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Revision 18166, 133.5 KB checked in by ghudson, 22 years ago (diff)
This commit was generated by cvs2svn to compensate for changes in r18165, which included commits to RCS files with non-trunk default branches.

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1	/* png.h - header file for PNG reference library
2	*
3	* libpng version 1.2.5 - October 3, 2002
4	* Copyright (c) 1998-2002 Glenn Randers-Pehrson
5	* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
6	* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
7	*
8	* Authors and maintainers:
9	* libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
10	* libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
11	* libpng versions 0.97, January 1998, through 1.2.5 - October 3, 2002: Glenn
12	* See also "Contributing Authors", below.
13	*
14	* Note about libpng version numbers:
15	*
16	* Due to various miscommunications, unforeseen code incompatibilities
17	* and occasional factors outside the authors' control, version numbering
18	* on the library has not always been consistent and straightforward.
19	* The following table summarizes matters since version 0.89c, which was
20	* the first widely used release:
21	*
22	* source png.h png.h shared-lib
23	* version string int version
24	* ------- ------ ----- ----------
25	* 0.89c "1.0 beta 3" 0.89 89 1.0.89
26	* 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]
27	* 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]
28	* 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]
29	* 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]
30	* 0.97c 0.97 97 2.0.97
31	* 0.98 0.98 98 2.0.98
32	* 0.99 0.99 98 2.0.99
33	* 0.99a-m 0.99 99 2.0.99
34	* 1.00 1.00 100 2.1.0 [100 should be 10000]
35	* 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]
36	* 1.0.1 png.h string is 10001 2.1.0
37	* 1.0.1a-e identical to the 10002 from here on, the shared library
38	* 1.0.2 source version) 10002 is 2.V where V is the source code
39	* 1.0.2a-b 10003 version, except as noted.
40	* 1.0.3 10003
41	* 1.0.3a-d 10004
42	* 1.0.4 10004
43	* 1.0.4a-f 10005
44	* 1.0.5 (+ 2 patches) 10005
45	* 1.0.5a-d 10006
46	* 1.0.5e-r 10100 (not source compatible)
47	* 1.0.5s-v 10006 (not binary compatible)
48	* 1.0.6 (+ 3 patches) 10006 (still binary incompatible)
49	* 1.0.6d-f 10007 (still binary incompatible)
50	* 1.0.6g 10007
51	* 1.0.6h 10007 10.6h (testing xy.z so-numbering)
52	* 1.0.6i 10007 10.6i
53	* 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
54	* 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)
55	* 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
56	* 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
57	* 1.0.7 1 10007 (still compatible)
58	* 1.0.8beta1-4 1 10008 2.1.0.8beta1-4
59	* 1.0.8rc1 1 10008 2.1.0.8rc1
60	* 1.0.8 1 10008 2.1.0.8
61	* 1.0.9beta1-6 1 10009 2.1.0.9beta1-6
62	* 1.0.9rc1 1 10009 2.1.0.9rc1
63	* 1.0.9beta7-10 1 10009 2.1.0.9beta7-10
64	* 1.0.9rc2 1 10009 2.1.0.9rc2
65	* 1.0.9 1 10009 2.1.0.9
66	* 1.0.10beta1 1 10010 2.1.0.10beta1
67	* 1.0.10rc1 1 10010 2.1.0.10rc1
68	* 1.0.10 1 10010 2.1.0.10
69	* 1.0.11beta1-3 1 10011 2.1.0.11beta1-3
70	* 1.0.11rc1 1 10011 2.1.0.11rc1
71	* 1.0.11 1 10011 2.1.0.11
72	* 1.0.12beta1-2 2 10012 2.1.0.12beta1-2
73	* 1.0.12rc1 2 10012 2.1.0.12rc1
74	* 1.0.12 2 10012 2.1.0.12
75	* 1.1.0a-f - 10100 2.1.1.0a-f (branch abandoned)
76	* 1.2.0beta1-2 2 10200 2.1.2.0beta1-2
77	* 1.2.0beta3-5 3 10200 3.1.2.0beta3-5
78	* 1.2.0rc1 3 10200 3.1.2.0rc1
79	* 1.2.0 3 10200 3.1.2.0
80	* 1.2.1beta1-4 3 10201 3.1.2.1beta1-4
81	* 1.2.1rc1-2 3 10201 3.1.2.1rc1-2
82	* 1.2.1 3 10201 3.1.2.1
83	* 1.2.2beta1-6 12 10202 12.so.0.1.2.2beta1-6
84	* 1.0.13beta1 10 10013 10.so.0.1.0.13beta1
85	* 1.0.13rc1 10 10013 10.so.0.1.0.13rc1
86	* 1.2.2rc1 12 10202 12.so.0.1.2.2rc1
87	* 1.0.13 10 10013 10.so.0.1.0.13
88	* 1.2.2 12 10202 12.so.0.1.2.2
89	* 1.2.3rc1-6 12 10203 12.so.0.1.2.3rc1-6
90	* 1.2.3 12 10203 12.so.0.1.2.3
91	* 1.2.4beta1-3 13 10204 12.so.0.1.2.4beta1-3
92	* 1.0.14rc1 13 10014 10.so.0.1.0.14rc1
93	* 1.2.4rc1 13 10204 12.so.0.1.2.4rc1
94	* 1.0.14 10 10014 10.so.0.1.0.14
95	* 1.2.4 13 10204 12.so.0.1.2.4
96	* 1.2.5beta1-2 13 10205 12.so.0.1.2.5beta1-2
97	* 1.0.15rc1-3 10 10015 10.so.0.1.0.15rc1-3
98	* 1.2.5rc1-3 13 10205 12.so.0.1.2.5rc1-3
99	* 1.0.15 10 10015 10.so.0.1.0.15
100	* 1.2.5 13 10205 12.so.0.1.2.5
101	*
102	* Henceforth the source version will match the shared-library major
103	* and minor numbers; the shared-library major version number will be
104	* used for changes in backward compatibility, as it is intended. The
105	* PNG_LIBPNG_VER macro, which is not used within libpng but is available
106	* for applications, is an unsigned integer of the form xyyzz corresponding
107	* to the source version x.y.z (leading zeros in y and z). Beta versions
108	* were given the previous public release number plus a letter, until
109	* version 1.0.6j; from then on they were given the upcoming public
110	* release number plus "betaNN" or "rcN".
111	*
112	* Binary incompatibility exists only when applications make direct access
113	* to the info_ptr or png_ptr members through png.h, and the compiled
114	* application is loaded with a different version of the library.
115	*
116	* DLLNUM will change each time there are forward or backward changes
117	* in binary compatibility (e.g., when a new feature is added).
118	*
119	* See libpng.txt or libpng.3 for more information. The PNG specification
120	* is available as RFC 2083 <ftp://ftp.uu.net/graphics/png/documents/>
121	* and as a W3C Recommendation <http://www.w3.org/TR/REC.png.html>
122	*/
123
124	/*
125	* COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
126	*
127	* If you modify libpng you may insert additional notices immediately following
128	* this sentence.
129	*
130	* libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
131	* Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
132	* distributed according to the same disclaimer and license as libpng-1.0.6
133	* with the following individuals added to the list of Contributing Authors
134	*
135	* Simon-Pierre Cadieux
136	* Eric S. Raymond
137	* Gilles Vollant
138	*
139	* and with the following additions to the disclaimer:
140	*
141	* There is no warranty against interference with your enjoyment of the
142	* library or against infringement. There is no warranty that our
143	* efforts or the library will fulfill any of your particular purposes
144	* or needs. This library is provided with all faults, and the entire
145	* risk of satisfactory quality, performance, accuracy, and effort is with
146	* the user.
147	*
148	* libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
149	* Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson
150	* Distributed according to the same disclaimer and license as libpng-0.96,
151	* with the following individuals added to the list of Contributing Authors:
152	*
153	* Tom Lane
154	* Glenn Randers-Pehrson
155	* Willem van Schaik
156	*
157	* libpng versions 0.89, June 1996, through 0.96, May 1997, are
158	* Copyright (c) 1996, 1997 Andreas Dilger
159	* Distributed according to the same disclaimer and license as libpng-0.88,
160	* with the following individuals added to the list of Contributing Authors:
161	*
162	* John Bowler
163	* Kevin Bracey
164	* Sam Bushell
165	* Magnus Holmgren
166	* Greg Roelofs
167	* Tom Tanner
168	*
169	* libpng versions 0.5, May 1995, through 0.88, January 1996, are
170	* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
171	*
172	* For the purposes of this copyright and license, "Contributing Authors"
173	* is defined as the following set of individuals:
174	*
175	* Andreas Dilger
176	* Dave Martindale
177	* Guy Eric Schalnat
178	* Paul Schmidt
179	* Tim Wegner
180	*
181	* The PNG Reference Library is supplied "AS IS". The Contributing Authors
182	* and Group 42, Inc. disclaim all warranties, expressed or implied,
183	* including, without limitation, the warranties of merchantability and of
184	* fitness for any purpose. The Contributing Authors and Group 42, Inc.
185	* assume no liability for direct, indirect, incidental, special, exemplary,
186	* or consequential damages, which may result from the use of the PNG
187	* Reference Library, even if advised of the possibility of such damage.
188	*
189	* Permission is hereby granted to use, copy, modify, and distribute this
190	* source code, or portions hereof, for any purpose, without fee, subject
191	* to the following restrictions:
192	*
193	* 1. The origin of this source code must not be misrepresented.
194	*
195	* 2. Altered versions must be plainly marked as such and
196	* must not be misrepresented as being the original source.
197	*
198	* 3. This Copyright notice may not be removed or altered from
199	* any source or altered source distribution.
200	*
201	* The Contributing Authors and Group 42, Inc. specifically permit, without
202	* fee, and encourage the use of this source code as a component to
203	* supporting the PNG file format in commercial products. If you use this
204	* source code in a product, acknowledgment is not required but would be
205	* appreciated.
206	*/
207
208	/*
209	* A "png_get_copyright" function is available, for convenient use in "about"
210	* boxes and the like:
211	*
212	* printf("%s",png_get_copyright(NULL));
213	*
214	* Also, the PNG logo (in PNG format, of course) is supplied in the
215	* files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
216	*/
217
218	/*
219	* Libpng is OSI Certified Open Source Software. OSI Certified is a
220	* certification mark of the Open Source Initiative.
221	*/
222
223	/*
224	* The contributing authors would like to thank all those who helped
225	* with testing, bug fixes, and patience. This wouldn't have been
226	* possible without all of you.
227	*
228	* Thanks to Frank J. T. Wojcik for helping with the documentation.
229	*/
230
231	/*
232	* Y2K compliance in libpng:
233	* =========================
234	*
235	* October 3, 2002
236	*
237	* Since the PNG Development group is an ad-hoc body, we can't make
238	* an official declaration.
239	*
240	* This is your unofficial assurance that libpng from version 0.71 and
241	* upward through 1.2.5 are Y2K compliant. It is my belief that earlier
242	* versions were also Y2K compliant.
243	*
244	* Libpng only has three year fields. One is a 2-byte unsigned integer
245	* that will hold years up to 65535. The other two hold the date in text
246	* format, and will hold years up to 9999.
247	*
248	* The integer is
249	* "png_uint_16 year" in png_time_struct.
250	*
251	* The strings are
252	* "png_charp time_buffer" in png_struct and
253	* "near_time_buffer", which is a local character string in png.c.
254	*
255	* There are seven time-related functions:
256	* png.c: png_convert_to_rfc_1123() in png.c
257	* (formerly png_convert_to_rfc_1152() in error)
258	* png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
259	* png_convert_from_time_t() in pngwrite.c
260	* png_get_tIME() in pngget.c
261	* png_handle_tIME() in pngrutil.c, called in pngread.c
262	* png_set_tIME() in pngset.c
263	* png_write_tIME() in pngwutil.c, called in pngwrite.c
264	*
265	* All handle dates properly in a Y2K environment. The
266	* png_convert_from_time_t() function calls gmtime() to convert from system
267	* clock time, which returns (year - 1900), which we properly convert to
268	* the full 4-digit year. There is a possibility that applications using
269	* libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
270	* function, or that they are incorrectly passing only a 2-digit year
271	* instead of "year - 1900" into the png_convert_from_struct_tm() function,
272	* but this is not under our control. The libpng documentation has always
273	* stated that it works with 4-digit years, and the APIs have been
274	* documented as such.
275	*
276	* The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
277	* integer to hold the year, and can hold years as large as 65535.
278	*
279	* zlib, upon which libpng depends, is also Y2K compliant. It contains
280	* no date-related code.
281	*
282	* Glenn Randers-Pehrson
283	* libpng maintainer
284	* PNG Development Group
285	*/
286
287	#ifndef PNG_H
288	#define PNG_H
289
290	/* This is not the place to learn how to use libpng. The file libpng.txt
291	* describes how to use libpng, and the file example.c summarizes it
292	* with some code on which to build. This file is useful for looking
293	* at the actual function definitions and structure components.
294	*/
295
296	/* Version information for png.h - this should match the version in png.c */
297	#define PNG_LIBPNG_VER_STRING "1.2.5"
298
299	#define PNG_LIBPNG_VER_SONUM 0
300	#define PNG_LIBPNG_VER_DLLNUM %DLLNUM%
301
302	/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
303	#define PNG_LIBPNG_VER_MAJOR 1
304	#define PNG_LIBPNG_VER_MINOR 2
305	#define PNG_LIBPNG_VER_RELEASE 5
306	/* This should match the numeric part of the final component of
307	* PNG_LIBPNG_VER_STRING, omitting any leading zero: */
308
309	#define PNG_LIBPNG_VER_BUILD 0
310
311	#define PNG_LIBPNG_BUILD_ALPHA 1
312	#define PNG_LIBPNG_BUILD_BETA 2
313	#define PNG_LIBPNG_BUILD_RC 3
314	#define PNG_LIBPNG_BUILD_STABLE 4
315	#define PNG_LIBPNG_BUILD_TYPEMASK 7
316	#define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with STABLE only */
317	#define PNG_LIBPNG_BUILD_TYPE 4
318
319	/* Careful here. At one time, Guy wanted to use 082, but that would be octal.
320	* We must not include leading zeros.
321	* Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
322	* version 1.0.0 was mis-numbered 100 instead of 10000). From
323	* version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release */
324	#define PNG_LIBPNG_VER 10205 /* 1.2.5 */
325
326	#ifndef PNG_VERSION_INFO_ONLY
327
328	/* include the compression library's header */
329	#include "zlib.h"
330
331	/* include all user configurable info, including optional assembler routines */
332	#include "pngconf.h"
333
334	/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
335	#ifdef __cplusplus
336	extern "C" {
337	#endif /* __cplusplus */
338
339	/* This file is arranged in several sections. The first section contains
340	* structure and type definitions. The second section contains the external
341	* library functions, while the third has the internal library functions,
342	* which applications aren't expected to use directly.
343	*/
344
345	#ifndef PNG_NO_TYPECAST_NULL
346	#define int_p_NULL (int *)NULL
347	#define png_bytep_NULL (png_bytep)NULL
348	#define png_bytepp_NULL (png_bytepp)NULL
349	#define png_doublep_NULL (png_doublep)NULL
350	#define png_error_ptr_NULL (png_error_ptr)NULL
351	#define png_flush_ptr_NULL (png_flush_ptr)NULL
352	#define png_free_ptr_NULL (png_free_ptr)NULL
353	#define png_infopp_NULL (png_infopp)NULL
354	#define png_malloc_ptr_NULL (png_malloc_ptr)NULL
355	#define png_read_status_ptr_NULL (png_read_status_ptr)NULL
356	#define png_rw_ptr_NULL (png_rw_ptr)NULL
357	#define png_structp_NULL (png_structp)NULL
358	#define png_uint_16p_NULL (png_uint_16p)NULL
359	#define png_voidp_NULL (png_voidp)NULL
360	#define png_write_status_ptr_NULL (png_write_status_ptr)NULL
361	#else
362	#define int_p_NULL NULL
363	#define png_bytep_NULL NULL
364	#define png_bytepp_NULL NULL
365	#define png_doublep_NULL NULL
366	#define png_error_ptr_NULL NULL
367	#define png_flush_ptr_NULL NULL
368	#define png_free_ptr_NULL NULL
369	#define png_infopp_NULL NULL
370	#define png_malloc_ptr_NULL NULL
371	#define png_read_status_ptr_NULL NULL
372	#define png_rw_ptr_NULL NULL
373	#define png_structp_NULL NULL
374	#define png_uint_16p_NULL NULL
375	#define png_voidp_NULL NULL
376	#define png_write_status_ptr_NULL NULL
377	#endif
378
379	/* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
380	#if !defined(PNG_NO_EXTERN) \|\| defined(PNG_ALWAYS_EXTERN)
381	/* Version information for C files, stored in png.c. This had better match
382	* the version above.
383	*/
384	#ifdef PNG_USE_GLOBAL_ARRAYS
385	PNG_EXPORT_VAR (const char) png_libpng_ver[18];
386	/* need room for 99.99.99beta99z */
387	#else
388	#define png_libpng_ver png_get_header_ver(NULL)
389	#endif
390
391	#ifdef PNG_USE_GLOBAL_ARRAYS
392	/* This was removed in version 1.0.5c */
393	/* Structures to facilitate easy interlacing. See png.c for more details */
394	PNG_EXPORT_VAR (const int FARDATA) png_pass_start[7];
395	PNG_EXPORT_VAR (const int FARDATA) png_pass_inc[7];
396	PNG_EXPORT_VAR (const int FARDATA) png_pass_ystart[7];
397	PNG_EXPORT_VAR (const int FARDATA) png_pass_yinc[7];
398	PNG_EXPORT_VAR (const int FARDATA) png_pass_mask[7];
399	PNG_EXPORT_VAR (const int FARDATA) png_pass_dsp_mask[7];
400	#ifdef PNG_HAVE_ASSEMBLER_COMBINE_ROW
401	PNG_EXPORT_VAR (const int FARDATA) png_pass_width[7];
402	#endif
403	/* This isn't currently used. If you need it, see png.c for more details.
404	PNG_EXPORT_VAR (const int FARDATA) png_pass_height[7];
405	*/
406	#endif
407
408	#endif /* PNG_NO_EXTERN */
409
410	/* Three color definitions. The order of the red, green, and blue, (and the
411	* exact size) is not important, although the size of the fields need to
412	* be png_byte or png_uint_16 (as defined below).
413	*/
414	typedef struct png_color_struct
415	{
416	png_byte red;
417	png_byte green;
418	png_byte blue;
419	} png_color;
420	typedef png_color FAR * png_colorp;
421	typedef png_color FAR * FAR * png_colorpp;
422
423	typedef struct png_color_16_struct
424	{
425	png_byte index; /* used for palette files */
426	png_uint_16 red; /* for use in red green blue files */
427	png_uint_16 green;
428	png_uint_16 blue;
429	png_uint_16 gray; /* for use in grayscale files */
430	} png_color_16;
431	typedef png_color_16 FAR * png_color_16p;
432	typedef png_color_16 FAR * FAR * png_color_16pp;
433
434	typedef struct png_color_8_struct
435	{
436	png_byte red; /* for use in red green blue files */
437	png_byte green;
438	png_byte blue;
439	png_byte gray; /* for use in grayscale files */
440	png_byte alpha; /* for alpha channel files */
441	} png_color_8;
442	typedef png_color_8 FAR * png_color_8p;
443	typedef png_color_8 FAR * FAR * png_color_8pp;
444
445	/*
446	* The following two structures are used for the in-core representation
447	* of sPLT chunks.
448	*/
449	typedef struct png_sPLT_entry_struct
450	{
451	png_uint_16 red;
452	png_uint_16 green;
453	png_uint_16 blue;
454	png_uint_16 alpha;
455	png_uint_16 frequency;
456	} png_sPLT_entry;
457	typedef png_sPLT_entry FAR * png_sPLT_entryp;
458	typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;
459
460	/* When the depth of the sPLT palette is 8 bits, the color and alpha samples
461	* occupy the LSB of their respective members, and the MSB of each member
462	* is zero-filled. The frequency member always occupies the full 16 bits.
463	*/
464
465	typedef struct png_sPLT_struct
466	{
467	png_charp name; /* palette name */
468	png_byte depth; /* depth of palette samples */
469	png_sPLT_entryp entries; /* palette entries */
470	png_int_32 nentries; /* number of palette entries */
471	} png_sPLT_t;
472	typedef png_sPLT_t FAR * png_sPLT_tp;
473	typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
474
475	#ifdef PNG_TEXT_SUPPORTED
476	/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
477	* and whether that contents is compressed or not. The "key" field
478	* points to a regular zero-terminated C string. The "text", "lang", and
479	* "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
480	* However, the * structure returned by png_get_text() will always contain
481	* regular zero-terminated C strings (possibly empty), never NULL pointers,
482	* so they can be safely used in printf() and other string-handling functions.
483	*/
484	typedef struct png_text_struct
485	{
486	int compression; /* compression value:
487	-1: tEXt, none
488	0: zTXt, deflate
489	1: iTXt, none
490	2: iTXt, deflate */
491	png_charp key; /* keyword, 1-79 character description of "text" */
492	png_charp text; /* comment, may be an empty string (ie "")
493	or a NULL pointer */
494	png_size_t text_length; /* length of the text string */
495	#ifdef PNG_iTXt_SUPPORTED
496	png_size_t itxt_length; /* length of the itxt string */
497	png_charp lang; /* language code, 0-79 characters
498	or a NULL pointer */
499	png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
500	chars or a NULL pointer */
501	#endif
502	} png_text;
503	typedef png_text FAR * png_textp;
504	typedef png_text FAR * FAR * png_textpp;
505	#endif
506
507	/* Supported compression types for text in PNG files (tEXt, and zTXt).
508	* The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
509	#define PNG_TEXT_COMPRESSION_NONE_WR -3
510	#define PNG_TEXT_COMPRESSION_zTXt_WR -2
511	#define PNG_TEXT_COMPRESSION_NONE -1
512	#define PNG_TEXT_COMPRESSION_zTXt 0
513	#define PNG_ITXT_COMPRESSION_NONE 1
514	#define PNG_ITXT_COMPRESSION_zTXt 2
515	#define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
516
517	/* png_time is a way to hold the time in an machine independent way.
518	* Two conversions are provided, both from time_t and struct tm. There
519	* is no portable way to convert to either of these structures, as far
520	* as I know. If you know of a portable way, send it to me. As a side
521	* note - PNG has always been Year 2000 compliant!
522	*/
523	typedef struct png_time_struct
524	{
525	png_uint_16 year; /* full year, as in, 1995 */
526	png_byte month; /* month of year, 1 - 12 */
527	png_byte day; /* day of month, 1 - 31 */
528	png_byte hour; /* hour of day, 0 - 23 */
529	png_byte minute; /* minute of hour, 0 - 59 */
530	png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
531	} png_time;
532	typedef png_time FAR * png_timep;
533	typedef png_time FAR * FAR * png_timepp;
534
535	#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
536	/* png_unknown_chunk is a structure to hold queued chunks for which there is
537	* no specific support. The idea is that we can use this to queue
538	* up private chunks for output even though the library doesn't actually
539	* know about their semantics.
540	*/
541	typedef struct png_unknown_chunk_t
542	{
543	png_byte name[5];
544	png_byte *data;
545	png_size_t size;
546
547	/* libpng-using applications should NOT directly modify this byte. */
548	png_byte location; /* mode of operation at read time */
549	}
550	png_unknown_chunk;
551	typedef png_unknown_chunk FAR * png_unknown_chunkp;
552	typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
553	#endif
554
555	/* png_info is a structure that holds the information in a PNG file so
556	* that the application can find out the characteristics of the image.
557	* If you are reading the file, this structure will tell you what is
558	* in the PNG file. If you are writing the file, fill in the information
559	* you want to put into the PNG file, then call png_write_info().
560	* The names chosen should be very close to the PNG specification, so
561	* consult that document for information about the meaning of each field.
562	*
563	* With libpng < 0.95, it was only possible to directly set and read the
564	* the values in the png_info_struct, which meant that the contents and
565	* order of the values had to remain fixed. With libpng 0.95 and later,
566	* however, there are now functions that abstract the contents of
567	* png_info_struct from the application, so this makes it easier to use
568	* libpng with dynamic libraries, and even makes it possible to use
569	* libraries that don't have all of the libpng ancillary chunk-handing
570	* functionality.
571	*
572	* In any case, the order of the parameters in png_info_struct should NOT
573	* be changed for as long as possible to keep compatibility with applications
574	* that use the old direct-access method with png_info_struct.
575	*
576	* The following members may have allocated storage attached that should be
577	* cleaned up before the structure is discarded: palette, trans, text,
578	* pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
579	* splt_palettes, scal_unit, row_pointers, and unknowns. By default, these
580	* are automatically freed when the info structure is deallocated, if they were
581	* allocated internally by libpng. This behavior can be changed by means
582	* of the png_data_freer() function.
583	*
584	* More allocation details: all the chunk-reading functions that
585	* change these members go through the corresponding png_set_*
586	* functions. A function to clear these members is available: see
587	* png_free_data(). The png_set_* functions do not depend on being
588	* able to point info structure members to any of the storage they are
589	* passed (they make their own copies), EXCEPT that the png_set_text
590	* functions use the same storage passed to them in the text_ptr or
591	* itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
592	* functions do not make their own copies.
593	*/
594	typedef struct png_info_struct
595	{
596	/* the following are necessary for every PNG file */
597	png_uint_32 width; /* width of image in pixels (from IHDR) */
598	png_uint_32 height; /* height of image in pixels (from IHDR) */
599	png_uint_32 valid; /* valid chunk data (see PNG_INFO_ below) */
600	png_uint_32 rowbytes; /* bytes needed to hold an untransformed row */
601	png_colorp palette; /* array of color values (valid & PNG_INFO_PLTE) */
602	png_uint_16 num_palette; /* number of color entries in "palette" (PLTE) */
603	png_uint_16 num_trans; /* number of transparent palette color (tRNS) */
604	png_byte bit_depth; /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */
605	png_byte color_type; /* see PNG_COLOR_TYPE_ below (from IHDR) */
606	/* The following three should have been named _method not _type */
607	png_byte compression_type; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */
608	png_byte filter_type; /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
609	png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
610
611	/* The following is informational only on read, and not used on writes. */
612	png_byte channels; /* number of data channels per pixel (1, 2, 3, 4) */
613	png_byte pixel_depth; /* number of bits per pixel */
614	png_byte spare_byte; /* to align the data, and for future use */
615	png_byte signature[8]; /* magic bytes read by libpng from start of file */
616
617	/* The rest of the data is optional. If you are reading, check the
618	* valid field to see if the information in these are valid. If you
619	* are writing, set the valid field to those chunks you want written,
620	* and initialize the appropriate fields below.
621	*/
622
623	#if defined(PNG_gAMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
624	/* The gAMA chunk describes the gamma characteristics of the system
625	* on which the image was created, normally in the range [1.0, 2.5].
626	* Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
627	*/
628	float gamma; /* gamma value of image, if (valid & PNG_INFO_gAMA) */
629	#endif
630
631	#if defined(PNG_sRGB_SUPPORTED)
632	/* GR-P, 0.96a */
633	/* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
634	png_byte srgb_intent; /* sRGB rendering intent [0, 1, 2, or 3] */
635	#endif
636
637	#if defined(PNG_TEXT_SUPPORTED)
638	/* The tEXt, and zTXt chunks contain human-readable textual data in
639	* uncompressed, compressed, and optionally compressed forms, respectively.
640	* The data in "text" is an array of pointers to uncompressed,
641	* null-terminated C strings. Each chunk has a keyword that describes the
642	* textual data contained in that chunk. Keywords are not required to be
643	* unique, and the text string may be empty. Any number of text chunks may
644	* be in an image.
645	*/
646	int num_text; /* number of comments read/to write */
647	int max_text; /* current size of text array */
648	png_textp text; /* array of comments read/to write */
649	#endif /* PNG_TEXT_SUPPORTED */
650
651	#if defined(PNG_tIME_SUPPORTED)
652	/* The tIME chunk holds the last time the displayed image data was
653	* modified. See the png_time struct for the contents of this struct.
654	*/
655	png_time mod_time;
656	#endif
657
658	#if defined(PNG_sBIT_SUPPORTED)
659	/* The sBIT chunk specifies the number of significant high-order bits
660	* in the pixel data. Values are in the range [1, bit_depth], and are
661	* only specified for the channels in the pixel data. The contents of
662	* the low-order bits is not specified. Data is valid if
663	* (valid & PNG_INFO_sBIT) is non-zero.
664	*/
665	png_color_8 sig_bit; /* significant bits in color channels */
666	#endif
667
668	#if defined(PNG_tRNS_SUPPORTED) \|\| defined(PNG_READ_EXPAND_SUPPORTED) \|\| \
669	defined(PNG_READ_BACKGROUND_SUPPORTED)
670	/* The tRNS chunk supplies transparency data for paletted images and
671	* other image types that don't need a full alpha channel. There are
672	* "num_trans" transparency values for a paletted image, stored in the
673	* same order as the palette colors, starting from index 0. Values
674	* for the data are in the range [0, 255], ranging from fully transparent
675	* to fully opaque, respectively. For non-paletted images, there is a
676	* single color specified that should be treated as fully transparent.
677	* Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
678	*/
679	png_bytep trans; /* transparent values for paletted image */
680	png_color_16 trans_values; /* transparent color for non-palette image */
681	#endif
682
683	#if defined(PNG_bKGD_SUPPORTED) \|\| defined(PNG_READ_BACKGROUND_SUPPORTED)
684	/* The bKGD chunk gives the suggested image background color if the
685	* display program does not have its own background color and the image
686	* is needs to composited onto a background before display. The colors
687	* in "background" are normally in the same color space/depth as the
688	* pixel data. Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
689	*/
690	png_color_16 background;
691	#endif
692
693	#if defined(PNG_oFFs_SUPPORTED)
694	/* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
695	* and downwards from the top-left corner of the display, page, or other
696	* application-specific co-ordinate space. See the PNG_OFFSET_ defines
697	* below for the unit types. Valid if (valid & PNG_INFO_oFFs) non-zero.
698	*/
699	png_int_32 x_offset; /* x offset on page */
700	png_int_32 y_offset; /* y offset on page */
701	png_byte offset_unit_type; /* offset units type */
702	#endif
703
704	#if defined(PNG_pHYs_SUPPORTED)
705	/* The pHYs chunk gives the physical pixel density of the image for
706	* display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
707	* defines below). Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
708	*/
709	png_uint_32 x_pixels_per_unit; /* horizontal pixel density */
710	png_uint_32 y_pixels_per_unit; /* vertical pixel density */
711	png_byte phys_unit_type; /* resolution type (see PNG_RESOLUTION_ below) */
712	#endif
713
714	#if defined(PNG_hIST_SUPPORTED)
715	/* The hIST chunk contains the relative frequency or importance of the
716	* various palette entries, so that a viewer can intelligently select a
717	* reduced-color palette, if required. Data is an array of "num_palette"
718	* values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
719	* is non-zero.
720	*/
721	png_uint_16p hist;
722	#endif
723
724	#ifdef PNG_cHRM_SUPPORTED
725	/* The cHRM chunk describes the CIE color characteristics of the monitor
726	* on which the PNG was created. This data allows the viewer to do gamut
727	* mapping of the input image to ensure that the viewer sees the same
728	* colors in the image as the creator. Values are in the range
729	* [0.0, 0.8]. Data valid if (valid & PNG_INFO_cHRM) non-zero.
730	*/
731	#ifdef PNG_FLOATING_POINT_SUPPORTED
732	float x_white;
733	float y_white;
734	float x_red;
735	float y_red;
736	float x_green;
737	float y_green;
738	float x_blue;
739	float y_blue;
740	#endif
741	#endif
742
743	#if defined(PNG_pCAL_SUPPORTED)
744	/* The pCAL chunk describes a transformation between the stored pixel
745	* values and original physical data values used to create the image.
746	* The integer range [0, 2^bit_depth - 1] maps to the floating-point
747	* range given by [pcal_X0, pcal_X1], and are further transformed by a
748	* (possibly non-linear) transformation function given by "pcal_type"
749	* and "pcal_params" into "pcal_units". Please see the PNG_EQUATION_
750	* defines below, and the PNG-Group's PNG extensions document for a
751	* complete description of the transformations and how they should be
752	* implemented, and for a description of the ASCII parameter strings.
753	* Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
754	*/
755	png_charp pcal_purpose; /* pCAL chunk description string */
756	png_int_32 pcal_X0; /* minimum value */
757	png_int_32 pcal_X1; /* maximum value */
758	png_charp pcal_units; /* Latin-1 string giving physical units */
759	png_charpp pcal_params; /* ASCII strings containing parameter values */
760	png_byte pcal_type; /* equation type (see PNG_EQUATION_ below) */
761	png_byte pcal_nparams; /* number of parameters given in pcal_params */
762	#endif
763
764	/* New members added in libpng-1.0.6 */
765	#ifdef PNG_FREE_ME_SUPPORTED
766	png_uint_32 free_me; /* flags items libpng is responsible for freeing */
767	#endif
768
769	#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
770	/* storage for unknown chunks that the library doesn't recognize. */
771	png_unknown_chunkp unknown_chunks;
772	png_size_t unknown_chunks_num;
773	#endif
774
775	#if defined(PNG_iCCP_SUPPORTED)
776	/* iCCP chunk data. */
777	png_charp iccp_name; /* profile name */
778	png_charp iccp_profile; /* International Color Consortium profile data */
779	/* Note to maintainer: should be png_bytep */
780	png_uint_32 iccp_proflen; /* ICC profile data length */
781	png_byte iccp_compression; /* Always zero */
782	#endif
783
784	#if defined(PNG_sPLT_SUPPORTED)
785	/* data on sPLT chunks (there may be more than one). */
786	png_sPLT_tp splt_palettes;
787	png_uint_32 splt_palettes_num;
788	#endif
789
790	#if defined(PNG_sCAL_SUPPORTED)
791	/* The sCAL chunk describes the actual physical dimensions of the
792	* subject matter of the graphic. The chunk contains a unit specification
793	* a byte value, and two ASCII strings representing floating-point
794	* values. The values are width and height corresponsing to one pixel
795	* in the image. This external representation is converted to double
796	* here. Data values are valid if (valid & PNG_INFO_sCAL) is non-zero.
797	*/
798	png_byte scal_unit; /* unit of physical scale */
799	#ifdef PNG_FLOATING_POINT_SUPPORTED
800	double scal_pixel_width; /* width of one pixel */
801	double scal_pixel_height; /* height of one pixel */
802	#endif
803	#ifdef PNG_FIXED_POINT_SUPPORTED
804	png_charp scal_s_width; /* string containing height */
805	png_charp scal_s_height; /* string containing width */
806	#endif
807	#endif
808
809	#if defined(PNG_INFO_IMAGE_SUPPORTED)
810	/* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS) non-zero */
811	/* Data valid if (valid & PNG_INFO_IDAT) non-zero */
812	png_bytepp row_pointers; /* the image bits */
813	#endif
814
815	#if defined(PNG_FIXED_POINT_SUPPORTED) && defined(PNG_gAMA_SUPPORTED)
816	png_fixed_point int_gamma; /* gamma of image, if (valid & PNG_INFO_gAMA) */
817	#endif
818
819	#if defined(PNG_cHRM_SUPPORTED) && defined(PNG_FIXED_POINT_SUPPORTED)
820	png_fixed_point int_x_white;
821	png_fixed_point int_y_white;
822	png_fixed_point int_x_red;
823	png_fixed_point int_y_red;
824	png_fixed_point int_x_green;
825	png_fixed_point int_y_green;
826	png_fixed_point int_x_blue;
827	png_fixed_point int_y_blue;
828	#endif
829
830	} png_info;
831
832	typedef png_info FAR * png_infop;
833	typedef png_info FAR * FAR * png_infopp;
834
835	/* Maximum positive integer used in PNG is (2^31)-1 */
836	#define PNG_MAX_UINT ((png_uint_32)0x7fffffffL)
837
838	/* These describe the color_type field in png_info. */
839	/* color type masks */
840	#define PNG_COLOR_MASK_PALETTE 1
841	#define PNG_COLOR_MASK_COLOR 2
842	#define PNG_COLOR_MASK_ALPHA 4
843
844	/* color types. Note that not all combinations are legal */
845	#define PNG_COLOR_TYPE_GRAY 0
846	#define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR \| PNG_COLOR_MASK_PALETTE)
847	#define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
848	#define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR \| PNG_COLOR_MASK_ALPHA)
849	#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
850	/* aliases */
851	#define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
852	#define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
853
854	/* This is for compression type. PNG 1.0-1.2 only define the single type. */
855	#define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
856	#define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
857
858	/* This is for filter type. PNG 1.0-1.2 only define the single type. */
859	#define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
860	#define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
861	#define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
862
863	/* These are for the interlacing type. These values should NOT be changed. */
864	#define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
865	#define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
866	#define PNG_INTERLACE_LAST 2 /* Not a valid value */
867
868	/* These are for the oFFs chunk. These values should NOT be changed. */
869	#define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
870	#define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
871	#define PNG_OFFSET_LAST 2 /* Not a valid value */
872
873	/* These are for the pCAL chunk. These values should NOT be changed. */
874	#define PNG_EQUATION_LINEAR 0 /* Linear transformation */
875	#define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
876	#define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
877	#define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
878	#define PNG_EQUATION_LAST 4 /* Not a valid value */
879
880	/* These are for the sCAL chunk. These values should NOT be changed. */
881	#define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
882	#define PNG_SCALE_METER 1 /* meters per pixel */
883	#define PNG_SCALE_RADIAN 2 /* radians per pixel */
884	#define PNG_SCALE_LAST 3 /* Not a valid value */
885
886	/* These are for the pHYs chunk. These values should NOT be changed. */
887	#define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
888	#define PNG_RESOLUTION_METER 1 /* pixels/meter */
889	#define PNG_RESOLUTION_LAST 2 /* Not a valid value */
890
891	/* These are for the sRGB chunk. These values should NOT be changed. */
892	#define PNG_sRGB_INTENT_PERCEPTUAL 0
893	#define PNG_sRGB_INTENT_RELATIVE 1
894	#define PNG_sRGB_INTENT_SATURATION 2
895	#define PNG_sRGB_INTENT_ABSOLUTE 3
896	#define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
897
898	/* This is for text chunks */
899	#define PNG_KEYWORD_MAX_LENGTH 79
900
901	/* Maximum number of entries in PLTE/sPLT/tRNS arrays */
902	#define PNG_MAX_PALETTE_LENGTH 256
903
904	/* These determine if an ancillary chunk's data has been successfully read
905	* from the PNG header, or if the application has filled in the corresponding
906	* data in the info_struct to be written into the output file. The values
907	* of the PNG_INFO_<chunk> defines should NOT be changed.
908	*/
909	#define PNG_INFO_gAMA 0x0001
910	#define PNG_INFO_sBIT 0x0002
911	#define PNG_INFO_cHRM 0x0004
912	#define PNG_INFO_PLTE 0x0008
913	#define PNG_INFO_tRNS 0x0010
914	#define PNG_INFO_bKGD 0x0020
915	#define PNG_INFO_hIST 0x0040
916	#define PNG_INFO_pHYs 0x0080
917	#define PNG_INFO_oFFs 0x0100
918	#define PNG_INFO_tIME 0x0200
919	#define PNG_INFO_pCAL 0x0400
920	#define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */
921	#define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */
922	#define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */
923	#define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */
924	#define PNG_INFO_IDAT 0x8000L /* ESR, 1.0.6 */
925
926	/* This is used for the transformation routines, as some of them
927	* change these values for the row. It also should enable using
928	* the routines for other purposes.
929	*/
930	typedef struct png_row_info_struct
931	{
932	png_uint_32 width; /* width of row */
933	png_uint_32 rowbytes; /* number of bytes in row */
934	png_byte color_type; /* color type of row */
935	png_byte bit_depth; /* bit depth of row */
936	png_byte channels; /* number of channels (1, 2, 3, or 4) */
937	png_byte pixel_depth; /* bits per pixel (depth * channels) */
938	} png_row_info;
939
940	typedef png_row_info FAR * png_row_infop;
941	typedef png_row_info FAR * FAR * png_row_infopp;
942
943	/* These are the function types for the I/O functions and for the functions
944	* that allow the user to override the default I/O functions with his or her
945	* own. The png_error_ptr type should match that of user-supplied warning
946	* and error functions, while the png_rw_ptr type should match that of the
947	* user read/write data functions.
948	*/
949	typedef struct png_struct_def png_struct;
950	typedef png_struct FAR * png_structp;
951
952	typedef void (PNGAPI *png_error_ptr) PNGARG((png_structp, png_const_charp));
953	typedef void (PNGAPI *png_rw_ptr) PNGARG((png_structp, png_bytep, png_size_t));
954	typedef void (PNGAPI *png_flush_ptr) PNGARG((png_structp));
955	typedef void (PNGAPI *png_read_status_ptr) PNGARG((png_structp, png_uint_32,
956	int));
957	typedef void (PNGAPI *png_write_status_ptr) PNGARG((png_structp, png_uint_32,
958	int));
959
960	#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
961	typedef void (PNGAPI *png_progressive_info_ptr) PNGARG((png_structp, png_infop));
962	typedef void (PNGAPI *png_progressive_end_ptr) PNGARG((png_structp, png_infop));
963	typedef void (PNGAPI *png_progressive_row_ptr) PNGARG((png_structp, png_bytep,
964	png_uint_32, int));
965	#endif
966
967	#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) \|\| \
968	defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) \|\| \
969	defined(PNG_LEGACY_SUPPORTED)
970	typedef void (PNGAPI *png_user_transform_ptr) PNGARG((png_structp,
971	png_row_infop, png_bytep));
972	#endif
973
974	#if defined(PNG_USER_CHUNKS_SUPPORTED)
975	typedef int (PNGAPI *png_user_chunk_ptr) PNGARG((png_structp, png_unknown_chunkp));
976	#endif
977	#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
978	typedef void (PNGAPI *png_unknown_chunk_ptr) PNGARG((png_structp));
979	#endif
980
981	/* Transform masks for the high-level interface */
982	#define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
983	#define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
984	#define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
985	#define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
986	#define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
987	#define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
988	#define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
989	#define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
990	#define PNG_TRANSFORM_BGR 0x0080 /* read and write */
991	#define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
992	#define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
993	#define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
994	#define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* WRITE only */
995
996	/* Flags for MNG supported features */
997	#define PNG_FLAG_MNG_EMPTY_PLTE 0x01
998	#define PNG_FLAG_MNG_FILTER_64 0x04
999	#define PNG_ALL_MNG_FEATURES 0x05
1000
1001	typedef png_voidp (*png_malloc_ptr) PNGARG((png_structp, png_size_t));
1002	typedef void (*png_free_ptr) PNGARG((png_structp, png_voidp));
1003
1004	/* The structure that holds the information to read and write PNG files.
1005	* The only people who need to care about what is inside of this are the
1006	* people who will be modifying the library for their own special needs.
1007	* It should NOT be accessed directly by an application, except to store
1008	* the jmp_buf.
1009	*/
1010
1011	struct png_struct_def
1012	{
1013	#ifdef PNG_SETJMP_SUPPORTED
1014	jmp_buf jmpbuf; /* used in png_error */
1015	#endif
1016	png_error_ptr error_fn; /* function for printing errors and aborting */
1017	png_error_ptr warning_fn; /* function for printing warnings */
1018	png_voidp error_ptr; /* user supplied struct for error functions */
1019	png_rw_ptr write_data_fn; /* function for writing output data */
1020	png_rw_ptr read_data_fn; /* function for reading input data */
1021	png_voidp io_ptr; /* ptr to application struct for I/O functions */
1022
1023	#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
1024	png_user_transform_ptr read_user_transform_fn; /* user read transform */
1025	#endif
1026
1027	#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1028	png_user_transform_ptr write_user_transform_fn; /* user write transform */
1029	#endif
1030
1031	/* These were added in libpng-1.0.2 */
1032	#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
1033	#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) \|\| \
1034	defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1035	png_voidp user_transform_ptr; /* user supplied struct for user transform */
1036	png_byte user_transform_depth; /* bit depth of user transformed pixels */
1037	png_byte user_transform_channels; /* channels in user transformed pixels */
1038	#endif
1039	#endif
1040
1041	png_uint_32 mode; /* tells us where we are in the PNG file */
1042	png_uint_32 flags; /* flags indicating various things to libpng */
1043	png_uint_32 transformations; /* which transformations to perform */
1044
1045	z_stream zstream; /* pointer to decompression structure (below) */
1046	png_bytep zbuf; /* buffer for zlib */
1047	png_size_t zbuf_size; /* size of zbuf */
1048	int zlib_level; /* holds zlib compression level */
1049	int zlib_method; /* holds zlib compression method */
1050	int zlib_window_bits; /* holds zlib compression window bits */
1051	int zlib_mem_level; /* holds zlib compression memory level */
1052	int zlib_strategy; /* holds zlib compression strategy */
1053
1054	png_uint_32 width; /* width of image in pixels */
1055	png_uint_32 height; /* height of image in pixels */
1056	png_uint_32 num_rows; /* number of rows in current pass */
1057	png_uint_32 usr_width; /* width of row at start of write */
1058	png_uint_32 rowbytes; /* size of row in bytes */
1059	png_uint_32 irowbytes; /* size of current interlaced row in bytes */
1060	png_uint_32 iwidth; /* width of current interlaced row in pixels */
1061	png_uint_32 row_number; /* current row in interlace pass */
1062	png_bytep prev_row; /* buffer to save previous (unfiltered) row */
1063	png_bytep row_buf; /* buffer to save current (unfiltered) row */
1064	png_bytep sub_row; /* buffer to save "sub" row when filtering */
1065	png_bytep up_row; /* buffer to save "up" row when filtering */
1066	png_bytep avg_row; /* buffer to save "avg" row when filtering */
1067	png_bytep paeth_row; /* buffer to save "Paeth" row when filtering */
1068	png_row_info row_info; /* used for transformation routines */
1069
1070	png_uint_32 idat_size; /* current IDAT size for read */
1071	png_uint_32 crc; /* current chunk CRC value */
1072	png_colorp palette; /* palette from the input file */
1073	png_uint_16 num_palette; /* number of color entries in palette */
1074	png_uint_16 num_trans; /* number of transparency values */
1075	png_byte chunk_name[5]; /* null-terminated name of current chunk */
1076	png_byte compression; /* file compression type (always 0) */
1077	png_byte filter; /* file filter type (always 0) */
1078	png_byte interlaced; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
1079	png_byte pass; /* current interlace pass (0 - 6) */
1080	png_byte do_filter; /* row filter flags (see PNG_FILTER_ below ) */
1081	png_byte color_type; /* color type of file */
1082	png_byte bit_depth; /* bit depth of file */
1083	png_byte usr_bit_depth; /* bit depth of users row */
1084	png_byte pixel_depth; /* number of bits per pixel */
1085	png_byte channels; /* number of channels in file */
1086	png_byte usr_channels; /* channels at start of write */
1087	png_byte sig_bytes; /* magic bytes read/written from start of file */
1088
1089	#if defined(PNG_READ_FILLER_SUPPORTED) \|\| defined(PNG_WRITE_FILLER_SUPPORTED)
1090	#ifdef PNG_LEGACY_SUPPORTED
1091	png_byte filler; /* filler byte for pixel expansion */
1092	#else
1093	png_uint_16 filler; /* filler bytes for pixel expansion */
1094	#endif
1095	#endif
1096
1097	#if defined(PNG_bKGD_SUPPORTED)
1098	png_byte background_gamma_type;
1099	# ifdef PNG_FLOATING_POINT_SUPPORTED
1100	float background_gamma;
1101	# endif
1102	png_color_16 background; /* background color in screen gamma space */
1103	#if defined(PNG_READ_GAMMA_SUPPORTED)
1104	png_color_16 background_1; /* background normalized to gamma 1.0 */
1105	#endif
1106	#endif /* PNG_bKGD_SUPPORTED */
1107
1108	#if defined(PNG_WRITE_FLUSH_SUPPORTED)
1109	png_flush_ptr output_flush_fn;/* Function for flushing output */
1110	png_uint_32 flush_dist; /* how many rows apart to flush, 0 - no flush */
1111	png_uint_32 flush_rows; /* number of rows written since last flush */
1112	#endif
1113
1114	#if defined(PNG_READ_GAMMA_SUPPORTED) \|\| defined(PNG_READ_BACKGROUND_SUPPORTED)
1115	int gamma_shift; /* number of "insignificant" bits 16-bit gamma */
1116	#ifdef PNG_FLOATING_POINT_SUPPORTED
1117	float gamma; /* file gamma value */
1118	float screen_gamma; /* screen gamma value (display_exponent) */
1119	#endif
1120	#endif
1121
1122	#if defined(PNG_READ_GAMMA_SUPPORTED) \|\| defined(PNG_READ_BACKGROUND_SUPPORTED)
1123	png_bytep gamma_table; /* gamma table for 8-bit depth files */
1124	png_bytep gamma_from_1; /* converts from 1.0 to screen */
1125	png_bytep gamma_to_1; /* converts from file to 1.0 */
1126	png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */
1127	png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */
1128	png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */
1129	#endif
1130
1131	#if defined(PNG_READ_GAMMA_SUPPORTED) \|\| defined(PNG_sBIT_SUPPORTED)
1132	png_color_8 sig_bit; /* significant bits in each available channel */
1133	#endif
1134
1135	#if defined(PNG_READ_SHIFT_SUPPORTED) \|\| defined(PNG_WRITE_SHIFT_SUPPORTED)
1136	png_color_8 shift; /* shift for significant bit tranformation */
1137	#endif
1138
1139	#if defined(PNG_tRNS_SUPPORTED) \|\| defined(PNG_READ_BACKGROUND_SUPPORTED) \
1140	\|\| defined(PNG_READ_EXPAND_SUPPORTED) \|\| defined(PNG_READ_BACKGROUND_SUPPORTED)
1141	png_bytep trans; /* transparency values for paletted files */
1142	png_color_16 trans_values; /* transparency values for non-paletted files */
1143	#endif
1144
1145	png_read_status_ptr read_row_fn; /* called after each row is decoded */
1146	png_write_status_ptr write_row_fn; /* called after each row is encoded */
1147	#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1148	png_progressive_info_ptr info_fn; /* called after header data fully read */
1149	png_progressive_row_ptr row_fn; /* called after each prog. row is decoded */
1150	png_progressive_end_ptr end_fn; /* called after image is complete */
1151	png_bytep save_buffer_ptr; /* current location in save_buffer */
1152	png_bytep save_buffer; /* buffer for previously read data */
1153	png_bytep current_buffer_ptr; /* current location in current_buffer */
1154	png_bytep current_buffer; /* buffer for recently used data */
1155	png_uint_32 push_length; /* size of current input chunk */
1156	png_uint_32 skip_length; /* bytes to skip in input data */
1157	png_size_t save_buffer_size; /* amount of data now in save_buffer */
1158	png_size_t save_buffer_max; /* total size of save_buffer */
1159	png_size_t buffer_size; /* total amount of available input data */
1160	png_size_t current_buffer_size; /* amount of data now in current_buffer */
1161	int process_mode; /* what push library is currently doing */
1162	int cur_palette; /* current push library palette index */
1163
1164	# if defined(PNG_TEXT_SUPPORTED)
1165	png_size_t current_text_size; /* current size of text input data */
1166	png_size_t current_text_left; /* how much text left to read in input */
1167	png_charp current_text; /* current text chunk buffer */
1168	png_charp current_text_ptr; /* current location in current_text */
1169	# endif /* PNG_PROGRESSIVE_READ_SUPPORTED && PNG_TEXT_SUPPORTED */
1170
1171	#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1172
1173	#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
1174	/* for the Borland special 64K segment handler */
1175	png_bytepp offset_table_ptr;
1176	png_bytep offset_table;
1177	png_uint_16 offset_table_number;
1178	png_uint_16 offset_table_count;
1179	png_uint_16 offset_table_count_free;
1180	#endif
1181
1182	#if defined(PNG_READ_DITHER_SUPPORTED)
1183	png_bytep palette_lookup; /* lookup table for dithering */
1184	png_bytep dither_index; /* index translation for palette files */
1185	#endif
1186
1187	#if defined(PNG_READ_DITHER_SUPPORTED) \|\| defined(PNG_hIST_SUPPORTED)
1188	png_uint_16p hist; /* histogram */
1189	#endif
1190
1191	#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
1192	png_byte heuristic_method; /* heuristic for row filter selection */
1193	png_byte num_prev_filters; /* number of weights for previous rows */
1194	png_bytep prev_filters; /* filter type(s) of previous row(s) */
1195	png_uint_16p filter_weights; /* weight(s) for previous line(s) */
1196	png_uint_16p inv_filter_weights; /* 1/weight(s) for previous line(s) */
1197	png_uint_16p filter_costs; /* relative filter calculation cost */
1198	png_uint_16p inv_filter_costs; /* 1/relative filter calculation cost */
1199	#endif
1200
1201	#if defined(PNG_TIME_RFC1123_SUPPORTED)
1202	png_charp time_buffer; /* String to hold RFC 1123 time text */
1203	#endif
1204
1205	/* New members added in libpng-1.0.6 */
1206
1207	#ifdef PNG_FREE_ME_SUPPORTED
1208	png_uint_32 free_me; /* flags items libpng is responsible for freeing */
1209	#endif
1210
1211	#if defined(PNG_USER_CHUNKS_SUPPORTED)
1212	png_voidp user_chunk_ptr;
1213	png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
1214	#endif
1215
1216	#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
1217	int num_chunk_list;
1218	png_bytep chunk_list;
1219	#endif
1220
1221	/* New members added in libpng-1.0.3 */
1222	#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
1223	png_byte rgb_to_gray_status;
1224	/* These were changed from png_byte in libpng-1.0.6 */
1225	png_uint_16 rgb_to_gray_red_coeff;
1226	png_uint_16 rgb_to_gray_green_coeff;
1227	png_uint_16 rgb_to_gray_blue_coeff;
1228	#endif
1229
1230	/* New member added in libpng-1.0.4 (renamed in 1.0.9) */
1231	#if defined(PNG_MNG_FEATURES_SUPPORTED) \|\| \
1232	defined(PNG_READ_EMPTY_PLTE_SUPPORTED) \|\| \
1233	defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1234	/* changed from png_byte to png_uint_32 at version 1.2.0 */
1235	#ifdef PNG_1_0_X
1236	png_byte mng_features_permitted;
1237	#else
1238	png_uint_32 mng_features_permitted;
1239	#endif /* PNG_1_0_X */
1240	#endif
1241
1242	/* New member added in libpng-1.0.7 */
1243	#if defined(PNG_READ_GAMMA_SUPPORTED) \|\| defined(PNG_READ_BACKGROUND_SUPPORTED)
1244	png_fixed_point int_gamma;
1245	#endif
1246
1247	/* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
1248	#if defined(PNG_MNG_FEATURES_SUPPORTED)
1249	png_byte filter_type;
1250	#endif
1251
1252	#if defined(PNG_1_0_X) \|\| (defined(PNG_DEBUG) && defined(PNG_USE_PNGGCCRD))
1253	/* New member added in libpng-1.0.10, ifdef'ed out in 1.2.0 */
1254	png_uint_32 row_buf_size;
1255	#endif
1256
1257	/* New members added in libpng-1.2.0 */
1258	#if !defined(PNG_1_0_X) && defined(PNG_ASSEMBLER_CODE_SUPPORTED)
1259	png_byte mmx_bitdepth_threshold;
1260	png_uint_32 mmx_rowbytes_threshold;
1261	png_uint_32 asm_flags;
1262	#endif
1263
1264	/* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
1265	#ifdef PNG_USER_MEM_SUPPORTED
1266	png_voidp mem_ptr; /* user supplied struct for mem functions */
1267	png_malloc_ptr malloc_fn; /* function for allocating memory */
1268	png_free_ptr free_fn; /* function for freeing memory */
1269	#endif
1270
1271	/* New member added in libpng-1.0.13 and 1.2.0 */
1272	png_bytep big_row_buf; /* buffer to save current (unfiltered) row */
1273
1274	#if defined(PNG_READ_DITHER_SUPPORTED)
1275	/* The following three members were added at version 1.0.14 and 1.2.4 */
1276	png_bytep dither_sort; /* working sort array */
1277	png_bytep index_to_palette; /* where the original index currently is */
1278	/* in the palette */
1279	png_bytep palette_to_index; /* which original index points to this */
1280	/* palette color */
1281	#endif
1282
1283	};
1284
1285
1286	/* This prevents a compiler error in png.c if png.c and png.h are both at
1287	version 1.2.5
1288	*/
1289	typedef png_structp version_1_2_5;
1290
1291	typedef png_struct FAR * FAR * png_structpp;
1292
1293	/* Here are the function definitions most commonly used. This is not
1294	* the place to find out how to use libpng. See libpng.txt for the
1295	* full explanation, see example.c for the summary. This just provides
1296	* a simple one line description of the use of each function.
1297	*/
1298
1299	/* Returns the version number of the library */
1300	extern PNG_EXPORT(png_uint_32,png_access_version_number) PNGARG((void));
1301
1302	/* Tell lib we have already handled the first <num_bytes> magic bytes.
1303	* Handling more than 8 bytes from the beginning of the file is an error.
1304	*/
1305	extern PNG_EXPORT(void,png_set_sig_bytes) PNGARG((png_structp png_ptr,
1306	int num_bytes));
1307
1308	/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
1309	* PNG file. Returns zero if the supplied bytes match the 8-byte PNG
1310	* signature, and non-zero otherwise. Having num_to_check == 0 or
1311	* start > 7 will always fail (ie return non-zero).
1312	*/
1313	extern PNG_EXPORT(int,png_sig_cmp) PNGARG((png_bytep sig, png_size_t start,
1314	png_size_t num_to_check));
1315
1316	/* Simple signature checking function. This is the same as calling
1317	* png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
1318	*/
1319	extern PNG_EXPORT(int,png_check_sig) PNGARG((png_bytep sig, int num));
1320
1321	/* Allocate and initialize png_ptr struct for reading, and any other memory. */
1322	extern PNG_EXPORT(png_structp,png_create_read_struct)
1323	PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1324	png_error_ptr error_fn, png_error_ptr warn_fn));
1325
1326	/* Allocate and initialize png_ptr struct for writing, and any other memory */
1327	extern PNG_EXPORT(png_structp,png_create_write_struct)
1328	PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1329	png_error_ptr error_fn, png_error_ptr warn_fn));
1330
1331	extern PNG_EXPORT(png_uint_32,png_get_compression_buffer_size)
1332	PNGARG((png_structp png_ptr));
1333
1334	extern PNG_EXPORT(void,png_set_compression_buffer_size)
1335	PNGARG((png_structp png_ptr, png_uint_32 size));
1336
1337	/* Reset the compression stream */
1338	extern PNG_EXPORT(int,png_reset_zstream) PNGARG((png_structp png_ptr));
1339
1340	/* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
1341	#ifdef PNG_USER_MEM_SUPPORTED
1342	extern PNG_EXPORT(png_structp,png_create_read_struct_2)
1343	PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1344	png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1345	png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1346	extern PNG_EXPORT(png_structp,png_create_write_struct_2)
1347	PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1348	png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1349	png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1350	#endif
1351
1352	/* Write a PNG chunk - size, type, (optional) data, CRC. */
1353	extern PNG_EXPORT(void,png_write_chunk) PNGARG((png_structp png_ptr,
1354	png_bytep chunk_name, png_bytep data, png_size_t length));
1355
1356	/* Write the start of a PNG chunk - length and chunk name. */
1357	extern PNG_EXPORT(void,png_write_chunk_start) PNGARG((png_structp png_ptr,
1358	png_bytep chunk_name, png_uint_32 length));
1359
1360	/* Write the data of a PNG chunk started with png_write_chunk_start(). */
1361	extern PNG_EXPORT(void,png_write_chunk_data) PNGARG((png_structp png_ptr,
1362	png_bytep data, png_size_t length));
1363
1364	/* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1365	extern PNG_EXPORT(void,png_write_chunk_end) PNGARG((png_structp png_ptr));
1366
1367	/* Allocate and initialize the info structure */
1368	extern PNG_EXPORT(png_infop,png_create_info_struct)
1369	PNGARG((png_structp png_ptr));
1370
1371	/* Initialize the info structure (old interface - DEPRECATED) */
1372	extern PNG_EXPORT(void,png_info_init) PNGARG((png_infop info_ptr));
1373	#undef png_info_init
1374	#define png_info_init(info_ptr) png_info_init_3(&info_ptr, sizeof(png_info));
1375	extern PNG_EXPORT(void,png_info_init_3) PNGARG((png_infopp info_ptr,
1376	png_size_t png_info_struct_size));
1377
1378	/* Writes all the PNG information before the image. */
1379	extern PNG_EXPORT(void,png_write_info_before_PLTE) PNGARG((png_structp png_ptr,
1380	png_infop info_ptr));
1381	extern PNG_EXPORT(void,png_write_info) PNGARG((png_structp png_ptr,
1382	png_infop info_ptr));
1383
1384	/* read the information before the actual image data. */
1385	extern PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr,
1386	png_infop info_ptr));
1387
1388	#if defined(PNG_TIME_RFC1123_SUPPORTED)
1389	extern PNG_EXPORT(png_charp,png_convert_to_rfc1123)
1390	PNGARG((png_structp png_ptr, png_timep ptime));
1391	#endif
1392
1393	#if !defined(_WIN32_WCE)
1394	/* "time.h" functions are not supported on WindowsCE */
1395	#if defined(PNG_WRITE_tIME_SUPPORTED)
1396	/* convert from a struct tm to png_time */
1397	extern PNG_EXPORT(void,png_convert_from_struct_tm) PNGARG((png_timep ptime,
1398	struct tm FAR * ttime));
1399
1400	/* convert from time_t to png_time. Uses gmtime() */
1401	extern PNG_EXPORT(void,png_convert_from_time_t) PNGARG((png_timep ptime,
1402	time_t ttime));
1403	#endif /* PNG_WRITE_tIME_SUPPORTED */
1404	#endif /* _WIN32_WCE */
1405
1406	#if defined(PNG_READ_EXPAND_SUPPORTED)
1407	/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1408	extern PNG_EXPORT(void,png_set_expand) PNGARG((png_structp png_ptr));
1409	extern PNG_EXPORT(void,png_set_gray_1_2_4_to_8) PNGARG((png_structp png_ptr));
1410	extern PNG_EXPORT(void,png_set_palette_to_rgb) PNGARG((png_structp png_ptr));
1411	extern PNG_EXPORT(void,png_set_tRNS_to_alpha) PNGARG((png_structp png_ptr));
1412	#endif
1413
1414	#if defined(PNG_READ_BGR_SUPPORTED) \|\| defined(PNG_WRITE_BGR_SUPPORTED)
1415	/* Use blue, green, red order for pixels. */
1416	extern PNG_EXPORT(void,png_set_bgr) PNGARG((png_structp png_ptr));
1417	#endif
1418
1419	#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
1420	/* Expand the grayscale to 24-bit RGB if necessary. */
1421	extern PNG_EXPORT(void,png_set_gray_to_rgb) PNGARG((png_structp png_ptr));
1422	#endif
1423
1424	#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
1425	/* Reduce RGB to grayscale. */
1426	#ifdef PNG_FLOATING_POINT_SUPPORTED
1427	extern PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr,
1428	int error_action, double red, double green ));
1429	#endif
1430	extern PNG_EXPORT(void,png_set_rgb_to_gray_fixed) PNGARG((png_structp png_ptr,
1431	int error_action, png_fixed_point red, png_fixed_point green ));
1432	extern PNG_EXPORT(png_byte,png_get_rgb_to_gray_status) PNGARG((png_structp
1433	png_ptr));
1434	#endif
1435
1436	extern PNG_EXPORT(void,png_build_grayscale_palette) PNGARG((int bit_depth,
1437	png_colorp palette));
1438
1439	#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1440	extern PNG_EXPORT(void,png_set_strip_alpha) PNGARG((png_structp png_ptr));
1441	#endif
1442
1443	#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) \|\| \
1444	defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1445	extern PNG_EXPORT(void,png_set_swap_alpha) PNGARG((png_structp png_ptr));
1446	#endif
1447
1448	#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) \|\| \
1449	defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1450	extern PNG_EXPORT(void,png_set_invert_alpha) PNGARG((png_structp png_ptr));
1451	#endif
1452
1453	#if defined(PNG_READ_FILLER_SUPPORTED) \|\| defined(PNG_WRITE_FILLER_SUPPORTED)
1454	/* Add a filler byte to 24-bit RGB images. */
1455	extern PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr,
1456	png_uint_32 filler, int flags));
1457	/* The values of the PNG_FILLER_ defines should NOT be changed */
1458	#define PNG_FILLER_BEFORE 0
1459	#define PNG_FILLER_AFTER 1
1460	#endif /* PNG_READ_FILLER_SUPPORTED \|\| PNG_WRITE_FILLER_SUPPORTED */
1461
1462	#if defined(PNG_READ_SWAP_SUPPORTED) \|\| defined(PNG_WRITE_SWAP_SUPPORTED)
1463	/* Swap bytes in 16-bit depth files. */
1464	extern PNG_EXPORT(void,png_set_swap) PNGARG((png_structp png_ptr));
1465	#endif
1466
1467	#if defined(PNG_READ_PACK_SUPPORTED) \|\| defined(PNG_WRITE_PACK_SUPPORTED)
1468	/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1469	extern PNG_EXPORT(void,png_set_packing) PNGARG((png_structp png_ptr));
1470	#endif
1471
1472	#if defined(PNG_READ_PACKSWAP_SUPPORTED) \|\| defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1473	/* Swap packing order of pixels in bytes. */
1474	extern PNG_EXPORT(void,png_set_packswap) PNGARG((png_structp png_ptr));
1475	#endif
1476
1477	#if defined(PNG_READ_SHIFT_SUPPORTED) \|\| defined(PNG_WRITE_SHIFT_SUPPORTED)
1478	/* Converts files to legal bit depths. */
1479	extern PNG_EXPORT(void,png_set_shift) PNGARG((png_structp png_ptr,
1480	png_color_8p true_bits));
1481	#endif
1482
1483	#if defined(PNG_READ_INTERLACING_SUPPORTED) \|\| \
1484	defined(PNG_WRITE_INTERLACING_SUPPORTED)
1485	/* Have the code handle the interlacing. Returns the number of passes. */
1486	extern PNG_EXPORT(int,png_set_interlace_handling) PNGARG((png_structp png_ptr));
1487	#endif
1488
1489	#if defined(PNG_READ_INVERT_SUPPORTED) \|\| defined(PNG_WRITE_INVERT_SUPPORTED)
1490	/* Invert monochrome files */
1491	extern PNG_EXPORT(void,png_set_invert_mono) PNGARG((png_structp png_ptr));
1492	#endif
1493
1494	#if defined(PNG_READ_BACKGROUND_SUPPORTED)
1495	/* Handle alpha and tRNS by replacing with a background color. */
1496	#ifdef PNG_FLOATING_POINT_SUPPORTED
1497	extern PNG_EXPORT(void,png_set_background) PNGARG((png_structp png_ptr,
1498	png_color_16p background_color, int background_gamma_code,
1499	int need_expand, double background_gamma));
1500	#endif
1501	#define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1502	#define PNG_BACKGROUND_GAMMA_SCREEN 1
1503	#define PNG_BACKGROUND_GAMMA_FILE 2
1504	#define PNG_BACKGROUND_GAMMA_UNIQUE 3
1505	#endif
1506
1507	#if defined(PNG_READ_16_TO_8_SUPPORTED)
1508	/* strip the second byte of information from a 16-bit depth file. */
1509	extern PNG_EXPORT(void,png_set_strip_16) PNGARG((png_structp png_ptr));
1510	#endif
1511
1512	#if defined(PNG_READ_DITHER_SUPPORTED)
1513	/* Turn on dithering, and reduce the palette to the number of colors available. */
1514	extern PNG_EXPORT(void,png_set_dither) PNGARG((png_structp png_ptr,
1515	png_colorp palette, int num_palette, int maximum_colors,
1516	png_uint_16p histogram, int full_dither));
1517	#endif
1518
1519	#if defined(PNG_READ_GAMMA_SUPPORTED)
1520	/* Handle gamma correction. Screen_gamma=(display_exponent) */
1521	#ifdef PNG_FLOATING_POINT_SUPPORTED
1522	extern PNG_EXPORT(void,png_set_gamma) PNGARG((png_structp png_ptr,
1523	double screen_gamma, double default_file_gamma));
1524	#endif
1525	#endif
1526
1527	#if defined(PNG_READ_EMPTY_PLTE_SUPPORTED) \|\| \
1528	defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1529	/* Permit or disallow empty PLTE (0: not permitted, 1: permitted) */
1530	/* Deprecated and will be removed. Use png_permit_mng_features() instead. */
1531	extern PNG_EXPORT(void,png_permit_empty_plte) PNGARG((png_structp png_ptr,
1532	int empty_plte_permitted));
1533	#endif
1534
1535	#if defined(PNG_WRITE_FLUSH_SUPPORTED)
1536	/* Set how many lines between output flushes - 0 for no flushing */
1537	extern PNG_EXPORT(void,png_set_flush) PNGARG((png_structp png_ptr, int nrows));
1538	/* Flush the current PNG output buffer */
1539	extern PNG_EXPORT(void,png_write_flush) PNGARG((png_structp png_ptr));
1540	#endif
1541
1542	/* optional update palette with requested transformations */
1543	extern PNG_EXPORT(void,png_start_read_image) PNGARG((png_structp png_ptr));
1544
1545	/* optional call to update the users info structure */
1546	extern PNG_EXPORT(void,png_read_update_info) PNGARG((png_structp png_ptr,
1547	png_infop info_ptr));
1548
1549	/* read one or more rows of image data. */
1550	extern PNG_EXPORT(void,png_read_rows) PNGARG((png_structp png_ptr,
1551	png_bytepp row, png_bytepp display_row, png_uint_32 num_rows));
1552
1553	/* read a row of data. */
1554	extern PNG_EXPORT(void,png_read_row) PNGARG((png_structp png_ptr,
1555	png_bytep row,
1556	png_bytep display_row));
1557
1558	/* read the whole image into memory at once. */
1559	extern PNG_EXPORT(void,png_read_image) PNGARG((png_structp png_ptr,
1560	png_bytepp image));
1561
1562	/* write a row of image data */
1563	extern PNG_EXPORT(void,png_write_row) PNGARG((png_structp png_ptr,
1564	png_bytep row));
1565
1566	/* write a few rows of image data */
1567	extern PNG_EXPORT(void,png_write_rows) PNGARG((png_structp png_ptr,
1568	png_bytepp row, png_uint_32 num_rows));
1569
1570	/* write the image data */
1571	extern PNG_EXPORT(void,png_write_image) PNGARG((png_structp png_ptr,
1572	png_bytepp image));
1573
1574	/* writes the end of the PNG file. */
1575	extern PNG_EXPORT(void,png_write_end) PNGARG((png_structp png_ptr,
1576	png_infop info_ptr));
1577
1578	/* read the end of the PNG file. */
1579	extern PNG_EXPORT(void,png_read_end) PNGARG((png_structp png_ptr,
1580	png_infop info_ptr));
1581
1582	/* free any memory associated with the png_info_struct */
1583	extern PNG_EXPORT(void,png_destroy_info_struct) PNGARG((png_structp png_ptr,
1584	png_infopp info_ptr_ptr));
1585
1586	/* free any memory associated with the png_struct and the png_info_structs */
1587	extern PNG_EXPORT(void,png_destroy_read_struct) PNGARG((png_structpp
1588	png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1589
1590	/* free all memory used by the read (old method - NOT DLL EXPORTED) */
1591	extern void png_read_destroy PNGARG((png_structp png_ptr, png_infop info_ptr,
1592	png_infop end_info_ptr));
1593
1594	/* free any memory associated with the png_struct and the png_info_structs */
1595	extern PNG_EXPORT(void,png_destroy_write_struct)
1596	PNGARG((png_structpp png_ptr_ptr, png_infopp info_ptr_ptr));
1597
1598	/* free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */
1599	extern void png_write_destroy PNGARG((png_structp png_ptr));
1600
1601	/* set the libpng method of handling chunk CRC errors */
1602	extern PNG_EXPORT(void,png_set_crc_action) PNGARG((png_structp png_ptr,
1603	int crit_action, int ancil_action));
1604
1605	/* Values for png_set_crc_action() to say how to handle CRC errors in
1606	* ancillary and critical chunks, and whether to use the data contained
1607	* therein. Note that it is impossible to "discard" data in a critical
1608	* chunk. For versions prior to 0.90, the action was always error/quit,
1609	* whereas in version 0.90 and later, the action for CRC errors in ancillary
1610	* chunks is warn/discard. These values should NOT be changed.
1611	*
1612	* value action:critical action:ancillary
1613	*/
1614	#define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1615	#define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1616	#define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1617	#define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1618	#define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1619	#define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1620
1621	/* These functions give the user control over the scan-line filtering in
1622	* libpng and the compression methods used by zlib. These functions are
1623	* mainly useful for testing, as the defaults should work with most users.
1624	* Those users who are tight on memory or want faster performance at the
1625	* expense of compression can modify them. See the compression library
1626	* header file (zlib.h) for an explination of the compression functions.
1627	*/
1628
1629	/* set the filtering method(s) used by libpng. Currently, the only valid
1630	* value for "method" is 0.
1631	*/
1632	extern PNG_EXPORT(void,png_set_filter) PNGARG((png_structp png_ptr, int method,
1633	int filters));
1634
1635	/* Flags for png_set_filter() to say which filters to use. The flags
1636	* are chosen so that they don't conflict with real filter types
1637	* below, in case they are supplied instead of the #defined constants.
1638	* These values should NOT be changed.
1639	*/
1640	#define PNG_NO_FILTERS 0x00
1641	#define PNG_FILTER_NONE 0x08
1642	#define PNG_FILTER_SUB 0x10
1643	#define PNG_FILTER_UP 0x20
1644	#define PNG_FILTER_AVG 0x40
1645	#define PNG_FILTER_PAETH 0x80
1646	#define PNG_ALL_FILTERS (PNG_FILTER_NONE \| PNG_FILTER_SUB \| PNG_FILTER_UP \| \
1647	PNG_FILTER_AVG \| PNG_FILTER_PAETH)
1648
1649	/* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1650	* These defines should NOT be changed.
1651	*/
1652	#define PNG_FILTER_VALUE_NONE 0
1653	#define PNG_FILTER_VALUE_SUB 1
1654	#define PNG_FILTER_VALUE_UP 2
1655	#define PNG_FILTER_VALUE_AVG 3
1656	#define PNG_FILTER_VALUE_PAETH 4
1657	#define PNG_FILTER_VALUE_LAST 5
1658
1659	#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* EXPERIMENTAL */
1660	/* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
1661	* defines, either the default (minimum-sum-of-absolute-differences), or
1662	* the experimental method (weighted-minimum-sum-of-absolute-differences).
1663	*
1664	* Weights are factors >= 1.0, indicating how important it is to keep the
1665	* filter type consistent between rows. Larger numbers mean the current
1666	* filter is that many times as likely to be the same as the "num_weights"
1667	* previous filters. This is cumulative for each previous row with a weight.
1668	* There needs to be "num_weights" values in "filter_weights", or it can be
1669	* NULL if the weights aren't being specified. Weights have no influence on
1670	* the selection of the first row filter. Well chosen weights can (in theory)
1671	* improve the compression for a given image.
1672	*
1673	* Costs are factors >= 1.0 indicating the relative decoding costs of a
1674	* filter type. Higher costs indicate more decoding expense, and are
1675	* therefore less likely to be selected over a filter with lower computational
1676	* costs. There needs to be a value in "filter_costs" for each valid filter
1677	* type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
1678	* setting the costs. Costs try to improve the speed of decompression without
1679	* unduly increasing the compressed image size.
1680	*
1681	* A negative weight or cost indicates the default value is to be used, and
1682	* values in the range [0.0, 1.0) indicate the value is to remain unchanged.
1683	* The default values for both weights and costs are currently 1.0, but may
1684	* change if good general weighting/cost heuristics can be found. If both
1685	* the weights and costs are set to 1.0, this degenerates the WEIGHTED method
1686	* to the UNWEIGHTED method, but with added encoding time/computation.
1687	*/
1688	#ifdef PNG_FLOATING_POINT_SUPPORTED
1689	extern PNG_EXPORT(void,png_set_filter_heuristics) PNGARG((png_structp png_ptr,
1690	int heuristic_method, int num_weights, png_doublep filter_weights,
1691	png_doublep filter_costs));
1692	#endif
1693	#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1694
1695	/* Heuristic used for row filter selection. These defines should NOT be
1696	* changed.
1697	*/
1698	#define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
1699	#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
1700	#define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
1701	#define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
1702
1703	/* Set the library compression level. Currently, valid values range from
1704	* 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1705	* (0 - no compression, 9 - "maximal" compression). Note that tests have
1706	* shown that zlib compression levels 3-6 usually perform as well as level 9
1707	* for PNG images, and do considerably fewer caclulations. In the future,
1708	* these values may not correspond directly to the zlib compression levels.
1709	*/
1710	extern PNG_EXPORT(void,png_set_compression_level) PNGARG((png_structp png_ptr,
1711	int level));
1712
1713	extern PNG_EXPORT(void,png_set_compression_mem_level)
1714	PNGARG((png_structp png_ptr, int mem_level));
1715
1716	extern PNG_EXPORT(void,png_set_compression_strategy)
1717	PNGARG((png_structp png_ptr, int strategy));
1718
1719	extern PNG_EXPORT(void,png_set_compression_window_bits)
1720	PNGARG((png_structp png_ptr, int window_bits));
1721
1722	extern PNG_EXPORT(void,png_set_compression_method) PNGARG((png_structp png_ptr,
1723	int method));
1724
1725	/* These next functions are called for input/output, memory, and error
1726	* handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
1727	* and call standard C I/O routines such as fread(), fwrite(), and
1728	* fprintf(). These functions can be made to use other I/O routines
1729	* at run time for those applications that need to handle I/O in a
1730	* different manner by calling png_set_???_fn(). See libpng.txt for
1731	* more information.
1732	*/
1733
1734	#if !defined(PNG_NO_STDIO)
1735	/* Initialize the input/output for the PNG file to the default functions. */
1736	extern PNG_EXPORT(void,png_init_io) PNGARG((png_structp png_ptr, png_FILE_p fp));
1737	#endif
1738
1739	/* Replace the (error and abort), and warning functions with user
1740	* supplied functions. If no messages are to be printed you must still
1741	* write and use replacement functions. The replacement error_fn should
1742	* still do a longjmp to the last setjmp location if you are using this
1743	* method of error handling. If error_fn or warning_fn is NULL, the
1744	* default function will be used.
1745	*/
1746
1747	extern PNG_EXPORT(void,png_set_error_fn) PNGARG((png_structp png_ptr,
1748	png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
1749
1750	/* Return the user pointer associated with the error functions */
1751	extern PNG_EXPORT(png_voidp,png_get_error_ptr) PNGARG((png_structp png_ptr));
1752
1753	/* Replace the default data output functions with a user supplied one(s).
1754	* If buffered output is not used, then output_flush_fn can be set to NULL.
1755	* If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
1756	* output_flush_fn will be ignored (and thus can be NULL).
1757	*/
1758	extern PNG_EXPORT(void,png_set_write_fn) PNGARG((png_structp png_ptr,
1759	png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
1760
1761	/* Replace the default data input function with a user supplied one. */
1762	extern PNG_EXPORT(void,png_set_read_fn) PNGARG((png_structp png_ptr,
1763	png_voidp io_ptr, png_rw_ptr read_data_fn));
1764
1765	/* Return the user pointer associated with the I/O functions */
1766	extern PNG_EXPORT(png_voidp,png_get_io_ptr) PNGARG((png_structp png_ptr));
1767
1768	extern PNG_EXPORT(void,png_set_read_status_fn) PNGARG((png_structp png_ptr,
1769	png_read_status_ptr read_row_fn));
1770
1771	extern PNG_EXPORT(void,png_set_write_status_fn) PNGARG((png_structp png_ptr,
1772	png_write_status_ptr write_row_fn));
1773
1774	#ifdef PNG_USER_MEM_SUPPORTED
1775	/* Replace the default memory allocation functions with user supplied one(s). */
1776	extern PNG_EXPORT(void,png_set_mem_fn) PNGARG((png_structp png_ptr,
1777	png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1778	/* Return the user pointer associated with the memory functions */
1779	extern PNG_EXPORT(png_voidp,png_get_mem_ptr) PNGARG((png_structp png_ptr));
1780	#endif
1781
1782	#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) \|\| \
1783	defined(PNG_LEGACY_SUPPORTED)
1784	extern PNG_EXPORT(void,png_set_read_user_transform_fn) PNGARG((png_structp
1785	png_ptr, png_user_transform_ptr read_user_transform_fn));
1786	#endif
1787
1788	#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) \|\| \
1789	defined(PNG_LEGACY_SUPPORTED)
1790	extern PNG_EXPORT(void,png_set_write_user_transform_fn) PNGARG((png_structp
1791	png_ptr, png_user_transform_ptr write_user_transform_fn));
1792	#endif
1793
1794	#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) \|\| \
1795	defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) \|\| \
1796	defined(PNG_LEGACY_SUPPORTED)
1797	extern PNG_EXPORT(void,png_set_user_transform_info) PNGARG((png_structp
1798	png_ptr, png_voidp user_transform_ptr, int user_transform_depth,
1799	int user_transform_channels));
1800	/* Return the user pointer associated with the user transform functions */
1801	extern PNG_EXPORT(png_voidp,png_get_user_transform_ptr)
1802	PNGARG((png_structp png_ptr));
1803	#endif
1804
1805	#ifdef PNG_USER_CHUNKS_SUPPORTED
1806	extern PNG_EXPORT(void,png_set_read_user_chunk_fn) PNGARG((png_structp png_ptr,
1807	png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
1808	extern PNG_EXPORT(png_voidp,png_get_user_chunk_ptr) PNGARG((png_structp
1809	png_ptr));
1810	#endif
1811
1812	#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1813	/* Sets the function callbacks for the push reader, and a pointer to a
1814	* user-defined structure available to the callback functions.
1815	*/
1816	extern PNG_EXPORT(void,png_set_progressive_read_fn) PNGARG((png_structp png_ptr,
1817	png_voidp progressive_ptr,
1818	png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
1819	png_progressive_end_ptr end_fn));
1820
1821	/* returns the user pointer associated with the push read functions */
1822	extern PNG_EXPORT(png_voidp,png_get_progressive_ptr)
1823	PNGARG((png_structp png_ptr));
1824
1825	/* function to be called when data becomes available */
1826	extern PNG_EXPORT(void,png_process_data) PNGARG((png_structp png_ptr,
1827	png_infop info_ptr, png_bytep buffer, png_size_t buffer_size));
1828
1829	/* function that combines rows. Not very much different than the
1830	* png_combine_row() call. Is this even used?????
1831	*/
1832	extern PNG_EXPORT(void,png_progressive_combine_row) PNGARG((png_structp png_ptr,
1833	png_bytep old_row, png_bytep new_row));
1834	#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1835
1836	extern PNG_EXPORT(png_voidp,png_malloc) PNGARG((png_structp png_ptr,
1837	png_uint_32 size));
1838
1839	#if defined(PNG_1_0_X)
1840	# define png_malloc_warn png_malloc
1841	#else
1842	/* Added at libpng version 1.2.4 */
1843	extern PNG_EXPORT(png_voidp,png_malloc_warn) PNGARG((png_structp png_ptr,
1844	png_uint_32 size));
1845	#endif
1846
1847	/* frees a pointer allocated by png_malloc() */
1848	extern PNG_EXPORT(void,png_free) PNGARG((png_structp png_ptr, png_voidp ptr));
1849
1850	#if defined(PNG_1_0_X)
1851	/* Function to allocate memory for zlib. */
1852	extern PNG_EXPORT(voidpf,png_zalloc) PNGARG((voidpf png_ptr, uInt items,
1853	uInt size));
1854
1855	/* Function to free memory for zlib */
1856	extern PNG_EXPORT(void,png_zfree) PNGARG((voidpf png_ptr, voidpf ptr));
1857	#endif
1858
1859	/* Free data that was allocated internally */
1860	extern PNG_EXPORT(void,png_free_data) PNGARG((png_structp png_ptr,
1861	png_infop info_ptr, png_uint_32 free_me, int num));
1862	#ifdef PNG_FREE_ME_SUPPORTED
1863	/* Reassign responsibility for freeing existing data, whether allocated
1864	* by libpng or by the application */
1865	extern PNG_EXPORT(void,png_data_freer) PNGARG((png_structp png_ptr,
1866	png_infop info_ptr, int freer, png_uint_32 mask));
1867	#endif
1868	/* assignments for png_data_freer */
1869	#define PNG_DESTROY_WILL_FREE_DATA 1
1870	#define PNG_SET_WILL_FREE_DATA 1
1871	#define PNG_USER_WILL_FREE_DATA 2
1872	/* Flags for png_ptr->free_me and info_ptr->free_me */
1873	#define PNG_FREE_HIST 0x0008
1874	#define PNG_FREE_ICCP 0x0010
1875	#define PNG_FREE_SPLT 0x0020
1876	#define PNG_FREE_ROWS 0x0040
1877	#define PNG_FREE_PCAL 0x0080
1878	#define PNG_FREE_SCAL 0x0100
1879	#define PNG_FREE_UNKN 0x0200
1880	#define PNG_FREE_LIST 0x0400
1881	#define PNG_FREE_PLTE 0x1000
1882	#define PNG_FREE_TRNS 0x2000
1883	#define PNG_FREE_TEXT 0x4000
1884	#define PNG_FREE_ALL 0x7fff
1885	#define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT\|PNG_FREE_TEXT\|PNG_FREE_UNKN */
1886
1887	#ifdef PNG_USER_MEM_SUPPORTED
1888	extern PNG_EXPORT(png_voidp,png_malloc_default) PNGARG((png_structp png_ptr,
1889	png_uint_32 size));
1890	extern PNG_EXPORT(void,png_free_default) PNGARG((png_structp png_ptr,
1891	png_voidp ptr));
1892	#endif
1893
1894	extern PNG_EXPORT(png_voidp,png_memcpy_check) PNGARG((png_structp png_ptr,
1895	png_voidp s1, png_voidp s2, png_uint_32 size));
1896
1897	extern PNG_EXPORT(png_voidp,png_memset_check) PNGARG((png_structp png_ptr,
1898	png_voidp s1, int value, png_uint_32 size));
1899
1900	#if defined(USE_FAR_KEYWORD) /* memory model conversion function */
1901	extern void *png_far_to_near PNGARG((png_structp png_ptr,png_voidp ptr,
1902	int check));
1903	#endif /* USE_FAR_KEYWORD */
1904
1905	/* Fatal error in PNG image of libpng - can't continue */
1906	extern PNG_EXPORT(void,png_error) PNGARG((png_structp png_ptr,
1907	png_const_charp error_message));
1908
1909	/* The same, but the chunk name is prepended to the error string. */
1910	extern PNG_EXPORT(void,png_chunk_error) PNGARG((png_structp png_ptr,
1911	png_const_charp error_message));
1912
1913	/* Non-fatal error in libpng. Can continue, but may have a problem. */
1914	extern PNG_EXPORT(void,png_warning) PNGARG((png_structp png_ptr,
1915	png_const_charp warning_message));
1916
1917	/* Non-fatal error in libpng, chunk name is prepended to message. */
1918	extern PNG_EXPORT(void,png_chunk_warning) PNGARG((png_structp png_ptr,
1919	png_const_charp warning_message));
1920
1921	/* The png_set_<chunk> functions are for storing values in the png_info_struct.
1922	* Similarly, the png_get_<chunk> calls are used to read values from the
1923	* png_info_struct, either storing the parameters in the passed variables, or
1924	* setting pointers into the png_info_struct where the data is stored. The
1925	* png_get_<chunk> functions return a non-zero value if the data was available
1926	* in info_ptr, or return zero and do not change any of the parameters if the
1927	* data was not available.
1928	*
1929	* These functions should be used instead of directly accessing png_info
1930	* to avoid problems with future changes in the size and internal layout of
1931	* png_info_struct.
1932	*/
1933	/* Returns "flag" if chunk data is valid in info_ptr. */
1934	extern PNG_EXPORT(png_uint_32,png_get_valid) PNGARG((png_structp png_ptr,
1935	png_infop info_ptr, png_uint_32 flag));
1936
1937	/* Returns number of bytes needed to hold a transformed row. */
1938	extern PNG_EXPORT(png_uint_32,png_get_rowbytes) PNGARG((png_structp png_ptr,
1939	png_infop info_ptr));
1940
1941	#if defined(PNG_INFO_IMAGE_SUPPORTED)
1942	/* Returns row_pointers, which is an array of pointers to scanlines that was
1943	returned from png_read_png(). */
1944	extern PNG_EXPORT(png_bytepp,png_get_rows) PNGARG((png_structp png_ptr,
1945	png_infop info_ptr));
1946	/* Set row_pointers, which is an array of pointers to scanlines for use
1947	by png_write_png(). */
1948	extern PNG_EXPORT(void,png_set_rows) PNGARG((png_structp png_ptr,
1949	png_infop info_ptr, png_bytepp row_pointers));
1950	#endif
1951
1952	/* Returns number of color channels in image. */
1953	extern PNG_EXPORT(png_byte,png_get_channels) PNGARG((png_structp png_ptr,
1954	png_infop info_ptr));
1955
1956	#ifdef PNG_EASY_ACCESS_SUPPORTED
1957	/* Returns image width in pixels. */
1958	extern PNG_EXPORT(png_uint_32, png_get_image_width) PNGARG((png_structp
1959	png_ptr, png_infop info_ptr));
1960
1961	/* Returns image height in pixels. */
1962	extern PNG_EXPORT(png_uint_32, png_get_image_height) PNGARG((png_structp
1963	png_ptr, png_infop info_ptr));
1964
1965	/* Returns image bit_depth. */
1966	extern PNG_EXPORT(png_byte, png_get_bit_depth) PNGARG((png_structp
1967	png_ptr, png_infop info_ptr));
1968
1969	/* Returns image color_type. */
1970	extern PNG_EXPORT(png_byte, png_get_color_type) PNGARG((png_structp
1971	png_ptr, png_infop info_ptr));
1972
1973	/* Returns image filter_type. */
1974	extern PNG_EXPORT(png_byte, png_get_filter_type) PNGARG((png_structp
1975	png_ptr, png_infop info_ptr));
1976
1977	/* Returns image interlace_type. */
1978	extern PNG_EXPORT(png_byte, png_get_interlace_type) PNGARG((png_structp
1979	png_ptr, png_infop info_ptr));
1980
1981	/* Returns image compression_type. */
1982	extern PNG_EXPORT(png_byte, png_get_compression_type) PNGARG((png_structp
1983	png_ptr, png_infop info_ptr));
1984
1985	/* Returns image resolution in pixels per meter, from pHYs chunk data. */
1986	extern PNG_EXPORT(png_uint_32, png_get_pixels_per_meter) PNGARG((png_structp
1987	png_ptr, png_infop info_ptr));
1988	extern PNG_EXPORT(png_uint_32, png_get_x_pixels_per_meter) PNGARG((png_structp
1989	png_ptr, png_infop info_ptr));
1990	extern PNG_EXPORT(png_uint_32, png_get_y_pixels_per_meter) PNGARG((png_structp
1991	png_ptr, png_infop info_ptr));
1992
1993	/* Returns pixel aspect ratio, computed from pHYs chunk data. */
1994	#ifdef PNG_FLOATING_POINT_SUPPORTED
1995	extern PNG_EXPORT(float, png_get_pixel_aspect_ratio) PNGARG((png_structp
1996	png_ptr, png_infop info_ptr));
1997	#endif
1998
1999	/* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
2000	extern PNG_EXPORT(png_int_32, png_get_x_offset_pixels) PNGARG((png_structp
2001	png_ptr, png_infop info_ptr));
2002	extern PNG_EXPORT(png_int_32, png_get_y_offset_pixels) PNGARG((png_structp
2003	png_ptr, png_infop info_ptr));
2004	extern PNG_EXPORT(png_int_32, png_get_x_offset_microns) PNGARG((png_structp
2005	png_ptr, png_infop info_ptr));
2006	extern PNG_EXPORT(png_int_32, png_get_y_offset_microns) PNGARG((png_structp
2007	png_ptr, png_infop info_ptr));
2008
2009	#endif /* PNG_EASY_ACCESS_SUPPORTED */
2010
2011	/* Returns pointer to signature string read from PNG header */
2012	extern PNG_EXPORT(png_bytep,png_get_signature) PNGARG((png_structp png_ptr,
2013	png_infop info_ptr));
2014
2015	#if defined(PNG_bKGD_SUPPORTED)
2016	extern PNG_EXPORT(png_uint_32,png_get_bKGD) PNGARG((png_structp png_ptr,
2017	png_infop info_ptr, png_color_16p *background));
2018	#endif
2019
2020	#if defined(PNG_bKGD_SUPPORTED)
2021	extern PNG_EXPORT(void,png_set_bKGD) PNGARG((png_structp png_ptr,
2022	png_infop info_ptr, png_color_16p background));
2023	#endif
2024
2025	#if defined(PNG_cHRM_SUPPORTED)
2026	#ifdef PNG_FLOATING_POINT_SUPPORTED
2027	extern PNG_EXPORT(png_uint_32,png_get_cHRM) PNGARG((png_structp png_ptr,
2028	png_infop info_ptr, double white_x, double white_y, double *red_x,
2029	double red_y, double green_x, double green_y, double blue_x,
2030	double *blue_y));
2031	#endif
2032	#ifdef PNG_FIXED_POINT_SUPPORTED
2033	extern PNG_EXPORT(png_uint_32,png_get_cHRM_fixed) PNGARG((png_structp png_ptr,
2034	png_infop info_ptr, png_fixed_point *int_white_x, png_fixed_point
2035	int_white_y, png_fixed_point int_red_x, png_fixed_point *int_red_y,
2036	png_fixed_point int_green_x, png_fixed_point int_green_y, png_fixed_point
2037	int_blue_x, png_fixed_point int_blue_y));
2038	#endif
2039	#endif
2040
2041	#if defined(PNG_cHRM_SUPPORTED)
2042	#ifdef PNG_FLOATING_POINT_SUPPORTED
2043	extern PNG_EXPORT(void,png_set_cHRM) PNGARG((png_structp png_ptr,
2044	png_infop info_ptr, double white_x, double white_y, double red_x,
2045	double red_y, double green_x, double green_y, double blue_x, double blue_y));
2046	#endif
2047	#ifdef PNG_FIXED_POINT_SUPPORTED
2048	extern PNG_EXPORT(void,png_set_cHRM_fixed) PNGARG((png_structp png_ptr,
2049	png_infop info_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y,
2050	png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
2051	int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
2052	png_fixed_point int_blue_y));
2053	#endif
2054	#endif
2055
2056	#if defined(PNG_gAMA_SUPPORTED)
2057	#ifdef PNG_FLOATING_POINT_SUPPORTED
2058	extern PNG_EXPORT(png_uint_32,png_get_gAMA) PNGARG((png_structp png_ptr,
2059	png_infop info_ptr, double *file_gamma));
2060	#endif
2061	extern PNG_EXPORT(png_uint_32,png_get_gAMA_fixed) PNGARG((png_structp png_ptr,
2062	png_infop info_ptr, png_fixed_point *int_file_gamma));
2063	#endif
2064
2065	#if defined(PNG_gAMA_SUPPORTED)
2066	#ifdef PNG_FLOATING_POINT_SUPPORTED
2067	extern PNG_EXPORT(void,png_set_gAMA) PNGARG((png_structp png_ptr,
2068	png_infop info_ptr, double file_gamma));
2069	#endif
2070	extern PNG_EXPORT(void,png_set_gAMA_fixed) PNGARG((png_structp png_ptr,
2071	png_infop info_ptr, png_fixed_point int_file_gamma));
2072	#endif
2073
2074	#if defined(PNG_hIST_SUPPORTED)
2075	extern PNG_EXPORT(png_uint_32,png_get_hIST) PNGARG((png_structp png_ptr,
2076	png_infop info_ptr, png_uint_16p *hist));
2077	#endif
2078
2079	#if defined(PNG_hIST_SUPPORTED)
2080	extern PNG_EXPORT(void,png_set_hIST) PNGARG((png_structp png_ptr,
2081	png_infop info_ptr, png_uint_16p hist));
2082	#endif
2083
2084	extern PNG_EXPORT(png_uint_32,png_get_IHDR) PNGARG((png_structp png_ptr,
2085	png_infop info_ptr, png_uint_32 width, png_uint_32 height,
2086	int bit_depth, int color_type, int *interlace_method,
2087	int compression_method, int filter_method));
2088
2089	extern PNG_EXPORT(void,png_set_IHDR) PNGARG((png_structp png_ptr,
2090	png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
2091	int color_type, int interlace_method, int compression_method,
2092	int filter_method));
2093
2094	#if defined(PNG_oFFs_SUPPORTED)
2095	extern PNG_EXPORT(png_uint_32,png_get_oFFs) PNGARG((png_structp png_ptr,
2096	png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2097	int *unit_type));
2098	#endif
2099
2100	#if defined(PNG_oFFs_SUPPORTED)
2101	extern PNG_EXPORT(void,png_set_oFFs) PNGARG((png_structp png_ptr,
2102	png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2103	int unit_type));
2104	#endif
2105
2106	#if defined(PNG_pCAL_SUPPORTED)
2107	extern PNG_EXPORT(png_uint_32,png_get_pCAL) PNGARG((png_structp png_ptr,
2108	png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 *X1,
2109	int type, int nparams, png_charp units, png_charpp params));
2110	#endif
2111
2112	#if defined(PNG_pCAL_SUPPORTED)
2113	extern PNG_EXPORT(void,png_set_pCAL) PNGARG((png_structp png_ptr,
2114	png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1,
2115	int type, int nparams, png_charp units, png_charpp params));
2116	#endif
2117
2118	#if defined(PNG_pHYs_SUPPORTED)
2119	extern PNG_EXPORT(png_uint_32,png_get_pHYs) PNGARG((png_structp png_ptr,
2120	png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int *unit_type));
2121	#endif
2122
2123	#if defined(PNG_pHYs_SUPPORTED)
2124	extern PNG_EXPORT(void,png_set_pHYs) PNGARG((png_structp png_ptr,
2125	png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2126	#endif
2127
2128	extern PNG_EXPORT(png_uint_32,png_get_PLTE) PNGARG((png_structp png_ptr,
2129	png_infop info_ptr, png_colorp palette, int num_palette));
2130
2131	extern PNG_EXPORT(void,png_set_PLTE) PNGARG((png_structp png_ptr,
2132	png_infop info_ptr, png_colorp palette, int num_palette));
2133
2134	#if defined(PNG_sBIT_SUPPORTED)
2135	extern PNG_EXPORT(png_uint_32,png_get_sBIT) PNGARG((png_structp png_ptr,
2136	png_infop info_ptr, png_color_8p *sig_bit));
2137	#endif
2138
2139	#if defined(PNG_sBIT_SUPPORTED)
2140	extern PNG_EXPORT(void,png_set_sBIT) PNGARG((png_structp png_ptr,
2141	png_infop info_ptr, png_color_8p sig_bit));
2142	#endif
2143
2144	#if defined(PNG_sRGB_SUPPORTED)
2145	extern PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr,
2146	png_infop info_ptr, int *intent));
2147	#endif
2148
2149	#if defined(PNG_sRGB_SUPPORTED)
2150	extern PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr,
2151	png_infop info_ptr, int intent));
2152	extern PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr,
2153	png_infop info_ptr, int intent));
2154	#endif
2155
2156	#if defined(PNG_iCCP_SUPPORTED)
2157	extern PNG_EXPORT(png_uint_32,png_get_iCCP) PNGARG((png_structp png_ptr,
2158	png_infop info_ptr, png_charpp name, int *compression_type,
2159	png_charpp profile, png_uint_32 *proflen));
2160	/* Note to maintainer: profile should be png_bytepp */
2161	#endif
2162
2163	#if defined(PNG_iCCP_SUPPORTED)
2164	extern PNG_EXPORT(void,png_set_iCCP) PNGARG((png_structp png_ptr,
2165	png_infop info_ptr, png_charp name, int compression_type,
2166	png_charp profile, png_uint_32 proflen));
2167	/* Note to maintainer: profile should be png_bytep */
2168	#endif
2169
2170	#if defined(PNG_sPLT_SUPPORTED)
2171	extern PNG_EXPORT(png_uint_32,png_get_sPLT) PNGARG((png_structp png_ptr,
2172	png_infop info_ptr, png_sPLT_tpp entries));
2173	#endif
2174
2175	#if defined(PNG_sPLT_SUPPORTED)
2176	extern PNG_EXPORT(void,png_set_sPLT) PNGARG((png_structp png_ptr,
2177	png_infop info_ptr, png_sPLT_tp entries, int nentries));
2178	#endif
2179
2180	#if defined(PNG_TEXT_SUPPORTED)
2181	/* png_get_text also returns the number of text chunks in num_text /
2182	extern PNG_EXPORT(png_uint_32,png_get_text) PNGARG((png_structp png_ptr,
2183	png_infop info_ptr, png_textp text_ptr, int num_text));
2184	#endif
2185
2186	/*
2187	* Note while png_set_text() will accept a structure whose text,
2188	* language, and translated keywords are NULL pointers, the structure
2189	* returned by png_get_text will always contain regular
2190	* zero-terminated C strings. They might be empty strings but
2191	* they will never be NULL pointers.
2192	*/
2193
2194	#if defined(PNG_TEXT_SUPPORTED)
2195	extern PNG_EXPORT(void,png_set_text) PNGARG((png_structp png_ptr,
2196	png_infop info_ptr, png_textp text_ptr, int num_text));
2197	#endif
2198
2199	#if defined(PNG_tIME_SUPPORTED)
2200	extern PNG_EXPORT(png_uint_32,png_get_tIME) PNGARG((png_structp png_ptr,
2201	png_infop info_ptr, png_timep *mod_time));
2202	#endif
2203
2204	#if defined(PNG_tIME_SUPPORTED)
2205	extern PNG_EXPORT(void,png_set_tIME) PNGARG((png_structp png_ptr,
2206	png_infop info_ptr, png_timep mod_time));
2207	#endif
2208
2209	#if defined(PNG_tRNS_SUPPORTED)
2210	extern PNG_EXPORT(png_uint_32,png_get_tRNS) PNGARG((png_structp png_ptr,
2211	png_infop info_ptr, png_bytep trans, int num_trans,
2212	png_color_16p *trans_values));
2213	#endif
2214
2215	#if defined(PNG_tRNS_SUPPORTED)
2216	extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
2217	png_infop info_ptr, png_bytep trans, int num_trans,
2218	png_color_16p trans_values));
2219	#endif
2220
2221	#if defined(PNG_tRNS_SUPPORTED)
2222	#endif
2223
2224	#if defined(PNG_sCAL_SUPPORTED)
2225	#ifdef PNG_FLOATING_POINT_SUPPORTED
2226	extern PNG_EXPORT(png_uint_32,png_get_sCAL) PNGARG((png_structp png_ptr,
2227	png_infop info_ptr, int unit, double width, double *height));
2228	#else
2229	#ifdef PNG_FIXED_POINT_SUPPORTED
2230	extern PNG_EXPORT(png_uint_32,png_get_sCAL_s) PNGARG((png_structp png_ptr,
2231	png_infop info_ptr, int *unit, png_charpp swidth, png_charpp sheight));
2232	#endif
2233	#endif
2234	#endif /* PNG_sCAL_SUPPORTED */
2235
2236	#if defined(PNG_sCAL_SUPPORTED)
2237	#ifdef PNG_FLOATING_POINT_SUPPORTED
2238	extern PNG_EXPORT(void,png_set_sCAL) PNGARG((png_structp png_ptr,
2239	png_infop info_ptr, int unit, double width, double height));
2240	#endif
2241	#ifdef PNG_FIXED_POINT_SUPPORTED
2242	extern PNG_EXPORT(void,png_set_sCAL_s) PNGARG((png_structp png_ptr,
2243	png_infop info_ptr, int unit, png_charp swidth, png_charp sheight));
2244	#endif
2245	#endif /* PNG_sCAL_SUPPORTED \|\| PNG_WRITE_sCAL_SUPPORTED */
2246
2247	#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
2248	/* provide a list of chunks and how they are to be handled, if the built-in
2249	handling or default unknown chunk handling is not desired. Any chunks not
2250	listed will be handled in the default manner. The IHDR and IEND chunks
2251	must not be listed.
2252	keep = 0: follow default behavour
2253	= 1: do not keep
2254	= 2: keep only if safe-to-copy
2255	= 3: keep even if unsafe-to-copy
2256	*/
2257	extern PNG_EXPORT(void, png_set_keep_unknown_chunks) PNGARG((png_structp
2258	png_ptr, int keep, png_bytep chunk_list, int num_chunks));
2259	extern PNG_EXPORT(void, png_set_unknown_chunks) PNGARG((png_structp png_ptr,
2260	png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns));
2261	extern PNG_EXPORT(void, png_set_unknown_chunk_location)
2262	PNGARG((png_structp png_ptr, png_infop info_ptr, int chunk, int location));
2263	extern PNG_EXPORT(png_uint_32,png_get_unknown_chunks) PNGARG((png_structp
2264	png_ptr, png_infop info_ptr, png_unknown_chunkpp entries));
2265	#endif
2266	#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2267	PNG_EXPORT(int,png_handle_as_unknown) PNGARG((png_structp png_ptr, png_bytep
2268	chunk_name));
2269	#endif
2270
2271	/* Png_free_data() will turn off the "valid" flag for anything it frees.
2272	If you need to turn it off for a chunk that your application has freed,
2273	you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); */
2274	extern PNG_EXPORT(void, png_set_invalid) PNGARG((png_structp png_ptr,
2275	png_infop info_ptr, int mask));
2276
2277	#if defined(PNG_INFO_IMAGE_SUPPORTED)
2278	/* The "params" pointer is currently not used and is for future expansion. */
2279	extern PNG_EXPORT(void, png_read_png) PNGARG((png_structp png_ptr,
2280	png_infop info_ptr,
2281	int transforms,
2282	png_voidp params));
2283	extern PNG_EXPORT(void, png_write_png) PNGARG((png_structp png_ptr,
2284	png_infop info_ptr,
2285	int transforms,
2286	png_voidp params));
2287	#endif
2288
2289	/* Define PNG_DEBUG at compile time for debugging information. Higher
2290	* numbers for PNG_DEBUG mean more debugging information. This has
2291	* only been added since version 0.95 so it is not implemented throughout
2292	* libpng yet, but more support will be added as needed.
2293	*/
2294	#ifdef PNG_DEBUG
2295	#if (PNG_DEBUG > 0)
2296	#if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER)
2297	#include <crtdbg.h>
2298	#if (PNG_DEBUG > 1)
2299	#define png_debug(l,m) _RPT0(_CRT_WARN,m)
2300	#define png_debug1(l,m,p1) _RPT1(_CRT_WARN,m,p1)
2301	#define png_debug2(l,m,p1,p2) _RPT2(_CRT_WARN,m,p1,p2)
2302	#endif
2303	#else /* PNG_DEBUG_FILE \|\| !_MSC_VER */
2304	#ifndef PNG_DEBUG_FILE
2305	#define PNG_DEBUG_FILE stderr
2306	#endif /* PNG_DEBUG_FILE */
2307	#if (PNG_DEBUG > 1)
2308	#define png_debug(l,m) \
2309	{ \
2310	int num_tabs=l; \
2311	fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
2312	(num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":"")))); \
2313	}
2314	#define png_debug1(l,m,p1) \
2315	{ \
2316	int num_tabs=l; \
2317	fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
2318	(num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1); \
2319	}
2320	#define png_debug2(l,m,p1,p2) \
2321	{ \
2322	int num_tabs=l; \
2323	fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
2324	(num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1,p2); \
2325	}
2326	#endif /* (PNG_DEBUG > 1) */
2327	#endif /* _MSC_VER */
2328	#endif /* (PNG_DEBUG > 0) */
2329	#endif /* PNG_DEBUG */
2330	#ifndef png_debug
2331	#define png_debug(l, m)
2332	#endif
2333	#ifndef png_debug1
2334	#define png_debug1(l, m, p1)
2335	#endif
2336	#ifndef png_debug2
2337	#define png_debug2(l, m, p1, p2)
2338	#endif
2339
2340	extern PNG_EXPORT(png_bytep,png_sig_bytes) PNGARG((void));
2341
2342	extern PNG_EXPORT(png_charp,png_get_copyright) PNGARG((png_structp png_ptr));
2343	extern PNG_EXPORT(png_charp,png_get_header_ver) PNGARG((png_structp png_ptr));
2344	extern PNG_EXPORT(png_charp,png_get_header_version) PNGARG((png_structp png_ptr));
2345	extern PNG_EXPORT(png_charp,png_get_libpng_ver) PNGARG((png_structp png_ptr));
2346
2347	#ifdef PNG_MNG_FEATURES_SUPPORTED
2348	extern PNG_EXPORT(png_uint_32,png_permit_mng_features) PNGARG((png_structp
2349	png_ptr, png_uint_32 mng_features_permitted));
2350	#endif
2351
2352	/* Added to version 1.2.0 */
2353	#if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
2354	#define PNG_ASM_FLAG_MMX_SUPPORT_COMPILED 0x01 /* not user-settable */
2355	#define PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU 0x02 /* not user-settable */
2356	#define PNG_ASM_FLAG_MMX_READ_COMBINE_ROW 0x04
2357	#define PNG_ASM_FLAG_MMX_READ_INTERLACE 0x08
2358	#define PNG_ASM_FLAG_MMX_READ_FILTER_SUB 0x10
2359	#define PNG_ASM_FLAG_MMX_READ_FILTER_UP 0x20
2360	#define PNG_ASM_FLAG_MMX_READ_FILTER_AVG 0x40
2361	#define PNG_ASM_FLAG_MMX_READ_FILTER_PAETH 0x80
2362	#define PNG_ASM_FLAGS_INITIALIZED 0x80000000 /* not user-settable */
2363
2364	#define PNG_MMX_READ_FLAGS ( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW \
2365	\| PNG_ASM_FLAG_MMX_READ_INTERLACE \
2366	\| PNG_ASM_FLAG_MMX_READ_FILTER_SUB \
2367	\| PNG_ASM_FLAG_MMX_READ_FILTER_UP \
2368	\| PNG_ASM_FLAG_MMX_READ_FILTER_AVG \
2369	\| PNG_ASM_FLAG_MMX_READ_FILTER_PAETH )
2370	#define PNG_MMX_WRITE_FLAGS ( 0 )
2371
2372	#define PNG_MMX_FLAGS ( PNG_ASM_FLAG_MMX_SUPPORT_COMPILED \
2373	\| PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU \
2374	\| PNG_MMX_READ_FLAGS \
2375	\| PNG_MMX_WRITE_FLAGS )
2376
2377	#define PNG_SELECT_READ 1
2378	#define PNG_SELECT_WRITE 2
2379
2380
2381	#if !defined(PNG_1_0_X)
2382	/* pngget.c */
2383	extern PNG_EXPORT(png_uint_32,png_get_mmx_flagmask)
2384	PNGARG((int flag_select, int *compilerID));
2385
2386	/* pngget.c */
2387	extern PNG_EXPORT(png_uint_32,png_get_asm_flagmask)
2388	PNGARG((int flag_select));
2389
2390	/* pngget.c */
2391	extern PNG_EXPORT(png_uint_32,png_get_asm_flags)
2392	PNGARG((png_structp png_ptr));
2393
2394	/* pngget.c */
2395	extern PNG_EXPORT(png_byte,png_get_mmx_bitdepth_threshold)
2396	PNGARG((png_structp png_ptr));
2397
2398	/* pngget.c */
2399	extern PNG_EXPORT(png_uint_32,png_get_mmx_rowbytes_threshold)
2400	PNGARG((png_structp png_ptr));
2401
2402	/* pngset.c */
2403	extern PNG_EXPORT(void,png_set_asm_flags)
2404	PNGARG((png_structp png_ptr, png_uint_32 asm_flags));
2405
2406	/* pngset.c */
2407	extern PNG_EXPORT(void,png_set_mmx_thresholds)
2408	PNGARG((png_structp png_ptr, png_byte mmx_bitdepth_threshold,
2409	png_uint_32 mmx_rowbytes_threshold));
2410
2411	#endif /* PNG_1_0_X */
2412	#endif /* PNG_ASSEMBLER_CODE_SUPPORTED */
2413
2414	#if !defined(PNG_1_0_X)
2415	/* png.c, pnggccrd.c, or pngvcrd.c */
2416	extern PNG_EXPORT(int,png_mmx_support) PNGARG((void));
2417
2418	/* Strip the prepended error numbers ("#nnn ") from error and warning
2419	* messages before passing them to the error or warning handler. */
2420	#ifdef PNG_ERROR_NUMBERS_SUPPORTED
2421	extern PNG_EXPORT(void,png_set_strip_error_numbers) PNGARG((png_structp
2422	png_ptr, png_uint_32 strip_mode));
2423	#endif
2424	#endif /* PNG_1_0_X */
2425
2426	/* Maintainer: Put new public prototypes here ^, in libpng.3, and project defs */
2427
2428	#define PNG_HEADER_VERSION_STRING \
2429	" libpng version 1.2.5 - October 3, 2002 (header)\n"
2430
2431	#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2432	/* With these routines we avoid an integer divide, which will be slower on
2433	* most machines. However, it does take more operations than the corresponding
2434	* divide method, so it may be slower on a few RISC systems. There are two
2435	* shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2436	*
2437	* Note that the rounding factors are NOT supposed to be the same! 128 and
2438	* 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2439	* standard method.
2440	*
2441	* [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2442	*/
2443
2444	/* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2445
2446	# define png_composite(composite, fg, alpha, bg) \
2447	{ png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) * (png_uint_16)(alpha) \
2448	+ (png_uint_16)(bg)*(png_uint_16)(255 - \
2449	(png_uint_16)(alpha)) + (png_uint_16)128); \
2450	(composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
2451
2452	# define png_composite_16(composite, fg, alpha, bg) \
2453	{ png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) * (png_uint_32)(alpha) \
2454	+ (png_uint_32)(bg)*(png_uint_32)(65535L - \
2455	(png_uint_32)(alpha)) + (png_uint_32)32768L); \
2456	(composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
2457
2458	#else /* standard method using integer division */
2459
2460	# define png_composite(composite, fg, alpha, bg) \
2461	(composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2462	(png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2463	(png_uint_16)127) / 255)
2464
2465	# define png_composite_16(composite, fg, alpha, bg) \
2466	(composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2467	(png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) + \
2468	(png_uint_32)32767) / (png_uint_32)65535L)
2469
2470	#endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
2471
2472	/* These next functions are used internally in the code. They generally
2473	* shouldn't be used unless you are writing code to add or replace some
2474	* functionality in libpng. More information about most functions can
2475	* be found in the files where the functions are located.
2476	*/
2477
2478	#if defined(PNG_INTERNAL)
2479
2480	/* Various modes of operation. Note that after an init, mode is set to
2481	* zero automatically when the structure is created.
2482	*/
2483	#define PNG_HAVE_IHDR 0x01
2484	#define PNG_HAVE_PLTE 0x02
2485	#define PNG_HAVE_IDAT 0x04
2486	#define PNG_AFTER_IDAT 0x08
2487	#define PNG_HAVE_IEND 0x10
2488	#define PNG_HAVE_gAMA 0x20
2489	#define PNG_HAVE_cHRM 0x40
2490	#define PNG_HAVE_sRGB 0x80
2491	#define PNG_HAVE_CHUNK_HEADER 0x100
2492	#define PNG_WROTE_tIME 0x200
2493	#define PNG_WROTE_INFO_BEFORE_PLTE 0x400
2494	#define PNG_BACKGROUND_IS_GRAY 0x800
2495	#define PNG_HAVE_PNG_SIGNATURE 0x1000
2496
2497	/* flags for the transformations the PNG library does on the image data */
2498	#define PNG_BGR 0x0001
2499	#define PNG_INTERLACE 0x0002
2500	#define PNG_PACK 0x0004
2501	#define PNG_SHIFT 0x0008
2502	#define PNG_SWAP_BYTES 0x0010
2503	#define PNG_INVERT_MONO 0x0020
2504	#define PNG_DITHER 0x0040
2505	#define PNG_BACKGROUND 0x0080
2506	#define PNG_BACKGROUND_EXPAND 0x0100
2507	/* 0x0200 unused */
2508	#define PNG_16_TO_8 0x0400
2509	#define PNG_RGBA 0x0800
2510	#define PNG_EXPAND 0x1000
2511	#define PNG_GAMMA 0x2000
2512	#define PNG_GRAY_TO_RGB 0x4000
2513	#define PNG_FILLER 0x8000L
2514	#define PNG_PACKSWAP 0x10000L
2515	#define PNG_SWAP_ALPHA 0x20000L
2516	#define PNG_STRIP_ALPHA 0x40000L
2517	#define PNG_INVERT_ALPHA 0x80000L
2518	#define PNG_USER_TRANSFORM 0x100000L
2519	#define PNG_RGB_TO_GRAY_ERR 0x200000L
2520	#define PNG_RGB_TO_GRAY_WARN 0x400000L
2521	#define PNG_RGB_TO_GRAY 0x600000L /* two bits, RGB_TO_GRAY_ERR\|WARN */
2522
2523	/* flags for png_create_struct */
2524	#define PNG_STRUCT_PNG 0x0001
2525	#define PNG_STRUCT_INFO 0x0002
2526
2527	/* Scaling factor for filter heuristic weighting calculations */
2528	#define PNG_WEIGHT_SHIFT 8
2529	#define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
2530	#define PNG_COST_SHIFT 3
2531	#define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
2532
2533	/* flags for the png_ptr->flags rather than declaring a byte for each one */
2534	#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001
2535	#define PNG_FLAG_ZLIB_CUSTOM_LEVEL 0x0002
2536	#define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL 0x0004
2537	#define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS 0x0008
2538	#define PNG_FLAG_ZLIB_CUSTOM_METHOD 0x0010
2539	#define PNG_FLAG_ZLIB_FINISHED 0x0020
2540	#define PNG_FLAG_ROW_INIT 0x0040
2541	#define PNG_FLAG_FILLER_AFTER 0x0080
2542	#define PNG_FLAG_CRC_ANCILLARY_USE 0x0100
2543	#define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200
2544	#define PNG_FLAG_CRC_CRITICAL_USE 0x0400
2545	#define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800
2546	#define PNG_FLAG_FREE_PLTE 0x1000
2547	#define PNG_FLAG_FREE_TRNS 0x2000
2548	#define PNG_FLAG_FREE_HIST 0x4000
2549	#define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000L
2550	#define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000L
2551	#define PNG_FLAG_LIBRARY_MISMATCH 0x20000L
2552	#define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000L
2553	#define PNG_FLAG_STRIP_ERROR_TEXT 0x80000L
2554	#define PNG_FLAG_MALLOC_NULL_MEM_OK 0x100000L
2555
2556	/* For use in png_set_keep_unknown, png_handle_as_unknown */
2557	#define HANDLE_CHUNK_AS_DEFAULT 0
2558	#define HANDLE_CHUNK_NEVER 1
2559	#define HANDLE_CHUNK_IF_SAFE 2
2560	#define HANDLE_CHUNK_ALWAYS 3
2561
2562	#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE \| \
2563	PNG_FLAG_CRC_ANCILLARY_NOWARN)
2564
2565	#define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE \| \
2566	PNG_FLAG_CRC_CRITICAL_IGNORE)
2567
2568	#define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK \| \
2569	PNG_FLAG_CRC_CRITICAL_MASK)
2570
2571	/* save typing and make code easier to understand */
2572	#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
2573	abs((int)((c1).green) - (int)((c2).green)) + \
2574	abs((int)((c1).blue) - (int)((c2).blue)))
2575
2576	/* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
2577	#if !defined(PNG_NO_EXTERN) \|\| defined(PNG_ALWAYS_EXTERN)
2578	/* place to hold the signature string for a PNG file. */
2579	#ifdef PNG_USE_GLOBAL_ARRAYS
2580	PNG_EXPORT_VAR (const png_byte FARDATA) png_sig[8];
2581	#else
2582	#define png_sig png_sig_bytes(NULL)
2583	#endif
2584	#endif /* PNG_NO_EXTERN */
2585
2586	/* Constant strings for known chunk types. If you need to add a chunk,
2587	* define the name here, and add an invocation of the macro in png.c and
2588	* wherever it's needed.
2589	*/
2590	#define PNG_IHDR const png_byte png_IHDR[5] = { 73, 72, 68, 82, '\0'}
2591	#define PNG_IDAT const png_byte png_IDAT[5] = { 73, 68, 65, 84, '\0'}
2592	#define PNG_IEND const png_byte png_IEND[5] = { 73, 69, 78, 68, '\0'}
2593	#define PNG_PLTE const png_byte png_PLTE[5] = { 80, 76, 84, 69, '\0'}
2594	#define PNG_bKGD const png_byte png_bKGD[5] = { 98, 75, 71, 68, '\0'}
2595	#define PNG_cHRM const png_byte png_cHRM[5] = { 99, 72, 82, 77, '\0'}
2596	#define PNG_gAMA const png_byte png_gAMA[5] = {103, 65, 77, 65, '\0'}
2597	#define PNG_hIST const png_byte png_hIST[5] = {104, 73, 83, 84, '\0'}
2598	#define PNG_iCCP const png_byte png_iCCP[5] = {105, 67, 67, 80, '\0'}
2599	#define PNG_iTXt const png_byte png_iTXt[5] = {105, 84, 88, 116, '\0'}
2600	#define PNG_oFFs const png_byte png_oFFs[5] = {111, 70, 70, 115, '\0'}
2601	#define PNG_pCAL const png_byte png_pCAL[5] = {112, 67, 65, 76, '\0'}
2602	#define PNG_sCAL const png_byte png_sCAL[5] = {115, 67, 65, 76, '\0'}
2603	#define PNG_pHYs const png_byte png_pHYs[5] = {112, 72, 89, 115, '\0'}
2604	#define PNG_sBIT const png_byte png_sBIT[5] = {115, 66, 73, 84, '\0'}
2605	#define PNG_sPLT const png_byte png_sPLT[5] = {115, 80, 76, 84, '\0'}
2606	#define PNG_sRGB const png_byte png_sRGB[5] = {115, 82, 71, 66, '\0'}
2607	#define PNG_tEXt const png_byte png_tEXt[5] = {116, 69, 88, 116, '\0'}
2608	#define PNG_tIME const png_byte png_tIME[5] = {116, 73, 77, 69, '\0'}
2609	#define PNG_tRNS const png_byte png_tRNS[5] = {116, 82, 78, 83, '\0'}
2610	#define PNG_zTXt const png_byte png_zTXt[5] = {122, 84, 88, 116, '\0'}
2611
2612	#ifdef PNG_USE_GLOBAL_ARRAYS
2613	PNG_EXPORT_VAR (const png_byte FARDATA) png_IHDR[5];
2614	PNG_EXPORT_VAR (const png_byte FARDATA) png_IDAT[5];
2615	PNG_EXPORT_VAR (const png_byte FARDATA) png_IEND[5];
2616	PNG_EXPORT_VAR (const png_byte FARDATA) png_PLTE[5];
2617	PNG_EXPORT_VAR (const png_byte FARDATA) png_bKGD[5];
2618	PNG_EXPORT_VAR (const png_byte FARDATA) png_cHRM[5];
2619	PNG_EXPORT_VAR (const png_byte FARDATA) png_gAMA[5];
2620	PNG_EXPORT_VAR (const png_byte FARDATA) png_hIST[5];
2621	PNG_EXPORT_VAR (const png_byte FARDATA) png_iCCP[5];
2622	PNG_EXPORT_VAR (const png_byte FARDATA) png_iTXt[5];
2623	PNG_EXPORT_VAR (const png_byte FARDATA) png_oFFs[5];
2624	PNG_EXPORT_VAR (const png_byte FARDATA) png_pCAL[5];
2625	PNG_EXPORT_VAR (const png_byte FARDATA) png_sCAL[5];
2626	PNG_EXPORT_VAR (const png_byte FARDATA) png_pHYs[5];
2627	PNG_EXPORT_VAR (const png_byte FARDATA) png_sBIT[5];
2628	PNG_EXPORT_VAR (const png_byte FARDATA) png_sPLT[5];
2629	PNG_EXPORT_VAR (const png_byte FARDATA) png_sRGB[5];
2630	PNG_EXPORT_VAR (const png_byte FARDATA) png_tEXt[5];
2631	PNG_EXPORT_VAR (const png_byte FARDATA) png_tIME[5];
2632	PNG_EXPORT_VAR (const png_byte FARDATA) png_tRNS[5];
2633	PNG_EXPORT_VAR (const png_byte FARDATA) png_zTXt[5];
2634	#endif /* PNG_USE_GLOBAL_ARRAYS */
2635
2636
2637	/* Inline macros to do direct reads of bytes from the input buffer. These
2638	* require that you are using an architecture that uses PNG byte ordering
2639	* (MSB first) and supports unaligned data storage. I think that PowerPC
2640	* in big-endian mode and 680x0 are the only ones that will support this.
2641	* The x86 line of processors definitely do not. The png_get_int_32()
2642	* routine also assumes we are using two's complement format for negative
2643	* values, which is almost certainly true.
2644	*/
2645	#if defined(PNG_READ_BIG_ENDIAN_SUPPORTED)
2646	# if defined(PNG_pCAL_SUPPORTED) \|\| defined(PNG_oFFs_SUPPORTED)
2647	# define png_get_int_32(buf) ( *((png_int_32p) (buf)))
2648	# endif
2649	# define png_get_uint_32(buf) ( *((png_uint_32p) (buf)))
2650	# define png_get_uint_16(buf) ( *((png_uint_16p) (buf)))
2651	#else
2652	# if defined(PNG_pCAL_SUPPORTED) \|\| defined(PNG_oFFs_SUPPORTED)
2653	PNG_EXTERN png_int_32 png_get_int_32 PNGARG((png_bytep buf));
2654	# endif
2655	PNG_EXTERN png_uint_32 png_get_uint_32 PNGARG((png_bytep buf));
2656	PNG_EXTERN png_uint_16 png_get_uint_16 PNGARG((png_bytep buf));
2657	#endif /* !PNG_READ_BIG_ENDIAN_SUPPORTED */
2658
2659	/* Initialize png_ptr struct for reading, and allocate any other memory.
2660	* (old interface - DEPRECATED - use png_create_read_struct instead).
2661	*/
2662	extern PNG_EXPORT(void,png_read_init) PNGARG((png_structp png_ptr));
2663	#undef png_read_init
2664	#define png_read_init(png_ptr) png_read_init_3(&png_ptr, \
2665	PNG_LIBPNG_VER_STRING, sizeof(png_struct));
2666	extern PNG_EXPORT(void,png_read_init_3) PNGARG((png_structpp ptr_ptr,
2667	png_const_charp user_png_ver, png_size_t png_struct_size));
2668	extern PNG_EXPORT(void,png_read_init_2) PNGARG((png_structp png_ptr,
2669	png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
2670	png_info_size));
2671
2672	/* Initialize png_ptr struct for writing, and allocate any other memory.
2673	* (old interface - DEPRECATED - use png_create_write_struct instead).
2674	*/
2675	extern PNG_EXPORT(void,png_write_init) PNGARG((png_structp png_ptr));
2676	#undef png_write_init
2677	#define png_write_init(png_ptr) png_write_init_3(&png_ptr, \
2678	PNG_LIBPNG_VER_STRING, sizeof(png_struct));
2679	extern PNG_EXPORT(void,png_write_init_3) PNGARG((png_structpp ptr_ptr,
2680	png_const_charp user_png_ver, png_size_t png_struct_size));
2681	extern PNG_EXPORT(void,png_write_init_2) PNGARG((png_structp png_ptr,
2682	png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
2683	png_info_size));
2684
2685	/* Allocate memory for an internal libpng struct */
2686	PNG_EXTERN png_voidp png_create_struct PNGARG((int type));
2687
2688	/* Free memory from internal libpng struct */
2689	PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr));
2690
2691	PNG_EXTERN png_voidp png_create_struct_2 PNGARG((int type, png_malloc_ptr
2692	malloc_fn, png_voidp mem_ptr));
2693	PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr,
2694	png_free_ptr free_fn, png_voidp mem_ptr));
2695
2696	/* Free any memory that info_ptr points to and reset struct. */
2697	PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr,
2698	png_infop info_ptr));
2699
2700	#ifndef PNG_1_0_X
2701	/* Function to allocate memory for zlib. */
2702	PNG_EXTERN voidpf png_zalloc PNGARG((voidpf png_ptr, uInt items, uInt size));
2703
2704	/* Function to free memory for zlib */
2705	PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr));
2706
2707	/* Next four functions are used internally as callbacks. PNGAPI is required
2708	* but not PNG_EXPORT. PNGAPI added at libpng version 1.2.3. */
2709
2710	PNG_EXTERN void PNGAPI png_default_read_data PNGARG((png_structp png_ptr,
2711	png_bytep data, png_size_t length));
2712
2713	#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
2714	PNG_EXTERN void PNGAPI png_push_fill_buffer PNGARG((png_structp png_ptr,
2715	png_bytep buffer, png_size_t length));
2716	#endif
2717
2718	PNG_EXTERN void PNGAPI png_default_write_data PNGARG((png_structp png_ptr,
2719	png_bytep data, png_size_t length));
2720
2721	#if defined(PNG_WRITE_FLUSH_SUPPORTED)
2722	#if !defined(PNG_NO_STDIO)
2723	PNG_EXTERN void PNGAPI png_default_flush PNGARG((png_structp png_ptr));
2724	#endif
2725	#endif
2726	#else /* PNG_1_0_X */
2727	#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
2728	PNG_EXTERN void png_push_fill_buffer PNGARG((png_structp png_ptr,
2729	png_bytep buffer, png_size_t length));
2730	#endif
2731	#endif /* PNG_1_0_X */
2732
2733	/* Reset the CRC variable */
2734	PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr));
2735
2736	/* Write the "data" buffer to whatever output you are using. */
2737	PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr, png_bytep data,
2738	png_size_t length));
2739
2740	/* Read data from whatever input you are using into the "data" buffer */
2741	PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data,
2742	png_size_t length));
2743
2744	/* Read bytes into buf, and update png_ptr->crc */
2745	PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
2746	png_size_t length));
2747
2748	/* Decompress data in a chunk that uses compression */
2749	#if defined(PNG_zTXt_SUPPORTED) \|\| defined(PNG_iTXt_SUPPORTED) \|\| \
2750	defined(PNG_iCCP_SUPPORTED) \|\| defined(PNG_sPLT_SUPPORTED)
2751	PNG_EXTERN png_charp png_decompress_chunk PNGARG((png_structp png_ptr,
2752	int comp_type, png_charp chunkdata, png_size_t chunklength,
2753	png_size_t prefix_length, png_size_t *data_length));
2754	#endif
2755
2756	/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
2757	PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip));
2758
2759	/* Read the CRC from the file and compare it to the libpng calculated CRC */
2760	PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr));
2761
2762	/* Calculate the CRC over a section of data. Note that we are only
2763	* passing a maximum of 64K on systems that have this as a memory limit,
2764	* since this is the maximum buffer size we can specify.
2765	*/
2766	PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr, png_bytep ptr,
2767	png_size_t length));
2768
2769	#if defined(PNG_WRITE_FLUSH_SUPPORTED)
2770	PNG_EXTERN void png_flush PNGARG((png_structp png_ptr));
2771	#endif
2772
2773
2774	/* Place a 32-bit number into a buffer in PNG byte order (big-endian).
2775	* The only currently known PNG chunks that use signed numbers are
2776	* the ancillary extension chunks, oFFs and pCAL.
2777	*/
2778	PNG_EXTERN void png_save_uint_32 PNGARG((png_bytep buf, png_uint_32 i));
2779
2780	#if defined(PNG_WRITE_pCAL_SUPPORTED) \|\| defined(PNG_WRITE_oFFs_SUPPORTED)
2781	PNG_EXTERN void png_save_int_32 PNGARG((png_bytep buf, png_int_32 i));
2782	#endif
2783
2784	/* Place a 16-bit number into a buffer in PNG byte order.
2785	* The parameter is declared unsigned int, not png_uint_16,
2786	* just to avoid potential problems on pre-ANSI C compilers.
2787	*/
2788	PNG_EXTERN void png_save_uint_16 PNGARG((png_bytep buf, unsigned int i));
2789
2790	/* simple function to write the signature */
2791	PNG_EXTERN void png_write_sig PNGARG((png_structp png_ptr));
2792
2793	/* write various chunks */
2794
2795	/* Write the IHDR chunk, and update the png_struct with the necessary
2796	* information.
2797	*/
2798	PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width,
2799	png_uint_32 height,
2800	int bit_depth, int color_type, int compression_method, int filter_method,
2801	int interlace_method));
2802
2803	PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr, png_colorp palette,
2804	png_uint_32 num_pal));
2805
2806	PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data,
2807	png_size_t length));
2808
2809	PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr));
2810
2811	#if defined(PNG_WRITE_gAMA_SUPPORTED)
2812	#ifdef PNG_FLOATING_POINT_SUPPORTED
2813	PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma));
2814	#endif
2815	#ifdef PNG_FIXED_POINT_SUPPORTED
2816	PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr, png_fixed_point
2817	file_gamma));
2818	#endif
2819	#endif
2820
2821	#if defined(PNG_WRITE_sBIT_SUPPORTED)
2822	PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr, png_color_8p sbit,
2823	int color_type));
2824	#endif
2825
2826	#if defined(PNG_WRITE_cHRM_SUPPORTED)
2827	#ifdef PNG_FLOATING_POINT_SUPPORTED
2828	PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr,
2829	double white_x, double white_y,
2830	double red_x, double red_y, double green_x, double green_y,
2831	double blue_x, double blue_y));
2832	#endif
2833	#ifdef PNG_FIXED_POINT_SUPPORTED
2834	PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr,
2835	png_fixed_point int_white_x, png_fixed_point int_white_y,
2836	png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
2837	int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
2838	png_fixed_point int_blue_y));
2839	#endif
2840	#endif
2841
2842	#if defined(PNG_WRITE_sRGB_SUPPORTED)
2843	PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
2844	int intent));
2845	#endif
2846
2847	#if defined(PNG_WRITE_iCCP_SUPPORTED)
2848	PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr,
2849	png_charp name, int compression_type,
2850	png_charp profile, int proflen));
2851	/* Note to maintainer: profile should be png_bytep */
2852	#endif
2853
2854	#if defined(PNG_WRITE_sPLT_SUPPORTED)
2855	PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr,
2856	png_sPLT_tp palette));
2857	#endif
2858
2859	#if defined(PNG_WRITE_tRNS_SUPPORTED)
2860	PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr, png_bytep trans,
2861	png_color_16p values, int number, int color_type));
2862	#endif
2863
2864	#if defined(PNG_WRITE_bKGD_SUPPORTED)
2865	PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr,
2866	png_color_16p values, int color_type));
2867	#endif
2868
2869	#if defined(PNG_WRITE_hIST_SUPPORTED)
2870	PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, png_uint_16p hist,
2871	int num_hist));
2872	#endif
2873
2874	#if defined(PNG_WRITE_TEXT_SUPPORTED) \|\| defined(PNG_WRITE_pCAL_SUPPORTED) \|\| \
2875	defined(PNG_WRITE_iCCP_SUPPORTED) \|\| defined(PNG_WRITE_sPLT_SUPPORTED)
2876	PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
2877	png_charp key, png_charpp new_key));
2878	#endif
2879
2880	#if defined(PNG_WRITE_tEXt_SUPPORTED)
2881	PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_charp key,
2882	png_charp text, png_size_t text_len));
2883	#endif
2884
2885	#if defined(PNG_WRITE_zTXt_SUPPORTED)
2886	PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_charp key,
2887	png_charp text, png_size_t text_len, int compression));
2888	#endif
2889
2890	#if defined(PNG_WRITE_iTXt_SUPPORTED)
2891	PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr,
2892	int compression, png_charp key, png_charp lang, png_charp lang_key,
2893	png_charp text));
2894	#endif
2895
2896	#if defined(PNG_TEXT_SUPPORTED) /* Added at version 1.0.14 and 1.2.4 */
2897	PNG_EXTERN int png_set_text_2 PNGARG((png_structp png_ptr,
2898	png_infop info_ptr, png_textp text_ptr, int num_text));
2899	#endif
2900
2901	#if defined(PNG_WRITE_oFFs_SUPPORTED)
2902	PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr,
2903	png_int_32 x_offset, png_int_32 y_offset, int unit_type));
2904	#endif
2905
2906	#if defined(PNG_WRITE_pCAL_SUPPORTED)
2907	PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose,
2908	png_int_32 X0, png_int_32 X1, int type, int nparams,
2909	png_charp units, png_charpp params));
2910	#endif
2911
2912	#if defined(PNG_WRITE_pHYs_SUPPORTED)
2913	PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr,
2914	png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
2915	int unit_type));
2916	#endif
2917
2918	#if defined(PNG_WRITE_tIME_SUPPORTED)
2919	PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr,
2920	png_timep mod_time));
2921	#endif
2922
2923	#if defined(PNG_WRITE_sCAL_SUPPORTED)
2924	#if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
2925	PNG_EXTERN void png_write_sCAL PNGARG((png_structp png_ptr,
2926	int unit, double width, double height));
2927	#else
2928	#ifdef PNG_FIXED_POINT_SUPPORTED
2929	PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr,
2930	int unit, png_charp width, png_charp height));
2931	#endif
2932	#endif
2933	#endif
2934
2935	/* Called when finished processing a row of data */
2936	PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr));
2937
2938	/* Internal use only. Called before first row of data */
2939	PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr));
2940
2941	#if defined(PNG_READ_GAMMA_SUPPORTED)
2942	PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr));
2943	#endif
2944
2945	/* combine a row of data, dealing with alpha, etc. if requested */
2946	PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row,
2947	int mask));
2948
2949	#if defined(PNG_READ_INTERLACING_SUPPORTED)
2950	/* expand an interlaced row */
2951	/* OLD pre-1.0.9 interface:
2952	PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info,
2953	png_bytep row, int pass, png_uint_32 transformations));
2954	*/
2955	PNG_EXTERN void png_do_read_interlace PNGARG((png_structp png_ptr));
2956	#endif
2957
2958	/* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */
2959
2960	#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
2961	/* grab pixels out of a row for an interlaced pass */
2962	PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info,
2963	png_bytep row, int pass));
2964	#endif
2965
2966	/* unfilter a row */
2967	PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr,
2968	png_row_infop row_info, png_bytep row, png_bytep prev_row, int filter));
2969
2970	/* Choose the best filter to use and filter the row data */
2971	PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
2972	png_row_infop row_info));
2973
2974	/* Write out the filtered row. */
2975	PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr,
2976	png_bytep filtered_row));
2977	/* finish a row while reading, dealing with interlacing passes, etc. */
2978	PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
2979
2980	/* initialize the row buffers, etc. */
2981	PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr));
2982	/* optional call to update the users info structure */
2983	PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
2984	png_infop info_ptr));
2985
2986	/* these are the functions that do the transformations */
2987	#if defined(PNG_READ_FILLER_SUPPORTED)
2988	PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info,
2989	png_bytep row, png_uint_32 filler, png_uint_32 flags));
2990	#endif
2991
2992	#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
2993	PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info,
2994	png_bytep row));
2995	#endif
2996
2997	#if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
2998	PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info,
2999	png_bytep row));
3000	#endif
3001
3002	#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
3003	PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info,
3004	png_bytep row));
3005	#endif
3006
3007	#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
3008	PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info,
3009	png_bytep row));
3010	#endif
3011
3012	#if defined(PNG_WRITE_FILLER_SUPPORTED) \|\| \
3013	defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
3014	PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info,
3015	png_bytep row, png_uint_32 flags));
3016	#endif
3017
3018	#if defined(PNG_READ_SWAP_SUPPORTED) \|\| defined(PNG_WRITE_SWAP_SUPPORTED)
3019	PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info, png_bytep row));
3020	#endif
3021
3022	#if defined(PNG_READ_PACKSWAP_SUPPORTED) \|\| defined(PNG_WRITE_PACKSWAP_SUPPORTED)
3023	PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info, png_bytep row));
3024	#endif
3025
3026	#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
3027	PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr, png_row_infop
3028	row_info, png_bytep row));
3029	#endif
3030
3031	#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
3032	PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info,
3033	png_bytep row));
3034	#endif
3035
3036	#if defined(PNG_READ_PACK_SUPPORTED)
3037	PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info, png_bytep row));
3038	#endif
3039
3040	#if defined(PNG_READ_SHIFT_SUPPORTED)
3041	PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info, png_bytep row,
3042	png_color_8p sig_bits));
3043	#endif
3044
3045	#if defined(PNG_READ_INVERT_SUPPORTED) \|\| defined(PNG_WRITE_INVERT_SUPPORTED)
3046	PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info, png_bytep row));
3047	#endif
3048
3049	#if defined(PNG_READ_16_TO_8_SUPPORTED)
3050	PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info, png_bytep row));
3051	#endif
3052
3053	#if defined(PNG_READ_DITHER_SUPPORTED)
3054	PNG_EXTERN void png_do_dither PNGARG((png_row_infop row_info,
3055	png_bytep row, png_bytep palette_lookup, png_bytep dither_lookup));
3056
3057	# if defined(PNG_CORRECT_PALETTE_SUPPORTED)
3058	PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr,
3059	png_colorp palette, int num_palette));
3060	# endif
3061	#endif
3062
3063	#if defined(PNG_READ_BGR_SUPPORTED) \|\| defined(PNG_WRITE_BGR_SUPPORTED)
3064	PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info, png_bytep row));
3065	#endif
3066
3067	#if defined(PNG_WRITE_PACK_SUPPORTED)
3068	PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info,
3069	png_bytep row, png_uint_32 bit_depth));
3070	#endif
3071
3072	#if defined(PNG_WRITE_SHIFT_SUPPORTED)
3073	PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info, png_bytep row,
3074	png_color_8p bit_depth));
3075	#endif
3076
3077	#if defined(PNG_READ_BACKGROUND_SUPPORTED)
3078	#if defined(PNG_READ_GAMMA_SUPPORTED)
3079	PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
3080	png_color_16p trans_values, png_color_16p background,
3081	png_color_16p background_1,
3082	png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,
3083	png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,
3084	png_uint_16pp gamma_16_to_1, int gamma_shift));
3085	#else
3086	PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
3087	png_color_16p trans_values, png_color_16p background));
3088	#endif
3089	#endif
3090
3091	#if defined(PNG_READ_GAMMA_SUPPORTED)
3092	PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info, png_bytep row,
3093	png_bytep gamma_table, png_uint_16pp gamma_16_table,
3094	int gamma_shift));
3095	#endif
3096
3097	#if defined(PNG_READ_EXPAND_SUPPORTED)
3098	PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info,
3099	png_bytep row, png_colorp palette, png_bytep trans, int num_trans));
3100	PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info,
3101	png_bytep row, png_color_16p trans_value));
3102	#endif
3103
3104	/* The following decodes the appropriate chunks, and does error correction,
3105	* then calls the appropriate callback for the chunk if it is valid.
3106	*/
3107
3108	/* decode the IHDR chunk */
3109	PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr,
3110	png_uint_32 length));
3111	PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr,
3112	png_uint_32 length));
3113	PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr,
3114	png_uint_32 length));
3115
3116	#if defined(PNG_READ_bKGD_SUPPORTED)
3117	PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr,
3118	png_uint_32 length));
3119	#endif
3120
3121	#if defined(PNG_READ_cHRM_SUPPORTED)
3122	PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr,
3123	png_uint_32 length));
3124	#endif
3125
3126	#if defined(PNG_READ_gAMA_SUPPORTED)
3127	PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr,
3128	png_uint_32 length));
3129	#endif
3130
3131	#if defined(PNG_READ_hIST_SUPPORTED)
3132	PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr,
3133	png_uint_32 length));
3134	#endif
3135
3136	#if defined(PNG_READ_iCCP_SUPPORTED)
3137	extern void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr,
3138	png_uint_32 length));
3139	#endif /* PNG_READ_iCCP_SUPPORTED */
3140
3141	#if defined(PNG_READ_iTXt_SUPPORTED)
3142	PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3143	png_uint_32 length));
3144	#endif
3145
3146	#if defined(PNG_READ_oFFs_SUPPORTED)
3147	PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr,
3148	png_uint_32 length));
3149	#endif
3150
3151	#if defined(PNG_READ_pCAL_SUPPORTED)
3152	PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
3153	png_uint_32 length));
3154	#endif
3155
3156	#if defined(PNG_READ_pHYs_SUPPORTED)
3157	PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr,
3158	png_uint_32 length));
3159	#endif
3160
3161	#if defined(PNG_READ_sBIT_SUPPORTED)
3162	PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr,
3163	png_uint_32 length));
3164	#endif
3165
3166	#if defined(PNG_READ_sCAL_SUPPORTED)
3167	PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
3168	png_uint_32 length));
3169	#endif
3170
3171	#if defined(PNG_READ_sPLT_SUPPORTED)
3172	extern void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr,
3173	png_uint_32 length));
3174	#endif /* PNG_READ_sPLT_SUPPORTED */
3175
3176	#if defined(PNG_READ_sRGB_SUPPORTED)
3177	PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr,
3178	png_uint_32 length));
3179	#endif
3180
3181	#if defined(PNG_READ_tEXt_SUPPORTED)
3182	PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3183	png_uint_32 length));
3184	#endif
3185
3186	#if defined(PNG_READ_tIME_SUPPORTED)
3187	PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr,
3188	png_uint_32 length));
3189	#endif
3190
3191	#if defined(PNG_READ_tRNS_SUPPORTED)
3192	PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr,
3193	png_uint_32 length));
3194	#endif
3195
3196	#if defined(PNG_READ_zTXt_SUPPORTED)
3197	PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3198	png_uint_32 length));
3199	#endif
3200
3201	PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
3202	png_infop info_ptr, png_uint_32 length));
3203
3204	PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
3205	png_bytep chunk_name));
3206
3207	/* handle the transformations for reading and writing */
3208	PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr));
3209	PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr));
3210
3211	PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr));
3212
3213	#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3214	PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
3215	png_infop info_ptr));
3216	PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr,
3217	png_infop info_ptr));
3218	PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr));
3219	PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr,
3220	png_uint_32 length));
3221	PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr));
3222	PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr));
3223	PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr,
3224	png_bytep buffer, png_size_t buffer_length));
3225	PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr));
3226	PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr,
3227	png_bytep buffer, png_size_t buffer_length));
3228	PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr));
3229	PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr,
3230	png_infop info_ptr, png_uint_32 length));
3231	PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr,
3232	png_infop info_ptr));
3233	PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr,
3234	png_infop info_ptr));
3235	PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr, png_bytep row));
3236	PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr,
3237	png_infop info_ptr));
3238	PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr,
3239	png_infop info_ptr));
3240	PNG_EXTERN void png_read_push_finish_row PNGARG((png_structp png_ptr));
3241	#if defined(PNG_READ_tEXt_SUPPORTED)
3242	PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr,
3243	png_infop info_ptr, png_uint_32 length));
3244	PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr,
3245	png_infop info_ptr));
3246	#endif
3247	#if defined(PNG_READ_zTXt_SUPPORTED)
3248	PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr,
3249	png_infop info_ptr, png_uint_32 length));
3250	PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr,
3251	png_infop info_ptr));
3252	#endif
3253	#if defined(PNG_READ_iTXt_SUPPORTED)
3254	PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr,
3255	png_infop info_ptr, png_uint_32 length));
3256	PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr,
3257	png_infop info_ptr));
3258	#endif
3259
3260	#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
3261
3262	#ifdef PNG_MNG_FEATURES_SUPPORTED
3263	PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info,
3264	png_bytep row));
3265	PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info,
3266	png_bytep row));
3267	#endif
3268
3269	#if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
3270	/* png.c / / PRIVATE */
3271	PNG_EXTERN void png_init_mmx_flags PNGARG((png_structp png_ptr));
3272	#endif
3273	/* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
3274
3275	#endif /* PNG_INTERNAL */
3276
3277	#ifdef __cplusplus
3278	}
3279	#endif
3280
3281	#endif /* PNG_VERSION_INFO_ONLY */
3282	/* do not put anything past this line */
3283	#endif /* PNG_H */

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