pngcrush  1.8.13
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png.h
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1 
2 /* png.h - header file for PNG reference library
3  *
4  * libpng version 1.6.32, August 24, 2017
5  *
6  * Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson
7  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
8  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
9  *
10  * This code is released under the libpng license (See LICENSE, below)
11  *
12  * Authors and maintainers:
13  * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
14  * libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger
15  * libpng versions 0.97, January 1998, through 1.6.32, August 24, 2017:
16  * Glenn Randers-Pehrson.
17  * See also "Contributing Authors", below.
18  */
19 
20 /*
21  * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
22  *
23  * If you modify libpng you may insert additional notices immediately following
24  * this sentence.
25  *
26  * This code is released under the libpng license.
27  *
28  * libpng versions 1.0.7, July 1, 2000 through 1.6.32, August 24, 2017 are
29  * Copyright (c) 2000-2002, 2004, 2006-2017 Glenn Randers-Pehrson, are
30  * derived from libpng-1.0.6, and are distributed according to the same
31  * disclaimer and license as libpng-1.0.6 with the following individuals
32  * added to the list of Contributing Authors:
33  *
34  * Simon-Pierre Cadieux
35  * Eric S. Raymond
36  * Mans Rullgard
37  * Cosmin Truta
38  * Gilles Vollant
39  * James Yu
40  * Mandar Sahastrabuddhe
41  * Google Inc.
42  * Vadim Barkov
43  *
44  * and with the following additions to the disclaimer:
45  *
46  * There is no warranty against interference with your enjoyment of the
47  * library or against infringement. There is no warranty that our
48  * efforts or the library will fulfill any of your particular purposes
49  * or needs. This library is provided with all faults, and the entire
50  * risk of satisfactory quality, performance, accuracy, and effort is with
51  * the user.
52  *
53  * Some files in the "contrib" directory and some configure-generated
54  * files that are distributed with libpng have other copyright owners and
55  * are released under other open source licenses.
56  *
57  * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
58  * Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
59  * libpng-0.96, and are distributed according to the same disclaimer and
60  * license as libpng-0.96, with the following individuals added to the list
61  * of Contributing Authors:
62  *
63  * Tom Lane
64  * Glenn Randers-Pehrson
65  * Willem van Schaik
66  *
67  * libpng versions 0.89, June 1996, through 0.96, May 1997, are
68  * Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88,
69  * and are distributed according to the same disclaimer and license as
70  * libpng-0.88, with the following individuals added to the list of
71  * Contributing Authors:
72  *
73  * John Bowler
74  * Kevin Bracey
75  * Sam Bushell
76  * Magnus Holmgren
77  * Greg Roelofs
78  * Tom Tanner
79  *
80  * Some files in the "scripts" directory have other copyright owners
81  * but are released under this license.
82  *
83  * libpng versions 0.5, May 1995, through 0.88, January 1996, are
84  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
85  *
86  * For the purposes of this copyright and license, "Contributing Authors"
87  * is defined as the following set of individuals:
88  *
89  * Andreas Dilger
90  * Dave Martindale
91  * Guy Eric Schalnat
92  * Paul Schmidt
93  * Tim Wegner
94  *
95  * The PNG Reference Library is supplied "AS IS". The Contributing Authors
96  * and Group 42, Inc. disclaim all warranties, expressed or implied,
97  * including, without limitation, the warranties of merchantability and of
98  * fitness for any purpose. The Contributing Authors and Group 42, Inc.
99  * assume no liability for direct, indirect, incidental, special, exemplary,
100  * or consequential damages, which may result from the use of the PNG
101  * Reference Library, even if advised of the possibility of such damage.
102  *
103  * Permission is hereby granted to use, copy, modify, and distribute this
104  * source code, or portions hereof, for any purpose, without fee, subject
105  * to the following restrictions:
106  *
107  * 1. The origin of this source code must not be misrepresented.
108  *
109  * 2. Altered versions must be plainly marked as such and must not
110  * be misrepresented as being the original source.
111  *
112  * 3. This Copyright notice may not be removed or altered from any
113  * source or altered source distribution.
114  *
115  * The Contributing Authors and Group 42, Inc. specifically permit, without
116  * fee, and encourage the use of this source code as a component to
117  * supporting the PNG file format in commercial products. If you use this
118  * source code in a product, acknowledgment is not required but would be
119  * appreciated.
120  *
121  * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.
122  *
123  * TRADEMARK:
124  *
125  * The name "libpng" has not been registered by the Copyright owner
126  * as a trademark in any jurisdiction. However, because libpng has
127  * been distributed and maintained world-wide, continually since 1995,
128  * the Copyright owner claims "common-law trademark protection" in any
129  * jurisdiction where common-law trademark is recognized.
130  *
131  * OSI CERTIFICATION:
132  *
133  * Libpng is OSI Certified Open Source Software. OSI Certified Open Source is
134  * a certification mark of the Open Source Initiative. OSI has not addressed
135  * the additional disclaimers inserted at version 1.0.7.
136  *
137  * EXPORT CONTROL:
138  *
139  * The Copyright owner believes that the Export Control Classification
140  * Number (ECCN) for libpng is EAR99, which means not subject to export
141  * controls or International Traffic in Arms Regulations (ITAR) because
142  * it is open source, publicly available software, that does not contain
143  * any encryption software. See the EAR, paragraphs 734.3(b)(3) and
144  * 734.7(b).
145  */
146 
147 /*
148  * A "png_get_copyright" function is available, for convenient use in "about"
149  * boxes and the like:
150  *
151  * printf("%s", png_get_copyright(NULL));
152  *
153  * Also, the PNG logo (in PNG format, of course) is supplied in the
154  * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
155  */
156 
157 /*
158  * The contributing authors would like to thank all those who helped
159  * with testing, bug fixes, and patience. This wouldn't have been
160  * possible without all of you.
161  *
162  * Thanks to Frank J. T. Wojcik for helping with the documentation.
163  */
164 
165 /* Note about libpng version numbers:
166  *
167  * Due to various miscommunications, unforeseen code incompatibilities
168  * and occasional factors outside the authors' control, version numbering
169  * on the library has not always been consistent and straightforward.
170  * The following table summarizes matters since version 0.89c, which was
171  * the first widely used release:
172  *
173  * source png.h png.h shared-lib
174  * version string int version
175  * ------- ------ ----- ----------
176  * 0.89c "1.0 beta 3" 0.89 89 1.0.89
177  * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]
178  * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]
179  * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]
180  * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]
181  * 0.97c 0.97 97 2.0.97
182  * 0.98 0.98 98 2.0.98
183  * 0.99 0.99 98 2.0.99
184  * 0.99a-m 0.99 99 2.0.99
185  * 1.00 1.00 100 2.1.0 [100 should be 10000]
186  * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]
187  * 1.0.1 png.h string is 10001 2.1.0
188  * 1.0.1a-e identical to the 10002 from here on, the shared library
189  * 1.0.2 source version) 10002 is 2.V where V is the source code
190  * 1.0.2a-b 10003 version, except as noted.
191  * 1.0.3 10003
192  * 1.0.3a-d 10004
193  * 1.0.4 10004
194  * 1.0.4a-f 10005
195  * 1.0.5 (+ 2 patches) 10005
196  * 1.0.5a-d 10006
197  * 1.0.5e-r 10100 (not source compatible)
198  * 1.0.5s-v 10006 (not binary compatible)
199  * 1.0.6 (+ 3 patches) 10006 (still binary incompatible)
200  * 1.0.6d-f 10007 (still binary incompatible)
201  * 1.0.6g 10007
202  * 1.0.6h 10007 10.6h (testing xy.z so-numbering)
203  * 1.0.6i 10007 10.6i
204  * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
205  * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)
206  * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
207  * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
208  * 1.0.7 1 10007 (still compatible)
209  * ...
210  * 1.0.19 10 10019 10.so.0.19[.0]
211  * ...
212  * 1.2.57 13 10257 12.so.0.57[.0]
213  * ...
214  * 1.5.28 15 10527 15.so.15.28[.0]
215  * ...
216  * 1.6.32 16 10632 16.so.16.32[.0]
217  *
218  * Henceforth the source version will match the shared-library major
219  * and minor numbers; the shared-library major version number will be
220  * used for changes in backward compatibility, as it is intended. The
221  * PNG_LIBPNG_VER macro, which is not used within libpng but is available
222  * for applications, is an unsigned integer of the form xyyzz corresponding
223  * to the source version x.y.z (leading zeros in y and z). Beta versions
224  * were given the previous public release number plus a letter, until
225  * version 1.0.6j; from then on they were given the upcoming public
226  * release number plus "betaNN" or "rcNN".
227  *
228  * Binary incompatibility exists only when applications make direct access
229  * to the info_ptr or png_ptr members through png.h, and the compiled
230  * application is loaded with a different version of the library.
231  *
232  * DLLNUM will change each time there are forward or backward changes
233  * in binary compatibility (e.g., when a new feature is added).
234  *
235  * See libpng.txt or libpng.3 for more information. The PNG specification
236  * is available as a W3C Recommendation and as an ISO Specification,
237  * <https://www.w3.org/TR/2003/REC-PNG-20031110/
238  */
239 
240 /*
241  * Y2K compliance in libpng:
242  * =========================
243  *
244  * August 24, 2017
245  *
246  * Since the PNG Development group is an ad-hoc body, we can't make
247  * an official declaration.
248  *
249  * This is your unofficial assurance that libpng from version 0.71 and
250  * upward through 1.6.32 are Y2K compliant. It is my belief that
251  * earlier versions were also Y2K compliant.
252  *
253  * Libpng only has two year fields. One is a 2-byte unsigned integer
254  * that will hold years up to 65535. The other, which is deprecated,
255  * holds the date in text format, and will hold years up to 9999.
256  *
257  * The integer is
258  * "png_uint_16 year" in png_time_struct.
259  *
260  * The string is
261  * "char time_buffer[29]" in png_struct. This is no longer used
262  * in libpng-1.6.x and will be removed from libpng-1.7.0.
263  *
264  * There are seven time-related functions:
265  * png.c: png_convert_to_rfc_1123_buffer() in png.c
266  * (formerly png_convert_to_rfc_1123() prior to libpng-1.5.x and
267  * png_convert_to_rfc_1152() in error prior to libpng-0.98)
268  * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
269  * png_convert_from_time_t() in pngwrite.c
270  * png_get_tIME() in pngget.c
271  * png_handle_tIME() in pngrutil.c, called in pngread.c
272  * png_set_tIME() in pngset.c
273  * png_write_tIME() in pngwutil.c, called in pngwrite.c
274  *
275  * All handle dates properly in a Y2K environment. The
276  * png_convert_from_time_t() function calls gmtime() to convert from system
277  * clock time, which returns (year - 1900), which we properly convert to
278  * the full 4-digit year. There is a possibility that libpng applications
279  * are not passing 4-digit years into the png_convert_to_rfc_1123_buffer()
280  * function, or that they are incorrectly passing only a 2-digit year
281  * instead of "year - 1900" into the png_convert_from_struct_tm() function,
282  * but this is not under our control. The libpng documentation has always
283  * stated that it works with 4-digit years, and the APIs have been
284  * documented as such.
285  *
286  * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
287  * integer to hold the year, and can hold years as large as 65535.
288  *
289  * zlib, upon which libpng depends, is also Y2K compliant. It contains
290  * no date-related code.
291  *
292  * Glenn Randers-Pehrson
293  * libpng maintainer
294  * PNG Development Group
295  */
296 
297 #ifndef PNG_H
298 #define PNG_H
299 
300 /* This is not the place to learn how to use libpng. The file libpng-manual.txt
301  * describes how to use libpng, and the file example.c summarizes it
302  * with some code on which to build. This file is useful for looking
303  * at the actual function definitions and structure components. If that
304  * file has been stripped from your copy of libpng, you can find it at
305  * <http://www.libpng.org/pub/png/libpng-manual.txt>
306  *
307  * If you just need to read a PNG file and don't want to read the documentation
308  * skip to the end of this file and read the section entitled 'simplified API'.
309  */
310 
311 /* Version information for png.h - this should match the version in png.c */
312 #define PNG_LIBPNG_VER_STRING "1.6.32"
313 #define PNG_HEADER_VERSION_STRING " libpng version 1.6.32 - August 24, 2017\n"
314 
315 #define PNG_LIBPNG_VER_SONUM 16
316 #define PNG_LIBPNG_VER_DLLNUM 16
317 
318 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
319 #define PNG_LIBPNG_VER_MAJOR 1
320 #define PNG_LIBPNG_VER_MINOR 6
321 #define PNG_LIBPNG_VER_RELEASE 32
322 
323 /* This should match the numeric part of the final component of
324  * PNG_LIBPNG_VER_STRING, omitting any leading zero:
325  */
326 
327 #define PNG_LIBPNG_VER_BUILD 0
328 
329 /* Release Status */
330 #define PNG_LIBPNG_BUILD_ALPHA 1
331 #define PNG_LIBPNG_BUILD_BETA 2
332 #define PNG_LIBPNG_BUILD_RC 3
333 #define PNG_LIBPNG_BUILD_STABLE 4
334 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
335 
336 /* Release-Specific Flags */
337 #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
338  PNG_LIBPNG_BUILD_STABLE only */
339 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
340  PNG_LIBPNG_BUILD_SPECIAL */
341 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
342  PNG_LIBPNG_BUILD_PRIVATE */
343 
344 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
345 
346 /* Careful here. At one time, Guy wanted to use 082, but that would be octal.
347  * We must not include leading zeros.
348  * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
349  * version 1.0.0 was mis-numbered 100 instead of 10000). From
350  * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release
351  */
352 #define PNG_LIBPNG_VER 10632 /* 1.6.32 */
353 
354 /* Library configuration: these options cannot be changed after
355  * the library has been built.
356  */
357 #ifndef PNGLCONF_H
358 /* If pnglibconf.h is missing, you can
359  * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h
360  */
361 # include "pnglibconf.h"
362 #endif
363 
364 #ifndef PNG_VERSION_INFO_ONLY
365 /* Machine specific configuration. */
366 # include "pngconf.h"
367 #endif
368 
369 /*
370  * Added at libpng-1.2.8
371  *
372  * Ref MSDN: Private as priority over Special
373  * VS_FF_PRIVATEBUILD File *was not* built using standard release
374  * procedures. If this value is given, the StringFileInfo block must
375  * contain a PrivateBuild string.
376  *
377  * VS_FF_SPECIALBUILD File *was* built by the original company using
378  * standard release procedures but is a variation of the standard
379  * file of the same version number. If this value is given, the
380  * StringFileInfo block must contain a SpecialBuild string.
381  */
382 
383 #ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */
384 # define PNG_LIBPNG_BUILD_TYPE \
385  (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
386 #else
387 # ifdef PNG_LIBPNG_SPECIALBUILD
388 # define PNG_LIBPNG_BUILD_TYPE \
389  (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
390 # else
391 # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
392 # endif
393 #endif
394 
395 #ifndef PNG_VERSION_INFO_ONLY
396 
397 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
398 #ifdef __cplusplus
399 extern "C" {
400 #endif /* __cplusplus */
401 
402 /* Version information for C files, stored in png.c. This had better match
403  * the version above.
404  */
405 #define png_libpng_ver png_get_header_ver(NULL)
406 
407 /* This file is arranged in several sections:
408  *
409  * 1. [omitted]
410  * 2. Any configuration options that can be specified by for the application
411  * code when it is built. (Build time configuration is in pnglibconf.h)
412  * 3. Type definitions (base types are defined in pngconf.h), structure
413  * definitions.
414  * 4. Exported library functions.
415  * 5. Simplified API.
416  * 6. Implementation options.
417  *
418  * The library source code has additional files (principally pngpriv.h) that
419  * allow configuration of the library.
420  */
421 
422 /* Section 1: [omitted] */
423 
424 /* Section 2: run time configuration
425  * See pnglibconf.h for build time configuration
426  *
427  * Run time configuration allows the application to choose between
428  * implementations of certain arithmetic APIs. The default is set
429  * at build time and recorded in pnglibconf.h, but it is safe to
430  * override these (and only these) settings. Note that this won't
431  * change what the library does, only application code, and the
432  * settings can (and probably should) be made on a per-file basis
433  * by setting the #defines before including png.h
434  *
435  * Use macros to read integers from PNG data or use the exported
436  * functions?
437  * PNG_USE_READ_MACROS: use the macros (see below) Note that
438  * the macros evaluate their argument multiple times.
439  * PNG_NO_USE_READ_MACROS: call the relevant library function.
440  *
441  * Use the alternative algorithm for compositing alpha samples that
442  * does not use division?
443  * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division'
444  * algorithm.
445  * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm.
446  *
447  * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is
448  * false?
449  * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error
450  * APIs to png_warning.
451  * Otherwise the calls are mapped to png_error.
452  */
453 
454 /* Section 3: type definitions, including structures and compile time
455  * constants.
456  * See pngconf.h for base types that vary by machine/system
457  */
458 
459 /* This triggers a compiler error in png.c, if png.c and png.h
460  * do not agree upon the version number.
461  */
463 
464 /* Basic control structions. Read libpng-manual.txt or libpng.3 for more info.
465  *
466  * png_struct is the cache of information used while reading or writing a single
467  * PNG file. One of these is always required, although the simplified API
468  * (below) hides the creation and destruction of it.
469  */
470 typedef struct png_struct_def png_struct;
474 
475 /* png_info contains information read from or to be written to a PNG file. One
476  * or more of these must exist while reading or creating a PNG file. The
477  * information is not used by libpng during read but is used to control what
478  * gets written when a PNG file is created. "png_get_" function calls read
479  * information during read and "png_set_" functions calls write information
480  * when creating a PNG.
481  * been moved into a separate header file that is not accessible to
482  * applications. Read libpng-manual.txt or libpng.3 for more info.
483  */
484 typedef struct png_info_def png_info;
485 typedef png_info * png_infop;
486 typedef const png_info * png_const_infop;
487 typedef png_info * * png_infopp;
488 
489 /* Types with names ending 'p' are pointer types. The corresponding types with
490  * names ending 'rp' are identical pointer types except that the pointer is
491  * marked 'restrict', which means that it is the only pointer to the object
492  * passed to the function. Applications should not use the 'restrict' types;
493  * it is always valid to pass 'p' to a pointer with a function argument of the
494  * corresponding 'rp' type. Different compilers have different rules with
495  * regard to type matching in the presence of 'restrict'. For backward
496  * compatibility libpng callbacks never have 'restrict' in their parameters and,
497  * consequentially, writing portable application code is extremely difficult if
498  * an attempt is made to use 'restrict'.
499  */
504 
505 /* Three color definitions. The order of the red, green, and blue, (and the
506  * exact size) is not important, although the size of the fields need to
507  * be png_byte or png_uint_16 (as defined below).
508  */
509 typedef struct png_color_struct
510 {
511  png_byte red;
512  png_byte green;
513  png_byte blue;
514 } png_color;
516 typedef const png_color * png_const_colorp;
517 typedef png_color * * png_colorpp;
518 
519 typedef struct png_color_16_struct
520 {
521  png_byte index; /* used for palette files */
522  png_uint_16 red; /* for use in red green blue files */
523  png_uint_16 green;
524  png_uint_16 blue;
525  png_uint_16 gray; /* for use in grayscale files */
526 } png_color_16;
530 
531 typedef struct png_color_8_struct
532 {
533  png_byte red; /* for use in red green blue files */
534  png_byte green;
535  png_byte blue;
536  png_byte gray; /* for use in grayscale files */
537  png_byte alpha; /* for alpha channel files */
538 } png_color_8;
542 
543 /*
544  * The following two structures are used for the in-core representation
545  * of sPLT chunks.
546  */
547 typedef struct png_sPLT_entry_struct
548 {
549  png_uint_16 red;
550  png_uint_16 green;
551  png_uint_16 blue;
552  png_uint_16 alpha;
553  png_uint_16 frequency;
558 
559 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples
560  * occupy the LSB of their respective members, and the MSB of each member
561  * is zero-filled. The frequency member always occupies the full 16 bits.
562  */
563 
564 typedef struct png_sPLT_struct
565 {
566  png_charp name; /* palette name */
567  png_byte depth; /* depth of palette samples */
568  png_sPLT_entryp entries; /* palette entries */
569  png_int_32 nentries; /* number of palette entries */
570 } png_sPLT_t;
574 
575 #ifdef PNG_TEXT_SUPPORTED
576 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
577  * and whether that contents is compressed or not. The "key" field
578  * points to a regular zero-terminated C string. The "text" fields can be a
579  * regular C string, an empty string, or a NULL pointer.
580  * However, the structure returned by png_get_text() will always contain
581  * the "text" field as a regular zero-terminated C string (possibly
582  * empty), never a NULL pointer, so it can be safely used in printf() and
583  * other string-handling functions. Note that the "itxt_length", "lang", and
584  * "lang_key" members of the structure only exist when the library is built
585  * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by
586  * default without iTXt support. Also note that when iTXt *is* supported,
587  * the "lang" and "lang_key" fields contain NULL pointers when the
588  * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or
589  * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the
590  * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag"
591  * which is always 0 or 1, or its "compression method" which is always 0.
592  */
593 typedef struct png_text_struct
594 {
595  int compression; /* compression value:
596  -1: tEXt, none
597  0: zTXt, deflate
598  1: iTXt, none
599  2: iTXt, deflate */
600  png_charp key; /* keyword, 1-79 character description of "text" */
601  png_charp text; /* comment, may be an empty string (ie "")
602  or a NULL pointer */
603  png_size_t text_length; /* length of the text string */
604  png_size_t itxt_length; /* length of the itxt string */
605  png_charp lang; /* language code, 0-79 characters
606  or a NULL pointer */
607  png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
608  chars or a NULL pointer */
609 } png_text;
610 typedef png_text * png_textp;
611 typedef const png_text * png_const_textp;
612 typedef png_text * * png_textpp;
613 #endif
614 
615 /* Supported compression types for text in PNG files (tEXt, and zTXt).
616  * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
617 #define PNG_TEXT_COMPRESSION_NONE_WR -3
618 #define PNG_TEXT_COMPRESSION_zTXt_WR -2
619 #define PNG_TEXT_COMPRESSION_NONE -1
620 #define PNG_TEXT_COMPRESSION_zTXt 0
621 #define PNG_ITXT_COMPRESSION_NONE 1
622 #define PNG_ITXT_COMPRESSION_zTXt 2
623 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
624 
625 /* png_time is a way to hold the time in an machine independent way.
626  * Two conversions are provided, both from time_t and struct tm. There
627  * is no portable way to convert to either of these structures, as far
628  * as I know. If you know of a portable way, send it to me. As a side
629  * note - PNG has always been Year 2000 compliant!
630  */
631 typedef struct png_time_struct
632 {
633  png_uint_16 year; /* full year, as in, 1995 */
634  png_byte month; /* month of year, 1 - 12 */
635  png_byte day; /* day of month, 1 - 31 */
636  png_byte hour; /* hour of day, 0 - 23 */
637  png_byte minute; /* minute of hour, 0 - 59 */
638  png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
639 } png_time;
640 typedef png_time * png_timep;
641 typedef const png_time * png_const_timep;
642 typedef png_time * * png_timepp;
643 
644 #if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\
645  defined(PNG_USER_CHUNKS_SUPPORTED)
646 /* png_unknown_chunk is a structure to hold queued chunks for which there is
647  * no specific support. The idea is that we can use this to queue
648  * up private chunks for output even though the library doesn't actually
649  * know about their semantics.
650  *
651  * The data in the structure is set by libpng on read and used on write.
652  */
653 typedef struct png_unknown_chunk_t
654 {
655  png_byte name[5]; /* Textual chunk name with '\0' terminator */
656  png_byte *data; /* Data, should not be modified on read! */
658 
659  /* On write 'location' must be set using the flag values listed below.
660  * Notice that on read it is set by libpng however the values stored have
661  * more bits set than are listed below. Always treat the value as a
662  * bitmask. On write set only one bit - setting multiple bits may cause the
663  * chunk to be written in multiple places.
664  */
665  png_byte location; /* mode of operation at read time */
666 }
668 
672 #endif
673 
674 /* Flag values for the unknown chunk location byte. */
675 #define PNG_HAVE_IHDR 0x01
676 #define PNG_HAVE_PLTE 0x02
677 #define PNG_AFTER_IDAT 0x08
678 
679 /* Maximum positive integer used in PNG is (2^31)-1 */
680 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
681 #define PNG_UINT_32_MAX ((png_uint_32)(-1))
682 #define PNG_SIZE_MAX ((png_size_t)(-1))
683 
684 /* These are constants for fixed point values encoded in the
685  * PNG specification manner (x100000)
686  */
687 #define PNG_FP_1 100000
688 #define PNG_FP_HALF 50000
689 #define PNG_FP_MAX ((png_fixed_point)0x7fffffffL)
690 #define PNG_FP_MIN (-PNG_FP_MAX)
691 
692 /* These describe the color_type field in png_info. */
693 /* color type masks */
694 #define PNG_COLOR_MASK_PALETTE 1
695 #define PNG_COLOR_MASK_COLOR 2
696 #define PNG_COLOR_MASK_ALPHA 4
697 
698 /* color types. Note that not all combinations are legal */
699 #define PNG_COLOR_TYPE_GRAY 0
700 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
701 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
702 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
703 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
704 /* aliases */
705 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
706 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
707 
708 /* This is for compression type. PNG 1.0-1.2 only define the single type. */
709 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
710 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
711 
712 /* This is for filter type. PNG 1.0-1.2 only define the single type. */
713 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
714 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
715 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
716 
717 /* These are for the interlacing type. These values should NOT be changed. */
718 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
719 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
720 #define PNG_INTERLACE_LAST 2 /* Not a valid value */
721 
722 /* These are for the oFFs chunk. These values should NOT be changed. */
723 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
724 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
725 #define PNG_OFFSET_LAST 2 /* Not a valid value */
726 
727 /* These are for the pCAL chunk. These values should NOT be changed. */
728 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */
729 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
730 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
731 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
732 #define PNG_EQUATION_LAST 4 /* Not a valid value */
733 
734 /* These are for the sCAL chunk. These values should NOT be changed. */
735 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
736 #define PNG_SCALE_METER 1 /* meters per pixel */
737 #define PNG_SCALE_RADIAN 2 /* radians per pixel */
738 #define PNG_SCALE_LAST 3 /* Not a valid value */
739 
740 /* These are for the pHYs chunk. These values should NOT be changed. */
741 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
742 #define PNG_RESOLUTION_METER 1 /* pixels/meter */
743 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */
744 
745 /* These are for the sRGB chunk. These values should NOT be changed. */
746 #define PNG_sRGB_INTENT_PERCEPTUAL 0
747 #define PNG_sRGB_INTENT_RELATIVE 1
748 #define PNG_sRGB_INTENT_SATURATION 2
749 #define PNG_sRGB_INTENT_ABSOLUTE 3
750 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
751 
752 /* This is for text chunks */
753 #define PNG_KEYWORD_MAX_LENGTH 79
754 
755 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */
756 #define PNG_MAX_PALETTE_LENGTH 256
757 
758 /* These determine if an ancillary chunk's data has been successfully read
759  * from the PNG header, or if the application has filled in the corresponding
760  * data in the info_struct to be written into the output file. The values
761  * of the PNG_INFO_<chunk> defines should NOT be changed.
762  */
763 #define PNG_INFO_gAMA 0x0001U
764 #define PNG_INFO_sBIT 0x0002U
765 #define PNG_INFO_cHRM 0x0004U
766 #define PNG_INFO_PLTE 0x0008U
767 #define PNG_INFO_tRNS 0x0010U
768 #define PNG_INFO_bKGD 0x0020U
769 #define PNG_INFO_hIST 0x0040U
770 #define PNG_INFO_pHYs 0x0080U
771 #define PNG_INFO_oFFs 0x0100U
772 #define PNG_INFO_tIME 0x0200U
773 #define PNG_INFO_pCAL 0x0400U
774 #define PNG_INFO_sRGB 0x0800U /* GR-P, 0.96a */
775 #define PNG_INFO_iCCP 0x1000U /* ESR, 1.0.6 */
776 #define PNG_INFO_sPLT 0x2000U /* ESR, 1.0.6 */
777 #define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */
778 #define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */
779 #define PNG_INFO_eXIf 0x10000U /* GR-P, 1.6.31 */
780 
781 /* This is used for the transformation routines, as some of them
782  * change these values for the row. It also should enable using
783  * the routines for other purposes.
784  */
785 typedef struct png_row_info_struct
786 {
787  png_uint_32 width; /* width of row */
788  png_size_t rowbytes; /* number of bytes in row */
789  png_byte color_type; /* color type of row */
790  png_byte bit_depth; /* bit depth of row */
791  png_byte channels; /* number of channels (1, 2, 3, or 4) */
792  png_byte pixel_depth; /* bits per pixel (depth * channels) */
793 } png_row_info;
794 
797 
798 /* These are the function types for the I/O functions and for the functions
799  * that allow the user to override the default I/O functions with his or her
800  * own. The png_error_ptr type should match that of user-supplied warning
801  * and error functions, while the png_rw_ptr type should match that of the
802  * user read/write data functions. Note that the 'write' function must not
803  * modify the buffer it is passed. The 'read' function, on the other hand, is
804  * expected to return the read data in the buffer.
805  */
809 typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32,
810  int));
811 typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32,
812  int));
813 
814 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
815 typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop));
816 typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop));
817 
818 /* The following callback receives png_uint_32 row_number, int pass for the
819  * png_bytep data of the row. When transforming an interlaced image the
820  * row number is the row number within the sub-image of the interlace pass, so
821  * the value will increase to the height of the sub-image (not the full image)
822  * then reset to 0 for the next pass.
823  *
824  * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
825  * find the output pixel (x,y) given an interlaced sub-image pixel
826  * (row,col,pass). (See below for these macros.)
827  */
828 typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep,
829  png_uint_32, int));
830 #endif
831 
832 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
833  defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
836 #endif
837 
838 #ifdef PNG_USER_CHUNKS_SUPPORTED
839 typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp,
841 #endif
842 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
843 /* not used anywhere */
844 /* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */
845 #endif
846 
847 #ifdef PNG_SETJMP_SUPPORTED
848 /* This must match the function definition in <setjmp.h>, and the application
849  * must include this before png.h to obtain the definition of jmp_buf. The
850  * function is required to be PNG_NORETURN, but this is not checked. If the
851  * function does return the application will crash via an abort() or similar
852  * system level call.
853  *
854  * If you get a warning here while building the library you may need to make
855  * changes to ensure that pnglibconf.h records the calling convention used by
856  * your compiler. This may be very difficult - try using a different compiler
857  * to build the library!
858  */
859 PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef);
860 #endif
861 
862 /* Transform masks for the high-level interface */
863 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
864 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
865 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
866 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
867 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
868 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
869 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
870 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
871 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */
872 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
873 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
874 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
875 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */
876 /* Added to libpng-1.2.34 */
877 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
878 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
879 /* Added to libpng-1.4.0 */
880 #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
881 /* Added to libpng-1.5.4 */
882 #define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */
883 #if INT_MAX >= 0x8000 /* else this might break */
884 #define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */
885 #endif
886 
887 /* Flags for MNG supported features */
888 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01
889 #define PNG_FLAG_MNG_FILTER_64 0x04
890 #define PNG_ALL_MNG_FEATURES 0x05
891 
892 /* NOTE: prior to 1.5 these functions had no 'API' style declaration,
893  * this allowed the zlib default functions to be used on Windows
894  * platforms. In 1.5 the zlib default malloc (which just calls malloc and
895  * ignores the first argument) should be completely compatible with the
896  * following.
897  */
901 
902 /* Section 4: exported functions
903  * Here are the function definitions most commonly used. This is not
904  * the place to find out how to use libpng. See libpng-manual.txt for the
905  * full explanation, see example.c for the summary. This just provides
906  * a simple one line description of the use of each function.
907  *
908  * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in
909  * pngconf.h and in the *.dfn files in the scripts directory.
910  *
911  * PNG_EXPORT(ordinal, type, name, (args));
912  *
913  * ordinal: ordinal that is used while building
914  * *.def files. The ordinal value is only
915  * relevant when preprocessing png.h with
916  * the *.dfn files for building symbol table
917  * entries, and are removed by pngconf.h.
918  * type: return type of the function
919  * name: function name
920  * args: function arguments, with types
921  *
922  * When we wish to append attributes to a function prototype we use
923  * the PNG_EXPORTA() macro instead.
924  *
925  * PNG_EXPORTA(ordinal, type, name, (args), attributes);
926  *
927  * ordinal, type, name, and args: same as in PNG_EXPORT().
928  * attributes: function attributes
929  */
930 
931 /* Returns the version number of the library */
932 PNG_EXPORT(1, png_uint_32, png_access_version_number, (void));
933 
934 /* Tell lib we have already handled the first <num_bytes> magic bytes.
935  * Handling more than 8 bytes from the beginning of the file is an error.
936  */
937 PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes));
938 
939 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
940  * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
941  * signature, and non-zero otherwise. Having num_to_check == 0 or
942  * start > 7 will always fail (ie return non-zero).
943  */
944 PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, png_size_t start,
945  png_size_t num_to_check));
946 
947 /* Simple signature checking function. This is the same as calling
948  * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
949  */
950 #define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n))
951 
952 /* Allocate and initialize png_ptr struct for reading, and any other memory. */
954  (png_const_charp user_png_ver, png_voidp error_ptr,
955  png_error_ptr error_fn, png_error_ptr warn_fn),
956  PNG_ALLOCATED);
957 
958 /* Allocate and initialize png_ptr struct for writing, and any other memory */
960  (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
961  png_error_ptr warn_fn),
962  PNG_ALLOCATED);
963 
965  (png_const_structrp png_ptr));
966 
968  png_size_t size));
969 
970 /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
971  * match up.
972  */
973 #ifdef PNG_SETJMP_SUPPORTED
974 /* This function returns the jmp_buf built in to *png_ptr. It must be
975  * supplied with an appropriate 'longjmp' function to use on that jmp_buf
976  * unless the default error function is overridden in which case NULL is
977  * acceptable. The size of the jmp_buf is checked against the actual size
978  * allocated by the library - the call will return NULL on a mismatch
979  * indicating an ABI mismatch.
980  */
981 PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr,
982  png_longjmp_ptr longjmp_fn, size_t jmp_buf_size));
983 # define png_jmpbuf(png_ptr) \
984  (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf))))
985 #else
986 # define png_jmpbuf(png_ptr) \
987  (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
988 #endif
989 /* This function should be used by libpng applications in place of
990  * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it
991  * will use it; otherwise it will call PNG_ABORT(). This function was
992  * added in libpng-1.5.0.
993  */
994 PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val),
995  PNG_NORETURN);
996 
997 #ifdef PNG_READ_SUPPORTED
998 /* Reset the compression stream */
1000 #endif
1001 
1002 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
1003 #ifdef PNG_USER_MEM_SUPPORTED
1005  (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1006  png_error_ptr warn_fn,
1007  png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
1008  PNG_ALLOCATED);
1010  (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1011  png_error_ptr warn_fn,
1012  png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
1013  PNG_ALLOCATED);
1014 #endif
1015 
1016 /* Write the PNG file signature. */
1017 PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr));
1018 
1019 /* Write a PNG chunk - size, type, (optional) data, CRC. */
1021  chunk_name, png_const_bytep data, png_size_t length));
1022 
1023 /* Write the start of a PNG chunk - length and chunk name. */
1024 PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr,
1025  png_const_bytep chunk_name, png_uint_32 length));
1026 
1027 /* Write the data of a PNG chunk started with png_write_chunk_start(). */
1028 PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr,
1030 
1031 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1032 PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr));
1033 
1034 /* Allocate and initialize the info structure */
1036  PNG_ALLOCATED);
1037 
1038 /* DEPRECATED: this function allowed init structures to be created using the
1039  * default allocation method (typically malloc). Use is deprecated in 1.6.0 and
1040  * the API will be removed in the future.
1041  */
1042 PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr,
1043  png_size_t png_info_struct_size), PNG_DEPRECATED);
1044 
1045 /* Writes all the PNG information before the image. */
1047  (png_structrp png_ptr, png_const_inforp info_ptr));
1048 PNG_EXPORT(21, void, png_write_info,
1049  (png_structrp png_ptr, png_const_inforp info_ptr));
1050 
1051 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1052 /* Read the information before the actual image data. */
1053 PNG_EXPORT(22, void, png_read_info,
1054  (png_structrp png_ptr, png_inforp info_ptr));
1055 #endif
1056 
1057 #ifdef PNG_TIME_RFC1123_SUPPORTED
1058  /* Convert to a US string format: there is no localization support in this
1059  * routine. The original implementation used a 29 character buffer in
1060  * png_struct, this will be removed in future versions.
1061  */
1062 #if PNG_LIBPNG_VER < 10700
1063 /* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */
1064 PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr,
1066 #endif
1067 PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29],
1068  png_const_timep ptime));
1069 #endif
1070 
1071 #ifdef PNG_CONVERT_tIME_SUPPORTED
1072 /* Convert from a struct tm to png_time */
1074  const struct tm * ttime));
1075 
1076 /* Convert from time_t to png_time. Uses gmtime() */
1077 PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime));
1078 #endif /* CONVERT_tIME */
1079 
1080 #ifdef PNG_READ_EXPAND_SUPPORTED
1081 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1082 PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr));
1084 PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr));
1085 PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr));
1086 #endif
1087 
1088 #ifdef PNG_READ_EXPAND_16_SUPPORTED
1089 /* Expand to 16-bit channels, forces conversion of palette to RGB and expansion
1090  * of a tRNS chunk if present.
1091  */
1092 PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr));
1093 #endif
1094 
1095 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1096 /* Use blue, green, red order for pixels. */
1097 PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr));
1098 #endif
1099 
1100 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1101 /* Expand the grayscale to 24-bit RGB if necessary. */
1102 PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr));
1103 #endif
1104 
1105 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1106 /* Reduce RGB to grayscale. */
1107 #define PNG_ERROR_ACTION_NONE 1
1108 #define PNG_ERROR_ACTION_WARN 2
1109 #define PNG_ERROR_ACTION_ERROR 3
1110 #define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/
1111 
1112 PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr,
1113  int error_action, double red, double green))
1115  int error_action, png_fixed_point red, png_fixed_point green))
1116 
1118  png_ptr));
1119 #endif
1120 
1121 #ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
1122 PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,
1123  png_colorp palette));
1124 #endif
1125 
1126 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED
1127 /* How the alpha channel is interpreted - this affects how the color channels
1128  * of a PNG file are returned to the calling application when an alpha channel,
1129  * or a tRNS chunk in a palette file, is present.
1130  *
1131  * This has no effect on the way pixels are written into a PNG output
1132  * datastream. The color samples in a PNG datastream are never premultiplied
1133  * with the alpha samples.
1134  *
1135  * The default is to return data according to the PNG specification: the alpha
1136  * channel is a linear measure of the contribution of the pixel to the
1137  * corresponding composited pixel, and the color channels are unassociated
1138  * (not premultiplied). The gamma encoded color channels must be scaled
1139  * according to the contribution and to do this it is necessary to undo
1140  * the encoding, scale the color values, perform the composition and reencode
1141  * the values. This is the 'PNG' mode.
1142  *
1143  * The alternative is to 'associate' the alpha with the color information by
1144  * storing color channel values that have been scaled by the alpha.
1145  * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes
1146  * (the latter being the two common names for associated alpha color channels).
1147  *
1148  * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha
1149  * value is equal to the maximum value.
1150  *
1151  * The final choice is to gamma encode the alpha channel as well. This is
1152  * broken because, in practice, no implementation that uses this choice
1153  * correctly undoes the encoding before handling alpha composition. Use this
1154  * choice only if other serious errors in the software or hardware you use
1155  * mandate it; the typical serious error is for dark halos to appear around
1156  * opaque areas of the composited PNG image because of arithmetic overflow.
1157  *
1158  * The API function png_set_alpha_mode specifies which of these choices to use
1159  * with an enumerated 'mode' value and the gamma of the required output:
1160  */
1161 #define PNG_ALPHA_PNG 0 /* according to the PNG standard */
1162 #define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */
1163 #define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */
1164 #define PNG_ALPHA_PREMULTIPLIED 1 /* as above */
1165 #define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */
1166 #define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */
1167 
1168 PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode,
1169  double output_gamma))
1171  int mode, png_fixed_point output_gamma))
1172 #endif
1173 
1174 #if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)
1175 /* The output_gamma value is a screen gamma in libpng terminology: it expresses
1176  * how to decode the output values, not how they are encoded.
1177  */
1178 #define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */
1179 #define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */
1180 #define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */
1181 #define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */
1182 #endif
1183 
1184 /* The following are examples of calls to png_set_alpha_mode to achieve the
1185  * required overall gamma correction and, where necessary, alpha
1186  * premultiplication.
1187  *
1188  * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
1189  * This is the default libpng handling of the alpha channel - it is not
1190  * pre-multiplied into the color components. In addition the call states
1191  * that the output is for a sRGB system and causes all PNG files without gAMA
1192  * chunks to be assumed to be encoded using sRGB.
1193  *
1194  * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
1195  * In this case the output is assumed to be something like an sRGB conformant
1196  * display preceeded by a power-law lookup table of power 1.45. This is how
1197  * early Mac systems behaved.
1198  *
1199  * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
1200  * This is the classic Jim Blinn approach and will work in academic
1201  * environments where everything is done by the book. It has the shortcoming
1202  * of assuming that input PNG data with no gamma information is linear - this
1203  * is unlikely to be correct unless the PNG files where generated locally.
1204  * Most of the time the output precision will be so low as to show
1205  * significant banding in dark areas of the image.
1206  *
1207  * png_set_expand_16(pp);
1208  * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
1209  * This is a somewhat more realistic Jim Blinn inspired approach. PNG files
1210  * are assumed to have the sRGB encoding if not marked with a gamma value and
1211  * the output is always 16 bits per component. This permits accurate scaling
1212  * and processing of the data. If you know that your input PNG files were
1213  * generated locally you might need to replace PNG_DEFAULT_sRGB with the
1214  * correct value for your system.
1215  *
1216  * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
1217  * If you just need to composite the PNG image onto an existing background
1218  * and if you control the code that does this you can use the optimization
1219  * setting. In this case you just copy completely opaque pixels to the
1220  * output. For pixels that are not completely transparent (you just skip
1221  * those) you do the composition math using png_composite or png_composite_16
1222  * below then encode the resultant 8-bit or 16-bit values to match the output
1223  * encoding.
1224  *
1225  * Other cases
1226  * If neither the PNG nor the standard linear encoding work for you because
1227  * of the software or hardware you use then you have a big problem. The PNG
1228  * case will probably result in halos around the image. The linear encoding
1229  * will probably result in a washed out, too bright, image (it's actually too
1230  * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably
1231  * substantially reduce the halos. Alternatively try:
1232  *
1233  * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);
1234  * This option will also reduce the halos, but there will be slight dark
1235  * halos round the opaque parts of the image where the background is light.
1236  * In the OPTIMIZED mode the halos will be light halos where the background
1237  * is dark. Take your pick - the halos are unavoidable unless you can get
1238  * your hardware/software fixed! (The OPTIMIZED approach is slightly
1239  * faster.)
1240  *
1241  * When the default gamma of PNG files doesn't match the output gamma.
1242  * If you have PNG files with no gamma information png_set_alpha_mode allows
1243  * you to provide a default gamma, but it also sets the ouput gamma to the
1244  * matching value. If you know your PNG files have a gamma that doesn't
1245  * match the output you can take advantage of the fact that
1246  * png_set_alpha_mode always sets the output gamma but only sets the PNG
1247  * default if it is not already set:
1248  *
1249  * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
1250  * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
1251  * The first call sets both the default and the output gamma values, the
1252  * second call overrides the output gamma without changing the default. This
1253  * is easier than achieving the same effect with png_set_gamma. You must use
1254  * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will
1255  * fire if more than one call to png_set_alpha_mode and png_set_background is
1256  * made in the same read operation, however multiple calls with PNG_ALPHA_PNG
1257  * are ignored.
1258  */
1259 
1260 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1261 PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr));
1262 #endif
1263 
1264 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1265  defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1266 PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr));
1267 #endif
1268 
1269 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1270  defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1271 PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr));
1272 #endif
1273 
1274 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1275 /* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
1276 PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler,
1277  int flags));
1278 /* The values of the PNG_FILLER_ defines should NOT be changed */
1279 # define PNG_FILLER_BEFORE 0
1280 # define PNG_FILLER_AFTER 1
1281 /* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
1282 PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr,
1283  png_uint_32 filler, int flags));
1284 #endif /* READ_FILLER || WRITE_FILLER */
1285 
1286 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1287 /* Swap bytes in 16-bit depth files. */
1288 PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr));
1289 #endif
1290 
1291 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1292 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1293 PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr));
1294 #endif
1295 
1296 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1297  defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1298 /* Swap packing order of pixels in bytes. */
1299 PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr));
1300 #endif
1301 
1302 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1303 /* Converts files to legal bit depths. */
1305  true_bits));
1306 #endif
1307 
1308 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1309  defined(PNG_WRITE_INTERLACING_SUPPORTED)
1310 /* Have the code handle the interlacing. Returns the number of passes.
1311  * MUST be called before png_read_update_info or png_start_read_image,
1312  * otherwise it will not have the desired effect. Note that it is still
1313  * necessary to call png_read_row or png_read_rows png_get_image_height
1314  * times for each pass.
1315 */
1317 #endif
1318 
1319 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1320 /* Invert monochrome files */
1321 PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr));
1322 #endif
1323 
1324 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1325 /* Handle alpha and tRNS by replacing with a background color. Prior to
1326  * libpng-1.5.4 this API must not be called before the PNG file header has been
1327  * read. Doing so will result in unexpected behavior and possible warnings or
1328  * errors if the PNG file contains a bKGD chunk.
1329  */
1330 PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr,
1331  png_const_color_16p background_color, int background_gamma_code,
1332  int need_expand, double background_gamma))
1334  png_const_color_16p background_color, int background_gamma_code,
1335  int need_expand, png_fixed_point background_gamma))
1336 #endif
1337 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1338 # define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1339 # define PNG_BACKGROUND_GAMMA_SCREEN 1
1340 # define PNG_BACKGROUND_GAMMA_FILE 2
1341 # define PNG_BACKGROUND_GAMMA_UNIQUE 3
1342 #endif
1343 
1344 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
1345 /* Scale a 16-bit depth file down to 8-bit, accurately. */
1346 PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr));
1347 #endif
1348 
1349 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
1350 #define PNG_READ_16_TO_8_SUPPORTED /* Name prior to 1.5.4 */
1351 /* Strip the second byte of information from a 16-bit depth file. */
1352 PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr));
1353 #endif
1354 
1355 #ifdef PNG_READ_QUANTIZE_SUPPORTED
1356 /* Turn on quantizing, and reduce the palette to the number of colors
1357  * available.
1358  */
1359 PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr,
1360  png_colorp palette, int num_palette, int maximum_colors,
1361  png_const_uint_16p histogram, int full_quantize));
1362 #endif
1363 
1364 #ifdef PNG_READ_GAMMA_SUPPORTED
1365 /* The threshold on gamma processing is configurable but hard-wired into the
1366  * library. The following is the floating point variant.
1367  */
1368 #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001)
1369 
1370 /* Handle gamma correction. Screen_gamma=(display_exponent).
1371  * NOTE: this API simply sets the screen and file gamma values. It will
1372  * therefore override the value for gamma in a PNG file if it is called after
1373  * the file header has been read - use with care - call before reading the PNG
1374  * file for best results!
1375  *
1376  * These routines accept the same gamma values as png_set_alpha_mode (described
1377  * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either
1378  * API (floating point or fixed.) Notice, however, that the 'file_gamma' value
1379  * is the inverse of a 'screen gamma' value.
1380  */
1381 PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr,
1382  double screen_gamma, double override_file_gamma))
1384  png_fixed_point screen_gamma, png_fixed_point override_file_gamma))
1385 #endif
1386 
1387 #ifdef PNG_WRITE_FLUSH_SUPPORTED
1388 /* Set how many lines between output flushes - 0 for no flushing */
1389 PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows));
1390 /* Flush the current PNG output buffer */
1391 PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr));
1392 #endif
1393 
1394 /* Optional update palette with requested transformations */
1395 PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr));
1396 
1397 /* Optional call to update the users info structure */
1398 PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr,
1399  png_inforp info_ptr));
1400 
1401 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1402 /* Read one or more rows of image data. */
1403 PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row,
1404  png_bytepp display_row, png_uint_32 num_rows));
1405 #endif
1406 
1407 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1408 /* Read a row of data. */
1409 PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row,
1410  png_bytep display_row));
1411 #endif
1412 
1413 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1414 /* Read the whole image into memory at once. */
1415 PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image));
1416 #endif
1417 
1418 /* Write a row of image data */
1419 PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr,
1420  png_const_bytep row));
1421 
1422 /* Write a few rows of image data: (*row) is not written; however, the type
1423  * is declared as writeable to maintain compatibility with previous versions
1424  * of libpng and to allow the 'display_row' array from read_rows to be passed
1425  * unchanged to write_rows.
1426  */
1427 PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row,
1428  png_uint_32 num_rows));
1429 
1430 /* Write the image data */
1431 PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image));
1432 
1433 /* Write the end of the PNG file. */
1434 PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr,
1435  png_inforp info_ptr));
1436 
1437 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1438 /* Read the end of the PNG file. */
1439 PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr));
1440 #endif
1441 
1442 /* Free any memory associated with the png_info_struct */
1444  png_infopp info_ptr_ptr));
1445 
1446 /* Free any memory associated with the png_struct and the png_info_structs */
1447 PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr,
1448  png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1449 
1450 /* Free any memory associated with the png_struct and the png_info_structs */
1451 PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr,
1452  png_infopp info_ptr_ptr));
1453 
1454 /* Set the libpng method of handling chunk CRC errors */
1455 PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action,
1456  int ancil_action));
1457 
1458 /* Values for png_set_crc_action() say how to handle CRC errors in
1459  * ancillary and critical chunks, and whether to use the data contained
1460  * therein. Note that it is impossible to "discard" data in a critical
1461  * chunk. For versions prior to 0.90, the action was always error/quit,
1462  * whereas in version 0.90 and later, the action for CRC errors in ancillary
1463  * chunks is warn/discard. These values should NOT be changed.
1464  *
1465  * value action:critical action:ancillary
1466  */
1467 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1468 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1469 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1470 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1471 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1472 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1473 
1474 #ifdef PNG_WRITE_SUPPORTED
1475 /* These functions give the user control over the scan-line filtering in
1476  * libpng and the compression methods used by zlib. These functions are
1477  * mainly useful for testing, as the defaults should work with most users.
1478  * Those users who are tight on memory or want faster performance at the
1479  * expense of compression can modify them. See the compression library
1480  * header file (zlib.h) for an explination of the compression functions.
1481  */
1482 
1483 /* Set the filtering method(s) used by libpng. Currently, the only valid
1484  * value for "method" is 0.
1485  */
1486 PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method,
1487  int filters));
1488 #endif /* WRITE */
1489 
1490 /* Flags for png_set_filter() to say which filters to use. The flags
1491  * are chosen so that they don't conflict with real filter types
1492  * below, in case they are supplied instead of the #defined constants.
1493  * These values should NOT be changed.
1494  */
1495 #define PNG_NO_FILTERS 0x00
1496 #define PNG_FILTER_NONE 0x08
1497 #define PNG_FILTER_SUB 0x10
1498 #define PNG_FILTER_UP 0x20
1499 #define PNG_FILTER_AVG 0x40
1500 #define PNG_FILTER_PAETH 0x80
1501 #define PNG_FAST_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP)
1502 #define PNG_ALL_FILTERS (PNG_FAST_FILTERS | PNG_FILTER_AVG | PNG_FILTER_PAETH)
1503 
1504 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1505  * These defines should NOT be changed.
1506  */
1507 #define PNG_FILTER_VALUE_NONE 0
1508 #define PNG_FILTER_VALUE_SUB 1
1509 #define PNG_FILTER_VALUE_UP 2
1510 #define PNG_FILTER_VALUE_AVG 3
1511 #define PNG_FILTER_VALUE_PAETH 4
1512 #define PNG_FILTER_VALUE_LAST 5
1513 
1514 #ifdef PNG_WRITE_SUPPORTED
1515 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */
1517  int heuristic_method, int num_weights, png_const_doublep filter_weights,
1518  png_const_doublep filter_costs))
1520  (png_structrp png_ptr, int heuristic_method, int num_weights,
1521  png_const_fixed_point_p filter_weights,
1522  png_const_fixed_point_p filter_costs))
1523 #endif /* WRITE_WEIGHTED_FILTER */
1524 
1525 /* The following are no longer used and will be removed from libpng-1.7: */
1526 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
1527 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
1528 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
1529 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
1530 
1531 /* Set the library compression level. Currently, valid values range from
1532  * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1533  * (0 - no compression, 9 - "maximal" compression). Note that tests have
1534  * shown that zlib compression levels 3-6 usually perform as well as level 9
1535  * for PNG images, and do considerably fewer caclulations. In the future,
1536  * these values may not correspond directly to the zlib compression levels.
1537  */
1538 #ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
1540  int level));
1541 
1543  int mem_level));
1544 
1546  int strategy));
1547 
1548 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1549  * smaller value of window_bits if it can do so safely.
1550  */
1552  int window_bits));
1553 
1555  int method));
1556 #endif /* WRITE_CUSTOMIZE_COMPRESSION */
1557 
1558 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
1559 /* Also set zlib parameters for compressing non-IDAT chunks */
1561  int level));
1562 
1564  int mem_level));
1565 
1567  int strategy));
1568 
1569 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1570  * smaller value of window_bits if it can do so safely.
1571  */
1573  (png_structrp png_ptr, int window_bits));
1574 
1576  int method));
1577 #endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
1578 #endif /* WRITE */
1579 
1580 /* These next functions are called for input/output, memory, and error
1581  * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
1582  * and call standard C I/O routines such as fread(), fwrite(), and
1583  * fprintf(). These functions can be made to use other I/O routines
1584  * at run time for those applications that need to handle I/O in a
1585  * different manner by calling png_set_???_fn(). See libpng-manual.txt for
1586  * more information.
1587  */
1588 
1589 #ifdef PNG_STDIO_SUPPORTED
1590 /* Initialize the input/output for the PNG file to the default functions. */
1591 PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp));
1592 #endif
1593 
1594 /* Replace the (error and abort), and warning functions with user
1595  * supplied functions. If no messages are to be printed you must still
1596  * write and use replacement functions. The replacement error_fn should
1597  * still do a longjmp to the last setjmp location if you are using this
1598  * method of error handling. If error_fn or warning_fn is NULL, the
1599  * default function will be used.
1600  */
1601 
1602 PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr,
1603  png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
1604 
1605 /* Return the user pointer associated with the error functions */
1607 
1608 /* Replace the default data output functions with a user supplied one(s).
1609  * If buffered output is not used, then output_flush_fn can be set to NULL.
1610  * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
1611  * output_flush_fn will be ignored (and thus can be NULL).
1612  * It is probably a mistake to use NULL for output_flush_fn if
1613  * write_data_fn is not also NULL unless you have built libpng with
1614  * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
1615  * default flush function, which uses the standard *FILE structure, will
1616  * be used.
1617  */
1618 PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr,
1619  png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
1620 
1621 /* Replace the default data input function with a user supplied one. */
1622 PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr,
1623  png_rw_ptr read_data_fn));
1624 
1625 /* Return the user pointer associated with the I/O functions */
1627 
1628 PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr,
1629  png_read_status_ptr read_row_fn));
1630 
1631 PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr,
1632  png_write_status_ptr write_row_fn));
1633 
1634 #ifdef PNG_USER_MEM_SUPPORTED
1635 /* Replace the default memory allocation functions with user supplied one(s). */
1636 PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr,
1637  png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1638 /* Return the user pointer associated with the memory functions */
1640 #endif
1641 
1642 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
1644  png_user_transform_ptr read_user_transform_fn));
1645 #endif
1646 
1647 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1649  png_user_transform_ptr write_user_transform_fn));
1650 #endif
1651 
1652 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
1654  png_voidp user_transform_ptr, int user_transform_depth,
1655  int user_transform_channels));
1656 /* Return the user pointer associated with the user transform functions */
1658  (png_const_structrp png_ptr));
1659 #endif
1660 
1661 #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
1662 /* Return information about the row currently being processed. Note that these
1663  * APIs do not fail but will return unexpected results if called outside a user
1664  * transform callback. Also note that when transforming an interlaced image the
1665  * row number is the row number within the sub-image of the interlace pass, so
1666  * the value will increase to the height of the sub-image (not the full image)
1667  * then reset to 0 for the next pass.
1668  *
1669  * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
1670  * find the output pixel (x,y) given an interlaced sub-image pixel
1671  * (row,col,pass). (See below for these macros.)
1672  */
1675 #endif
1676 
1677 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED
1678 /* This callback is called only for *unknown* chunks. If
1679  * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known
1680  * chunks to be treated as unknown, however in this case the callback must do
1681  * any processing required by the chunk (e.g. by calling the appropriate
1682  * png_set_ APIs.)
1683  *
1684  * There is no write support - on write, by default, all the chunks in the
1685  * 'unknown' list are written in the specified position.
1686  *
1687  * The integer return from the callback function is interpreted thus:
1688  *
1689  * negative: An error occurred; png_chunk_error will be called.
1690  * zero: The chunk was not handled, the chunk will be saved. A critical
1691  * chunk will cause an error at this point unless it is to be saved.
1692  * positive: The chunk was handled, libpng will ignore/discard it.
1693  *
1694  * See "INTERACTION WTIH USER CHUNK CALLBACKS" below for important notes about
1695  * how this behavior will change in libpng 1.7
1696  */
1698  png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
1699 #endif
1700 
1701 #ifdef PNG_USER_CHUNKS_SUPPORTED
1702 PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr));
1703 #endif
1704 
1705 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1706 /* Sets the function callbacks for the push reader, and a pointer to a
1707  * user-defined structure available to the callback functions.
1708  */
1710  png_voidp progressive_ptr, png_progressive_info_ptr info_fn,
1711  png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn));
1712 
1713 /* Returns the user pointer associated with the push read functions */
1715  (png_const_structrp png_ptr));
1716 
1717 /* Function to be called when data becomes available */
1718 PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr,
1719  png_inforp info_ptr, png_bytep buffer, png_size_t buffer_size));
1720 
1721 /* A function which may be called *only* within png_process_data to stop the
1722  * processing of any more data. The function returns the number of bytes
1723  * remaining, excluding any that libpng has cached internally. A subsequent
1724  * call to png_process_data must supply these bytes again. If the argument
1725  * 'save' is set to true the routine will first save all the pending data and
1726  * will always return 0.
1727  */
1729 
1730 /* A function which may be called *only* outside (after) a call to
1731  * png_process_data. It returns the number of bytes of data to skip in the
1732  * input. Normally it will return 0, but if it returns a non-zero value the
1733  * application must skip than number of bytes of input data and pass the
1734  * following data to the next call to png_process_data.
1735  */
1736 PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp));
1737 
1738 /* Function that combines rows. 'new_row' is a flag that should come from
1739  * the callback and be non-NULL if anything needs to be done; the library
1740  * stores its own version of the new data internally and ignores the passed
1741  * in value.
1742  */
1744  png_bytep old_row, png_const_bytep new_row));
1745 #endif /* PROGRESSIVE_READ */
1746 
1749 /* Added at libpng version 1.4.0 */
1752 
1753 /* Added at libpng version 1.2.4 */
1756 
1757 /* Frees a pointer allocated by png_malloc() */
1758 PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr));
1759 
1760 /* Free data that was allocated internally */
1761 PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr,
1762  png_inforp info_ptr, png_uint_32 free_me, int num));
1763 
1764 /* Reassign responsibility for freeing existing data, whether allocated
1765  * by libpng or by the application; this works on the png_info structure passed
1766  * in, it does not change the state for other png_info structures.
1767  *
1768  * It is unlikely that this function works correctly as of 1.6.0 and using it
1769  * may result either in memory leaks or double free of allocated data.
1770  */
1771 PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr,
1772  png_inforp info_ptr, int freer, png_uint_32 mask));
1773 
1774 /* Assignments for png_data_freer */
1775 #define PNG_DESTROY_WILL_FREE_DATA 1
1776 #define PNG_SET_WILL_FREE_DATA 1
1777 #define PNG_USER_WILL_FREE_DATA 2
1778 /* Flags for png_ptr->free_me and info_ptr->free_me */
1779 #define PNG_FREE_HIST 0x0008U
1780 #define PNG_FREE_ICCP 0x0010U
1781 #define PNG_FREE_SPLT 0x0020U
1782 #define PNG_FREE_ROWS 0x0040U
1783 #define PNG_FREE_PCAL 0x0080U
1784 #define PNG_FREE_SCAL 0x0100U
1785 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
1786 # define PNG_FREE_UNKN 0x0200U
1787 #endif
1788 /* PNG_FREE_LIST 0x0400U removed in 1.6.0 because it is ignored */
1789 #define PNG_FREE_PLTE 0x1000U
1790 #define PNG_FREE_TRNS 0x2000U
1791 #define PNG_FREE_TEXT 0x4000U
1792 #define PNG_FREE_EXIF 0x8000U /* Added at libpng-1.6.31 */
1793 #define PNG_FREE_ALL 0xffffU
1794 #define PNG_FREE_MUL 0x4220U /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
1795 
1796 #ifdef PNG_USER_MEM_SUPPORTED
1799 PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr,
1800  png_voidp ptr), PNG_DEPRECATED);
1801 #endif
1802 
1803 #ifdef PNG_ERROR_TEXT_SUPPORTED
1804 /* Fatal error in PNG image of libpng - can't continue */
1805 PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr,
1806  png_const_charp error_message), PNG_NORETURN);
1807 
1808 /* The same, but the chunk name is prepended to the error string. */
1809 PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr,
1810  png_const_charp error_message), PNG_NORETURN);
1811 
1812 #else
1813 /* Fatal error in PNG image of libpng - can't continue */
1814 PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN);
1815 # define png_error(s1,s2) png_err(s1)
1816 # define png_chunk_error(s1,s2) png_err(s1)
1817 #endif
1818 
1819 #ifdef PNG_WARNINGS_SUPPORTED
1820 /* Non-fatal error in libpng. Can continue, but may have a problem. */
1821 PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr,
1822  png_const_charp warning_message));
1823 
1824 /* Non-fatal error in libpng, chunk name is prepended to message. */
1825 PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr,
1826  png_const_charp warning_message));
1827 #else
1828 # define png_warning(s1,s2) ((void)(s1))
1829 # define png_chunk_warning(s1,s2) ((void)(s1))
1830 #endif
1831 
1832 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
1833 /* Benign error in libpng. Can continue, but may have a problem.
1834  * User can choose whether to handle as a fatal error or as a warning. */
1835 PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr,
1836  png_const_charp warning_message));
1837 
1838 #ifdef PNG_READ_SUPPORTED
1839 /* Same, chunk name is prepended to message (only during read) */
1841  png_const_charp warning_message));
1842 #endif
1843 
1845  (png_structrp png_ptr, int allowed));
1846 #else
1847 # ifdef PNG_ALLOW_BENIGN_ERRORS
1848 # define png_benign_error png_warning
1849 # define png_chunk_benign_error png_chunk_warning
1850 # else
1851 # define png_benign_error png_error
1852 # define png_chunk_benign_error png_chunk_error
1853 # endif
1854 #endif
1855 
1856 /* The png_set_<chunk> functions are for storing values in the png_info_struct.
1857  * Similarly, the png_get_<chunk> calls are used to read values from the
1858  * png_info_struct, either storing the parameters in the passed variables, or
1859  * setting pointers into the png_info_struct where the data is stored. The
1860  * png_get_<chunk> functions return a non-zero value if the data was available
1861  * in info_ptr, or return zero and do not change any of the parameters if the
1862  * data was not available.
1863  *
1864  * These functions should be used instead of directly accessing png_info
1865  * to avoid problems with future changes in the size and internal layout of
1866  * png_info_struct.
1867  */
1868 /* Returns "flag" if chunk data is valid in info_ptr. */
1869 PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr,
1870  png_const_inforp info_ptr, png_uint_32 flag));
1871 
1872 /* Returns number of bytes needed to hold a transformed row. */
1874  png_const_inforp info_ptr));
1875 
1876 #ifdef PNG_INFO_IMAGE_SUPPORTED
1877 /* Returns row_pointers, which is an array of pointers to scanlines that was
1878  * returned from png_read_png().
1879  */
1880 PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr,
1881  png_const_inforp info_ptr));
1882 
1883 /* Set row_pointers, which is an array of pointers to scanlines for use
1884  * by png_write_png().
1885  */
1886 PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr,
1887  png_inforp info_ptr, png_bytepp row_pointers));
1888 #endif
1889 
1890 /* Returns number of color channels in image. */
1891 PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr,
1892  png_const_inforp info_ptr));
1893 
1894 #ifdef PNG_EASY_ACCESS_SUPPORTED
1895 /* Returns image width in pixels. */
1896 PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr,
1897  png_const_inforp info_ptr));
1898 
1899 /* Returns image height in pixels. */
1900 PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr,
1901  png_const_inforp info_ptr));
1902 
1903 /* Returns image bit_depth. */
1904 PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr,
1905  png_const_inforp info_ptr));
1906 
1907 /* Returns image color_type. */
1908 PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr,
1909  png_const_inforp info_ptr));
1910 
1911 /* Returns image filter_type. */
1912 PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr,
1913  png_const_inforp info_ptr));
1914 
1915 /* Returns image interlace_type. */
1916 PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr,
1917  png_const_inforp info_ptr));
1918 
1919 /* Returns image compression_type. */
1920 PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr,
1921  png_const_inforp info_ptr));
1922 
1923 /* Returns image resolution in pixels per meter, from pHYs chunk data. */
1924 PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter,
1925  (png_const_structrp png_ptr, png_const_inforp info_ptr));
1926 PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter,
1927  (png_const_structrp png_ptr, png_const_inforp info_ptr));
1928 PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter,
1929  (png_const_structrp png_ptr, png_const_inforp info_ptr));
1930 
1931 /* Returns pixel aspect ratio, computed from pHYs chunk data. */
1932 PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio,
1933  (png_const_structrp png_ptr, png_const_inforp info_ptr))
1934 PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed,
1935  (png_const_structrp png_ptr, png_const_inforp info_ptr))
1936 
1937 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
1938 PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels,
1939  (png_const_structrp png_ptr, png_const_inforp info_ptr));
1940 PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels,
1941  (png_const_structrp png_ptr, png_const_inforp info_ptr));
1942 PNG_EXPORT(128, png_int_32, png_get_x_offset_microns,
1943  (png_const_structrp png_ptr, png_const_inforp info_ptr));
1944 PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,
1945  (png_const_structrp png_ptr, png_const_inforp info_ptr));
1946 
1947 #endif /* EASY_ACCESS */
1948 
1949 #ifdef PNG_READ_SUPPORTED
1950 /* Returns pointer to signature string read from PNG header */
1952  png_const_inforp info_ptr));
1953 #endif
1954 
1955 #ifdef PNG_bKGD_SUPPORTED
1956 PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr,
1957  png_inforp info_ptr, png_color_16p *background));
1958 #endif
1959 
1960 #ifdef PNG_bKGD_SUPPORTED
1961 PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr,
1962  png_inforp info_ptr, png_const_color_16p background));
1963 #endif
1964 
1965 #ifdef PNG_cHRM_SUPPORTED
1966 PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr,
1967  png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x,
1968  double *red_y, double *green_x, double *green_y, double *blue_x,
1969  double *blue_y))
1970 PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr,
1971  png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z,
1972  double *green_X, double *green_Y, double *green_Z, double *blue_X,
1973  double *blue_Y, double *blue_Z))
1974 PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed,
1975  (png_const_structrp png_ptr, png_const_inforp info_ptr,
1976  png_fixed_point *int_white_x, png_fixed_point *int_white_y,
1977  png_fixed_point *int_red_x, png_fixed_point *int_red_y,
1978  png_fixed_point *int_green_x, png_fixed_point *int_green_y,
1979  png_fixed_point *int_blue_x, png_fixed_point *int_blue_y))
1980 PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed,
1981  (png_const_structrp png_ptr, png_const_inforp info_ptr,
1982  png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
1983  png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
1984  png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
1985  png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
1986  png_fixed_point *int_blue_Z))
1987 #endif
1988 
1989 #ifdef PNG_cHRM_SUPPORTED
1990 PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr,
1991  png_inforp info_ptr,
1992  double white_x, double white_y, double red_x, double red_y, double green_x,
1993  double green_y, double blue_x, double blue_y))
1995  png_inforp info_ptr, double red_X, double red_Y, double red_Z,
1996  double green_X, double green_Y, double green_Z, double blue_X,
1997  double blue_Y, double blue_Z))
1999  png_inforp info_ptr, png_fixed_point int_white_x,
2000  png_fixed_point int_white_y, png_fixed_point int_red_x,
2001  png_fixed_point int_red_y, png_fixed_point int_green_x,
2002  png_fixed_point int_green_y, png_fixed_point int_blue_x,
2003  png_fixed_point int_blue_y))
2005  png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y,
2006  png_fixed_point int_red_Z, png_fixed_point int_green_X,
2007  png_fixed_point int_green_Y, png_fixed_point int_green_Z,
2008  png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
2009  png_fixed_point int_blue_Z))
2010 #endif
2011 
2012 #ifdef PNG_eXIf_SUPPORTED
2013 PNG_EXPORT(246, png_uint_32, png_get_eXIf, (png_const_structrp png_ptr,
2014  png_inforp info_ptr, png_bytep *exif));
2015 PNG_EXPORT(247, void, png_set_eXIf, (png_const_structrp png_ptr,
2016  png_inforp info_ptr, const png_bytep exif));
2017 
2018 PNG_EXPORT(248, png_uint_32, png_get_eXIf_1, (png_const_structrp png_ptr,
2019  png_const_inforp info_ptr, png_uint_32 *num_exif, png_bytep *exif));
2020 PNG_EXPORT(249, void, png_set_eXIf_1, (png_const_structrp png_ptr,
2021  png_inforp info_ptr, const png_uint_32 num_exif, const png_bytep exif));
2022 #endif
2023 
2024 #ifdef PNG_gAMA_SUPPORTED
2025 PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr,
2026  png_const_inforp info_ptr, double *file_gamma))
2027 PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed,
2028  (png_const_structrp png_ptr, png_const_inforp info_ptr,
2029  png_fixed_point *int_file_gamma))
2030 #endif
2031 
2032 #ifdef PNG_gAMA_SUPPORTED
2033 PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr,
2034  png_inforp info_ptr, double file_gamma))
2036  png_inforp info_ptr, png_fixed_point int_file_gamma))
2037 #endif
2038 
2039 #ifdef PNG_hIST_SUPPORTED
2040 PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr,
2041  png_inforp info_ptr, png_uint_16p *hist));
2042 PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr,
2043  png_inforp info_ptr, png_const_uint_16p hist));
2044 #endif
2045 
2046 PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr,
2047  png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height,
2048  int *bit_depth, int *color_type, int *interlace_method,
2049  int *compression_method, int *filter_method));
2050 
2051 PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr,
2052  png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
2053  int color_type, int interlace_method, int compression_method,
2054  int filter_method));
2055 
2056 #ifdef PNG_oFFs_SUPPORTED
2057 PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr,
2058  png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
2059  int *unit_type));
2060 #endif
2061 
2062 #ifdef PNG_oFFs_SUPPORTED
2063 PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr,
2064  png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2065  int unit_type));
2066 #endif
2067 
2068 #ifdef PNG_pCAL_SUPPORTED
2069 PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr,
2070  png_inforp info_ptr, png_charp *purpose, png_int_32 *X0,
2071  png_int_32 *X1, int *type, int *nparams, png_charp *units,
2072  png_charpp *params));
2073 #endif
2074 
2075 #ifdef PNG_pCAL_SUPPORTED
2076 PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr,
2077  png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1,
2078  int type, int nparams, png_const_charp units, png_charpp params));
2079 #endif
2080 
2081 #ifdef PNG_pHYs_SUPPORTED
2082 PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr,
2083  png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
2084  int *unit_type));
2085 #endif
2086 
2087 #ifdef PNG_pHYs_SUPPORTED
2088 PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr,
2089  png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2090 #endif
2091 
2092 PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr,
2093  png_inforp info_ptr, png_colorp *palette, int *num_palette));
2094 
2095 PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr,
2097 
2098 #ifdef PNG_sBIT_SUPPORTED
2099 PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr,
2100  png_inforp info_ptr, png_color_8p *sig_bit));
2101 #endif
2102 
2103 #ifdef PNG_sBIT_SUPPORTED
2104 PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr,
2105  png_inforp info_ptr, png_const_color_8p sig_bit));
2106 #endif
2107 
2108 #ifdef PNG_sRGB_SUPPORTED
2109 PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr,
2110  png_const_inforp info_ptr, int *file_srgb_intent));
2111 #endif
2112 
2113 #ifdef PNG_sRGB_SUPPORTED
2114 PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr,
2115  png_inforp info_ptr, int srgb_intent));
2117  png_inforp info_ptr, int srgb_intent));
2118 #endif
2119 
2120 #ifdef PNG_iCCP_SUPPORTED
2121 PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr,
2122  png_inforp info_ptr, png_charpp name, int *compression_type,
2123  png_bytepp profile, png_uint_32 *proflen));
2124 #endif
2125 
2126 #ifdef PNG_iCCP_SUPPORTED
2127 PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr,
2128  png_inforp info_ptr, png_const_charp name, int compression_type,
2129  png_const_bytep profile, png_uint_32 proflen));
2130 #endif
2131 
2132 #ifdef PNG_sPLT_SUPPORTED
2133 PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr,
2134  png_inforp info_ptr, png_sPLT_tpp entries));
2135 #endif
2136 
2137 #ifdef PNG_sPLT_SUPPORTED
2138 PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr,
2139  png_inforp info_ptr, png_const_sPLT_tp entries, int nentries));
2140 #endif
2141 
2142 #ifdef PNG_TEXT_SUPPORTED
2143 /* png_get_text also returns the number of text chunks in *num_text */
2144 PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr,
2145  png_inforp info_ptr, png_textp *text_ptr, int *num_text));
2146 #endif
2147 
2148 /* Note while png_set_text() will accept a structure whose text,
2149  * language, and translated keywords are NULL pointers, the structure
2150  * returned by png_get_text will always contain regular
2151  * zero-terminated C strings. They might be empty strings but
2152  * they will never be NULL pointers.
2153  */
2154 
2155 #ifdef PNG_TEXT_SUPPORTED
2156 PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr,
2157  png_inforp info_ptr, png_const_textp text_ptr, int num_text));
2158 #endif
2159 
2160 #ifdef PNG_tIME_SUPPORTED
2161 PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr,
2162  png_inforp info_ptr, png_timep *mod_time));
2163 #endif
2164 
2165 #ifdef PNG_tIME_SUPPORTED
2166 PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr,
2167  png_inforp info_ptr, png_const_timep mod_time));
2168 #endif
2169 
2170 #ifdef PNG_tRNS_SUPPORTED
2171 PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr,
2172  png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans,
2173  png_color_16p *trans_color));
2174 #endif
2175 
2176 #ifdef PNG_tRNS_SUPPORTED
2177 PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr,
2178  png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans,
2179  png_const_color_16p trans_color));
2180 #endif
2181 
2182 #ifdef PNG_sCAL_SUPPORTED
2183 PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr,
2184  png_const_inforp info_ptr, int *unit, double *width, double *height))
2185 #if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \
2186  defined(PNG_FLOATING_POINT_SUPPORTED)
2187 /* NOTE: this API is currently implemented using floating point arithmetic,
2188  * consequently it can only be used on systems with floating point support.
2189  * In any case the range of values supported by png_fixed_point is small and it
2190  * is highly recommended that png_get_sCAL_s be used instead.
2191  */
2192 PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed,
2193  (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
2195 #endif
2196 PNG_EXPORT(169, png_uint_32, png_get_sCAL_s,
2197  (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
2198  png_charpp swidth, png_charpp sheight));
2199 
2200 PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr,
2201  png_inforp info_ptr, int unit, double width, double height))
2203  png_inforp info_ptr, int unit, png_fixed_point width,
2205 PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr,
2206  png_inforp info_ptr, int unit,
2207  png_const_charp swidth, png_const_charp sheight));
2208 #endif /* sCAL */
2209 
2210 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
2211 /* Provide the default handling for all unknown chunks or, optionally, for
2212  * specific unknown chunks.
2213  *
2214  * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was
2215  * ignored and the default was used, the per-chunk setting only had an effect on
2216  * write. If you wish to have chunk-specific handling on read in code that must
2217  * work on earlier versions you must use a user chunk callback to specify the
2218  * desired handling (keep or discard.)
2219  *
2220  * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The
2221  * parameter is interpreted as follows:
2222  *
2223  * READ:
2224  * PNG_HANDLE_CHUNK_AS_DEFAULT:
2225  * Known chunks: do normal libpng processing, do not keep the chunk (but
2226  * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
2227  * Unknown chunks: for a specific chunk use the global default, when used
2228  * as the default discard the chunk data.
2229  * PNG_HANDLE_CHUNK_NEVER:
2230  * Discard the chunk data.
2231  * PNG_HANDLE_CHUNK_IF_SAFE:
2232  * Keep the chunk data if the chunk is not critical else raise a chunk
2233  * error.
2234  * PNG_HANDLE_CHUNK_ALWAYS:
2235  * Keep the chunk data.
2236  *
2237  * If the chunk data is saved it can be retrieved using png_get_unknown_chunks,
2238  * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent
2239  * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks
2240  * it simply resets the behavior to the libpng default.
2241  *
2242  * INTERACTION WTIH USER CHUNK CALLBACKS:
2243  * The per-chunk handling is always used when there is a png_user_chunk_ptr
2244  * callback and the callback returns 0; the chunk is then always stored *unless*
2245  * it is critical and the per-chunk setting is other than ALWAYS. Notice that
2246  * the global default is *not* used in this case. (In effect the per-chunk
2247  * value is incremented to at least IF_SAFE.)
2248  *
2249  * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and
2250  * per-chunk defaults will be honored. If you want to preserve the current
2251  * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE
2252  * as the default - if you don't do this libpng 1.6 will issue a warning.
2253  *
2254  * If you want unhandled unknown chunks to be discarded in libpng 1.6 and
2255  * earlier simply return '1' (handled).
2256  *
2257  * PNG_HANDLE_AS_UNKNOWN_SUPPORTED:
2258  * If this is *not* set known chunks will always be handled by libpng and
2259  * will never be stored in the unknown chunk list. Known chunks listed to
2260  * png_set_keep_unknown_chunks will have no effect. If it is set then known
2261  * chunks listed with a keep other than AS_DEFAULT will *never* be processed
2262  * by libpng, in addition critical chunks must either be processed by the
2263  * callback or saved.
2264  *
2265  * The IHDR and IEND chunks must not be listed. Because this turns off the
2266  * default handling for chunks that would otherwise be recognized the
2267  * behavior of libpng transformations may well become incorrect!
2268  *
2269  * WRITE:
2270  * When writing chunks the options only apply to the chunks specified by
2271  * png_set_unknown_chunks (below), libpng will *always* write known chunks
2272  * required by png_set_ calls and will always write the core critical chunks
2273  * (as required for PLTE).
2274  *
2275  * Each chunk in the png_set_unknown_chunks list is looked up in the
2276  * png_set_keep_unknown_chunks list to find the keep setting, this is then
2277  * interpreted as follows:
2278  *
2279  * PNG_HANDLE_CHUNK_AS_DEFAULT:
2280  * Write safe-to-copy chunks and write other chunks if the global
2281  * default is set to _ALWAYS, otherwise don't write this chunk.
2282  * PNG_HANDLE_CHUNK_NEVER:
2283  * Do not write the chunk.
2284  * PNG_HANDLE_CHUNK_IF_SAFE:
2285  * Write the chunk if it is safe-to-copy, otherwise do not write it.
2286  * PNG_HANDLE_CHUNK_ALWAYS:
2287  * Write the chunk.
2288  *
2289  * Note that the default behavior is effectively the opposite of the read case -
2290  * in read unknown chunks are not stored by default, in write they are written
2291  * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different
2292  * - on write the safe-to-copy bit is checked, on read the critical bit is
2293  * checked and on read if the chunk is critical an error will be raised.
2294  *
2295  * num_chunks:
2296  * ===========
2297  * If num_chunks is positive, then the "keep" parameter specifies the manner
2298  * for handling only those chunks appearing in the chunk_list array,
2299  * otherwise the chunk list array is ignored.
2300  *
2301  * If num_chunks is 0 the "keep" parameter specifies the default behavior for
2302  * unknown chunks, as described above.
2303  *
2304  * If num_chunks is negative, then the "keep" parameter specifies the manner
2305  * for handling all unknown chunks plus all chunks recognized by libpng
2306  * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to
2307  * be processed by libpng.
2308  */
2309 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2311  int keep, png_const_bytep chunk_list, int num_chunks));
2312 #endif /* HANDLE_AS_UNKNOWN */
2313 
2314 /* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned;
2315  * the result is therefore true (non-zero) if special handling is required,
2316  * false for the default handling.
2317  */
2319  png_const_bytep chunk_name));
2320 #endif /* SET_UNKNOWN_CHUNKS */
2321 
2322 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
2324  png_inforp info_ptr, png_const_unknown_chunkp unknowns,
2325  int num_unknowns));
2326  /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added
2327  * unknowns to the location currently stored in the png_struct. This is
2328  * invariably the wrong value on write. To fix this call the following API
2329  * for each chunk in the list with the correct location. If you know your
2330  * code won't be compiled on earlier versions you can rely on
2331  * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing
2332  * the correct thing.
2333  */
2334 
2336  (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location));
2337 
2339  png_inforp info_ptr, png_unknown_chunkpp entries));
2340 #endif
2341 
2342 /* Png_free_data() will turn off the "valid" flag for anything it frees.
2343  * If you need to turn it off for a chunk that your application has freed,
2344  * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
2345  */
2346 PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr,
2347  png_inforp info_ptr, int mask));
2348 
2349 #ifdef PNG_INFO_IMAGE_SUPPORTED
2350 /* The "params" pointer is currently not used and is for future expansion. */
2351 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
2352 PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr,
2353  int transforms, png_voidp params));
2354 #endif
2355 #ifdef PNG_WRITE_SUPPORTED
2356 PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr,
2357  int transforms, png_voidp params));
2358 #endif
2359 #endif
2360 
2362  (png_const_structrp png_ptr));
2364  (png_const_structrp png_ptr));
2366  (png_const_structrp png_ptr));
2368  (png_const_structrp png_ptr));
2369 
2370 #ifdef PNG_MNG_FEATURES_SUPPORTED
2371 PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr,
2372  png_uint_32 mng_features_permitted));
2373 #endif
2374 
2375 /* For use in png_set_keep_unknown, added to version 1.2.6 */
2376 #define PNG_HANDLE_CHUNK_AS_DEFAULT 0
2377 #define PNG_HANDLE_CHUNK_NEVER 1
2378 #define PNG_HANDLE_CHUNK_IF_SAFE 2
2379 #define PNG_HANDLE_CHUNK_ALWAYS 3
2380 #define PNG_HANDLE_CHUNK_LAST 4
2381 
2382 /* Strip the prepended error numbers ("#nnn ") from error and warning
2383  * messages before passing them to the error or warning handler.
2384  */
2385 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
2386 PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr,
2387  png_uint_32 strip_mode));
2388 #endif
2389 
2390 /* Added in libpng-1.2.6 */
2391 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
2392 PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr,
2393  png_uint_32 user_width_max, png_uint_32 user_height_max));
2394 PNG_EXPORT(187, png_uint_32, png_get_user_width_max,
2395  (png_const_structrp png_ptr));
2396 PNG_EXPORT(188, png_uint_32, png_get_user_height_max,
2397  (png_const_structrp png_ptr));
2398 /* Added in libpng-1.4.0 */
2399 PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr,
2400  png_uint_32 user_chunk_cache_max));
2401 PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max,
2402  (png_const_structrp png_ptr));
2403 /* Added in libpng-1.4.1 */
2404 PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr,
2405  png_alloc_size_t user_chunk_cache_max));
2407  (png_const_structrp png_ptr));
2408 #endif
2409 
2410 #if defined(PNG_INCH_CONVERSIONS_SUPPORTED)
2411 PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch,
2412  (png_const_structrp png_ptr, png_const_inforp info_ptr));
2413 
2414 PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch,
2415  (png_const_structrp png_ptr, png_const_inforp info_ptr));
2416 
2417 PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch,
2418  (png_const_structrp png_ptr, png_const_inforp info_ptr));
2419 
2420 PNG_FP_EXPORT(196, float, png_get_x_offset_inches,
2421  (png_const_structrp png_ptr, png_const_inforp info_ptr))
2422 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2423 PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed,
2424  (png_const_structrp png_ptr, png_const_inforp info_ptr))
2425 #endif
2426 
2427 PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr,
2428  png_const_inforp info_ptr))
2429 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2430 PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed,
2431  (png_const_structrp png_ptr, png_const_inforp info_ptr))
2432 #endif
2433 
2434 # ifdef PNG_pHYs_SUPPORTED
2435 PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr,
2436  png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
2437  int *unit_type));
2438 # endif /* pHYs */
2439 #endif /* INCH_CONVERSIONS */
2440 
2441 /* Added in libpng-1.4.0 */
2442 #ifdef PNG_IO_STATE_SUPPORTED
2443 PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr));
2444 
2445 /* Removed from libpng 1.6; use png_get_io_chunk_type. */
2446 PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr),
2448 
2449 PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
2450  (png_const_structrp png_ptr));
2451 
2452 /* The flags returned by png_get_io_state() are the following: */
2453 # define PNG_IO_NONE 0x0000 /* no I/O at this moment */
2454 # define PNG_IO_READING 0x0001 /* currently reading */
2455 # define PNG_IO_WRITING 0x0002 /* currently writing */
2456 # define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */
2457 # define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */
2458 # define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */
2459 # define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */
2460 # define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */
2461 # define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */
2462 #endif /* IO_STATE */
2463 
2464 /* Interlace support. The following macros are always defined so that if
2465  * libpng interlace handling is turned off the macros may be used to handle
2466  * interlaced images within the application.
2467  */
2468 #define PNG_INTERLACE_ADAM7_PASSES 7
2469 
2470 /* Two macros to return the first row and first column of the original,
2471  * full, image which appears in a given pass. 'pass' is in the range 0
2472  * to 6 and the result is in the range 0 to 7.
2473  */
2474 #define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7)
2475 #define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7)
2476 
2477 /* A macro to return the offset between pixels in the output row for a pair of
2478  * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that
2479  * follows. Note that ROW_OFFSET is the offset from one row to the next whereas
2480  * COL_OFFSET is from one column to the next, within a row.
2481  */
2482 #define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8)
2483 #define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1))
2484 
2485 /* Two macros to help evaluate the number of rows or columns in each
2486  * pass. This is expressed as a shift - effectively log2 of the number or
2487  * rows or columns in each 8x8 tile of the original image.
2488  */
2489 #define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)
2490 #define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)
2491 
2492 /* Hence two macros to determine the number of rows or columns in a given
2493  * pass of an image given its height or width. In fact these macros may
2494  * return non-zero even though the sub-image is empty, because the other
2495  * dimension may be empty for a small image.
2496  */
2497 #define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\
2498  -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass))
2499 #define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\
2500  -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass))
2501 
2502 /* For the reader row callbacks (both progressive and sequential) it is
2503  * necessary to find the row in the output image given a row in an interlaced
2504  * image, so two more macros:
2505  */
2506 #define PNG_ROW_FROM_PASS_ROW(y_in, pass) \
2507  (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))
2508 #define PNG_COL_FROM_PASS_COL(x_in, pass) \
2509  (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))
2510 
2511 /* Two macros which return a boolean (0 or 1) saying whether the given row
2512  * or column is in a particular pass. These use a common utility macro that
2513  * returns a mask for a given pass - the offset 'off' selects the row or
2514  * column version. The mask has the appropriate bit set for each column in
2515  * the tile.
2516  */
2517 #define PNG_PASS_MASK(pass,off) ( \
2518  ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \
2519  ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0))
2520 
2521 #define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
2522  ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
2523 #define PNG_COL_IN_INTERLACE_PASS(x, pass) \
2524  ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
2525 
2526 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2527 /* With these routines we avoid an integer divide, which will be slower on
2528  * most machines. However, it does take more operations than the corresponding
2529  * divide method, so it may be slower on a few RISC systems. There are two
2530  * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2531  *
2532  * Note that the rounding factors are NOT supposed to be the same! 128 and
2533  * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2534  * standard method.
2535  *
2536  * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2537  */
2538 
2539  /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2540 
2541 # define png_composite(composite, fg, alpha, bg) \
2542  { \
2543  png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
2544  * (png_uint_16)(alpha) \
2545  + (png_uint_16)(bg)*(png_uint_16)(255 \
2546  - (png_uint_16)(alpha)) + 128); \
2547  (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); \
2548  }
2549 
2550 # define png_composite_16(composite, fg, alpha, bg) \
2551  { \
2552  png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
2553  * (png_uint_32)(alpha) \
2554  + (png_uint_32)(bg)*(65535 \
2555  - (png_uint_32)(alpha)) + 32768); \
2556  (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); \
2557  }
2558 
2559 #else /* Standard method using integer division */
2560 
2561 # define png_composite(composite, fg, alpha, bg) \
2562  (composite) = \
2563  (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2564  (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2565  127) / 255))
2566 
2567 # define png_composite_16(composite, fg, alpha, bg) \
2568  (composite) = \
2569  (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2570  (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \
2571  32767) / 65535))
2572 #endif /* READ_COMPOSITE_NODIV */
2573 
2574 #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
2575 PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf));
2576 PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf));
2577 PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf));
2578 #endif
2579 
2580 PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr,
2581  png_const_bytep buf));
2582 /* No png_get_int_16 -- may be added if there's a real need for it. */
2583 
2584 /* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
2585 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2586 PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i));
2587 #endif
2588 #ifdef PNG_SAVE_INT_32_SUPPORTED
2589 PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i));
2590 #endif
2591 
2592 /* Place a 16-bit number into a buffer in PNG byte order.
2593  * The parameter is declared unsigned int, not png_uint_16,
2594  * just to avoid potential problems on pre-ANSI C compilers.
2595  */
2596 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2597 PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));
2598 /* No png_save_int_16 -- may be added if there's a real need for it. */
2599 #endif
2600 
2601 #ifdef PNG_USE_READ_MACROS
2602 /* Inline macros to do direct reads of bytes from the input buffer.
2603  * The png_get_int_32() routine assumes we are using two's complement
2604  * format for negative values, which is almost certainly true.
2605  */
2606 # define PNG_get_uint_32(buf) \
2607  (((png_uint_32)(*(buf)) << 24) + \
2608  ((png_uint_32)(*((buf) + 1)) << 16) + \
2609  ((png_uint_32)(*((buf) + 2)) << 8) + \
2610  ((png_uint_32)(*((buf) + 3))))
2611 
2612  /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
2613  * function) incorrectly returned a value of type png_uint_32.
2614  */
2615 # define PNG_get_uint_16(buf) \
2616  ((png_uint_16) \
2617  (((unsigned int)(*(buf)) << 8) + \
2618  ((unsigned int)(*((buf) + 1)))))
2619 
2620 # define PNG_get_int_32(buf) \
2621  ((png_int_32)((*(buf) & 0x80) \
2622  ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \
2623  : (png_int_32)png_get_uint_32(buf)))
2624 
2625 /* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h,
2626  * but defining a macro name prefixed with PNG_PREFIX.
2627  */
2628 # ifndef PNG_PREFIX
2629 # define png_get_uint_32(buf) PNG_get_uint_32(buf)
2630 # define png_get_uint_16(buf) PNG_get_uint_16(buf)
2631 # define png_get_int_32(buf) PNG_get_int_32(buf)
2632 # endif
2633 #else
2634 # ifdef PNG_PREFIX
2635  /* No macros; revert to the (redefined) function */
2636 # define PNG_get_uint_32 (png_get_uint_32)
2637 # define PNG_get_uint_16 (png_get_uint_16)
2638 # define PNG_get_int_32 (png_get_int_32)
2639 # endif
2640 #endif
2641 
2642 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
2644  (png_structrp png_ptr, int allowed));
2645 # ifdef PNG_GET_PALETTE_MAX_SUPPORTED
2647  png_const_infop info_ptr));
2648 # endif
2649 #endif /* CHECK_FOR_INVALID_INDEX */
2650 
2651 /*******************************************************************************
2652  * Section 5: SIMPLIFIED API
2653  *******************************************************************************
2654  *
2655  * Please read the documentation in libpng-manual.txt (TODO: write said
2656  * documentation) if you don't understand what follows.
2657  *
2658  * The simplified API hides the details of both libpng and the PNG file format
2659  * itself. It allows PNG files to be read into a very limited number of
2660  * in-memory bitmap formats or to be written from the same formats. If these
2661  * formats do not accomodate your needs then you can, and should, use the more
2662  * sophisticated APIs above - these support a wide variety of in-memory formats
2663  * and a wide variety of sophisticated transformations to those formats as well
2664  * as a wide variety of APIs to manipulate ancillary information.
2665  *
2666  * To read a PNG file using the simplified API:
2667  *
2668  * 1) Declare a 'png_image' structure (see below) on the stack, set the
2669  * version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL
2670  * (this is REQUIRED, your program may crash if you don't do it.)
2671  * 2) Call the appropriate png_image_begin_read... function.
2672  * 3) Set the png_image 'format' member to the required sample format.
2673  * 4) Allocate a buffer for the image and, if required, the color-map.
2674  * 5) Call png_image_finish_read to read the image and, if required, the
2675  * color-map into your buffers.
2676  *
2677  * There are no restrictions on the format of the PNG input itself; all valid
2678  * color types, bit depths, and interlace methods are acceptable, and the
2679  * input image is transformed as necessary to the requested in-memory format
2680  * during the png_image_finish_read() step. The only caveat is that if you
2681  * request a color-mapped image from a PNG that is full-color or makes
2682  * complex use of an alpha channel the transformation is extremely lossy and the
2683  * result may look terrible.
2684  *
2685  * To write a PNG file using the simplified API:
2686  *
2687  * 1) Declare a 'png_image' structure on the stack and memset() it to all zero.
2688  * 2) Initialize the members of the structure that describe the image, setting
2689  * the 'format' member to the format of the image samples.
2690  * 3) Call the appropriate png_image_write... function with a pointer to the
2691  * image and, if necessary, the color-map to write the PNG data.
2692  *
2693  * png_image is a structure that describes the in-memory format of an image
2694  * when it is being read or defines the in-memory format of an image that you
2695  * need to write:
2696  */
2697 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \
2698  defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
2699 
2700 #define PNG_IMAGE_VERSION 1
2701 
2702 typedef struct png_control *png_controlp;
2703 typedef struct
2704 {
2705  png_controlp opaque; /* Initialize to NULL, free with png_image_free */
2706  png_uint_32 version; /* Set to PNG_IMAGE_VERSION */
2707  png_uint_32 width; /* Image width in pixels (columns) */
2708  png_uint_32 height; /* Image height in pixels (rows) */
2709  png_uint_32 format; /* Image format as defined below */
2710  png_uint_32 flags; /* A bit mask containing informational flags */
2711  png_uint_32 colormap_entries;
2712  /* Number of entries in the color-map */
2713 
2714  /* In the event of an error or warning the following field will be set to a
2715  * non-zero value and the 'message' field will contain a '\0' terminated
2716  * string with the libpng error or warning message. If both warnings and
2717  * an error were encountered, only the error is recorded. If there
2718  * are multiple warnings, only the first one is recorded.
2719  *
2720  * The upper 30 bits of this value are reserved, the low two bits contain
2721  * a value as follows:
2722  */
2723 # define PNG_IMAGE_WARNING 1
2724 # define PNG_IMAGE_ERROR 2
2725  /*
2726  * The result is a two-bit code such that a value more than 1 indicates
2727  * a failure in the API just called:
2728  *
2729  * 0 - no warning or error
2730  * 1 - warning
2731  * 2 - error
2732  * 3 - error preceded by warning
2733  */
2734 # define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1)
2735 
2736  png_uint_32 warning_or_error;
2737 
2738  char message[64];
2739 } png_image, *png_imagep;
2740 
2741 /* The samples of the image have one to four channels whose components have
2742  * original values in the range 0 to 1.0:
2743  *
2744  * 1: A single gray or luminance channel (G).
2745  * 2: A gray/luminance channel and an alpha channel (GA).
2746  * 3: Three red, green, blue color channels (RGB).
2747  * 4: Three color channels and an alpha channel (RGBA).
2748  *
2749  * The components are encoded in one of two ways:
2750  *
2751  * a) As a small integer, value 0..255, contained in a single byte. For the
2752  * alpha channel the original value is simply value/255. For the color or
2753  * luminance channels the value is encoded according to the sRGB specification
2754  * and matches the 8-bit format expected by typical display devices.
2755  *
2756  * The color/gray channels are not scaled (pre-multiplied) by the alpha
2757  * channel and are suitable for passing to color management software.
2758  *
2759  * b) As a value in the range 0..65535, contained in a 2-byte integer. All
2760  * channels can be converted to the original value by dividing by 65535; all
2761  * channels are linear. Color channels use the RGB encoding (RGB end-points) of
2762  * the sRGB specification. This encoding is identified by the
2763  * PNG_FORMAT_FLAG_LINEAR flag below.
2764  *
2765  * When the simplified API needs to convert between sRGB and linear colorspaces,
2766  * the actual sRGB transfer curve defined in the sRGB specification (see the
2767  * article at https://en.wikipedia.org/wiki/SRGB) is used, not the gamma=1/2.2
2768  * approximation used elsewhere in libpng.
2769  *
2770  * When an alpha channel is present it is expected to denote pixel coverage
2771  * of the color or luminance channels and is returned as an associated alpha
2772  * channel: the color/gray channels are scaled (pre-multiplied) by the alpha
2773  * value.
2774  *
2775  * The samples are either contained directly in the image data, between 1 and 8
2776  * bytes per pixel according to the encoding, or are held in a color-map indexed
2777  * by bytes in the image data. In the case of a color-map the color-map entries
2778  * are individual samples, encoded as above, and the image data has one byte per
2779  * pixel to select the relevant sample from the color-map.
2780  */
2781 
2782 /* PNG_FORMAT_*
2783  *
2784  * #defines to be used in png_image::format. Each #define identifies a
2785  * particular layout of sample data and, if present, alpha values. There are
2786  * separate defines for each of the two component encodings.
2787  *
2788  * A format is built up using single bit flag values. All combinations are
2789  * valid. Formats can be built up from the flag values or you can use one of
2790  * the predefined values below. When testing formats always use the FORMAT_FLAG
2791  * macros to test for individual features - future versions of the library may
2792  * add new flags.
2793  *
2794  * When reading or writing color-mapped images the format should be set to the
2795  * format of the entries in the color-map then png_image_{read,write}_colormap
2796  * called to read or write the color-map and set the format correctly for the
2797  * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly!
2798  *
2799  * NOTE: libpng can be built with particular features disabled. If you see
2800  * compiler errors because the definition of one of the following flags has been
2801  * compiled out it is because libpng does not have the required support. It is
2802  * possible, however, for the libpng configuration to enable the format on just
2803  * read or just write; in that case you may see an error at run time. You can
2804  * guard against this by checking for the definition of the appropriate
2805  * "_SUPPORTED" macro, one of:
2806  *
2807  * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED
2808  */
2809 #define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */
2810 #define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */
2811 #define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */
2812 #define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */
2813 
2814 #ifdef PNG_FORMAT_BGR_SUPPORTED
2815 # define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */
2816 #endif
2817 
2818 #ifdef PNG_FORMAT_AFIRST_SUPPORTED
2819 # define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */
2820 #endif
2821 
2822 /* Commonly used formats have predefined macros.
2823  *
2824  * First the single byte (sRGB) formats:
2825  */
2826 #define PNG_FORMAT_GRAY 0
2827 #define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA
2828 #define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST)
2829 #define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR
2830 #define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR)
2831 #define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA)
2832 #define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST)
2833 #define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA)
2834 #define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST)
2835 
2836 /* Then the linear 2-byte formats. When naming these "Y" is used to
2837  * indicate a luminance (gray) channel.
2838  */
2839 #define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR
2840 #define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA)
2841 #define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR)
2842 #define PNG_FORMAT_LINEAR_RGB_ALPHA \
2843  (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA)
2844 
2845 /* With color-mapped formats the image data is one byte for each pixel, the byte
2846  * is an index into the color-map which is formatted as above. To obtain a
2847  * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP
2848  * to one of the above definitions, or you can use one of the definitions below.
2849  */
2850 #define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP)
2851 #define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP)
2852 #define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP)
2853 #define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP)
2854 #define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP)
2855 #define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP)
2856 
2857 /* PNG_IMAGE macros
2858  *
2859  * These are convenience macros to derive information from a png_image
2860  * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the
2861  * actual image sample values - either the entries in the color-map or the
2862  * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values
2863  * for the pixels and will always return 1 for color-mapped formats. The
2864  * remaining macros return information about the rows in the image and the
2865  * complete image.
2866  *
2867  * NOTE: All the macros that take a png_image::format parameter are compile time
2868  * constants if the format parameter is, itself, a constant. Therefore these
2869  * macros can be used in array declarations and case labels where required.
2870  * Similarly the macros are also pre-processor constants (sizeof is not used) so
2871  * they can be used in #if tests.
2872  *
2873  * First the information about the samples.
2874  */
2875 #define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\
2876  (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1)
2877  /* Return the total number of channels in a given format: 1..4 */
2878 
2879 #define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\
2880  ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1)
2881  /* Return the size in bytes of a single component of a pixel or color-map
2882  * entry (as appropriate) in the image: 1 or 2.
2883  */
2884 
2885 #define PNG_IMAGE_SAMPLE_SIZE(fmt)\
2886  (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt))
2887  /* This is the size of the sample data for one sample. If the image is
2888  * color-mapped it is the size of one color-map entry (and image pixels are
2889  * one byte in size), otherwise it is the size of one image pixel.
2890  */
2891 
2892 #define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\
2893  (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256)
2894  /* The maximum size of the color-map required by the format expressed in a
2895  * count of components. This can be used to compile-time allocate a
2896  * color-map:
2897  *
2898  * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)];
2899  *
2900  * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)];
2901  *
2902  * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the
2903  * information from one of the png_image_begin_read_ APIs and dynamically
2904  * allocate the required memory.
2905  */
2906 
2907 /* Corresponding information about the pixels */
2908 #define PNG_IMAGE_PIXEL_(test,fmt)\
2909  (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt))
2910 
2911 #define PNG_IMAGE_PIXEL_CHANNELS(fmt)\
2912  PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt)
2913  /* The number of separate channels (components) in a pixel; 1 for a
2914  * color-mapped image.
2915  */
2916 
2917 #define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\
2918  PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt)
2919  /* The size, in bytes, of each component in a pixel; 1 for a color-mapped
2920  * image.
2921  */
2922 
2923 #define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt)
2924  /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */
2925 
2926 /* Information about the whole row, or whole image */
2927 #define PNG_IMAGE_ROW_STRIDE(image)\
2928  (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width)
2929  /* Return the total number of components in a single row of the image; this
2930  * is the minimum 'row stride', the minimum count of components between each
2931  * row. For a color-mapped image this is the minimum number of bytes in a
2932  * row.
2933  *
2934  * WARNING: this macro overflows for some images with more than one component
2935  * and very large image widths. libpng will refuse to process an image where
2936  * this macro would overflow.
2937  */
2938 
2939 #define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\
2940  (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride))
2941  /* Return the size, in bytes, of an image buffer given a png_image and a row
2942  * stride - the number of components to leave space for in each row.
2943  *
2944  * WARNING: this macro overflows a 32-bit integer for some large PNG images,
2945  * libpng will refuse to process an image where such an overflow would occur.
2946  */
2947 
2948 #define PNG_IMAGE_SIZE(image)\
2949  PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image))
2950  /* Return the size, in bytes, of the image in memory given just a png_image;
2951  * the row stride is the minimum stride required for the image.
2952  */
2953 
2954 #define PNG_IMAGE_COLORMAP_SIZE(image)\
2955  (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries)
2956  /* Return the size, in bytes, of the color-map of this image. If the image
2957  * format is not a color-map format this will return a size sufficient for
2958  * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if
2959  * you don't want to allocate a color-map in this case.
2960  */
2961 
2962 /* PNG_IMAGE_FLAG_*
2963  *
2964  * Flags containing additional information about the image are held in the
2965  * 'flags' field of png_image.
2966  */
2967 #define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01
2968  /* This indicates the the RGB values of the in-memory bitmap do not
2969  * correspond to the red, green and blue end-points defined by sRGB.
2970  */
2971 
2972 #define PNG_IMAGE_FLAG_FAST 0x02
2973  /* On write emphasise speed over compression; the resultant PNG file will be
2974  * larger but will be produced significantly faster, particular for large
2975  * images. Do not use this option for images which will be distributed, only
2976  * used it when producing intermediate files that will be read back in
2977  * repeatedly. For a typical 24-bit image the option will double the read
2978  * speed at the cost of increasing the image size by 25%, however for many
2979  * more compressible images the PNG file can be 10 times larger with only a
2980  * slight speed gain.
2981  */
2982 
2983 #define PNG_IMAGE_FLAG_16BIT_sRGB 0x04
2984  /* On read if the image is a 16-bit per component image and there is no gAMA
2985  * or sRGB chunk assume that the components are sRGB encoded. Notice that
2986  * images output by the simplified API always have gamma information; setting
2987  * this flag only affects the interpretation of 16-bit images from an
2988  * external source. It is recommended that the application expose this flag
2989  * to the user; the user can normally easily recognize the difference between
2990  * linear and sRGB encoding. This flag has no effect on write - the data
2991  * passed to the write APIs must have the correct encoding (as defined
2992  * above.)
2993  *
2994  * If the flag is not set (the default) input 16-bit per component data is
2995  * assumed to be linear.
2996  *
2997  * NOTE: the flag can only be set after the png_image_begin_read_ call,
2998  * because that call initializes the 'flags' field.
2999  */
3000 
3001 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED
3002 /* READ APIs
3003  * ---------
3004  *
3005  * The png_image passed to the read APIs must have been initialized by setting
3006  * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.)
3007  */
3008 #ifdef PNG_STDIO_SUPPORTED
3009 PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image,
3010  const char *file_name));
3011  /* The named file is opened for read and the image header is filled in
3012  * from the PNG header in the file.
3013  */
3014 
3015 PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image,
3016  FILE* file));
3017  /* The PNG header is read from the stdio FILE object. */
3018 #endif /* STDIO */
3019 
3020 PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image,
3022  /* The PNG header is read from the given memory buffer. */
3023 
3024 PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image,
3025  png_const_colorp background, void *buffer, png_int_32 row_stride,
3026  void *colormap));
3027  /* Finish reading the image into the supplied buffer and clean up the
3028  * png_image structure.
3029  *
3030  * row_stride is the step, in byte or 2-byte units as appropriate,
3031  * between adjacent rows. A positive stride indicates that the top-most row
3032  * is first in the buffer - the normal top-down arrangement. A negative
3033  * stride indicates that the bottom-most row is first in the buffer.
3034  *
3035  * background need only be supplied if an alpha channel must be removed from
3036  * a png_byte format and the removal is to be done by compositing on a solid
3037  * color; otherwise it may be NULL and any composition will be done directly
3038  * onto the buffer. The value is an sRGB color to use for the background,
3039  * for grayscale output the green channel is used.
3040  *
3041  * background must be supplied when an alpha channel must be removed from a
3042  * single byte color-mapped output format, in other words if:
3043  *
3044  * 1) The original format from png_image_begin_read_from_* had
3045  * PNG_FORMAT_FLAG_ALPHA set.
3046  * 2) The format set by the application does not.
3047  * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and
3048  * PNG_FORMAT_FLAG_LINEAR *not* set.
3049  *
3050  * For linear output removing the alpha channel is always done by compositing
3051  * on black and background is ignored.
3052  *
3053  * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must
3054  * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE.
3055  * image->colormap_entries will be updated to the actual number of entries
3056  * written to the colormap; this may be less than the original value.
3057  */
3058 
3059 PNG_EXPORT(238, void, png_image_free, (png_imagep image));
3060  /* Free any data allocated by libpng in image->opaque, setting the pointer to
3061  * NULL. May be called at any time after the structure is initialized.
3062  */
3063 #endif /* SIMPLIFIED_READ */
3064 
3065 #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
3066 /* WRITE APIS
3067  * ----------
3068  * For write you must initialize a png_image structure to describe the image to
3069  * be written. To do this use memset to set the whole structure to 0 then
3070  * initialize fields describing your image.
3071  *
3072  * version: must be set to PNG_IMAGE_VERSION
3073  * opaque: must be initialized to NULL
3074  * width: image width in pixels
3075  * height: image height in rows
3076  * format: the format of the data (image and color-map) you wish to write
3077  * flags: set to 0 unless one of the defined flags applies; set
3078  * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB
3079  * values do not correspond to the colors in sRGB.
3080  * colormap_entries: set to the number of entries in the color-map (0 to 256)
3081  */
3082 #ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
3083 PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image,
3084  const char *file, int convert_to_8bit, const void *buffer,
3085  png_int_32 row_stride, const void *colormap));
3086  /* Write the image to the named file. */
3087 
3088 PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file,
3089  int convert_to_8_bit, const void *buffer, png_int_32 row_stride,
3090  const void *colormap));
3091  /* Write the image to the given (FILE*). */
3092 #endif /* SIMPLIFIED_WRITE_STDIO */
3093 
3094 /* With all write APIs if image is in one of the linear formats with 16-bit
3095  * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG
3096  * gamma encoded according to the sRGB specification, otherwise a 16-bit linear
3097  * encoded PNG file is written.
3098  *
3099  * With color-mapped data formats the colormap parameter point to a color-map
3100  * with at least image->colormap_entries encoded in the specified format. If
3101  * the format is linear the written PNG color-map will be converted to sRGB
3102  * regardless of the convert_to_8_bit flag.
3103  *
3104  * With all APIs row_stride is handled as in the read APIs - it is the spacing
3105  * from one row to the next in component sized units (1 or 2 bytes) and if
3106  * negative indicates a bottom-up row layout in the buffer. If row_stride is
3107  * zero, libpng will calculate it for you from the image width and number of
3108  * channels.
3109  *
3110  * Note that the write API does not support interlacing, sub-8-bit pixels or
3111  * most ancillary chunks. If you need to write text chunks (e.g. for copyright
3112  * notices) you need to use one of the other APIs.
3113  */
3114 
3115 PNG_EXPORT(245, int, png_image_write_to_memory, (png_imagep image, void *memory,
3116  png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8_bit,
3117  const void *buffer, png_int_32 row_stride, const void *colormap));
3118  /* Write the image to the given memory buffer. The function both writes the
3119  * whole PNG data stream to *memory and updates *memory_bytes with the count
3120  * of bytes written.
3121  *
3122  * 'memory' may be NULL. In this case *memory_bytes is not read however on
3123  * success the number of bytes which would have been written will still be
3124  * stored in *memory_bytes. On failure *memory_bytes will contain 0.
3125  *
3126  * If 'memory' is not NULL it must point to memory[*memory_bytes] of
3127  * writeable memory.
3128  *
3129  * If the function returns success memory[*memory_bytes] (if 'memory' is not
3130  * NULL) contains the written PNG data. *memory_bytes will always be less
3131  * than or equal to the original value.
3132  *
3133  * If the function returns false and *memory_bytes was not changed an error
3134  * occured during write. If *memory_bytes was changed, or is not 0 if
3135  * 'memory' was NULL, the write would have succeeded but for the memory
3136  * buffer being too small. *memory_bytes contains the required number of
3137  * bytes and will be bigger that the original value.
3138  */
3139 
3140 #define png_image_write_get_memory_size(image, size, convert_to_8_bit, buffer,\
3141  row_stride, colormap)\
3142  png_image_write_to_memory(&(image), 0, &(size), convert_to_8_bit, buffer,\
3143  row_stride, colormap)
3144  /* Return the amount of memory in 'size' required to compress this image.
3145  * The png_image structure 'image' must be filled in as in the above
3146  * function and must not be changed before the actual write call, the buffer
3147  * and all other parameters must also be identical to that in the final
3148  * write call. The 'size' variable need not be initialized.
3149  *
3150  * NOTE: the macro returns true/false, if false is returned 'size' will be
3151  * set to zero and the write failed and probably will fail if tried again.
3152  */
3153 
3154 /* You can pre-allocate the buffer by making sure it is of sufficient size
3155  * regardless of the amount of compression achieved. The buffer size will
3156  * always be bigger than the original image and it will never be filled. The
3157  * following macros are provided to assist in allocating the buffer.
3158  */
3159 #define PNG_IMAGE_DATA_SIZE(image) (PNG_IMAGE_SIZE(image)+(image).height)
3160  /* The number of uncompressed bytes in the PNG byte encoding of the image;
3161  * uncompressing the PNG IDAT data will give this number of bytes.
3162  *
3163  * NOTE: while PNG_IMAGE_SIZE cannot overflow for an image in memory this
3164  * macro can because of the extra bytes used in the PNG byte encoding. You
3165  * need to avoid this macro if your image size approaches 2^30 in width or
3166  * height. The same goes for the remainder of these macros; they all produce
3167  * bigger numbers than the actual in-memory image size.
3168  */
3169 #ifndef PNG_ZLIB_MAX_SIZE
3170 # define PNG_ZLIB_MAX_SIZE(b) ((b)+(((b)+7U)>>3)+(((b)+63U)>>6)+11U)
3171  /* An upper bound on the number of compressed bytes given 'b' uncompressed
3172  * bytes. This is based on deflateBounds() in zlib; different
3173  * implementations of zlib compression may conceivably produce more data so
3174  * if your zlib implementation is not zlib itself redefine this macro
3175  * appropriately.
3176  */
3177 #endif
3178 
3179 #define PNG_IMAGE_COMPRESSED_SIZE_MAX(image)\
3180  PNG_ZLIB_MAX_SIZE((png_alloc_size_t)PNG_IMAGE_DATA_SIZE(image))
3181  /* An upper bound on the size of the data in the PNG IDAT chunks. */
3182 
3183 #define PNG_IMAGE_PNG_SIZE_MAX_(image, image_size)\
3184  ((8U/*sig*/+25U/*IHDR*/+16U/*gAMA*/+44U/*cHRM*/+12U/*IEND*/+\
3185  (((image).format&PNG_FORMAT_FLAG_COLORMAP)?/*colormap: PLTE, tRNS*/\
3186  12U+3U*(image).colormap_entries/*PLTE data*/+\
3187  (((image).format&PNG_FORMAT_FLAG_ALPHA)?\
3188  12U/*tRNS*/+(image).colormap_entries:0U):0U)+\
3189  12U)+(12U*((image_size)/PNG_ZBUF_SIZE))/*IDAT*/+(image_size))
3190  /* A helper for the following macro; if your compiler cannot handle the
3191  * following macro use this one with the result of
3192  * PNG_IMAGE_COMPRESSED_SIZE_MAX(image) as the second argument (most
3193  * compilers should handle this just fine.)
3194  */
3195 
3196 #define PNG_IMAGE_PNG_SIZE_MAX(image)\
3197  PNG_IMAGE_PNG_SIZE_MAX_(image, PNG_IMAGE_COMPRESSED_SIZE_MAX(image))
3198  /* An upper bound on the total length of the PNG data stream for 'image'.
3199  * The result is of type png_alloc_size_t, on 32-bit systems this may
3200  * overflow even though PNG_IMAGE_DATA_SIZE does not overflow; the write will
3201  * run out of buffer space but return a corrected size which should work.
3202  */
3203 #endif /* SIMPLIFIED_WRITE */
3204 /*******************************************************************************
3205  * END OF SIMPLIFIED API
3206  ******************************************************************************/
3207 #endif /* SIMPLIFIED_{READ|WRITE} */
3208 
3209 /*******************************************************************************
3210  * Section 6: IMPLEMENTATION OPTIONS
3211  *******************************************************************************
3212  *
3213  * Support for arbitrary implementation-specific optimizations. The API allows
3214  * particular options to be turned on or off. 'Option' is the number of the
3215  * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given
3216  * by the PNG_OPTION_ defines below.
3217  *
3218  * HARDWARE: normally hardware capabilites, such as the Intel SSE instructions,
3219  * are detected at run time, however sometimes it may be impossible
3220  * to do this in user mode, in which case it is necessary to discover
3221  * the capabilities in an OS specific way. Such capabilities are
3222  * listed here when libpng has support for them and must be turned
3223  * ON by the application if present.
3224  *
3225  * SOFTWARE: sometimes software optimizations actually result in performance
3226  * decrease on some architectures or systems, or with some sets of
3227  * PNG images. 'Software' options allow such optimizations to be
3228  * selected at run time.
3229  */
3230 #ifdef PNG_SET_OPTION_SUPPORTED
3231 #ifdef PNG_ARM_NEON_API_SUPPORTED
3232 # define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */
3233 #endif
3234 #define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */
3235 #define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */
3236 #ifdef PNG_MIPS_MSA_API_SUPPORTED
3237 # define PNG_MIPS_MSA 6 /* HARDWARE: MIPS Msa SIMD instructions supported */
3238 #endif
3239 #define PNG_IGNORE_ADLER32 8
3240 #ifdef PNG_POWERPC_VSX_API_SUPPORTED
3241 # define PNG_POWERPC_VSX 10 /* HARDWARE: PowerPC VSX SIMD instructions supported */
3242 #endif
3243 #define PNG_OPTION_NEXT 12 /* Next option - numbers must be even */
3245 /* Return values: NOTE: there are four values and 'off' is *not* zero */
3246 #define PNG_OPTION_UNSET 0 /* Unset - defaults to off */
3247 #define PNG_OPTION_INVALID 1 /* Option number out of range */
3248 #define PNG_OPTION_OFF 2
3249 #define PNG_OPTION_ON 3
3250 
3251 PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option,
3252  int onoff));
3253 #endif /* SET_OPTION */
3254 
3255 /*******************************************************************************
3256  * END OF HARDWARE AND SOFTWARE OPTIONS
3257  ******************************************************************************/
3258 
3259 /* Maintainer: Put new public prototypes here ^, in libpng.3, in project
3260  * defs, and in scripts/symbols.def.
3261  */
3262 
3263 /* The last ordinal number (this is the *last* one already used; the next
3264  * one to use is one more than this.)
3265  */
3266 #ifdef PNG_EXPORT_LAST_ORDINAL
3267  PNG_EXPORT_LAST_ORDINAL(249);
3268 #endif
3269 
3270 #ifdef __cplusplus
3271 }
3272 #endif
3273 
3274 #endif /* PNG_VERSION_INFO_ONLY */
3275 /* Do not put anything past this line */
3276 #endif /* PNG_H */
png_unknown_chunk_t::location
png_byte location
Definition: png.h:665
png_set_compression_buffer_size
PNG_IMPEXP void() png_set_compression_buffer_size(png_structrp png_ptr, png_size_t size)
Definition: pngset.c:1566
png_get_oFFs
PNG_IMPEXP png_uint_32() png_get_oFFs(png_const_structrp png_ptr, png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y, int *unit_type)
Definition: pngget.c:869
png_chunk_benign_error
PNG_IMPEXP void() png_chunk_benign_error(png_const_structrp png_ptr, png_const_charp warning_message)
Definition: pngerror.c:514
PNG_FP_EXPORT
#define PNG_FP_EXPORT(ordinal, type, name, args)
Definition: pngconf.h:459
png_row_infop
png_row_info * png_row_infop
Definition: png.h:795
png_get_palette_max
PNG_IMPEXP int() png_get_palette_max(png_const_structp png_ptr, png_const_infop info_ptr)
Definition: pngget.c:1238
png_get_sRGB
PNG_IMPEXP png_uint_32() png_get_sRGB(png_const_structrp png_ptr, png_const_inforp info_ptr, int *file_srgb_intent)
Definition: pngget.c:718
png_set_pHYs
PNG_IMPEXP void() png_set_pHYs(png_const_structrp png_ptr, png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type)
Definition: pngset.c:556
png_set_alpha_mode_fixed
void png_set_alpha_mode_fixed(png_structrp png_ptr, int mode, png_fixed_point output_gamma)
Definition: pngrtran.c:276
png_longjmp
PNG_IMPEXP void() png_longjmp(png_const_structrp png_ptr, int val)
Definition: pngerror.c:758
png_set_expand_gray_1_2_4_to_8
PNG_IMPEXP void() png_set_expand_gray_1_2_4_to_8(png_structrp png_ptr)
Definition: pngrtran.c:901
png_set_text_compression_method
PNG_IMPEXP void() png_set_text_compression_method(png_structrp png_ptr, int method)
Definition: pngwrite.c:1301
PNG_NORETURN
#define PNG_NORETURN
Definition: pngconf.h:442
png_set_text
PNG_IMPEXP void() png_set_text(png_const_structrp png_ptr, png_inforp info_ptr, png_const_textp text_ptr, int num_text)
Definition: pngset.c:762
png_process_data
void png_process_data(png_structrp png_ptr, png_inforp info_ptr, png_bytep buffer, png_size_t buffer_size)
Definition: pngpread.c:36
png_const_bytep
const typedef png_byte * png_const_bytep
Definition: pngconf.h:585
png_read_rows
PNG_IMPEXP void() png_read_rows(png_structrp png_ptr, png_bytepp row, png_bytepp display_row, png_uint_32 num_rows)
Definition: pngread.c:668
png_save_int_32
PNG_IMPEXP void() png_save_int_32(png_bytep buf, png_int_32 i)
Definition: png.c:726
png_error
PNG_IMPEXP void() png_error(png_const_structrp png_ptr, png_const_charp error_message)
Definition: pngerror.c:40
png_get_cHRM
PNG_IMPEXP png_uint_32() png_get_cHRM(png_const_structrp png_ptr, png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x, double *red_y, double *green_x, double *green_y, double *blue_x, double *blue_y)
Definition: pngget.c:512
png_get_valid
PNG_IMPEXP png_uint_32() png_get_valid(png_const_structrp png_ptr, png_const_inforp info_ptr, png_uint_32 flag)
Definition: pngget.c:20
png_set_user_limits
PNG_IMPEXP void() png_set_user_limits(png_structrp png_ptr, png_uint_32 user_width_max, png_uint_32 user_height_max)
Definition: pngset.c:1636
png_const_fixed_point_p
const typedef png_fixed_point * png_const_fixed_point_p
Definition: pngconf.h:597
png_text
struct png_text_struct png_text
png_color_8p
png_color_8 * png_color_8p
Definition: png.h:539
png_infopp
png_info ** png_infopp
Definition: png.h:487
png_get_user_height_max
PNG_IMPEXP png_uint_32() png_get_user_height_max(png_const_structrp png_ptr)
Definition: pngget.c:1200
png_write_info_before_PLTE
PNG_IMPEXP void() png_write_info_before_PLTE(png_structrp png_ptr, png_const_inforp info_ptr)
Definition: pngwrite.c:84
png_set_sBIT
PNG_IMPEXP void() png_set_sBIT(png_const_structrp png_ptr, png_inforp info_ptr, png_const_color_8p sig_bit)
Definition: pngset.c:638
png_get_uint_31
PNG_IMPEXP png_uint_32() png_get_uint_31(png_const_structrp png_ptr, png_const_bytep buf)
Definition: pngrutil.c:22
png_get_user_width_max
PNG_IMPEXP png_uint_32() png_get_user_width_max(png_const_structrp png_ptr)
Definition: pngget.c:1194
png_set_keep_unknown_chunks
PNG_IMPEXP void() png_set_keep_unknown_chunks(png_structrp png_ptr, int keep, png_const_bytep chunk_list, int num_chunks)
Definition: pngset.c:1372
png_set_write_status_fn
PNG_IMPEXP void() png_set_write_status_fn(png_structrp png_ptr, png_write_status_ptr write_row_fn)
Definition: pngwrite.c:1317
png_destroy_write_struct
PNG_IMPEXP void() png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
Definition: pngwrite.c:979
png_data_freer
PNG_IMPEXP void() png_data_freer(png_const_structrp png_ptr, png_inforp info_ptr, int freer, png_uint_32 mask)
Definition: png.c:452
png_time_struct::second
png_byte second
Definition: png.h:638
png_flush_ptr
void(* png_flush_ptr)(png_structp)
Definition: png.h:808
png_get_bKGD
PNG_IMPEXP png_uint_32() png_get_bKGD(png_const_structrp png_ptr, png_inforp info_ptr, png_color_16p *background)
Definition: pngget.c:488
png_sig_cmp
PNG_IMPEXP int() png_sig_cmp(png_const_bytep sig, png_size_t start, png_size_t num_to_check)
Definition: png.c:74
png_set_eXIf_1
PNG_IMPEXP void() png_set_eXIf_1(png_const_structrp png_ptr, png_inforp info_ptr, const png_uint_32 num_exif, const png_bytep exif)
Definition: pngset.c:148
png_color_16_struct::blue
png_uint_16 blue
Definition: png.h:524
png_convert_from_struct_tm
void png_convert_from_struct_tm(png_timep ptime, const struct tm *ttime)
Definition: pngwrite.c:472
png_get_text
PNG_IMPEXP int() png_get_text(png_const_structrp png_ptr, png_inforp info_ptr, png_textp *text_ptr, int *num_text)
Definition: pngget.c:1048
png_voidp
void * png_voidp
Definition: pngconf.h:582
png_color_16_struct
Definition: png.h:519
png_set_sCAL_s
PNG_IMPEXP void() png_set_sCAL_s(png_const_structrp png_ptr, png_inforp info_ptr, int unit, png_const_charp swidth, png_const_charp sheight)
Definition: pngset.c:430
png_get_header_version
PNG_IMPEXP png_const_charp() png_get_header_version(png_const_structrp png_ptr)
Definition: png.c:858
png_set_cHRM
PNG_IMPEXP void() png_set_cHRM(png_const_structrp png_ptr, png_inforp info_ptr, double white_x, double white_y, double red_x, double red_y, double green_x, double green_y, double blue_x, double blue_y)
Definition: pngset.c:102
png_get_hIST
PNG_IMPEXP png_uint_32() png_get_hIST(png_const_structrp png_ptr, png_inforp info_ptr, png_uint_16p *hist)
Definition: pngget.c:807
png_unknown_chunkp
png_unknown_chunk * png_unknown_chunkp
Definition: png.h:669
png_sPLT_entry_struct::green
png_uint_16 green
Definition: png.h:550
PNG_EXPORTA
#define PNG_EXPORTA(ordinal, type, name, args, attributes)
Definition: pngconf.h:306
png_sPLT_entry
struct png_sPLT_entry_struct png_sPLT_entry
png_set_write_user_transform_fn
PNG_IMPEXP void() png_set_write_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr write_user_transform_fn)
Definition: pngwrite.c:1327
png_sPLT_entry_struct::red
png_uint_16 red
Definition: png.h:549
png_get_copyright
PNG_IMPEXP png_const_charp() png_get_copyright(png_const_structrp png_ptr)
Definition: png.c:811
png_color_16
struct png_color_16_struct png_color_16
PNG_CALLBACK
#define PNG_CALLBACK(type, name, args)
Definition: pngconf.h:325
num_trans
int num_trans
Definition: pngcrush.c:2338
png_charp
char * png_charp
Definition: pngconf.h:594
png_get_error_ptr
PNG_IMPEXP png_voidp() png_get_error_ptr(png_const_structrp png_ptr)
Definition: pngerror.c:856
png_color_8_struct::alpha
png_byte alpha
Definition: png.h:537
png_get_mem_ptr
PNG_IMPEXP png_voidp() png_get_mem_ptr(png_const_structrp png_ptr)
Definition: pngmem.c:276
png_get_eXIf_1
PNG_IMPEXP png_uint_32() png_get_eXIf_1(png_const_structrp png_ptr, png_const_inforp info_ptr, png_uint_32 *num_exif, png_bytep *exif)
Definition: pngget.c:788
png_get_sCAL
PNG_IMPEXP png_uint_32() png_get_sCAL(png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, double *width, double *height)
Definition: pngget.c:943
png_colorpp
png_color ** png_colorpp
Definition: png.h:517
png_set_interlace_handling
PNG_IMPEXP int() png_set_interlace_handling(png_structrp png_ptr)
Definition: pngtrans.c:99
png_structpp
png_struct ** png_structpp
Definition: png.h:473
png_free_default
PNG_DEPRECATED PNG_IMPEXP void() png_free_default(png_const_structrp png_ptr, png_voidp ptr)
Definition: pngmem.c:246
png_image_write_to_memory
int png_image_write_to_memory(png_imagep image, void *memory, png_alloc_size_t *memory_bytes, int convert_to_8bit, const void *buffer, png_int_32 row_stride, const void *colormap)
Definition: pngwrite.c:2213
png_set_gamma_fixed
PNG_IMPEXP void() png_set_gamma_fixed(png_structrp png_ptr, png_fixed_point screen_gamma, png_fixed_point override_file_gamma)
Definition: pngrtran.c:805
png_bytepp
png_byte ** png_bytepp
Definition: pngconf.h:611
png_process_data_skip
png_uint_32 png_process_data_skip(png_structrp png_ptr)
Definition: pngpread.c:78
png_const_sPLT_entryp
const typedef png_sPLT_entry * png_const_sPLT_entryp
Definition: png.h:556
png_colorp
png_color * png_colorp
Definition: png.h:515
png_sPLT_struct
Definition: png.h:564
png_longjmp_ptr
void(* png_longjmp_ptr)(jmp_buf, int)
Definition: png.h:859
method
static int method
Definition: pngcrush.c:2291
png_get_current_row_number
PNG_IMPEXP png_uint_32() png_get_current_row_number(png_const_structrp)
Definition: pngtrans.c:844
png_set_tIME
PNG_IMPEXP void() png_set_tIME(png_const_structrp png_ptr, png_inforp info_ptr, png_const_timep mod_time)
Definition: pngset.c:968
png_color_16_struct::gray
png_uint_16 gray
Definition: png.h:525
png_get_header_ver
PNG_IMPEXP png_const_charp() png_get_header_ver(png_const_structrp png_ptr)
Definition: png.c:850
png_write_status_ptr
void(* png_write_status_ptr)(png_structp, png_uint_32, int)
Definition: png.h:812
png_bytep
png_byte * png_bytep
Definition: pngconf.h:584
png_set_read_user_transform_fn
PNG_IMPEXP void() png_set_read_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr read_user_transform_fn)
Definition: pngrtran.c:1060
png_calloc
PNG_IMPEXP png_voidp() png_calloc(png_const_structrp png_ptr, png_alloc_size_t size)
Definition: pngmem.c:50
png_set_add_alpha
PNG_IMPEXP void() png_set_add_alpha(png_structrp png_ptr, png_uint_32 filler, int flags)
Definition: pngtrans.c:205
png_get_cHRM_XYZ
PNG_IMPEXP png_uint_32() png_get_cHRM_XYZ(png_const_structrp png_ptr, png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z, double *green_X, double *green_Y, double *green_Z, double *blue_X, double *blue_Y, double *blue_Z)
Definition: pngget.c:558
png_sPLT_entrypp
png_sPLT_entry ** png_sPLT_entrypp
Definition: png.h:557
png_set_option
PNG_IMPEXP int() png_set_option(png_structrp png_ptr, int option, int onoff)
Definition: png.c:4338
png_infop
png_info * png_infop
Definition: png.h:485
png_set_sig_bytes
PNG_IMPEXP void() png_set_sig_bytes(png_structrp png_ptr, int num_bytes)
Definition: png.c:47
png_benign_error
PNG_IMPEXP void() png_benign_error(png_const_structrp png_ptr, png_const_charp warning_message)
Definition: pngerror.c:362
png_write_sig
PNG_IMPEXP void() png_write_sig(png_structrp png_ptr)
Definition: pngwutil.c:51
png_row_infopp
png_row_info ** png_row_infopp
Definition: png.h:796
png_timepp
png_time ** png_timepp
Definition: png.h:642
png_const_colorp
const typedef png_color * png_const_colorp
Definition: png.h:516
png_set_scale_16
PNG_IMPEXP void() png_set_scale_16(png_structrp png_ptr)
Definition: pngrtran.c:172
png_free_ptr
void(* png_free_ptr)(png_structp, png_voidp)
Definition: png.h:900
png_text_struct::itxt_length
png_size_t itxt_length
Definition: png.h:604
png_libpng_version_1_6_32
char * png_libpng_version_1_6_32
Definition: png.h:462
png_alloc_size_t
png_size_t png_alloc_size_t
Definition: pngconf.h:562
png_set_progressive_read_fn
void png_set_progressive_read_fn(png_structrp png_ptr, png_voidp progressive_ptr, png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn)
Definition: pngpread.c:1074
PNG_FIXED_EXPORT
#define PNG_FIXED_EXPORT(ordinal, type, name, args)
Definition: pngconf.h:467
png_destroy_read_struct
PNG_IMPEXP void() png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr)
Definition: pngread.c:1028
png_set_sRGB
PNG_IMPEXP void() png_set_sRGB(png_const_structrp png_ptr, png_inforp info_ptr, int srgb_intent)
Definition: pngset.c:653
png_create_read_struct_2
PNG_IMPEXP png_structp() png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn)
Definition: pngread.c:53
png_read_info
PNG_IMPEXP void() png_read_info(png_structrp png_ptr, png_inforp info_ptr)
Definition: pngread.c:102
png_const_sPLT_tp
const typedef png_sPLT_t * png_const_sPLT_tp
Definition: png.h:572
png_unknown_chunk_t::name
png_byte name[5]
Definition: png.h:655
png_textpp
png_text ** png_textpp
Definition: png.h:612
png_get_sBIT
PNG_IMPEXP png_uint_32() png_get_sBIT(png_const_structrp png_ptr, png_inforp info_ptr, png_color_8p *sig_bit)
Definition: pngget.c:1030
png_time
struct png_time_struct png_time
png_set_gAMA_fixed
PNG_IMPEXP void() png_set_gAMA_fixed(png_const_structrp png_ptr, png_inforp info_ptr, png_fixed_point int_file_gamma)
Definition: pngset.c:186
png_reset_zstream
PNG_DEPRECATED PNG_IMPEXP int() png_reset_zstream(png_structrp png_ptr)
Definition: png.c:980
png_const_unknown_chunkp
const typedef png_unknown_chunk * png_const_unknown_chunkp
Definition: png.h:670
png_color_16pp
png_color_16 ** png_color_16pp
Definition: png.h:529
png_row_info_struct::width
png_uint_32 width
Definition: png.h:787
png_get_signature
PNG_IMPEXP png_const_bytep() png_get_signature(png_const_structrp png_ptr, png_const_inforp info_ptr)
Definition: pngget.c:477
png_set_invalid
PNG_IMPEXP void() png_set_invalid(png_const_structrp png_ptr, png_inforp info_ptr, int mask)
Definition: pngset.c:1626
png_sPLT_entryp
png_sPLT_entry * png_sPLT_entryp
Definition: png.h:555
png_image_begin_read_from_file
int png_image_begin_read_from_file(png_imagep image, const char *file_name)
Definition: pngread.c:1519
png_get_chunk_cache_max
PNG_IMPEXP png_uint_32() png_get_chunk_cache_max(png_const_structrp png_ptr)
Definition: pngget.c:1207
png_unknown_chunk
struct png_unknown_chunk_t png_unknown_chunk
png_set_text_compression_mem_level
PNG_IMPEXP void() png_set_text_compression_mem_level(png_structrp png_ptr, int mem_level)
Definition: pngwrite.c:1255
png_set_eXIf
PNG_IMPEXP void() png_set_eXIf(png_const_structrp png_ptr, png_inforp info_ptr, const png_bytep exif)
Definition: pngset.c:139
png_chunk_warning
PNG_IMPEXP void() png_chunk_warning(png_const_structrp png_ptr, png_const_charp warning_message)
Definition: pngerror.c:497
png_sPLT_entry_struct::blue
png_uint_16 blue
Definition: png.h:551
width
static png_uint_32 width
Definition: pngcrush.c:2136
PNG_ALLOCATED
#define PNG_ALLOCATED
Definition: pngconf.h:445
png_set_benign_errors
PNG_IMPEXP void() png_set_benign_errors(png_structrp png_ptr, int allowed)
Definition: pngset.c:1671
png_set_tRNS_to_alpha
PNG_IMPEXP void() png_set_tRNS_to_alpha(png_structrp png_ptr)
Definition: pngrtran.c:913
png_set_user_transform_info
PNG_IMPEXP void() png_set_user_transform_info(png_structrp png_ptr, png_voidp user_transform_ptr, int user_transform_depth, int user_transform_channels)
Definition: pngtrans.c:802
png_process_data_pause
png_size_t png_process_data_pause(png_structrp png_ptr, int save)
Definition: pngpread.c:51
png_time_struct::year
png_uint_16 year
Definition: png.h:633
png_time_struct::month
png_byte month
Definition: png.h:634
png_text_struct
Definition: png.h:593
png_set_read_status_fn
PNG_IMPEXP void() png_set_read_status_fn(png_structrp png_ptr, png_read_status_ptr read_row_fn)
Definition: pngread.c:1054
png_get_IHDR
PNG_IMPEXP png_uint_32() png_get_IHDR(png_const_structrp png_ptr, png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height, int *bit_depth, int *color_type, int *interlace_method, int *compression_method, int *filter_method)
Definition: pngget.c:824
png_set_rgb_to_gray_fixed
PNG_IMPEXP void() png_set_rgb_to_gray_fixed(png_structrp png_ptr, int error_action, png_fixed_point red, png_fixed_point green)
Definition: pngrtran.c:957
png_get_unknown_chunks
PNG_IMPEXP int() png_get_unknown_chunks(png_const_structrp png_ptr, png_inforp info_ptr, png_unknown_chunkpp entries)
Definition: pngget.c:1138
png_row_info
struct png_row_info_struct png_row_info
png_set_invert_mono
void png_set_invert_mono(png_structrp png_ptr)
Definition: pngtrans.c:250
png_set_shift
PNG_IMPEXP void() png_set_shift(png_structrp png_ptr, png_const_color_8p true_bits)
Definition: pngtrans.c:84
png_control::size
png_size_t size
Definition: pngpriv.h:2033
png_start_read_image
PNG_IMPEXP void() png_start_read_image(png_structrp png_ptr)
Definition: pngread.c:308
png_const_uint_16p
const typedef png_uint_16 * png_const_uint_16p
Definition: pngconf.h:591
PNGARG
#define PNGARG(arglist)
Definition: pngconf.h:100
png_color_8pp
png_color_8 ** png_color_8pp
Definition: png.h:541
png_get_rowbytes
PNG_IMPEXP png_size_t() png_get_rowbytes(png_const_structrp png_ptr, png_const_inforp info_ptr)
Definition: pngget.c:30
PNGCAPI
#define PNGCAPI
Definition: pngconf.h:261
png_set_unknown_chunks
PNG_IMPEXP void() png_set_unknown_chunks(png_const_structrp png_ptr, png_inforp info_ptr, png_const_unknown_chunkp unknowns, int num_unknowns)
Definition: pngset.c:1200
png_set_gamma
PNG_IMPEXP void() png_set_gamma(png_structrp png_ptr, double screen_gamma, double override_file_gamma)
Definition: pngrtran.c:845
png_color
struct png_color_struct png_color
png_error_ptr
void(* png_error_ptr)(png_structp, png_const_charp)
Definition: png.h:806
png_get_sCAL_fixed
PNG_IMPEXP png_uint_32() png_get_sCAL_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, png_fixed_point *width, png_fixed_point *height)
Definition: pngget.c:920
png_set_expand_16
PNG_IMPEXP void() png_set_expand_16(png_structrp png_ptr)
Definition: pngrtran.c:929
png_get_iCCP
PNG_IMPEXP png_uint_32() png_get_iCCP(png_const_structrp png_ptr, png_inforp info_ptr, png_charpp name, int *compression_type, png_bytepp profile, png_uint_32 *proflen)
Definition: pngget.c:736
png_color_8_struct::gray
png_byte gray
Definition: png.h:536
png_sPLT_t
struct png_sPLT_struct png_sPLT_t
png_get_cHRM_XYZ_fixed
PNG_IMPEXP png_uint_32() png_get_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr, png_fixed_point *int_red_X, png_fixed_point *int_red_Y, png_fixed_point *int_red_Z, png_fixed_point *int_green_X, png_fixed_point *int_green_Y, png_fixed_point *int_green_Z, png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y, png_fixed_point *int_blue_Z)
Definition: pngget.c:604
png_malloc
PNG_IMPEXP png_voidp() png_malloc(png_const_structrp png_ptr, png_alloc_size_t size)
Definition: pngmem.c:172
png_info_def
Definition: pnginfo.h:55
png_set_check_for_invalid_index
PNG_IMPEXP void() png_set_check_for_invalid_index(png_structrp png_ptr, int allowed)
Definition: pngset.c:1701
png_row_info_struct::channels
png_byte channels
Definition: png.h:791
png_set_packswap
PNG_IMPEXP void() png_set_packswap(png_structrp png_ptr)
Definition: pngtrans.c:70
png_get_sPLT
PNG_IMPEXP int() png_get_sPLT(png_const_structrp png_ptr, png_inforp info_ptr, png_sPLT_tpp entries)
Definition: pngget.c:763
png_set_compression_window_bits
PNG_IMPEXP void() png_set_compression_window_bits(png_structrp png_ptr, int window_bits)
Definition: pngwrite.c:1197
png_color_16_struct::green
png_uint_16 green
Definition: png.h:523
png_write_image
PNG_IMPEXP void() png_write_image(png_structrp png_ptr, png_bytepp image)
Definition: pngwrite.c:601
png_write_png
void png_write_png(png_structrp png_ptr, png_inforp info_ptr, int transforms, voidp params)
Definition: pngwrite.c:1343
png_row_info_struct::color_type
png_byte color_type
Definition: png.h:789
png_color_struct::blue
png_byte blue
Definition: png.h:513
png_image_begin_read_from_memory
int png_image_begin_read_from_memory(png_imagep image, png_const_voidp memory, png_size_t size)
Definition: pngread.c:1587
png_text_struct::key
png_charp key
Definition: png.h:600
png_text_struct::text
png_charp text
Definition: png.h:601
PNG_EXPORT
#define PNG_EXPORT(ordinal, type, name, args)
Definition: pngconf.h:316
png_set_gAMA
PNG_IMPEXP void() png_set_gAMA(png_const_structrp png_ptr, png_inforp info_ptr, double file_gamma)
Definition: pngset.c:200
png_time_struct
Definition: png.h:631
png_color_16p
png_color_16 * png_color_16p
Definition: png.h:527
png_set_unknown_chunk_location
PNG_IMPEXP void() png_set_unknown_chunk_location(png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location)
Definition: pngset.c:1299
png_color_struct::green
png_byte green
Definition: png.h:512
png_unknown_chunkpp
png_unknown_chunk ** png_unknown_chunkpp
Definition: png.h:671
png_image_write_to_stdio
int png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit, const void *buffer, png_int_32 row_stride, const void *colormap)
Definition: pngwrite.c:2280
png_set_sCAL_fixed
PNG_IMPEXP void() png_set_sCAL_fixed(png_const_structrp png_ptr, png_inforp info_ptr, int unit, png_fixed_point width, png_fixed_point height)
Definition: pngset.c:527
png_set_cHRM_XYZ
PNG_IMPEXP void() png_set_cHRM_XYZ(png_const_structrp png_ptr, png_inforp info_ptr, double red_X, double red_Y, double red_Z, double green_X, double green_Y, double green_Z, double blue_X, double blue_Y, double blue_Z)
Definition: pngset.c:118
png_get_user_transform_ptr
PNG_IMPEXP png_voidp() png_get_user_transform_ptr(png_const_structrp png_ptr)
Definition: pngtrans.c:833
png_get_uint_16
#define png_get_uint_16(buf)
Definition: png.h:2630
png_set_rgb_to_gray
PNG_IMPEXP void() png_set_rgb_to_gray(png_structrp png_ptr, int error_action, double red, double green)
Definition: pngrtran.c:1046
png_get_current_pass_number
PNG_IMPEXP png_byte() png_get_current_pass_number(png_const_structrp)
Definition: pngtrans.c:856
png_sPLT_struct::nentries
png_int_32 nentries
Definition: png.h:569
png_const_charp
const typedef char * png_const_charp
Definition: pngconf.h:595
png_color_8_struct
Definition: png.h:531
num_palette
static int num_palette
Definition: pngcrush.c:2349
png_set_background_fixed
PNG_IMPEXP void() png_set_background_fixed(png_structrp png_ptr, png_const_color_16p background_color, int background_gamma_code, int need_expand, png_fixed_point background_gamma)
Definition: pngrtran.c:126
png_inforp
png_info * png_inforp
Definition: png.h:502
png_convert_from_time_t
void png_convert_from_time_t(png_timep ptime, time_t ttime)
Definition: pngwrite.c:485
png_write_row
PNG_IMPEXP void() png_write_row(png_structrp png_ptr, png_const_bytep row)
Definition: pngwrite.c:698
png_sPLT_entry_struct::frequency
png_uint_16 frequency
Definition: png.h:553
png_set_longjmp_fn
PNG_IMPEXP jmp_buf *() png_set_longjmp_fn(png_structrp png_ptr, png_longjmp_ptr longjmp_fn, size_t jmp_buf_size)
Definition: pngerror.c:597
buffer
char buffer[256]
Definition: pngcrush.c:2214
png_set_error_fn
PNG_IMPEXP void() png_set_error_fn(png_structrp png_ptr, png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn)
Definition: pngerror.c:835
png_info_init_3
PNG_DEPRECATED PNG_IMPEXP void() png_info_init_3(png_infopp info_ptr, png_size_t png_info_struct_size)
Definition: png.c:425
png_set_tRNS
PNG_IMPEXP void() png_set_tRNS(png_structrp png_ptr, png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans, png_const_color_16p trans_color)
Definition: pngset.c:994
png_control::memory
png_const_bytep memory
Definition: pngpriv.h:2032
png_color_struct
Definition: png.h:509
png_control
Definition: pngpriv.h:2026
png_rw_ptr
void(* png_rw_ptr)(png_structp, png_bytep, png_size_t)
Definition: png.h:807
png_set_text_compression_level
PNG_IMPEXP void() png_set_text_compression_level(png_structrp png_ptr, int level)
Definition: pngwrite.c:1244
png_color_8_struct::blue
png_byte blue
Definition: png.h:535
png_const_textp
const typedef png_text * png_const_textp
Definition: png.h:611
png_get_libpng_ver
PNG_IMPEXP png_const_charp() png_get_libpng_ver(png_const_structrp png_ptr)
Definition: png.c:843
png_set_compression_strategy
PNG_IMPEXP void() png_set_compression_strategy(png_structrp png_ptr, int strategy)
Definition: pngwrite.c:1180
png_set_text_compression_window_bits
PNG_IMPEXP void() png_set_text_compression_window_bits(png_structrp png_ptr, int window_bits)
Definition: pngwrite.c:1280
png_handle_as_unknown
PNG_IMPEXP int() png_handle_as_unknown(png_const_structrp png_ptr, png_const_bytep chunk_name)
Definition: png.c:932
png_set_pCAL
PNG_IMPEXP void() png_set_pCAL(png_const_structrp png_ptr, png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams, png_const_charp units, png_charpp params)
Definition: pngset.c:312
png_image_finish_read
int png_image_finish_read(png_imagep image, png_const_colorp background, void *buffer, png_int_32 row_stride, void *colormap)
Definition: pngread.c:4115
png_set_alpha_mode
void png_set_alpha_mode(png_structrp png_ptr, int mode, double output_gamma)
Definition: pngrtran.c:389
png_set_chunk_cache_max
PNG_IMPEXP void() png_set_chunk_cache_max(png_structrp png_ptr, png_uint_32 user_chunk_cache_max)
Definition: pngset.c:1652
png_get_uint_32
#define png_get_uint_32(buf)
Definition: png.h:2629
png_set_rows
void png_set_rows(png_const_structrp png_ptr, png_inforp info_ptr, png_bytepp row_pointers)
Definition: pngset.c:1546
png_text_struct::lang_key
png_charp lang_key
Definition: png.h:607
png_row_info_struct::pixel_depth
png_byte pixel_depth
Definition: png.h:792
png_unknown_chunk_t::data
png_byte * data
Definition: png.h:656
png_sPLT_entry_struct
Definition: png.h:547
png_set_chunk_malloc_max
PNG_IMPEXP void() png_set_chunk_malloc_max(png_structrp png_ptr, png_alloc_size_t user_chunk_cache_max)
Definition: pngset.c:1660
png_get_io_ptr
PNG_IMPEXP png_voidp() png_get_io_ptr(png_const_structrp png_ptr)
Definition: png.c:686
png_set_text_compression_strategy
PNG_IMPEXP void() png_set_text_compression_strategy(png_structrp png_ptr, int strategy)
Definition: pngwrite.c:1266
png_get_sCAL_s
PNG_IMPEXP png_uint_32() png_get_sCAL_s(png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit, png_charpp swidth, png_charpp sheight)
Definition: pngget.c:959
png_write_chunk_start
PNG_IMPEXP void() png_write_chunk_start(png_structrp png_ptr, png_const_bytep chunk_name, png_uint_32 length)
Definition: pngwutil.c:115
png_get_tIME
PNG_IMPEXP png_uint_32() png_get_tIME(png_const_structrp png_ptr, png_inforp info_ptr, png_timep *mod_time)
Definition: pngget.c:1074
png_struct_def
Definition: pngstruct.h:143
png_charpp
char ** png_charpp
Definition: pngconf.h:617
png_structp
png_struct * png_structp
Definition: png.h:472
png_set_swap_alpha
void png_set_swap_alpha(png_structrp png_ptr)
Definition: pngtrans.c:223
png_read_end
PNG_IMPEXP void() png_read_end(png_structrp png_ptr, png_inforp info_ptr)
Definition: pngread.c:789
png_const_inforp
const typedef png_info * png_const_inforp
Definition: png.h:503
png_save_uint_16
PNG_IMPEXP void() png_save_uint_16(png_bytep buf, unsigned int i)
Definition: pngwutil.c:37
png_const_voidp
const typedef void * png_const_voidp
Definition: pngconf.h:583
png_get_cHRM_fixed
PNG_IMPEXP png_uint_32() png_get_cHRM_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr, png_fixed_point *int_white_x, png_fixed_point *int_white_y, png_fixed_point *int_red_x, png_fixed_point *int_red_y, png_fixed_point *int_green_x, png_fixed_point *int_green_y, png_fixed_point *int_blue_x, png_fixed_point *int_blue_y)
Definition: pngget.c:641
palette
static png_colorp palette
Definition: pngcrush.c:2348
height
static png_uint_32 height
Definition: pngcrush.c:2136
png_create_write_struct_2
PNG_IMPEXP png_structp() png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn)
Definition: pngwrite.c:513
png_set_sRGB_gAMA_and_cHRM
PNG_IMPEXP void() png_set_sRGB_gAMA_and_cHRM(png_const_structrp png_ptr, png_inforp info_ptr, int srgb_intent)
Definition: pngset.c:665
png_set_filter
PNG_IMPEXP void() png_set_filter(png_structrp png_ptr, int method, int filters)
Definition: pngwrite.c:1000
png_set_filter_heuristics_fixed
void png_set_filter_heuristics_fixed(png_structrp png_ptr, int heuristic_method, int num_weights, png_const_fixed_point_p filter_weights, png_const_fixed_point_p filter_costs)
Definition: pngwrite.c:1143
png_read_status_ptr
void(* png_read_status_ptr)(png_structp, png_uint_32, int)
Definition: png.h:810
png_write_chunk_end
PNG_IMPEXP void() png_write_chunk_end(png_structrp png_ptr)
Definition: pngwutil.c:147
png_uint_16p
png_uint_16 * png_uint_16p
Definition: pngconf.h:590
png_get_gAMA
PNG_IMPEXP png_uint_32() png_get_gAMA(png_const_structrp png_ptr, png_const_inforp info_ptr, double *file_gamma)
Definition: pngget.c:697
png_write_flush
PNG_IMPEXP void() png_write_flush(png_structrp png_ptr)
Definition: pngwrite.c:920
png_read_image
PNG_IMPEXP void() png_read_image(png_structrp png_ptr, png_bytepp image)
Definition: pngread.c:723
png_set_strip_alpha
PNG_IMPEXP void() png_set_strip_alpha(png_structrp png_ptr)
Definition: pngrtran.c:199
png_set_cHRM_XYZ_fixed
PNG_IMPEXP void() png_set_cHRM_XYZ_fixed(png_const_structrp png_ptr, png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y, png_fixed_point int_red_Z, png_fixed_point int_green_X, png_fixed_point int_green_Y, png_fixed_point int_green_Z, png_fixed_point int_blue_X, png_fixed_point int_blue_Y, png_fixed_point int_blue_Z)
Definition: pngset.c:69
png_row_info_struct::rowbytes
png_size_t rowbytes
Definition: png.h:788
png_warning
PNG_IMPEXP void() png_warning(png_const_structrp png_ptr, png_const_charp warning_message)
Definition: pngerror.c:216
png_image_begin_read_from_stdio
int png_image_begin_read_from_stdio(png_imagep image, FILE *file)
Definition: pngread.c:1489
png_sPLT_entry_struct::alpha
png_uint_16 alpha
Definition: png.h:552
png_const_structp
const typedef png_struct * png_const_structp
Definition: png.h:471
png_set_expand
PNG_IMPEXP void() png_set_expand(png_structrp png_ptr)
Definition: pngrtran.c:859
png_sPLT_tpp
png_sPLT_t ** png_sPLT_tpp
Definition: png.h:573
png_set_oFFs
PNG_IMPEXP void() png_set_oFFs(png_const_structrp png_ptr, png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y, int unit_type)
Definition: pngset.c:295
png_malloc_ptr
png_voidp(* png_malloc_ptr)(png_structp, png_alloc_size_t)
Definition: png.h:899
png_chunk_error
PNG_IMPEXP void() png_chunk_error(png_const_structrp png_ptr, png_const_charp error_message)
Definition: pngerror.c:481
png_set_flush
PNG_IMPEXP void() png_set_flush(png_structrp png_ptr, int nrows)
Definition: pngwrite.c:908
png_color_8_struct::red
png_byte red
Definition: png.h:533
png_set_iCCP
PNG_IMPEXP void() png_set_iCCP(png_const_structrp png_ptr, png_inforp info_ptr, png_const_charp name, int compression_type, png_const_bytep profile, png_uint_32 proflen)
Definition: pngset.c:688
png_malloc_default
PNG_DEPRECATED PNG_IMPEXP png_voidp() png_malloc_default(png_const_structrp png_ptr, png_alloc_size_t size)
Definition: pngmem.c:190
png_size_t
size_t png_size_t
Definition: pngconf.h:527
png_time_struct::minute
png_byte minute
Definition: png.h:637
png_color_16_struct::index
png_byte index
Definition: png.h:521
png_write_info
PNG_IMPEXP void() png_write_info(png_structrp png_ptr, png_const_inforp info_ptr)
Definition: pngwrite.c:192
png_image_write_to_file
int png_image_write_to_file(png_imagep image, const char *file_name, int convert_to_8bit, const void *buffer, png_int_32 row_stride, const void *colormap)
Definition: pngwrite.c:2329
interlace_method
static int interlace_method
Definition: pngcrush.c:2155
png_get_pCAL
PNG_IMPEXP png_uint_32() png_get_pCAL(png_const_structrp png_ptr, png_inforp info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type, int *nparams, png_charp *units, png_charpp *params)
Definition: pngget.c:890
png_user_transform_ptr
void(* png_user_transform_ptr)(png_structp, png_row_infop, png_bytep)
Definition: png.h:835
png_set_compression_mem_level
PNG_IMPEXP void() png_set_compression_mem_level(png_structrp png_ptr, int mem_level)
Definition: pngwrite.c:1169
png_init_io
PNG_IMPEXP void() png_init_io(png_structrp png_ptr, png_FILE_p fp)
Definition: png.c:703
png_get_gAMA_fixed
PNG_IMPEXP png_uint_32() png_get_gAMA_fixed(png_const_structrp png_ptr, png_const_inforp info_ptr, png_fixed_point *int_file_gamma)
Definition: pngget.c:678
png_malloc_warn
PNG_IMPEXP png_voidp() png_malloc_warn(png_const_structrp png_ptr, png_alloc_size_t size)
Definition: pngmem.c:213
png_get_compression_buffer_size
PNG_IMPEXP png_size_t() png_get_compression_buffer_size(png_const_structrp png_ptr)
Definition: pngget.c:1168
png_read_row
PNG_IMPEXP void() png_read_row(png_structrp png_ptr, png_bytep row, png_bytep display_row)
Definition: pngread.c:393
png_set_bgr
void png_set_bgr(png_structrp png_ptr)
Definition: pngtrans.c:21
png_set_cHRM_fixed
PNG_IMPEXP void() png_set_cHRM_fixed(png_const_structrp png_ptr, png_inforp info_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y, png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x, png_fixed_point int_blue_y)
Definition: pngset.c:40
png_save_uint_32
PNG_IMPEXP void() png_save_uint_32(png_bytep buf, png_uint_32 i)
Definition: pngwutil.c:24
png_color_struct::red
png_byte red
Definition: png.h:511
png_get_PLTE
PNG_IMPEXP png_uint_32() png_get_PLTE(png_const_structrp png_ptr, png_inforp info_ptr, png_colorp *palette, int *num_palette)
Definition: pngget.c:1011
png_set_sPLT
PNG_IMPEXP void() png_set_sPLT(png_const_structrp png_ptr, png_inforp info_ptr, png_const_sPLT_tp entries, int nentries)
Definition: pngset.c:1062
png_create_read_struct
PNG_IMPEXP png_structp() png_create_read_struct(png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warn_fn)
Definition: pngread.c:37
png_const_color_8p
const typedef png_color_8 * png_const_color_8p
Definition: png.h:540
png_get_tRNS
PNG_IMPEXP png_uint_32() png_get_tRNS(png_const_structrp png_ptr, png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans, png_color_16p *trans_color)
Definition: pngget.c:1092
png_const_color_16p
const typedef png_color_16 * png_const_color_16p
Definition: png.h:528
png_row_info_struct
Definition: png.h:785
png_set_crc_action
PNG_IMPEXP void() png_set_crc_action(png_structrp png_ptr, int crit_action, int ancil_action)
Definition: pngrtran.c:25
png_get_eXIf
PNG_IMPEXP png_uint_32() png_get_eXIf(png_const_structrp png_ptr, png_inforp info_ptr, png_bytep *exif)
Definition: pngget.c:778
png_unknown_chunk_t
Definition: png.h:653
png_textp
png_text * png_textp
Definition: png.h:610
png_const_structrp
const typedef png_struct * png_const_structrp
Definition: png.h:501
png_set_mem_fn
PNG_IMPEXP void() png_set_mem_fn(png_structrp png_ptr, png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn)
Definition: pngmem.c:260
PNG_RESTRICT
#define PNG_RESTRICT
Definition: pngconf.h:451
png_color_8_struct::green
png_byte green
Definition: png.h:534
png_get_int_32
#define png_get_int_32(buf)
Definition: png.h:2631
png_write_end
PNG_IMPEXP void() png_write_end(png_structrp png_ptr, png_inforp info_ptr)
Definition: pngwrite.c:358
png_const_infop
const typedef png_info * png_const_infop
Definition: png.h:486
png_set_swap
void png_set_swap(png_structrp png_ptr)
Definition: pngtrans.c:35
png_set_strip_16
PNG_IMPEXP void() png_set_strip_16(png_structrp png_ptr)
Definition: pngrtran.c:186
png_fixed_point
png_int_32 png_fixed_point
Definition: pngconf.h:579
png_structrp
png_struct * png_structrp
Definition: png.h:500
length
png_uint_32 length
Definition: png.c:2253
png_set_PLTE
PNG_IMPEXP void() png_set_PLTE(png_structrp png_ptr, png_inforp info_ptr, png_const_colorp palette, int num_palette)
Definition: pngset.c:572
png_set_quantize
void png_set_quantize(png_structrp png_ptr, png_colorp palette, int num_palette, int maximum_colors, png_const_uint_16p histogram, int full_quantize)
Definition: pngrtran.c:417
png_progressive_combine_row
void png_progressive_combine_row(png_const_structrp png_ptr, png_bytep old_row, png_const_bytep new_row)
Definition: pngpread.c:1058
png_get_progressive_ptr
png_voidp png_get_progressive_ptr(png_const_structrp png_ptr)
Definition: pngpread.c:1089
png_time_struct::day
png_byte day
Definition: png.h:635
PNG_FUNCTION
#define PNG_FUNCTION(type, name, args, attributes)
Definition: pngconf.h:293
png_set_read_user_chunk_fn
void png_set_read_user_chunk_fn(png_structrp png_ptr, png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn)
Definition: pngset.c:1531
png_sPLT_tp
png_sPLT_t * png_sPLT_tp
Definition: png.h:571
png_sPLT_struct::entries
png_sPLT_entryp entries
Definition: png.h:568
png_set_hIST
PNG_IMPEXP void() png_set_hIST(png_const_structrp png_ptr, png_inforp info_ptr, png_const_uint_16p hist)
Definition: pngset.c:210
png_text_struct::lang
png_charp lang
Definition: png.h:605
png_color_8
struct png_color_8_struct png_color_8
png_access_version_number
PNG_IMPEXP png_uint_32() png_access_version_number(void)
Definition: png.c:992
png_set_bKGD
PNG_IMPEXP void() png_set_bKGD(png_const_structrp png_ptr, png_inforp info_ptr, png_const_color_16p background)
Definition: pngset.c:25
png_set_palette_to_rgb
PNG_IMPEXP void() png_set_palette_to_rgb(png_structrp png_ptr)
Definition: pngrtran.c:889
png_write_rows
PNG_IMPEXP void() png_write_rows(png_structrp png_ptr, png_bytepp row, png_uint_32 num_rows)
Definition: pngwrite.c:579
png_set_filter_heuristics
void png_set_filter_heuristics(png_structrp png_ptr, int heuristic_method, int num_weights, png_const_doublep filter_weights, png_const_doublep filter_costs)
Definition: pngwrite.c:1129
pngconf.h
png_create_info_struct
PNG_IMPEXP png_infop() png_create_info_struct(png_const_structrp png_ptr)
Definition: png.c:354
png_row_info_struct::bit_depth
png_byte bit_depth
Definition: png.h:790
png_set_invert_alpha
void png_set_invert_alpha(png_structrp png_ptr)
Definition: pngtrans.c:237
png_get_chunk_malloc_max
PNG_IMPEXP png_alloc_size_t() png_get_chunk_malloc_max(png_const_structrp png_ptr)
Definition: pngget.c:1214
PNG_REMOVED
#define PNG_REMOVED(ordinal, type, name, args, attributes)
Definition: pngconf.h:321
png_set_compression_level
PNG_IMPEXP void() png_set_compression_level(png_structrp png_ptr, int level)
Definition: pngwrite.c:1158
png_set_IHDR
PNG_IMPEXP void() png_set_IHDR(png_const_structrp png_ptr, png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth, int color_type, int interlace_method, int compression_method, int filter_method)
Definition: pngset.c:254
png_color_16_struct::red
png_uint_16 red
Definition: png.h:522
png_time_struct::hour
png_byte hour
Definition: png.h:636
png_control::png_ptr
png_structp png_ptr
Definition: pngpriv.h:2028
png_destroy_info_struct
PNG_IMPEXP void() png_destroy_info_struct(png_const_structrp png_ptr, png_infopp info_ptr_ptr)
Definition: png.c:386
png_set_compression_method
PNG_IMPEXP void() png_set_compression_method(png_structrp png_ptr, int method)
Definition: pngwrite.c:1224
png_timep
png_time * png_timep
Definition: png.h:640
png_set_background
PNG_IMPEXP void() png_set_background(png_structrp png_ptr, png_const_color_16p background_color, int background_gamma_code, int need_expand, double background_gamma)
Definition: pngrtran.c:156
png_set_sCAL
PNG_IMPEXP void() png_set_sCAL(png_const_structrp png_ptr, png_inforp info_ptr, int unit, double width, double height)
Definition: pngset.c:497
png_text_struct::compression
int compression
Definition: png.h:595
png_get_pHYs
PNG_IMPEXP png_uint_32() png_get_pHYs(png_const_structrp png_ptr, png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)
Definition: pngget.c:977
png_unknown_chunk_t::size
png_size_t size
Definition: png.h:657
pnglibconf.h
png_set_filler
PNG_IMPEXP void() png_set_filler(png_structrp png_ptr, png_uint_32 filler, int flags)
Definition: pngtrans.c:120
png_free
PNG_IMPEXP void() png_free(png_const_structrp png_ptr, png_voidp ptr)
Definition: pngmem.c:232
PNG_DEPRECATED
#define PNG_DEPRECATED
Definition: pngconf.h:436
png_read_png
void png_read_png(png_structrp png_ptr, png_inforp info_ptr, int transforms, voidp params)
Definition: pngread.c:1066
png_set_gray_to_rgb
PNG_IMPEXP void() png_set_gray_to_rgb(png_structrp png_ptr)
Definition: pngrtran.c:942
png_sPLT_struct::depth
png_byte depth
Definition: png.h:567
png_set_write_fn
PNG_IMPEXP void() png_set_write_fn(png_structrp png_ptr, png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)
Definition: pngwio.c:122
png_const_timep
const typedef png_time * png_const_timep
Definition: png.h:641
png_write_chunk_data
PNG_IMPEXP void() png_write_chunk_data(png_structrp png_ptr, png_const_bytep data, png_size_t length)
Definition: pngwutil.c:127
png_set_read_fn
PNG_IMPEXP void() png_set_read_fn(png_structrp png_ptr, png_voidp io_ptr, png_rw_ptr read_data_fn)
Definition: pngrio.c:87
png_get_rgb_to_gray_status
PNG_IMPEXP png_byte() png_get_rgb_to_gray_status(png_const_structrp png_ptr)
Definition: pngget.c:1153
png_create_write_struct
PNG_IMPEXP png_structp() png_create_write_struct(png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warn_fn)
Definition: pngwrite.c:499
png_sPLT_struct::name
png_charp name
Definition: png.h:566
png_text_struct::text_length
png_size_t text_length
Definition: png.h:603
png_write_chunk
PNG_IMPEXP void() png_write_chunk(png_structrp png_ptr, png_const_bytep chunk_name, png_const_bytep data, png_size_t length)
Definition: pngwutil.c:193
png_read_update_info
PNG_IMPEXP void() png_read_update_info(png_structrp png_ptr, png_inforp info_ptr)
Definition: pngread.c:277
png_get_channels
PNG_IMPEXP png_byte() png_get_channels(png_const_structrp png_ptr, png_const_inforp info_ptr)
Definition: pngget.c:467
png_free_data
PNG_IMPEXP void() png_free_data(png_const_structrp png_ptr, png_inforp info_ptr, png_uint_32 free_me, int num)
Definition: png.c:471
png_set_packing
PNG_IMPEXP void() png_set_packing(png_structrp png_ptr)
Definition: pngtrans.c:50
png_permit_mng_features
PNG_IMPEXP png_uint_32() png_permit_mng_features(png_structrp png_ptr, png_uint_32 mng_features_permitted)
Definition: pngset.c:1329