1
2	/* png.h - header file for PNG reference library
3	*
4	* libpng version 1.6.37 - April 14, 2019
5	*
6	* Copyright (c) 2018-2019 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 1.6.37, April 2019:
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) 1995-2019 The PNG Reference Library Authors.
31	* * Copyright (c) 2018-2019 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	* 1.6.37 16 10637 16.so.16.37[.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 "1.6.37"
282	#define PNG_HEADER_VERSION_STRING " libpng version 1.6.37 - April 14, 2019\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 37
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 10637 /* 1.6.37 */
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	#define PNG_APNG_SUPPORTED
334	#define PNG_READ_APNG_SUPPORTED
335	#define PNG_WRITE_APNG_SUPPORTED
336
337	#ifndef PNG_VERSION_INFO_ONLY
338	/* Machine specific configuration. */
339	# include "pngconf.h"
340	#endif
341
342	/*
343	* Added at libpng-1.2.8
344	*
345	* Ref MSDN: Private as priority over Special
346	* VS_FF_PRIVATEBUILD File *was not* built using standard release
347	* procedures. If this value is given, the StringFileInfo block must
348	* contain a PrivateBuild string.
349	*
350	* VS_FF_SPECIALBUILD File *was* built by the original company using
351	* standard release procedures but is a variation of the standard
352	* file of the same version number. If this value is given, the
353	* StringFileInfo block must contain a SpecialBuild string.
354	*/
355
356	#ifdef PNG_USER_PRIVATEBUILD /* From pnglibconf.h */
357	# define PNG_LIBPNG_BUILD_TYPE \
358	(PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
359	#else
360	# ifdef PNG_LIBPNG_SPECIALBUILD
361	# define PNG_LIBPNG_BUILD_TYPE \
362	(PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
363	# else
364	# define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
365	# endif
366	#endif
367
368	#ifndef PNG_VERSION_INFO_ONLY
369
370	/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
371	#ifdef __cplusplus
372	extern "C" {
373	#endif /* __cplusplus */
374
375	/* Version information for C files, stored in png.c. This had better match
376	* the version above.
377	*/
378	#define png_libpng_ver png_get_header_ver(NULL)
379
380	/* This file is arranged in several sections:
381	*
382	* 1. [omitted]
383	* 2. Any configuration options that can be specified by for the application
384	* code when it is built. (Build time configuration is in pnglibconf.h)
385	* 3. Type definitions (base types are defined in pngconf.h), structure
386	* definitions.
387	* 4. Exported library functions.
388	* 5. Simplified API.
389	* 6. Implementation options.
390	*
391	* The library source code has additional files (principally pngpriv.h) that
392	* allow configuration of the library.
393	*/
394
395	/* Section 1: [omitted] */
396
397	/* Section 2: run time configuration
398	* See pnglibconf.h for build time configuration
399	*
400	* Run time configuration allows the application to choose between
401	* implementations of certain arithmetic APIs. The default is set
402	* at build time and recorded in pnglibconf.h, but it is safe to
403	* override these (and only these) settings. Note that this won't
404	* change what the library does, only application code, and the
405	* settings can (and probably should) be made on a per-file basis
406	* by setting the #defines before including png.h
407	*
408	* Use macros to read integers from PNG data or use the exported
409	* functions?
410	* PNG_USE_READ_MACROS: use the macros (see below) Note that
411	* the macros evaluate their argument multiple times.
412	* PNG_NO_USE_READ_MACROS: call the relevant library function.
413	*
414	* Use the alternative algorithm for compositing alpha samples that
415	* does not use division?
416	* PNG_READ_COMPOSITE_NODIV_SUPPORTED: use the 'no division'
417	* algorithm.
418	* PNG_NO_READ_COMPOSITE_NODIV: use the 'division' algorithm.
419	*
420	* How to handle benign errors if PNG_ALLOW_BENIGN_ERRORS is
421	* false?
422	* PNG_ALLOW_BENIGN_ERRORS: map calls to the benign error
423	* APIs to png_warning.
424	* Otherwise the calls are mapped to png_error.
425	*/
426
427	/* Section 3: type definitions, including structures and compile time
428	* constants.
429	* See pngconf.h for base types that vary by machine/system
430	*/
431
432	#ifdef PNG_APNG_SUPPORTED
433	/* dispose_op flags from inside fcTL */
434	#define PNG_DISPOSE_OP_NONE 0x00U
435	#define PNG_DISPOSE_OP_BACKGROUND 0x01U
436	#define PNG_DISPOSE_OP_PREVIOUS 0x02U
437
438	/* blend_op flags from inside fcTL */
439	#define PNG_BLEND_OP_SOURCE 0x00U
440	#define PNG_BLEND_OP_OVER 0x01U
441	#endif /* PNG_APNG_SUPPORTED */
442
443	/* This triggers a compiler error in png.c, if png.c and png.h
444	* do not agree upon the version number.
445	*/
446	typedef char* png_libpng_version_1_6_37;
447
448	/* Basic control structions. Read libpng-manual.txt or libpng.3 for more info.
449	*
450	* png_struct is the cache of information used while reading or writing a single
451	* PNG file. One of these is always required, although the simplified API
452	* (below) hides the creation and destruction of it.
453	*/
454	typedef struct png_struct_def png_struct;
455	typedef const png_struct * png_const_structp;
456	typedef png_struct * png_structp;
457	typedef png_struct * * png_structpp;
458
459	/* png_info contains information read from or to be written to a PNG file. One
460	* or more of these must exist while reading or creating a PNG file. The
461	* information is not used by libpng during read but is used to control what
462	* gets written when a PNG file is created. "png_get_" function calls read
463	* information during read and "png_set_" functions calls write information
464	* when creating a PNG.
465	* been moved into a separate header file that is not accessible to
466	* applications. Read libpng-manual.txt or libpng.3 for more info.
467	*/
468	typedef struct png_info_def png_info;
469	typedef png_info * png_infop;
470	typedef const png_info * png_const_infop;
471	typedef png_info * * png_infopp;
472
473	/* Types with names ending 'p' are pointer types. The corresponding types with
474	* names ending 'rp' are identical pointer types except that the pointer is
475	* marked 'restrict', which means that it is the only pointer to the object
476	* passed to the function. Applications should not use the 'restrict' types;
477	* it is always valid to pass 'p' to a pointer with a function argument of the
478	* corresponding 'rp' type. Different compilers have different rules with
479	* regard to type matching in the presence of 'restrict'. For backward
480	* compatibility libpng callbacks never have 'restrict' in their parameters and,
481	* consequentially, writing portable application code is extremely difficult if
482	* an attempt is made to use 'restrict'.
483	*/
484	typedef png_struct * PNG_RESTRICT png_structrp;
485	typedef const png_struct * PNG_RESTRICT png_const_structrp;
486	typedef png_info * PNG_RESTRICT png_inforp;
487	typedef const png_info * PNG_RESTRICT png_const_inforp;
488
489	/* Three color definitions. The order of the red, green, and blue, (and the
490	* exact size) is not important, although the size of the fields need to
491	* be png_byte or png_uint_16 (as defined below).
492	*/
493	typedef struct png_color_struct
494	{
495	png_byte red;
496	png_byte green;
497	png_byte blue;
498	} png_color;
499	typedef png_color * png_colorp;
500	typedef const png_color * png_const_colorp;
501	typedef png_color * * png_colorpp;
502
503	typedef struct png_color_16_struct
504	{
505	png_byte index; /* used for palette files */
506	png_uint_16 red; /* for use in red green blue files */
507	png_uint_16 green;
508	png_uint_16 blue;
509	png_uint_16 gray; /* for use in grayscale files */
510	} png_color_16;
511	typedef png_color_16 * png_color_16p;
512	typedef const png_color_16 * png_const_color_16p;
513	typedef png_color_16 * * png_color_16pp;
514
515	typedef struct png_color_8_struct
516	{
517	png_byte red; /* for use in red green blue files */
518	png_byte green;
519	png_byte blue;
520	png_byte gray; /* for use in grayscale files */
521	png_byte alpha; /* for alpha channel files */
522	} png_color_8;
523	typedef png_color_8 * png_color_8p;
524	typedef const png_color_8 * png_const_color_8p;
525	typedef png_color_8 * * png_color_8pp;
526
527	/*
528	* The following two structures are used for the in-core representation
529	* of sPLT chunks.
530	*/
531	typedef struct png_sPLT_entry_struct
532	{
533	png_uint_16 red;
534	png_uint_16 green;
535	png_uint_16 blue;
536	png_uint_16 alpha;
537	png_uint_16 frequency;
538	} png_sPLT_entry;
539	typedef png_sPLT_entry * png_sPLT_entryp;
540	typedef const png_sPLT_entry * png_const_sPLT_entryp;
541	typedef png_sPLT_entry * * png_sPLT_entrypp;
542
543	/* When the depth of the sPLT palette is 8 bits, the color and alpha samples
544	* occupy the LSB of their respective members, and the MSB of each member
545	* is zero-filled. The frequency member always occupies the full 16 bits.
546	*/
547
548	typedef struct png_sPLT_struct
549	{
550	png_charp name; /* palette name */
551	png_byte depth; /* depth of palette samples */
552	png_sPLT_entryp entries; /* palette entries */
553	png_int_32 nentries; /* number of palette entries */
554	} png_sPLT_t;
555	typedef png_sPLT_t * png_sPLT_tp;
556	typedef const png_sPLT_t * png_const_sPLT_tp;
557	typedef png_sPLT_t * * png_sPLT_tpp;
558
559	#ifdef PNG_TEXT_SUPPORTED
560	/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
561	* and whether that contents is compressed or not. The "key" field
562	* points to a regular zero-terminated C string. The "text" fields can be a
563	* regular C string, an empty string, or a NULL pointer.
564	* However, the structure returned by png_get_text() will always contain
565	* the "text" field as a regular zero-terminated C string (possibly
566	* empty), never a NULL pointer, so it can be safely used in printf() and
567	* other string-handling functions. Note that the "itxt_length", "lang", and
568	* "lang_key" members of the structure only exist when the library is built
569	* with iTXt chunk support. Prior to libpng-1.4.0 the library was built by
570	* default without iTXt support. Also note that when iTXt *is* supported,
571	* the "lang" and "lang_key" fields contain NULL pointers when the
572	* "compression" field contains * PNG_TEXT_COMPRESSION_NONE or
573	* PNG_TEXT_COMPRESSION_zTXt. Note that the "compression value" is not the
574	* same as what appears in the PNG tEXt/zTXt/iTXt chunk's "compression flag"
575	* which is always 0 or 1, or its "compression method" which is always 0.
576	*/
577	typedef struct png_text_struct
578	{
579	int compression; /* compression value:
580	-1: tEXt, none
581	0: zTXt, deflate
582	1: iTXt, none
583	2: iTXt, deflate */
584	png_charp key; /* keyword, 1-79 character description of "text" */
585	png_charp text; /* comment, may be an empty string (ie "")
586	or a NULL pointer */
587	size_t text_length; /* length of the text string */
588	size_t itxt_length; /* length of the itxt string */
589	png_charp lang; /* language code, 0-79 characters
590	or a NULL pointer */
591	png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
592	chars or a NULL pointer */
593	} png_text;
594	typedef png_text * png_textp;
595	typedef const png_text * png_const_textp;
596	typedef png_text * * png_textpp;
597	#endif
598
599	/* Supported compression types for text in PNG files (tEXt, and zTXt).
600	* The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
601	#define PNG_TEXT_COMPRESSION_NONE_WR -3
602	#define PNG_TEXT_COMPRESSION_zTXt_WR -2
603	#define PNG_TEXT_COMPRESSION_NONE -1
604	#define PNG_TEXT_COMPRESSION_zTXt 0
605	#define PNG_ITXT_COMPRESSION_NONE 1
606	#define PNG_ITXT_COMPRESSION_zTXt 2
607	#define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
608
609	/* png_time is a way to hold the time in an machine independent way.
610	* Two conversions are provided, both from time_t and struct tm. There
611	* is no portable way to convert to either of these structures, as far
612	* as I know. If you know of a portable way, send it to me. As a side
613	* note - PNG has always been Year 2000 compliant!
614	*/
615	typedef struct png_time_struct
616	{
617	png_uint_16 year; /* full year, as in, 1995 */
618	png_byte month; /* month of year, 1 - 12 */
619	png_byte day; /* day of month, 1 - 31 */
620	png_byte hour; /* hour of day, 0 - 23 */
621	png_byte minute; /* minute of hour, 0 - 59 */
622	png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
623	} png_time;
624	typedef png_time * png_timep;
625	typedef const png_time * png_const_timep;
626	typedef png_time * * png_timepp;
627
628	#if defined(PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED) ||\
629	defined(PNG_USER_CHUNKS_SUPPORTED)
630	/* png_unknown_chunk is a structure to hold queued chunks for which there is
631	* no specific support. The idea is that we can use this to queue
632	* up private chunks for output even though the library doesn't actually
633	* know about their semantics.
634	*
635	* The data in the structure is set by libpng on read and used on write.
636	*/
637	typedef struct png_unknown_chunk_t
638	{
639	png_byte name[5]; /* Textual chunk name with '\0' terminator */
640	png_byte *data; /* Data, should not be modified on read! */
641	size_t size;
642
643	/* On write 'location' must be set using the flag values listed below.
644	* Notice that on read it is set by libpng however the values stored have
645	* more bits set than are listed below. Always treat the value as a
646	* bitmask. On write set only one bit - setting multiple bits may cause the
647	* chunk to be written in multiple places.
648	*/
649	png_byte location; /* mode of operation at read time */
650	}
651	png_unknown_chunk;
652
653	typedef png_unknown_chunk * png_unknown_chunkp;
654	typedef const png_unknown_chunk * png_const_unknown_chunkp;
655	typedef png_unknown_chunk * * png_unknown_chunkpp;
656	#endif
657
658	/* Flag values for the unknown chunk location byte. */
659	#define PNG_HAVE_IHDR 0x01
660	#define PNG_HAVE_PLTE 0x02
661	#define PNG_AFTER_IDAT 0x08
662
663	/* Maximum positive integer used in PNG is (2^31)-1 */
664	#define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
665	#define PNG_UINT_32_MAX ((png_uint_32)(-1))
666	#define PNG_SIZE_MAX ((size_t)(-1))
667
668	/* These are constants for fixed point values encoded in the
669	* PNG specification manner (x100000)
670	*/
671	#define PNG_FP_1 100000
672	#define PNG_FP_HALF 50000
673	#define PNG_FP_MAX ((png_fixed_point)0x7fffffffL)
674	#define PNG_FP_MIN (-PNG_FP_MAX)
675
676	/* These describe the color_type field in png_info. */
677	/* color type masks */
678	#define PNG_COLOR_MASK_PALETTE 1
679	#define PNG_COLOR_MASK_COLOR 2
680	#define PNG_COLOR_MASK_ALPHA 4
681
682	/* color types. Note that not all combinations are legal */
683	#define PNG_COLOR_TYPE_GRAY 0
684	#define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
685	#define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
686	#define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
687	#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
688	/* aliases */
689	#define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
690	#define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
691
692	/* This is for compression type. PNG 1.0-1.2 only define the single type. */
693	#define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
694	#define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
695
696	/* This is for filter type. PNG 1.0-1.2 only define the single type. */
697	#define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
698	#define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
699	#define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
700
701	/* These are for the interlacing type. These values should NOT be changed. */
702	#define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
703	#define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
704	#define PNG_INTERLACE_LAST 2 /* Not a valid value */
705
706	/* These are for the oFFs chunk. These values should NOT be changed. */
707	#define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
708	#define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
709	#define PNG_OFFSET_LAST 2 /* Not a valid value */
710
711	/* These are for the pCAL chunk. These values should NOT be changed. */
712	#define PNG_EQUATION_LINEAR 0 /* Linear transformation */
713	#define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
714	#define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
715	#define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
716	#define PNG_EQUATION_LAST 4 /* Not a valid value */
717
718	/* These are for the sCAL chunk. These values should NOT be changed. */
719	#define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
720	#define PNG_SCALE_METER 1 /* meters per pixel */
721	#define PNG_SCALE_RADIAN 2 /* radians per pixel */
722	#define PNG_SCALE_LAST 3 /* Not a valid value */
723
724	/* These are for the pHYs chunk. These values should NOT be changed. */
725	#define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
726	#define PNG_RESOLUTION_METER 1 /* pixels/meter */
727	#define PNG_RESOLUTION_LAST 2 /* Not a valid value */
728
729	/* These are for the sRGB chunk. These values should NOT be changed. */
730	#define PNG_sRGB_INTENT_PERCEPTUAL 0
731	#define PNG_sRGB_INTENT_RELATIVE 1
732	#define PNG_sRGB_INTENT_SATURATION 2
733	#define PNG_sRGB_INTENT_ABSOLUTE 3
734	#define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
735
736	/* This is for text chunks */
737	#define PNG_KEYWORD_MAX_LENGTH 79
738
739	/* Maximum number of entries in PLTE/sPLT/tRNS arrays */
740	#define PNG_MAX_PALETTE_LENGTH 256
741
742	/* These determine if an ancillary chunk's data has been successfully read
743	* from the PNG header, or if the application has filled in the corresponding
744	* data in the info_struct to be written into the output file. The values
745	* of the PNG_INFO_<chunk> defines should NOT be changed.
746	*/
747	#define PNG_INFO_gAMA 0x0001U
748	#define PNG_INFO_sBIT 0x0002U
749	#define PNG_INFO_cHRM 0x0004U
750	#define PNG_INFO_PLTE 0x0008U
751	#define PNG_INFO_tRNS 0x0010U
752	#define PNG_INFO_bKGD 0x0020U
753	#define PNG_INFO_hIST 0x0040U
754	#define PNG_INFO_pHYs 0x0080U
755	#define PNG_INFO_oFFs 0x0100U
756	#define PNG_INFO_tIME 0x0200U
757	#define PNG_INFO_pCAL 0x0400U
758	#define PNG_INFO_sRGB 0x0800U /* GR-P, 0.96a */
759	#define PNG_INFO_iCCP 0x1000U /* ESR, 1.0.6 */
760	#define PNG_INFO_sPLT 0x2000U /* ESR, 1.0.6 */
761	#define PNG_INFO_sCAL 0x4000U /* ESR, 1.0.6 */
762	#define PNG_INFO_IDAT 0x8000U /* ESR, 1.0.6 */
763	#define PNG_INFO_eXIf 0x10000U /* GR-P, 1.6.31 */
764	#ifdef PNG_APNG_SUPPORTED
765	#define PNG_INFO_acTL 0x20000U
766	#define PNG_INFO_fcTL 0x40000U
767	#endif
768
769	/* This is used for the transformation routines, as some of them
770	* change these values for the row. It also should enable using
771	* the routines for other purposes.
772	*/
773	typedef struct png_row_info_struct
774	{
775	png_uint_32 width; /* width of row */
776	size_t rowbytes; /* number of bytes in row */
777	png_byte color_type; /* color type of row */
778	png_byte bit_depth; /* bit depth of row */
779	png_byte channels; /* number of channels (1, 2, 3, or 4) */
780	png_byte pixel_depth; /* bits per pixel (depth * channels) */
781	} png_row_info;
782
783	typedef png_row_info * png_row_infop;
784	typedef png_row_info * * png_row_infopp;
785
786	/* These are the function types for the I/O functions and for the functions
787	* that allow the user to override the default I/O functions with his or her
788	* own. The png_error_ptr type should match that of user-supplied warning
789	* and error functions, while the png_rw_ptr type should match that of the
790	* user read/write data functions. Note that the 'write' function must not
791	* modify the buffer it is passed. The 'read' function, on the other hand, is
792	* expected to return the read data in the buffer.
793	*/
794	typedef PNG_CALLBACK(void, *png_error_ptr, (png_structp, png_const_charp));
795	typedef PNG_CALLBACK(void, *png_rw_ptr, (png_structp, png_bytep, size_t));
796	typedef PNG_CALLBACK(void, *png_flush_ptr, (png_structp));
797	typedef PNG_CALLBACK(void, *png_read_status_ptr, (png_structp, png_uint_32,
798	int));
799	typedef PNG_CALLBACK(void, *png_write_status_ptr, (png_structp, png_uint_32,
800	int));
801
802	#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
803	typedef PNG_CALLBACK(void, *png_progressive_info_ptr, (png_structp, png_infop));
804	typedef PNG_CALLBACK(void, *png_progressive_end_ptr, (png_structp, png_infop));
805	#ifdef PNG_APNG_SUPPORTED
806	typedef PNG_CALLBACK(void, *png_progressive_frame_ptr, (png_structp,
807	png_uint_32));
808	#endif
809
810	/* The following callback receives png_uint_32 row_number, int pass for the
811	* png_bytep data of the row. When transforming an interlaced image the
812	* row number is the row number within the sub-image of the interlace pass, so
813	* the value will increase to the height of the sub-image (not the full image)
814	* then reset to 0 for the next pass.
815	*
816	* Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
817	* find the output pixel (x,y) given an interlaced sub-image pixel
818	* (row,col,pass). (See below for these macros.)
819	*/
820	typedef PNG_CALLBACK(void, *png_progressive_row_ptr, (png_structp, png_bytep,
821	png_uint_32, int));
822	#endif
823
824	#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
825	defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
826	typedef PNG_CALLBACK(void, *png_user_transform_ptr, (png_structp, png_row_infop,
827	png_bytep));
828	#endif
829
830	#ifdef PNG_USER_CHUNKS_SUPPORTED
831	typedef PNG_CALLBACK(int, *png_user_chunk_ptr, (png_structp,
832	png_unknown_chunkp));
833	#endif
834	#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
835	/* not used anywhere */
836	/* typedef PNG_CALLBACK(void, *png_unknown_chunk_ptr, (png_structp)); */
837	#endif
838
839	#ifdef PNG_SETJMP_SUPPORTED
840	/* This must match the function definition in <setjmp.h>, and the application
841	* must include this before png.h to obtain the definition of jmp_buf. The
842	* function is required to be PNG_NORETURN, but this is not checked. If the
843	* function does return the application will crash via an abort() or similar
844	* system level call.
845	*
846	* If you get a warning here while building the library you may need to make
847	* changes to ensure that pnglibconf.h records the calling convention used by
848	* your compiler. This may be very difficult - try using a different compiler
849	* to build the library!
850	*/
851	PNG_FUNCTION(void, (PNGCAPI *png_longjmp_ptr), PNGARG((jmp_buf, int)), typedef);
852	#endif
853
854	/* Transform masks for the high-level interface */
855	#define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
856	#define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
857	#define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
858	#define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
859	#define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
860	#define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
861	#define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
862	#define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
863	#define PNG_TRANSFORM_BGR 0x0080 /* read and write */
864	#define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
865	#define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
866	#define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
867	#define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only */
868	/* Added to libpng-1.2.34 */
869	#define PNG_TRANSFORM_STRIP_FILLER_BEFORE PNG_TRANSFORM_STRIP_FILLER
870	#define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
871	/* Added to libpng-1.4.0 */
872	#define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
873	/* Added to libpng-1.5.4 */
874	#define PNG_TRANSFORM_EXPAND_16 0x4000 /* read only */
875	#if INT_MAX >= 0x8000 /* else this might break */
876	#define PNG_TRANSFORM_SCALE_16 0x8000 /* read only */
877	#endif
878
879	/* Flags for MNG supported features */
880	#define PNG_FLAG_MNG_EMPTY_PLTE 0x01
881	#define PNG_FLAG_MNG_FILTER_64 0x04
882	#define PNG_ALL_MNG_FEATURES 0x05
883
884	/* NOTE: prior to 1.5 these functions had no 'API' style declaration,
885	* this allowed the zlib default functions to be used on Windows
886	* platforms. In 1.5 the zlib default malloc (which just calls malloc and
887	* ignores the first argument) should be completely compatible with the
888	* following.
889	*/
890	typedef PNG_CALLBACK(png_voidp, *png_malloc_ptr, (png_structp,
891	png_alloc_size_t));
892	typedef PNG_CALLBACK(void, *png_free_ptr, (png_structp, png_voidp));
893
894	/* Section 4: exported functions
895	* Here are the function definitions most commonly used. This is not
896	* the place to find out how to use libpng. See libpng-manual.txt for the
897	* full explanation, see example.c for the summary. This just provides
898	* a simple one line description of the use of each function.
899	*
900	* The PNG_EXPORT() and PNG_EXPORTA() macros used below are defined in
901	* pngconf.h and in the *.dfn files in the scripts directory.
902	*
903	* PNG_EXPORT(ordinal, type, name, (args));
904	*
905	* ordinal: ordinal that is used while building
906	* *.def files. The ordinal value is only
907	* relevant when preprocessing png.h with
908	* the *.dfn files for building symbol table
909	* entries, and are removed by pngconf.h.
910	* type: return type of the function
911	* name: function name
912	* args: function arguments, with types
913	*
914	* When we wish to append attributes to a function prototype we use
915	* the PNG_EXPORTA() macro instead.
916	*
917	* PNG_EXPORTA(ordinal, type, name, (args), attributes);
918	*
919	* ordinal, type, name, and args: same as in PNG_EXPORT().
920	* attributes: function attributes
921	*/
922
923	/* Returns the version number of the library */
924	PNG_EXPORT(1, png_uint_32, png_access_version_number, (void));
925
926	/* Tell lib we have already handled the first <num_bytes> magic bytes.
927	* Handling more than 8 bytes from the beginning of the file is an error.
928	*/
929	PNG_EXPORT(2, void, png_set_sig_bytes, (png_structrp png_ptr, int num_bytes));
930
931	/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
932	* PNG file. Returns zero if the supplied bytes match the 8-byte PNG
933	* signature, and non-zero otherwise. Having num_to_check == 0 or
934	* start > 7 will always fail (ie return non-zero).
935	*/
936	PNG_EXPORT(3, int, png_sig_cmp, (png_const_bytep sig, size_t start,
937	size_t num_to_check));
938
939	/* Simple signature checking function. This is the same as calling
940	* png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
941	*/
942	#define png_check_sig(sig, n) !png_sig_cmp((sig), 0, (n))
943
944	/* Allocate and initialize png_ptr struct for reading, and any other memory. */
945	PNG_EXPORTA(4, png_structp, png_create_read_struct,
946	(png_const_charp user_png_ver, png_voidp error_ptr,
947	png_error_ptr error_fn, png_error_ptr warn_fn),
948	PNG_ALLOCATED);
949
950	/* Allocate and initialize png_ptr struct for writing, and any other memory */
951	PNG_EXPORTA(5, png_structp, png_create_write_struct,
952	(png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
953	png_error_ptr warn_fn),
954	PNG_ALLOCATED);
955
956	PNG_EXPORT(6, size_t, png_get_compression_buffer_size,
957	(png_const_structrp png_ptr));
958
959	PNG_EXPORT(7, void, png_set_compression_buffer_size, (png_structrp png_ptr,
960	size_t size));
961
962	/* Moved from pngconf.h in 1.4.0 and modified to ensure setjmp/longjmp
963	* match up.
964	*/
965	#ifdef PNG_SETJMP_SUPPORTED
966	/* This function returns the jmp_buf built in to *png_ptr. It must be
967	* supplied with an appropriate 'longjmp' function to use on that jmp_buf
968	* unless the default error function is overridden in which case NULL is
969	* acceptable. The size of the jmp_buf is checked against the actual size
970	* allocated by the library - the call will return NULL on a mismatch
971	* indicating an ABI mismatch.
972	*/
973	PNG_EXPORT(8, jmp_buf*, png_set_longjmp_fn, (png_structrp png_ptr,
974	png_longjmp_ptr longjmp_fn, size_t jmp_buf_size));
975	# define png_jmpbuf(png_ptr) \
976	(*png_set_longjmp_fn((png_ptr), longjmp, (sizeof (jmp_buf))))
977	#else
978	# define png_jmpbuf(png_ptr) \
979	(LIBPNG_WAS_COMPILED_WITH__PNG_NO_SETJMP)
980	#endif
981	/* This function should be used by libpng applications in place of
982	* longjmp(png_ptr->jmpbuf, val). If longjmp_fn() has been set, it
983	* will use it; otherwise it will call PNG_ABORT(). This function was
984	* added in libpng-1.5.0.
985	*/
986	PNG_EXPORTA(9, void, png_longjmp, (png_const_structrp png_ptr, int val),
987	PNG_NORETURN);
988
989	#ifdef PNG_READ_SUPPORTED
990	/* Reset the compression stream */
991	PNG_EXPORTA(10, int, png_reset_zstream, (png_structrp png_ptr), PNG_DEPRECATED);
992	#endif
993
994	/* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
995	#ifdef PNG_USER_MEM_SUPPORTED
996	PNG_EXPORTA(11, png_structp, png_create_read_struct_2,
997	(png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
998	png_error_ptr warn_fn,
999	png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
1000	PNG_ALLOCATED);
1001	PNG_EXPORTA(12, png_structp, png_create_write_struct_2,
1002	(png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn,
1003	png_error_ptr warn_fn,
1004	png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn),
1005	PNG_ALLOCATED);
1006	#endif
1007
1008	/* Write the PNG file signature. */
1009	PNG_EXPORT(13, void, png_write_sig, (png_structrp png_ptr));
1010
1011	/* Write a PNG chunk - size, type, (optional) data, CRC. */
1012	PNG_EXPORT(14, void, png_write_chunk, (png_structrp png_ptr, png_const_bytep
1013	chunk_name, png_const_bytep data, size_t length));
1014
1015	/* Write the start of a PNG chunk - length and chunk name. */
1016	PNG_EXPORT(15, void, png_write_chunk_start, (png_structrp png_ptr,
1017	png_const_bytep chunk_name, png_uint_32 length));
1018
1019	/* Write the data of a PNG chunk started with png_write_chunk_start(). */
1020	PNG_EXPORT(16, void, png_write_chunk_data, (png_structrp png_ptr,
1021	png_const_bytep data, size_t length));
1022
1023	/* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1024	PNG_EXPORT(17, void, png_write_chunk_end, (png_structrp png_ptr));
1025
1026	/* Allocate and initialize the info structure */
1027	PNG_EXPORTA(18, png_infop, png_create_info_struct, (png_const_structrp png_ptr),
1028	PNG_ALLOCATED);
1029
1030	/* DEPRECATED: this function allowed init structures to be created using the
1031	* default allocation method (typically malloc). Use is deprecated in 1.6.0 and
1032	* the API will be removed in the future.
1033	*/
1034	PNG_EXPORTA(19, void, png_info_init_3, (png_infopp info_ptr,
1035	size_t png_info_struct_size), PNG_DEPRECATED);
1036
1037	/* Writes all the PNG information before the image. */
1038	PNG_EXPORT(20, void, png_write_info_before_PLTE,
1039	(png_structrp png_ptr, png_const_inforp info_ptr));
1040	PNG_EXPORT(21, void, png_write_info,
1041	(png_structrp png_ptr, png_const_inforp info_ptr));
1042
1043	#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1044	/* Read the information before the actual image data. */
1045	PNG_EXPORT(22, void, png_read_info,
1046	(png_structrp png_ptr, png_inforp info_ptr));
1047	#endif
1048
1049	#ifdef PNG_TIME_RFC1123_SUPPORTED
1050	/* Convert to a US string format: there is no localization support in this
1051	* routine. The original implementation used a 29 character buffer in
1052	* png_struct, this will be removed in future versions.
1053	*/
1054	#if PNG_LIBPNG_VER < 10700
1055	/* To do: remove this from libpng17 (and from libpng17/png.c and pngstruct.h) */
1056	PNG_EXPORTA(23, png_const_charp, png_convert_to_rfc1123, (png_structrp png_ptr,
1057	png_const_timep ptime),PNG_DEPRECATED);
1058	#endif
1059	PNG_EXPORT(241, int, png_convert_to_rfc1123_buffer, (char out[29],
1060	png_const_timep ptime));
1061	#endif
1062
1063	#ifdef PNG_CONVERT_tIME_SUPPORTED
1064	/* Convert from a struct tm to png_time */
1065	PNG_EXPORT(24, void, png_convert_from_struct_tm, (png_timep ptime,
1066	const struct tm * ttime));
1067
1068	/* Convert from time_t to png_time. Uses gmtime() */
1069	PNG_EXPORT(25, void, png_convert_from_time_t, (png_timep ptime, time_t ttime));
1070	#endif /* CONVERT_tIME */
1071
1072	#ifdef PNG_READ_EXPAND_SUPPORTED
1073	/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1074	PNG_EXPORT(26, void, png_set_expand, (png_structrp png_ptr));
1075	PNG_EXPORT(27, void, png_set_expand_gray_1_2_4_to_8, (png_structrp png_ptr));
1076	PNG_EXPORT(28, void, png_set_palette_to_rgb, (png_structrp png_ptr));
1077	PNG_EXPORT(29, void, png_set_tRNS_to_alpha, (png_structrp png_ptr));
1078	#endif
1079
1080	#ifdef PNG_READ_EXPAND_16_SUPPORTED
1081	/* Expand to 16-bit channels, forces conversion of palette to RGB and expansion
1082	* of a tRNS chunk if present.
1083	*/
1084	PNG_EXPORT(221, void, png_set_expand_16, (png_structrp png_ptr));
1085	#endif
1086
1087	#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1088	/* Use blue, green, red order for pixels. */
1089	PNG_EXPORT(30, void, png_set_bgr, (png_structrp png_ptr));
1090	#endif
1091
1092	#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1093	/* Expand the grayscale to 24-bit RGB if necessary. */
1094	PNG_EXPORT(31, void, png_set_gray_to_rgb, (png_structrp png_ptr));
1095	#endif
1096
1097	#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1098	/* Reduce RGB to grayscale. */
1099	#define PNG_ERROR_ACTION_NONE 1
1100	#define PNG_ERROR_ACTION_WARN 2
1101	#define PNG_ERROR_ACTION_ERROR 3
1102	#define PNG_RGB_TO_GRAY_DEFAULT (-1)/*for red/green coefficients*/
1103
1104	PNG_FP_EXPORT(32, void, png_set_rgb_to_gray, (png_structrp png_ptr,
1105	int error_action, double red, double green))
1106	PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structrp png_ptr,
1107	int error_action, png_fixed_point red, png_fixed_point green))
1108
1109	PNG_EXPORT(34, png_byte, png_get_rgb_to_gray_status, (png_const_structrp
1110	png_ptr));
1111	#endif
1112
1113	#ifdef PNG_BUILD_GRAYSCALE_PALETTE_SUPPORTED
1114	PNG_EXPORT(35, void, png_build_grayscale_palette, (int bit_depth,
1115	png_colorp palette));
1116	#endif
1117
1118	#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
1119	/* How the alpha channel is interpreted - this affects how the color channels
1120	* of a PNG file are returned to the calling application when an alpha channel,
1121	* or a tRNS chunk in a palette file, is present.
1122	*
1123	* This has no effect on the way pixels are written into a PNG output
1124	* datastream. The color samples in a PNG datastream are never premultiplied
1125	* with the alpha samples.
1126	*
1127	* The default is to return data according to the PNG specification: the alpha
1128	* channel is a linear measure of the contribution of the pixel to the
1129	* corresponding composited pixel, and the color channels are unassociated
1130	* (not premultiplied). The gamma encoded color channels must be scaled
1131	* according to the contribution and to do this it is necessary to undo
1132	* the encoding, scale the color values, perform the composition and re-encode
1133	* the values. This is the 'PNG' mode.
1134	*
1135	* The alternative is to 'associate' the alpha with the color information by
1136	* storing color channel values that have been scaled by the alpha.
1137	* image. These are the 'STANDARD', 'ASSOCIATED' or 'PREMULTIPLIED' modes
1138	* (the latter being the two common names for associated alpha color channels).
1139	*
1140	* For the 'OPTIMIZED' mode, a pixel is treated as opaque only if the alpha
1141	* value is equal to the maximum value.
1142	*
1143	* The final choice is to gamma encode the alpha channel as well. This is
1144	* broken because, in practice, no implementation that uses this choice
1145	* correctly undoes the encoding before handling alpha composition. Use this
1146	* choice only if other serious errors in the software or hardware you use
1147	* mandate it; the typical serious error is for dark halos to appear around
1148	* opaque areas of the composited PNG image because of arithmetic overflow.
1149	*
1150	* The API function png_set_alpha_mode specifies which of these choices to use
1151	* with an enumerated 'mode' value and the gamma of the required output:
1152	*/
1153	#define PNG_ALPHA_PNG 0 /* according to the PNG standard */
1154	#define PNG_ALPHA_STANDARD 1 /* according to Porter/Duff */
1155	#define PNG_ALPHA_ASSOCIATED 1 /* as above; this is the normal practice */
1156	#define PNG_ALPHA_PREMULTIPLIED 1 /* as above */
1157	#define PNG_ALPHA_OPTIMIZED 2 /* 'PNG' for opaque pixels, else 'STANDARD' */
1158	#define PNG_ALPHA_BROKEN 3 /* the alpha channel is gamma encoded */
1159
1160	PNG_FP_EXPORT(227, void, png_set_alpha_mode, (png_structrp png_ptr, int mode,
1161	double output_gamma))
1162	PNG_FIXED_EXPORT(228, void, png_set_alpha_mode_fixed, (png_structrp png_ptr,
1163	int mode, png_fixed_point output_gamma))
1164	#endif
1165
1166	#if defined(PNG_GAMMA_SUPPORTED) || defined(PNG_READ_ALPHA_MODE_SUPPORTED)
1167	/* The output_gamma value is a screen gamma in libpng terminology: it expresses
1168	* how to decode the output values, not how they are encoded.
1169	*/
1170	#define PNG_DEFAULT_sRGB -1 /* sRGB gamma and color space */
1171	#define PNG_GAMMA_MAC_18 -2 /* Old Mac '1.8' gamma and color space */
1172	#define PNG_GAMMA_sRGB 220000 /* Television standards--matches sRGB gamma */
1173	#define PNG_GAMMA_LINEAR PNG_FP_1 /* Linear */
1174	#endif
1175
1176	/* The following are examples of calls to png_set_alpha_mode to achieve the
1177	* required overall gamma correction and, where necessary, alpha
1178	* premultiplication.
1179	*
1180	* png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
1181	* This is the default libpng handling of the alpha channel - it is not
1182	* pre-multiplied into the color components. In addition the call states
1183	* that the output is for a sRGB system and causes all PNG files without gAMA
1184	* chunks to be assumed to be encoded using sRGB.
1185	*
1186	* png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
1187	* In this case the output is assumed to be something like an sRGB conformant
1188	* display preceded by a power-law lookup table of power 1.45. This is how
1189	* early Mac systems behaved.
1190	*
1191	* png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_GAMMA_LINEAR);
1192	* This is the classic Jim Blinn approach and will work in academic
1193	* environments where everything is done by the book. It has the shortcoming
1194	* of assuming that input PNG data with no gamma information is linear - this
1195	* is unlikely to be correct unless the PNG files where generated locally.
1196	* Most of the time the output precision will be so low as to show
1197	* significant banding in dark areas of the image.
1198	*
1199	* png_set_expand_16(pp);
1200	* png_set_alpha_mode(pp, PNG_ALPHA_STANDARD, PNG_DEFAULT_sRGB);
1201	* This is a somewhat more realistic Jim Blinn inspired approach. PNG files
1202	* are assumed to have the sRGB encoding if not marked with a gamma value and
1203	* the output is always 16 bits per component. This permits accurate scaling
1204	* and processing of the data. If you know that your input PNG files were
1205	* generated locally you might need to replace PNG_DEFAULT_sRGB with the
1206	* correct value for your system.
1207	*
1208	* png_set_alpha_mode(pp, PNG_ALPHA_OPTIMIZED, PNG_DEFAULT_sRGB);
1209	* If you just need to composite the PNG image onto an existing background
1210	* and if you control the code that does this you can use the optimization
1211	* setting. In this case you just copy completely opaque pixels to the
1212	* output. For pixels that are not completely transparent (you just skip
1213	* those) you do the composition math using png_composite or png_composite_16
1214	* below then encode the resultant 8-bit or 16-bit values to match the output
1215	* encoding.
1216	*
1217	* Other cases
1218	* If neither the PNG nor the standard linear encoding work for you because
1219	* of the software or hardware you use then you have a big problem. The PNG
1220	* case will probably result in halos around the image. The linear encoding
1221	* will probably result in a washed out, too bright, image (it's actually too
1222	* contrasty.) Try the ALPHA_OPTIMIZED mode above - this will probably
1223	* substantially reduce the halos. Alternatively try:
1224	*
1225	* png_set_alpha_mode(pp, PNG_ALPHA_BROKEN, PNG_DEFAULT_sRGB);
1226	* This option will also reduce the halos, but there will be slight dark
1227	* halos round the opaque parts of the image where the background is light.
1228	* In the OPTIMIZED mode the halos will be light halos where the background
1229	* is dark. Take your pick - the halos are unavoidable unless you can get
1230	* your hardware/software fixed! (The OPTIMIZED approach is slightly
1231	* faster.)
1232	*
1233	* When the default gamma of PNG files doesn't match the output gamma.
1234	* If you have PNG files with no gamma information png_set_alpha_mode allows
1235	* you to provide a default gamma, but it also sets the output gamma to the
1236	* matching value. If you know your PNG files have a gamma that doesn't
1237	* match the output you can take advantage of the fact that
1238	* png_set_alpha_mode always sets the output gamma but only sets the PNG
1239	* default if it is not already set:
1240	*
1241	* png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_DEFAULT_sRGB);
1242	* png_set_alpha_mode(pp, PNG_ALPHA_PNG, PNG_GAMMA_MAC);
1243	* The first call sets both the default and the output gamma values, the
1244	* second call overrides the output gamma without changing the default. This
1245	* is easier than achieving the same effect with png_set_gamma. You must use
1246	* PNG_ALPHA_PNG for the first call - internal checking in png_set_alpha will
1247	* fire if more than one call to png_set_alpha_mode and png_set_background is
1248	* made in the same read operation, however multiple calls with PNG_ALPHA_PNG
1249	* are ignored.
1250	*/
1251
1252	#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1253	PNG_EXPORT(36, void, png_set_strip_alpha, (png_structrp png_ptr));
1254	#endif
1255
1256	#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1257	defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1258	PNG_EXPORT(37, void, png_set_swap_alpha, (png_structrp png_ptr));
1259	#endif
1260
1261	#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1262	defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1263	PNG_EXPORT(38, void, png_set_invert_alpha, (png_structrp png_ptr));
1264	#endif
1265
1266	#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1267	/* Add a filler byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
1268	PNG_EXPORT(39, void, png_set_filler, (png_structrp png_ptr, png_uint_32 filler,
1269	int flags));
1270	/* The values of the PNG_FILLER_ defines should NOT be changed */
1271	# define PNG_FILLER_BEFORE 0
1272	# define PNG_FILLER_AFTER 1
1273	/* Add an alpha byte to 8-bit or 16-bit Gray or 24-bit or 48-bit RGB images. */
1274	PNG_EXPORT(40, void, png_set_add_alpha, (png_structrp png_ptr,
1275	png_uint_32 filler, int flags));
1276	#endif /* READ_FILLER || WRITE_FILLER */
1277
1278	#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1279	/* Swap bytes in 16-bit depth files. */
1280	PNG_EXPORT(41, void, png_set_swap, (png_structrp png_ptr));
1281	#endif
1282
1283	#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1284	/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1285	PNG_EXPORT(42, void, png_set_packing, (png_structrp png_ptr));
1286	#endif
1287
1288	#if defined(PNG_READ_PACKSWAP_SUPPORTED) || \
1289	defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1290	/* Swap packing order of pixels in bytes. */
1291	PNG_EXPORT(43, void, png_set_packswap, (png_structrp png_ptr));
1292	#endif
1293
1294	#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1295	/* Converts files to legal bit depths. */
1296	PNG_EXPORT(44, void, png_set_shift, (png_structrp png_ptr, png_const_color_8p
1297	true_bits));
1298	#endif
1299
1300	#if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1301	defined(PNG_WRITE_INTERLACING_SUPPORTED)
1302	/* Have the code handle the interlacing. Returns the number of passes.
1303	* MUST be called before png_read_update_info or png_start_read_image,
1304	* otherwise it will not have the desired effect. Note that it is still
1305	* necessary to call png_read_row or png_read_rows png_get_image_height
1306	* times for each pass.
1307	*/
1308	PNG_EXPORT(45, int, png_set_interlace_handling, (png_structrp png_ptr));
1309	#endif
1310
1311	#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1312	/* Invert monochrome files */
1313	PNG_EXPORT(46, void, png_set_invert_mono, (png_structrp png_ptr));
1314	#endif
1315
1316	#ifdef PNG_READ_BACKGROUND_SUPPORTED
1317	/* Handle alpha and tRNS by replacing with a background color. Prior to
1318	* libpng-1.5.4 this API must not be called before the PNG file header has been
1319	* read. Doing so will result in unexpected behavior and possible warnings or
1320	* errors if the PNG file contains a bKGD chunk.
1321	*/
1322	PNG_FP_EXPORT(47, void, png_set_background, (png_structrp png_ptr,
1323	png_const_color_16p background_color, int background_gamma_code,
1324	int need_expand, double background_gamma))
1325	PNG_FIXED_EXPORT(215, void, png_set_background_fixed, (png_structrp png_ptr,
1326	png_const_color_16p background_color, int background_gamma_code,
1327	int need_expand, png_fixed_point background_gamma))
1328	#endif
1329	#ifdef PNG_READ_BACKGROUND_SUPPORTED
1330	# define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1331	# define PNG_BACKGROUND_GAMMA_SCREEN 1
1332	# define PNG_BACKGROUND_GAMMA_FILE 2
1333	# define PNG_BACKGROUND_GAMMA_UNIQUE 3
1334	#endif
1335
1336	#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
1337	/* Scale a 16-bit depth file down to 8-bit, accurately. */
1338	PNG_EXPORT(229, void, png_set_scale_16, (png_structrp png_ptr));
1339	#endif
1340
1341	#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
1342	#define PNG_READ_16_TO_8_SUPPORTED /* Name prior to 1.5.4 */
1343	/* Strip the second byte of information from a 16-bit depth file. */
1344	PNG_EXPORT(48, void, png_set_strip_16, (png_structrp png_ptr));
1345	#endif
1346
1347	#ifdef PNG_READ_QUANTIZE_SUPPORTED
1348	/* Turn on quantizing, and reduce the palette to the number of colors
1349	* available.
1350	*/
1351	PNG_EXPORT(49, void, png_set_quantize, (png_structrp png_ptr,
1352	png_colorp palette, int num_palette, int maximum_colors,
1353	png_const_uint_16p histogram, int full_quantize));
1354	#endif
1355
1356	#ifdef PNG_READ_GAMMA_SUPPORTED
1357	/* The threshold on gamma processing is configurable but hard-wired into the
1358	* library. The following is the floating point variant.
1359	*/
1360	#define PNG_GAMMA_THRESHOLD (PNG_GAMMA_THRESHOLD_FIXED*.00001)
1361
1362	/* Handle gamma correction. Screen_gamma=(display_exponent).
1363	* NOTE: this API simply sets the screen and file gamma values. It will
1364	* therefore override the value for gamma in a PNG file if it is called after
1365	* the file header has been read - use with care - call before reading the PNG
1366	* file for best results!
1367	*
1368	* These routines accept the same gamma values as png_set_alpha_mode (described
1369	* above). The PNG_GAMMA_ defines and PNG_DEFAULT_sRGB can be passed to either
1370	* API (floating point or fixed.) Notice, however, that the 'file_gamma' value
1371	* is the inverse of a 'screen gamma' value.
1372	*/
1373	PNG_FP_EXPORT(50, void, png_set_gamma, (png_structrp png_ptr,
1374	double screen_gamma, double override_file_gamma))
1375	PNG_FIXED_EXPORT(208, void, png_set_gamma_fixed, (png_structrp png_ptr,
1376	png_fixed_point screen_gamma, png_fixed_point override_file_gamma))
1377	#endif
1378
1379	#ifdef PNG_WRITE_FLUSH_SUPPORTED
1380	/* Set how many lines between output flushes - 0 for no flushing */
1381	PNG_EXPORT(51, void, png_set_flush, (png_structrp png_ptr, int nrows));
1382	/* Flush the current PNG output buffer */
1383	PNG_EXPORT(52, void, png_write_flush, (png_structrp png_ptr));
1384	#endif
1385
1386	/* Optional update palette with requested transformations */
1387	PNG_EXPORT(53, void, png_start_read_image, (png_structrp png_ptr));
1388
1389	/* Optional call to update the users info structure */
1390	PNG_EXPORT(54, void, png_read_update_info, (png_structrp png_ptr,
1391	png_inforp info_ptr));
1392
1393	#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1394	/* Read one or more rows of image data. */
1395	PNG_EXPORT(55, void, png_read_rows, (png_structrp png_ptr, png_bytepp row,
1396	png_bytepp display_row, png_uint_32 num_rows));
1397	#endif
1398
1399	#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1400	/* Read a row of data. */
1401	PNG_EXPORT(56, void, png_read_row, (png_structrp png_ptr, png_bytep row,
1402	png_bytep display_row));
1403	#endif
1404
1405	#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1406	/* Read the whole image into memory at once. */
1407	PNG_EXPORT(57, void, png_read_image, (png_structrp png_ptr, png_bytepp image));
1408	#endif
1409
1410	/* Write a row of image data */
1411	PNG_EXPORT(58, void, png_write_row, (png_structrp png_ptr,
1412	png_const_bytep row));
1413
1414	/* Write a few rows of image data: (*row) is not written; however, the type
1415	* is declared as writeable to maintain compatibility with previous versions
1416	* of libpng and to allow the 'display_row' array from read_rows to be passed
1417	* unchanged to write_rows.
1418	*/
1419	PNG_EXPORT(59, void, png_write_rows, (png_structrp png_ptr, png_bytepp row,
1420	png_uint_32 num_rows));
1421
1422	/* Write the image data */
1423	PNG_EXPORT(60, void, png_write_image, (png_structrp png_ptr, png_bytepp image));
1424
1425	/* Write the end of the PNG file. */
1426	PNG_EXPORT(61, void, png_write_end, (png_structrp png_ptr,
1427	png_inforp info_ptr));
1428
1429	#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1430	/* Read the end of the PNG file. */
1431	PNG_EXPORT(62, void, png_read_end, (png_structrp png_ptr, png_inforp info_ptr));
1432	#endif
1433
1434	/* Free any memory associated with the png_info_struct */
1435	PNG_EXPORT(63, void, png_destroy_info_struct, (png_const_structrp png_ptr,
1436	png_infopp info_ptr_ptr));
1437
1438	/* Free any memory associated with the png_struct and the png_info_structs */
1439	PNG_EXPORT(64, void, png_destroy_read_struct, (png_structpp png_ptr_ptr,
1440	png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1441
1442	/* Free any memory associated with the png_struct and the png_info_structs */
1443	PNG_EXPORT(65, void, png_destroy_write_struct, (png_structpp png_ptr_ptr,
1444	png_infopp info_ptr_ptr));
1445
1446	/* Set the libpng method of handling chunk CRC errors */
1447	PNG_EXPORT(66, void, png_set_crc_action, (png_structrp png_ptr, int crit_action,
1448	int ancil_action));
1449
1450	/* Values for png_set_crc_action() say how to handle CRC errors in
1451	* ancillary and critical chunks, and whether to use the data contained
1452	* therein. Note that it is impossible to "discard" data in a critical
1453	* chunk. For versions prior to 0.90, the action was always error/quit,
1454	* whereas in version 0.90 and later, the action for CRC errors in ancillary
1455	* chunks is warn/discard. These values should NOT be changed.
1456	*
1457	* value action:critical action:ancillary
1458	*/
1459	#define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1460	#define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1461	#define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1462	#define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1463	#define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1464	#define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1465
1466	#ifdef PNG_WRITE_SUPPORTED
1467	/* These functions give the user control over the scan-line filtering in
1468	* libpng and the compression methods used by zlib. These functions are
1469	* mainly useful for testing, as the defaults should work with most users.
1470	* Those users who are tight on memory or want faster performance at the
1471	* expense of compression can modify them. See the compression library
1472	* header file (zlib.h) for an explination of the compression functions.
1473	*/
1474
1475	/* Set the filtering method(s) used by libpng. Currently, the only valid
1476	* value for "method" is 0.
1477	*/
1478	PNG_EXPORT(67, void, png_set_filter, (png_structrp png_ptr, int method,
1479	int filters));
1480	#endif /* WRITE */
1481
1482	/* Flags for png_set_filter() to say which filters to use. The flags
1483	* are chosen so that they don't conflict with real filter types
1484	* below, in case they are supplied instead of the #defined constants.
1485	* These values should NOT be changed.
1486	*/
1487	#define PNG_NO_FILTERS 0x00
1488	#define PNG_FILTER_NONE 0x08
1489	#define PNG_FILTER_SUB 0x10
1490	#define PNG_FILTER_UP 0x20
1491	#define PNG_FILTER_AVG 0x40
1492	#define PNG_FILTER_PAETH 0x80
1493	#define PNG_FAST_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP)
1494	#define PNG_ALL_FILTERS (PNG_FAST_FILTERS | PNG_FILTER_AVG | PNG_FILTER_PAETH)
1495
1496	/* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1497	* These defines should NOT be changed.
1498	*/
1499	#define PNG_FILTER_VALUE_NONE 0
1500	#define PNG_FILTER_VALUE_SUB 1
1501	#define PNG_FILTER_VALUE_UP 2
1502	#define PNG_FILTER_VALUE_AVG 3
1503	#define PNG_FILTER_VALUE_PAETH 4
1504	#define PNG_FILTER_VALUE_LAST 5
1505
1506	#ifdef PNG_WRITE_SUPPORTED
1507	#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */
1508	PNG_FP_EXPORT(68, void, png_set_filter_heuristics, (png_structrp png_ptr,
1509	int heuristic_method, int num_weights, png_const_doublep filter_weights,
1510	png_const_doublep filter_costs))
1511	PNG_FIXED_EXPORT(209, void, png_set_filter_heuristics_fixed,
1512	(png_structrp png_ptr, int heuristic_method, int num_weights,
1513	png_const_fixed_point_p filter_weights,
1514	png_const_fixed_point_p filter_costs))
1515	#endif /* WRITE_WEIGHTED_FILTER */
1516
1517	/* The following are no longer used and will be removed from libpng-1.7: */
1518	#define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
1519	#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
1520	#define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
1521	#define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
1522
1523	/* Set the library compression level. Currently, valid values range from
1524	* 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1525	* (0 - no compression, 9 - "maximal" compression). Note that tests have
1526	* shown that zlib compression levels 3-6 usually perform as well as level 9
1527	* for PNG images, and do considerably fewer caclulations. In the future,
1528	* these values may not correspond directly to the zlib compression levels.
1529	*/
1530	#ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED
1531	PNG_EXPORT(69, void, png_set_compression_level, (png_structrp png_ptr,
1532	int level));
1533
1534	PNG_EXPORT(70, void, png_set_compression_mem_level, (png_structrp png_ptr,
1535	int mem_level));
1536
1537	PNG_EXPORT(71, void, png_set_compression_strategy, (png_structrp png_ptr,
1538	int strategy));
1539
1540	/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1541	* smaller value of window_bits if it can do so safely.
1542	*/
1543	PNG_EXPORT(72, void, png_set_compression_window_bits, (png_structrp png_ptr,
1544	int window_bits));
1545
1546	PNG_EXPORT(73, void, png_set_compression_method, (png_structrp png_ptr,
1547	int method));
1548	#endif /* WRITE_CUSTOMIZE_COMPRESSION */
1549
1550	#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
1551	/* Also set zlib parameters for compressing non-IDAT chunks */
1552	PNG_EXPORT(222, void, png_set_text_compression_level, (png_structrp png_ptr,
1553	int level));
1554
1555	PNG_EXPORT(223, void, png_set_text_compression_mem_level, (png_structrp png_ptr,
1556	int mem_level));
1557
1558	PNG_EXPORT(224, void, png_set_text_compression_strategy, (png_structrp png_ptr,
1559	int strategy));
1560
1561	/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1562	* smaller value of window_bits if it can do so safely.
1563	*/
1564	PNG_EXPORT(225, void, png_set_text_compression_window_bits,
1565	(png_structrp png_ptr, int window_bits));
1566
1567	PNG_EXPORT(226, void, png_set_text_compression_method, (png_structrp png_ptr,
1568	int method));
1569	#endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */
1570	#endif /* WRITE */
1571
1572	/* These next functions are called for input/output, memory, and error
1573	* handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
1574	* and call standard C I/O routines such as fread(), fwrite(), and
1575	* fprintf(). These functions can be made to use other I/O routines
1576	* at run time for those applications that need to handle I/O in a
1577	* different manner by calling png_set_???_fn(). See libpng-manual.txt for
1578	* more information.
1579	*/
1580
1581	#ifdef PNG_STDIO_SUPPORTED
1582	/* Initialize the input/output for the PNG file to the default functions. */
1583	PNG_EXPORT(74, void, png_init_io, (png_structrp png_ptr, png_FILE_p fp));
1584	#endif
1585
1586	/* Replace the (error and abort), and warning functions with user
1587	* supplied functions. If no messages are to be printed you must still
1588	* write and use replacement functions. The replacement error_fn should
1589	* still do a longjmp to the last setjmp location if you are using this
1590	* method of error handling. If error_fn or warning_fn is NULL, the
1591	* default function will be used.
1592	*/
1593
1594	PNG_EXPORT(75, void, png_set_error_fn, (png_structrp png_ptr,
1595	png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
1596
1597	/* Return the user pointer associated with the error functions */
1598	PNG_EXPORT(76, png_voidp, png_get_error_ptr, (png_const_structrp png_ptr));
1599
1600	/* Replace the default data output functions with a user supplied one(s).
1601	* If buffered output is not used, then output_flush_fn can be set to NULL.
1602	* If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
1603	* output_flush_fn will be ignored (and thus can be NULL).
1604	* It is probably a mistake to use NULL for output_flush_fn if
1605	* write_data_fn is not also NULL unless you have built libpng with
1606	* PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
1607	* default flush function, which uses the standard *FILE structure, will
1608	* be used.
1609	*/
1610	PNG_EXPORT(77, void, png_set_write_fn, (png_structrp png_ptr, png_voidp io_ptr,
1611	png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
1612
1613	/* Replace the default data input function with a user supplied one. */
1614	PNG_EXPORT(78, void, png_set_read_fn, (png_structrp png_ptr, png_voidp io_ptr,
1615	png_rw_ptr read_data_fn));
1616
1617	/* Return the user pointer associated with the I/O functions */
1618	PNG_EXPORT(79, png_voidp, png_get_io_ptr, (png_const_structrp png_ptr));
1619
1620	PNG_EXPORT(80, void, png_set_read_status_fn, (png_structrp png_ptr,
1621	png_read_status_ptr read_row_fn));
1622
1623	PNG_EXPORT(81, void, png_set_write_status_fn, (png_structrp png_ptr,
1624	png_write_status_ptr write_row_fn));
1625
1626	#ifdef PNG_USER_MEM_SUPPORTED
1627	/* Replace the default memory allocation functions with user supplied one(s). */
1628	PNG_EXPORT(82, void, png_set_mem_fn, (png_structrp png_ptr, png_voidp mem_ptr,
1629	png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1630	/* Return the user pointer associated with the memory functions */
1631	PNG_EXPORT(83, png_voidp, png_get_mem_ptr, (png_const_structrp png_ptr));
1632	#endif
1633
1634	#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
1635	PNG_EXPORT(84, void, png_set_read_user_transform_fn, (png_structrp png_ptr,
1636	png_user_transform_ptr read_user_transform_fn));
1637	#endif
1638
1639	#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1640	PNG_EXPORT(85, void, png_set_write_user_transform_fn, (png_structrp png_ptr,
1641	png_user_transform_ptr write_user_transform_fn));
1642	#endif
1643
1644	#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
1645	PNG_EXPORT(86, void, png_set_user_transform_info, (png_structrp png_ptr,
1646	png_voidp user_transform_ptr, int user_transform_depth,
1647	int user_transform_channels));
1648	/* Return the user pointer associated with the user transform functions */
1649	PNG_EXPORT(87, png_voidp, png_get_user_transform_ptr,
1650	(png_const_structrp png_ptr));
1651	#endif
1652
1653	#ifdef PNG_USER_TRANSFORM_INFO_SUPPORTED
1654	/* Return information about the row currently being processed. Note that these
1655	* APIs do not fail but will return unexpected results if called outside a user
1656	* transform callback. Also note that when transforming an interlaced image the
1657	* row number is the row number within the sub-image of the interlace pass, so
1658	* the value will increase to the height of the sub-image (not the full image)
1659	* then reset to 0 for the next pass.
1660	*
1661	* Use PNG_ROW_FROM_PASS_ROW(row, pass) and PNG_COL_FROM_PASS_COL(col, pass) to
1662	* find the output pixel (x,y) given an interlaced sub-image pixel
1663	* (row,col,pass). (See below for these macros.)
1664	*/
1665	PNG_EXPORT(217, png_uint_32, png_get_current_row_number, (png_const_structrp));
1666	PNG_EXPORT(218, png_byte, png_get_current_pass_number, (png_const_structrp));
1667	#endif
1668
1669	#ifdef PNG_READ_USER_CHUNKS_SUPPORTED
1670	/* This callback is called only for *unknown* chunks. If
1671	* PNG_HANDLE_AS_UNKNOWN_SUPPORTED is set then it is possible to set known
1672	* chunks to be treated as unknown, however in this case the callback must do
1673	* any processing required by the chunk (e.g. by calling the appropriate
1674	* png_set_ APIs.)
1675	*
1676	* There is no write support - on write, by default, all the chunks in the
1677	* 'unknown' list are written in the specified position.
1678	*
1679	* The integer return from the callback function is interpreted thus:
1680	*
1681	* negative: An error occurred; png_chunk_error will be called.
1682	* zero: The chunk was not handled, the chunk will be saved. A critical
1683	* chunk will cause an error at this point unless it is to be saved.
1684	* positive: The chunk was handled, libpng will ignore/discard it.
1685	*
1686	* See "INTERACTION WITH USER CHUNK CALLBACKS" below for important notes about
1687	* how this behavior will change in libpng 1.7
1688	*/
1689	PNG_EXPORT(88, void, png_set_read_user_chunk_fn, (png_structrp png_ptr,
1690	png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
1691	#endif
1692
1693	#ifdef PNG_USER_CHUNKS_SUPPORTED
1694	PNG_EXPORT(89, png_voidp, png_get_user_chunk_ptr, (png_const_structrp png_ptr));
1695	#endif
1696
1697	#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1698	/* Sets the function callbacks for the push reader, and a pointer to a
1699	* user-defined structure available to the callback functions.
1700	*/
1701	PNG_EXPORT(90, void, png_set_progressive_read_fn, (png_structrp png_ptr,
1702	png_voidp progressive_ptr, png_progressive_info_ptr info_fn,
1703	png_progressive_row_ptr row_fn, png_progressive_end_ptr end_fn));
1704
1705	/* Returns the user pointer associated with the push read functions */
1706	PNG_EXPORT(91, png_voidp, png_get_progressive_ptr,
1707	(png_const_structrp png_ptr));
1708
1709	/* Function to be called when data becomes available */
1710	PNG_EXPORT(92, void, png_process_data, (png_structrp png_ptr,
1711	png_inforp info_ptr, png_bytep buffer, size_t buffer_size));
1712
1713	/* A function which may be called *only* within png_process_data to stop the
1714	* processing of any more data. The function returns the number of bytes
1715	* remaining, excluding any that libpng has cached internally. A subsequent
1716	* call to png_process_data must supply these bytes again. If the argument
1717	* 'save' is set to true the routine will first save all the pending data and
1718	* will always return 0.
1719	*/
1720	PNG_EXPORT(219, size_t, png_process_data_pause, (png_structrp, int save));
1721
1722	/* A function which may be called *only* outside (after) a call to
1723	* png_process_data. It returns the number of bytes of data to skip in the
1724	* input. Normally it will return 0, but if it returns a non-zero value the
1725	* application must skip than number of bytes of input data and pass the
1726	* following data to the next call to png_process_data.
1727	*/
1728	PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp));
1729
1730	/* Function that combines rows. 'new_row' is a flag that should come from
1731	* the callback and be non-NULL if anything needs to be done; the library
1732	* stores its own version of the new data internally and ignores the passed
1733	* in value.
1734	*/
1735	PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr,
1736	png_bytep old_row, png_const_bytep new_row));
1737	#endif /* PROGRESSIVE_READ */
1738
1739	PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr,
1740	png_alloc_size_t size), PNG_ALLOCATED);
1741	/* Added at libpng version 1.4.0 */
1742	PNG_EXPORTA(95, png_voidp, png_calloc, (png_const_structrp png_ptr,
1743	png_alloc_size_t size), PNG_ALLOCATED);
1744
1745	/* Added at libpng version 1.2.4 */
1746	PNG_EXPORTA(96, png_voidp, png_malloc_warn, (png_const_structrp png_ptr,
1747	png_alloc_size_t size), PNG_ALLOCATED);
1748
1749	/* Frees a pointer allocated by png_malloc() */
1750	PNG_EXPORT(97, void, png_free, (png_const_structrp png_ptr, png_voidp ptr));
1751
1752	/* Free data that was allocated internally */
1753	PNG_EXPORT(98, void, png_free_data, (png_const_structrp png_ptr,
1754	png_inforp info_ptr, png_uint_32 free_me, int num));
1755
1756	/* Reassign responsibility for freeing existing data, whether allocated
1757	* by libpng or by the application; this works on the png_info structure passed
1758	* in, it does not change the state for other png_info structures.
1759	*
1760	* It is unlikely that this function works correctly as of 1.6.0 and using it
1761	* may result either in memory leaks or double free of allocated data.
1762	*/
1763	PNG_EXPORT(99, void, png_data_freer, (png_const_structrp png_ptr,
1764	png_inforp info_ptr, int freer, png_uint_32 mask));
1765
1766	/* Assignments for png_data_freer */
1767	#define PNG_DESTROY_WILL_FREE_DATA 1
1768	#define PNG_SET_WILL_FREE_DATA 1
1769	#define PNG_USER_WILL_FREE_DATA 2
1770	/* Flags for png_ptr->free_me and info_ptr->free_me */
1771	#define PNG_FREE_HIST 0x0008U
1772	#define PNG_FREE_ICCP 0x0010U
1773	#define PNG_FREE_SPLT 0x0020U
1774	#define PNG_FREE_ROWS 0x0040U
1775	#define PNG_FREE_PCAL 0x0080U
1776	#define PNG_FREE_SCAL 0x0100U
1777	#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
1778	# define PNG_FREE_UNKN 0x0200U
1779	#endif
1780	/* PNG_FREE_LIST 0x0400U removed in 1.6.0 because it is ignored */
1781	#define PNG_FREE_PLTE 0x1000U
1782	#define PNG_FREE_TRNS 0x2000U
1783	#define PNG_FREE_TEXT 0x4000U
1784	#define PNG_FREE_EXIF 0x8000U /* Added at libpng-1.6.31 */
1785	#define PNG_FREE_ALL 0xffffU
1786	#define PNG_FREE_MUL 0x4220U /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
1787
1788	#ifdef PNG_USER_MEM_SUPPORTED
1789	PNG_EXPORTA(100, png_voidp, png_malloc_default, (png_const_structrp png_ptr,
1790	png_alloc_size_t size), PNG_ALLOCATED PNG_DEPRECATED);
1791	PNG_EXPORTA(101, void, png_free_default, (png_const_structrp png_ptr,
1792	png_voidp ptr), PNG_DEPRECATED);
1793	#endif
1794
1795	#ifdef PNG_ERROR_TEXT_SUPPORTED
1796	/* Fatal error in PNG image of libpng - can't continue */
1797	PNG_EXPORTA(102, void, png_error, (png_const_structrp png_ptr,
1798	png_const_charp error_message), PNG_NORETURN);
1799
1800	/* The same, but the chunk name is prepended to the error string. */
1801	PNG_EXPORTA(103, void, png_chunk_error, (png_const_structrp png_ptr,
1802	png_const_charp error_message), PNG_NORETURN);
1803
1804	#else
1805	/* Fatal error in PNG image of libpng - can't continue */
1806	PNG_EXPORTA(104, void, png_err, (png_const_structrp png_ptr), PNG_NORETURN);
1807	# define png_error(s1,s2) png_err(s1)
1808	# define png_chunk_error(s1,s2) png_err(s1)
1809	#endif
1810
1811	#ifdef PNG_WARNINGS_SUPPORTED
1812	/* Non-fatal error in libpng. Can continue, but may have a problem. */
1813	PNG_EXPORT(105, void, png_warning, (png_const_structrp png_ptr,
1814	png_const_charp warning_message));
1815
1816	/* Non-fatal error in libpng, chunk name is prepended to message. */
1817	PNG_EXPORT(106, void, png_chunk_warning, (png_const_structrp png_ptr,
1818	png_const_charp warning_message));
1819	#else
1820	# define png_warning(s1,s2) ((void)(s1))
1821	# define png_chunk_warning(s1,s2) ((void)(s1))
1822	#endif
1823
1824	#ifdef PNG_BENIGN_ERRORS_SUPPORTED
1825	/* Benign error in libpng. Can continue, but may have a problem.
1826	* User can choose whether to handle as a fatal error or as a warning. */
1827	PNG_EXPORT(107, void, png_benign_error, (png_const_structrp png_ptr,
1828	png_const_charp warning_message));
1829
1830	#ifdef PNG_READ_SUPPORTED
1831	/* Same, chunk name is prepended to message (only during read) */
1832	PNG_EXPORT(108, void, png_chunk_benign_error, (png_const_structrp png_ptr,
1833	png_const_charp warning_message));
1834	#endif
1835
1836	PNG_EXPORT(109, void, png_set_benign_errors,
1837	(png_structrp png_ptr, int allowed));
1838	#else
1839	# ifdef PNG_ALLOW_BENIGN_ERRORS
1840	# define png_benign_error png_warning
1841	# define png_chunk_benign_error png_chunk_warning
1842	# else
1843	# define png_benign_error png_error
1844	# define png_chunk_benign_error png_chunk_error
1845	# endif
1846	#endif
1847
1848	/* The png_set_<chunk> functions are for storing values in the png_info_struct.
1849	* Similarly, the png_get_<chunk> calls are used to read values from the
1850	* png_info_struct, either storing the parameters in the passed variables, or
1851	* setting pointers into the png_info_struct where the data is stored. The
1852	* png_get_<chunk> functions return a non-zero value if the data was available
1853	* in info_ptr, or return zero and do not change any of the parameters if the
1854	* data was not available.
1855	*
1856	* These functions should be used instead of directly accessing png_info
1857	* to avoid problems with future changes in the size and internal layout of
1858	* png_info_struct.
1859	*/
1860	/* Returns "flag" if chunk data is valid in info_ptr. */
1861	PNG_EXPORT(110, png_uint_32, png_get_valid, (png_const_structrp png_ptr,
1862	png_const_inforp info_ptr, png_uint_32 flag));
1863
1864	/* Returns number of bytes needed to hold a transformed row. */
1865	PNG_EXPORT(111, size_t, png_get_rowbytes, (png_const_structrp png_ptr,
1866	png_const_inforp info_ptr));
1867
1868	#ifdef PNG_INFO_IMAGE_SUPPORTED
1869	/* Returns row_pointers, which is an array of pointers to scanlines that was
1870	* returned from png_read_png().
1871	*/
1872	PNG_EXPORT(112, png_bytepp, png_get_rows, (png_const_structrp png_ptr,
1873	png_const_inforp info_ptr));
1874
1875	/* Set row_pointers, which is an array of pointers to scanlines for use
1876	* by png_write_png().
1877	*/
1878	PNG_EXPORT(113, void, png_set_rows, (png_const_structrp png_ptr,
1879	png_inforp info_ptr, png_bytepp row_pointers));
1880	#endif
1881
1882	/* Returns number of color channels in image. */
1883	PNG_EXPORT(114, png_byte, png_get_channels, (png_const_structrp png_ptr,
1884	png_const_inforp info_ptr));
1885
1886	#ifdef PNG_EASY_ACCESS_SUPPORTED
1887	/* Returns image width in pixels. */
1888	PNG_EXPORT(115, png_uint_32, png_get_image_width, (png_const_structrp png_ptr,
1889	png_const_inforp info_ptr));
1890
1891	/* Returns image height in pixels. */
1892	PNG_EXPORT(116, png_uint_32, png_get_image_height, (png_const_structrp png_ptr,
1893	png_const_inforp info_ptr));
1894
1895	/* Returns image bit_depth. */
1896	PNG_EXPORT(117, png_byte, png_get_bit_depth, (png_const_structrp png_ptr,
1897	png_const_inforp info_ptr));
1898
1899	/* Returns image color_type. */
1900	PNG_EXPORT(118, png_byte, png_get_color_type, (png_const_structrp png_ptr,
1901	png_const_inforp info_ptr));
1902
1903	/* Returns image filter_type. */
1904	PNG_EXPORT(119, png_byte, png_get_filter_type, (png_const_structrp png_ptr,
1905	png_const_inforp info_ptr));
1906
1907	/* Returns image interlace_type. */
1908	PNG_EXPORT(120, png_byte, png_get_interlace_type, (png_const_structrp png_ptr,
1909	png_const_inforp info_ptr));
1910
1911	/* Returns image compression_type. */
1912	PNG_EXPORT(121, png_byte, png_get_compression_type, (png_const_structrp png_ptr,
1913	png_const_inforp info_ptr));
1914
1915	/* Returns image resolution in pixels per meter, from pHYs chunk data. */
1916	PNG_EXPORT(122, png_uint_32, png_get_pixels_per_meter,
1917	(png_const_structrp png_ptr, png_const_inforp info_ptr));
1918	PNG_EXPORT(123, png_uint_32, png_get_x_pixels_per_meter,
1919	(png_const_structrp png_ptr, png_const_inforp info_ptr));
1920	PNG_EXPORT(124, png_uint_32, png_get_y_pixels_per_meter,
1921	(png_const_structrp png_ptr, png_const_inforp info_ptr));
1922
1923	/* Returns pixel aspect ratio, computed from pHYs chunk data. */
1924	PNG_FP_EXPORT(125, float, png_get_pixel_aspect_ratio,
1925	(png_const_structrp png_ptr, png_const_inforp info_ptr))
1926	PNG_FIXED_EXPORT(210, png_fixed_point, png_get_pixel_aspect_ratio_fixed,
1927	(png_const_structrp png_ptr, png_const_inforp info_ptr))
1928
1929	/* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
1930	PNG_EXPORT(126, png_int_32, png_get_x_offset_pixels,
1931	(png_const_structrp png_ptr, png_const_inforp info_ptr));
1932	PNG_EXPORT(127, png_int_32, png_get_y_offset_pixels,
1933	(png_const_structrp png_ptr, png_const_inforp info_ptr));
1934	PNG_EXPORT(128, png_int_32, png_get_x_offset_microns,
1935	(png_const_structrp png_ptr, png_const_inforp info_ptr));
1936	PNG_EXPORT(129, png_int_32, png_get_y_offset_microns,
1937	(png_const_structrp png_ptr, png_const_inforp info_ptr));
1938
1939	#endif /* EASY_ACCESS */
1940
1941	#ifdef PNG_READ_SUPPORTED
1942	/* Returns pointer to signature string read from PNG header */
1943	PNG_EXPORT(130, png_const_bytep, png_get_signature, (png_const_structrp png_ptr,
1944	png_const_inforp info_ptr));
1945	#endif
1946
1947	#ifdef PNG_bKGD_SUPPORTED
1948	PNG_EXPORT(131, png_uint_32, png_get_bKGD, (png_const_structrp png_ptr,
1949	png_inforp info_ptr, png_color_16p *background));
1950	#endif
1951
1952	#ifdef PNG_bKGD_SUPPORTED
1953	PNG_EXPORT(132, void, png_set_bKGD, (png_const_structrp png_ptr,
1954	png_inforp info_ptr, png_const_color_16p background));
1955	#endif
1956
1957	#ifdef PNG_cHRM_SUPPORTED
1958	PNG_FP_EXPORT(133, png_uint_32, png_get_cHRM, (png_const_structrp png_ptr,
1959	png_const_inforp info_ptr, double *white_x, double *white_y, double *red_x,
1960	double *red_y, double *green_x, double *green_y, double *blue_x,
1961	double *blue_y))
1962	PNG_FP_EXPORT(230, png_uint_32, png_get_cHRM_XYZ, (png_const_structrp png_ptr,
1963	png_const_inforp info_ptr, double *red_X, double *red_Y, double *red_Z,
1964	double *green_X, double *green_Y, double *green_Z, double *blue_X,
1965	double *blue_Y, double *blue_Z))
1966	PNG_FIXED_EXPORT(134, png_uint_32, png_get_cHRM_fixed,
1967	(png_const_structrp png_ptr, png_const_inforp info_ptr,
1968	png_fixed_point *int_white_x, png_fixed_point *int_white_y,
1969	png_fixed_point *int_red_x, png_fixed_point *int_red_y,
1970	png_fixed_point *int_green_x, png_fixed_point *int_green_y,
1971	png_fixed_point *int_blue_x, png_fixed_point *int_blue_y))
1972	PNG_FIXED_EXPORT(231, png_uint_32, png_get_cHRM_XYZ_fixed,
1973	(png_const_structrp png_ptr, png_const_inforp info_ptr,
1974	png_fixed_point *int_red_X, png_fixed_point *int_red_Y,
1975	png_fixed_point *int_red_Z, png_fixed_point *int_green_X,
1976	png_fixed_point *int_green_Y, png_fixed_point *int_green_Z,
1977	png_fixed_point *int_blue_X, png_fixed_point *int_blue_Y,
1978	png_fixed_point *int_blue_Z))
1979	#endif
1980
1981	#ifdef PNG_cHRM_SUPPORTED
1982	PNG_FP_EXPORT(135, void, png_set_cHRM, (png_const_structrp png_ptr,
1983	png_inforp info_ptr,
1984	double white_x, double white_y, double red_x, double red_y, double green_x,
1985	double green_y, double blue_x, double blue_y))
1986	PNG_FP_EXPORT(232, void, png_set_cHRM_XYZ, (png_const_structrp png_ptr,
1987	png_inforp info_ptr, double red_X, double red_Y, double red_Z,
1988	double green_X, double green_Y, double green_Z, double blue_X,
1989	double blue_Y, double blue_Z))
1990	PNG_FIXED_EXPORT(136, void, png_set_cHRM_fixed, (png_const_structrp png_ptr,
1991	png_inforp info_ptr, png_fixed_point int_white_x,
1992	png_fixed_point int_white_y, png_fixed_point int_red_x,
1993	png_fixed_point int_red_y, png_fixed_point int_green_x,
1994	png_fixed_point int_green_y, png_fixed_point int_blue_x,
1995	png_fixed_point int_blue_y))
1996	PNG_FIXED_EXPORT(233, void, png_set_cHRM_XYZ_fixed, (png_const_structrp png_ptr,
1997	png_inforp info_ptr, png_fixed_point int_red_X, png_fixed_point int_red_Y,
1998	png_fixed_point int_red_Z, png_fixed_point int_green_X,
1999	png_fixed_point int_green_Y, png_fixed_point int_green_Z,
2000	png_fixed_point int_blue_X, png_fixed_point int_blue_Y,
2001	png_fixed_point int_blue_Z))
2002	#endif
2003
2004	#ifdef PNG_eXIf_SUPPORTED
2005	PNG_EXPORT(246, png_uint_32, png_get_eXIf, (png_const_structrp png_ptr,
2006	png_inforp info_ptr, png_bytep *exif));
2007	PNG_EXPORT(247, void, png_set_eXIf, (png_const_structrp png_ptr,
2008	png_inforp info_ptr, png_bytep exif));
2009
2010	PNG_EXPORT(248, png_uint_32, png_get_eXIf_1, (png_const_structrp png_ptr,
2011	png_const_inforp info_ptr, png_uint_32 *num_exif, png_bytep *exif));
2012	PNG_EXPORT(249, void, png_set_eXIf_1, (png_const_structrp png_ptr,
2013	png_inforp info_ptr, png_uint_32 num_exif, png_bytep exif));
2014	#endif
2015
2016	#ifdef PNG_gAMA_SUPPORTED
2017	PNG_FP_EXPORT(137, png_uint_32, png_get_gAMA, (png_const_structrp png_ptr,
2018	png_const_inforp info_ptr, double *file_gamma))
2019	PNG_FIXED_EXPORT(138, png_uint_32, png_get_gAMA_fixed,
2020	(png_const_structrp png_ptr, png_const_inforp info_ptr,
2021	png_fixed_point *int_file_gamma))
2022	#endif
2023
2024	#ifdef PNG_gAMA_SUPPORTED
2025	PNG_FP_EXPORT(139, void, png_set_gAMA, (png_const_structrp png_ptr,
2026	png_inforp info_ptr, double file_gamma))
2027	PNG_FIXED_EXPORT(140, void, png_set_gAMA_fixed, (png_const_structrp png_ptr,
2028	png_inforp info_ptr, png_fixed_point int_file_gamma))
2029	#endif
2030
2031	#ifdef PNG_hIST_SUPPORTED
2032	PNG_EXPORT(141, png_uint_32, png_get_hIST, (png_const_structrp png_ptr,
2033	png_inforp info_ptr, png_uint_16p *hist));
2034	PNG_EXPORT(142, void, png_set_hIST, (png_const_structrp png_ptr,
2035	png_inforp info_ptr, png_const_uint_16p hist));
2036	#endif
2037
2038	PNG_EXPORT(143, png_uint_32, png_get_IHDR, (png_const_structrp png_ptr,
2039	png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height,
2040	int *bit_depth, int *color_type, int *interlace_method,
2041	int *compression_method, int *filter_method));
2042
2043	PNG_EXPORT(144, void, png_set_IHDR, (png_const_structrp png_ptr,
2044	png_inforp info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
2045	int color_type, int interlace_method, int compression_method,
2046	int filter_method));
2047
2048	#ifdef PNG_oFFs_SUPPORTED
2049	PNG_EXPORT(145, png_uint_32, png_get_oFFs, (png_const_structrp png_ptr,
2050	png_const_inforp info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
2051	int *unit_type));
2052	#endif
2053
2054	#ifdef PNG_oFFs_SUPPORTED
2055	PNG_EXPORT(146, void, png_set_oFFs, (png_const_structrp png_ptr,
2056	png_inforp info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2057	int unit_type));
2058	#endif
2059
2060	#ifdef PNG_pCAL_SUPPORTED
2061	PNG_EXPORT(147, png_uint_32, png_get_pCAL, (png_const_structrp png_ptr,
2062	png_inforp info_ptr, png_charp *purpose, png_int_32 *X0,
2063	png_int_32 *X1, int *type, int *nparams, png_charp *units,
2064	png_charpp *params));
2065	#endif
2066
2067	#ifdef PNG_pCAL_SUPPORTED
2068	PNG_EXPORT(148, void, png_set_pCAL, (png_const_structrp png_ptr,
2069	png_inforp info_ptr, png_const_charp purpose, png_int_32 X0, png_int_32 X1,
2070	int type, int nparams, png_const_charp units, png_charpp params));
2071	#endif
2072
2073	#ifdef PNG_pHYs_SUPPORTED
2074	PNG_EXPORT(149, png_uint_32, png_get_pHYs, (png_const_structrp png_ptr,
2075	png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
2076	int *unit_type));
2077	#endif
2078
2079	#ifdef PNG_pHYs_SUPPORTED
2080	PNG_EXPORT(150, void, png_set_pHYs, (png_const_structrp png_ptr,
2081	png_inforp info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2082	#endif
2083
2084	PNG_EXPORT(151, png_uint_32, png_get_PLTE, (png_const_structrp png_ptr,
2085	png_inforp info_ptr, png_colorp *palette, int *num_palette));
2086
2087	PNG_EXPORT(152, void, png_set_PLTE, (png_structrp png_ptr,
2088	png_inforp info_ptr, png_const_colorp palette, int num_palette));
2089
2090	#ifdef PNG_sBIT_SUPPORTED
2091	PNG_EXPORT(153, png_uint_32, png_get_sBIT, (png_const_structrp png_ptr,
2092	png_inforp info_ptr, png_color_8p *sig_bit));
2093	#endif
2094
2095	#ifdef PNG_sBIT_SUPPORTED
2096	PNG_EXPORT(154, void, png_set_sBIT, (png_const_structrp png_ptr,
2097	png_inforp info_ptr, png_const_color_8p sig_bit));
2098	#endif
2099
2100	#ifdef PNG_sRGB_SUPPORTED
2101	PNG_EXPORT(155, png_uint_32, png_get_sRGB, (png_const_structrp png_ptr,
2102	png_const_inforp info_ptr, int *file_srgb_intent));
2103	#endif
2104
2105	#ifdef PNG_sRGB_SUPPORTED
2106	PNG_EXPORT(156, void, png_set_sRGB, (png_const_structrp png_ptr,
2107	png_inforp info_ptr, int srgb_intent));
2108	PNG_EXPORT(157, void, png_set_sRGB_gAMA_and_cHRM, (png_const_structrp png_ptr,
2109	png_inforp info_ptr, int srgb_intent));
2110	#endif
2111
2112	#ifdef PNG_iCCP_SUPPORTED
2113	PNG_EXPORT(158, png_uint_32, png_get_iCCP, (png_const_structrp png_ptr,
2114	png_inforp info_ptr, png_charpp name, int *compression_type,
2115	png_bytepp profile, png_uint_32 *proflen));
2116	#endif
2117
2118	#ifdef PNG_iCCP_SUPPORTED
2119	PNG_EXPORT(159, void, png_set_iCCP, (png_const_structrp png_ptr,
2120	png_inforp info_ptr, png_const_charp name, int compression_type,
2121	png_const_bytep profile, png_uint_32 proflen));
2122	#endif
2123
2124	#ifdef PNG_sPLT_SUPPORTED
2125	PNG_EXPORT(160, int, png_get_sPLT, (png_const_structrp png_ptr,
2126	png_inforp info_ptr, png_sPLT_tpp entries));
2127	#endif
2128
2129	#ifdef PNG_sPLT_SUPPORTED
2130	PNG_EXPORT(161, void, png_set_sPLT, (png_const_structrp png_ptr,
2131	png_inforp info_ptr, png_const_sPLT_tp entries, int nentries));
2132	#endif
2133
2134	#ifdef PNG_TEXT_SUPPORTED
2135	/* png_get_text also returns the number of text chunks in *num_text */
2136	PNG_EXPORT(162, int, png_get_text, (png_const_structrp png_ptr,
2137	png_inforp info_ptr, png_textp *text_ptr, int *num_text));
2138	#endif
2139
2140	/* Note while png_set_text() will accept a structure whose text,
2141	* language, and translated keywords are NULL pointers, the structure
2142	* returned by png_get_text will always contain regular
2143	* zero-terminated C strings. They might be empty strings but
2144	* they will never be NULL pointers.
2145	*/
2146
2147	#ifdef PNG_TEXT_SUPPORTED
2148	PNG_EXPORT(163, void, png_set_text, (png_const_structrp png_ptr,
2149	png_inforp info_ptr, png_const_textp text_ptr, int num_text));
2150	#endif
2151
2152	#ifdef PNG_tIME_SUPPORTED
2153	PNG_EXPORT(164, png_uint_32, png_get_tIME, (png_const_structrp png_ptr,
2154	png_inforp info_ptr, png_timep *mod_time));
2155	#endif
2156
2157	#ifdef PNG_tIME_SUPPORTED
2158	PNG_EXPORT(165, void, png_set_tIME, (png_const_structrp png_ptr,
2159	png_inforp info_ptr, png_const_timep mod_time));
2160	#endif
2161
2162	#ifdef PNG_tRNS_SUPPORTED
2163	PNG_EXPORT(166, png_uint_32, png_get_tRNS, (png_const_structrp png_ptr,
2164	png_inforp info_ptr, png_bytep *trans_alpha, int *num_trans,
2165	png_color_16p *trans_color));
2166	#endif
2167
2168	#ifdef PNG_tRNS_SUPPORTED
2169	PNG_EXPORT(167, void, png_set_tRNS, (png_structrp png_ptr,
2170	png_inforp info_ptr, png_const_bytep trans_alpha, int num_trans,
2171	png_const_color_16p trans_color));
2172	#endif
2173
2174	#ifdef PNG_sCAL_SUPPORTED
2175	PNG_FP_EXPORT(168, png_uint_32, png_get_sCAL, (png_const_structrp png_ptr,
2176	png_const_inforp info_ptr, int *unit, double *width, double *height))
2177	#if defined(PNG_FLOATING_ARITHMETIC_SUPPORTED) || \
2178	defined(PNG_FLOATING_POINT_SUPPORTED)
2179	/* NOTE: this API is currently implemented using floating point arithmetic,
2180	* consequently it can only be used on systems with floating point support.
2181	* In any case the range of values supported by png_fixed_point is small and it
2182	* is highly recommended that png_get_sCAL_s be used instead.
2183	*/
2184	PNG_FIXED_EXPORT(214, png_uint_32, png_get_sCAL_fixed,
2185	(png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
2186	png_fixed_point *width, png_fixed_point *height))
2187	#endif
2188	PNG_EXPORT(169, png_uint_32, png_get_sCAL_s,
2189	(png_const_structrp png_ptr, png_const_inforp info_ptr, int *unit,
2190	png_charpp swidth, png_charpp sheight));
2191
2192	PNG_FP_EXPORT(170, void, png_set_sCAL, (png_const_structrp png_ptr,
2193	png_inforp info_ptr, int unit, double width, double height))
2194	PNG_FIXED_EXPORT(213, void, png_set_sCAL_fixed, (png_const_structrp png_ptr,
2195	png_inforp info_ptr, int unit, png_fixed_point width,
2196	png_fixed_point height))
2197	PNG_EXPORT(171, void, png_set_sCAL_s, (png_const_structrp png_ptr,
2198	png_inforp info_ptr, int unit,
2199	png_const_charp swidth, png_const_charp sheight));
2200	#endif /* sCAL */
2201
2202	#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
2203	/* Provide the default handling for all unknown chunks or, optionally, for
2204	* specific unknown chunks.
2205	*
2206	* NOTE: prior to 1.6.0 the handling specified for particular chunks on read was
2207	* ignored and the default was used, the per-chunk setting only had an effect on
2208	* write. If you wish to have chunk-specific handling on read in code that must
2209	* work on earlier versions you must use a user chunk callback to specify the
2210	* desired handling (keep or discard.)
2211	*
2212	* The 'keep' parameter is a PNG_HANDLE_CHUNK_ value as listed below. The
2213	* parameter is interpreted as follows:
2214	*
2215	* READ:
2216	* PNG_HANDLE_CHUNK_AS_DEFAULT:
2217	* Known chunks: do normal libpng processing, do not keep the chunk (but
2218	* see the comments below about PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
2219	* Unknown chunks: for a specific chunk use the global default, when used
2220	* as the default discard the chunk data.
2221	* PNG_HANDLE_CHUNK_NEVER:
2222	* Discard the chunk data.
2223	* PNG_HANDLE_CHUNK_IF_SAFE:
2224	* Keep the chunk data if the chunk is not critical else raise a chunk
2225	* error.
2226	* PNG_HANDLE_CHUNK_ALWAYS:
2227	* Keep the chunk data.
2228	*
2229	* If the chunk data is saved it can be retrieved using png_get_unknown_chunks,
2230	* below. Notice that specifying "AS_DEFAULT" as a global default is equivalent
2231	* to specifying "NEVER", however when "AS_DEFAULT" is used for specific chunks
2232	* it simply resets the behavior to the libpng default.
2233	*
2234	* INTERACTION WITH USER CHUNK CALLBACKS:
2235	* The per-chunk handling is always used when there is a png_user_chunk_ptr
2236	* callback and the callback returns 0; the chunk is then always stored *unless*
2237	* it is critical and the per-chunk setting is other than ALWAYS. Notice that
2238	* the global default is *not* used in this case. (In effect the per-chunk
2239	* value is incremented to at least IF_SAFE.)
2240	*
2241	* IMPORTANT NOTE: this behavior will change in libpng 1.7 - the global and
2242	* per-chunk defaults will be honored. If you want to preserve the current
2243	* behavior when your callback returns 0 you must set PNG_HANDLE_CHUNK_IF_SAFE
2244	* as the default - if you don't do this libpng 1.6 will issue a warning.
2245	*
2246	* If you want unhandled unknown chunks to be discarded in libpng 1.6 and
2247	* earlier simply return '1' (handled).
2248	*
2249	* PNG_HANDLE_AS_UNKNOWN_SUPPORTED:
2250	* If this is *not* set known chunks will always be handled by libpng and
2251	* will never be stored in the unknown chunk list. Known chunks listed to
2252	* png_set_keep_unknown_chunks will have no effect. If it is set then known
2253	* chunks listed with a keep other than AS_DEFAULT will *never* be processed
2254	* by libpng, in addition critical chunks must either be processed by the
2255	* callback or saved.
2256	*
2257	* The IHDR and IEND chunks must not be listed. Because this turns off the
2258	* default handling for chunks that would otherwise be recognized the
2259	* behavior of libpng transformations may well become incorrect!
2260	*
2261	* WRITE:
2262	* When writing chunks the options only apply to the chunks specified by
2263	* png_set_unknown_chunks (below), libpng will *always* write known chunks
2264	* required by png_set_ calls and will always write the core critical chunks
2265	* (as required for PLTE).
2266	*
2267	* Each chunk in the png_set_unknown_chunks list is looked up in the
2268	* png_set_keep_unknown_chunks list to find the keep setting, this is then
2269	* interpreted as follows:
2270	*
2271	* PNG_HANDLE_CHUNK_AS_DEFAULT:
2272	* Write safe-to-copy chunks and write other chunks if the global
2273	* default is set to _ALWAYS, otherwise don't write this chunk.
2274	* PNG_HANDLE_CHUNK_NEVER:
2275	* Do not write the chunk.
2276	* PNG_HANDLE_CHUNK_IF_SAFE:
2277	* Write the chunk if it is safe-to-copy, otherwise do not write it.
2278	* PNG_HANDLE_CHUNK_ALWAYS:
2279	* Write the chunk.
2280	*
2281	* Note that the default behavior is effectively the opposite of the read case -
2282	* in read unknown chunks are not stored by default, in write they are written
2283	* by default. Also the behavior of PNG_HANDLE_CHUNK_IF_SAFE is very different
2284	* - on write the safe-to-copy bit is checked, on read the critical bit is
2285	* checked and on read if the chunk is critical an error will be raised.
2286	*
2287	* num_chunks:
2288	* ===========
2289	* If num_chunks is positive, then the "keep" parameter specifies the manner
2290	* for handling only those chunks appearing in the chunk_list array,
2291	* otherwise the chunk list array is ignored.
2292	*
2293	* If num_chunks is 0 the "keep" parameter specifies the default behavior for
2294	* unknown chunks, as described above.
2295	*
2296	* If num_chunks is negative, then the "keep" parameter specifies the manner
2297	* for handling all unknown chunks plus all chunks recognized by libpng
2298	* except for the IHDR, PLTE, tRNS, IDAT, and IEND chunks (which continue to
2299	* be processed by libpng.
2300	*/
2301	#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2302	PNG_EXPORT(172, void, png_set_keep_unknown_chunks, (png_structrp png_ptr,
2303	int keep, png_const_bytep chunk_list, int num_chunks));
2304	#endif /* HANDLE_AS_UNKNOWN */
2305
2306	/* The "keep" PNG_HANDLE_CHUNK_ parameter for the specified chunk is returned;
2307	* the result is therefore true (non-zero) if special handling is required,
2308	* false for the default handling.
2309	*/
2310	PNG_EXPORT(173, int, png_handle_as_unknown, (png_const_structrp png_ptr,
2311	png_const_bytep chunk_name));
2312	#endif /* SET_UNKNOWN_CHUNKS */
2313
2314	#ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
2315	PNG_EXPORT(174, void, png_set_unknown_chunks, (png_const_structrp png_ptr,
2316	png_inforp info_ptr, png_const_unknown_chunkp unknowns,
2317	int num_unknowns));
2318	/* NOTE: prior to 1.6.0 this routine set the 'location' field of the added
2319	* unknowns to the location currently stored in the png_struct. This is
2320	* invariably the wrong value on write. To fix this call the following API
2321	* for each chunk in the list with the correct location. If you know your
2322	* code won't be compiled on earlier versions you can rely on
2323	* png_set_unknown_chunks(write-ptr, png_get_unknown_chunks(read-ptr)) doing
2324	* the correct thing.
2325	*/
2326
2327	PNG_EXPORT(175, void, png_set_unknown_chunk_location,
2328	(png_const_structrp png_ptr, png_inforp info_ptr, int chunk, int location));
2329
2330	PNG_EXPORT(176, int, png_get_unknown_chunks, (png_const_structrp png_ptr,
2331	png_inforp info_ptr, png_unknown_chunkpp entries));
2332	#endif
2333
2334	/* Png_free_data() will turn off the "valid" flag for anything it frees.
2335	* If you need to turn it off for a chunk that your application has freed,
2336	* you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
2337	*/
2338	PNG_EXPORT(177, void, png_set_invalid, (png_const_structrp png_ptr,
2339	png_inforp info_ptr, int mask));
2340
2341	#ifdef PNG_INFO_IMAGE_SUPPORTED
2342	/* The "params" pointer is currently not used and is for future expansion. */
2343	#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
2344	PNG_EXPORT(178, void, png_read_png, (png_structrp png_ptr, png_inforp info_ptr,
2345	int transforms, png_voidp params));
2346	#endif
2347	#ifdef PNG_WRITE_SUPPORTED
2348	PNG_EXPORT(179, void, png_write_png, (png_structrp png_ptr, png_inforp info_ptr,
2349	int transforms, png_voidp params));
2350	#endif
2351	#endif
2352
2353	PNG_EXPORT(180, png_const_charp, png_get_copyright,
2354	(png_const_structrp png_ptr));
2355	PNG_EXPORT(181, png_const_charp, png_get_header_ver,
2356	(png_const_structrp png_ptr));
2357	PNG_EXPORT(182, png_const_charp, png_get_header_version,
2358	(png_const_structrp png_ptr));
2359	PNG_EXPORT(183, png_const_charp, png_get_libpng_ver,
2360	(png_const_structrp png_ptr));
2361
2362	#ifdef PNG_MNG_FEATURES_SUPPORTED
2363	PNG_EXPORT(184, png_uint_32, png_permit_mng_features, (png_structrp png_ptr,
2364	png_uint_32 mng_features_permitted));
2365	#endif
2366
2367	/* For use in png_set_keep_unknown, added to version 1.2.6 */
2368	#define PNG_HANDLE_CHUNK_AS_DEFAULT 0
2369	#define PNG_HANDLE_CHUNK_NEVER 1
2370	#define PNG_HANDLE_CHUNK_IF_SAFE 2
2371	#define PNG_HANDLE_CHUNK_ALWAYS 3
2372	#define PNG_HANDLE_CHUNK_LAST 4
2373
2374	/* Strip the prepended error numbers ("#nnn ") from error and warning
2375	* messages before passing them to the error or warning handler.
2376	*/
2377	#ifdef PNG_ERROR_NUMBERS_SUPPORTED
2378	PNG_EXPORT(185, void, png_set_strip_error_numbers, (png_structrp png_ptr,
2379	png_uint_32 strip_mode));
2380	#endif
2381
2382	/* Added in libpng-1.2.6 */
2383	#ifdef PNG_SET_USER_LIMITS_SUPPORTED
2384	PNG_EXPORT(186, void, png_set_user_limits, (png_structrp png_ptr,
2385	png_uint_32 user_width_max, png_uint_32 user_height_max));
2386	PNG_EXPORT(187, png_uint_32, png_get_user_width_max,
2387	(png_const_structrp png_ptr));
2388	PNG_EXPORT(188, png_uint_32, png_get_user_height_max,
2389	(png_const_structrp png_ptr));
2390	/* Added in libpng-1.4.0 */
2391	PNG_EXPORT(189, void, png_set_chunk_cache_max, (png_structrp png_ptr,
2392	png_uint_32 user_chunk_cache_max));
2393	PNG_EXPORT(190, png_uint_32, png_get_chunk_cache_max,
2394	(png_const_structrp png_ptr));
2395	/* Added in libpng-1.4.1 */
2396	PNG_EXPORT(191, void, png_set_chunk_malloc_max, (png_structrp png_ptr,
2397	png_alloc_size_t user_chunk_cache_max));
2398	PNG_EXPORT(192, png_alloc_size_t, png_get_chunk_malloc_max,
2399	(png_const_structrp png_ptr));
2400	#endif
2401
2402	#if defined(PNG_INCH_CONVERSIONS_SUPPORTED)
2403	PNG_EXPORT(193, png_uint_32, png_get_pixels_per_inch,
2404	(png_const_structrp png_ptr, png_const_inforp info_ptr));
2405
2406	PNG_EXPORT(194, png_uint_32, png_get_x_pixels_per_inch,
2407	(png_const_structrp png_ptr, png_const_inforp info_ptr));
2408
2409	PNG_EXPORT(195, png_uint_32, png_get_y_pixels_per_inch,
2410	(png_const_structrp png_ptr, png_const_inforp info_ptr));
2411
2412	PNG_FP_EXPORT(196, float, png_get_x_offset_inches,
2413	(png_const_structrp png_ptr, png_const_inforp info_ptr))
2414	#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2415	PNG_FIXED_EXPORT(211, png_fixed_point, png_get_x_offset_inches_fixed,
2416	(png_const_structrp png_ptr, png_const_inforp info_ptr))
2417	#endif
2418
2419	PNG_FP_EXPORT(197, float, png_get_y_offset_inches, (png_const_structrp png_ptr,
2420	png_const_inforp info_ptr))
2421	#ifdef PNG_FIXED_POINT_SUPPORTED /* otherwise not implemented. */
2422	PNG_FIXED_EXPORT(212, png_fixed_point, png_get_y_offset_inches_fixed,
2423	(png_const_structrp png_ptr, png_const_inforp info_ptr))
2424	#endif
2425
2426	# ifdef PNG_pHYs_SUPPORTED
2427	PNG_EXPORT(198, png_uint_32, png_get_pHYs_dpi, (png_const_structrp png_ptr,
2428	png_const_inforp info_ptr, png_uint_32 *res_x, png_uint_32 *res_y,
2429	int *unit_type));
2430	# endif /* pHYs */
2431	#endif /* INCH_CONVERSIONS */
2432
2433	/* Added in libpng-1.4.0 */
2434	#ifdef PNG_IO_STATE_SUPPORTED
2435	PNG_EXPORT(199, png_uint_32, png_get_io_state, (png_const_structrp png_ptr));
2436
2437	/* Removed from libpng 1.6; use png_get_io_chunk_type. */
2438	PNG_REMOVED(200, png_const_bytep, png_get_io_chunk_name, (png_structrp png_ptr),
2439	PNG_DEPRECATED)
2440
2441	PNG_EXPORT(216, png_uint_32, png_get_io_chunk_type,
2442	(png_const_structrp png_ptr));
2443
2444	/* The flags returned by png_get_io_state() are the following: */
2445	# define PNG_IO_NONE 0x0000 /* no I/O at this moment */
2446	# define PNG_IO_READING 0x0001 /* currently reading */
2447	# define PNG_IO_WRITING 0x0002 /* currently writing */
2448	# define PNG_IO_SIGNATURE 0x0010 /* currently at the file signature */
2449	# define PNG_IO_CHUNK_HDR 0x0020 /* currently at the chunk header */
2450	# define PNG_IO_CHUNK_DATA 0x0040 /* currently at the chunk data */
2451	# define PNG_IO_CHUNK_CRC 0x0080 /* currently at the chunk crc */
2452	# define PNG_IO_MASK_OP 0x000f /* current operation: reading/writing */
2453	# define PNG_IO_MASK_LOC 0x00f0 /* current location: sig/hdr/data/crc */
2454	#endif /* IO_STATE */
2455
2456	/* Interlace support. The following macros are always defined so that if
2457	* libpng interlace handling is turned off the macros may be used to handle
2458	* interlaced images within the application.
2459	*/
2460	#define PNG_INTERLACE_ADAM7_PASSES 7
2461
2462	/* Two macros to return the first row and first column of the original,
2463	* full, image which appears in a given pass. 'pass' is in the range 0
2464	* to 6 and the result is in the range 0 to 7.
2465	*/
2466	#define PNG_PASS_START_ROW(pass) (((1&~(pass))<<(3-((pass)>>1)))&7)
2467	#define PNG_PASS_START_COL(pass) (((1& (pass))<<(3-(((pass)+1)>>1)))&7)
2468
2469	/* A macro to return the offset between pixels in the output row for a pair of
2470	* pixels in the input - effectively the inverse of the 'COL_SHIFT' macro that
2471	* follows. Note that ROW_OFFSET is the offset from one row to the next whereas
2472	* COL_OFFSET is from one column to the next, within a row.
2473	*/
2474	#define PNG_PASS_ROW_OFFSET(pass) ((pass)>2?(8>>(((pass)-1)>>1)):8)
2475	#define PNG_PASS_COL_OFFSET(pass) (1<<((7-(pass))>>1))
2476
2477	/* Two macros to help evaluate the number of rows or columns in each
2478	* pass. This is expressed as a shift - effectively log2 of the number or
2479	* rows or columns in each 8x8 tile of the original image.
2480	*/
2481	#define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)
2482	#define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)
2483
2484	/* Hence two macros to determine the number of rows or columns in a given
2485	* pass of an image given its height or width. In fact these macros may
2486	* return non-zero even though the sub-image is empty, because the other
2487	* dimension may be empty for a small image.
2488	*/
2489	#define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\
2490	-1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass))
2491	#define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\
2492	-1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass))
2493
2494	/* For the reader row callbacks (both progressive and sequential) it is
2495	* necessary to find the row in the output image given a row in an interlaced
2496	* image, so two more macros:
2497	*/
2498	#define PNG_ROW_FROM_PASS_ROW(y_in, pass) \
2499	(((y_in)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))
2500	#define PNG_COL_FROM_PASS_COL(x_in, pass) \
2501	(((x_in)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))
2502
2503	/* Two macros which return a boolean (0 or 1) saying whether the given row
2504	* or column is in a particular pass. These use a common utility macro that
2505	* returns a mask for a given pass - the offset 'off' selects the row or
2506	* column version. The mask has the appropriate bit set for each column in
2507	* the tile.
2508	*/
2509	#define PNG_PASS_MASK(pass,off) ( \
2510	((0x110145AF>>(((7-(off))-(pass))<<2)) & 0xF) | \
2511	((0x01145AF0>>(((7-(off))-(pass))<<2)) & 0xF0))
2512
2513	#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
2514	((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
2515	#define PNG_COL_IN_INTERLACE_PASS(x, pass) \
2516	((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
2517
2518	#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2519	/* With these routines we avoid an integer divide, which will be slower on
2520	* most machines. However, it does take more operations than the corresponding
2521	* divide method, so it may be slower on a few RISC systems. There are two
2522	* shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2523	*
2524	* Note that the rounding factors are NOT supposed to be the same! 128 and
2525	* 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2526	* standard method.
2527	*
2528	* [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2529	*/
2530
2531	/* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2532
2533	# define png_composite(composite, fg, alpha, bg) \
2534	{ \
2535	png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) \
2536	* (png_uint_16)(alpha) \
2537	+ (png_uint_16)(bg)*(png_uint_16)(255 \
2538	- (png_uint_16)(alpha)) + 128); \
2539	(composite) = (png_byte)(((temp + (temp >> 8)) >> 8) & 0xff); \
2540	}
2541
2542	# define png_composite_16(composite, fg, alpha, bg) \
2543	{ \
2544	png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) \
2545	* (png_uint_32)(alpha) \
2546	+ (png_uint_32)(bg)*(65535 \
2547	- (png_uint_32)(alpha)) + 32768); \
2548	(composite) = (png_uint_16)(0xffff & ((temp + (temp >> 16)) >> 16)); \
2549	}
2550
2551	#else /* Standard method using integer division */
2552
2553	# define png_composite(composite, fg, alpha, bg) \
2554	(composite) = \
2555	(png_byte)(0xff & (((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2556	(png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2557	127) / 255))
2558
2559	# define png_composite_16(composite, fg, alpha, bg) \
2560	(composite) = \
2561	(png_uint_16)(0xffff & (((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2562	(png_uint_32)(bg)*(png_uint_32)(65535 - (png_uint_32)(alpha)) + \
2563	32767) / 65535))
2564	#endif /* READ_COMPOSITE_NODIV */
2565
2566	#ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
2567	PNG_EXPORT(201, png_uint_32, png_get_uint_32, (png_const_bytep buf));
2568	PNG_EXPORT(202, png_uint_16, png_get_uint_16, (png_const_bytep buf));
2569	PNG_EXPORT(203, png_int_32, png_get_int_32, (png_const_bytep buf));
2570	#endif
2571
2572	PNG_EXPORT(204, png_uint_32, png_get_uint_31, (png_const_structrp png_ptr,
2573	png_const_bytep buf));
2574	/* No png_get_int_16 -- may be added if there's a real need for it. */
2575
2576	/* Place a 32-bit number into a buffer in PNG byte order (big-endian). */
2577	#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2578	PNG_EXPORT(205, void, png_save_uint_32, (png_bytep buf, png_uint_32 i));
2579	#endif
2580	#ifdef PNG_SAVE_INT_32_SUPPORTED
2581	PNG_EXPORT(206, void, png_save_int_32, (png_bytep buf, png_int_32 i));
2582	#endif
2583
2584	/* Place a 16-bit number into a buffer in PNG byte order.
2585	* The parameter is declared unsigned int, not png_uint_16,
2586	* just to avoid potential problems on pre-ANSI C compilers.
2587	*/
2588	#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
2589	PNG_EXPORT(207, void, png_save_uint_16, (png_bytep buf, unsigned int i));
2590	/* No png_save_int_16 -- may be added if there's a real need for it. */
2591	#endif
2592
2593	#ifdef PNG_USE_READ_MACROS
2594	/* Inline macros to do direct reads of bytes from the input buffer.
2595	* The png_get_int_32() routine assumes we are using two's complement
2596	* format for negative values, which is almost certainly true.
2597	*/
2598	# define PNG_get_uint_32(buf) \
2599	(((png_uint_32)(*(buf)) << 24) + \
2600	((png_uint_32)(*((buf) + 1)) << 16) + \
2601	((png_uint_32)(*((buf) + 2)) << 8) + \
2602	((png_uint_32)(*((buf) + 3))))
2603
2604	/* From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the
2605	* function) incorrectly returned a value of type png_uint_32.
2606	*/
2607	# define PNG_get_uint_16(buf) \
2608	((png_uint_16) \
2609	(((unsigned int)(*(buf)) << 8) + \
2610	((unsigned int)(*((buf) + 1)))))
2611
2612	# define PNG_get_int_32(buf) \
2613	((png_int_32)((*(buf) & 0x80) \
2614	? -((png_int_32)(((png_get_uint_32(buf)^0xffffffffU)+1U)&0x7fffffffU)) \
2615	: (png_int_32)png_get_uint_32(buf)))
2616
2617	/* If PNG_PREFIX is defined the same thing as below happens in pnglibconf.h,
2618	* but defining a macro name prefixed with PNG_PREFIX.
2619	*/
2620	# ifndef PNG_PREFIX
2621	# define png_get_uint_32(buf) PNG_get_uint_32(buf)
2622	# define png_get_uint_16(buf) PNG_get_uint_16(buf)
2623	# define png_get_int_32(buf) PNG_get_int_32(buf)
2624	# endif
2625	#else
2626	# ifdef PNG_PREFIX
2627	/* No macros; revert to the (redefined) function */
2628	# define PNG_get_uint_32 (png_get_uint_32)
2629	# define PNG_get_uint_16 (png_get_uint_16)
2630	# define PNG_get_int_32 (png_get_int_32)
2631	# endif
2632	#endif
2633
2634	#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
2635	PNG_EXPORT(242, void, png_set_check_for_invalid_index,
2636	(png_structrp png_ptr, int allowed));
2637	# ifdef PNG_GET_PALETTE_MAX_SUPPORTED
2638	PNG_EXPORT(243, int, png_get_palette_max, (png_const_structp png_ptr,
2639	png_const_infop info_ptr));
2640	# endif
2641	#endif /* CHECK_FOR_INVALID_INDEX */
2642
2643	/*******************************************************************************
2644	* Section 5: SIMPLIFIED API
2645	*******************************************************************************
2646	*
2647	* Please read the documentation in libpng-manual.txt (TODO: write said
2648	* documentation) if you don't understand what follows.
2649	*
2650	* The simplified API hides the details of both libpng and the PNG file format
2651	* itself. It allows PNG files to be read into a very limited number of
2652	* in-memory bitmap formats or to be written from the same formats. If these
2653	* formats do not accommodate your needs then you can, and should, use the more
2654	* sophisticated APIs above - these support a wide variety of in-memory formats
2655	* and a wide variety of sophisticated transformations to those formats as well
2656	* as a wide variety of APIs to manipulate ancillary information.
2657	*
2658	* To read a PNG file using the simplified API:
2659	*
2660	* 1) Declare a 'png_image' structure (see below) on the stack, set the
2661	* version field to PNG_IMAGE_VERSION and the 'opaque' pointer to NULL
2662	* (this is REQUIRED, your program may crash if you don't do it.)
2663	* 2) Call the appropriate png_image_begin_read... function.
2664	* 3) Set the png_image 'format' member to the required sample format.
2665	* 4) Allocate a buffer for the image and, if required, the color-map.
2666	* 5) Call png_image_finish_read to read the image and, if required, the
2667	* color-map into your buffers.
2668	*
2669	* There are no restrictions on the format of the PNG input itself; all valid
2670	* color types, bit depths, and interlace methods are acceptable, and the
2671	* input image is transformed as necessary to the requested in-memory format
2672	* during the png_image_finish_read() step. The only caveat is that if you
2673	* request a color-mapped image from a PNG that is full-color or makes
2674	* complex use of an alpha channel the transformation is extremely lossy and the
2675	* result may look terrible.
2676	*
2677	* To write a PNG file using the simplified API:
2678	*
2679	* 1) Declare a 'png_image' structure on the stack and memset() it to all zero.
2680	* 2) Initialize the members of the structure that describe the image, setting
2681	* the 'format' member to the format of the image samples.
2682	* 3) Call the appropriate png_image_write... function with a pointer to the
2683	* image and, if necessary, the color-map to write the PNG data.
2684	*
2685	* png_image is a structure that describes the in-memory format of an image
2686	* when it is being read or defines the in-memory format of an image that you
2687	* need to write:
2688	*/
2689	#if defined(PNG_SIMPLIFIED_READ_SUPPORTED) || \
2690	defined(PNG_SIMPLIFIED_WRITE_SUPPORTED)
2691
2692	#define PNG_IMAGE_VERSION 1
2693
2694	typedef struct png_control *png_controlp;
2695	typedef struct
2696	{
2697	png_controlp opaque; /* Initialize to NULL, free with png_image_free */
2698	png_uint_32 version; /* Set to PNG_IMAGE_VERSION */
2699	png_uint_32 width; /* Image width in pixels (columns) */
2700	png_uint_32 height; /* Image height in pixels (rows) */
2701	png_uint_32 format; /* Image format as defined below */
2702	png_uint_32 flags; /* A bit mask containing informational flags */
2703	png_uint_32 colormap_entries;
2704	/* Number of entries in the color-map */
2705
2706	/* In the event of an error or warning the following field will be set to a
2707	* non-zero value and the 'message' field will contain a '\0' terminated
2708	* string with the libpng error or warning message. If both warnings and
2709	* an error were encountered, only the error is recorded. If there
2710	* are multiple warnings, only the first one is recorded.
2711	*
2712	* The upper 30 bits of this value are reserved, the low two bits contain
2713	* a value as follows:
2714	*/
2715	# define PNG_IMAGE_WARNING 1
2716	# define PNG_IMAGE_ERROR 2
2717	/*
2718	* The result is a two-bit code such that a value more than 1 indicates
2719	* a failure in the API just called:
2720	*
2721	* 0 - no warning or error
2722	* 1 - warning
2723	* 2 - error
2724	* 3 - error preceded by warning
2725	*/
2726	# define PNG_IMAGE_FAILED(png_cntrl) ((((png_cntrl).warning_or_error)&0x03)>1)
2727
2728	png_uint_32 warning_or_error;
2729
2730	char message[64];
2731	} png_image, *png_imagep;
2732
2733	/* The samples of the image have one to four channels whose components have
2734	* original values in the range 0 to 1.0:
2735	*
2736	* 1: A single gray or luminance channel (G).
2737	* 2: A gray/luminance channel and an alpha channel (GA).
2738	* 3: Three red, green, blue color channels (RGB).
2739	* 4: Three color channels and an alpha channel (RGBA).
2740	*
2741	* The components are encoded in one of two ways:
2742	*
2743	* a) As a small integer, value 0..255, contained in a single byte. For the
2744	* alpha channel the original value is simply value/255. For the color or
2745	* luminance channels the value is encoded according to the sRGB specification
2746	* and matches the 8-bit format expected by typical display devices.
2747	*
2748	* The color/gray channels are not scaled (pre-multiplied) by the alpha
2749	* channel and are suitable for passing to color management software.
2750	*
2751	* b) As a value in the range 0..65535, contained in a 2-byte integer. All
2752	* channels can be converted to the original value by dividing by 65535; all
2753	* channels are linear. Color channels use the RGB encoding (RGB end-points) of
2754	* the sRGB specification. This encoding is identified by the
2755	* PNG_FORMAT_FLAG_LINEAR flag below.
2756	*
2757	* When the simplified API needs to convert between sRGB and linear colorspaces,
2758	* the actual sRGB transfer curve defined in the sRGB specification (see the
2759	* article at <https://en.wikipedia.org/wiki/SRGB>) is used, not the gamma=1/2.2
2760	* approximation used elsewhere in libpng.
2761	*
2762	* When an alpha channel is present it is expected to denote pixel coverage
2763	* of the color or luminance channels and is returned as an associated alpha
2764	* channel: the color/gray channels are scaled (pre-multiplied) by the alpha
2765	* value.
2766	*
2767	* The samples are either contained directly in the image data, between 1 and 8
2768	* bytes per pixel according to the encoding, or are held in a color-map indexed
2769	* by bytes in the image data. In the case of a color-map the color-map entries
2770	* are individual samples, encoded as above, and the image data has one byte per
2771	* pixel to select the relevant sample from the color-map.
2772	*/
2773
2774	/* PNG_FORMAT_*
2775	*
2776	* #defines to be used in png_image::format. Each #define identifies a
2777	* particular layout of sample data and, if present, alpha values. There are
2778	* separate defines for each of the two component encodings.
2779	*
2780	* A format is built up using single bit flag values. All combinations are
2781	* valid. Formats can be built up from the flag values or you can use one of
2782	* the predefined values below. When testing formats always use the FORMAT_FLAG
2783	* macros to test for individual features - future versions of the library may
2784	* add new flags.
2785	*
2786	* When reading or writing color-mapped images the format should be set to the
2787	* format of the entries in the color-map then png_image_{read,write}_colormap
2788	* called to read or write the color-map and set the format correctly for the
2789	* image data. Do not set the PNG_FORMAT_FLAG_COLORMAP bit directly!
2790	*
2791	* NOTE: libpng can be built with particular features disabled. If you see
2792	* compiler errors because the definition of one of the following flags has been
2793	* compiled out it is because libpng does not have the required support. It is
2794	* possible, however, for the libpng configuration to enable the format on just
2795	* read or just write; in that case you may see an error at run time. You can
2796	* guard against this by checking for the definition of the appropriate
2797	* "_SUPPORTED" macro, one of:
2798	*
2799	* PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED
2800	*/
2801	#define PNG_FORMAT_FLAG_ALPHA 0x01U /* format with an alpha channel */
2802	#define PNG_FORMAT_FLAG_COLOR 0x02U /* color format: otherwise grayscale */
2803	#define PNG_FORMAT_FLAG_LINEAR 0x04U /* 2-byte channels else 1-byte */
2804	#define PNG_FORMAT_FLAG_COLORMAP 0x08U /* image data is color-mapped */
2805
2806	#ifdef PNG_FORMAT_BGR_SUPPORTED
2807	# define PNG_FORMAT_FLAG_BGR 0x10U /* BGR colors, else order is RGB */
2808	#endif
2809
2810	#ifdef PNG_FORMAT_AFIRST_SUPPORTED
2811	# define PNG_FORMAT_FLAG_AFIRST 0x20U /* alpha channel comes first */
2812	#endif
2813
2814	#define PNG_FORMAT_FLAG_ASSOCIATED_ALPHA 0x40U /* alpha channel is associated */
2815
2816	/* Commonly used formats have predefined macros.
2817	*
2818	* First the single byte (sRGB) formats:
2819	*/
2820	#define PNG_FORMAT_GRAY 0
2821	#define PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA
2822	#define PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST)
2823	#define PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR
2824	#define PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR)
2825	#define PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA)
2826	#define PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST)
2827	#define PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA)
2828	#define PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST)
2829
2830	/* Then the linear 2-byte formats. When naming these "Y" is used to
2831	* indicate a luminance (gray) channel.
2832	*/
2833	#define PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR
2834	#define PNG_FORMAT_LINEAR_Y_ALPHA (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA)
2835	#define PNG_FORMAT_LINEAR_RGB (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR)
2836	#define PNG_FORMAT_LINEAR_RGB_ALPHA \
2837	(PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA)
2838
2839	/* With color-mapped formats the image data is one byte for each pixel, the byte
2840	* is an index into the color-map which is formatted as above. To obtain a
2841	* color-mapped format it is sufficient just to add the PNG_FOMAT_FLAG_COLORMAP
2842	* to one of the above definitions, or you can use one of the definitions below.
2843	*/
2844	#define PNG_FORMAT_RGB_COLORMAP (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_COLORMAP)
2845	#define PNG_FORMAT_BGR_COLORMAP (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_COLORMAP)
2846	#define PNG_FORMAT_RGBA_COLORMAP (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_COLORMAP)
2847	#define PNG_FORMAT_ARGB_COLORMAP (PNG_FORMAT_ARGB|PNG_FORMAT_FLAG_COLORMAP)
2848	#define PNG_FORMAT_BGRA_COLORMAP (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_COLORMAP)
2849	#define PNG_FORMAT_ABGR_COLORMAP (PNG_FORMAT_ABGR|PNG_FORMAT_FLAG_COLORMAP)
2850
2851	/* PNG_IMAGE macros
2852	*
2853	* These are convenience macros to derive information from a png_image
2854	* structure. The PNG_IMAGE_SAMPLE_ macros return values appropriate to the
2855	* actual image sample values - either the entries in the color-map or the
2856	* pixels in the image. The PNG_IMAGE_PIXEL_ macros return corresponding values
2857	* for the pixels and will always return 1 for color-mapped formats. The
2858	* remaining macros return information about the rows in the image and the
2859	* complete image.
2860	*
2861	* NOTE: All the macros that take a png_image::format parameter are compile time
2862	* constants if the format parameter is, itself, a constant. Therefore these
2863	* macros can be used in array declarations and case labels where required.
2864	* Similarly the macros are also pre-processor constants (sizeof is not used) so
2865	* they can be used in #if tests.
2866	*
2867	* First the information about the samples.
2868	*/
2869	#define PNG_IMAGE_SAMPLE_CHANNELS(fmt)\
2870	(((fmt)&(PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_ALPHA))+1)
2871	/* Return the total number of channels in a given format: 1..4 */
2872
2873	#define PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt)\
2874	((((fmt) & PNG_FORMAT_FLAG_LINEAR) >> 2)+1)
2875	/* Return the size in bytes of a single component of a pixel or color-map
2876	* entry (as appropriate) in the image: 1 or 2.
2877	*/
2878
2879	#define PNG_IMAGE_SAMPLE_SIZE(fmt)\
2880	(PNG_IMAGE_SAMPLE_CHANNELS(fmt) * PNG_IMAGE_SAMPLE_COMPONENT_SIZE(fmt))
2881	/* This is the size of the sample data for one sample. If the image is
2882	* color-mapped it is the size of one color-map entry (and image pixels are
2883	* one byte in size), otherwise it is the size of one image pixel.
2884	*/
2885
2886	#define PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(fmt)\
2887	(PNG_IMAGE_SAMPLE_CHANNELS(fmt) * 256)
2888	/* The maximum size of the color-map required by the format expressed in a
2889	* count of components. This can be used to compile-time allocate a
2890	* color-map:
2891	*
2892	* png_uint_16 colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(linear_fmt)];
2893	*
2894	* png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)];
2895	*
2896	* Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the
2897	* information from one of the png_image_begin_read_ APIs and dynamically
2898	* allocate the required memory.
2899	*/
2900
2901	/* Corresponding information about the pixels */
2902	#define PNG_IMAGE_PIXEL_(test,fmt)\
2903	(((fmt)&PNG_FORMAT_FLAG_COLORMAP)?1:test(fmt))
2904
2905	#define PNG_IMAGE_PIXEL_CHANNELS(fmt)\
2906	PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_CHANNELS,fmt)
2907	/* The number of separate channels (components) in a pixel; 1 for a
2908	* color-mapped image.
2909	*/
2910
2911	#define PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)\
2912	PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_COMPONENT_SIZE,fmt)
2913	/* The size, in bytes, of each component in a pixel; 1 for a color-mapped
2914	* image.
2915	*/
2916
2917	#define PNG_IMAGE_PIXEL_SIZE(fmt) PNG_IMAGE_PIXEL_(PNG_IMAGE_SAMPLE_SIZE,fmt)
2918	/* The size, in bytes, of a complete pixel; 1 for a color-mapped image. */
2919
2920	/* Information about the whole row, or whole image */
2921	#define PNG_IMAGE_ROW_STRIDE(image)\
2922	(PNG_IMAGE_PIXEL_CHANNELS((image).format) * (image).width)
2923	/* Return the total number of components in a single row of the image; this
2924	* is the minimum 'row stride', the minimum count of components between each
2925	* row. For a color-mapped image this is the minimum number of bytes in a
2926	* row.
2927	*
2928	* WARNING: this macro overflows for some images with more than one component
2929	* and very large image widths. libpng will refuse to process an image where
2930	* this macro would overflow.
2931	*/
2932
2933	#define PNG_IMAGE_BUFFER_SIZE(image, row_stride)\
2934	(PNG_IMAGE_PIXEL_COMPONENT_SIZE((image).format)*(image).height*(row_stride))
2935	/* Return the size, in bytes, of an image buffer given a png_image and a row
2936	* stride - the number of components to leave space for in each row.
2937	*
2938	* WARNING: this macro overflows a 32-bit integer for some large PNG images,
2939	* libpng will refuse to process an image where such an overflow would occur.
2940	*/
2941
2942	#define PNG_IMAGE_SIZE(image)\
2943	PNG_IMAGE_BUFFER_SIZE(image, PNG_IMAGE_ROW_STRIDE(image))
2944	/* Return the size, in bytes, of the image in memory given just a png_image;
2945	* the row stride is the minimum stride required for the image.
2946	*/
2947
2948	#define PNG_IMAGE_COLORMAP_SIZE(image)\
2949	(PNG_IMAGE_SAMPLE_SIZE((image).format) * (image).colormap_entries)
2950	/* Return the size, in bytes, of the color-map of this image. If the image
2951	* format is not a color-map format this will return a size sufficient for
2952	* 256 entries in the given format; check PNG_FORMAT_FLAG_COLORMAP if
2953	* you don't want to allocate a color-map in this case.
2954	*/
2955
2956	/* PNG_IMAGE_FLAG_*
2957	*
2958	* Flags containing additional information about the image are held in the
2959	* 'flags' field of png_image.
2960	*/
2961	#define PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB 0x01
2962	/* This indicates that the RGB values of the in-memory bitmap do not
2963	* correspond to the red, green and blue end-points defined by sRGB.
2964	*/
2965
2966	#define PNG_IMAGE_FLAG_FAST 0x02
2967	/* On write emphasise speed over compression; the resultant PNG file will be
2968	* larger but will be produced significantly faster, particular for large
2969	* images. Do not use this option for images which will be distributed, only
2970	* used it when producing intermediate files that will be read back in
2971	* repeatedly. For a typical 24-bit image the option will double the read
2972	* speed at the cost of increasing the image size by 25%, however for many
2973	* more compressible images the PNG file can be 10 times larger with only a
2974	* slight speed gain.
2975	*/
2976
2977	#define PNG_IMAGE_FLAG_16BIT_sRGB 0x04
2978	/* On read if the image is a 16-bit per component image and there is no gAMA
2979	* or sRGB chunk assume that the components are sRGB encoded. Notice that
2980	* images output by the simplified API always have gamma information; setting
2981	* this flag only affects the interpretation of 16-bit images from an
2982	* external source. It is recommended that the application expose this flag
2983	* to the user; the user can normally easily recognize the difference between
2984	* linear and sRGB encoding. This flag has no effect on write - the data
2985	* passed to the write APIs must have the correct encoding (as defined
2986	* above.)
2987	*
2988	* If the flag is not set (the default) input 16-bit per component data is
2989	* assumed to be linear.
2990	*
2991	* NOTE: the flag can only be set after the png_image_begin_read_ call,
2992	* because that call initializes the 'flags' field.
2993	*/
2994
2995	#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
2996	/* READ APIs
2997	* ---------
2998	*
2999	* The png_image passed to the read APIs must have been initialized by setting
3000	* the png_controlp field 'opaque' to NULL (or, safer, memset the whole thing.)
3001	*/
3002	#ifdef PNG_STDIO_SUPPORTED
3003	PNG_EXPORT(234, int, png_image_begin_read_from_file, (png_imagep image,
3004	const char *file_name));
3005	/* The named file is opened for read and the image header is filled in
3006	* from the PNG header in the file.
3007	*/
3008
3009	PNG_EXPORT(235, int, png_image_begin_read_from_stdio, (png_imagep image,
3010	FILE* file));
3011	/* The PNG header is read from the stdio FILE object. */
3012	#endif /* STDIO */
3013
3014	PNG_EXPORT(236, int, png_image_begin_read_from_memory, (png_imagep image,
3015	png_const_voidp memory, size_t size));
3016	/* The PNG header is read from the given memory buffer. */
3017
3018	PNG_EXPORT(237, int, png_image_finish_read, (png_imagep image,
3019	png_const_colorp background, void *buffer, png_int_32 row_stride,
3020	void *colormap));
3021	/* Finish reading the image into the supplied buffer and clean up the
3022	* png_image structure.
3023	*
3024	* row_stride is the step, in byte or 2-byte units as appropriate,
3025	* between adjacent rows. A positive stride indicates that the top-most row
3026	* is first in the buffer - the normal top-down arrangement. A negative
3027	* stride indicates that the bottom-most row is first in the buffer.
3028	*
3029	* background need only be supplied if an alpha channel must be removed from
3030	* a png_byte format and the removal is to be done by compositing on a solid
3031	* color; otherwise it may be NULL and any composition will be done directly
3032	* onto the buffer. The value is an sRGB color to use for the background,
3033	* for grayscale output the green channel is used.
3034	*
3035	* background must be supplied when an alpha channel must be removed from a
3036	* single byte color-mapped output format, in other words if:
3037	*
3038	* 1) The original format from png_image_begin_read_from_* had
3039	* PNG_FORMAT_FLAG_ALPHA set.
3040	* 2) The format set by the application does not.
3041	* 3) The format set by the application has PNG_FORMAT_FLAG_COLORMAP set and
3042	* PNG_FORMAT_FLAG_LINEAR *not* set.
3043	*
3044	* For linear output removing the alpha channel is always done by compositing
3045	* on black and background is ignored.
3046	*
3047	* colormap must be supplied when PNG_FORMAT_FLAG_COLORMAP is set. It must
3048	* be at least the size (in bytes) returned by PNG_IMAGE_COLORMAP_SIZE.
3049	* image->colormap_entries will be updated to the actual number of entries
3050	* written to the colormap; this may be less than the original value.
3051	*/
3052
3053	PNG_EXPORT(238, void, png_image_free, (png_imagep image));
3054	/* Free any data allocated by libpng in image->opaque, setting the pointer to
3055	* NULL. May be called at any time after the structure is initialized.
3056	*/
3057	#endif /* SIMPLIFIED_READ */
3058
3059	#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
3060	/* WRITE APIS
3061	* ----------
3062	* For write you must initialize a png_image structure to describe the image to
3063	* be written. To do this use memset to set the whole structure to 0 then
3064	* initialize fields describing your image.
3065	*
3066	* version: must be set to PNG_IMAGE_VERSION
3067	* opaque: must be initialized to NULL
3068	* width: image width in pixels
3069	* height: image height in rows
3070	* format: the format of the data (image and color-map) you wish to write
3071	* flags: set to 0 unless one of the defined flags applies; set
3072	* PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images where the RGB
3073	* values do not correspond to the colors in sRGB.
3074	* colormap_entries: set to the number of entries in the color-map (0 to 256)
3075	*/
3076	#ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
3077	PNG_EXPORT(239, int, png_image_write_to_file, (png_imagep image,
3078	const char *file, int convert_to_8bit, const void *buffer,
3079	png_int_32 row_stride, const void *colormap));
3080	/* Write the image to the named file. */
3081
3082	PNG_EXPORT(240, int, png_image_write_to_stdio, (png_imagep image, FILE *file,
3083	int convert_to_8_bit, const void *buffer, png_int_32 row_stride,
3084	const void *colormap));
3085	/* Write the image to the given (FILE*). */
3086	#endif /* SIMPLIFIED_WRITE_STDIO */
3087
3088	/* With all write APIs if image is in one of the linear formats with 16-bit
3089	* data then setting convert_to_8_bit will cause the output to be an 8-bit PNG
3090	* gamma encoded according to the sRGB specification, otherwise a 16-bit linear
3091	* encoded PNG file is written.
3092	*
3093	* With color-mapped data formats the colormap parameter point to a color-map
3094	* with at least image->colormap_entries encoded in the specified format. If
3095	* the format is linear the written PNG color-map will be converted to sRGB
3096	* regardless of the convert_to_8_bit flag.
3097	*
3098	* With all APIs row_stride is handled as in the read APIs - it is the spacing
3099	* from one row to the next in component sized units (1 or 2 bytes) and if
3100	* negative indicates a bottom-up row layout in the buffer. If row_stride is
3101	* zero, libpng will calculate it for you from the image width and number of
3102	* channels.
3103	*
3104	* Note that the write API does not support interlacing, sub-8-bit pixels or
3105	* most ancillary chunks. If you need to write text chunks (e.g. for copyright
3106	* notices) you need to use one of the other APIs.
3107	*/
3108
3109	PNG_EXPORT(245, int, png_image_write_to_memory, (png_imagep image, void *memory,
3110	png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8_bit,
3111	const void *buffer, png_int_32 row_stride, const void *colormap));
3112	/* Write the image to the given memory buffer. The function both writes the
3113	* whole PNG data stream to *memory and updates *memory_bytes with the count
3114	* of bytes written.
3115	*
3116	* 'memory' may be NULL. In this case *memory_bytes is not read however on
3117	* success the number of bytes which would have been written will still be
3118	* stored in *memory_bytes. On failure *memory_bytes will contain 0.
3119	*
3120	* If 'memory' is not NULL it must point to memory[*memory_bytes] of
3121	* writeable memory.
3122	*
3123	* If the function returns success memory[*memory_bytes] (if 'memory' is not
3124	* NULL) contains the written PNG data. *memory_bytes will always be less
3125	* than or equal to the original value.
3126	*
3127	* If the function returns false and *memory_bytes was not changed an error
3128	* occurred during write. If *memory_bytes was changed, or is not 0 if
3129	* 'memory' was NULL, the write would have succeeded but for the memory
3130	* buffer being too small. *memory_bytes contains the required number of
3131	* bytes and will be bigger that the original value.
3132	*/
3133
3134	#define png_image_write_get_memory_size(image, size, convert_to_8_bit, buffer,\
3135	row_stride, colormap)\
3136	png_image_write_to_memory(&(image), 0, &(size), convert_to_8_bit, buffer,\
3137	row_stride, colormap)
3138	/* Return the amount of memory in 'size' required to compress this image.
3139	* The png_image structure 'image' must be filled in as in the above
3140	* function and must not be changed before the actual write call, the buffer
3141	* and all other parameters must also be identical to that in the final
3142	* write call. The 'size' variable need not be initialized.
3143	*
3144	* NOTE: the macro returns true/false, if false is returned 'size' will be
3145	* set to zero and the write failed and probably will fail if tried again.
3146	*/
3147
3148	/* You can pre-allocate the buffer by making sure it is of sufficient size
3149	* regardless of the amount of compression achieved. The buffer size will
3150	* always be bigger than the original image and it will never be filled. The
3151	* following macros are provided to assist in allocating the buffer.
3152	*/
3153	#define PNG_IMAGE_DATA_SIZE(image) (PNG_IMAGE_SIZE(image)+(image).height)
3154	/* The number of uncompressed bytes in the PNG byte encoding of the image;
3155	* uncompressing the PNG IDAT data will give this number of bytes.
3156	*
3157	* NOTE: while PNG_IMAGE_SIZE cannot overflow for an image in memory this
3158	* macro can because of the extra bytes used in the PNG byte encoding. You
3159	* need to avoid this macro if your image size approaches 2^30 in width or
3160	* height. The same goes for the remainder of these macros; they all produce
3161	* bigger numbers than the actual in-memory image size.
3162	*/
3163	#ifndef PNG_ZLIB_MAX_SIZE
3164	# define PNG_ZLIB_MAX_SIZE(b) ((b)+(((b)+7U)>>3)+(((b)+63U)>>6)+11U)
3165	/* An upper bound on the number of compressed bytes given 'b' uncompressed
3166	* bytes. This is based on deflateBounds() in zlib; different
3167	* implementations of zlib compression may conceivably produce more data so
3168	* if your zlib implementation is not zlib itself redefine this macro
3169	* appropriately.
3170	*/
3171	#endif
3172
3173	#define PNG_IMAGE_COMPRESSED_SIZE_MAX(image)\
3174	PNG_ZLIB_MAX_SIZE((png_alloc_size_t)PNG_IMAGE_DATA_SIZE(image))
3175	/* An upper bound on the size of the data in the PNG IDAT chunks. */
3176
3177	#define PNG_IMAGE_PNG_SIZE_MAX_(image, image_size)\
3178	((8U/*sig*/+25U/*IHDR*/+16U/*gAMA*/+44U/*cHRM*/+12U/*IEND*/+\
3179	(((image).format&PNG_FORMAT_FLAG_COLORMAP)?/*colormap: PLTE, tRNS*/\
3180	12U+3U*(image).colormap_entries/*PLTE data*/+\
3181	(((image).format&PNG_FORMAT_FLAG_ALPHA)?\
3182	12U/*tRNS*/+(image).colormap_entries:0U):0U)+\
3183	12U)+(12U*((image_size)/PNG_ZBUF_SIZE))/*IDAT*/+(image_size))
3184	/* A helper for the following macro; if your compiler cannot handle the
3185	* following macro use this one with the result of
3186	* PNG_IMAGE_COMPRESSED_SIZE_MAX(image) as the second argument (most
3187	* compilers should handle this just fine.)
3188	*/
3189
3190	#define PNG_IMAGE_PNG_SIZE_MAX(image)\
3191	PNG_IMAGE_PNG_SIZE_MAX_(image, PNG_IMAGE_COMPRESSED_SIZE_MAX(image))
3192	/* An upper bound on the total length of the PNG data stream for 'image'.
3193	* The result is of type png_alloc_size_t, on 32-bit systems this may
3194	* overflow even though PNG_IMAGE_DATA_SIZE does not overflow; the write will
3195	* run out of buffer space but return a corrected size which should work.
3196	*/
3197	#endif /* SIMPLIFIED_WRITE */
3198	/*******************************************************************************
3199	* END OF SIMPLIFIED API
3200	******************************************************************************/
3201	#endif /* SIMPLIFIED_{READ|WRITE} */
3202
3203	/*******************************************************************************
3204	* Section 6: IMPLEMENTATION OPTIONS
3205	*******************************************************************************
3206	*
3207	* Support for arbitrary implementation-specific optimizations. The API allows
3208	* particular options to be turned on or off. 'Option' is the number of the
3209	* option and 'onoff' is 0 (off) or non-0 (on). The value returned is given
3210	* by the PNG_OPTION_ defines below.
3211	*
3212	* HARDWARE: normally hardware capabilities, such as the Intel SSE instructions,
3213	* are detected at run time, however sometimes it may be impossible
3214	* to do this in user mode, in which case it is necessary to discover
3215	* the capabilities in an OS specific way. Such capabilities are
3216	* listed here when libpng has support for them and must be turned
3217	* ON by the application if present.
3218	*
3219	* SOFTWARE: sometimes software optimizations actually result in performance
3220	* decrease on some architectures or systems, or with some sets of
3221	* PNG images. 'Software' options allow such optimizations to be
3222	* selected at run time.
3223	*/
3224	#ifdef PNG_SET_OPTION_SUPPORTED
3225	#ifdef PNG_ARM_NEON_API_SUPPORTED
3226	# define PNG_ARM_NEON 0 /* HARDWARE: ARM Neon SIMD instructions supported */
3227	#endif
3228	#define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */
3229	#define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */
3230	#ifdef PNG_MIPS_MSA_API_SUPPORTED
3231	# define PNG_MIPS_MSA 6 /* HARDWARE: MIPS Msa SIMD instructions supported */
3232	#endif
3233	#define PNG_IGNORE_ADLER32 8
3234	#ifdef PNG_POWERPC_VSX_API_SUPPORTED
3235	# define PNG_POWERPC_VSX 10 /* HARDWARE: PowerPC VSX SIMD instructions supported */
3236	#endif
3237	#define PNG_OPTION_NEXT 12 /* Next option - numbers must be even */
3238
3239	/* Return values: NOTE: there are four values and 'off' is *not* zero */
3240	#define PNG_OPTION_UNSET 0 /* Unset - defaults to off */
3241	#define PNG_OPTION_INVALID 1 /* Option number out of range */
3242	#define PNG_OPTION_OFF 2
3243	#define PNG_OPTION_ON 3
3244
3245	PNG_EXPORT(244, int, png_set_option, (png_structrp png_ptr, int option,
3246	int onoff));
3247	#endif /* SET_OPTION */
3248
3249	/*******************************************************************************
3250	* END OF HARDWARE AND SOFTWARE OPTIONS
3251	******************************************************************************/
3252	#ifdef PNG_APNG_SUPPORTED
3253	PNG_EXPORT(250, png_uint_32, png_get_acTL, (png_structp png_ptr,
3254	png_infop info_ptr, png_uint_32 *num_frames, png_uint_32 *num_plays));
3255
3256	PNG_EXPORT(251, png_uint_32, png_set_acTL, (png_structp png_ptr,
3257	png_infop info_ptr, png_uint_32 num_frames, png_uint_32 num_plays));
3258
3259	PNG_EXPORT(252, png_uint_32, png_get_num_frames, (png_structp png_ptr,
3260	png_infop info_ptr));
3261
3262	PNG_EXPORT(253, png_uint_32, png_get_num_plays, (png_structp png_ptr,
3263	png_infop info_ptr));
3264
3265	PNG_EXPORT(254, png_uint_32, png_get_next_frame_fcTL,
3266	(png_structp png_ptr, png_infop info_ptr, png_uint_32 *width,
3267	png_uint_32 *height, png_uint_32 *x_offset, png_uint_32 *y_offset,
3268	png_uint_16 *delay_num, png_uint_16 *delay_den, png_byte *dispose_op,
3269	png_byte *blend_op));
3270
3271	PNG_EXPORT(255, png_uint_32, png_set_next_frame_fcTL,
3272	(png_structp png_ptr, png_infop info_ptr, png_uint_32 width,
3273	png_uint_32 height, png_uint_32 x_offset, png_uint_32 y_offset,
3274	png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op,
3275	png_byte blend_op));
3276
3277	PNG_EXPORT(256, png_uint_32, png_get_next_frame_width,
3278	(png_structp png_ptr, png_infop info_ptr));
3279	PNG_EXPORT(257, png_uint_32, png_get_next_frame_height,
3280	(png_structp png_ptr, png_infop info_ptr));
3281	PNG_EXPORT(258, png_uint_32, png_get_next_frame_x_offset,
3282	(png_structp png_ptr, png_infop info_ptr));
3283	PNG_EXPORT(259, png_uint_32, png_get_next_frame_y_offset,
3284	(png_structp png_ptr, png_infop info_ptr));
3285	PNG_EXPORT(260, png_uint_16, png_get_next_frame_delay_num,
3286	(png_structp png_ptr, png_infop info_ptr));
3287	PNG_EXPORT(261, png_uint_16, png_get_next_frame_delay_den,
3288	(png_structp png_ptr, png_infop info_ptr));
3289	PNG_EXPORT(262, png_byte, png_get_next_frame_dispose_op,
3290	(png_structp png_ptr, png_infop info_ptr));
3291	PNG_EXPORT(263, png_byte, png_get_next_frame_blend_op,
3292	(png_structp png_ptr, png_infop info_ptr));
3293	PNG_EXPORT(264, png_byte, png_get_first_frame_is_hidden,
3294	(png_structp png_ptr, png_infop info_ptr));
3295	PNG_EXPORT(265, png_uint_32, png_set_first_frame_is_hidden,
3296	(png_structp png_ptr, png_infop info_ptr, png_byte is_hidden));
3297
3298	#ifdef PNG_READ_APNG_SUPPORTED
3299	PNG_EXPORT(266, void, png_read_frame_head, (png_structp png_ptr,
3300	png_infop info_ptr));
3301	#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3302	PNG_EXPORT(267, void, png_set_progressive_frame_fn, (png_structp png_ptr,
3303	png_progressive_frame_ptr frame_info_fn,
3304	png_progressive_frame_ptr frame_end_fn));
3305	#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
3306	#endif /* PNG_READ_APNG_SUPPORTED */
3307
3308	#ifdef PNG_WRITE_APNG_SUPPORTED
3309	PNG_EXPORT(268, void, png_write_frame_head, (png_structp png_ptr,
3310	png_infop info_ptr, png_bytepp row_pointers,
3311	png_uint_32 width, png_uint_32 height,
3312	png_uint_32 x_offset, png_uint_32 y_offset,
3313	png_uint_16 delay_num, png_uint_16 delay_den, png_byte dispose_op,
3314	png_byte blend_op));
3315
3316	PNG_EXPORT(269, void, png_write_frame_tail, (png_structp png_ptr,
3317	png_infop info_ptr));
3318	#endif /* PNG_WRITE_APNG_SUPPORTED */
3319	#endif /* PNG_APNG_SUPPORTED */
3320
3321	/* Maintainer: Put new public prototypes here ^, in libpng.3, in project
3322	* defs, and in scripts/symbols.def.
3323	*/
3324
3325	/* The last ordinal number (this is the *last* one already used; the next
3326	* one to use is one more than this.)
3327	*/
3328	#ifdef PNG_EXPORT_LAST_ORDINAL
3329	#ifdef PNG_APNG_SUPPORTED
3330	PNG_EXPORT_LAST_ORDINAL(269);
3331	#else
3332	PNG_EXPORT_LAST_ORDINAL(249);
3333	#endif /* PNG_APNG_SUPPORTED */
3334	#endif
3335
3336	#ifdef __cplusplus
3337	}
3338	#endif
3339
3340	#endif /* PNG_VERSION_INFO_ONLY */
3341	/* Do not put anything past this line */
3342	#endif /* PNG_H */
3343