH)
1615
1616/* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1617 * These defines should NOT be changed.
1618 */
1619#define PNG_FILTER_VALUE_NONE 0
1620#define PNG_FILTER_VALUE_SUB 1
1621#define PNG_FILTER_VALUE_UP 2
1622#define PNG_FILTER_VALUE_AVG 3
1623#define PNG_FILTER_VALUE_PAETH 4
1624#define PNG_FILTER_VALUE_LAST 5
1625
1626#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* EXPERIMENTAL */
1627/* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
1628 * defines, either the default (minimum-sum-of-absolute-differences), or
1629 * the experimental method (weighted-minimum-sum-of-absolute-differences).
1630 *
1631 * Weights are factors >= 1.0, indicating how important it is to keep the
1632 * filter type consistent between rows. Larger numbers mean the current
1633 * filter is that many times as likely to be the same as the "num_weights"
1634 * previous filters. This is cumulative for each previous row with a weight.
1635 * There needs to be "num_weights" values in "filter_weights", or it can be
1636 * NULL if the weights aren't being specified. Weights have no influence on
1637 * the selection of the first row filter. Well chosen weights can (in theory)
1638 * improve the compression for a given image.
1639 *
1640 * Costs are factors >= 1.0 indicating the relative decoding costs of a
1641 * filter type. Higher costs indicate more decoding expense, and are
1642 * therefore less likely to be selected over a filter with lower computational
1643 * costs. There needs to be a value in "filter_costs" for each valid filter
1644 * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
1645 * setting the costs. Costs try to improve the speed of decompression without
1646 * unduly increasing the compressed image size.
1647 *
1648 * A negative weight or cost indicates the default value is to be used, and
1649 * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
1650 * The default values for both weights and costs are currently 1.0, but may
1651 * change if good general weighting/cost heuristics can be found. If both
1652 * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
1653 * to the UNWEIGHTED method, but with added encoding time/computation.
1654 */
1655PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structp png_ptr,
1656 int heuristic_method, int num_weights, png_const_doublep filter_weights,
1657 png_const_doublep filter_costs));
1658PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
1659 (png_structp png_ptr,
1660 int heuristic_method, int num_weights, png_const_fixed_point_p
1661 filter_weights, png_const_fixed_point_p filter_costs));
1662#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1663
1664/* Heuristic used for row filter selection. These defines should NOT be
1665 * changed.
1666 */
1667#define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
1668#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
1669#define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
1670#define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
1671
1672#ifdef PNG_WRITE_SUPPORTED
1673/* Set the library compression level. Currently, valid values range from
1674 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1675 * (0 - no compression, 9 - "maximal" compression). Note that tests have
1676 * shown that zlib compression levels 3-6 usually perform as well as level 9
1677 * for PNG images, and do considerably fewer caclulations. In the future,
1678 * these values may not correspond directly to the zlib compression levels.
1679 */
1680PNG_EXPORT(69, void, png_set_compression_level,
1681 (png_structp png_ptr, int level));
1682
1683PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structp png_ptr,
1684 int mem_level));
1685
1686PNG_EXPORT(71, void, png_set_compression_strategy, (png_structp png_ptr,
1687 int strategy));
1688
1689/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1690 * smaller value of window_bits if it can do so safely.
1691 */
1692PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structp png_ptr,
1693 int window_bits));
1694
1695PNG_EXPORT(73, void, png_set_compression_method, (png_structp png_ptr,
1696 int method));
1697#endif
1698
1699#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
1700/* Also set zlib parameters for compressing non-IDAT chunks */
1701PNG_EXPORT(222, void, png_set_text_compression_level,
1702 (png_structp png_ptr, int level));
1703
1704PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structp png_ptr,
1705 int mem_level));
1706
1707PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structp png_ptr,
1708 int strategy));
1709
1710/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1711 * smaller value of window_bits if it can do so safely.
1712 */
1713PNG_EXPORT(225, void, png_set_text_compression_window_bits, (png_structp
1714 png_ptr, int window_bits));
1715
1716PNG_EXPORT(226, void, png_set_text_compression_method, (png_structp png_ptr,
1717 int method));
1718#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */
1719
1720/* These next functions are called for input/output, memory, and error
1721 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
1722 * and call standard C I/O routines such as fread(), fwrite(), and
1723 * fprintf(). These functions can be made to use other I/O routines
1724 * at run time for those applications that need to handle I/O in a
1725 * different manner by calling png_set_???_fn(). See libpng-manual.txt for
1726 * more information.
1727 */
1728
1729#ifdef PNG_STDIO_SUPPORTED
1730/* Initialize the input/output for the PNG file to the default functions. */
1731PNG_EXPORT(74, void, png_init_io, (png_structp png_ptr, png_FILE_p fp));
1732#endif
1733
1734/* Replace the (error and abort), and warning functions with user
1735 * supplied functions. If no messages are to be printed you must still
1736 * write and use replacement functions. The replacement error_fn should
1737 * still do a longjmp to the last setjmp location if you are using this
1738 * method of error handling. If error_fn or warning_fn is NULL, the
1739 * default function will be used.
1740 */
1741
1742PNG_EXPORT(75, void, png_set_error_fn,
1743 (png_structp png_ptr, png_voidp error_ptr,
1744 png_error_ptr error_fn, png_error_ptr warning_fn));
1745
1746/* Return the user pointer associated with the error functions */
1747PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structp png_ptr));
1748
1749/* Replace the default data output functions with a user supplied one(s).
1750 * If buffered output is not used, then output_flush_fn can be set to NULL.
1751 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
1752 * output_flush_fn will be ignored (and thus can be NULL).
1753 * It is probably a mistake to use NULL for output_flush_fn if
1754 * write_data_fn is not also NULL unless you have built libpng with
1755 * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
1756 * default flush function, which uses the standard *FILE structure, will
1757 * be used.
1758 */
1759PNG_EXPORT(77, void, png_set_write_fn, (png_structp png_ptr, png_voidp io_ptr,
1760 png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
1761
1762/* Replace the default data input function with a user supplied one. */
1763PNG_EXPORT(78, void, png_set_read_fn, (png_structp png_ptr, png_voidp io_ptr,
1764 png_rw_ptr read_data_fn));
1765
1766/* Return the user pointer associated with the I/O functions */
1767PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_structp png_ptr));
1768
1769PNG_EXPORT(80, void, png_set_read_status_fn, (png_structp png_ptr,
1770 png_read_status_ptr read_row_fn));
1771
1772PNG_EXPORT(81, void, png_set_write_status_fn, (png_structp png_ptr,
1773 png_write_status_ptr write_row_fn));
1774
1775#ifdef PNG_USER_MEM_SUPPORTED
1776/* Replace the default memory allocation functions with user supplied one(s). */
1777PNG_EXPORT(82, void, png_set_mem_fn, (png_structp png_ptr, png_voidp mem_ptr,
1778 png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1779/* Return the user pointer associated with the memory functions */
1780PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structp png_ptr));
1781#endif
1782
1783#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
1784PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structp png_ptr,
1785 png_user_transform_ptr read_user_transform_fn));
1786#endif
1787
1788#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1789PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structp png_ptr,
1790 png_user_transform_ptr write_user_transform_fn));
1791#endif
1792
1793#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
1794PNG_EXPORT(86, void, png_set_user_transform_info, (png_structp png_ptr,
1795 png_voidp user_transform_ptr, int user_transform_depth,
1796 int user_transform_channels));
1797/* Return the user pointer associated with the user transform functions */
1798PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr,
1799 (png_const_structp png_ptr));
1800#endif
1801
1802#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
1803/* Return information about the row currently being processed. Note that these
1804 * APIs do not fail but will return unexpected results if called outside a user
1805 * transform callback. Also note that when transforming an interlaced image the
1806 * row number is the row number within the sub-image of the interlace pass, so
1807 * the value will increase to the height of the sub-image (not the full image)
1808 * then reset to 0 for the next pass.
1809 *
1810 * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
1811 * find the output pixel (x,y) given an interlaced sub-image pixel
1812 * (row,col,pass). (See below for these macros.)
1813 */
1814PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structp));
1815PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structp));
1816#endif
1817
1818#ifdef PNG_USER_CHUNKS_SUPPORTED
1819PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structp png_ptr,
1820 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
1821PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structp png_ptr));
1822#endif
1823
1824#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1825/* Sets the function callbacks for the push reader, and a pointer to a
1826 * user-defined structure available to the callback functions.
1827 */
1828PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structp png_ptr,
1829 png_voidp progressive_ptr, png_progressive_info_ptr info_fn,
1830 png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn));
1831
1832/* Returns the user pointer associated with the push read functions */
1833PNG_EXPORT(91, png_voidp, png_get_progressive_ptr, (png_const_structp png_ptr));
1834
1835/* Function to be called when data becomes available */
1836PNG_EXPORT(92, void, png_process_data,
1837 (png_structp png_ptr, png_infop info_ptr,
1838 png_bytep buffer, png_size_t buffer_size));
1839
1840/* A function which may be called *only* within png_process_data to stop the
1841 * processing of any more data. The function returns the number of bytes
1842 * remaining, excluding any that libpng has cached internally. A subsequent
1843 * call to png_process_data must supply these bytes again. If the argument
1844 * 'save' is set to true the routine will first save all the pending data and
1845 * will always return 0.
1846 */
1847PNG_EXPORT(219, png_size_t, png_process_data_pause, (png_structp, int save));
1848
1849/* A function which may be called *only* outside (after) a call to
1850 * png_process_data. It returns the number of bytes of data to skip in the
1851 * input. Normally it will return 0, but if it returns a non-zero value the
1852 * application must skip than number of bytes of input data and pass the
1853 * following data to the next call to png_process_data.
1854 */
1855PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structp));
1856
1857#ifdef PNG_READ_INTERLACING_SUPPORTED
1858/* Function that combines rows. 'new_row' is a flag that should come from
1859 * the callback and be non-NULL if anything needs to be done; the library
1860 * stores its own version of the new data internally and ignores the passed
1861 * in value.
1862 */
1863PNG_EXPORT(93, void, png_progressive_combine_row, (png_structp png_ptr,
1864 png_bytep old_row, png_const_bytep new_row));
1865#endif /* PNG_READ_INTERLACING_SUPPORTED */
1866#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1867
1868PNG_EXPORTA(94, png_voidp, png_malloc,
1869 (png_structp png_ptr, png_alloc_size_t size),
1870 PNG_ALLOCATED);
1871/* Added at libpng version 1.4.0 */
1872PNG_EXPORTA(95, png_voidp, png_calloc,
1873 (png_structp png_ptr, png_alloc_size_t size),
1874 PNG_ALLOCATED);
1875
1876/* Added at libpng version 1.2.4 */
1877PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_structp png_ptr,
1878 png_alloc_size_t size), PNG_ALLOCATED);
1879
1880/* Frees a pointer allocated by png_malloc() */
1881PNG_EXPORT(97, void, png_free, (png_structp png_ptr, png_voidp ptr));
1882
1883/* Free data that was allocated internally */
1884PNG_EXPORT(98, void, png_free_data,
1885 (png_structp png_ptr, png_infop info_ptr, png_uint_32 free_me, int num));
1886
1887/* Reassign responsibility for freeing existing data, whether allocated
1888 * by libpng or by the application */
1889PNG_EXPORT(99, void, png_data_freer,
1890 (png_structp png_ptr, png_infop info_ptr, int freer, png_uint_32 mask));
1891
1892/* Assignments for png_data_freer */
1893#define PNG_DESTROY_WILL_FREE_DATA 1
1894#define PNG_SET_WILL_FREE_DATA 1
1895#define PNG_USER_WILL_FREE_DATA 2
1896/* Flags for png_ptr->free_me and info_ptr->free_me */
1897#define PNG_FREE_HIST 0x0008
1898#define PNG_FREE_ICCP 0x0010
1899#define PNG_FREE_SPLT 0x0020
1900#define PNG_FREE_ROWS 0x0040
1901#define PNG_FREE_PCAL 0x0080
1902#define PNG_FREE_SCAL 0x0100
1903#define PNG_FREE_UNKN 0x0200
1904#define PNG_FREE_LIST 0x0400
1905#define PNG_FREE_PLTE 0x1000
1906#define PNG_FREE_TRNS 0x2000
1907#define PNG_FREE_TEXT 0x4000
1908#define PNG_FREE_ALL 0x7fff
1909#define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
1910
1911#ifdef PNG_USER_MEM_SUPPORTED
1912PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_structp png_ptr,
1913 png_alloc_size_t size), PNG_ALLOCATED);
1914PNG_EXPORT(101, void, png_free_default, (png_structp png_ptr, png_voidp ptr));
1915#endif
1916
1917#ifdef PNG_ERROR_TEXT_SUPPORTED
1918/* Fatal error in PNG image of libpng - can't continue */
1919PNG_EXPORTA(102, void, png_error,
1920 (png_structp png_ptr, png_const_charp error_message),
1921 PNG_NORETURN);
1922
1923/* The same, but the chunk name is prepended to the error string. */
1924PNG_EXPORTA(103, void, png_chunk_error, (png_structp png_ptr,
1925 png_const_charp error_message), PNG_NORETURN);
1926
1927#else
1928/* Fatal error in PNG image of libpng - can't continue */
1929PNG_EXPORTA(104, void, png_err, (png_structp png_ptr), PNG_NORETURN);
1930#endif
1931
1932#ifdef PNG_WARNINGS_SUPPORTED
1933/* Non-fatal error in libpng. Can continue, but may have a problem. */
1934PNG_EXPORT(105, void, png_warning, (png_structp png_ptr,
1935 png_const_charp warning_message));
1936
1937/* Non-fatal error in libpng, chunk name is prepended to message. */
1938PNG_EXPORT(106, void, png_chunk_warning, (png_structp png_ptr,
1939 png_const_charp warning_message));
1940#endif
1941
1942#ifdef PNG_BENIGN_ERRORS_SUPPORTED
1943/* Benign error in libpng. Can continue, but may have a problem.
1944 * User can choose whether to handle as a fatal error or as a warning. */
1945# undef png_benign_error
1946PNG_EXPORT(107, void, png_benign_error, (png_structp png_ptr,
1947 png_const_charp warning_message));
1948
1949/* Same, chunk name is prepended to message. */
1950# undef png_chunk_benign_error
1951PNG_EXPORT(108, void, png_chunk_benign_error, (png_structp png_ptr,
1952 png_const_charp warning_message));
1953
1954PNG_EXPORT(109, void, png_set_benign_errors,
1955 (png_structp png_ptr, int allowed));
1956#else
1957# ifdef PNG_ALLOW_BENIGN_ERRORS
1958# define png_benign_error png_warning
1959# define png_chunk_benign_error png_chunk_warning
1960# else
1961# define png_benign_error png_error
1962# define png_chunk_benign_error png_chunk_error
1963# endif
1964#endif
1965
1966/* The png_set_<chunk> functions are for storing values in the png_info_struct.
1967 * Similarly, the png_get_<chunk> calls are used to read values from the
1968 * png_info_struct, either storing the parameters in the passed variables, or
1969 * setting pointers into the png_info_struct where the data is stored. The
1970 * png_get_<chunk> functions return a non-zero value if the data was available
1971 * in info_ptr, or return zero and do not change any of the parameters if the
1972 * data was not available.
1973 *
1974 * These functions should be used instead of directly accessing png_info
1975 * to avoid problems with future changes in the size and internal layout of
1976 * png_info_struct.
1977 */
1978/* Returns "flag" if chunk data is valid in info_ptr. */
1979PNG_EXPORT(110, png_uint_32, png_get_valid,
1980 (png_const_structp png_ptr, png_const_infop info_ptr,
1981 png_uint_32 flag));
1982
1983/* Returns number of bytes needed to hold a transformed row. */
1984PNG_EXPORT(111, png_size_t, png_get_rowbytes, (png_const_structp png_ptr,
1985 png_const_infop info_ptr));
1986
1987#ifdef PNG_INFO_IMAGE_SUPPORTED
1988/* Returns row_pointers, which is an array of pointers to scanlines that was
1989 * returned from png_read_png().
1990 */
1991PNG_EXPORT(112, png_bytepp, png_get_rows,
1992 (png_const_structp png_ptr, png_const_infop info_ptr));
1993/* Set row_pointers, which is an array of pointers to scanlines for use
1994 * by png_write_png().
1995 */
1996PNG_EXPORT(113, void, png_set_rows, (png_structp png_ptr,
1997 png_infop info_ptr, png_bytepp row_pointers));
1998#endif
1999
2000/* Returns number of color channels in image. */
2001PNG_EXPORT(114, png_byte, png_get_channels,
2002 (png_const_structp png_ptr, png_const_infop info_ptr));
2003
2004#ifdef PNG_EASY_ACCESS_SUPPORTED
2005/* Returns image width in pixels. */
2006PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structp png_ptr,
2007 png_const_infop info_ptr));
2008
2009/* Returns image height in pixels. */
2010PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structp png_ptr,
2011 png_const_infop info_ptr));
2012
2013/* Returns image bit_depth. */
2014PNG_EXPORT(117, png_byte, png_get_bit_depth,
2015 (png_const_structp png_ptr, png_const_infop info_ptr));
2016
2017/* Returns image color_type. */
2018PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structp png_ptr,
2019 png_const_infop info_ptr));
2020
2021/* Returns image filter_type. */
2022PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structp png_ptr,
2023 png_const_infop info_ptr));
2024
2025/* Returns image interlace_type. */
2026PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structp png_ptr,
2027 png_const_infop info_ptr));
2028
2029/* Returns image compression_type. */
2030PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structp png_ptr,
2031 png_const_infop info_ptr));
2032
2033/* Returns image resolution in pixels per meter, from pHYs chunk data. */
2034PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter,
2035 (png_const_structp png_ptr, png_const_infop info_ptr));
2036PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter,
2037 (png_const_structp png_ptr, png_const_infop info_ptr));
2038PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter,
2039 (png_const_structp png_ptr, png_const_infop info_ptr));
2040
2041/* Returns pixel aspect ratio, computed from pHYs chunk data. */
2042PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio,
2043 (png_const_structp png_ptr, png_const_infop info_ptr));
2044PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed,
2045 (png_const_structp png_ptr, png_const_infop info_ptr));
2046
2047/* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
2048PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels,
2049 (png_const_structp png_ptr, png_const_infop info_ptr));
2050PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels,
2051 (png_const_structp png_ptr, png_const_infop info_ptr));
2052PNG_EXPORT(128, png_int_32, png_get_x_offset_microns,
2053 (png_const_structp png_ptr, png_const_infop info_ptr));
2054PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,
2055 (png_const_structp png_ptr, png_const_infop info_ptr));
2056
2057#endif /* PNG_EASY_ACCESS_SUPPORTED */
2058
2059/* Returns pointer to signature string read from PNG header */
2060PNG_EXPORT(130, png_const_bytep, png_get_signature,
2061 (png_const_structp png_ptr, png_infop info_ptr));
2062
2063#ifdef PNG_bKGD_SUPPORTED
2064PNG_EXPORT(131, png_uint_32, png_get_bKGD,
2065 (png_const_structp png_ptr, png_infop info_ptr,
2066 png_color_16p *background));
2067#endif
2068
2069#ifdef PNG_bKGD_SUPPORTED
2070PNG_EXPORT(132, void, png_set_bKGD, (png_structp png_ptr, png_infop info_ptr,
2071 png_const_color_16p background));
2072#endif
2073
2074#ifdef PNG_cHRM_SUPPORTED
2075PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structp png_ptr,
2076 png_const_infop info_ptr, double *white_x, double *white_y, double *red_x,
2077 double *red_y, double *green_x, double *green_y, double *blue_x,
2078 double *blue_y));
2079PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_structp png_ptr,
2080 png_const_infop info_ptr, double *red_X, double *red_Y, double *red_Z,
2081 double *green_X, double *green_Y, double *green_Z, double *blue_X,
2082 double *blue_Y, double *blue_Z));
2083#ifdef PNG_FIXED_POINT_SUPPORTED /* Otherwise not implemented */
2084PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed,
2085 (png_const_structp png_ptr,
2086 png_const_infop info_ptr, png_fixed_point *int_white_x,
2087 png_fixed_point *int_white_y, png_fixed_point *int_red_x,
2088 png_fixed_point *int_red_y, png_fixed_point *int_green_x,
2089 png_fixed_point *int_green_y, png_fixed_point *int_blue_x,
2090 png_fixed_point *int_blue_y));
2091#endif
2092PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed,
2093 (png_structp png_ptr, png_const_infop info_ptr,
2094 png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
2095 png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
2096 png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
2097 png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
2098 png_fixed_point *int_blue_Z));
2099#endif
2100
2101#ifdef PNG_cHRM_SUPPORTED
2102PNG_FP_EXPORT(135, void, png_set_cHRM,
2103 (png_structp png_ptr, png_infop info_ptr,
2104 double white_x, double white_y, double red_x, double red_y, double green_x,
2105 double green_y, double blue_x, double blue_y));
2106PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_structp png_ptr,
2107 png_infop info_ptr, double red_X, double red_Y, double red_Z,
2108 double green_X, double green_Y, double green_Z, double blue_X,
2109 double blue_Y, double blue_Z));
2110PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_structp png_ptr,
2111 png_infop info_ptr, png_fixed_point int_white_x,
2112 png_fixed_point int_white_y, png_fixed_point int_red_x,
2113 png_fixed_point int_red_y, png_fixed_point int_green_x,
2114 png_fixed_point int_green_y, png_fixed_point int_blue_x,
2115 png_fixed_point int_blue_y));
2116PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_structp png_ptr,
2117 png_infop info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y,
2118 png_fixed_point int_red_Z, png_fixed_point int_green_X,
2119 png_fixed_point int_green_Y, png_fixed_point int_green_Z,
2120 png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
2121 png_fixed_point int_blue_Z));
2122#endif
2123
2124#ifdef PNG_gAMA_SUPPORTED
2125PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA,
2126 (png_const_structp png_ptr, png_const_infop info_ptr,
2127 double *file_gamma));
2128PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed,
2129 (png_const_structp png_ptr, png_const_infop info_ptr,
2130 png_fixed_point *int_file_gamma));
2131#endif
2132
2133#ifdef PNG_gAMA_SUPPORTED
2134PNG_FP_EXPORT(139, void, png_set_gAMA, (png_structp png_ptr,
2135 png_infop info_ptr, double file_gamma));
2136PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_structp png_ptr,
2137 png_infop info_ptr, png_fixed_point int_file_gamma));
2138#endif
2139
2140#ifdef PNG_hIST_SUPPORTED
2141PNG_EXPORT(141, png_uint_32, png_get_hIST,
2142 (png_const_structp png_ptr, png_const_infop info_ptr,
2143 png_uint_16p *hist));
2144#endif
2145
2146#ifdef PNG_hIST_SUPPORTED
2147PNG_EXPORT(142, void, png_set_hIST, (png_structp png_ptr,
2148 png_infop info_ptr, png_const_uint_16p hist));
2149#endif
2150
2151PNG_EXPORT(143, png_uint_32, png_get_IHDR,
2152 (png_structp png_ptr, png_infop info_ptr,
2153 png_uint_32 *width, png_uint_32 *height, int *bit_depth, int *color_type,
2154 int *interlace_method, int *compression_method, int *filter_method));
2155
2156PNG_EXPORT(144, void, png_set_IHDR,
2157 (png_structp png_ptr, png_infop info_ptr,
2158 png_uint_32 width, png_uint_32 height, int bit_depth, int color_type,
2159 int interlace_method, int compression_method, int filter_method));
2160
2161#ifdef PNG_oFFs_SUPPORTED
2162PNG_EXPORT(145, png_uint_32, png_get_oFFs,
2163 (png_const_structp png_ptr, png_const_infop info_ptr,
2164 png_int_32 *offset_x, png_int_32 *offset_y, int *unit_type));
2165#endif
2166
2167#ifdef PNG_oFFs_SUPPORTED
2168PNG_EXPORT(146, void, png_set_oFFs,
2169 (png_structp png_ptr, png_infop info_ptr,
2170 png_int_32 offset_x, png_int_32 offset_y, int unit_type));
2171#endif
2172
2173#ifdef PNG_pCAL_SUPPORTED
2174PNG_EXPORT(147, png_uint_32, png_get_pCAL,
2175 (png_const_structp png_ptr, png_const_infop info_ptr,
2176 png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type,
2177 int *nparams,
2178 png_charp *units, png_charpp *params));
2179#endif
2180
2181#ifdef PNG_pCAL_SUPPORTED
2182PNG_EXPORT(148, void, png_set_pCAL, (png_structp png_ptr,
2183 png_infop info_ptr,
2184 png_const_charp purpose, png_int_32 X0, png_int_32 X1, int type,
2185 int nparams, png_const_charp units, png_charpp params));
2186#endif
2187
2188#ifdef PNG_pHYs_SUPPORTED
2189PNG_EXPORT(149, png_uint_32, png_get_pHYs,
2190 (png_const_structp png_ptr, png_const_infop info_ptr,
2191 png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
2192#endif
2193
2194#ifdef PNG_pHYs_SUPPORTED
2195PNG_EXPORT(150, void, png_set_pHYs,
2196 (png_structp png_ptr, png_infop info_ptr,
2197 png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2198#endif
2199
2200PNG_EXPORT(151, png_uint_32, png_get_PLTE,
2201 (png_const_structp png_ptr, png_const_infop info_ptr,
2202 png_colorp *palette, int *num_palette));
2203
2204PNG_EXPORT(152, void, png_set_PLTE,
2205 (png_structp png_ptr, png_infop info_ptr,
2206 png_const_colorp palette, int num_palette));
2207
2208#ifdef PNG_sBIT_SUPPORTED
2209PNG_EXPORT(153, png_uint_32, png_get_sBIT,
2210 (png_const_structp png_ptr, png_infop info_ptr,
2211 png_color_8p *sig_bit));
2212#endif
2213
2214#ifdef PNG_sBIT_SUPPORTED
2215PNG_EXPORT(154, void, png_set_sBIT,
2216 (png_structp png_ptr, png_infop info_ptr, png_const_color_8p sig_bit));
2217#endif
2218
2219#ifdef PNG_sRGB_SUPPORTED
2220PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structp png_ptr,
2221 png_const_infop info_ptr, int *file_srgb_intent));
2222#endif
2223
2224#ifdef PNG_sRGB_SUPPORTED
2225PNG_EXPORT(156, void, png_set_sRGB,
2226 (png_structp png_ptr, png_infop info_ptr, int srgb_intent));
2227PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_structp png_ptr,
2228 png_infop info_ptr, int srgb_intent));
2229#endif
2230
2231#ifdef PNG_iCCP_SUPPORTED
2232PNG_EXPORT(158, png_uint_32, png_get_iCCP,
2233 (png_const_structp png_ptr, png_const_infop info_ptr,
2234 png_charpp name, int *compression_type, png_bytepp profile,
2235 png_uint_32 *proflen));
2236#endif
2237
2238#ifdef PNG_iCCP_SUPPORTED
2239PNG_EXPORT(159, void, png_set_iCCP,
2240 (png_structp png_ptr, png_infop info_ptr,
2241 png_const_charp name, int compression_type, png_const_bytep profile,
2242 png_uint_32 proflen));
2243#endif
2244
2245#ifdef PNG_sPLT_SUPPORTED
2246PNG_EXPORT(160, png_uint_32, png_get_sPLT,
2247 (png_const_structp png_ptr, png_const_infop info_ptr,
2248 png_sPLT_tpp entries));
2249#endif
2250
2251#ifdef PNG_sPLT_SUPPORTED
2252PNG_EXPORT(161, void, png_set_sPLT,
2253 (png_structp png_ptr, png_infop info_ptr,
2254 png_const_sPLT_tp entries, int nentries));
2255#endif
2256
2257#ifdef PNG_TEXT_SUPPORTED
2258/* png_get_text also returns the number of text chunks in *num_text */
2259PNG_EXPORT(162, png_uint_32, png_get_text,
2260 (png_const_structp png_ptr, png_const_infop info_ptr,
2261 png_textp *text_ptr, int *num_text));
2262#endif
2263
2264/* Note while png_set_text() will accept a structure whose text,
2265 * language, and translated keywords are NULL pointers, the structure
2266 * returned by png_get_text will always contain regular
2267 * zero-terminated C strings. They might be empty strings but
2268 * they will never be NULL pointers.
2269 */
2270
2271#ifdef PNG_TEXT_SUPPORTED
2272PNG_EXPORT(163, void, png_set_text,
2273 (png_structp png_ptr, png_infop info_ptr,
2274 png_const_textp text_ptr, int num_text));
2275#endif
2276
2277#ifdef PNG_tIME_SUPPORTED
2278PNG_EXPORT(164, png_uint_32, png_get_tIME,
2279 (png_const_structp png_ptr, png_infop info_ptr, png_timep *mod_time));
2280#endif
2281
2282#ifdef PNG_tIME_SUPPORTED
2283PNG_EXPORT(165, void, png_set_tIME,
2284 (png_structp png_ptr, png_infop info_ptr, png_const_timep mod_time));
2285#endif
2286
2287#ifdef PNG_tRNS_SUPPORTED
2288PNG_EXPORT(166, png_uint_32, png_get_tRNS,
2289 (png_const_structp png_ptr, png_infop info_ptr,
2290 png_bytep *trans_alpha, int *num_trans, png_color_16p *trans_color));
2291#endif
2292
2293#ifdef PNG_tRNS_SUPPORTED
2294PNG_EXPORT(167, void, png_set_tRNS,
2295 (png_structp png_ptr, png_infop info_ptr,
2296 png_const_bytep trans_alpha, int num_trans,
2297 png_const_color_16p trans_color));
2298#endif
2299
2300#ifdef PNG_sCAL_SUPPORTED
2301PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL,
2302 (png_const_structp png_ptr, png_const_infop info_ptr,
2303 int *unit, double *width, double *height));
2304#ifdef PNG_FLOATING_ARITHMETIC_SUPPORTED
2305/* NOTE: this API is currently implemented using floating point arithmetic,
2306 * consequently it can only be used on systems with floating point support.
2307 * In any case the range of values supported by png_fixed_point is small and it
2308 * is highly recommended that png_get_sCAL_s be used instead.
2309 */
2310PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed,
2311 (png_structp png_ptr, png_const_infop info_ptr, int *unit,
2312 png_fixed_point *width,
2313 png_fixed_point *height));
2314#endif
2315PNG_EXPORT(169, png_uint_32, png_get_sCAL_s,
2316 (png_const_structp png_ptr, png_const_infop info_ptr,
2317 int *unit, png_charpp swidth, png_charpp sheight));
2318
2319PNG_FP_EXPORT(170, void, png_set_sCAL,
2320 (png_structp png_ptr, png_infop info_ptr,
2321 int unit, double width, double height));
2322PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_structp png_ptr,
2323 png_infop info_ptr, int unit, png_fixed_point width,
2324 png_fixed_point height));
2325PNG_EXPORT(171, void, png_set_sCAL_s,
2326 (png_structp png_ptr, png_infop info_ptr,
2327 int unit, png_const_charp swidth, png_const_charp sheight));
2328#endif /* PNG_sCAL_SUPPORTED */
2329
2330#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2331/* Provide a list of chunks and how they are to be handled, if the built-in
2332 handling or default unknown chunk handling is not desired. Any chunks not
2333 listed will be handled in the default manner. The IHDR and IEND chunks
2334 must not be listed. Because this turns off the default handling for chunks
2335 that would otherwise be recognized the behavior of libpng transformations may
2336 well become incorrect!
2337 keep = 0: PNG_HANDLE_CHUNK_AS_DEFAULT: follow default behavior
2338 = 1: PNG_HANDLE_CHUNK_NEVER: do not keep
2339 = 2: PNG_HANDLE_CHUNK_IF_SAFE: keep only if safe-to-copy
2340 = 3: PNG_HANDLE_CHUNK_ALWAYS: keep even if unsafe-to-copy
2341*/
2342PNG_EXPORT(172, void, png_set_keep_unknown_chunks,
2343 (png_structp png_ptr, int keep,
2344 png_const_bytep chunk_list, int num_chunks));
2345
2346/* The handling code is returned; the result is therefore true (non-zero) if
2347 * special handling is required, false for the default handling.
2348 */
2349PNG_EXPORT(173, int, png_handle_as_unknown, (png_structp png_ptr,
2350 png_const_bytep chunk_name));
2351#endif
2352#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
2353PNG_EXPORT(174, void, png_set_unknown_chunks, (png_structp png_ptr,
2354 png_infop info_ptr, png_const_unknown_chunkp unknowns,
2355 int num_unknowns));
2356PNG_EXPORT(175, void, png_set_unknown_chunk_location,
2357 (png_structp png_ptr, png_infop info_ptr, int chunk, int location));
2358PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structp png_ptr,
2359 png_const_infop info_ptr, png_unknown_chunkpp entries));
2360#endif
2361
2362/* Png_free_data() will turn off the "valid" flag for anything it frees.
2363 * If you need to turn it off for a chunk that your application has freed,
2364 * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
2365 */
2366PNG_EXPORT(177, void, png_set_invalid,
2367 (png_structp png_ptr, png_infop info_ptr, int mask));
2368
2369#ifdef PNG_INFO_IMAGE_SUPPORTED
2370/* The "params" pointer is currently not used and is for future expansion. */
2371PNG_EXPORT(178, void, png_read_png, (png_structp png_ptr, png_infop info_ptr,
2372 int transforms, png_voidp params));
2373PNG_EXPORT(179, void, png_write_png, (png_structp png_ptr, png_infop info_ptr,
2374 int transforms, png_voidp params));
2375#endif
2376
2377PNG_EXPORT(180, png_const_charp, png_get_copyright,
2378 (png_const_structp png_ptr));
2379PNG_EXPORT(181, png_const_charp, png_get_header_ver,
2380 (png_const_structp png_ptr));
2381PNG_EXPORT(182, png_const_charp, png_get_header_version,
2382 (png_const_structp png_ptr));
2383PNG_EXPORT(183, png_const_charp, png_get_libpng_ver,
2384 (png_const_structp png_ptr));
2385
2386#ifdef PNG_MNG_FEATURES_SUPPORTED
2387PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structp png_ptr,
2388 png_uint_32 mng_features_permitted));
2389#endif
2390
2391/* For use in png_set_keep_unknown, added to version 1.2.6 */
2392#define PNG_HANDLE_CHUNK_AS_DEFAULT 0
2393#define PNG_HANDLE_CHUNK_NEVER 1
2394#define PNG_HANDLE_CHUNK_IF_SAFE 2
2395#define PNG_HANDLE_CHUNK_ALWAYS 3
2396
2397/* Strip the prepended error numbers ("#nnn ") from error and warning
2398 * messages before passing them to the error or warning handler.
2399 */
2400#ifdef PNG_ERROR_NUMBERS_SUPPORTED
2401PNG_EXPORT(185, void, png_set_strip_error_numbers,
2402 (png_structp png_ptr,
2403 png_uint_32 strip_mode));
2404#endif
2405
2406/* Added in libpng-1.2.6 */
2407#ifdef PNG_SET_USER_LIMITS_SUPPORTED
2408PNG_EXPORT(186, void, png_set_user_limits, (png_structp png_ptr,
2409 png_uint_32 user_width_max, png_uint_32 user_height_max));
2410PNG_EXPORT(187, png_uint_32, png_get_user_width_max,
2411 (png_const_structp png_ptr));
2412PNG_EXPORT(188, png_uint_32, png_get_user_height_max,
2413 (png_const_structp png_ptr));
2414/* Added in libpng-1.4.0 */
2415PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structp png_ptr,
2416 png_uint_32 user_chunk_cache_max));
2417PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max,
2418 (png_const_structp png_ptr));
2419/* Added in libpng-1.4.1 */
2420PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structp png_ptr,
2421 png_alloc_size_t user_chunk_cache_max));
2422PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max,
2423 (png_const_structp png_ptr));
2424#endif
2425
2426#if defined(PNG_INCH_CONVERSIONS_SUPPORTED)
2427PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch,
2428 (png_const_structp png_ptr, png_const_infop info_ptr));
2429
2430PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch,
2431 (png_const_structp png_ptr, png_const_infop info_ptr));
2432
2433PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch,
2434 (png_const_structp png_ptr, png_const_infop info_ptr));
2435
2436PNG_FP_EXPORT(196, float, png_get_x_offset_inches,
2437 (png_const_structp png_ptr, png_const_infop info_ptr));
2438#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2439PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed,
2440 (png_structp png_ptr, png_const_infop info_ptr));
2441#endif
2442
2443PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structp png_ptr,
2444 png_const_infop info_ptr));
2445#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2446PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed,
2447 (png_structp png_ptr, png_const_infop info_ptr));
2448#endif
2449
2450# ifdef PNG_pHYs_SUPPORTED
2451PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structp png_ptr,
2452 png_const_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
2453 int *unit_type));
2454# endif /* PNG_pHYs_SUPPORTED */
2455#endif /* PNG_INCH_CONVERSIONS_SUPPORTED */
2456
2457/* Added in libpng-1.4.0 */
2458#ifdef PNG_IO_STATE_SUPPORTED
2459PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_structp png_ptr));
2460
2461PNG_EXPORTA(200, png_const_bytep, png_get_io_chunk_name,
2462 (png_structp png_ptr), PNG_DEPRECATED);
2463PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
2464 (png_const_structp png_ptr));
2465
2466/* The flags returned by png_get_io_state() are the following: */
2467# define PNG_IO_NONE 0x0000 /* no I/O at this moment */
2468# define PNG_IO_READING 0x0001 /* currently reading */
2469# define PNG_IO_WRITING 0x0002 /* currently writing */
2470# define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */
2471# define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */
2472# define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */
2473# define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */
2474# define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */
2475# define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */
2476#endif /* ?PNG_IO_STATE_SUPPORTED */
2477
2478/* Interlace support. The following macros are always defined so that if
2479 * libpng interlace handling is turned off the macros may be used to handle
2480 * interlaced images within the application.
2481 */
2482#define PNG_INTERLACE_ADAM7_PASSES 7
2483
2484/* Two macros to return the first row and first column of the original,
2485 * full, image which appears in a given pass. 'pass' is in the range 0
2486 * to 6 and the result is in the range 0 to 7.
2487 */
2488#define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7)
2489#define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7)
2490
2491/* A macro to return the offset between pixels in the output row for a pair of
2492 * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that
2493 * follows. Note that ROW_OFFSET is the offset from one row to the next whereas
2494 * COL_OFFSET is from one column to the next, within a row.
2495 */
2496#define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8)
2497#define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1))
2498
2499/* Two macros to help evaluate the number of rows or columns in each
2500 * pass. This is expressed as a shift - effectively log2 of the number or
2501 * rows or columns in each 8x8 tile of the original image.
2502 */
2503#define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)
2504#define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)
2505
2506/* Hence two macros to determine the number of rows or columns in a given
2507 * pass of an image given its height or width. In fact these macros may
2508 * return non-zero even though the sub-image is empty, because the other
2509 * dimension may be empty for a small image.
2510 */
2511#define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\
2512 -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass))
2513#define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\
2514 -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass))
2515
2516/* For the reader row callbacks (both progressive and sequential) it is
2517 * necessary to find the row in the output image given a row in an interlaced
2518 * image, so two more macros:
2519 */
2520#define PNG_ROW_FROM_PASS_ROW(yIn, pass) \
2521 (((yIn)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))
2522#define PNG_COL_FROM_PASS_COL(xIn, pass) \
2523 (((xIn)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))
2524
2525/* Two macros which return a boolean (0 or 1) saying whether the given row
2526 * or column is in a particular pass. These use a common utility macro that
2527 * returns a mask for a given pass - the offset 'off' selects the row or
2528 * column version. The mask has the appropriate bit set for each column in
2529 * the tile.
2530 */
2531#define PNG_PASS_MASK(pass,off) ( \
2532 ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \
2533 ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0))
2534
2535#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
2536 ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
2537#define PNG_COL_IN_INTERLACE_PASS(x, pass) \
2538 ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
2539
2540#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2541/* With these routines we avoid an integer divide, which will be slower on
2542 * most machines. However, it does take more operations than the corresponding
2543 * divide method, so it may be slower on a few RISC systems. There are two
2544 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2545 *
2546 * Note that the rounding factors are NOT supposed to be the same! 128 and
2547 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2548 * standard method.
2549 *
2550 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2551 */
2552
2553 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2554
2555# define png_composite(composite, fg, alpha, bg) \
2556 { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
2557 * (png_uint_16)(alpha) \
2558 + (png_uint_16)(bg)*(png_uint_16)(255 \
2559 - (png_uint_16)(alpha)) + 128); \
2560 (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
2561
2562# define png_composite_16(composite, fg, alpha, bg) \
2563 { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
2564 * (png_uint_32)(alpha) \
2565 + (png_uint_32)(bg)*(65535 \
2566 - (png_uint_32)(alpha)) + 32768); \
2567 (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
2568
2569#else /* Standard method using integer division */
2570
2571# define png_composite(composite, fg, alpha, bg) \
2572 (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2573 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2574 127) / 255)
2575
2576# define png_composite_16(composite, fg, alpha, bg) \
2577 (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2578 (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \
2579 32767) / 65535)
2580#endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
2581
2582#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
2583PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf));
2584PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf));
2585PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf));
2586#endif
2587
2588PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_structp png_ptr,
2589 png_const_bytep buf));
2590/* No png_get_int_16 -- may be added if there's a real need for it. */
2591
2592/* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
2593#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2594PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i));
2595#endif
2596#ifdef PNG_SAVE_INT_32_SUPPORTED
2597PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i));
2598#endif
2599
2600/* Place a 16-bit number into a buffer in PNG byte order.
2601 * The parameter is declared unsigned int, not png_uint_16,
2602 * just to avoid potential problems on pre-ANSI C compilers.
2603 */
2604#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2605PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));
2606/* No png_save_int_16 -- may be added if there's a real need for it. */
2607#endif
2608
2609#ifdef PNG_USE_READ_MACROS
2610/* Inline macros to do direct reads of bytes from the input buffer.
2611 * The png_get_int_32() routine assumes we are using two's complement
2612 * format for negative values, which is almost certainly true.
2613 */
2614# define png_get_uint_32(buf) \
2615 (((png_uint_32)(*(buf)) << 24) + \
2616 ((png_uint_32)(*((buf) + 1)) << 16) + \
2617 ((png_uint_32)(*((buf) + 2)) << 8) + \
2618 ((png_uint_32)(*((buf) + 3))))
2619
2620 /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
2621 * function) incorrectly returned a value of type png_uint_32.
2622 */
2623# define png_get_uint_16(buf) \
2624 ((png_uint_16) \
2625 (((unsigned int)(*(buf)) << 8) + \
2626 ((unsigned int)(*((buf) + 1)))))
2627
2628# define png_get_int_32(buf) \
2629 ((png_int_32)((*(buf) & 0x80) \
2630 ? -((png_int_32)((png_get_uint_32(buf) ^ 0xffffffffL) + 1)) \
2631 : (png_int_32)png_get_uint_32(buf)))
2632#endif
2633
2634/* Maintainer: Put new public prototypes here ^, in libpng.3, and project
2635 * defs
2636 */
2637
2638/* The last ordinal number (this is the *last* one already used; the next
2639 * one to use is one more than this.) Maintainer, remember to add an entry to
2640 * scripts/symbols.def as well.
2641 */
2642#ifdef PNG_EXPORT_LAST_ORDINAL
2643 PNG_EXPORT_LAST_ORDINAL(233);
2644#endif
2645
2646#ifdef __cplusplus
2647}
2648#endif
2649
2650#endif /* PNG_VERSION_INFO_ONLY */
2651/* Do not put anything past this line */
2652#endif /* PNG_H */
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