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libpng12/png.h
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1 /* png.h - header file for PNG reference library
2  *
3  * libpng version 1.2.37 - June 4, 2009
4  * Copyright (c) 1998-2009 Glenn Randers-Pehrson
5  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
6  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
7  *
8  * Authors and maintainers:
9  * libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
10  * libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
11  * libpng versions 0.97, January 1998, through 1.2.37 - June 4, 2009: Glenn
12  * See also "Contributing Authors", below.
13  *
14  * Note about libpng version numbers:
15  *
16  * Due to various miscommunications, unforeseen code incompatibilities
17  * and occasional factors outside the authors' control, version numbering
18  * on the library has not always been consistent and straightforward.
19  * The following table summarizes matters since version 0.89c, which was
20  * the first widely used release:
21  *
22  * source png.h png.h shared-lib
23  * version string int version
24  * ------- ------ ----- ----------
25  * 0.89c "1.0 beta 3" 0.89 89 1.0.89
26  * 0.90 "1.0 beta 4" 0.90 90 0.90 [should have been 2.0.90]
27  * 0.95 "1.0 beta 5" 0.95 95 0.95 [should have been 2.0.95]
28  * 0.96 "1.0 beta 6" 0.96 96 0.96 [should have been 2.0.96]
29  * 0.97b "1.00.97 beta 7" 1.00.97 97 1.0.1 [should have been 2.0.97]
30  * 0.97c 0.97 97 2.0.97
31  * 0.98 0.98 98 2.0.98
32  * 0.99 0.99 98 2.0.99
33  * 0.99a-m 0.99 99 2.0.99
34  * 1.00 1.00 100 2.1.0 [100 should be 10000]
35  * 1.0.0 (from here on, the 100 2.1.0 [100 should be 10000]
36  * 1.0.1 png.h string is 10001 2.1.0
37  * 1.0.1a-e identical to the 10002 from here on, the shared library
38  * 1.0.2 source version) 10002 is 2.V where V is the source code
39  * 1.0.2a-b 10003 version, except as noted.
40  * 1.0.3 10003
41  * 1.0.3a-d 10004
42  * 1.0.4 10004
43  * 1.0.4a-f 10005
44  * 1.0.5 (+ 2 patches) 10005
45  * 1.0.5a-d 10006
46  * 1.0.5e-r 10100 (not source compatible)
47  * 1.0.5s-v 10006 (not binary compatible)
48  * 1.0.6 (+ 3 patches) 10006 (still binary incompatible)
49  * 1.0.6d-f 10007 (still binary incompatible)
50  * 1.0.6g 10007
51  * 1.0.6h 10007 10.6h (testing xy.z so-numbering)
52  * 1.0.6i 10007 10.6i
53  * 1.0.6j 10007 2.1.0.6j (incompatible with 1.0.0)
54  * 1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14 (binary compatible)
55  * 1.0.7beta15-18 1 10007 2.1.0.7beta15-18 (binary compatible)
56  * 1.0.7rc1-2 1 10007 2.1.0.7rc1-2 (binary compatible)
57  * 1.0.7 1 10007 (still compatible)
58  * 1.0.8beta1-4 1 10008 2.1.0.8beta1-4
59  * 1.0.8rc1 1 10008 2.1.0.8rc1
60  * 1.0.8 1 10008 2.1.0.8
61  * 1.0.9beta1-6 1 10009 2.1.0.9beta1-6
62  * 1.0.9rc1 1 10009 2.1.0.9rc1
63  * 1.0.9beta7-10 1 10009 2.1.0.9beta7-10
64  * 1.0.9rc2 1 10009 2.1.0.9rc2
65  * 1.0.9 1 10009 2.1.0.9
66  * 1.0.10beta1 1 10010 2.1.0.10beta1
67  * 1.0.10rc1 1 10010 2.1.0.10rc1
68  * 1.0.10 1 10010 2.1.0.10
69  * 1.0.11beta1-3 1 10011 2.1.0.11beta1-3
70  * 1.0.11rc1 1 10011 2.1.0.11rc1
71  * 1.0.11 1 10011 2.1.0.11
72  * 1.0.12beta1-2 2 10012 2.1.0.12beta1-2
73  * 1.0.12rc1 2 10012 2.1.0.12rc1
74  * 1.0.12 2 10012 2.1.0.12
75  * 1.1.0a-f - 10100 2.1.1.0a-f (branch abandoned)
76  * 1.2.0beta1-2 2 10200 2.1.2.0beta1-2
77  * 1.2.0beta3-5 3 10200 3.1.2.0beta3-5
78  * 1.2.0rc1 3 10200 3.1.2.0rc1
79  * 1.2.0 3 10200 3.1.2.0
80  * 1.2.1beta1-4 3 10201 3.1.2.1beta1-4
81  * 1.2.1rc1-2 3 10201 3.1.2.1rc1-2
82  * 1.2.1 3 10201 3.1.2.1
83  * 1.2.2beta1-6 12 10202 12.so.0.1.2.2beta1-6
84  * 1.0.13beta1 10 10013 10.so.0.1.0.13beta1
85  * 1.0.13rc1 10 10013 10.so.0.1.0.13rc1
86  * 1.2.2rc1 12 10202 12.so.0.1.2.2rc1
87  * 1.0.13 10 10013 10.so.0.1.0.13
88  * 1.2.2 12 10202 12.so.0.1.2.2
89  * 1.2.3rc1-6 12 10203 12.so.0.1.2.3rc1-6
90  * 1.2.3 12 10203 12.so.0.1.2.3
91  * 1.2.4beta1-3 13 10204 12.so.0.1.2.4beta1-3
92  * 1.0.14rc1 13 10014 10.so.0.1.0.14rc1
93  * 1.2.4rc1 13 10204 12.so.0.1.2.4rc1
94  * 1.0.14 10 10014 10.so.0.1.0.14
95  * 1.2.4 13 10204 12.so.0.1.2.4
96  * 1.2.5beta1-2 13 10205 12.so.0.1.2.5beta1-2
97  * 1.0.15rc1-3 10 10015 10.so.0.1.0.15rc1-3
98  * 1.2.5rc1-3 13 10205 12.so.0.1.2.5rc1-3
99  * 1.0.15 10 10015 10.so.0.1.0.15
100  * 1.2.5 13 10205 12.so.0.1.2.5
101  * 1.2.6beta1-4 13 10206 12.so.0.1.2.6beta1-4
102  * 1.0.16 10 10016 10.so.0.1.0.16
103  * 1.2.6 13 10206 12.so.0.1.2.6
104  * 1.2.7beta1-2 13 10207 12.so.0.1.2.7beta1-2
105  * 1.0.17rc1 10 10017 10.so.0.1.0.17rc1
106  * 1.2.7rc1 13 10207 12.so.0.1.2.7rc1
107  * 1.0.17 10 10017 10.so.0.1.0.17
108  * 1.2.7 13 10207 12.so.0.1.2.7
109  * 1.2.8beta1-5 13 10208 12.so.0.1.2.8beta1-5
110  * 1.0.18rc1-5 10 10018 10.so.0.1.0.18rc1-5
111  * 1.2.8rc1-5 13 10208 12.so.0.1.2.8rc1-5
112  * 1.0.18 10 10018 10.so.0.1.0.18
113  * 1.2.8 13 10208 12.so.0.1.2.8
114  * 1.2.9beta1-3 13 10209 12.so.0.1.2.9beta1-3
115  * 1.2.9beta4-11 13 10209 12.so.0.9[.0]
116  * 1.2.9rc1 13 10209 12.so.0.9[.0]
117  * 1.2.9 13 10209 12.so.0.9[.0]
118  * 1.2.10beta1-8 13 10210 12.so.0.10[.0]
119  * 1.2.10rc1-3 13 10210 12.so.0.10[.0]
120  * 1.2.10 13 10210 12.so.0.10[.0]
121  * 1.2.11beta1-4 13 10211 12.so.0.11[.0]
122  * 1.0.19rc1-5 10 10019 10.so.0.19[.0]
123  * 1.2.11rc1-5 13 10211 12.so.0.11[.0]
124  * 1.0.19 10 10019 10.so.0.19[.0]
125  * 1.2.11 13 10211 12.so.0.11[.0]
126  * 1.0.20 10 10020 10.so.0.20[.0]
127  * 1.2.12 13 10212 12.so.0.12[.0]
128  * 1.2.13beta1 13 10213 12.so.0.13[.0]
129  * 1.0.21 10 10021 10.so.0.21[.0]
130  * 1.2.13 13 10213 12.so.0.13[.0]
131  * 1.2.14beta1-2 13 10214 12.so.0.14[.0]
132  * 1.0.22rc1 10 10022 10.so.0.22[.0]
133  * 1.2.14rc1 13 10214 12.so.0.14[.0]
134  * 1.0.22 10 10022 10.so.0.22[.0]
135  * 1.2.14 13 10214 12.so.0.14[.0]
136  * 1.2.15beta1-6 13 10215 12.so.0.15[.0]
137  * 1.0.23rc1-5 10 10023 10.so.0.23[.0]
138  * 1.2.15rc1-5 13 10215 12.so.0.15[.0]
139  * 1.0.23 10 10023 10.so.0.23[.0]
140  * 1.2.15 13 10215 12.so.0.15[.0]
141  * 1.2.16beta1-2 13 10216 12.so.0.16[.0]
142  * 1.2.16rc1 13 10216 12.so.0.16[.0]
143  * 1.0.24 10 10024 10.so.0.24[.0]
144  * 1.2.16 13 10216 12.so.0.16[.0]
145  * 1.2.17beta1-2 13 10217 12.so.0.17[.0]
146  * 1.0.25rc1 10 10025 10.so.0.25[.0]
147  * 1.2.17rc1-3 13 10217 12.so.0.17[.0]
148  * 1.0.25 10 10025 10.so.0.25[.0]
149  * 1.2.17 13 10217 12.so.0.17[.0]
150  * 1.0.26 10 10026 10.so.0.26[.0]
151  * 1.2.18 13 10218 12.so.0.18[.0]
152  * 1.2.19beta1-31 13 10219 12.so.0.19[.0]
153  * 1.0.27rc1-6 10 10027 10.so.0.27[.0]
154  * 1.2.19rc1-6 13 10219 12.so.0.19[.0]
155  * 1.0.27 10 10027 10.so.0.27[.0]
156  * 1.2.19 13 10219 12.so.0.19[.0]
157  * 1.2.20beta01-04 13 10220 12.so.0.20[.0]
158  * 1.0.28rc1-6 10 10028 10.so.0.28[.0]
159  * 1.2.20rc1-6 13 10220 12.so.0.20[.0]
160  * 1.0.28 10 10028 10.so.0.28[.0]
161  * 1.2.20 13 10220 12.so.0.20[.0]
162  * 1.2.21beta1-2 13 10221 12.so.0.21[.0]
163  * 1.2.21rc1-3 13 10221 12.so.0.21[.0]
164  * 1.0.29 10 10029 10.so.0.29[.0]
165  * 1.2.21 13 10221 12.so.0.21[.0]
166  * 1.2.22beta1-4 13 10222 12.so.0.22[.0]
167  * 1.0.30rc1 10 10030 10.so.0.30[.0]
168  * 1.2.22rc1 13 10222 12.so.0.22[.0]
169  * 1.0.30 10 10030 10.so.0.30[.0]
170  * 1.2.22 13 10222 12.so.0.22[.0]
171  * 1.2.23beta01-05 13 10223 12.so.0.23[.0]
172  * 1.2.23rc01 13 10223 12.so.0.23[.0]
173  * 1.2.23 13 10223 12.so.0.23[.0]
174  * 1.2.24beta01-02 13 10224 12.so.0.24[.0]
175  * 1.2.24rc01 13 10224 12.so.0.24[.0]
176  * 1.2.24 13 10224 12.so.0.24[.0]
177  * 1.2.25beta01-06 13 10225 12.so.0.25[.0]
178  * 1.2.25rc01-02 13 10225 12.so.0.25[.0]
179  * 1.0.31 10 10031 10.so.0.31[.0]
180  * 1.2.25 13 10225 12.so.0.25[.0]
181  * 1.2.26beta01-06 13 10226 12.so.0.26[.0]
182  * 1.2.26rc01 13 10226 12.so.0.26[.0]
183  * 1.2.26 13 10226 12.so.0.26[.0]
184  * 1.0.32 10 10032 10.so.0.32[.0]
185  * 1.2.27beta01-06 13 10227 12.so.0.27[.0]
186  * 1.2.27rc01 13 10227 12.so.0.27[.0]
187  * 1.0.33 10 10033 10.so.0.33[.0]
188  * 1.2.27 13 10227 12.so.0.27[.0]
189  * 1.0.34 10 10034 10.so.0.34[.0]
190  * 1.2.28 13 10228 12.so.0.28[.0]
191  * 1.2.29beta01-03 13 10229 12.so.0.29[.0]
192  * 1.2.29rc01 13 10229 12.so.0.29[.0]
193  * 1.0.35 10 10035 10.so.0.35[.0]
194  * 1.2.29 13 10229 12.so.0.29[.0]
195  * 1.0.37 10 10037 10.so.0.37[.0]
196  * 1.2.30beta01-04 13 10230 12.so.0.30[.0]
197  * 1.0.38rc01-08 10 10038 10.so.0.38[.0]
198  * 1.2.30rc01-08 13 10230 12.so.0.30[.0]
199  * 1.0.38 10 10038 10.so.0.38[.0]
200  * 1.2.30 13 10230 12.so.0.30[.0]
201  * 1.0.39rc01-03 10 10039 10.so.0.39[.0]
202  * 1.2.31rc01-03 13 10231 12.so.0.31[.0]
203  * 1.0.39 10 10039 10.so.0.39[.0]
204  * 1.2.31 13 10231 12.so.0.31[.0]
205  * 1.2.32beta01-02 13 10232 12.so.0.32[.0]
206  * 1.0.40rc01 10 10040 10.so.0.40[.0]
207  * 1.2.32rc01 13 10232 12.so.0.32[.0]
208  * 1.0.40 10 10040 10.so.0.40[.0]
209  * 1.2.32 13 10232 12.so.0.32[.0]
210  * 1.2.33beta01-02 13 10233 12.so.0.33[.0]
211  * 1.2.33rc01-02 13 10233 12.so.0.33[.0]
212  * 1.0.41rc01 10 10041 10.so.0.41[.0]
213  * 1.2.33 13 10233 12.so.0.33[.0]
214  * 1.0.41 10 10041 10.so.0.41[.0]
215  * 1.2.34beta01-07 13 10234 12.so.0.34[.0]
216  * 1.0.42rc01 10 10042 10.so.0.42[.0]
217  * 1.2.34rc01 13 10234 12.so.0.34[.0]
218  * 1.0.42 10 10042 10.so.0.42[.0]
219  * 1.2.34 13 10234 12.so.0.34[.0]
220  * 1.2.35beta01-03 13 10235 12.so.0.35[.0]
221  * 1.0.43rc01-02 10 10043 10.so.0.43[.0]
222  * 1.2.35rc01-02 13 10235 12.so.0.35[.0]
223  * 1.0.43 10 10043 10.so.0.43[.0]
224  * 1.2.35 13 10235 12.so.0.35[.0]
225  * 1.2.36beta01-05 13 10236 12.so.0.36[.0]
226  * 1.2.36rc01 13 10236 12.so.0.36[.0]
227  * 1.0.44 10 10044 10.so.0.44[.0]
228  * 1.2.36 13 10236 12.so.0.36[.0]
229  * 1.2.37beta01-03 13 10237 12.so.0.37[.0]
230  * 1.2.37rc01 13 10237 12.so.0.37[.0]
231  * 1.2.37 13 10237 12.so.0.37[.0]
232  *
233  * Henceforth the source version will match the shared-library major
234  * and minor numbers; the shared-library major version number will be
235  * used for changes in backward compatibility, as it is intended. The
236  * PNG_LIBPNG_VER macro, which is not used within libpng but is available
237  * for applications, is an unsigned integer of the form xyyzz corresponding
238  * to the source version x.y.z (leading zeros in y and z). Beta versions
239  * were given the previous public release number plus a letter, until
240  * version 1.0.6j; from then on they were given the upcoming public
241  * release number plus "betaNN" or "rcNN".
242  *
243  * Binary incompatibility exists only when applications make direct access
244  * to the info_ptr or png_ptr members through png.h, and the compiled
245  * application is loaded with a different version of the library.
246  *
247  * DLLNUM will change each time there are forward or backward changes
248  * in binary compatibility (e.g., when a new feature is added).
249  *
250  * See libpng.txt or libpng.3 for more information. The PNG specification
251  * is available as a W3C Recommendation and as an ISO Specification,
252  * <http://www.w3.org/TR/2003/REC-PNG-20031110/
253  */
254 
255 /*
256  * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
257  *
258  * If you modify libpng you may insert additional notices immediately following
259  * this sentence.
260  *
261  * libpng versions 1.2.6, August 15, 2004, through 1.2.37, June 4, 2009, are
262  * Copyright (c) 2004, 2006-2009 Glenn Randers-Pehrson, and are
263  * distributed according to the same disclaimer and license as libpng-1.2.5
264  * with the following individual added to the list of Contributing Authors:
265  *
266  * Cosmin Truta
267  *
268  * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
269  * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
270  * distributed according to the same disclaimer and license as libpng-1.0.6
271  * with the following individuals added to the list of Contributing Authors:
272  *
273  * Simon-Pierre Cadieux
274  * Eric S. Raymond
275  * Gilles Vollant
276  *
277  * and with the following additions to the disclaimer:
278  *
279  * There is no warranty against interference with your enjoyment of the
280  * library or against infringement. There is no warranty that our
281  * efforts or the library will fulfill any of your particular purposes
282  * or needs. This library is provided with all faults, and the entire
283  * risk of satisfactory quality, performance, accuracy, and effort is with
284  * the user.
285  *
286  * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
287  * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are
288  * distributed according to the same disclaimer and license as libpng-0.96,
289  * with the following individuals added to the list of Contributing Authors:
290  *
291  * Tom Lane
292  * Glenn Randers-Pehrson
293  * Willem van Schaik
294  *
295  * libpng versions 0.89, June 1996, through 0.96, May 1997, are
296  * Copyright (c) 1996, 1997 Andreas Dilger
297  * Distributed according to the same disclaimer and license as libpng-0.88,
298  * with the following individuals added to the list of Contributing Authors:
299  *
300  * John Bowler
301  * Kevin Bracey
302  * Sam Bushell
303  * Magnus Holmgren
304  * Greg Roelofs
305  * Tom Tanner
306  *
307  * libpng versions 0.5, May 1995, through 0.88, January 1996, are
308  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
309  *
310  * For the purposes of this copyright and license, "Contributing Authors"
311  * is defined as the following set of individuals:
312  *
313  * Andreas Dilger
314  * Dave Martindale
315  * Guy Eric Schalnat
316  * Paul Schmidt
317  * Tim Wegner
318  *
319  * The PNG Reference Library is supplied "AS IS". The Contributing Authors
320  * and Group 42, Inc. disclaim all warranties, expressed or implied,
321  * including, without limitation, the warranties of merchantability and of
322  * fitness for any purpose. The Contributing Authors and Group 42, Inc.
323  * assume no liability for direct, indirect, incidental, special, exemplary,
324  * or consequential damages, which may result from the use of the PNG
325  * Reference Library, even if advised of the possibility of such damage.
326  *
327  * Permission is hereby granted to use, copy, modify, and distribute this
328  * source code, or portions hereof, for any purpose, without fee, subject
329  * to the following restrictions:
330  *
331  * 1. The origin of this source code must not be misrepresented.
332  *
333  * 2. Altered versions must be plainly marked as such and
334  * must not be misrepresented as being the original source.
335  *
336  * 3. This Copyright notice may not be removed or altered from
337  * any source or altered source distribution.
338  *
339  * The Contributing Authors and Group 42, Inc. specifically permit, without
340  * fee, and encourage the use of this source code as a component to
341  * supporting the PNG file format in commercial products. If you use this
342  * source code in a product, acknowledgment is not required but would be
343  * appreciated.
344  */
345 
346 /*
347  * A "png_get_copyright" function is available, for convenient use in "about"
348  * boxes and the like:
349  *
350  * printf("%s",png_get_copyright(NULL));
351  *
352  * Also, the PNG logo (in PNG format, of course) is supplied in the
353  * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
354  */
355 
356 /*
357  * Libpng is OSI Certified Open Source Software. OSI Certified is a
358  * certification mark of the Open Source Initiative.
359  */
360 
361 /*
362  * The contributing authors would like to thank all those who helped
363  * with testing, bug fixes, and patience. This wouldn't have been
364  * possible without all of you.
365  *
366  * Thanks to Frank J. T. Wojcik for helping with the documentation.
367  */
368 
369 /*
370  * Y2K compliance in libpng:
371  * =========================
372  *
373  * June 4, 2009
374  *
375  * Since the PNG Development group is an ad-hoc body, we can't make
376  * an official declaration.
377  *
378  * This is your unofficial assurance that libpng from version 0.71 and
379  * upward through 1.2.37 are Y2K compliant. It is my belief that earlier
380  * versions were also Y2K compliant.
381  *
382  * Libpng only has three year fields. One is a 2-byte unsigned integer
383  * that will hold years up to 65535. The other two hold the date in text
384  * format, and will hold years up to 9999.
385  *
386  * The integer is
387  * "png_uint_16 year" in png_time_struct.
388  *
389  * The strings are
390  * "png_charp time_buffer" in png_struct and
391  * "near_time_buffer", which is a local character string in png.c.
392  *
393  * There are seven time-related functions:
394  * png.c: png_convert_to_rfc_1123() in png.c
395  * (formerly png_convert_to_rfc_1152() in error)
396  * png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
397  * png_convert_from_time_t() in pngwrite.c
398  * png_get_tIME() in pngget.c
399  * png_handle_tIME() in pngrutil.c, called in pngread.c
400  * png_set_tIME() in pngset.c
401  * png_write_tIME() in pngwutil.c, called in pngwrite.c
402  *
403  * All handle dates properly in a Y2K environment. The
404  * png_convert_from_time_t() function calls gmtime() to convert from system
405  * clock time, which returns (year - 1900), which we properly convert to
406  * the full 4-digit year. There is a possibility that applications using
407  * libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
408  * function, or that they are incorrectly passing only a 2-digit year
409  * instead of "year - 1900" into the png_convert_from_struct_tm() function,
410  * but this is not under our control. The libpng documentation has always
411  * stated that it works with 4-digit years, and the APIs have been
412  * documented as such.
413  *
414  * The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
415  * integer to hold the year, and can hold years as large as 65535.
416  *
417  * zlib, upon which libpng depends, is also Y2K compliant. It contains
418  * no date-related code.
419  *
420  * Glenn Randers-Pehrson
421  * libpng maintainer
422  * PNG Development Group
423  */
424 
425 #ifndef PNG_H
426 #define PNG_H
427 
428 /* This is not the place to learn how to use libpng. The file libpng.txt
429  * describes how to use libpng, and the file example.c summarizes it
430  * with some code on which to build. This file is useful for looking
431  * at the actual function definitions and structure components.
432  */
433 
434 /* Version information for png.h - this should match the version in png.c */
435 #define PNG_LIBPNG_VER_STRING "1.2.37"
436 #define PNG_HEADER_VERSION_STRING \
437  " libpng version 1.2.37 - June 4, 2009\n"
438 
439 #define PNG_LIBPNG_VER_SONUM 0
440 #define PNG_LIBPNG_VER_DLLNUM 13
441 
442 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
443 #define PNG_LIBPNG_VER_MAJOR 1
444 #define PNG_LIBPNG_VER_MINOR 2
445 #define PNG_LIBPNG_VER_RELEASE 37
446 /* This should match the numeric part of the final component of
447  * PNG_LIBPNG_VER_STRING, omitting any leading zero: */
448 
449 #define PNG_LIBPNG_VER_BUILD 0
450 
451 /* Release Status */
452 #define PNG_LIBPNG_BUILD_ALPHA 1
453 #define PNG_LIBPNG_BUILD_BETA 2
454 #define PNG_LIBPNG_BUILD_RC 3
455 #define PNG_LIBPNG_BUILD_STABLE 4
456 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
457 
458 /* Release-Specific Flags */
459 #define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
460  PNG_LIBPNG_BUILD_STABLE only */
461 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
462  PNG_LIBPNG_BUILD_SPECIAL */
463 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
464  PNG_LIBPNG_BUILD_PRIVATE */
465 
466 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
467 
468 /* Careful here. At one time, Guy wanted to use 082, but that would be octal.
469  * We must not include leading zeros.
470  * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
471  * version 1.0.0 was mis-numbered 100 instead of 10000). From
472  * version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release */
473 #define PNG_LIBPNG_VER 10237 /* 1.2.37 */
474 
475 #ifndef PNG_VERSION_INFO_ONLY
476 /* include the compression library's header */
477 #include "zlib.h"
478 #endif
479 
480 /* include all user configurable info, including optional assembler routines */
481 #include "pngconf.h"
482 
483 /*
484  * Added at libpng-1.2.8 */
485 /* Ref MSDN: Private as priority over Special
486  * VS_FF_PRIVATEBUILD File *was not* built using standard release
487  * procedures. If this value is given, the StringFileInfo block must
488  * contain a PrivateBuild string.
489  *
490  * VS_FF_SPECIALBUILD File *was* built by the original company using
491  * standard release procedures but is a variation of the standard
492  * file of the same version number. If this value is given, the
493  * StringFileInfo block must contain a SpecialBuild string.
494  */
495 
496 #if defined(PNG_USER_PRIVATEBUILD)
497 # define PNG_LIBPNG_BUILD_TYPE \
498  (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
499 #else
500 # if defined(PNG_LIBPNG_SPECIALBUILD)
501 # define PNG_LIBPNG_BUILD_TYPE \
502  (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
503 # else
504 # define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
505 # endif
506 #endif
507 
508 #ifndef PNG_VERSION_INFO_ONLY
509 
510 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
511 #ifdef __cplusplus
512 extern "C" {
513 #endif /* __cplusplus */
514 
515 /* This file is arranged in several sections. The first section contains
516  * structure and type definitions. The second section contains the external
517  * library functions, while the third has the internal library functions,
518  * which applications aren't expected to use directly.
519  */
520 
521 #ifndef PNG_NO_TYPECAST_NULL
522 #define int_p_NULL (int *)NULL
523 #define png_bytep_NULL (png_bytep)NULL
524 #define png_bytepp_NULL (png_bytepp)NULL
525 #define png_doublep_NULL (png_doublep)NULL
526 #define png_error_ptr_NULL (png_error_ptr)NULL
527 #define png_flush_ptr_NULL (png_flush_ptr)NULL
528 #define png_free_ptr_NULL (png_free_ptr)NULL
529 #define png_infopp_NULL (png_infopp)NULL
530 #define png_malloc_ptr_NULL (png_malloc_ptr)NULL
531 #define png_read_status_ptr_NULL (png_read_status_ptr)NULL
532 #define png_rw_ptr_NULL (png_rw_ptr)NULL
533 #define png_structp_NULL (png_structp)NULL
534 #define png_uint_16p_NULL (png_uint_16p)NULL
535 #define png_voidp_NULL (png_voidp)NULL
536 #define png_write_status_ptr_NULL (png_write_status_ptr)NULL
537 #else
538 #define int_p_NULL NULL
539 #define png_bytep_NULL NULL
540 #define png_bytepp_NULL NULL
541 #define png_doublep_NULL NULL
542 #define png_error_ptr_NULL NULL
543 #define png_flush_ptr_NULL NULL
544 #define png_free_ptr_NULL NULL
545 #define png_infopp_NULL NULL
546 #define png_malloc_ptr_NULL NULL
547 #define png_read_status_ptr_NULL NULL
548 #define png_rw_ptr_NULL NULL
549 #define png_structp_NULL NULL
550 #define png_uint_16p_NULL NULL
551 #define png_voidp_NULL NULL
552 #define png_write_status_ptr_NULL NULL
553 #endif
554 
555 /* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
556 #if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
557 /* Version information for C files, stored in png.c. This had better match
558  * the version above.
559  */
560 #ifdef PNG_USE_GLOBAL_ARRAYS
561 PNG_EXPORT_VAR (PNG_CONST char) png_libpng_ver[18];
562  /* need room for 99.99.99beta99z */
563 #else
564 #define png_libpng_ver png_get_header_ver(NULL)
565 #endif
566 
567 #ifdef PNG_USE_GLOBAL_ARRAYS
568 /* This was removed in version 1.0.5c */
569 /* Structures to facilitate easy interlacing. See png.c for more details */
570 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_start[7];
571 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_inc[7];
572 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_ystart[7];
573 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_yinc[7];
574 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_mask[7];
575 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_dsp_mask[7];
576 /* This isn't currently used. If you need it, see png.c for more details.
577 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_height[7];
578 */
579 #endif
580 
581 #endif /* PNG_NO_EXTERN */
582 
583 /* Three color definitions. The order of the red, green, and blue, (and the
584  * exact size) is not important, although the size of the fields need to
585  * be png_byte or png_uint_16 (as defined below).
586  */
587 typedef struct png_color_struct
588 {
592 } png_color;
595 
596 typedef struct png_color_16_struct
597 {
598  png_byte index; /* used for palette files */
599  png_uint_16 red; /* for use in red green blue files */
602  png_uint_16 gray; /* for use in grayscale files */
603 } png_color_16;
606 
607 typedef struct png_color_8_struct
608 {
609  png_byte red; /* for use in red green blue files */
612  png_byte gray; /* for use in grayscale files */
613  png_byte alpha; /* for alpha channel files */
614 } png_color_8;
617 
618 /*
619  * The following two structures are used for the in-core representation
620  * of sPLT chunks.
621  */
622 typedef struct png_sPLT_entry_struct
623 {
632 
633 /* When the depth of the sPLT palette is 8 bits, the color and alpha samples
634  * occupy the LSB of their respective members, and the MSB of each member
635  * is zero-filled. The frequency member always occupies the full 16 bits.
636  */
637 
638 typedef struct png_sPLT_struct
639 {
640  png_charp name; /* palette name */
641  png_byte depth; /* depth of palette samples */
642  png_sPLT_entryp entries; /* palette entries */
643  png_int_32 nentries; /* number of palette entries */
644 } png_sPLT_t;
647 
648 #ifdef PNG_TEXT_SUPPORTED
649 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
650  * and whether that contents is compressed or not. The "key" field
651  * points to a regular zero-terminated C string. The "text", "lang", and
652  * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
653  * However, the * structure returned by png_get_text() will always contain
654  * regular zero-terminated C strings (possibly empty), never NULL pointers,
655  * so they can be safely used in printf() and other string-handling functions.
656  */
657 typedef struct png_text_struct
658 {
659  int compression; /* compression value:
660  -1: tEXt, none
661  0: zTXt, deflate
662  1: iTXt, none
663  2: iTXt, deflate */
664  png_charp key; /* keyword, 1-79 character description of "text" */
665  png_charp text; /* comment, may be an empty string (ie "")
666  or a NULL pointer */
667  png_size_t text_length; /* length of the text string */
668 #ifdef PNG_iTXt_SUPPORTED
669  png_size_t itxt_length; /* length of the itxt string */
670  png_charp lang; /* language code, 0-79 characters
671  or a NULL pointer */
672  png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
673  chars or a NULL pointer */
674 #endif
675 } png_text;
678 #endif
679 
680 /* Supported compression types for text in PNG files (tEXt, and zTXt).
681  * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */
682 #define PNG_TEXT_COMPRESSION_NONE_WR -3
683 #define PNG_TEXT_COMPRESSION_zTXt_WR -2
684 #define PNG_TEXT_COMPRESSION_NONE -1
685 #define PNG_TEXT_COMPRESSION_zTXt 0
686 #define PNG_ITXT_COMPRESSION_NONE 1
687 #define PNG_ITXT_COMPRESSION_zTXt 2
688 #define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
689 
690 /* png_time is a way to hold the time in an machine independent way.
691  * Two conversions are provided, both from time_t and struct tm. There
692  * is no portable way to convert to either of these structures, as far
693  * as I know. If you know of a portable way, send it to me. As a side
694  * note - PNG has always been Year 2000 compliant!
695  */
696 typedef struct png_time_struct
697 {
698  png_uint_16 year; /* full year, as in, 1995 */
699  png_byte month; /* month of year, 1 - 12 */
700  png_byte day; /* day of month, 1 - 31 */
701  png_byte hour; /* hour of day, 0 - 23 */
702  png_byte minute; /* minute of hour, 0 - 59 */
703  png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
704 } png_time;
707 
708 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
709 /* png_unknown_chunk is a structure to hold queued chunks for which there is
710  * no specific support. The idea is that we can use this to queue
711  * up private chunks for output even though the library doesn't actually
712  * know about their semantics.
713  */
714 #define PNG_CHUNK_NAME_LENGTH 5
715 typedef struct png_unknown_chunk_t
716 {
720 
721  /* libpng-using applications should NOT directly modify this byte. */
722  png_byte location; /* mode of operation at read time */
723 }
727 #endif
728 
729 /* png_info is a structure that holds the information in a PNG file so
730  * that the application can find out the characteristics of the image.
731  * If you are reading the file, this structure will tell you what is
732  * in the PNG file. If you are writing the file, fill in the information
733  * you want to put into the PNG file, then call png_write_info().
734  * The names chosen should be very close to the PNG specification, so
735  * consult that document for information about the meaning of each field.
736  *
737  * With libpng < 0.95, it was only possible to directly set and read the
738  * the values in the png_info_struct, which meant that the contents and
739  * order of the values had to remain fixed. With libpng 0.95 and later,
740  * however, there are now functions that abstract the contents of
741  * png_info_struct from the application, so this makes it easier to use
742  * libpng with dynamic libraries, and even makes it possible to use
743  * libraries that don't have all of the libpng ancillary chunk-handing
744  * functionality.
745  *
746  * In any case, the order of the parameters in png_info_struct should NOT
747  * be changed for as long as possible to keep compatibility with applications
748  * that use the old direct-access method with png_info_struct.
749  *
750  * The following members may have allocated storage attached that should be
751  * cleaned up before the structure is discarded: palette, trans, text,
752  * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
753  * splt_palettes, scal_unit, row_pointers, and unknowns. By default, these
754  * are automatically freed when the info structure is deallocated, if they were
755  * allocated internally by libpng. This behavior can be changed by means
756  * of the png_data_freer() function.
757  *
758  * More allocation details: all the chunk-reading functions that
759  * change these members go through the corresponding png_set_*
760  * functions. A function to clear these members is available: see
761  * png_free_data(). The png_set_* functions do not depend on being
762  * able to point info structure members to any of the storage they are
763  * passed (they make their own copies), EXCEPT that the png_set_text
764  * functions use the same storage passed to them in the text_ptr or
765  * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
766  * functions do not make their own copies.
767  */
768 typedef struct png_info_struct
769 {
770  /* the following are necessary for every PNG file */
771  png_uint_32 width; /* width of image in pixels (from IHDR) */
772  png_uint_32 height; /* height of image in pixels (from IHDR) */
773  png_uint_32 valid; /* valid chunk data (see PNG_INFO_ below) */
774  png_uint_32 rowbytes; /* bytes needed to hold an untransformed row */
775  png_colorp palette; /* array of color values (valid & PNG_INFO_PLTE) */
776  png_uint_16 num_palette; /* number of color entries in "palette" (PLTE) */
777  png_uint_16 num_trans; /* number of transparent palette color (tRNS) */
778  png_byte bit_depth; /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */
779  png_byte color_type; /* see PNG_COLOR_TYPE_ below (from IHDR) */
780  /* The following three should have been named *_method not *_type */
781  png_byte compression_type; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */
782  png_byte filter_type; /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
783  png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
784 
785  /* The following is informational only on read, and not used on writes. */
786  png_byte channels; /* number of data channels per pixel (1, 2, 3, 4) */
787  png_byte pixel_depth; /* number of bits per pixel */
788  png_byte spare_byte; /* to align the data, and for future use */
789  png_byte signature[8]; /* magic bytes read by libpng from start of file */
790 
791  /* The rest of the data is optional. If you are reading, check the
792  * valid field to see if the information in these are valid. If you
793  * are writing, set the valid field to those chunks you want written,
794  * and initialize the appropriate fields below.
795  */
796 
797 #if defined(PNG_gAMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
798  /* The gAMA chunk describes the gamma characteristics of the system
799  * on which the image was created, normally in the range [1.0, 2.5].
800  * Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
801  */
802  float gamma; /* gamma value of image, if (valid & PNG_INFO_gAMA) */
803 #endif
804 
805 #if defined(PNG_sRGB_SUPPORTED)
806  /* GR-P, 0.96a */
807  /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
808  png_byte srgb_intent; /* sRGB rendering intent [0, 1, 2, or 3] */
809 #endif
810 
811 #if defined(PNG_TEXT_SUPPORTED)
812  /* The tEXt, and zTXt chunks contain human-readable textual data in
813  * uncompressed, compressed, and optionally compressed forms, respectively.
814  * The data in "text" is an array of pointers to uncompressed,
815  * null-terminated C strings. Each chunk has a keyword that describes the
816  * textual data contained in that chunk. Keywords are not required to be
817  * unique, and the text string may be empty. Any number of text chunks may
818  * be in an image.
819  */
820  int num_text; /* number of comments read/to write */
821  int max_text; /* current size of text array */
822  png_textp text; /* array of comments read/to write */
823 #endif /* PNG_TEXT_SUPPORTED */
824 
825 #if defined(PNG_tIME_SUPPORTED)
826  /* The tIME chunk holds the last time the displayed image data was
827  * modified. See the png_time struct for the contents of this struct.
828  */
830 #endif
831 
832 #if defined(PNG_sBIT_SUPPORTED)
833  /* The sBIT chunk specifies the number of significant high-order bits
834  * in the pixel data. Values are in the range [1, bit_depth], and are
835  * only specified for the channels in the pixel data. The contents of
836  * the low-order bits is not specified. Data is valid if
837  * (valid & PNG_INFO_sBIT) is non-zero.
838  */
839  png_color_8 sig_bit; /* significant bits in color channels */
840 #endif
841 
842 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
843 defined(PNG_READ_BACKGROUND_SUPPORTED)
844  /* The tRNS chunk supplies transparency data for paletted images and
845  * other image types that don't need a full alpha channel. There are
846  * "num_trans" transparency values for a paletted image, stored in the
847  * same order as the palette colors, starting from index 0. Values
848  * for the data are in the range [0, 255], ranging from fully transparent
849  * to fully opaque, respectively. For non-paletted images, there is a
850  * single color specified that should be treated as fully transparent.
851  * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
852  */
853  png_bytep trans; /* transparent values for paletted image */
854  png_color_16 trans_values; /* transparent color for non-palette image */
855 #endif
856 
857 #if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
858  /* The bKGD chunk gives the suggested image background color if the
859  * display program does not have its own background color and the image
860  * is needs to composited onto a background before display. The colors
861  * in "background" are normally in the same color space/depth as the
862  * pixel data. Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
863  */
865 #endif
866 
867 #if defined(PNG_oFFs_SUPPORTED)
868  /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
869  * and downwards from the top-left corner of the display, page, or other
870  * application-specific co-ordinate space. See the PNG_OFFSET_ defines
871  * below for the unit types. Valid if (valid & PNG_INFO_oFFs) non-zero.
872  */
873  png_int_32 x_offset; /* x offset on page */
874  png_int_32 y_offset; /* y offset on page */
875  png_byte offset_unit_type; /* offset units type */
876 #endif
877 
878 #if defined(PNG_pHYs_SUPPORTED)
879  /* The pHYs chunk gives the physical pixel density of the image for
880  * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
881  * defines below). Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
882  */
883  png_uint_32 x_pixels_per_unit; /* horizontal pixel density */
884  png_uint_32 y_pixels_per_unit; /* vertical pixel density */
885  png_byte phys_unit_type; /* resolution type (see PNG_RESOLUTION_ below) */
886 #endif
887 
888 #if defined(PNG_hIST_SUPPORTED)
889  /* The hIST chunk contains the relative frequency or importance of the
890  * various palette entries, so that a viewer can intelligently select a
891  * reduced-color palette, if required. Data is an array of "num_palette"
892  * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
893  * is non-zero.
894  */
896 #endif
897 
898 #ifdef PNG_cHRM_SUPPORTED
899  /* The cHRM chunk describes the CIE color characteristics of the monitor
900  * on which the PNG was created. This data allows the viewer to do gamut
901  * mapping of the input image to ensure that the viewer sees the same
902  * colors in the image as the creator. Values are in the range
903  * [0.0, 0.8]. Data valid if (valid & PNG_INFO_cHRM) non-zero.
904  */
905 #ifdef PNG_FLOATING_POINT_SUPPORTED
906  float x_white;
907  float y_white;
908  float x_red;
909  float y_red;
910  float x_green;
911  float y_green;
912  float x_blue;
913  float y_blue;
914 #endif
915 #endif
916 
917 #if defined(PNG_pCAL_SUPPORTED)
918  /* The pCAL chunk describes a transformation between the stored pixel
919  * values and original physical data values used to create the image.
920  * The integer range [0, 2^bit_depth - 1] maps to the floating-point
921  * range given by [pcal_X0, pcal_X1], and are further transformed by a
922  * (possibly non-linear) transformation function given by "pcal_type"
923  * and "pcal_params" into "pcal_units". Please see the PNG_EQUATION_
924  * defines below, and the PNG-Group's PNG extensions document for a
925  * complete description of the transformations and how they should be
926  * implemented, and for a description of the ASCII parameter strings.
927  * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
928  */
929  png_charp pcal_purpose; /* pCAL chunk description string */
930  png_int_32 pcal_X0; /* minimum value */
931  png_int_32 pcal_X1; /* maximum value */
932  png_charp pcal_units; /* Latin-1 string giving physical units */
933  png_charpp pcal_params; /* ASCII strings containing parameter values */
934  png_byte pcal_type; /* equation type (see PNG_EQUATION_ below) */
935  png_byte pcal_nparams; /* number of parameters given in pcal_params */
936 #endif
937 
938 /* New members added in libpng-1.0.6 */
939 #ifdef PNG_FREE_ME_SUPPORTED
940  png_uint_32 free_me; /* flags items libpng is responsible for freeing */
941 #endif
942 
943 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
944  /* storage for unknown chunks that the library doesn't recognize. */
945  png_unknown_chunkp unknown_chunks;
947 #endif
948 
949 #if defined(PNG_iCCP_SUPPORTED)
950  /* iCCP chunk data. */
951  png_charp iccp_name; /* profile name */
952  png_charp iccp_profile; /* International Color Consortium profile data */
953  /* Note to maintainer: should be png_bytep */
954  png_uint_32 iccp_proflen; /* ICC profile data length */
955  png_byte iccp_compression; /* Always zero */
956 #endif
957 
958 #if defined(PNG_sPLT_SUPPORTED)
959  /* data on sPLT chunks (there may be more than one). */
960  png_sPLT_tp splt_palettes;
962 #endif
963 
964 #if defined(PNG_sCAL_SUPPORTED)
965  /* The sCAL chunk describes the actual physical dimensions of the
966  * subject matter of the graphic. The chunk contains a unit specification
967  * a byte value, and two ASCII strings representing floating-point
968  * values. The values are width and height corresponsing to one pixel
969  * in the image. This external representation is converted to double
970  * here. Data values are valid if (valid & PNG_INFO_sCAL) is non-zero.
971  */
972  png_byte scal_unit; /* unit of physical scale */
973 #ifdef PNG_FLOATING_POINT_SUPPORTED
974  double scal_pixel_width; /* width of one pixel */
975  double scal_pixel_height; /* height of one pixel */
976 #endif
977 #ifdef PNG_FIXED_POINT_SUPPORTED
978  png_charp scal_s_width; /* string containing height */
979  png_charp scal_s_height; /* string containing width */
980 #endif
981 #endif
982 
983 #if defined(PNG_INFO_IMAGE_SUPPORTED)
984  /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS) non-zero */
985  /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
986  png_bytepp row_pointers; /* the image bits */
987 #endif
988 
989 #if defined(PNG_FIXED_POINT_SUPPORTED) && defined(PNG_gAMA_SUPPORTED)
990  png_fixed_point int_gamma; /* gamma of image, if (valid & PNG_INFO_gAMA) */
991 #endif
992 
993 #if defined(PNG_cHRM_SUPPORTED) && defined(PNG_FIXED_POINT_SUPPORTED)
1002 #endif
1003 
1004 } png_info;
1005 
1008 
1009 /* Maximum positive integer used in PNG is (2^31)-1 */
1010 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
1011 #define PNG_UINT_32_MAX ((png_uint_32)(-1))
1012 #define PNG_SIZE_MAX ((png_size_t)(-1))
1013 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1014 /* PNG_MAX_UINT is deprecated; use PNG_UINT_31_MAX instead. */
1015 #define PNG_MAX_UINT PNG_UINT_31_MAX
1016 #endif
1017 
1018 /* These describe the color_type field in png_info. */
1019 /* color type masks */
1020 #define PNG_COLOR_MASK_PALETTE 1
1021 #define PNG_COLOR_MASK_COLOR 2
1022 #define PNG_COLOR_MASK_ALPHA 4
1023 
1024 /* color types. Note that not all combinations are legal */
1025 #define PNG_COLOR_TYPE_GRAY 0
1026 #define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
1027 #define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
1028 #define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
1029 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
1030 /* aliases */
1031 #define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
1032 #define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
1033 
1034 /* This is for compression type. PNG 1.0-1.2 only define the single type. */
1035 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
1036 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
1037 
1038 /* This is for filter type. PNG 1.0-1.2 only define the single type. */
1039 #define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
1040 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
1041 #define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
1042 
1043 /* These are for the interlacing type. These values should NOT be changed. */
1044 #define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
1045 #define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
1046 #define PNG_INTERLACE_LAST 2 /* Not a valid value */
1047 
1048 /* These are for the oFFs chunk. These values should NOT be changed. */
1049 #define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
1050 #define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
1051 #define PNG_OFFSET_LAST 2 /* Not a valid value */
1052 
1053 /* These are for the pCAL chunk. These values should NOT be changed. */
1054 #define PNG_EQUATION_LINEAR 0 /* Linear transformation */
1055 #define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
1056 #define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
1057 #define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
1058 #define PNG_EQUATION_LAST 4 /* Not a valid value */
1059 
1060 /* These are for the sCAL chunk. These values should NOT be changed. */
1061 #define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
1062 #define PNG_SCALE_METER 1 /* meters per pixel */
1063 #define PNG_SCALE_RADIAN 2 /* radians per pixel */
1064 #define PNG_SCALE_LAST 3 /* Not a valid value */
1065 
1066 /* These are for the pHYs chunk. These values should NOT be changed. */
1067 #define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
1068 #define PNG_RESOLUTION_METER 1 /* pixels/meter */
1069 #define PNG_RESOLUTION_LAST 2 /* Not a valid value */
1070 
1071 /* These are for the sRGB chunk. These values should NOT be changed. */
1072 #define PNG_sRGB_INTENT_PERCEPTUAL 0
1073 #define PNG_sRGB_INTENT_RELATIVE 1
1074 #define PNG_sRGB_INTENT_SATURATION 2
1075 #define PNG_sRGB_INTENT_ABSOLUTE 3
1076 #define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
1077 
1078 /* This is for text chunks */
1079 #define PNG_KEYWORD_MAX_LENGTH 79
1080 
1081 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */
1082 #define PNG_MAX_PALETTE_LENGTH 256
1083 
1084 /* These determine if an ancillary chunk's data has been successfully read
1085  * from the PNG header, or if the application has filled in the corresponding
1086  * data in the info_struct to be written into the output file. The values
1087  * of the PNG_INFO_<chunk> defines should NOT be changed.
1088  */
1089 #define PNG_INFO_gAMA 0x0001
1090 #define PNG_INFO_sBIT 0x0002
1091 #define PNG_INFO_cHRM 0x0004
1092 #define PNG_INFO_PLTE 0x0008
1093 #define PNG_INFO_tRNS 0x0010
1094 #define PNG_INFO_bKGD 0x0020
1095 #define PNG_INFO_hIST 0x0040
1096 #define PNG_INFO_pHYs 0x0080
1097 #define PNG_INFO_oFFs 0x0100
1098 #define PNG_INFO_tIME 0x0200
1099 #define PNG_INFO_pCAL 0x0400
1100 #define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */
1101 #define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */
1102 #define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */
1103 #define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */
1104 #define PNG_INFO_IDAT 0x8000L /* ESR, 1.0.6 */
1105 
1106 /* This is used for the transformation routines, as some of them
1107  * change these values for the row. It also should enable using
1108  * the routines for other purposes.
1109  */
1110 typedef struct png_row_info_struct
1111 {
1112  png_uint_32 width; /* width of row */
1113  png_uint_32 rowbytes; /* number of bytes in row */
1114  png_byte color_type; /* color type of row */
1115  png_byte bit_depth; /* bit depth of row */
1116  png_byte channels; /* number of channels (1, 2, 3, or 4) */
1117  png_byte pixel_depth; /* bits per pixel (depth * channels) */
1118 } png_row_info;
1119 
1122 
1123 /* These are the function types for the I/O functions and for the functions
1124  * that allow the user to override the default I/O functions with his or her
1125  * own. The png_error_ptr type should match that of user-supplied warning
1126  * and error functions, while the png_rw_ptr type should match that of the
1127  * user read/write data functions.
1128  */
1131 
1132 typedef void (PNGAPI *png_error_ptr) PNGARG((png_structp, png_const_charp));
1133 typedef void (PNGAPI *png_rw_ptr) PNGARG((png_structp, png_bytep, png_size_t));
1134 typedef void (PNGAPI *png_flush_ptr) PNGARG((png_structp));
1135 typedef void (PNGAPI *png_read_status_ptr) PNGARG((png_structp, png_uint_32,
1136  int));
1137 typedef void (PNGAPI *png_write_status_ptr) PNGARG((png_structp, png_uint_32,
1138  int));
1139 
1140 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1141 typedef void (PNGAPI *png_progressive_info_ptr) PNGARG((png_structp, png_infop));
1142 typedef void (PNGAPI *png_progressive_end_ptr) PNGARG((png_structp, png_infop));
1143 typedef void (PNGAPI *png_progressive_row_ptr) PNGARG((png_structp, png_bytep,
1144  png_uint_32, int));
1145 #endif
1146 
1147 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1148  defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
1149  defined(PNG_LEGACY_SUPPORTED)
1150 typedef void (PNGAPI *png_user_transform_ptr) PNGARG((png_structp,
1151  png_row_infop, png_bytep));
1152 #endif
1153 
1154 #if defined(PNG_USER_CHUNKS_SUPPORTED)
1155 typedef int (PNGAPI *png_user_chunk_ptr) PNGARG((png_structp, png_unknown_chunkp));
1156 #endif
1157 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
1158 typedef void (PNGAPI *png_unknown_chunk_ptr) PNGARG((png_structp));
1159 #endif
1160 
1161 /* Transform masks for the high-level interface */
1162 #define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
1163 #define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
1164 #define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
1165 #define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
1166 #define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
1167 #define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
1168 #define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
1169 #define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
1170 #define PNG_TRANSFORM_BGR 0x0080 /* read and write */
1171 #define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
1172 #define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
1173 #define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
1174 #define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* WRITE only, deprecated */
1175 /* Added to libpng-1.2.34 */
1176 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE 0x0800 /* WRITE only */
1177 #define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* WRITE only */
1178 
1179 /* Flags for MNG supported features */
1180 #define PNG_FLAG_MNG_EMPTY_PLTE 0x01
1181 #define PNG_FLAG_MNG_FILTER_64 0x04
1182 #define PNG_ALL_MNG_FEATURES 0x05
1183 
1184 typedef png_voidp (*png_malloc_ptr) PNGARG((png_structp, png_size_t));
1185 typedef void (*png_free_ptr) PNGARG((png_structp, png_voidp));
1186 
1187 /* The structure that holds the information to read and write PNG files.
1188  * The only people who need to care about what is inside of this are the
1189  * people who will be modifying the library for their own special needs.
1190  * It should NOT be accessed directly by an application, except to store
1191  * the jmp_buf.
1192  */
1193 
1195 {
1196 #ifdef PNG_SETJMP_SUPPORTED
1197  jmp_buf jmpbuf; /* used in png_error */
1198 #endif
1199  png_error_ptr error_fn; /* function for printing errors and aborting */
1200  png_error_ptr warning_fn; /* function for printing warnings */
1201  png_voidp error_ptr; /* user supplied struct for error functions */
1202  png_rw_ptr write_data_fn; /* function for writing output data */
1203  png_rw_ptr read_data_fn; /* function for reading input data */
1204  png_voidp io_ptr; /* ptr to application struct for I/O functions */
1205 
1206 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
1207  png_user_transform_ptr read_user_transform_fn; /* user read transform */
1208 #endif
1209 
1210 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1211  png_user_transform_ptr write_user_transform_fn; /* user write transform */
1212 #endif
1213 
1214 /* These were added in libpng-1.0.2 */
1215 #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
1216 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1217  defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1218  png_voidp user_transform_ptr; /* user supplied struct for user transform */
1219  png_byte user_transform_depth; /* bit depth of user transformed pixels */
1220  png_byte user_transform_channels; /* channels in user transformed pixels */
1221 #endif
1222 #endif
1223 
1224  png_uint_32 mode; /* tells us where we are in the PNG file */
1225  png_uint_32 flags; /* flags indicating various things to libpng */
1226  png_uint_32 transformations; /* which transformations to perform */
1227 
1228  z_stream zstream; /* pointer to decompression structure (below) */
1229  png_bytep zbuf; /* buffer for zlib */
1230  png_size_t zbuf_size; /* size of zbuf */
1231  int zlib_level; /* holds zlib compression level */
1232  int zlib_method; /* holds zlib compression method */
1233  int zlib_window_bits; /* holds zlib compression window bits */
1234  int zlib_mem_level; /* holds zlib compression memory level */
1235  int zlib_strategy; /* holds zlib compression strategy */
1236 
1237  png_uint_32 width; /* width of image in pixels */
1238  png_uint_32 height; /* height of image in pixels */
1239  png_uint_32 num_rows; /* number of rows in current pass */
1240  png_uint_32 usr_width; /* width of row at start of write */
1241  png_uint_32 rowbytes; /* size of row in bytes */
1242  png_uint_32 irowbytes; /* size of current interlaced row in bytes */
1243  png_uint_32 iwidth; /* width of current interlaced row in pixels */
1244  png_uint_32 row_number; /* current row in interlace pass */
1245  png_bytep prev_row; /* buffer to save previous (unfiltered) row */
1246  png_bytep row_buf; /* buffer to save current (unfiltered) row */
1247 #ifndef PNG_NO_WRITE_FILTER
1248  png_bytep sub_row; /* buffer to save "sub" row when filtering */
1249  png_bytep up_row; /* buffer to save "up" row when filtering */
1250  png_bytep avg_row; /* buffer to save "avg" row when filtering */
1251  png_bytep paeth_row; /* buffer to save "Paeth" row when filtering */
1252 #endif
1253  png_row_info row_info; /* used for transformation routines */
1254 
1255  png_uint_32 idat_size; /* current IDAT size for read */
1256  png_uint_32 crc; /* current chunk CRC value */
1257  png_colorp palette; /* palette from the input file */
1258  png_uint_16 num_palette; /* number of color entries in palette */
1259  png_uint_16 num_trans; /* number of transparency values */
1260  png_byte chunk_name[5]; /* null-terminated name of current chunk */
1261  png_byte compression; /* file compression type (always 0) */
1262  png_byte filter; /* file filter type (always 0) */
1263  png_byte interlaced; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
1264  png_byte pass; /* current interlace pass (0 - 6) */
1265  png_byte do_filter; /* row filter flags (see PNG_FILTER_ below ) */
1266  png_byte color_type; /* color type of file */
1267  png_byte bit_depth; /* bit depth of file */
1268  png_byte usr_bit_depth; /* bit depth of users row */
1269  png_byte pixel_depth; /* number of bits per pixel */
1270  png_byte channels; /* number of channels in file */
1271  png_byte usr_channels; /* channels at start of write */
1272  png_byte sig_bytes; /* magic bytes read/written from start of file */
1273 
1274 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1275 #ifdef PNG_LEGACY_SUPPORTED
1276  png_byte filler; /* filler byte for pixel expansion */
1277 #else
1278  png_uint_16 filler; /* filler bytes for pixel expansion */
1279 #endif
1280 #endif
1281 
1282 #if defined(PNG_bKGD_SUPPORTED)
1284 # ifdef PNG_FLOATING_POINT_SUPPORTED
1286 # endif
1287  png_color_16 background; /* background color in screen gamma space */
1288 #if defined(PNG_READ_GAMMA_SUPPORTED)
1289  png_color_16 background_1; /* background normalized to gamma 1.0 */
1290 #endif
1291 #endif /* PNG_bKGD_SUPPORTED */
1292 
1293 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
1294  png_flush_ptr output_flush_fn;/* Function for flushing output */
1295  png_uint_32 flush_dist; /* how many rows apart to flush, 0 - no flush */
1296  png_uint_32 flush_rows; /* number of rows written since last flush */
1297 #endif
1298 
1299 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1300  int gamma_shift; /* number of "insignificant" bits 16-bit gamma */
1301 #ifdef PNG_FLOATING_POINT_SUPPORTED
1302  float gamma; /* file gamma value */
1303  float screen_gamma; /* screen gamma value (display_exponent) */
1304 #endif
1305 #endif
1306 
1307 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1308  png_bytep gamma_table; /* gamma table for 8-bit depth files */
1309  png_bytep gamma_from_1; /* converts from 1.0 to screen */
1310  png_bytep gamma_to_1; /* converts from file to 1.0 */
1311  png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */
1312  png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */
1313  png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */
1314 #endif
1315 
1316 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
1317  png_color_8 sig_bit; /* significant bits in each available channel */
1318 #endif
1319 
1320 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1321  png_color_8 shift; /* shift for significant bit tranformation */
1322 #endif
1323 
1324 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
1325  || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1326  png_bytep trans; /* transparency values for paletted files */
1327  png_color_16 trans_values; /* transparency values for non-paletted files */
1328 #endif
1329 
1330  png_read_status_ptr read_row_fn; /* called after each row is decoded */
1331  png_write_status_ptr write_row_fn; /* called after each row is encoded */
1332 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1333  png_progressive_info_ptr info_fn; /* called after header data fully read */
1334  png_progressive_row_ptr row_fn; /* called after each prog. row is decoded */
1335  png_progressive_end_ptr end_fn; /* called after image is complete */
1336  png_bytep save_buffer_ptr; /* current location in save_buffer */
1337  png_bytep save_buffer; /* buffer for previously read data */
1338  png_bytep current_buffer_ptr; /* current location in current_buffer */
1339  png_bytep current_buffer; /* buffer for recently used data */
1340  png_uint_32 push_length; /* size of current input chunk */
1341  png_uint_32 skip_length; /* bytes to skip in input data */
1342  png_size_t save_buffer_size; /* amount of data now in save_buffer */
1343  png_size_t save_buffer_max; /* total size of save_buffer */
1344  png_size_t buffer_size; /* total amount of available input data */
1345  png_size_t current_buffer_size; /* amount of data now in current_buffer */
1346  int process_mode; /* what push library is currently doing */
1347  int cur_palette; /* current push library palette index */
1348 
1349 # if defined(PNG_TEXT_SUPPORTED)
1350  png_size_t current_text_size; /* current size of text input data */
1351  png_size_t current_text_left; /* how much text left to read in input */
1352  png_charp current_text; /* current text chunk buffer */
1353  png_charp current_text_ptr; /* current location in current_text */
1354 # endif /* PNG_TEXT_SUPPORTED */
1355 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1356 
1357 #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
1358 /* for the Borland special 64K segment handler */
1359  png_bytepp offset_table_ptr;
1360  png_bytep offset_table;
1361  png_uint_16 offset_table_number;
1362  png_uint_16 offset_table_count;
1363  png_uint_16 offset_table_count_free;
1364 #endif
1365 
1366 #if defined(PNG_READ_DITHER_SUPPORTED)
1367  png_bytep palette_lookup; /* lookup table for dithering */
1368  png_bytep dither_index; /* index translation for palette files */
1369 #endif
1370 
1371 #if defined(PNG_READ_DITHER_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
1372  png_uint_16p hist; /* histogram */
1373 #endif
1374 
1375 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
1376  png_byte heuristic_method; /* heuristic for row filter selection */
1377  png_byte num_prev_filters; /* number of weights for previous rows */
1378  png_bytep prev_filters; /* filter type(s) of previous row(s) */
1379  png_uint_16p filter_weights; /* weight(s) for previous line(s) */
1380  png_uint_16p inv_filter_weights; /* 1/weight(s) for previous line(s) */
1381  png_uint_16p filter_costs; /* relative filter calculation cost */
1382  png_uint_16p inv_filter_costs; /* 1/relative filter calculation cost */
1383 #endif
1384 
1385 #if defined(PNG_TIME_RFC1123_SUPPORTED)
1386  png_charp time_buffer; /* String to hold RFC 1123 time text */
1387 #endif
1388 
1389 /* New members added in libpng-1.0.6 */
1390 
1391 #ifdef PNG_FREE_ME_SUPPORTED
1392  png_uint_32 free_me; /* flags items libpng is responsible for freeing */
1393 #endif
1394 
1395 #if defined(PNG_USER_CHUNKS_SUPPORTED)
1396  png_voidp user_chunk_ptr;
1397  png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
1398 #endif
1399 
1400 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
1403 #endif
1404 
1405 /* New members added in libpng-1.0.3 */
1406 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
1408  /* These were changed from png_byte in libpng-1.0.6 */
1412 #endif
1413 
1414 /* New member added in libpng-1.0.4 (renamed in 1.0.9) */
1415 #if defined(PNG_MNG_FEATURES_SUPPORTED) || \
1416  defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1417  defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1418 /* changed from png_byte to png_uint_32 at version 1.2.0 */
1419 #ifdef PNG_1_0_X
1421 #else
1423 #endif /* PNG_1_0_X */
1424 #endif
1425 
1426 /* New member added in libpng-1.0.7 */
1427 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1429 #endif
1430 
1431 /* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
1432 #if defined(PNG_MNG_FEATURES_SUPPORTED)
1434 #endif
1435 
1436 #if defined(PNG_1_0_X)
1437 /* New member added in libpng-1.0.10, ifdef'ed out in 1.2.0 */
1438  png_uint_32 row_buf_size;
1439 #endif
1440 
1441 /* New members added in libpng-1.2.0 */
1442 #if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
1443 # if !defined(PNG_1_0_X)
1444 # if defined(PNG_MMX_CODE_SUPPORTED)
1445  png_byte mmx_bitdepth_threshold;
1446  png_uint_32 mmx_rowbytes_threshold;
1447 # endif
1448  png_uint_32 asm_flags;
1449 # endif
1450 #endif
1451 
1452 /* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
1453 #ifdef PNG_USER_MEM_SUPPORTED
1454  png_voidp mem_ptr; /* user supplied struct for mem functions */
1455  png_malloc_ptr malloc_fn; /* function for allocating memory */
1456  png_free_ptr free_fn; /* function for freeing memory */
1457 #endif
1458 
1459 /* New member added in libpng-1.0.13 and 1.2.0 */
1460  png_bytep big_row_buf; /* buffer to save current (unfiltered) row */
1461 
1462 #if defined(PNG_READ_DITHER_SUPPORTED)
1463 /* The following three members were added at version 1.0.14 and 1.2.4 */
1464  png_bytep dither_sort; /* working sort array */
1465  png_bytep index_to_palette; /* where the original index currently is */
1466  /* in the palette */
1467  png_bytep palette_to_index; /* which original index points to this */
1468  /* palette color */
1469 #endif
1470 
1471 /* New members added in libpng-1.0.16 and 1.2.6 */
1473 
1474 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
1477 #endif
1478 
1479 /* New member added in libpng-1.0.25 and 1.2.17 */
1480 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
1481  /* storage for unknown chunk that the library doesn't recognize. */
1483 #endif
1484 
1485 /* New members added in libpng-1.2.26 */
1487 
1488 /* New member added in libpng-1.2.30 */
1489  png_charp chunkdata; /* buffer for reading chunk data */
1490 
1491 };
1492 
1493 
1494 /* This triggers a compiler error in png.c, if png.c and png.h
1495  * do not agree upon the version number.
1496  */
1497 typedef png_structp version_1_2_37;
1498 
1500 
1501 /* Here are the function definitions most commonly used. This is not
1502  * the place to find out how to use libpng. See libpng.txt for the
1503  * full explanation, see example.c for the summary. This just provides
1504  * a simple one line description of the use of each function.
1505  */
1506 
1507 /* Returns the version number of the library */
1508 extern PNG_EXPORT(png_uint_32,png_access_version_number) PNGARG((void));
1509 
1510 /* Tell lib we have already handled the first <num_bytes> magic bytes.
1511  * Handling more than 8 bytes from the beginning of the file is an error.
1512  */
1513 extern PNG_EXPORT(void,png_set_sig_bytes) PNGARG((png_structp png_ptr,
1514  int num_bytes));
1515 
1516 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
1517  * PNG file. Returns zero if the supplied bytes match the 8-byte PNG
1518  * signature, and non-zero otherwise. Having num_to_check == 0 or
1519  * start > 7 will always fail (ie return non-zero).
1520  */
1521 extern PNG_EXPORT(int,png_sig_cmp) PNGARG((png_bytep sig, png_size_t start,
1523 
1524 /* Simple signature checking function. This is the same as calling
1525  * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
1526  */
1527 extern PNG_EXPORT(int,png_check_sig) PNGARG((png_bytep sig, int num));
1528 
1529 /* Allocate and initialize png_ptr struct for reading, and any other memory. */
1530 extern PNG_EXPORT(png_structp,png_create_read_struct)
1532  png_error_ptr error_fn, png_error_ptr warn_fn));
1533 
1534 /* Allocate and initialize png_ptr struct for writing, and any other memory */
1535 extern PNG_EXPORT(png_structp,png_create_write_struct)
1536  PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1537  png_error_ptr error_fn, png_error_ptr warn_fn));
1538 
1539 #ifdef PNG_WRITE_SUPPORTED
1540 extern PNG_EXPORT(png_uint_32,png_get_compression_buffer_size)
1541  PNGARG((png_structp png_ptr));
1542 #endif
1543 
1544 #ifdef PNG_WRITE_SUPPORTED
1545 extern PNG_EXPORT(void,png_set_compression_buffer_size)
1546  PNGARG((png_structp png_ptr, png_uint_32 size));
1547 #endif
1548 
1549 /* Reset the compression stream */
1550 extern PNG_EXPORT(int,png_reset_zstream) PNGARG((png_structp png_ptr));
1551 
1552 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
1553 #ifdef PNG_USER_MEM_SUPPORTED
1554 extern PNG_EXPORT(png_structp,png_create_read_struct_2)
1555  PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1556  png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1557  png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1558 extern PNG_EXPORT(png_structp,png_create_write_struct_2)
1559  PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1560  png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1561  png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1562 #endif
1563 
1564 /* Write a PNG chunk - size, type, (optional) data, CRC. */
1565 extern PNG_EXPORT(void,png_write_chunk) PNGARG((png_structp png_ptr,
1567 
1568 /* Write the start of a PNG chunk - length and chunk name. */
1569 extern PNG_EXPORT(void,png_write_chunk_start) PNGARG((png_structp png_ptr,
1570  png_bytep chunk_name, png_uint_32 length));
1571 
1572 /* Write the data of a PNG chunk started with png_write_chunk_start(). */
1573 extern PNG_EXPORT(void,png_write_chunk_data) PNGARG((png_structp png_ptr,
1574  png_bytep data, png_size_t length));
1575 
1576 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1577 extern PNG_EXPORT(void,png_write_chunk_end) PNGARG((png_structp png_ptr));
1578 
1579 /* Allocate and initialize the info structure */
1580 extern PNG_EXPORT(png_infop,png_create_info_struct)
1581  PNGARG((png_structp png_ptr));
1582 
1583 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1584 /* Initialize the info structure (old interface - DEPRECATED) */
1585 extern PNG_EXPORT(void,png_info_init) PNGARG((png_infop info_ptr));
1586 #undef png_info_init
1587 #define png_info_init(info_ptr) png_info_init_3(&info_ptr,\
1588  png_sizeof(png_info));
1589 #endif
1590 
1591 extern PNG_EXPORT(void,png_info_init_3) PNGARG((png_infopp info_ptr,
1593 
1594 /* Writes all the PNG information before the image. */
1595 extern PNG_EXPORT(void,png_write_info_before_PLTE) PNGARG((png_structp png_ptr,
1596  png_infop info_ptr));
1597 extern PNG_EXPORT(void,png_write_info) PNGARG((png_structp png_ptr,
1598  png_infop info_ptr));
1599 
1600 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1601 /* read the information before the actual image data. */
1602 extern PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr,
1603  png_infop info_ptr));
1604 #endif
1605 
1606 #if defined(PNG_TIME_RFC1123_SUPPORTED)
1607 extern PNG_EXPORT(png_charp,png_convert_to_rfc1123)
1608  PNGARG((png_structp png_ptr, png_timep ptime));
1609 #endif
1610 
1611 #if !defined(_WIN32_WCE)
1612 /* "time.h" functions are not supported on WindowsCE */
1613 #if defined(PNG_WRITE_tIME_SUPPORTED)
1614 /* convert from a struct tm to png_time */
1615 extern PNG_EXPORT(void,png_convert_from_struct_tm) PNGARG((png_timep ptime,
1616  struct tm FAR * ttime));
1617 
1618 /* convert from time_t to png_time. Uses gmtime() */
1619 extern PNG_EXPORT(void,png_convert_from_time_t) PNGARG((png_timep ptime,
1620  time_t ttime));
1621 #endif /* PNG_WRITE_tIME_SUPPORTED */
1622 #endif /* _WIN32_WCE */
1623 
1624 #if defined(PNG_READ_EXPAND_SUPPORTED)
1625 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1626 extern PNG_EXPORT(void,png_set_expand) PNGARG((png_structp png_ptr));
1627 #if !defined(PNG_1_0_X)
1628 extern PNG_EXPORT(void,png_set_expand_gray_1_2_4_to_8) PNGARG((png_structp
1629  png_ptr));
1630 #endif
1631 extern PNG_EXPORT(void,png_set_palette_to_rgb) PNGARG((png_structp png_ptr));
1632 extern PNG_EXPORT(void,png_set_tRNS_to_alpha) PNGARG((png_structp png_ptr));
1633 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1634 /* Deprecated */
1635 extern PNG_EXPORT(void,png_set_gray_1_2_4_to_8) PNGARG((png_structp png_ptr));
1636 #endif
1637 #endif
1638 
1639 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1640 /* Use blue, green, red order for pixels. */
1641 extern PNG_EXPORT(void,png_set_bgr) PNGARG((png_structp png_ptr));
1642 #endif
1643 
1644 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
1645 /* Expand the grayscale to 24-bit RGB if necessary. */
1646 extern PNG_EXPORT(void,png_set_gray_to_rgb) PNGARG((png_structp png_ptr));
1647 #endif
1648 
1649 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
1650 /* Reduce RGB to grayscale. */
1651 #ifdef PNG_FLOATING_POINT_SUPPORTED
1652 extern PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr,
1653  int error_action, double red, double green ));
1654 #endif
1655 extern PNG_EXPORT(void,png_set_rgb_to_gray_fixed) PNGARG((png_structp png_ptr,
1656  int error_action, png_fixed_point red, png_fixed_point green ));
1657 extern PNG_EXPORT(png_byte,png_get_rgb_to_gray_status) PNGARG((png_structp
1658  png_ptr));
1659 #endif
1660 
1661 extern PNG_EXPORT(void,png_build_grayscale_palette) PNGARG((int bit_depth,
1662  png_colorp palette));
1663 
1664 #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1665 extern PNG_EXPORT(void,png_set_strip_alpha) PNGARG((png_structp png_ptr));
1666 #endif
1667 
1668 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1669  defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1670 extern PNG_EXPORT(void,png_set_swap_alpha) PNGARG((png_structp png_ptr));
1671 #endif
1672 
1673 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1674  defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1675 extern PNG_EXPORT(void,png_set_invert_alpha) PNGARG((png_structp png_ptr));
1676 #endif
1677 
1678 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1679 /* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
1680 extern PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr,
1682 /* The values of the PNG_FILLER_ defines should NOT be changed */
1683 #define PNG_FILLER_BEFORE 0
1684 #define PNG_FILLER_AFTER 1
1685 /* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
1686 #if !defined(PNG_1_0_X)
1687 extern PNG_EXPORT(void,png_set_add_alpha) PNGARG((png_structp png_ptr,
1688  png_uint_32 filler, int flags));
1689 #endif
1690 #endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
1691 
1692 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1693 /* Swap bytes in 16-bit depth files. */
1694 extern PNG_EXPORT(void,png_set_swap) PNGARG((png_structp png_ptr));
1695 #endif
1696 
1697 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1698 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1699 extern PNG_EXPORT(void,png_set_packing) PNGARG((png_structp png_ptr));
1700 #endif
1701 
1702 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1703 /* Swap packing order of pixels in bytes. */
1704 extern PNG_EXPORT(void,png_set_packswap) PNGARG((png_structp png_ptr));
1705 #endif
1706 
1707 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1708 /* Converts files to legal bit depths. */
1709 extern PNG_EXPORT(void,png_set_shift) PNGARG((png_structp png_ptr,
1710  png_color_8p true_bits));
1711 #endif
1712 
1713 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1714  defined(PNG_WRITE_INTERLACING_SUPPORTED)
1715 /* Have the code handle the interlacing. Returns the number of passes. */
1716 extern PNG_EXPORT(int,png_set_interlace_handling) PNGARG((png_structp png_ptr));
1717 #endif
1718 
1719 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1720 /* Invert monochrome files */
1721 extern PNG_EXPORT(void,png_set_invert_mono) PNGARG((png_structp png_ptr));
1722 #endif
1723 
1724 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
1725 /* Handle alpha and tRNS by replacing with a background color. */
1726 #ifdef PNG_FLOATING_POINT_SUPPORTED
1727 extern PNG_EXPORT(void,png_set_background) PNGARG((png_structp png_ptr,
1729  int need_expand, double background_gamma));
1730 #endif
1731 #define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1732 #define PNG_BACKGROUND_GAMMA_SCREEN 1
1733 #define PNG_BACKGROUND_GAMMA_FILE 2
1734 #define PNG_BACKGROUND_GAMMA_UNIQUE 3
1735 #endif
1736 
1737 #if defined(PNG_READ_16_TO_8_SUPPORTED)
1738 /* strip the second byte of information from a 16-bit depth file. */
1739 extern PNG_EXPORT(void,png_set_strip_16) PNGARG((png_structp png_ptr));
1740 #endif
1741 
1742 #if defined(PNG_READ_DITHER_SUPPORTED)
1743 /* Turn on dithering, and reduce the palette to the number of colors available. */
1744 extern PNG_EXPORT(void,png_set_dither) PNGARG((png_structp png_ptr,
1745  png_colorp palette, int num_palette, int maximum_colors,
1747 #endif
1748 
1749 #if defined(PNG_READ_GAMMA_SUPPORTED)
1750 /* Handle gamma correction. Screen_gamma=(display_exponent) */
1751 #ifdef PNG_FLOATING_POINT_SUPPORTED
1752 extern PNG_EXPORT(void,png_set_gamma) PNGARG((png_structp png_ptr,
1754 #endif
1755 #endif
1756 
1757 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1758 #if defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1759  defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1760 /* Permit or disallow empty PLTE (0: not permitted, 1: permitted) */
1761 /* Deprecated and will be removed. Use png_permit_mng_features() instead. */
1762 extern PNG_EXPORT(void,png_permit_empty_plte) PNGARG((png_structp png_ptr,
1764 #endif
1765 #endif
1766 
1767 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
1768 /* Set how many lines between output flushes - 0 for no flushing */
1769 extern PNG_EXPORT(void,png_set_flush) PNGARG((png_structp png_ptr, int nrows));
1770 /* Flush the current PNG output buffer */
1771 extern PNG_EXPORT(void,png_write_flush) PNGARG((png_structp png_ptr));
1772 #endif
1773 
1774 /* optional update palette with requested transformations */
1775 extern PNG_EXPORT(void,png_start_read_image) PNGARG((png_structp png_ptr));
1776 
1777 /* optional call to update the users info structure */
1778 extern PNG_EXPORT(void,png_read_update_info) PNGARG((png_structp png_ptr,
1779  png_infop info_ptr));
1780 
1781 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1782 /* read one or more rows of image data. */
1783 extern PNG_EXPORT(void,png_read_rows) PNGARG((png_structp png_ptr,
1785 #endif
1786 
1787 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1788 /* read a row of data. */
1789 extern PNG_EXPORT(void,png_read_row) PNGARG((png_structp png_ptr,
1790  png_bytep row,
1791  png_bytep display_row));
1792 #endif
1793 
1794 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1795 /* read the whole image into memory at once. */
1796 extern PNG_EXPORT(void,png_read_image) PNGARG((png_structp png_ptr,
1798 #endif
1799 
1800 /* write a row of image data */
1801 extern PNG_EXPORT(void,png_write_row) PNGARG((png_structp png_ptr,
1802  png_bytep row));
1803 
1804 /* write a few rows of image data */
1805 extern PNG_EXPORT(void,png_write_rows) PNGARG((png_structp png_ptr,
1806  png_bytepp row, png_uint_32 num_rows));
1807 
1808 /* write the image data */
1809 extern PNG_EXPORT(void,png_write_image) PNGARG((png_structp png_ptr,
1810  png_bytepp image));
1811 
1812 /* writes the end of the PNG file. */
1813 extern PNG_EXPORT(void,png_write_end) PNGARG((png_structp png_ptr,
1814  png_infop info_ptr));
1815 
1816 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1817 /* read the end of the PNG file. */
1818 extern PNG_EXPORT(void,png_read_end) PNGARG((png_structp png_ptr,
1819  png_infop info_ptr));
1820 #endif
1821 
1822 /* free any memory associated with the png_info_struct */
1823 extern PNG_EXPORT(void,png_destroy_info_struct) PNGARG((png_structp png_ptr,
1824  png_infopp info_ptr_ptr));
1825 
1826 /* free any memory associated with the png_struct and the png_info_structs */
1827 extern PNG_EXPORT(void,png_destroy_read_struct) PNGARG((png_structpp
1828  png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1829 
1830 /* free all memory used by the read (old method - NOT DLL EXPORTED) */
1831 /* Debian note: exporting as it is required by legacy applications */
1832 extern PNG_EXPORT(void,png_read_destroy) PNGARG((png_structp png_ptr, png_infop info_ptr,
1833  png_infop end_info_ptr));
1834 
1835 /* free any memory associated with the png_struct and the png_info_structs */
1836 extern PNG_EXPORT(void,png_destroy_write_struct)
1837  PNGARG((png_structpp png_ptr_ptr, png_infopp info_ptr_ptr));
1838 
1839 /* free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */
1840 /* Debian note: exporting as it is required by legacy applications */
1841 extern PNG_EXPORT(void,png_write_destroy) PNGARG((png_structp png_ptr));
1842 
1843 /* set the libpng method of handling chunk CRC errors */
1844 extern PNG_EXPORT(void,png_set_crc_action) PNGARG((png_structp png_ptr,
1846 
1847 /* Values for png_set_crc_action() to say how to handle CRC errors in
1848  * ancillary and critical chunks, and whether to use the data contained
1849  * therein. Note that it is impossible to "discard" data in a critical
1850  * chunk. For versions prior to 0.90, the action was always error/quit,
1851  * whereas in version 0.90 and later, the action for CRC errors in ancillary
1852  * chunks is warn/discard. These values should NOT be changed.
1853  *
1854  * value action:critical action:ancillary
1855  */
1856 #define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1857 #define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1858 #define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1859 #define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1860 #define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1861 #define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1862 
1863 /* These functions give the user control over the scan-line filtering in
1864  * libpng and the compression methods used by zlib. These functions are
1865  * mainly useful for testing, as the defaults should work with most users.
1866  * Those users who are tight on memory or want faster performance at the
1867  * expense of compression can modify them. See the compression library
1868  * header file (zlib.h) for an explination of the compression functions.
1869  */
1870 
1871 /* set the filtering method(s) used by libpng. Currently, the only valid
1872  * value for "method" is 0.
1873  */
1874 extern PNG_EXPORT(void,png_set_filter) PNGARG((png_structp png_ptr, int method,
1875  int filters));
1876 
1877 /* Flags for png_set_filter() to say which filters to use. The flags
1878  * are chosen so that they don't conflict with real filter types
1879  * below, in case they are supplied instead of the #defined constants.
1880  * These values should NOT be changed.
1881  */
1882 #define PNG_NO_FILTERS 0x00
1883 #define PNG_FILTER_NONE 0x08
1884 #define PNG_FILTER_SUB 0x10
1885 #define PNG_FILTER_UP 0x20
1886 #define PNG_FILTER_AVG 0x40
1887 #define PNG_FILTER_PAETH 0x80
1888 #define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
1889  PNG_FILTER_AVG | PNG_FILTER_PAETH)
1890 
1891 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1892  * These defines should NOT be changed.
1893  */
1894 #define PNG_FILTER_VALUE_NONE 0
1895 #define PNG_FILTER_VALUE_SUB 1
1896 #define PNG_FILTER_VALUE_UP 2
1897 #define PNG_FILTER_VALUE_AVG 3
1898 #define PNG_FILTER_VALUE_PAETH 4
1899 #define PNG_FILTER_VALUE_LAST 5
1900 
1901 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* EXPERIMENTAL */
1902 /* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
1903  * defines, either the default (minimum-sum-of-absolute-differences), or
1904  * the experimental method (weighted-minimum-sum-of-absolute-differences).
1905  *
1906  * Weights are factors >= 1.0, indicating how important it is to keep the
1907  * filter type consistent between rows. Larger numbers mean the current
1908  * filter is that many times as likely to be the same as the "num_weights"
1909  * previous filters. This is cumulative for each previous row with a weight.
1910  * There needs to be "num_weights" values in "filter_weights", or it can be
1911  * NULL if the weights aren't being specified. Weights have no influence on
1912  * the selection of the first row filter. Well chosen weights can (in theory)
1913  * improve the compression for a given image.
1914  *
1915  * Costs are factors >= 1.0 indicating the relative decoding costs of a
1916  * filter type. Higher costs indicate more decoding expense, and are
1917  * therefore less likely to be selected over a filter with lower computational
1918  * costs. There needs to be a value in "filter_costs" for each valid filter
1919  * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
1920  * setting the costs. Costs try to improve the speed of decompression without
1921  * unduly increasing the compressed image size.
1922  *
1923  * A negative weight or cost indicates the default value is to be used, and
1924  * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
1925  * The default values for both weights and costs are currently 1.0, but may
1926  * change if good general weighting/cost heuristics can be found. If both
1927  * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
1928  * to the UNWEIGHTED method, but with added encoding time/computation.
1929  */
1930 #ifdef PNG_FLOATING_POINT_SUPPORTED
1931 extern PNG_EXPORT(void,png_set_filter_heuristics) PNGARG((png_structp png_ptr,
1934 #endif
1935 #endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1936 
1937 /* Heuristic used for row filter selection. These defines should NOT be
1938  * changed.
1939  */
1940 #define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
1941 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
1942 #define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
1943 #define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
1944 
1945 /* Set the library compression level. Currently, valid values range from
1946  * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1947  * (0 - no compression, 9 - "maximal" compression). Note that tests have
1948  * shown that zlib compression levels 3-6 usually perform as well as level 9
1949  * for PNG images, and do considerably fewer caclulations. In the future,
1950  * these values may not correspond directly to the zlib compression levels.
1951  */
1952 extern PNG_EXPORT(void,png_set_compression_level) PNGARG((png_structp png_ptr,
1953  int level));
1954 
1955 extern PNG_EXPORT(void,png_set_compression_mem_level)
1956  PNGARG((png_structp png_ptr, int mem_level));
1957 
1958 extern PNG_EXPORT(void,png_set_compression_strategy)
1959  PNGARG((png_structp png_ptr, int strategy));
1960 
1961 extern PNG_EXPORT(void,png_set_compression_window_bits)
1962  PNGARG((png_structp png_ptr, int window_bits));
1963 
1964 extern PNG_EXPORT(void,png_set_compression_method) PNGARG((png_structp png_ptr,
1965  int method));
1966 
1967 /* These next functions are called for input/output, memory, and error
1968  * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
1969  * and call standard C I/O routines such as fread(), fwrite(), and
1970  * fprintf(). These functions can be made to use other I/O routines
1971  * at run time for those applications that need to handle I/O in a
1972  * different manner by calling png_set_???_fn(). See libpng.txt for
1973  * more information.
1974  */
1975 
1976 #if !defined(PNG_NO_STDIO)
1977 /* Initialize the input/output for the PNG file to the default functions. */
1978 extern PNG_EXPORT(void,png_init_io) PNGARG((png_structp png_ptr, png_FILE_p fp));
1979 #endif
1980 
1981 /* Replace the (error and abort), and warning functions with user
1982  * supplied functions. If no messages are to be printed you must still
1983  * write and use replacement functions. The replacement error_fn should
1984  * still do a longjmp to the last setjmp location if you are using this
1985  * method of error handling. If error_fn or warning_fn is NULL, the
1986  * default function will be used.
1987  */
1988 
1989 extern PNG_EXPORT(void,png_set_error_fn) PNGARG((png_structp png_ptr,
1990  png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
1991 
1992 /* Return the user pointer associated with the error functions */
1993 extern PNG_EXPORT(png_voidp,png_get_error_ptr) PNGARG((png_structp png_ptr));
1994 
1995 /* Replace the default data output functions with a user supplied one(s).
1996  * If buffered output is not used, then output_flush_fn can be set to NULL.
1997  * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
1998  * output_flush_fn will be ignored (and thus can be NULL).
1999  * It is probably a mistake to use NULL for output_flush_fn if
2000  * write_data_fn is not also NULL unless you have built libpng with
2001  * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
2002  * default flush function, which uses the standard *FILE structure, will
2003  * be used.
2004  */
2005 extern PNG_EXPORT(void,png_set_write_fn) PNGARG((png_structp png_ptr,
2006  png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
2007 
2008 /* Replace the default data input function with a user supplied one. */
2009 extern PNG_EXPORT(void,png_set_read_fn) PNGARG((png_structp png_ptr,
2010  png_voidp io_ptr, png_rw_ptr read_data_fn));
2011 
2012 /* Return the user pointer associated with the I/O functions */
2013 extern PNG_EXPORT(png_voidp,png_get_io_ptr) PNGARG((png_structp png_ptr));
2014 
2015 extern PNG_EXPORT(void,png_set_read_status_fn) PNGARG((png_structp png_ptr,
2016  png_read_status_ptr read_row_fn));
2017 
2018 extern PNG_EXPORT(void,png_set_write_status_fn) PNGARG((png_structp png_ptr,
2019  png_write_status_ptr write_row_fn));
2020 
2021 #ifdef PNG_USER_MEM_SUPPORTED
2022 /* Replace the default memory allocation functions with user supplied one(s). */
2023 extern PNG_EXPORT(void,png_set_mem_fn) PNGARG((png_structp png_ptr,
2024  png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn));
2025 /* Return the user pointer associated with the memory functions */
2026 extern PNG_EXPORT(png_voidp,png_get_mem_ptr) PNGARG((png_structp png_ptr));
2027 #endif
2028 
2029 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
2030  defined(PNG_LEGACY_SUPPORTED)
2031 extern PNG_EXPORT(void,png_set_read_user_transform_fn) PNGARG((png_structp
2032  png_ptr, png_user_transform_ptr read_user_transform_fn));
2033 #endif
2034 
2035 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
2036  defined(PNG_LEGACY_SUPPORTED)
2037 extern PNG_EXPORT(void,png_set_write_user_transform_fn) PNGARG((png_structp
2038  png_ptr, png_user_transform_ptr write_user_transform_fn));
2039 #endif
2040 
2041 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
2042  defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
2043  defined(PNG_LEGACY_SUPPORTED)
2044 extern PNG_EXPORT(void,png_set_user_transform_info) PNGARG((png_structp
2045  png_ptr, png_voidp user_transform_ptr, int user_transform_depth,
2047 /* Return the user pointer associated with the user transform functions */
2048 extern PNG_EXPORT(png_voidp,png_get_user_transform_ptr)
2049  PNGARG((png_structp png_ptr));
2050 #endif
2051 
2052 #ifdef PNG_USER_CHUNKS_SUPPORTED
2053 extern PNG_EXPORT(void,png_set_read_user_chunk_fn) PNGARG((png_structp png_ptr,
2054  png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
2055 extern PNG_EXPORT(png_voidp,png_get_user_chunk_ptr) PNGARG((png_structp
2056  png_ptr));
2057 #endif
2058 
2059 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
2060 /* Sets the function callbacks for the push reader, and a pointer to a
2061  * user-defined structure available to the callback functions.
2062  */
2063 extern PNG_EXPORT(void,png_set_progressive_read_fn) PNGARG((png_structp png_ptr,
2064  png_voidp progressive_ptr,
2065  png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
2066  png_progressive_end_ptr end_fn));
2067 
2068 /* returns the user pointer associated with the push read functions */
2069 extern PNG_EXPORT(png_voidp,png_get_progressive_ptr)
2070  PNGARG((png_structp png_ptr));
2071 
2072 /* function to be called when data becomes available */
2073 extern PNG_EXPORT(void,png_process_data) PNGARG((png_structp png_ptr,
2074  png_infop info_ptr, png_bytep buffer, png_size_t buffer_size));
2075 
2076 /* function that combines rows. Not very much different than the
2077  * png_combine_row() call. Is this even used?????
2078  */
2079 extern PNG_EXPORT(void,png_progressive_combine_row) PNGARG((png_structp png_ptr,
2081 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
2082 
2083 extern PNG_EXPORT(png_voidp,png_malloc) PNGARG((png_structp png_ptr,
2084  png_uint_32 size));
2085 
2086 #if defined(PNG_1_0_X)
2087 # define png_malloc_warn png_malloc
2088 #else
2089 /* Added at libpng version 1.2.4 */
2090 extern PNG_EXPORT(png_voidp,png_malloc_warn) PNGARG((png_structp png_ptr,
2091  png_uint_32 size));
2092 #endif
2093 
2094 /* frees a pointer allocated by png_malloc() */
2095 extern PNG_EXPORT(void,png_free) PNGARG((png_structp png_ptr, png_voidp ptr));
2096 
2097 #if defined(PNG_1_0_X)
2098 /* Function to allocate memory for zlib. */
2099 extern PNG_EXPORT(voidpf,png_zalloc) PNGARG((voidpf png_ptr, uInt items,
2100  uInt size));
2101 
2102 /* Function to free memory for zlib */
2103 extern PNG_EXPORT(void,png_zfree) PNGARG((voidpf png_ptr, voidpf ptr));
2104 #endif
2105 
2106 /* Free data that was allocated internally */
2107 extern PNG_EXPORT(void,png_free_data) PNGARG((png_structp png_ptr,
2108  png_infop info_ptr, png_uint_32 free_me, int num));
2109 #ifdef PNG_FREE_ME_SUPPORTED
2110 /* Reassign responsibility for freeing existing data, whether allocated
2111  * by libpng or by the application */
2112 extern PNG_EXPORT(void,png_data_freer) PNGARG((png_structp png_ptr,
2113  png_infop info_ptr, int freer, png_uint_32 mask));
2114 #endif
2115 /* assignments for png_data_freer */
2116 #define PNG_DESTROY_WILL_FREE_DATA 1
2117 #define PNG_SET_WILL_FREE_DATA 1
2118 #define PNG_USER_WILL_FREE_DATA 2
2119 /* Flags for png_ptr->free_me and info_ptr->free_me */
2120 #define PNG_FREE_HIST 0x0008
2121 #define PNG_FREE_ICCP 0x0010
2122 #define PNG_FREE_SPLT 0x0020
2123 #define PNG_FREE_ROWS 0x0040
2124 #define PNG_FREE_PCAL 0x0080
2125 #define PNG_FREE_SCAL 0x0100
2126 #define PNG_FREE_UNKN 0x0200
2127 #define PNG_FREE_LIST 0x0400
2128 #define PNG_FREE_PLTE 0x1000
2129 #define PNG_FREE_TRNS 0x2000
2130 #define PNG_FREE_TEXT 0x4000
2131 #define PNG_FREE_ALL 0x7fff
2132 #define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
2133 
2134 #ifdef PNG_USER_MEM_SUPPORTED
2135 extern PNG_EXPORT(png_voidp,png_malloc_default) PNGARG((png_structp png_ptr,
2136  png_uint_32 size));
2137 extern PNG_EXPORT(void,png_free_default) PNGARG((png_structp png_ptr,
2138  png_voidp ptr));
2139 #endif
2140 
2141 extern PNG_EXPORT(png_voidp,png_memcpy_check) PNGARG((png_structp png_ptr,
2142  png_voidp s1, png_voidp s2, png_uint_32 size));
2143 
2144 extern PNG_EXPORT(png_voidp,png_memset_check) PNGARG((png_structp png_ptr,
2145  png_voidp s1, int value, png_uint_32 size));
2146 
2147 #if defined(USE_FAR_KEYWORD) /* memory model conversion function */
2148 extern void *png_far_to_near PNGARG((png_structp png_ptr,png_voidp ptr,
2149  int check));
2150 #endif /* USE_FAR_KEYWORD */
2151 
2152 #ifndef PNG_NO_ERROR_TEXT
2153 /* Fatal error in PNG image of libpng - can't continue */
2154 extern PNG_EXPORT(void,png_error) PNGARG((png_structp png_ptr,
2156 
2157 /* The same, but the chunk name is prepended to the error string. */
2158 extern PNG_EXPORT(void,png_chunk_error) PNGARG((png_structp png_ptr,
2159  png_const_charp error_message));
2160 #else
2161 /* Fatal error in PNG image of libpng - can't continue */
2162 extern PNG_EXPORT(void,png_err) PNGARG((png_structp png_ptr));
2163 #endif
2164 
2165 #ifndef PNG_NO_WARNINGS
2166 /* Non-fatal error in libpng. Can continue, but may have a problem. */
2167 extern PNG_EXPORT(void,png_warning) PNGARG((png_structp png_ptr,
2169 
2170 #ifdef PNG_READ_SUPPORTED
2171 /* Non-fatal error in libpng, chunk name is prepended to message. */
2172 extern PNG_EXPORT(void,png_chunk_warning) PNGARG((png_structp png_ptr,
2173  png_const_charp warning_message));
2174 #endif /* PNG_READ_SUPPORTED */
2175 #endif /* PNG_NO_WARNINGS */
2176 
2177 /* The png_set_<chunk> functions are for storing values in the png_info_struct.
2178  * Similarly, the png_get_<chunk> calls are used to read values from the
2179  * png_info_struct, either storing the parameters in the passed variables, or
2180  * setting pointers into the png_info_struct where the data is stored. The
2181  * png_get_<chunk> functions return a non-zero value if the data was available
2182  * in info_ptr, or return zero and do not change any of the parameters if the
2183  * data was not available.
2184  *
2185  * These functions should be used instead of directly accessing png_info
2186  * to avoid problems with future changes in the size and internal layout of
2187  * png_info_struct.
2188  */
2189 /* Returns "flag" if chunk data is valid in info_ptr. */
2190 extern PNG_EXPORT(png_uint_32,png_get_valid) PNGARG((png_structp png_ptr,
2191 png_infop info_ptr, png_uint_32 flag));
2192 
2193 /* Returns number of bytes needed to hold a transformed row. */
2194 extern PNG_EXPORT(png_uint_32,png_get_rowbytes) PNGARG((png_structp png_ptr,
2195 png_infop info_ptr));
2196 
2197 #if defined(PNG_INFO_IMAGE_SUPPORTED)
2198 /* Returns row_pointers, which is an array of pointers to scanlines that was
2199 returned from png_read_png(). */
2200 extern PNG_EXPORT(png_bytepp,png_get_rows) PNGARG((png_structp png_ptr,
2201 png_infop info_ptr));
2202 /* Set row_pointers, which is an array of pointers to scanlines for use
2203 by png_write_png(). */
2204 extern PNG_EXPORT(void,png_set_rows) PNGARG((png_structp png_ptr,
2205  png_infop info_ptr, png_bytepp row_pointers));
2206 #endif
2207 
2208 /* Returns number of color channels in image. */
2209 extern PNG_EXPORT(png_byte,png_get_channels) PNGARG((png_structp png_ptr,
2210 png_infop info_ptr));
2211 
2212 #ifdef PNG_EASY_ACCESS_SUPPORTED
2213 /* Returns image width in pixels. */
2214 extern PNG_EXPORT(png_uint_32, png_get_image_width) PNGARG((png_structp
2215 png_ptr, png_infop info_ptr));
2216 
2217 /* Returns image height in pixels. */
2218 extern PNG_EXPORT(png_uint_32, png_get_image_height) PNGARG((png_structp
2219 png_ptr, png_infop info_ptr));
2220 
2221 /* Returns image bit_depth. */
2222 extern PNG_EXPORT(png_byte, png_get_bit_depth) PNGARG((png_structp
2223 png_ptr, png_infop info_ptr));
2224 
2225 /* Returns image color_type. */
2226 extern PNG_EXPORT(png_byte, png_get_color_type) PNGARG((png_structp
2227 png_ptr, png_infop info_ptr));
2228 
2229 /* Returns image filter_type. */
2230 extern PNG_EXPORT(png_byte, png_get_filter_type) PNGARG((png_structp
2231 png_ptr, png_infop info_ptr));
2232 
2233 /* Returns image interlace_type. */
2234 extern PNG_EXPORT(png_byte, png_get_interlace_type) PNGARG((png_structp
2235 png_ptr, png_infop info_ptr));
2236 
2237 /* Returns image compression_type. */
2238 extern PNG_EXPORT(png_byte, png_get_compression_type) PNGARG((png_structp
2239 png_ptr, png_infop info_ptr));
2240 
2241 /* Returns image resolution in pixels per meter, from pHYs chunk data. */
2242 extern PNG_EXPORT(png_uint_32, png_get_pixels_per_meter) PNGARG((png_structp
2243 png_ptr, png_infop info_ptr));
2244 extern PNG_EXPORT(png_uint_32, png_get_x_pixels_per_meter) PNGARG((png_structp
2245 png_ptr, png_infop info_ptr));
2246 extern PNG_EXPORT(png_uint_32, png_get_y_pixels_per_meter) PNGARG((png_structp
2247 png_ptr, png_infop info_ptr));
2248 
2249 /* Returns pixel aspect ratio, computed from pHYs chunk data. */
2250 #ifdef PNG_FLOATING_POINT_SUPPORTED
2251 extern PNG_EXPORT(float, png_get_pixel_aspect_ratio) PNGARG((png_structp
2252 png_ptr, png_infop info_ptr));
2253 #endif
2254 
2255 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
2256 extern PNG_EXPORT(png_int_32, png_get_x_offset_pixels) PNGARG((png_structp
2257 png_ptr, png_infop info_ptr));
2258 extern PNG_EXPORT(png_int_32, png_get_y_offset_pixels) PNGARG((png_structp
2259 png_ptr, png_infop info_ptr));
2260 extern PNG_EXPORT(png_int_32, png_get_x_offset_microns) PNGARG((png_structp
2261 png_ptr, png_infop info_ptr));
2262 extern PNG_EXPORT(png_int_32, png_get_y_offset_microns) PNGARG((png_structp
2263 png_ptr, png_infop info_ptr));
2264 
2265 #endif /* PNG_EASY_ACCESS_SUPPORTED */
2266 
2267 /* Returns pointer to signature string read from PNG header */
2268 extern PNG_EXPORT(png_bytep,png_get_signature) PNGARG((png_structp png_ptr,
2269 png_infop info_ptr));
2270 
2271 #if defined(PNG_bKGD_SUPPORTED)
2272 extern PNG_EXPORT(png_uint_32,png_get_bKGD) PNGARG((png_structp png_ptr,
2273  png_infop info_ptr, png_color_16p *background));
2274 #endif
2275 
2276 #if defined(PNG_bKGD_SUPPORTED)
2277 extern PNG_EXPORT(void,png_set_bKGD) PNGARG((png_structp png_ptr,
2278  png_infop info_ptr, png_color_16p background));
2279 #endif
2280 
2281 #if defined(PNG_cHRM_SUPPORTED)
2282 #ifdef PNG_FLOATING_POINT_SUPPORTED
2283 extern PNG_EXPORT(png_uint_32,png_get_cHRM) PNGARG((png_structp png_ptr,
2284  png_infop info_ptr, double *white_x, double *white_y, double *red_x,
2285  double *red_y, double *green_x, double *green_y, double *blue_x,
2286  double *blue_y));
2287 #endif
2288 #ifdef PNG_FIXED_POINT_SUPPORTED
2289 extern PNG_EXPORT(png_uint_32,png_get_cHRM_fixed) PNGARG((png_structp png_ptr,
2294 #endif
2295 #endif
2296 
2297 #if defined(PNG_cHRM_SUPPORTED)
2298 #ifdef PNG_FLOATING_POINT_SUPPORTED
2299 extern PNG_EXPORT(void,png_set_cHRM) PNGARG((png_structp png_ptr,
2300  png_infop info_ptr, double white_x, double white_y, double red_x,
2301  double red_y, double green_x, double green_y, double blue_x, double blue_y));
2302 #endif
2303 #ifdef PNG_FIXED_POINT_SUPPORTED
2304 extern PNG_EXPORT(void,png_set_cHRM_fixed) PNGARG((png_structp png_ptr,
2305  png_infop info_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y,
2306  png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
2307  int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
2308  png_fixed_point int_blue_y));
2309 #endif
2310 #endif
2311 
2312 #if defined(PNG_gAMA_SUPPORTED)
2313 #ifdef PNG_FLOATING_POINT_SUPPORTED
2314 extern PNG_EXPORT(png_uint_32,png_get_gAMA) PNGARG((png_structp png_ptr,
2315  png_infop info_ptr, double *file_gamma));
2316 #endif
2317 extern PNG_EXPORT(png_uint_32,png_get_gAMA_fixed) PNGARG((png_structp png_ptr,
2318  png_infop info_ptr, png_fixed_point *int_file_gamma));
2319 #endif
2320 
2321 #if defined(PNG_gAMA_SUPPORTED)
2322 #ifdef PNG_FLOATING_POINT_SUPPORTED
2323 extern PNG_EXPORT(void,png_set_gAMA) PNGARG((png_structp png_ptr,
2324  png_infop info_ptr, double file_gamma));
2325 #endif
2326 extern PNG_EXPORT(void,png_set_gAMA_fixed) PNGARG((png_structp png_ptr,
2327  png_infop info_ptr, png_fixed_point int_file_gamma));
2328 #endif
2329 
2330 #if defined(PNG_hIST_SUPPORTED)
2331 extern PNG_EXPORT(png_uint_32,png_get_hIST) PNGARG((png_structp png_ptr,
2332  png_infop info_ptr, png_uint_16p *hist));
2333 #endif
2334 
2335 #if defined(PNG_hIST_SUPPORTED)
2336 extern PNG_EXPORT(void,png_set_hIST) PNGARG((png_structp png_ptr,
2337  png_infop info_ptr, png_uint_16p hist));
2338 #endif
2339 
2340 extern PNG_EXPORT(png_uint_32,png_get_IHDR) PNGARG((png_structp png_ptr,
2341  png_infop info_ptr, png_uint_32 *width, png_uint_32 *height,
2342  int *bit_depth, int *color_type, int *interlace_method,
2343  int *compression_method, int *filter_method));
2344 
2345 extern PNG_EXPORT(void,png_set_IHDR) PNGARG((png_structp png_ptr,
2346  png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
2347  int color_type, int interlace_method, int compression_method,
2348  int filter_method));
2349 
2350 #if defined(PNG_oFFs_SUPPORTED)
2351 extern PNG_EXPORT(png_uint_32,png_get_oFFs) PNGARG((png_structp png_ptr,
2352  png_infop info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
2353  int *unit_type));
2354 #endif
2355 
2356 #if defined(PNG_oFFs_SUPPORTED)
2357 extern PNG_EXPORT(void,png_set_oFFs) PNGARG((png_structp png_ptr,
2358  png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2359  int unit_type));
2360 #endif
2361 
2362 #if defined(PNG_pCAL_SUPPORTED)
2363 extern PNG_EXPORT(png_uint_32,png_get_pCAL) PNGARG((png_structp png_ptr,
2364  png_infop info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1,
2365  int *type, int *nparams, png_charp *units, png_charpp *params));
2366 #endif
2367 
2368 #if defined(PNG_pCAL_SUPPORTED)
2369 extern PNG_EXPORT(void,png_set_pCAL) PNGARG((png_structp png_ptr,
2370  png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1,
2371  int type, int nparams, png_charp units, png_charpp params));
2372 #endif
2373 
2374 #if defined(PNG_pHYs_SUPPORTED)
2375 extern PNG_EXPORT(png_uint_32,png_get_pHYs) PNGARG((png_structp png_ptr,
2376  png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
2377 #endif
2378 
2379 #if defined(PNG_pHYs_SUPPORTED)
2380 extern PNG_EXPORT(void,png_set_pHYs) PNGARG((png_structp png_ptr,
2381  png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2382 #endif
2383 
2384 extern PNG_EXPORT(png_uint_32,png_get_PLTE) PNGARG((png_structp png_ptr,
2385  png_infop info_ptr, png_colorp *palette, int *num_palette));
2386 
2387 extern PNG_EXPORT(void,png_set_PLTE) PNGARG((png_structp png_ptr,
2388  png_infop info_ptr, png_colorp palette, int num_palette));
2389 
2390 #if defined(PNG_sBIT_SUPPORTED)
2391 extern PNG_EXPORT(png_uint_32,png_get_sBIT) PNGARG((png_structp png_ptr,
2392  png_infop info_ptr, png_color_8p *sig_bit));
2393 #endif
2394 
2395 #if defined(PNG_sBIT_SUPPORTED)
2396 extern PNG_EXPORT(void,png_set_sBIT) PNGARG((png_structp png_ptr,
2397  png_infop info_ptr, png_color_8p sig_bit));
2398 #endif
2399 
2400 #if defined(PNG_sRGB_SUPPORTED)
2401 extern PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr,
2402  png_infop info_ptr, int *intent));
2403 #endif
2404 
2405 #if defined(PNG_sRGB_SUPPORTED)
2406 extern PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr,
2407  png_infop info_ptr, int intent));
2408 extern PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr,
2409  png_infop info_ptr, int intent));
2410 #endif
2411 
2412 #if defined(PNG_iCCP_SUPPORTED)
2413 extern PNG_EXPORT(png_uint_32,png_get_iCCP) PNGARG((png_structp png_ptr,
2414  png_infop info_ptr, png_charpp name, int *compression_type,
2415  png_charpp profile, png_uint_32 *proflen));
2416  /* Note to maintainer: profile should be png_bytepp */
2417 #endif
2418 
2419 #if defined(PNG_iCCP_SUPPORTED)
2420 extern PNG_EXPORT(void,png_set_iCCP) PNGARG((png_structp png_ptr,
2421  png_infop info_ptr, png_charp name, int compression_type,
2422  png_charp profile, png_uint_32 proflen));
2423  /* Note to maintainer: profile should be png_bytep */
2424 #endif
2425 
2426 #if defined(PNG_sPLT_SUPPORTED)
2427 extern PNG_EXPORT(png_uint_32,png_get_sPLT) PNGARG((png_structp png_ptr,
2428  png_infop info_ptr, png_sPLT_tpp entries));
2429 #endif
2430 
2431 #if defined(PNG_sPLT_SUPPORTED)
2432 extern PNG_EXPORT(void,png_set_sPLT) PNGARG((png_structp png_ptr,
2433  png_infop info_ptr, png_sPLT_tp entries, int nentries));
2434 #endif
2435 
2436 #if defined(PNG_TEXT_SUPPORTED)
2437 /* png_get_text also returns the number of text chunks in *num_text */
2438 extern PNG_EXPORT(png_uint_32,png_get_text) PNGARG((png_structp png_ptr,
2439  png_infop info_ptr, png_textp *text_ptr, int *num_text));
2440 #endif
2441 
2442 /*
2443  * Note while png_set_text() will accept a structure whose text,
2444  * language, and translated keywords are NULL pointers, the structure
2445  * returned by png_get_text will always contain regular
2446  * zero-terminated C strings. They might be empty strings but
2447  * they will never be NULL pointers.
2448  */
2449 
2450 #if defined(PNG_TEXT_SUPPORTED)
2451 extern PNG_EXPORT(void,png_set_text) PNGARG((png_structp png_ptr,
2452  png_infop info_ptr, png_textp text_ptr, int num_text));
2453 #endif
2454 
2455 #if defined(PNG_tIME_SUPPORTED)
2456 extern PNG_EXPORT(png_uint_32,png_get_tIME) PNGARG((png_structp png_ptr,
2457  png_infop info_ptr, png_timep *mod_time));
2458 #endif
2459 
2460 #if defined(PNG_tIME_SUPPORTED)
2461 extern PNG_EXPORT(void,png_set_tIME) PNGARG((png_structp png_ptr,
2462  png_infop info_ptr, png_timep mod_time));
2463 #endif
2464 
2465 #if defined(PNG_tRNS_SUPPORTED)
2466 extern PNG_EXPORT(png_uint_32,png_get_tRNS) PNGARG((png_structp png_ptr,
2467  png_infop info_ptr, png_bytep *trans, int *num_trans,
2468  png_color_16p *trans_values));
2469 #endif
2470 
2471 #if defined(PNG_tRNS_SUPPORTED)
2472 extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
2473  png_infop info_ptr, png_bytep trans, int num_trans,
2474  png_color_16p trans_values));
2475 #endif
2476 
2477 #if defined(PNG_tRNS_SUPPORTED)
2478 #endif
2479 
2480 #if defined(PNG_sCAL_SUPPORTED)
2481 #ifdef PNG_FLOATING_POINT_SUPPORTED
2482 extern PNG_EXPORT(png_uint_32,png_get_sCAL) PNGARG((png_structp png_ptr,
2483  png_infop info_ptr, int *unit, double *width, double *height));
2484 #else
2485 #ifdef PNG_FIXED_POINT_SUPPORTED
2486 extern PNG_EXPORT(png_uint_32,png_get_sCAL_s) PNGARG((png_structp png_ptr,
2487  png_infop info_ptr, int *unit, png_charpp swidth, png_charpp sheight));
2488 #endif
2489 #endif
2490 #endif /* PNG_sCAL_SUPPORTED */
2491 
2492 #if defined(PNG_sCAL_SUPPORTED)
2493 #ifdef PNG_FLOATING_POINT_SUPPORTED
2494 extern PNG_EXPORT(void,png_set_sCAL) PNGARG((png_structp png_ptr,
2495  png_infop info_ptr, int unit, double width, double height));
2496 #else
2497 #ifdef PNG_FIXED_POINT_SUPPORTED
2498 extern PNG_EXPORT(void,png_set_sCAL_s) PNGARG((png_structp png_ptr,
2499  png_infop info_ptr, int unit, png_charp swidth, png_charp sheight));
2500 #endif
2501 #endif
2502 #endif /* PNG_sCAL_SUPPORTED || PNG_WRITE_sCAL_SUPPORTED */
2503 
2504 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
2505 /* provide a list of chunks and how they are to be handled, if the built-in
2506  handling or default unknown chunk handling is not desired. Any chunks not
2507  listed will be handled in the default manner. The IHDR and IEND chunks
2508  must not be listed.
2509  keep = 0: follow default behaviour
2510  = 1: do not keep
2511  = 2: keep only if safe-to-copy
2512  = 3: keep even if unsafe-to-copy
2513 */
2514 extern PNG_EXPORT(void, png_set_keep_unknown_chunks) PNGARG((png_structp
2515  png_ptr, int keep, png_bytep chunk_list, int num_chunks));
2516 extern PNG_EXPORT(void, png_set_unknown_chunks) PNGARG((png_structp png_ptr,
2517  png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns));
2518 extern PNG_EXPORT(void, png_set_unknown_chunk_location)
2519  PNGARG((png_structp png_ptr, png_infop info_ptr, int chunk, int location));
2520 extern PNG_EXPORT(png_uint_32,png_get_unknown_chunks) PNGARG((png_structp
2521  png_ptr, png_infop info_ptr, png_unknown_chunkpp entries));
2522 #endif
2523 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2524 PNG_EXPORT(int,png_handle_as_unknown) PNGARG((png_structp png_ptr, png_bytep
2525  chunk_name));
2526 #endif
2527 
2528 /* Png_free_data() will turn off the "valid" flag for anything it frees.
2529  If you need to turn it off for a chunk that your application has freed,
2530  you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK); */
2531 extern PNG_EXPORT(void, png_set_invalid) PNGARG((png_structp png_ptr,
2532  png_infop info_ptr, int mask));
2533 
2534 #if defined(PNG_INFO_IMAGE_SUPPORTED)
2535 /* The "params" pointer is currently not used and is for future expansion. */
2536 extern PNG_EXPORT(void, png_read_png) PNGARG((png_structp png_ptr,
2537  png_infop info_ptr,
2538  int transforms,
2539  png_voidp params));
2540 extern PNG_EXPORT(void, png_write_png) PNGARG((png_structp png_ptr,
2541  png_infop info_ptr,
2542  int transforms,
2543  png_voidp params));
2544 #endif
2545 
2546 /* Define PNG_DEBUG at compile time for debugging information. Higher
2547  * numbers for PNG_DEBUG mean more debugging information. This has
2548  * only been added since version 0.95 so it is not implemented throughout
2549  * libpng yet, but more support will be added as needed.
2550  */
2551 #ifdef PNG_DEBUG
2552 #if (PNG_DEBUG > 0)
2553 #if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER)
2554 #include <crtdbg.h>
2555 #if (PNG_DEBUG > 1)
2556 #ifndef _DEBUG
2557 # define _DEBUG
2558 #endif
2559 #ifndef png_debug
2560 #define png_debug(l,m) _RPT0(_CRT_WARN,m PNG_STRING_NEWLINE)
2561 #endif
2562 #ifndef png_debug1
2563 #define png_debug1(l,m,p1) _RPT1(_CRT_WARN,m PNG_STRING_NEWLINE,p1)
2564 #endif
2565 #ifndef png_debug2
2566 #define png_debug2(l,m,p1,p2) _RPT2(_CRT_WARN,m PNG_STRING_NEWLINE,p1,p2)
2567 #endif
2568 #endif
2569 #else /* PNG_DEBUG_FILE || !_MSC_VER */
2570 #ifndef PNG_DEBUG_FILE
2571 #define PNG_DEBUG_FILE stderr
2572 #endif /* PNG_DEBUG_FILE */
2573 
2574 #if (PNG_DEBUG > 1)
2575 /* Note: ["%s"m PNG_STRING_NEWLINE] probably does not work on
2576  * non-ISO compilers */
2577 # ifdef __STDC__
2578 # ifndef png_debug
2579 # define png_debug(l,m) \
2580  { \
2581  int num_tabs=l; \
2582  fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
2583  (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":"")))); \
2584  }
2585 # endif
2586 # ifndef png_debug1
2587 # define png_debug1(l,m,p1) \
2588  { \
2589  int num_tabs=l; \
2590  fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
2591  (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1); \
2592  }
2593 # endif
2594 # ifndef png_debug2
2595 # define png_debug2(l,m,p1,p2) \
2596  { \
2597  int num_tabs=l; \
2598  fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
2599  (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1,p2); \
2600  }
2601 # endif
2602 # else /* __STDC __ */
2603 # ifndef png_debug
2604 # define png_debug(l,m) \
2605  { \
2606  int num_tabs=l; \
2607  char format[256]; \
2608  snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
2609  (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
2610  m,PNG_STRING_NEWLINE); \
2611  fprintf(PNG_DEBUG_FILE,format); \
2612  }
2613 # endif
2614 # ifndef png_debug1
2615 # define png_debug1(l,m,p1) \
2616  { \
2617  int num_tabs=l; \
2618  char format[256]; \
2619  snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
2620  (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
2621  m,PNG_STRING_NEWLINE); \
2622  fprintf(PNG_DEBUG_FILE,format,p1); \
2623  }
2624 # endif
2625 # ifndef png_debug2
2626 # define png_debug2(l,m,p1,p2) \
2627  { \
2628  int num_tabs=l; \
2629  char format[256]; \
2630  snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
2631  (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
2632  m,PNG_STRING_NEWLINE); \
2633  fprintf(PNG_DEBUG_FILE,format,p1,p2); \
2634  }
2635 # endif
2636 # endif /* __STDC __ */
2637 #endif /* (PNG_DEBUG > 1) */
2638 
2639 #endif /* _MSC_VER */
2640 #endif /* (PNG_DEBUG > 0) */
2641 #endif /* PNG_DEBUG */
2642 #ifndef png_debug
2643 #define png_debug(l, m)
2644 #endif
2645 #ifndef png_debug1
2646 #define png_debug1(l, m, p1)
2647 #endif
2648 #ifndef png_debug2
2649 #define png_debug2(l, m, p1, p2)
2650 #endif
2651 
2652 extern PNG_EXPORT(png_charp,png_get_copyright) PNGARG((png_structp png_ptr));
2653 extern PNG_EXPORT(png_charp,png_get_header_ver) PNGARG((png_structp png_ptr));
2654 extern PNG_EXPORT(png_charp,png_get_header_version) PNGARG((png_structp png_ptr));
2655 extern PNG_EXPORT(png_charp,png_get_libpng_ver) PNGARG((png_structp png_ptr));
2656 
2657 #ifdef PNG_MNG_FEATURES_SUPPORTED
2658 extern PNG_EXPORT(png_uint_32,png_permit_mng_features) PNGARG((png_structp
2659  png_ptr, png_uint_32 mng_features_permitted));
2660 #endif
2661 
2662 /* For use in png_set_keep_unknown, added to version 1.2.6 */
2663 #define PNG_HANDLE_CHUNK_AS_DEFAULT 0
2664 #define PNG_HANDLE_CHUNK_NEVER 1
2665 #define PNG_HANDLE_CHUNK_IF_SAFE 2
2666 #define PNG_HANDLE_CHUNK_ALWAYS 3
2667 
2668 /* Added to version 1.2.0 */
2669 #if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
2670 #if defined(PNG_MMX_CODE_SUPPORTED)
2671 #define PNG_ASM_FLAG_MMX_SUPPORT_COMPILED 0x01 /* not user-settable */
2672 #define PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU 0x02 /* not user-settable */
2673 #define PNG_ASM_FLAG_MMX_READ_COMBINE_ROW 0x04
2674 #define PNG_ASM_FLAG_MMX_READ_INTERLACE 0x08
2675 #define PNG_ASM_FLAG_MMX_READ_FILTER_SUB 0x10
2676 #define PNG_ASM_FLAG_MMX_READ_FILTER_UP 0x20
2677 #define PNG_ASM_FLAG_MMX_READ_FILTER_AVG 0x40
2678 #define PNG_ASM_FLAG_MMX_READ_FILTER_PAETH 0x80
2679 #define PNG_ASM_FLAGS_INITIALIZED 0x80000000 /* not user-settable */
2680 
2681 #define PNG_MMX_READ_FLAGS ( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW \
2682  | PNG_ASM_FLAG_MMX_READ_INTERLACE \
2683  | PNG_ASM_FLAG_MMX_READ_FILTER_SUB \
2684  | PNG_ASM_FLAG_MMX_READ_FILTER_UP \
2685  | PNG_ASM_FLAG_MMX_READ_FILTER_AVG \
2686  | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH )
2687 #define PNG_MMX_WRITE_FLAGS ( 0 )
2688 
2689 #define PNG_MMX_FLAGS ( PNG_ASM_FLAG_MMX_SUPPORT_COMPILED \
2690  | PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU \
2691  | PNG_MMX_READ_FLAGS \
2692  | PNG_MMX_WRITE_FLAGS )
2693 
2694 #define PNG_SELECT_READ 1
2695 #define PNG_SELECT_WRITE 2
2696 #endif /* PNG_MMX_CODE_SUPPORTED */
2697 
2698 #if !defined(PNG_1_0_X)
2699 /* pngget.c */
2700 extern PNG_EXPORT(png_uint_32,png_get_mmx_flagmask)
2701  PNGARG((int flag_select, int *compilerID));
2702 
2703 /* pngget.c */
2704 extern PNG_EXPORT(png_uint_32,png_get_asm_flagmask)
2705  PNGARG((int flag_select));
2706 
2707 /* pngget.c */
2708 extern PNG_EXPORT(png_uint_32,png_get_asm_flags)
2709  PNGARG((png_structp png_ptr));
2710 
2711 /* pngget.c */
2712 extern PNG_EXPORT(png_byte,png_get_mmx_bitdepth_threshold)
2713  PNGARG((png_structp png_ptr));
2714 
2715 /* pngget.c */
2716 extern PNG_EXPORT(png_uint_32,png_get_mmx_rowbytes_threshold)
2717  PNGARG((png_structp png_ptr));
2718 
2719 /* pngset.c */
2720 extern PNG_EXPORT(void,png_set_asm_flags)
2721  PNGARG((png_structp png_ptr, png_uint_32 asm_flags));
2722 
2723 /* pngset.c */
2724 extern PNG_EXPORT(void,png_set_mmx_thresholds)
2725  PNGARG((png_structp png_ptr, png_byte mmx_bitdepth_threshold,
2726  png_uint_32 mmx_rowbytes_threshold));
2727 
2728 #endif /* PNG_1_0_X */
2729 
2730 #if !defined(PNG_1_0_X)
2731 /* png.c, pnggccrd.c, or pngvcrd.c */
2732 extern PNG_EXPORT(int,png_mmx_support) PNGARG((void));
2733 #endif /* PNG_1_0_X */
2734 #endif /* PNG_ASSEMBLER_CODE_SUPPORTED */
2735 
2736 /* Strip the prepended error numbers ("#nnn ") from error and warning
2737  * messages before passing them to the error or warning handler. */
2738 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
2739 extern PNG_EXPORT(void,png_set_strip_error_numbers) PNGARG((png_structp
2740  png_ptr, png_uint_32 strip_mode));
2741 #endif
2742 
2743 /* Added at libpng-1.2.6 */
2744 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
2745 extern PNG_EXPORT(void,png_set_user_limits) PNGARG((png_structp
2746  png_ptr, png_uint_32 user_width_max, png_uint_32 user_height_max));
2747 extern PNG_EXPORT(png_uint_32,png_get_user_width_max) PNGARG((png_structp
2748  png_ptr));
2749 extern PNG_EXPORT(png_uint_32,png_get_user_height_max) PNGARG((png_structp
2750  png_ptr));
2751 #endif
2752 
2753 
2754 /* Maintainer: Put new public prototypes here ^, in libpng.3, and project defs */
2755 
2756 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2757 /* With these routines we avoid an integer divide, which will be slower on
2758  * most machines. However, it does take more operations than the corresponding
2759  * divide method, so it may be slower on a few RISC systems. There are two
2760  * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2761  *
2762  * Note that the rounding factors are NOT supposed to be the same! 128 and
2763  * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2764  * standard method.
2765  *
2766  * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2767  */
2768 
2769  /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2770 
2771 # define png_composite(composite, fg, alpha, bg) \
2772  { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) * (png_uint_16)(alpha) \
2773  + (png_uint_16)(bg)*(png_uint_16)(255 - \
2774  (png_uint_16)(alpha)) + (png_uint_16)128); \
2775  (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
2776 
2777 # define png_composite_16(composite, fg, alpha, bg) \
2778  { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) * (png_uint_32)(alpha) \
2779  + (png_uint_32)(bg)*(png_uint_32)(65535L - \
2780  (png_uint_32)(alpha)) + (png_uint_32)32768L); \
2781  (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
2782 
2783 #else /* standard method using integer division */
2784 
2785 # define png_composite(composite, fg, alpha, bg) \
2786  (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2787  (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2788  (png_uint_16)127) / 255)
2789 
2790 # define png_composite_16(composite, fg, alpha, bg) \
2791  (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2792  (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) + \
2793  (png_uint_32)32767) / (png_uint_32)65535L)
2794 
2795 #endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
2796 
2797 /* Inline macros to do direct reads of bytes from the input buffer. These
2798  * require that you are using an architecture that uses PNG byte ordering
2799  * (MSB first) and supports unaligned data storage. I think that PowerPC
2800  * in big-endian mode and 680x0 are the only ones that will support this.
2801  * The x86 line of processors definitely do not. The png_get_int_32()
2802  * routine also assumes we are using two's complement format for negative
2803  * values, which is almost certainly true.
2804  */
2805 #if defined(PNG_READ_BIG_ENDIAN_SUPPORTED)
2806 # define png_get_uint_32(buf) ( *((png_uint_32p) (buf)))
2807 # define png_get_uint_16(buf) ( *((png_uint_16p) (buf)))
2808 # define png_get_int_32(buf) ( *((png_int_32p) (buf)))
2809 #else
2810 extern PNG_EXPORT(png_uint_32,png_get_uint_32) PNGARG((png_bytep buf));
2811 extern PNG_EXPORT(png_uint_16,png_get_uint_16) PNGARG((png_bytep buf));
2812 extern PNG_EXPORT(png_int_32,png_get_int_32) PNGARG((png_bytep buf));
2813 #endif /* !PNG_READ_BIG_ENDIAN_SUPPORTED */
2814 extern PNG_EXPORT(png_uint_32,png_get_uint_31)
2815  PNGARG((png_structp png_ptr, png_bytep buf));
2816 /* No png_get_int_16 -- may be added if there's a real need for it. */
2817 
2818 /* Place a 32-bit number into a buffer in PNG byte order (big-endian).
2819  */
2820 extern PNG_EXPORT(void,png_save_uint_32)
2821  PNGARG((png_bytep buf, png_uint_32 i));
2822 extern PNG_EXPORT(void,png_save_int_32)
2823  PNGARG((png_bytep buf, png_int_32 i));
2824 
2825 /* Place a 16-bit number into a buffer in PNG byte order.
2826  * The parameter is declared unsigned int, not png_uint_16,
2827  * just to avoid potential problems on pre-ANSI C compilers.
2828  */
2829 extern PNG_EXPORT(void,png_save_uint_16)
2830  PNGARG((png_bytep buf, unsigned int i));
2831 /* No png_save_int_16 -- may be added if there's a real need for it. */
2832 
2833 /* ************************************************************************* */
2834 
2835 /* These next functions are used internally in the code. They generally
2836  * shouldn't be used unless you are writing code to add or replace some
2837  * functionality in libpng. More information about most functions can
2838  * be found in the files where the functions are located.
2839  */
2840 
2841 
2842 /* Various modes of operation, that are visible to applications because
2843  * they are used for unknown chunk location.
2844  */
2845 #define PNG_HAVE_IHDR 0x01
2846 #define PNG_HAVE_PLTE 0x02
2847 #define PNG_HAVE_IDAT 0x04
2848 #define PNG_AFTER_IDAT 0x08 /* Have complete zlib datastream */
2849 #define PNG_HAVE_IEND 0x10
2850 
2851 #if defined(PNG_INTERNAL)
2852 
2853 /* More modes of operation. Note that after an init, mode is set to
2854  * zero automatically when the structure is created.
2855  */
2856 #define PNG_HAVE_gAMA 0x20
2857 #define PNG_HAVE_cHRM 0x40
2858 #define PNG_HAVE_sRGB 0x80
2859 #define PNG_HAVE_CHUNK_HEADER 0x100
2860 #define PNG_WROTE_tIME 0x200
2861 #define PNG_WROTE_INFO_BEFORE_PLTE 0x400
2862 #define PNG_BACKGROUND_IS_GRAY 0x800
2863 #define PNG_HAVE_PNG_SIGNATURE 0x1000
2864 #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
2865 
2866 /* flags for the transformations the PNG library does on the image data */
2867 #define PNG_BGR 0x0001
2868 #define PNG_INTERLACE 0x0002
2869 #define PNG_PACK 0x0004
2870 #define PNG_SHIFT 0x0008
2871 #define PNG_SWAP_BYTES 0x0010
2872 #define PNG_INVERT_MONO 0x0020
2873 #define PNG_DITHER 0x0040
2874 #define PNG_BACKGROUND 0x0080
2875 #define PNG_BACKGROUND_EXPAND 0x0100
2876  /* 0x0200 unused */
2877 #define PNG_16_TO_8 0x0400
2878 #define PNG_RGBA 0x0800
2879 #define PNG_EXPAND 0x1000
2880 #define PNG_GAMMA 0x2000
2881 #define PNG_GRAY_TO_RGB 0x4000
2882 #define PNG_FILLER 0x8000L
2883 #define PNG_PACKSWAP 0x10000L
2884 #define PNG_SWAP_ALPHA 0x20000L
2885 #define PNG_STRIP_ALPHA 0x40000L
2886 #define PNG_INVERT_ALPHA 0x80000L
2887 #define PNG_USER_TRANSFORM 0x100000L
2888 #define PNG_RGB_TO_GRAY_ERR 0x200000L
2889 #define PNG_RGB_TO_GRAY_WARN 0x400000L
2890 #define PNG_RGB_TO_GRAY 0x600000L /* two bits, RGB_TO_GRAY_ERR|WARN */
2891  /* 0x800000L Unused */
2892 #define PNG_ADD_ALPHA 0x1000000L /* Added to libpng-1.2.7 */
2893 #define PNG_EXPAND_tRNS 0x2000000L /* Added to libpng-1.2.9 */
2894  /* 0x4000000L unused */
2895  /* 0x8000000L unused */
2896  /* 0x10000000L unused */
2897  /* 0x20000000L unused */
2898  /* 0x40000000L unused */
2899 
2900 /* flags for png_create_struct */
2901 #define PNG_STRUCT_PNG 0x0001
2902 #define PNG_STRUCT_INFO 0x0002
2903 
2904 /* Scaling factor for filter heuristic weighting calculations */
2905 #define PNG_WEIGHT_SHIFT 8
2906 #define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
2907 #define PNG_COST_SHIFT 3
2908 #define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
2909 
2910 /* flags for the png_ptr->flags rather than declaring a byte for each one */
2911 #define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001
2912 #define PNG_FLAG_ZLIB_CUSTOM_LEVEL 0x0002
2913 #define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL 0x0004
2914 #define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS 0x0008
2915 #define PNG_FLAG_ZLIB_CUSTOM_METHOD 0x0010
2916 #define PNG_FLAG_ZLIB_FINISHED 0x0020
2917 #define PNG_FLAG_ROW_INIT 0x0040
2918 #define PNG_FLAG_FILLER_AFTER 0x0080
2919 #define PNG_FLAG_CRC_ANCILLARY_USE 0x0100
2920 #define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200
2921 #define PNG_FLAG_CRC_CRITICAL_USE 0x0400
2922 #define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800
2923 #define PNG_FLAG_FREE_PLTE 0x1000
2924 #define PNG_FLAG_FREE_TRNS 0x2000
2925 #define PNG_FLAG_FREE_HIST 0x4000
2926 #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000L
2927 #define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000L
2928 #define PNG_FLAG_LIBRARY_MISMATCH 0x20000L
2929 #define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000L
2930 #define PNG_FLAG_STRIP_ERROR_TEXT 0x80000L
2931 #define PNG_FLAG_MALLOC_NULL_MEM_OK 0x100000L
2932 #define PNG_FLAG_ADD_ALPHA 0x200000L /* Added to libpng-1.2.8 */
2933 #define PNG_FLAG_STRIP_ALPHA 0x400000L /* Added to libpng-1.2.8 */
2934  /* 0x800000L unused */
2935  /* 0x1000000L unused */
2936  /* 0x2000000L unused */
2937  /* 0x4000000L unused */
2938  /* 0x8000000L unused */
2939  /* 0x10000000L unused */
2940  /* 0x20000000L unused */
2941  /* 0x40000000L unused */
2942 
2943 #define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
2944  PNG_FLAG_CRC_ANCILLARY_NOWARN)
2945 
2946 #define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE | \
2947  PNG_FLAG_CRC_CRITICAL_IGNORE)
2948 
2949 #define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK | \
2950  PNG_FLAG_CRC_CRITICAL_MASK)
2951 
2952 /* save typing and make code easier to understand */
2953 
2954 #define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
2955  abs((int)((c1).green) - (int)((c2).green)) + \
2956  abs((int)((c1).blue) - (int)((c2).blue)))
2957 
2958 /* Added to libpng-1.2.6 JB */
2959 #define PNG_ROWBYTES(pixel_bits, width) \
2960  ((pixel_bits) >= 8 ? \
2961  ((width) * (((png_uint_32)(pixel_bits)) >> 3)) : \
2962  (( ((width) * ((png_uint_32)(pixel_bits))) + 7) >> 3) )
2963 
2964 /* PNG_OUT_OF_RANGE returns true if value is outside the range
2965  ideal-delta..ideal+delta. Each argument is evaluated twice.
2966  "ideal" and "delta" should be constants, normally simple
2967  integers, "value" a variable. Added to libpng-1.2.6 JB */
2968 #define PNG_OUT_OF_RANGE(value, ideal, delta) \
2969  ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
2970 
2971 /* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
2972 #if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
2973 /* place to hold the signature string for a PNG file. */
2974 #ifdef PNG_USE_GLOBAL_ARRAYS
2975  PNG_EXPORT_VAR (PNG_CONST png_byte FARDATA) png_sig[8];
2976 #else
2977 #endif
2978 #endif /* PNG_NO_EXTERN */
2979 
2980 /* Constant strings for known chunk types. If you need to add a chunk,
2981  * define the name here, and add an invocation of the macro in png.c and
2982  * wherever it's needed.
2983  */
2984 #define PNG_IHDR png_byte png_IHDR[5] = { 73, 72, 68, 82, '\0'}
2985 #define PNG_IDAT png_byte png_IDAT[5] = { 73, 68, 65, 84, '\0'}
2986 #define PNG_IEND png_byte png_IEND[5] = { 73, 69, 78, 68, '\0'}
2987 #define PNG_PLTE png_byte png_PLTE[5] = { 80, 76, 84, 69, '\0'}
2988 #define PNG_bKGD png_byte png_bKGD[5] = { 98, 75, 71, 68, '\0'}
2989 #define PNG_cHRM png_byte png_cHRM[5] = { 99, 72, 82, 77, '\0'}
2990 #define PNG_gAMA png_byte png_gAMA[5] = {103, 65, 77, 65, '\0'}
2991 #define PNG_hIST png_byte png_hIST[5] = {104, 73, 83, 84, '\0'}
2992 #define PNG_iCCP png_byte png_iCCP[5] = {105, 67, 67, 80, '\0'}
2993 #define PNG_iTXt png_byte png_iTXt[5] = {105, 84, 88, 116, '\0'}
2994 #define PNG_oFFs png_byte png_oFFs[5] = {111, 70, 70, 115, '\0'}
2995 #define PNG_pCAL png_byte png_pCAL[5] = {112, 67, 65, 76, '\0'}
2996 #define PNG_sCAL png_byte png_sCAL[5] = {115, 67, 65, 76, '\0'}
2997 #define PNG_pHYs png_byte png_pHYs[5] = {112, 72, 89, 115, '\0'}
2998 #define PNG_sBIT png_byte png_sBIT[5] = {115, 66, 73, 84, '\0'}
2999 #define PNG_sPLT png_byte png_sPLT[5] = {115, 80, 76, 84, '\0'}
3000 #define PNG_sRGB png_byte png_sRGB[5] = {115, 82, 71, 66, '\0'}
3001 #define PNG_tEXt png_byte png_tEXt[5] = {116, 69, 88, 116, '\0'}
3002 #define PNG_tIME png_byte png_tIME[5] = {116, 73, 77, 69, '\0'}
3003 #define PNG_tRNS png_byte png_tRNS[5] = {116, 82, 78, 83, '\0'}
3004 #define PNG_zTXt png_byte png_zTXt[5] = {122, 84, 88, 116, '\0'}
3005 
3006 #ifdef PNG_USE_GLOBAL_ARRAYS
3007 PNG_EXPORT_VAR (png_byte FARDATA) png_IHDR[5];
3008 PNG_EXPORT_VAR (png_byte FARDATA) png_IDAT[5];
3009 PNG_EXPORT_VAR (png_byte FARDATA) png_IEND[5];
3010 PNG_EXPORT_VAR (png_byte FARDATA) png_PLTE[5];
3011 PNG_EXPORT_VAR (png_byte FARDATA) png_bKGD[5];
3012 PNG_EXPORT_VAR (png_byte FARDATA) png_cHRM[5];
3013 PNG_EXPORT_VAR (png_byte FARDATA) png_gAMA[5];
3014 PNG_EXPORT_VAR (png_byte FARDATA) png_hIST[5];
3015 PNG_EXPORT_VAR (png_byte FARDATA) png_iCCP[5];
3016 PNG_EXPORT_VAR (png_byte FARDATA) png_iTXt[5];
3017 PNG_EXPORT_VAR (png_byte FARDATA) png_oFFs[5];
3018 PNG_EXPORT_VAR (png_byte FARDATA) png_pCAL[5];
3019 PNG_EXPORT_VAR (png_byte FARDATA) png_sCAL[5];
3020 PNG_EXPORT_VAR (png_byte FARDATA) png_pHYs[5];
3021 PNG_EXPORT_VAR (png_byte FARDATA) png_sBIT[5];
3022 PNG_EXPORT_VAR (png_byte FARDATA) png_sPLT[5];
3023 PNG_EXPORT_VAR (png_byte FARDATA) png_sRGB[5];
3024 PNG_EXPORT_VAR (png_byte FARDATA) png_tEXt[5];
3025 PNG_EXPORT_VAR (png_byte FARDATA) png_tIME[5];
3026 PNG_EXPORT_VAR (png_byte FARDATA) png_tRNS[5];
3027 PNG_EXPORT_VAR (png_byte FARDATA) png_zTXt[5];
3028 #endif /* PNG_USE_GLOBAL_ARRAYS */
3029 
3030 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
3031 /* Initialize png_ptr struct for reading, and allocate any other memory.
3032  * (old interface - DEPRECATED - use png_create_read_struct instead).
3033  */
3034 extern PNG_EXPORT(void,png_read_init) PNGARG((png_structp png_ptr));
3035 #undef png_read_init
3036 #define png_read_init(png_ptr) png_read_init_3(&png_ptr, \
3037  PNG_LIBPNG_VER_STRING, png_sizeof(png_struct));
3038 #endif
3039 
3040 extern PNG_EXPORT(void,png_read_init_3) PNGARG((png_structpp ptr_ptr,
3041  png_const_charp user_png_ver, png_size_t png_struct_size));
3042 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
3043 extern PNG_EXPORT(void,png_read_init_2) PNGARG((png_structp png_ptr,
3044  png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
3045  png_info_size));
3046 #endif
3047 
3048 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
3049 /* Initialize png_ptr struct for writing, and allocate any other memory.
3050  * (old interface - DEPRECATED - use png_create_write_struct instead).
3051  */
3052 extern PNG_EXPORT(void,png_write_init) PNGARG((png_structp png_ptr));
3053 #undef png_write_init
3054 #define png_write_init(png_ptr) png_write_init_3(&png_ptr, \
3055  PNG_LIBPNG_VER_STRING, png_sizeof(png_struct));
3056 #endif
3057 
3058 extern PNG_EXPORT(void,png_write_init_3) PNGARG((png_structpp ptr_ptr,
3059  png_const_charp user_png_ver, png_size_t png_struct_size));
3060 extern PNG_EXPORT(void,png_write_init_2) PNGARG((png_structp png_ptr,
3061  png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
3062  png_info_size));
3063 
3064 /* Allocate memory for an internal libpng struct */
3065 PNG_EXTERN png_voidp png_create_struct PNGARG((int type));
3066 
3067 /* Free memory from internal libpng struct */
3068 PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr));
3069 
3070 PNG_EXTERN png_voidp png_create_struct_2 PNGARG((int type, png_malloc_ptr
3071  malloc_fn, png_voidp mem_ptr));
3072 PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr,
3073  png_free_ptr free_fn, png_voidp mem_ptr));
3074 
3075 /* Free any memory that info_ptr points to and reset struct. */
3076 PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr,
3077  png_infop info_ptr));
3078 
3079 #ifndef PNG_1_0_X
3080 /* Function to allocate memory for zlib. */
3081 PNG_EXTERN voidpf png_zalloc PNGARG((voidpf png_ptr, uInt items, uInt size));
3082 
3083 /* Function to free memory for zlib */
3084 PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr));
3085 
3086 #ifdef PNG_SIZE_T
3087 /* Function to convert a sizeof an item to png_sizeof item */
3088  PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size));
3089 #endif
3090 
3091 /* Next four functions are used internally as callbacks. PNGAPI is required
3092  * but not PNG_EXPORT. PNGAPI added at libpng version 1.2.3. */
3093 
3094 PNG_EXTERN void PNGAPI png_default_read_data PNGARG((png_structp png_ptr,
3095  png_bytep data, png_size_t length));
3096 
3097 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3098 PNG_EXTERN void PNGAPI png_push_fill_buffer PNGARG((png_structp png_ptr,
3099  png_bytep buffer, png_size_t length));
3100 #endif
3101 
3102 PNG_EXTERN void PNGAPI png_default_write_data PNGARG((png_structp png_ptr,
3103  png_bytep data, png_size_t length));
3104 
3105 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
3106 #if !defined(PNG_NO_STDIO)
3107 PNG_EXTERN void PNGAPI png_default_flush PNGARG((png_structp png_ptr));
3108 #endif
3109 #endif
3110 #else /* PNG_1_0_X */
3111 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3112 PNG_EXTERN void png_push_fill_buffer PNGARG((png_structp png_ptr,
3113  png_bytep buffer, png_size_t length));
3114 #endif
3115 #endif /* PNG_1_0_X */
3116 
3117 /* Reset the CRC variable */
3118 PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr));
3119 
3120 /* Write the "data" buffer to whatever output you are using. */
3121 PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr, png_bytep data,
3122  png_size_t length));
3123 
3124 /* Read data from whatever input you are using into the "data" buffer */
3125 PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data,
3126  png_size_t length));
3127 
3128 /* Read bytes into buf, and update png_ptr->crc */
3129 PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
3130  png_size_t length));
3131 
3132 /* Decompress data in a chunk that uses compression */
3133 #if defined(PNG_zTXt_SUPPORTED) || defined(PNG_iTXt_SUPPORTED) || \
3134  defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED)
3135 PNG_EXTERN void png_decompress_chunk PNGARG((png_structp png_ptr,
3136  int comp_type, png_size_t chunklength,
3137  png_size_t prefix_length, png_size_t *data_length));
3138 #endif
3139 
3140 /* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
3141 PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip));
3142 
3143 /* Read the CRC from the file and compare it to the libpng calculated CRC */
3144 PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr));
3145 
3146 /* Calculate the CRC over a section of data. Note that we are only
3147  * passing a maximum of 64K on systems that have this as a memory limit,
3148  * since this is the maximum buffer size we can specify.
3149  */
3150 PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr, png_bytep ptr,
3151  png_size_t length));
3152 
3153 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
3154 PNG_EXTERN void png_flush PNGARG((png_structp png_ptr));
3155 #endif
3156 
3157 /* simple function to write the signature */
3158 PNG_EXTERN void png_write_sig PNGARG((png_structp png_ptr));
3159 
3160 /* write various chunks */
3161 
3162 /* Write the IHDR chunk, and update the png_struct with the necessary
3163  * information.
3164  */
3165 PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width,
3166  png_uint_32 height,
3167  int bit_depth, int color_type, int compression_method, int filter_method,
3168  int interlace_method));
3169 
3170 PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr, png_colorp palette,
3171  png_uint_32 num_pal));
3172 
3173 PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data,
3174  png_size_t length));
3175 
3176 PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr));
3177 
3178 #if defined(PNG_WRITE_gAMA_SUPPORTED)
3179 #ifdef PNG_FLOATING_POINT_SUPPORTED
3180 PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma));
3181 #endif
3182 #ifdef PNG_FIXED_POINT_SUPPORTED
3183 PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr, png_fixed_point
3184  file_gamma));
3185 #endif
3186 #endif
3187 
3188 #if defined(PNG_WRITE_sBIT_SUPPORTED)
3189 PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr, png_color_8p sbit,
3190  int color_type));
3191 #endif
3192 
3193 #if defined(PNG_WRITE_cHRM_SUPPORTED)
3194 #ifdef PNG_FLOATING_POINT_SUPPORTED
3195 PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr,
3196  double white_x, double white_y,
3197  double red_x, double red_y, double green_x, double green_y,
3198  double blue_x, double blue_y));
3199 #endif
3200 #ifdef PNG_FIXED_POINT_SUPPORTED
3201 PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr,
3202  png_fixed_point int_white_x, png_fixed_point int_white_y,
3203  png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
3204  int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
3205  png_fixed_point int_blue_y));
3206 #endif
3207 #endif
3208 
3209 #if defined(PNG_WRITE_sRGB_SUPPORTED)
3210 PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
3211  int intent));
3212 #endif
3213 
3214 #if defined(PNG_WRITE_iCCP_SUPPORTED)
3215 PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr,
3216  png_charp name, int compression_type,
3217  png_charp profile, int proflen));
3218  /* Note to maintainer: profile should be png_bytep */
3219 #endif
3220 
3221 #if defined(PNG_WRITE_sPLT_SUPPORTED)
3222 PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr,
3223  png_sPLT_tp palette));
3224 #endif
3225 
3226 #if defined(PNG_WRITE_tRNS_SUPPORTED)
3227 PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr, png_bytep trans,
3228  png_color_16p values, int number, int color_type));
3229 #endif
3230 
3231 #if defined(PNG_WRITE_bKGD_SUPPORTED)
3232 PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr,
3233  png_color_16p values, int color_type));
3234 #endif
3235 
3236 #if defined(PNG_WRITE_hIST_SUPPORTED)
3237 PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, png_uint_16p hist,
3238  int num_hist));
3239 #endif
3240 
3241 #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
3242  defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
3243 PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
3244  png_charp key, png_charpp new_key));
3245 #endif
3246 
3247 #if defined(PNG_WRITE_tEXt_SUPPORTED)
3248 PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_charp key,
3249  png_charp text, png_size_t text_len));
3250 #endif
3251 
3252 #if defined(PNG_WRITE_zTXt_SUPPORTED)
3253 PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_charp key,
3254  png_charp text, png_size_t text_len, int compression));
3255 #endif
3256 
3257 #if defined(PNG_WRITE_iTXt_SUPPORTED)
3258 PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr,
3259  int compression, png_charp key, png_charp lang, png_charp lang_key,
3260  png_charp text));
3261 #endif
3262 
3263 #if defined(PNG_TEXT_SUPPORTED) /* Added at version 1.0.14 and 1.2.4 */
3264 PNG_EXTERN int png_set_text_2 PNGARG((png_structp png_ptr,
3265  png_infop info_ptr, png_textp text_ptr, int num_text));
3266 #endif
3267 
3268 #if defined(PNG_WRITE_oFFs_SUPPORTED)
3269 PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr,
3270  png_int_32 x_offset, png_int_32 y_offset, int unit_type));
3271 #endif
3272 
3273 #if defined(PNG_WRITE_pCAL_SUPPORTED)
3274 PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose,
3275  png_int_32 X0, png_int_32 X1, int type, int nparams,
3276  png_charp units, png_charpp params));
3277 #endif
3278 
3279 #if defined(PNG_WRITE_pHYs_SUPPORTED)
3280 PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr,
3281  png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
3282  int unit_type));
3283 #endif
3284 
3285 #if defined(PNG_WRITE_tIME_SUPPORTED)
3286 PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr,
3287  png_timep mod_time));
3288 #endif
3289 
3290 #if defined(PNG_WRITE_sCAL_SUPPORTED)
3291 #if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
3292 PNG_EXTERN void png_write_sCAL PNGARG((png_structp png_ptr,
3293  int unit, double width, double height));
3294 #else
3295 #ifdef PNG_FIXED_POINT_SUPPORTED
3296 PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr,
3297  int unit, png_charp width, png_charp height));
3298 #endif
3299 #endif
3300 #endif
3301 
3302 /* Called when finished processing a row of data */
3303 PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr));
3304 
3305 /* Internal use only. Called before first row of data */
3306 PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr));
3307 
3308 #if defined(PNG_READ_GAMMA_SUPPORTED)
3309 PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr));
3310 #endif
3311 
3312 /* combine a row of data, dealing with alpha, etc. if requested */
3313 PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row,
3314  int mask));
3315 
3316 #if defined(PNG_READ_INTERLACING_SUPPORTED)
3317 /* expand an interlaced row */
3318 /* OLD pre-1.0.9 interface:
3319 PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info,
3320  png_bytep row, int pass, png_uint_32 transformations));
3321  */
3322 PNG_EXTERN void png_do_read_interlace PNGARG((png_structp png_ptr));
3323 #endif
3324 
3325 /* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */
3326 
3327 #if defined(PNG_WRITE_INTERLACING_SUPPORTED)
3328 /* grab pixels out of a row for an interlaced pass */
3329 PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info,
3330  png_bytep row, int pass));
3331 #endif
3332 
3333 /* unfilter a row */
3334 PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr,
3335  png_row_infop row_info, png_bytep row, png_bytep prev_row, int filter));
3336 
3337 /* Choose the best filter to use and filter the row data */
3338 PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
3339  png_row_infop row_info));
3340 
3341 /* Write out the filtered row. */
3342 PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr,
3343  png_bytep filtered_row));
3344 /* finish a row while reading, dealing with interlacing passes, etc. */
3345 PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
3346 
3347 /* initialize the row buffers, etc. */
3348 PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr));
3349 /* optional call to update the users info structure */
3350 PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
3351  png_infop info_ptr));
3352 
3353 /* these are the functions that do the transformations */
3354 #if defined(PNG_READ_FILLER_SUPPORTED)
3355 PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info,
3356  png_bytep row, png_uint_32 filler, png_uint_32 flags));
3357 #endif
3358 
3359 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
3360 PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info,
3361  png_bytep row));
3362 #endif
3363 
3364 #if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
3365 PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info,
3366  png_bytep row));
3367 #endif
3368 
3369 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
3370 PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info,
3371  png_bytep row));
3372 #endif
3373 
3374 #if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
3375 PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info,
3376  png_bytep row));
3377 #endif
3378 
3379 #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
3380  defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
3381 PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info,
3382  png_bytep row, png_uint_32 flags));
3383 #endif
3384 
3385 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
3386 PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info, png_bytep row));
3387 #endif
3388 
3389 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
3390 PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info, png_bytep row));
3391 #endif
3392 
3393 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
3394 PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr, png_row_infop
3395  row_info, png_bytep row));
3396 #endif
3397 
3398 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
3399 PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info,
3400  png_bytep row));
3401 #endif
3402 
3403 #if defined(PNG_READ_PACK_SUPPORTED)
3404 PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info, png_bytep row));
3405 #endif
3406 
3407 #if defined(PNG_READ_SHIFT_SUPPORTED)
3408 PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info, png_bytep row,
3409  png_color_8p sig_bits));
3410 #endif
3411 
3412 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
3413 PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info, png_bytep row));
3414 #endif
3415 
3416 #if defined(PNG_READ_16_TO_8_SUPPORTED)
3417 PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info, png_bytep row));
3418 #endif
3419 
3420 #if defined(PNG_READ_DITHER_SUPPORTED)
3421 PNG_EXTERN void png_do_dither PNGARG((png_row_infop row_info,
3422  png_bytep row, png_bytep palette_lookup, png_bytep dither_lookup));
3423 
3424 # if defined(PNG_CORRECT_PALETTE_SUPPORTED)
3425 PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr,
3426  png_colorp palette, int num_palette));
3427 # endif
3428 #endif
3429 
3430 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
3431 PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info, png_bytep row));
3432 #endif
3433 
3434 #if defined(PNG_WRITE_PACK_SUPPORTED)
3435 PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info,
3436  png_bytep row, png_uint_32 bit_depth));
3437 #endif
3438 
3439 #if defined(PNG_WRITE_SHIFT_SUPPORTED)
3440 PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info, png_bytep row,
3441  png_color_8p bit_depth));
3442 #endif
3443 
3444 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
3445 #if defined(PNG_READ_GAMMA_SUPPORTED)
3446 PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
3447  png_color_16p trans_values, png_color_16p background,
3448  png_color_16p background_1,
3452 #else
3453 PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
3454  png_color_16p trans_values, png_color_16p background));
3455 #endif
3456 #endif
3457 
3458 #if defined(PNG_READ_GAMMA_SUPPORTED)
3459 PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info, png_bytep row,
3461  int gamma_shift));
3462 #endif
3463 
3464 #if defined(PNG_READ_EXPAND_SUPPORTED)
3465 PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info,
3466  png_bytep row, png_colorp palette, png_bytep trans, int num_trans));
3467 PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info,
3468  png_bytep row, png_color_16p trans_value));
3469 #endif
3470 
3471 /* The following decodes the appropriate chunks, and does error correction,
3472  * then calls the appropriate callback for the chunk if it is valid.
3473  */
3474 
3475 /* decode the IHDR chunk */
3476 PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr,
3477  png_uint_32 length));
3478 PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr,
3479  png_uint_32 length));
3480 PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr,
3481  png_uint_32 length));
3482 
3483 #if defined(PNG_READ_bKGD_SUPPORTED)
3484 PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr,
3485  png_uint_32 length));
3486 #endif
3487 
3488 #if defined(PNG_READ_cHRM_SUPPORTED)
3489 PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr,
3490  png_uint_32 length));
3491 #endif
3492 
3493 #if defined(PNG_READ_gAMA_SUPPORTED)
3494 PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr,
3495  png_uint_32 length));
3496 #endif
3497 
3498 #if defined(PNG_READ_hIST_SUPPORTED)
3499 PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr,
3500  png_uint_32 length));
3501 #endif
3502 
3503 #if defined(PNG_READ_iCCP_SUPPORTED)
3504 extern void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr,
3505  png_uint_32 length));
3506 #endif /* PNG_READ_iCCP_SUPPORTED */
3507 
3508 #if defined(PNG_READ_iTXt_SUPPORTED)
3509 PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3510  png_uint_32 length));
3511 #endif
3512 
3513 #if defined(PNG_READ_oFFs_SUPPORTED)
3514 PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr,
3515  png_uint_32 length));
3516 #endif
3517 
3518 #if defined(PNG_READ_pCAL_SUPPORTED)
3519 PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
3520  png_uint_32 length));
3521 #endif
3522 
3523 #if defined(PNG_READ_pHYs_SUPPORTED)
3524 PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr,
3525  png_uint_32 length));
3526 #endif
3527 
3528 #if defined(PNG_READ_sBIT_SUPPORTED)
3529 PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr,
3530  png_uint_32 length));
3531 #endif
3532 
3533 #if defined(PNG_READ_sCAL_SUPPORTED)
3534 PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
3535  png_uint_32 length));
3536 #endif
3537 
3538 #if defined(PNG_READ_sPLT_SUPPORTED)
3539 extern void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr,
3540  png_uint_32 length));
3541 #endif /* PNG_READ_sPLT_SUPPORTED */
3542 
3543 #if defined(PNG_READ_sRGB_SUPPORTED)
3544 PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr,
3545  png_uint_32 length));
3546 #endif
3547 
3548 #if defined(PNG_READ_tEXt_SUPPORTED)
3549 PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3550  png_uint_32 length));
3551 #endif
3552 
3553 #if defined(PNG_READ_tIME_SUPPORTED)
3554 PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr,
3555  png_uint_32 length));
3556 #endif
3557 
3558 #if defined(PNG_READ_tRNS_SUPPORTED)
3559 PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr,
3560  png_uint_32 length));
3561 #endif
3562 
3563 #if defined(PNG_READ_zTXt_SUPPORTED)
3564 PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3565  png_uint_32 length));
3566 #endif
3567 
3568 PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
3569  png_infop info_ptr, png_uint_32 length));
3570 
3571 PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
3572  png_bytep chunk_name));
3573 
3574 /* handle the transformations for reading and writing */
3575 PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr));
3576 PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr));
3577 
3578 PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr));
3579 
3580 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3581 PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
3582  png_infop info_ptr));
3583 PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr,
3584  png_infop info_ptr));
3585 PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr));
3586 PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr,
3587  png_uint_32 length));
3588 PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr));
3589 PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr));
3590 PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr,
3591  png_bytep buffer, png_size_t buffer_length));
3592 PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr));
3593 PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr,
3594  png_bytep buffer, png_size_t buffer_length));
3595 PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr));
3596 PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr,
3597  png_infop info_ptr, png_uint_32 length));
3598 PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr,
3599  png_infop info_ptr));
3600 PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr,
3601  png_infop info_ptr));
3602 PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr, png_bytep row));
3603 PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr,
3604  png_infop info_ptr));
3605 PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr,
3606  png_infop info_ptr));
3607 PNG_EXTERN void png_read_push_finish_row PNGARG((png_structp png_ptr));
3608 #if defined(PNG_READ_tEXt_SUPPORTED)
3609 PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr,
3610  png_infop info_ptr, png_uint_32 length));
3611 PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr,
3612  png_infop info_ptr));
3613 #endif
3614 #if defined(PNG_READ_zTXt_SUPPORTED)
3615 PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr,
3616  png_infop info_ptr, png_uint_32 length));
3617 PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr,
3618  png_infop info_ptr));
3619 #endif
3620 #if defined(PNG_READ_iTXt_SUPPORTED)
3621 PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr,
3622  png_infop info_ptr, png_uint_32 length));
3623 PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr,
3624  png_infop info_ptr));
3625 #endif
3626 
3627 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
3628 
3629 #ifdef PNG_MNG_FEATURES_SUPPORTED
3630 PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info,
3631  png_bytep row));
3632 PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info,
3633  png_bytep row));
3634 #endif
3635 
3636 #if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
3637 #if defined(PNG_MMX_CODE_SUPPORTED)
3638 /* png.c */ /* PRIVATE */
3639 PNG_EXTERN void png_init_mmx_flags PNGARG((png_structp png_ptr));
3640 #endif
3641 #endif
3642 
3643 #if defined(PNG_INCH_CONVERSIONS) && defined(PNG_FLOATING_POINT_SUPPORTED)
3644 PNG_EXTERN png_uint_32 png_get_pixels_per_inch PNGARG((png_structp png_ptr,
3645 png_infop info_ptr));
3646 
3647 PNG_EXTERN png_uint_32 png_get_x_pixels_per_inch PNGARG((png_structp png_ptr,
3648 png_infop info_ptr));
3649 
3650 PNG_EXTERN png_uint_32 png_get_y_pixels_per_inch PNGARG((png_structp png_ptr,
3651 png_infop info_ptr));
3652 
3653 PNG_EXTERN float png_get_x_offset_inches PNGARG((png_structp png_ptr,
3654 png_infop info_ptr));
3655 
3656 PNG_EXTERN float png_get_y_offset_inches PNGARG((png_structp png_ptr,
3657 png_infop info_ptr));
3658 
3659 #if defined(PNG_pHYs_SUPPORTED)
3660 PNG_EXTERN png_uint_32 png_get_pHYs_dpi PNGARG((png_structp png_ptr,
3661 png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
3662 #endif /* PNG_pHYs_SUPPORTED */
3663 #endif /* PNG_INCH_CONVERSIONS && PNG_FLOATING_POINT_SUPPORTED */
3664 
3665 /* Read the chunk header (length + type name) */
3666 PNG_EXTERN png_uint_32 png_read_chunk_header PNGARG((png_structp png_ptr));
3667 
3668 /* Added at libpng version 1.2.34 */
3669 #if defined(PNG_cHRM_SUPPORTED)
3670 PNG_EXTERN int png_check_cHRM_fixed PNGARG((png_structp png_ptr,
3671  png_fixed_point int_white_x, png_fixed_point int_white_y,
3672  png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
3673  int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
3674  png_fixed_point int_blue_y));
3675 #endif
3676 
3677 /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
3678 
3679 #endif /* PNG_INTERNAL */
3680 
3681 #ifdef __cplusplus
3682 }
3683 #endif
3684 
3685 #endif /* PNG_VERSION_INFO_ONLY */
3686 /* do not put anything past this line */
3687 #endif /* PNG_H */