png.h source code [Modules/Image/Contrib/LibPNG/include/png.h]

1
2	/ png.h - header file for PNG reference library*
3	*
4	* libpng version 1.6.42
5	*
6	* Copyright (c) 2018-2024 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 versions 1.6.36, December 2018, through 1.6.42, January 2024:
19	* Cosmin Truta
20	* See also "Contributing Authors", below.
21	*/
22
23	/*
24	* COPYRIGHT NOTICE, DISCLAIMER, and LICENSE
25	* =========================================
26	*
27	* PNG Reference Library License version 2
28	* ---------------------------------------
29	*
30	* * Copyright (c) 1995-2024 The PNG Reference Library Authors.
31	* * Copyright (c) 2018-2024 Cosmin Truta.
32	* * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson.
33	* * Copyright (c) 1996-1997 Andreas Dilger.
34	* * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
35	*
36	* The software is supplied "as is", without warranty of any kind,
37	* express or implied, including, without limitation, the warranties
38	* of merchantability, fitness for a particular purpose, title, and
39	* non-infringement. In no event shall the Copyright owners, or
40	* anyone distributing the software, be liable for any damages or
41	* other liability, whether in contract, tort or otherwise, arising
42	* from, out of, or in connection with the software, or the use or
43	* other dealings in the software, even if advised of the possibility
44	* of such damage.
45	*
46	* Permission is hereby granted to use, copy, modify, and distribute
47	* this software, or portions hereof, for any purpose, without fee,
48	* subject to the following restrictions:
49	*
50	* 1. The origin of this software must not be misrepresented; you
51	* must not claim that you wrote the original software. If you
52	* use this software in a product, an acknowledgment in the product
53	* documentation would be appreciated, but is not required.
54	*
55	* 2. Altered source versions must be plainly marked as such, and must
56	* not be misrepresented as being the original software.
57	*
58	* 3. This Copyright notice may not be removed or altered from any
59	* source or altered source distribution.
60	*
61	*
62	* PNG Reference Library License version 1 (for libpng 0.5 through 1.6.35)
63	* -----------------------------------------------------------------------
64	*
65	* libpng versions 1.0.7, July 1, 2000, through 1.6.35, July 15, 2018 are
66	* Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson, are
67	* derived from libpng-1.0.6, and are distributed according to the same
68	* disclaimer and license as libpng-1.0.6 with the following individuals
69	* added to the list of Contributing Authors:
70	*
71	* Simon-Pierre Cadieux
72	* Eric S. Raymond
73	* Mans Rullgard
74	* Cosmin Truta
75	* Gilles Vollant
76	* James Yu
77	* Mandar Sahastrabuddhe
78	* Google Inc.
79	* Vadim Barkov
80	*
81	* and with the following additions to the disclaimer:
82	*
83	* There is no warranty against interference with your enjoyment of
84	* the library or against infringement. There is no warranty that our
85	* efforts or the library will fulfill any of your particular purposes
86	* or needs. This library is provided with all faults, and the entire
87	* risk of satisfactory quality, performance, accuracy, and effort is
88	* with the user.
89	*
90	* Some files in the "contrib" directory and some configure-generated
91	* files that are distributed with libpng have other copyright owners, and
92	* are released under other open source licenses.
93	*
94	* libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
95	* Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from
96	* libpng-0.96, and are distributed according to the same disclaimer and
97	* license as libpng-0.96, with the following individuals added to the
98	* list of Contributing Authors:
99	*
100	* Tom Lane
101	* Glenn Randers-Pehrson
102	* Willem van Schaik
103	*
104	* libpng versions 0.89, June 1996, through 0.96, May 1997, are
105	* Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88,
106	* and are distributed according to the same disclaimer and license as
107	* libpng-0.88, with the following individuals added to the list of
108	* Contributing Authors:
109	*
110	* John Bowler
111	* Kevin Bracey
112	* Sam Bushell
113	* Magnus Holmgren
114	* Greg Roelofs
115	* Tom Tanner
116	*
117	* Some files in the "scripts" directory have other copyright owners,
118	* but are released under this license.
119	*
120	* libpng versions 0.5, May 1995, through 0.88, January 1996, are
121	* Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.
122	*
123	* For the purposes of this copyright and license, "Contributing Authors"
124	* is defined as the following set of individuals:
125	*
126	* Andreas Dilger
127	* Dave Martindale
128	* Guy Eric Schalnat
129	* Paul Schmidt
130	* Tim Wegner
131	*
132	* The PNG Reference Library is supplied "AS IS". The Contributing
133	* Authors and Group 42, Inc. disclaim all warranties, expressed or
134	* implied, including, without limitation, the warranties of
135	* merchantability and of fitness for any purpose. The Contributing
136	* Authors and Group 42, Inc. assume no liability for direct, indirect,
137	* incidental, special, exemplary, or consequential damages, which may
138	* result from the use of the PNG Reference Library, even if advised of
139	* the possibility of such damage.
140	*
141	* Permission is hereby granted to use, copy, modify, and distribute this
142	* source code, or portions hereof, for any purpose, without fee, subject
143	* to the following restrictions:
144	*
145	* 1. The origin of this source code must not be misrepresented.
146	*
147	* 2. Altered versions must be plainly marked as such and must not
148	* be misrepresented as being the original source.
149	*
150	* 3. This Copyright notice may not be removed or altered from any
151	* source or altered source distribution.
152	*
153	* The Contributing Authors and Group 42, Inc. specifically permit,
154	* without fee, and encourage the use of this source code as a component
155	* to supporting the PNG file format in commercial products. If you use
156	* this source code in a product, acknowledgment is not required but would
157	* be appreciated.
158	*
159	* END OF COPYRIGHT NOTICE, DISCLAIMER, and LICENSE.
160	*
161	* TRADEMARK
162	* =========
163	*
164	* The name "libpng" has not been registered by the Copyright owners
165	* as a trademark in any jurisdiction. However, because libpng has
166	* been distributed and maintained world-wide, continually since 1995,
167	* the Copyright owners claim "common-law trademark protection" in any
168	* jurisdiction where common-law trademark is recognized.
169	*/
170
171	/*
172	* A "png_get_copyright" function is available, for convenient use in "about"
173	* boxes and the like:
174	*
175	* printf("%s", png_get_copyright(NULL));
176	*
177	* Also, the PNG logo (in PNG format, of course) is supplied in the
178	* files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
179	*/
180
181	/*
182	* The contributing authors would like to thank all those who helped
183	* with testing, bug fixes, and patience. This wouldn't have been
184	* possible without all of you.
185	*
186	* Thanks to Frank J. T. Wojcik for helping with the documentation.
187	*/
188
189	/ Note about libpng version numbers:*
190	*
191	* Due to various miscommunications, unforeseen code incompatibilities
192	* and occasional factors outside the authors' control, version numbering
193	* on the library has not always been consistent and straightforward.
194	* The following table summarizes matters since version 0.89c, which was
195	* the first widely used release:
196	*
197	* source png.h png.h shared-lib
198	* version string int version
199	* ------- ------ ----- ----------
200	* 0.89c "1.0 beta 3" 0.89 89 1.0.89
201	* 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]
202	* 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]
203	* 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]
204	* 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]
205	* 0.97c 0.97 97 2.0.97
206	* 0.98 0.98 98 2.0.98
207	* 0.99 0.99 98 2.0.99
208	* 0.99a-m 0.99 99 2.0.99
209	* 1.00 1.00 100 2.1.0 [100 should be 10000]
210	* 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]
211	* 1.0.1 png.h string is 10001 2.1.0
212	* 1.0.1a-e identical to the 10002 from here on, the shared library
213	* 1.0.2 source version) 10002 is 2.V where V is the source code
214	* 1.0.2a-b 10003 version, except as noted.
215	* 1.0.3 10003
216	* 1.0.3a-d 10004
217	* 1.0.4 10004
218	* 1.0.4a-f 10005
219	* 1.0.5 (+ 2 patches) 10005
220	* 1.0.5a-d 10006
221	* 1.0.5e-r 10100 (not source compatible)
222	* 1.0.5s-v 10006 (not binary compatible)
223	* 1.0.6 (+ 3 patches) 10006 (still binary incompatible)
224	* 1.0.6d-f 10007 (still binary incompatible)
225	* 1.0.6g 10007
226	* 1.0.6h 10007 10.6h (testing xy.z so-numbering)
227	* 1.0.6i 10007 10.6i
228	* 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
229	* 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)
230	* 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
231	* 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
232	* 1.0.7 1 10007 (still compatible)
233	* ...
234	* 1.0.69 10 10069 10.so.0.69[.0]
235	* ...
236	* 1.2.59 13 10259 12.so.0.59[.0]
237	* ...
238	* 1.4.20 14 10420 14.so.0.20[.0]
239	* ...
240	* 1.5.30 15 10530 15.so.15.30[.0]
241	* ...
242	* 1.6.42 16 10641 16.so.16.41[.0]
243	*
244	* Henceforth the source version will match the shared-library major and
245	* minor numbers; the shared-library major version number will be used for
246	* changes in backward compatibility, as it is intended.
247	* The PNG_LIBPNG_VER macro, which is not used within libpng but is
248	* available for applications, is an unsigned integer of the form XYYZZ
249	* corresponding to the source version X.Y.Z (leading zeros in Y and Z).
250	* Beta versions were given the previous public release number plus a
251	* letter, until version 1.0.6j; from then on they were given the upcoming
252	* public release number plus "betaNN" or "rcNN".
253	*
254	* Binary incompatibility exists only when applications make direct access
255	* to the info_ptr or png_ptr members through png.h, and the compiled
256	* application is loaded with a different version of the library.
257	*
258	* DLLNUM will change each time there are forward or backward changes
259	* in binary compatibility (e.g., when a new feature is added).
260	*
261	* See libpng.txt or libpng.3 for more information. The PNG specification
262	* is available as a W3C Recommendation and as an ISO/IEC Standard; see
263	* <https://www.w3.org/TR/2003/REC-PNG-20031110/>
264	*/
265
266	#ifndef PNG_H
267	#define PNG_H
268
269	/ This is not the place to learn how to use libpng. The file libpng-manual.txt*
270	* describes how to use libpng, and the file example.c summarizes it
271	* with some code on which to build. This file is useful for looking
272	* at the actual function definitions and structure components. If that
273	* file has been stripped from your copy of libpng, you can find it at
274	* <http://www.libpng.org/pub/png/libpng-manual.txt>
275	*
276	* If you just need to read a PNG file and don't want to read the documentation
277	* skip to the end of this file and read the section entitled 'simplified API'.
278	*/
279
280	/ Version information for png.h - this should match the version in png.c /
281	#define PNG_LIBPNG_VER_STRING "1.6.42"
282	#define PNG_HEADER_VERSION_STRING " libpng version " PNG_LIBPNG_VER_STRING "\n"
283
284	#define PNG_LIBPNG_VER_SONUM 16
285	#define PNG_LIBPNG_VER_DLLNUM 16
286
287	/ These should match the first 3 components of PNG_LIBPNG_VER_STRING: /
288	#define PNG_LIBPNG_VER_MAJOR 1
289	#define PNG_LIBPNG_VER_MINOR 6
290	#define PNG_LIBPNG_VER_RELEASE 42
291
292	/ This should be zero for a public release, or non-zero for a*
293	* development version. [Deprecated]
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 10641 /* 1.6.42 */
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	*/
431	typedef char* png_libpng_version_1_6_42;
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;
440	typedef const png_struct * png_const_structp;
441	typedef png_struct * png_structp;
442	typedef png_struct * * png_structpp;
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	*/
469	typedef png_struct * PNG_RESTRICT png_structrp;
470	typedef const png_struct * PNG_RESTRICT png_const_structrp;
471	typedef png_info * PNG_RESTRICT png_inforp;
472	typedef const png_info * PNG_RESTRICT png_const_inforp;
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;
484	typedef png_color * png_colorp;
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;
496	typedef png_color_16 * png_color_16p;
497	typedef const png_color_16 * png_const_color_16p;
498	typedef png_color_16 * * png_color_16pp;
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;
508	typedef png_color_8 * png_color_8p;
509	typedef const png_color_8 * png_const_color_8p;
510	typedef png_color_8 * * png_color_8pp;
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;
523	} png_sPLT_entry;
524	typedef png_sPLT_entry * png_sPLT_entryp;
525	typedef const png_sPLT_entry * png_const_sPLT_entryp;
526	typedef png_sPLT_entry * * png_sPLT_entrypp;
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;
540	typedef png_sPLT_t * png_sPLT_tp;
541	typedef const png_sPLT_t * png_const_sPLT_tp;
542	typedef png_sPLT_t * * png_sPLT_tpp;
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	}
636	png_unknown_chunk;
637
638	typedef png_unknown_chunk * png_unknown_chunkp;
639	typedef const png_unknown_chunk * png_const_unknown_chunkp;
640	typedef png_unknown_chunk * * png_unknown_chunkpp;
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
764	typedef png_row_info * png_row_infop;
765	typedef png_row_info * * png_row_infopp;
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 ~0U > 0xffffU /* or else this might break on a 16-bit machine */
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,
868	png_alloc_size_t));
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 (i.e. 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) == 0).
918	*/
919	#define png_check_sig(sig, n) (png_sig_cmp((sig), 0, (n)) == 0) /* DEPRECATED */
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 explanation 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))
1488	PNG_FIXED_EXPORT(`209`, void, png_set_filter_heuristics_fixed,
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 calculations. 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,
1717	png_alloc_size_t size), PNG_ALLOCATED);
1718	/ Added at libpng version 1.4.0 /
1719	PNG_EXPORTA(`95`, png_voidp, png_calloc, (png_const_structrp png_ptr,
1720	png_alloc_size_t size), PNG_ALLOCATED);
1721
1722	/ Added at libpng version 1.2.4 /
1723	PNG_EXPORTA(`96`, png_voidp, png_malloc_warn, (png_const_structrp png_ptr,
1724	png_alloc_size_t size), PNG_ALLOCATED);
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 the responsibility for freeing existing data, whether allocated*
1734	* by libpng or by the application; this works on the png_info structure passed
1735	* in, without changing the state for other png_info structures.
1736	*/
1737	PNG_EXPORT(`99`, void, png_data_freer, (png_const_structrp png_ptr,
1738	png_inforp info_ptr, int freer, png_uint_32 mask));
1739
1740	/ Assignments for png_data_freer /
1741	#define PNG_DESTROY_WILL_FREE_DATA 1
1742	#define PNG_SET_WILL_FREE_DATA 1
1743	#define PNG_USER_WILL_FREE_DATA 2
1744	/ Flags for png_ptr->free_me and info_ptr->free_me /
1745	#define PNG_FREE_HIST 0x0008U
1746	#define PNG_FREE_ICCP 0x0010U
1747	#define PNG_FREE_SPLT 0x0020U
1748	#define PNG_FREE_ROWS 0x0040U
1749	#define PNG_FREE_PCAL 0x0080U
1750	#define PNG_FREE_SCAL 0x0100U
1751	#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
1752	# define PNG_FREE_UNKN 0x0200U
1753	#endif
1754	/ PNG_FREE_LIST 0x0400U removed in 1.6.0 because it is ignored /
1755	#define PNG_FREE_PLTE 0x1000U
1756	#define PNG_FREE_TRNS 0x2000U
1757	#define PNG_FREE_TEXT 0x4000U
1758	#define PNG_FREE_EXIF 0x8000U /* Added at libpng-1.6.31 */
1759	#define PNG_FREE_ALL 0xffffU
1760	#define PNG_FREE_MUL 0x4220U /* PNG_FREE_SPLT\|PNG_FREE_TEXT\|PNG_FREE_UNKN */
1761
1762	#ifdef PNG_USER_MEM_SUPPORTED
1763	PNG_EXPORTA(`100`, png_voidp, png_malloc_default, (png_const_structrp png_ptr,
1764	png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED);
1765	PNG_EXPORTA(`101`, void, png_free_default, (png_const_structrp png_ptr,
1766	png_voidp ptr), PNG_DEPRECATED);
1767	#endif
1768
1769	#ifdef PNG_ERROR_TEXT_SUPPORTED
1770	/ Fatal error in PNG image of libpng - can't continue /
1771	PNG_EXPORTA(`102`, void, png_error, (png_const_structrp png_ptr,
1772	png_const_charp error_message), PNG_NORETURN);
1773
1774	/ The same, but the chunk name is prepended to the error string. /
1775	PNG_EXPORTA(`103`, void, png_chunk_error, (png_const_structrp png_ptr,
1776	png_const_charp error_message), PNG_NORETURN);
1777
1778	#else
1779	/ Fatal error in PNG image of libpng - can't continue /
1780	PNG_EXPORTA(`104`, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN);
1781	# define png_error(s1,s2) png_err(s1)
1782	# define png_chunk_error(s1,s2) png_err(s1)
1783	#endif
1784
1785	#ifdef PNG_WARNINGS_SUPPORTED
1786	/ Non-fatal error in libpng. Can continue, but may have a problem. /
1787	PNG_EXPORT(`105`, void, png_warning, (png_const_structrp png_ptr,
1788	png_const_charp warning_message));
1789
1790	/ Non-fatal error in libpng, chunk name is prepended to message. /
1791	PNG_EXPORT(`106`, void, png_chunk_warning, (png_const_structrp png_ptr,
1792	png_const_charp warning_message));
1793	#else
1794	# define png_warning(s1,s2) ((void)(s1))
1795	# define png_chunk_warning(s1,s2) ((void)(s1))
1796	#endif
1797
1798	#ifdef PNG_BENIGN_ERRORS_SUPPORTED
1799	/ Benign error in libpng. Can continue, but may have a problem.*
1800	* User can choose whether to handle as a fatal error or as a warning. */
1801	PNG_EXPORT(`107`, void, png_benign_error, (png_const_structrp png_ptr,
1802	png_const_charp warning_message));
1803
1804	#ifdef PNG_READ_SUPPORTED
1805	/ Same, chunk name is prepended to message (only during read) /
1806	PNG_EXPORT(`108`, void, png_chunk_benign_error, (png_const_structrp png_ptr,
1807	png_const_charp warning_message));
1808	#endif
1809
1810	PNG_EXPORT(`109`, void, png_set_benign_errors,
1811	(png_structrp png_ptr, int allowed));
1812	#else
1813	# ifdef PNG_ALLOW_BENIGN_ERRORS
1814	# define png_benign_error png_warning
1815	# define png_chunk_benign_error png_chunk_warning
1816	# else
1817	# define png_benign_error png_error
1818	# define png_chunk_benign_error png_chunk_error
1819	# endif
1820	#endif
1821
1822	/ The png_set_<chunk> functions are for storing values in the png_info_struct.*
1823	* Similarly, the png_get_<chunk> calls are used to read values from the
1824	* png_info_struct, either storing the parameters in the passed variables, or
1825	* setting pointers into the png_info_struct where the data is stored. The
1826	* png_get_<chunk> functions return a non-zero value if the data was available
1827	* in info_ptr, or return zero and do not change any of the parameters if the
1828	* data was not available.
1829	*
1830	* These functions should be used instead of directly accessing png_info
1831	* to avoid problems with future changes in the size and internal layout of
1832	* png_info_struct.
1833	*/
1834	/ Returns "flag" if chunk data is valid in info_ptr. /
1835	PNG_EXPORT(`110`, png_uint_32, png_get_valid, (png_const_structrp png_ptr,
1836	png_const_inforp info_ptr, png_uint_32 flag));
1837
1838	/ Returns number of bytes needed to hold a transformed row. /
1839	PNG_EXPORT(`111`, size_t, png_get_rowbytes, (png_const_structrp png_ptr,
1840	png_const_inforp info_ptr));
1841
1842	#ifdef PNG_INFO_IMAGE_SUPPORTED
1843	/ Returns row_pointers, which is an array of pointers to scanlines that was*
1844	* returned from png_read_png().
1845	*/
1846	PNG_EXPORT(`112`, png_bytepp, png_get_rows, (png_const_structrp png_ptr,
1847	png_const_inforp info_ptr));
1848
1849	/ Set row_pointers, which is an array of pointers to scanlines for use*
1850	* by png_write_png().
1851	*/
1852	PNG_EXPORT(`113`, void, png_set_rows, (png_const_structrp png_ptr,
1853	png_inforp info_ptr, png_bytepp row_pointers));
1854	#endif
1855
1856	/ Returns number of color channels in image. /
1857	PNG_EXPORT(`114`, png_byte, png_get_channels, (png_const_structrp png_ptr,
1858	png_const_inforp info_ptr));
1859
1860	#ifdef PNG_EASY_ACCESS_SUPPORTED
1861	/ Returns image width in pixels. /
1862	PNG_EXPORT(`115`, png_uint_32, png_get_image_width, (png_const_structrp png_ptr,
1863	png_const_inforp info_ptr));
1864
1865	/ Returns image height in pixels. /
1866	PNG_EXPORT(`116`, png_uint_32, png_get_image_height, (png_const_structrp png_ptr,
1867	png_const_inforp info_ptr));
1868
1869	/ Returns image bit_depth. /
1870	PNG_EXPORT(`117`, png_byte, png_get_bit_depth, (png_const_structrp png_ptr,
1871	png_const_inforp info_ptr));
1872
1873	/ Returns image color_type. /
1874	PNG_EXPORT(`118`, png_byte, png_get_color_type, (png_const_structrp png_ptr,
1875	png_const_inforp info_ptr));
1876
1877	/ Returns image filter_type. /
1878	PNG_EXPORT(`119`, png_byte, png_get_filter_type, (png_const_structrp png_ptr,
1879	png_const_inforp info_ptr));
1880
1881	/ Returns image interlace_type. /
1882	PNG_EXPORT(`120`, png_byte, png_get_interlace_type, (png_const_structrp png_ptr,
1883	png_const_inforp info_ptr));
1884
1885	/ Returns image compression_type. /
1886	PNG_EXPORT(`121`, png_byte, png_get_compression_type, (png_const_structrp png_ptr,
1887	png_const_inforp info_ptr));
1888
1889	/ Returns image resolution in pixels per meter, from pHYs chunk data. /
1890	PNG_EXPORT(`122`, png_uint_32, png_get_pixels_per_meter,
1891	(png_const_structrp png_ptr, png_const_inforp info_ptr));
1892	PNG_EXPORT(`123`, png_uint_32, png_get_x_pixels_per_meter,
1893	(png_const_structrp png_ptr, png_const_inforp info_ptr));
1894	PNG_EXPORT(`124`, png_uint_32, png_get_y_pixels_per_meter,
1895	(png_const_structrp png_ptr, png_const_inforp info_ptr));
1896
1897	/ Returns pixel aspect ratio, computed from pHYs chunk data. /
1898	PNG_FP_EXPORT(`125`, float, png_get_pixel_aspect_ratio,
1899	(png_const_structrp png_ptr, png_const_inforp info_ptr))
1900	PNG_FIXED_EXPORT(`210`, png_fixed_point, png_get_pixel_aspect_ratio_fixed,
1901	(png_const_structrp png_ptr, png_const_inforp info_ptr))
1902
1903	/ Returns image x, y offset in pixels or microns, from oFFs chunk data. /
1904	PNG_EXPORT(`126`, png_int_32, png_get_x_offset_pixels,
1905	(png_const_structrp png_ptr, png_const_inforp info_ptr));
1906	PNG_EXPORT(`127`, png_int_32, png_get_y_offset_pixels,
1907	(png_const_structrp png_ptr, png_const_inforp info_ptr));
1908	PNG_EXPORT(`128`, png_int_32, png_get_x_offset_microns,
1909	(png_const_structrp png_ptr, png_const_inforp info_ptr));
1910	PNG_EXPORT(`129`, png_int_32, png_get_y_offset_microns,
1911	(png_const_structrp png_ptr, png_const_inforp info_ptr));
1912
1913	#endif /* EASY_ACCESS */
1914
1915	#ifdef PNG_READ_SUPPORTED
1916	/ Returns pointer to signature string read from PNG header /
1917	PNG_EXPORT(`130`, png_const_bytep, png_get_signature, (png_const_structrp png_ptr,
1918	png_const_inforp info_ptr));
1919	#endif
1920
1921	#ifdef PNG_bKGD_SUPPORTED
1922	PNG_EXPORT(`131`, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr,
1923	png_inforp info_ptr, png_color_16p *background));
1924	#endif
1925
1926	#ifdef PNG_bKGD_SUPPORTED
1927	PNG_EXPORT(`132`, void, png_set_bKGD, (png_const_structrp png_ptr,
1928	png_inforp info_ptr, png_const_color_16p background));
1929	#endif
1930
1931	#ifdef PNG_cHRM_SUPPORTED
1932	PNG_FP_EXPORT(`133`, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr,
1933	png_const_inforp info_ptr, double white_x, double* white_y, double* *red_x,
1934	double red_y, double* green_x, double* green_y, double* *blue_x,
1935	double *blue_y))
1936	PNG_FP_EXPORT(`230`, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr,
1937	png_const_inforp info_ptr, double red_X, double* red_Y, double* *red_Z,
1938	double green_X, double* green_Y, double* green_Z, double* *blue_X,
1939	double blue_Y, double* *blue_Z))
1940	PNG_FIXED_EXPORT(`134`, png_uint_32, png_get_cHRM_fixed,
1941	(png_const_structrp png_ptr, png_const_inforp info_ptr,
1942	png_fixed_point int_white_x, png_fixed_point int_white_y,
1943	png_fixed_point int_red_x, png_fixed_point int_red_y,
1944	png_fixed_point int_green_x, png_fixed_point int_green_y,
1945	png_fixed_point int_blue_x, png_fixed_point int_blue_y))
1946	PNG_FIXED_EXPORT(`231`, png_uint_32, png_get_cHRM_XYZ_fixed,
1947	(png_const_structrp png_ptr, png_const_inforp info_ptr,
1948	png_fixed_point int_red_X, png_fixed_point int_red_Y,
1949	png_fixed_point int_red_Z, png_fixed_point int_green_X,
1950	png_fixed_point int_green_Y, png_fixed_point int_green_Z,
1951	png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
1952	png_fixed_point *int_blue_Z))
1953	#endif
1954
1955	#ifdef PNG_cHRM_SUPPORTED
1956	PNG_FP_EXPORT(`135`, void, png_set_cHRM, (png_const_structrp png_ptr,
1957	png_inforp info_ptr,
1958	double white_x, double white_y, double red_x, double red_y, double green_x,
1959	double green_y, double blue_x, double blue_y))
1960	PNG_FP_EXPORT(`232`, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr,
1961	png_inforp info_ptr, double red_X, double red_Y, double red_Z,
1962	double green_X, double green_Y, double green_Z, double blue_X,
1963	double blue_Y, double blue_Z))
1964	PNG_FIXED_EXPORT(`136`, void, png_set_cHRM_fixed, (png_const_structrp png_ptr,
1965	png_inforp info_ptr, png_fixed_point int_white_x,
1966	png_fixed_point int_white_y, png_fixed_point int_red_x,
1967	png_fixed_point int_red_y, png_fixed_point int_green_x,
1968	png_fixed_point int_green_y, png_fixed_point int_blue_x,
1969	png_fixed_point int_blue_y))
1970	PNG_FIXED_EXPORT(`233`, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr,
1971	png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y,
1972	png_fixed_point int_red_Z, png_fixed_point int_green_X,
1973	png_fixed_point int_green_Y, png_fixed_point int_green_Z,
1974	png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
1975	png_fixed_point int_blue_Z))
1976	#endif
1977
1978	#ifdef PNG_eXIf_SUPPORTED
1979	PNG_EXPORT(`246`, png_uint_32, png_get_eXIf, (png_const_structrp png_ptr,
1980	png_inforp info_ptr, png_bytep *exif));
1981	PNG_EXPORT(`247`, void, png_set_eXIf, (png_const_structrp png_ptr,
1982	png_inforp info_ptr, png_bytep exif));
1983
1984	PNG_EXPORT(`248`, png_uint_32, png_get_eXIf_1, (png_const_structrp png_ptr,
1985	png_const_inforp info_ptr, png_uint_32 num_exif, png_bytep exif));
1986	PNG_EXPORT(`249`, void, png_set_eXIf_1, (png_const_structrp png_ptr,
1987	png_inforp info_ptr, png_uint_32 num_exif, png_bytep exif));
1988	#endif
1989
1990	#ifdef PNG_gAMA_SUPPORTED
1991	PNG_FP_EXPORT(`137`, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr,
1992	png_const_inforp info_ptr, double *file_gamma))
1993	PNG_FIXED_EXPORT(`138`, png_uint_32, png_get_gAMA_fixed,
1994	(png_const_structrp png_ptr, png_const_inforp info_ptr,
1995	png_fixed_point *int_file_gamma))
1996	#endif
1997
1998	#ifdef PNG_gAMA_SUPPORTED
1999	PNG_FP_EXPORT(`139`, void, png_set_gAMA, (png_const_structrp png_ptr,
2000	png_inforp info_ptr, double file_gamma))
2001	PNG_FIXED_EXPORT(`140`, void, png_set_gAMA_fixed, (png_const_structrp png_ptr,
2002	png_inforp info_ptr, png_fixed_point int_file_gamma))
2003	#endif
2004
2005	#ifdef PNG_hIST_SUPPORTED
2006	PNG_EXPORT(`141`, png_uint_32, png_get_hIST, (png_const_structrp png_ptr,
2007	png_inforp info_ptr, png_uint_16p *hist));
2008	PNG_EXPORT(`142`, void, png_set_hIST, (png_const_structrp png_ptr,
2009	png_inforp info_ptr, png_const_uint_16p hist));
2010	#endif
2011
2012	PNG_EXPORT(`143`, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr,
2013	png_const_inforp info_ptr, png_uint_32 width, png_uint_32 height,
2014	int bit_depth, int* color_type, int* *interlace_method,
2015	int compression_method, int* *filter_method));
2016
2017	PNG_EXPORT(`144`, void, png_set_IHDR, (png_const_structrp png_ptr,
2018	png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
2019	int color_type, int interlace_method, int compression_method,
2020	int filter_method));
2021
2022	#ifdef PNG_oFFs_SUPPORTED
2023	PNG_EXPORT(`145`, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr,
2024	png_const_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2025	int *unit_type));
2026	#endif
2027
2028	#ifdef PNG_oFFs_SUPPORTED
2029	PNG_EXPORT(`146`, void, png_set_oFFs, (png_const_structrp png_ptr,
2030	png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2031	int unit_type));
2032	#endif
2033
2034	#ifdef PNG_pCAL_SUPPORTED
2035	PNG_EXPORT(`147`, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr,
2036	png_inforp info_ptr, png_charp purpose, png_int_32 X0,
2037	png_int_32 X1, int* type, int* nparams, png_charp units,
2038	png_charpp *params));
2039	#endif
2040
2041	#ifdef PNG_pCAL_SUPPORTED
2042	PNG_EXPORT(`148`, void, png_set_pCAL, (png_const_structrp png_ptr,
2043	png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1,
2044	int type, int nparams, png_const_charp units, png_charpp params));
2045	#endif
2046
2047	#ifdef PNG_pHYs_SUPPORTED
2048	PNG_EXPORT(`149`, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr,
2049	png_const_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y,
2050	int *unit_type));
2051	#endif
2052
2053	#ifdef PNG_pHYs_SUPPORTED
2054	PNG_EXPORT(`150`, void, png_set_pHYs, (png_const_structrp png_ptr,
2055	png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2056	#endif
2057
2058	PNG_EXPORT(`151`, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr,
2059	png_inforp info_ptr, png_colorp palette, int* *num_palette));
2060
2061	PNG_EXPORT(`152`, void, png_set_PLTE, (png_structrp png_ptr,
2062	png_inforp info_ptr, png_const_colorp palette, int num_palette));
2063
2064	#ifdef PNG_sBIT_SUPPORTED
2065	PNG_EXPORT(`153`, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr,
2066	png_inforp info_ptr, png_color_8p *sig_bit));
2067	#endif
2068
2069	#ifdef PNG_sBIT_SUPPORTED
2070	PNG_EXPORT(`154`, void, png_set_sBIT, (png_const_structrp png_ptr,
2071	png_inforp info_ptr, png_const_color_8p sig_bit));
2072	#endif
2073
2074	#ifdef PNG_sRGB_SUPPORTED
2075	PNG_EXPORT(`155`, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr,
2076	png_const_inforp info_ptr, int *file_srgb_intent));
2077	#endif
2078
2079	#ifdef PNG_sRGB_SUPPORTED
2080	PNG_EXPORT(`156`, void, png_set_sRGB, (png_const_structrp png_ptr,
2081	png_inforp info_ptr, int srgb_intent));
2082	PNG_EXPORT(`157`, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr,
2083	png_inforp info_ptr, int srgb_intent));
2084	#endif
2085
2086	#ifdef PNG_iCCP_SUPPORTED
2087	PNG_EXPORT(`158`, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr,
2088	png_inforp info_ptr, png_charpp name, int *compression_type,
2089	png_bytepp profile, png_uint_32 *proflen));
2090	#endif
2091
2092	#ifdef PNG_iCCP_SUPPORTED
2093	PNG_EXPORT(`159`, void, png_set_iCCP, (png_const_structrp png_ptr,
2094	png_inforp info_ptr, png_const_charp name, int compression_type,
2095	png_const_bytep profile, png_uint_32 proflen));
2096	#endif
2097
2098	#ifdef PNG_sPLT_SUPPORTED
2099	PNG_EXPORT(`160`, int, png_get_sPLT, (png_const_structrp png_ptr,
2100	png_inforp info_ptr, png_sPLT_tpp entries));
2101	#endif
2102
2103	#ifdef PNG_sPLT_SUPPORTED
2104	PNG_EXPORT(`161`, void, png_set_sPLT, (png_const_structrp png_ptr,
2105	png_inforp info_ptr, png_const_sPLT_tp entries, int nentries));
2106	#endif
2107
2108	#ifdef PNG_TEXT_SUPPORTED
2109	/ png_get_text also returns the number of text chunks in num_text /*
2110	PNG_EXPORT(`162`, int, png_get_text, (png_const_structrp png_ptr,
2111	png_inforp info_ptr, png_textp text_ptr, int* *num_text));
2112	#endif
2113
2114	/ Note while png_set_text() will accept a structure whose text,*
2115	* language, and translated keywords are NULL pointers, the structure
2116	* returned by png_get_text will always contain regular
2117	* zero-terminated C strings. They might be empty strings but
2118	* they will never be NULL pointers.
2119	*/
2120
2121	#ifdef PNG_TEXT_SUPPORTED
2122	PNG_EXPORT(`163`, void, png_set_text, (png_const_structrp png_ptr,
2123	png_inforp info_ptr, png_const_textp text_ptr, int num_text));
2124	#endif
2125
2126	#ifdef PNG_tIME_SUPPORTED
2127	PNG_EXPORT(`164`, png_uint_32, png_get_tIME, (png_const_structrp png_ptr,
2128	png_inforp info_ptr, png_timep *mod_time));
2129	#endif
2130
2131	#ifdef PNG_tIME_SUPPORTED
2132	PNG_EXPORT(`165`, void, png_set_tIME, (png_const_structrp png_ptr,
2133	png_inforp info_ptr, png_const_timep mod_time));
2134	#endif
2135
2136	#ifdef PNG_tRNS_SUPPORTED
2137	PNG_EXPORT(`166`, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr,
2138	png_inforp info_ptr, png_bytep trans_alpha, int* *num_trans,
2139	png_color_16p *trans_color));
2140	#endif
2141
2142	#ifdef PNG_tRNS_SUPPORTED
2143	PNG_EXPORT(`167`, void, png_set_tRNS, (png_structrp png_ptr,
2144	png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans,
2145	png_const_color_16p trans_color));
2146	#endif
2147
2148	#ifdef PNG_sCAL_SUPPORTED
2149	PNG_FP_EXPORT(`168`, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr,
2150	png_const_inforp info_ptr, int unit, double* width, double* *height))
2151	#if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) \|\| \
2152	defined(PNG_FLOATING_POINT_SUPPORTED)
2153	/ NOTE: this API is currently implemented using floating point arithmetic,*
2154	* consequently it can only be used on systems with floating point support.
2155	* In any case the range of values supported by png_fixed_point is small and it
2156	* is highly recommended that png_get_sCAL_s be used instead.
2157	*/
2158	PNG_FIXED_EXPORT(`214`, png_uint_32, png_get_sCAL_fixed,
2159	(png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
2160	png_fixed_point width, png_fixed_point height))
2161	#endif
2162	PNG_EXPORT(`169`, png_uint_32, png_get_sCAL_s,
2163	(png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
2164	png_charpp swidth, png_charpp sheight));
2165
2166	PNG_FP_EXPORT(`170`, void, png_set_sCAL, (png_const_structrp png_ptr,
2167	png_inforp info_ptr, int unit, double width, double height))
2168	PNG_FIXED_EXPORT(`213`, void, png_set_sCAL_fixed, (png_const_structrp png_ptr,
2169	png_inforp info_ptr, int unit, png_fixed_point width,
2170	png_fixed_point height))
2171	PNG_EXPORT(`171`, void, png_set_sCAL_s, (png_const_structrp png_ptr,
2172	png_inforp info_ptr, int unit,
2173	png_const_charp swidth, png_const_charp sheight));
2174	#endif /* sCAL */
2175
2176	#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
2177	/ Provide the default handling for all unknown chunks or, optionally, for*
2178	* specific unknown chunks.
2179	*
2180	* NOTE: prior to 1.6.0 the handling specified for particular chunks on read was
2181	* ignored and the default was used, the per-chunk setting only had an effect on
2182	* write. If you wish to have chunk-specific handling on read in code that must
2183	* work on earlier versions you must use a user chunk callback to specify the
2184	* desired handling (keep or discard.)
2185	*
2186	* The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The
2187	* parameter is interpreted as follows:
2188	*
2189	* READ:
2190	* PNG_HANDLE_CHUNK_AS_DEFAULT:
2191	* Known chunks: do normal libpng processing, do not keep the chunk (but
2192	* see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
2193	* Unknown chunks: for a specific chunk use the global default, when used
2194	* as the default discard the chunk data.
2195	* PNG_HANDLE_CHUNK_NEVER:
2196	* Discard the chunk data.
2197	* PNG_HANDLE_CHUNK_IF_SAFE:
2198	* Keep the chunk data if the chunk is not critical else raise a chunk
2199	* error.
2200	* PNG_HANDLE_CHUNK_ALWAYS:
2201	* Keep the chunk data.
2202	*
2203	* If the chunk data is saved it can be retrieved using png_get_unknown_chunks,
2204	* below. Notice that specifying "AS_DEFAULT" as a global default is equivalent
2205	* to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks
2206	* it simply resets the behavior to the libpng default.
2207	*
2208	* INTERACTION WITH USER CHUNK CALLBACKS:
2209	* The per-chunk handling is always used when there is a png_user_chunk_ptr
2210	* callback and the callback returns 0; the chunk is then always stored unless
2211	* it is critical and the per-chunk setting is other than ALWAYS. Notice that
2212	* the global default is not used in this case. (In effect the per-chunk
2213	* value is incremented to at least IF_SAFE.)
2214	*
2215	* IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and
2216	* per-chunk defaults will be honored. If you want to preserve the current
2217	* behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE
2218	* as the default - if you don't do this libpng 1.6 will issue a warning.
2219	*
2220	* If you want unhandled unknown chunks to be discarded in libpng 1.6 and
2221	* earlier simply return '1' (handled).
2222	*
2223	* PNG_HANDLE_AS_UNKNOWN_SUPPORTED:
2224	* If this is not set known chunks will always be handled by libpng and
2225	* will never be stored in the unknown chunk list. Known chunks listed to
2226	* png_set_keep_unknown_chunks will have no effect. If it is set then known
2227	* chunks listed with a keep other than AS_DEFAULT will never be processed
2228	* by libpng, in addition critical chunks must either be processed by the
2229	* callback or saved.
2230	*
2231	* The IHDR and IEND chunks must not be listed. Because this turns off the
2232	* default handling for chunks that would otherwise be recognized the
2233	* behavior of libpng transformations may well become incorrect!
2234	*
2235	* WRITE:
2236	* When writing chunks the options only apply to the chunks specified by
2237	* png_set_unknown_chunks (below), libpng will always write known chunks
2238	* required by png_set_ calls and will always write the core critical chunks
2239	* (as required for PLTE).
2240	*
2241	* Each chunk in the png_set_unknown_chunks list is looked up in the
2242	* png_set_keep_unknown_chunks list to find the keep setting, this is then
2243	* interpreted as follows:
2244	*
2245	* PNG_HANDLE_CHUNK_AS_DEFAULT:
2246	* Write safe-to-copy chunks and write other chunks if the global
2247	* default is set to _ALWAYS, otherwise don't write this chunk.
2248	* PNG_HANDLE_CHUNK_NEVER:
2249	* Do not write the chunk.
2250	* PNG_HANDLE_CHUNK_IF_SAFE:
2251	* Write the chunk if it is safe-to-copy, otherwise do not write it.
2252	* PNG_HANDLE_CHUNK_ALWAYS:
2253	* Write the chunk.
2254	*
2255	* Note that the default behavior is effectively the opposite of the read case -
2256	* in read unknown chunks are not stored by default, in write they are written
2257	* by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different
2258	* - on write the safe-to-copy bit is checked, on read the critical bit is
2259	* checked and on read if the chunk is critical an error will be raised.
2260	*
2261	* num_chunks:
2262	* ===========
2263	* If num_chunks is positive, then the "keep" parameter specifies the manner
2264	* for handling only those chunks appearing in the chunk_list array,
2265	* otherwise the chunk list array is ignored.
2266	*
2267	* If num_chunks is 0 the "keep" parameter specifies the default behavior for
2268	* unknown chunks, as described above.
2269	*
2270	* If num_chunks is negative, then the "keep" parameter specifies the manner
2271	* for handling all unknown chunks plus all chunks recognized by libpng
2272	* except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to
2273	* be processed by libpng.
2274	*/
2275	#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2276	PNG_EXPORT(`172`, void, png_set_keep_unknown_chunks, (png_structrp png_ptr,
2277	int keep, png_const_bytep chunk_list, int num_chunks));
2278	#endif /* HANDLE_AS_UNKNOWN */
2279
2280	/ The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned;*
2281	* the result is therefore true (non-zero) if special handling is required,
2282	* false for the default handling.
2283	*/
2284	PNG_EXPORT(`173`, int, png_handle_as_unknown, (png_const_structrp png_ptr,
2285	png_const_bytep chunk_name));
2286	#endif /* SET_UNKNOWN_CHUNKS */
2287
2288	#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
2289	PNG_EXPORT(`174`, void, png_set_unknown_chunks, (png_const_structrp png_ptr,
2290	png_inforp info_ptr, png_const_unknown_chunkp unknowns,
2291	int num_unknowns));
2292	/ NOTE: prior to 1.6.0 this routine set the 'location' field of the added*
2293	* unknowns to the location currently stored in the png_struct. This is
2294	* invariably the wrong value on write. To fix this call the following API
2295	* for each chunk in the list with the correct location. If you know your
2296	* code won't be compiled on earlier versions you can rely on
2297	* png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing
2298	* the correct thing.
2299	*/
2300
2301	PNG_EXPORT(`175`, void, png_set_unknown_chunk_location,
2302	(png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location));
2303
2304	PNG_EXPORT(`176`, int, png_get_unknown_chunks, (png_const_structrp png_ptr,
2305	png_inforp info_ptr, png_unknown_chunkpp entries));
2306	#endif
2307
2308	/ Png_free_data() will turn off the "valid" flag for anything it frees.*
2309	* If you need to turn it off for a chunk that your application has freed,
2310	* you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
2311	*/
2312	PNG_EXPORT(`177`, void, png_set_invalid, (png_const_structrp png_ptr,
2313	png_inforp info_ptr, int mask));
2314
2315	#ifdef PNG_INFO_IMAGE_SUPPORTED
2316	/ The "params" pointer is currently not used and is for future expansion. /
2317	#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
2318	PNG_EXPORT(`178`, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr,
2319	int transforms, png_voidp params));
2320	#endif
2321	#ifdef PNG_WRITE_SUPPORTED
2322	PNG_EXPORT(`179`, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr,
2323	int transforms, png_voidp params));
2324	#endif
2325	#endif
2326
2327	PNG_EXPORT(`180`, png_const_charp, png_get_copyright,
2328	(png_const_structrp png_ptr));
2329	PNG_EXPORT(`181`, png_const_charp, png_get_header_ver,
2330	(png_const_structrp png_ptr));
2331	PNG_EXPORT(`182`, png_const_charp, png_get_header_version,
2332	(png_const_structrp png_ptr));
2333	PNG_EXPORT(`183`, png_const_charp, png_get_libpng_ver,
2334	(png_const_structrp png_ptr));
2335
2336	#ifdef PNG_MNG_FEATURES_SUPPORTED
2337	PNG_EXPORT(`184`, png_uint_32, png_permit_mng_features, (png_structrp png_ptr,
2338	png_uint_32 mng_features_permitted));
2339	#endif
2340
2341	/ For use in png_set_keep_unknown, added to version 1.2.6 /
2342	#define PNG_HANDLE_CHUNK_AS_DEFAULT 0
2343	#define PNG_HANDLE_CHUNK_NEVER 1
2344	#define PNG_HANDLE_CHUNK_IF_SAFE 2
2345	#define PNG_HANDLE_CHUNK_ALWAYS 3
2346	#define PNG_HANDLE_CHUNK_LAST 4
2347
2348	/ Strip the prepended error numbers ("#nnn ") from error and warning*
2349	* messages before passing them to the error or warning handler.
2350	*/
2351	#ifdef PNG_ERROR_NUMBERS_SUPPORTED
2352	PNG_EXPORT(`185`, void, png_set_strip_error_numbers, (png_structrp png_ptr,
2353	png_uint_32 strip_mode));
2354	#endif
2355
2356	/ Added in libpng-1.2.6 /
2357	#ifdef PNG_SET_USER_LIMITS_SUPPORTED
2358	PNG_EXPORT(`186`, void, png_set_user_limits, (png_structrp png_ptr,
2359	png_uint_32 user_width_max, png_uint_32 user_height_max));
2360	PNG_EXPORT(`187`, png_uint_32, png_get_user_width_max,
2361	(png_const_structrp png_ptr));
2362	PNG_EXPORT(`188`, png_uint_32, png_get_user_height_max,
2363	(png_const_structrp png_ptr));
2364	/ Added in libpng-1.4.0 /
2365	PNG_EXPORT(`189`, void, png_set_chunk_cache_max, (png_structrp png_ptr,
2366	png_uint_32 user_chunk_cache_max));
2367	PNG_EXPORT(`190`, png_uint_32, png_get_chunk_cache_max,
2368	(png_const_structrp png_ptr));
2369	/ Added in libpng-1.4.1 /
2370	PNG_EXPORT(`191`, void, png_set_chunk_malloc_max, (png_structrp png_ptr,
2371	png_alloc_size_t user_chunk_cache_max));
2372	PNG_EXPORT(`192`, png_alloc_size_t, png_get_chunk_malloc_max,
2373	(png_const_structrp png_ptr));
2374	#endif
2375
2376	#if defined(PNG_INCH_CONVERSIONS_SUPPORTED)
2377	PNG_EXPORT(`193`, png_uint_32, png_get_pixels_per_inch,
2378	(png_const_structrp png_ptr, png_const_inforp info_ptr));
2379
2380	PNG_EXPORT(`194`, png_uint_32, png_get_x_pixels_per_inch,
2381	(png_const_structrp png_ptr, png_const_inforp info_ptr));
2382
2383	PNG_EXPORT(`195`, png_uint_32, png_get_y_pixels_per_inch,
2384	(png_const_structrp png_ptr, png_const_inforp info_ptr));
2385
2386	PNG_FP_EXPORT(`196`, float, png_get_x_offset_inches,
2387	(png_const_structrp png_ptr, png_const_inforp info_ptr))
2388	#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2389	PNG_FIXED_EXPORT(`211`, png_fixed_point, png_get_x_offset_inches_fixed,
2390	(png_const_structrp png_ptr, png_const_inforp info_ptr))
2391	#endif
2392
2393	PNG_FP_EXPORT(`197`, float, png_get_y_offset_inches, (png_const_structrp png_ptr,
2394	png_const_inforp info_ptr))
2395	#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2396	PNG_FIXED_EXPORT(`212`, png_fixed_point, png_get_y_offset_inches_fixed,
2397	(png_const_structrp png_ptr, png_const_inforp info_ptr))
2398	#endif
2399
2400	# ifdef PNG_pHYs_SUPPORTED
2401	PNG_EXPORT(`198`, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr,
2402	png_const_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y,
2403	int *unit_type));
2404	# endif /* pHYs */
2405	#endif /* INCH_CONVERSIONS */
2406
2407	/ Added in libpng-1.4.0 /
2408	#ifdef PNG_IO_STATE_SUPPORTED
2409	PNG_EXPORT(`199`, png_uint_32, png_get_io_state, (png_const_structrp png_ptr));
2410
2411	/ Removed from libpng 1.6; use png_get_io_chunk_type. /
2412	PNG_REMOVED(`200`, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr),
2413	PNG_DEPRECATED)
2414
2415	PNG_EXPORT(`216`, png_uint_32, png_get_io_chunk_type,
2416	(png_const_structrp png_ptr));
2417
2418	/ The flags returned by png_get_io_state() are the following: /
2419	# define PNG_IO_NONE 0x0000 /* no I/O at this moment */
2420	# define PNG_IO_READING 0x0001 /* currently reading */
2421	# define PNG_IO_WRITING 0x0002 /* currently writing */
2422	# define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */
2423	# define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */
2424	# define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */
2425	# define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */
2426	# define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */
2427	# define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */
2428	#endif /* IO_STATE */
2429
2430	/ Interlace support. The following macros are always defined so that if*
2431	* libpng interlace handling is turned off the macros may be used to handle
2432	* interlaced images within the application.
2433	*/
2434	#define PNG_INTERLACE_ADAM7_PASSES 7
2435
2436	/ Two macros to return the first row and first column of the original,*
2437	* full, image which appears in a given pass. 'pass' is in the range 0
2438	* to 6 and the result is in the range 0 to 7.
2439	*/
2440	#define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7)
2441	#define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7)
2442
2443	/ A macro to return the offset between pixels in the output row for a pair of*
2444	* pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that
2445	* follows. Note that ROW_OFFSET is the offset from one row to the next whereas
2446	* COL_OFFSET is from one column to the next, within a row.
2447	*/
2448	#define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8)
2449	#define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1))
2450
2451	/ Two macros to help evaluate the number of rows or columns in each*
2452	* pass. This is expressed as a shift - effectively log2 of the number or
2453	* rows or columns in each 8x8 tile of the original image.
2454	*/
2455	#define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)
2456	#define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)
2457
2458	/ Hence two macros to determine the number of rows or columns in a given*
2459	* pass of an image given its height or width. In fact these macros may
2460	* return non-zero even though the sub-image is empty, because the other
2461	* dimension may be empty for a small image.
2462	*/
2463	#define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\
2464	-1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass))
2465	#define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\
2466	-1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass))
2467
2468	/ For the reader row callbacks (both progressive and sequential) it is*
2469	* necessary to find the row in the output image given a row in an interlaced
2470	* image, so two more macros:
2471	*/
2472	#define PNG_ROW_FROM_PASS_ROW(y_in, pass) \
2473	(((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))
2474	#define PNG_COL_FROM_PASS_COL(x_in, pass) \
2475	(((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))
2476
2477	/ Two macros which return a boolean (0 or 1) saying whether the given row*
2478	* or column is in a particular pass. These use a common utility macro that
2479	* returns a mask for a given pass - the offset 'off' selects the row or
2480	* column version. The mask has the appropriate bit set for each column in
2481	* the tile.
2482	*/
2483	#define PNG_PASS_MASK(pass,off) ( \
2484	((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) \| \
2485	((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0))
2486
2487	#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
2488	((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
2489	#define PNG_COL_IN_INTERLACE_PASS(x, pass) \
2490	((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
2491
2492	#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2493	/ With these routines we avoid an integer divide, which will be slower on*
2494	* most machines. However, it does take more operations than the corresponding
2495	* divide method, so it may be slower on a few RISC systems. There are two
2496	* shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2497	*
2498	* Note that the rounding factors are NOT supposed to be the same! 128 and
2499	* 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2500	* standard method.
2501	*
2502	* [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2503	*/
2504
2505	/ fg and bg should be in `gamma 1.0' space; alpha is the opacity /
2506
2507	# define png_composite(composite, fg, alpha, bg) \
2508	{ \
2509	png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
2510	* (png_uint_16)(alpha) \
2511	+ (png_uint_16)(bg)*(png_uint_16)(255 \
2512	- (png_uint_16)(alpha)) + 128); \
2513	(composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); \
2514	}
2515
2516	# define png_composite_16(composite, fg, alpha, bg) \
2517	{ \
2518	png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
2519	* (png_uint_32)(alpha) \
2520	+ (png_uint_32)(bg)*(65535 \
2521	- (png_uint_32)(alpha)) + 32768); \
2522	(composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); \
2523	}
2524
2525	#else /* Standard method using integer division */
2526
2527	# define png_composite(composite, fg, alpha, bg) \
2528	(composite) = \
2529	(png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2530	(png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2531	127) / 255))
2532
2533	# define png_composite_16(composite, fg, alpha, bg) \
2534	(composite) = \
2535	(png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2536	(png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \
2537	32767) / 65535))
2538	#endif /* READ_COMPOSITE_NODIV */
2539
2540	#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
2541	PNG_EXPORT(`201`, png_uint_32, png_get_uint_32, (png_const_bytep buf));
2542	PNG_EXPORT(`202`, png_uint_16, png_get_uint_16, (png_const_bytep buf));
2543	PNG_EXPORT(`203`, png_int_32, png_get_int_32, (png_const_bytep buf));
2544	#endif
2545
2546	PNG_EXPORT(`204`, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr,
2547	png_const_bytep buf));
2548	/ No png_get_int_16 -- may be added if there's a real need for it. /
2549
2550	/ Place a 32-bit number into a buffer in PNG byte order (big-endian). /
2551	#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2552	PNG_EXPORT(`205`, void, png_save_uint_32, (png_bytep buf, png_uint_32 i));
2553	#endif
2554	#ifdef PNG_SAVE_INT_32_SUPPORTED
2555	PNG_EXPORT(`206`, void, png_save_int_32, (png_bytep buf, png_int_32 i));
2556	#endif
2557
2558	/ Place a 16-bit number into a buffer in PNG byte order.*
2559	* The parameter is declared unsigned int, not png_uint_16,
2560	* just to avoid potential problems on pre-ANSI C compilers.
2561	*/
2562	#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2563	PNG_EXPORT(`207`, void, png_save_uint_16, (png_bytep buf, unsigned int i));
2564	/ No png_save_int_16 -- may be added if there's a real need for it. /
2565	#endif
2566
2567	#ifdef PNG_USE_READ_MACROS
2568	/ Inline macros to do direct reads of bytes from the input buffer.*
2569	* The png_get_int_32() routine assumes we are using two's complement
2570	* format for negative values, which is almost certainly true.
2571	*/
2572	# define PNG_get_uint_32(buf) \
2573	(((png_uint_32)(*(buf)) << 24) + \
2574	((png_uint_32)(*((buf) + 1)) << 16) + \
2575	((png_uint_32)(*((buf) + 2)) << 8) + \
2576	((png_uint_32)(*((buf) + 3))))
2577
2578	/ From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the*
2579	* function) incorrectly returned a value of type png_uint_32.
2580	*/
2581	# define PNG_get_uint_16(buf) \
2582	((png_uint_16) \
2583	(((unsigned int)(*(buf)) << 8) + \
2584	((unsigned int)(*((buf) + 1)))))
2585
2586	# define PNG_get_int_32(buf) \
2587	((png_int_32)((*(buf) & 0x80) \
2588	? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \
2589	: (png_int_32)png_get_uint_32(buf)))
2590
2591	/ If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h,*
2592	* but defining a macro name prefixed with PNG_PREFIX.
2593	*/
2594	# ifndef PNG_PREFIX
2595	# define png_get_uint_32(buf) PNG_get_uint_32(buf)
2596	# define png_get_uint_16(buf) PNG_get_uint_16(buf)
2597	# define png_get_int_32(buf) PNG_get_int_32(buf)
2598	# endif
2599	#else
2600	# ifdef PNG_PREFIX
2601	/ No macros; revert to the (redefined) function /
2602	# define PNG_get_uint_32 (png_get_uint_32)
2603	# define PNG_get_uint_16 (png_get_uint_16)
2604	# define PNG_get_int_32 (png_get_int_32)
2605	# endif
2606	#endif
2607
2608	#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
2609	PNG_EXPORT(`242`, void, png_set_check_for_invalid_index,
2610	(png_structrp png_ptr, int allowed));
2611	# ifdef PNG_GET_PALETTE_MAX_SUPPORTED
2612	PNG_EXPORT(`243`, int, png_get_palette_max, (png_const_structp png_ptr,
2613	png_const_infop info_ptr));
2614	# endif
2615	#endif /* CHECK_FOR_INVALID_INDEX */
2616
2617	/*******************************************************************************
2618	* Section 5: SIMPLIFIED API
2619	*******************************************************************************
2620	*
2621	* Please read the documentation in libpng-manual.txt (TODO: write said
2622	* documentation) if you don't understand what follows.
2623	*
2624	* The simplified API hides the details of both libpng and the PNG file format
2625	* itself. It allows PNG files to be read into a very limited number of
2626	* in-memory bitmap formats or to be written from the same formats. If these
2627	* formats do not accommodate your needs then you can, and should, use the more
2628	* sophisticated APIs above - these support a wide variety of in-memory formats
2629	* and a wide variety of sophisticated transformations to those formats as well
2630	* as a wide variety of APIs to manipulate ancillary information.
2631	*
2632	* To read a PNG file using the simplified API:
2633	*
2634	* 1) Declare a 'png_image' structure (see below) on the stack, set the
2635	* version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL
2636	* (this is REQUIRED, your program may crash if you don't do it.)
2637	* 2) Call the appropriate png_image_begin_read... function.
2638	* 3) Set the png_image 'format' member to the required sample format.
2639	* 4) Allocate a buffer for the image and, if required, the color-map.
2640	* 5) Call png_image_finish_read to read the image and, if required, the
2641	* color-map into your buffers.
2642	*
2643	* There are no restrictions on the format of the PNG input itself; all valid
2644	* color types, bit depths, and interlace methods are acceptable, and the
2645	* input image is transformed as necessary to the requested in-memory format
2646	* during the png_image_finish_read() step. The only caveat is that if you
2647	* request a color-mapped image from a PNG that is full-color or makes
2648	* complex use of an alpha channel the transformation is extremely lossy and the
2649	* result may look terrible.
2650	*
2651	* To write a PNG file using the simplified API:
2652	*
2653	* 1) Declare a 'png_image' structure on the stack and memset() it to all zero.
2654	* 2) Initialize the members of the structure that describe the image, setting
2655	* the 'format' member to the format of the image samples.
2656	* 3) Call the appropriate png_image_write... function with a pointer to the
2657	* image and, if necessary, the color-map to write the PNG data.
2658	*
2659	* png_image is a structure that describes the in-memory format of an image
2660	* when it is being read or defines the in-memory format of an image that you
2661	* need to write:
2662	*/
2663	#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) \|\| \
2664	defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
2665
2666	#define PNG_IMAGE_VERSION 1
2667
2668	typedef struct png_control *png_controlp;
2669	typedef struct
2670	{
2671	png_controlp opaque; / Initialize to NULL, free with png_image_free /
2672	png_uint_32 version; / Set to PNG_IMAGE_VERSION /
2673	png_uint_32 width; / Image width in pixels (columns) /
2674	png_uint_32 height; / Image height in pixels (rows) /
2675	png_uint_32 format; / Image format as defined below /
2676	png_uint_32 flags; / A bit mask containing informational flags /
2677	png_uint_32 colormap_entries;
2678	/ Number of entries in the color-map /
2679
2680	/ In the event of an error or warning the following field will be set to a*
2681	* non-zero value and the 'message' field will contain a '\0' terminated
2682	* string with the libpng error or warning message. If both warnings and
2683	* an error were encountered, only the error is recorded. If there
2684	* are multiple warnings, only the first one is recorded.
2685	*
2686	* The upper 30 bits of this value are reserved, the low two bits contain
2687	* a value as follows:
2688	*/
2689	# define PNG_IMAGE_WARNING 1
2690	# define PNG_IMAGE_ERROR 2
2691	/*
2692	* The result is a two-bit code such that a value more than 1 indicates
2693	* a failure in the API just called:
2694	*
2695	* 0 - no warning or error
2696	* 1 - warning
2697	* 2 - error
2698	* 3 - error preceded by warning
2699	*/
2700	# define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1)
2701
2702	png_uint_32 warning_or_error;
2703
2704	char message[`64`];
2705	} png_image, *png_imagep;
2706
2707	/ The samples of the image have one to four channels whose components have*
2708	* original values in the range 0 to 1.0:
2709	*
2710	* 1: A single gray or luminance channel (G).
2711	* 2: A gray/luminance channel and an alpha channel (GA).
2712	* 3: Three red, green, blue color channels (RGB).
2713	* 4: Three color channels and an alpha channel (RGBA).
2714	*
2715	* The components are encoded in one of two ways:
2716	*
2717	* a) As a small integer, value 0..255, contained in a single byte. For the
2718	* alpha channel the original value is simply value/255. For the color or
2719	* luminance channels the value is encoded according to the sRGB specification
2720	* and matches the 8-bit format expected by typical display devices.
2721	*
2722	* The color/gray channels are not scaled (pre-multiplied) by the alpha
2723	* channel and are suitable for passing to color management software.
2724	*
2725	* b) As a value in the range 0..65535, contained in a 2-byte integer. All
2726	* channels can be converted to the original value by dividing by 65535; all
2727	* channels are linear. Color channels use the RGB encoding (RGB end-points) of
2728	* the sRGB specification. This encoding is identified by the
2729	* PNG_FORMAT_FLAG_LINEAR flag below.
2730	*
2731	* When the simplified API needs to convert between sRGB and linear colorspaces,
2732	* the actual sRGB transfer curve defined in the sRGB specification (see the
2733	* article at <https://en.wikipedia.org/wiki/SRGB>) is used, not the gamma=1/2.2
2734	* approximation used elsewhere in libpng.
2735	*
2736	* When an alpha channel is present it is expected to denote pixel coverage
2737	* of the color or luminance channels and is returned as an associated alpha
2738	* channel: the color/gray channels are scaled (pre-multiplied) by the alpha
2739	* value.
2740	*
2741	* The samples are either contained directly in the image data, between 1 and 8
2742	* bytes per pixel according to the encoding, or are held in a color-map indexed
2743	* by bytes in the image data. In the case of a color-map the color-map entries
2744	* are individual samples, encoded as above, and the image data has one byte per
2745	* pixel to select the relevant sample from the color-map.
2746	*/
2747
2748	/* PNG_FORMAT_*
2749	*
2750	* #defines to be used in png_image::format. Each #define identifies a
2751	* particular layout of sample data and, if present, alpha values. There are
2752	* separate defines for each of the two component encodings.
2753	*
2754	* A format is built up using single bit flag values. All combinations are
2755	* valid. Formats can be built up from the flag values or you can use one of
2756	* the predefined values below. When testing formats always use the FORMAT_FLAG
2757	* macros to test for individual features - future versions of the library may
2758	* add new flags.
2759	*
2760	* When reading or writing color-mapped images the format should be set to the
2761	* format of the entries in the color-map then png_image_{read,write}_colormap
2762	* called to read or write the color-map and set the format correctly for the
2763	* image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly!
2764	*
2765	* NOTE: libpng can be built with particular features disabled. If you see
2766	* compiler errors because the definition of one of the following flags has been
2767	* compiled out it is because libpng does not have the required support. It is
2768	* possible, however, for the libpng configuration to enable the format on just
2769	* read or just write; in that case you may see an error at run time. You can
2770	* guard against this by checking for the definition of the appropriate
2771	* "_SUPPORTED" macro, one of:
2772	*
2773	* PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED
2774	*/
2775	#define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */
2776	#define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */
2777	#define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */
2778	#define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */
2779
2780	#ifdef PNG_FORMAT_BGR_SUPPORTED
2781	# define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */
2782	#endif
2783
2784	#ifdef PNG_FORMAT_AFIRST_SUPPORTED
2785	# define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */
2786	#endif
2787
2788	#define PNG_FORMAT_FLAG_ASSOCIATED_ALPHA 0x40U /* alpha channel is associated */
2789
2790	/ Commonly used formats have predefined macros.*
2791	*
2792	* First the single byte (sRGB) formats:
2793	*/
2794	#define PNG_FORMAT_GRAY 0
2795	#define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA
2796	#define PNG_FORMAT_AG (PNG_FORMAT_GA\|PNG_FORMAT_FLAG_AFIRST)
2797	#define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR
2798	#define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR\|PNG_FORMAT_FLAG_BGR)
2799	#define PNG_FORMAT_RGBA (PNG_FORMAT_RGB\|PNG_FORMAT_FLAG_ALPHA)
2800	#define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA\|PNG_FORMAT_FLAG_AFIRST)
2801	#define PNG_FORMAT_BGRA (PNG_FORMAT_BGR\|PNG_FORMAT_FLAG_ALPHA)
2802	#define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA\|PNG_FORMAT_FLAG_AFIRST)
2803
2804	/ Then the linear 2-byte formats. When naming these "Y" is used to*
2805	* indicate a luminance (gray) channel.
2806	*/
2807	#define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR
2808	#define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR\|PNG_FORMAT_FLAG_ALPHA)
2809	#define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR\|PNG_FORMAT_FLAG_COLOR)
2810	#define PNG_FORMAT_LINEAR_RGB_ALPHA \
2811	(PNG_FORMAT_FLAG_LINEAR\|PNG_FORMAT_FLAG_COLOR\|PNG_FORMAT_FLAG_ALPHA)
2812
2813	/ With color-mapped formats the image data is one byte for each pixel, the byte*
2814	* is an index into the color-map which is formatted as above. To obtain a
2815	* color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP
2816	* to one of the above definitions, or you can use one of the definitions below.
2817	*/
2818	#define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB\|PNG_FORMAT_FLAG_COLORMAP)
2819	#define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR\|PNG_FORMAT_FLAG_COLORMAP)
2820	#define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA\|PNG_FORMAT_FLAG_COLORMAP)
2821	#define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB\|PNG_FORMAT_FLAG_COLORMAP)
2822	#define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA\|PNG_FORMAT_FLAG_COLORMAP)
2823	#define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR\|PNG_FORMAT_FLAG_COLORMAP)
2824
2825	/ PNG_IMAGE macros*
2826	*
2827	* These are convenience macros to derive information from a png_image
2828	* structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the
2829	* actual image sample values - either the entries in the color-map or the
2830	* pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values
2831	* for the pixels and will always return 1 for color-mapped formats. The
2832	* remaining macros return information about the rows in the image and the
2833	* complete image.
2834	*
2835	* NOTE: All the macros that take a png_image::format parameter are compile time
2836	* constants if the format parameter is, itself, a constant. Therefore these
2837	* macros can be used in array declarations and case labels where required.
2838	* Similarly the macros are also pre-processor constants (sizeof is not used) so
2839	* they can be used in #if tests.
2840	*
2841	* First the information about the samples.
2842	*/
2843	#define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\
2844	(((fmt)&(PNG_FORMAT_FLAG_COLOR\|PNG_FORMAT_FLAG_ALPHA))+1)
2845	/ Return the total number of channels in a given format: 1..4 /
2846
2847	#define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\
2848	((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1)
2849	/ Return the size in bytes of a single component of a pixel or color-map*
2850	* entry (as appropriate) in the image: 1 or 2.
2851	*/
2852
2853	#define PNG_IMAGE_SAMPLE_SIZE(fmt)\
2854	(PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt))
2855	/ This is the size of the sample data for one sample. If the image is*
2856	* color-mapped it is the size of one color-map entry (and image pixels are
2857	* one byte in size), otherwise it is the size of one image pixel.
2858	*/
2859
2860	#define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\
2861	(PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256)
2862	/ The maximum size of the color-map required by the format expressed in a*
2863	* count of components. This can be used to compile-time allocate a
2864	* color-map:
2865	*
2866	* png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)];
2867	*
2868	* png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)];
2869	*
2870	* Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the
2871	* information from one of the png_image_begin_read_ APIs and dynamically
2872	* allocate the required memory.
2873	*/
2874
2875	/ Corresponding information about the pixels /
2876	#define PNG_IMAGE_PIXEL_(test,fmt)\
2877	(((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt))
2878
2879	#define PNG_IMAGE_PIXEL_CHANNELS(fmt)\
2880	PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt)
2881	/ The number of separate channels (components) in a pixel; 1 for a*
2882	* color-mapped image.
2883	*/
2884
2885	#define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\
2886	PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt)
2887	/ The size, in bytes, of each component in a pixel; 1 for a color-mapped*
2888	* image.
2889	*/
2890
2891	#define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt)
2892	/ The size, in bytes, of a complete pixel; 1 for a color-mapped image. /
2893
2894	/ Information about the whole row, or whole image /
2895	#define PNG_IMAGE_ROW_STRIDE(image)\
2896	(PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width)
2897	/ Return the total number of components in a single row of the image; this*
2898	* is the minimum 'row stride', the minimum count of components between each
2899	* row. For a color-mapped image this is the minimum number of bytes in a
2900	* row.
2901	*
2902	* WARNING: this macro overflows for some images with more than one component
2903	* and very large image widths. libpng will refuse to process an image where
2904	* this macro would overflow.
2905	*/
2906
2907	#define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\
2908	(PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)(image).height(row_stride))
2909	/ Return the size, in bytes, of an image buffer given a png_image and a row*
2910	* stride - the number of components to leave space for in each row.
2911	*
2912	* WARNING: this macro overflows a 32-bit integer for some large PNG images,
2913	* libpng will refuse to process an image where such an overflow would occur.
2914	*/
2915
2916	#define PNG_IMAGE_SIZE(image)\
2917	PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image))
2918	/ Return the size, in bytes, of the image in memory given just a png_image;*
2919	* the row stride is the minimum stride required for the image.
2920	*/
2921
2922	#define PNG_IMAGE_COLORMAP_SIZE(image)\
2923	(PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries)
2924	/ Return the size, in bytes, of the color-map of this image. If the image*
2925	* format is not a color-map format this will return a size sufficient for
2926	* 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if
2927	* you don't want to allocate a color-map in this case.
2928	*/
2929
2930	/* PNG_IMAGE_FLAG_*
2931	*
2932	* Flags containing additional information about the image are held in the
2933	* 'flags' field of png_image.
2934	*/
2935	#define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01
2936	/ This indicates that the RGB values of the in-memory bitmap do not*
2937	* correspond to the red, green and blue end-points defined by sRGB.
2938	*/
2939
2940	#define PNG_IMAGE_FLAG_FAST 0x02
2941	/ On write emphasise speed over compression; the resultant PNG file will be*
2942	* larger but will be produced significantly faster, particular for large
2943	* images. Do not use this option for images which will be distributed, only
2944	* used it when producing intermediate files that will be read back in
2945	* repeatedly. For a typical 24-bit image the option will double the read
2946	* speed at the cost of increasing the image size by 25%, however for many
2947	* more compressible images the PNG file can be 10 times larger with only a
2948	* slight speed gain.
2949	*/
2950
2951	#define PNG_IMAGE_FLAG_16BIT_sRGB 0x04
2952	/ On read if the image is a 16-bit per component image and there is no gAMA*
2953	* or sRGB chunk assume that the components are sRGB encoded. Notice that
2954	* images output by the simplified API always have gamma information; setting
2955	* this flag only affects the interpretation of 16-bit images from an
2956	* external source. It is recommended that the application expose this flag
2957	* to the user; the user can normally easily recognize the difference between
2958	* linear and sRGB encoding. This flag has no effect on write - the data
2959	* passed to the write APIs must have the correct encoding (as defined
2960	* above.)
2961	*
2962	* If the flag is not set (the default) input 16-bit per component data is
2963	* assumed to be linear.
2964	*
2965	* NOTE: the flag can only be set after the png_image_begin_read_ call,
2966	* because that call initializes the 'flags' field.
2967	*/
2968
2969	#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
2970	/ READ APIs*
2971	* ---------
2972	*
2973	* The png_image passed to the read APIs must have been initialized by setting
2974	* the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.)
2975	*/
2976	#ifdef PNG_STDIO_SUPPORTED
2977	PNG_EXPORT(`234`, int, png_image_begin_read_from_file, (png_imagep image,
2978	const char *file_name));
2979	/ The named file is opened for read and the image header is filled in*
2980	* from the PNG header in the file.
2981	*/
2982
2983	PNG_EXPORT(`235`, int, png_image_begin_read_from_stdio, (png_imagep image,
2984	FILE* file));
2985	/ The PNG header is read from the stdio FILE object. /
2986	#endif /* STDIO */
2987
2988	PNG_EXPORT(`236`, int, png_image_begin_read_from_memory, (png_imagep image,
2989	png_const_voidp memory, size_t size));
2990	/ The PNG header is read from the given memory buffer. /
2991
2992	PNG_EXPORT(`237`, int, png_image_finish_read, (png_imagep image,
2993	png_const_colorp background, void *buffer, png_int_32 row_stride,
2994	void *colormap));
2995	/ Finish reading the image into the supplied buffer and clean up the*
2996	* png_image structure.
2997	*
2998	* row_stride is the step, in byte or 2-byte units as appropriate,
2999	* between adjacent rows. A positive stride indicates that the top-most row
3000	* is first in the buffer - the normal top-down arrangement. A negative
3001	* stride indicates that the bottom-most row is first in the buffer.
3002	*
3003	* background need only be supplied if an alpha channel must be removed from
3004	* a png_byte format and the removal is to be done by compositing on a solid
3005	* color; otherwise it may be NULL and any composition will be done directly
3006	* onto the buffer. The value is an sRGB color to use for the background,
3007	* for grayscale output the green channel is used.
3008	*
3009	* background must be supplied when an alpha channel must be removed from a
3010	* single byte color-mapped output format, in other words if:
3011	*
3012	* 1) The original format from png_image_begin_read_from_* had
3013	* PNG_FORMAT_FLAG_ALPHA set.
3014	* 2) The format set by the application does not.
3015	* 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and
3016	* PNG_FORMAT_FLAG_LINEAR not set.
3017	*
3018	* For linear output removing the alpha channel is always done by compositing
3019	* on black and background is ignored.
3020	*
3021	* colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must
3022	* be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE.
3023	* image->colormap_entries will be updated to the actual number of entries
3024	* written to the colormap; this may be less than the original value.
3025	*/
3026
3027	PNG_EXPORT(`238`, void, png_image_free, (png_imagep image));
3028	/ Free any data allocated by libpng in image->opaque, setting the pointer to*
3029	* NULL. May be called at any time after the structure is initialized.
3030	*/
3031	#endif /* SIMPLIFIED_READ */
3032
3033	#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
3034	/ WRITE APIS*
3035	* ----------
3036	* For write you must initialize a png_image structure to describe the image to
3037	* be written. To do this use memset to set the whole structure to 0 then
3038	* initialize fields describing your image.
3039	*
3040	* version: must be set to PNG_IMAGE_VERSION
3041	* opaque: must be initialized to NULL
3042	* width: image width in pixels
3043	* height: image height in rows
3044	* format: the format of the data (image and color-map) you wish to write
3045	* flags: set to 0 unless one of the defined flags applies; set
3046	* PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB
3047	* values do not correspond to the colors in sRGB.
3048	* colormap_entries: set to the number of entries in the color-map (0 to 256)
3049	*/
3050	#ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
3051	PNG_EXPORT(`239`, int, png_image_write_to_file, (png_imagep image,
3052	const char file, int* convert_to_8bit, const void *buffer,
3053	png_int_32 row_stride, const void *colormap));
3054	/ Write the image to the named file. /
3055
3056	PNG_EXPORT(`240`, int, png_image_write_to_stdio, (png_imagep image, FILE *file,
3057	int convert_to_8_bit, const void *buffer, png_int_32 row_stride,
3058	const void *colormap));
3059	/ Write the image to the given (FILE). /*
3060	#endif /* SIMPLIFIED_WRITE_STDIO */
3061
3062	/ With all write APIs if image is in one of the linear formats with 16-bit*
3063	* data then setting convert_to_8_bit will cause the output to be an 8-bit PNG
3064	* gamma encoded according to the sRGB specification, otherwise a 16-bit linear
3065	* encoded PNG file is written.
3066	*
3067	* With color-mapped data formats the colormap parameter point to a color-map
3068	* with at least image->colormap_entries encoded in the specified format. If
3069	* the format is linear the written PNG color-map will be converted to sRGB
3070	* regardless of the convert_to_8_bit flag.
3071	*
3072	* With all APIs row_stride is handled as in the read APIs - it is the spacing
3073	* from one row to the next in component sized units (1 or 2 bytes) and if
3074	* negative indicates a bottom-up row layout in the buffer. If row_stride is
3075	* zero, libpng will calculate it for you from the image width and number of
3076	* channels.
3077	*
3078	* Note that the write API does not support interlacing, sub-8-bit pixels or
3079	* most ancillary chunks. If you need to write text chunks (e.g. for copyright
3080	* notices) you need to use one of the other APIs.
3081	*/
3082
3083	PNG_EXPORT(`245`, int, png_image_write_to_memory, (png_imagep image, void *memory,
3084	png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8_bit,
3085	const void buffer, png_int_32 row_stride, const* void *colormap));
3086	/ Write the image to the given memory buffer. The function both writes the*
3087	* whole PNG data stream to memory and updates memory_bytes with the count
3088	* of bytes written.
3089	*
3090	* 'memory' may be NULL. In this case *memory_bytes is not read however on
3091	* success the number of bytes which would have been written will still be
3092	* stored in memory_bytes. On failure memory_bytes will contain 0.
3093	*
3094	* If 'memory' is not NULL it must point to memory[*memory_bytes] of
3095	* writeable memory.
3096	*
3097	* If the function returns success memory[*memory_bytes] (if 'memory' is not
3098	* NULL) contains the written PNG data. *memory_bytes will always be less
3099	* than or equal to the original value.
3100	*
3101	* If the function returns false and *memory_bytes was not changed an error
3102	* occurred during write. If *memory_bytes was changed, or is not 0 if
3103	* 'memory' was NULL, the write would have succeeded but for the memory
3104	* buffer being too small. *memory_bytes contains the required number of
3105	* bytes and will be bigger that the original value.
3106	*/
3107
3108	#define png_image_write_get_memory_size(image, size, convert_to_8_bit, buffer,\
3109	row_stride, colormap)\
3110	png_image_write_to_memory(&(image), 0, &(size), convert_to_8_bit, buffer,\
3111	row_stride, colormap)
3112	/ Return the amount of memory in 'size' required to compress this image.*
3113	* The png_image structure 'image' must be filled in as in the above
3114	* function and must not be changed before the actual write call, the buffer
3115	* and all other parameters must also be identical to that in the final
3116	* write call. The 'size' variable need not be initialized.
3117	*
3118	* NOTE: the macro returns true/false, if false is returned 'size' will be
3119	* set to zero and the write failed and probably will fail if tried again.
3120	*/
3121
3122	/ You can pre-allocate the buffer by making sure it is of sufficient size*
3123	* regardless of the amount of compression achieved. The buffer size will
3124	* always be bigger than the original image and it will never be filled. The
3125	* following macros are provided to assist in allocating the buffer.
3126	*/
3127	#define PNG_IMAGE_DATA_SIZE(image) (PNG_IMAGE_SIZE(image)+(image).height)
3128	/ The number of uncompressed bytes in the PNG byte encoding of the image;*
3129	* uncompressing the PNG IDAT data will give this number of bytes.
3130	*
3131	* NOTE: while PNG_IMAGE_SIZE cannot overflow for an image in memory this
3132	* macro can because of the extra bytes used in the PNG byte encoding. You
3133	* need to avoid this macro if your image size approaches 2^30 in width or
3134	* height. The same goes for the remainder of these macros; they all produce
3135	* bigger numbers than the actual in-memory image size.
3136	*/
3137	#ifndef PNG_ZLIB_MAX_SIZE
3138	# define PNG_ZLIB_MAX_SIZE(b) ((b)+(((b)+7U)>>3)+(((b)+63U)>>6)+11U)
3139	/ An upper bound on the number of compressed bytes given 'b' uncompressed*
3140	* bytes. This is based on deflateBounds() in zlib; different
3141	* implementations of zlib compression may conceivably produce more data so
3142	* if your zlib implementation is not zlib itself redefine this macro
3143	* appropriately.
3144	*/
3145	#endif
3146
3147	#define PNG_IMAGE_COMPRESSED_SIZE_MAX(image)\
3148	PNG_ZLIB_MAX_SIZE((png_alloc_size_t)PNG_IMAGE_DATA_SIZE(image))
3149	/ An upper bound on the size of the data in the PNG IDAT chunks. /
3150
3151	#define PNG_IMAGE_PNG_SIZE_MAX_(image, image_size)\
3152	((8U/sig/+25U/IHDR/+16U/gAMA/+44U/cHRM/+12U/IEND/+\
3153	(((image).format&PNG_FORMAT_FLAG_COLORMAP)?/colormap: PLTE, tRNS/\
3154	12U+3U(image).colormap_entries/PLTE data*/+\
3155	(((image).format&PNG_FORMAT_FLAG_ALPHA)?\
3156	12U/tRNS/+(image).colormap_entries:0U):0U)+\
3157	12U)+(12U((image_size)/PNG_ZBUF_SIZE))/IDAT*/+(image_size))
3158	/ A helper for the following macro; if your compiler cannot handle the*
3159	* following macro use this one with the result of
3160	* PNG_IMAGE_COMPRESSED_SIZE_MAX(image) as the second argument (most
3161	* compilers should handle this just fine.)
3162	*/
3163
3164	#define PNG_IMAGE_PNG_SIZE_MAX(image)\
3165	PNG_IMAGE_PNG_SIZE_MAX_(image, PNG_IMAGE_COMPRESSED_SIZE_MAX(image))
3166	/ An upper bound on the total length of the PNG data stream for 'image'.*
3167	* The result is of type png_alloc_size_t, on 32-bit systems this may
3168	* overflow even though PNG_IMAGE_DATA_SIZE does not overflow; the write will
3169	* run out of buffer space but return a corrected size which should work.
3170	*/
3171	#endif /* SIMPLIFIED_WRITE */
3172	/*******************************************************************************
3173	* END OF SIMPLIFIED API
3174	******************************************************************************/
3175	#endif /* SIMPLIFIED_{READ\|WRITE} */
3176
3177	/*******************************************************************************
3178	* Section 6: IMPLEMENTATION OPTIONS
3179	*******************************************************************************
3180	*
3181	* Support for arbitrary implementation-specific optimizations. The API allows
3182	* particular options to be turned on or off. 'Option' is the number of the
3183	* option and 'onoff' is 0 (off) or non-0 (on). The value returned is given
3184	* by the PNG_OPTION_ defines below.
3185	*
3186	* HARDWARE: normally hardware capabilities, such as the Intel SSE instructions,
3187	* are detected at run time, however sometimes it may be impossible
3188	* to do this in user mode, in which case it is necessary to discover
3189	* the capabilities in an OS specific way. Such capabilities are
3190	* listed here when libpng has support for them and must be turned
3191	* ON by the application if present.
3192	*
3193	* SOFTWARE: sometimes software optimizations actually result in performance
3194	* decrease on some architectures or systems, or with some sets of
3195	* PNG images. 'Software' options allow such optimizations to be
3196	* selected at run time.
3197	*/
3198	#ifdef PNG_SET_OPTION_SUPPORTED
3199	#ifdef PNG_ARM_NEON_API_SUPPORTED
3200	# define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */
3201	#endif
3202	#define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */
3203	#define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */
3204	#ifdef PNG_MIPS_MSA_API_SUPPORTED
3205	# define PNG_MIPS_MSA 6 /* HARDWARE: MIPS Msa SIMD instructions supported */
3206	#endif
3207	#ifdef PNG_DISABLE_ADLER32_CHECK_SUPPORTED
3208	# define PNG_IGNORE_ADLER32 8 /* SOFTWARE: disable Adler32 check on IDAT */
3209	#endif
3210	#ifdef PNG_POWERPC_VSX_API_SUPPORTED
3211	# define PNG_POWERPC_VSX 10 /* HARDWARE: PowerPC VSX SIMD instructions
3212	* supported */
3213	#endif
3214	#ifdef PNG_MIPS_MMI_API_SUPPORTED
3215	# define PNG_MIPS_MMI 12 /* HARDWARE: MIPS MMI SIMD instructions supported */
3216	#endif
3217
3218	#define PNG_OPTION_NEXT 14 /* Next option - numbers must be even */
3219
3220	/ Return values: NOTE: there are four values and 'off' is not zero /
3221	#define PNG_OPTION_UNSET 0 /* Unset - defaults to off */
3222	#define PNG_OPTION_INVALID 1 /* Option number out of range */
3223	#define PNG_OPTION_OFF 2
3224	#define PNG_OPTION_ON 3
3225
3226	PNG_EXPORT(`244`, int, png_set_option, (png_structrp png_ptr, int option,
3227	int onoff));
3228	#endif /* SET_OPTION */
3229
3230	/*******************************************************************************
3231	* END OF HARDWARE AND SOFTWARE OPTIONS
3232	******************************************************************************/
3233
3234	/ Maintainer: Put new public prototypes here ^, in libpng.3, in project*
3235	* defs, and in scripts/symbols.def.
3236	*/
3237
3238	/ The last ordinal number (this is the last one already used; the next*
3239	* one to use is one more than this.)
3240	*/
3241	#ifdef PNG_EXPORT_LAST_ORDINAL
3242	PNG_EXPORT_LAST_ORDINAL(`249`);
3243	#endif
3244
3245	#ifdef __cplusplus
3246	}
3247	#endif
3248
3249	#endif /* PNG_VERSION_INFO_ONLY */
3250	/ Do not put anything past this line /
3251	#endif /* PNG_H */
3252

Source File Modules/Image/Contrib/LibPNG/include/png.hHome Page Browse Root

Source File Modules/Image/Contrib/LibPNG/include/png.h
Home Page Browse Root