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2/* png.h - header file for PNG reference library
3 *
4 * libpng version 1.2.20 - September 8, 2007
5 * Copyright (c) 1998-2007 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 * Authors and maintainers:
10 * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
11 * libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
12 * libpng versions 0.97, January 1998, through 1.2.20 - September 8, 2007: Glenn
13 * See also "Contributing Authors", below.
14 *
15 * Note about libpng version numbers:
16 *
17 * Due to various miscommunications, unforeseen code incompatibilities
18 * and occasional factors outside the authors' control, version numbering
19 * on the library has not always been consistent and straightforward.
20 * The following table summarizes matters since version 0.89c, which was
21 * the first widely used release:
22 *
23 * source png.h png.h shared-lib
24 * version string int version
25 * ------- ------ ----- ----------
26 * 0.89c "1.0 beta 3" 0.89 89 1.0.89
27 * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]
28 * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]
29 * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]
30 * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]
31 * 0.97c 0.97 97 2.0.97
32 * 0.98 0.98 98 2.0.98
33 * 0.99 0.99 98 2.0.99
34 * 0.99a-m 0.99 99 2.0.99
35 * 1.00 1.00 100 2.1.0 [100 should be 10000]
36 * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]
37 * 1.0.1 png.h string is 10001 2.1.0
38 * 1.0.1a-e identical to the 10002 from here on, the shared library
39 * 1.0.2 source version) 10002 is 2.V where V is the source code
40 * 1.0.2a-b 10003 version, except as noted.
41 * 1.0.3 10003
42 * 1.0.3a-d 10004
43 * 1.0.4 10004
44 * 1.0.4a-f 10005
45 * 1.0.5 (+ 2 patches) 10005
46 * 1.0.5a-d 10006
47 * 1.0.5e-r 10100 (not source compatible)
48 * 1.0.5s-v 10006 (not binary compatible)
49 * 1.0.6 (+ 3 patches) 10006 (still binary incompatible)
50 * 1.0.6d-f 10007 (still binary incompatible)
51 * 1.0.6g 10007
52 * 1.0.6h 10007 10.6h (testing xy.z so-numbering)
53 * 1.0.6i 10007 10.6i
54 * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
55 * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)
56 * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
57 * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
58 * 1.0.7 1 10007 (still compatible)
59 * 1.0.8beta1-4 1 10008 2.1.0.8beta1-4
60 * 1.0.8rc1 1 10008 2.1.0.8rc1
61 * 1.0.8 1 10008 2.1.0.8
62 * 1.0.9beta1-6 1 10009 2.1.0.9beta1-6
63 * 1.0.9rc1 1 10009 2.1.0.9rc1
64 * 1.0.9beta7-10 1 10009 2.1.0.9beta7-10
65 * 1.0.9rc2 1 10009 2.1.0.9rc2
66 * 1.0.9 1 10009 2.1.0.9
67 * 1.0.10beta1 1 10010 2.1.0.10beta1
68 * 1.0.10rc1 1 10010 2.1.0.10rc1
69 * 1.0.10 1 10010 2.1.0.10
70 * 1.0.11beta1-3 1 10011 2.1.0.11beta1-3
71 * 1.0.11rc1 1 10011 2.1.0.11rc1
72 * 1.0.11 1 10011 2.1.0.11
73 * 1.0.12beta1-2 2 10012 2.1.0.12beta1-2
74 * 1.0.12rc1 2 10012 2.1.0.12rc1
75 * 1.0.12 2 10012 2.1.0.12
76 * 1.1.0a-f - 10100 2.1.1.0a-f (branch abandoned)
77 * 1.2.0beta1-2 2 10200 2.1.2.0beta1-2
78 * 1.2.0beta3-5 3 10200 3.1.2.0beta3-5
79 * 1.2.0rc1 3 10200 3.1.2.0rc1
80 * 1.2.0 3 10200 3.1.2.0
81 * 1.2.1beta1-4 3 10201 3.1.2.1beta1-4
82 * 1.2.1rc1-2 3 10201 3.1.2.1rc1-2
83 * 1.2.1 3 10201 3.1.2.1
84 * 1.2.2beta1-6 12 10202 12.so.0.1.2.2beta1-6
85 * 1.0.13beta1 10 10013 10.so.0.1.0.13beta1
86 * 1.0.13rc1 10 10013 10.so.0.1.0.13rc1
87 * 1.2.2rc1 12 10202 12.so.0.1.2.2rc1
88 * 1.0.13 10 10013 10.so.0.1.0.13
89 * 1.2.2 12 10202 12.so.0.1.2.2
90 * 1.2.3rc1-6 12 10203 12.so.0.1.2.3rc1-6
91 * 1.2.3 12 10203 12.so.0.1.2.3
92 * 1.2.4beta1-3 13 10204 12.so.0.1.2.4beta1-3
93 * 1.0.14rc1 13 10014 10.so.0.1.0.14rc1
94 * 1.2.4rc1 13 10204 12.so.0.1.2.4rc1
95 * 1.0.14 10 10014 10.so.0.1.0.14
96 * 1.2.4 13 10204 12.so.0.1.2.4
97 * 1.2.5beta1-2 13 10205 12.so.0.1.2.5beta1-2
98 * 1.0.15rc1-3 10 10015 10.so.0.1.0.15rc1-3
99 * 1.2.5rc1-3 13 10205 12.so.0.1.2.5rc1-3
100 * 1.0.15 10 10015 10.so.0.1.0.15
101 * 1.2.5 13 10205 12.so.0.1.2.5
102 * 1.2.6beta1-4 13 10206 12.so.0.1.2.6beta1-4
103 * 1.0.16 10 10016 10.so.0.1.0.16
104 * 1.2.6 13 10206 12.so.0.1.2.6
105 * 1.2.7beta1-2 13 10207 12.so.0.1.2.7beta1-2
106 * 1.0.17rc1 10 10017 10.so.0.1.0.17rc1
107 * 1.2.7rc1 13 10207 12.so.0.1.2.7rc1
108 * 1.0.17 10 10017 10.so.0.1.0.17
109 * 1.2.7 13 10207 12.so.0.1.2.7
110 * 1.2.8beta1-5 13 10208 12.so.0.1.2.8beta1-5
111 * 1.0.18rc1-5 10 10018 10.so.0.1.0.18rc1-5
112 * 1.2.8rc1-5 13 10208 12.so.0.1.2.8rc1-5
113 * 1.0.18 10 10018 10.so.0.1.0.18
114 * 1.2.8 13 10208 12.so.0.1.2.8
115 * 1.2.9beta1-3 13 10209 12.so.0.1.2.9beta1-3
116 * 1.2.9beta4-11 13 10209 12.so.0.9[.0]
117 * 1.2.9rc1 13 10209 12.so.0.9[.0]
118 * 1.2.9 13 10209 12.so.0.9[.0]
119 * 1.2.10beta1-8 13 10210 12.so.0.10[.0]
120 * 1.2.10rc1-3 13 10210 12.so.0.10[.0]
121 * 1.2.10 13 10210 12.so.0.10[.0]
122 * 1.2.11beta1-4 13 10211 12.so.0.11[.0]
123 * 1.0.19rc1-5 10 10019 10.so.0.19[.0]
124 * 1.2.11rc1-5 13 10211 12.so.0.11[.0]
125 * 1.0.19 10 10019 10.so.0.19[.0]
126 * 1.2.11 13 10211 12.so.0.11[.0]
127 * 1.0.20 10 10020 10.so.0.20[.0]
128 * 1.2.12 13 10212 12.so.0.12[.0]
129 * 1.2.13beta1 13 10213 12.so.0.13[.0]
130 * 1.0.21 10 10021 10.so.0.21[.0]
131 * 1.2.13 13 10213 12.so.0.13[.0]
132 * 1.2.14beta1-2 13 10214 12.so.0.14[.0]
133 * 1.0.22rc1 10 10022 10.so.0.22[.0]
134 * 1.2.14rc1 13 10214 12.so.0.14[.0]
135 * 1.0.22 10 10022 10.so.0.22[.0]
136 * 1.2.14 13 10214 12.so.0.14[.0]
137 * 1.2.15beta1-6 13 10215 12.so.0.15[.0]
138 * 1.0.23rc1-5 10 10023 10.so.0.23[.0]
139 * 1.2.15rc1-5 13 10215 12.so.0.15[.0]
140 * 1.0.23 10 10023 10.so.0.23[.0]
141 * 1.2.15 13 10215 12.so.0.15[.0]
142 * 1.2.16beta1-2 13 10216 12.so.0.16[.0]
143 * 1.2.16rc1 13 10216 12.so.0.16[.0]
144 * 1.0.24 10 10024 10.so.0.24[.0]
145 * 1.2.16 13 10216 12.so.0.16[.0]
146 * 1.2.17beta1-2 13 10217 12.so.0.17[.0]
147 * 1.0.25rc1 10 10025 10.so.0.25[.0]
148 * 1.2.17rc1-3 13 10217 12.so.0.17[.0]
149 * 1.0.25 10 10025 10.so.0.25[.0]
150 * 1.2.17 13 10217 12.so.0.17[.0]
151 * 1.0.26 10 10026 10.so.0.26[.0]
152 * 1.2.18 13 10218 12.so.0.18[.0]
153 * 1.2.19beta1-31 13 10219 12.so.0.19[.0]
154 * 1.0.27rc1-6 10 10027 10.so.0.27[.0]
155 * 1.2.19rc1-6 13 10219 12.so.0.19[.0]
156 * 1.0.27 10 10027 10.so.0.27[.0]
157 * 1.2.19 13 10219 12.so.0.19[.0]
158 * 1.2.20beta01-04 13 10220 12.so.0.20[.0]
159 * 1.0.28rc1-6 10 10028 10.so.0.28[.0]
160 * 1.2.20rc1-6 13 10220 12.so.0.20[.0]
161 * 1.0.28 10 10028 10.so.0.28[.0]
162 * 1.2.20 13 10220 12.so.0.20[.0]
163 *
164 * Henceforth the source version will match the shared-library major
165 * and minor numbers; the shared-library major version number will be
166 * used for changes in backward compatibility, as it is intended. The
167 * PNG_LIBPNG_VER macro, which is not used within libpng but is available
168 * for applications, is an unsigned integer of the form xyyzz corresponding
169 * to the source version x.y.z (leading zeros in y and z). Beta versions
170 * were given the previous public release number plus a letter, until
171 * version 1.0.6j; from then on they were given the upcoming public
172 * release number plus "betaNN" or "rcN".
173 *
174 * Binary incompatibility exists only when applications make direct access
175 * to the info_ptr or png_ptr members through png.h, and the compiled
176 * application is loaded with a different version of the library.
177 *
178 * DLLNUM will change each time there are forward or backward changes
179 * in binary compatibility (e.g., when a new feature is added).
180 *
181 * See libpng.txt or libpng.3 for more information. The PNG specification
182 * is available as a W3C Recommendation and as an ISO Specification,
183 * <http://www.w3.org/TR/2003/REC-PNG-20031110/
184 */
185
186/*
187 * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
188 *
189 * If you modify libpng you may insert additional notices immediately following
190 * this sentence.
191 *
192 * libpng versions 1.2.6, August 15, 2004, through 1.2.20, September 8, 2007, are
193 * Copyright (c) 2004, 2006-2007 Glenn Randers-Pehrson, and are
194 * distributed according to the same disclaimer and license as libpng-1.2.5
195 * with the following individual added to the list of Contributing Authors:
196 *
197 * Cosmin Truta
198 *
199 * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
200 * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
201 * distributed according to the same disclaimer and license as libpng-1.0.6
202 * with the following individuals added to the list of Contributing Authors:
203 *
204 * Simon-Pierre Cadieux
205 * Eric S. Raymond
206 * Gilles Vollant
207 *
208 * and with the following additions to the disclaimer:
209 *
210 * There is no warranty against interference with your enjoyment of the
211 * library or against infringement. There is no warranty that our
212 * efforts or the library will fulfill any of your particular purposes
213 * or needs. This library is provided with all faults, and the entire
214 * risk of satisfactory quality, performance, accuracy, and effort is with
215 * the user.
216 *
217 * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
218 * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are
219 * distributed according to the same disclaimer and license as libpng-0.96,
220 * with the following individuals added to the list of Contributing Authors:
221 *
222 * Tom Lane
223 * Glenn Randers-Pehrson
224 * Willem van Schaik
225 *
226 * libpng versions 0.89, June 1996, through 0.96, May 1997, are
227 * Copyright (c) 1996, 1997 Andreas Dilger
228 * Distributed according to the same disclaimer and license as libpng-0.88,
229 * with the following individuals added to the list of Contributing Authors:
230 *
231 * John Bowler
232 * Kevin Bracey
233 * Sam Bushell
234 * Magnus Holmgren
235 * Greg Roelofs
236 * Tom Tanner
237 *
238 * libpng versions 0.5, May 1995, through 0.88, January 1996, are
239 * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
240 *
241 * For the purposes of this copyright and license, "Contributing Authors"
242 * is defined as the following set of individuals:
243 *
244 * Andreas Dilger
245 * Dave Martindale
246 * Guy Eric Schalnat
247 * Paul Schmidt
248 * Tim Wegner
249 *
250 * The PNG Reference Library is supplied "AS IS". The Contributing Authors
251 * and Group 42, Inc. disclaim all warranties, expressed or implied,
252 * including, without limitation, the warranties of merchantability and of
253 * fitness for any purpose. The Contributing Authors and Group 42, Inc.
254 * assume no liability for direct, indirect, incidental, special, exemplary,
255 * or consequential damages, which may result from the use of the PNG
256 * Reference Library, even if advised of the possibility of such damage.
257 *
258 * Permission is hereby granted to use, copy, modify, and distribute this
259 * source code, or portions hereof, for any purpose, without fee, subject
260 * to the following restrictions:
261 *
262 * 1. The origin of this source code must not be misrepresented.
263 *
264 * 2. Altered versions must be plainly marked as such and
265 * must not be misrepresented as being the original source.
266 *
267 * 3. This Copyright notice may not be removed or altered from
268 * any source or altered source distribution.
269 *
270 * The Contributing Authors and Group 42, Inc. specifically permit, without
271 * fee, and encourage the use of this source code as a component to
272 * supporting the PNG file format in commercial products. If you use this
273 * source code in a product, acknowledgment is not required but would be
274 * appreciated.
275 */
276
277/*
278 * A "png_get_copyright" function is available, for convenient use in "about"
279 * boxes and the like:
280 *
281 * printf("%s",png_get_copyright(NULL));
282 *
283 * Also, the PNG logo (in PNG format, of course) is supplied in the
284 * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
285 */
286
287/*
288 * Libpng is OSI Certified Open Source Software. OSI Certified is a
289 * certification mark of the Open Source Initiative.
290 */
291
292/*
293 * The contributing authors would like to thank all those who helped
294 * with testing, bug fixes, and patience. This wouldn't have been
295 * possible without all of you.
296 *
297 * Thanks to Frank J. T. Wojcik for helping with the documentation.
298 */
299
300/*
301 * Y2K compliance in libpng:
302 * =========================
303 *
304 * September 8, 2007
305 *
306 * Since the PNG Development group is an ad-hoc body, we can't make
307 * an official declaration.
308 *
309 * This is your unofficial assurance that libpng from version 0.71 and
310 * upward through 1.2.20 are Y2K compliant. It is my belief that earlier
311 * versions were also Y2K compliant.
312 *
313 * Libpng only has three year fields. One is a 2-byte unsigned integer
314 * that will hold years up to 65535. The other two hold the date in text
315 * format, and will hold years up to 9999.
316 *
317 * The integer is
318 * "png_uint_16 year" in png_time_struct.
319 *
320 * The strings are
321 * "png_charp time_buffer" in png_struct and
322 * "near_time_buffer", which is a local character string in png.c.
323 *
324 * There are seven time-related functions:
325 * png.c: png_convert_to_rfc_1123() in png.c
326 * (formerly png_convert_to_rfc_1152() in error)
327 * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
328 * png_convert_from_time_t() in pngwrite.c
329 * png_get_tIME() in pngget.c
330 * png_handle_tIME() in pngrutil.c, called in pngread.c
331 * png_set_tIME() in pngset.c
332 * png_write_tIME() in pngwutil.c, called in pngwrite.c
333 *
334 * All handle dates properly in a Y2K environment. The
335 * png_convert_from_time_t() function calls gmtime() to convert from system
336 * clock time, which returns (year - 1900), which we properly convert to
337 * the full 4-digit year. There is a possibility that applications using
338 * libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
339 * function, or that they are incorrectly passing only a 2-digit year
340 * instead of "year - 1900" into the png_convert_from_struct_tm() function,
341 * but this is not under our control. The libpng documentation has always
342 * stated that it works with 4-digit years, and the APIs have been
343 * documented as such.
344 *
345 * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
346 * integer to hold the year, and can hold years as large as 65535.
347 *
348 * zlib, upon which libpng depends, is also Y2K compliant. It contains
349 * no date-related code.
350 *
351 * Glenn Randers-Pehrson
352 * libpng maintainer
353 * PNG Development Group
354 */
355
356#ifndef PNG_H
357#define PNG_H
358
359/* This is not the place to learn how to use libpng. The file libpng.txt
360 * describes how to use libpng, and the file example.c summarizes it
361 * with some code on which to build. This file is useful for looking
362 * at the actual function definitions and structure components.
363 */
364
365/* Version information for png.h - this should match the version in png.c */
366#define PNG_LIBPNG_VER_STRING "1.2.20"
367#define PNG_HEADER_VERSION_STRING \
368 " libpng version 1.2.20 - September 8, 2007\n"
369
370#define PNG_LIBPNG_VER_SONUM 0
371#define PNG_LIBPNG_VER_DLLNUM 13
372
373/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
374#define PNG_LIBPNG_VER_MAJOR 1
375#define PNG_LIBPNG_VER_MINOR 2
376#define PNG_LIBPNG_VER_RELEASE 20
377/* This should match the numeric part of the final component of
378 * PNG_LIBPNG_VER_STRING, omitting any leading zero: */
379
380#define PNG_LIBPNG_VER_BUILD 0
381
382/* Release Status */
383#define PNG_LIBPNG_BUILD_ALPHA 1
384#define PNG_LIBPNG_BUILD_BETA 2
385#define PNG_LIBPNG_BUILD_RC 3
386#define PNG_LIBPNG_BUILD_STABLE 4
387#define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
388
389/* Release-Specific Flags */
390#define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
391 PNG_LIBPNG_BUILD_STABLE only */
392#define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
393 PNG_LIBPNG_BUILD_SPECIAL */
394#define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
395 PNG_LIBPNG_BUILD_PRIVATE */
396
397#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
398
399/* Careful here. At one time, Guy wanted to use 082, but that would be octal.
400 * We must not include leading zeros.
401 * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
402 * version 1.0.0 was mis-numbered 100 instead of 10000). From
403 * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release */
404#define PNG_LIBPNG_VER 10220 /* 1.2.20 */
405
406#ifndef PNG_VERSION_INFO_ONLY
407/* include the compression library's header */
408#include "zlib.h"
409#endif
410
411/* include all user configurable info, including optional assembler routines */
412#include "pngconf.h"
413
414/*
415 * Added at libpng-1.2.8 */
416/* Ref MSDN: Private as priority over Special
417 * VS_FF_PRIVATEBUILD File *was not* built using standard release
418 * procedures. If this value is given, the StringFileInfo block must
419 * contain a PrivateBuild string.
420 *
421 * VS_FF_SPECIALBUILD File *was* built by the original company using
422 * standard release procedures but is a variation of the standard
423 * file of the same version number. If this value is given, the
424 * StringFileInfo block must contain a SpecialBuild string.
425 */
426
427#if defined(PNG_USER_PRIVATEBUILD)
428# define PNG_LIBPNG_BUILD_TYPE \
429 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
430#else
431# if defined(PNG_LIBPNG_SPECIALBUILD)
432# define PNG_LIBPNG_BUILD_TYPE \
433 (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
434# else
435# define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
436# endif
437#endif
438
439#ifndef PNG_VERSION_INFO_ONLY
440
441/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
442#ifdef __cplusplus
443extern "C" {
444#endif /* __cplusplus */
445
446/* This file is arranged in several sections. The first section contains
447 * structure and type definitions. The second section contains the external
448 * library functions, while the third has the internal library functions,
449 * which applications aren't expected to use directly.
450 */
451
452#ifndef PNG_NO_TYPECAST_NULL
453#define int_p_NULL (int *)NULL
454#define png_bytep_NULL (png_bytep)NULL
455#define png_bytepp_NULL (png_bytepp)NULL
456#define png_doublep_NULL (png_doublep)NULL
457#define png_error_ptr_NULL (png_error_ptr)NULL
458#define png_flush_ptr_NULL (png_flush_ptr)NULL
459#define png_free_ptr_NULL (png_free_ptr)NULL
460#define png_infopp_NULL (png_infopp)NULL
461#define png_malloc_ptr_NULL (png_malloc_ptr)NULL
462#define png_read_status_ptr_NULL (png_read_status_ptr)NULL
463#define png_rw_ptr_NULL (png_rw_ptr)NULL
464#define png_structp_NULL (png_structp)NULL
465#define png_uint_16p_NULL (png_uint_16p)NULL
466#define png_voidp_NULL (png_voidp)NULL
467#define png_write_status_ptr_NULL (png_write_status_ptr)NULL
468#else
469#define int_p_NULL NULL
470#define png_bytep_NULL NULL
471#define png_bytepp_NULL NULL
472#define png_doublep_NULL NULL
473#define png_error_ptr_NULL NULL
474#define png_flush_ptr_NULL NULL
475#define png_free_ptr_NULL NULL
476#define png_infopp_NULL NULL
477#define png_malloc_ptr_NULL NULL
478#define png_read_status_ptr_NULL NULL
479#define png_rw_ptr_NULL NULL
480#define png_structp_NULL NULL
481#define png_uint_16p_NULL NULL
482#define png_voidp_NULL NULL
483#define png_write_status_ptr_NULL NULL
484#endif
485
486/* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
487#if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
488/* Version information for C files, stored in png.c. This had better match
489 * the version above.
490 */
491#ifdef PNG_USE_GLOBAL_ARRAYS
492PNG_EXPORT_VAR (PNG_CONST char) png_libpng_ver[18];
493 /* need room for 99.99.99beta99z */
494#else
495#define png_libpng_ver png_get_header_ver(NULL)
496#endif
497
498#ifdef PNG_USE_GLOBAL_ARRAYS
499/* This was removed in version 1.0.5c */
500/* Structures to facilitate easy interlacing. See png.c for more details */
501PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_start[7];
502PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_inc[7];
503PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_ystart[7];
504PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_yinc[7];
505PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_mask[7];
506PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_dsp_mask[7];
507/* This isn't currently used. If you need it, see png.c for more details.
508PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_height[7];
509*/
510#endif
511
512#endif /* PNG_NO_EXTERN */
513
514/* Three color definitions. The order of the red, green, and blue, (and the
515 * exact size) is not important, although the size of the fields need to
516 * be png_byte or png_uint_16 (as defined below).
517 */
518typedef struct png_color_struct
519{
520 png_byte red;
521 png_byte green;
522 png_byte blue;
523} png_color;
524typedef png_color FAR * png_colorp;
525typedef png_color FAR * FAR * png_colorpp;
526
527typedef struct png_color_16_struct
528{
529 png_byte index; /* used for palette files */
530 png_uint_16 red; /* for use in red green blue files */
531 png_uint_16 green;
532 png_uint_16 blue;
533 png_uint_16 gray; /* for use in grayscale files */
534} png_color_16;
535typedef png_color_16 FAR * png_color_16p;
536typedef png_color_16 FAR * FAR * png_color_16pp;
537
538typedef struct png_color_8_struct
539{
540 png_byte red; /* for use in red green blue files */
541 png_byte green;
542 png_byte blue;
543 png_byte gray; /* for use in grayscale files */
544 png_byte alpha; /* for alpha channel files */
545} png_color_8;
546typedef png_color_8 FAR * png_color_8p;
547typedef png_color_8 FAR * FAR * png_color_8pp;
548
549/*
550 * The following two structures are used for the in-core representation
551 * of sPLT chunks.
552 */
553typedef struct png_sPLT_entry_struct
554{
555 png_uint_16 red;
556 png_uint_16 green;
557 png_uint_16 blue;
558 png_uint_16 alpha;
559 png_uint_16 frequency;
560} png_sPLT_entry;
561typedef png_sPLT_entry FAR * png_sPLT_entryp;
562typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;
563
564/* When the depth of the sPLT palette is 8 bits, the color and alpha samples
565 * occupy the LSB of their respective members, and the MSB of each member
566 * is zero-filled. The frequency member always occupies the full 16 bits.
567 */
568
569typedef struct png_sPLT_struct
570{
571 png_charp name; /* palette name */
572 png_byte depth; /* depth of palette samples */
573 png_sPLT_entryp entries; /* palette entries */
574 png_int_32 nentries; /* number of palette entries */
575} png_sPLT_t;
576typedef png_sPLT_t FAR * png_sPLT_tp;
577typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
578
579#ifdef PNG_TEXT_SUPPORTED
580/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
581 * and whether that contents is compressed or not. The "key" field
582 * points to a regular zero-terminated C string. The "text", "lang", and
583 * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
584 * However, the * structure returned by png_get_text() will always contain
585 * regular zero-terminated C strings (possibly empty), never NULL pointers,
586 * so they can be safely used in printf() and other string-handling functions.
587 */
588typedef struct png_text_struct
589{
590 int compression; /* compression value:
591 -1: tEXt, none
592 0: zTXt, deflate
593 1: iTXt, none
594 2: iTXt, deflate */
595 png_charp key; /* keyword, 1-79 character description of "text" */
596 png_charp text; /* comment, may be an empty string (ie "")
597 or a NULL pointer */
598 png_size_t text_length; /* length of the text string */
599#ifdef PNG_iTXt_SUPPORTED
600 png_size_t itxt_length; /* length of the itxt string */
601 png_charp lang; /* language code, 0-79 characters
602 or a NULL pointer */
603 png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
604 chars or a NULL pointer */
605#endif
606} png_text;
607typedef png_text FAR * png_textp;
608typedef png_text FAR * FAR * png_textpp;
609#endif
610
611/* Supported compression types for text in PNG files (tEXt, and zTXt).
612 * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
613#define PNG_TEXT_COMPRESSION_NONE_WR -3
614#define PNG_TEXT_COMPRESSION_zTXt_WR -2
615#define PNG_TEXT_COMPRESSION_NONE -1
616#define PNG_TEXT_COMPRESSION_zTXt 0
617#define PNG_ITXT_COMPRESSION_NONE 1
618#define PNG_ITXT_COMPRESSION_zTXt 2
619#define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
620
621/* png_time is a way to hold the time in an machine independent way.
622 * Two conversions are provided, both from time_t and struct tm. There
623 * is no portable way to convert to either of these structures, as far
624 * as I know. If you know of a portable way, send it to me. As a side
625 * note - PNG has always been Year 2000 compliant!
626 */
627typedef struct png_time_struct
628{
629 png_uint_16 year; /* full year, as in, 1995 */
630 png_byte month; /* month of year, 1 - 12 */
631 png_byte day; /* day of month, 1 - 31 */
632 png_byte hour; /* hour of day, 0 - 23 */
633 png_byte minute; /* minute of hour, 0 - 59 */
634 png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
635} png_time;
636typedef png_time FAR * png_timep;
637typedef png_time FAR * FAR * png_timepp;
638
639#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
640/* png_unknown_chunk is a structure to hold queued chunks for which there is
641 * no specific support. The idea is that we can use this to queue
642 * up private chunks for output even though the library doesn't actually
643 * know about their semantics.
644 */
645typedef struct png_unknown_chunk_t
646{
647 png_byte name[5];
648 png_byte *data;
649 png_size_t size;
650
651 /* libpng-using applications should NOT directly modify this byte. */
652 png_byte location; /* mode of operation at read time */
653}
654png_unknown_chunk;
655typedef png_unknown_chunk FAR * png_unknown_chunkp;
656typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
657#endif
658
659/* png_info is a structure that holds the information in a PNG file so
660 * that the application can find out the characteristics of the image.
661 * If you are reading the file, this structure will tell you what is
662 * in the PNG file. If you are writing the file, fill in the information
663 * you want to put into the PNG file, then call png_write_info().
664 * The names chosen should be very close to the PNG specification, so
665 * consult that document for information about the meaning of each field.
666 *
667 * With libpng < 0.95, it was only possible to directly set and read the
668 * the values in the png_info_struct, which meant that the contents and
669 * order of the values had to remain fixed. With libpng 0.95 and later,
670 * however, there are now functions that abstract the contents of
671 * png_info_struct from the application, so this makes it easier to use
672 * libpng with dynamic libraries, and even makes it possible to use
673 * libraries that don't have all of the libpng ancillary chunk-handing
674 * functionality.
675 *
676 * In any case, the order of the parameters in png_info_struct should NOT
677 * be changed for as long as possible to keep compatibility with applications
678 * that use the old direct-access method with png_info_struct.
679 *
680 * The following members may have allocated storage attached that should be
681 * cleaned up before the structure is discarded: palette, trans, text,
682 * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
683 * splt_palettes, scal_unit, row_pointers, and unknowns. By default, these
684 * are automatically freed when the info structure is deallocated, if they were
685 * allocated internally by libpng. This behavior can be changed by means
686 * of the png_data_freer() function.
687 *
688 * More allocation details: all the chunk-reading functions that
689 * change these members go through the corresponding png_set_*
690 * functions. A function to clear these members is available: see
691 * png_free_data(). The png_set_* functions do not depend on being
692 * able to point info structure members to any of the storage they are
693 * passed (they make their own copies), EXCEPT that the png_set_text
694 * functions use the same storage passed to them in the text_ptr or
695 * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
696 * functions do not make their own copies.
697 */
698typedef struct png_info_struct
699{
700 /* the following are necessary for every PNG file */
701 png_uint_32 width; /* width of image in pixels (from IHDR) */
702 png_uint_32 height; /* height of image in pixels (from IHDR) */
703 png_uint_32 valid; /* valid chunk data (see PNG_INFO_ below) */
704 png_uint_32 rowbytes; /* bytes needed to hold an untransformed row */
705 png_colorp palette; /* array of color values (valid & PNG_INFO_PLTE) */
706 png_uint_16 num_palette; /* number of color entries in "palette" (PLTE) */
707 png_uint_16 num_trans; /* number of transparent palette color (tRNS) */
708 png_byte bit_depth; /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */
709 png_byte color_type; /* see PNG_COLOR_TYPE_ below (from IHDR) */
710 /* The following three should have been named *_method not *_type */
711 png_byte compression_type; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */
712 png_byte filter_type; /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
713 png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
714
715 /* The following is informational only on read, and not used on writes. */
716 png_byte channels; /* number of data channels per pixel (1, 2, 3, 4) */
717 png_byte pixel_depth; /* number of bits per pixel */
718 png_byte spare_byte; /* to align the data, and for future use */
719 png_byte signature[8]; /* magic bytes read by libpng from start of file */
720
721 /* The rest of the data is optional. If you are reading, check the
722 * valid field to see if the information in these are valid. If you
723 * are writing, set the valid field to those chunks you want written,
724 * and initialize the appropriate fields below.
725 */
726
727#if defined(PNG_gAMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
728 /* The gAMA chunk describes the gamma characteristics of the system
729 * on which the image was created, normally in the range [1.0, 2.5].
730 * Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
731 */
732 float gamma; /* gamma value of image, if (valid & PNG_INFO_gAMA) */
733#endif
734
735#if defined(PNG_sRGB_SUPPORTED)
736 /* GR-P, 0.96a */
737 /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
738 png_byte srgb_intent; /* sRGB rendering intent [0, 1, 2, or 3] */
739#endif
740
741#if defined(PNG_TEXT_SUPPORTED)
742 /* The tEXt, and zTXt chunks contain human-readable textual data in
743 * uncompressed, compressed, and optionally compressed forms, respectively.
744 * The data in "text" is an array of pointers to uncompressed,
745 * null-terminated C strings. Each chunk has a keyword that describes the
746 * textual data contained in that chunk. Keywords are not required to be
747 * unique, and the text string may be empty. Any number of text chunks may
748 * be in an image.
749 */
750 int num_text; /* number of comments read/to write */
751 int max_text; /* current size of text array */
752 png_textp text; /* array of comments read/to write */
753#endif /* PNG_TEXT_SUPPORTED */
754
755#if defined(PNG_tIME_SUPPORTED)
756 /* The tIME chunk holds the last time the displayed image data was
757 * modified. See the png_time struct for the contents of this struct.
758 */
759 png_time mod_time;
760#endif
761
762#if defined(PNG_sBIT_SUPPORTED)
763 /* The sBIT chunk specifies the number of significant high-order bits
764 * in the pixel data. Values are in the range [1, bit_depth], and are
765 * only specified for the channels in the pixel data. The contents of
766 * the low-order bits is not specified. Data is valid if
767 * (valid & PNG_INFO_sBIT) is non-zero.
768 */
769 png_color_8 sig_bit; /* significant bits in color channels */
770#endif
771
772#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
773defined(PNG_READ_BACKGROUND_SUPPORTED)
774 /* The tRNS chunk supplies transparency data for paletted images and
775 * other image types that don't need a full alpha channel. There are
776 * "num_trans" transparency values for a paletted image, stored in the
777 * same order as the palette colors, starting from index 0. Values
778 * for the data are in the range [0, 255], ranging from fully transparent
779 * to fully opaque, respectively. For non-paletted images, there is a
780 * single color specified that should be treated as fully transparent.
781 * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
782 */
783 png_bytep trans; /* transparent values for paletted image */
784 png_color_16 trans_values; /* transparent color for non-palette image */
785#endif
786
787#if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
788 /* The bKGD chunk gives the suggested image background color if the
789 * display program does not have its own background color and the image
790 * is needs to composited onto a background before display. The colors
791 * in "background" are normally in the same color space/depth as the
792 * pixel data. Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
793 */
794 png_color_16 background;
795#endif
796
797#if defined(PNG_oFFs_SUPPORTED)
798 /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
799 * and downwards from the top-left corner of the display, page, or other
800 * application-specific co-ordinate space. See the PNG_OFFSET_ defines
801 * below for the unit types. Valid if (valid & PNG_INFO_oFFs) non-zero.
802 */
803 png_int_32 x_offset; /* x offset on page */
804 png_int_32 y_offset; /* y offset on page */
805 png_byte offset_unit_type; /* offset units type */
806#endif
807
808#if defined(PNG_pHYs_SUPPORTED)
809 /* The pHYs chunk gives the physical pixel density of the image for
810 * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
811 * defines below). Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
812 */
813 png_uint_32 x_pixels_per_unit; /* horizontal pixel density */
814 png_uint_32 y_pixels_per_unit; /* vertical pixel density */
815 png_byte phys_unit_type; /* resolution type (see PNG_RESOLUTION_ below) */
816#endif
817
818#if defined(PNG_hIST_SUPPORTED)
819 /* The hIST chunk contains the relative frequency or importance of the
820 * various palette entries, so that a viewer can intelligently select a
821 * reduced-color palette, if required. Data is an array of "num_palette"
822 * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
823 * is non-zero.
824 */
825 png_uint_16p hist;
826#endif
827
828#ifdef PNG_cHRM_SUPPORTED
829 /* The cHRM chunk describes the CIE color characteristics of the monitor
830 * on which the PNG was created. This data allows the viewer to do gamut
831 * mapping of the input image to ensure that the viewer sees the same
832 * colors in the image as the creator. Values are in the range
833 * [0.0, 0.8]. Data valid if (valid & PNG_INFO_cHRM) non-zero.
834 */
835#ifdef PNG_FLOATING_POINT_SUPPORTED
836 float x_white;
837 float y_white;
838 float x_red;
839 float y_red;
840 float x_green;
841 float y_green;
842 float x_blue;
843 float y_blue;
844#endif
845#endif
846
847#if defined(PNG_pCAL_SUPPORTED)
848 /* The pCAL chunk describes a transformation between the stored pixel
849 * values and original physical data values used to create the image.
850 * The integer range [0, 2^bit_depth - 1] maps to the floating-point
851 * range given by [pcal_X0, pcal_X1], and are further transformed by a
852 * (possibly non-linear) transformation function given by "pcal_type"
853 * and "pcal_params" into "pcal_units". Please see the PNG_EQUATION_
854 * defines below, and the PNG-Group's PNG extensions document for a
855 * complete description of the transformations and how they should be
856 * implemented, and for a description of the ASCII parameter strings.
857 * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
858 */
859 png_charp pcal_purpose; /* pCAL chunk description string */
860 png_int_32 pcal_X0; /* minimum value */
861 png_int_32 pcal_X1; /* maximum value */
862 png_charp pcal_units; /* Latin-1 string giving physical units */
863 png_charpp pcal_params; /* ASCII strings containing parameter values */
864 png_byte pcal_type; /* equation type (see PNG_EQUATION_ below) */
865 png_byte pcal_nparams; /* number of parameters given in pcal_params */
866#endif
867
868/* New members added in libpng-1.0.6 */
869#ifdef PNG_FREE_ME_SUPPORTED
870 png_uint_32 free_me; /* flags items libpng is responsible for freeing */
871#endif
872
873#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
874 /* storage for unknown chunks that the library doesn't recognize. */
875 png_unknown_chunkp unknown_chunks;
876 png_size_t unknown_chunks_num;
877#endif
878
879#if defined(PNG_iCCP_SUPPORTED)
880 /* iCCP chunk data. */
881 png_charp iccp_name; /* profile name */
882 png_charp iccp_profile; /* International Color Consortium profile data */
883 /* Note to maintainer: should be png_bytep */
884 png_uint_32 iccp_proflen; /* ICC profile data length */
885 png_byte iccp_compression; /* Always zero */
886#endif
887
888#if defined(PNG_sPLT_SUPPORTED)
889 /* data on sPLT chunks (there may be more than one). */
890 png_sPLT_tp splt_palettes;
891 png_uint_32 splt_palettes_num;
892#endif
893
894#if defined(PNG_sCAL_SUPPORTED)
895 /* The sCAL chunk describes the actual physical dimensions of the
896 * subject matter of the graphic. The chunk contains a unit specification
897 * a byte value, and two ASCII strings representing floating-point
898 * values. The values are width and height corresponsing to one pixel
899 * in the image. This external representation is converted to double
900 * here. Data values are valid if (valid & PNG_INFO_sCAL) is non-zero.
901 */
902 png_byte scal_unit; /* unit of physical scale */
903#ifdef PNG_FLOATING_POINT_SUPPORTED
904 double scal_pixel_width; /* width of one pixel */
905 double scal_pixel_height; /* height of one pixel */
906#endif
907#ifdef PNG_FIXED_POINT_SUPPORTED
908 png_charp scal_s_width; /* string containing height */
909 png_charp scal_s_height; /* string containing width */
910#endif
911#endif
912
913#if defined(PNG_INFO_IMAGE_SUPPORTED)
914 /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS) non-zero */
915 /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
916 png_bytepp row_pointers; /* the image bits */
917#endif
918
919#if defined(PNG_FIXED_POINT_SUPPORTED) && defined(PNG_gAMA_SUPPORTED)
920 png_fixed_point int_gamma; /* gamma of image, if (valid & PNG_INFO_gAMA) */
921#endif
922
923#if defined(PNG_cHRM_SUPPORTED) && defined(PNG_FIXED_POINT_SUPPORTED)
924 png_fixed_point int_x_white;
925 png_fixed_point int_y_white;
926 png_fixed_point int_x_red;
927 png_fixed_point int_y_red;
928 png_fixed_point int_x_green;
929 png_fixed_point int_y_green;
930 png_fixed_point int_x_blue;
931 png_fixed_point int_y_blue;
932#endif
933
934} png_info;
935
936typedef png_info FAR * png_infop;
937typedef png_info FAR * FAR * png_infopp;
938
939/* Maximum positive integer used in PNG is (2^31)-1 */
940#define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
941#define PNG_UINT_32_MAX ((png_uint_32)(-1))
942#define PNG_SIZE_MAX ((png_size_t)(-1))
943#if defined(PNG_1_0_X) || defined (PNG_1_2_X)
944/* PNG_MAX_UINT is deprecated; use PNG_UINT_31_MAX instead. */
945#define PNG_MAX_UINT PNG_UINT_31_MAX
946#endif
947
948/* These describe the color_type field in png_info. */
949/* color type masks */
950#define PNG_COLOR_MASK_PALETTE 1
951#define PNG_COLOR_MASK_COLOR 2
952#define PNG_COLOR_MASK_ALPHA 4
953
954/* color types. Note that not all combinations are legal */
955#define PNG_COLOR_TYPE_GRAY 0
956#define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
957#define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
958#define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
959#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
960/* aliases */
961#define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
962#define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
963
964/* This is for compression type. PNG 1.0-1.2 only define the single type. */
965#define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
966#define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
967
968/* This is for filter type. PNG 1.0-1.2 only define the single type. */
969#define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
970#define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
971#define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
972
973/* These are for the interlacing type. These values should NOT be changed. */
974#define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
975#define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
976#define PNG_INTERLACE_LAST 2 /* Not a valid value */
977
978/* These are for the oFFs chunk. These values should NOT be changed. */
979#define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
980#define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
981#define PNG_OFFSET_LAST 2 /* Not a valid value */
982
983/* These are for the pCAL chunk. These values should NOT be changed. */
984#define PNG_EQUATION_LINEAR 0 /* Linear transformation */
985#define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
986#define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
987#define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
988#define PNG_EQUATION_LAST 4 /* Not a valid value */
989
990/* These are for the sCAL chunk. These values should NOT be changed. */
991#define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
992#define PNG_SCALE_METER 1 /* meters per pixel */
993#define PNG_SCALE_RADIAN 2 /* radians per pixel */
994#define PNG_SCALE_LAST 3 /* Not a valid value */
995
996/* These are for the pHYs chunk. These values should NOT be changed. */
997#define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
998#define PNG_RESOLUTION_METER 1 /* pixels/meter */
999#define PNG_RESOLUTION_LAST 2 /* Not a valid value */
1000
1001/* These are for the sRGB chunk. These values should NOT be changed. */
1002#define PNG_sRGB_INTENT_PERCEPTUAL 0
1003#define PNG_sRGB_INTENT_RELATIVE 1
1004#define PNG_sRGB_INTENT_SATURATION 2
1005#define PNG_sRGB_INTENT_ABSOLUTE 3
1006#define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
1007
1008/* This is for text chunks */
1009#define PNG_KEYWORD_MAX_LENGTH 79
1010
1011/* Maximum number of entries in PLTE/sPLT/tRNS arrays */
1012#define PNG_MAX_PALETTE_LENGTH 256
1013
1014/* These determine if an ancillary chunk's data has been successfully read
1015 * from the PNG header, or if the application has filled in the corresponding
1016 * data in the info_struct to be written into the output file. The values
1017 * of the PNG_INFO_<chunk> defines should NOT be changed.
1018 */
1019#define PNG_INFO_gAMA 0x0001
1020#define PNG_INFO_sBIT 0x0002
1021#define PNG_INFO_cHRM 0x0004
1022#define PNG_INFO_PLTE 0x0008
1023#define PNG_INFO_tRNS 0x0010
1024#define PNG_INFO_bKGD 0x0020
1025#define PNG_INFO_hIST 0x0040
1026#define PNG_INFO_pHYs 0x0080
1027#define PNG_INFO_oFFs 0x0100
1028#define PNG_INFO_tIME 0x0200
1029#define PNG_INFO_pCAL 0x0400
1030#define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */
1031#define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */
1032#define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */
1033#define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */
1034#define PNG_INFO_IDAT 0x8000L /* ESR, 1.0.6 */
1035
1036/* This is used for the transformation routines, as some of them
1037 * change these values for the row. It also should enable using
1038 * the routines for other purposes.
1039 */
1040typedef struct png_row_info_struct
1041{
1042 png_uint_32 width; /* width of row */
1043 png_uint_32 rowbytes; /* number of bytes in row */
1044 png_byte color_type; /* color type of row */
1045 png_byte bit_depth; /* bit depth of row */
1046 png_byte channels; /* number of channels (1, 2, 3, or 4) */
1047 png_byte pixel_depth; /* bits per pixel (depth * channels) */
1048} png_row_info;
1049
1050typedef png_row_info FAR * png_row_infop;
1051typedef png_row_info FAR * FAR * png_row_infopp;
1052
1053/* These are the function types for the I/O functions and for the functions
1054 * that allow the user to override the default I/O functions with his or her
1055 * own. The png_error_ptr type should match that of user-supplied warning
1056 * and error functions, while the png_rw_ptr type should match that of the
1057 * user read/write data functions.
1058 */
1059typedef struct png_struct_def png_struct;
1060typedef png_struct FAR * png_structp;
1061
1062typedef void (PNGAPI *png_error_ptr) PNGARG((png_structp, png_const_charp));
1063typedef void (PNGAPI *png_rw_ptr) PNGARG((png_structp, png_bytep, png_size_t));
1064typedef void (PNGAPI *png_flush_ptr) PNGARG((png_structp));
1065typedef void (PNGAPI *png_read_status_ptr) PNGARG((png_structp, png_uint_32,
1066 int));
1067typedef void (PNGAPI *png_write_status_ptr) PNGARG((png_structp, png_uint_32,
1068 int));
1069
1070#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1071typedef void (PNGAPI *png_progressive_info_ptr) PNGARG((png_structp, png_infop));
1072typedef void (PNGAPI *png_progressive_end_ptr) PNGARG((png_structp, png_infop));
1073typedef void (PNGAPI *png_progressive_row_ptr) PNGARG((png_structp, png_bytep,
1074 png_uint_32, int));
1075#endif
1076
1077#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1078 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
1079 defined(PNG_LEGACY_SUPPORTED)
1080typedef void (PNGAPI *png_user_transform_ptr) PNGARG((png_structp,
1081 png_row_infop, png_bytep));
1082#endif
1083
1084#if defined(PNG_USER_CHUNKS_SUPPORTED)
1085typedef int (PNGAPI *png_user_chunk_ptr) PNGARG((png_structp, png_unknown_chunkp));
1086#endif
1087#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
1088typedef void (PNGAPI *png_unknown_chunk_ptr) PNGARG((png_structp));
1089#endif
1090
1091/* Transform masks for the high-level interface */
1092#define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
1093#define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
1094#define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
1095#define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
1096#define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
1097#define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
1098#define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
1099#define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
1100#define PNG_TRANSFORM_BGR 0x0080 /* read and write */
1101#define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
1102#define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
1103#define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
1104#define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* WRITE only */
1105
1106/* Flags for MNG supported features */
1107#define PNG_FLAG_MNG_EMPTY_PLTE 0x01
1108#define PNG_FLAG_MNG_FILTER_64 0x04
1109#define PNG_ALL_MNG_FEATURES 0x05
1110
1111typedef png_voidp (*png_malloc_ptr) PNGARG((png_structp, png_size_t));
1112typedef void (*png_free_ptr) PNGARG((png_structp, png_voidp));
1113
1114/* The structure that holds the information to read and write PNG files.
1115 * The only people who need to care about what is inside of this are the
1116 * people who will be modifying the library for their own special needs.
1117 * It should NOT be accessed directly by an application, except to store
1118 * the jmp_buf.
1119 */
1120
1121struct png_struct_def
1122{
1123#ifdef PNG_SETJMP_SUPPORTED
1124 jmp_buf jmpbuf; /* used in png_error */
1125#endif
1126 png_error_ptr error_fn; /* function for printing errors and aborting */
1127 png_error_ptr warning_fn; /* function for printing warnings */
1128 png_voidp error_ptr; /* user supplied struct for error functions */
1129 png_rw_ptr write_data_fn; /* function for writing output data */
1130 png_rw_ptr read_data_fn; /* function for reading input data */
1131 png_voidp io_ptr; /* ptr to application struct for I/O functions */
1132
1133#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
1134 png_user_transform_ptr read_user_transform_fn; /* user read transform */
1135#endif
1136
1137#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1138 png_user_transform_ptr write_user_transform_fn; /* user write transform */
1139#endif
1140
1141/* These were added in libpng-1.0.2 */
1142#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
1143#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1144 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1145 png_voidp user_transform_ptr; /* user supplied struct for user transform */
1146 png_byte user_transform_depth; /* bit depth of user transformed pixels */
1147 png_byte user_transform_channels; /* channels in user transformed pixels */
1148#endif
1149#endif
1150
1151 png_uint_32 mode; /* tells us where we are in the PNG file */
1152 png_uint_32 flags; /* flags indicating various things to libpng */
1153 png_uint_32 transformations; /* which transformations to perform */
1154
1155 z_stream zstream; /* pointer to decompression structure (below) */
1156 png_bytep zbuf; /* buffer for zlib */
1157 png_size_t zbuf_size; /* size of zbuf */
1158 int zlib_level; /* holds zlib compression level */
1159 int zlib_method; /* holds zlib compression method */
1160 int zlib_window_bits; /* holds zlib compression window bits */
1161 int zlib_mem_level; /* holds zlib compression memory level */
1162 int zlib_strategy; /* holds zlib compression strategy */
1163
1164 png_uint_32 width; /* width of image in pixels */
1165 png_uint_32 height; /* height of image in pixels */
1166 png_uint_32 num_rows; /* number of rows in current pass */
1167 png_uint_32 usr_width; /* width of row at start of write */
1168 png_uint_32 rowbytes; /* size of row in bytes */
1169 png_uint_32 irowbytes; /* size of current interlaced row in bytes */
1170 png_uint_32 iwidth; /* width of current interlaced row in pixels */
1171 png_uint_32 row_number; /* current row in interlace pass */
1172 png_bytep prev_row; /* buffer to save previous (unfiltered) row */
1173 png_bytep row_buf; /* buffer to save current (unfiltered) row */
1174 png_bytep sub_row; /* buffer to save "sub" row when filtering */
1175 png_bytep up_row; /* buffer to save "up" row when filtering */
1176 png_bytep avg_row; /* buffer to save "avg" row when filtering */
1177 png_bytep paeth_row; /* buffer to save "Paeth" row when filtering */
1178 png_row_info row_info; /* used for transformation routines */
1179
1180 png_uint_32 idat_size; /* current IDAT size for read */
1181 png_uint_32 crc; /* current chunk CRC value */
1182 png_colorp palette; /* palette from the input file */
1183 png_uint_16 num_palette; /* number of color entries in palette */
1184 png_uint_16 num_trans; /* number of transparency values */
1185 png_byte chunk_name[5]; /* null-terminated name of current chunk */
1186 png_byte compression; /* file compression type (always 0) */
1187 png_byte filter; /* file filter type (always 0) */
1188 png_byte interlaced; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
1189 png_byte pass; /* current interlace pass (0 - 6) */
1190 png_byte do_filter; /* row filter flags (see PNG_FILTER_ below ) */
1191 png_byte color_type; /* color type of file */
1192 png_byte bit_depth; /* bit depth of file */
1193 png_byte usr_bit_depth; /* bit depth of users row */
1194 png_byte pixel_depth; /* number of bits per pixel */
1195 png_byte channels; /* number of channels in file */
1196 png_byte usr_channels; /* channels at start of write */
1197 png_byte sig_bytes; /* magic bytes read/written from start of file */
1198
1199#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1200#ifdef PNG_LEGACY_SUPPORTED
1201 png_byte filler; /* filler byte for pixel expansion */
1202#else
1203 png_uint_16 filler; /* filler bytes for pixel expansion */
1204#endif
1205#endif
1206
1207#if defined(PNG_bKGD_SUPPORTED)
1208 png_byte background_gamma_type;
1209# ifdef PNG_FLOATING_POINT_SUPPORTED
1210 float background_gamma;
1211# endif
1212 png_color_16 background; /* background color in screen gamma space */
1213#if defined(PNG_READ_GAMMA_SUPPORTED)
1214 png_color_16 background_1; /* background normalized to gamma 1.0 */
1215#endif
1216#endif /* PNG_bKGD_SUPPORTED */
1217
1218#if defined(PNG_WRITE_FLUSH_SUPPORTED)
1219 png_flush_ptr output_flush_fn;/* Function for flushing output */
1220 png_uint_32 flush_dist; /* how many rows apart to flush, 0 - no flush */
1221 png_uint_32 flush_rows; /* number of rows written since last flush */
1222#endif
1223
1224#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1225 int gamma_shift; /* number of "insignificant" bits 16-bit gamma */
1226#ifdef PNG_FLOATING_POINT_SUPPORTED
1227 float gamma; /* file gamma value */
1228 float screen_gamma; /* screen gamma value (display_exponent) */
1229#endif
1230#endif
1231
1232#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1233 png_bytep gamma_table; /* gamma table for 8-bit depth files */
1234 png_bytep gamma_from_1; /* converts from 1.0 to screen */
1235 png_bytep gamma_to_1; /* converts from file to 1.0 */
1236 png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */
1237 png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */
1238 png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */
1239#endif
1240
1241#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
1242 png_color_8 sig_bit; /* significant bits in each available channel */
1243#endif
1244
1245#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1246 png_color_8 shift; /* shift for significant bit tranformation */
1247#endif
1248
1249#if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
1250 || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1251 png_bytep trans; /* transparency values for paletted files */
1252 png_color_16 trans_values; /* transparency values for non-paletted files */
1253#endif
1254
1255 png_read_status_ptr read_row_fn; /* called after each row is decoded */
1256 png_write_status_ptr write_row_fn; /* called after each row is encoded */
1257#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1258 png_progressive_info_ptr info_fn; /* called after header data fully read */
1259 png_progressive_row_ptr row_fn; /* called after each prog. row is decoded */
1260 png_progressive_end_ptr end_fn; /* called after image is complete */
1261 png_bytep save_buffer_ptr; /* current location in save_buffer */
1262 png_bytep save_buffer; /* buffer for previously read data */
1263 png_bytep current_buffer_ptr; /* current location in current_buffer */
1264 png_bytep current_buffer; /* buffer for recently used data */
1265 png_uint_32 push_length; /* size of current input chunk */
1266 png_uint_32 skip_length; /* bytes to skip in input data */
1267 png_size_t save_buffer_size; /* amount of data now in save_buffer */
1268 png_size_t save_buffer_max; /* total size of save_buffer */
1269 png_size_t buffer_size; /* total amount of available input data */
1270 png_size_t current_buffer_size; /* amount of data now in current_buffer */
1271 int process_mode; /* what push library is currently doing */
1272 int cur_palette; /* current push library palette index */
1273
1274# if defined(PNG_TEXT_SUPPORTED)
1275 png_size_t current_text_size; /* current size of text input data */
1276 png_size_t current_text_left; /* how much text left to read in input */
1277 png_charp current_text; /* current text chunk buffer */
1278 png_charp current_text_ptr; /* current location in current_text */
1279# endif /* PNG_TEXT_SUPPORTED */
1280#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1281
1282#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
1283/* for the Borland special 64K segment handler */
1284 png_bytepp offset_table_ptr;
1285 png_bytep offset_table;
1286 png_uint_16 offset_table_number;
1287 png_uint_16 offset_table_count;
1288 png_uint_16 offset_table_count_free;
1289#endif
1290
1291#if defined(PNG_READ_DITHER_SUPPORTED)
1292 png_bytep palette_lookup; /* lookup table for dithering */
1293 png_bytep dither_index; /* index translation for palette files */
1294#endif
1295
1296#if defined(PNG_READ_DITHER_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
1297 png_uint_16p hist; /* histogram */
1298#endif
1299
1300#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
1301 png_byte heuristic_method; /* heuristic for row filter selection */
1302 png_byte num_prev_filters; /* number of weights for previous rows */
1303 png_bytep prev_filters; /* filter type(s) of previous row(s) */
1304 png_uint_16p filter_weights; /* weight(s) for previous line(s) */
1305 png_uint_16p inv_filter_weights; /* 1/weight(s) for previous line(s) */
1306 png_uint_16p filter_costs; /* relative filter calculation cost */
1307 png_uint_16p inv_filter_costs; /* 1/relative filter calculation cost */
1308#endif
1309
1310#if defined(PNG_TIME_RFC1123_SUPPORTED)
1311 png_charp time_buffer; /* String to hold RFC 1123 time text */
1312#endif
1313
1314/* New members added in libpng-1.0.6 */
1315
1316#ifdef PNG_FREE_ME_SUPPORTED
1317 png_uint_32 free_me; /* flags items libpng is responsible for freeing */
1318#endif
1319
1320#if defined(PNG_USER_CHUNKS_SUPPORTED)
1321 png_voidp user_chunk_ptr;
1322 png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
1323#endif
1324
1325#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
1326 int num_chunk_list;
1327 png_bytep chunk_list;
1328#endif
1329
1330/* New members added in libpng-1.0.3 */
1331#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
1332 png_byte rgb_to_gray_status;
1333 /* These were changed from png_byte in libpng-1.0.6 */
1334 png_uint_16 rgb_to_gray_red_coeff;
1335 png_uint_16 rgb_to_gray_green_coeff;
1336 png_uint_16 rgb_to_gray_blue_coeff;
1337#endif
1338
1339/* New member added in libpng-1.0.4 (renamed in 1.0.9) */
1340#if defined(PNG_MNG_FEATURES_SUPPORTED) || \
1341 defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1342 defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1343/* changed from png_byte to png_uint_32 at version 1.2.0 */
1344#ifdef PNG_1_0_X
1345 png_byte mng_features_permitted;
1346#else
1347 png_uint_32 mng_features_permitted;
1348#endif /* PNG_1_0_X */
1349#endif
1350
1351/* New member added in libpng-1.0.7 */
1352#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1353 png_fixed_point int_gamma;
1354#endif
1355
1356/* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
1357#if defined(PNG_MNG_FEATURES_SUPPORTED)
1358 png_byte filter_type;
1359#endif
1360
1361#if defined(PNG_1_0_X)
1362/* New member added in libpng-1.0.10, ifdef'ed out in 1.2.0 */
1363 png_uint_32 row_buf_size;
1364#endif
1365
1366/* New members added in libpng-1.2.0 */
1367#if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
1368# if !defined(PNG_1_0_X)
1369# if defined(PNG_MMX_CODE_SUPPORTED)
1370 png_byte mmx_bitdepth_threshold;
1371 png_uint_32 mmx_rowbytes_threshold;
1372# endif
1373 png_uint_32 asm_flags;
1374# endif
1375#endif
1376
1377/* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
1378#ifdef PNG_USER_MEM_SUPPORTED
1379 png_voidp mem_ptr; /* user supplied struct for mem functions */
1380 png_malloc_ptr malloc_fn; /* function for allocating memory */
1381 png_free_ptr free_fn; /* function for freeing memory */
1382#endif
1383
1384/* New member added in libpng-1.0.13 and 1.2.0 */
1385 png_bytep big_row_buf; /* buffer to save current (unfiltered) row */
1386
1387#if defined(PNG_READ_DITHER_SUPPORTED)
1388/* The following three members were added at version 1.0.14 and 1.2.4 */
1389 png_bytep dither_sort; /* working sort array */
1390 png_bytep index_to_palette; /* where the original index currently is */
1391 /* in the palette */
1392 png_bytep palette_to_index; /* which original index points to this */
1393 /* palette color */
1394#endif
1395
1396/* New members added in libpng-1.0.16 and 1.2.6 */
1397 png_byte compression_type;
1398
1399#ifdef PNG_SET_USER_LIMITS_SUPPORTED
1400 png_uint_32 user_width_max;
1401 png_uint_32 user_height_max;
1402#endif
1403
1404/* New member added in libpng-1.0.25 and 1.2.17 */
1405#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
1406 /* storage for unknown chunk that the library doesn't recognize. */
1407 png_unknown_chunk unknown_chunk;
1408#endif
1409};
1410
1411
1412/* This triggers a compiler error in png.c, if png.c and png.h
1413 * do not agree upon the version number.
1414 */
1415typedef png_structp version_1_2_20;
1416
1417typedef png_struct FAR * FAR * png_structpp;
1418
1419/* Here are the function definitions most commonly used. This is not
1420 * the place to find out how to use libpng. See libpng.txt for the
1421 * full explanation, see example.c for the summary. This just provides
1422 * a simple one line description of the use of each function.
1423 */
1424
1425/* Returns the version number of the library */
1426extern PNG_EXPORT(png_uint_32,png_access_version_number) PNGARG((void));
1427
1428/* Tell lib we have already handled the first <num_bytes> magic bytes.
1429 * Handling more than 8 bytes from the beginning of the file is an error.
1430 */
1431extern PNG_EXPORT(void,png_set_sig_bytes) PNGARG((png_structp png_ptr,
1432 int num_bytes));
1433
1434/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
1435 * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
1436 * signature, and non-zero otherwise. Having num_to_check == 0 or
1437 * start > 7 will always fail (ie return non-zero).
1438 */
1439extern PNG_EXPORT(int,png_sig_cmp) PNGARG((png_bytep sig, png_size_t start,
1440 png_size_t num_to_check));
1441
1442/* Simple signature checking function. This is the same as calling
1443 * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
1444 */
1445extern PNG_EXPORT(int,png_check_sig) PNGARG((png_bytep sig, int num));
1446
1447/* Allocate and initialize png_ptr struct for reading, and any other memory. */
1448extern PNG_EXPORT(png_structp,png_create_read_struct)
1449 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1450 png_error_ptr error_fn, png_error_ptr warn_fn));
1451
1452/* Allocate and initialize png_ptr struct for writing, and any other memory */
1453extern PNG_EXPORT(png_structp,png_create_write_struct)
1454 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1455 png_error_ptr error_fn, png_error_ptr warn_fn));
1456
1457#ifdef PNG_WRITE_SUPPORTED
1458extern PNG_EXPORT(png_uint_32,png_get_compression_buffer_size)
1459 PNGARG((png_structp png_ptr));
1460#endif
1461
1462#ifdef PNG_WRITE_SUPPORTED
1463extern PNG_EXPORT(void,png_set_compression_buffer_size)
1464 PNGARG((png_structp png_ptr, png_uint_32 size));
1465#endif
1466
1467/* Reset the compression stream */
1468extern PNG_EXPORT(int,png_reset_zstream) PNGARG((png_structp png_ptr));
1469
1470/* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
1471#ifdef PNG_USER_MEM_SUPPORTED
1472extern PNG_EXPORT(png_structp,png_create_read_struct_2)
1473 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1474 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1475 png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1476extern PNG_EXPORT(png_structp,png_create_write_struct_2)
1477 PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1478 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1479 png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1480#endif
1481
1482/* Write a PNG chunk - size, type, (optional) data, CRC. */
1483extern PNG_EXPORT(void,png_write_chunk) PNGARG((png_structp png_ptr,
1484 png_bytep chunk_name, png_bytep data, png_size_t length));
1485
1486/* Write the start of a PNG chunk - length and chunk name. */
1487extern PNG_EXPORT(void,png_write_chunk_start) PNGARG((png_structp png_ptr,
1488 png_bytep chunk_name, png_uint_32 length));
1489
1490/* Write the data of a PNG chunk started with png_write_chunk_start(). */
1491extern PNG_EXPORT(void,png_write_chunk_data) PNGARG((png_structp png_ptr,
1492 png_bytep data, png_size_t length));
1493
1494/* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1495extern PNG_EXPORT(void,png_write_chunk_end) PNGARG((png_structp png_ptr));
1496
1497/* Allocate and initialize the info structure */
1498extern PNG_EXPORT(png_infop,png_create_info_struct)
1499 PNGARG((png_structp png_ptr));
1500
1501#if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1502/* Initialize the info structure (old interface - DEPRECATED) */
1503extern PNG_EXPORT(void,png_info_init) PNGARG((png_infop info_ptr));
1504#undef png_info_init
1505#define png_info_init(info_ptr) png_info_init_3(&info_ptr,\
1506 png_sizeof(png_info));
1507#endif
1508
1509extern PNG_EXPORT(void,png_info_init_3) PNGARG((png_infopp info_ptr,
1510 png_size_t png_info_struct_size));
1511
1512/* Writes all the PNG information before the image. */
1513extern PNG_EXPORT(void,png_write_info_before_PLTE) PNGARG((png_structp png_ptr,
1514 png_infop info_ptr));
1515extern PNG_EXPORT(void,png_write_info) PNGARG((png_structp png_ptr,
1516 png_infop info_ptr));
1517
1518#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1519/* read the information before the actual image data. */
1520extern PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr,
1521 png_infop info_ptr));
1522#endif
1523
1524#if defined(PNG_TIME_RFC1123_SUPPORTED)
1525extern PNG_EXPORT(png_charp,png_convert_to_rfc1123)
1526 PNGARG((png_structp png_ptr, png_timep ptime));
1527#endif
1528
1529#if !defined(_WIN32_WCE)
1530/* "time.h" functions are not supported on WindowsCE */
1531#if defined(PNG_WRITE_tIME_SUPPORTED)
1532/* convert from a struct tm to png_time */
1533extern PNG_EXPORT(void,png_convert_from_struct_tm) PNGARG((png_timep ptime,
1534 struct tm FAR * ttime));
1535
1536/* convert from time_t to png_time. Uses gmtime() */
1537extern PNG_EXPORT(void,png_convert_from_time_t) PNGARG((png_timep ptime,
1538 time_t ttime));
1539#endif /* PNG_WRITE_tIME_SUPPORTED */
1540#endif /* _WIN32_WCE */
1541
1542#if defined(PNG_READ_EXPAND_SUPPORTED)
1543/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1544extern PNG_EXPORT(void,png_set_expand) PNGARG((png_structp png_ptr));
1545#if !defined(PNG_1_0_X)
1546extern PNG_EXPORT(void,png_set_expand_gray_1_2_4_to_8) PNGARG((png_structp
1547 png_ptr));
1548#endif
1549extern PNG_EXPORT(void,png_set_palette_to_rgb) PNGARG((png_structp png_ptr));
1550extern PNG_EXPORT(void,png_set_tRNS_to_alpha) PNGARG((png_structp png_ptr));
1551#if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1552/* Deprecated */
1553extern PNG_EXPORT(void,png_set_gray_1_2_4_to_8) PNGARG((png_structp png_ptr));
1554#endif
1555#endif
1556
1557#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1558/* Use blue, green, red order for pixels. */
1559extern PNG_EXPORT(void,png_set_bgr) PNGARG((png_structp png_ptr));
1560#endif
1561
1562#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
1563/* Expand the grayscale to 24-bit RGB if necessary. */
1564extern PNG_EXPORT(void,png_set_gray_to_rgb) PNGARG((png_structp png_ptr));
1565#endif
1566
1567#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
1568/* Reduce RGB to grayscale. */
1569#ifdef PNG_FLOATING_POINT_SUPPORTED
1570extern PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr,
1571 int error_action, double red, double green ));
1572#endif
1573extern PNG_EXPORT(void,png_set_rgb_to_gray_fixed) PNGARG((png_structp png_ptr,
1574 int error_action, png_fixed_point red, png_fixed_point green ));
1575extern PNG_EXPORT(png_byte,png_get_rgb_to_gray_status) PNGARG((png_structp
1576 png_ptr));
1577#endif
1578
1579extern PNG_EXPORT(void,png_build_grayscale_palette) PNGARG((int bit_depth,
1580 png_colorp palette));
1581
1582#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1583extern PNG_EXPORT(void,png_set_strip_alpha) PNGARG((png_structp png_ptr));
1584#endif
1585
1586#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1587 defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1588extern PNG_EXPORT(void,png_set_swap_alpha) PNGARG((png_structp png_ptr));
1589#endif
1590
1591#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1592 defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1593extern PNG_EXPORT(void,png_set_invert_alpha) PNGARG((png_structp png_ptr));
1594#endif
1595
1596#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1597/* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
1598extern PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr,
1599 png_uint_32 filler, int flags));
1600/* The values of the PNG_FILLER_ defines should NOT be changed */
1601#define PNG_FILLER_BEFORE 0
1602#define PNG_FILLER_AFTER 1
1603/* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
1604#if !defined(PNG_1_0_X)
1605extern PNG_EXPORT(void,png_set_add_alpha) PNGARG((png_structp png_ptr,
1606 png_uint_32 filler, int flags));
1607#endif
1608#endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
1609
1610#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1611/* Swap bytes in 16-bit depth files. */
1612extern PNG_EXPORT(void,png_set_swap) PNGARG((png_structp png_ptr));
1613#endif
1614
1615#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1616/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1617extern PNG_EXPORT(void,png_set_packing) PNGARG((png_structp png_ptr));
1618#endif
1619
1620#if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1621/* Swap packing order of pixels in bytes. */
1622extern PNG_EXPORT(void,png_set_packswap) PNGARG((png_structp png_ptr));
1623#endif
1624
1625#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1626/* Converts files to legal bit depths. */
1627extern PNG_EXPORT(void,png_set_shift) PNGARG((png_structp png_ptr,
1628 png_color_8p true_bits));
1629#endif
1630
1631#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1632 defined(PNG_WRITE_INTERLACING_SUPPORTED)
1633/* Have the code handle the interlacing. Returns the number of passes. */
1634extern PNG_EXPORT(int,png_set_interlace_handling) PNGARG((png_structp png_ptr));
1635#endif
1636
1637#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1638/* Invert monochrome files */
1639extern PNG_EXPORT(void,png_set_invert_mono) PNGARG((png_structp png_ptr));
1640#endif
1641
1642#if defined(PNG_READ_BACKGROUND_SUPPORTED)
1643/* Handle alpha and tRNS by replacing with a background color. */
1644#ifdef PNG_FLOATING_POINT_SUPPORTED
1645extern PNG_EXPORT(void,png_set_background) PNGARG((png_structp png_ptr,
1646 png_color_16p background_color, int background_gamma_code,
1647 int need_expand, double background_gamma));
1648#endif
1649#define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1650#define PNG_BACKGROUND_GAMMA_SCREEN 1
1651#define PNG_BACKGROUND_GAMMA_FILE 2
1652#define PNG_BACKGROUND_GAMMA_UNIQUE 3
1653#endif
1654
1655#if defined(PNG_READ_16_TO_8_SUPPORTED)
1656/* strip the second byte of information from a 16-bit depth file. */
1657extern PNG_EXPORT(void,png_set_strip_16) PNGARG((png_structp png_ptr));
1658#endif
1659
1660#if defined(PNG_READ_DITHER_SUPPORTED)
1661/* Turn on dithering, and reduce the palette to the number of colors available. */
1662extern PNG_EXPORT(void,png_set_dither) PNGARG((png_structp png_ptr,
1663 png_colorp palette, int num_palette, int maximum_colors,
1664 png_uint_16p histogram, int full_dither));
1665#endif
1666
1667#if defined(PNG_READ_GAMMA_SUPPORTED)
1668/* Handle gamma correction. Screen_gamma=(display_exponent) */
1669#ifdef PNG_FLOATING_POINT_SUPPORTED
1670extern PNG_EXPORT(void,png_set_gamma) PNGARG((png_structp png_ptr,
1671 double screen_gamma, double default_file_gamma));
1672#endif
1673#endif
1674
1675#if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1676#if defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1677 defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1678/* Permit or disallow empty PLTE (0: not permitted, 1: permitted) */
1679/* Deprecated and will be removed. Use png_permit_mng_features() instead. */
1680extern PNG_EXPORT(void,png_permit_empty_plte) PNGARG((png_structp png_ptr,
1681 int empty_plte_permitted));
1682#endif
1683#endif
1684
1685#if defined(PNG_WRITE_FLUSH_SUPPORTED)
1686/* Set how many lines between output flushes - 0 for no flushing */
1687extern PNG_EXPORT(void,png_set_flush) PNGARG((png_structp png_ptr, int nrows));
1688/* Flush the current PNG output buffer */
1689extern PNG_EXPORT(void,png_write_flush) PNGARG((png_structp png_ptr));
1690#endif
1691
1692/* optional update palette with requested transformations */
1693extern PNG_EXPORT(void,png_start_read_image) PNGARG((png_structp png_ptr));
1694
1695/* optional call to update the users info structure */
1696extern PNG_EXPORT(void,png_read_update_info) PNGARG((png_structp png_ptr,
1697 png_infop info_ptr));
1698
1699#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1700/* read one or more rows of image data. */
1701extern PNG_EXPORT(void,png_read_rows) PNGARG((png_structp png_ptr,
1702 png_bytepp row, png_bytepp display_row, png_uint_32 num_rows));
1703#endif
1704
1705#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1706/* read a row of data. */
1707extern PNG_EXPORT(void,png_read_row) PNGARG((png_structp png_ptr,
1708 png_bytep row,
1709 png_bytep display_row));
1710#endif
1711
1712#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1713/* read the whole image into memory at once. */
1714extern PNG_EXPORT(void,png_read_image) PNGARG((png_structp png_ptr,
1715 png_bytepp image));
1716#endif
1717
1718/* write a row of image data */
1719extern PNG_EXPORT(void,png_write_row) PNGARG((png_structp png_ptr,
1720 png_bytep row));
1721
1722/* write a few rows of image data */
1723extern PNG_EXPORT(void,png_write_rows) PNGARG((png_structp png_ptr,
1724 png_bytepp row, png_uint_32 num_rows));
1725
1726/* write the image data */
1727extern PNG_EXPORT(void,png_write_image) PNGARG((png_structp png_ptr,
1728 png_bytepp image));
1729
1730/* writes the end of the PNG file. */
1731extern PNG_EXPORT(void,png_write_end) PNGARG((png_structp png_ptr,
1732 png_infop info_ptr));
1733
1734#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1735/* read the end of the PNG file. */
1736extern PNG_EXPORT(void,png_read_end) PNGARG((png_structp png_ptr,
1737 png_infop info_ptr));
1738#endif
1739
1740/* free any memory associated with the png_info_struct */
1741extern PNG_EXPORT(void,png_destroy_info_struct) PNGARG((png_structp png_ptr,
1742 png_infopp info_ptr_ptr));
1743
1744/* free any memory associated with the png_struct and the png_info_structs */
1745extern PNG_EXPORT(void,png_destroy_read_struct) PNGARG((png_structpp
1746 png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1747
1748/* free all memory used by the read (old method - NOT DLL EXPORTED) */
1749extern void png_read_destroy PNGARG((png_structp png_ptr, png_infop info_ptr,
1750 png_infop end_info_ptr));
1751
1752/* free any memory associated with the png_struct and the png_info_structs */
1753extern PNG_EXPORT(void,png_destroy_write_struct)
1754 PNGARG((png_structpp png_ptr_ptr, png_infopp info_ptr_ptr));
1755
1756/* free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */
1757extern void png_write_destroy PNGARG((png_structp png_ptr));
1758
1759/* set the libpng method of handling chunk CRC errors */
1760extern PNG_EXPORT(void,png_set_crc_action) PNGARG((png_structp png_ptr,
1761 int crit_action, int ancil_action));
1762
1763/* Values for png_set_crc_action() to say how to handle CRC errors in
1764 * ancillary and critical chunks, and whether to use the data contained
1765 * therein. Note that it is impossible to "discard" data in a critical
1766 * chunk. For versions prior to 0.90, the action was always error/quit,
1767 * whereas in version 0.90 and later, the action for CRC errors in ancillary
1768 * chunks is warn/discard. These values should NOT be changed.
1769 *
1770 * value action:critical action:ancillary
1771 */
1772#define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1773#define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1774#define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1775#define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1776#define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1777#define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1778
1779/* These functions give the user control over the scan-line filtering in
1780 * libpng and the compression methods used by zlib. These functions are
1781 * mainly useful for testing, as the defaults should work with most users.
1782 * Those users who are tight on memory or want faster performance at the
1783 * expense of compression can modify them. See the compression library
1784 * header file (zlib.h) for an explination of the compression functions.
1785 */
1786
1787/* set the filtering method(s) used by libpng. Currently, the only valid
1788 * value for "method" is 0.
1789 */
1790extern PNG_EXPORT(void,png_set_filter) PNGARG((png_structp png_ptr, int method,
1791 int filters));
1792
1793/* Flags for png_set_filter() to say which filters to use. The flags
1794 * are chosen so that they don't conflict with real filter types
1795 * below, in case they are supplied instead of the #defined constants.
1796 * These values should NOT be changed.
1797 */
1798#define PNG_NO_FILTERS 0x00
1799#define PNG_FILTER_NONE 0x08
1800#define PNG_FILTER_SUB 0x10
1801#define PNG_FILTER_UP 0x20
1802#define PNG_FILTER_AVG 0x40
1803#define PNG_FILTER_PAETH 0x80
1804#define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
1805 PNG_FILTER_AVG | PNG_FILTER_PAETH)
1806
1807/* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1808 * These defines should NOT be changed.
1809 */
1810#define PNG_FILTER_VALUE_NONE 0
1811#define PNG_FILTER_VALUE_SUB 1
1812#define PNG_FILTER_VALUE_UP 2
1813#define PNG_FILTER_VALUE_AVG 3
1814#define PNG_FILTER_VALUE_PAETH 4
1815#define PNG_FILTER_VALUE_LAST 5
1816
1817#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* EXPERIMENTAL */
1818/* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
1819 * defines, either the default (minimum-sum-of-absolute-differences), or
1820 * the experimental method (weighted-minimum-sum-of-absolute-differences).
1821 *
1822 * Weights are factors >= 1.0, indicating how important it is to keep the
1823 * filter type consistent between rows. Larger numbers mean the current
1824 * filter is that many times as likely to be the same as the "num_weights"
1825 * previous filters. This is cumulative for each previous row with a weight.
1826 * There needs to be "num_weights" values in "filter_weights", or it can be
1827 * NULL if the weights aren't being specified. Weights have no influence on
1828 * the selection of the first row filter. Well chosen weights can (in theory)
1829 * improve the compression for a given image.
1830 *
1831 * Costs are factors >= 1.0 indicating the relative decoding costs of a
1832 * filter type. Higher costs indicate more decoding expense, and are
1833 * therefore less likely to be selected over a filter with lower computational
1834 * costs. There needs to be a value in "filter_costs" for each valid filter
1835 * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
1836 * setting the costs. Costs try to improve the speed of decompression without
1837 * unduly increasing the compressed image size.
1838 *
1839 * A negative weight or cost indicates the default value is to be used, and
1840 * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
1841 * The default values for both weights and costs are currently 1.0, but may
1842 * change if good general weighting/cost heuristics can be found. If both
1843 * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
1844 * to the UNWEIGHTED method, but with added encoding time/computation.
1845 */
1846#ifdef PNG_FLOATING_POINT_SUPPORTED
1847extern PNG_EXPORT(void,png_set_filter_heuristics) PNGARG((png_structp png_ptr,
1848 int heuristic_method, int num_weights, png_doublep filter_weights,
1849 png_doublep filter_costs));
1850#endif
1851#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1852
1853/* Heuristic used for row filter selection. These defines should NOT be
1854 * changed.
1855 */
1856#define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
1857#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
1858#define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
1859#define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
1860
1861/* Set the library compression level. Currently, valid values range from
1862 * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1863 * (0 - no compression, 9 - "maximal" compression). Note that tests have
1864 * shown that zlib compression levels 3-6 usually perform as well as level 9
1865 * for PNG images, and do considerably fewer caclulations. In the future,
1866 * these values may not correspond directly to the zlib compression levels.
1867 */
1868extern PNG_EXPORT(void,png_set_compression_level) PNGARG((png_structp png_ptr,
1869 int level));
1870
1871extern PNG_EXPORT(void,png_set_compression_mem_level)
1872 PNGARG((png_structp png_ptr, int mem_level));
1873
1874extern PNG_EXPORT(void,png_set_compression_strategy)
1875 PNGARG((png_structp png_ptr, int strategy));
1876
1877extern PNG_EXPORT(void,png_set_compression_window_bits)
1878 PNGARG((png_structp png_ptr, int window_bits));
1879
1880extern PNG_EXPORT(void,png_set_compression_method) PNGARG((png_structp png_ptr,
1881 int method));
1882
1883/* These next functions are called for input/output, memory, and error
1884 * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
1885 * and call standard C I/O routines such as fread(), fwrite(), and
1886 * fprintf(). These functions can be made to use other I/O routines
1887 * at run time for those applications that need to handle I/O in a
1888 * different manner by calling png_set_???_fn(). See libpng.txt for
1889 * more information.
1890 */
1891
1892#if !defined(PNG_NO_STDIO)
1893/* Initialize the input/output for the PNG file to the default functions. */
1894extern PNG_EXPORT(void,png_init_io) PNGARG((png_structp png_ptr, png_FILE_p fp));
1895#endif
1896
1897/* Replace the (error and abort), and warning functions with user
1898 * supplied functions. If no messages are to be printed you must still
1899 * write and use replacement functions. The replacement error_fn should
1900 * still do a longjmp to the last setjmp location if you are using this
1901 * method of error handling. If error_fn or warning_fn is NULL, the
1902 * default function will be used.
1903 */
1904
1905extern PNG_EXPORT(void,png_set_error_fn) PNGARG((png_structp png_ptr,
1906 png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
1907
1908/* Return the user pointer associated with the error functions */
1909extern PNG_EXPORT(png_voidp,png_get_error_ptr) PNGARG((png_structp png_ptr));
1910
1911/* Replace the default data output functions with a user supplied one(s).
1912 * If buffered output is not used, then output_flush_fn can be set to NULL.
1913 * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
1914 * output_flush_fn will be ignored (and thus can be NULL).
1915 */
1916extern PNG_EXPORT(void,png_set_write_fn) PNGARG((png_structp png_ptr,
1917 png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
1918
1919/* Replace the default data input function with a user supplied one. */
1920extern PNG_EXPORT(void,png_set_read_fn) PNGARG((png_structp png_ptr,
1921 png_voidp io_ptr, png_rw_ptr read_data_fn));
1922
1923/* Return the user pointer associated with the I/O functions */
1924extern PNG_EXPORT(png_voidp,png_get_io_ptr) PNGARG((png_structp png_ptr));
1925
1926extern PNG_EXPORT(void,png_set_read_status_fn) PNGARG((png_structp png_ptr,
1927 png_read_status_ptr read_row_fn));
1928
1929extern PNG_EXPORT(void,png_set_write_status_fn) PNGARG((png_structp png_ptr,
1930 png_write_status_ptr write_row_fn));
1931
1932#ifdef PNG_USER_MEM_SUPPORTED
1933/* Replace the default memory allocation functions with user supplied one(s). */
1934extern PNG_EXPORT(void,png_set_mem_fn) PNGARG((png_structp png_ptr,
1935 png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1936/* Return the user pointer associated with the memory functions */
1937extern PNG_EXPORT(png_voidp,png_get_mem_ptr) PNGARG((png_structp png_ptr));
1938#endif
1939
1940#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1941 defined(PNG_LEGACY_SUPPORTED)
1942extern PNG_EXPORT(void,png_set_read_user_transform_fn) PNGARG((png_structp
1943 png_ptr, png_user_transform_ptr read_user_transform_fn));
1944#endif
1945
1946#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
1947 defined(PNG_LEGACY_SUPPORTED)
1948extern PNG_EXPORT(void,png_set_write_user_transform_fn) PNGARG((png_structp
1949 png_ptr, png_user_transform_ptr write_user_transform_fn));
1950#endif
1951
1952#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1953 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
1954 defined(PNG_LEGACY_SUPPORTED)
1955extern PNG_EXPORT(void,png_set_user_transform_info) PNGARG((png_structp
1956 png_ptr, png_voidp user_transform_ptr, int user_transform_depth,
1957 int user_transform_channels));
1958/* Return the user pointer associated with the user transform functions */
1959extern PNG_EXPORT(png_voidp,png_get_user_transform_ptr)
1960 PNGARG((png_structp png_ptr));
1961#endif
1962
1963#ifdef PNG_USER_CHUNKS_SUPPORTED
1964extern PNG_EXPORT(void,png_set_read_user_chunk_fn) PNGARG((png_structp png_ptr,
1965 png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
1966extern PNG_EXPORT(png_voidp,png_get_user_chunk_ptr) PNGARG((png_structp
1967 png_ptr));
1968#endif
1969
1970#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1971/* Sets the function callbacks for the push reader, and a pointer to a
1972 * user-defined structure available to the callback functions.
1973 */
1974extern PNG_EXPORT(void,png_set_progressive_read_fn) PNGARG((png_structp png_ptr,
1975 png_voidp progressive_ptr,
1976 png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
1977 png_progressive_end_ptr end_fn));
1978
1979/* returns the user pointer associated with the push read functions */
1980extern PNG_EXPORT(png_voidp,png_get_progressive_ptr)
1981 PNGARG((png_structp png_ptr));
1982
1983/* function to be called when data becomes available */
1984extern PNG_EXPORT(void,png_process_data) PNGARG((png_structp png_ptr,
1985 png_infop info_ptr, png_bytep buffer, png_size_t buffer_size));
1986
1987/* function that combines rows. Not very much different than the
1988 * png_combine_row() call. Is this even used?????
1989 */
1990extern PNG_EXPORT(void,png_progressive_combine_row) PNGARG((png_structp png_ptr,
1991 png_bytep old_row, png_bytep new_row));
1992#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1993
1994extern PNG_EXPORT(png_voidp,png_malloc) PNGARG((png_structp png_ptr,
1995 png_uint_32 size));
1996
1997#if defined(PNG_1_0_X)
1998# define png_malloc_warn png_malloc
1999#else
2000/* Added at libpng version 1.2.4 */
2001extern PNG_EXPORT(png_voidp,png_malloc_warn) PNGARG((png_structp png_ptr,
2002 png_uint_32 size));
2003#endif
2004
2005/* frees a pointer allocated by png_malloc() */
2006extern PNG_EXPORT(void,png_free) PNGARG((png_structp png_ptr, png_voidp ptr));
2007
2008#if defined(PNG_1_0_X)
2009/* Function to allocate memory for zlib. */
2010extern PNG_EXPORT(voidpf,png_zalloc) PNGARG((voidpf png_ptr, uInt items,
2011 uInt size));
2012
2013/* Function to free memory for zlib */
2014extern PNG_EXPORT(void,png_zfree) PNGARG((voidpf png_ptr, voidpf ptr));
2015#endif
2016
2017/* Free data that was allocated internally */
2018extern PNG_EXPORT(void,png_free_data) PNGARG((png_structp png_ptr,
2019 png_infop info_ptr, png_uint_32 free_me, int num));
2020#ifdef PNG_FREE_ME_SUPPORTED
2021/* Reassign responsibility for freeing existing data, whether allocated
2022 * by libpng or by the application */
2023extern PNG_EXPORT(void,png_data_freer) PNGARG((png_structp png_ptr,
2024 png_infop info_ptr, int freer, png_uint_32 mask));
2025#endif
2026/* assignments for png_data_freer */
2027#define PNG_DESTROY_WILL_FREE_DATA 1
2028#define PNG_SET_WILL_FREE_DATA 1
2029#define PNG_USER_WILL_FREE_DATA 2
2030/* Flags for png_ptr->free_me and info_ptr->free_me */
2031#define PNG_FREE_HIST 0x0008
2032#define PNG_FREE_ICCP 0x0010
2033#define PNG_FREE_SPLT 0x0020
2034#define PNG_FREE_ROWS 0x0040
2035#define PNG_FREE_PCAL 0x0080
2036#define PNG_FREE_SCAL 0x0100
2037#define PNG_FREE_UNKN 0x0200
2038#define PNG_FREE_LIST 0x0400
2039#define PNG_FREE_PLTE 0x1000
2040#define PNG_FREE_TRNS 0x2000
2041#define PNG_FREE_TEXT 0x4000
2042#define PNG_FREE_ALL 0x7fff
2043#define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
2044
2045#ifdef PNG_USER_MEM_SUPPORTED
2046extern PNG_EXPORT(png_voidp,png_malloc_default) PNGARG((png_structp png_ptr,
2047 png_uint_32 size));
2048extern PNG_EXPORT(void,png_free_default) PNGARG((png_structp png_ptr,
2049 png_voidp ptr));
2050#endif
2051
2052extern PNG_EXPORT(png_voidp,png_memcpy_check) PNGARG((png_structp png_ptr,
2053 png_voidp s1, png_voidp s2, png_uint_32 size));
2054
2055extern PNG_EXPORT(png_voidp,png_memset_check) PNGARG((png_structp png_ptr,
2056 png_voidp s1, int value, png_uint_32 size));
2057
2058#if defined(USE_FAR_KEYWORD) /* memory model conversion function */
2059extern void *png_far_to_near PNGARG((png_structp png_ptr,png_voidp ptr,
2060 int check));
2061#endif /* USE_FAR_KEYWORD */
2062
2063#ifndef PNG_NO_ERROR_TEXT
2064/* Fatal error in PNG image of libpng - can't continue */
2065extern PNG_EXPORT(void,png_error) PNGARG((png_structp png_ptr,
2066 png_const_charp error_message));
2067
2068/* The same, but the chunk name is prepended to the error string. */
2069extern PNG_EXPORT(void,png_chunk_error) PNGARG((png_structp png_ptr,
2070 png_const_charp error_message));
2071#else
2072/* Fatal error in PNG image of libpng - can't continue */
2073extern PNG_EXPORT(void,png_err) PNGARG((png_structp png_ptr));
2074#endif
2075
2076#ifndef PNG_NO_WARNINGS
2077/* Non-fatal error in libpng. Can continue, but may have a problem. */
2078extern PNG_EXPORT(void,png_warning) PNGARG((png_structp png_ptr,
2079 png_const_charp warning_message));
2080
2081#ifdef PNG_READ_SUPPORTED
2082/* Non-fatal error in libpng, chunk name is prepended to message. */
2083extern PNG_EXPORT(void,png_chunk_warning) PNGARG((png_structp png_ptr,
2084 png_const_charp warning_message));
2085#endif /* PNG_READ_SUPPORTED */
2086#endif /* PNG_NO_WARNINGS */
2087
2088/* The png_set_<chunk> functions are for storing values in the png_info_struct.
2089 * Similarly, the png_get_<chunk> calls are used to read values from the
2090 * png_info_struct, either storing the parameters in the passed variables, or
2091 * setting pointers into the png_info_struct where the data is stored. The
2092 * png_get_<chunk> functions return a non-zero value if the data was available
2093 * in info_ptr, or return zero and do not change any of the parameters if the
2094 * data was not available.
2095 *
2096 * These functions should be used instead of directly accessing png_info
2097 * to avoid problems with future changes in the size and internal layout of
2098 * png_info_struct.
2099 */
2100/* Returns "flag" if chunk data is valid in info_ptr. */
2101extern PNG_EXPORT(png_uint_32,png_get_valid) PNGARG((png_structp png_ptr,
2102png_infop info_ptr, png_uint_32 flag));
2103
2104/* Returns number of bytes needed to hold a transformed row. */
2105extern PNG_EXPORT(png_uint_32,png_get_rowbytes) PNGARG((png_structp png_ptr,
2106png_infop info_ptr));
2107
2108#if defined(PNG_INFO_IMAGE_SUPPORTED)
2109/* Returns row_pointers, which is an array of pointers to scanlines that was
2110returned from png_read_png(). */
2111extern PNG_EXPORT(png_bytepp,png_get_rows) PNGARG((png_structp png_ptr,
2112png_infop info_ptr));
2113/* Set row_pointers, which is an array of pointers to scanlines for use
2114by png_write_png(). */
2115extern PNG_EXPORT(void,png_set_rows) PNGARG((png_structp png_ptr,
2116 png_infop info_ptr, png_bytepp row_pointers));
2117#endif
2118
2119/* Returns number of color channels in image. */
2120extern PNG_EXPORT(png_byte,png_get_channels) PNGARG((png_structp png_ptr,
2121png_infop info_ptr));
2122
2123#ifdef PNG_EASY_ACCESS_SUPPORTED
2124/* Returns image width in pixels. */
2125extern PNG_EXPORT(png_uint_32, png_get_image_width) PNGARG((png_structp
2126png_ptr, png_infop info_ptr));
2127
2128/* Returns image height in pixels. */
2129extern PNG_EXPORT(png_uint_32, png_get_image_height) PNGARG((png_structp
2130png_ptr, png_infop info_ptr));
2131
2132/* Returns image bit_depth. */
2133extern PNG_EXPORT(png_byte, png_get_bit_depth) PNGARG((png_structp
2134png_ptr, png_infop info_ptr));
2135
2136/* Returns image color_type. */
2137extern PNG_EXPORT(png_byte, png_get_color_type) PNGARG((png_structp
2138png_ptr, png_infop info_ptr));
2139
2140/* Returns image filter_type. */
2141extern PNG_EXPORT(png_byte, png_get_filter_type) PNGARG((png_structp
2142png_ptr, png_infop info_ptr));
2143
2144/* Returns image interlace_type. */
2145extern PNG_EXPORT(png_byte, png_get_interlace_type) PNGARG((png_structp
2146png_ptr, png_infop info_ptr));
2147
2148/* Returns image compression_type. */
2149extern PNG_EXPORT(png_byte, png_get_compression_type) PNGARG((png_structp
2150png_ptr, png_infop info_ptr));
2151
2152/* Returns image resolution in pixels per meter, from pHYs chunk data. */
2153extern PNG_EXPORT(png_uint_32, png_get_pixels_per_meter) PNGARG((png_structp
2154png_ptr, png_infop info_ptr));
2155extern PNG_EXPORT(png_uint_32, png_get_x_pixels_per_meter) PNGARG((png_structp
2156png_ptr, png_infop info_ptr));
2157extern PNG_EXPORT(png_uint_32, png_get_y_pixels_per_meter) PNGARG((png_structp
2158png_ptr, png_infop info_ptr));
2159
2160/* Returns pixel aspect ratio, computed from pHYs chunk data. */
2161#ifdef PNG_FLOATING_POINT_SUPPORTED
2162extern PNG_EXPORT(float, png_get_pixel_aspect_ratio) PNGARG((png_structp
2163png_ptr, png_infop info_ptr));
2164#endif
2165
2166/* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
2167extern PNG_EXPORT(png_int_32, png_get_x_offset_pixels) PNGARG((png_structp
2168png_ptr, png_infop info_ptr));
2169extern PNG_EXPORT(png_int_32, png_get_y_offset_pixels) PNGARG((png_structp
2170png_ptr, png_infop info_ptr));
2171extern PNG_EXPORT(png_int_32, png_get_x_offset_microns) PNGARG((png_structp
2172png_ptr, png_infop info_ptr));
2173extern PNG_EXPORT(png_int_32, png_get_y_offset_microns) PNGARG((png_structp
2174png_ptr, png_infop info_ptr));
2175
2176#endif /* PNG_EASY_ACCESS_SUPPORTED */
2177
2178/* Returns pointer to signature string read from PNG header */
2179extern PNG_EXPORT(png_bytep,png_get_signature) PNGARG((png_structp png_ptr,
2180png_infop info_ptr));
2181
2182#if defined(PNG_bKGD_SUPPORTED)
2183extern PNG_EXPORT(png_uint_32,png_get_bKGD) PNGARG((png_structp png_ptr,
2184 png_infop info_ptr, png_color_16p *background));
2185#endif
2186
2187#if defined(PNG_bKGD_SUPPORTED)
2188extern PNG_EXPORT(void,png_set_bKGD) PNGARG((png_structp png_ptr,
2189 png_infop info_ptr, png_color_16p background));
2190#endif
2191
2192#if defined(PNG_cHRM_SUPPORTED)
2193#ifdef PNG_FLOATING_POINT_SUPPORTED
2194extern PNG_EXPORT(png_uint_32,png_get_cHRM) PNGARG((png_structp png_ptr,
2195 png_infop info_ptr, double *white_x, double *white_y, double *red_x,
2196 double *red_y, double *green_x, double *green_y, double *blue_x,
2197 double *blue_y));
2198#endif
2199#ifdef PNG_FIXED_POINT_SUPPORTED
2200extern PNG_EXPORT(png_uint_32,png_get_cHRM_fixed) PNGARG((png_structp png_ptr,
2201 png_infop info_ptr, png_fixed_point *int_white_x, png_fixed_point
2202 *int_white_y, png_fixed_point *int_red_x, png_fixed_point *int_red_y,
2203 png_fixed_point *int_green_x, png_fixed_point *int_green_y, png_fixed_point
2204 *int_blue_x, png_fixed_point *int_blue_y));
2205#endif
2206#endif
2207
2208#if defined(PNG_cHRM_SUPPORTED)
2209#ifdef PNG_FLOATING_POINT_SUPPORTED
2210extern PNG_EXPORT(void,png_set_cHRM) PNGARG((png_structp png_ptr,
2211 png_infop info_ptr, double white_x, double white_y, double red_x,
2212 double red_y, double green_x, double green_y, double blue_x, double blue_y));
2213#endif
2214#ifdef PNG_FIXED_POINT_SUPPORTED
2215extern PNG_EXPORT(void,png_set_cHRM_fixed) PNGARG((png_structp png_ptr,
2216 png_infop info_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y,
2217 png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
2218 int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
2219 png_fixed_point int_blue_y));
2220#endif
2221#endif
2222
2223#if defined(PNG_gAMA_SUPPORTED)
2224#ifdef PNG_FLOATING_POINT_SUPPORTED
2225extern PNG_EXPORT(png_uint_32,png_get_gAMA) PNGARG((png_structp png_ptr,
2226 png_infop info_ptr, double *file_gamma));
2227#endif
2228extern PNG_EXPORT(png_uint_32,png_get_gAMA_fixed) PNGARG((png_structp png_ptr,
2229 png_infop info_ptr, png_fixed_point *int_file_gamma));
2230#endif
2231
2232#if defined(PNG_gAMA_SUPPORTED)
2233#ifdef PNG_FLOATING_POINT_SUPPORTED
2234extern PNG_EXPORT(void,png_set_gAMA) PNGARG((png_structp png_ptr,
2235 png_infop info_ptr, double file_gamma));
2236#endif
2237extern PNG_EXPORT(void,png_set_gAMA_fixed) PNGARG((png_structp png_ptr,
2238 png_infop info_ptr, png_fixed_point int_file_gamma));
2239#endif
2240
2241#if defined(PNG_hIST_SUPPORTED)
2242extern PNG_EXPORT(png_uint_32,png_get_hIST) PNGARG((png_structp png_ptr,
2243 png_infop info_ptr, png_uint_16p *hist));
2244#endif
2245
2246#if defined(PNG_hIST_SUPPORTED)
2247extern PNG_EXPORT(void,png_set_hIST) PNGARG((png_structp png_ptr,
2248 png_infop info_ptr, png_uint_16p hist));
2249#endif
2250
2251extern PNG_EXPORT(png_uint_32,png_get_IHDR) PNGARG((png_structp png_ptr,
2252 png_infop info_ptr, png_uint_32 *width, png_uint_32 *height,
2253 int *bit_depth, int *color_type, int *interlace_method,
2254 int *compression_method, int *filter_method));
2255
2256extern PNG_EXPORT(void,png_set_IHDR) PNGARG((png_structp png_ptr,
2257 png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
2258 int color_type, int interlace_method, int compression_method,
2259 int filter_method));
2260
2261#if defined(PNG_oFFs_SUPPORTED)
2262extern PNG_EXPORT(png_uint_32,png_get_oFFs) PNGARG((png_structp png_ptr,
2263 png_infop info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
2264 int *unit_type));
2265#endif
2266
2267#if defined(PNG_oFFs_SUPPORTED)
2268extern PNG_EXPORT(void,png_set_oFFs) PNGARG((png_structp png_ptr,
2269 png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2270 int unit_type));
2271#endif
2272
2273#if defined(PNG_pCAL_SUPPORTED)
2274extern PNG_EXPORT(png_uint_32,png_get_pCAL) PNGARG((png_structp png_ptr,
2275 png_infop info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1,
2276 int *type, int *nparams, png_charp *units, png_charpp *params));
2277#endif
2278
2279#if defined(PNG_pCAL_SUPPORTED)
2280extern PNG_EXPORT(void,png_set_pCAL) PNGARG((png_structp png_ptr,
2281 png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1,
2282 int type, int nparams, png_charp units, png_charpp params));
2283#endif
2284
2285#if defined(PNG_pHYs_SUPPORTED)
2286extern PNG_EXPORT(png_uint_32,png_get_pHYs) PNGARG((png_structp png_ptr,
2287 png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
2288#endif
2289
2290#if defined(PNG_pHYs_SUPPORTED)
2291extern PNG_EXPORT(void,png_set_pHYs) PNGARG((png_structp png_ptr,
2292 png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2293#endif
2294
2295extern PNG_EXPORT(png_uint_32,png_get_PLTE) PNGARG((png_structp png_ptr,
2296 png_infop info_ptr, png_colorp *palette, int *num_palette));
2297
2298extern PNG_EXPORT(void,png_set_PLTE) PNGARG((png_structp png_ptr,
2299 png_infop info_ptr, png_colorp palette, int num_palette));
2300
2301#if defined(PNG_sBIT_SUPPORTED)
2302extern PNG_EXPORT(png_uint_32,png_get_sBIT) PNGARG((png_structp png_ptr,
2303 png_infop info_ptr, png_color_8p *sig_bit));
2304#endif
2305
2306#if defined(PNG_sBIT_SUPPORTED)
2307extern PNG_EXPORT(void,png_set_sBIT) PNGARG((png_structp png_ptr,
2308 png_infop info_ptr, png_color_8p sig_bit));
2309#endif
2310
2311#if defined(PNG_sRGB_SUPPORTED)
2312extern PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr,
2313 png_infop info_ptr, int *intent));
2314#endif
2315
2316#if defined(PNG_sRGB_SUPPORTED)
2317extern PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr,
2318 png_infop info_ptr, int intent));
2319extern PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr,
2320 png_infop info_ptr, int intent));
2321#endif
2322
2323#if defined(PNG_iCCP_SUPPORTED)
2324extern PNG_EXPORT(png_uint_32,png_get_iCCP) PNGARG((png_structp png_ptr,
2325 png_infop info_ptr, png_charpp name, int *compression_type,
2326 png_charpp profile, png_uint_32 *proflen));
2327 /* Note to maintainer: profile should be png_bytepp */
2328#endif
2329
2330#if defined(PNG_iCCP_SUPPORTED)
2331extern PNG_EXPORT(void,png_set_iCCP) PNGARG((png_structp png_ptr,
2332 png_infop info_ptr, png_charp name, int compression_type,
2333 png_charp profile, png_uint_32 proflen));
2334 /* Note to maintainer: profile should be png_bytep */
2335#endif
2336
2337#if defined(PNG_sPLT_SUPPORTED)
2338extern PNG_EXPORT(png_uint_32,png_get_sPLT) PNGARG((png_structp png_ptr,
2339 png_infop info_ptr, png_sPLT_tpp entries));
2340#endif
2341
2342#if defined(PNG_sPLT_SUPPORTED)
2343extern PNG_EXPORT(void,png_set_sPLT) PNGARG((png_structp png_ptr,
2344 png_infop info_ptr, png_sPLT_tp entries, int nentries));
2345#endif
2346
2347#if defined(PNG_TEXT_SUPPORTED)
2348/* png_get_text also returns the number of text chunks in *num_text */
2349extern PNG_EXPORT(png_uint_32,png_get_text) PNGARG((png_structp png_ptr,
2350 png_infop info_ptr, png_textp *text_ptr, int *num_text));
2351#endif
2352
2353/*
2354 * Note while png_set_text() will accept a structure whose text,
2355 * language, and translated keywords are NULL pointers, the structure
2356 * returned by png_get_text will always contain regular
2357 * zero-terminated C strings. They might be empty strings but
2358 * they will never be NULL pointers.
2359 */
2360
2361#if defined(PNG_TEXT_SUPPORTED)
2362extern PNG_EXPORT(void,png_set_text) PNGARG((png_structp png_ptr,
2363 png_infop info_ptr, png_textp text_ptr, int num_text));
2364#endif
2365
2366#if defined(PNG_tIME_SUPPORTED)
2367extern PNG_EXPORT(png_uint_32,png_get_tIME) PNGARG((png_structp png_ptr,
2368 png_infop info_ptr, png_timep *mod_time));
2369#endif
2370
2371#if defined(PNG_tIME_SUPPORTED)
2372extern PNG_EXPORT(void,png_set_tIME) PNGARG((png_structp png_ptr,
2373 png_infop info_ptr, png_timep mod_time));
2374#endif
2375
2376#if defined(PNG_tRNS_SUPPORTED)
2377extern PNG_EXPORT(png_uint_32,png_get_tRNS) PNGARG((png_structp png_ptr,
2378 png_infop info_ptr, png_bytep *trans, int *num_trans,
2379 png_color_16p *trans_values));
2380#endif
2381
2382#if defined(PNG_tRNS_SUPPORTED)
2383extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
2384 png_infop info_ptr, png_bytep trans, int num_trans,
2385 png_color_16p trans_values));
2386#endif
2387
2388#if defined(PNG_tRNS_SUPPORTED)
2389#endif
2390
2391#if defined(PNG_sCAL_SUPPORTED)
2392#ifdef PNG_FLOATING_POINT_SUPPORTED
2393extern PNG_EXPORT(png_uint_32,png_get_sCAL) PNGARG((png_structp png_ptr,
2394 png_infop info_ptr, int *unit, double *width, double *height));
2395#else
2396#ifdef PNG_FIXED_POINT_SUPPORTED
2397extern PNG_EXPORT(png_uint_32,png_get_sCAL_s) PNGARG((png_structp png_ptr,
2398 png_infop info_ptr, int *unit, png_charpp swidth, png_charpp sheight));
2399#endif
2400#endif
2401#endif /* PNG_sCAL_SUPPORTED */
2402
2403#if defined(PNG_sCAL_SUPPORTED)
2404#ifdef PNG_FLOATING_POINT_SUPPORTED
2405extern PNG_EXPORT(void,png_set_sCAL) PNGARG((png_structp png_ptr,
2406 png_infop info_ptr, int unit, double width, double height));
2407#else
2408#ifdef PNG_FIXED_POINT_SUPPORTED
2409extern PNG_EXPORT(void,png_set_sCAL_s) PNGARG((png_structp png_ptr,
2410 png_infop info_ptr, int unit, png_charp swidth, png_charp sheight));
2411#endif
2412#endif
2413#endif /* PNG_sCAL_SUPPORTED || PNG_WRITE_sCAL_SUPPORTED */
2414
2415#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
2416/* provide a list of chunks and how they are to be handled, if the built-in
2417 handling or default unknown chunk handling is not desired. Any chunks not
2418 listed will be handled in the default manner. The IHDR and IEND chunks
2419 must not be listed.
2420 keep = 0: follow default behaviour
2421 = 1: do not keep
2422 = 2: keep only if safe-to-copy
2423 = 3: keep even if unsafe-to-copy
2424*/
2425extern PNG_EXPORT(void, png_set_keep_unknown_chunks) PNGARG((png_structp
2426 png_ptr, int keep, png_bytep chunk_list, int num_chunks));
2427extern PNG_EXPORT(void, png_set_unknown_chunks) PNGARG((png_structp png_ptr,
2428 png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns));
2429extern PNG_EXPORT(void, png_set_unknown_chunk_location)
2430 PNGARG((png_structp png_ptr, png_infop info_ptr, int chunk, int location));
2431extern PNG_EXPORT(png_uint_32,png_get_unknown_chunks) PNGARG((png_structp
2432 png_ptr, png_infop info_ptr, png_unknown_chunkpp entries));
2433#endif
2434#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2435PNG_EXPORT(int,png_handle_as_unknown) PNGARG((png_structp png_ptr, png_bytep
2436 chunk_name));
2437#endif
2438
2439/* Png_free_data() will turn off the "valid" flag for anything it frees.
2440 If you need to turn it off for a chunk that your application has freed,
2441 you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); */
2442extern PNG_EXPORT(void, png_set_invalid) PNGARG((png_structp png_ptr,
2443 png_infop info_ptr, int mask));
2444
2445#if defined(PNG_INFO_IMAGE_SUPPORTED)
2446/* The "params" pointer is currently not used and is for future expansion. */
2447extern PNG_EXPORT(void, png_read_png) PNGARG((png_structp png_ptr,
2448 png_infop info_ptr,
2449 int transforms,
2450 png_voidp params));
2451extern PNG_EXPORT(void, png_write_png) PNGARG((png_structp png_ptr,
2452 png_infop info_ptr,
2453 int transforms,
2454 png_voidp params));
2455#endif
2456
2457/* Define PNG_DEBUG at compile time for debugging information. Higher
2458 * numbers for PNG_DEBUG mean more debugging information. This has
2459 * only been added since version 0.95 so it is not implemented throughout
2460 * libpng yet, but more support will be added as needed.
2461 */
2462#ifdef PNG_DEBUG
2463#if (PNG_DEBUG > 0)
2464#if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER)
2465#include <crtdbg.h>
2466#if (PNG_DEBUG > 1)
2467#define png_debug(l,m) _RPT0(_CRT_WARN,m)
2468#define png_debug1(l,m,p1) _RPT1(_CRT_WARN,m,p1)
2469#define png_debug2(l,m,p1,p2) _RPT2(_CRT_WARN,m,p1,p2)
2470#endif
2471#else /* PNG_DEBUG_FILE || !_MSC_VER */
2472#ifndef PNG_DEBUG_FILE
2473#define PNG_DEBUG_FILE stderr
2474#endif /* PNG_DEBUG_FILE */
2475#if (PNG_DEBUG > 1)
2476#define png_debug(l,m) \
2477{ \
2478 int num_tabs=l; \
2479 fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
2480 (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":"")))); \
2481}
2482#define png_debug1(l,m,p1) \
2483{ \
2484 int num_tabs=l; \
2485 fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
2486 (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1); \
2487}
2488#define png_debug2(l,m,p1,p2) \
2489{ \
2490 int num_tabs=l; \
2491 fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
2492 (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1,p2); \
2493}
2494#endif /* (PNG_DEBUG > 1) */
2495#endif /* _MSC_VER */
2496#endif /* (PNG_DEBUG > 0) */
2497#endif /* PNG_DEBUG */
2498#ifndef png_debug
2499#define png_debug(l, m)
2500#endif
2501#ifndef png_debug1
2502#define png_debug1(l, m, p1)
2503#endif
2504#ifndef png_debug2
2505#define png_debug2(l, m, p1, p2)
2506#endif
2507
2508extern PNG_EXPORT(png_charp,png_get_copyright) PNGARG((png_structp png_ptr));
2509extern PNG_EXPORT(png_charp,png_get_header_ver) PNGARG((png_structp png_ptr));
2510extern PNG_EXPORT(png_charp,png_get_header_version) PNGARG((png_structp png_ptr));
2511extern PNG_EXPORT(png_charp,png_get_libpng_ver) PNGARG((png_structp png_ptr));
2512
2513#ifdef PNG_MNG_FEATURES_SUPPORTED
2514extern PNG_EXPORT(png_uint_32,png_permit_mng_features) PNGARG((png_structp
2515 png_ptr, png_uint_32 mng_features_permitted));
2516#endif
2517
2518/* For use in png_set_keep_unknown, added to version 1.2.6 */
2519#define PNG_HANDLE_CHUNK_AS_DEFAULT 0
2520#define PNG_HANDLE_CHUNK_NEVER 1
2521#define PNG_HANDLE_CHUNK_IF_SAFE 2
2522#define PNG_HANDLE_CHUNK_ALWAYS 3
2523
2524/* Added to version 1.2.0 */
2525#if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
2526#if defined(PNG_MMX_CODE_SUPPORTED)
2527#define PNG_ASM_FLAG_MMX_SUPPORT_COMPILED 0x01 /* not user-settable */
2528#define PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU 0x02 /* not user-settable */
2529#define PNG_ASM_FLAG_MMX_READ_COMBINE_ROW 0x04
2530#define PNG_ASM_FLAG_MMX_READ_INTERLACE 0x08
2531#define PNG_ASM_FLAG_MMX_READ_FILTER_SUB 0x10
2532#define PNG_ASM_FLAG_MMX_READ_FILTER_UP 0x20
2533#define PNG_ASM_FLAG_MMX_READ_FILTER_AVG 0x40
2534#define PNG_ASM_FLAG_MMX_READ_FILTER_PAETH 0x80
2535#define PNG_ASM_FLAGS_INITIALIZED 0x80000000 /* not user-settable */
2536
2537#define PNG_MMX_READ_FLAGS ( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW \
2538 | PNG_ASM_FLAG_MMX_READ_INTERLACE \
2539 | PNG_ASM_FLAG_MMX_READ_FILTER_SUB \
2540 | PNG_ASM_FLAG_MMX_READ_FILTER_UP \
2541 | PNG_ASM_FLAG_MMX_READ_FILTER_AVG \
2542 | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH )
2543#define PNG_MMX_WRITE_FLAGS ( 0 )
2544
2545#define PNG_MMX_FLAGS ( PNG_ASM_FLAG_MMX_SUPPORT_COMPILED \
2546 | PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU \
2547 | PNG_MMX_READ_FLAGS \
2548 | PNG_MMX_WRITE_FLAGS )
2549
2550#define PNG_SELECT_READ 1
2551#define PNG_SELECT_WRITE 2
2552#endif /* PNG_MMX_CODE_SUPPORTED */
2553
2554#if !defined(PNG_1_0_X)
2555/* pngget.c */
2556extern PNG_EXPORT(png_uint_32,png_get_mmx_flagmask)
2557 PNGARG((int flag_select, int *compilerID));
2558
2559/* pngget.c */
2560extern PNG_EXPORT(png_uint_32,png_get_asm_flagmask)
2561 PNGARG((int flag_select));
2562
2563/* pngget.c */
2564extern PNG_EXPORT(png_uint_32,png_get_asm_flags)
2565 PNGARG((png_structp png_ptr));
2566
2567/* pngget.c */
2568extern PNG_EXPORT(png_byte,png_get_mmx_bitdepth_threshold)
2569 PNGARG((png_structp png_ptr));
2570
2571/* pngget.c */
2572extern PNG_EXPORT(png_uint_32,png_get_mmx_rowbytes_threshold)
2573 PNGARG((png_structp png_ptr));
2574
2575/* pngset.c */
2576extern PNG_EXPORT(void,png_set_asm_flags)
2577 PNGARG((png_structp png_ptr, png_uint_32 asm_flags));
2578
2579/* pngset.c */
2580extern PNG_EXPORT(void,png_set_mmx_thresholds)
2581 PNGARG((png_structp png_ptr, png_byte mmx_bitdepth_threshold,
2582 png_uint_32 mmx_rowbytes_threshold));
2583
2584#endif /* PNG_1_0_X */
2585
2586#if !defined(PNG_1_0_X)
2587/* png.c, pnggccrd.c, or pngvcrd.c */
2588extern PNG_EXPORT(int,png_mmx_support) PNGARG((void));
2589#endif /* PNG_ASSEMBLER_CODE_SUPPORTED */
2590
2591/* Strip the prepended error numbers ("#nnn ") from error and warning
2592 * messages before passing them to the error or warning handler. */
2593#ifdef PNG_ERROR_NUMBERS_SUPPORTED
2594extern PNG_EXPORT(void,png_set_strip_error_numbers) PNGARG((png_structp
2595 png_ptr, png_uint_32 strip_mode));
2596#endif
2597
2598#endif /* PNG_1_0_X */
2599
2600/* Added at libpng-1.2.6 */
2601#ifdef PNG_SET_USER_LIMITS_SUPPORTED
2602extern PNG_EXPORT(void,png_set_user_limits) PNGARG((png_structp
2603 png_ptr, png_uint_32 user_width_max, png_uint_32 user_height_max));
2604extern PNG_EXPORT(png_uint_32,png_get_user_width_max) PNGARG((png_structp
2605 png_ptr));
2606extern PNG_EXPORT(png_uint_32,png_get_user_height_max) PNGARG((png_structp
2607 png_ptr));
2608#endif
2609
2610/* Maintainer: Put new public prototypes here ^, in libpng.3, and project defs */
2611
2612#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2613/* With these routines we avoid an integer divide, which will be slower on
2614 * most machines. However, it does take more operations than the corresponding
2615 * divide method, so it may be slower on a few RISC systems. There are two
2616 * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2617 *
2618 * Note that the rounding factors are NOT supposed to be the same! 128 and
2619 * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2620 * standard method.
2621 *
2622 * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2623 */
2624
2625 /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2626
2627# define png_composite(composite, fg, alpha, bg) \
2628 { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) * (png_uint_16)(alpha) \
2629 + (png_uint_16)(bg)*(png_uint_16)(255 - \
2630 (png_uint_16)(alpha)) + (png_uint_16)128); \
2631 (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
2632
2633# define png_composite_16(composite, fg, alpha, bg) \
2634 { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) * (png_uint_32)(alpha) \
2635 + (png_uint_32)(bg)*(png_uint_32)(65535L - \
2636 (png_uint_32)(alpha)) + (png_uint_32)32768L); \
2637 (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
2638
2639#else /* standard method using integer division */
2640
2641# define png_composite(composite, fg, alpha, bg) \
2642 (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2643 (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2644 (png_uint_16)127) / 255)
2645
2646# define png_composite_16(composite, fg, alpha, bg) \
2647 (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2648 (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) + \
2649 (png_uint_32)32767) / (png_uint_32)65535L)
2650
2651#endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
2652
2653/* Inline macros to do direct reads of bytes from the input buffer. These
2654 * require that you are using an architecture that uses PNG byte ordering
2655 * (MSB first) and supports unaligned data storage. I think that PowerPC
2656 * in big-endian mode and 680x0 are the only ones that will support this.
2657 * The x86 line of processors definitely do not. The png_get_int_32()
2658 * routine also assumes we are using two's complement format for negative
2659 * values, which is almost certainly true.
2660 */
2661#if defined(PNG_READ_BIG_ENDIAN_SUPPORTED)
2662# define png_get_uint_32(buf) ( *((png_uint_32p) (buf)))
2663# define png_get_uint_16(buf) ( *((png_uint_16p) (buf)))
2664# define png_get_int_32(buf) ( *((png_int_32p) (buf)))
2665#else
2666extern PNG_EXPORT(png_uint_32,png_get_uint_32) PNGARG((png_bytep buf));
2667extern PNG_EXPORT(png_uint_16,png_get_uint_16) PNGARG((png_bytep buf));
2668extern PNG_EXPORT(png_int_32,png_get_int_32) PNGARG((png_bytep buf));
2669#endif /* !PNG_READ_BIG_ENDIAN_SUPPORTED */
2670extern PNG_EXPORT(png_uint_32,png_get_uint_31)
2671 PNGARG((png_structp png_ptr, png_bytep buf));
2672/* No png_get_int_16 -- may be added if there's a real need for it. */
2673
2674/* Place a 32-bit number into a buffer in PNG byte order (big-endian).
2675 */
2676extern PNG_EXPORT(void,png_save_uint_32)
2677 PNGARG((png_bytep buf, png_uint_32 i));
2678extern PNG_EXPORT(void,png_save_int_32)
2679 PNGARG((png_bytep buf, png_int_32 i));
2680
2681/* Place a 16-bit number into a buffer in PNG byte order.
2682 * The parameter is declared unsigned int, not png_uint_16,
2683 * just to avoid potential problems on pre-ANSI C compilers.
2684 */
2685extern PNG_EXPORT(void,png_save_uint_16)
2686 PNGARG((png_bytep buf, unsigned int i));
2687/* No png_save_int_16 -- may be added if there's a real need for it. */
2688
2689/* ************************************************************************* */
2690
2691/* These next functions are used internally in the code. They generally
2692 * shouldn't be used unless you are writing code to add or replace some
2693 * functionality in libpng. More information about most functions can
2694 * be found in the files where the functions are located.
2695 */
2696
2697
2698/* Various modes of operation, that are visible to applications because
2699 * they are used for unknown chunk location.
2700 */
2701#define PNG_HAVE_IHDR 0x01
2702#define PNG_HAVE_PLTE 0x02
2703#define PNG_HAVE_IDAT 0x04
2704#define PNG_AFTER_IDAT 0x08 /* Have complete zlib datastream */
2705#define PNG_HAVE_IEND 0x10
2706
2707#if defined(PNG_INTERNAL)
2708
2709/* More modes of operation. Note that after an init, mode is set to
2710 * zero automatically when the structure is created.
2711 */
2712#define PNG_HAVE_gAMA 0x20
2713#define PNG_HAVE_cHRM 0x40
2714#define PNG_HAVE_sRGB 0x80
2715#define PNG_HAVE_CHUNK_HEADER 0x100
2716#define PNG_WROTE_tIME 0x200
2717#define PNG_WROTE_INFO_BEFORE_PLTE 0x400
2718#define PNG_BACKGROUND_IS_GRAY 0x800
2719#define PNG_HAVE_PNG_SIGNATURE 0x1000
2720#define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
2721
2722/* flags for the transformations the PNG library does on the image data */
2723#define PNG_BGR 0x0001
2724#define PNG_INTERLACE 0x0002
2725#define PNG_PACK 0x0004
2726#define PNG_SHIFT 0x0008
2727#define PNG_SWAP_BYTES 0x0010
2728#define PNG_INVERT_MONO 0x0020
2729#define PNG_DITHER 0x0040
2730#define PNG_BACKGROUND 0x0080
2731#define PNG_BACKGROUND_EXPAND 0x0100
2732 /* 0x0200 unused */
2733#define PNG_16_TO_8 0x0400
2734#define PNG_RGBA 0x0800
2735#define PNG_EXPAND 0x1000
2736#define PNG_GAMMA 0x2000
2737#define PNG_GRAY_TO_RGB 0x4000
2738#define PNG_FILLER 0x8000L
2739#define PNG_PACKSWAP 0x10000L
2740#define PNG_SWAP_ALPHA 0x20000L
2741#define PNG_STRIP_ALPHA 0x40000L
2742#define PNG_INVERT_ALPHA 0x80000L
2743#define PNG_USER_TRANSFORM 0x100000L
2744#define PNG_RGB_TO_GRAY_ERR 0x200000L
2745#define PNG_RGB_TO_GRAY_WARN 0x400000L
2746#define PNG_RGB_TO_GRAY 0x600000L /* two bits, RGB_TO_GRAY_ERR|WARN */
2747 /* 0x800000L Unused */
2748#define PNG_ADD_ALPHA 0x1000000L /* Added to libpng-1.2.7 */
2749#define PNG_EXPAND_tRNS 0x2000000L /* Added to libpng-1.2.9 */
2750 /* 0x4000000L unused */
2751 /* 0x8000000L unused */
2752 /* 0x10000000L unused */
2753 /* 0x20000000L unused */
2754 /* 0x40000000L unused */
2755
2756/* flags for png_create_struct */
2757#define PNG_STRUCT_PNG 0x0001
2758#define PNG_STRUCT_INFO 0x0002
2759
2760/* Scaling factor for filter heuristic weighting calculations */
2761#define PNG_WEIGHT_SHIFT 8
2762#define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
2763#define PNG_COST_SHIFT 3
2764#define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
2765
2766/* flags for the png_ptr->flags rather than declaring a byte for each one */
2767#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001
2768#define PNG_FLAG_ZLIB_CUSTOM_LEVEL 0x0002
2769#define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL 0x0004
2770#define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS 0x0008
2771#define PNG_FLAG_ZLIB_CUSTOM_METHOD 0x0010
2772#define PNG_FLAG_ZLIB_FINISHED 0x0020
2773#define PNG_FLAG_ROW_INIT 0x0040
2774#define PNG_FLAG_FILLER_AFTER 0x0080
2775#define PNG_FLAG_CRC_ANCILLARY_USE 0x0100
2776#define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200
2777#define PNG_FLAG_CRC_CRITICAL_USE 0x0400
2778#define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800
2779#define PNG_FLAG_FREE_PLTE 0x1000
2780#define PNG_FLAG_FREE_TRNS 0x2000
2781#define PNG_FLAG_FREE_HIST 0x4000
2782#define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000L
2783#define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000L
2784#define PNG_FLAG_LIBRARY_MISMATCH 0x20000L
2785#define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000L
2786#define PNG_FLAG_STRIP_ERROR_TEXT 0x80000L
2787#define PNG_FLAG_MALLOC_NULL_MEM_OK 0x100000L
2788#define PNG_FLAG_ADD_ALPHA 0x200000L /* Added to libpng-1.2.8 */
2789#define PNG_FLAG_STRIP_ALPHA 0x400000L /* Added to libpng-1.2.8 */
2790 /* 0x800000L unused */
2791 /* 0x1000000L unused */
2792 /* 0x2000000L unused */
2793 /* 0x4000000L unused */
2794 /* 0x8000000L unused */
2795 /* 0x10000000L unused */
2796 /* 0x20000000L unused */
2797 /* 0x40000000L unused */
2798
2799#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
2800 PNG_FLAG_CRC_ANCILLARY_NOWARN)
2801
2802#define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE | \
2803 PNG_FLAG_CRC_CRITICAL_IGNORE)
2804
2805#define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK | \
2806 PNG_FLAG_CRC_CRITICAL_MASK)
2807
2808/* save typing and make code easier to understand */
2809
2810#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
2811 abs((int)((c1).green) - (int)((c2).green)) + \
2812 abs((int)((c1).blue) - (int)((c2).blue)))
2813
2814/* Added to libpng-1.2.6 JB */
2815#define PNG_ROWBYTES(pixel_bits, width) \
2816 ((pixel_bits) >= 8 ? \
2817 ((width) * (((png_uint_32)(pixel_bits)) >> 3)) : \
2818 (( ((width) * ((png_uint_32)(pixel_bits))) + 7) >> 3) )
2819
2820/* PNG_OUT_OF_RANGE returns true if value is outside the range
2821 ideal-delta..ideal+delta. Each argument is evaluated twice.
2822 "ideal" and "delta" should be constants, normally simple
2823 integers, "value" a variable. Added to libpng-1.2.6 JB */
2824#define PNG_OUT_OF_RANGE(value, ideal, delta) \
2825 ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
2826
2827/* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
2828#if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
2829/* place to hold the signature string for a PNG file. */
2830#ifdef PNG_USE_GLOBAL_ARRAYS
2831 PNG_EXPORT_VAR (PNG_CONST png_byte FARDATA) png_sig[8];
2832#else
2833#endif
2834#endif /* PNG_NO_EXTERN */
2835
2836/* Constant strings for known chunk types. If you need to add a chunk,
2837 * define the name here, and add an invocation of the macro in png.c and
2838 * wherever it's needed.
2839 */
2840#define PNG_IHDR png_byte png_IHDR[5] = { 73, 72, 68, 82, '\0'}
2841#define PNG_IDAT png_byte png_IDAT[5] = { 73, 68, 65, 84, '\0'}
2842#define PNG_IEND png_byte png_IEND[5] = { 73, 69, 78, 68, '\0'}
2843#define PNG_PLTE png_byte png_PLTE[5] = { 80, 76, 84, 69, '\0'}
2844#define PNG_bKGD png_byte png_bKGD[5] = { 98, 75, 71, 68, '\0'}
2845#define PNG_cHRM png_byte png_cHRM[5] = { 99, 72, 82, 77, '\0'}
2846#define PNG_gAMA png_byte png_gAMA[5] = {103, 65, 77, 65, '\0'}
2847#define PNG_hIST png_byte png_hIST[5] = {104, 73, 83, 84, '\0'}
2848#define PNG_iCCP png_byte png_iCCP[5] = {105, 67, 67, 80, '\0'}
2849#define PNG_iTXt png_byte png_iTXt[5] = {105, 84, 88, 116, '\0'}
2850#define PNG_oFFs png_byte png_oFFs[5] = {111, 70, 70, 115, '\0'}
2851#define PNG_pCAL png_byte png_pCAL[5] = {112, 67, 65, 76, '\0'}
2852#define PNG_sCAL png_byte png_sCAL[5] = {115, 67, 65, 76, '\0'}
2853#define PNG_pHYs png_byte png_pHYs[5] = {112, 72, 89, 115, '\0'}
2854#define PNG_sBIT png_byte png_sBIT[5] = {115, 66, 73, 84, '\0'}
2855#define PNG_sPLT png_byte png_sPLT[5] = {115, 80, 76, 84, '\0'}
2856#define PNG_sRGB png_byte png_sRGB[5] = {115, 82, 71, 66, '\0'}
2857#define PNG_tEXt png_byte png_tEXt[5] = {116, 69, 88, 116, '\0'}
2858#define PNG_tIME png_byte png_tIME[5] = {116, 73, 77, 69, '\0'}
2859#define PNG_tRNS png_byte png_tRNS[5] = {116, 82, 78, 83, '\0'}
2860#define PNG_zTXt png_byte png_zTXt[5] = {122, 84, 88, 116, '\0'}
2861
2862#ifdef PNG_USE_GLOBAL_ARRAYS
2863PNG_EXPORT_VAR (png_byte FARDATA) png_IHDR[5];
2864PNG_EXPORT_VAR (png_byte FARDATA) png_IDAT[5];
2865PNG_EXPORT_VAR (png_byte FARDATA) png_IEND[5];
2866PNG_EXPORT_VAR (png_byte FARDATA) png_PLTE[5];
2867PNG_EXPORT_VAR (png_byte FARDATA) png_bKGD[5];
2868PNG_EXPORT_VAR (png_byte FARDATA) png_cHRM[5];
2869PNG_EXPORT_VAR (png_byte FARDATA) png_gAMA[5];
2870PNG_EXPORT_VAR (png_byte FARDATA) png_hIST[5];
2871PNG_EXPORT_VAR (png_byte FARDATA) png_iCCP[5];
2872PNG_EXPORT_VAR (png_byte FARDATA) png_iTXt[5];
2873PNG_EXPORT_VAR (png_byte FARDATA) png_oFFs[5];
2874PNG_EXPORT_VAR (png_byte FARDATA) png_pCAL[5];
2875PNG_EXPORT_VAR (png_byte FARDATA) png_sCAL[5];
2876PNG_EXPORT_VAR (png_byte FARDATA) png_pHYs[5];
2877PNG_EXPORT_VAR (png_byte FARDATA) png_sBIT[5];
2878PNG_EXPORT_VAR (png_byte FARDATA) png_sPLT[5];
2879PNG_EXPORT_VAR (png_byte FARDATA) png_sRGB[5];
2880PNG_EXPORT_VAR (png_byte FARDATA) png_tEXt[5];
2881PNG_EXPORT_VAR (png_byte FARDATA) png_tIME[5];
2882PNG_EXPORT_VAR (png_byte FARDATA) png_tRNS[5];
2883PNG_EXPORT_VAR (png_byte FARDATA) png_zTXt[5];
2884#endif /* PNG_USE_GLOBAL_ARRAYS */
2885
2886#if defined(PNG_1_0_X) || defined (PNG_1_2_X)
2887/* Initialize png_ptr struct for reading, and allocate any other memory.
2888 * (old interface - DEPRECATED - use png_create_read_struct instead).
2889 */
2890extern PNG_EXPORT(void,png_read_init) PNGARG((png_structp png_ptr));
2891#undef png_read_init
2892#define png_read_init(png_ptr) png_read_init_3(&png_ptr, \
2893 PNG_LIBPNG_VER_STRING, png_sizeof(png_struct));
2894#endif
2895
2896extern PNG_EXPORT(void,png_read_init_3) PNGARG((png_structpp ptr_ptr,
2897 png_const_charp user_png_ver, png_size_t png_struct_size));
2898#if defined(PNG_1_0_X) || defined (PNG_1_2_X)
2899extern PNG_EXPORT(void,png_read_init_2) PNGARG((png_structp png_ptr,
2900 png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
2901 png_info_size));
2902#endif
2903
2904#if defined(PNG_1_0_X) || defined (PNG_1_2_X)
2905/* Initialize png_ptr struct for writing, and allocate any other memory.
2906 * (old interface - DEPRECATED - use png_create_write_struct instead).
2907 */
2908extern PNG_EXPORT(void,png_write_init) PNGARG((png_structp png_ptr));
2909#undef png_write_init
2910#define png_write_init(png_ptr) png_write_init_3(&png_ptr, \
2911 PNG_LIBPNG_VER_STRING, png_sizeof(png_struct));
2912#endif
2913
2914extern PNG_EXPORT(void,png_write_init_3) PNGARG((png_structpp ptr_ptr,
2915 png_const_charp user_png_ver, png_size_t png_struct_size));
2916extern PNG_EXPORT(void,png_write_init_2) PNGARG((png_structp png_ptr,
2917 png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
2918 png_info_size));
2919
2920/* Allocate memory for an internal libpng struct */
2921PNG_EXTERN png_voidp png_create_struct PNGARG((int type));
2922
2923/* Free memory from internal libpng struct */
2924PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr));
2925
2926PNG_EXTERN png_voidp png_create_struct_2 PNGARG((int type, png_malloc_ptr
2927 malloc_fn, png_voidp mem_ptr));
2928PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr,
2929 png_free_ptr free_fn, png_voidp mem_ptr));
2930
2931/* Free any memory that info_ptr points to and reset struct. */
2932PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr,
2933 png_infop info_ptr));
2934
2935#ifndef PNG_1_0_X
2936/* Function to allocate memory for zlib. */
2937PNG_EXTERN voidpf png_zalloc PNGARG((voidpf png_ptr, uInt items, uInt size));
2938
2939/* Function to free memory for zlib */
2940PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr));
2941
2942#ifdef PNG_SIZE_T
2943/* Function to convert a sizeof an item to png_sizeof item */
2944 PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size));
2945#endif
2946
2947/* Next four functions are used internally as callbacks. PNGAPI is required
2948 * but not PNG_EXPORT. PNGAPI added at libpng version 1.2.3. */
2949
2950PNG_EXTERN void PNGAPI png_default_read_data PNGARG((png_structp png_ptr,
2951 png_bytep data, png_size_t length));
2952
2953#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
2954PNG_EXTERN void PNGAPI png_push_fill_buffer PNGARG((png_structp png_ptr,
2955 png_bytep buffer, png_size_t length));
2956#endif
2957
2958PNG_EXTERN void PNGAPI png_default_write_data PNGARG((png_structp png_ptr,
2959 png_bytep data, png_size_t length));
2960
2961#if defined(PNG_WRITE_FLUSH_SUPPORTED)
2962#if !defined(PNG_NO_STDIO)
2963PNG_EXTERN void PNGAPI png_default_flush PNGARG((png_structp png_ptr));
2964#endif
2965#endif
2966#else /* PNG_1_0_X */
2967#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
2968PNG_EXTERN void png_push_fill_buffer PNGARG((png_structp png_ptr,
2969 png_bytep buffer, png_size_t length));
2970#endif
2971#endif /* PNG_1_0_X */
2972
2973/* Reset the CRC variable */
2974PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr));
2975
2976/* Write the "data" buffer to whatever output you are using. */
2977PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr, png_bytep data,
2978 png_size_t length));
2979
2980/* Read data from whatever input you are using into the "data" buffer */
2981PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data,
2982 png_size_t length));
2983
2984/* Read bytes into buf, and update png_ptr->crc */
2985PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
2986 png_size_t length));
2987
2988/* Decompress data in a chunk that uses compression */
2989#if defined(PNG_zTXt_SUPPORTED) || defined(PNG_iTXt_SUPPORTED) || \
2990 defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED)
2991PNG_EXTERN png_charp png_decompress_chunk PNGARG((png_structp png_ptr,
2992 int comp_type, png_charp chunkdata, png_size_t chunklength,
2993 png_size_t prefix_length, png_size_t *data_length));
2994#endif
2995
2996/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
2997PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip));
2998
2999/* Read the CRC from the file and compare it to the libpng calculated CRC */
3000PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr));
3001
3002/* Calculate the CRC over a section of data. Note that we are only
3003 * passing a maximum of 64K on systems that have this as a memory limit,
3004 * since this is the maximum buffer size we can specify.
3005 */
3006PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr, png_bytep ptr,
3007 png_size_t length));
3008
3009#if defined(PNG_WRITE_FLUSH_SUPPORTED)
3010PNG_EXTERN void png_flush PNGARG((png_structp png_ptr));
3011#endif
3012
3013/* simple function to write the signature */
3014PNG_EXTERN void png_write_sig PNGARG((png_structp png_ptr));
3015
3016/* write various chunks */
3017
3018/* Write the IHDR chunk, and update the png_struct with the necessary
3019 * information.
3020 */
3021PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width,
3022 png_uint_32 height,
3023 int bit_depth, int color_type, int compression_method, int filter_method,
3024 int interlace_method));
3025
3026PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr, png_colorp palette,
3027 png_uint_32 num_pal));
3028
3029PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data,
3030 png_size_t length));
3031
3032PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr));
3033
3034#if defined(PNG_WRITE_gAMA_SUPPORTED)
3035#ifdef PNG_FLOATING_POINT_SUPPORTED
3036PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma));
3037#endif
3038#ifdef PNG_FIXED_POINT_SUPPORTED
3039PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr, png_fixed_point
3040 file_gamma));
3041#endif
3042#endif
3043
3044#if defined(PNG_WRITE_sBIT_SUPPORTED)
3045PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr, png_color_8p sbit,
3046 int color_type));
3047#endif
3048
3049#if defined(PNG_WRITE_cHRM_SUPPORTED)
3050#ifdef PNG_FLOATING_POINT_SUPPORTED
3051PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr,
3052 double white_x, double white_y,
3053 double red_x, double red_y, double green_x, double green_y,
3054 double blue_x, double blue_y));
3055#endif
3056#ifdef PNG_FIXED_POINT_SUPPORTED
3057PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr,
3058 png_fixed_point int_white_x, png_fixed_point int_white_y,
3059 png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
3060 int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
3061 png_fixed_point int_blue_y));
3062#endif
3063#endif
3064
3065#if defined(PNG_WRITE_sRGB_SUPPORTED)
3066PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
3067 int intent));
3068#endif
3069
3070#if defined(PNG_WRITE_iCCP_SUPPORTED)
3071PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr,
3072 png_charp name, int compression_type,
3073 png_charp profile, int proflen));
3074 /* Note to maintainer: profile should be png_bytep */
3075#endif
3076
3077#if defined(PNG_WRITE_sPLT_SUPPORTED)
3078PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr,
3079 png_sPLT_tp palette));
3080#endif
3081
3082#if defined(PNG_WRITE_tRNS_SUPPORTED)
3083PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr, png_bytep trans,
3084 png_color_16p values, int number, int color_type));
3085#endif
3086
3087#if defined(PNG_WRITE_bKGD_SUPPORTED)
3088PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr,
3089 png_color_16p values, int color_type));
3090#endif
3091
3092#if defined(PNG_WRITE_hIST_SUPPORTED)
3093PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, png_uint_16p hist,
3094 int num_hist));
3095#endif
3096
3097#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
3098 defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
3099PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
3100 png_charp key, png_charpp new_key));
3101#endif
3102
3103#if defined(PNG_WRITE_tEXt_SUPPORTED)
3104PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_charp key,
3105 png_charp text, png_size_t text_len));
3106#endif
3107
3108#if defined(PNG_WRITE_zTXt_SUPPORTED)
3109PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_charp key,
3110 png_charp text, png_size_t text_len, int compression));
3111#endif
3112
3113#if defined(PNG_WRITE_iTXt_SUPPORTED)
3114PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr,
3115 int compression, png_charp key, png_charp lang, png_charp lang_key,
3116 png_charp text));
3117#endif
3118
3119#if defined(PNG_TEXT_SUPPORTED) /* Added at version 1.0.14 and 1.2.4 */
3120PNG_EXTERN int png_set_text_2 PNGARG((png_structp png_ptr,
3121 png_infop info_ptr, png_textp text_ptr, int num_text));
3122#endif
3123
3124#if defined(PNG_WRITE_oFFs_SUPPORTED)
3125PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr,
3126 png_int_32 x_offset, png_int_32 y_offset, int unit_type));
3127#endif
3128
3129#if defined(PNG_WRITE_pCAL_SUPPORTED)
3130PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose,
3131 png_int_32 X0, png_int_32 X1, int type, int nparams,
3132 png_charp units, png_charpp params));
3133#endif
3134
3135#if defined(PNG_WRITE_pHYs_SUPPORTED)
3136PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr,
3137 png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
3138 int unit_type));
3139#endif
3140
3141#if defined(PNG_WRITE_tIME_SUPPORTED)
3142PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr,
3143 png_timep mod_time));
3144#endif
3145
3146#if defined(PNG_WRITE_sCAL_SUPPORTED)
3147#if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
3148PNG_EXTERN void png_write_sCAL PNGARG((png_structp png_ptr,
3149 int unit, double width, double height));
3150#else
3151#ifdef PNG_FIXED_POINT_SUPPORTED
3152PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr,
3153 int unit, png_charp width, png_charp height));
3154#endif
3155#endif
3156#endif
3157
3158/* Called when finished processing a row of data */
3159PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr));
3160
3161/* Internal use only. Called before first row of data */
3162PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr));
3163
3164#if defined(PNG_READ_GAMMA_SUPPORTED)
3165PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr));
3166#endif
3167
3168/* combine a row of data, dealing with alpha, etc. if requested */
3169PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row,
3170 int mask));
3171
3172#if defined(PNG_READ_INTERLACING_SUPPORTED)
3173/* expand an interlaced row */
3174/* OLD pre-1.0.9 interface:
3175PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info,
3176 png_bytep row, int pass, png_uint_32 transformations));
3177 */
3178PNG_EXTERN void png_do_read_interlace PNGARG((png_structp png_ptr));
3179#endif
3180
3181/* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */
3182
3183#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
3184/* grab pixels out of a row for an interlaced pass */
3185PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info,
3186 png_bytep row, int pass));
3187#endif
3188
3189/* unfilter a row */
3190PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr,
3191 png_row_infop row_info, png_bytep row, png_bytep prev_row, int filter));
3192
3193/* Choose the best filter to use and filter the row data */
3194PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
3195 png_row_infop row_info));
3196
3197/* Write out the filtered row. */
3198PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr,
3199 png_bytep filtered_row));
3200/* finish a row while reading, dealing with interlacing passes, etc. */
3201PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
3202
3203/* initialize the row buffers, etc. */
3204PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr));
3205/* optional call to update the users info structure */
3206PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
3207 png_infop info_ptr));
3208
3209/* these are the functions that do the transformations */
3210#if defined(PNG_READ_FILLER_SUPPORTED)
3211PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info,
3212 png_bytep row, png_uint_32 filler, png_uint_32 flags));
3213#endif
3214
3215#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
3216PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info,
3217 png_bytep row));
3218#endif
3219
3220#if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
3221PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info,
3222 png_bytep row));
3223#endif
3224
3225#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
3226PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info,
3227 png_bytep row));
3228#endif
3229
3230#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
3231PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info,
3232 png_bytep row));
3233#endif
3234
3235#if defined(PNG_WRITE_FILLER_SUPPORTED) || \
3236 defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
3237PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info,
3238 png_bytep row, png_uint_32 flags));
3239#endif
3240
3241#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
3242PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info, png_bytep row));
3243#endif
3244
3245#if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
3246PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info, png_bytep row));
3247#endif
3248
3249#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
3250PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr, png_row_infop
3251 row_info, png_bytep row));
3252#endif
3253
3254#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
3255PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info,
3256 png_bytep row));
3257#endif
3258
3259#if defined(PNG_READ_PACK_SUPPORTED)
3260PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info, png_bytep row));
3261#endif
3262
3263#if defined(PNG_READ_SHIFT_SUPPORTED)
3264PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info, png_bytep row,
3265 png_color_8p sig_bits));
3266#endif
3267
3268#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
3269PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info, png_bytep row));
3270#endif
3271
3272#if defined(PNG_READ_16_TO_8_SUPPORTED)
3273PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info, png_bytep row));
3274#endif
3275
3276#if defined(PNG_READ_DITHER_SUPPORTED)
3277PNG_EXTERN void png_do_dither PNGARG((png_row_infop row_info,
3278 png_bytep row, png_bytep palette_lookup, png_bytep dither_lookup));
3279
3280# if defined(PNG_CORRECT_PALETTE_SUPPORTED)
3281PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr,
3282 png_colorp palette, int num_palette));
3283# endif
3284#endif
3285
3286#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
3287PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info, png_bytep row));
3288#endif
3289
3290#if defined(PNG_WRITE_PACK_SUPPORTED)
3291PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info,
3292 png_bytep row, png_uint_32 bit_depth));
3293#endif
3294
3295#if defined(PNG_WRITE_SHIFT_SUPPORTED)
3296PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info, png_bytep row,
3297 png_color_8p bit_depth));
3298#endif
3299
3300#if defined(PNG_READ_BACKGROUND_SUPPORTED)
3301#if defined(PNG_READ_GAMMA_SUPPORTED)
3302PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
3303 png_color_16p trans_values, png_color_16p background,
3304 png_color_16p background_1,
3305 png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,
3306 png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,
3307 png_uint_16pp gamma_16_to_1, int gamma_shift));
3308#else
3309PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
3310 png_color_16p trans_values, png_color_16p background));
3311#endif
3312#endif
3313
3314#if defined(PNG_READ_GAMMA_SUPPORTED)
3315PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info, png_bytep row,
3316 png_bytep gamma_table, png_uint_16pp gamma_16_table,
3317 int gamma_shift));
3318#endif
3319
3320#if defined(PNG_READ_EXPAND_SUPPORTED)
3321PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info,
3322 png_bytep row, png_colorp palette, png_bytep trans, int num_trans));
3323PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info,
3324 png_bytep row, png_color_16p trans_value));
3325#endif
3326
3327/* The following decodes the appropriate chunks, and does error correction,
3328 * then calls the appropriate callback for the chunk if it is valid.
3329 */
3330
3331/* decode the IHDR chunk */
3332PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr,
3333 png_uint_32 length));
3334PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr,
3335 png_uint_32 length));
3336PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr,
3337 png_uint_32 length));
3338
3339#if defined(PNG_READ_bKGD_SUPPORTED)
3340PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr,
3341 png_uint_32 length));
3342#endif
3343
3344#if defined(PNG_READ_cHRM_SUPPORTED)
3345PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr,
3346 png_uint_32 length));
3347#endif
3348
3349#if defined(PNG_READ_gAMA_SUPPORTED)
3350PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr,
3351 png_uint_32 length));
3352#endif
3353
3354#if defined(PNG_READ_hIST_SUPPORTED)
3355PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr,
3356 png_uint_32 length));
3357#endif
3358
3359#if defined(PNG_READ_iCCP_SUPPORTED)
3360extern void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr,
3361 png_uint_32 length));
3362#endif /* PNG_READ_iCCP_SUPPORTED */
3363
3364#if defined(PNG_READ_iTXt_SUPPORTED)
3365PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3366 png_uint_32 length));
3367#endif
3368
3369#if defined(PNG_READ_oFFs_SUPPORTED)
3370PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr,
3371 png_uint_32 length));
3372#endif
3373
3374#if defined(PNG_READ_pCAL_SUPPORTED)
3375PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
3376 png_uint_32 length));
3377#endif
3378
3379#if defined(PNG_READ_pHYs_SUPPORTED)
3380PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr,
3381 png_uint_32 length));
3382#endif
3383
3384#if defined(PNG_READ_sBIT_SUPPORTED)
3385PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr,
3386 png_uint_32 length));
3387#endif
3388
3389#if defined(PNG_READ_sCAL_SUPPORTED)
3390PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
3391 png_uint_32 length));
3392#endif
3393
3394#if defined(PNG_READ_sPLT_SUPPORTED)
3395extern void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr,
3396 png_uint_32 length));
3397#endif /* PNG_READ_sPLT_SUPPORTED */
3398
3399#if defined(PNG_READ_sRGB_SUPPORTED)
3400PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr,
3401 png_uint_32 length));
3402#endif
3403
3404#if defined(PNG_READ_tEXt_SUPPORTED)
3405PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3406 png_uint_32 length));
3407#endif
3408
3409#if defined(PNG_READ_tIME_SUPPORTED)
3410PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr,
3411 png_uint_32 length));
3412#endif
3413
3414#if defined(PNG_READ_tRNS_SUPPORTED)
3415PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr,
3416 png_uint_32 length));
3417#endif
3418
3419#if defined(PNG_READ_zTXt_SUPPORTED)
3420PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3421 png_uint_32 length));
3422#endif
3423
3424PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
3425 png_infop info_ptr, png_uint_32 length));
3426
3427PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
3428 png_bytep chunk_name));
3429
3430/* handle the transformations for reading and writing */
3431PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr));
3432PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr));
3433
3434PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr));
3435
3436#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3437PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
3438 png_infop info_ptr));
3439PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr,
3440 png_infop info_ptr));
3441PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr));
3442PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr,
3443 png_uint_32 length));
3444PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr));
3445PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr));
3446PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr,
3447 png_bytep buffer, png_size_t buffer_length));
3448PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr));
3449PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr,
3450 png_bytep buffer, png_size_t buffer_length));
3451PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr));
3452PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr,
3453 png_infop info_ptr, png_uint_32 length));
3454PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr,
3455 png_infop info_ptr));
3456PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr,
3457 png_infop info_ptr));
3458PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr, png_bytep row));
3459PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr,
3460 png_infop info_ptr));
3461PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr,
3462 png_infop info_ptr));
3463PNG_EXTERN void png_read_push_finish_row PNGARG((png_structp png_ptr));
3464#if defined(PNG_READ_tEXt_SUPPORTED)
3465PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr,
3466 png_infop info_ptr, png_uint_32 length));
3467PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr,
3468 png_infop info_ptr));
3469#endif
3470#if defined(PNG_READ_zTXt_SUPPORTED)
3471PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr,
3472 png_infop info_ptr, png_uint_32 length));
3473PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr,
3474 png_infop info_ptr));
3475#endif
3476#if defined(PNG_READ_iTXt_SUPPORTED)
3477PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr,
3478 png_infop info_ptr, png_uint_32 length));
3479PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr,
3480 png_infop info_ptr));
3481#endif
3482
3483#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
3484
3485#ifdef PNG_MNG_FEATURES_SUPPORTED
3486PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info,
3487 png_bytep row));
3488PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info,
3489 png_bytep row));
3490#endif
3491
3492#if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
3493#if defined(PNG_MMX_CODE_SUPPORTED)
3494/* png.c */ /* PRIVATE */
3495PNG_EXTERN void png_init_mmx_flags PNGARG((png_structp png_ptr));
3496#endif
3497#endif
3498
3499#if defined(PNG_INCH_CONVERSIONS) && defined(PNG_FLOATING_POINT_SUPPORTED)
3500PNG_EXTERN png_uint_32 png_get_pixels_per_inch PNGARG((png_structp png_ptr,
3501png_infop info_ptr));
3502
3503PNG_EXTERN png_uint_32 png_get_x_pixels_per_inch PNGARG((png_structp png_ptr,
3504png_infop info_ptr));
3505
3506PNG_EXTERN png_uint_32 png_get_y_pixels_per_inch PNGARG((png_structp png_ptr,
3507png_infop info_ptr));
3508
3509PNG_EXTERN float png_get_x_offset_inches PNGARG((png_structp png_ptr,
3510png_infop info_ptr));
3511
3512PNG_EXTERN float png_get_y_offset_inches PNGARG((png_structp png_ptr,
3513png_infop info_ptr));
3514
3515#if defined(PNG_pHYs_SUPPORTED)
3516PNG_EXTERN png_uint_32 png_get_pHYs_dpi PNGARG((png_structp png_ptr,
3517png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
3518#endif /* PNG_pHYs_SUPPORTED */
3519#endif /* PNG_INCH_CONVERSIONS && PNG_FLOATING_POINT_SUPPORTED */
3520
3521/* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
3522
3523#endif /* PNG_INTERNAL */
3524
3525#ifdef __cplusplus
3526}
3527#endif
3528
3529#endif /* PNG_VERSION_INFO_ONLY */
3530/* do not put anything past this line */
3531#endif /* PNG_H */