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1 
2 /* png.h - header file for PNG reference library
3  *
4  * libpng version 1.2.19 - August 18, 2007
5  * Copyright (c) 1998-2007 Glenn Randers-Pehrson
6  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
7  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
8  *
9  * Authors and maintainers:
10  *  libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
11  *  libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
12  *  libpng versions 0.97, January 1998, through 1.2.19 - August 18, 2007: Glenn
13  *  See also "Contributing Authors", below.
14  *
15  * Note about libpng version numbers:
16  *
17  *    Due to various miscommunications, unforeseen code incompatibilities
18  *    and occasional factors outside the authors' control, version numbering
19  *    on the library has not always been consistent and straightforward.
20  *    The following table summarizes matters since version 0.89c, which was
21  *    the first widely used release:
22  *
23  *    source                 png.h  png.h  shared-lib
24  *    version                string   int  version
25  *    -------                ------ -----  ----------
26  *    0.89c "1.0 beta 3"     0.89      89  1.0.89
27  *    0.90  "1.0 beta 4"     0.90      90  0.90  [should have been 2.0.90]
28  *    0.95  "1.0 beta 5"     0.95      95  0.95  [should have been 2.0.95]
29  *    0.96  "1.0 beta 6"     0.96      96  0.96  [should have been 2.0.96]
30  *    0.97b "1.00.97 beta 7" 1.00.97   97  1.0.1 [should have been 2.0.97]
31  *    0.97c                  0.97      97  2.0.97
32  *    0.98                   0.98      98  2.0.98
33  *    0.99                   0.99      98  2.0.99
34  *    0.99a-m                0.99      99  2.0.99
35  *    1.00                   1.00     100  2.1.0 [100 should be 10000]
36  *    1.0.0      (from here on, the   100  2.1.0 [100 should be 10000]
37  *    1.0.1       png.h string is   10001  2.1.0
38  *    1.0.1a-e    identical to the  10002  from here on, the shared library
39  *    1.0.2       source version)   10002  is 2.V where V is the source code
40  *    1.0.2a-b                      10003  version, except as noted.
41  *    1.0.3                         10003
42  *    1.0.3a-d                      10004
43  *    1.0.4                         10004
44  *    1.0.4a-f                      10005
45  *    1.0.5 (+ 2 patches)           10005
46  *    1.0.5a-d                      10006
47  *    1.0.5e-r                      10100 (not source compatible)
48  *    1.0.5s-v                      10006 (not binary compatible)
49  *    1.0.6 (+ 3 patches)           10006 (still binary incompatible)
50  *    1.0.6d-f                      10007 (still binary incompatible)
51  *    1.0.6g                        10007
52  *    1.0.6h                        10007  10.6h (testing xy.z so-numbering)
53  *    1.0.6i                        10007  10.6i
54  *    1.0.6j                        10007  2.1.0.6j (incompatible with 1.0.0)
55  *    1.0.7beta11-14        DLLNUM  10007  2.1.0.7beta11-14 (binary compatible)
56  *    1.0.7beta15-18           1    10007  2.1.0.7beta15-18 (binary compatible)
57  *    1.0.7rc1-2               1    10007  2.1.0.7rc1-2 (binary compatible)
58  *    1.0.7                    1    10007  (still compatible)
59  *    1.0.8beta1-4             1    10008  2.1.0.8beta1-4
60  *    1.0.8rc1                 1    10008  2.1.0.8rc1
61  *    1.0.8                    1    10008  2.1.0.8
62  *    1.0.9beta1-6             1    10009  2.1.0.9beta1-6
63  *    1.0.9rc1                 1    10009  2.1.0.9rc1
64  *    1.0.9beta7-10            1    10009  2.1.0.9beta7-10
65  *    1.0.9rc2                 1    10009  2.1.0.9rc2
66  *    1.0.9                    1    10009  2.1.0.9
67  *    1.0.10beta1              1    10010  2.1.0.10beta1
68  *    1.0.10rc1                1    10010  2.1.0.10rc1
69  *    1.0.10                   1    10010  2.1.0.10
70  *    1.0.11beta1-3            1    10011  2.1.0.11beta1-3
71  *    1.0.11rc1                1    10011  2.1.0.11rc1
72  *    1.0.11                   1    10011  2.1.0.11
73  *    1.0.12beta1-2            2    10012  2.1.0.12beta1-2
74  *    1.0.12rc1                2    10012  2.1.0.12rc1
75  *    1.0.12                   2    10012  2.1.0.12
76  *    1.1.0a-f                 -    10100  2.1.1.0a-f (branch abandoned)
77  *    1.2.0beta1-2             2    10200  2.1.2.0beta1-2
78  *    1.2.0beta3-5             3    10200  3.1.2.0beta3-5
79  *    1.2.0rc1                 3    10200  3.1.2.0rc1
80  *    1.2.0                    3    10200  3.1.2.0
81  *    1.2.1beta1-4             3    10201  3.1.2.1beta1-4
82  *    1.2.1rc1-2               3    10201  3.1.2.1rc1-2
83  *    1.2.1                    3    10201  3.1.2.1
84  *    1.2.2beta1-6            12    10202  12.so.0.1.2.2beta1-6
85  *    1.0.13beta1             10    10013  10.so.0.1.0.13beta1
86  *    1.0.13rc1               10    10013  10.so.0.1.0.13rc1
87  *    1.2.2rc1                12    10202  12.so.0.1.2.2rc1
88  *    1.0.13                  10    10013  10.so.0.1.0.13
89  *    1.2.2                   12    10202  12.so.0.1.2.2
90  *    1.2.3rc1-6              12    10203  12.so.0.1.2.3rc1-6
91  *    1.2.3                   12    10203  12.so.0.1.2.3
92  *    1.2.4beta1-3            13    10204  12.so.0.1.2.4beta1-3
93  *    1.0.14rc1               13    10014  10.so.0.1.0.14rc1
94  *    1.2.4rc1                13    10204  12.so.0.1.2.4rc1
95  *    1.0.14                  10    10014  10.so.0.1.0.14
96  *    1.2.4                   13    10204  12.so.0.1.2.4
97  *    1.2.5beta1-2            13    10205  12.so.0.1.2.5beta1-2
98  *    1.0.15rc1-3             10    10015  10.so.0.1.0.15rc1-3
99  *    1.2.5rc1-3              13    10205  12.so.0.1.2.5rc1-3
100  *    1.0.15                  10    10015  10.so.0.1.0.15
101  *    1.2.5                   13    10205  12.so.0.1.2.5
102  *    1.2.6beta1-4            13    10206  12.so.0.1.2.6beta1-4
103  *    1.0.16                  10    10016  10.so.0.1.0.16
104  *    1.2.6                   13    10206  12.so.0.1.2.6
105  *    1.2.7beta1-2            13    10207  12.so.0.1.2.7beta1-2
106  *    1.0.17rc1               10    10017  10.so.0.1.0.17rc1
107  *    1.2.7rc1                13    10207  12.so.0.1.2.7rc1
108  *    1.0.17                  10    10017  10.so.0.1.0.17
109  *    1.2.7                   13    10207  12.so.0.1.2.7
110  *    1.2.8beta1-5            13    10208  12.so.0.1.2.8beta1-5
111  *    1.0.18rc1-5             10    10018  10.so.0.1.0.18rc1-5
112  *    1.2.8rc1-5              13    10208  12.so.0.1.2.8rc1-5
113  *    1.0.18                  10    10018  10.so.0.1.0.18
114  *    1.2.8                   13    10208  12.so.0.1.2.8
115  *    1.2.9beta1-3            13    10209  12.so.0.1.2.9beta1-3
116  *    1.2.9beta4-11           13    10209  12.so.0.9[.0]
117  *    1.2.9rc1                13    10209  12.so.0.9[.0]
118  *    1.2.9                   13    10209  12.so.0.9[.0]
119  *    1.2.10beta1-8           13    10210  12.so.0.10[.0]
120  *    1.2.10rc1-3             13    10210  12.so.0.10[.0]
121  *    1.2.10                  13    10210  12.so.0.10[.0]
122  *    1.2.11beta1-4           13    10211  12.so.0.11[.0]
123  *    1.0.19rc1-5             10    10019  10.so.0.19[.0]
124  *    1.2.11rc1-5             13    10211  12.so.0.11[.0]
125  *    1.0.19                  10    10019  10.so.0.19[.0]
126  *    1.2.11                  13    10211  12.so.0.11[.0]
127  *    1.0.20                  10    10020  10.so.0.20[.0]
128  *    1.2.12                  13    10212  12.so.0.12[.0]
129  *    1.2.13beta1             13    10213  12.so.0.13[.0]
130  *    1.0.21                  10    10021  10.so.0.21[.0]
131  *    1.2.13                  13    10213  12.so.0.13[.0]
132  *    1.2.14beta1-2           13    10214  12.so.0.14[.0]
133  *    1.0.22rc1               10    10022  10.so.0.22[.0]
134  *    1.2.14rc1               13    10214  12.so.0.14[.0]
135  *    1.0.22                  10    10022  10.so.0.22[.0]
136  *    1.2.14                  13    10214  12.so.0.14[.0]
137  *    1.2.15beta1-6           13    10215  12.so.0.15[.0]
138  *    1.0.23rc1-5             10    10023  10.so.0.23[.0]
139  *    1.2.15rc1-5             13    10215  12.so.0.15[.0]
140  *    1.0.23                  10    10023  10.so.0.23[.0]
141  *    1.2.15                  13    10215  12.so.0.15[.0]
142  *    1.2.16beta1-2           13    10216  12.so.0.16[.0]
143  *    1.2.16rc1               13    10216  12.so.0.16[.0]
144  *    1.0.24                  10    10024  10.so.0.24[.0]
145  *    1.2.16                  13    10216  12.so.0.16[.0]
146  *    1.2.17beta1-2           13    10217  12.so.0.17[.0]
147  *    1.0.25rc1               10    10025  10.so.0.25[.0]
148  *    1.2.17rc1-3             13    10217  12.so.0.17[.0]
149  *    1.0.25                  10    10025  10.so.0.25[.0]
150  *    1.2.17                  13    10217  12.so.0.17[.0]
151  *    1.0.26                  10    10026  10.so.0.26[.0]
152  *    1.2.18                  13    10218  12.so.0.18[.0]
153  *    1.2.19beta1-31          13    10219  12.so.0.19[.0]
154  *    1.0.27rc1-6             10    10027  10.so.0.27[.0]
155  *    1.2.19rc1-6             13    10219  12.so.0.19[.0]
156  *    1.0.27                  10    10027  10.so.0.27[.0]
157  *    1.2.19                  13    10219  12.so.0.19[.0]
158  *
159  *    Henceforth the source version will match the shared-library major
160  *    and minor numbers; the shared-library major version number will be
161  *    used for changes in backward compatibility, as it is intended.  The
162  *    PNG_LIBPNG_VER macro, which is not used within libpng but is available
163  *    for applications, is an unsigned integer of the form xyyzz corresponding
164  *    to the source version x.y.z (leading zeros in y and z).  Beta versions
165  *    were given the previous public release number plus a letter, until
166  *    version 1.0.6j; from then on they were given the upcoming public
167  *    release number plus "betaNN" or "rcN".
168  *
169  *    Binary incompatibility exists only when applications make direct access
170  *    to the info_ptr or png_ptr members through png.h, and the compiled
171  *    application is loaded with a different version of the library.
172  *
173  *    DLLNUM will change each time there are forward or backward changes
174  *    in binary compatibility (e.g., when a new feature is added).
175  *
176  * See libpng.txt or libpng.3 for more information.  The PNG specification
177  * is available as a W3C Recommendation and as an ISO Specification,
178  * <http://www.w3.org/TR/2003/REC-PNG-20031110/
179  */
180 
181 /*
182  * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
183  *
184  * If you modify libpng you may insert additional notices immediately following
185  * this sentence.
186  *
187  * libpng versions 1.2.6, August 15, 2004, through 1.2.19, August 18, 2007, are
188  * Copyright (c) 2004, 2006-2007 Glenn Randers-Pehrson, and are
189  * distributed according to the same disclaimer and license as libpng-1.2.5
190  * with the following individual added to the list of Contributing Authors:
191  *
192  *    Cosmin Truta
193  *
194  * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
195  * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
196  * distributed according to the same disclaimer and license as libpng-1.0.6
197  * with the following individuals added to the list of Contributing Authors:
198  *
199  *    Simon-Pierre Cadieux
200  *    Eric S. Raymond
201  *    Gilles Vollant
202  *
203  * and with the following additions to the disclaimer:
204  *
205  *    There is no warranty against interference with your enjoyment of the
206  *    library or against infringement.  There is no warranty that our
207  *    efforts or the library will fulfill any of your particular purposes
208  *    or needs.  This library is provided with all faults, and the entire
209  *    risk of satisfactory quality, performance, accuracy, and effort is with
210  *    the user.
211  *
212  * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
213  * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are
214  * distributed according to the same disclaimer and license as libpng-0.96,
215  * with the following individuals added to the list of Contributing Authors:
216  *
217  *    Tom Lane
218  *    Glenn Randers-Pehrson
219  *    Willem van Schaik
220  *
221  * libpng versions 0.89, June 1996, through 0.96, May 1997, are
222  * Copyright (c) 1996, 1997 Andreas Dilger
223  * Distributed according to the same disclaimer and license as libpng-0.88,
224  * with the following individuals added to the list of Contributing Authors:
225  *
226  *    John Bowler
227  *    Kevin Bracey
228  *    Sam Bushell
229  *    Magnus Holmgren
230  *    Greg Roelofs
231  *    Tom Tanner
232  *
233  * libpng versions 0.5, May 1995, through 0.88, January 1996, are
234  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
235  *
236  * For the purposes of this copyright and license, "Contributing Authors"
237  * is defined as the following set of individuals:
238  *
239  *    Andreas Dilger
240  *    Dave Martindale
241  *    Guy Eric Schalnat
242  *    Paul Schmidt
243  *    Tim Wegner
244  *
245  * The PNG Reference Library is supplied "AS IS".  The Contributing Authors
246  * and Group 42, Inc. disclaim all warranties, expressed or implied,
247  * including, without limitation, the warranties of merchantability and of
248  * fitness for any purpose.  The Contributing Authors and Group 42, Inc.
249  * assume no liability for direct, indirect, incidental, special, exemplary,
250  * or consequential damages, which may result from the use of the PNG
251  * Reference Library, even if advised of the possibility of such damage.
252  *
253  * Permission is hereby granted to use, copy, modify, and distribute this
254  * source code, or portions hereof, for any purpose, without fee, subject
255  * to the following restrictions:
256  *
257  * 1. The origin of this source code must not be misrepresented.
258  *
259  * 2. Altered versions must be plainly marked as such and
260  * must not be misrepresented as being the original source.
261  *
262  * 3. This Copyright notice may not be removed or altered from
263  *    any source or altered source distribution.
264  *
265  * The Contributing Authors and Group 42, Inc. specifically permit, without
266  * fee, and encourage the use of this source code as a component to
267  * supporting the PNG file format in commercial products.  If you use this
268  * source code in a product, acknowledgment is not required but would be
269  * appreciated.
270  */
271 
272 /*
273  * A "png_get_copyright" function is available, for convenient use in "about"
274  * boxes and the like:
275  *
276  * printf("%s",png_get_copyright(NULL));
277  *
278  * Also, the PNG logo (in PNG format, of course) is supplied in the
279  * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
280  */
281 
282 /*
283  * Libpng is OSI Certified Open Source Software.  OSI Certified is a
284  * certification mark of the Open Source Initiative.
285  */
286 
287 /*
288  * The contributing authors would like to thank all those who helped
289  * with testing, bug fixes, and patience.  This wouldn't have been
290  * possible without all of you.
291  *
292  * Thanks to Frank J. T. Wojcik for helping with the documentation.
293  */
294 
295 /*
296  * Y2K compliance in libpng:
297  * =========================
298  *
299  *    August 18, 2007
300  *
301  *    Since the PNG Development group is an ad-hoc body, we can't make
302  *    an official declaration.
303  *
304  *    This is your unofficial assurance that libpng from version 0.71 and
305  *    upward through 1.2.19 are Y2K compliant.  It is my belief that earlier
306  *    versions were also Y2K compliant.
307  *
308  *    Libpng only has three year fields.  One is a 2-byte unsigned integer
309  *    that will hold years up to 65535.  The other two hold the date in text
310  *    format, and will hold years up to 9999.
311  *
312  *    The integer is
313  *        "png_uint_16 year" in png_time_struct.
314  *
315  *    The strings are
316  *        "png_charp time_buffer" in png_struct and
317  *        "near_time_buffer", which is a local character string in png.c.
318  *
319  *    There are seven time-related functions:
320  *        png.c: png_convert_to_rfc_1123() in png.c
321  *          (formerly png_convert_to_rfc_1152() in error)
322  *        png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
323  *        png_convert_from_time_t() in pngwrite.c
324  *        png_get_tIME() in pngget.c
325  *        png_handle_tIME() in pngrutil.c, called in pngread.c
326  *        png_set_tIME() in pngset.c
327  *        png_write_tIME() in pngwutil.c, called in pngwrite.c
328  *
329  *    All handle dates properly in a Y2K environment.  The
330  *    png_convert_from_time_t() function calls gmtime() to convert from system
331  *    clock time, which returns (year - 1900), which we properly convert to
332  *    the full 4-digit year.  There is a possibility that applications using
333  *    libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
334  *    function, or that they are incorrectly passing only a 2-digit year
335  *    instead of "year - 1900" into the png_convert_from_struct_tm() function,
336  *    but this is not under our control.  The libpng documentation has always
337  *    stated that it works with 4-digit years, and the APIs have been
338  *    documented as such.
339  *
340  *    The tIME chunk itself is also Y2K compliant.  It uses a 2-byte unsigned
341  *    integer to hold the year, and can hold years as large as 65535.
342  *
343  *    zlib, upon which libpng depends, is also Y2K compliant.  It contains
344  *    no date-related code.
345  *
346  *       Glenn Randers-Pehrson
347  *       libpng maintainer
348  *       PNG Development Group
349  */
350 
351 #ifndef PNG_H
352 #define PNG_H
353 
354 /* This is not the place to learn how to use libpng.  The file libpng.txt
355  * describes how to use libpng, and the file example.c summarizes it
356  * with some code on which to build.  This file is useful for looking
357  * at the actual function definitions and structure components.
358  */
359 
360 /* Version information for png.h - this should match the version in png.c */
361 #define PNG_LIBPNG_VER_STRING "1.2.19"
362 #define PNG_HEADER_VERSION_STRING \
363    " libpng version 1.2.19 - August 18, 2007\n"
364 
365 #define PNG_LIBPNG_VER_SONUM   0
366 #define PNG_LIBPNG_VER_DLLNUM  13
367 
368 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
369 #define PNG_LIBPNG_VER_MAJOR   1
370 #define PNG_LIBPNG_VER_MINOR   2
371 #define PNG_LIBPNG_VER_RELEASE 19
372 /* This should match the numeric part of the final component of
373  * PNG_LIBPNG_VER_STRING, omitting any leading zero: */
374 
375 #define PNG_LIBPNG_VER_BUILD  0
376 
377 /* Release Status */
378 #define PNG_LIBPNG_BUILD_ALPHA    1
379 #define PNG_LIBPNG_BUILD_BETA     2
380 #define PNG_LIBPNG_BUILD_RC       3
381 #define PNG_LIBPNG_BUILD_STABLE   4
382 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
383 
384 /* Release-Specific Flags */
385 #define PNG_LIBPNG_BUILD_PATCH    8 /* Can be OR'ed with
386                                        PNG_LIBPNG_BUILD_STABLE only */
387 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
388                                        PNG_LIBPNG_BUILD_SPECIAL */
389 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
390                                        PNG_LIBPNG_BUILD_PRIVATE */
391 
392 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
393 
394 /* Careful here.  At one time, Guy wanted to use 082, but that would be octal.
395  * We must not include leading zeros.
396  * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
397  * version 1.0.0 was mis-numbered 100 instead of 10000).  From
398  * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=release */
399 #define PNG_LIBPNG_VER 10219 /* 1.2.19 */
400 
401 #ifndef PNG_VERSION_INFO_ONLY
402 /* include the compression library's header */
403 #include "zlib.h"
404 #endif
405 
406 /* include all user configurable info, including optional assembler routines */
407 #include "pngconf.h"
408 
409 /*
410  * Added at libpng-1.2.8 */
411 /* Ref MSDN: Private as priority over Special
412  * VS_FF_PRIVATEBUILD File *was not* built using standard release
413  * procedures. If this value is given, the StringFileInfo block must
414  * contain a PrivateBuild string.
415  *
416  * VS_FF_SPECIALBUILD File *was* built by the original company using
417  * standard release procedures but is a variation of the standard
418  * file of the same version number. If this value is given, the
419  * StringFileInfo block must contain a SpecialBuild string.
420  */
421 
422 #if defined(PNG_USER_PRIVATEBUILD)
423 #  define PNG_LIBPNG_BUILD_TYPE \
424           (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
425 #else
426 #  if defined(PNG_LIBPNG_SPECIALBUILD)
427 #    define PNG_LIBPNG_BUILD_TYPE \
428             (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
429 #  else
430 #    define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
431 #  endif
432 #endif
433 
434 #ifndef PNG_VERSION_INFO_ONLY
435 
436 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
437 #ifdef __cplusplus
438 extern "C" {
439 #endif /* __cplusplus */
440 
441 /* This file is arranged in several sections.  The first section contains
442  * structure and type definitions.  The second section contains the external
443  * library functions, while the third has the internal library functions,
444  * which applications aren't expected to use directly.
445  */
446 
447 #ifndef PNG_NO_TYPECAST_NULL
448 #define int_p_NULL                (int *)NULL
449 #define png_bytep_NULL            (png_bytep)NULL
450 #define png_bytepp_NULL           (png_bytepp)NULL
451 #define png_doublep_NULL          (png_doublep)NULL
452 #define png_error_ptr_NULL        (png_error_ptr)NULL
453 #define png_flush_ptr_NULL        (png_flush_ptr)NULL
454 #define png_free_ptr_NULL         (png_free_ptr)NULL
455 #define png_infopp_NULL           (png_infopp)NULL
456 #define png_malloc_ptr_NULL       (png_malloc_ptr)NULL
457 #define png_read_status_ptr_NULL  (png_read_status_ptr)NULL
458 #define png_rw_ptr_NULL           (png_rw_ptr)NULL
459 #define png_structp_NULL          (png_structp)NULL
460 #define png_uint_16p_NULL         (png_uint_16p)NULL
461 #define png_voidp_NULL            (png_voidp)NULL
462 #define png_write_status_ptr_NULL (png_write_status_ptr)NULL
463 #else
464 #define int_p_NULL                NULL
465 #define png_bytep_NULL            NULL
466 #define png_bytepp_NULL           NULL
467 #define png_doublep_NULL          NULL
468 #define png_error_ptr_NULL        NULL
469 #define png_flush_ptr_NULL        NULL
470 #define png_free_ptr_NULL         NULL
471 #define png_infopp_NULL           NULL
472 #define png_malloc_ptr_NULL       NULL
473 #define png_read_status_ptr_NULL  NULL
474 #define png_rw_ptr_NULL           NULL
475 #define png_structp_NULL          NULL
476 #define png_uint_16p_NULL         NULL
477 #define png_voidp_NULL            NULL
478 #define png_write_status_ptr_NULL NULL
479 #endif
480 
481 /* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
482 #if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
483 /* Version information for C files, stored in png.c.  This had better match
484  * the version above.
485  */
486 #ifdef PNG_USE_GLOBAL_ARRAYS
487 PNG_EXPORT_VAR (PNG_CONST char) png_libpng_ver[18];
488   /* need room for 99.99.99beta99z */
489 #else
490 #define png_libpng_ver png_get_header_ver(NULL)
491 #endif
492 
493 #ifdef PNG_USE_GLOBAL_ARRAYS
494 /* This was removed in version 1.0.5c */
495 /* Structures to facilitate easy interlacing.  See png.c for more details */
496 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_start[7];
497 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_inc[7];
498 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_ystart[7];
499 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_yinc[7];
500 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_mask[7];
501 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_dsp_mask[7];
502 #if defined(PNG_HAVE_MMX_COMBINE_ROW) || defined(PNG_OPTIMIZED_CODE_SUPPORTED)
503 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_width[7];
504 #endif
505 /* This isn't currently used.  If you need it, see png.c for more details.
506 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_height[7];
507 */
508 #endif
509 
510 #endif /* PNG_NO_EXTERN */
511 
512 /* Three color definitions.  The order of the red, green, and blue, (and the
513  * exact size) is not important, although the size of the fields need to
514  * be png_byte or png_uint_16 (as defined below).
515  */
516 typedef struct png_color_struct
517 {
518    png_byte red;
519    png_byte green;
520    png_byte blue;
521 } png_color;
522 typedef png_color FAR * png_colorp;
523 typedef png_color FAR * FAR * png_colorpp;
524 
525 typedef struct png_color_16_struct
526 {
527    png_byte index;    /* used for palette files */
528    png_uint_16 red;   /* for use in red green blue files */
529    png_uint_16 green;
530    png_uint_16 blue;
531    png_uint_16 gray;  /* for use in grayscale files */
532 } png_color_16;
533 typedef png_color_16 FAR * png_color_16p;
534 typedef png_color_16 FAR * FAR * png_color_16pp;
535 
536 typedef struct png_color_8_struct
537 {
538    png_byte red;   /* for use in red green blue files */
539    png_byte green;
540    png_byte blue;
541    png_byte gray;  /* for use in grayscale files */
542    png_byte alpha; /* for alpha channel files */
543 } png_color_8;
544 typedef png_color_8 FAR * png_color_8p;
545 typedef png_color_8 FAR * FAR * png_color_8pp;
546 
547 /*
548  * The following two structures are used for the in-core representation
549  * of sPLT chunks.
550  */
551 typedef struct png_sPLT_entry_struct
552 {
553    png_uint_16 red;
554    png_uint_16 green;
555    png_uint_16 blue;
556    png_uint_16 alpha;
557    png_uint_16 frequency;
558 } png_sPLT_entry;
559 typedef png_sPLT_entry FAR * png_sPLT_entryp;
560 typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;
561 
562 /*  When the depth of the sPLT palette is 8 bits, the color and alpha samples
563  *  occupy the LSB of their respective members, and the MSB of each member
564  *  is zero-filled.  The frequency member always occupies the full 16 bits.
565  */
566 
567 typedef struct png_sPLT_struct
568 {
569    png_charp name;           /* palette name */
570    png_byte depth;           /* depth of palette samples */
571    png_sPLT_entryp entries;  /* palette entries */
572    png_int_32 nentries;      /* number of palette entries */
573 } png_sPLT_t;
574 typedef png_sPLT_t FAR * png_sPLT_tp;
575 typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
576 
577 #ifdef PNG_TEXT_SUPPORTED
578 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
579  * and whether that contents is compressed or not.  The "key" field
580  * points to a regular zero-terminated C string.  The "text", "lang", and
581  * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
582  * However, the * structure returned by png_get_text() will always contain
583  * regular zero-terminated C strings (possibly empty), never NULL pointers,
584  * so they can be safely used in printf() and other string-handling functions.
585  */
586 typedef struct png_text_struct
587 {
588    int  compression;       /* compression value:
589                              -1: tEXt, none
590                               0: zTXt, deflate
591                               1: iTXt, none
592                               2: iTXt, deflate  */
593    png_charp key;          /* keyword, 1-79 character description of "text" */
594    png_charp text;         /* comment, may be an empty string (ie "")
595                               or a NULL pointer */
596    png_size_t text_length; /* length of the text string */
597 #ifdef PNG_iTXt_SUPPORTED
598    png_size_t itxt_length; /* length of the itxt string */
599    png_charp lang;         /* language code, 0-79 characters
600                               or a NULL pointer */
601    png_charp lang_key;     /* keyword translated UTF-8 string, 0 or more
602                               chars or a NULL pointer */
603 #endif
604 } png_text;
605 typedef png_text FAR * png_textp;
606 typedef png_text FAR * FAR * png_textpp;
607 #endif
608 
609 /* Supported compression types for text in PNG files (tEXt, and zTXt).
610  * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
611 #define PNG_TEXT_COMPRESSION_NONE_WR -3
612 #define PNG_TEXT_COMPRESSION_zTXt_WR -2
613 #define PNG_TEXT_COMPRESSION_NONE    -1
614 #define PNG_TEXT_COMPRESSION_zTXt     0
615 #define PNG_ITXT_COMPRESSION_NONE     1
616 #define PNG_ITXT_COMPRESSION_zTXt     2
617 #define PNG_TEXT_COMPRESSION_LAST     3  /* Not a valid value */
618 
619 /* png_time is a way to hold the time in an machine independent way.
620  * Two conversions are provided, both from time_t and struct tm.  There
621  * is no portable way to convert to either of these structures, as far
622  * as I know.  If you know of a portable way, send it to me.  As a side
623  * note - PNG has always been Year 2000 compliant!
624  */
625 typedef struct png_time_struct
626 {
627    png_uint_16 year; /* full year, as in, 1995 */
628    png_byte month;   /* month of year, 1 - 12 */
629    png_byte day;     /* day of month, 1 - 31 */
630    png_byte hour;    /* hour of day, 0 - 23 */
631    png_byte minute;  /* minute of hour, 0 - 59 */
632    png_byte second;  /* second of minute, 0 - 60 (for leap seconds) */
633 } png_time;
634 typedef png_time FAR * png_timep;
635 typedef png_time FAR * FAR * png_timepp;
636 
637 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
638 /* png_unknown_chunk is a structure to hold queued chunks for which there is
639  * no specific support.  The idea is that we can use this to queue
640  * up private chunks for output even though the library doesn't actually
641  * know about their semantics.
642  */
643 typedef struct png_unknown_chunk_t
644 {
645     png_byte name[5];
646     png_byte *data;
647     png_size_t size;
648 
649     /* libpng-using applications should NOT directly modify this byte. */
650     png_byte location; /* mode of operation at read time */
651 }
652 png_unknown_chunk;
653 typedef png_unknown_chunk FAR * png_unknown_chunkp;
654 typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
655 #endif
656 
657 /* png_info is a structure that holds the information in a PNG file so
658  * that the application can find out the characteristics of the image.
659  * If you are reading the file, this structure will tell you what is
660  * in the PNG file.  If you are writing the file, fill in the information
661  * you want to put into the PNG file, then call png_write_info().
662  * The names chosen should be very close to the PNG specification, so
663  * consult that document for information about the meaning of each field.
664  *
665  * With libpng < 0.95, it was only possible to directly set and read the
666  * the values in the png_info_struct, which meant that the contents and
667  * order of the values had to remain fixed.  With libpng 0.95 and later,
668  * however, there are now functions that abstract the contents of
669  * png_info_struct from the application, so this makes it easier to use
670  * libpng with dynamic libraries, and even makes it possible to use
671  * libraries that don't have all of the libpng ancillary chunk-handing
672  * functionality.
673  *
674  * In any case, the order of the parameters in png_info_struct should NOT
675  * be changed for as long as possible to keep compatibility with applications
676  * that use the old direct-access method with png_info_struct.
677  *
678  * The following members may have allocated storage attached that should be
679  * cleaned up before the structure is discarded: palette, trans, text,
680  * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
681  * splt_palettes, scal_unit, row_pointers, and unknowns.   By default, these
682  * are automatically freed when the info structure is deallocated, if they were
683  * allocated internally by libpng.  This behavior can be changed by means
684  * of the png_data_freer() function.
685  *
686  * More allocation details: all the chunk-reading functions that
687  * change these members go through the corresponding png_set_*
688  * functions.  A function to clear these members is available: see
689  * png_free_data().  The png_set_* functions do not depend on being
690  * able to point info structure members to any of the storage they are
691  * passed (they make their own copies), EXCEPT that the png_set_text
692  * functions use the same storage passed to them in the text_ptr or
693  * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
694  * functions do not make their own copies.
695  */
696 typedef struct png_info_struct
697 {
698    /* the following are necessary for every PNG file */
699    png_uint_32 width;       /* width of image in pixels (from IHDR) */
700    png_uint_32 height;      /* height of image in pixels (from IHDR) */
701    png_uint_32 valid;       /* valid chunk data (see PNG_INFO_ below) */
702    png_uint_32 rowbytes;    /* bytes needed to hold an untransformed row */
703    png_colorp palette;      /* array of color values (valid & PNG_INFO_PLTE) */
704    png_uint_16 num_palette; /* number of color entries in "palette" (PLTE) */
705    png_uint_16 num_trans;   /* number of transparent palette color (tRNS) */
706    png_byte bit_depth;      /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */
707    png_byte color_type;     /* see PNG_COLOR_TYPE_ below (from IHDR) */
708    /* The following three should have been named *_method not *_type */
709    png_byte compression_type; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */
710    png_byte filter_type;    /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
711    png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
712 
713    /* The following is informational only on read, and not used on writes. */
714    png_byte channels;       /* number of data channels per pixel (1, 2, 3, 4) */
715    png_byte pixel_depth;    /* number of bits per pixel */
716    png_byte spare_byte;     /* to align the data, and for future use */
717    png_byte signature[8];   /* magic bytes read by libpng from start of file */
718 
719    /* The rest of the data is optional.  If you are reading, check the
720     * valid field to see if the information in these are valid.  If you
721     * are writing, set the valid field to those chunks you want written,
722     * and initialize the appropriate fields below.
723     */
724 
725 #if defined(PNG_gAMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
726    /* The gAMA chunk describes the gamma characteristics of the system
727     * on which the image was created, normally in the range [1.0, 2.5].
728     * Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
729     */
730    float gamma; /* gamma value of image, if (valid & PNG_INFO_gAMA) */
731 #endif
732 
733 #if defined(PNG_sRGB_SUPPORTED)
734     /* GR-P, 0.96a */
735     /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
736    png_byte srgb_intent; /* sRGB rendering intent [0, 1, 2, or 3] */
737 #endif
738 
739 #if defined(PNG_TEXT_SUPPORTED)
740    /* The tEXt, and zTXt chunks contain human-readable textual data in
741     * uncompressed, compressed, and optionally compressed forms, respectively.
742     * The data in "text" is an array of pointers to uncompressed,
743     * null-terminated C strings. Each chunk has a keyword that describes the
744     * textual data contained in that chunk.  Keywords are not required to be
745     * unique, and the text string may be empty.  Any number of text chunks may
746     * be in an image.
747     */
748    int num_text; /* number of comments read/to write */
749    int max_text; /* current size of text array */
750    png_textp text; /* array of comments read/to write */
751 #endif /* PNG_TEXT_SUPPORTED */
752 
753 #if defined(PNG_tIME_SUPPORTED)
754    /* The tIME chunk holds the last time the displayed image data was
755     * modified.  See the png_time struct for the contents of this struct.
756     */
757    png_time mod_time;
758 #endif
759 
760 #if defined(PNG_sBIT_SUPPORTED)
761    /* The sBIT chunk specifies the number of significant high-order bits
762     * in the pixel data.  Values are in the range [1, bit_depth], and are
763     * only specified for the channels in the pixel data.  The contents of
764     * the low-order bits is not specified.  Data is valid if
765     * (valid & PNG_INFO_sBIT) is non-zero.
766     */
767    png_color_8 sig_bit; /* significant bits in color channels */
768 #endif
769 
770 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
771 defined(PNG_READ_BACKGROUND_SUPPORTED)
772    /* The tRNS chunk supplies transparency data for paletted images and
773     * other image types that don't need a full alpha channel.  There are
774     * "num_trans" transparency values for a paletted image, stored in the
775     * same order as the palette colors, starting from index 0.  Values
776     * for the data are in the range [0, 255], ranging from fully transparent
777     * to fully opaque, respectively.  For non-paletted images, there is a
778     * single color specified that should be treated as fully transparent.
779     * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
780     */
781    png_bytep trans; /* transparent values for paletted image */
782    png_color_16 trans_values; /* transparent color for non-palette image */
783 #endif
784 
785 #if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
786    /* The bKGD chunk gives the suggested image background color if the
787     * display program does not have its own background color and the image
788     * is needs to composited onto a background before display.  The colors
789     * in "background" are normally in the same color space/depth as the
790     * pixel data.  Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
791     */
792    png_color_16 background;
793 #endif
794 
795 #if defined(PNG_oFFs_SUPPORTED)
796    /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
797     * and downwards from the top-left corner of the display, page, or other
798     * application-specific co-ordinate space.  See the PNG_OFFSET_ defines
799     * below for the unit types.  Valid if (valid & PNG_INFO_oFFs) non-zero.
800     */
801    png_int_32 x_offset; /* x offset on page */
802    png_int_32 y_offset; /* y offset on page */
803    png_byte offset_unit_type; /* offset units type */
804 #endif
805 
806 #if defined(PNG_pHYs_SUPPORTED)
807    /* The pHYs chunk gives the physical pixel density of the image for
808     * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
809     * defines below).  Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
810     */
811    png_uint_32 x_pixels_per_unit; /* horizontal pixel density */
812    png_uint_32 y_pixels_per_unit; /* vertical pixel density */
813    png_byte phys_unit_type; /* resolution type (see PNG_RESOLUTION_ below) */
814 #endif
815 
816 #if defined(PNG_hIST_SUPPORTED)
817    /* The hIST chunk contains the relative frequency or importance of the
818     * various palette entries, so that a viewer can intelligently select a
819     * reduced-color palette, if required.  Data is an array of "num_palette"
820     * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
821     * is non-zero.
822     */
823    png_uint_16p hist;
824 #endif
825 
826 #ifdef PNG_cHRM_SUPPORTED
827    /* The cHRM chunk describes the CIE color characteristics of the monitor
828     * on which the PNG was created.  This data allows the viewer to do gamut
829     * mapping of the input image to ensure that the viewer sees the same
830     * colors in the image as the creator.  Values are in the range
831     * [0.0, 0.8].  Data valid if (valid & PNG_INFO_cHRM) non-zero.
832     */
833 #ifdef PNG_FLOATING_POINT_SUPPORTED
834    float x_white;
835    float y_white;
836    float x_red;
837    float y_red;
838    float x_green;
839    float y_green;
840    float x_blue;
841    float y_blue;
842 #endif
843 #endif
844 
845 #if defined(PNG_pCAL_SUPPORTED)
846    /* The pCAL chunk describes a transformation between the stored pixel
847     * values and original physical data values used to create the image.
848     * The integer range [0, 2^bit_depth - 1] maps to the floating-point
849     * range given by [pcal_X0, pcal_X1], and are further transformed by a
850     * (possibly non-linear) transformation function given by "pcal_type"
851     * and "pcal_params" into "pcal_units".  Please see the PNG_EQUATION_
852     * defines below, and the PNG-Group's PNG extensions document for a
853     * complete description of the transformations and how they should be
854     * implemented, and for a description of the ASCII parameter strings.
855     * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
856     */
857    png_charp pcal_purpose;  /* pCAL chunk description string */
858    png_int_32 pcal_X0;      /* minimum value */
859    png_int_32 pcal_X1;      /* maximum value */
860    png_charp pcal_units;    /* Latin-1 string giving physical units */
861    png_charpp pcal_params;  /* ASCII strings containing parameter values */
862    png_byte pcal_type;      /* equation type (see PNG_EQUATION_ below) */
863    png_byte pcal_nparams;   /* number of parameters given in pcal_params */
864 #endif
865 
866 /* New members added in libpng-1.0.6 */
867 #ifdef PNG_FREE_ME_SUPPORTED
868    png_uint_32 free_me;     /* flags items libpng is responsible for freeing */
869 #endif
870 
871 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
872    /* storage for unknown chunks that the library doesn't recognize. */
873    png_unknown_chunkp unknown_chunks;
874    png_size_t unknown_chunks_num;
875 #endif
876 
877 #if defined(PNG_iCCP_SUPPORTED)
878    /* iCCP chunk data. */
879    png_charp iccp_name;     /* profile name */
880    png_charp iccp_profile;  /* International Color Consortium profile data */
881                             /* Note to maintainer: should be png_bytep */
882    png_uint_32 iccp_proflen;  /* ICC profile data length */
883    png_byte iccp_compression; /* Always zero */
884 #endif
885 
886 #if defined(PNG_sPLT_SUPPORTED)
887    /* data on sPLT chunks (there may be more than one). */
888    png_sPLT_tp splt_palettes;
889    png_uint_32 splt_palettes_num;
890 #endif
891 
892 #if defined(PNG_sCAL_SUPPORTED)
893    /* The sCAL chunk describes the actual physical dimensions of the
894     * subject matter of the graphic.  The chunk contains a unit specification
895     * a byte value, and two ASCII strings representing floating-point
896     * values.  The values are width and height corresponsing to one pixel
897     * in the image.  This external representation is converted to double
898     * here.  Data values are valid if (valid & PNG_INFO_sCAL) is non-zero.
899     */
900    png_byte scal_unit;         /* unit of physical scale */
901 #ifdef PNG_FLOATING_POINT_SUPPORTED
902    double scal_pixel_width;    /* width of one pixel */
903    double scal_pixel_height;   /* height of one pixel */
904 #endif
905 #ifdef PNG_FIXED_POINT_SUPPORTED
906    png_charp scal_s_width;     /* string containing height */
907    png_charp scal_s_height;    /* string containing width */
908 #endif
909 #endif
910 
911 #if defined(PNG_INFO_IMAGE_SUPPORTED)
912    /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS) non-zero */
913    /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
914    png_bytepp row_pointers;        /* the image bits */
915 #endif
916 
917 #if defined(PNG_FIXED_POINT_SUPPORTED) && defined(PNG_gAMA_SUPPORTED)
918    png_fixed_point int_gamma; /* gamma of image, if (valid & PNG_INFO_gAMA) */
919 #endif
920 
921 #if defined(PNG_cHRM_SUPPORTED) && defined(PNG_FIXED_POINT_SUPPORTED)
922    png_fixed_point int_x_white;
923    png_fixed_point int_y_white;
924    png_fixed_point int_x_red;
925    png_fixed_point int_y_red;
926    png_fixed_point int_x_green;
927    png_fixed_point int_y_green;
928    png_fixed_point int_x_blue;
929    png_fixed_point int_y_blue;
930 #endif
931 
932 } png_info;
933 
934 typedef png_info FAR * png_infop;
935 typedef png_info FAR * FAR * png_infopp;
936 
937 /* Maximum positive integer used in PNG is (2^31)-1 */
938 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
939 #define PNG_UINT_32_MAX ((png_uint_32)(-1))
940 #define PNG_SIZE_MAX ((png_size_t)(-1))
941 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
942 /* PNG_MAX_UINT is deprecated; use PNG_UINT_31_MAX instead. */
943 #define PNG_MAX_UINT PNG_UINT_31_MAX
944 #endif
945 
946 /* These describe the color_type field in png_info. */
947 /* color type masks */
948 #define PNG_COLOR_MASK_PALETTE    1
949 #define PNG_COLOR_MASK_COLOR      2
950 #define PNG_COLOR_MASK_ALPHA      4
951 
952 /* color types.  Note that not all combinations are legal */
953 #define PNG_COLOR_TYPE_GRAY 0
954 #define PNG_COLOR_TYPE_PALETTE  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
955 #define PNG_COLOR_TYPE_RGB        (PNG_COLOR_MASK_COLOR)
956 #define PNG_COLOR_TYPE_RGB_ALPHA  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
957 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
958 /* aliases */
959 #define PNG_COLOR_TYPE_RGBA  PNG_COLOR_TYPE_RGB_ALPHA
960 #define PNG_COLOR_TYPE_GA  PNG_COLOR_TYPE_GRAY_ALPHA
961 
962 /* This is for compression type. PNG 1.0-1.2 only define the single type. */
963 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
964 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
965 
966 /* This is for filter type. PNG 1.0-1.2 only define the single type. */
967 #define PNG_FILTER_TYPE_BASE      0 /* Single row per-byte filtering */
968 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
969 #define PNG_FILTER_TYPE_DEFAULT   PNG_FILTER_TYPE_BASE
970 
971 /* These are for the interlacing type.  These values should NOT be changed. */
972 #define PNG_INTERLACE_NONE        0 /* Non-interlaced image */
973 #define PNG_INTERLACE_ADAM7       1 /* Adam7 interlacing */
974 #define PNG_INTERLACE_LAST        2 /* Not a valid value */
975 
976 /* These are for the oFFs chunk.  These values should NOT be changed. */
977 #define PNG_OFFSET_PIXEL          0 /* Offset in pixels */
978 #define PNG_OFFSET_MICROMETER     1 /* Offset in micrometers (1/10^6 meter) */
979 #define PNG_OFFSET_LAST           2 /* Not a valid value */
980 
981 /* These are for the pCAL chunk.  These values should NOT be changed. */
982 #define PNG_EQUATION_LINEAR       0 /* Linear transformation */
983 #define PNG_EQUATION_BASE_E       1 /* Exponential base e transform */
984 #define PNG_EQUATION_ARBITRARY    2 /* Arbitrary base exponential transform */
985 #define PNG_EQUATION_HYPERBOLIC   3 /* Hyperbolic sine transformation */
986 #define PNG_EQUATION_LAST         4 /* Not a valid value */
987 
988 /* These are for the sCAL chunk.  These values should NOT be changed. */
989 #define PNG_SCALE_UNKNOWN         0 /* unknown unit (image scale) */
990 #define PNG_SCALE_METER           1 /* meters per pixel */
991 #define PNG_SCALE_RADIAN          2 /* radians per pixel */
992 #define PNG_SCALE_LAST            3 /* Not a valid value */
993 
994 /* These are for the pHYs chunk.  These values should NOT be changed. */
995 #define PNG_RESOLUTION_UNKNOWN    0 /* pixels/unknown unit (aspect ratio) */
996 #define PNG_RESOLUTION_METER      1 /* pixels/meter */
997 #define PNG_RESOLUTION_LAST       2 /* Not a valid value */
998 
999 /* These are for the sRGB chunk.  These values should NOT be changed. */
1000 #define PNG_sRGB_INTENT_PERCEPTUAL 0
1001 #define PNG_sRGB_INTENT_RELATIVE   1
1002 #define PNG_sRGB_INTENT_SATURATION 2
1003 #define PNG_sRGB_INTENT_ABSOLUTE   3
1004 #define PNG_sRGB_INTENT_LAST       4 /* Not a valid value */
1005 
1006 /* This is for text chunks */
1007 #define PNG_KEYWORD_MAX_LENGTH     79
1008 
1009 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */
1010 #define PNG_MAX_PALETTE_LENGTH    256
1011 
1012 /* These determine if an ancillary chunk's data has been successfully read
1013  * from the PNG header, or if the application has filled in the corresponding
1014  * data in the info_struct to be written into the output file.  The values
1015  * of the PNG_INFO_<chunk> defines should NOT be changed.
1016  */
1017 #define PNG_INFO_gAMA 0x0001
1018 #define PNG_INFO_sBIT 0x0002
1019 #define PNG_INFO_cHRM 0x0004
1020 #define PNG_INFO_PLTE 0x0008
1021 #define PNG_INFO_tRNS 0x0010
1022 #define PNG_INFO_bKGD 0x0020
1023 #define PNG_INFO_hIST 0x0040
1024 #define PNG_INFO_pHYs 0x0080
1025 #define PNG_INFO_oFFs 0x0100
1026 #define PNG_INFO_tIME 0x0200
1027 #define PNG_INFO_pCAL 0x0400
1028 #define PNG_INFO_sRGB 0x0800   /* GR-P, 0.96a */
1029 #define PNG_INFO_iCCP 0x1000   /* ESR, 1.0.6 */
1030 #define PNG_INFO_sPLT 0x2000   /* ESR, 1.0.6 */
1031 #define PNG_INFO_sCAL 0x4000   /* ESR, 1.0.6 */
1032 #define PNG_INFO_IDAT 0x8000L  /* ESR, 1.0.6 */
1033 
1034 /* This is used for the transformation routines, as some of them
1035  * change these values for the row.  It also should enable using
1036  * the routines for other purposes.
1037  */
1038 typedef struct png_row_info_struct
1039 {
1040    png_uint_32 width; /* width of row */
1041    png_uint_32 rowbytes; /* number of bytes in row */
1042    png_byte color_type; /* color type of row */
1043    png_byte bit_depth; /* bit depth of row */
1044    png_byte channels; /* number of channels (1, 2, 3, or 4) */
1045    png_byte pixel_depth; /* bits per pixel (depth * channels) */
1046 } png_row_info;
1047 
1048 typedef png_row_info FAR * png_row_infop;
1049 typedef png_row_info FAR * FAR * png_row_infopp;
1050 
1051 /* These are the function types for the I/O functions and for the functions
1052  * that allow the user to override the default I/O functions with his or her
1053  * own.  The png_error_ptr type should match that of user-supplied warning
1054  * and error functions, while the png_rw_ptr type should match that of the
1055  * user read/write data functions.
1056  */
1057 typedef struct png_struct_def png_struct;
1058 typedef png_struct FAR * png_structp;
1059 
1060 typedef void (PNGAPI *png_error_ptr) PNGARG((png_structp, png_const_charp));
1061 typedef void (PNGAPI *png_rw_ptr) PNGARG((png_structp, png_bytep, png_size_t));
1062 typedef void (PNGAPI *png_flush_ptr) PNGARG((png_structp));
1063 typedef void (PNGAPI *png_read_status_ptr) PNGARG((png_structp, png_uint_32,
1064    int));
1065 typedef void (PNGAPI *png_write_status_ptr) PNGARG((png_structp, png_uint_32,
1066    int));
1067 
1068 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1069 typedef void (PNGAPI *png_progressive_info_ptr) PNGARG((png_structp, png_infop));
1070 typedef void (PNGAPI *png_progressive_end_ptr) PNGARG((png_structp, png_infop));
1071 typedef void (PNGAPI *png_progressive_row_ptr) PNGARG((png_structp, png_bytep,
1072    png_uint_32, int));
1073 #endif
1074 
1075 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1076     defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
1077     defined(PNG_LEGACY_SUPPORTED)
1078 typedef void (PNGAPI *png_user_transform_ptr) PNGARG((png_structp,
1079     png_row_infop, png_bytep));
1080 #endif
1081 
1082 #if defined(PNG_USER_CHUNKS_SUPPORTED)
1083 typedef int (PNGAPI *png_user_chunk_ptr) PNGARG((png_structp, png_unknown_chunkp));
1084 #endif
1085 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
1086 typedef void (PNGAPI *png_unknown_chunk_ptr) PNGARG((png_structp));
1087 #endif
1088 
1089 /* Transform masks for the high-level interface */
1090 #define PNG_TRANSFORM_IDENTITY       0x0000    /* read and write */
1091 #define PNG_TRANSFORM_STRIP_16       0x0001    /* read only */
1092 #define PNG_TRANSFORM_STRIP_ALPHA    0x0002    /* read only */
1093 #define PNG_TRANSFORM_PACKING        0x0004    /* read and write */
1094 #define PNG_TRANSFORM_PACKSWAP       0x0008    /* read and write */
1095 #define PNG_TRANSFORM_EXPAND         0x0010    /* read only */
1096 #define PNG_TRANSFORM_INVERT_MONO    0x0020    /* read and write */
1097 #define PNG_TRANSFORM_SHIFT          0x0040    /* read and write */
1098 #define PNG_TRANSFORM_BGR            0x0080    /* read and write */
1099 #define PNG_TRANSFORM_SWAP_ALPHA     0x0100    /* read and write */
1100 #define PNG_TRANSFORM_SWAP_ENDIAN    0x0200    /* read and write */
1101 #define PNG_TRANSFORM_INVERT_ALPHA   0x0400    /* read and write */
1102 #define PNG_TRANSFORM_STRIP_FILLER   0x0800    /* WRITE only */
1103 
1104 /* Flags for MNG supported features */
1105 #define PNG_FLAG_MNG_EMPTY_PLTE     0x01
1106 #define PNG_FLAG_MNG_FILTER_64      0x04
1107 #define PNG_ALL_MNG_FEATURES        0x05
1108 
1109 typedef png_voidp (*png_malloc_ptr) PNGARG((png_structp, png_size_t));
1110 typedef void (*png_free_ptr) PNGARG((png_structp, png_voidp));
1111 
1112 /* The structure that holds the information to read and write PNG files.
1113  * The only people who need to care about what is inside of this are the
1114  * people who will be modifying the library for their own special needs.
1115  * It should NOT be accessed directly by an application, except to store
1116  * the jmp_buf.
1117  */
1118 
1119 struct png_struct_def
1120 {
1121 #ifdef PNG_SETJMP_SUPPORTED
1122    jmp_buf jmpbuf;            /* used in png_error */
1123 #endif
1124    png_error_ptr error_fn;    /* function for printing errors and aborting */
1125    png_error_ptr warning_fn;  /* function for printing warnings */
1126    png_voidp error_ptr;       /* user supplied struct for error functions */
1127    png_rw_ptr write_data_fn;  /* function for writing output data */
1128    png_rw_ptr read_data_fn;   /* function for reading input data */
1129    png_voidp io_ptr;          /* ptr to application struct for I/O functions */
1130 
1131 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
1132    png_user_transform_ptr read_user_transform_fn; /* user read transform */
1133 #endif
1134 
1135 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1136    png_user_transform_ptr write_user_transform_fn; /* user write transform */
1137 #endif
1138 
1139 /* These were added in libpng-1.0.2 */
1140 #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
1141 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1142     defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1143    png_voidp user_transform_ptr; /* user supplied struct for user transform */
1144    png_byte user_transform_depth;    /* bit depth of user transformed pixels */
1145    png_byte user_transform_channels; /* channels in user transformed pixels */
1146 #endif
1147 #endif
1148 
1149    png_uint_32 mode;          /* tells us where we are in the PNG file */
1150    png_uint_32 flags;         /* flags indicating various things to libpng */
1151    png_uint_32 transformations; /* which transformations to perform */
1152 
1153    z_stream zstream;          /* pointer to decompression structure (below) */
1154    png_bytep zbuf;            /* buffer for zlib */
1155    png_size_t zbuf_size;      /* size of zbuf */
1156    int zlib_level;            /* holds zlib compression level */
1157    int zlib_method;           /* holds zlib compression method */
1158    int zlib_window_bits;      /* holds zlib compression window bits */
1159    int zlib_mem_level;        /* holds zlib compression memory level */
1160    int zlib_strategy;         /* holds zlib compression strategy */
1161 
1162    png_uint_32 width;         /* width of image in pixels */
1163    png_uint_32 height;        /* height of image in pixels */
1164    png_uint_32 num_rows;      /* number of rows in current pass */
1165    png_uint_32 usr_width;     /* width of row at start of write */
1166    png_uint_32 rowbytes;      /* size of row in bytes */
1167    png_uint_32 irowbytes;     /* size of current interlaced row in bytes */
1168    png_uint_32 iwidth;        /* width of current interlaced row in pixels */
1169    png_uint_32 row_number;    /* current row in interlace pass */
1170    png_bytep prev_row;        /* buffer to save previous (unfiltered) row */
1171    png_bytep row_buf;         /* buffer to save current (unfiltered) row */
1172    png_bytep sub_row;         /* buffer to save "sub" row when filtering */
1173    png_bytep up_row;          /* buffer to save "up" row when filtering */
1174    png_bytep avg_row;         /* buffer to save "avg" row when filtering */
1175    png_bytep paeth_row;       /* buffer to save "Paeth" row when filtering */
1176    png_row_info row_info;     /* used for transformation routines */
1177 
1178    png_uint_32 idat_size;     /* current IDAT size for read */
1179    png_uint_32 crc;           /* current chunk CRC value */
1180    png_colorp palette;        /* palette from the input file */
1181    png_uint_16 num_palette;   /* number of color entries in palette */
1182    png_uint_16 num_trans;     /* number of transparency values */
1183    png_byte chunk_name[5];    /* null-terminated name of current chunk */
1184    png_byte compression;      /* file compression type (always 0) */
1185    png_byte filter;           /* file filter type (always 0) */
1186    png_byte interlaced;       /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
1187    png_byte pass;             /* current interlace pass (0 - 6) */
1188    png_byte do_filter;        /* row filter flags (see PNG_FILTER_ below ) */
1189    png_byte color_type;       /* color type of file */
1190    png_byte bit_depth;        /* bit depth of file */
1191    png_byte usr_bit_depth;    /* bit depth of users row */
1192    png_byte pixel_depth;      /* number of bits per pixel */
1193    png_byte channels;         /* number of channels in file */
1194    png_byte usr_channels;     /* channels at start of write */
1195    png_byte sig_bytes;        /* magic bytes read/written from start of file */
1196 
1197 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1198 #ifdef PNG_LEGACY_SUPPORTED
1199    png_byte filler;           /* filler byte for pixel expansion */
1200 #else
1201    png_uint_16 filler;           /* filler bytes for pixel expansion */
1202 #endif
1203 #endif
1204 
1205 #if defined(PNG_bKGD_SUPPORTED)
1206    png_byte background_gamma_type;
1207 #  ifdef PNG_FLOATING_POINT_SUPPORTED
1208    float background_gamma;
1209 #  endif
1210    png_color_16 background;   /* background color in screen gamma space */
1211 #if defined(PNG_READ_GAMMA_SUPPORTED)
1212    png_color_16 background_1; /* background normalized to gamma 1.0 */
1213 #endif
1214 #endif /* PNG_bKGD_SUPPORTED */
1215 
1216 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
1217    png_flush_ptr output_flush_fn;/* Function for flushing output */
1218    png_uint_32 flush_dist;    /* how many rows apart to flush, 0 - no flush */
1219    png_uint_32 flush_rows;    /* number of rows written since last flush */
1220 #endif
1221 
1222 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1223    int gamma_shift;      /* number of "insignificant" bits 16-bit gamma */
1224 #ifdef PNG_FLOATING_POINT_SUPPORTED
1225    float gamma;          /* file gamma value */
1226    float screen_gamma;   /* screen gamma value (display_exponent) */
1227 #endif
1228 #endif
1229 
1230 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1231    png_bytep gamma_table;     /* gamma table for 8-bit depth files */
1232    png_bytep gamma_from_1;    /* converts from 1.0 to screen */
1233    png_bytep gamma_to_1;      /* converts from file to 1.0 */
1234    png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */
1235    png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */
1236    png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */
1237 #endif
1238 
1239 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
1240    png_color_8 sig_bit;       /* significant bits in each available channel */
1241 #endif
1242 
1243 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1244    png_color_8 shift;         /* shift for significant bit tranformation */
1245 #endif
1246 
1247 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
1248  || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1249    png_bytep trans;           /* transparency values for paletted files */
1250    png_color_16 trans_values; /* transparency values for non-paletted files */
1251 #endif
1252 
1253    png_read_status_ptr read_row_fn;   /* called after each row is decoded */
1254    png_write_status_ptr write_row_fn; /* called after each row is encoded */
1255 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1256    png_progressive_info_ptr info_fn; /* called after header data fully read */
1257    png_progressive_row_ptr row_fn;   /* called after each prog. row is decoded */
1258    png_progressive_end_ptr end_fn;   /* called after image is complete */
1259    png_bytep save_buffer_ptr;        /* current location in save_buffer */
1260    png_bytep save_buffer;            /* buffer for previously read data */
1261    png_bytep current_buffer_ptr;     /* current location in current_buffer */
1262    png_bytep current_buffer;         /* buffer for recently used data */
1263    png_uint_32 push_length;          /* size of current input chunk */
1264    png_uint_32 skip_length;          /* bytes to skip in input data */
1265    png_size_t save_buffer_size;      /* amount of data now in save_buffer */
1266    png_size_t save_buffer_max;       /* total size of save_buffer */
1267    png_size_t buffer_size;           /* total amount of available input data */
1268    png_size_t current_buffer_size;   /* amount of data now in current_buffer */
1269    int process_mode;                 /* what push library is currently doing */
1270    int cur_palette;                  /* current push library palette index */
1271 
1272 #  if defined(PNG_TEXT_SUPPORTED)
1273      png_size_t current_text_size;   /* current size of text input data */
1274      png_size_t current_text_left;   /* how much text left to read in input */
1275      png_charp current_text;         /* current text chunk buffer */
1276      png_charp current_text_ptr;     /* current location in current_text */
1277 #  endif /* PNG_PROGRESSIVE_READ_SUPPORTED && PNG_TEXT_SUPPORTED */
1278 
1279 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1280 
1281 #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
1282 /* for the Borland special 64K segment handler */
1283    png_bytepp offset_table_ptr;
1284    png_bytep offset_table;
1285    png_uint_16 offset_table_number;
1286    png_uint_16 offset_table_count;
1287    png_uint_16 offset_table_count_free;
1288 #endif
1289 
1290 #if defined(PNG_READ_DITHER_SUPPORTED)
1291    png_bytep palette_lookup;         /* lookup table for dithering */
1292    png_bytep dither_index;           /* index translation for palette files */
1293 #endif
1294 
1295 #if defined(PNG_READ_DITHER_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
1296    png_uint_16p hist;                /* histogram */
1297 #endif
1298 
1299 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
1300    png_byte heuristic_method;        /* heuristic for row filter selection */
1301    png_byte num_prev_filters;        /* number of weights for previous rows */
1302    png_bytep prev_filters;           /* filter type(s) of previous row(s) */
1303    png_uint_16p filter_weights;      /* weight(s) for previous line(s) */
1304    png_uint_16p inv_filter_weights;  /* 1/weight(s) for previous line(s) */
1305    png_uint_16p filter_costs;        /* relative filter calculation cost */
1306    png_uint_16p inv_filter_costs;    /* 1/relative filter calculation cost */
1307 #endif
1308 
1309 #if defined(PNG_TIME_RFC1123_SUPPORTED)
1310    png_charp time_buffer;            /* String to hold RFC 1123 time text */
1311 #endif
1312 
1313 /* New members added in libpng-1.0.6 */
1314 
1315 #ifdef PNG_FREE_ME_SUPPORTED
1316    png_uint_32 free_me;       /* flags items libpng is responsible for freeing */
1317 #endif
1318 
1319 #if defined(PNG_USER_CHUNKS_SUPPORTED)
1320    png_voidp user_chunk_ptr;
1321    png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
1322 #endif
1323 
1324 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
1325    int num_chunk_list;
1326    png_bytep chunk_list;
1327 #endif
1328 
1329 /* New members added in libpng-1.0.3 */
1330 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
1331    png_byte rgb_to_gray_status;
1332    /* These were changed from png_byte in libpng-1.0.6 */
1333    png_uint_16 rgb_to_gray_red_coeff;
1334    png_uint_16 rgb_to_gray_green_coeff;
1335    png_uint_16 rgb_to_gray_blue_coeff;
1336 #endif
1337 
1338 /* New member added in libpng-1.0.4 (renamed in 1.0.9) */
1339 #if defined(PNG_MNG_FEATURES_SUPPORTED) || \
1340     defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1341     defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1342 /* changed from png_byte to png_uint_32 at version 1.2.0 */
1343 #ifdef PNG_1_0_X
1344    png_byte mng_features_permitted;
1345 #else
1346    png_uint_32 mng_features_permitted;
1347 #endif /* PNG_1_0_X */
1348 #endif
1349 
1350 /* New member added in libpng-1.0.7 */
1351 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1352    png_fixed_point int_gamma;
1353 #endif
1354 
1355 /* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
1356 #if defined(PNG_MNG_FEATURES_SUPPORTED)
1357    png_byte filter_type;
1358 #endif
1359 
1360 #if defined(PNG_1_0_X)
1361 /* New member added in libpng-1.0.10, ifdef'ed out in 1.2.0 */
1362    png_uint_32 row_buf_size;
1363 #endif
1364 
1365 /* New members added in libpng-1.2.0 */
1366 #if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
1367 #  if !defined(PNG_1_0_X)
1368 #    if defined(PNG_MMX_CODE_SUPPORTED)
1369    png_byte     mmx_bitdepth_threshold;
1370    png_uint_32  mmx_rowbytes_threshold;
1371 #    endif
1372    png_uint_32  asm_flags;
1373 #  endif
1374 #endif
1375 
1376 /* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
1377 #ifdef PNG_USER_MEM_SUPPORTED
1378    png_voidp mem_ptr;                /* user supplied struct for mem functions */
1379    png_malloc_ptr malloc_fn;         /* function for allocating memory */
1380    png_free_ptr free_fn;             /* function for freeing memory */
1381 #endif
1382 
1383 /* New member added in libpng-1.0.13 and 1.2.0 */
1384    png_bytep big_row_buf;         /* buffer to save current (unfiltered) row */
1385 
1386 #if defined(PNG_READ_DITHER_SUPPORTED)
1387 /* The following three members were added at version 1.0.14 and 1.2.4 */
1388    png_bytep dither_sort;            /* working sort array */
1389    png_bytep index_to_palette;       /* where the original index currently is */
1390                                      /* in the palette */
1391    png_bytep palette_to_index;       /* which original index points to this */
1392                                      /* palette color */
1393 #endif
1394 
1395 /* New members added in libpng-1.0.16 and 1.2.6 */
1396    png_byte compression_type;
1397 
1398 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
1399    png_uint_32 user_width_max;
1400    png_uint_32 user_height_max;
1401 #endif
1402 
1403 /* New member added in libpng-1.0.25 and 1.2.17 */
1404 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
1405    /* storage for unknown chunk that the library doesn't recognize. */
1406    png_unknown_chunk unknown_chunk;
1407 #endif
1408 };
1409 
1410 
1411 /* This triggers a compiler error in png.c, if png.c and png.h
1412  * do not agree upon the version number.
1413  */
1414 typedef png_structp version_1_2_19;
1415 
1416 typedef png_struct FAR * FAR * png_structpp;
1417 
1418 /* Here are the function definitions most commonly used.  This is not
1419  * the place to find out how to use libpng.  See libpng.txt for the
1420  * full explanation, see example.c for the summary.  This just provides
1421  * a simple one line description of the use of each function.
1422  */
1423 
1424 /* Returns the version number of the library */
1425 extern PNG_EXPORT(png_uint_32,png_access_version_number) PNGARG((void));
1426 
1427 /* Tell lib we have already handled the first <num_bytes> magic bytes.
1428  * Handling more than 8 bytes from the beginning of the file is an error.
1429  */
1430 extern PNG_EXPORT(void,png_set_sig_bytes) PNGARG((png_structp png_ptr,
1431    int num_bytes));
1432 
1433 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
1434  * PNG file.  Returns zero if the supplied bytes match the 8-byte PNG
1435  * signature, and non-zero otherwise.  Having num_to_check == 0 or
1436  * start > 7 will always fail (ie return non-zero).
1437  */
1438 extern PNG_EXPORT(int,png_sig_cmp) PNGARG((png_bytep sig, png_size_t start,
1439    png_size_t num_to_check));
1440 
1441 /* Simple signature checking function.  This is the same as calling
1442  * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
1443  */
1444 extern PNG_EXPORT(int,png_check_sig) PNGARG((png_bytep sig, int num));
1445 
1446 /* Allocate and initialize png_ptr struct for reading, and any other memory. */
1447 extern PNG_EXPORT(png_structp,png_create_read_struct)
1448    PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1449    png_error_ptr error_fn, png_error_ptr warn_fn));
1450 
1451 /* Allocate and initialize png_ptr struct for writing, and any other memory */
1452 extern PNG_EXPORT(png_structp,png_create_write_struct)
1453    PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1454    png_error_ptr error_fn, png_error_ptr warn_fn));
1455 
1456 #ifdef PNG_WRITE_SUPPORTED
1457 extern PNG_EXPORT(png_uint_32,png_get_compression_buffer_size)
1458    PNGARG((png_structp png_ptr));
1459 #endif
1460 
1461 #ifdef PNG_WRITE_SUPPORTED
1462 extern PNG_EXPORT(void,png_set_compression_buffer_size)
1463    PNGARG((png_structp png_ptr, png_uint_32 size));
1464 #endif
1465 
1466 /* Reset the compression stream */
1467 extern PNG_EXPORT(int,png_reset_zstream) PNGARG((png_structp png_ptr));
1468 
1469 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
1470 #ifdef PNG_USER_MEM_SUPPORTED
1471 extern PNG_EXPORT(png_structp,png_create_read_struct_2)
1472    PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1473    png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1474    png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1475 extern PNG_EXPORT(png_structp,png_create_write_struct_2)
1476    PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1477    png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1478    png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1479 #endif
1480 
1481 /* Write a PNG chunk - size, type, (optional) data, CRC. */
1482 extern PNG_EXPORT(void,png_write_chunk) PNGARG((png_structp png_ptr,
1483    png_bytep chunk_name, png_bytep data, png_size_t length));
1484 
1485 /* Write the start of a PNG chunk - length and chunk name. */
1486 extern PNG_EXPORT(void,png_write_chunk_start) PNGARG((png_structp png_ptr,
1487    png_bytep chunk_name, png_uint_32 length));
1488 
1489 /* Write the data of a PNG chunk started with png_write_chunk_start(). */
1490 extern PNG_EXPORT(void,png_write_chunk_data) PNGARG((png_structp png_ptr,
1491    png_bytep data, png_size_t length));
1492 
1493 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1494 extern PNG_EXPORT(void,png_write_chunk_end) PNGARG((png_structp png_ptr));
1495 
1496 /* Allocate and initialize the info structure */
1497 extern PNG_EXPORT(png_infop,png_create_info_struct)
1498    PNGARG((png_structp png_ptr));
1499 
1500 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1501 /* Initialize the info structure (old interface - DEPRECATED) */
1502 extern PNG_EXPORT(void,png_info_init) PNGARG((png_infop info_ptr));
1503 #undef png_info_init
1504 #define png_info_init(info_ptr) png_info_init_3(&info_ptr,\
1505     png_sizeof(png_info));
1506 #endif
1507 
1508 extern PNG_EXPORT(void,png_info_init_3) PNGARG((png_infopp info_ptr,
1509     png_size_t png_info_struct_size));
1510 
1511 /* Writes all the PNG information before the image. */
1512 extern PNG_EXPORT(void,png_write_info_before_PLTE) PNGARG((png_structp png_ptr,
1513    png_infop info_ptr));
1514 extern PNG_EXPORT(void,png_write_info) PNGARG((png_structp png_ptr,
1515    png_infop info_ptr));
1516 
1517 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1518 /* read the information before the actual image data. */
1519 extern PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr,
1520    png_infop info_ptr));
1521 #endif
1522 
1523 #if defined(PNG_TIME_RFC1123_SUPPORTED)
1524 extern PNG_EXPORT(png_charp,png_convert_to_rfc1123)
1525    PNGARG((png_structp png_ptr, png_timep ptime));
1526 #endif
1527 
1528 #if !defined(_WIN32_WCE)
1529 /* "time.h" functions are not supported on WindowsCE */
1530 #if defined(PNG_WRITE_tIME_SUPPORTED)
1531 /* convert from a struct tm to png_time */
1532 extern PNG_EXPORT(void,png_convert_from_struct_tm) PNGARG((png_timep ptime,
1533    struct tm FAR * ttime));
1534 
1535 /* convert from time_t to png_time.  Uses gmtime() */
1536 extern PNG_EXPORT(void,png_convert_from_time_t) PNGARG((png_timep ptime,
1537    time_t ttime));
1538 #endif /* PNG_WRITE_tIME_SUPPORTED */
1539 #endif /* _WIN32_WCE */
1540 
1541 #if defined(PNG_READ_EXPAND_SUPPORTED)
1542 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1543 extern PNG_EXPORT(void,png_set_expand) PNGARG((png_structp png_ptr));
1544 #if !defined(PNG_1_0_X)
1545 extern PNG_EXPORT(void,png_set_expand_gray_1_2_4_to_8) PNGARG((png_structp
1546   png_ptr));
1547 #endif
1548 extern PNG_EXPORT(void,png_set_palette_to_rgb) PNGARG((png_structp png_ptr));
1549 extern PNG_EXPORT(void,png_set_tRNS_to_alpha) PNGARG((png_structp png_ptr));
1550 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1551 /* Deprecated */
1552 extern PNG_EXPORT(void,png_set_gray_1_2_4_to_8) PNGARG((png_structp png_ptr));
1553 #endif
1554 #endif
1555 
1556 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1557 /* Use blue, green, red order for pixels. */
1558 extern PNG_EXPORT(void,png_set_bgr) PNGARG((png_structp png_ptr));
1559 #endif
1560 
1561 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
1562 /* Expand the grayscale to 24-bit RGB if necessary. */
1563 extern PNG_EXPORT(void,png_set_gray_to_rgb) PNGARG((png_structp png_ptr));
1564 #endif
1565 
1566 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
1567 /* Reduce RGB to grayscale. */
1568 #ifdef PNG_FLOATING_POINT_SUPPORTED
1569 extern PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr,
1570    int error_action, double red, double green ));
1571 #endif
1572 extern PNG_EXPORT(void,png_set_rgb_to_gray_fixed) PNGARG((png_structp png_ptr,
1573    int error_action, png_fixed_point red, png_fixed_point green ));
1574 extern PNG_EXPORT(png_byte,png_get_rgb_to_gray_status) PNGARG((png_structp
1575    png_ptr));
1576 #endif
1577 
1578 extern PNG_EXPORT(void,png_build_grayscale_palette) PNGARG((int bit_depth,
1579    png_colorp palette));
1580 
1581 #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1582 extern PNG_EXPORT(void,png_set_strip_alpha) PNGARG((png_structp png_ptr));
1583 #endif
1584 
1585 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1586     defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1587 extern PNG_EXPORT(void,png_set_swap_alpha) PNGARG((png_structp png_ptr));
1588 #endif
1589 
1590 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1591     defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1592 extern PNG_EXPORT(void,png_set_invert_alpha) PNGARG((png_structp png_ptr));
1593 #endif
1594 
1595 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1596 /* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
1597 extern PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr,
1598    png_uint_32 filler, int flags));
1599 /* The values of the PNG_FILLER_ defines should NOT be changed */
1600 #define PNG_FILLER_BEFORE 0
1601 #define PNG_FILLER_AFTER 1
1602 /* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
1603 #if !defined(PNG_1_0_X)
1604 extern PNG_EXPORT(void,png_set_add_alpha) PNGARG((png_structp png_ptr,
1605    png_uint_32 filler, int flags));
1606 #endif
1607 #endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
1608 
1609 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1610 /* Swap bytes in 16-bit depth files. */
1611 extern PNG_EXPORT(void,png_set_swap) PNGARG((png_structp png_ptr));
1612 #endif
1613 
1614 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1615 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1616 extern PNG_EXPORT(void,png_set_packing) PNGARG((png_structp png_ptr));
1617 #endif
1618 
1619 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1620 /* Swap packing order of pixels in bytes. */
1621 extern PNG_EXPORT(void,png_set_packswap) PNGARG((png_structp png_ptr));
1622 #endif
1623 
1624 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1625 /* Converts files to legal bit depths. */
1626 extern PNG_EXPORT(void,png_set_shift) PNGARG((png_structp png_ptr,
1627    png_color_8p true_bits));
1628 #endif
1629 
1630 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1631     defined(PNG_WRITE_INTERLACING_SUPPORTED)
1632 /* Have the code handle the interlacing.  Returns the number of passes. */
1633 extern PNG_EXPORT(int,png_set_interlace_handling) PNGARG((png_structp png_ptr));
1634 #endif
1635 
1636 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1637 /* Invert monochrome files */
1638 extern PNG_EXPORT(void,png_set_invert_mono) PNGARG((png_structp png_ptr));
1639 #endif
1640 
1641 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
1642 /* Handle alpha and tRNS by replacing with a background color. */
1643 #ifdef PNG_FLOATING_POINT_SUPPORTED
1644 extern PNG_EXPORT(void,png_set_background) PNGARG((png_structp png_ptr,
1645    png_color_16p background_color, int background_gamma_code,
1646    int need_expand, double background_gamma));
1647 #endif
1648 #define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1649 #define PNG_BACKGROUND_GAMMA_SCREEN  1
1650 #define PNG_BACKGROUND_GAMMA_FILE    2
1651 #define PNG_BACKGROUND_GAMMA_UNIQUE  3
1652 #endif
1653 
1654 #if defined(PNG_READ_16_TO_8_SUPPORTED)
1655 /* strip the second byte of information from a 16-bit depth file. */
1656 extern PNG_EXPORT(void,png_set_strip_16) PNGARG((png_structp png_ptr));
1657 #endif
1658 
1659 #if defined(PNG_READ_DITHER_SUPPORTED)
1660 /* Turn on dithering, and reduce the palette to the number of colors available. */
1661 extern PNG_EXPORT(void,png_set_dither) PNGARG((png_structp png_ptr,
1662    png_colorp palette, int num_palette, int maximum_colors,
1663    png_uint_16p histogram, int full_dither));
1664 #endif
1665 
1666 #if defined(PNG_READ_GAMMA_SUPPORTED)
1667 /* Handle gamma correction. Screen_gamma=(display_exponent) */
1668 #ifdef PNG_FLOATING_POINT_SUPPORTED
1669 extern PNG_EXPORT(void,png_set_gamma) PNGARG((png_structp png_ptr,
1670    double screen_gamma, double default_file_gamma));
1671 #endif
1672 #endif
1673 
1674 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1675 #if defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1676     defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1677 /* Permit or disallow empty PLTE (0: not permitted, 1: permitted) */
1678 /* Deprecated and will be removed.  Use png_permit_mng_features() instead. */
1679 extern PNG_EXPORT(void,png_permit_empty_plte) PNGARG((png_structp png_ptr,
1680    int empty_plte_permitted));
1681 #endif
1682 #endif
1683 
1684 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
1685 /* Set how many lines between output flushes - 0 for no flushing */
1686 extern PNG_EXPORT(void,png_set_flush) PNGARG((png_structp png_ptr, int nrows));
1687 /* Flush the current PNG output buffer */
1688 extern PNG_EXPORT(void,png_write_flush) PNGARG((png_structp png_ptr));
1689 #endif
1690 
1691 /* optional update palette with requested transformations */
1692 extern PNG_EXPORT(void,png_start_read_image) PNGARG((png_structp png_ptr));
1693 
1694 /* optional call to update the users info structure */
1695 extern PNG_EXPORT(void,png_read_update_info) PNGARG((png_structp png_ptr,
1696    png_infop info_ptr));
1697 
1698 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1699 /* read one or more rows of image data. */
1700 extern PNG_EXPORT(void,png_read_rows) PNGARG((png_structp png_ptr,
1701    png_bytepp row, png_bytepp display_row, png_uint_32 num_rows));
1702 #endif
1703 
1704 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1705 /* read a row of data. */
1706 extern PNG_EXPORT(void,png_read_row) PNGARG((png_structp png_ptr,
1707    png_bytep row,
1708    png_bytep display_row));
1709 #endif
1710 
1711 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1712 /* read the whole image into memory at once. */
1713 extern PNG_EXPORT(void,png_read_image) PNGARG((png_structp png_ptr,
1714    png_bytepp image));
1715 #endif
1716 
1717 /* write a row of image data */
1718 extern PNG_EXPORT(void,png_write_row) PNGARG((png_structp png_ptr,
1719    png_bytep row));
1720 
1721 /* write a few rows of image data */
1722 extern PNG_EXPORT(void,png_write_rows) PNGARG((png_structp png_ptr,
1723    png_bytepp row, png_uint_32 num_rows));
1724 
1725 /* write the image data */
1726 extern PNG_EXPORT(void,png_write_image) PNGARG((png_structp png_ptr,
1727    png_bytepp image));
1728 
1729 /* writes the end of the PNG file. */
1730 extern PNG_EXPORT(void,png_write_end) PNGARG((png_structp png_ptr,
1731    png_infop info_ptr));
1732 
1733 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1734 /* read the end of the PNG file. */
1735 extern PNG_EXPORT(void,png_read_end) PNGARG((png_structp png_ptr,
1736    png_infop info_ptr));
1737 #endif
1738 
1739 /* free any memory associated with the png_info_struct */
1740 extern PNG_EXPORT(void,png_destroy_info_struct) PNGARG((png_structp png_ptr,
1741    png_infopp info_ptr_ptr));
1742 
1743 /* free any memory associated with the png_struct and the png_info_structs */
1744 extern PNG_EXPORT(void,png_destroy_read_struct) PNGARG((png_structpp
1745    png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1746 
1747 /* free all memory used by the read (old method - NOT DLL EXPORTED) */
1748 extern void png_read_destroy PNGARG((png_structp png_ptr, png_infop info_ptr,
1749    png_infop end_info_ptr));
1750 
1751 /* free any memory associated with the png_struct and the png_info_structs */
1752 extern PNG_EXPORT(void,png_destroy_write_struct)
1753    PNGARG((png_structpp png_ptr_ptr, png_infopp info_ptr_ptr));
1754 
1755 /* free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */
1756 extern void png_write_destroy PNGARG((png_structp png_ptr));
1757 
1758 /* set the libpng method of handling chunk CRC errors */
1759 extern PNG_EXPORT(void,png_set_crc_action) PNGARG((png_structp png_ptr,
1760    int crit_action, int ancil_action));
1761 
1762 /* Values for png_set_crc_action() to say how to handle CRC errors in
1763  * ancillary and critical chunks, and whether to use the data contained
1764  * therein.  Note that it is impossible to "discard" data in a critical
1765  * chunk.  For versions prior to 0.90, the action was always error/quit,
1766  * whereas in version 0.90 and later, the action for CRC errors in ancillary
1767  * chunks is warn/discard.  These values should NOT be changed.
1768  *
1769  *      value                       action:critical     action:ancillary
1770  */
1771 #define PNG_CRC_DEFAULT       0  /* error/quit          warn/discard data */
1772 #define PNG_CRC_ERROR_QUIT    1  /* error/quit          error/quit        */
1773 #define PNG_CRC_WARN_DISCARD  2  /* (INVALID)           warn/discard data */
1774 #define PNG_CRC_WARN_USE      3  /* warn/use data       warn/use data     */
1775 #define PNG_CRC_QUIET_USE     4  /* quiet/use data      quiet/use data    */
1776 #define PNG_CRC_NO_CHANGE     5  /* use current value   use current value */
1777 
1778 /* These functions give the user control over the scan-line filtering in
1779  * libpng and the compression methods used by zlib.  These functions are
1780  * mainly useful for testing, as the defaults should work with most users.
1781  * Those users who are tight on memory or want faster performance at the
1782  * expense of compression can modify them.  See the compression library
1783  * header file (zlib.h) for an explination of the compression functions.
1784  */
1785 
1786 /* set the filtering method(s) used by libpng.  Currently, the only valid
1787  * value for "method" is 0.
1788  */
1789 extern PNG_EXPORT(void,png_set_filter) PNGARG((png_structp png_ptr, int method,
1790    int filters));
1791 
1792 /* Flags for png_set_filter() to say which filters to use.  The flags
1793  * are chosen so that they don't conflict with real filter types
1794  * below, in case they are supplied instead of the #defined constants.
1795  * These values should NOT be changed.
1796  */
1797 #define PNG_NO_FILTERS     0x00
1798 #define PNG_FILTER_NONE    0x08
1799 #define PNG_FILTER_SUB     0x10
1800 #define PNG_FILTER_UP      0x20
1801 #define PNG_FILTER_AVG     0x40
1802 #define PNG_FILTER_PAETH   0x80
1803 #define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
1804                          PNG_FILTER_AVG | PNG_FILTER_PAETH)
1805 
1806 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1807  * These defines should NOT be changed.
1808  */
1809 #define PNG_FILTER_VALUE_NONE  0
1810 #define PNG_FILTER_VALUE_SUB   1
1811 #define PNG_FILTER_VALUE_UP    2
1812 #define PNG_FILTER_VALUE_AVG   3
1813 #define PNG_FILTER_VALUE_PAETH 4
1814 #define PNG_FILTER_VALUE_LAST  5
1815 
1816 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* EXPERIMENTAL */
1817 /* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
1818  * defines, either the default (minimum-sum-of-absolute-differences), or
1819  * the experimental method (weighted-minimum-sum-of-absolute-differences).
1820  *
1821  * Weights are factors >= 1.0, indicating how important it is to keep the
1822  * filter type consistent between rows.  Larger numbers mean the current
1823  * filter is that many times as likely to be the same as the "num_weights"
1824  * previous filters.  This is cumulative for each previous row with a weight.
1825  * There needs to be "num_weights" values in "filter_weights", or it can be
1826  * NULL if the weights aren't being specified.  Weights have no influence on
1827  * the selection of the first row filter.  Well chosen weights can (in theory)
1828  * improve the compression for a given image.
1829  *
1830  * Costs are factors >= 1.0 indicating the relative decoding costs of a
1831  * filter type.  Higher costs indicate more decoding expense, and are
1832  * therefore less likely to be selected over a filter with lower computational
1833  * costs.  There needs to be a value in "filter_costs" for each valid filter
1834  * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
1835  * setting the costs.  Costs try to improve the speed of decompression without
1836  * unduly increasing the compressed image size.
1837  *
1838  * A negative weight or cost indicates the default value is to be used, and
1839  * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
1840  * The default values for both weights and costs are currently 1.0, but may
1841  * change if good general weighting/cost heuristics can be found.  If both
1842  * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
1843  * to the UNWEIGHTED method, but with added encoding time/computation.
1844  */
1845 #ifdef PNG_FLOATING_POINT_SUPPORTED
1846 extern PNG_EXPORT(void,png_set_filter_heuristics) PNGARG((png_structp png_ptr,
1847    int heuristic_method, int num_weights, png_doublep filter_weights,
1848    png_doublep filter_costs));
1849 #endif
1850 #endif /*  PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1851 
1852 /* Heuristic used for row filter selection.  These defines should NOT be
1853  * changed.
1854  */
1855 #define PNG_FILTER_HEURISTIC_DEFAULT    0  /* Currently "UNWEIGHTED" */
1856 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1  /* Used by libpng < 0.95 */
1857 #define PNG_FILTER_HEURISTIC_WEIGHTED   2  /* Experimental feature */
1858 #define PNG_FILTER_HEURISTIC_LAST       3  /* Not a valid value */
1859 
1860 /* Set the library compression level.  Currently, valid values range from
1861  * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1862  * (0 - no compression, 9 - "maximal" compression).  Note that tests have
1863  * shown that zlib compression levels 3-6 usually perform as well as level 9
1864  * for PNG images, and do considerably fewer caclulations.  In the future,
1865  * these values may not correspond directly to the zlib compression levels.
1866  */
1867 extern PNG_EXPORT(void,png_set_compression_level) PNGARG((png_structp png_ptr,
1868    int level));
1869 
1870 extern PNG_EXPORT(void,png_set_compression_mem_level)
1871    PNGARG((png_structp png_ptr, int mem_level));
1872 
1873 extern PNG_EXPORT(void,png_set_compression_strategy)
1874    PNGARG((png_structp png_ptr, int strategy));
1875 
1876 extern PNG_EXPORT(void,png_set_compression_window_bits)
1877    PNGARG((png_structp png_ptr, int window_bits));
1878 
1879 extern PNG_EXPORT(void,png_set_compression_method) PNGARG((png_structp png_ptr,
1880    int method));
1881 
1882 /* These next functions are called for input/output, memory, and error
1883  * handling.  They are in the file pngrio.c, pngwio.c, and pngerror.c,
1884  * and call standard C I/O routines such as fread(), fwrite(), and
1885  * fprintf().  These functions can be made to use other I/O routines
1886  * at run time for those applications that need to handle I/O in a
1887  * different manner by calling png_set_???_fn().  See libpng.txt for
1888  * more information.
1889  */
1890 
1891 #if !defined(PNG_NO_STDIO)
1892 /* Initialize the input/output for the PNG file to the default functions. */
1893 extern PNG_EXPORT(void,png_init_io) PNGARG((png_structp png_ptr, png_FILE_p fp));
1894 #endif
1895 
1896 /* Replace the (error and abort), and warning functions with user
1897  * supplied functions.  If no messages are to be printed you must still
1898  * write and use replacement functions. The replacement error_fn should
1899  * still do a longjmp to the last setjmp location if you are using this
1900  * method of error handling.  If error_fn or warning_fn is NULL, the
1901  * default function will be used.
1902  */
1903 
1904 extern PNG_EXPORT(void,png_set_error_fn) PNGARG((png_structp png_ptr,
1905    png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
1906 
1907 /* Return the user pointer associated with the error functions */
1908 extern PNG_EXPORT(png_voidp,png_get_error_ptr) PNGARG((png_structp png_ptr));
1909 
1910 /* Replace the default data output functions with a user supplied one(s).
1911  * If buffered output is not used, then output_flush_fn can be set to NULL.
1912  * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
1913  * output_flush_fn will be ignored (and thus can be NULL).
1914  */
1915 extern PNG_EXPORT(void,png_set_write_fn) PNGARG((png_structp png_ptr,
1916    png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
1917 
1918 /* Replace the default data input function with a user supplied one. */
1919 extern PNG_EXPORT(void,png_set_read_fn) PNGARG((png_structp png_ptr,
1920    png_voidp io_ptr, png_rw_ptr read_data_fn));
1921 
1922 /* Return the user pointer associated with the I/O functions */
1923 extern PNG_EXPORT(png_voidp,png_get_io_ptr) PNGARG((png_structp png_ptr));
1924 
1925 extern PNG_EXPORT(void,png_set_read_status_fn) PNGARG((png_structp png_ptr,
1926    png_read_status_ptr read_row_fn));
1927 
1928 extern PNG_EXPORT(void,png_set_write_status_fn) PNGARG((png_structp png_ptr,
1929    png_write_status_ptr write_row_fn));
1930 
1931 #ifdef PNG_USER_MEM_SUPPORTED
1932 /* Replace the default memory allocation functions with user supplied one(s). */
1933 extern PNG_EXPORT(void,png_set_mem_fn) PNGARG((png_structp png_ptr,
1934    png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1935 /* Return the user pointer associated with the memory functions */
1936 extern PNG_EXPORT(png_voidp,png_get_mem_ptr) PNGARG((png_structp png_ptr));
1937 #endif
1938 
1939 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1940     defined(PNG_LEGACY_SUPPORTED)
1941 extern PNG_EXPORT(void,png_set_read_user_transform_fn) PNGARG((png_structp
1942    png_ptr, png_user_transform_ptr read_user_transform_fn));
1943 #endif
1944 
1945 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
1946     defined(PNG_LEGACY_SUPPORTED)
1947 extern PNG_EXPORT(void,png_set_write_user_transform_fn) PNGARG((png_structp
1948    png_ptr, png_user_transform_ptr write_user_transform_fn));
1949 #endif
1950 
1951 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1952     defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
1953     defined(PNG_LEGACY_SUPPORTED)
1954 extern PNG_EXPORT(void,png_set_user_transform_info) PNGARG((png_structp
1955    png_ptr, png_voidp user_transform_ptr, int user_transform_depth,
1956    int user_transform_channels));
1957 /* Return the user pointer associated with the user transform functions */
1958 extern PNG_EXPORT(png_voidp,png_get_user_transform_ptr)
1959    PNGARG((png_structp png_ptr));
1960 #endif
1961 
1962 #ifdef PNG_USER_CHUNKS_SUPPORTED
1963 extern PNG_EXPORT(void,png_set_read_user_chunk_fn) PNGARG((png_structp png_ptr,
1964    png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
1965 extern PNG_EXPORT(png_voidp,png_get_user_chunk_ptr) PNGARG((png_structp
1966    png_ptr));
1967 #endif
1968 
1969 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1970 /* Sets the function callbacks for the push reader, and a pointer to a
1971  * user-defined structure available to the callback functions.
1972  */
1973 extern PNG_EXPORT(void,png_set_progressive_read_fn) PNGARG((png_structp png_ptr,
1974    png_voidp progressive_ptr,
1975    png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
1976    png_progressive_end_ptr end_fn));
1977 
1978 /* returns the user pointer associated with the push read functions */
1979 extern PNG_EXPORT(png_voidp,png_get_progressive_ptr)
1980    PNGARG((png_structp png_ptr));
1981 
1982 /* function to be called when data becomes available */
1983 extern PNG_EXPORT(void,png_process_data) PNGARG((png_structp png_ptr,
1984    png_infop info_ptr, png_bytep buffer, png_size_t buffer_size));
1985 
1986 /* function that combines rows.  Not very much different than the
1987  * png_combine_row() call.  Is this even used?????
1988  */
1989 extern PNG_EXPORT(void,png_progressive_combine_row) PNGARG((png_structp png_ptr,
1990    png_bytep old_row, png_bytep new_row));
1991 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1992 
1993 extern PNG_EXPORT(png_voidp,png_malloc) PNGARG((png_structp png_ptr,
1994    png_uint_32 size));
1995 
1996 #if defined(PNG_1_0_X)
1997 #  define png_malloc_warn png_malloc
1998 #else
1999 /* Added at libpng version 1.2.4 */
2000 extern PNG_EXPORT(png_voidp,png_malloc_warn) PNGARG((png_structp png_ptr,
2001    png_uint_32 size));
2002 #endif
2003 
2004 /* frees a pointer allocated by png_malloc() */
2005 extern PNG_EXPORT(void,png_free) PNGARG((png_structp png_ptr, png_voidp ptr));
2006 
2007 #if defined(PNG_1_0_X)
2008 /* Function to allocate memory for zlib. */
2009 extern PNG_EXPORT(voidpf,png_zalloc) PNGARG((voidpf png_ptr, uInt items,
2010    uInt size));
2011 
2012 /* Function to free memory for zlib */
2013 extern PNG_EXPORT(void,png_zfree) PNGARG((voidpf png_ptr, voidpf ptr));
2014 #endif
2015 
2016 /* Free data that was allocated internally */
2017 extern PNG_EXPORT(void,png_free_data) PNGARG((png_structp png_ptr,
2018    png_infop info_ptr, png_uint_32 free_me, int num));
2019 #ifdef PNG_FREE_ME_SUPPORTED
2020 /* Reassign responsibility for freeing existing data, whether allocated
2021  * by libpng or by the application */
2022 extern PNG_EXPORT(void,png_data_freer) PNGARG((png_structp png_ptr,
2023    png_infop info_ptr, int freer, png_uint_32 mask));
2024 #endif
2025 /* assignments for png_data_freer */
2026 #define PNG_DESTROY_WILL_FREE_DATA 1
2027 #define PNG_SET_WILL_FREE_DATA 1
2028 #define PNG_USER_WILL_FREE_DATA 2
2029 /* Flags for png_ptr->free_me and info_ptr->free_me */
2030 #define PNG_FREE_HIST 0x0008
2031 #define PNG_FREE_ICCP 0x0010
2032 #define PNG_FREE_SPLT 0x0020
2033 #define PNG_FREE_ROWS 0x0040
2034 #define PNG_FREE_PCAL 0x0080
2035 #define PNG_FREE_SCAL 0x0100
2036 #define PNG_FREE_UNKN 0x0200
2037 #define PNG_FREE_LIST 0x0400
2038 #define PNG_FREE_PLTE 0x1000
2039 #define PNG_FREE_TRNS 0x2000
2040 #define PNG_FREE_TEXT 0x4000
2041 #define PNG_FREE_ALL  0x7fff
2042 #define PNG_FREE_MUL  0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
2043 
2044 #ifdef PNG_USER_MEM_SUPPORTED
2045 extern PNG_EXPORT(png_voidp,png_malloc_default) PNGARG((png_structp png_ptr,
2046    png_uint_32 size));
2047 extern PNG_EXPORT(void,png_free_default) PNGARG((png_structp png_ptr,
2048    png_voidp ptr));
2049 #endif
2050 
2051 extern PNG_EXPORT(png_voidp,png_memcpy_check) PNGARG((png_structp png_ptr,
2052    png_voidp s1, png_voidp s2, png_uint_32 size));
2053 
2054 extern PNG_EXPORT(png_voidp,png_memset_check) PNGARG((png_structp png_ptr,
2055    png_voidp s1, int value, png_uint_32 size));
2056 
2057 #if defined(USE_FAR_KEYWORD)  /* memory model conversion function */
2058 extern void *png_far_to_near PNGARG((png_structp png_ptr,png_voidp ptr,
2059    int check));
2060 #endif /* USE_FAR_KEYWORD */
2061 
2062 /* Fatal error in PNG image of libpng - can't continue */
2063 extern PNG_EXPORT(void,png_error) PNGARG((png_structp png_ptr,
2064    png_const_charp error_message));
2065 
2066 /* The same, but the chunk name is prepended to the error string. */
2067 extern PNG_EXPORT(void,png_chunk_error) PNGARG((png_structp png_ptr,
2068    png_const_charp error_message));
2069 
2070 #ifndef PNG_NO_WARNINGS
2071 /* Non-fatal error in libpng.  Can continue, but may have a problem. */
2072 extern PNG_EXPORT(void,png_warning) PNGARG((png_structp png_ptr,
2073    png_const_charp warning_message));
2074 
2075 #ifdef PNG_READ_SUPPORTED
2076 /* Non-fatal error in libpng, chunk name is prepended to message. */
2077 extern PNG_EXPORT(void,png_chunk_warning) PNGARG((png_structp png_ptr,
2078    png_const_charp warning_message));
2079 #endif /* PNG_READ_SUPPORTED */
2080 #endif /* PNG_NO_WARNINGS */
2081 
2082 /* The png_set_<chunk> functions are for storing values in the png_info_struct.
2083  * Similarly, the png_get_<chunk> calls are used to read values from the
2084  * png_info_struct, either storing the parameters in the passed variables, or
2085  * setting pointers into the png_info_struct where the data is stored.  The
2086  * png_get_<chunk> functions return a non-zero value if the data was available
2087  * in info_ptr, or return zero and do not change any of the parameters if the
2088  * data was not available.
2089  *
2090  * These functions should be used instead of directly accessing png_info
2091  * to avoid problems with future changes in the size and internal layout of
2092  * png_info_struct.
2093  */
2094 /* Returns "flag" if chunk data is valid in info_ptr. */
2095 extern PNG_EXPORT(png_uint_32,png_get_valid) PNGARG((png_structp png_ptr,
2096 png_infop info_ptr, png_uint_32 flag));
2097 
2098 /* Returns number of bytes needed to hold a transformed row. */
2099 extern PNG_EXPORT(png_uint_32,png_get_rowbytes) PNGARG((png_structp png_ptr,
2100 png_infop info_ptr));
2101 
2102 #if defined(PNG_INFO_IMAGE_SUPPORTED)
2103 /* Returns row_pointers, which is an array of pointers to scanlines that was
2104 returned from png_read_png(). */
2105 extern PNG_EXPORT(png_bytepp,png_get_rows) PNGARG((png_structp png_ptr,
2106 png_infop info_ptr));
2107 /* Set row_pointers, which is an array of pointers to scanlines for use
2108 by png_write_png(). */
2109 extern PNG_EXPORT(void,png_set_rows) PNGARG((png_structp png_ptr,
2110    png_infop info_ptr, png_bytepp row_pointers));
2111 #endif
2112 
2113 /* Returns number of color channels in image. */
2114 extern PNG_EXPORT(png_byte,png_get_channels) PNGARG((png_structp png_ptr,
2115 png_infop info_ptr));
2116 
2117 #ifdef PNG_EASY_ACCESS_SUPPORTED
2118 /* Returns image width in pixels. */
2119 extern PNG_EXPORT(png_uint_32, png_get_image_width) PNGARG((png_structp
2120 png_ptr, png_infop info_ptr));
2121 
2122 /* Returns image height in pixels. */
2123 extern PNG_EXPORT(png_uint_32, png_get_image_height) PNGARG((png_structp
2124 png_ptr, png_infop info_ptr));
2125 
2126 /* Returns image bit_depth. */
2127 extern PNG_EXPORT(png_byte, png_get_bit_depth) PNGARG((png_structp
2128 png_ptr, png_infop info_ptr));
2129 
2130 /* Returns image color_type. */
2131 extern PNG_EXPORT(png_byte, png_get_color_type) PNGARG((png_structp
2132 png_ptr, png_infop info_ptr));
2133 
2134 /* Returns image filter_type. */
2135 extern PNG_EXPORT(png_byte, png_get_filter_type) PNGARG((png_structp
2136 png_ptr, png_infop info_ptr));
2137 
2138 /* Returns image interlace_type. */
2139 extern PNG_EXPORT(png_byte, png_get_interlace_type) PNGARG((png_structp
2140 png_ptr, png_infop info_ptr));
2141 
2142 /* Returns image compression_type. */
2143 extern PNG_EXPORT(png_byte, png_get_compression_type) PNGARG((png_structp
2144 png_ptr, png_infop info_ptr));
2145 
2146 /* Returns image resolution in pixels per meter, from pHYs chunk data. */
2147 extern PNG_EXPORT(png_uint_32, png_get_pixels_per_meter) PNGARG((png_structp
2148 png_ptr, png_infop info_ptr));
2149 extern PNG_EXPORT(png_uint_32, png_get_x_pixels_per_meter) PNGARG((png_structp
2150 png_ptr, png_infop info_ptr));
2151 extern PNG_EXPORT(png_uint_32, png_get_y_pixels_per_meter) PNGARG((png_structp
2152 png_ptr, png_infop info_ptr));
2153 
2154 /* Returns pixel aspect ratio, computed from pHYs chunk data.  */
2155 #ifdef PNG_FLOATING_POINT_SUPPORTED
2156 extern PNG_EXPORT(float, png_get_pixel_aspect_ratio) PNGARG((png_structp
2157 png_ptr, png_infop info_ptr));
2158 #endif
2159 
2160 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
2161 extern PNG_EXPORT(png_int_32, png_get_x_offset_pixels) PNGARG((png_structp
2162 png_ptr, png_infop info_ptr));
2163 extern PNG_EXPORT(png_int_32, png_get_y_offset_pixels) PNGARG((png_structp
2164 png_ptr, png_infop info_ptr));
2165 extern PNG_EXPORT(png_int_32, png_get_x_offset_microns) PNGARG((png_structp
2166 png_ptr, png_infop info_ptr));
2167 extern PNG_EXPORT(png_int_32, png_get_y_offset_microns) PNGARG((png_structp
2168 png_ptr, png_infop info_ptr));
2169 
2170 #endif /* PNG_EASY_ACCESS_SUPPORTED */
2171 
2172 /* Returns pointer to signature string read from PNG header */
2173 extern PNG_EXPORT(png_bytep,png_get_signature) PNGARG((png_structp png_ptr,
2174 png_infop info_ptr));
2175 
2176 #if defined(PNG_bKGD_SUPPORTED)
2177 extern PNG_EXPORT(png_uint_32,png_get_bKGD) PNGARG((png_structp png_ptr,
2178    png_infop info_ptr, png_color_16p *background));
2179 #endif
2180 
2181 #if defined(PNG_bKGD_SUPPORTED)
2182 extern PNG_EXPORT(void,png_set_bKGD) PNGARG((png_structp png_ptr,
2183    png_infop info_ptr, png_color_16p background));
2184 #endif
2185 
2186 #if defined(PNG_cHRM_SUPPORTED)
2187 #ifdef PNG_FLOATING_POINT_SUPPORTED
2188 extern PNG_EXPORT(png_uint_32,png_get_cHRM) PNGARG((png_structp png_ptr,
2189    png_infop info_ptr, double *white_x, double *white_y, double *red_x,
2190    double *red_y, double *green_x, double *green_y, double *blue_x,
2191    double *blue_y));
2192 #endif
2193 #ifdef PNG_FIXED_POINT_SUPPORTED
2194 extern PNG_EXPORT(png_uint_32,png_get_cHRM_fixed) PNGARG((png_structp png_ptr,
2195    png_infop info_ptr, png_fixed_point *int_white_x, png_fixed_point
2196    *int_white_y, png_fixed_point *int_red_x, png_fixed_point *int_red_y,
2197    png_fixed_point *int_green_x, png_fixed_point *int_green_y, png_fixed_point
2198    *int_blue_x, png_fixed_point *int_blue_y));
2199 #endif
2200 #endif
2201 
2202 #if defined(PNG_cHRM_SUPPORTED)
2203 #ifdef PNG_FLOATING_POINT_SUPPORTED
2204 extern PNG_EXPORT(void,png_set_cHRM) PNGARG((png_structp png_ptr,
2205    png_infop info_ptr, double white_x, double white_y, double red_x,
2206    double red_y, double green_x, double green_y, double blue_x, double blue_y));
2207 #endif
2208 #ifdef PNG_FIXED_POINT_SUPPORTED
2209 extern PNG_EXPORT(void,png_set_cHRM_fixed) PNGARG((png_structp png_ptr,
2210    png_infop info_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y,
2211    png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
2212    int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
2213    png_fixed_point int_blue_y));
2214 #endif
2215 #endif
2216 
2217 #if defined(PNG_gAMA_SUPPORTED)
2218 #ifdef PNG_FLOATING_POINT_SUPPORTED
2219 extern PNG_EXPORT(png_uint_32,png_get_gAMA) PNGARG((png_structp png_ptr,
2220    png_infop info_ptr, double *file_gamma));
2221 #endif
2222 extern PNG_EXPORT(png_uint_32,png_get_gAMA_fixed) PNGARG((png_structp png_ptr,
2223    png_infop info_ptr, png_fixed_point *int_file_gamma));
2224 #endif
2225 
2226 #if defined(PNG_gAMA_SUPPORTED)
2227 #ifdef PNG_FLOATING_POINT_SUPPORTED
2228 extern PNG_EXPORT(void,png_set_gAMA) PNGARG((png_structp png_ptr,
2229    png_infop info_ptr, double file_gamma));
2230 #endif
2231 extern PNG_EXPORT(void,png_set_gAMA_fixed) PNGARG((png_structp png_ptr,
2232    png_infop info_ptr, png_fixed_point int_file_gamma));
2233 #endif
2234 
2235 #if defined(PNG_hIST_SUPPORTED)
2236 extern PNG_EXPORT(png_uint_32,png_get_hIST) PNGARG((png_structp png_ptr,
2237    png_infop info_ptr, png_uint_16p *hist));
2238 #endif
2239 
2240 #if defined(PNG_hIST_SUPPORTED)
2241 extern PNG_EXPORT(void,png_set_hIST) PNGARG((png_structp png_ptr,
2242    png_infop info_ptr, png_uint_16p hist));
2243 #endif
2244 
2245 extern PNG_EXPORT(png_uint_32,png_get_IHDR) PNGARG((png_structp png_ptr,
2246    png_infop info_ptr, png_uint_32 *width, png_uint_32 *height,
2247    int *bit_depth, int *color_type, int *interlace_method,
2248    int *compression_method, int *filter_method));
2249 
2250 extern PNG_EXPORT(void,png_set_IHDR) PNGARG((png_structp png_ptr,
2251    png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
2252    int color_type, int interlace_method, int compression_method,
2253    int filter_method));
2254 
2255 #if defined(PNG_oFFs_SUPPORTED)
2256 extern PNG_EXPORT(png_uint_32,png_get_oFFs) PNGARG((png_structp png_ptr,
2257    png_infop info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
2258    int *unit_type));
2259 #endif
2260 
2261 #if defined(PNG_oFFs_SUPPORTED)
2262 extern PNG_EXPORT(void,png_set_oFFs) PNGARG((png_structp png_ptr,
2263    png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2264    int unit_type));
2265 #endif
2266 
2267 #if defined(PNG_pCAL_SUPPORTED)
2268 extern PNG_EXPORT(png_uint_32,png_get_pCAL) PNGARG((png_structp png_ptr,
2269    png_infop info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1,
2270    int *type, int *nparams, png_charp *units, png_charpp *params));
2271 #endif
2272 
2273 #if defined(PNG_pCAL_SUPPORTED)
2274 extern PNG_EXPORT(void,png_set_pCAL) PNGARG((png_structp png_ptr,
2275    png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1,
2276    int type, int nparams, png_charp units, png_charpp params));
2277 #endif
2278 
2279 #if defined(PNG_pHYs_SUPPORTED)
2280 extern PNG_EXPORT(png_uint_32,png_get_pHYs) PNGARG((png_structp png_ptr,
2281    png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
2282 #endif
2283 
2284 #if defined(PNG_pHYs_SUPPORTED)
2285 extern PNG_EXPORT(void,png_set_pHYs) PNGARG((png_structp png_ptr,
2286    png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2287 #endif
2288 
2289 extern PNG_EXPORT(png_uint_32,png_get_PLTE) PNGARG((png_structp png_ptr,
2290    png_infop info_ptr, png_colorp *palette, int *num_palette));
2291 
2292 extern PNG_EXPORT(void,png_set_PLTE) PNGARG((png_structp png_ptr,
2293    png_infop info_ptr, png_colorp palette, int num_palette));
2294 
2295 #if defined(PNG_sBIT_SUPPORTED)
2296 extern PNG_EXPORT(png_uint_32,png_get_sBIT) PNGARG((png_structp png_ptr,
2297    png_infop info_ptr, png_color_8p *sig_bit));
2298 #endif
2299 
2300 #if defined(PNG_sBIT_SUPPORTED)
2301 extern PNG_EXPORT(void,png_set_sBIT) PNGARG((png_structp png_ptr,
2302    png_infop info_ptr, png_color_8p sig_bit));
2303 #endif
2304 
2305 #if defined(PNG_sRGB_SUPPORTED)
2306 extern PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr,
2307    png_infop info_ptr, int *intent));
2308 #endif
2309 
2310 #if defined(PNG_sRGB_SUPPORTED)
2311 extern PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr,
2312    png_infop info_ptr, int intent));
2313 extern PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr,
2314    png_infop info_ptr, int intent));
2315 #endif
2316 
2317 #if defined(PNG_iCCP_SUPPORTED)
2318 extern PNG_EXPORT(png_uint_32,png_get_iCCP) PNGARG((png_structp png_ptr,
2319    png_infop info_ptr, png_charpp name, int *compression_type,
2320    png_charpp profile, png_uint_32 *proflen));
2321    /* Note to maintainer: profile should be png_bytepp */
2322 #endif
2323 
2324 #if defined(PNG_iCCP_SUPPORTED)
2325 extern PNG_EXPORT(void,png_set_iCCP) PNGARG((png_structp png_ptr,
2326    png_infop info_ptr, png_charp name, int compression_type,
2327    png_charp profile, png_uint_32 proflen));
2328    /* Note to maintainer: profile should be png_bytep */
2329 #endif
2330 
2331 #if defined(PNG_sPLT_SUPPORTED)
2332 extern PNG_EXPORT(png_uint_32,png_get_sPLT) PNGARG((png_structp png_ptr,
2333    png_infop info_ptr, png_sPLT_tpp entries));
2334 #endif
2335 
2336 #if defined(PNG_sPLT_SUPPORTED)
2337 extern PNG_EXPORT(void,png_set_sPLT) PNGARG((png_structp png_ptr,
2338    png_infop info_ptr, png_sPLT_tp entries, int nentries));
2339 #endif
2340 
2341 #if defined(PNG_TEXT_SUPPORTED)
2342 /* png_get_text also returns the number of text chunks in *num_text */
2343 extern PNG_EXPORT(png_uint_32,png_get_text) PNGARG((png_structp png_ptr,
2344    png_infop info_ptr, png_textp *text_ptr, int *num_text));
2345 #endif
2346 
2347 /*
2348  *  Note while png_set_text() will accept a structure whose text,
2349  *  language, and  translated keywords are NULL pointers, the structure
2350  *  returned by png_get_text will always contain regular
2351  *  zero-terminated C strings.  They might be empty strings but
2352  *  they will never be NULL pointers.
2353  */
2354 
2355 #if defined(PNG_TEXT_SUPPORTED)
2356 extern PNG_EXPORT(void,png_set_text) PNGARG((png_structp png_ptr,
2357    png_infop info_ptr, png_textp text_ptr, int num_text));
2358 #endif
2359 
2360 #if defined(PNG_tIME_SUPPORTED)
2361 extern PNG_EXPORT(png_uint_32,png_get_tIME) PNGARG((png_structp png_ptr,
2362    png_infop info_ptr, png_timep *mod_time));
2363 #endif
2364 
2365 #if defined(PNG_tIME_SUPPORTED)
2366 extern PNG_EXPORT(void,png_set_tIME) PNGARG((png_structp png_ptr,
2367    png_infop info_ptr, png_timep mod_time));
2368 #endif
2369 
2370 #if defined(PNG_tRNS_SUPPORTED)
2371 extern PNG_EXPORT(png_uint_32,png_get_tRNS) PNGARG((png_structp png_ptr,
2372    png_infop info_ptr, png_bytep *trans, int *num_trans,
2373    png_color_16p *trans_values));
2374 #endif
2375 
2376 #if defined(PNG_tRNS_SUPPORTED)
2377 extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
2378    png_infop info_ptr, png_bytep trans, int num_trans,
2379    png_color_16p trans_values));
2380 #endif
2381 
2382 #if defined(PNG_tRNS_SUPPORTED)
2383 #endif
2384 
2385 #if defined(PNG_sCAL_SUPPORTED)
2386 #ifdef PNG_FLOATING_POINT_SUPPORTED
2387 extern PNG_EXPORT(png_uint_32,png_get_sCAL) PNGARG((png_structp png_ptr,
2388    png_infop info_ptr, int *unit, double *width, double *height));
2389 #else
2390 #ifdef PNG_FIXED_POINT_SUPPORTED
2391 extern PNG_EXPORT(png_uint_32,png_get_sCAL_s) PNGARG((png_structp png_ptr,
2392    png_infop info_ptr, int *unit, png_charpp swidth, png_charpp sheight));
2393 #endif
2394 #endif
2395 #endif /* PNG_sCAL_SUPPORTED */
2396 
2397 #if defined(PNG_sCAL_SUPPORTED)
2398 #ifdef PNG_FLOATING_POINT_SUPPORTED
2399 extern PNG_EXPORT(void,png_set_sCAL) PNGARG((png_structp png_ptr,
2400    png_infop info_ptr, int unit, double width, double height));
2401 #else
2402 #ifdef PNG_FIXED_POINT_SUPPORTED
2403 extern PNG_EXPORT(void,png_set_sCAL_s) PNGARG((png_structp png_ptr,
2404    png_infop info_ptr, int unit, png_charp swidth, png_charp sheight));
2405 #endif
2406 #endif
2407 #endif /* PNG_sCAL_SUPPORTED || PNG_WRITE_sCAL_SUPPORTED */
2408 
2409 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
2410 /* provide a list of chunks and how they are to be handled, if the built-in
2411    handling or default unknown chunk handling is not desired.  Any chunks not
2412    listed will be handled in the default manner.  The IHDR and IEND chunks
2413    must not be listed.
2414       keep = 0: follow default behaviour
2415            = 1: do not keep
2416            = 2: keep only if safe-to-copy
2417            = 3: keep even if unsafe-to-copy
2418 */
2419 extern PNG_EXPORT(void, png_set_keep_unknown_chunks) PNGARG((png_structp
2420    png_ptr, int keep, png_bytep chunk_list, int num_chunks));
2421 extern PNG_EXPORT(void, png_set_unknown_chunks) PNGARG((png_structp png_ptr,
2422    png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns));
2423 extern PNG_EXPORT(void, png_set_unknown_chunk_location)
2424    PNGARG((png_structp png_ptr, png_infop info_ptr, int chunk, int location));
2425 extern PNG_EXPORT(png_uint_32,png_get_unknown_chunks) PNGARG((png_structp
2426    png_ptr, png_infop info_ptr, png_unknown_chunkpp entries));
2427 #endif
2428 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2429 PNG_EXPORT(int,png_handle_as_unknown) PNGARG((png_structp png_ptr, png_bytep
2430    chunk_name));
2431 #endif
2432 
2433 /* Png_free_data() will turn off the "valid" flag for anything it frees.
2434    If you need to turn it off for a chunk that your application has freed,
2435    you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); */
2436 extern PNG_EXPORT(void, png_set_invalid) PNGARG((png_structp png_ptr,
2437    png_infop info_ptr, int mask));
2438 
2439 #if defined(PNG_INFO_IMAGE_SUPPORTED)
2440 /* The "params" pointer is currently not used and is for future expansion. */
2441 extern PNG_EXPORT(void, png_read_png) PNGARG((png_structp png_ptr,
2442                         png_infop info_ptr,
2443                         int transforms,
2444                         png_voidp params));
2445 extern PNG_EXPORT(void, png_write_png) PNGARG((png_structp png_ptr,
2446                         png_infop info_ptr,
2447                         int transforms,
2448                         png_voidp params));
2449 #endif
2450 
2451 /* Define PNG_DEBUG at compile time for debugging information.  Higher
2452  * numbers for PNG_DEBUG mean more debugging information.  This has
2453  * only been added since version 0.95 so it is not implemented throughout
2454  * libpng yet, but more support will be added as needed.
2455  */
2456 #ifdef PNG_DEBUG
2457 #if (PNG_DEBUG > 0)
2458 #if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER)
2459 #include <crtdbg.h>
2460 #if (PNG_DEBUG > 1)
2461 #define png_debug(l,m)  _RPT0(_CRT_WARN,m)
2462 #define png_debug1(l,m,p1)  _RPT1(_CRT_WARN,m,p1)
2463 #define png_debug2(l,m,p1,p2) _RPT2(_CRT_WARN,m,p1,p2)
2464 #endif
2465 #else /* PNG_DEBUG_FILE || !_MSC_VER */
2466 #ifndef PNG_DEBUG_FILE
2467 #define PNG_DEBUG_FILE stderr
2468 #endif /* PNG_DEBUG_FILE */
2469 #if (PNG_DEBUG > 1)
2470 #define png_debug(l,m) \
2471 { \
2472      int num_tabs=l; \
2473      fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
2474        (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":"")))); \
2475 }
2476 #define png_debug1(l,m,p1) \
2477 { \
2478      int num_tabs=l; \
2479      fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
2480        (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1); \
2481 }
2482 #define png_debug2(l,m,p1,p2) \
2483 { \
2484      int num_tabs=l; \
2485      fprintf(PNG_DEBUG_FILE,"%s"m,(num_tabs==1 ? "\t" : \
2486        (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1,p2); \
2487 }
2488 #endif /* (PNG_DEBUG > 1) */
2489 #endif /* _MSC_VER */
2490 #endif /* (PNG_DEBUG > 0) */
2491 #endif /* PNG_DEBUG */
2492 #ifndef png_debug
2493 #define png_debug(l, m)
2494 #endif
2495 #ifndef png_debug1
2496 #define png_debug1(l, m, p1)
2497 #endif
2498 #ifndef png_debug2
2499 #define png_debug2(l, m, p1, p2)
2500 #endif
2501 
2502 extern PNG_EXPORT(png_charp,png_get_copyright) PNGARG((png_structp png_ptr));
2503 extern PNG_EXPORT(png_charp,png_get_header_ver) PNGARG((png_structp png_ptr));
2504 extern PNG_EXPORT(png_charp,png_get_header_version) PNGARG((png_structp png_ptr));
2505 extern PNG_EXPORT(png_charp,png_get_libpng_ver) PNGARG((png_structp png_ptr));
2506 
2507 #ifdef PNG_MNG_FEATURES_SUPPORTED
2508 extern PNG_EXPORT(png_uint_32,png_permit_mng_features) PNGARG((png_structp
2509    png_ptr, png_uint_32 mng_features_permitted));
2510 #endif
2511 
2512 /* For use in png_set_keep_unknown, added to version 1.2.6 */
2513 #define PNG_HANDLE_CHUNK_AS_DEFAULT   0
2514 #define PNG_HANDLE_CHUNK_NEVER        1
2515 #define PNG_HANDLE_CHUNK_IF_SAFE      2
2516 #define PNG_HANDLE_CHUNK_ALWAYS       3
2517 
2518 /* Added to version 1.2.0 */
2519 #if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
2520 #if defined(PNG_MMX_CODE_SUPPORTED)
2521 #define PNG_ASM_FLAG_MMX_SUPPORT_COMPILED  0x01  /* not user-settable */
2522 #define PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU    0x02  /* not user-settable */
2523 #define PNG_ASM_FLAG_MMX_READ_COMBINE_ROW  0x04
2524 #define PNG_ASM_FLAG_MMX_READ_INTERLACE    0x08
2525 #define PNG_ASM_FLAG_MMX_READ_FILTER_SUB   0x10
2526 #define PNG_ASM_FLAG_MMX_READ_FILTER_UP    0x20
2527 #define PNG_ASM_FLAG_MMX_READ_FILTER_AVG   0x40
2528 #define PNG_ASM_FLAG_MMX_READ_FILTER_PAETH 0x80
2529 #define PNG_ASM_FLAGS_INITIALIZED          0x80000000  /* not user-settable */
2530 
2531 #define PNG_MMX_READ_FLAGS ( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW  \
2532                            | PNG_ASM_FLAG_MMX_READ_INTERLACE    \
2533                            | PNG_ASM_FLAG_MMX_READ_FILTER_SUB   \
2534                            | PNG_ASM_FLAG_MMX_READ_FILTER_UP    \
2535                            | PNG_ASM_FLAG_MMX_READ_FILTER_AVG   \
2536                            | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH )
2537 #define PNG_MMX_WRITE_FLAGS ( 0 )
2538 
2539 #define PNG_MMX_FLAGS ( PNG_ASM_FLAG_MMX_SUPPORT_COMPILED \
2540                       | PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU   \
2541                       | PNG_MMX_READ_FLAGS                \
2542                       | PNG_MMX_WRITE_FLAGS )
2543 
2544 #define PNG_SELECT_READ   1
2545 #define PNG_SELECT_WRITE  2
2546 #endif /* PNG_MMX_CODE_SUPPORTED */
2547 
2548 #if !defined(PNG_1_0_X)
2549 /* pngget.c */
2550 extern PNG_EXPORT(png_uint_32,png_get_mmx_flagmask)
2551    PNGARG((int flag_select, int *compilerID));
2552 
2553 /* pngget.c */
2554 extern PNG_EXPORT(png_uint_32,png_get_asm_flagmask)
2555    PNGARG((int flag_select));
2556 
2557 /* pngget.c */
2558 extern PNG_EXPORT(png_uint_32,png_get_asm_flags)
2559    PNGARG((png_structp png_ptr));
2560 
2561 /* pngget.c */
2562 extern PNG_EXPORT(png_byte,png_get_mmx_bitdepth_threshold)
2563    PNGARG((png_structp png_ptr));
2564 
2565 /* pngget.c */
2566 extern PNG_EXPORT(png_uint_32,png_get_mmx_rowbytes_threshold)
2567    PNGARG((png_structp png_ptr));
2568 
2569 /* pngset.c */
2570 extern PNG_EXPORT(void,png_set_asm_flags)
2571    PNGARG((png_structp png_ptr, png_uint_32 asm_flags));
2572 
2573 /* pngset.c */
2574 extern PNG_EXPORT(void,png_set_mmx_thresholds)
2575    PNGARG((png_structp png_ptr, png_byte mmx_bitdepth_threshold,
2576    png_uint_32 mmx_rowbytes_threshold));
2577 
2578 #endif /* PNG_1_0_X */
2579 
2580 #if !defined(PNG_1_0_X)
2581 /* png.c, pnggccrd.c, or pngvcrd.c */
2582 extern PNG_EXPORT(int,png_mmx_support) PNGARG((void));
2583 #endif /* PNG_ASSEMBLER_CODE_SUPPORTED */
2584 
2585 /* Strip the prepended error numbers ("#nnn ") from error and warning
2586  * messages before passing them to the error or warning handler. */
2587 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
2588 extern PNG_EXPORT(void,png_set_strip_error_numbers) PNGARG((png_structp
2589    png_ptr, png_uint_32 strip_mode));
2590 #endif
2591 
2592 #endif /* PNG_1_0_X */
2593 
2594 /* Added at libpng-1.2.6 */
2595 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
2596 extern PNG_EXPORT(void,png_set_user_limits) PNGARG((png_structp
2597    png_ptr, png_uint_32 user_width_max, png_uint_32 user_height_max));
2598 extern PNG_EXPORT(png_uint_32,png_get_user_width_max) PNGARG((png_structp
2599    png_ptr));
2600 extern PNG_EXPORT(png_uint_32,png_get_user_height_max) PNGARG((png_structp
2601    png_ptr));
2602 #endif
2603 
2604 /* Maintainer: Put new public prototypes here ^, in libpng.3, and project defs */
2605 
2606 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2607 /* With these routines we avoid an integer divide, which will be slower on
2608  * most machines.  However, it does take more operations than the corresponding
2609  * divide method, so it may be slower on a few RISC systems.  There are two
2610  * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2611  *
2612  * Note that the rounding factors are NOT supposed to be the same!  128 and
2613  * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2614  * standard method.
2615  *
2616  * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2617  */
2618 
2619  /* fg and bg should be in `gamma 1.0' space; alpha is the opacity          */
2620 
2621 #  define png_composite(composite, fg, alpha, bg)                            \
2622      { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) * (png_uint_16)(alpha) \
2623                         +        (png_uint_16)(bg)*(png_uint_16)(255 -       \
2624                         (png_uint_16)(alpha)) + (png_uint_16)128);           \
2625        (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
2626 
2627 #  define png_composite_16(composite, fg, alpha, bg)                         \
2628      { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) * (png_uint_32)(alpha) \
2629                         + (png_uint_32)(bg)*(png_uint_32)(65535L -           \
2630                         (png_uint_32)(alpha)) + (png_uint_32)32768L);        \
2631        (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
2632 
2633 #else  /* standard method using integer division */
2634 
2635 #  define png_composite(composite, fg, alpha, bg)                            \
2636      (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) +    \
2637        (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) +       \
2638        (png_uint_16)127) / 255)
2639 
2640 #  define png_composite_16(composite, fg, alpha, bg)                         \
2641      (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2642        (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) +      \
2643        (png_uint_32)32767) / (png_uint_32)65535L)
2644 
2645 #endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
2646 
2647 /* Inline macros to do direct reads of bytes from the input buffer.  These
2648  * require that you are using an architecture that uses PNG byte ordering
2649  * (MSB first) and supports unaligned data storage.  I think that PowerPC
2650  * in big-endian mode and 680x0 are the only ones that will support this.
2651  * The x86 line of processors definitely do not.  The png_get_int_32()
2652  * routine also assumes we are using two's complement format for negative
2653  * values, which is almost certainly true.
2654  */
2655 #if defined(PNG_READ_BIG_ENDIAN_SUPPORTED)
2656 #  define png_get_uint_32(buf) ( *((png_uint_32p) (buf)))
2657 #  define png_get_uint_16(buf) ( *((png_uint_16p) (buf)))
2658 #  define png_get_int_32(buf)  ( *((png_int_32p)  (buf)))
2659 #else
2660 extern PNG_EXPORT(png_uint_32,png_get_uint_32) PNGARG((png_bytep buf));
2661 extern PNG_EXPORT(png_uint_16,png_get_uint_16) PNGARG((png_bytep buf));
2662 extern PNG_EXPORT(png_int_32,png_get_int_32) PNGARG((png_bytep buf));
2663 #endif /* !PNG_READ_BIG_ENDIAN_SUPPORTED */
2664 extern PNG_EXPORT(png_uint_32,png_get_uint_31)
2665   PNGARG((png_structp png_ptr, png_bytep buf));
2666 /* No png_get_int_16 -- may be added if there's a real need for it. */
2667 
2668 /* Place a 32-bit number into a buffer in PNG byte order (big-endian).
2669  */
2670 extern PNG_EXPORT(void,png_save_uint_32)
2671    PNGARG((png_bytep buf, png_uint_32 i));
2672 extern PNG_EXPORT(void,png_save_int_32)
2673    PNGARG((png_bytep buf, png_int_32 i));
2674 
2675 /* Place a 16-bit number into a buffer in PNG byte order.
2676  * The parameter is declared unsigned int, not png_uint_16,
2677  * just to avoid potential problems on pre-ANSI C compilers.
2678  */
2679 extern PNG_EXPORT(void,png_save_uint_16)
2680    PNGARG((png_bytep buf, unsigned int i));
2681 /* No png_save_int_16 -- may be added if there's a real need for it. */
2682 
2683 /* ************************************************************************* */
2684 
2685 /* These next functions are used internally in the code.  They generally
2686  * shouldn't be used unless you are writing code to add or replace some
2687  * functionality in libpng.  More information about most functions can
2688  * be found in the files where the functions are located.
2689  */
2690 
2691 
2692 /* Various modes of operation, that are visible to applications because
2693  * they are used for unknown chunk location.
2694  */
2695 #define PNG_HAVE_IHDR               0x01
2696 #define PNG_HAVE_PLTE               0x02
2697 #define PNG_HAVE_IDAT               0x04
2698 #define PNG_AFTER_IDAT              0x08 /* Have complete zlib datastream */
2699 #define PNG_HAVE_IEND               0x10
2700 
2701 #if defined(PNG_INTERNAL)
2702 
2703 /* More modes of operation.  Note that after an init, mode is set to
2704  * zero automatically when the structure is created.
2705  */
2706 #define PNG_HAVE_gAMA               0x20
2707 #define PNG_HAVE_cHRM               0x40
2708 #define PNG_HAVE_sRGB               0x80
2709 #define PNG_HAVE_CHUNK_HEADER      0x100
2710 #define PNG_WROTE_tIME             0x200
2711 #define PNG_WROTE_INFO_BEFORE_PLTE 0x400
2712 #define PNG_BACKGROUND_IS_GRAY     0x800
2713 #define PNG_HAVE_PNG_SIGNATURE    0x1000
2714 #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
2715 
2716 /* flags for the transformations the PNG library does on the image data */
2717 #define PNG_BGR                0x0001
2718 #define PNG_INTERLACE          0x0002
2719 #define PNG_PACK               0x0004
2720 #define PNG_SHIFT              0x0008
2721 #define PNG_SWAP_BYTES         0x0010
2722 #define PNG_INVERT_MONO        0x0020
2723 #define PNG_DITHER             0x0040
2724 #define PNG_BACKGROUND         0x0080
2725 #define PNG_BACKGROUND_EXPAND  0x0100
2726                           /*   0x0200 unused */
2727 #define PNG_16_TO_8            0x0400
2728 #define PNG_RGBA               0x0800
2729 #define PNG_EXPAND             0x1000
2730 #define PNG_GAMMA              0x2000
2731 #define PNG_GRAY_TO_RGB        0x4000
2732 #define PNG_FILLER             0x8000L
2733 #define PNG_PACKSWAP          0x10000L
2734 #define PNG_SWAP_ALPHA        0x20000L
2735 #define PNG_STRIP_ALPHA       0x40000L
2736 #define PNG_INVERT_ALPHA      0x80000L
2737 #define PNG_USER_TRANSFORM   0x100000L
2738 #define PNG_RGB_TO_GRAY_ERR  0x200000L
2739 #define PNG_RGB_TO_GRAY_WARN 0x400000L
2740 #define PNG_RGB_TO_GRAY      0x600000L  /* two bits, RGB_TO_GRAY_ERR|WARN */
2741                        /*    0x800000L     Unused */
2742 #define PNG_ADD_ALPHA       0x1000000L  /* Added to libpng-1.2.7 */
2743 #define PNG_EXPAND_tRNS     0x2000000L  /* Added to libpng-1.2.9 */
2744                        /*   0x4000000L  unused */
2745                        /*   0x8000000L  unused */
2746                        /*  0x10000000L  unused */
2747                        /*  0x20000000L  unused */
2748                        /*  0x40000000L  unused */
2749 
2750 /* flags for png_create_struct */
2751 #define PNG_STRUCT_PNG   0x0001
2752 #define PNG_STRUCT_INFO  0x0002
2753 
2754 /* Scaling factor for filter heuristic weighting calculations */
2755 #define PNG_WEIGHT_SHIFT 8
2756 #define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
2757 #define PNG_COST_SHIFT 3
2758 #define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
2759 
2760 /* flags for the png_ptr->flags rather than declaring a byte for each one */
2761 #define PNG_FLAG_ZLIB_CUSTOM_STRATEGY     0x0001
2762 #define PNG_FLAG_ZLIB_CUSTOM_LEVEL        0x0002
2763 #define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL    0x0004
2764 #define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS  0x0008
2765 #define PNG_FLAG_ZLIB_CUSTOM_METHOD       0x0010
2766 #define PNG_FLAG_ZLIB_FINISHED            0x0020
2767 #define PNG_FLAG_ROW_INIT                 0x0040
2768 #define PNG_FLAG_FILLER_AFTER             0x0080
2769 #define PNG_FLAG_CRC_ANCILLARY_USE        0x0100
2770 #define PNG_FLAG_CRC_ANCILLARY_NOWARN     0x0200
2771 #define PNG_FLAG_CRC_CRITICAL_USE         0x0400
2772 #define PNG_FLAG_CRC_CRITICAL_IGNORE      0x0800
2773 #define PNG_FLAG_FREE_PLTE                0x1000
2774 #define PNG_FLAG_FREE_TRNS                0x2000
2775 #define PNG_FLAG_FREE_HIST                0x4000
2776 #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS      0x8000L
2777 #define PNG_FLAG_KEEP_UNSAFE_CHUNKS       0x10000L
2778 #define PNG_FLAG_LIBRARY_MISMATCH         0x20000L
2779 #define PNG_FLAG_STRIP_ERROR_NUMBERS      0x40000L
2780 #define PNG_FLAG_STRIP_ERROR_TEXT         0x80000L
2781 #define PNG_FLAG_MALLOC_NULL_MEM_OK       0x100000L
2782 #define PNG_FLAG_ADD_ALPHA                0x200000L  /* Added to libpng-1.2.8 */
2783 #define PNG_FLAG_STRIP_ALPHA              0x400000L  /* Added to libpng-1.2.8 */
2784                                   /*      0x800000L  unused */
2785                                   /*     0x1000000L  unused */
2786                                   /*     0x2000000L  unused */
2787                                   /*     0x4000000L  unused */
2788                                   /*     0x8000000L  unused */
2789                                   /*    0x10000000L  unused */
2790                                   /*    0x20000000L  unused */
2791                                   /*    0x40000000L  unused */
2792 
2793 #define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
2794                                      PNG_FLAG_CRC_ANCILLARY_NOWARN)
2795 
2796 #define PNG_FLAG_CRC_CRITICAL_MASK  (PNG_FLAG_CRC_CRITICAL_USE | \
2797                                      PNG_FLAG_CRC_CRITICAL_IGNORE)
2798 
2799 #define PNG_FLAG_CRC_MASK           (PNG_FLAG_CRC_ANCILLARY_MASK | \
2800                                      PNG_FLAG_CRC_CRITICAL_MASK)
2801 
2802 /* save typing and make code easier to understand */
2803 
2804 #define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
2805    abs((int)((c1).green) - (int)((c2).green)) + \
2806    abs((int)((c1).blue) - (int)((c2).blue)))
2807 
2808 /* Added to libpng-1.2.6 JB */
2809 #define PNG_ROWBYTES(pixel_bits, width) \
2810     ((pixel_bits) >= 8 ? \
2811     ((width) * (((png_uint_32)(pixel_bits)) >> 3)) : \
2812     (( ((width) * ((png_uint_32)(pixel_bits))) + 7) >> 3) )
2813 
2814 /* PNG_OUT_OF_RANGE returns true if value is outside the range
2815    ideal-delta..ideal+delta.  Each argument is evaluated twice.
2816    "ideal" and "delta" should be constants, normally simple
2817    integers, "value" a variable. Added to libpng-1.2.6 JB */
2818 #define PNG_OUT_OF_RANGE(value, ideal, delta) \
2819         ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
2820 
2821 /* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
2822 #if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
2823 /* place to hold the signature string for a PNG file. */
2824 #ifdef PNG_USE_GLOBAL_ARRAYS
2825    PNG_EXPORT_VAR (PNG_CONST png_byte FARDATA) png_sig[8];
2826 #else
2827 #endif
2828 #endif /* PNG_NO_EXTERN */
2829 
2830 /* Constant strings for known chunk types.  If you need to add a chunk,
2831  * define the name here, and add an invocation of the macro in png.c and
2832  * wherever it's needed.
2833  */
2834 #define PNG_IHDR png_byte png_IHDR[5] = { 73,  72,  68,  82, '\0'}
2835 #define PNG_IDAT png_byte png_IDAT[5] = { 73,  68,  65,  84, '\0'}
2836 #define PNG_IEND png_byte png_IEND[5] = { 73,  69,  78,  68, '\0'}
2837 #define PNG_PLTE png_byte png_PLTE[5] = { 80,  76,  84,  69, '\0'}
2838 #define PNG_bKGD png_byte png_bKGD[5] = { 98,  75,  71,  68, '\0'}
2839 #define PNG_cHRM png_byte png_cHRM[5] = { 99,  72,  82,  77, '\0'}
2840 #define PNG_gAMA png_byte png_gAMA[5] = {103,  65,  77,  65, '\0'}
2841 #define PNG_hIST png_byte png_hIST[5] = {104,  73,  83,  84, '\0'}
2842 #define PNG_iCCP png_byte png_iCCP[5] = {105,  67,  67,  80, '\0'}
2843 #define PNG_iTXt png_byte png_iTXt[5] = {105,  84,  88, 116, '\0'}
2844 #define PNG_oFFs png_byte png_oFFs[5] = {111,  70,  70, 115, '\0'}
2845 #define PNG_pCAL png_byte png_pCAL[5] = {112,  67,  65,  76, '\0'}
2846 #define PNG_sCAL png_byte png_sCAL[5] = {115,  67,  65,  76, '\0'}
2847 #define PNG_pHYs png_byte png_pHYs[5] = {112,  72,  89, 115, '\0'}
2848 #define PNG_sBIT png_byte png_sBIT[5] = {115,  66,  73,  84, '\0'}
2849 #define PNG_sPLT png_byte png_sPLT[5] = {115,  80,  76,  84, '\0'}
2850 #define PNG_sRGB png_byte png_sRGB[5] = {115,  82,  71,  66, '\0'}
2851 #define PNG_tEXt png_byte png_tEXt[5] = {116,  69,  88, 116, '\0'}
2852 #define PNG_tIME png_byte png_tIME[5] = {116,  73,  77,  69, '\0'}
2853 #define PNG_tRNS png_byte png_tRNS[5] = {116,  82,  78,  83, '\0'}
2854 #define PNG_zTXt png_byte png_zTXt[5] = {122,  84,  88, 116, '\0'}
2855 
2856 #ifdef PNG_USE_GLOBAL_ARRAYS
2857 PNG_EXPORT_VAR (png_byte FARDATA) png_IHDR[5];
2858 PNG_EXPORT_VAR (png_byte FARDATA) png_IDAT[5];
2859 PNG_EXPORT_VAR (png_byte FARDATA) png_IEND[5];
2860 PNG_EXPORT_VAR (png_byte FARDATA) png_PLTE[5];
2861 PNG_EXPORT_VAR (png_byte FARDATA) png_bKGD[5];
2862 PNG_EXPORT_VAR (png_byte FARDATA) png_cHRM[5];
2863 PNG_EXPORT_VAR (png_byte FARDATA) png_gAMA[5];
2864 PNG_EXPORT_VAR (png_byte FARDATA) png_hIST[5];
2865 PNG_EXPORT_VAR (png_byte FARDATA) png_iCCP[5];
2866 PNG_EXPORT_VAR (png_byte FARDATA) png_iTXt[5];
2867 PNG_EXPORT_VAR (png_byte FARDATA) png_oFFs[5];
2868 PNG_EXPORT_VAR (png_byte FARDATA) png_pCAL[5];
2869 PNG_EXPORT_VAR (png_byte FARDATA) png_sCAL[5];
2870 PNG_EXPORT_VAR (png_byte FARDATA) png_pHYs[5];
2871 PNG_EXPORT_VAR (png_byte FARDATA) png_sBIT[5];
2872 PNG_EXPORT_VAR (png_byte FARDATA) png_sPLT[5];
2873 PNG_EXPORT_VAR (png_byte FARDATA) png_sRGB[5];
2874 PNG_EXPORT_VAR (png_byte FARDATA) png_tEXt[5];
2875 PNG_EXPORT_VAR (png_byte FARDATA) png_tIME[5];
2876 PNG_EXPORT_VAR (png_byte FARDATA) png_tRNS[5];
2877 PNG_EXPORT_VAR (png_byte FARDATA) png_zTXt[5];
2878 #endif /* PNG_USE_GLOBAL_ARRAYS */
2879 
2880 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
2881 /* Initialize png_ptr struct for reading, and allocate any other memory.
2882  * (old interface - DEPRECATED - use png_create_read_struct instead).
2883  */
2884 extern PNG_EXPORT(void,png_read_init) PNGARG((png_structp png_ptr));
2885 #undef png_read_init
2886 #define png_read_init(png_ptr) png_read_init_3(&png_ptr, \
2887     PNG_LIBPNG_VER_STRING,  png_sizeof(png_struct));
2888 #endif
2889 
2890 extern PNG_EXPORT(void,png_read_init_3) PNGARG((png_structpp ptr_ptr,
2891     png_const_charp user_png_ver, png_size_t png_struct_size));
2892 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
2893 extern PNG_EXPORT(void,png_read_init_2) PNGARG((png_structp png_ptr,
2894     png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
2895     png_info_size));
2896 #endif
2897 
2898 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
2899 /* Initialize png_ptr struct for writing, and allocate any other memory.
2900  * (old interface - DEPRECATED - use png_create_write_struct instead).
2901  */
2902 extern PNG_EXPORT(void,png_write_init) PNGARG((png_structp png_ptr));
2903 #undef png_write_init
2904 #define png_write_init(png_ptr) png_write_init_3(&png_ptr, \
2905     PNG_LIBPNG_VER_STRING, png_sizeof(png_struct));
2906 #endif
2907 
2908 extern PNG_EXPORT(void,png_write_init_3) PNGARG((png_structpp ptr_ptr,
2909     png_const_charp user_png_ver, png_size_t png_struct_size));
2910 extern PNG_EXPORT(void,png_write_init_2) PNGARG((png_structp png_ptr,
2911     png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
2912     png_info_size));
2913 
2914 /* Allocate memory for an internal libpng struct */
2915 PNG_EXTERN png_voidp png_create_struct PNGARG((int type));
2916 
2917 /* Free memory from internal libpng struct */
2918 PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr));
2919 
2920 PNG_EXTERN png_voidp png_create_struct_2 PNGARG((int type, png_malloc_ptr
2921   malloc_fn, png_voidp mem_ptr));
2922 PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr,
2923    png_free_ptr free_fn, png_voidp mem_ptr));
2924 
2925 /* Free any memory that info_ptr points to and reset struct. */
2926 PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr,
2927    png_infop info_ptr));
2928 
2929 #ifndef PNG_1_0_X
2930 /* Function to allocate memory for zlib. */
2931 PNG_EXTERN voidpf png_zalloc PNGARG((voidpf png_ptr, uInt items, uInt size));
2932 
2933 /* Function to free memory for zlib */
2934 PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr));
2935 
2936 #ifdef PNG_SIZE_T
2937 /* Function to convert a sizeof an item to png_sizeof item */
2938    PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size));
2939 #endif
2940 
2941 /* Next four functions are used internally as callbacks.  PNGAPI is required
2942  * but not PNG_EXPORT.  PNGAPI added at libpng version 1.2.3. */
2943 
2944 PNG_EXTERN void PNGAPI png_default_read_data PNGARG((png_structp png_ptr,
2945    png_bytep data, png_size_t length));
2946 
2947 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
2948 PNG_EXTERN void PNGAPI png_push_fill_buffer PNGARG((png_structp png_ptr,
2949    png_bytep buffer, png_size_t length));
2950 #endif
2951 
2952 PNG_EXTERN void PNGAPI png_default_write_data PNGARG((png_structp png_ptr,
2953    png_bytep data, png_size_t length));
2954 
2955 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
2956 #if !defined(PNG_NO_STDIO)
2957 PNG_EXTERN void PNGAPI png_default_flush PNGARG((png_structp png_ptr));
2958 #endif
2959 #endif
2960 #else /* PNG_1_0_X */
2961 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
2962 PNG_EXTERN void png_push_fill_buffer PNGARG((png_structp png_ptr,
2963    png_bytep buffer, png_size_t length));
2964 #endif
2965 #endif /* PNG_1_0_X */
2966 
2967 /* Reset the CRC variable */
2968 PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr));
2969 
2970 /* Write the "data" buffer to whatever output you are using. */
2971 PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr, png_bytep data,
2972    png_size_t length));
2973 
2974 /* Read data from whatever input you are using into the "data" buffer */
2975 PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data,
2976    png_size_t length));
2977 
2978 /* Read bytes into buf, and update png_ptr->crc */
2979 PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
2980    png_size_t length));
2981 
2982 /* Decompress data in a chunk that uses compression */
2983 #if defined(PNG_zTXt_SUPPORTED) || defined(PNG_iTXt_SUPPORTED) || \
2984     defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED)
2985 PNG_EXTERN png_charp png_decompress_chunk PNGARG((png_structp png_ptr,
2986    int comp_type, png_charp chunkdata, png_size_t chunklength,
2987    png_size_t prefix_length, png_size_t *data_length));
2988 #endif
2989 
2990 /* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
2991 PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip));
2992 
2993 /* Read the CRC from the file and compare it to the libpng calculated CRC */
2994 PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr));
2995 
2996 /* Calculate the CRC over a section of data.  Note that we are only
2997  * passing a maximum of 64K on systems that have this as a memory limit,
2998  * since this is the maximum buffer size we can specify.
2999  */
3000 PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr, png_bytep ptr,
3001    png_size_t length));
3002 
3003 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
3004 PNG_EXTERN void png_flush PNGARG((png_structp png_ptr));
3005 #endif
3006 
3007 /* simple function to write the signature */
3008 PNG_EXTERN void png_write_sig PNGARG((png_structp png_ptr));
3009 
3010 /* write various chunks */
3011 
3012 /* Write the IHDR chunk, and update the png_struct with the necessary
3013  * information.
3014  */
3015 PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width,
3016    png_uint_32 height,
3017    int bit_depth, int color_type, int compression_method, int filter_method,
3018    int interlace_method));
3019 
3020 PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr, png_colorp palette,
3021    png_uint_32 num_pal));
3022 
3023 PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data,
3024    png_size_t length));
3025 
3026 PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr));
3027 
3028 #if defined(PNG_WRITE_gAMA_SUPPORTED)
3029 #ifdef PNG_FLOATING_POINT_SUPPORTED
3030 PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma));
3031 #endif
3032 #ifdef PNG_FIXED_POINT_SUPPORTED
3033 PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr, png_fixed_point
3034     file_gamma));
3035 #endif
3036 #endif
3037 
3038 #if defined(PNG_WRITE_sBIT_SUPPORTED)
3039 PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr, png_color_8p sbit,
3040    int color_type));
3041 #endif
3042 
3043 #if defined(PNG_WRITE_cHRM_SUPPORTED)
3044 #ifdef PNG_FLOATING_POINT_SUPPORTED
3045 PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr,
3046    double white_x, double white_y,
3047    double red_x, double red_y, double green_x, double green_y,
3048    double blue_x, double blue_y));
3049 #endif
3050 #ifdef PNG_FIXED_POINT_SUPPORTED
3051 PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr,
3052    png_fixed_point int_white_x, png_fixed_point int_white_y,
3053    png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
3054    int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
3055    png_fixed_point int_blue_y));
3056 #endif
3057 #endif
3058 
3059 #if defined(PNG_WRITE_sRGB_SUPPORTED)
3060 PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
3061    int intent));
3062 #endif
3063 
3064 #if defined(PNG_WRITE_iCCP_SUPPORTED)
3065 PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr,
3066    png_charp name, int compression_type,
3067    png_charp profile, int proflen));
3068    /* Note to maintainer: profile should be png_bytep */
3069 #endif
3070 
3071 #if defined(PNG_WRITE_sPLT_SUPPORTED)
3072 PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr,
3073    png_sPLT_tp palette));
3074 #endif
3075 
3076 #if defined(PNG_WRITE_tRNS_SUPPORTED)
3077 PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr, png_bytep trans,
3078    png_color_16p values, int number, int color_type));
3079 #endif
3080 
3081 #if defined(PNG_WRITE_bKGD_SUPPORTED)
3082 PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr,
3083    png_color_16p values, int color_type));
3084 #endif
3085 
3086 #if defined(PNG_WRITE_hIST_SUPPORTED)
3087 PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, png_uint_16p hist,
3088    int num_hist));
3089 #endif
3090 
3091 #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
3092     defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
3093 PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
3094    png_charp key, png_charpp new_key));
3095 #endif
3096 
3097 #if defined(PNG_WRITE_tEXt_SUPPORTED)
3098 PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_charp key,
3099    png_charp text, png_size_t text_len));
3100 #endif
3101 
3102 #if defined(PNG_WRITE_zTXt_SUPPORTED)
3103 PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_charp key,
3104    png_charp text, png_size_t text_len, int compression));
3105 #endif
3106 
3107 #if defined(PNG_WRITE_iTXt_SUPPORTED)
3108 PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr,
3109    int compression, png_charp key, png_charp lang, png_charp lang_key,
3110    png_charp text));
3111 #endif
3112 
3113 #if defined(PNG_TEXT_SUPPORTED)  /* Added at version 1.0.14 and 1.2.4 */
3114 PNG_EXTERN int png_set_text_2 PNGARG((png_structp png_ptr,
3115    png_infop info_ptr, png_textp text_ptr, int num_text));
3116 #endif
3117 
3118 #if defined(PNG_WRITE_oFFs_SUPPORTED)
3119 PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr,
3120    png_int_32 x_offset, png_int_32 y_offset, int unit_type));
3121 #endif
3122 
3123 #if defined(PNG_WRITE_pCAL_SUPPORTED)
3124 PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose,
3125    png_int_32 X0, png_int_32 X1, int type, int nparams,
3126    png_charp units, png_charpp params));
3127 #endif
3128 
3129 #if defined(PNG_WRITE_pHYs_SUPPORTED)
3130 PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr,
3131    png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
3132    int unit_type));
3133 #endif
3134 
3135 #if defined(PNG_WRITE_tIME_SUPPORTED)
3136 PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr,
3137    png_timep mod_time));
3138 #endif
3139 
3140 #if defined(PNG_WRITE_sCAL_SUPPORTED)
3141 #if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
3142 PNG_EXTERN void png_write_sCAL PNGARG((png_structp png_ptr,
3143    int unit, double width, double height));
3144 #else
3145 #ifdef PNG_FIXED_POINT_SUPPORTED
3146 PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr,
3147    int unit, png_charp width, png_charp height));
3148 #endif
3149 #endif
3150 #endif
3151 
3152 /* Called when finished processing a row of data */
3153 PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr));
3154 
3155 /* Internal use only.   Called before first row of data */
3156 PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr));
3157 
3158 #if defined(PNG_READ_GAMMA_SUPPORTED)
3159 PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr));
3160 #endif
3161 
3162 /* combine a row of data, dealing with alpha, etc. if requested */
3163 PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row,
3164    int mask));
3165 
3166 #if defined(PNG_READ_INTERLACING_SUPPORTED)
3167 /* expand an interlaced row */
3168 /* OLD pre-1.0.9 interface:
3169 PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info,
3170    png_bytep row, int pass, png_uint_32 transformations));
3171  */
3172 PNG_EXTERN void png_do_read_interlace PNGARG((png_structp png_ptr));
3173 #endif
3174 
3175 /* GRR TO DO (2.0 or whenever):  simplify other internal calling interfaces */
3176 
3177 #if defined(PNG_WRITE_INTERLACING_SUPPORTED)
3178 /* grab pixels out of a row for an interlaced pass */
3179 PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info,
3180    png_bytep row, int pass));
3181 #endif
3182 
3183 /* unfilter a row */
3184 PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr,
3185    png_row_infop row_info, png_bytep row, png_bytep prev_row, int filter));
3186 
3187 /* Choose the best filter to use and filter the row data */
3188 PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
3189    png_row_infop row_info));
3190 
3191 /* Write out the filtered row. */
3192 PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr,
3193    png_bytep filtered_row));
3194 /* finish a row while reading, dealing with interlacing passes, etc. */
3195 PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
3196 
3197 /* initialize the row buffers, etc. */
3198 PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr));
3199 /* optional call to update the users info structure */
3200 PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
3201    png_infop info_ptr));
3202 
3203 /* these are the functions that do the transformations */
3204 #if defined(PNG_READ_FILLER_SUPPORTED)
3205 PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info,
3206    png_bytep row, png_uint_32 filler, png_uint_32 flags));
3207 #endif
3208 
3209 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
3210 PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info,
3211    png_bytep row));
3212 #endif
3213 
3214 #if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
3215 PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info,
3216    png_bytep row));
3217 #endif
3218 
3219 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
3220 PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info,
3221    png_bytep row));
3222 #endif
3223 
3224 #if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
3225 PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info,
3226    png_bytep row));
3227 #endif
3228 
3229 #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
3230     defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
3231 PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info,
3232    png_bytep row, png_uint_32 flags));
3233 #endif
3234 
3235 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
3236 PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info, png_bytep row));
3237 #endif
3238 
3239 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
3240 PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info, png_bytep row));
3241 #endif
3242 
3243 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
3244 PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr, png_row_infop
3245    row_info, png_bytep row));
3246 #endif
3247 
3248 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
3249 PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info,
3250    png_bytep row));
3251 #endif
3252 
3253 #if defined(PNG_READ_PACK_SUPPORTED)
3254 PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info, png_bytep row));
3255 #endif
3256 
3257 #if defined(PNG_READ_SHIFT_SUPPORTED)
3258 PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info, png_bytep row,
3259    png_color_8p sig_bits));
3260 #endif
3261 
3262 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
3263 PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info, png_bytep row));
3264 #endif
3265 
3266 #if defined(PNG_READ_16_TO_8_SUPPORTED)
3267 PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info, png_bytep row));
3268 #endif
3269 
3270 #if defined(PNG_READ_DITHER_SUPPORTED)
3271 PNG_EXTERN void png_do_dither PNGARG((png_row_infop row_info,
3272    png_bytep row, png_bytep palette_lookup, png_bytep dither_lookup));
3273 
3274 #  if defined(PNG_CORRECT_PALETTE_SUPPORTED)
3275 PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr,
3276    png_colorp palette, int num_palette));
3277 #  endif
3278 #endif
3279 
3280 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
3281 PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info, png_bytep row));
3282 #endif
3283 
3284 #if defined(PNG_WRITE_PACK_SUPPORTED)
3285 PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info,
3286    png_bytep row, png_uint_32 bit_depth));
3287 #endif
3288 
3289 #if defined(PNG_WRITE_SHIFT_SUPPORTED)
3290 PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info, png_bytep row,
3291    png_color_8p bit_depth));
3292 #endif
3293 
3294 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
3295 #if defined(PNG_READ_GAMMA_SUPPORTED)
3296 PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
3297    png_color_16p trans_values, png_color_16p background,
3298    png_color_16p background_1,
3299    png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,
3300    png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,
3301    png_uint_16pp gamma_16_to_1, int gamma_shift));
3302 #else
3303 PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
3304    png_color_16p trans_values, png_color_16p background));
3305 #endif
3306 #endif
3307 
3308 #if defined(PNG_READ_GAMMA_SUPPORTED)
3309 PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info, png_bytep row,
3310    png_bytep gamma_table, png_uint_16pp gamma_16_table,
3311    int gamma_shift));
3312 #endif
3313 
3314 #if defined(PNG_READ_EXPAND_SUPPORTED)
3315 PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info,
3316    png_bytep row, png_colorp palette, png_bytep trans, int num_trans));
3317 PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info,
3318    png_bytep row, png_color_16p trans_value));
3319 #endif
3320 
3321 /* The following decodes the appropriate chunks, and does error correction,
3322  * then calls the appropriate callback for the chunk if it is valid.
3323  */
3324 
3325 /* decode the IHDR chunk */
3326 PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr,
3327    png_uint_32 length));
3328 PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr,
3329    png_uint_32 length));
3330 PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr,
3331    png_uint_32 length));
3332 
3333 #if defined(PNG_READ_bKGD_SUPPORTED)
3334 PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr,
3335    png_uint_32 length));
3336 #endif
3337 
3338 #if defined(PNG_READ_cHRM_SUPPORTED)
3339 PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr,
3340    png_uint_32 length));
3341 #endif
3342 
3343 #if defined(PNG_READ_gAMA_SUPPORTED)
3344 PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr,
3345    png_uint_32 length));
3346 #endif
3347 
3348 #if defined(PNG_READ_hIST_SUPPORTED)
3349 PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr,
3350    png_uint_32 length));
3351 #endif
3352 
3353 #if defined(PNG_READ_iCCP_SUPPORTED)
3354 extern void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr,
3355    png_uint_32 length));
3356 #endif /* PNG_READ_iCCP_SUPPORTED */
3357 
3358 #if defined(PNG_READ_iTXt_SUPPORTED)
3359 PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3360    png_uint_32 length));
3361 #endif
3362 
3363 #if defined(PNG_READ_oFFs_SUPPORTED)
3364 PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr,
3365    png_uint_32 length));
3366 #endif
3367 
3368 #if defined(PNG_READ_pCAL_SUPPORTED)
3369 PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
3370    png_uint_32 length));
3371 #endif
3372 
3373 #if defined(PNG_READ_pHYs_SUPPORTED)
3374 PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr,
3375    png_uint_32 length));
3376 #endif
3377 
3378 #if defined(PNG_READ_sBIT_SUPPORTED)
3379 PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr,
3380    png_uint_32 length));
3381 #endif
3382 
3383 #if defined(PNG_READ_sCAL_SUPPORTED)
3384 PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
3385    png_uint_32 length));
3386 #endif
3387 
3388 #if defined(PNG_READ_sPLT_SUPPORTED)
3389 extern void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr,
3390    png_uint_32 length));
3391 #endif /* PNG_READ_sPLT_SUPPORTED */
3392 
3393 #if defined(PNG_READ_sRGB_SUPPORTED)
3394 PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr,
3395    png_uint_32 length));
3396 #endif
3397 
3398 #if defined(PNG_READ_tEXt_SUPPORTED)
3399 PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3400    png_uint_32 length));
3401 #endif
3402 
3403 #if defined(PNG_READ_tIME_SUPPORTED)
3404 PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr,
3405    png_uint_32 length));
3406 #endif
3407 
3408 #if defined(PNG_READ_tRNS_SUPPORTED)
3409 PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr,
3410    png_uint_32 length));
3411 #endif
3412 
3413 #if defined(PNG_READ_zTXt_SUPPORTED)
3414 PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3415    png_uint_32 length));
3416 #endif
3417 
3418 PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
3419    png_infop info_ptr, png_uint_32 length));
3420 
3421 PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
3422    png_bytep chunk_name));
3423 
3424 /* handle the transformations for reading and writing */
3425 PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr));
3426 PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr));
3427 
3428 PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr));
3429 
3430 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3431 PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
3432    png_infop info_ptr));
3433 PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr,
3434    png_infop info_ptr));
3435 PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr));
3436 PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr,
3437    png_uint_32 length));
3438 PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr));
3439 PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr));
3440 PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr,
3441    png_bytep buffer, png_size_t buffer_length));
3442 PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr));
3443 PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr,
3444    png_bytep buffer, png_size_t buffer_length));
3445 PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr));
3446 PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr,
3447    png_infop info_ptr, png_uint_32 length));
3448 PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr,
3449    png_infop info_ptr));
3450 PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr,
3451    png_infop info_ptr));
3452 PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr, png_bytep row));
3453 PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr,
3454    png_infop info_ptr));
3455 PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr,
3456    png_infop info_ptr));
3457 PNG_EXTERN void png_read_push_finish_row PNGARG((png_structp png_ptr));
3458 #if defined(PNG_READ_tEXt_SUPPORTED)
3459 PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr,
3460    png_infop info_ptr, png_uint_32 length));
3461 PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr,
3462    png_infop info_ptr));
3463 #endif
3464 #if defined(PNG_READ_zTXt_SUPPORTED)
3465 PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr,
3466    png_infop info_ptr, png_uint_32 length));
3467 PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr,
3468    png_infop info_ptr));
3469 #endif
3470 #if defined(PNG_READ_iTXt_SUPPORTED)
3471 PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr,
3472    png_infop info_ptr, png_uint_32 length));
3473 PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr,
3474    png_infop info_ptr));
3475 #endif
3476 
3477 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
3478 
3479 #ifdef PNG_MNG_FEATURES_SUPPORTED
3480 PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info,
3481    png_bytep row));
3482 PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info,
3483    png_bytep row));
3484 #endif
3485 
3486 #if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
3487 #if defined(PNG_MMX_CODE_SUPPORTED)
3488 /* png.c */ /* PRIVATE */
3489 PNG_EXTERN void png_init_mmx_flags PNGARG((png_structp png_ptr));
3490 #endif
3491 #endif
3492 
3493 #if defined(PNG_INCH_CONVERSIONS) && defined(PNG_FLOATING_POINT_SUPPORTED)
3494 PNG_EXTERN png_uint_32 png_get_pixels_per_inch PNGARG((png_structp png_ptr,
3495 png_infop info_ptr));
3496 
3497 PNG_EXTERN png_uint_32 png_get_x_pixels_per_inch PNGARG((png_structp png_ptr,
3498 png_infop info_ptr));
3499 
3500 PNG_EXTERN png_uint_32 png_get_y_pixels_per_inch PNGARG((png_structp png_ptr,
3501 png_infop info_ptr));
3502 
3503 PNG_EXTERN float png_get_x_offset_inches PNGARG((png_structp png_ptr,
3504 png_infop info_ptr));
3505 
3506 PNG_EXTERN float png_get_y_offset_inches PNGARG((png_structp png_ptr,
3507 png_infop info_ptr));
3508 
3509 #if defined(PNG_pHYs_SUPPORTED)
3510 PNG_EXTERN png_uint_32 png_get_pHYs_dpi PNGARG((png_structp png_ptr,
3511 png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
3512 #endif /* PNG_pHYs_SUPPORTED */
3513 #endif  /* PNG_INCH_CONVERSIONS && PNG_FLOATING_POINT_SUPPORTED */
3514 
3515 /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
3516 
3517 #endif /* PNG_INTERNAL */
3518 
3519 #ifdef __cplusplus
3520 }
3521 #endif
3522 
3523 #endif /* PNG_VERSION_INFO_ONLY */
3524 /* do not put anything past this line */
3525 #endif /* PNG_H */
3526