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png.h
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1 
2 /* png.h - header file for PNG reference library
3  *
4  * libpng version 1.6.36 - December 1, 2018
5  *
6  * Copyright (c) 2018 Cosmin Truta
7  * Copyright (c) 1998-2002,2004,2006-2018 Glenn Randers-Pehrson
8  * Copyright (c) 1996-1997 Andreas Dilger
9  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
10  *
11  * This code is released under the libpng license. (See LICENSE, below.)
12  *
13  * Authors and maintainers:
14  * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
15  * libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger
16  * libpng versions 0.97, January 1998, through 1.6.35, July 2018:
17  * Glenn Randers-Pehrson.
18  * libpng version 1.6.36, December 1, 2018: Cosmin Truta
19  * See also "Contributing Authors", below.
20  */
21 
22 /*
23  * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE
24  * =========================================
25  *
26  * PNG Reference Library License version 2
27  * ---------------------------------------
28  *
29  * * Copyright (c) 1995-2018 The PNG Reference Library Authors.
30  * * Copyright (c) 2018 Cosmin Truta.
31  * * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson.
32  * * Copyright (c) 1996-1997 Andreas Dilger.
33  * * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
34  *
35  * The software is supplied "as is", without warranty of any kind,
36  * express or implied, including, without limitation, the warranties
37  * of merchantability, fitness for a particular purpose, title, and
38  * non-infringement. In no even shall the Copyright owners, or
39  * anyone distributing the software, be liable for any damages or
40  * other liability, whether in contract, tort or otherwise, arising
41  * from, out of, or in connection with the software, or the use or
42  * other dealings in the software, even if advised of the possibility
43  * of such damage.
44  *
45  * Permission is hereby granted to use, copy, modify, and distribute
46  * this software, or portions hereof, for any purpose, without fee,
47  * subject to the following restrictions:
48  *
49  * 1. The origin of this software must not be misrepresented; you
50  * must not claim that you wrote the original software. If you
51  * use this software in a product, an acknowledgment in the product
52  * documentation would be appreciated, but is not required.
53  *
54  * 2. Altered source versions must be plainly marked as such, and must
55  * not be misrepresented as being the original software.
56  *
57  * 3. This Copyright notice may not be removed or altered from any
58  * source or altered source distribution.
59  *
60  *
61  * PNG Reference Library License version 1 (for libpng 0.5 through 1.6.35)
62  * -----------------------------------------------------------------------
63  *
64  * libpng versions 1.0.7, July 1, 2000 through 1.6.35, July 15, 2018 are
65  * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson, are
66  * derived from libpng-1.0.6, and are distributed according to the same
67  * disclaimer and license as libpng-1.0.6 with the following individuals
68  * added to the list of Contributing Authors:
69  *
70  * Simon-Pierre Cadieux
71  * Eric S. Raymond
72  * Mans Rullgard
73  * Cosmin Truta
74  * Gilles Vollant
75  * James Yu
76  * Mandar Sahastrabuddhe
77  * Google Inc.
78  * Vadim Barkov
79  *
80  * and with the following additions to the disclaimer:
81  *
82  * There is no warranty against interference with your enjoyment of
83  * the library or against infringement. There is no warranty that our
84  * efforts or the library will fulfill any of your particular purposes
85  * or needs. This library is provided with all faults, and the entire
86  * risk of satisfactory quality, performance, accuracy, and effort is
87  * with the user.
88  *
89  * Some files in the "contrib" directory and some configure-generated
90  * files that are distributed with libpng have other copyright owners, and
91  * are released under other open source licenses.
92  *
93  * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
94  * Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
95  * libpng-0.96, and are distributed according to the same disclaimer and
96  * license as libpng-0.96, with the following individuals added to the
97  * list of Contributing Authors:
98  *
99  * Tom Lane
100  * Glenn Randers-Pehrson
101  * Willem van Schaik
102  *
103  * libpng versions 0.89, June 1996, through 0.96, May 1997, are
104  * Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88,
105  * and are distributed according to the same disclaimer and license as
106  * libpng-0.88, with the following individuals added to the list of
107  * Contributing Authors:
108  *
109  * John Bowler
110  * Kevin Bracey
111  * Sam Bushell
112  * Magnus Holmgren
113  * Greg Roelofs
114  * Tom Tanner
115  *
116  * Some files in the "scripts" directory have other copyright owners,
117  * but are released under this license.
118  *
119  * libpng versions 0.5, May 1995, through 0.88, January 1996, are
120  * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
121  *
122  * For the purposes of this copyright and license, "Contributing Authors"
123  * is defined as the following set of individuals:
124  *
125  * Andreas Dilger
126  * Dave Martindale
127  * Guy Eric Schalnat
128  * Paul Schmidt
129  * Tim Wegner
130  *
131  * The PNG Reference Library is supplied "AS IS". The Contributing
132  * Authors and Group 42, Inc. disclaim all warranties, expressed or
133  * implied, including, without limitation, the warranties of
134  * merchantability and of fitness for any purpose. The Contributing
135  * Authors and Group 42, Inc. assume no liability for direct, indirect,
136  * incidental, special, exemplary, or consequential damages, which may
137  * result from the use of the PNG Reference Library, even if advised of
138  * the possibility of such damage.
139  *
140  * Permission is hereby granted to use, copy, modify, and distribute this
141  * source code, or portions hereof, for any purpose, without fee, subject
142  * to the following restrictions:
143  *
144  * 1. The origin of this source code must not be misrepresented.
145  *
146  * 2. Altered versions must be plainly marked as such and must not
147  * be misrepresented as being the original source.
148  *
149  * 3. This Copyright notice may not be removed or altered from any
150  * source or altered source distribution.
151  *
152  * The Contributing Authors and Group 42, Inc. specifically permit,
153  * without fee, and encourage the use of this source code as a component
154  * to supporting the PNG file format in commercial products. If you use
155  * this source code in a product, acknowledgment is not required but would
156  * be appreciated.
157  *
158  * END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.
159  *
160  * TRADEMARK
161  * =========
162  *
163  * The name "libpng" has not been registered by the Copyright owners
164  * as a trademark in any jurisdiction. However, because libpng has
165  * been distributed and maintained world-wide, continually since 1995,
166  * the Copyright owners claim "common-law trademark protection" in any
167  * jurisdiction where common-law trademark is recognized.
168  */
169 
170 /*
171  * A "png_get_copyright" function is available, for convenient use in "about"
172  * boxes and the like:
173  *
174  * printf("%s", png_get_copyright(NULL));
175  *
176  * Also, the PNG logo (in PNG format, of course) is supplied in the
177  * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
178  */
179 
180 /*
181  * The contributing authors would like to thank all those who helped
182  * with testing, bug fixes, and patience. This wouldn't have been
183  * possible without all of you.
184  *
185  * Thanks to Frank J. T. Wojcik for helping with the documentation.
186  */
187 
188 /* Note about libpng version numbers:
189  *
190  * Due to various miscommunications, unforeseen code incompatibilities
191  * and occasional factors outside the authors' control, version numbering
192  * on the library has not always been consistent and straightforward.
193  * The following table summarizes matters since version 0.89c, which was
194  * the first widely used release:
195  *
196  * source png.h png.h shared-lib
197  * version string int version
198  * ------- ------ ----- ----------
199  * 0.89c "1.0 beta 3" 0.89 89 1.0.89
200  * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]
201  * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]
202  * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]
203  * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]
204  * 0.97c 0.97 97 2.0.97
205  * 0.98 0.98 98 2.0.98
206  * 0.99 0.99 98 2.0.99
207  * 0.99a-m 0.99 99 2.0.99
208  * 1.00 1.00 100 2.1.0 [100 should be 10000]
209  * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]
210  * 1.0.1 png.h string is 10001 2.1.0
211  * 1.0.1a-e identical to the 10002 from here on, the shared library
212  * 1.0.2 source version) 10002 is 2.V where V is the source code
213  * 1.0.2a-b 10003 version, except as noted.
214  * 1.0.3 10003
215  * 1.0.3a-d 10004
216  * 1.0.4 10004
217  * 1.0.4a-f 10005
218  * 1.0.5 (+ 2 patches) 10005
219  * 1.0.5a-d 10006
220  * 1.0.5e-r 10100 (not source compatible)
221  * 1.0.5s-v 10006 (not binary compatible)
222  * 1.0.6 (+ 3 patches) 10006 (still binary incompatible)
223  * 1.0.6d-f 10007 (still binary incompatible)
224  * 1.0.6g 10007
225  * 1.0.6h 10007 10.6h (testing xy.z so-numbering)
226  * 1.0.6i 10007 10.6i
227  * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
228  * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)
229  * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
230  * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
231  * 1.0.7 1 10007 (still compatible)
232  * ...
233  * 1.0.69 10 10069 10.so.0.69[.0]
234  * ...
235  * 1.2.59 13 10259 12.so.0.59[.0]
236  * ...
237  * 1.4.20 14 10420 14.so.0.20[.0]
238  * ...
239  * 1.5.30 15 10530 15.so.15.30[.0]
240  * ...
241  * 1.6.36 16 10636 16.so.16.36[.0]
242  *
243  * Henceforth the source version will match the shared-library major and
244  * minor numbers; the shared-library major version number will be used for
245  * changes in backward compatibility, as it is intended.
246  * The PNG_LIBPNG_VER macro, which is not used within libpng but is
247  * available for applications, is an unsigned integer of the form XYYZZ
248  * corresponding to the source version X.Y.Z (leading zeros in Y and Z).
249  * Beta versions were given the previous public release number plus a
250  * letter, until version 1.0.6j; from then on they were given the upcoming
251  * public release number plus "betaNN" or "rcNN".
252  *
253  * Binary incompatibility exists only when applications make direct access
254  * to the info_ptr or png_ptr members through png.h, and the compiled
255  * application is loaded with a different version of the library.
256  *
257  * DLLNUM will change each time there are forward or backward changes
258  * in binary compatibility (e.g., when a new feature is added).
259  *
260  * See libpng.txt or libpng.3 for more information. The PNG specification
261  * is available as a W3C Recommendation and as an ISO/IEC Standard; see
262  * <https://www.w3.org/TR/2003/REC-PNG-20031110/>
263  */
264 
265 #ifndef PNG_H
266 #define PNG_H
267 
268 /* This is not the place to learn how to use libpng. The file libpng-manual.txt
269  * describes how to use libpng, and the file example.c summarizes it
270  * with some code on which to build. This file is useful for looking
271  * at the actual function definitions and structure components. If that
272  * file has been stripped from your copy of libpng, you can find it at
273  * <http://www.libpng.org/pub/png/libpng-manual.txt>
274  *
275  * If you just need to read a PNG file and don't want to read the documentation
276  * skip to the end of this file and read the section entitled 'simplified API'.
277  */
278 
279 /* Version information for png.h - this should match the version in png.c */
280 #define PNG_LIBPNG_VER_STRING "1.6.36"
281 #define PNG_HEADER_VERSION_STRING " libpng version 1.6.36 - December 1, 2018\n"
282 
283 #define PNG_LIBPNG_VER_SONUM 16
284 #define PNG_LIBPNG_VER_DLLNUM 16
285 
286 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
287 #define PNG_LIBPNG_VER_MAJOR 1
288 #define PNG_LIBPNG_VER_MINOR 6
289 #define PNG_LIBPNG_VER_RELEASE 36
290 
291 /* This should match the numeric part of the final component of
292  * PNG_LIBPNG_VER_STRING, omitting any leading zero:
293  */
294 
295 #define PNG_LIBPNG_VER_BUILD 0
296 
297 /* Release Status */
298 #define PNG_LIBPNG_BUILD_ALPHA 1
299 #define PNG_LIBPNG_BUILD_BETA 2
300 #define PNG_LIBPNG_BUILD_RC 3
301 #define PNG_LIBPNG_BUILD_STABLE 4
302 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
303 
304 /* Release-Specific Flags */
305 #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
306  PNG_LIBPNG_BUILD_STABLE only */
307 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
308  PNG_LIBPNG_BUILD_SPECIAL */
309 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
310  PNG_LIBPNG_BUILD_PRIVATE */
311 
312 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
313 
314 /* Careful here. At one time, Guy wanted to use 082, but that
315  * would be octal. We must not include leading zeros.
316  * Versions 0.7 through 1.0.0 were in the range 0 to 100 here
317  * (only version 1.0.0 was mis-numbered 100 instead of 10000).
318  * From version 1.0.1 it is:
319  * XXYYZZ, where XX=major, YY=minor, ZZ=release
320  */
321 #define PNG_LIBPNG_VER 10636 /* 1.6.36 */
322 
323 /* Library configuration: these options cannot be changed after
324  * the library has been built.
325  */
326 #ifndef PNGLCONF_H
327 /* If pnglibconf.h is missing, you can
328  * copy scripts/pnglibconf.h.prebuilt to pnglibconf.h
329  */
330 # include "pnglibconf.h"
331 #endif
332 
333 #ifndef PNG_VERSION_INFO_ONLY
334 /* Machine specific configuration. */
335 # include "pngconf.h"
336 #endif
337 
338 /*
339  * Added at libpng-1.2.8
340  *
341  * Ref MSDN: Private as priority over Special
342  * VS_FF_PRIVATEBUILD File *was not* built using standard release
343  * procedures. If this value is given, the StringFileInfo block must
344  * contain a PrivateBuild string.
345  *
346  * VS_FF_SPECIALBUILD File *was* built by the original company using
347  * standard release procedures but is a variation of the standard
348  * file of the same version number. If this value is given, the
349  * StringFileInfo block must contain a SpecialBuild string.
350  */
351 
352 #ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */
353 # define PNG_LIBPNG_BUILD_TYPE \
354  (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
355 #else
356 # ifdef PNG_LIBPNG_SPECIALBUILD
357 # define PNG_LIBPNG_BUILD_TYPE \
358  (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
359 # else
360 # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
361 # endif
362 #endif
363 
364 #ifndef PNG_VERSION_INFO_ONLY
365 
366 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
367 #ifdef __cplusplus
368 extern "C" {
369 #endif /* __cplusplus */
370 
371 /* Version information for C files, stored in png.c. This had better match
372  * the version above.
373  */
374 #define png_libpng_ver png_get_header_ver(NULL)
375 
376 /* This file is arranged in several sections:
377  *
378  * 1. [omitted]
379  * 2. Any configuration options that can be specified by for the application
380  * code when it is built. (Build time configuration is in pnglibconf.h)
381  * 3. Type definitions (base types are defined in pngconf.h), structure
382  * definitions.
383  * 4. Exported library functions.
384  * 5. Simplified API.
385  * 6. Implementation options.
386  *
387  * The library source code has additional files (principally pngpriv.h) that
388  * allow configuration of the library.
389  */
390 
391 /* Section 1: [omitted] */
392 
393 /* Section 2: run time configuration
394  * See pnglibconf.h for build time configuration
395  *
396  * Run time configuration allows the application to choose between
397  * implementations of certain arithmetic APIs. The default is set
398  * at build time and recorded in pnglibconf.h, but it is safe to
399  * override these (and only these) settings. Note that this won't
400  * change what the library does, only application code, and the
401  * settings can (and probably should) be made on a per-file basis
402  * by setting the #defines before including png.h
403  *
404  * Use macros to read integers from PNG data or use the exported
405  * functions?
406  * PNG_USE_READ_MACROS: use the macros (see below) Note that
407  * the macros evaluate their argument multiple times.
408  * PNG_NO_USE_READ_MACROS: call the relevant library function.
409  *
410  * Use the alternative algorithm for compositing alpha samples that
411  * does not use division?
412  * PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division'
413  * algorithm.
414  * PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm.
415  *
416  * How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is
417  * false?
418  * PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error
419  * APIs to png_warning.
420  * Otherwise the calls are mapped to png_error.
421  */
422 
423 /* Section 3: type definitions, including structures and compile time
424  * constants.
425  * See pngconf.h for base types that vary by machine/system
426  */
427 
428 /* This triggers a compiler error in png.c, if png.c and png.h
429  * do not agree upon the version number.
430  */
432 
433 /* Basic control structions. Read libpng-manual.txt or libpng.3 for more info.
434  *
435  * png_struct is the cache of information used while reading or writing a single
436  * PNG file. One of these is always required, although the simplified API
437  * (below) hides the creation and destruction of it.
438  */
439 typedef struct png_struct_def png_struct;
443 
444 /* png_info contains information read from or to be written to a PNG file. One
445  * or more of these must exist while reading or creating a PNG file. The
446  * information is not used by libpng during read but is used to control what
447  * gets written when a PNG file is created. "png_get_" function calls read
448  * information during read and "png_set_" functions calls write information
449  * when creating a PNG.
450  * been moved into a separate header file that is not accessible to
451  * applications. Read libpng-manual.txt or libpng.3 for more info.
452  */
453 typedef struct png_info_def png_info;
454 typedef png_info * png_infop;
455 typedef const png_info * png_const_infop;
456 typedef png_info * * png_infopp;
457 
458 /* Types with names ending 'p' are pointer types. The corresponding types with
459  * names ending 'rp' are identical pointer types except that the pointer is
460  * marked 'restrict', which means that it is the only pointer to the object
461  * passed to the function. Applications should not use the 'restrict' types;
462  * it is always valid to pass 'p' to a pointer with a function argument of the
463  * corresponding 'rp' type. Different compilers have different rules with
464  * regard to type matching in the presence of 'restrict'. For backward
465  * compatibility libpng callbacks never have 'restrict' in their parameters and,
466  * consequentially, writing portable application code is extremely difficult if
467  * an attempt is made to use 'restrict'.
468  */
473 
474 /* Three color definitions. The order of the red, green, and blue, (and the
475  * exact size) is not important, although the size of the fields need to
476  * be png_byte or png_uint_16 (as defined below).
477  */
478 typedef struct png_color_struct
479 {
480  png_byte red;
481  png_byte green;
482  png_byte blue;
483 } png_color;
485 typedef const png_color * png_const_colorp;
486 typedef png_color * * png_colorpp;
487 
488 typedef struct png_color_16_struct
489 {
490  png_byte index; /* used for palette files */
491  png_uint_16 red; /* for use in red green blue files */
492  png_uint_16 green;
493  png_uint_16 blue;
494  png_uint_16 gray; /* for use in grayscale files */
495 } png_color_16;
499 
500 typedef struct png_color_8_struct
501 {
502  png_byte red; /* for use in red green blue files */
503  png_byte green;
504  png_byte blue;
505  png_byte gray; /* for use in grayscale files */
506  png_byte alpha; /* for alpha channel files */
507 } png_color_8;
511 
512 /*
513  * The following two structures are used for the in-core representation
514  * of sPLT chunks.
515  */
516 typedef struct png_sPLT_entry_struct
517 {
518  png_uint_16 red;
519  png_uint_16 green;
520  png_uint_16 blue;
521  png_uint_16 alpha;
522  png_uint_16 frequency;
527 
528 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples
529  * occupy the LSB of their respective members, and the MSB of each member
530  * is zero-filled. The frequency member always occupies the full 16 bits.
531  */
532 
533 typedef struct png_sPLT_struct
534 {
535  png_charp name; /* palette name */
536  png_byte depth; /* depth of palette samples */
537  png_sPLT_entryp entries; /* palette entries */
538  png_int_32 nentries; /* number of palette entries */
539 } png_sPLT_t;
543 
544 #ifdef PNG_TEXT_SUPPORTED
545 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
546  * and whether that contents is compressed or not. The "key" field
547  * points to a regular zero-terminated C string. The "text" fields can be a
548  * regular C string, an empty string, or a NULL pointer.
549  * However, the structure returned by png_get_text() will always contain
550  * the "text" field as a regular zero-terminated C string (possibly
551  * empty), never a NULL pointer, so it can be safely used in printf() and
552  * other string-handling functions. Note that the "itxt_length", "lang", and
553  * "lang_key" members of the structure only exist when the library is built
554  * with iTXt chunk support. Prior to libpng-1.4.0 the library was built by
555  * default without iTXt support. Also note that when iTXt *is* supported,
556  * the "lang" and "lang_key" fields contain NULL pointers when the
557  * "compression" field contains * PNG_TEXT_COMPRESSION_NONE or
558  * PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the
559  * same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag"
560  * which is always 0 or 1, or its "compression method" which is always 0.
561  */
562 typedef struct png_text_struct
563 {
564  int compression; /* compression value:
565  -1: tEXt, none
566  0: zTXt, deflate
567  1: iTXt, none
568  2: iTXt, deflate */
569  png_charp key; /* keyword, 1-79 character description of "text" */
570  png_charp text; /* comment, may be an empty string (ie "")
571  or a NULL pointer */
572  size_t text_length; /* length of the text string */
573  size_t itxt_length; /* length of the itxt string */
574  png_charp lang; /* language code, 0-79 characters
575  or a NULL pointer */
576  png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
577  chars or a NULL pointer */
578 } png_text;
579 typedef png_text * png_textp;
580 typedef const png_text * png_const_textp;
581 typedef png_text * * png_textpp;
582 #endif
583 
584 /* Supported compression types for text in PNG files (tEXt, and zTXt).
585  * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
586 #define PNG_TEXT_COMPRESSION_NONE_WR -3
587 #define PNG_TEXT_COMPRESSION_zTXt_WR -2
588 #define PNG_TEXT_COMPRESSION_NONE -1
589 #define PNG_TEXT_COMPRESSION_zTXt 0
590 #define PNG_ITXT_COMPRESSION_NONE 1
591 #define PNG_ITXT_COMPRESSION_zTXt 2
592 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
593 
594 /* png_time is a way to hold the time in an machine independent way.
595  * Two conversions are provided, both from time_t and struct tm. There
596  * is no portable way to convert to either of these structures, as far
597  * as I know. If you know of a portable way, send it to me. As a side
598  * note - PNG has always been Year 2000 compliant!
599  */
600 typedef struct png_time_struct
601 {
602  png_uint_16 year; /* full year, as in, 1995 */
603  png_byte month; /* month of year, 1 - 12 */
604  png_byte day; /* day of month, 1 - 31 */
605  png_byte hour; /* hour of day, 0 - 23 */
606  png_byte minute; /* minute of hour, 0 - 59 */
607  png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
608 } png_time;
609 typedef png_time * png_timep;
610 typedef const png_time * png_const_timep;
611 typedef png_time * * png_timepp;
612 
613 #if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\
614  defined(PNG_USER_CHUNKS_SUPPORTED)
615 /* png_unknown_chunk is a structure to hold queued chunks for which there is
616  * no specific support. The idea is that we can use this to queue
617  * up private chunks for output even though the library doesn't actually
618  * know about their semantics.
619  *
620  * The data in the structure is set by libpng on read and used on write.
621  */
622 typedef struct png_unknown_chunk_t
623 {
624  png_byte name[5]; /* Textual chunk name with '\0' terminator */
625  png_byte *data; /* Data, should not be modified on read! */
626  size_t size;
627 
628  /* On write 'location' must be set using the flag values listed below.
629  * Notice that on read it is set by libpng however the values stored have
630  * more bits set than are listed below. Always treat the value as a
631  * bitmask. On write set only one bit - setting multiple bits may cause the
632  * chunk to be written in multiple places.
633  */
634  png_byte location; /* mode of operation at read time */
635 }
637 
641 #endif
642 
643 /* Flag values for the unknown chunk location byte. */
644 #define PNG_HAVE_IHDR 0x01
645 #define PNG_HAVE_PLTE 0x02
646 #define PNG_AFTER_IDAT 0x08
647 
648 /* Maximum positive integer used in PNG is (2^31)-1 */
649 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
650 #define PNG_UINT_32_MAX ((png_uint_32)(-1))
651 #define PNG_SIZE_MAX ((size_t)(-1))
652 
653 /* These are constants for fixed point values encoded in the
654  * PNG specification manner (x100000)
655  */
656 #define PNG_FP_1 100000
657 #define PNG_FP_HALF 50000
658 #define PNG_FP_MAX ((png_fixed_point)0x7fffffffL)
659 #define PNG_FP_MIN (-PNG_FP_MAX)
660 
661 /* These describe the color_type field in png_info. */
662 /* color type masks */
663 #define PNG_COLOR_MASK_PALETTE 1
664 #define PNG_COLOR_MASK_COLOR 2
665 #define PNG_COLOR_MASK_ALPHA 4
666 
667 /* color types. Note that not all combinations are legal */
668 #define PNG_COLOR_TYPE_GRAY 0
669 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
670 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
671 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
672 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
673 /* aliases */
674 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
675 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
676 
677 /* This is for compression type. PNG 1.0-1.2 only define the single type. */
678 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
679 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
680 
681 /* This is for filter type. PNG 1.0-1.2 only define the single type. */
682 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
683 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
684 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
685 
686 /* These are for the interlacing type. These values should NOT be changed. */
687 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
688 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
689 #define PNG_INTERLACE_LAST 2 /* Not a valid value */
690 
691 /* These are for the oFFs chunk. These values should NOT be changed. */
692 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
693 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
694 #define PNG_OFFSET_LAST 2 /* Not a valid value */
695 
696 /* These are for the pCAL chunk. These values should NOT be changed. */
697 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */
698 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
699 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
700 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
701 #define PNG_EQUATION_LAST 4 /* Not a valid value */
702 
703 /* These are for the sCAL chunk. These values should NOT be changed. */
704 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
705 #define PNG_SCALE_METER 1 /* meters per pixel */
706 #define PNG_SCALE_RADIAN 2 /* radians per pixel */
707 #define PNG_SCALE_LAST 3 /* Not a valid value */
708 
709 /* These are for the pHYs chunk. These values should NOT be changed. */
710 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
711 #define PNG_RESOLUTION_METER 1 /* pixels/meter */
712 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */
713 
714 /* These are for the sRGB chunk. These values should NOT be changed. */
715 #define PNG_sRGB_INTENT_PERCEPTUAL 0
716 #define PNG_sRGB_INTENT_RELATIVE 1
717 #define PNG_sRGB_INTENT_SATURATION 2
718 #define PNG_sRGB_INTENT_ABSOLUTE 3
719 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
720 
721 /* This is for text chunks */
722 #define PNG_KEYWORD_MAX_LENGTH 79
723 
724 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */
725 #define PNG_MAX_PALETTE_LENGTH 256
726 
727 /* These determine if an ancillary chunk's data has been successfully read
728  * from the PNG header, or if the application has filled in the corresponding
729  * data in the info_struct to be written into the output file. The values
730  * of the PNG_INFO_<chunk> defines should NOT be changed.
731  */
732 #define PNG_INFO_gAMA 0x0001U
733 #define PNG_INFO_sBIT 0x0002U
734 #define PNG_INFO_cHRM 0x0004U
735 #define PNG_INFO_PLTE 0x0008U
736 #define PNG_INFO_tRNS 0x0010U
737 #define PNG_INFO_bKGD 0x0020U
738 #define PNG_INFO_hIST 0x0040U
739 #define PNG_INFO_pHYs 0x0080U
740 #define PNG_INFO_oFFs 0x0100U
741 #define PNG_INFO_tIME 0x0200U
742 #define PNG_INFO_pCAL 0x0400U
743 #define PNG_INFO_sRGB 0x0800U /* GR-P, 0.96a */
744 #define PNG_INFO_iCCP 0x1000U /* ESR, 1.0.6 */
745 #define PNG_INFO_sPLT 0x2000U /* ESR, 1.0.6 */
746 #define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */
747 #define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */
748 #define PNG_INFO_eXIf 0x10000U /* GR-P, 1.6.31 */
749 
750 /* This is used for the transformation routines, as some of them
751  * change these values for the row. It also should enable using
752  * the routines for other purposes.
753  */
754 typedef struct png_row_info_struct
755 {
756  png_uint_32 width; /* width of row */
757  size_t rowbytes; /* number of bytes in row */
758  png_byte color_type; /* color type of row */
759  png_byte bit_depth; /* bit depth of row */
760  png_byte channels; /* number of channels (1, 2, 3, or 4) */
761  png_byte pixel_depth; /* bits per pixel (depth * channels) */
762 } png_row_info;
763 
766 
767 /* These are the function types for the I/O functions and for the functions
768  * that allow the user to override the default I/O functions with his or her
769  * own. The png_error_ptr type should match that of user-supplied warning
770  * and error functions, while the png_rw_ptr type should match that of the
771  * user read/write data functions. Note that the 'write' function must not
772  * modify the buffer it is passed. The 'read' function, on the other hand, is
773  * expected to return the read data in the buffer.
774  */
775 typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp));
776 typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, size_t));
777 typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp));
778 typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32,
779  int));
780 typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32,
781  int));
782 
783 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
784 typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop));
785 typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop));
786 
787 /* The following callback receives png_uint_32 row_number, int pass for the
788  * png_bytep data of the row. When transforming an interlaced image the
789  * row number is the row number within the sub-image of the interlace pass, so
790  * the value will increase to the height of the sub-image (not the full image)
791  * then reset to 0 for the next pass.
792  *
793  * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
794  * find the output pixel (x,y) given an interlaced sub-image pixel
795  * (row,col,pass). (See below for these macros.)
796  */
797 typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep,
798  png_uint_32, int));
799 #endif
800 
801 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
802  defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
803 typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop,
804  png_bytep));
805 #endif
806 
807 #ifdef PNG_USER_CHUNKS_SUPPORTED
808 typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp,
809  png_unknown_chunkp));
810 #endif
811 #ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
812 /* not used anywhere */
813 /* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */
814 #endif
815 
816 #ifdef PNG_SETJMP_SUPPORTED
817 /* This must match the function definition in <setjmp.h>, and the application
818  * must include this before png.h to obtain the definition of jmp_buf. The
819  * function is required to be PNG_NORETURN, but this is not checked. If the
820  * function does return the application will crash via an abort() or similar
821  * system level call.
822  *
823  * If you get a warning here while building the library you may need to make
824  * changes to ensure that pnglibconf.h records the calling convention used by
825  * your compiler. This may be very difficult - try using a different compiler
826  * to build the library!
827  */
828 PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef);
829 #endif
830 
831 /* Transform masks for the high-level interface */
832 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
833 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
834 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
835 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
836 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
837 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
838 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
839 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
840 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */
841 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
842 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
843 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
844 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */
845 /* Added to libpng-1.2.34 */
846 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
847 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
848 /* Added to libpng-1.4.0 */
849 #define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
850 /* Added to libpng-1.5.4 */
851 #define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */
852 #if INT_MAX >= 0x8000 /* else this might break */
853 #define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */
854 #endif
855 
856 /* Flags for MNG supported features */
857 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01
858 #define PNG_FLAG_MNG_FILTER_64 0x04
859 #define PNG_ALL_MNG_FEATURES 0x05
860 
861 /* NOTE: prior to 1.5 these functions had no 'API' style declaration,
862  * this allowed the zlib default functions to be used on Windows
863  * platforms. In 1.5 the zlib default malloc (which just calls malloc and
864  * ignores the first argument) should be completely compatible with the
865  * following.
866  */
867 typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp,
869 typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp));
870 
871 /* Section 4: exported functions
872  * Here are the function definitions most commonly used. This is not
873  * the place to find out how to use libpng. See libpng-manual.txt for the
874  * full explanation, see example.c for the summary. This just provides
875  * a simple one line description of the use of each function.
876  *
877  * The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in
878  * pngconf.h and in the *.dfn files in the scripts directory.
879  *
880  * PNG_EXPORT(ordinal, type, name, (args));
881  *
882  * ordinal: ordinal that is used while building
883  * *.def files. The ordinal value is only
884  * relevant when preprocessing png.h with
885  * the *.dfn files for building symbol table
886  * entries, and are removed by pngconf.h.
887  * type: return type of the function
888  * name: function name
889  * args: function arguments, with types
890  *
891  * When we wish to append attributes to a function prototype we use
892  * the PNG_EXPORTA() macro instead.
893  *
894  * PNG_EXPORTA(ordinal, type, name, (args), attributes);
895  *
896  * ordinal, type, name, and args: same as in PNG_EXPORT().
897  * attributes: function attributes
898  */
899 
900 /* Returns the version number of the library */
901 PNG_EXPORT(1, png_uint_32, png_access_version_number, (void));
902 
903 /* Tell lib we have already handled the first <num_bytes> magic bytes.
904  * Handling more than 8 bytes from the beginning of the file is an error.
905  */
906 PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes));
907 
908 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
909  * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
910  * signature, and non-zero otherwise. Having num_to_check == 0 or
911  * start > 7 will always fail (ie return non-zero).
912  */
913 PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, size_t start,
914  size_t num_to_check));
915 
916 /* Simple signature checking function. This is the same as calling
917  * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
918  */
919 #define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n))
920 
921 /* Allocate and initialize png_ptr struct for reading, and any other memory. */
922 PNG_EXPORTA(4, png_structp, png_create_read_struct,
923  (png_const_charp user_png_ver, png_voidp error_ptr,
924  png_error_ptr error_fn, png_error_ptr warn_fn),
925  PNG_ALLOCATED);
926 
927 /* Allocate and initialize png_ptr struct for writing, and any other memory */
928 PNG_EXPORTA(5, png_structp, png_create_write_struct,
929  (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
930  png_error_ptr warn_fn),
931  PNG_ALLOCATED);
932 
933 PNG_EXPORT(6, size_t, png_get_compression_buffer_size,
934  (png_const_structrp png_ptr));
935 
936 PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr,
937  size_t size));
938 
939 /* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
940  * match up.
941  */
942 #ifdef PNG_SETJMP_SUPPORTED
943 /* This function returns the jmp_buf built in to *png_ptr. It must be
944  * supplied with an appropriate 'longjmp' function to use on that jmp_buf
945  * unless the default error function is overridden in which case NULL is
946  * acceptable. The size of the jmp_buf is checked against the actual size
947  * allocated by the library - the call will return NULL on a mismatch
948  * indicating an ABI mismatch.
949  */
950 PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr,
951  png_longjmp_ptr longjmp_fn, size_t jmp_buf_size));
952 # define png_jmpbuf(png_ptr) \
953  (*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf))))
954 #else
955 # define png_jmpbuf(png_ptr) \
956  (LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
957 #endif
958 /* This function should be used by libpng applications in place of
959  * longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it
960  * will use it; otherwise it will call PNG_ABORT(). This function was
961  * added in libpng-1.5.0.
962  */
963 PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val),
964  PNG_NORETURN);
965 
966 #ifdef PNG_READ_SUPPORTED
967 /* Reset the compression stream */
968 PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED);
969 #endif
970 
971 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
972 #ifdef PNG_USER_MEM_SUPPORTED
973 PNG_EXPORTA(11, png_structp, png_create_read_struct_2,
974  (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
975  png_error_ptr warn_fn,
976  png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
977  PNG_ALLOCATED);
978 PNG_EXPORTA(12, png_structp, png_create_write_struct_2,
979  (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
980  png_error_ptr warn_fn,
981  png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
982  PNG_ALLOCATED);
983 #endif
984 
985 /* Write the PNG file signature. */
986 PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr));
987 
988 /* Write a PNG chunk - size, type, (optional) data, CRC. */
989 PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep
990  chunk_name, png_const_bytep data, size_t length));
991 
992 /* Write the start of a PNG chunk - length and chunk name. */
993 PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr,
994  png_const_bytep chunk_name, png_uint_32 length));
995 
996 /* Write the data of a PNG chunk started with png_write_chunk_start(). */
997 PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr,
998  png_const_bytep data, size_t length));
999 
1000 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1001 PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr));
1002 
1003 /* Allocate and initialize the info structure */
1004 PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr),
1005  PNG_ALLOCATED);
1006 
1007 /* DEPRECATED: this function allowed init structures to be created using the
1008  * default allocation method (typically malloc). Use is deprecated in 1.6.0 and
1009  * the API will be removed in the future.
1010  */
1011 PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr,
1012  size_t png_info_struct_size), PNG_DEPRECATED);
1013 
1014 /* Writes all the PNG information before the image. */
1015 PNG_EXPORT(20, void, png_write_info_before_PLTE,
1016  (png_structrp png_ptr, png_const_inforp info_ptr));
1017 PNG_EXPORT(21, void, png_write_info,
1018  (png_structrp png_ptr, png_const_inforp info_ptr));
1019 
1020 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1021 /* Read the information before the actual image data. */
1022 PNG_EXPORT(22, void, png_read_info,
1023  (png_structrp png_ptr, png_inforp info_ptr));
1024 #endif
1025 
1026 #ifdef PNG_TIME_RFC1123_SUPPORTED
1027  /* Convert to a US string format: there is no localization support in this
1028  * routine. The original implementation used a 29 character buffer in
1029  * png_struct, this will be removed in future versions.
1030  */
1031 #if PNG_LIBPNG_VER < 10700
1032 /* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */
1033 PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr,
1034  png_const_timep ptime),PNG_DEPRECATED);
1035 #endif
1036 PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29],
1037  png_const_timep ptime));
1038 #endif
1039 
1040 #ifdef PNG_CONVERT_tIME_SUPPORTED
1041 /* Convert from a struct tm to png_time */
1042 PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime,
1043  const struct tm * ttime));
1044 
1045 /* Convert from time_t to png_time. Uses gmtime() */
1046 PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime));
1047 #endif /* CONVERT_tIME */
1048 
1049 #ifdef PNG_READ_EXPAND_SUPPORTED
1050 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1051 PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr));
1052 PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr));
1053 PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr));
1054 PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr));
1055 #endif
1056 
1057 #ifdef PNG_READ_EXPAND_16_SUPPORTED
1058 /* Expand to 16-bit channels, forces conversion of palette to RGB and expansion
1059  * of a tRNS chunk if present.
1060  */
1061 PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr));
1062 #endif
1063 
1064 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1065 /* Use blue, green, red order for pixels. */
1066 PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr));
1067 #endif
1068 
1069 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1070 /* Expand the grayscale to 24-bit RGB if necessary. */
1071 PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr));
1072 #endif
1073 
1074 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1075 /* Reduce RGB to grayscale. */
1076 #define PNG_ERROR_ACTION_NONE 1
1077 #define PNG_ERROR_ACTION_WARN 2
1078 #define PNG_ERROR_ACTION_ERROR 3
1079 #define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/
1080 
1081 PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr,
1082  int error_action, double red, double green))
1083 PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr,
1084  int error_action, png_fixed_point red, png_fixed_point green))
1085 
1086 PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp
1087  png_ptr));
1088 #endif
1089 
1090 #ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
1091 PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,
1092  png_colorp palette));
1093 #endif
1094 
1095 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED
1096 /* How the alpha channel is interpreted - this affects how the color channels
1097  * of a PNG file are returned to the calling application when an alpha channel,
1098  * or a tRNS chunk in a palette file, is present.
1099  *
1100  * This has no effect on the way pixels are written into a PNG output
1101  * datastream. The color samples in a PNG datastream are never premultiplied
1102  * with the alpha samples.
1103  *
1104  * The default is to return data according to the PNG specification: the alpha
1105  * channel is a linear measure of the contribution of the pixel to the
1106  * corresponding composited pixel, and the color channels are unassociated
1107  * (not premultiplied). The gamma encoded color channels must be scaled
1108  * according to the contribution and to do this it is necessary to undo
1109  * the encoding, scale the color values, perform the composition and re-encode
1110  * the values. This is the 'PNG' mode.
1111  *
1112  * The alternative is to 'associate' the alpha with the color information by
1113  * storing color channel values that have been scaled by the alpha.
1114  * image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes
1115  * (the latter being the two common names for associated alpha color channels).
1116  *
1117  * For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha
1118  * value is equal to the maximum value.
1119  *
1120  * The final choice is to gamma encode the alpha channel as well. This is
1121  * broken because, in practice, no implementation that uses this choice
1122  * correctly undoes the encoding before handling alpha composition. Use this
1123  * choice only if other serious errors in the software or hardware you use
1124  * mandate it; the typical serious error is for dark halos to appear around
1125  * opaque areas of the composited PNG image because of arithmetic overflow.
1126  *
1127  * The API function png_set_alpha_mode specifies which of these choices to use
1128  * with an enumerated 'mode' value and the gamma of the required output:
1129  */
1130 #define PNG_ALPHA_PNG 0 /* according to the PNG standard */
1131 #define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */
1132 #define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */
1133 #define PNG_ALPHA_PREMULTIPLIED 1 /* as above */
1134 #define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */
1135 #define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */
1136 
1137 PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode,
1138  double output_gamma))
1139 PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr,
1140  int mode, png_fixed_point output_gamma))
1141 #endif
1142 
1143 #if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)
1144 /* The output_gamma value is a screen gamma in libpng terminology: it expresses
1145  * how to decode the output values, not how they are encoded.
1146  */
1147 #define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */
1148 #define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */
1149 #define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */
1150 #define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */
1151 #endif
1152 
1153 /* The following are examples of calls to png_set_alpha_mode to achieve the
1154  * required overall gamma correction and, where necessary, alpha
1155  * premultiplication.
1156  *
1157  * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
1158  * This is the default libpng handling of the alpha channel - it is not
1159  * pre-multiplied into the color components. In addition the call states
1160  * that the output is for a sRGB system and causes all PNG files without gAMA
1161  * chunks to be assumed to be encoded using sRGB.
1162  *
1163  * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
1164  * In this case the output is assumed to be something like an sRGB conformant
1165  * display preceded by a power-law lookup table of power 1.45. This is how
1166  * early Mac systems behaved.
1167  *
1168  * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
1169  * This is the classic Jim Blinn approach and will work in academic
1170  * environments where everything is done by the book. It has the shortcoming
1171  * of assuming that input PNG data with no gamma information is linear - this
1172  * is unlikely to be correct unless the PNG files where generated locally.
1173  * Most of the time the output precision will be so low as to show
1174  * significant banding in dark areas of the image.
1175  *
1176  * png_set_expand_16(pp);
1177  * png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
1178  * This is a somewhat more realistic Jim Blinn inspired approach. PNG files
1179  * are assumed to have the sRGB encoding if not marked with a gamma value and
1180  * the output is always 16 bits per component. This permits accurate scaling
1181  * and processing of the data. If you know that your input PNG files were
1182  * generated locally you might need to replace PNG_DEFAULT_sRGB with the
1183  * correct value for your system.
1184  *
1185  * png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
1186  * If you just need to composite the PNG image onto an existing background
1187  * and if you control the code that does this you can use the optimization
1188  * setting. In this case you just copy completely opaque pixels to the
1189  * output. For pixels that are not completely transparent (you just skip
1190  * those) you do the composition math using png_composite or png_composite_16
1191  * below then encode the resultant 8-bit or 16-bit values to match the output
1192  * encoding.
1193  *
1194  * Other cases
1195  * If neither the PNG nor the standard linear encoding work for you because
1196  * of the software or hardware you use then you have a big problem. The PNG
1197  * case will probably result in halos around the image. The linear encoding
1198  * will probably result in a washed out, too bright, image (it's actually too
1199  * contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably
1200  * substantially reduce the halos. Alternatively try:
1201  *
1202  * png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);
1203  * This option will also reduce the halos, but there will be slight dark
1204  * halos round the opaque parts of the image where the background is light.
1205  * In the OPTIMIZED mode the halos will be light halos where the background
1206  * is dark. Take your pick - the halos are unavoidable unless you can get
1207  * your hardware/software fixed! (The OPTIMIZED approach is slightly
1208  * faster.)
1209  *
1210  * When the default gamma of PNG files doesn't match the output gamma.
1211  * If you have PNG files with no gamma information png_set_alpha_mode allows
1212  * you to provide a default gamma, but it also sets the output gamma to the
1213  * matching value. If you know your PNG files have a gamma that doesn't
1214  * match the output you can take advantage of the fact that
1215  * png_set_alpha_mode always sets the output gamma but only sets the PNG
1216  * default if it is not already set:
1217  *
1218  * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
1219  * png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
1220  * The first call sets both the default and the output gamma values, the
1221  * second call overrides the output gamma without changing the default. This
1222  * is easier than achieving the same effect with png_set_gamma. You must use
1223  * PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will
1224  * fire if more than one call to png_set_alpha_mode and png_set_background is
1225  * made in the same read operation, however multiple calls with PNG_ALPHA_PNG
1226  * are ignored.
1227  */
1228 
1229 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1230 PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr));
1231 #endif
1232 
1233 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1234  defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1235 PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr));
1236 #endif
1237 
1238 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1239  defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1240 PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr));
1241 #endif
1242 
1243 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1244 /* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
1245 PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler,
1246  int flags));
1247 /* The values of the PNG_FILLER_ defines should NOT be changed */
1248 # define PNG_FILLER_BEFORE 0
1249 # define PNG_FILLER_AFTER 1
1250 /* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
1251 PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr,
1252  png_uint_32 filler, int flags));
1253 #endif /* READ_FILLER || WRITE_FILLER */
1254 
1255 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1256 /* Swap bytes in 16-bit depth files. */
1257 PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr));
1258 #endif
1259 
1260 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1261 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1262 PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr));
1263 #endif
1264 
1265 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1266  defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1267 /* Swap packing order of pixels in bytes. */
1268 PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr));
1269 #endif
1270 
1271 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1272 /* Converts files to legal bit depths. */
1273 PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p
1274  true_bits));
1275 #endif
1276 
1277 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1278  defined(PNG_WRITE_INTERLACING_SUPPORTED)
1279 /* Have the code handle the interlacing. Returns the number of passes.
1280  * MUST be called before png_read_update_info or png_start_read_image,
1281  * otherwise it will not have the desired effect. Note that it is still
1282  * necessary to call png_read_row or png_read_rows png_get_image_height
1283  * times for each pass.
1284 */
1285 PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr));
1286 #endif
1287 
1288 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1289 /* Invert monochrome files */
1290 PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr));
1291 #endif
1292 
1293 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1294 /* Handle alpha and tRNS by replacing with a background color. Prior to
1295  * libpng-1.5.4 this API must not be called before the PNG file header has been
1296  * read. Doing so will result in unexpected behavior and possible warnings or
1297  * errors if the PNG file contains a bKGD chunk.
1298  */
1299 PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr,
1300  png_const_color_16p background_color, int background_gamma_code,
1301  int need_expand, double background_gamma))
1302 PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr,
1303  png_const_color_16p background_color, int background_gamma_code,
1304  int need_expand, png_fixed_point background_gamma))
1305 #endif
1306 #ifdef PNG_READ_BACKGROUND_SUPPORTED
1307 # define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1308 # define PNG_BACKGROUND_GAMMA_SCREEN 1
1309 # define PNG_BACKGROUND_GAMMA_FILE 2
1310 # define PNG_BACKGROUND_GAMMA_UNIQUE 3
1311 #endif
1312 
1313 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
1314 /* Scale a 16-bit depth file down to 8-bit, accurately. */
1315 PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr));
1316 #endif
1317 
1318 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
1319 #define PNG_READ_16_TO_8_SUPPORTED /* Name prior to 1.5.4 */
1320 /* Strip the second byte of information from a 16-bit depth file. */
1321 PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr));
1322 #endif
1323 
1324 #ifdef PNG_READ_QUANTIZE_SUPPORTED
1325 /* Turn on quantizing, and reduce the palette to the number of colors
1326  * available.
1327  */
1328 PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr,
1329  png_colorp palette, int num_palette, int maximum_colors,
1330  png_const_uint_16p histogram, int full_quantize));
1331 #endif
1332 
1333 #ifdef PNG_READ_GAMMA_SUPPORTED
1334 /* The threshold on gamma processing is configurable but hard-wired into the
1335  * library. The following is the floating point variant.
1336  */
1337 #define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001)
1338 
1339 /* Handle gamma correction. Screen_gamma=(display_exponent).
1340  * NOTE: this API simply sets the screen and file gamma values. It will
1341  * therefore override the value for gamma in a PNG file if it is called after
1342  * the file header has been read - use with care - call before reading the PNG
1343  * file for best results!
1344  *
1345  * These routines accept the same gamma values as png_set_alpha_mode (described
1346  * above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either
1347  * API (floating point or fixed.) Notice, however, that the 'file_gamma' value
1348  * is the inverse of a 'screen gamma' value.
1349  */
1350 PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr,
1351  double screen_gamma, double override_file_gamma))
1352 PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr,
1353  png_fixed_point screen_gamma, png_fixed_point override_file_gamma))
1354 #endif
1355 
1356 #ifdef PNG_WRITE_FLUSH_SUPPORTED
1357 /* Set how many lines between output flushes - 0 for no flushing */
1358 PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows));
1359 /* Flush the current PNG output buffer */
1360 PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr));
1361 #endif
1362 
1363 /* Optional update palette with requested transformations */
1364 PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr));
1365 
1366 /* Optional call to update the users info structure */
1367 PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr,
1368  png_inforp info_ptr));
1369 
1370 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1371 /* Read one or more rows of image data. */
1372 PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row,
1373  png_bytepp display_row, png_uint_32 num_rows));
1374 #endif
1375 
1376 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1377 /* Read a row of data. */
1378 PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row,
1379  png_bytep display_row));
1380 #endif
1381 
1382 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1383 /* Read the whole image into memory at once. */
1384 PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image));
1385 #endif
1386 
1387 /* Write a row of image data */
1388 PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr,
1389  png_const_bytep row));
1390 
1391 /* Write a few rows of image data: (*row) is not written; however, the type
1392  * is declared as writeable to maintain compatibility with previous versions
1393  * of libpng and to allow the 'display_row' array from read_rows to be passed
1394  * unchanged to write_rows.
1395  */
1396 PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row,
1397  png_uint_32 num_rows));
1398 
1399 /* Write the image data */
1400 PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image));
1401 
1402 /* Write the end of the PNG file. */
1403 PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr,
1404  png_inforp info_ptr));
1405 
1406 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1407 /* Read the end of the PNG file. */
1408 PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr));
1409 #endif
1410 
1411 /* Free any memory associated with the png_info_struct */
1412 PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr,
1413  png_infopp info_ptr_ptr));
1414 
1415 /* Free any memory associated with the png_struct and the png_info_structs */
1416 PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr,
1417  png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1418 
1419 /* Free any memory associated with the png_struct and the png_info_structs */
1420 PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr,
1421  png_infopp info_ptr_ptr));
1422 
1423 /* Set the libpng method of handling chunk CRC errors */
1424 PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action,
1425  int ancil_action));
1426 
1427 /* Values for png_set_crc_action() say how to handle CRC errors in
1428  * ancillary and critical chunks, and whether to use the data contained
1429  * therein. Note that it is impossible to "discard" data in a critical
1430  * chunk. For versions prior to 0.90, the action was always error/quit,
1431  * whereas in version 0.90 and later, the action for CRC errors in ancillary
1432  * chunks is warn/discard. These values should NOT be changed.
1433  *
1434  * value action:critical action:ancillary
1435  */
1436 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1437 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1438 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1439 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1440 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1441 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1442 
1443 #ifdef PNG_WRITE_SUPPORTED
1444 /* These functions give the user control over the scan-line filtering in
1445  * libpng and the compression methods used by zlib. These functions are
1446  * mainly useful for testing, as the defaults should work with most users.
1447  * Those users who are tight on memory or want faster performance at the
1448  * expense of compression can modify them. See the compression library
1449  * header file (zlib.h) for an explination of the compression functions.
1450  */
1451 
1452 /* Set the filtering method(s) used by libpng. Currently, the only valid
1453  * value for "method" is 0.
1454  */
1455 PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method,
1456  int filters));
1457 #endif /* WRITE */
1458 
1459 /* Flags for png_set_filter() to say which filters to use. The flags
1460  * are chosen so that they don't conflict with real filter types
1461  * below, in case they are supplied instead of the #defined constants.
1462  * These values should NOT be changed.
1463  */
1464 #define PNG_NO_FILTERS 0x00
1465 #define PNG_FILTER_NONE 0x08
1466 #define PNG_FILTER_SUB 0x10
1467 #define PNG_FILTER_UP 0x20
1468 #define PNG_FILTER_AVG 0x40
1469 #define PNG_FILTER_PAETH 0x80
1470 #define PNG_FAST_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP)
1471 #define PNG_ALL_FILTERS (PNG_FAST_FILTERS | PNG_FILTER_AVG | PNG_FILTER_PAETH)
1472 
1473 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1474  * These defines should NOT be changed.
1475  */
1476 #define PNG_FILTER_VALUE_NONE 0
1477 #define PNG_FILTER_VALUE_SUB 1
1478 #define PNG_FILTER_VALUE_UP 2
1479 #define PNG_FILTER_VALUE_AVG 3
1480 #define PNG_FILTER_VALUE_PAETH 4
1481 #define PNG_FILTER_VALUE_LAST 5
1482 
1483 #ifdef PNG_WRITE_SUPPORTED
1484 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */
1485 PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr,
1486  int heuristic_method, int num_weights, png_const_doublep filter_weights,
1487  png_const_doublep filter_costs))
1489  (png_structrp png_ptr, int heuristic_method, int num_weights,
1490  png_const_fixed_point_p filter_weights,
1491  png_const_fixed_point_p filter_costs))
1492 #endif /* WRITE_WEIGHTED_FILTER */
1493 
1494 /* The following are no longer used and will be removed from libpng-1.7: */
1495 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
1496 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
1497 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
1498 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
1499 
1500 /* Set the library compression level. Currently, valid values range from
1501  * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1502  * (0 - no compression, 9 - "maximal" compression). Note that tests have
1503  * shown that zlib compression levels 3-6 usually perform as well as level 9
1504  * for PNG images, and do considerably fewer caclulations. In the future,
1505  * these values may not correspond directly to the zlib compression levels.
1506  */
1507 #ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
1508 PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr,
1509  int level));
1510 
1511 PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr,
1512  int mem_level));
1513 
1514 PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr,
1515  int strategy));
1516 
1517 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1518  * smaller value of window_bits if it can do so safely.
1519  */
1520 PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr,
1521  int window_bits));
1522 
1523 PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr,
1524  int method));
1525 #endif /* WRITE_CUSTOMIZE_COMPRESSION */
1526 
1527 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
1528 /* Also set zlib parameters for compressing non-IDAT chunks */
1529 PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr,
1530  int level));
1531 
1532 PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr,
1533  int mem_level));
1534 
1535 PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr,
1536  int strategy));
1537 
1538 /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1539  * smaller value of window_bits if it can do so safely.
1540  */
1541 PNG_EXPORT(225, void, png_set_text_compression_window_bits,
1542  (png_structrp png_ptr, int window_bits));
1543 
1544 PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr,
1545  int method));
1546 #endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
1547 #endif /* WRITE */
1548 
1549 /* These next functions are called for input/output, memory, and error
1550  * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
1551  * and call standard C I/O routines such as fread(), fwrite(), and
1552  * fprintf(). These functions can be made to use other I/O routines
1553  * at run time for those applications that need to handle I/O in a
1554  * different manner by calling png_set_???_fn(). See libpng-manual.txt for
1555  * more information.
1556  */
1557 
1558 #ifdef PNG_STDIO_SUPPORTED
1559 /* Initialize the input/output for the PNG file to the default functions. */
1560 PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp));
1561 #endif
1562 
1563 /* Replace the (error and abort), and warning functions with user
1564  * supplied functions. If no messages are to be printed you must still
1565  * write and use replacement functions. The replacement error_fn should
1566  * still do a longjmp to the last setjmp location if you are using this
1567  * method of error handling. If error_fn or warning_fn is NULL, the
1568  * default function will be used.
1569  */
1570 
1571 PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr,
1572  png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
1573 
1574 /* Return the user pointer associated with the error functions */
1575 PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr));
1576 
1577 /* Replace the default data output functions with a user supplied one(s).
1578  * If buffered output is not used, then output_flush_fn can be set to NULL.
1579  * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
1580  * output_flush_fn will be ignored (and thus can be NULL).
1581  * It is probably a mistake to use NULL for output_flush_fn if
1582  * write_data_fn is not also NULL unless you have built libpng with
1583  * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
1584  * default flush function, which uses the standard *FILE structure, will
1585  * be used.
1586  */
1587 PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr,
1588  png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
1589 
1590 /* Replace the default data input function with a user supplied one. */
1591 PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr,
1592  png_rw_ptr read_data_fn));
1593 
1594 /* Return the user pointer associated with the I/O functions */
1595 PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr));
1596 
1597 PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr,
1598  png_read_status_ptr read_row_fn));
1599 
1600 PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr,
1601  png_write_status_ptr write_row_fn));
1602 
1603 #ifdef PNG_USER_MEM_SUPPORTED
1604 /* Replace the default memory allocation functions with user supplied one(s). */
1605 PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr,
1606  png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1607 /* Return the user pointer associated with the memory functions */
1608 PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr));
1609 #endif
1610 
1611 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
1612 PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr,
1613  png_user_transform_ptr read_user_transform_fn));
1614 #endif
1615 
1616 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1617 PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr,
1618  png_user_transform_ptr write_user_transform_fn));
1619 #endif
1620 
1621 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
1622 PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr,
1623  png_voidp user_transform_ptr, int user_transform_depth,
1624  int user_transform_channels));
1625 /* Return the user pointer associated with the user transform functions */
1626 PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr,
1627  (png_const_structrp png_ptr));
1628 #endif
1629 
1630 #ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
1631 /* Return information about the row currently being processed. Note that these
1632  * APIs do not fail but will return unexpected results if called outside a user
1633  * transform callback. Also note that when transforming an interlaced image the
1634  * row number is the row number within the sub-image of the interlace pass, so
1635  * the value will increase to the height of the sub-image (not the full image)
1636  * then reset to 0 for the next pass.
1637  *
1638  * Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
1639  * find the output pixel (x,y) given an interlaced sub-image pixel
1640  * (row,col,pass). (See below for these macros.)
1641  */
1642 PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp));
1643 PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp));
1644 #endif
1645 
1646 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED
1647 /* This callback is called only for *unknown* chunks. If
1648  * PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known
1649  * chunks to be treated as unknown, however in this case the callback must do
1650  * any processing required by the chunk (e.g. by calling the appropriate
1651  * png_set_ APIs.)
1652  *
1653  * There is no write support - on write, by default, all the chunks in the
1654  * 'unknown' list are written in the specified position.
1655  *
1656  * The integer return from the callback function is interpreted thus:
1657  *
1658  * negative: An error occurred; png_chunk_error will be called.
1659  * zero: The chunk was not handled, the chunk will be saved. A critical
1660  * chunk will cause an error at this point unless it is to be saved.
1661  * positive: The chunk was handled, libpng will ignore/discard it.
1662  *
1663  * See "INTERACTION WITH USER CHUNK CALLBACKS" below for important notes about
1664  * how this behavior will change in libpng 1.7
1665  */
1666 PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr,
1667  png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
1668 #endif
1669 
1670 #ifdef PNG_USER_CHUNKS_SUPPORTED
1671 PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr));
1672 #endif
1673 
1674 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1675 /* Sets the function callbacks for the push reader, and a pointer to a
1676  * user-defined structure available to the callback functions.
1677  */
1678 PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr,
1679  png_voidp progressive_ptr, png_progressive_info_ptr info_fn,
1680  png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn));
1681 
1682 /* Returns the user pointer associated with the push read functions */
1683 PNG_EXPORT(91, png_voidp, png_get_progressive_ptr,
1684  (png_const_structrp png_ptr));
1685 
1686 /* Function to be called when data becomes available */
1687 PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr,
1688  png_inforp info_ptr, png_bytep buffer, size_t buffer_size));
1689 
1690 /* A function which may be called *only* within png_process_data to stop the
1691  * processing of any more data. The function returns the number of bytes
1692  * remaining, excluding any that libpng has cached internally. A subsequent
1693  * call to png_process_data must supply these bytes again. If the argument
1694  * 'save' is set to true the routine will first save all the pending data and
1695  * will always return 0.
1696  */
1697 PNG_EXPORT(219, size_t, png_process_data_pause, (png_structrp, int save));
1698 
1699 /* A function which may be called *only* outside (after) a call to
1700  * png_process_data. It returns the number of bytes of data to skip in the
1701  * input. Normally it will return 0, but if it returns a non-zero value the
1702  * application must skip than number of bytes of input data and pass the
1703  * following data to the next call to png_process_data.
1704  */
1705 PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp));
1706 
1707 /* Function that combines rows. 'new_row' is a flag that should come from
1708  * the callback and be non-NULL if anything needs to be done; the library
1709  * stores its own version of the new data internally and ignores the passed
1710  * in value.
1711  */
1712 PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr,
1713  png_bytep old_row, png_const_bytep new_row));
1714 #endif /* PROGRESSIVE_READ */
1715 
1716 PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr,
1718 /* Added at libpng version 1.4.0 */
1719 PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr,
1721 
1722 /* Added at libpng version 1.2.4 */
1723 PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr,
1725 
1726 /* Frees a pointer allocated by png_malloc() */
1727 PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr));
1728 
1729 /* Free data that was allocated internally */
1730 PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr,
1731  png_inforp info_ptr, png_uint_32 free_me, int num));
1732 
1733 /* Reassign responsibility for freeing existing data, whether allocated
1734  * by libpng or by the application; this works on the png_info structure passed
1735  * in, it does not change the state for other png_info structures.
1736  *
1737  * It is unlikely that this function works correctly as of 1.6.0 and using it
1738  * may result either in memory leaks or double free of allocated data.
1739  */
1740 PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr,
1741  png_inforp info_ptr, int freer, png_uint_32 mask));
1742 
1743 /* Assignments for png_data_freer */
1744 #define PNG_DESTROY_WILL_FREE_DATA 1
1745 #define PNG_SET_WILL_FREE_DATA 1
1746 #define PNG_USER_WILL_FREE_DATA 2
1747 /* Flags for png_ptr->free_me and info_ptr->free_me */
1748 #define PNG_FREE_HIST 0x0008U
1749 #define PNG_FREE_ICCP 0x0010U
1750 #define PNG_FREE_SPLT 0x0020U
1751 #define PNG_FREE_ROWS 0x0040U
1752 #define PNG_FREE_PCAL 0x0080U
1753 #define PNG_FREE_SCAL 0x0100U
1754 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
1755 # define PNG_FREE_UNKN 0x0200U
1756 #endif
1757 /* PNG_FREE_LIST 0x0400U removed in 1.6.0 because it is ignored */
1758 #define PNG_FREE_PLTE 0x1000U
1759 #define PNG_FREE_TRNS 0x2000U
1760 #define PNG_FREE_TEXT 0x4000U
1761 #define PNG_FREE_EXIF 0x8000U /* Added at libpng-1.6.31 */
1762 #define PNG_FREE_ALL 0xffffU
1763 #define PNG_FREE_MUL 0x4220U /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
1764 
1765 #ifdef PNG_USER_MEM_SUPPORTED
1766 PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr,
1768 PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr,
1770 #endif
1771 
1772 #ifdef PNG_ERROR_TEXT_SUPPORTED
1773 /* Fatal error in PNG image of libpng - can't continue */
1774 PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr,
1775  png_const_charp error_message), PNG_NORETURN);
1776 
1777 /* The same, but the chunk name is prepended to the error string. */
1778 PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr,
1779  png_const_charp error_message), PNG_NORETURN);
1780 
1781 #else
1782 /* Fatal error in PNG image of libpng - can't continue */
1783 PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN);
1784 # define png_error(s1,s2) png_err(s1)
1785 # define png_chunk_error(s1,s2) png_err(s1)
1786 #endif
1787 
1788 #ifdef PNG_WARNINGS_SUPPORTED
1789 /* Non-fatal error in libpng. Can continue, but may have a problem. */
1790 PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr,
1791  png_const_charp warning_message));
1792 
1793 /* Non-fatal error in libpng, chunk name is prepended to message. */
1794 PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr,
1795  png_const_charp warning_message));
1796 #else
1797 # define png_warning(s1,s2) ((void)(s1))
1798 # define png_chunk_warning(s1,s2) ((void)(s1))
1799 #endif
1800 
1801 #ifdef PNG_BENIGN_ERRORS_SUPPORTED
1802 /* Benign error in libpng. Can continue, but may have a problem.
1803  * User can choose whether to handle as a fatal error or as a warning. */
1804 PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr,
1805  png_const_charp warning_message));
1806 
1807 #ifdef PNG_READ_SUPPORTED
1808 /* Same, chunk name is prepended to message (only during read) */
1809 PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr,
1810  png_const_charp warning_message));
1811 #endif
1812 
1813 PNG_EXPORT(109, void, png_set_benign_errors,
1814  (png_structrp png_ptr, int allowed));
1815 #else
1816 # ifdef PNG_ALLOW_BENIGN_ERRORS
1817 # define png_benign_error png_warning
1818 # define png_chunk_benign_error png_chunk_warning
1819 # else
1820 # define png_benign_error png_error
1821 # define png_chunk_benign_error png_chunk_error
1822 # endif
1823 #endif
1824 
1825 /* The png_set_<chunk> functions are for storing values in the png_info_struct.
1826  * Similarly, the png_get_<chunk> calls are used to read values from the
1827  * png_info_struct, either storing the parameters in the passed variables, or
1828  * setting pointers into the png_info_struct where the data is stored. The
1829  * png_get_<chunk> functions return a non-zero value if the data was available
1830  * in info_ptr, or return zero and do not change any of the parameters if the
1831  * data was not available.
1832  *
1833  * These functions should be used instead of directly accessing png_info
1834  * to avoid problems with future changes in the size and internal layout of
1835  * png_info_struct.
1836  */
1837 /* Returns "flag" if chunk data is valid in info_ptr. */
1838 PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr,
1839  png_const_inforp info_ptr, png_uint_32 flag));
1840 
1841 /* Returns number of bytes needed to hold a transformed row. */
1842 PNG_EXPORT(111, size_t, png_get_rowbytes, (png_const_structrp png_ptr,
1843  png_const_inforp info_ptr));
1844 
1845 #ifdef PNG_INFO_IMAGE_SUPPORTED
1846 /* Returns row_pointers, which is an array of pointers to scanlines that was
1847  * returned from png_read_png().
1848  */
1849 PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr,
1850  png_const_inforp info_ptr));
1851 
1852 /* Set row_pointers, which is an array of pointers to scanlines for use
1853  * by png_write_png().
1854  */
1855 PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr,
1856  png_inforp info_ptr, png_bytepp row_pointers));
1857 #endif
1858 
1859 /* Returns number of color channels in image. */
1860 PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr,
1861  png_const_inforp info_ptr));
1862 
1863 #ifdef PNG_EASY_ACCESS_SUPPORTED
1864 /* Returns image width in pixels. */
1865 PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr,
1866  png_const_inforp info_ptr));
1867 
1868 /* Returns image height in pixels. */
1869 PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr,
1870  png_const_inforp info_ptr));
1871 
1872 /* Returns image bit_depth. */
1873 PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr,
1874  png_const_inforp info_ptr));
1875 
1876 /* Returns image color_type. */
1877 PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr,
1878  png_const_inforp info_ptr));
1879 
1880 /* Returns image filter_type. */
1881 PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr,
1882  png_const_inforp info_ptr));
1883 
1884 /* Returns image interlace_type. */
1885 PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr,
1886  png_const_inforp info_ptr));
1887 
1888 /* Returns image compression_type. */
1889 PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr,
1890  png_const_inforp info_ptr));
1891 
1892 /* Returns image resolution in pixels per meter, from pHYs chunk data. */
1893 PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter,
1894  (png_const_structrp png_ptr, png_const_inforp info_ptr));
1895 PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter,
1896  (png_const_structrp png_ptr, png_const_inforp info_ptr));
1897 PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter,
1898  (png_const_structrp png_ptr, png_const_inforp info_ptr));
1899 
1900 /* Returns pixel aspect ratio, computed from pHYs chunk data. */
1901 PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio,
1902  (png_const_structrp png_ptr, png_const_inforp info_ptr))
1904  (png_const_structrp png_ptr, png_const_inforp info_ptr))
1905 
1906 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
1907 PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels,
1908  (png_const_structrp png_ptr, png_const_inforp info_ptr));
1909 PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels,
1910  (png_const_structrp png_ptr, png_const_inforp info_ptr));
1911 PNG_EXPORT(128, png_int_32, png_get_x_offset_microns,
1912  (png_const_structrp png_ptr, png_const_inforp info_ptr));
1913 PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,
1914  (png_const_structrp png_ptr, png_const_inforp info_ptr));
1915 
1916 #endif /* EASY_ACCESS */
1917 
1918 #ifdef PNG_READ_SUPPORTED
1919 /* Returns pointer to signature string read from PNG header */
1920 PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr,
1921  png_const_inforp info_ptr));
1922 #endif
1923 
1924 #ifdef PNG_bKGD_SUPPORTED
1925 PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr,
1926  png_inforp info_ptr, png_color_16p *background));
1927 #endif
1928 
1929 #ifdef PNG_bKGD_SUPPORTED
1930 PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr,
1931  png_inforp info_ptr, png_const_color_16p background));
1932 #endif
1933 
1934 #ifdef PNG_cHRM_SUPPORTED
1935 PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr,
1936  png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x,
1937  double *red_y, double *green_x, double *green_y, double *blue_x,
1938  double *blue_y))
1939 PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr,
1940  png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z,
1941  double *green_X, double *green_Y, double *green_Z, double *blue_X,
1942  double *blue_Y, double *blue_Z))
1943 PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed,
1944  (png_const_structrp png_ptr, png_const_inforp info_ptr,
1945  png_fixed_point *int_white_x, png_fixed_point *int_white_y,
1946  png_fixed_point *int_red_x, png_fixed_point *int_red_y,
1947  png_fixed_point *int_green_x, png_fixed_point *int_green_y,
1948  png_fixed_point *int_blue_x, png_fixed_point *int_blue_y))
1949 PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed,
1950  (png_const_structrp png_ptr, png_const_inforp info_ptr,
1955  png_fixed_point *int_blue_Z))
1956 #endif
1957 
1958 #ifdef PNG_cHRM_SUPPORTED
1959 PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr,
1960  png_inforp info_ptr,
1961  double white_x, double white_y, double red_x, double red_y, double green_x,
1962  double green_y, double blue_x, double blue_y))
1963 PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr,
1964  png_inforp info_ptr, double red_X, double red_Y, double red_Z,
1965  double green_X, double green_Y, double green_Z, double blue_X,
1966  double blue_Y, double blue_Z))
1967 PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr,
1968  png_inforp info_ptr, png_fixed_point int_white_x,
1969  png_fixed_point int_white_y, png_fixed_point int_red_x,
1970  png_fixed_point int_red_y, png_fixed_point int_green_x,
1971  png_fixed_point int_green_y, png_fixed_point int_blue_x,
1972  png_fixed_point int_blue_y))
1973 PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr,
1974  png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y,
1975  png_fixed_point int_red_Z, png_fixed_point int_green_X,
1976  png_fixed_point int_green_Y, png_fixed_point int_green_Z,
1977  png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
1978  png_fixed_point int_blue_Z))
1979 #endif
1980 
1981 #ifdef PNG_eXIf_SUPPORTED
1982 PNG_EXPORT(246, png_uint_32, png_get_eXIf, (png_const_structrp png_ptr,
1983  png_inforp info_ptr, png_bytep *exif));
1984 PNG_EXPORT(247, void, png_set_eXIf, (png_const_structrp png_ptr,
1985  png_inforp info_ptr, png_bytep exif));
1986 
1987 PNG_EXPORT(248, png_uint_32, png_get_eXIf_1, (png_const_structrp png_ptr,
1988  png_const_inforp info_ptr, png_uint_32 *num_exif, png_bytep *exif));
1989 PNG_EXPORT(249, void, png_set_eXIf_1, (png_const_structrp png_ptr,
1990  png_inforp info_ptr, png_uint_32 num_exif, png_bytep exif));
1991 #endif
1992 
1993 #ifdef PNG_gAMA_SUPPORTED
1994 PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr,
1995  png_const_inforp info_ptr, double *file_gamma))
1996 PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed,
1997  (png_const_structrp png_ptr, png_const_inforp info_ptr,
1998  png_fixed_point *int_file_gamma))
1999 #endif
2000 
2001 #ifdef PNG_gAMA_SUPPORTED
2002 PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr,
2003  png_inforp info_ptr, double file_gamma))
2004 PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr,
2005  png_inforp info_ptr, png_fixed_point int_file_gamma))
2006 #endif
2007 
2008 #ifdef PNG_hIST_SUPPORTED
2009 PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr,
2010  png_inforp info_ptr, png_uint_16p *hist));
2011 PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr,
2012  png_inforp info_ptr, png_const_uint_16p hist));
2013 #endif
2014 
2015 PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr,
2016  png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height,
2017  int *bit_depth, int *color_type, int *interlace_method,
2018  int *compression_method, int *filter_method));
2019 
2020 PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr,
2021  png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
2022  int color_type, int interlace_method, int compression_method,
2023  int filter_method));
2024 
2025 #ifdef PNG_oFFs_SUPPORTED
2026 PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr,
2027  png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
2028  int *unit_type));
2029 #endif
2030 
2031 #ifdef PNG_oFFs_SUPPORTED
2032 PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr,
2033  png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2034  int unit_type));
2035 #endif
2036 
2037 #ifdef PNG_pCAL_SUPPORTED
2038 PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr,
2039  png_inforp info_ptr, png_charp *purpose, png_int_32 *X0,
2040  png_int_32 *X1, int *type, int *nparams, png_charp *units,
2041  png_charpp *params));
2042 #endif
2043 
2044 #ifdef PNG_pCAL_SUPPORTED
2045 PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr,
2046  png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1,
2047  int type, int nparams, png_const_charp units, png_charpp params));
2048 #endif
2049 
2050 #ifdef PNG_pHYs_SUPPORTED
2051 PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr,
2052  png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
2053  int *unit_type));
2054 #endif
2055 
2056 #ifdef PNG_pHYs_SUPPORTED
2057 PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr,
2058  png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2059 #endif
2060 
2061 PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr,
2062  png_inforp info_ptr, png_colorp *palette, int *num_palette));
2063 
2064 PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr,
2065  png_inforp info_ptr, png_const_colorp palette, int num_palette));
2066 
2067 #ifdef PNG_sBIT_SUPPORTED
2068 PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr,
2069  png_inforp info_ptr, png_color_8p *sig_bit));
2070 #endif
2071 
2072 #ifdef PNG_sBIT_SUPPORTED
2073 PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr,
2074  png_inforp info_ptr, png_const_color_8p sig_bit));
2075 #endif
2076 
2077 #ifdef PNG_sRGB_SUPPORTED
2078 PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr,
2079  png_const_inforp info_ptr, int *file_srgb_intent));
2080 #endif
2081 
2082 #ifdef PNG_sRGB_SUPPORTED
2083 PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr,
2084  png_inforp info_ptr, int srgb_intent));
2085 PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr,
2086  png_inforp info_ptr, int srgb_intent));
2087 #endif
2088 
2089 #ifdef PNG_iCCP_SUPPORTED
2090 PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr,
2091  png_inforp info_ptr, png_charpp name, int *compression_type,
2092  png_bytepp profile, png_uint_32 *proflen));
2093 #endif
2094 
2095 #ifdef PNG_iCCP_SUPPORTED
2096 PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr,
2097  png_inforp info_ptr, png_const_charp name, int compression_type,
2098  png_const_bytep profile, png_uint_32 proflen));
2099 #endif
2100 
2101 #ifdef PNG_sPLT_SUPPORTED
2102 PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr,
2103  png_inforp info_ptr, png_sPLT_tpp entries));
2104 #endif
2105 
2106 #ifdef PNG_sPLT_SUPPORTED
2107 PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr,
2108  png_inforp info_ptr, png_const_sPLT_tp entries, int nentries));
2109 #endif
2110 
2111 #ifdef PNG_TEXT_SUPPORTED
2112 /* png_get_text also returns the number of text chunks in *num_text */
2113 PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr,
2114  png_inforp info_ptr, png_textp *text_ptr, int *num_text));
2115 #endif
2116 
2117 /* Note while png_set_text() will accept a structure whose text,
2118  * language, and translated keywords are NULL pointers, the structure
2119  * returned by png_get_text will always contain regular
2120  * zero-terminated C strings. They might be empty strings but
2121  * they will never be NULL pointers.
2122  */
2123 
2124 #ifdef PNG_TEXT_SUPPORTED
2125 PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr,
2126  png_inforp info_ptr, png_const_textp text_ptr, int num_text));
2127 #endif
2128 
2129 #ifdef PNG_tIME_SUPPORTED
2130 PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr,
2131  png_inforp info_ptr, png_timep *mod_time));
2132 #endif
2133 
2134 #ifdef PNG_tIME_SUPPORTED
2135 PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr,
2136  png_inforp info_ptr, png_const_timep mod_time));
2137 #endif
2138 
2139 #ifdef PNG_tRNS_SUPPORTED
2140 PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr,
2141  png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans,
2142  png_color_16p *trans_color));
2143 #endif
2144 
2145 #ifdef PNG_tRNS_SUPPORTED
2146 PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr,
2147  png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans,
2148  png_const_color_16p trans_color));
2149 #endif
2150 
2151 #ifdef PNG_sCAL_SUPPORTED
2152 PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr,
2153  png_const_inforp info_ptr, int *unit, double *width, double *height))
2154 #if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \
2155  defined(PNG_FLOATING_POINT_SUPPORTED)
2156 /* NOTE: this API is currently implemented using floating point arithmetic,
2157  * consequently it can only be used on systems with floating point support.
2158  * In any case the range of values supported by png_fixed_point is small and it
2159  * is highly recommended that png_get_sCAL_s be used instead.
2160  */
2162  (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
2163  png_fixed_point *width, png_fixed_point *height))
2164 #endif
2165 PNG_EXPORT(169, png_uint_32, png_get_sCAL_s,
2166  (png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
2167  png_charpp swidth, png_charpp sheight));
2168 
2169 PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr,
2170  png_inforp info_ptr, int unit, double width, double height))
2171 PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr,
2172  png_inforp info_ptr, int unit, png_fixed_point width,
2173  png_fixed_point height))
2174 PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr,
2175  png_inforp info_ptr, int unit,
2176  png_const_charp swidth, png_const_charp sheight));
2177 #endif /* sCAL */
2178 
2179 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
2180 /* Provide the default handling for all unknown chunks or, optionally, for
2181  * specific unknown chunks.
2182  *
2183  * NOTE: prior to 1.6.0 the handling specified for particular chunks on read was
2184  * ignored and the default was used, the per-chunk setting only had an effect on
2185  * write. If you wish to have chunk-specific handling on read in code that must
2186  * work on earlier versions you must use a user chunk callback to specify the
2187  * desired handling (keep or discard.)
2188  *
2189  * The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The
2190  * parameter is interpreted as follows:
2191  *
2192  * READ:
2193  * PNG_HANDLE_CHUNK_AS_DEFAULT:
2194  * Known chunks: do normal libpng processing, do not keep the chunk (but
2195  * see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
2196  * Unknown chunks: for a specific chunk use the global default, when used
2197  * as the default discard the chunk data.
2198  * PNG_HANDLE_CHUNK_NEVER:
2199  * Discard the chunk data.
2200  * PNG_HANDLE_CHUNK_IF_SAFE:
2201  * Keep the chunk data if the chunk is not critical else raise a chunk
2202  * error.
2203  * PNG_HANDLE_CHUNK_ALWAYS:
2204  * Keep the chunk data.
2205  *
2206  * If the chunk data is saved it can be retrieved using png_get_unknown_chunks,
2207  * below. Notice that specifying "AS_DEFAULT" as a global default is equivalent
2208  * to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks
2209  * it simply resets the behavior to the libpng default.
2210  *
2211  * INTERACTION WITH USER CHUNK CALLBACKS:
2212  * The per-chunk handling is always used when there is a png_user_chunk_ptr
2213  * callback and the callback returns 0; the chunk is then always stored *unless*
2214  * it is critical and the per-chunk setting is other than ALWAYS. Notice that
2215  * the global default is *not* used in this case. (In effect the per-chunk
2216  * value is incremented to at least IF_SAFE.)
2217  *
2218  * IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and
2219  * per-chunk defaults will be honored. If you want to preserve the current
2220  * behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE
2221  * as the default - if you don't do this libpng 1.6 will issue a warning.
2222  *
2223  * If you want unhandled unknown chunks to be discarded in libpng 1.6 and
2224  * earlier simply return '1' (handled).
2225  *
2226  * PNG_HANDLE_AS_UNKNOWN_SUPPORTED:
2227  * If this is *not* set known chunks will always be handled by libpng and
2228  * will never be stored in the unknown chunk list. Known chunks listed to
2229  * png_set_keep_unknown_chunks will have no effect. If it is set then known
2230  * chunks listed with a keep other than AS_DEFAULT will *never* be processed
2231  * by libpng, in addition critical chunks must either be processed by the
2232  * callback or saved.
2233  *
2234  * The IHDR and IEND chunks must not be listed. Because this turns off the
2235  * default handling for chunks that would otherwise be recognized the
2236  * behavior of libpng transformations may well become incorrect!
2237  *
2238  * WRITE:
2239  * When writing chunks the options only apply to the chunks specified by
2240  * png_set_unknown_chunks (below), libpng will *always* write known chunks
2241  * required by png_set_ calls and will always write the core critical chunks
2242  * (as required for PLTE).
2243  *
2244  * Each chunk in the png_set_unknown_chunks list is looked up in the
2245  * png_set_keep_unknown_chunks list to find the keep setting, this is then
2246  * interpreted as follows:
2247  *
2248  * PNG_HANDLE_CHUNK_AS_DEFAULT:
2249  * Write safe-to-copy chunks and write other chunks if the global
2250  * default is set to _ALWAYS, otherwise don't write this chunk.
2251  * PNG_HANDLE_CHUNK_NEVER:
2252  * Do not write the chunk.
2253  * PNG_HANDLE_CHUNK_IF_SAFE:
2254  * Write the chunk if it is safe-to-copy, otherwise do not write it.
2255  * PNG_HANDLE_CHUNK_ALWAYS:
2256  * Write the chunk.
2257  *
2258  * Note that the default behavior is effectively the opposite of the read case -
2259  * in read unknown chunks are not stored by default, in write they are written
2260  * by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different
2261  * - on write the safe-to-copy bit is checked, on read the critical bit is
2262  * checked and on read if the chunk is critical an error will be raised.
2263  *
2264  * num_chunks:
2265  * ===========
2266  * If num_chunks is positive, then the "keep" parameter specifies the manner
2267  * for handling only those chunks appearing in the chunk_list array,
2268  * otherwise the chunk list array is ignored.
2269  *
2270  * If num_chunks is 0 the "keep" parameter specifies the default behavior for
2271  * unknown chunks, as described above.
2272  *
2273  * If num_chunks is negative, then the "keep" parameter specifies the manner
2274  * for handling all unknown chunks plus all chunks recognized by libpng
2275  * except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to
2276  * be processed by libpng.
2277  */
2278 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2279 PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr,
2280  int keep, png_const_bytep chunk_list, int num_chunks));
2281 #endif /* HANDLE_AS_UNKNOWN */
2282 
2283 /* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned;
2284  * the result is therefore true (non-zero) if special handling is required,
2285  * false for the default handling.
2286  */
2287 PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr,
2288  png_const_bytep chunk_name));
2289 #endif /* SET_UNKNOWN_CHUNKS */
2290 
2291 #ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
2292 PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr,
2293  png_inforp info_ptr, png_const_unknown_chunkp unknowns,
2294  int num_unknowns));
2295  /* NOTE: prior to 1.6.0 this routine set the 'location' field of the added
2296  * unknowns to the location currently stored in the png_struct. This is
2297  * invariably the wrong value on write. To fix this call the following API
2298  * for each chunk in the list with the correct location. If you know your
2299  * code won't be compiled on earlier versions you can rely on
2300  * png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing
2301  * the correct thing.
2302  */
2303 
2304 PNG_EXPORT(175, void, png_set_unknown_chunk_location,
2305  (png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location));
2306 
2307 PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr,
2308  png_inforp info_ptr, png_unknown_chunkpp entries));
2309 #endif
2310 
2311 /* Png_free_data() will turn off the "valid" flag for anything it frees.
2312  * If you need to turn it off for a chunk that your application has freed,
2313  * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
2314  */
2315 PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr,
2316  png_inforp info_ptr, int mask));
2317 
2318 #ifdef PNG_INFO_IMAGE_SUPPORTED
2319 /* The "params" pointer is currently not used and is for future expansion. */
2320 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
2321 PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr,
2322  int transforms, png_voidp params));
2323 #endif
2324 #ifdef PNG_WRITE_SUPPORTED
2325 PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr,
2326  int transforms, png_voidp params));
2327 #endif
2328 #endif
2329 
2330 PNG_EXPORT(180, png_const_charp, png_get_copyright,
2331  (png_const_structrp png_ptr));
2332 PNG_EXPORT(181, png_const_charp, png_get_header_ver,
2333  (png_const_structrp png_ptr));
2334 PNG_EXPORT(182, png_const_charp, png_get_header_version,
2335  (png_const_structrp png_ptr));
2336 PNG_EXPORT(183, png_const_charp, png_get_libpng_ver,
2337  (png_const_structrp png_ptr));
2338 
2339 #ifdef PNG_MNG_FEATURES_SUPPORTED
2340 PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr,
2341  png_uint_32 mng_features_permitted));
2342 #endif
2343 
2344 /* For use in png_set_keep_unknown, added to version 1.2.6 */
2345 #define PNG_HANDLE_CHUNK_AS_DEFAULT 0
2346 #define PNG_HANDLE_CHUNK_NEVER 1
2347 #define PNG_HANDLE_CHUNK_IF_SAFE 2
2348 #define PNG_HANDLE_CHUNK_ALWAYS 3
2349 #define PNG_HANDLE_CHUNK_LAST 4
2350 
2351 /* Strip the prepended error numbers ("#nnn ") from error and warning
2352  * messages before passing them to the error or warning handler.
2353  */
2354 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
2355 PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr,
2356  png_uint_32 strip_mode));
2357 #endif
2358 
2359 /* Added in libpng-1.2.6 */
2360 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
2361 PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr,
2362  png_uint_32 user_width_max, png_uint_32 user_height_max));
2363 PNG_EXPORT(187, png_uint_32, png_get_user_width_max,
2364  (png_const_structrp png_ptr));
2365 PNG_EXPORT(188, png_uint_32, png_get_user_height_max,
2366  (png_const_structrp png_ptr));
2367 /* Added in libpng-1.4.0 */
2368 PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr,
2369  png_uint_32 user_chunk_cache_max));
2370 PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max,
2371  (png_const_structrp png_ptr));
2372 /* Added in libpng-1.4.1 */
2373 PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr,
2374  png_alloc_size_t user_chunk_cache_max));
2375 PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max,
2376  (png_const_structrp png_ptr));
2377 #endif
2378 
2379 #if defined(PNG_INCH_CONVERSIONS_SUPPORTED)
2380 PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch,
2381  (png_const_structrp png_ptr, png_const_inforp info_ptr));
2382 
2383 PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch,
2384  (png_const_structrp png_ptr, png_const_inforp info_ptr));
2385 
2386 PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch,
2387  (png_const_structrp png_ptr, png_const_inforp info_ptr));
2388 
2389 PNG_FP_EXPORT(196, float, png_get_x_offset_inches,
2390  (png_const_structrp png_ptr, png_const_inforp info_ptr))
2391 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2393  (png_const_structrp png_ptr, png_const_inforp info_ptr))
2394 #endif
2395 
2396 PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr,
2397  png_const_inforp info_ptr))
2398 #ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2400  (png_const_structrp png_ptr, png_const_inforp info_ptr))
2401 #endif
2402 
2403 # ifdef PNG_pHYs_SUPPORTED
2404 PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr,
2405  png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
2406  int *unit_type));
2407 # endif /* pHYs */
2408 #endif /* INCH_CONVERSIONS */
2409 
2410 /* Added in libpng-1.4.0 */
2411 #ifdef PNG_IO_STATE_SUPPORTED
2412 PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr));
2413 
2414 /* Removed from libpng 1.6; use png_get_io_chunk_type. */
2415 PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr),
2417 
2418 PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
2419  (png_const_structrp png_ptr));
2420 
2421 /* The flags returned by png_get_io_state() are the following: */
2422 # define PNG_IO_NONE 0x0000 /* no I/O at this moment */
2423 # define PNG_IO_READING 0x0001 /* currently reading */
2424 # define PNG_IO_WRITING 0x0002 /* currently writing */
2425 # define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */
2426 # define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */
2427 # define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */
2428 # define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */
2429 # define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */
2430 # define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */
2431 #endif /* IO_STATE */
2432 
2433 /* Interlace support. The following macros are always defined so that if
2434  * libpng interlace handling is turned off the macros may be used to handle
2435  * interlaced images within the application.
2436  */
2437 #define PNG_INTERLACE_ADAM7_PASSES 7
2438 
2439 /* Two macros to return the first row and first column of the original,
2440  * full, image which appears in a given pass. 'pass' is in the range 0
2441  * to 6 and the result is in the range 0 to 7.
2442  */
2443 #define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7)
2444 #define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7)
2445 
2446 /* A macro to return the offset between pixels in the output row for a pair of
2447  * pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that
2448  * follows. Note that ROW_OFFSET is the offset from one row to the next whereas
2449  * COL_OFFSET is from one column to the next, within a row.
2450  */
2451 #define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8)
2452 #define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1))
2453 
2454 /* Two macros to help evaluate the number of rows or columns in each
2455  * pass. This is expressed as a shift - effectively log2 of the number or
2456  * rows or columns in each 8x8 tile of the original image.
2457  */
2458 #define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)
2459 #define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)
2460 
2461 /* Hence two macros to determine the number of rows or columns in a given
2462  * pass of an image given its height or width. In fact these macros may
2463  * return non-zero even though the sub-image is empty, because the other
2464  * dimension may be empty for a small image.
2465  */
2466 #define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\
2467  -1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass))
2468 #define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\
2469  -1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass))
2470 
2471 /* For the reader row callbacks (both progressive and sequential) it is
2472  * necessary to find the row in the output image given a row in an interlaced
2473  * image, so two more macros:
2474  */
2475 #define PNG_ROW_FROM_PASS_ROW(y_in, pass) \
2476  (((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))
2477 #define PNG_COL_FROM_PASS_COL(x_in, pass) \
2478  (((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))
2479 
2480 /* Two macros which return a boolean (0 or 1) saying whether the given row
2481  * or column is in a particular pass. These use a common utility macro that
2482  * returns a mask for a given pass - the offset 'off' selects the row or
2483  * column version. The mask has the appropriate bit set for each column in
2484  * the tile.
2485  */
2486 #define PNG_PASS_MASK(pass,off) ( \
2487  ((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \
2488  ((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0))
2489 
2490 #define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
2491  ((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
2492 #define PNG_COL_IN_INTERLACE_PASS(x, pass) \
2493  ((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
2494 
2495 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2496 /* With these routines we avoid an integer divide, which will be slower on
2497  * most machines. However, it does take more operations than the corresponding
2498  * divide method, so it may be slower on a few RISC systems. There are two
2499  * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2500  *
2501  * Note that the rounding factors are NOT supposed to be the same! 128 and
2502  * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2503  * standard method.
2504  *
2505  * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2506  */
2507 
2508  /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2509 
2510 # define png_composite(composite, fg, alpha, bg) \
2511  { \
2512  png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
2513  * (png_uint_16)(alpha) \
2514  + (png_uint_16)(bg)*(png_uint_16)(255 \
2515  - (png_uint_16)(alpha)) + 128); \
2516  (composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); \
2517  }
2518 
2519 # define png_composite_16(composite, fg, alpha, bg) \
2520  { \
2521  png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
2522  * (png_uint_32)(alpha) \
2523  + (png_uint_32)(bg)*(65535 \
2524  - (png_uint_32)(alpha)) + 32768); \
2525  (composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); \
2526  }
2527 
2528 #else /* Standard method using integer division */
2529 
2530 # define png_composite(composite, fg, alpha, bg) \
2531  (composite) = \
2532  (png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2533  (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2534  127) / 255))
2535 
2536 # define png_composite_16(composite, fg, alpha, bg) \
2537  (composite) = \
2538  (png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2539  (png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \
2540  32767) / 65535))
2541 #endif /* READ_COMPOSITE_NODIV */
2542 
2543 #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
2544 PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf));
2545 PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf));
2546 PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf));
2547 #endif
2548 
2549 PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr,
2550  png_const_bytep buf));
2551 /* No png_get_int_16 -- may be added if there's a real need for it. */
2552 
2553 /* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
2554 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2555 PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i));
2556 #endif
2557 #ifdef PNG_SAVE_INT_32_SUPPORTED
2558 PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i));
2559 #endif
2560 
2561 /* Place a 16-bit number into a buffer in PNG byte order.
2562  * The parameter is declared unsigned int, not png_uint_16,
2563  * just to avoid potential problems on pre-ANSI C compilers.
2564  */
2565 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2566 PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));
2567 /* No png_save_int_16 -- may be added if there's a real need for it. */
2568 #endif
2569 
2570 #ifdef PNG_USE_READ_MACROS
2571 /* Inline macros to do direct reads of bytes from the input buffer.
2572  * The png_get_int_32() routine assumes we are using two's complement
2573  * format for negative values, which is almost certainly true.
2574  */
2575 # define PNG_get_uint_32(buf) \
2576  (((png_uint_32)(*(buf)) << 24) + \
2577  ((png_uint_32)(*((buf) + 1)) << 16) + \
2578  ((png_uint_32)(*((buf) + 2)) << 8) + \
2579  ((png_uint_32)(*((buf) + 3))))
2580 
2581  /* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
2582  * function) incorrectly returned a value of type png_uint_32.
2583  */
2584 # define PNG_get_uint_16(buf) \
2585  ((png_uint_16) \
2586  (((unsigned int)(*(buf)) << 8) + \
2587  ((unsigned int)(*((buf) + 1)))))
2588 
2589 # define PNG_get_int_32(buf) \
2590  ((png_int_32)((*(buf) & 0x80) \
2591  ? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \
2592  : (png_int_32)png_get_uint_32(buf)))
2593 
2594 /* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h,
2595  * but defining a macro name prefixed with PNG_PREFIX.
2596  */
2597 # ifndef PNG_PREFIX
2598 # define png_get_uint_32(buf) PNG_get_uint_32(buf)
2599 # define png_get_uint_16(buf) PNG_get_uint_16(buf)
2600 # define png_get_int_32(buf) PNG_get_int_32(buf)
2601 # endif
2602 #else
2603 # ifdef PNG_PREFIX
2604  /* No macros; revert to the (redefined) function */
2605 # define PNG_get_uint_32 (png_get_uint_32)
2606 # define PNG_get_uint_16 (png_get_uint_16)
2607 # define PNG_get_int_32 (png_get_int_32)
2608 # endif
2609 #endif
2610 
2611 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
2612 PNG_EXPORT(242, void, png_set_check_for_invalid_index,
2613  (png_structrp png_ptr, int allowed));
2614 # ifdef PNG_GET_PALETTE_MAX_SUPPORTED
2615 PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr,
2616  png_const_infop info_ptr));
2617 # endif
2618 #endif /* CHECK_FOR_INVALID_INDEX */
2619 
2620 /*******************************************************************************
2621  * Section 5: SIMPLIFIED API
2622  *******************************************************************************
2623  *
2624  * Please read the documentation in libpng-manual.txt (TODO: write said
2625  * documentation) if you don't understand what follows.
2626  *
2627  * The simplified API hides the details of both libpng and the PNG file format
2628  * itself. It allows PNG files to be read into a very limited number of
2629  * in-memory bitmap formats or to be written from the same formats. If these
2630  * formats do not accommodate your needs then you can, and should, use the more
2631  * sophisticated APIs above - these support a wide variety of in-memory formats
2632  * and a wide variety of sophisticated transformations to those formats as well
2633  * as a wide variety of APIs to manipulate ancillary information.
2634  *
2635  * To read a PNG file using the simplified API:
2636  *
2637  * 1) Declare a 'png_image' structure (see below) on the stack, set the
2638  * version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL
2639  * (this is REQUIRED, your program may crash if you don't do it.)
2640  * 2) Call the appropriate png_image_begin_read... function.
2641  * 3) Set the png_image 'format' member to the required sample format.
2642  * 4) Allocate a buffer for the image and, if required, the color-map.
2643  * 5) Call png_image_finish_read to read the image and, if required, the
2644  * color-map into your buffers.
2645  *
2646  * There are no restrictions on the format of the PNG input itself; all valid
2647  * color types, bit depths, and interlace methods are acceptable, and the
2648  * input image is transformed as necessary to the requested in-memory format
2649  * during the png_image_finish_read() step. The only caveat is that if you
2650  * request a color-mapped image from a PNG that is full-color or makes
2651  * complex use of an alpha channel the transformation is extremely lossy and the
2652  * result may look terrible.
2653  *
2654  * To write a PNG file using the simplified API:
2655  *
2656  * 1) Declare a 'png_image' structure on the stack and memset() it to all zero.
2657  * 2) Initialize the members of the structure that describe the image, setting
2658  * the 'format' member to the format of the image samples.
2659  * 3) Call the appropriate png_image_write... function with a pointer to the
2660  * image and, if necessary, the color-map to write the PNG data.
2661  *
2662  * png_image is a structure that describes the in-memory format of an image
2663  * when it is being read or defines the in-memory format of an image that you
2664  * need to write:
2665  */
2666 #if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \
2667  defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
2668 
2669 #define PNG_IMAGE_VERSION 1
2670 
2671 typedef struct png_control *png_controlp;
2672 typedef struct
2673 {
2674  png_controlp opaque; /* Initialize to NULL, free with png_image_free */
2675  png_uint_32 version; /* Set to PNG_IMAGE_VERSION */
2676  png_uint_32 width; /* Image width in pixels (columns) */
2677  png_uint_32 height; /* Image height in pixels (rows) */
2678  png_uint_32 format; /* Image format as defined below */
2679  png_uint_32 flags; /* A bit mask containing informational flags */
2680  png_uint_32 colormap_entries;
2681  /* Number of entries in the color-map */
2682 
2683  /* In the event of an error or warning the following field will be set to a
2684  * non-zero value and the 'message' field will contain a '\0' terminated
2685  * string with the libpng error or warning message. If both warnings and
2686  * an error were encountered, only the error is recorded. If there
2687  * are multiple warnings, only the first one is recorded.
2688  *
2689  * The upper 30 bits of this value are reserved, the low two bits contain
2690  * a value as follows:
2691  */
2692 # define PNG_IMAGE_WARNING 1
2693 # define PNG_IMAGE_ERROR 2
2694  /*
2695  * The result is a two-bit code such that a value more than 1 indicates
2696  * a failure in the API just called:
2697  *
2698  * 0 - no warning or error
2699  * 1 - warning
2700  * 2 - error
2701  * 3 - error preceded by warning
2702  */
2703 # define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1)
2704 
2705  png_uint_32 warning_or_error;
2706 
2707  char message[64];
2708 } png_image, *png_imagep;
2709 
2710 /* The samples of the image have one to four channels whose components have
2711  * original values in the range 0 to 1.0:
2712  *
2713  * 1: A single gray or luminance channel (G).
2714  * 2: A gray/luminance channel and an alpha channel (GA).
2715  * 3: Three red, green, blue color channels (RGB).
2716  * 4: Three color channels and an alpha channel (RGBA).
2717  *
2718  * The components are encoded in one of two ways:
2719  *
2720  * a) As a small integer, value 0..255, contained in a single byte. For the
2721  * alpha channel the original value is simply value/255. For the color or
2722  * luminance channels the value is encoded according to the sRGB specification
2723  * and matches the 8-bit format expected by typical display devices.
2724  *
2725  * The color/gray channels are not scaled (pre-multiplied) by the alpha
2726  * channel and are suitable for passing to color management software.
2727  *
2728  * b) As a value in the range 0..65535, contained in a 2-byte integer. All
2729  * channels can be converted to the original value by dividing by 65535; all
2730  * channels are linear. Color channels use the RGB encoding (RGB end-points) of
2731  * the sRGB specification. This encoding is identified by the
2732  * PNG_FORMAT_FLAG_LINEAR flag below.
2733  *
2734  * When the simplified API needs to convert between sRGB and linear colorspaces,
2735  * the actual sRGB transfer curve defined in the sRGB specification (see the
2736  * article at <https://en.wikipedia.org/wiki/SRGB>) is used, not the gamma=1/2.2
2737  * approximation used elsewhere in libpng.
2738  *
2739  * When an alpha channel is present it is expected to denote pixel coverage
2740  * of the color or luminance channels and is returned as an associated alpha
2741  * channel: the color/gray channels are scaled (pre-multiplied) by the alpha
2742  * value.
2743  *
2744  * The samples are either contained directly in the image data, between 1 and 8
2745  * bytes per pixel according to the encoding, or are held in a color-map indexed
2746  * by bytes in the image data. In the case of a color-map the color-map entries
2747  * are individual samples, encoded as above, and the image data has one byte per
2748  * pixel to select the relevant sample from the color-map.
2749  */
2750 
2751 /* PNG_FORMAT_*
2752  *
2753  * #defines to be used in png_image::format. Each #define identifies a
2754  * particular layout of sample data and, if present, alpha values. There are
2755  * separate defines for each of the two component encodings.
2756  *
2757  * A format is built up using single bit flag values. All combinations are
2758  * valid. Formats can be built up from the flag values or you can use one of
2759  * the predefined values below. When testing formats always use the FORMAT_FLAG
2760  * macros to test for individual features - future versions of the library may
2761  * add new flags.
2762  *
2763  * When reading or writing color-mapped images the format should be set to the
2764  * format of the entries in the color-map then png_image_{read,write}_colormap
2765  * called to read or write the color-map and set the format correctly for the
2766  * image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly!
2767  *
2768  * NOTE: libpng can be built with particular features disabled. If you see
2769  * compiler errors because the definition of one of the following flags has been
2770  * compiled out it is because libpng does not have the required support. It is
2771  * possible, however, for the libpng configuration to enable the format on just
2772  * read or just write; in that case you may see an error at run time. You can
2773  * guard against this by checking for the definition of the appropriate
2774  * "_SUPPORTED" macro, one of:
2775  *
2776  * PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED
2777  */
2778 #define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */
2779 #define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */
2780 #define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */
2781 #define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */
2782 
2783 #ifdef PNG_FORMAT_BGR_SUPPORTED
2784 # define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */
2785 #endif
2786 
2787 #ifdef PNG_FORMAT_AFIRST_SUPPORTED
2788 # define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */
2789 #endif
2790 
2791 #define PNG_FORMAT_FLAG_ASSOCIATED_ALPHA 0x40U /* alpha channel is associated */
2792 
2793 /* Commonly used formats have predefined macros.
2794  *
2795  * First the single byte (sRGB) formats:
2796  */
2797 #define PNG_FORMAT_GRAY 0
2798 #define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA
2799 #define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST)
2800 #define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR
2801 #define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR)
2802 #define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA)
2803 #define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST)
2804 #define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA)
2805 #define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST)
2806 
2807 /* Then the linear 2-byte formats. When naming these "Y" is used to
2808  * indicate a luminance (gray) channel.
2809  */
2810 #define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR
2811 #define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA)
2812 #define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR)
2813 #define PNG_FORMAT_LINEAR_RGB_ALPHA \
2814  (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA)
2815 
2816 /* With color-mapped formats the image data is one byte for each pixel, the byte
2817  * is an index into the color-map which is formatted as above. To obtain a
2818  * color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP
2819  * to one of the above definitions, or you can use one of the definitions below.
2820  */
2821 #define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP)
2822 #define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP)
2823 #define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP)
2824 #define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP)
2825 #define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP)
2826 #define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP)
2827 
2828 /* PNG_IMAGE macros
2829  *
2830  * These are convenience macros to derive information from a png_image
2831  * structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the
2832  * actual image sample values - either the entries in the color-map or the
2833  * pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values
2834  * for the pixels and will always return 1 for color-mapped formats. The
2835  * remaining macros return information about the rows in the image and the
2836  * complete image.
2837  *
2838  * NOTE: All the macros that take a png_image::format parameter are compile time
2839  * constants if the format parameter is, itself, a constant. Therefore these
2840  * macros can be used in array declarations and case labels where required.
2841  * Similarly the macros are also pre-processor constants (sizeof is not used) so
2842  * they can be used in #if tests.
2843  *
2844  * First the information about the samples.
2845  */
2846 #define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\
2847  (((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1)
2848  /* Return the total number of channels in a given format: 1..4 */
2849 
2850 #define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\
2851  ((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1)
2852  /* Return the size in bytes of a single component of a pixel or color-map
2853  * entry (as appropriate) in the image: 1 or 2.
2854  */
2855 
2856 #define PNG_IMAGE_SAMPLE_SIZE(fmt)\
2857  (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt))
2858  /* This is the size of the sample data for one sample. If the image is
2859  * color-mapped it is the size of one color-map entry (and image pixels are
2860  * one byte in size), otherwise it is the size of one image pixel.
2861  */
2862 
2863 #define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\
2864  (PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256)
2865  /* The maximum size of the color-map required by the format expressed in a
2866  * count of components. This can be used to compile-time allocate a
2867  * color-map:
2868  *
2869  * png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)];
2870  *
2871  * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)];
2872  *
2873  * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the
2874  * information from one of the png_image_begin_read_ APIs and dynamically
2875  * allocate the required memory.
2876  */
2877 
2878 /* Corresponding information about the pixels */
2879 #define PNG_IMAGE_PIXEL_(test,fmt)\
2880  (((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt))
2881 
2882 #define PNG_IMAGE_PIXEL_CHANNELS(fmt)\
2883  PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt)
2884  /* The number of separate channels (components) in a pixel; 1 for a
2885  * color-mapped image.
2886  */
2887 
2888 #define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\
2889  PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt)
2890  /* The size, in bytes, of each component in a pixel; 1 for a color-mapped
2891  * image.
2892  */
2893 
2894 #define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt)
2895  /* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */
2896 
2897 /* Information about the whole row, or whole image */
2898 #define PNG_IMAGE_ROW_STRIDE(image)\
2899  (PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width)
2900  /* Return the total number of components in a single row of the image; this
2901  * is the minimum 'row stride', the minimum count of components between each
2902  * row. For a color-mapped image this is the minimum number of bytes in a
2903  * row.
2904  *
2905  * WARNING: this macro overflows for some images with more than one component
2906  * and very large image widths. libpng will refuse to process an image where
2907  * this macro would overflow.
2908  */
2909 
2910 #define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\
2911  (PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride))
2912  /* Return the size, in bytes, of an image buffer given a png_image and a row
2913  * stride - the number of components to leave space for in each row.
2914  *
2915  * WARNING: this macro overflows a 32-bit integer for some large PNG images,
2916  * libpng will refuse to process an image where such an overflow would occur.
2917  */
2918 
2919 #define PNG_IMAGE_SIZE(image)\
2920  PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image))
2921  /* Return the size, in bytes, of the image in memory given just a png_image;
2922  * the row stride is the minimum stride required for the image.
2923  */
2924 
2925 #define PNG_IMAGE_COLORMAP_SIZE(image)\
2926  (PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries)
2927  /* Return the size, in bytes, of the color-map of this image. If the image
2928  * format is not a color-map format this will return a size sufficient for
2929  * 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if
2930  * you don't want to allocate a color-map in this case.
2931  */
2932 
2933 /* PNG_IMAGE_FLAG_*
2934  *
2935  * Flags containing additional information about the image are held in the
2936  * 'flags' field of png_image.
2937  */
2938 #define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01
2939  /* This indicates that the RGB values of the in-memory bitmap do not
2940  * correspond to the red, green and blue end-points defined by sRGB.
2941  */
2942 
2943 #define PNG_IMAGE_FLAG_FAST 0x02
2944  /* On write emphasise speed over compression; the resultant PNG file will be
2945  * larger but will be produced significantly faster, particular for large
2946  * images. Do not use this option for images which will be distributed, only
2947  * used it when producing intermediate files that will be read back in
2948  * repeatedly. For a typical 24-bit image the option will double the read
2949  * speed at the cost of increasing the image size by 25%, however for many
2950  * more compressible images the PNG file can be 10 times larger with only a
2951  * slight speed gain.
2952  */
2953 
2954 #define PNG_IMAGE_FLAG_16BIT_sRGB 0x04
2955  /* On read if the image is a 16-bit per component image and there is no gAMA
2956  * or sRGB chunk assume that the components are sRGB encoded. Notice that
2957  * images output by the simplified API always have gamma information; setting
2958  * this flag only affects the interpretation of 16-bit images from an
2959  * external source. It is recommended that the application expose this flag
2960  * to the user; the user can normally easily recognize the difference between
2961  * linear and sRGB encoding. This flag has no effect on write - the data
2962  * passed to the write APIs must have the correct encoding (as defined
2963  * above.)
2964  *
2965  * If the flag is not set (the default) input 16-bit per component data is
2966  * assumed to be linear.
2967  *
2968  * NOTE: the flag can only be set after the png_image_begin_read_ call,
2969  * because that call initializes the 'flags' field.
2970  */
2971 
2972 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED
2973 /* READ APIs
2974  * ---------
2975  *
2976  * The png_image passed to the read APIs must have been initialized by setting
2977  * the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.)
2978  */
2979 #ifdef PNG_STDIO_SUPPORTED
2980 PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image,
2981  const char *file_name));
2982  /* The named file is opened for read and the image header is filled in
2983  * from the PNG header in the file.
2984  */
2985 
2986 PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image,
2987  FILE* file));
2988  /* The PNG header is read from the stdio FILE object. */
2989 #endif /* STDIO */
2990 
2991 PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image,
2992  png_const_voidp memory, size_t size));
2993  /* The PNG header is read from the given memory buffer. */
2994 
2995 PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image,
2996  png_const_colorp background, void *buffer, png_int_32 row_stride,
2997  void *colormap));
2998  /* Finish reading the image into the supplied buffer and clean up the
2999  * png_image structure.
3000  *
3001  * row_stride is the step, in byte or 2-byte units as appropriate,
3002  * between adjacent rows. A positive stride indicates that the top-most row
3003  * is first in the buffer - the normal top-down arrangement. A negative
3004  * stride indicates that the bottom-most row is first in the buffer.
3005  *
3006  * background need only be supplied if an alpha channel must be removed from
3007  * a png_byte format and the removal is to be done by compositing on a solid
3008  * color; otherwise it may be NULL and any composition will be done directly
3009  * onto the buffer. The value is an sRGB color to use for the background,
3010  * for grayscale output the green channel is used.
3011  *
3012  * background must be supplied when an alpha channel must be removed from a
3013  * single byte color-mapped output format, in other words if:
3014  *
3015  * 1) The original format from png_image_begin_read_from_* had
3016  * PNG_FORMAT_FLAG_ALPHA set.
3017  * 2) The format set by the application does not.
3018  * 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and
3019  * PNG_FORMAT_FLAG_LINEAR *not* set.
3020  *
3021  * For linear output removing the alpha channel is always done by compositing
3022  * on black and background is ignored.
3023  *
3024  * colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must
3025  * be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE.
3026  * image->colormap_entries will be updated to the actual number of entries
3027  * written to the colormap; this may be less than the original value.
3028  */
3029 
3030 PNG_EXPORT(238, void, png_image_free, (png_imagep image));
3031  /* Free any data allocated by libpng in image->opaque, setting the pointer to
3032  * NULL. May be called at any time after the structure is initialized.
3033  */
3034 #endif /* SIMPLIFIED_READ */
3035 
3036 #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
3037 /* WRITE APIS
3038  * ----------
3039  * For write you must initialize a png_image structure to describe the image to
3040  * be written. To do this use memset to set the whole structure to 0 then
3041  * initialize fields describing your image.
3042  *
3043  * version: must be set to PNG_IMAGE_VERSION
3044  * opaque: must be initialized to NULL
3045  * width: image width in pixels
3046  * height: image height in rows
3047  * format: the format of the data (image and color-map) you wish to write
3048  * flags: set to 0 unless one of the defined flags applies; set
3049  * PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB
3050  * values do not correspond to the colors in sRGB.
3051  * colormap_entries: set to the number of entries in the color-map (0 to 256)
3052  */
3053 #ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
3054 PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image,
3055  const char *file, int convert_to_8bit, const void *buffer,
3056  png_int_32 row_stride, const void *colormap));
3057  /* Write the image to the named file. */
3058 
3059 PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file,
3060  int convert_to_8_bit, const void *buffer, png_int_32 row_stride,
3061  const void *colormap));
3062  /* Write the image to the given (FILE*). */
3063 #endif /* SIMPLIFIED_WRITE_STDIO */
3064 
3065 /* With all write APIs if image is in one of the linear formats with 16-bit
3066  * data then setting convert_to_8_bit will cause the output to be an 8-bit PNG
3067  * gamma encoded according to the sRGB specification, otherwise a 16-bit linear
3068  * encoded PNG file is written.
3069  *
3070  * With color-mapped data formats the colormap parameter point to a color-map
3071  * with at least image->colormap_entries encoded in the specified format. If
3072  * the format is linear the written PNG color-map will be converted to sRGB
3073  * regardless of the convert_to_8_bit flag.
3074  *
3075  * With all APIs row_stride is handled as in the read APIs - it is the spacing
3076  * from one row to the next in component sized units (1 or 2 bytes) and if
3077  * negative indicates a bottom-up row layout in the buffer. If row_stride is
3078  * zero, libpng will calculate it for you from the image width and number of
3079  * channels.
3080  *
3081  * Note that the write API does not support interlacing, sub-8-bit pixels or
3082  * most ancillary chunks. If you need to write text chunks (e.g. for copyright
3083  * notices) you need to use one of the other APIs.
3084  */
3085 
3086 PNG_EXPORT(245, int, png_image_write_to_memory, (png_imagep image, void *memory,
3087  png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8_bit,
3088  const void *buffer, png_int_32 row_stride, const void *colormap));
3089  /* Write the image to the given memory buffer. The function both writes the
3090  * whole PNG data stream to *memory and updates *memory_bytes with the count
3091  * of bytes written.
3092  *
3093  * 'memory' may be NULL. In this case *memory_bytes is not read however on
3094  * success the number of bytes which would have been written will still be
3095  * stored in *memory_bytes. On failure *memory_bytes will contain 0.
3096  *
3097  * If 'memory' is not NULL it must point to memory[*memory_bytes] of
3098  * writeable memory.
3099  *
3100  * If the function returns success memory[*memory_bytes] (if 'memory' is not
3101  * NULL) contains the written PNG data. *memory_bytes will always be less
3102  * than or equal to the original value.
3103  *
3104  * If the function returns false and *memory_bytes was not changed an error
3105  * occurred during write. If *memory_bytes was changed, or is not 0 if
3106  * 'memory' was NULL, the write would have succeeded but for the memory
3107  * buffer being too small. *memory_bytes contains the required number of
3108  * bytes and will be bigger that the original value.
3109  */
3110 
3111 #define png_image_write_get_memory_size(image, size, convert_to_8_bit, buffer,\
3112  row_stride, colormap)\
3113  png_image_write_to_memory(&(image), 0, &(size), convert_to_8_bit, buffer,\
3114  row_stride, colormap)
3115  /* Return the amount of memory in 'size' required to compress this image.
3116  * The png_image structure 'image' must be filled in as in the above
3117  * function and must not be changed before the actual write call, the buffer
3118  * and all other parameters must also be identical to that in the final
3119  * write call. The 'size' variable need not be initialized.
3120  *
3121  * NOTE: the macro returns true/false, if false is returned 'size' will be
3122  * set to zero and the write failed and probably will fail if tried again.
3123  */
3124 
3125 /* You can pre-allocate the buffer by making sure it is of sufficient size
3126  * regardless of the amount of compression achieved. The buffer size will
3127  * always be bigger than the original image and it will never be filled. The
3128  * following macros are provided to assist in allocating the buffer.
3129  */
3130 #define PNG_IMAGE_DATA_SIZE(image) (PNG_IMAGE_SIZE(image)+(image).height)
3131  /* The number of uncompressed bytes in the PNG byte encoding of the image;
3132  * uncompressing the PNG IDAT data will give this number of bytes.
3133  *
3134  * NOTE: while PNG_IMAGE_SIZE cannot overflow for an image in memory this
3135  * macro can because of the extra bytes used in the PNG byte encoding. You
3136  * need to avoid this macro if your image size approaches 2^30 in width or
3137  * height. The same goes for the remainder of these macros; they all produce
3138  * bigger numbers than the actual in-memory image size.
3139  */
3140 #ifndef PNG_ZLIB_MAX_SIZE
3141 # define PNG_ZLIB_MAX_SIZE(b) ((b)+(((b)+7U)>>3)+(((b)+63U)>>6)+11U)
3142  /* An upper bound on the number of compressed bytes given 'b' uncompressed
3143  * bytes. This is based on deflateBounds() in zlib; different
3144  * implementations of zlib compression may conceivably produce more data so
3145  * if your zlib implementation is not zlib itself redefine this macro
3146  * appropriately.
3147  */
3148 #endif
3149 
3150 #define PNG_IMAGE_COMPRESSED_SIZE_MAX(image)\
3151  PNG_ZLIB_MAX_SIZE((png_alloc_size_t)PNG_IMAGE_DATA_SIZE(image))
3152  /* An upper bound on the size of the data in the PNG IDAT chunks. */
3153 
3154 #define PNG_IMAGE_PNG_SIZE_MAX_(image, image_size)\
3155  ((8U/*sig*/+25U/*IHDR*/+16U/*gAMA*/+44U/*cHRM*/+12U/*IEND*/+\
3156  (((image).format&PNG_FORMAT_FLAG_COLORMAP)?/*colormap: PLTE, tRNS*/\
3157  12U+3U*(image).colormap_entries/*PLTE data*/+\
3158  (((image).format&PNG_FORMAT_FLAG_ALPHA)?\
3159  12U/*tRNS*/+(image).colormap_entries:0U):0U)+\
3160  12U)+(12U*((image_size)/PNG_ZBUF_SIZE))/*IDAT*/+(image_size))
3161  /* A helper for the following macro; if your compiler cannot handle the
3162  * following macro use this one with the result of
3163  * PNG_IMAGE_COMPRESSED_SIZE_MAX(image) as the second argument (most
3164  * compilers should handle this just fine.)
3165  */
3166 
3167 #define PNG_IMAGE_PNG_SIZE_MAX(image)\
3168  PNG_IMAGE_PNG_SIZE_MAX_(image, PNG_IMAGE_COMPRESSED_SIZE_MAX(image))
3169  /* An upper bound on the total length of the PNG data stream for 'image'.
3170  * The result is of type png_alloc_size_t, on 32-bit systems this may
3171  * overflow even though PNG_IMAGE_DATA_SIZE does not overflow; the write will
3172  * run out of buffer space but return a corrected size which should work.
3173  */
3174 #endif /* SIMPLIFIED_WRITE */
3175 /*******************************************************************************
3176  * END OF SIMPLIFIED API
3177  ******************************************************************************/
3178 #endif /* SIMPLIFIED_{READ|WRITE} */
3179 
3180 /*******************************************************************************
3181  * Section 6: IMPLEMENTATION OPTIONS
3182  *******************************************************************************
3183  *
3184  * Support for arbitrary implementation-specific optimizations. The API allows
3185  * particular options to be turned on or off. 'Option' is the number of the
3186  * option and 'onoff' is 0 (off) or non-0 (on). The value returned is given
3187  * by the PNG_OPTION_ defines below.
3188  *
3189  * HARDWARE: normally hardware capabilities, such as the Intel SSE instructions,
3190  * are detected at run time, however sometimes it may be impossible
3191  * to do this in user mode, in which case it is necessary to discover
3192  * the capabilities in an OS specific way. Such capabilities are
3193  * listed here when libpng has support for them and must be turned
3194  * ON by the application if present.
3195  *
3196  * SOFTWARE: sometimes software optimizations actually result in performance
3197  * decrease on some architectures or systems, or with some sets of
3198  * PNG images. 'Software' options allow such optimizations to be
3199  * selected at run time.
3200  */
3201 #ifdef PNG_SET_OPTION_SUPPORTED
3202 #ifdef PNG_ARM_NEON_API_SUPPORTED
3203 # define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */
3204 #endif
3205 #define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */
3206 #define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */
3207 #ifdef PNG_MIPS_MSA_API_SUPPORTED
3208 # define PNG_MIPS_MSA 6 /* HARDWARE: MIPS Msa SIMD instructions supported */
3209 #endif
3210 #define PNG_IGNORE_ADLER32 8
3211 #ifdef PNG_POWERPC_VSX_API_SUPPORTED
3212 # define PNG_POWERPC_VSX 10 /* HARDWARE: PowerPC VSX SIMD instructions supported */
3213 #endif
3214 #define PNG_OPTION_NEXT 12 /* Next option - numbers must be even */
3215 
3216 /* Return values: NOTE: there are four values and 'off' is *not* zero */
3217 #define PNG_OPTION_UNSET 0 /* Unset - defaults to off */
3218 #define PNG_OPTION_INVALID 1 /* Option number out of range */
3219 #define PNG_OPTION_OFF 2
3220 #define PNG_OPTION_ON 3
3221 
3222 PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option,
3223  int onoff));
3224 #endif /* SET_OPTION */
3225 
3226 /*******************************************************************************
3227  * END OF HARDWARE AND SOFTWARE OPTIONS
3228  ******************************************************************************/
3229 
3230 /* Maintainer: Put new public prototypes here ^, in libpng.3, in project
3231  * defs, and in scripts/symbols.def.
3232  */
3233 
3234 /* The last ordinal number (this is the *last* one already used; the next
3235  * one to use is one more than this.)
3236  */
3237 #ifdef PNG_EXPORT_LAST_ORDINAL
3238  PNG_EXPORT_LAST_ORDINAL(249);
3239 #endif
3240 
3241 #ifdef __cplusplus
3242 }
3243 #endif
3244 
3245 #endif /* PNG_VERSION_INFO_ONLY */
3246 /* Do not put anything past this line */
3247 #endif /* PNG_H */
OIIO_API std::vector< imagesize_t > histogram(const ImageBuf &src, int channel=0, int bins=256, float min=0.0f, float max=1.0f, bool ignore_empty=false, ROI roi={}, int nthreads=0)
png_int_32 nentries
Definition: png.h:538
const png_sPLT_entry * png_const_sPLT_entryp
Definition: png.h:525
png_const_structrp png_const_inforp double double double double double double double double double *blue_Z png_const_structrp png_const_inforp png_fixed_point png_fixed_point png_fixed_point * int_red_Z
Definition: png.h:1949
png_color * png_colorp
Definition: png.h:484
png_time ** png_timepp
Definition: png.h:611
#define PNGCAPI
Definition: pngconf.h:255
png_const_structrp png_const_inforp double double double double double double double double double *blue_Z png_const_structrp png_const_inforp png_fixed_point * int_red_X
Definition: png.h:1949
png_color_16 ** png_color_16pp
Definition: png.h:498
struct png_sPLT_struct png_sPLT_t
png_const_structrp png_const_inforp double double double double double double double double double *blue_Z png_get_cHRM_XYZ_fixed
Definition: png.h:1949
png_byte blue
Definition: png.h:504
png_const_structrp png_const_inforp info_ptr
Definition: png.h:1939
PNG_FP_EXPORT(32, void, png_set_rgb_to_gray,(png_structrp png_ptr, int error_action, double red, double green)) PNG_FIXED_EXPORT(33
png_sPLT_t ** png_sPLT_tpp
Definition: png.h:542
png_unknown_chunk ** png_unknown_chunkpp
Definition: png.h:640
png_charp text
Definition: png.h:570
png_structrp png_ptr
Definition: png.h:1083
GLsizeiptr size
Definition: glew.h:1681
PNG_EXPORTA(4, 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), PNG_ALLOCATED)
png_uint_32 width
Definition: png.h:2676
GLuint const GLchar * name
Definition: glew.h:1814
png_const_structrp png_const_inforp double double double double double double double double double *blue_Z png_const_structrp png_const_inforp png_fixed_point png_fixed_point png_fixed_point png_fixed_point png_fixed_point png_fixed_point png_fixed_point png_fixed_point * int_blue_Y
Definition: png.h:1949
const png_color * png_const_colorp
Definition: png.h:485
png_const_structrp png_const_inforp double double double double double double double double double *blue_Z PNG_FIXED_EXPORT(134, 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)) PNG_FIXED_EXPORT(231
png_byte red
Definition: png.h:502
int compression
Definition: png.h:564
#define png_get_int_32(buf)
Definition: png.h:2600
png_text ** png_textpp
Definition: png.h:581
png_uint_16 frequency
Definition: png.h:522
GLenum mode
Definition: glew.h:2163
GLint GLint GLint GLint GLint GLint GLsizei width
Definition: glew.h:1252
png_controlp opaque
Definition: png.h:2674
GLuint const GLfloat * val
Definition: glew.h:2794
png_const_structrp png_const_inforp double double double double double double * green_Z
Definition: png.h:1939
png_structrp int int num_weights
Definition: png.h:1488
png_const_structrp png_const_inforp double double double double double double double double double *blue_Z png_const_structrp png_const_inforp png_fixed_point png_fixed_point png_fixed_point png_fixed_point png_fixed_point png_fixed_point png_fixed_point png_fixed_point png_fixed_point *int_blue_Z png_const_structrp png_inforp double double double double double double double double double blue_Z png_set_cHRM_XYZ_fixed
Definition: png.h:1973
GLenum GLsizei GLsizei GLsizei GLsizei GLbitfield flags
Definition: glew.h:2864
#define png_get_uint_32(buf)
Definition: png.h:2598
png_uint_16 blue
Definition: png.h:493
png_info * png_infop
Definition: png.h:454
char ** png_charpp
Definition: pngconf.h:612
#define PNG_ALLOCATED
Definition: pngconf.h:439
png_const_structrp png_const_inforp double double double double double double double double double *blue_Z png_const_structrp png_const_inforp png_fixed_point png_fixed_point png_fixed_point png_fixed_point png_fixed_point png_fixed_point png_fixed_point * int_blue_X
Definition: png.h:1949
GLuint GLenum option
Definition: glew.h:3288
png_uint_16 gray
Definition: png.h:494
const png_color_8 * png_const_color_8p
Definition: png.h:509
GLint GLint GLint GLint GLint GLint GLsizei GLsizei height
Definition: glew.h:1252
png_byte green
Definition: png.h:503
png_byte red
Definition: png.h:480
png_get_pixel_aspect_ratio_fixed
Definition: png.h:1903
png_uint_32
Definition: png.h:1939
const png_text * png_const_textp
Definition: png.h:580
PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name,(png_structrp png_ptr), PNG_DEPRECATED) PNG_EXPORT(216
png_color_16 * png_color_16p
Definition: png.h:496
png_uint_32 flags
Definition: png.h:2679
struct png_struct_def png_struct
Definition: png.h:439
png_struct *PNG_RESTRICT png_structrp
Definition: png.h:469
png_uint_32 warning_or_error
Definition: png.h:2705
png_charp lang
Definition: png.h:574
png_uint_16 alpha
Definition: png.h:521
struct png_text_struct png_text
GLenum GLint GLuint mask
Definition: glew.h:1845
png_int_32 png_fixed_point
Definition: pngconf.h:574
struct png_control * png_controlp
Definition: png.h:2671
png_set_alpha_mode_fixed
Definition: png.h:1139
struct png_info_def png_info
Definition: png.h:453
GLboolean red
Definition: glew.h:2171
struct png_sPLT_entry_struct png_sPLT_entry
GLenum GLsizei GLenum GLenum const void * image
Definition: glew.h:4943
png_color_8 ** png_color_8pp
Definition: png.h:510
png_const_structrp png_const_inforp double double double double double double double double double *blue_Z png_const_structrp png_const_inforp png_fixed_point png_fixed_point * int_red_Y
Definition: png.h:1949
png_set_filter_heuristics_fixed
Definition: png.h:1488
char * png_charp
Definition: pngconf.h:589
#define PNG_RESTRICT
Definition: pngconf.h:445
png_byte hour
Definition: png.h:605
png_structrp int error_action
Definition: png.h:1083
struct png_image * png_imagep
png_const_structrp png_const_inforp double double double * red_Z
Definition: png.h:1939
png_set_background_fixed
Definition: png.h:1302
png_const_structrp png_const_inforp double double double double double double double double double *blue_Z png_const_structrp png_const_inforp png_fixed_point png_fixed_point png_fixed_point png_fixed_point png_fixed_point * int_green_Y
Definition: png.h:1949
png_uint_32 width
Definition: png.h:756
png_const_structrp png_const_inforp double double double double double double double double double *blue_Z png_const_structrp png_const_inforp png_fixed_point png_fixed_point png_fixed_point png_fixed_point png_fixed_point png_fixed_point * int_green_Z
Definition: png.h:1949
png_sPLT_entry * png_sPLT_entryp
Definition: png.h:524
png_color ** png_colorpp
Definition: png.h:486
const png_struct *PNG_RESTRICT png_const_structrp
Definition: png.h:470
png_charp key
Definition: png.h:569
PNG_EXPORT(1, png_uint_32, png_access_version_number,(void))
struct png_color_8_struct png_color_8
png_const_structrp png_const_inforp double * red_X
Definition: png.h:1939
png_color_8 * png_color_8p
Definition: png.h:508
struct png_color_struct png_color
png_byte second
Definition: png.h:607
png_uint_32 format
Definition: png.h:2678
png_byte color_type
Definition: png.h:758
png_uint_16 blue
Definition: png.h:520
png_uint_16 green
Definition: png.h:492
png_byte channels
Definition: png.h:760
char * png_libpng_version_1_6_36
Definition: png.h:431
png_const_structrp png_const_inforp double double double double double double double double double *blue_Z png_const_structrp png_const_inforp png_fixed_point png_fixed_point png_fixed_point png_fixed_point png_fixed_point png_fixed_point png_fixed_point png_fixed_point png_fixed_point *int_blue_Z png_set_cHRM_XYZ
Definition: png.h:1963
png_get_x_offset_inches_fixed
Definition: png.h:2392
png_structrp png_const_color_16p background_color
Definition: png.h:1302
GLuint buffer
Definition: glew.h:1680
GLint GLenum GLsizei GLint GLsizei const void * data
Definition: glew.h:1379
png_info *PNG_RESTRICT png_inforp
Definition: png.h:471
png_unknown_chunk * png_unknown_chunkp
Definition: png.h:638
struct png_time_struct png_time
png_byte depth
Definition: png.h:536
png_set_sCAL_fixed
Definition: png.h:2171
const png_info *PNG_RESTRICT png_const_inforp
Definition: png.h:472
png_structrp png_const_color_16p int background_gamma_code
Definition: png.h:1302
png_byte minute
Definition: png.h:606
GLsizei GLenum GLuint GLuint GLsizei GLchar * message
Definition: glew.h:2581
png_uint_32 version
Definition: png.h:2675
GLuint GLsizei GLsizei * length
Definition: glew.h:1825
const png_info * png_const_infop
Definition: png.h:455
png_sPLT_entryp entries
Definition: png.h:537
GLclampf green
Definition: glew.h:1520
size_t png_alloc_size_t
Definition: pngconf.h:557
png_const_structrp png_const_inforp int * unit
Definition: png.h:2161
png_get_gAMA_fixed
Definition: png.h:1996
png_const_structrp png_const_inforp png_fixed_point *int_file_gamma png_set_gAMA_fixed
Definition: png.h:2004
png_byte * png_bytep
Definition: pngconf.h:579
PNG_FUNCTION(void,(PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef)
png_byte pixel_depth
Definition: png.h:761
png_const_structrp png_const_inforp info_ptr png_get_y_offset_inches_fixed
Definition: png.h:2399
png_const_structrp png_const_inforp double double double double * green_X
Definition: png.h:1939
GLuint GLuint GLsizei GLenum type
Definition: glew.h:1253
png_text * png_textp
Definition: png.h:579
png_const_structrp png_const_inforp double double double double double double double * blue_X
Definition: png.h:1939
png_const_structrp png_const_inforp double double double double double double double double * blue_Y
Definition: png.h:1939
Definition: png.h:516
GLuint start
Definition: glew.h:1253
size_t size
Definition: png.h:626
png_byte location
Definition: png.h:634
struct png_row_info_struct png_row_info
const png_struct * png_const_structp
Definition: png.h:440
png_structrp png_fixed_point screen_gamma
Definition: png.h:1352
png_uint_16 green
Definition: png.h:519
#define png_get_uint_16(buf)
Definition: png.h:2599
png_structrp png_const_color_16p int int need_expand
Definition: png.h:1302
png_byte index
Definition: png.h:490
png_set_rgb_to_gray_fixed
Definition: png.h:1083
png_const_structrp png_const_inforp double double double double double * green_Y
Definition: png.h:1939
png_uint_16 red
Definition: png.h:518
png_get_sCAL_fixed
Definition: png.h:2161
typedef PNG_CALLBACK(void,*png_error_ptr,(png_structp, png_const_charp))
png_byte day
Definition: png.h:604
GLuint num
Definition: glew.h:2690
const void * ptr(const T *p)
Definition: format.h:3292
const png_unknown_chunk * png_const_unknown_chunkp
Definition: png.h:639
#define PNG_NORETURN
Definition: pngconf.h:436
png_struct * png_structp
Definition: png.h:441
png_struct ** png_structpp
Definition: png.h:442
const png_sPLT_t * png_const_sPLT_tp
Definition: png.h:541
struct png_color_16_struct png_color_16
png_const_structrp png_const_inforp double double * red_Y
Definition: png.h:1939
size_t itxt_length
Definition: png.h:573
png_time * png_timep
Definition: png.h:609
png_uint_32 height
Definition: png.h:2677
png_byte month
Definition: png.h:603
png_sPLT_entry ** png_sPLT_entrypp
Definition: png.h:526
png_charp lang_key
Definition: png.h:576
const GLfloat * params
Definition: glew.h:1531
struct png_unknown_chunk_t png_unknown_chunk
const char * png_const_charp
Definition: pngconf.h:590
png_byte alpha
Definition: png.h:506
png_const_structrp png_const_inforp double double double double double double double double double *blue_Z png_const_structrp png_const_inforp png_fixed_point png_fixed_point png_fixed_point png_fixed_point * int_green_X
Definition: png.h:1949
GLint location
Definition: glew.h:1835
png_uint_16 * png_uint_16p
Definition: pngconf.h:585
png_row_info * png_row_infop
Definition: png.h:764
png_uint_32 colormap_entries
Definition: png.h:2680
void * png_voidp
Definition: pngconf.h:577
png_get_io_chunk_type
Definition: png.h:2418
const png_byte * png_const_bytep
Definition: pngconf.h:580
png_uint_16 red
Definition: png.h:491
png_get_cHRM_XYZ
Definition: png.h:1939
png_sPLT_t * png_sPLT_tp
Definition: png.h:540
GLenum GLenum void * row
Definition: glew.h:4965
#define PNGARG(arglist)
Definition: pngconf.h:94
GLenum GLuint GLsizei const GLchar * buf
Definition: glew.h:2580
const png_color_16 * png_const_color_16p
Definition: png.h:497
size_t text_length
Definition: png.h:572
png_byte gray
Definition: png.h:505
png_structrp int heuristic_method
Definition: png.h:1488
png_row_info ** png_row_infopp
Definition: png.h:765
png_structrp int int png_const_fixed_point_p filter_weights
Definition: png.h:1488
const png_time * png_const_timep
Definition: png.h:610
GLint level
Definition: glew.h:1252
size_t rowbytes
Definition: png.h:757
const png_uint_16 * png_const_uint_16p
Definition: pngconf.h:586
const png_fixed_point * png_const_fixed_point_p
Definition: pngconf.h:592
GLfloat units
Definition: glew.h:10289
png_uint_16 year
Definition: png.h:602
png_set_gamma_fixed
Definition: png.h:1352
png_byte green
Definition: png.h:481
png_info ** png_infopp
Definition: png.h:456
png_byte bit_depth
Definition: png.h:759
png_byte blue
Definition: png.h:482
png_byte * data
Definition: png.h:625
#define PNG_DEPRECATED
Definition: pngconf.h:430
png_charp name
Definition: png.h:535
png_byte ** png_bytepp
Definition: pngconf.h:606
const void * png_const_voidp
Definition: pngconf.h:578