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1 /* png.h - header file for PNG reference library
2  *
3  * libpng version 1.2.38 - July 16, 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  * This code is released under the libpng license (See LICENSE, below)
9  *
10  * Authors and maintainers:
11  *  libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
12  *  libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
13  *  libpng versions 0.97, January 1998, through 1.2.38 - July 16, 2009: Glenn
14  *  See also "Contributing Authors", below.
15  *
16  * Note about libpng version numbers:
17  *
18  *    Due to various miscommunications, unforeseen code incompatibilities
19  *    and occasional factors outside the authors' control, version numbering
20  *    on the library has not always been consistent and straightforward.
21  *    The following table summarizes matters since version 0.89c, which was
22  *    the first widely used release:
23  *
24  *    source                 png.h  png.h  shared-lib
25  *    version                string   int  version
26  *    -------                ------ -----  ----------
27  *    0.89c "1.0 beta 3"     0.89      89  1.0.89
28  *    0.90  "1.0 beta 4"     0.90      90  0.90  [should have been 2.0.90]
29  *    0.95  "1.0 beta 5"     0.95      95  0.95  [should have been 2.0.95]
30  *    0.96  "1.0 beta 6"     0.96      96  0.96  [should have been 2.0.96]
31  *    0.97b "1.00.97 beta 7" 1.00.97   97  1.0.1 [should have been 2.0.97]
32  *    0.97c                  0.97      97  2.0.97
33  *    0.98                   0.98      98  2.0.98
34  *    0.99                   0.99      98  2.0.99
35  *    0.99a-m                0.99      99  2.0.99
36  *    1.00                   1.00     100  2.1.0 [100 should be 10000]
37  *    1.0.0      (from here on, the   100  2.1.0 [100 should be 10000]
38  *    1.0.1       png.h string is   10001  2.1.0
39  *    1.0.1a-e    identical to the  10002  from here on, the shared library
40  *    1.0.2       source version)   10002  is 2.V where V is the source code
41  *    1.0.2a-b                      10003  version, except as noted.
42  *    1.0.3                         10003
43  *    1.0.3a-d                      10004
44  *    1.0.4                         10004
45  *    1.0.4a-f                      10005
46  *    1.0.5 (+ 2 patches)           10005
47  *    1.0.5a-d                      10006
48  *    1.0.5e-r                      10100 (not source compatible)
49  *    1.0.5s-v                      10006 (not binary compatible)
50  *    1.0.6 (+ 3 patches)           10006 (still binary incompatible)
51  *    1.0.6d-f                      10007 (still binary incompatible)
52  *    1.0.6g                        10007
53  *    1.0.6h                        10007  10.6h (testing xy.z so-numbering)
54  *    1.0.6i                        10007  10.6i
55  *    1.0.6j                        10007  2.1.0.6j (incompatible with 1.0.0)
56  *    1.0.7beta11-14        DLLNUM  10007  2.1.0.7beta11-14 (binary compatible)
57  *    1.0.7beta15-18           1    10007  2.1.0.7beta15-18 (binary compatible)
58  *    1.0.7rc1-2               1    10007  2.1.0.7rc1-2 (binary compatible)
59  *    1.0.7                    1    10007  (still compatible)
60  *    1.0.8beta1-4             1    10008  2.1.0.8beta1-4
61  *    1.0.8rc1                 1    10008  2.1.0.8rc1
62  *    1.0.8                    1    10008  2.1.0.8
63  *    1.0.9beta1-6             1    10009  2.1.0.9beta1-6
64  *    1.0.9rc1                 1    10009  2.1.0.9rc1
65  *    1.0.9beta7-10            1    10009  2.1.0.9beta7-10
66  *    1.0.9rc2                 1    10009  2.1.0.9rc2
67  *    1.0.9                    1    10009  2.1.0.9
68  *    1.0.10beta1              1    10010  2.1.0.10beta1
69  *    1.0.10rc1                1    10010  2.1.0.10rc1
70  *    1.0.10                   1    10010  2.1.0.10
71  *    1.0.11beta1-3            1    10011  2.1.0.11beta1-3
72  *    1.0.11rc1                1    10011  2.1.0.11rc1
73  *    1.0.11                   1    10011  2.1.0.11
74  *    1.0.12beta1-2            2    10012  2.1.0.12beta1-2
75  *    1.0.12rc1                2    10012  2.1.0.12rc1
76  *    1.0.12                   2    10012  2.1.0.12
77  *    1.1.0a-f                 -    10100  2.1.1.0a-f (branch abandoned)
78  *    1.2.0beta1-2             2    10200  2.1.2.0beta1-2
79  *    1.2.0beta3-5             3    10200  3.1.2.0beta3-5
80  *    1.2.0rc1                 3    10200  3.1.2.0rc1
81  *    1.2.0                    3    10200  3.1.2.0
82  *    1.2.1beta1-4             3    10201  3.1.2.1beta1-4
83  *    1.2.1rc1-2               3    10201  3.1.2.1rc1-2
84  *    1.2.1                    3    10201  3.1.2.1
85  *    1.2.2beta1-6            12    10202  12.so.0.1.2.2beta1-6
86  *    1.0.13beta1             10    10013  10.so.0.1.0.13beta1
87  *    1.0.13rc1               10    10013  10.so.0.1.0.13rc1
88  *    1.2.2rc1                12    10202  12.so.0.1.2.2rc1
89  *    1.0.13                  10    10013  10.so.0.1.0.13
90  *    1.2.2                   12    10202  12.so.0.1.2.2
91  *    1.2.3rc1-6              12    10203  12.so.0.1.2.3rc1-6
92  *    1.2.3                   12    10203  12.so.0.1.2.3
93  *    1.2.4beta1-3            13    10204  12.so.0.1.2.4beta1-3
94  *    1.0.14rc1               13    10014  10.so.0.1.0.14rc1
95  *    1.2.4rc1                13    10204  12.so.0.1.2.4rc1
96  *    1.0.14                  10    10014  10.so.0.1.0.14
97  *    1.2.4                   13    10204  12.so.0.1.2.4
98  *    1.2.5beta1-2            13    10205  12.so.0.1.2.5beta1-2
99  *    1.0.15rc1-3             10    10015  10.so.0.1.0.15rc1-3
100  *    1.2.5rc1-3              13    10205  12.so.0.1.2.5rc1-3
101  *    1.0.15                  10    10015  10.so.0.1.0.15
102  *    1.2.5                   13    10205  12.so.0.1.2.5
103  *    1.2.6beta1-4            13    10206  12.so.0.1.2.6beta1-4
104  *    1.0.16                  10    10016  10.so.0.1.0.16
105  *    1.2.6                   13    10206  12.so.0.1.2.6
106  *    1.2.7beta1-2            13    10207  12.so.0.1.2.7beta1-2
107  *    1.0.17rc1               10    10017  10.so.0.1.0.17rc1
108  *    1.2.7rc1                13    10207  12.so.0.1.2.7rc1
109  *    1.0.17                  10    10017  10.so.0.1.0.17
110  *    1.2.7                   13    10207  12.so.0.1.2.7
111  *    1.2.8beta1-5            13    10208  12.so.0.1.2.8beta1-5
112  *    1.0.18rc1-5             10    10018  10.so.0.1.0.18rc1-5
113  *    1.2.8rc1-5              13    10208  12.so.0.1.2.8rc1-5
114  *    1.0.18                  10    10018  10.so.0.1.0.18
115  *    1.2.8                   13    10208  12.so.0.1.2.8
116  *    1.2.9beta1-3            13    10209  12.so.0.1.2.9beta1-3
117  *    1.2.9beta4-11           13    10209  12.so.0.9[.0]
118  *    1.2.9rc1                13    10209  12.so.0.9[.0]
119  *    1.2.9                   13    10209  12.so.0.9[.0]
120  *    1.2.10beta1-8           13    10210  12.so.0.10[.0]
121  *    1.2.10rc1-3             13    10210  12.so.0.10[.0]
122  *    1.2.10                  13    10210  12.so.0.10[.0]
123  *    1.2.11beta1-4           13    10211  12.so.0.11[.0]
124  *    1.0.19rc1-5             10    10019  10.so.0.19[.0]
125  *    1.2.11rc1-5             13    10211  12.so.0.11[.0]
126  *    1.0.19                  10    10019  10.so.0.19[.0]
127  *    1.2.11                  13    10211  12.so.0.11[.0]
128  *    1.0.20                  10    10020  10.so.0.20[.0]
129  *    1.2.12                  13    10212  12.so.0.12[.0]
130  *    1.2.13beta1             13    10213  12.so.0.13[.0]
131  *    1.0.21                  10    10021  10.so.0.21[.0]
132  *    1.2.13                  13    10213  12.so.0.13[.0]
133  *    1.2.14beta1-2           13    10214  12.so.0.14[.0]
134  *    1.0.22rc1               10    10022  10.so.0.22[.0]
135  *    1.2.14rc1               13    10214  12.so.0.14[.0]
136  *    1.0.22                  10    10022  10.so.0.22[.0]
137  *    1.2.14                  13    10214  12.so.0.14[.0]
138  *    1.2.15beta1-6           13    10215  12.so.0.15[.0]
139  *    1.0.23rc1-5             10    10023  10.so.0.23[.0]
140  *    1.2.15rc1-5             13    10215  12.so.0.15[.0]
141  *    1.0.23                  10    10023  10.so.0.23[.0]
142  *    1.2.15                  13    10215  12.so.0.15[.0]
143  *    1.2.16beta1-2           13    10216  12.so.0.16[.0]
144  *    1.2.16rc1               13    10216  12.so.0.16[.0]
145  *    1.0.24                  10    10024  10.so.0.24[.0]
146  *    1.2.16                  13    10216  12.so.0.16[.0]
147  *    1.2.17beta1-2           13    10217  12.so.0.17[.0]
148  *    1.0.25rc1               10    10025  10.so.0.25[.0]
149  *    1.2.17rc1-3             13    10217  12.so.0.17[.0]
150  *    1.0.25                  10    10025  10.so.0.25[.0]
151  *    1.2.17                  13    10217  12.so.0.17[.0]
152  *    1.0.26                  10    10026  10.so.0.26[.0]
153  *    1.2.18                  13    10218  12.so.0.18[.0]
154  *    1.2.19beta1-31          13    10219  12.so.0.19[.0]
155  *    1.0.27rc1-6             10    10027  10.so.0.27[.0]
156  *    1.2.19rc1-6             13    10219  12.so.0.19[.0]
157  *    1.0.27                  10    10027  10.so.0.27[.0]
158  *    1.2.19                  13    10219  12.so.0.19[.0]
159  *    1.2.20beta01-04         13    10220  12.so.0.20[.0]
160  *    1.0.28rc1-6             10    10028  10.so.0.28[.0]
161  *    1.2.20rc1-6             13    10220  12.so.0.20[.0]
162  *    1.0.28                  10    10028  10.so.0.28[.0]
163  *    1.2.20                  13    10220  12.so.0.20[.0]
164  *    1.2.21beta1-2           13    10221  12.so.0.21[.0]
165  *    1.2.21rc1-3             13    10221  12.so.0.21[.0]
166  *    1.0.29                  10    10029  10.so.0.29[.0]
167  *    1.2.21                  13    10221  12.so.0.21[.0]
168  *    1.2.22beta1-4           13    10222  12.so.0.22[.0]
169  *    1.0.30rc1               10    10030  10.so.0.30[.0]
170  *    1.2.22rc1               13    10222  12.so.0.22[.0]
171  *    1.0.30                  10    10030  10.so.0.30[.0]
172  *    1.2.22                  13    10222  12.so.0.22[.0]
173  *    1.2.23beta01-05         13    10223  12.so.0.23[.0]
174  *    1.2.23rc01              13    10223  12.so.0.23[.0]
175  *    1.2.23                  13    10223  12.so.0.23[.0]
176  *    1.2.24beta01-02         13    10224  12.so.0.24[.0]
177  *    1.2.24rc01              13    10224  12.so.0.24[.0]
178  *    1.2.24                  13    10224  12.so.0.24[.0]
179  *    1.2.25beta01-06         13    10225  12.so.0.25[.0]
180  *    1.2.25rc01-02           13    10225  12.so.0.25[.0]
181  *    1.0.31                  10    10031  10.so.0.31[.0]
182  *    1.2.25                  13    10225  12.so.0.25[.0]
183  *    1.2.26beta01-06         13    10226  12.so.0.26[.0]
184  *    1.2.26rc01              13    10226  12.so.0.26[.0]
185  *    1.2.26                  13    10226  12.so.0.26[.0]
186  *    1.0.32                  10    10032  10.so.0.32[.0]
187  *    1.2.27beta01-06         13    10227  12.so.0.27[.0]
188  *    1.2.27rc01              13    10227  12.so.0.27[.0]
189  *    1.0.33                  10    10033  10.so.0.33[.0]
190  *    1.2.27                  13    10227  12.so.0.27[.0]
191  *    1.0.34                  10    10034  10.so.0.34[.0]
192  *    1.2.28                  13    10228  12.so.0.28[.0]
193  *    1.2.29beta01-03         13    10229  12.so.0.29[.0]
194  *    1.2.29rc01              13    10229  12.so.0.29[.0]
195  *    1.0.35                  10    10035  10.so.0.35[.0]
196  *    1.2.29                  13    10229  12.so.0.29[.0]
197  *    1.0.37                  10    10037  10.so.0.37[.0]
198  *    1.2.30beta01-04         13    10230  12.so.0.30[.0]
199  *    1.0.38rc01-08           10    10038  10.so.0.38[.0]
200  *    1.2.30rc01-08           13    10230  12.so.0.30[.0]
201  *    1.0.38                  10    10038  10.so.0.38[.0]
202  *    1.2.30                  13    10230  12.so.0.30[.0]
203  *    1.0.39rc01-03           10    10039  10.so.0.39[.0]
204  *    1.2.31rc01-03           13    10231  12.so.0.31[.0]
205  *    1.0.39                  10    10039  10.so.0.39[.0]
206  *    1.2.31                  13    10231  12.so.0.31[.0]
207  *    1.2.32beta01-02         13    10232  12.so.0.32[.0]
208  *    1.0.40rc01              10    10040  10.so.0.40[.0]
209  *    1.2.32rc01              13    10232  12.so.0.32[.0]
210  *    1.0.40                  10    10040  10.so.0.40[.0]
211  *    1.2.32                  13    10232  12.so.0.32[.0]
212  *    1.2.33beta01-02         13    10233  12.so.0.33[.0]
213  *    1.2.33rc01-02           13    10233  12.so.0.33[.0]
214  *    1.0.41rc01              10    10041  10.so.0.41[.0]
215  *    1.2.33                  13    10233  12.so.0.33[.0]
216  *    1.0.41                  10    10041  10.so.0.41[.0]
217  *    1.2.34beta01-07         13    10234  12.so.0.34[.0]
218  *    1.0.42rc01              10    10042  10.so.0.42[.0]
219  *    1.2.34rc01              13    10234  12.so.0.34[.0]
220  *    1.0.42                  10    10042  10.so.0.42[.0]
221  *    1.2.34                  13    10234  12.so.0.34[.0]
222  *    1.2.35beta01-03         13    10235  12.so.0.35[.0]
223  *    1.0.43rc01-02           10    10043  10.so.0.43[.0]
224  *    1.2.35rc01-02           13    10235  12.so.0.35[.0]
225  *    1.0.43                  10    10043  10.so.0.43[.0]
226  *    1.2.35                  13    10235  12.so.0.35[.0]
227  *    1.2.36beta01-05         13    10236  12.so.0.36[.0]
228  *    1.2.36rc01              13    10236  12.so.0.36[.0]
229  *    1.0.44                  10    10044  10.so.0.44[.0]
230  *    1.2.36                  13    10236  12.so.0.36[.0]
231  *    1.2.37beta01-03         13    10237  12.so.0.37[.0]
232  *    1.2.37rc01              13    10237  12.so.0.37[.0]
233  *    1.2.37                  13    10237  12.so.0.37[.0]
234  *    1.2.45                  10    10045  12.so.0.45[.0]
235  *    1.0.46                  10    10046  10.so.0.46[.0]
236  *    1.2.38beta01            13    10238  12.so.0.38[.0]
237  *    1.2.38rc01-03           13    10238  12.so.0.38[.0]
238  *    1.0.47                  10    10047  10.so.0.47[.0]
239  *    1.2.38                  13    10238  12.so.0.38[.0]
240  *
241  *    Henceforth the source version will match the shared-library major
242  *    and minor numbers; the shared-library major version number will be
243  *    used for changes in backward compatibility, as it is intended.  The
244  *    PNG_LIBPNG_VER macro, which is not used within libpng but is available
245  *    for applications, is an unsigned integer of the form xyyzz corresponding
246  *    to the source version x.y.z (leading zeros in y and z).  Beta versions
247  *    were given the previous public release number plus a letter, until
248  *    version 1.0.6j; from then on they were given the upcoming public
249  *    release number plus "betaNN" or "rcNN".
250  *
251  *    Binary incompatibility exists only when applications make direct access
252  *    to the info_ptr or png_ptr members through png.h, and the compiled
253  *    application is loaded with a different version of the library.
254  *
255  *    DLLNUM will change each time there are forward or backward changes
256  *    in binary compatibility (e.g., when a new feature is added).
257  *
258  * See libpng.txt or libpng.3 for more information.  The PNG specification
259  * is available as a W3C Recommendation and as an ISO Specification,
260  * <http://www.w3.org/TR/2003/REC-PNG-20031110/
261  */
262 
263 /*
264  * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
265  *
266  * If you modify libpng you may insert additional notices immediately following
267  * this sentence.
268  *
269  * This code is released under the libpng license.
270  *
271  * libpng versions 1.2.6, August 15, 2004, through 1.2.38, July 16, 2009, are
272  * Copyright (c) 2004, 2006-2009 Glenn Randers-Pehrson, and are
273  * distributed according to the same disclaimer and license as libpng-1.2.5
274  * with the following individual added to the list of Contributing Authors:
275  *
276  *    Cosmin Truta
277  *
278  * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
279  * Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
280  * distributed according to the same disclaimer and license as libpng-1.0.6
281  * with the following individuals added to the list of Contributing Authors:
282  *
283  *    Simon-Pierre Cadieux
284  *    Eric S. Raymond
285  *    Gilles Vollant
286  *
287  * and with the following additions to the disclaimer:
288  *
289  *    There is no warranty against interference with your enjoyment of the
290  *    library or against infringement.  There is no warranty that our
291  *    efforts or the library will fulfill any of your particular purposes
292  *    or needs.  This library is provided with all faults, and the entire
293  *    risk of satisfactory quality, performance, accuracy, and effort is with
294  *    the user.
295  *
296  * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
297  * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are
298  * distributed according to the same disclaimer and license as libpng-0.96,
299  * with the following individuals added to the list of Contributing Authors:
300  *
301  *    Tom Lane
302  *    Glenn Randers-Pehrson
303  *    Willem van Schaik
304  *
305  * libpng versions 0.89, June 1996, through 0.96, May 1997, are
306  * Copyright (c) 1996, 1997 Andreas Dilger
307  * Distributed according to the same disclaimer and license as libpng-0.88,
308  * with the following individuals added to the list of Contributing Authors:
309  *
310  *    John Bowler
311  *    Kevin Bracey
312  *    Sam Bushell
313  *    Magnus Holmgren
314  *    Greg Roelofs
315  *    Tom Tanner
316  *
317  * libpng versions 0.5, May 1995, through 0.88, January 1996, are
318  * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
319  *
320  * For the purposes of this copyright and license, "Contributing Authors"
321  * is defined as the following set of individuals:
322  *
323  *    Andreas Dilger
324  *    Dave Martindale
325  *    Guy Eric Schalnat
326  *    Paul Schmidt
327  *    Tim Wegner
328  *
329  * The PNG Reference Library is supplied "AS IS".  The Contributing Authors
330  * and Group 42, Inc. disclaim all warranties, expressed or implied,
331  * including, without limitation, the warranties of merchantability and of
332  * fitness for any purpose.  The Contributing Authors and Group 42, Inc.
333  * assume no liability for direct, indirect, incidental, special, exemplary,
334  * or consequential damages, which may result from the use of the PNG
335  * Reference Library, even if advised of the possibility of such damage.
336  *
337  * Permission is hereby granted to use, copy, modify, and distribute this
338  * source code, or portions hereof, for any purpose, without fee, subject
339  * to the following restrictions:
340  *
341  * 1. The origin of this source code must not be misrepresented.
342  *
343  * 2. Altered versions must be plainly marked as such and
344  * must not be misrepresented as being the original source.
345  *
346  * 3. This Copyright notice may not be removed or altered from
347  *    any source or altered source distribution.
348  *
349  * The Contributing Authors and Group 42, Inc. specifically permit, without
350  * fee, and encourage the use of this source code as a component to
351  * supporting the PNG file format in commercial products.  If you use this
352  * source code in a product, acknowledgment is not required but would be
353  * appreciated.
354  */
355 
356 /*
357  * A "png_get_copyright" function is available, for convenient use in "about"
358  * boxes and the like:
359  *
360  * printf("%s",png_get_copyright(NULL));
361  *
362  * Also, the PNG logo (in PNG format, of course) is supplied in the
363  * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
364  */
365 
366 /*
367  * Libpng is OSI Certified Open Source Software.  OSI Certified is a
368  * certification mark of the Open Source Initiative.
369  */
370 
371 /*
372  * The contributing authors would like to thank all those who helped
373  * with testing, bug fixes, and patience.  This wouldn't have been
374  * possible without all of you.
375  *
376  * Thanks to Frank J. T. Wojcik for helping with the documentation.
377  */
378 
379 /*
380  * Y2K compliance in libpng:
381  * =========================
382  *
383  *    July 16, 2009
384  *
385  *    Since the PNG Development group is an ad-hoc body, we can't make
386  *    an official declaration.
387  *
388  *    This is your unofficial assurance that libpng from version 0.71 and
389  *    upward through 1.2.38 are Y2K compliant.  It is my belief that earlier
390  *    versions were also Y2K compliant.
391  *
392  *    Libpng only has three year fields.  One is a 2-byte unsigned integer
393  *    that will hold years up to 65535.  The other two hold the date in text
394  *    format, and will hold years up to 9999.
395  *
396  *    The integer is
397  *        "png_uint_16 year" in png_time_struct.
398  *
399  *    The strings are
400  *        "png_charp time_buffer" in png_struct and
401  *        "near_time_buffer", which is a local character string in png.c.
402  *
403  *    There are seven time-related functions:
404  *        png.c: png_convert_to_rfc_1123() in png.c
405  *          (formerly png_convert_to_rfc_1152() in error)
406  *        png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
407  *        png_convert_from_time_t() in pngwrite.c
408  *        png_get_tIME() in pngget.c
409  *        png_handle_tIME() in pngrutil.c, called in pngread.c
410  *        png_set_tIME() in pngset.c
411  *        png_write_tIME() in pngwutil.c, called in pngwrite.c
412  *
413  *    All handle dates properly in a Y2K environment.  The
414  *    png_convert_from_time_t() function calls gmtime() to convert from system
415  *    clock time, which returns (year - 1900), which we properly convert to
416  *    the full 4-digit year.  There is a possibility that applications using
417  *    libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
418  *    function, or that they are incorrectly passing only a 2-digit year
419  *    instead of "year - 1900" into the png_convert_from_struct_tm() function,
420  *    but this is not under our control.  The libpng documentation has always
421  *    stated that it works with 4-digit years, and the APIs have been
422  *    documented as such.
423  *
424  *    The tIME chunk itself is also Y2K compliant.  It uses a 2-byte unsigned
425  *    integer to hold the year, and can hold years as large as 65535.
426  *
427  *    zlib, upon which libpng depends, is also Y2K compliant.  It contains
428  *    no date-related code.
429  *
430  *       Glenn Randers-Pehrson
431  *       libpng maintainer
432  *       PNG Development Group
433  */
434 
435 #ifndef PNG_H
436 #define PNG_H
437 
438 /* This is not the place to learn how to use libpng.  The file libpng.txt
439  * describes how to use libpng, and the file example.c summarizes it
440  * with some code on which to build.  This file is useful for looking
441  * at the actual function definitions and structure components.
442  */
443 
444 /* Version information for png.h - this should match the version in png.c */
445 #define PNG_LIBPNG_VER_STRING "1.2.38"
446 #define PNG_HEADER_VERSION_STRING \
447    " libpng version 1.2.38 - July 16, 2009\n"
448 
449 #define PNG_LIBPNG_VER_SONUM   0
450 #define PNG_LIBPNG_VER_DLLNUM  13
451 
452 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
453 #define PNG_LIBPNG_VER_MAJOR   1
454 #define PNG_LIBPNG_VER_MINOR   2
455 #define PNG_LIBPNG_VER_RELEASE 38
456 /* This should match the numeric part of the final component of
457  * PNG_LIBPNG_VER_STRING, omitting any leading zero:
458  */
459 
460 #define PNG_LIBPNG_VER_BUILD  0
461 
462 /* Release Status */
463 #define PNG_LIBPNG_BUILD_ALPHA    1
464 #define PNG_LIBPNG_BUILD_BETA     2
465 #define PNG_LIBPNG_BUILD_RC       3
466 #define PNG_LIBPNG_BUILD_STABLE   4
467 #define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
468 
469 /* Release-Specific Flags */
470 #define PNG_LIBPNG_BUILD_PATCH    8 /* Can be OR'ed with
471                                        PNG_LIBPNG_BUILD_STABLE only */
472 #define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
473                                        PNG_LIBPNG_BUILD_SPECIAL */
474 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
475                                        PNG_LIBPNG_BUILD_PRIVATE */
476 
477 #define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
478 
479 /* Careful here.  At one time, Guy wanted to use 082, but that would be octal.
480  * We must not include leading zeros.
481  * Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
482  * version 1.0.0 was mis-numbered 100 instead of 10000).  From
483  * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=release
484  */
485 #define PNG_LIBPNG_VER 10238 /* 1.2.38 */
486 
487 #ifndef PNG_VERSION_INFO_ONLY
488 /* include the compression library's header */
489 #include "zlib.h"
490 #endif
491 
492 /* include all user configurable info, including optional assembler routines */
493 #include "pngconf.h"
494 
495 /*
496  * Added at libpng-1.2.8 */
497 /* Ref MSDN: Private as priority over Special
498  * VS_FF_PRIVATEBUILD File *was not* built using standard release
499  * procedures. If this value is given, the StringFileInfo block must
500  * contain a PrivateBuild string.
501  *
502  * VS_FF_SPECIALBUILD File *was* built by the original company using
503  * standard release procedures but is a variation of the standard
504  * file of the same version number. If this value is given, the
505  * StringFileInfo block must contain a SpecialBuild string.
506  */
507 
508 #if defined(PNG_USER_PRIVATEBUILD)
509 #  define PNG_LIBPNG_BUILD_TYPE \
510           (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_PRIVATE)
511 #else
512 #  if defined(PNG_LIBPNG_SPECIALBUILD)
513 #    define PNG_LIBPNG_BUILD_TYPE \
514             (PNG_LIBPNG_BUILD_BASE_TYPE | PNG_LIBPNG_BUILD_SPECIAL)
515 #  else
516 #    define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
517 #  endif
518 #endif
519 
520 #ifndef PNG_VERSION_INFO_ONLY
521 
522 /* Inhibit C++ name-mangling for libpng functions but not for system calls. */
523 #ifdef __cplusplus
524 extern "C" {
525 #endif /* __cplusplus */
526 
527 /* This file is arranged in several sections.  The first section contains
528  * structure and type definitions.  The second section contains the external
529  * library functions, while the third has the internal library functions,
530  * which applications aren't expected to use directly.
531  */
532 
533 #ifndef PNG_NO_TYPECAST_NULL
534 #define int_p_NULL                (int *)NULL
535 #define png_bytep_NULL            (png_bytep)NULL
536 #define png_bytepp_NULL           (png_bytepp)NULL
537 #define png_doublep_NULL          (png_doublep)NULL
538 #define png_error_ptr_NULL        (png_error_ptr)NULL
539 #define png_flush_ptr_NULL        (png_flush_ptr)NULL
540 #define png_free_ptr_NULL         (png_free_ptr)NULL
541 #define png_infopp_NULL           (png_infopp)NULL
542 #define png_malloc_ptr_NULL       (png_malloc_ptr)NULL
543 #define png_read_status_ptr_NULL  (png_read_status_ptr)NULL
544 #define png_rw_ptr_NULL           (png_rw_ptr)NULL
545 #define png_structp_NULL          (png_structp)NULL
546 #define png_uint_16p_NULL         (png_uint_16p)NULL
547 #define png_voidp_NULL            (png_voidp)NULL
548 #define png_write_status_ptr_NULL (png_write_status_ptr)NULL
549 #else
550 #define int_p_NULL                NULL
551 #define png_bytep_NULL            NULL
552 #define png_bytepp_NULL           NULL
553 #define png_doublep_NULL          NULL
554 #define png_error_ptr_NULL        NULL
555 #define png_flush_ptr_NULL        NULL
556 #define png_free_ptr_NULL         NULL
557 #define png_infopp_NULL           NULL
558 #define png_malloc_ptr_NULL       NULL
559 #define png_read_status_ptr_NULL  NULL
560 #define png_rw_ptr_NULL           NULL
561 #define png_structp_NULL          NULL
562 #define png_uint_16p_NULL         NULL
563 #define png_voidp_NULL            NULL
564 #define png_write_status_ptr_NULL NULL
565 #endif
566 
567 /* Variables declared in png.c - only it needs to define PNG_NO_EXTERN */
568 #if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
569 /* Version information for C files, stored in png.c.  This had better match
570  * the version above.
571  */
572 #ifdef PNG_USE_GLOBAL_ARRAYS
573 PNG_EXPORT_VAR (PNG_CONST char) png_libpng_ver[18];
574   /* need room for 99.99.99beta99z */
575 #else
576 #define png_libpng_ver png_get_header_ver(NULL)
577 #endif
578 
579 #ifdef PNG_USE_GLOBAL_ARRAYS
580 /* This was removed in version 1.0.5c */
581 /* Structures to facilitate easy interlacing.  See png.c for more details */
582 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_start[7];
583 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_inc[7];
584 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_ystart[7];
585 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_yinc[7];
586 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_mask[7];
587 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_dsp_mask[7];
588 /* This isn't currently used.  If you need it, see png.c for more details.
589 PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_height[7];
590 */
591 #endif
592 
593 #endif /* PNG_NO_EXTERN */
594 
595 /* Three color definitions.  The order of the red, green, and blue, (and the
596  * exact size) is not important, although the size of the fields need to
597  * be png_byte or png_uint_16 (as defined below).
598  */
599 typedef struct png_color_struct
600 {
601    png_byte red;
602    png_byte green;
603    png_byte blue;
604 } png_color;
605 typedef png_color FAR * png_colorp;
606 typedef png_color FAR * FAR * png_colorpp;
607 
608 typedef struct png_color_16_struct
609 {
610    png_byte index;    /* used for palette files */
611    png_uint_16 red;   /* for use in red green blue files */
612    png_uint_16 green;
613    png_uint_16 blue;
614    png_uint_16 gray;  /* for use in grayscale files */
615 } png_color_16;
616 typedef png_color_16 FAR * png_color_16p;
617 typedef png_color_16 FAR * FAR * png_color_16pp;
618 
619 typedef struct png_color_8_struct
620 {
621    png_byte red;   /* for use in red green blue files */
622    png_byte green;
623    png_byte blue;
624    png_byte gray;  /* for use in grayscale files */
625    png_byte alpha; /* for alpha channel files */
626 } png_color_8;
627 typedef png_color_8 FAR * png_color_8p;
628 typedef png_color_8 FAR * FAR * png_color_8pp;
629 
630 /*
631  * The following two structures are used for the in-core representation
632  * of sPLT chunks.
633  */
634 typedef struct png_sPLT_entry_struct
635 {
636    png_uint_16 red;
637    png_uint_16 green;
638    png_uint_16 blue;
639    png_uint_16 alpha;
640    png_uint_16 frequency;
641 } png_sPLT_entry;
642 typedef png_sPLT_entry FAR * png_sPLT_entryp;
643 typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;
644 
645 /*  When the depth of the sPLT palette is 8 bits, the color and alpha samples
646  *  occupy the LSB of their respective members, and the MSB of each member
647  *  is zero-filled.  The frequency member always occupies the full 16 bits.
648  */
649 
650 typedef struct png_sPLT_struct
651 {
652    png_charp name;           /* palette name */
653    png_byte depth;           /* depth of palette samples */
654    png_sPLT_entryp entries;  /* palette entries */
655    png_int_32 nentries;      /* number of palette entries */
656 } png_sPLT_t;
657 typedef png_sPLT_t FAR * png_sPLT_tp;
658 typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
659 
660 #ifdef PNG_TEXT_SUPPORTED
661 /* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
662  * and whether that contents is compressed or not.  The "key" field
663  * points to a regular zero-terminated C string.  The "text", "lang", and
664  * "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
665  * However, the * structure returned by png_get_text() will always contain
666  * regular zero-terminated C strings (possibly empty), never NULL pointers,
667  * so they can be safely used in printf() and other string-handling functions.
668  */
669 typedef struct png_text_struct
670 {
671    int  compression;       /* compression value:
672                              -1: tEXt, none
673                               0: zTXt, deflate
674                               1: iTXt, none
675                               2: iTXt, deflate  */
676    png_charp key;          /* keyword, 1-79 character description of "text" */
677    png_charp text;         /* comment, may be an empty string (ie "")
678                               or a NULL pointer */
679    png_size_t text_length; /* length of the text string */
680 #ifdef PNG_iTXt_SUPPORTED
681    png_size_t itxt_length; /* length of the itxt string */
682    png_charp lang;         /* language code, 0-79 characters
683                               or a NULL pointer */
684    png_charp lang_key;     /* keyword translated UTF-8 string, 0 or more
685                               chars or a NULL pointer */
686 #endif
687 } png_text;
688 typedef png_text FAR * png_textp;
689 typedef png_text FAR * FAR * png_textpp;
690 #endif
691 
692 /* Supported compression types for text in PNG files (tEXt, and zTXt).
693  * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed.
694  */
695 #define PNG_TEXT_COMPRESSION_NONE_WR -3
696 #define PNG_TEXT_COMPRESSION_zTXt_WR -2
697 #define PNG_TEXT_COMPRESSION_NONE    -1
698 #define PNG_TEXT_COMPRESSION_zTXt     0
699 #define PNG_ITXT_COMPRESSION_NONE     1
700 #define PNG_ITXT_COMPRESSION_zTXt     2
701 #define PNG_TEXT_COMPRESSION_LAST     3  /* Not a valid value */
702 
703 /* png_time is a way to hold the time in an machine independent way.
704  * Two conversions are provided, both from time_t and struct tm.  There
705  * is no portable way to convert to either of these structures, as far
706  * as I know.  If you know of a portable way, send it to me.  As a side
707  * note - PNG has always been Year 2000 compliant!
708  */
709 typedef struct png_time_struct
710 {
711    png_uint_16 year; /* full year, as in, 1995 */
712    png_byte month;   /* month of year, 1 - 12 */
713    png_byte day;     /* day of month, 1 - 31 */
714    png_byte hour;    /* hour of day, 0 - 23 */
715    png_byte minute;  /* minute of hour, 0 - 59 */
716    png_byte second;  /* second of minute, 0 - 60 (for leap seconds) */
717 } png_time;
718 typedef png_time FAR * png_timep;
719 typedef png_time FAR * FAR * png_timepp;
720 
721 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
722  defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
723 /* png_unknown_chunk is a structure to hold queued chunks for which there is
724  * no specific support.  The idea is that we can use this to queue
725  * up private chunks for output even though the library doesn't actually
726  * know about their semantics.
727  */
728 #define PNG_CHUNK_NAME_LENGTH 5
729 typedef struct png_unknown_chunk_t
730 {
731     png_byte name[PNG_CHUNK_NAME_LENGTH];
732     png_byte *data;
733     png_size_t size;
734 
735     /* libpng-using applications should NOT directly modify this byte. */
736     png_byte location; /* mode of operation at read time */
737 }
738 png_unknown_chunk;
739 typedef png_unknown_chunk FAR * png_unknown_chunkp;
740 typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
741 #endif
742 
743 /* png_info is a structure that holds the information in a PNG file so
744  * that the application can find out the characteristics of the image.
745  * If you are reading the file, this structure will tell you what is
746  * in the PNG file.  If you are writing the file, fill in the information
747  * you want to put into the PNG file, then call png_write_info().
748  * The names chosen should be very close to the PNG specification, so
749  * consult that document for information about the meaning of each field.
750  *
751  * With libpng < 0.95, it was only possible to directly set and read the
752  * the values in the png_info_struct, which meant that the contents and
753  * order of the values had to remain fixed.  With libpng 0.95 and later,
754  * however, there are now functions that abstract the contents of
755  * png_info_struct from the application, so this makes it easier to use
756  * libpng with dynamic libraries, and even makes it possible to use
757  * libraries that don't have all of the libpng ancillary chunk-handing
758  * functionality.
759  *
760  * In any case, the order of the parameters in png_info_struct should NOT
761  * be changed for as long as possible to keep compatibility with applications
762  * that use the old direct-access method with png_info_struct.
763  *
764  * The following members may have allocated storage attached that should be
765  * cleaned up before the structure is discarded: palette, trans, text,
766  * pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
767  * splt_palettes, scal_unit, row_pointers, and unknowns.   By default, these
768  * are automatically freed when the info structure is deallocated, if they were
769  * allocated internally by libpng.  This behavior can be changed by means
770  * of the png_data_freer() function.
771  *
772  * More allocation details: all the chunk-reading functions that
773  * change these members go through the corresponding png_set_*
774  * functions.  A function to clear these members is available: see
775  * png_free_data().  The png_set_* functions do not depend on being
776  * able to point info structure members to any of the storage they are
777  * passed (they make their own copies), EXCEPT that the png_set_text
778  * functions use the same storage passed to them in the text_ptr or
779  * itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
780  * functions do not make their own copies.
781  */
782 typedef struct png_info_struct
783 {
784    /* the following are necessary for every PNG file */
785    png_uint_32 width;       /* width of image in pixels (from IHDR) */
786    png_uint_32 height;      /* height of image in pixels (from IHDR) */
787    png_uint_32 valid;       /* valid chunk data (see PNG_INFO_ below) */
788    png_uint_32 rowbytes;    /* bytes needed to hold an untransformed row */
789    png_colorp palette;      /* array of color values (valid & PNG_INFO_PLTE) */
790    png_uint_16 num_palette; /* number of color entries in "palette" (PLTE) */
791    png_uint_16 num_trans;   /* number of transparent palette color (tRNS) */
792    png_byte bit_depth;      /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */
793    png_byte color_type;     /* see PNG_COLOR_TYPE_ below (from IHDR) */
794    /* The following three should have been named *_method not *_type */
795    png_byte compression_type; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */
796    png_byte filter_type;    /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
797    png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
798 
799    /* The following is informational only on read, and not used on writes. */
800    png_byte channels;       /* number of data channels per pixel (1, 2, 3, 4) */
801    png_byte pixel_depth;    /* number of bits per pixel */
802    png_byte spare_byte;     /* to align the data, and for future use */
803    png_byte signature[8];   /* magic bytes read by libpng from start of file */
804 
805    /* The rest of the data is optional.  If you are reading, check the
806     * valid field to see if the information in these are valid.  If you
807     * are writing, set the valid field to those chunks you want written,
808     * and initialize the appropriate fields below.
809     */
810 
811 #if defined(PNG_gAMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
812    /* The gAMA chunk describes the gamma characteristics of the system
813     * on which the image was created, normally in the range [1.0, 2.5].
814     * Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
815     */
816    float gamma; /* gamma value of image, if (valid & PNG_INFO_gAMA) */
817 #endif
818 
819 #if defined(PNG_sRGB_SUPPORTED)
820     /* GR-P, 0.96a */
821     /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
822    png_byte srgb_intent; /* sRGB rendering intent [0, 1, 2, or 3] */
823 #endif
824 
825 #if defined(PNG_TEXT_SUPPORTED)
826    /* The tEXt, and zTXt chunks contain human-readable textual data in
827     * uncompressed, compressed, and optionally compressed forms, respectively.
828     * The data in "text" is an array of pointers to uncompressed,
829     * null-terminated C strings. Each chunk has a keyword that describes the
830     * textual data contained in that chunk.  Keywords are not required to be
831     * unique, and the text string may be empty.  Any number of text chunks may
832     * be in an image.
833     */
834    int num_text; /* number of comments read/to write */
835    int max_text; /* current size of text array */
836    png_textp text; /* array of comments read/to write */
837 #endif /* PNG_TEXT_SUPPORTED */
838 
839 #if defined(PNG_tIME_SUPPORTED)
840    /* The tIME chunk holds the last time the displayed image data was
841     * modified.  See the png_time struct for the contents of this struct.
842     */
843    png_time mod_time;
844 #endif
845 
846 #if defined(PNG_sBIT_SUPPORTED)
847    /* The sBIT chunk specifies the number of significant high-order bits
848     * in the pixel data.  Values are in the range [1, bit_depth], and are
849     * only specified for the channels in the pixel data.  The contents of
850     * the low-order bits is not specified.  Data is valid if
851     * (valid & PNG_INFO_sBIT) is non-zero.
852     */
853    png_color_8 sig_bit; /* significant bits in color channels */
854 #endif
855 
856 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_EXPAND_SUPPORTED) || \
857 defined(PNG_READ_BACKGROUND_SUPPORTED)
858    /* The tRNS chunk supplies transparency data for paletted images and
859     * other image types that don't need a full alpha channel.  There are
860     * "num_trans" transparency values for a paletted image, stored in the
861     * same order as the palette colors, starting from index 0.  Values
862     * for the data are in the range [0, 255], ranging from fully transparent
863     * to fully opaque, respectively.  For non-paletted images, there is a
864     * single color specified that should be treated as fully transparent.
865     * Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
866     */
867    png_bytep trans; /* transparent values for paletted image */
868    png_color_16 trans_values; /* transparent color for non-palette image */
869 #endif
870 
871 #if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
872    /* The bKGD chunk gives the suggested image background color if the
873     * display program does not have its own background color and the image
874     * is needs to composited onto a background before display.  The colors
875     * in "background" are normally in the same color space/depth as the
876     * pixel data.  Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
877     */
878    png_color_16 background;
879 #endif
880 
881 #if defined(PNG_oFFs_SUPPORTED)
882    /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
883     * and downwards from the top-left corner of the display, page, or other
884     * application-specific co-ordinate space.  See the PNG_OFFSET_ defines
885     * below for the unit types.  Valid if (valid & PNG_INFO_oFFs) non-zero.
886     */
887    png_int_32 x_offset; /* x offset on page */
888    png_int_32 y_offset; /* y offset on page */
889    png_byte offset_unit_type; /* offset units type */
890 #endif
891 
892 #if defined(PNG_pHYs_SUPPORTED)
893    /* The pHYs chunk gives the physical pixel density of the image for
894     * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
895     * defines below).  Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
896     */
897    png_uint_32 x_pixels_per_unit; /* horizontal pixel density */
898    png_uint_32 y_pixels_per_unit; /* vertical pixel density */
899    png_byte phys_unit_type; /* resolution type (see PNG_RESOLUTION_ below) */
900 #endif
901 
902 #if defined(PNG_hIST_SUPPORTED)
903    /* The hIST chunk contains the relative frequency or importance of the
904     * various palette entries, so that a viewer can intelligently select a
905     * reduced-color palette, if required.  Data is an array of "num_palette"
906     * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
907     * is non-zero.
908     */
909    png_uint_16p hist;
910 #endif
911 
912 #ifdef PNG_cHRM_SUPPORTED
913    /* The cHRM chunk describes the CIE color characteristics of the monitor
914     * on which the PNG was created.  This data allows the viewer to do gamut
915     * mapping of the input image to ensure that the viewer sees the same
916     * colors in the image as the creator.  Values are in the range
917     * [0.0, 0.8].  Data valid if (valid & PNG_INFO_cHRM) non-zero.
918     */
919 #ifdef PNG_FLOATING_POINT_SUPPORTED
920    float x_white;
921    float y_white;
922    float x_red;
923    float y_red;
924    float x_green;
925    float y_green;
926    float x_blue;
927    float y_blue;
928 #endif
929 #endif
930 
931 #if defined(PNG_pCAL_SUPPORTED)
932    /* The pCAL chunk describes a transformation between the stored pixel
933     * values and original physical data values used to create the image.
934     * The integer range [0, 2^bit_depth - 1] maps to the floating-point
935     * range given by [pcal_X0, pcal_X1], and are further transformed by a
936     * (possibly non-linear) transformation function given by "pcal_type"
937     * and "pcal_params" into "pcal_units".  Please see the PNG_EQUATION_
938     * defines below, and the PNG-Group's PNG extensions document for a
939     * complete description of the transformations and how they should be
940     * implemented, and for a description of the ASCII parameter strings.
941     * Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
942     */
943    png_charp pcal_purpose;  /* pCAL chunk description string */
944    png_int_32 pcal_X0;      /* minimum value */
945    png_int_32 pcal_X1;      /* maximum value */
946    png_charp pcal_units;    /* Latin-1 string giving physical units */
947    png_charpp pcal_params;  /* ASCII strings containing parameter values */
948    png_byte pcal_type;      /* equation type (see PNG_EQUATION_ below) */
949    png_byte pcal_nparams;   /* number of parameters given in pcal_params */
950 #endif
951 
952 /* New members added in libpng-1.0.6 */
953 #ifdef PNG_FREE_ME_SUPPORTED
954    png_uint_32 free_me;     /* flags items libpng is responsible for freeing */
955 #endif
956 
957 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) || \
958  defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
959    /* Storage for unknown chunks that the library doesn't recognize. */
960    png_unknown_chunkp unknown_chunks;
961    png_size_t unknown_chunks_num;
962 #endif
963 
964 #if defined(PNG_iCCP_SUPPORTED)
965    /* iCCP chunk data. */
966    png_charp iccp_name;     /* profile name */
967    png_charp iccp_profile;  /* International Color Consortium profile data */
968                             /* Note to maintainer: should be png_bytep */
969    png_uint_32 iccp_proflen;  /* ICC profile data length */
970    png_byte iccp_compression; /* Always zero */
971 #endif
972 
973 #if defined(PNG_sPLT_SUPPORTED)
974    /* Data on sPLT chunks (there may be more than one). */
975    png_sPLT_tp splt_palettes;
976    png_uint_32 splt_palettes_num;
977 #endif
978 
979 #if defined(PNG_sCAL_SUPPORTED)
980    /* The sCAL chunk describes the actual physical dimensions of the
981     * subject matter of the graphic.  The chunk contains a unit specification
982     * a byte value, and two ASCII strings representing floating-point
983     * values.  The values are width and height corresponsing to one pixel
984     * in the image.  This external representation is converted to double
985     * here.  Data values are valid if (valid & PNG_INFO_sCAL) is non-zero.
986     */
987    png_byte scal_unit;         /* unit of physical scale */
988 #ifdef PNG_FLOATING_POINT_SUPPORTED
989    double scal_pixel_width;    /* width of one pixel */
990    double scal_pixel_height;   /* height of one pixel */
991 #endif
992 #ifdef PNG_FIXED_POINT_SUPPORTED
993    png_charp scal_s_width;     /* string containing height */
994    png_charp scal_s_height;    /* string containing width */
995 #endif
996 #endif
997 
998 #if defined(PNG_INFO_IMAGE_SUPPORTED)
999    /* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS) non-zero */
1000    /* Data valid if (valid & PNG_INFO_IDAT) non-zero */
1001    png_bytepp row_pointers;        /* the image bits */
1002 #endif
1003 
1004 #if defined(PNG_FIXED_POINT_SUPPORTED) && defined(PNG_gAMA_SUPPORTED)
1005    png_fixed_point int_gamma; /* gamma of image, if (valid & PNG_INFO_gAMA) */
1006 #endif
1007 
1008 #if defined(PNG_cHRM_SUPPORTED) && defined(PNG_FIXED_POINT_SUPPORTED)
1009    png_fixed_point int_x_white;
1010    png_fixed_point int_y_white;
1011    png_fixed_point int_x_red;
1012    png_fixed_point int_y_red;
1013    png_fixed_point int_x_green;
1014    png_fixed_point int_y_green;
1015    png_fixed_point int_x_blue;
1016    png_fixed_point int_y_blue;
1017 #endif
1018 
1019 } png_info;
1020 
1021 typedef png_info FAR * png_infop;
1022 typedef png_info FAR * FAR * png_infopp;
1023 
1024 /* Maximum positive integer used in PNG is (2^31)-1 */
1025 #define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
1026 #define PNG_UINT_32_MAX ((png_uint_32)(-1))
1027 #define PNG_SIZE_MAX ((png_size_t)(-1))
1028 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1029 /* PNG_MAX_UINT is deprecated; use PNG_UINT_31_MAX instead. */
1030 #define PNG_MAX_UINT PNG_UINT_31_MAX
1031 #endif
1032 
1033 /* These describe the color_type field in png_info. */
1034 /* color type masks */
1035 #define PNG_COLOR_MASK_PALETTE    1
1036 #define PNG_COLOR_MASK_COLOR      2
1037 #define PNG_COLOR_MASK_ALPHA      4
1038 
1039 /* color types.  Note that not all combinations are legal */
1040 #define PNG_COLOR_TYPE_GRAY 0
1041 #define PNG_COLOR_TYPE_PALETTE  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE)
1042 #define PNG_COLOR_TYPE_RGB        (PNG_COLOR_MASK_COLOR)
1043 #define PNG_COLOR_TYPE_RGB_ALPHA  (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA)
1044 #define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
1045 /* aliases */
1046 #define PNG_COLOR_TYPE_RGBA  PNG_COLOR_TYPE_RGB_ALPHA
1047 #define PNG_COLOR_TYPE_GA  PNG_COLOR_TYPE_GRAY_ALPHA
1048 
1049 /* This is for compression type. PNG 1.0-1.2 only define the single type. */
1050 #define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
1051 #define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
1052 
1053 /* This is for filter type. PNG 1.0-1.2 only define the single type. */
1054 #define PNG_FILTER_TYPE_BASE      0 /* Single row per-byte filtering */
1055 #define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
1056 #define PNG_FILTER_TYPE_DEFAULT   PNG_FILTER_TYPE_BASE
1057 
1058 /* These are for the interlacing type.  These values should NOT be changed. */
1059 #define PNG_INTERLACE_NONE        0 /* Non-interlaced image */
1060 #define PNG_INTERLACE_ADAM7       1 /* Adam7 interlacing */
1061 #define PNG_INTERLACE_LAST        2 /* Not a valid value */
1062 
1063 /* These are for the oFFs chunk.  These values should NOT be changed. */
1064 #define PNG_OFFSET_PIXEL          0 /* Offset in pixels */
1065 #define PNG_OFFSET_MICROMETER     1 /* Offset in micrometers (1/10^6 meter) */
1066 #define PNG_OFFSET_LAST           2 /* Not a valid value */
1067 
1068 /* These are for the pCAL chunk.  These values should NOT be changed. */
1069 #define PNG_EQUATION_LINEAR       0 /* Linear transformation */
1070 #define PNG_EQUATION_BASE_E       1 /* Exponential base e transform */
1071 #define PNG_EQUATION_ARBITRARY    2 /* Arbitrary base exponential transform */
1072 #define PNG_EQUATION_HYPERBOLIC   3 /* Hyperbolic sine transformation */
1073 #define PNG_EQUATION_LAST         4 /* Not a valid value */
1074 
1075 /* These are for the sCAL chunk.  These values should NOT be changed. */
1076 #define PNG_SCALE_UNKNOWN         0 /* unknown unit (image scale) */
1077 #define PNG_SCALE_METER           1 /* meters per pixel */
1078 #define PNG_SCALE_RADIAN          2 /* radians per pixel */
1079 #define PNG_SCALE_LAST            3 /* Not a valid value */
1080 
1081 /* These are for the pHYs chunk.  These values should NOT be changed. */
1082 #define PNG_RESOLUTION_UNKNOWN    0 /* pixels/unknown unit (aspect ratio) */
1083 #define PNG_RESOLUTION_METER      1 /* pixels/meter */
1084 #define PNG_RESOLUTION_LAST       2 /* Not a valid value */
1085 
1086 /* These are for the sRGB chunk.  These values should NOT be changed. */
1087 #define PNG_sRGB_INTENT_PERCEPTUAL 0
1088 #define PNG_sRGB_INTENT_RELATIVE   1
1089 #define PNG_sRGB_INTENT_SATURATION 2
1090 #define PNG_sRGB_INTENT_ABSOLUTE   3
1091 #define PNG_sRGB_INTENT_LAST       4 /* Not a valid value */
1092 
1093 /* This is for text chunks */
1094 #define PNG_KEYWORD_MAX_LENGTH     79
1095 
1096 /* Maximum number of entries in PLTE/sPLT/tRNS arrays */
1097 #define PNG_MAX_PALETTE_LENGTH    256
1098 
1099 /* These determine if an ancillary chunk's data has been successfully read
1100  * from the PNG header, or if the application has filled in the corresponding
1101  * data in the info_struct to be written into the output file.  The values
1102  * of the PNG_INFO_<chunk> defines should NOT be changed.
1103  */
1104 #define PNG_INFO_gAMA 0x0001
1105 #define PNG_INFO_sBIT 0x0002
1106 #define PNG_INFO_cHRM 0x0004
1107 #define PNG_INFO_PLTE 0x0008
1108 #define PNG_INFO_tRNS 0x0010
1109 #define PNG_INFO_bKGD 0x0020
1110 #define PNG_INFO_hIST 0x0040
1111 #define PNG_INFO_pHYs 0x0080
1112 #define PNG_INFO_oFFs 0x0100
1113 #define PNG_INFO_tIME 0x0200
1114 #define PNG_INFO_pCAL 0x0400
1115 #define PNG_INFO_sRGB 0x0800   /* GR-P, 0.96a */
1116 #define PNG_INFO_iCCP 0x1000   /* ESR, 1.0.6 */
1117 #define PNG_INFO_sPLT 0x2000   /* ESR, 1.0.6 */
1118 #define PNG_INFO_sCAL 0x4000   /* ESR, 1.0.6 */
1119 #define PNG_INFO_IDAT 0x8000L  /* ESR, 1.0.6 */
1120 
1121 /* This is used for the transformation routines, as some of them
1122  * change these values for the row.  It also should enable using
1123  * the routines for other purposes.
1124  */
1125 typedef struct png_row_info_struct
1126 {
1127    png_uint_32 width; /* width of row */
1128    png_uint_32 rowbytes; /* number of bytes in row */
1129    png_byte color_type; /* color type of row */
1130    png_byte bit_depth; /* bit depth of row */
1131    png_byte channels; /* number of channels (1, 2, 3, or 4) */
1132    png_byte pixel_depth; /* bits per pixel (depth * channels) */
1133 } png_row_info;
1134 
1135 typedef png_row_info FAR * png_row_infop;
1136 typedef png_row_info FAR * FAR * png_row_infopp;
1137 
1138 /* These are the function types for the I/O functions and for the functions
1139  * that allow the user to override the default I/O functions with his or her
1140  * own.  The png_error_ptr type should match that of user-supplied warning
1141  * and error functions, while the png_rw_ptr type should match that of the
1142  * user read/write data functions.
1143  */
1144 typedef struct png_struct_def png_struct;
1145 typedef png_struct FAR * png_structp;
1146 
1147 typedef void (PNGAPI *png_error_ptr) PNGARG((png_structp, png_const_charp));
1148 typedef void (PNGAPI *png_rw_ptr) PNGARG((png_structp, png_bytep, png_size_t));
1149 typedef void (PNGAPI *png_flush_ptr) PNGARG((png_structp));
1150 typedef void (PNGAPI *png_read_status_ptr) PNGARG((png_structp, png_uint_32,
1151    int));
1152 typedef void (PNGAPI *png_write_status_ptr) PNGARG((png_structp, png_uint_32,
1153    int));
1154 
1155 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1156 typedef void (PNGAPI *png_progressive_info_ptr) PNGARG((png_structp, png_infop));
1157 typedef void (PNGAPI *png_progressive_end_ptr) PNGARG((png_structp, png_infop));
1158 typedef void (PNGAPI *png_progressive_row_ptr) PNGARG((png_structp, png_bytep,
1159    png_uint_32, int));
1160 #endif
1161 
1162 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1163     defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
1164     defined(PNG_LEGACY_SUPPORTED)
1165 typedef void (PNGAPI *png_user_transform_ptr) PNGARG((png_structp,
1166     png_row_infop, png_bytep));
1167 #endif
1168 
1169 #if defined(PNG_USER_CHUNKS_SUPPORTED)
1170 typedef int (PNGAPI *png_user_chunk_ptr) PNGARG((png_structp, png_unknown_chunkp));
1171 #endif
1172 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
1173 typedef void (PNGAPI *png_unknown_chunk_ptr) PNGARG((png_structp));
1174 #endif
1175 
1176 /* Transform masks for the high-level interface */
1177 #define PNG_TRANSFORM_IDENTITY       0x0000    /* read and write */
1178 #define PNG_TRANSFORM_STRIP_16       0x0001    /* read only */
1179 #define PNG_TRANSFORM_STRIP_ALPHA    0x0002    /* read only */
1180 #define PNG_TRANSFORM_PACKING        0x0004    /* read and write */
1181 #define PNG_TRANSFORM_PACKSWAP       0x0008    /* read and write */
1182 #define PNG_TRANSFORM_EXPAND         0x0010    /* read only */
1183 #define PNG_TRANSFORM_INVERT_MONO    0x0020    /* read and write */
1184 #define PNG_TRANSFORM_SHIFT          0x0040    /* read and write */
1185 #define PNG_TRANSFORM_BGR            0x0080    /* read and write */
1186 #define PNG_TRANSFORM_SWAP_ALPHA     0x0100    /* read and write */
1187 #define PNG_TRANSFORM_SWAP_ENDIAN    0x0200    /* read and write */
1188 #define PNG_TRANSFORM_INVERT_ALPHA   0x0400    /* read and write */
1189 #define PNG_TRANSFORM_STRIP_FILLER   0x0800    /* WRITE only, deprecated */
1190 /* Added to libpng-1.2.34 */
1191 #define PNG_TRANSFORM_STRIP_FILLER_BEFORE 0x0800  /* WRITE only */
1192 #define PNG_TRANSFORM_STRIP_FILLER_AFTER  0x1000  /* WRITE only */
1193 
1194 /* Flags for MNG supported features */
1195 #define PNG_FLAG_MNG_EMPTY_PLTE     0x01
1196 #define PNG_FLAG_MNG_FILTER_64      0x04
1197 #define PNG_ALL_MNG_FEATURES        0x05
1198 
1199 typedef png_voidp (*png_malloc_ptr) PNGARG((png_structp, png_size_t));
1200 typedef void (*png_free_ptr) PNGARG((png_structp, png_voidp));
1201 
1202 /* The structure that holds the information to read and write PNG files.
1203  * The only people who need to care about what is inside of this are the
1204  * people who will be modifying the library for their own special needs.
1205  * It should NOT be accessed directly by an application, except to store
1206  * the jmp_buf.
1207  */
1208 
1209 struct png_struct_def
1210 {
1211 #ifdef PNG_SETJMP_SUPPORTED
1212    jmp_buf jmpbuf;            /* used in png_error */
1213 #endif
1214    png_error_ptr error_fn;    /* function for printing errors and aborting */
1215    png_error_ptr warning_fn;  /* function for printing warnings */
1216    png_voidp error_ptr;       /* user supplied struct for error functions */
1217    png_rw_ptr write_data_fn;  /* function for writing output data */
1218    png_rw_ptr read_data_fn;   /* function for reading input data */
1219    png_voidp io_ptr;          /* ptr to application struct for I/O functions */
1220 
1221 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
1222    png_user_transform_ptr read_user_transform_fn; /* user read transform */
1223 #endif
1224 
1225 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1226    png_user_transform_ptr write_user_transform_fn; /* user write transform */
1227 #endif
1228 
1229 /* These were added in libpng-1.0.2 */
1230 #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
1231 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
1232     defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1233    png_voidp user_transform_ptr; /* user supplied struct for user transform */
1234    png_byte user_transform_depth;    /* bit depth of user transformed pixels */
1235    png_byte user_transform_channels; /* channels in user transformed pixels */
1236 #endif
1237 #endif
1238 
1239    png_uint_32 mode;          /* tells us where we are in the PNG file */
1240    png_uint_32 flags;         /* flags indicating various things to libpng */
1241    png_uint_32 transformations; /* which transformations to perform */
1242 
1243    z_stream zstream;          /* pointer to decompression structure (below) */
1244    png_bytep zbuf;            /* buffer for zlib */
1245    png_size_t zbuf_size;      /* size of zbuf */
1246    int zlib_level;            /* holds zlib compression level */
1247    int zlib_method;           /* holds zlib compression method */
1248    int zlib_window_bits;      /* holds zlib compression window bits */
1249    int zlib_mem_level;        /* holds zlib compression memory level */
1250    int zlib_strategy;         /* holds zlib compression strategy */
1251 
1252    png_uint_32 width;         /* width of image in pixels */
1253    png_uint_32 height;        /* height of image in pixels */
1254    png_uint_32 num_rows;      /* number of rows in current pass */
1255    png_uint_32 usr_width;     /* width of row at start of write */
1256    png_uint_32 rowbytes;      /* size of row in bytes */
1257    png_uint_32 irowbytes;     /* size of current interlaced row in bytes */
1258    png_uint_32 iwidth;        /* width of current interlaced row in pixels */
1259    png_uint_32 row_number;    /* current row in interlace pass */
1260    png_bytep prev_row;        /* buffer to save previous (unfiltered) row */
1261    png_bytep row_buf;         /* buffer to save current (unfiltered) row */
1262 #ifndef PNG_NO_WRITE_FILTER
1263    png_bytep sub_row;         /* buffer to save "sub" row when filtering */
1264    png_bytep up_row;          /* buffer to save "up" row when filtering */
1265    png_bytep avg_row;         /* buffer to save "avg" row when filtering */
1266    png_bytep paeth_row;       /* buffer to save "Paeth" row when filtering */
1267 #endif
1268    png_row_info row_info;     /* used for transformation routines */
1269 
1270    png_uint_32 idat_size;     /* current IDAT size for read */
1271    png_uint_32 crc;           /* current chunk CRC value */
1272    png_colorp palette;        /* palette from the input file */
1273    png_uint_16 num_palette;   /* number of color entries in palette */
1274    png_uint_16 num_trans;     /* number of transparency values */
1275    png_byte chunk_name[5];    /* null-terminated name of current chunk */
1276    png_byte compression;      /* file compression type (always 0) */
1277    png_byte filter;           /* file filter type (always 0) */
1278    png_byte interlaced;       /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
1279    png_byte pass;             /* current interlace pass (0 - 6) */
1280    png_byte do_filter;        /* row filter flags (see PNG_FILTER_ below ) */
1281    png_byte color_type;       /* color type of file */
1282    png_byte bit_depth;        /* bit depth of file */
1283    png_byte usr_bit_depth;    /* bit depth of users row */
1284    png_byte pixel_depth;      /* number of bits per pixel */
1285    png_byte channels;         /* number of channels in file */
1286    png_byte usr_channels;     /* channels at start of write */
1287    png_byte sig_bytes;        /* magic bytes read/written from start of file */
1288 
1289 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1290 #ifdef PNG_LEGACY_SUPPORTED
1291    png_byte filler;           /* filler byte for pixel expansion */
1292 #else
1293    png_uint_16 filler;           /* filler bytes for pixel expansion */
1294 #endif
1295 #endif
1296 
1297 #if defined(PNG_bKGD_SUPPORTED)
1298    png_byte background_gamma_type;
1299 #  ifdef PNG_FLOATING_POINT_SUPPORTED
1300    float background_gamma;
1301 #  endif
1302    png_color_16 background;   /* background color in screen gamma space */
1303 #if defined(PNG_READ_GAMMA_SUPPORTED)
1304    png_color_16 background_1; /* background normalized to gamma 1.0 */
1305 #endif
1306 #endif /* PNG_bKGD_SUPPORTED */
1307 
1308 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
1309    png_flush_ptr output_flush_fn; /* Function for flushing output */
1310    png_uint_32 flush_dist;    /* how many rows apart to flush, 0 - no flush */
1311    png_uint_32 flush_rows;    /* number of rows written since last flush */
1312 #endif
1313 
1314 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1315    int gamma_shift;      /* number of "insignificant" bits 16-bit gamma */
1316 #ifdef PNG_FLOATING_POINT_SUPPORTED
1317    float gamma;          /* file gamma value */
1318    float screen_gamma;   /* screen gamma value (display_exponent) */
1319 #endif
1320 #endif
1321 
1322 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1323    png_bytep gamma_table;     /* gamma table for 8-bit depth files */
1324    png_bytep gamma_from_1;    /* converts from 1.0 to screen */
1325    png_bytep gamma_to_1;      /* converts from file to 1.0 */
1326    png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */
1327    png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */
1328    png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */
1329 #endif
1330 
1331 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
1332    png_color_8 sig_bit;       /* significant bits in each available channel */
1333 #endif
1334 
1335 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1336    png_color_8 shift;         /* shift for significant bit tranformation */
1337 #endif
1338 
1339 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
1340  || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1341    png_bytep trans;           /* transparency values for paletted files */
1342    png_color_16 trans_values; /* transparency values for non-paletted files */
1343 #endif
1344 
1345    png_read_status_ptr read_row_fn;   /* called after each row is decoded */
1346    png_write_status_ptr write_row_fn; /* called after each row is encoded */
1347 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1348    png_progressive_info_ptr info_fn; /* called after header data fully read */
1349    png_progressive_row_ptr row_fn;   /* called after each prog. row is decoded */
1350    png_progressive_end_ptr end_fn;   /* called after image is complete */
1351    png_bytep save_buffer_ptr;        /* current location in save_buffer */
1352    png_bytep save_buffer;            /* buffer for previously read data */
1353    png_bytep current_buffer_ptr;     /* current location in current_buffer */
1354    png_bytep current_buffer;         /* buffer for recently used data */
1355    png_uint_32 push_length;          /* size of current input chunk */
1356    png_uint_32 skip_length;          /* bytes to skip in input data */
1357    png_size_t save_buffer_size;      /* amount of data now in save_buffer */
1358    png_size_t save_buffer_max;       /* total size of save_buffer */
1359    png_size_t buffer_size;           /* total amount of available input data */
1360    png_size_t current_buffer_size;   /* amount of data now in current_buffer */
1361    int process_mode;                 /* what push library is currently doing */
1362    int cur_palette;                  /* current push library palette index */
1363 
1364 #  if defined(PNG_TEXT_SUPPORTED)
1365      png_size_t current_text_size;   /* current size of text input data */
1366      png_size_t current_text_left;   /* how much text left to read in input */
1367      png_charp current_text;         /* current text chunk buffer */
1368      png_charp current_text_ptr;     /* current location in current_text */
1369 #  endif /* PNG_TEXT_SUPPORTED */
1370 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1371 
1372 #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
1373 /* for the Borland special 64K segment handler */
1374    png_bytepp offset_table_ptr;
1375    png_bytep offset_table;
1376    png_uint_16 offset_table_number;
1377    png_uint_16 offset_table_count;
1378    png_uint_16 offset_table_count_free;
1379 #endif
1380 
1381 #if defined(PNG_READ_DITHER_SUPPORTED)
1382    png_bytep palette_lookup;         /* lookup table for dithering */
1383    png_bytep dither_index;           /* index translation for palette files */
1384 #endif
1385 
1386 #if defined(PNG_READ_DITHER_SUPPORTED) || defined(PNG_hIST_SUPPORTED)
1387    png_uint_16p hist;                /* histogram */
1388 #endif
1389 
1390 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
1391    png_byte heuristic_method;        /* heuristic for row filter selection */
1392    png_byte num_prev_filters;        /* number of weights for previous rows */
1393    png_bytep prev_filters;           /* filter type(s) of previous row(s) */
1394    png_uint_16p filter_weights;      /* weight(s) for previous line(s) */
1395    png_uint_16p inv_filter_weights;  /* 1/weight(s) for previous line(s) */
1396    png_uint_16p filter_costs;        /* relative filter calculation cost */
1397    png_uint_16p inv_filter_costs;    /* 1/relative filter calculation cost */
1398 #endif
1399 
1400 #if defined(PNG_TIME_RFC1123_SUPPORTED)
1401    png_charp time_buffer;            /* String to hold RFC 1123 time text */
1402 #endif
1403 
1404 /* New members added in libpng-1.0.6 */
1405 
1406 #ifdef PNG_FREE_ME_SUPPORTED
1407    png_uint_32 free_me;   /* flags items libpng is responsible for freeing */
1408 #endif
1409 
1410 #if defined(PNG_USER_CHUNKS_SUPPORTED)
1411    png_voidp user_chunk_ptr;
1412    png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
1413 #endif
1414 
1415 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
1416    int num_chunk_list;
1417    png_bytep chunk_list;
1418 #endif
1419 
1420 /* New members added in libpng-1.0.3 */
1421 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
1422    png_byte rgb_to_gray_status;
1423    /* These were changed from png_byte in libpng-1.0.6 */
1424    png_uint_16 rgb_to_gray_red_coeff;
1425    png_uint_16 rgb_to_gray_green_coeff;
1426    png_uint_16 rgb_to_gray_blue_coeff;
1427 #endif
1428 
1429 /* New member added in libpng-1.0.4 (renamed in 1.0.9) */
1430 #if defined(PNG_MNG_FEATURES_SUPPORTED) || \
1431     defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1432     defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1433 /* changed from png_byte to png_uint_32 at version 1.2.0 */
1434 #ifdef PNG_1_0_X
1435    png_byte mng_features_permitted;
1436 #else
1437    png_uint_32 mng_features_permitted;
1438 #endif /* PNG_1_0_X */
1439 #endif
1440 
1441 /* New member added in libpng-1.0.7 */
1442 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1443    png_fixed_point int_gamma;
1444 #endif
1445 
1446 /* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
1447 #if defined(PNG_MNG_FEATURES_SUPPORTED)
1448    png_byte filter_type;
1449 #endif
1450 
1451 #if defined(PNG_1_0_X)
1452 /* New member added in libpng-1.0.10, ifdef'ed out in 1.2.0 */
1453    png_uint_32 row_buf_size;
1454 #endif
1455 
1456 /* New members added in libpng-1.2.0 */
1457 #if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
1458 #  if !defined(PNG_1_0_X)
1459 #    if defined(PNG_MMX_CODE_SUPPORTED)
1460    png_byte     mmx_bitdepth_threshold;
1461    png_uint_32  mmx_rowbytes_threshold;
1462 #    endif
1463    png_uint_32  asm_flags;
1464 #  endif
1465 #endif
1466 
1467 /* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
1468 #ifdef PNG_USER_MEM_SUPPORTED
1469    png_voidp mem_ptr;            /* user supplied struct for mem functions */
1470    png_malloc_ptr malloc_fn;     /* function for allocating memory */
1471    png_free_ptr free_fn;         /* function for freeing memory */
1472 #endif
1473 
1474 /* New member added in libpng-1.0.13 and 1.2.0 */
1475    png_bytep big_row_buf;        /* buffer to save current (unfiltered) row */
1476 
1477 #if defined(PNG_READ_DITHER_SUPPORTED)
1478 /* The following three members were added at version 1.0.14 and 1.2.4 */
1479    png_bytep dither_sort;        /* working sort array */
1480    png_bytep index_to_palette;   /* where the original index currently is */
1481                                  /* in the palette */
1482    png_bytep palette_to_index;   /* which original index points to this */
1483                                  /* palette color */
1484 #endif
1485 
1486 /* New members added in libpng-1.0.16 and 1.2.6 */
1487    png_byte compression_type;
1488 
1489 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
1490    png_uint_32 user_width_max;
1491    png_uint_32 user_height_max;
1492 #endif
1493 
1494 /* New member added in libpng-1.0.25 and 1.2.17 */
1495 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
1496    /* Storage for unknown chunk that the library doesn't recognize. */
1497    png_unknown_chunk unknown_chunk;
1498 #endif
1499 
1500 /* New members added in libpng-1.2.26 */
1501   png_uint_32 old_big_row_buf_size, old_prev_row_size;
1502 
1503 /* New member added in libpng-1.2.30 */
1504   png_charp chunkdata;  /* buffer for reading chunk data */
1505 
1506 };
1507 
1508 
1509 /* This triggers a compiler error in png.c, if png.c and png.h
1510  * do not agree upon the version number.
1511  */
1512 typedef png_structp version_1_2_38;
1513 
1514 typedef png_struct FAR * FAR * png_structpp;
1515 
1516 /* Here are the function definitions most commonly used.  This is not
1517  * the place to find out how to use libpng.  See libpng.txt for the
1518  * full explanation, see example.c for the summary.  This just provides
1519  * a simple one line description of the use of each function.
1520  */
1521 
1522 /* Returns the version number of the library */
1523 extern PNG_EXPORT(png_uint_32,png_access_version_number) PNGARG((void));
1524 
1525 /* Tell lib we have already handled the first <num_bytes> magic bytes.
1526  * Handling more than 8 bytes from the beginning of the file is an error.
1527  */
1528 extern PNG_EXPORT(void,png_set_sig_bytes) PNGARG((png_structp png_ptr,
1529    int num_bytes));
1530 
1531 /* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
1532  * PNG file.  Returns zero if the supplied bytes match the 8-byte PNG
1533  * signature, and non-zero otherwise.  Having num_to_check == 0 or
1534  * start > 7 will always fail (ie return non-zero).
1535  */
1536 extern PNG_EXPORT(int,png_sig_cmp) PNGARG((png_bytep sig, png_size_t start,
1537    png_size_t num_to_check));
1538 
1539 /* Simple signature checking function.  This is the same as calling
1540  * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
1541  */
1542 extern PNG_EXPORT(int,png_check_sig) PNGARG((png_bytep sig, int num));
1543 
1544 /* Allocate and initialize png_ptr struct for reading, and any other memory. */
1545 extern PNG_EXPORT(png_structp,png_create_read_struct)
1546    PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1547    png_error_ptr error_fn, png_error_ptr warn_fn));
1548 
1549 /* Allocate and initialize png_ptr struct for writing, and any other memory */
1550 extern PNG_EXPORT(png_structp,png_create_write_struct)
1551    PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1552    png_error_ptr error_fn, png_error_ptr warn_fn));
1553 
1554 #ifdef PNG_WRITE_SUPPORTED
1555 extern PNG_EXPORT(png_uint_32,png_get_compression_buffer_size)
1556    PNGARG((png_structp png_ptr));
1557 #endif
1558 
1559 #ifdef PNG_WRITE_SUPPORTED
1560 extern PNG_EXPORT(void,png_set_compression_buffer_size)
1561    PNGARG((png_structp png_ptr, png_uint_32 size));
1562 #endif
1563 
1564 /* Reset the compression stream */
1565 extern PNG_EXPORT(int,png_reset_zstream) PNGARG((png_structp png_ptr));
1566 
1567 /* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
1568 #ifdef PNG_USER_MEM_SUPPORTED
1569 extern PNG_EXPORT(png_structp,png_create_read_struct_2)
1570    PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1571    png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1572    png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1573 extern PNG_EXPORT(png_structp,png_create_write_struct_2)
1574    PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1575    png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1576    png_malloc_ptr malloc_fn, png_free_ptr free_fn));
1577 #endif
1578 
1579 /* Write a PNG chunk - size, type, (optional) data, CRC. */
1580 extern PNG_EXPORT(void,png_write_chunk) PNGARG((png_structp png_ptr,
1581    png_bytep chunk_name, png_bytep data, png_size_t length));
1582 
1583 /* Write the start of a PNG chunk - length and chunk name. */
1584 extern PNG_EXPORT(void,png_write_chunk_start) PNGARG((png_structp png_ptr,
1585    png_bytep chunk_name, png_uint_32 length));
1586 
1587 /* Write the data of a PNG chunk started with png_write_chunk_start(). */
1588 extern PNG_EXPORT(void,png_write_chunk_data) PNGARG((png_structp png_ptr,
1589    png_bytep data, png_size_t length));
1590 
1591 /* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1592 extern PNG_EXPORT(void,png_write_chunk_end) PNGARG((png_structp png_ptr));
1593 
1594 /* Allocate and initialize the info structure */
1595 extern PNG_EXPORT(png_infop,png_create_info_struct)
1596    PNGARG((png_structp png_ptr));
1597 
1598 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1599 /* Initialize the info structure (old interface - DEPRECATED) */
1600 extern PNG_EXPORT(void,png_info_init) PNGARG((png_infop info_ptr));
1601 #undef png_info_init
1602 #define png_info_init(info_ptr) png_info_init_3(&info_ptr,\
1603     png_sizeof(png_info));
1604 #endif
1605 
1606 extern PNG_EXPORT(void,png_info_init_3) PNGARG((png_infopp info_ptr,
1607     png_size_t png_info_struct_size));
1608 
1609 /* Writes all the PNG information before the image. */
1610 extern PNG_EXPORT(void,png_write_info_before_PLTE) PNGARG((png_structp png_ptr,
1611    png_infop info_ptr));
1612 extern PNG_EXPORT(void,png_write_info) PNGARG((png_structp png_ptr,
1613    png_infop info_ptr));
1614 
1615 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1616 /* Read the information before the actual image data. */
1617 extern PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr,
1618    png_infop info_ptr));
1619 #endif
1620 
1621 #if defined(PNG_TIME_RFC1123_SUPPORTED)
1622 extern PNG_EXPORT(png_charp,png_convert_to_rfc1123)
1623    PNGARG((png_structp png_ptr, png_timep ptime));
1624 #endif
1625 
1626 #if !defined(_WIN32_WCE)
1627 /* "time.h" functions are not supported on WindowsCE */
1628 #if defined(PNG_WRITE_tIME_SUPPORTED)
1629 /* Convert from a struct tm to png_time */
1630 extern PNG_EXPORT(void,png_convert_from_struct_tm) PNGARG((png_timep ptime,
1631    struct tm FAR * ttime));
1632 
1633 /* Convert from time_t to png_time.  Uses gmtime() */
1634 extern PNG_EXPORT(void,png_convert_from_time_t) PNGARG((png_timep ptime,
1635    time_t ttime));
1636 #endif /* PNG_WRITE_tIME_SUPPORTED */
1637 #endif /* _WIN32_WCE */
1638 
1639 #if defined(PNG_READ_EXPAND_SUPPORTED)
1640 /* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1641 extern PNG_EXPORT(void,png_set_expand) PNGARG((png_structp png_ptr));
1642 #if !defined(PNG_1_0_X)
1643 extern PNG_EXPORT(void,png_set_expand_gray_1_2_4_to_8) PNGARG((png_structp
1644   png_ptr));
1645 #endif
1646 extern PNG_EXPORT(void,png_set_palette_to_rgb) PNGARG((png_structp png_ptr));
1647 extern PNG_EXPORT(void,png_set_tRNS_to_alpha) PNGARG((png_structp png_ptr));
1648 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1649 /* Deprecated */
1650 extern PNG_EXPORT(void,png_set_gray_1_2_4_to_8) PNGARG((png_structp png_ptr));
1651 #endif
1652 #endif
1653 
1654 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
1655 /* Use blue, green, red order for pixels. */
1656 extern PNG_EXPORT(void,png_set_bgr) PNGARG((png_structp png_ptr));
1657 #endif
1658 
1659 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
1660 /* Expand the grayscale to 24-bit RGB if necessary. */
1661 extern PNG_EXPORT(void,png_set_gray_to_rgb) PNGARG((png_structp png_ptr));
1662 #endif
1663 
1664 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
1665 /* Reduce RGB to grayscale. */
1666 #ifdef PNG_FLOATING_POINT_SUPPORTED
1667 extern PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr,
1668    int error_action, double red, double green ));
1669 #endif
1670 extern PNG_EXPORT(void,png_set_rgb_to_gray_fixed) PNGARG((png_structp png_ptr,
1671    int error_action, png_fixed_point red, png_fixed_point green ));
1672 extern PNG_EXPORT(png_byte,png_get_rgb_to_gray_status) PNGARG((png_structp
1673    png_ptr));
1674 #endif
1675 
1676 extern PNG_EXPORT(void,png_build_grayscale_palette) PNGARG((int bit_depth,
1677    png_colorp palette));
1678 
1679 #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
1680 extern PNG_EXPORT(void,png_set_strip_alpha) PNGARG((png_structp png_ptr));
1681 #endif
1682 
1683 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \
1684     defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1685 extern PNG_EXPORT(void,png_set_swap_alpha) PNGARG((png_structp png_ptr));
1686 #endif
1687 
1688 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
1689     defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1690 extern PNG_EXPORT(void,png_set_invert_alpha) PNGARG((png_structp png_ptr));
1691 #endif
1692 
1693 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
1694 /* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
1695 extern PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr,
1696    png_uint_32 filler, int flags));
1697 /* The values of the PNG_FILLER_ defines should NOT be changed */
1698 #define PNG_FILLER_BEFORE 0
1699 #define PNG_FILLER_AFTER 1
1700 /* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
1701 #if !defined(PNG_1_0_X)
1702 extern PNG_EXPORT(void,png_set_add_alpha) PNGARG((png_structp png_ptr,
1703    png_uint_32 filler, int flags));
1704 #endif
1705 #endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */
1706 
1707 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
1708 /* Swap bytes in 16-bit depth files. */
1709 extern PNG_EXPORT(void,png_set_swap) PNGARG((png_structp png_ptr));
1710 #endif
1711 
1712 #if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
1713 /* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1714 extern PNG_EXPORT(void,png_set_packing) PNGARG((png_structp png_ptr));
1715 #endif
1716 
1717 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1718 /* Swap packing order of pixels in bytes. */
1719 extern PNG_EXPORT(void,png_set_packswap) PNGARG((png_structp png_ptr));
1720 #endif
1721 
1722 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
1723 /* Converts files to legal bit depths. */
1724 extern PNG_EXPORT(void,png_set_shift) PNGARG((png_structp png_ptr,
1725    png_color_8p true_bits));
1726 #endif
1727 
1728 #if defined(PNG_READ_INTERLACING_SUPPORTED) || \
1729     defined(PNG_WRITE_INTERLACING_SUPPORTED)
1730 /* Have the code handle the interlacing.  Returns the number of passes. */
1731 extern PNG_EXPORT(int,png_set_interlace_handling) PNGARG((png_structp png_ptr));
1732 #endif
1733 
1734 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
1735 /* Invert monochrome files */
1736 extern PNG_EXPORT(void,png_set_invert_mono) PNGARG((png_structp png_ptr));
1737 #endif
1738 
1739 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
1740 /* Handle alpha and tRNS by replacing with a background color. */
1741 #ifdef PNG_FLOATING_POINT_SUPPORTED
1742 extern PNG_EXPORT(void,png_set_background) PNGARG((png_structp png_ptr,
1743    png_color_16p background_color, int background_gamma_code,
1744    int need_expand, double background_gamma));
1745 #endif
1746 #define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1747 #define PNG_BACKGROUND_GAMMA_SCREEN  1
1748 #define PNG_BACKGROUND_GAMMA_FILE    2
1749 #define PNG_BACKGROUND_GAMMA_UNIQUE  3
1750 #endif
1751 
1752 #if defined(PNG_READ_16_TO_8_SUPPORTED)
1753 /* Strip the second byte of information from a 16-bit depth file. */
1754 extern PNG_EXPORT(void,png_set_strip_16) PNGARG((png_structp png_ptr));
1755 #endif
1756 
1757 #if defined(PNG_READ_DITHER_SUPPORTED)
1758 /* Turn on dithering, and reduce the palette to the number of colors available. */
1759 extern PNG_EXPORT(void,png_set_dither) PNGARG((png_structp png_ptr,
1760    png_colorp palette, int num_palette, int maximum_colors,
1761    png_uint_16p histogram, int full_dither));
1762 #endif
1763 
1764 #if defined(PNG_READ_GAMMA_SUPPORTED)
1765 /* Handle gamma correction. Screen_gamma=(display_exponent) */
1766 #ifdef PNG_FLOATING_POINT_SUPPORTED
1767 extern PNG_EXPORT(void,png_set_gamma) PNGARG((png_structp png_ptr,
1768    double screen_gamma, double default_file_gamma));
1769 #endif
1770 #endif
1771 
1772 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
1773 #if defined(PNG_READ_EMPTY_PLTE_SUPPORTED) || \
1774     defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1775 /* Permit or disallow empty PLTE (0: not permitted, 1: permitted) */
1776 /* Deprecated and will be removed.  Use png_permit_mng_features() instead. */
1777 extern PNG_EXPORT(void,png_permit_empty_plte) PNGARG((png_structp png_ptr,
1778    int empty_plte_permitted));
1779 #endif
1780 #endif
1781 
1782 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
1783 /* Set how many lines between output flushes - 0 for no flushing */
1784 extern PNG_EXPORT(void,png_set_flush) PNGARG((png_structp png_ptr, int nrows));
1785 /* Flush the current PNG output buffer */
1786 extern PNG_EXPORT(void,png_write_flush) PNGARG((png_structp png_ptr));
1787 #endif
1788 
1789 /* Optional update palette with requested transformations */
1790 extern PNG_EXPORT(void,png_start_read_image) PNGARG((png_structp png_ptr));
1791 
1792 /* Optional call to update the users info structure */
1793 extern PNG_EXPORT(void,png_read_update_info) PNGARG((png_structp png_ptr,
1794    png_infop info_ptr));
1795 
1796 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1797 /* Read one or more rows of image data. */
1798 extern PNG_EXPORT(void,png_read_rows) PNGARG((png_structp png_ptr,
1799    png_bytepp row, png_bytepp display_row, png_uint_32 num_rows));
1800 #endif
1801 
1802 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1803 /* Read a row of data. */
1804 extern PNG_EXPORT(void,png_read_row) PNGARG((png_structp png_ptr,
1805    png_bytep row,
1806    png_bytep display_row));
1807 #endif
1808 
1809 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1810 /* Read the whole image into memory at once. */
1811 extern PNG_EXPORT(void,png_read_image) PNGARG((png_structp png_ptr,
1812    png_bytepp image));
1813 #endif
1814 
1815 /* Write a row of image data */
1816 extern PNG_EXPORT(void,png_write_row) PNGARG((png_structp png_ptr,
1817    png_bytep row));
1818 
1819 /* Write a few rows of image data */
1820 extern PNG_EXPORT(void,png_write_rows) PNGARG((png_structp png_ptr,
1821    png_bytepp row, png_uint_32 num_rows));
1822 
1823 /* Write the image data */
1824 extern PNG_EXPORT(void,png_write_image) PNGARG((png_structp png_ptr,
1825    png_bytepp image));
1826 
1827 /* Writes the end of the PNG file. */
1828 extern PNG_EXPORT(void,png_write_end) PNGARG((png_structp png_ptr,
1829    png_infop info_ptr));
1830 
1831 #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1832 /* Read the end of the PNG file. */
1833 extern PNG_EXPORT(void,png_read_end) PNGARG((png_structp png_ptr,
1834    png_infop info_ptr));
1835 #endif
1836 
1837 /* Free any memory associated with the png_info_struct */
1838 extern PNG_EXPORT(void,png_destroy_info_struct) PNGARG((png_structp png_ptr,
1839    png_infopp info_ptr_ptr));
1840 
1841 /* Free any memory associated with the png_struct and the png_info_structs */
1842 extern PNG_EXPORT(void,png_destroy_read_struct) PNGARG((png_structpp
1843    png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1844 
1845 /* Free all memory used by the read (old method - NOT DLL EXPORTED) */
1846 extern void png_read_destroy PNGARG((png_structp png_ptr, png_infop info_ptr,
1847    png_infop end_info_ptr));
1848 
1849 /* Free any memory associated with the png_struct and the png_info_structs */
1850 extern PNG_EXPORT(void,png_destroy_write_struct)
1851    PNGARG((png_structpp png_ptr_ptr, png_infopp info_ptr_ptr));
1852 
1853 /* Free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */
1854 extern void png_write_destroy PNGARG((png_structp png_ptr));
1855 
1856 /* Set the libpng method of handling chunk CRC errors */
1857 extern PNG_EXPORT(void,png_set_crc_action) PNGARG((png_structp png_ptr,
1858    int crit_action, int ancil_action));
1859 
1860 /* Values for png_set_crc_action() to say how to handle CRC errors in
1861  * ancillary and critical chunks, and whether to use the data contained
1862  * therein.  Note that it is impossible to "discard" data in a critical
1863  * chunk.  For versions prior to 0.90, the action was always error/quit,
1864  * whereas in version 0.90 and later, the action for CRC errors in ancillary
1865  * chunks is warn/discard.  These values should NOT be changed.
1866  *
1867  *      value                       action:critical     action:ancillary
1868  */
1869 #define PNG_CRC_DEFAULT       0  /* error/quit          warn/discard data */
1870 #define PNG_CRC_ERROR_QUIT    1  /* error/quit          error/quit        */
1871 #define PNG_CRC_WARN_DISCARD  2  /* (INVALID)           warn/discard data */
1872 #define PNG_CRC_WARN_USE      3  /* warn/use data       warn/use data     */
1873 #define PNG_CRC_QUIET_USE     4  /* quiet/use data      quiet/use data    */
1874 #define PNG_CRC_NO_CHANGE     5  /* use current value   use current value */
1875 
1876 /* These functions give the user control over the scan-line filtering in
1877  * libpng and the compression methods used by zlib.  These functions are
1878  * mainly useful for testing, as the defaults should work with most users.
1879  * Those users who are tight on memory or want faster performance at the
1880  * expense of compression can modify them.  See the compression library
1881  * header file (zlib.h) for an explination of the compression functions.
1882  */
1883 
1884 /* Set the filtering method(s) used by libpng.  Currently, the only valid
1885  * value for "method" is 0.
1886  */
1887 extern PNG_EXPORT(void,png_set_filter) PNGARG((png_structp png_ptr, int method,
1888    int filters));
1889 
1890 /* Flags for png_set_filter() to say which filters to use.  The flags
1891  * are chosen so that they don't conflict with real filter types
1892  * below, in case they are supplied instead of the #defined constants.
1893  * These values should NOT be changed.
1894  */
1895 #define PNG_NO_FILTERS     0x00
1896 #define PNG_FILTER_NONE    0x08
1897 #define PNG_FILTER_SUB     0x10
1898 #define PNG_FILTER_UP      0x20
1899 #define PNG_FILTER_AVG     0x40
1900 #define PNG_FILTER_PAETH   0x80
1901 #define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \
1902                          PNG_FILTER_AVG | PNG_FILTER_PAETH)
1903 
1904 /* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1905  * These defines should NOT be changed.
1906  */
1907 #define PNG_FILTER_VALUE_NONE  0
1908 #define PNG_FILTER_VALUE_SUB   1
1909 #define PNG_FILTER_VALUE_UP    2
1910 #define PNG_FILTER_VALUE_AVG   3
1911 #define PNG_FILTER_VALUE_PAETH 4
1912 #define PNG_FILTER_VALUE_LAST  5
1913 
1914 #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* EXPERIMENTAL */
1915 /* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
1916  * defines, either the default (minimum-sum-of-absolute-differences), or
1917  * the experimental method (weighted-minimum-sum-of-absolute-differences).
1918  *
1919  * Weights are factors >= 1.0, indicating how important it is to keep the
1920  * filter type consistent between rows.  Larger numbers mean the current
1921  * filter is that many times as likely to be the same as the "num_weights"
1922  * previous filters.  This is cumulative for each previous row with a weight.
1923  * There needs to be "num_weights" values in "filter_weights", or it can be
1924  * NULL if the weights aren't being specified.  Weights have no influence on
1925  * the selection of the first row filter.  Well chosen weights can (in theory)
1926  * improve the compression for a given image.
1927  *
1928  * Costs are factors >= 1.0 indicating the relative decoding costs of a
1929  * filter type.  Higher costs indicate more decoding expense, and are
1930  * therefore less likely to be selected over a filter with lower computational
1931  * costs.  There needs to be a value in "filter_costs" for each valid filter
1932  * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
1933  * setting the costs.  Costs try to improve the speed of decompression without
1934  * unduly increasing the compressed image size.
1935  *
1936  * A negative weight or cost indicates the default value is to be used, and
1937  * values in the range [0.0, 1.0) indicate the value is to remain unchanged.
1938  * The default values for both weights and costs are currently 1.0, but may
1939  * change if good general weighting/cost heuristics can be found.  If both
1940  * the weights and costs are set to 1.0, this degenerates the WEIGHTED method
1941  * to the UNWEIGHTED method, but with added encoding time/computation.
1942  */
1943 #ifdef PNG_FLOATING_POINT_SUPPORTED
1944 extern PNG_EXPORT(void,png_set_filter_heuristics) PNGARG((png_structp png_ptr,
1945    int heuristic_method, int num_weights, png_doublep filter_weights,
1946    png_doublep filter_costs));
1947 #endif
1948 #endif /*  PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1949 
1950 /* Heuristic used for row filter selection.  These defines should NOT be
1951  * changed.
1952  */
1953 #define PNG_FILTER_HEURISTIC_DEFAULT    0  /* Currently "UNWEIGHTED" */
1954 #define PNG_FILTER_HEURISTIC_UNWEIGHTED 1  /* Used by libpng < 0.95 */
1955 #define PNG_FILTER_HEURISTIC_WEIGHTED   2  /* Experimental feature */
1956 #define PNG_FILTER_HEURISTIC_LAST       3  /* Not a valid value */
1957 
1958 /* Set the library compression level.  Currently, valid values range from
1959  * 0 - 9, corresponding directly to the zlib compression levels 0 - 9
1960  * (0 - no compression, 9 - "maximal" compression).  Note that tests have
1961  * shown that zlib compression levels 3-6 usually perform as well as level 9
1962  * for PNG images, and do considerably fewer caclulations.  In the future,
1963  * these values may not correspond directly to the zlib compression levels.
1964  */
1965 extern PNG_EXPORT(void,png_set_compression_level) PNGARG((png_structp png_ptr,
1966    int level));
1967 
1968 extern PNG_EXPORT(void,png_set_compression_mem_level)
1969    PNGARG((png_structp png_ptr, int mem_level));
1970 
1971 extern PNG_EXPORT(void,png_set_compression_strategy)
1972    PNGARG((png_structp png_ptr, int strategy));
1973 
1974 extern PNG_EXPORT(void,png_set_compression_window_bits)
1975    PNGARG((png_structp png_ptr, int window_bits));
1976 
1977 extern PNG_EXPORT(void,png_set_compression_method) PNGARG((png_structp png_ptr,
1978    int method));
1979 
1980 /* These next functions are called for input/output, memory, and error
1981  * handling.  They are in the file pngrio.c, pngwio.c, and pngerror.c,
1982  * and call standard C I/O routines such as fread(), fwrite(), and
1983  * fprintf().  These functions can be made to use other I/O routines
1984  * at run time for those applications that need to handle I/O in a
1985  * different manner by calling png_set_???_fn().  See libpng.txt for
1986  * more information.
1987  */
1988 
1989 #if !defined(PNG_NO_STDIO)
1990 /* Initialize the input/output for the PNG file to the default functions. */
1991 extern PNG_EXPORT(void,png_init_io) PNGARG((png_structp png_ptr, png_FILE_p fp));
1992 #endif
1993 
1994 /* Replace the (error and abort), and warning functions with user
1995  * supplied functions.  If no messages are to be printed you must still
1996  * write and use replacement functions. The replacement error_fn should
1997  * still do a longjmp to the last setjmp location if you are using this
1998  * method of error handling.  If error_fn or warning_fn is NULL, the
1999  * default function will be used.
2000  */
2001 
2002 extern PNG_EXPORT(void,png_set_error_fn) PNGARG((png_structp png_ptr,
2003    png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
2004 
2005 /* Return the user pointer associated with the error functions */
2006 extern PNG_EXPORT(png_voidp,png_get_error_ptr) PNGARG((png_structp png_ptr));
2007 
2008 /* Replace the default data output functions with a user supplied one(s).
2009  * If buffered output is not used, then output_flush_fn can be set to NULL.
2010  * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
2011  * output_flush_fn will be ignored (and thus can be NULL).
2012  * It is probably a mistake to use NULL for output_flush_fn if
2013  * write_data_fn is not also NULL unless you have built libpng with
2014  * PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
2015  * default flush function, which uses the standard *FILE structure, will
2016  * be used.
2017  */
2018 extern PNG_EXPORT(void,png_set_write_fn) PNGARG((png_structp png_ptr,
2019    png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
2020 
2021 /* Replace the default data input function with a user supplied one. */
2022 extern PNG_EXPORT(void,png_set_read_fn) PNGARG((png_structp png_ptr,
2023    png_voidp io_ptr, png_rw_ptr read_data_fn));
2024 
2025 /* Return the user pointer associated with the I/O functions */
2026 extern PNG_EXPORT(png_voidp,png_get_io_ptr) PNGARG((png_structp png_ptr));
2027 
2028 extern PNG_EXPORT(void,png_set_read_status_fn) PNGARG((png_structp png_ptr,
2029    png_read_status_ptr read_row_fn));
2030 
2031 extern PNG_EXPORT(void,png_set_write_status_fn) PNGARG((png_structp png_ptr,
2032    png_write_status_ptr write_row_fn));
2033 
2034 #ifdef PNG_USER_MEM_SUPPORTED
2035 /* Replace the default memory allocation functions with user supplied one(s). */
2036 extern PNG_EXPORT(void,png_set_mem_fn) PNGARG((png_structp png_ptr,
2037    png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn));
2038 /* Return the user pointer associated with the memory functions */
2039 extern PNG_EXPORT(png_voidp,png_get_mem_ptr) PNGARG((png_structp png_ptr));
2040 #endif
2041 
2042 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
2043     defined(PNG_LEGACY_SUPPORTED)
2044 extern PNG_EXPORT(void,png_set_read_user_transform_fn) PNGARG((png_structp
2045    png_ptr, png_user_transform_ptr read_user_transform_fn));
2046 #endif
2047 
2048 #if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
2049     defined(PNG_LEGACY_SUPPORTED)
2050 extern PNG_EXPORT(void,png_set_write_user_transform_fn) PNGARG((png_structp
2051    png_ptr, png_user_transform_ptr write_user_transform_fn));
2052 #endif
2053 
2054 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
2055     defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
2056     defined(PNG_LEGACY_SUPPORTED)
2057 extern PNG_EXPORT(void,png_set_user_transform_info) PNGARG((png_structp
2058    png_ptr, png_voidp user_transform_ptr, int user_transform_depth,
2059    int user_transform_channels));
2060 /* Return the user pointer associated with the user transform functions */
2061 extern PNG_EXPORT(png_voidp,png_get_user_transform_ptr)
2062    PNGARG((png_structp png_ptr));
2063 #endif
2064 
2065 #ifdef PNG_USER_CHUNKS_SUPPORTED
2066 extern PNG_EXPORT(void,png_set_read_user_chunk_fn) PNGARG((png_structp png_ptr,
2067    png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
2068 extern PNG_EXPORT(png_voidp,png_get_user_chunk_ptr) PNGARG((png_structp
2069    png_ptr));
2070 #endif
2071 
2072 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
2073 /* Sets the function callbacks for the push reader, and a pointer to a
2074  * user-defined structure available to the callback functions.
2075  */
2076 extern PNG_EXPORT(void,png_set_progressive_read_fn) PNGARG((png_structp png_ptr,
2077    png_voidp progressive_ptr,
2078    png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
2079    png_progressive_end_ptr end_fn));
2080 
2081 /* Returns the user pointer associated with the push read functions */
2082 extern PNG_EXPORT(png_voidp,png_get_progressive_ptr)
2083    PNGARG((png_structp png_ptr));
2084 
2085 /* Function to be called when data becomes available */
2086 extern PNG_EXPORT(void,png_process_data) PNGARG((png_structp png_ptr,
2087    png_infop info_ptr, png_bytep buffer, png_size_t buffer_size));
2088 
2089 /* function that combines rows.  Not very much different than the
2090  * png_combine_row() call.  Is this even used?????
2091  */
2092 extern PNG_EXPORT(void,png_progressive_combine_row) PNGARG((png_structp png_ptr,
2093    png_bytep old_row, png_bytep new_row));
2094 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
2095 
2096 extern PNG_EXPORT(png_voidp,png_malloc) PNGARG((png_structp png_ptr,
2097    png_uint_32 size));
2098 
2099 #if defined(PNG_1_0_X)
2100 #  define png_malloc_warn png_malloc
2101 #else
2102 /* Added at libpng version 1.2.4 */
2103 extern PNG_EXPORT(png_voidp,png_malloc_warn) PNGARG((png_structp png_ptr,
2104    png_uint_32 size));
2105 #endif
2106 
2107 /* Frees a pointer allocated by png_malloc() */
2108 extern PNG_EXPORT(void,png_free) PNGARG((png_structp png_ptr, png_voidp ptr));
2109 
2110 #if defined(PNG_1_0_X)
2111 /* Function to allocate memory for zlib. */
2112 extern PNG_EXPORT(voidpf,png_zalloc) PNGARG((voidpf png_ptr, uInt items,
2113    uInt size));
2114 
2115 /* Function to free memory for zlib */
2116 extern PNG_EXPORT(void,png_zfree) PNGARG((voidpf png_ptr, voidpf ptr));
2117 #endif
2118 
2119 /* Free data that was allocated internally */
2120 extern PNG_EXPORT(void,png_free_data) PNGARG((png_structp png_ptr,
2121    png_infop info_ptr, png_uint_32 free_me, int num));
2122 #ifdef PNG_FREE_ME_SUPPORTED
2123 /* Reassign responsibility for freeing existing data, whether allocated
2124  * by libpng or by the application
2125  */
2126 extern PNG_EXPORT(void,png_data_freer) PNGARG((png_structp png_ptr,
2127    png_infop info_ptr, int freer, png_uint_32 mask));
2128 #endif
2129 /* Assignments for png_data_freer */
2130 #define PNG_DESTROY_WILL_FREE_DATA 1
2131 #define PNG_SET_WILL_FREE_DATA 1
2132 #define PNG_USER_WILL_FREE_DATA 2
2133 /* Flags for png_ptr->free_me and info_ptr->free_me */
2134 #define PNG_FREE_HIST 0x0008
2135 #define PNG_FREE_ICCP 0x0010
2136 #define PNG_FREE_SPLT 0x0020
2137 #define PNG_FREE_ROWS 0x0040
2138 #define PNG_FREE_PCAL 0x0080
2139 #define PNG_FREE_SCAL 0x0100
2140 #define PNG_FREE_UNKN 0x0200
2141 #define PNG_FREE_LIST 0x0400
2142 #define PNG_FREE_PLTE 0x1000
2143 #define PNG_FREE_TRNS 0x2000
2144 #define PNG_FREE_TEXT 0x4000
2145 #define PNG_FREE_ALL  0x7fff
2146 #define PNG_FREE_MUL  0x4220 /* PNG_FREE_SPLT|PNG_FREE_TEXT|PNG_FREE_UNKN */
2147 
2148 #ifdef PNG_USER_MEM_SUPPORTED
2149 extern PNG_EXPORT(png_voidp,png_malloc_default) PNGARG((png_structp png_ptr,
2150    png_uint_32 size));
2151 extern PNG_EXPORT(void,png_free_default) PNGARG((png_structp png_ptr,
2152    png_voidp ptr));
2153 #endif
2154 
2155 extern PNG_EXPORT(png_voidp,png_memcpy_check) PNGARG((png_structp png_ptr,
2156    png_voidp s1, png_voidp s2, png_uint_32 size));
2157 
2158 extern PNG_EXPORT(png_voidp,png_memset_check) PNGARG((png_structp png_ptr,
2159    png_voidp s1, int value, png_uint_32 size));
2160 
2161 #if defined(USE_FAR_KEYWORD)  /* memory model conversion function */
2162 extern void *png_far_to_near PNGARG((png_structp png_ptr,png_voidp ptr,
2163    int check));
2164 #endif /* USE_FAR_KEYWORD */
2165 
2166 #ifndef PNG_NO_ERROR_TEXT
2167 /* Fatal error in PNG image of libpng - can't continue */
2168 extern PNG_EXPORT(void,png_error) PNGARG((png_structp png_ptr,
2169    png_const_charp error_message));
2170 
2171 /* The same, but the chunk name is prepended to the error string. */
2172 extern PNG_EXPORT(void,png_chunk_error) PNGARG((png_structp png_ptr,
2173    png_const_charp error_message));
2174 #else
2175 /* Fatal error in PNG image of libpng - can't continue */
2176 extern PNG_EXPORT(void,png_err) PNGARG((png_structp png_ptr));
2177 #endif
2178 
2179 #ifndef PNG_NO_WARNINGS
2180 /* Non-fatal error in libpng.  Can continue, but may have a problem. */
2181 extern PNG_EXPORT(void,png_warning) PNGARG((png_structp png_ptr,
2182    png_const_charp warning_message));
2183 
2184 #ifdef PNG_READ_SUPPORTED
2185 /* Non-fatal error in libpng, chunk name is prepended to message. */
2186 extern PNG_EXPORT(void,png_chunk_warning) PNGARG((png_structp png_ptr,
2187    png_const_charp warning_message));
2188 #endif /* PNG_READ_SUPPORTED */
2189 #endif /* PNG_NO_WARNINGS */
2190 
2191 /* The png_set_<chunk> functions are for storing values in the png_info_struct.
2192  * Similarly, the png_get_<chunk> calls are used to read values from the
2193  * png_info_struct, either storing the parameters in the passed variables, or
2194  * setting pointers into the png_info_struct where the data is stored.  The
2195  * png_get_<chunk> functions return a non-zero value if the data was available
2196  * in info_ptr, or return zero and do not change any of the parameters if the
2197  * data was not available.
2198  *
2199  * These functions should be used instead of directly accessing png_info
2200  * to avoid problems with future changes in the size and internal layout of
2201  * png_info_struct.
2202  */
2203 /* Returns "flag" if chunk data is valid in info_ptr. */
2204 extern PNG_EXPORT(png_uint_32,png_get_valid) PNGARG((png_structp png_ptr,
2205 png_infop info_ptr, png_uint_32 flag));
2206 
2207 /* Returns number of bytes needed to hold a transformed row. */
2208 extern PNG_EXPORT(png_uint_32,png_get_rowbytes) PNGARG((png_structp png_ptr,
2209 png_infop info_ptr));
2210 
2211 #if defined(PNG_INFO_IMAGE_SUPPORTED)
2212 /* Returns row_pointers, which is an array of pointers to scanlines that was
2213  * returned from png_read_png().
2214  */
2215 extern PNG_EXPORT(png_bytepp,png_get_rows) PNGARG((png_structp png_ptr,
2216 png_infop info_ptr));
2217 /* Set row_pointers, which is an array of pointers to scanlines for use
2218  * by png_write_png().
2219  */
2220 extern PNG_EXPORT(void,png_set_rows) PNGARG((png_structp png_ptr,
2221    png_infop info_ptr, png_bytepp row_pointers));
2222 #endif
2223 
2224 /* Returns number of color channels in image. */
2225 extern PNG_EXPORT(png_byte,png_get_channels) PNGARG((png_structp png_ptr,
2226 png_infop info_ptr));
2227 
2228 #ifdef PNG_EASY_ACCESS_SUPPORTED
2229 /* Returns image width in pixels. */
2230 extern PNG_EXPORT(png_uint_32, png_get_image_width) PNGARG((png_structp
2231 png_ptr, png_infop info_ptr));
2232 
2233 /* Returns image height in pixels. */
2234 extern PNG_EXPORT(png_uint_32, png_get_image_height) PNGARG((png_structp
2235 png_ptr, png_infop info_ptr));
2236 
2237 /* Returns image bit_depth. */
2238 extern PNG_EXPORT(png_byte, png_get_bit_depth) PNGARG((png_structp
2239 png_ptr, png_infop info_ptr));
2240 
2241 /* Returns image color_type. */
2242 extern PNG_EXPORT(png_byte, png_get_color_type) PNGARG((png_structp
2243 png_ptr, png_infop info_ptr));
2244 
2245 /* Returns image filter_type. */
2246 extern PNG_EXPORT(png_byte, png_get_filter_type) PNGARG((png_structp
2247 png_ptr, png_infop info_ptr));
2248 
2249 /* Returns image interlace_type. */
2250 extern PNG_EXPORT(png_byte, png_get_interlace_type) PNGARG((png_structp
2251 png_ptr, png_infop info_ptr));
2252 
2253 /* Returns image compression_type. */
2254 extern PNG_EXPORT(png_byte, png_get_compression_type) PNGARG((png_structp
2255 png_ptr, png_infop info_ptr));
2256 
2257 /* Returns image resolution in pixels per meter, from pHYs chunk data. */
2258 extern PNG_EXPORT(png_uint_32, png_get_pixels_per_meter) PNGARG((png_structp
2259 png_ptr, png_infop info_ptr));
2260 extern PNG_EXPORT(png_uint_32, png_get_x_pixels_per_meter) PNGARG((png_structp
2261 png_ptr, png_infop info_ptr));
2262 extern PNG_EXPORT(png_uint_32, png_get_y_pixels_per_meter) PNGARG((png_structp
2263 png_ptr, png_infop info_ptr));
2264 
2265 /* Returns pixel aspect ratio, computed from pHYs chunk data.  */
2266 #ifdef PNG_FLOATING_POINT_SUPPORTED
2267 extern PNG_EXPORT(float, png_get_pixel_aspect_ratio) PNGARG((png_structp
2268 png_ptr, png_infop info_ptr));
2269 #endif
2270 
2271 /* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
2272 extern PNG_EXPORT(png_int_32, png_get_x_offset_pixels) PNGARG((png_structp
2273 png_ptr, png_infop info_ptr));
2274 extern PNG_EXPORT(png_int_32, png_get_y_offset_pixels) PNGARG((png_structp
2275 png_ptr, png_infop info_ptr));
2276 extern PNG_EXPORT(png_int_32, png_get_x_offset_microns) PNGARG((png_structp
2277 png_ptr, png_infop info_ptr));
2278 extern PNG_EXPORT(png_int_32, png_get_y_offset_microns) PNGARG((png_structp
2279 png_ptr, png_infop info_ptr));
2280 
2281 #endif /* PNG_EASY_ACCESS_SUPPORTED */
2282 
2283 /* Returns pointer to signature string read from PNG header */
2284 extern PNG_EXPORT(png_bytep,png_get_signature) PNGARG((png_structp png_ptr,
2285 png_infop info_ptr));
2286 
2287 #if defined(PNG_bKGD_SUPPORTED)
2288 extern PNG_EXPORT(png_uint_32,png_get_bKGD) PNGARG((png_structp png_ptr,
2289    png_infop info_ptr, png_color_16p *background));
2290 #endif
2291 
2292 #if defined(PNG_bKGD_SUPPORTED)
2293 extern PNG_EXPORT(void,png_set_bKGD) PNGARG((png_structp png_ptr,
2294    png_infop info_ptr, png_color_16p background));
2295 #endif
2296 
2297 #if defined(PNG_cHRM_SUPPORTED)
2298 #ifdef PNG_FLOATING_POINT_SUPPORTED
2299 extern PNG_EXPORT(png_uint_32,png_get_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,
2302    double *blue_y));
2303 #endif
2304 #ifdef PNG_FIXED_POINT_SUPPORTED
2305 extern PNG_EXPORT(png_uint_32,png_get_cHRM_fixed) PNGARG((png_structp png_ptr,
2306    png_infop info_ptr, png_fixed_point *int_white_x, png_fixed_point
2307    *int_white_y, png_fixed_point *int_red_x, png_fixed_point *int_red_y,
2308    png_fixed_point *int_green_x, png_fixed_point *int_green_y, png_fixed_point
2309    *int_blue_x, png_fixed_point *int_blue_y));
2310 #endif
2311 #endif
2312 
2313 #if defined(PNG_cHRM_SUPPORTED)
2314 #ifdef PNG_FLOATING_POINT_SUPPORTED
2315 extern PNG_EXPORT(void,png_set_cHRM) PNGARG((png_structp png_ptr,
2316    png_infop info_ptr, double white_x, double white_y, double red_x,
2317    double red_y, double green_x, double green_y, double blue_x, double blue_y));
2318 #endif
2319 #ifdef PNG_FIXED_POINT_SUPPORTED
2320 extern PNG_EXPORT(void,png_set_cHRM_fixed) PNGARG((png_structp png_ptr,
2321    png_infop info_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y,
2322    png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
2323    int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
2324    png_fixed_point int_blue_y));
2325 #endif
2326 #endif
2327 
2328 #if defined(PNG_gAMA_SUPPORTED)
2329 #ifdef PNG_FLOATING_POINT_SUPPORTED
2330 extern PNG_EXPORT(png_uint_32,png_get_gAMA) PNGARG((png_structp png_ptr,
2331    png_infop info_ptr, double *file_gamma));
2332 #endif
2333 extern PNG_EXPORT(png_uint_32,png_get_gAMA_fixed) PNGARG((png_structp png_ptr,
2334    png_infop info_ptr, png_fixed_point *int_file_gamma));
2335 #endif
2336 
2337 #if defined(PNG_gAMA_SUPPORTED)
2338 #ifdef PNG_FLOATING_POINT_SUPPORTED
2339 extern PNG_EXPORT(void,png_set_gAMA) PNGARG((png_structp png_ptr,
2340    png_infop info_ptr, double file_gamma));
2341 #endif
2342 extern PNG_EXPORT(void,png_set_gAMA_fixed) PNGARG((png_structp png_ptr,
2343    png_infop info_ptr, png_fixed_point int_file_gamma));
2344 #endif
2345 
2346 #if defined(PNG_hIST_SUPPORTED)
2347 extern PNG_EXPORT(png_uint_32,png_get_hIST) PNGARG((png_structp png_ptr,
2348    png_infop info_ptr, png_uint_16p *hist));
2349 #endif
2350 
2351 #if defined(PNG_hIST_SUPPORTED)
2352 extern PNG_EXPORT(void,png_set_hIST) PNGARG((png_structp png_ptr,
2353    png_infop info_ptr, png_uint_16p hist));
2354 #endif
2355 
2356 extern PNG_EXPORT(png_uint_32,png_get_IHDR) PNGARG((png_structp png_ptr,
2357    png_infop info_ptr, png_uint_32 *width, png_uint_32 *height,
2358    int *bit_depth, int *color_type, int *interlace_method,
2359    int *compression_method, int *filter_method));
2360 
2361 extern PNG_EXPORT(void,png_set_IHDR) PNGARG((png_structp png_ptr,
2362    png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
2363    int color_type, int interlace_method, int compression_method,
2364    int filter_method));
2365 
2366 #if defined(PNG_oFFs_SUPPORTED)
2367 extern PNG_EXPORT(png_uint_32,png_get_oFFs) PNGARG((png_structp png_ptr,
2368    png_infop info_ptr, png_int_32 *offset_x, png_int_32 *offset_y,
2369    int *unit_type));
2370 #endif
2371 
2372 #if defined(PNG_oFFs_SUPPORTED)
2373 extern PNG_EXPORT(void,png_set_oFFs) PNGARG((png_structp png_ptr,
2374    png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2375    int unit_type));
2376 #endif
2377 
2378 #if defined(PNG_pCAL_SUPPORTED)
2379 extern PNG_EXPORT(png_uint_32,png_get_pCAL) PNGARG((png_structp png_ptr,
2380    png_infop info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1,
2381    int *type, int *nparams, png_charp *units, png_charpp *params));
2382 #endif
2383 
2384 #if defined(PNG_pCAL_SUPPORTED)
2385 extern PNG_EXPORT(void,png_set_pCAL) PNGARG((png_structp png_ptr,
2386    png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1,
2387    int type, int nparams, png_charp units, png_charpp params));
2388 #endif
2389 
2390 #if defined(PNG_pHYs_SUPPORTED)
2391 extern PNG_EXPORT(png_uint_32,png_get_pHYs) PNGARG((png_structp png_ptr,
2392    png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
2393 #endif
2394 
2395 #if defined(PNG_pHYs_SUPPORTED)
2396 extern PNG_EXPORT(void,png_set_pHYs) PNGARG((png_structp png_ptr,
2397    png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2398 #endif
2399 
2400 extern PNG_EXPORT(png_uint_32,png_get_PLTE) PNGARG((png_structp png_ptr,
2401    png_infop info_ptr, png_colorp *palette, int *num_palette));
2402 
2403 extern PNG_EXPORT(void,png_set_PLTE) PNGARG((png_structp png_ptr,
2404    png_infop info_ptr, png_colorp palette, int num_palette));
2405 
2406 #if defined(PNG_sBIT_SUPPORTED)
2407 extern PNG_EXPORT(png_uint_32,png_get_sBIT) PNGARG((png_structp png_ptr,
2408    png_infop info_ptr, png_color_8p *sig_bit));
2409 #endif
2410 
2411 #if defined(PNG_sBIT_SUPPORTED)
2412 extern PNG_EXPORT(void,png_set_sBIT) PNGARG((png_structp png_ptr,
2413    png_infop info_ptr, png_color_8p sig_bit));
2414 #endif
2415 
2416 #if defined(PNG_sRGB_SUPPORTED)
2417 extern PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr,
2418    png_infop info_ptr, int *intent));
2419 #endif
2420 
2421 #if defined(PNG_sRGB_SUPPORTED)
2422 extern PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr,
2423    png_infop info_ptr, int intent));
2424 extern PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr,
2425    png_infop info_ptr, int intent));
2426 #endif
2427 
2428 #if defined(PNG_iCCP_SUPPORTED)
2429 extern PNG_EXPORT(png_uint_32,png_get_iCCP) PNGARG((png_structp png_ptr,
2430    png_infop info_ptr, png_charpp name, int *compression_type,
2431    png_charpp profile, png_uint_32 *proflen));
2432    /* Note to maintainer: profile should be png_bytepp */
2433 #endif
2434 
2435 #if defined(PNG_iCCP_SUPPORTED)
2436 extern PNG_EXPORT(void,png_set_iCCP) PNGARG((png_structp png_ptr,
2437    png_infop info_ptr, png_charp name, int compression_type,
2438    png_charp profile, png_uint_32 proflen));
2439    /* Note to maintainer: profile should be png_bytep */
2440 #endif
2441 
2442 #if defined(PNG_sPLT_SUPPORTED)
2443 extern PNG_EXPORT(png_uint_32,png_get_sPLT) PNGARG((png_structp png_ptr,
2444    png_infop info_ptr, png_sPLT_tpp entries));
2445 #endif
2446 
2447 #if defined(PNG_sPLT_SUPPORTED)
2448 extern PNG_EXPORT(void,png_set_sPLT) PNGARG((png_structp png_ptr,
2449    png_infop info_ptr, png_sPLT_tp entries, int nentries));
2450 #endif
2451 
2452 #if defined(PNG_TEXT_SUPPORTED)
2453 /* png_get_text also returns the number of text chunks in *num_text */
2454 extern PNG_EXPORT(png_uint_32,png_get_text) PNGARG((png_structp png_ptr,
2455    png_infop info_ptr, png_textp *text_ptr, int *num_text));
2456 #endif
2457 
2458 /*
2459  *  Note while png_set_text() will accept a structure whose text,
2460  *  language, and  translated keywords are NULL pointers, the structure
2461  *  returned by png_get_text will always contain regular
2462  *  zero-terminated C strings.  They might be empty strings but
2463  *  they will never be NULL pointers.
2464  */
2465 
2466 #if defined(PNG_TEXT_SUPPORTED)
2467 extern PNG_EXPORT(void,png_set_text) PNGARG((png_structp png_ptr,
2468    png_infop info_ptr, png_textp text_ptr, int num_text));
2469 #endif
2470 
2471 #if defined(PNG_tIME_SUPPORTED)
2472 extern PNG_EXPORT(png_uint_32,png_get_tIME) PNGARG((png_structp png_ptr,
2473    png_infop info_ptr, png_timep *mod_time));
2474 #endif
2475 
2476 #if defined(PNG_tIME_SUPPORTED)
2477 extern PNG_EXPORT(void,png_set_tIME) PNGARG((png_structp png_ptr,
2478    png_infop info_ptr, png_timep mod_time));
2479 #endif
2480 
2481 #if defined(PNG_tRNS_SUPPORTED)
2482 extern PNG_EXPORT(png_uint_32,png_get_tRNS) PNGARG((png_structp png_ptr,
2483    png_infop info_ptr, png_bytep *trans, int *num_trans,
2484    png_color_16p *trans_values));
2485 #endif
2486 
2487 #if defined(PNG_tRNS_SUPPORTED)
2488 extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
2489    png_infop info_ptr, png_bytep trans, int num_trans,
2490    png_color_16p trans_values));
2491 #endif
2492 
2493 #if defined(PNG_tRNS_SUPPORTED)
2494 #endif
2495 
2496 #if defined(PNG_sCAL_SUPPORTED)
2497 #ifdef PNG_FLOATING_POINT_SUPPORTED
2498 extern PNG_EXPORT(png_uint_32,png_get_sCAL) PNGARG((png_structp png_ptr,
2499    png_infop info_ptr, int *unit, double *width, double *height));
2500 #else
2501 #ifdef PNG_FIXED_POINT_SUPPORTED
2502 extern PNG_EXPORT(png_uint_32,png_get_sCAL_s) PNGARG((png_structp png_ptr,
2503    png_infop info_ptr, int *unit, png_charpp swidth, png_charpp sheight));
2504 #endif
2505 #endif
2506 #endif /* PNG_sCAL_SUPPORTED */
2507 
2508 #if defined(PNG_sCAL_SUPPORTED)
2509 #ifdef PNG_FLOATING_POINT_SUPPORTED
2510 extern PNG_EXPORT(void,png_set_sCAL) PNGARG((png_structp png_ptr,
2511    png_infop info_ptr, int unit, double width, double height));
2512 #else
2513 #ifdef PNG_FIXED_POINT_SUPPORTED
2514 extern PNG_EXPORT(void,png_set_sCAL_s) PNGARG((png_structp png_ptr,
2515    png_infop info_ptr, int unit, png_charp swidth, png_charp sheight));
2516 #endif
2517 #endif
2518 #endif /* PNG_sCAL_SUPPORTED || PNG_WRITE_sCAL_SUPPORTED */
2519 
2520 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2521 /* Provide a list of chunks and how they are to be handled, if the built-in
2522    handling or default unknown chunk handling is not desired.  Any chunks not
2523    listed will be handled in the default manner.  The IHDR and IEND chunks
2524    must not be listed.
2525       keep = 0: follow default behaviour
2526            = 1: do not keep
2527            = 2: keep only if safe-to-copy
2528            = 3: keep even if unsafe-to-copy
2529 */
2530 extern PNG_EXPORT(void, png_set_keep_unknown_chunks) PNGARG((png_structp
2531    png_ptr, int keep, png_bytep chunk_list, int num_chunks));
2532 PNG_EXPORT(int,png_handle_as_unknown) PNGARG((png_structp png_ptr, png_bytep
2533    chunk_name));
2534 #endif
2535 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
2536 extern PNG_EXPORT(void, png_set_unknown_chunks) PNGARG((png_structp png_ptr,
2537    png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns));
2538 extern PNG_EXPORT(void, png_set_unknown_chunk_location)
2539    PNGARG((png_structp png_ptr, png_infop info_ptr, int chunk, int location));
2540 extern PNG_EXPORT(png_uint_32,png_get_unknown_chunks) PNGARG((png_structp
2541    png_ptr, png_infop info_ptr, png_unknown_chunkpp entries));
2542 #endif
2543 
2544 /* Png_free_data() will turn off the "valid" flag for anything it frees.
2545  * If you need to turn it off for a chunk that your application has freed,
2546  * you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
2547  */
2548 extern PNG_EXPORT(void, png_set_invalid) PNGARG((png_structp png_ptr,
2549    png_infop info_ptr, int mask));
2550 
2551 #if defined(PNG_INFO_IMAGE_SUPPORTED)
2552 /* The "params" pointer is currently not used and is for future expansion. */
2553 extern PNG_EXPORT(void, png_read_png) PNGARG((png_structp png_ptr,
2554                         png_infop info_ptr,
2555                         int transforms,
2556                         png_voidp params));
2557 extern PNG_EXPORT(void, png_write_png) PNGARG((png_structp png_ptr,
2558                         png_infop info_ptr,
2559                         int transforms,
2560                         png_voidp params));
2561 #endif
2562 
2563 /* Define PNG_DEBUG at compile time for debugging information.  Higher
2564  * numbers for PNG_DEBUG mean more debugging information.  This has
2565  * only been added since version 0.95 so it is not implemented throughout
2566  * libpng yet, but more support will be added as needed.
2567  */
2568 #ifdef PNG_DEBUG
2569 #if (PNG_DEBUG > 0)
2570 #if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER)
2571 #include <crtdbg.h>
2572 #if (PNG_DEBUG > 1)
2573 #ifndef _DEBUG
2574 #  define _DEBUG
2575 #endif
2576 #ifndef png_debug
2577 #define png_debug(l,m)  _RPT0(_CRT_WARN,m PNG_STRING_NEWLINE)
2578 #endif
2579 #ifndef png_debug1
2580 #define png_debug1(l,m,p1)  _RPT1(_CRT_WARN,m PNG_STRING_NEWLINE,p1)
2581 #endif
2582 #ifndef png_debug2
2583 #define png_debug2(l,m,p1,p2) _RPT2(_CRT_WARN,m PNG_STRING_NEWLINE,p1,p2)
2584 #endif
2585 #endif
2586 #else /* PNG_DEBUG_FILE || !_MSC_VER */
2587 #ifndef PNG_DEBUG_FILE
2588 #define PNG_DEBUG_FILE stderr
2589 #endif /* PNG_DEBUG_FILE */
2590 
2591 #if (PNG_DEBUG > 1)
2592 /* Note: ["%s"m PNG_STRING_NEWLINE] probably does not work on non-ISO
2593  * compilers.
2594  */
2595 #  ifdef __STDC__
2596 #    ifndef png_debug
2597 #      define png_debug(l,m) \
2598        { \
2599        int num_tabs=l; \
2600        fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
2601          (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":"")))); \
2602        }
2603 #    endif
2604 #    ifndef png_debug1
2605 #      define png_debug1(l,m,p1) \
2606        { \
2607        int num_tabs=l; \
2608        fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
2609          (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1); \
2610        }
2611 #    endif
2612 #    ifndef png_debug2
2613 #      define png_debug2(l,m,p1,p2) \
2614        { \
2615        int num_tabs=l; \
2616        fprintf(PNG_DEBUG_FILE,"%s"m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
2617          (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1,p2); \
2618        }
2619 #    endif
2620 #  else /* __STDC __ */
2621 #    ifndef png_debug
2622 #      define png_debug(l,m) \
2623        { \
2624        int num_tabs=l; \
2625        char format[256]; \
2626        snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
2627          (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
2628          m,PNG_STRING_NEWLINE); \
2629        fprintf(PNG_DEBUG_FILE,format); \
2630        }
2631 #    endif
2632 #    ifndef png_debug1
2633 #      define png_debug1(l,m,p1) \
2634        { \
2635        int num_tabs=l; \
2636        char format[256]; \
2637        snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
2638          (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
2639          m,PNG_STRING_NEWLINE); \
2640        fprintf(PNG_DEBUG_FILE,format,p1); \
2641        }
2642 #    endif
2643 #    ifndef png_debug2
2644 #      define png_debug2(l,m,p1,p2) \
2645        { \
2646        int num_tabs=l; \
2647        char format[256]; \
2648        snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
2649          (num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
2650          m,PNG_STRING_NEWLINE); \
2651        fprintf(PNG_DEBUG_FILE,format,p1,p2); \
2652        }
2653 #    endif
2654 #  endif /* __STDC __ */
2655 #endif /* (PNG_DEBUG > 1) */
2656 
2657 #endif /* _MSC_VER */
2658 #endif /* (PNG_DEBUG > 0) */
2659 #endif /* PNG_DEBUG */
2660 #ifndef png_debug
2661 #define png_debug(l, m)
2662 #endif
2663 #ifndef png_debug1
2664 #define png_debug1(l, m, p1)
2665 #endif
2666 #ifndef png_debug2
2667 #define png_debug2(l, m, p1, p2)
2668 #endif
2669 
2670 extern PNG_EXPORT(png_charp,png_get_copyright) PNGARG((png_structp png_ptr));
2671 extern PNG_EXPORT(png_charp,png_get_header_ver) PNGARG((png_structp png_ptr));
2672 extern PNG_EXPORT(png_charp,png_get_header_version) PNGARG((png_structp png_ptr));
2673 extern PNG_EXPORT(png_charp,png_get_libpng_ver) PNGARG((png_structp png_ptr));
2674 
2675 #ifdef PNG_MNG_FEATURES_SUPPORTED
2676 extern PNG_EXPORT(png_uint_32,png_permit_mng_features) PNGARG((png_structp
2677    png_ptr, png_uint_32 mng_features_permitted));
2678 #endif
2679 
2680 /* For use in png_set_keep_unknown, added to version 1.2.6 */
2681 #define PNG_HANDLE_CHUNK_AS_DEFAULT   0
2682 #define PNG_HANDLE_CHUNK_NEVER        1
2683 #define PNG_HANDLE_CHUNK_IF_SAFE      2
2684 #define PNG_HANDLE_CHUNK_ALWAYS       3
2685 
2686 /* Added to version 1.2.0 */
2687 #if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
2688 #if defined(PNG_MMX_CODE_SUPPORTED)
2689 #define PNG_ASM_FLAG_MMX_SUPPORT_COMPILED  0x01  /* not user-settable */
2690 #define PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU    0x02  /* not user-settable */
2691 #define PNG_ASM_FLAG_MMX_READ_COMBINE_ROW  0x04
2692 #define PNG_ASM_FLAG_MMX_READ_INTERLACE    0x08
2693 #define PNG_ASM_FLAG_MMX_READ_FILTER_SUB   0x10
2694 #define PNG_ASM_FLAG_MMX_READ_FILTER_UP    0x20
2695 #define PNG_ASM_FLAG_MMX_READ_FILTER_AVG   0x40
2696 #define PNG_ASM_FLAG_MMX_READ_FILTER_PAETH 0x80
2697 #define PNG_ASM_FLAGS_INITIALIZED          0x80000000  /* not user-settable */
2698 
2699 #define PNG_MMX_READ_FLAGS ( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW  \
2700                            | PNG_ASM_FLAG_MMX_READ_INTERLACE    \
2701                            | PNG_ASM_FLAG_MMX_READ_FILTER_SUB   \
2702                            | PNG_ASM_FLAG_MMX_READ_FILTER_UP    \
2703                            | PNG_ASM_FLAG_MMX_READ_FILTER_AVG   \
2704                            | PNG_ASM_FLAG_MMX_READ_FILTER_PAETH )
2705 #define PNG_MMX_WRITE_FLAGS ( 0 )
2706 
2707 #define PNG_MMX_FLAGS ( PNG_ASM_FLAG_MMX_SUPPORT_COMPILED \
2708                       | PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU   \
2709                       | PNG_MMX_READ_FLAGS                \
2710                       | PNG_MMX_WRITE_FLAGS )
2711 
2712 #define PNG_SELECT_READ   1
2713 #define PNG_SELECT_WRITE  2
2714 #endif /* PNG_MMX_CODE_SUPPORTED */
2715 
2716 #if !defined(PNG_1_0_X)
2717 /* pngget.c */
2718 extern PNG_EXPORT(png_uint_32,png_get_mmx_flagmask)
2719    PNGARG((int flag_select, int *compilerID));
2720 
2721 /* pngget.c */
2722 extern PNG_EXPORT(png_uint_32,png_get_asm_flagmask)
2723    PNGARG((int flag_select));
2724 
2725 /* pngget.c */
2726 extern PNG_EXPORT(png_uint_32,png_get_asm_flags)
2727    PNGARG((png_structp png_ptr));
2728 
2729 /* pngget.c */
2730 extern PNG_EXPORT(png_byte,png_get_mmx_bitdepth_threshold)
2731    PNGARG((png_structp png_ptr));
2732 
2733 /* pngget.c */
2734 extern PNG_EXPORT(png_uint_32,png_get_mmx_rowbytes_threshold)
2735    PNGARG((png_structp png_ptr));
2736 
2737 /* pngset.c */
2738 extern PNG_EXPORT(void,png_set_asm_flags)
2739    PNGARG((png_structp png_ptr, png_uint_32 asm_flags));
2740 
2741 /* pngset.c */
2742 extern PNG_EXPORT(void,png_set_mmx_thresholds)
2743    PNGARG((png_structp png_ptr, png_byte mmx_bitdepth_threshold,
2744    png_uint_32 mmx_rowbytes_threshold));
2745 
2746 #endif /* PNG_1_0_X */
2747 
2748 #if !defined(PNG_1_0_X)
2749 /* png.c, pnggccrd.c, or pngvcrd.c */
2750 extern PNG_EXPORT(int,png_mmx_support) PNGARG((void));
2751 #endif /* PNG_1_0_X */
2752 #endif /* PNG_ASSEMBLER_CODE_SUPPORTED */
2753 
2754 /* Strip the prepended error numbers ("#nnn ") from error and warning
2755  * messages before passing them to the error or warning handler.
2756  */
2757 #ifdef PNG_ERROR_NUMBERS_SUPPORTED
2758 extern PNG_EXPORT(void,png_set_strip_error_numbers) PNGARG((png_structp
2759    png_ptr, png_uint_32 strip_mode));
2760 #endif
2761 
2762 /* Added at libpng-1.2.6 */
2763 #ifdef PNG_SET_USER_LIMITS_SUPPORTED
2764 extern PNG_EXPORT(void,png_set_user_limits) PNGARG((png_structp
2765    png_ptr, png_uint_32 user_width_max, png_uint_32 user_height_max));
2766 extern PNG_EXPORT(png_uint_32,png_get_user_width_max) PNGARG((png_structp
2767    png_ptr));
2768 extern PNG_EXPORT(png_uint_32,png_get_user_height_max) PNGARG((png_structp
2769    png_ptr));
2770 #endif
2771 
2772 
2773 /* Maintainer: Put new public prototypes here ^, in libpng.3, and in
2774  * project defs
2775  */
2776 
2777 #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2778 /* With these routines we avoid an integer divide, which will be slower on
2779  * most machines.  However, it does take more operations than the corresponding
2780  * divide method, so it may be slower on a few RISC systems.  There are two
2781  * shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2782  *
2783  * Note that the rounding factors are NOT supposed to be the same!  128 and
2784  * 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2785  * standard method.
2786  *
2787  * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2788  */
2789 
2790  /* fg and bg should be in `gamma 1.0' space; alpha is the opacity          */
2791 
2792 #  define png_composite(composite, fg, alpha, bg)                            \
2793      { png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) * (png_uint_16)(alpha) \
2794                         +        (png_uint_16)(bg)*(png_uint_16)(255 -       \
2795                         (png_uint_16)(alpha)) + (png_uint_16)128);           \
2796        (composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
2797 
2798 #  define png_composite_16(composite, fg, alpha, bg)                         \
2799      { png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) * (png_uint_32)(alpha) \
2800                         + (png_uint_32)(bg)*(png_uint_32)(65535L -           \
2801                         (png_uint_32)(alpha)) + (png_uint_32)32768L);        \
2802        (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
2803 
2804 #else  /* Standard method using integer division */
2805 
2806 #  define png_composite(composite, fg, alpha, bg)                            \
2807      (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) +    \
2808        (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) +       \
2809        (png_uint_16)127) / 255)
2810 
2811 #  define png_composite_16(composite, fg, alpha, bg)                         \
2812      (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2813        (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) +      \
2814        (png_uint_32)32767) / (png_uint_32)65535L)
2815 
2816 #endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
2817 
2818 /* Inline macros to do direct reads of bytes from the input buffer.  These
2819  * require that you are using an architecture that uses PNG byte ordering
2820  * (MSB first) and supports unaligned data storage.  I think that PowerPC
2821  * in big-endian mode and 680x0 are the only ones that will support this.
2822  * The x86 line of processors definitely do not.  The png_get_int_32()
2823  * routine also assumes we are using two's complement format for negative
2824  * values, which is almost certainly true.
2825  */
2826 #if defined(PNG_READ_BIG_ENDIAN_SUPPORTED)
2827 #  define png_get_uint_32(buf) ( *((png_uint_32p) (buf)))
2828 #  define png_get_uint_16(buf) ( *((png_uint_16p) (buf)))
2829 #  define png_get_int_32(buf)  ( *((png_int_32p)  (buf)))
2830 #else
2831 extern PNG_EXPORT(png_uint_32,png_get_uint_32) PNGARG((png_bytep buf));
2832 extern PNG_EXPORT(png_uint_16,png_get_uint_16) PNGARG((png_bytep buf));
2833 extern PNG_EXPORT(png_int_32,png_get_int_32) PNGARG((png_bytep buf));
2834 #endif /* !PNG_READ_BIG_ENDIAN_SUPPORTED */
2835 extern PNG_EXPORT(png_uint_32,png_get_uint_31)
2836   PNGARG((png_structp png_ptr, png_bytep buf));
2837 /* No png_get_int_16 -- may be added if there's a real need for it. */
2838 
2839 /* Place a 32-bit number into a buffer in PNG byte order (big-endian).
2840  */
2841 extern PNG_EXPORT(void,png_save_uint_32)
2842    PNGARG((png_bytep buf, png_uint_32 i));
2843 extern PNG_EXPORT(void,png_save_int_32)
2844    PNGARG((png_bytep buf, png_int_32 i));
2845 
2846 /* Place a 16-bit number into a buffer in PNG byte order.
2847  * The parameter is declared unsigned int, not png_uint_16,
2848  * just to avoid potential problems on pre-ANSI C compilers.
2849  */
2850 extern PNG_EXPORT(void,png_save_uint_16)
2851    PNGARG((png_bytep buf, unsigned int i));
2852 /* No png_save_int_16 -- may be added if there's a real need for it. */
2853 
2854 /* ************************************************************************* */
2855 
2856 /* These next functions are used internally in the code.  They generally
2857  * shouldn't be used unless you are writing code to add or replace some
2858  * functionality in libpng.  More information about most functions can
2859  * be found in the files where the functions are located.
2860  */
2861 
2862 
2863 /* Various modes of operation, that are visible to applications because
2864  * they are used for unknown chunk location.
2865  */
2866 #define PNG_HAVE_IHDR               0x01
2867 #define PNG_HAVE_PLTE               0x02
2868 #define PNG_HAVE_IDAT               0x04
2869 #define PNG_AFTER_IDAT              0x08 /* Have complete zlib datastream */
2870 #define PNG_HAVE_IEND               0x10
2871 
2872 #if defined(PNG_INTERNAL)
2873 
2874 /* More modes of operation.  Note that after an init, mode is set to
2875  * zero automatically when the structure is created.
2876  */
2877 #define PNG_HAVE_gAMA               0x20
2878 #define PNG_HAVE_cHRM               0x40
2879 #define PNG_HAVE_sRGB               0x80
2880 #define PNG_HAVE_CHUNK_HEADER      0x100
2881 #define PNG_WROTE_tIME             0x200
2882 #define PNG_WROTE_INFO_BEFORE_PLTE 0x400
2883 #define PNG_BACKGROUND_IS_GRAY     0x800
2884 #define PNG_HAVE_PNG_SIGNATURE    0x1000
2885 #define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
2886 
2887 /* Flags for the transformations the PNG library does on the image data */
2888 #define PNG_BGR                0x0001
2889 #define PNG_INTERLACE          0x0002
2890 #define PNG_PACK               0x0004
2891 #define PNG_SHIFT              0x0008
2892 #define PNG_SWAP_BYTES         0x0010
2893 #define PNG_INVERT_MONO        0x0020
2894 #define PNG_DITHER             0x0040
2895 #define PNG_BACKGROUND         0x0080
2896 #define PNG_BACKGROUND_EXPAND  0x0100
2897                           /*   0x0200 unused */
2898 #define PNG_16_TO_8            0x0400
2899 #define PNG_RGBA               0x0800
2900 #define PNG_EXPAND             0x1000
2901 #define PNG_GAMMA              0x2000
2902 #define PNG_GRAY_TO_RGB        0x4000
2903 #define PNG_FILLER             0x8000L
2904 #define PNG_PACKSWAP          0x10000L
2905 #define PNG_SWAP_ALPHA        0x20000L
2906 #define PNG_STRIP_ALPHA       0x40000L
2907 #define PNG_INVERT_ALPHA      0x80000L
2908 #define PNG_USER_TRANSFORM   0x100000L
2909 #define PNG_RGB_TO_GRAY_ERR  0x200000L
2910 #define PNG_RGB_TO_GRAY_WARN 0x400000L
2911 #define PNG_RGB_TO_GRAY      0x600000L  /* two bits, RGB_TO_GRAY_ERR|WARN */
2912                        /*    0x800000L     Unused */
2913 #define PNG_ADD_ALPHA       0x1000000L  /* Added to libpng-1.2.7 */
2914 #define PNG_EXPAND_tRNS     0x2000000L  /* Added to libpng-1.2.9 */
2915                        /*   0x4000000L  unused */
2916                        /*   0x8000000L  unused */
2917                        /*  0x10000000L  unused */
2918                        /*  0x20000000L  unused */
2919                        /*  0x40000000L  unused */
2920 
2921 /* Flags for png_create_struct */
2922 #define PNG_STRUCT_PNG   0x0001
2923 #define PNG_STRUCT_INFO  0x0002
2924 
2925 /* Scaling factor for filter heuristic weighting calculations */
2926 #define PNG_WEIGHT_SHIFT 8
2927 #define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
2928 #define PNG_COST_SHIFT 3
2929 #define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
2930 
2931 /* Flags for the png_ptr->flags rather than declaring a byte for each one */
2932 #define PNG_FLAG_ZLIB_CUSTOM_STRATEGY     0x0001
2933 #define PNG_FLAG_ZLIB_CUSTOM_LEVEL        0x0002
2934 #define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL    0x0004
2935 #define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS  0x0008
2936 #define PNG_FLAG_ZLIB_CUSTOM_METHOD       0x0010
2937 #define PNG_FLAG_ZLIB_FINISHED            0x0020
2938 #define PNG_FLAG_ROW_INIT                 0x0040
2939 #define PNG_FLAG_FILLER_AFTER             0x0080
2940 #define PNG_FLAG_CRC_ANCILLARY_USE        0x0100
2941 #define PNG_FLAG_CRC_ANCILLARY_NOWARN     0x0200
2942 #define PNG_FLAG_CRC_CRITICAL_USE         0x0400
2943 #define PNG_FLAG_CRC_CRITICAL_IGNORE      0x0800
2944 #define PNG_FLAG_FREE_PLTE                0x1000
2945 #define PNG_FLAG_FREE_TRNS                0x2000
2946 #define PNG_FLAG_FREE_HIST                0x4000
2947 #define PNG_FLAG_KEEP_UNKNOWN_CHUNKS      0x8000L
2948 #define PNG_FLAG_KEEP_UNSAFE_CHUNKS       0x10000L
2949 #define PNG_FLAG_LIBRARY_MISMATCH         0x20000L
2950 #define PNG_FLAG_STRIP_ERROR_NUMBERS      0x40000L
2951 #define PNG_FLAG_STRIP_ERROR_TEXT         0x80000L
2952 #define PNG_FLAG_MALLOC_NULL_MEM_OK       0x100000L
2953 #define PNG_FLAG_ADD_ALPHA                0x200000L  /* Added to libpng-1.2.8 */
2954 #define PNG_FLAG_STRIP_ALPHA              0x400000L  /* Added to libpng-1.2.8 */
2955                                   /*      0x800000L  unused */
2956                                   /*     0x1000000L  unused */
2957                                   /*     0x2000000L  unused */
2958                                   /*     0x4000000L  unused */
2959                                   /*     0x8000000L  unused */
2960                                   /*    0x10000000L  unused */
2961                                   /*    0x20000000L  unused */
2962                                   /*    0x40000000L  unused */
2963 
2964 #define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \
2965                                      PNG_FLAG_CRC_ANCILLARY_NOWARN)
2966 
2967 #define PNG_FLAG_CRC_CRITICAL_MASK  (PNG_FLAG_CRC_CRITICAL_USE | \
2968                                      PNG_FLAG_CRC_CRITICAL_IGNORE)
2969 
2970 #define PNG_FLAG_CRC_MASK           (PNG_FLAG_CRC_ANCILLARY_MASK | \
2971                                      PNG_FLAG_CRC_CRITICAL_MASK)
2972 
2973 /* Save typing and make code easier to understand */
2974 
2975 #define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
2976    abs((int)((c1).green) - (int)((c2).green)) + \
2977    abs((int)((c1).blue) - (int)((c2).blue)))
2978 
2979 /* Added to libpng-1.2.6 JB */
2980 #define PNG_ROWBYTES(pixel_bits, width) \
2981     ((pixel_bits) >= 8 ? \
2982     ((width) * (((png_uint_32)(pixel_bits)) >> 3)) : \
2983     (( ((width) * ((png_uint_32)(pixel_bits))) + 7) >> 3) )
2984 
2985 /* PNG_OUT_OF_RANGE returns true if value is outside the range
2986  * ideal-delta..ideal+delta.  Each argument is evaluated twice.
2987  * "ideal" and "delta" should be constants, normally simple
2988  * integers, "value" a variable. Added to libpng-1.2.6 JB
2989  */
2990 #define PNG_OUT_OF_RANGE(value, ideal, delta) \
2991         ( (value) < (ideal)-(delta) || (value) > (ideal)+(delta) )
2992 
2993 /* Variables declared in png.c - only it needs to define PNG_NO_EXTERN */
2994 #if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN)
2995 /* place to hold the signature string for a PNG file. */
2996 #ifdef PNG_USE_GLOBAL_ARRAYS
2997    PNG_EXPORT_VAR (PNG_CONST png_byte FARDATA) png_sig[8];
2998 #else
2999 #endif
3000 #endif /* PNG_NO_EXTERN */
3001 
3002 /* Constant strings for known chunk types.  If you need to add a chunk,
3003  * define the name here, and add an invocation of the macro in png.c and
3004  * wherever it's needed.
3005  */
3006 #define PNG_IHDR png_byte png_IHDR[5] = { 73,  72,  68,  82, '\0'}
3007 #define PNG_IDAT png_byte png_IDAT[5] = { 73,  68,  65,  84, '\0'}
3008 #define PNG_IEND png_byte png_IEND[5] = { 73,  69,  78,  68, '\0'}
3009 #define PNG_PLTE png_byte png_PLTE[5] = { 80,  76,  84,  69, '\0'}
3010 #define PNG_bKGD png_byte png_bKGD[5] = { 98,  75,  71,  68, '\0'}
3011 #define PNG_cHRM png_byte png_cHRM[5] = { 99,  72,  82,  77, '\0'}
3012 #define PNG_gAMA png_byte png_gAMA[5] = {103,  65,  77,  65, '\0'}
3013 #define PNG_hIST png_byte png_hIST[5] = {104,  73,  83,  84, '\0'}
3014 #define PNG_iCCP png_byte png_iCCP[5] = {105,  67,  67,  80, '\0'}
3015 #define PNG_iTXt png_byte png_iTXt[5] = {105,  84,  88, 116, '\0'}
3016 #define PNG_oFFs png_byte png_oFFs[5] = {111,  70,  70, 115, '\0'}
3017 #define PNG_pCAL png_byte png_pCAL[5] = {112,  67,  65,  76, '\0'}
3018 #define PNG_sCAL png_byte png_sCAL[5] = {115,  67,  65,  76, '\0'}
3019 #define PNG_pHYs png_byte png_pHYs[5] = {112,  72,  89, 115, '\0'}
3020 #define PNG_sBIT png_byte png_sBIT[5] = {115,  66,  73,  84, '\0'}
3021 #define PNG_sPLT png_byte png_sPLT[5] = {115,  80,  76,  84, '\0'}
3022 #define PNG_sRGB png_byte png_sRGB[5] = {115,  82,  71,  66, '\0'}
3023 #define PNG_tEXt png_byte png_tEXt[5] = {116,  69,  88, 116, '\0'}
3024 #define PNG_tIME png_byte png_tIME[5] = {116,  73,  77,  69, '\0'}
3025 #define PNG_tRNS png_byte png_tRNS[5] = {116,  82,  78,  83, '\0'}
3026 #define PNG_zTXt png_byte png_zTXt[5] = {122,  84,  88, 116, '\0'}
3027 
3028 #ifdef PNG_USE_GLOBAL_ARRAYS
3029 PNG_EXPORT_VAR (png_byte FARDATA) png_IHDR[5];
3030 PNG_EXPORT_VAR (png_byte FARDATA) png_IDAT[5];
3031 PNG_EXPORT_VAR (png_byte FARDATA) png_IEND[5];
3032 PNG_EXPORT_VAR (png_byte FARDATA) png_PLTE[5];
3033 PNG_EXPORT_VAR (png_byte FARDATA) png_bKGD[5];
3034 PNG_EXPORT_VAR (png_byte FARDATA) png_cHRM[5];
3035 PNG_EXPORT_VAR (png_byte FARDATA) png_gAMA[5];
3036 PNG_EXPORT_VAR (png_byte FARDATA) png_hIST[5];
3037 PNG_EXPORT_VAR (png_byte FARDATA) png_iCCP[5];
3038 PNG_EXPORT_VAR (png_byte FARDATA) png_iTXt[5];
3039 PNG_EXPORT_VAR (png_byte FARDATA) png_oFFs[5];
3040 PNG_EXPORT_VAR (png_byte FARDATA) png_pCAL[5];
3041 PNG_EXPORT_VAR (png_byte FARDATA) png_sCAL[5];
3042 PNG_EXPORT_VAR (png_byte FARDATA) png_pHYs[5];
3043 PNG_EXPORT_VAR (png_byte FARDATA) png_sBIT[5];
3044 PNG_EXPORT_VAR (png_byte FARDATA) png_sPLT[5];
3045 PNG_EXPORT_VAR (png_byte FARDATA) png_sRGB[5];
3046 PNG_EXPORT_VAR (png_byte FARDATA) png_tEXt[5];
3047 PNG_EXPORT_VAR (png_byte FARDATA) png_tIME[5];
3048 PNG_EXPORT_VAR (png_byte FARDATA) png_tRNS[5];
3049 PNG_EXPORT_VAR (png_byte FARDATA) png_zTXt[5];
3050 #endif /* PNG_USE_GLOBAL_ARRAYS */
3051 
3052 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
3053 /* Initialize png_ptr struct for reading, and allocate any other memory.
3054  * (old interface - DEPRECATED - use png_create_read_struct instead).
3055  */
3056 extern PNG_EXPORT(void,png_read_init) PNGARG((png_structp png_ptr));
3057 #undef png_read_init
3058 #define png_read_init(png_ptr) png_read_init_3(&png_ptr, \
3059     PNG_LIBPNG_VER_STRING,  png_sizeof(png_struct));
3060 #endif
3061 
3062 extern PNG_EXPORT(void,png_read_init_3) PNGARG((png_structpp ptr_ptr,
3063     png_const_charp user_png_ver, png_size_t png_struct_size));
3064 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
3065 extern PNG_EXPORT(void,png_read_init_2) PNGARG((png_structp png_ptr,
3066     png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
3067     png_info_size));
3068 #endif
3069 
3070 #if defined(PNG_1_0_X) || defined (PNG_1_2_X)
3071 /* Initialize png_ptr struct for writing, and allocate any other memory.
3072  * (old interface - DEPRECATED - use png_create_write_struct instead).
3073  */
3074 extern PNG_EXPORT(void,png_write_init) PNGARG((png_structp png_ptr));
3075 #undef png_write_init
3076 #define png_write_init(png_ptr) png_write_init_3(&png_ptr, \
3077     PNG_LIBPNG_VER_STRING, png_sizeof(png_struct));
3078 #endif
3079 
3080 extern PNG_EXPORT(void,png_write_init_3) PNGARG((png_structpp ptr_ptr,
3081     png_const_charp user_png_ver, png_size_t png_struct_size));
3082 extern PNG_EXPORT(void,png_write_init_2) PNGARG((png_structp png_ptr,
3083     png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
3084     png_info_size));
3085 
3086 /* Allocate memory for an internal libpng struct */
3087 PNG_EXTERN png_voidp png_create_struct PNGARG((int type));
3088 
3089 /* Free memory from internal libpng struct */
3090 PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr));
3091 
3092 PNG_EXTERN png_voidp png_create_struct_2 PNGARG((int type, png_malloc_ptr
3093   malloc_fn, png_voidp mem_ptr));
3094 PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr,
3095    png_free_ptr free_fn, png_voidp mem_ptr));
3096 
3097 /* Free any memory that info_ptr points to and reset struct. */
3098 PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr,
3099    png_infop info_ptr));
3100 
3101 #ifndef PNG_1_0_X
3102 /* Function to allocate memory for zlib. */
3103 PNG_EXTERN voidpf png_zalloc PNGARG((voidpf png_ptr, uInt items, uInt size));
3104 
3105 /* Function to free memory for zlib */
3106 PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr));
3107 
3108 #ifdef PNG_SIZE_T
3109 /* Function to convert a sizeof an item to png_sizeof item */
3110    PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size));
3111 #endif
3112 
3113 /* Next four functions are used internally as callbacks.  PNGAPI is required
3114  * but not PNG_EXPORT.  PNGAPI added at libpng version 1.2.3.
3115  */
3116 
3117 PNG_EXTERN void PNGAPI png_default_read_data PNGARG((png_structp png_ptr,
3118    png_bytep data, png_size_t length));
3119 
3120 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3121 PNG_EXTERN void PNGAPI png_push_fill_buffer PNGARG((png_structp png_ptr,
3122    png_bytep buffer, png_size_t length));
3123 #endif
3124 
3125 PNG_EXTERN void PNGAPI png_default_write_data PNGARG((png_structp png_ptr,
3126    png_bytep data, png_size_t length));
3127 
3128 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
3129 #if !defined(PNG_NO_STDIO)
3130 PNG_EXTERN void PNGAPI png_default_flush PNGARG((png_structp png_ptr));
3131 #endif
3132 #endif
3133 #else /* PNG_1_0_X */
3134 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3135 PNG_EXTERN void png_push_fill_buffer PNGARG((png_structp png_ptr,
3136    png_bytep buffer, png_size_t length));
3137 #endif
3138 #endif /* PNG_1_0_X */
3139 
3140 /* Reset the CRC variable */
3141 PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr));
3142 
3143 /* Write the "data" buffer to whatever output you are using. */
3144 PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr, png_bytep data,
3145    png_size_t length));
3146 
3147 /* Read data from whatever input you are using into the "data" buffer */
3148 PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data,
3149    png_size_t length));
3150 
3151 /* Read bytes into buf, and update png_ptr->crc */
3152 PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
3153    png_size_t length));
3154 
3155 /* Decompress data in a chunk that uses compression */
3156 #if defined(PNG_zTXt_SUPPORTED) || defined(PNG_iTXt_SUPPORTED) || \
3157     defined(PNG_iCCP_SUPPORTED) || defined(PNG_sPLT_SUPPORTED)
3158 PNG_EXTERN void png_decompress_chunk PNGARG((png_structp png_ptr,
3159    int comp_type, png_size_t chunklength,
3160    png_size_t prefix_length, png_size_t *data_length));
3161 #endif
3162 
3163 /* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
3164 PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip));
3165 
3166 /* Read the CRC from the file and compare it to the libpng calculated CRC */
3167 PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr));
3168 
3169 /* Calculate the CRC over a section of data.  Note that we are only
3170  * passing a maximum of 64K on systems that have this as a memory limit,
3171  * since this is the maximum buffer size we can specify.
3172  */
3173 PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr, png_bytep ptr,
3174    png_size_t length));
3175 
3176 #if defined(PNG_WRITE_FLUSH_SUPPORTED)
3177 PNG_EXTERN void png_flush PNGARG((png_structp png_ptr));
3178 #endif
3179 
3180 /* Simple function to write the signature */
3181 PNG_EXTERN void png_write_sig PNGARG((png_structp png_ptr));
3182 
3183 /* Write various chunks */
3184 
3185 /* Write the IHDR chunk, and update the png_struct with the necessary
3186  * information.
3187  */
3188 PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width,
3189    png_uint_32 height,
3190    int bit_depth, int color_type, int compression_method, int filter_method,
3191    int interlace_method));
3192 
3193 PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr, png_colorp palette,
3194    png_uint_32 num_pal));
3195 
3196 PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data,
3197    png_size_t length));
3198 
3199 PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr));
3200 
3201 #if defined(PNG_WRITE_gAMA_SUPPORTED)
3202 #ifdef PNG_FLOATING_POINT_SUPPORTED
3203 PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma));
3204 #endif
3205 #ifdef PNG_FIXED_POINT_SUPPORTED
3206 PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr, png_fixed_point
3207     file_gamma));
3208 #endif
3209 #endif
3210 
3211 #if defined(PNG_WRITE_sBIT_SUPPORTED)
3212 PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr, png_color_8p sbit,
3213    int color_type));
3214 #endif
3215 
3216 #if defined(PNG_WRITE_cHRM_SUPPORTED)
3217 #ifdef PNG_FLOATING_POINT_SUPPORTED
3218 PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr,
3219    double white_x, double white_y,
3220    double red_x, double red_y, double green_x, double green_y,
3221    double blue_x, double blue_y));
3222 #endif
3223 #ifdef PNG_FIXED_POINT_SUPPORTED
3224 PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr,
3225    png_fixed_point int_white_x, png_fixed_point int_white_y,
3226    png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
3227    int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
3228    png_fixed_point int_blue_y));
3229 #endif
3230 #endif
3231 
3232 #if defined(PNG_WRITE_sRGB_SUPPORTED)
3233 PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
3234    int intent));
3235 #endif
3236 
3237 #if defined(PNG_WRITE_iCCP_SUPPORTED)
3238 PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr,
3239    png_charp name, int compression_type,
3240    png_charp profile, int proflen));
3241    /* Note to maintainer: profile should be png_bytep */
3242 #endif
3243 
3244 #if defined(PNG_WRITE_sPLT_SUPPORTED)
3245 PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr,
3246    png_sPLT_tp palette));
3247 #endif
3248 
3249 #if defined(PNG_WRITE_tRNS_SUPPORTED)
3250 PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr, png_bytep trans,
3251    png_color_16p values, int number, int color_type));
3252 #endif
3253 
3254 #if defined(PNG_WRITE_bKGD_SUPPORTED)
3255 PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr,
3256    png_color_16p values, int color_type));
3257 #endif
3258 
3259 #if defined(PNG_WRITE_hIST_SUPPORTED)
3260 PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, png_uint_16p hist,
3261    int num_hist));
3262 #endif
3263 
3264 #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
3265     defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
3266 PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
3267    png_charp key, png_charpp new_key));
3268 #endif
3269 
3270 #if defined(PNG_WRITE_tEXt_SUPPORTED)
3271 PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_charp key,
3272    png_charp text, png_size_t text_len));
3273 #endif
3274 
3275 #if defined(PNG_WRITE_zTXt_SUPPORTED)
3276 PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_charp key,
3277    png_charp text, png_size_t text_len, int compression));
3278 #endif
3279 
3280 #if defined(PNG_WRITE_iTXt_SUPPORTED)
3281 PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr,
3282    int compression, png_charp key, png_charp lang, png_charp lang_key,
3283    png_charp text));
3284 #endif
3285 
3286 #if defined(PNG_TEXT_SUPPORTED)  /* Added at version 1.0.14 and 1.2.4 */
3287 PNG_EXTERN int png_set_text_2 PNGARG((png_structp png_ptr,
3288    png_infop info_ptr, png_textp text_ptr, int num_text));
3289 #endif
3290 
3291 #if defined(PNG_WRITE_oFFs_SUPPORTED)
3292 PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr,
3293    png_int_32 x_offset, png_int_32 y_offset, int unit_type));
3294 #endif
3295 
3296 #if defined(PNG_WRITE_pCAL_SUPPORTED)
3297 PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose,
3298    png_int_32 X0, png_int_32 X1, int type, int nparams,
3299    png_charp units, png_charpp params));
3300 #endif
3301 
3302 #if defined(PNG_WRITE_pHYs_SUPPORTED)
3303 PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr,
3304    png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
3305    int unit_type));
3306 #endif
3307 
3308 #if defined(PNG_WRITE_tIME_SUPPORTED)
3309 PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr,
3310    png_timep mod_time));
3311 #endif
3312 
3313 #if defined(PNG_WRITE_sCAL_SUPPORTED)
3314 #if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
3315 PNG_EXTERN void png_write_sCAL PNGARG((png_structp png_ptr,
3316    int unit, double width, double height));
3317 #else
3318 #ifdef PNG_FIXED_POINT_SUPPORTED
3319 PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr,
3320    int unit, png_charp width, png_charp height));
3321 #endif
3322 #endif
3323 #endif
3324 
3325 /* Called when finished processing a row of data */
3326 PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr));
3327 
3328 /* Internal use only.   Called before first row of data */
3329 PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr));
3330 
3331 #if defined(PNG_READ_GAMMA_SUPPORTED)
3332 PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr));
3333 #endif
3334 
3335 /* Combine a row of data, dealing with alpha, etc. if requested */
3336 PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row,
3337    int mask));
3338 
3339 #if defined(PNG_READ_INTERLACING_SUPPORTED)
3340 /* Expand an interlaced row */
3341 /* OLD pre-1.0.9 interface:
3342 PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info,
3343    png_bytep row, int pass, png_uint_32 transformations));
3344  */
3345 PNG_EXTERN void png_do_read_interlace PNGARG((png_structp png_ptr));
3346 #endif
3347 
3348 /* GRR TO DO (2.0 or whenever):  simplify other internal calling interfaces */
3349 
3350 #if defined(PNG_WRITE_INTERLACING_SUPPORTED)
3351 /* Grab pixels out of a row for an interlaced pass */
3352 PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info,
3353    png_bytep row, int pass));
3354 #endif
3355 
3356 /* Unfilter a row */
3357 PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr,
3358    png_row_infop row_info, png_bytep row, png_bytep prev_row, int filter));
3359 
3360 /* Choose the best filter to use and filter the row data */
3361 PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
3362    png_row_infop row_info));
3363 
3364 /* Write out the filtered row. */
3365 PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr,
3366    png_bytep filtered_row));
3367 /* Finish a row while reading, dealing with interlacing passes, etc. */
3368 PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
3369 
3370 /* Initialize the row buffers, etc. */
3371 PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr));
3372 /* Optional call to update the users info structure */
3373 PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
3374    png_infop info_ptr));
3375 
3376 /* These are the functions that do the transformations */
3377 #if defined(PNG_READ_FILLER_SUPPORTED)
3378 PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info,
3379    png_bytep row, png_uint_32 filler, png_uint_32 flags));
3380 #endif
3381 
3382 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
3383 PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info,
3384    png_bytep row));
3385 #endif
3386 
3387 #if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
3388 PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info,
3389    png_bytep row));
3390 #endif
3391 
3392 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
3393 PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info,
3394    png_bytep row));
3395 #endif
3396 
3397 #if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
3398 PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info,
3399    png_bytep row));
3400 #endif
3401 
3402 #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
3403     defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
3404 PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info,
3405    png_bytep row, png_uint_32 flags));
3406 #endif
3407 
3408 #if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED)
3409 PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info, png_bytep row));
3410 #endif
3411 
3412 #if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED)
3413 PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info, png_bytep row));
3414 #endif
3415 
3416 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
3417 PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr, png_row_infop
3418    row_info, png_bytep row));
3419 #endif
3420 
3421 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
3422 PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info,
3423    png_bytep row));
3424 #endif
3425 
3426 #if defined(PNG_READ_PACK_SUPPORTED)
3427 PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info, png_bytep row));
3428 #endif
3429 
3430 #if defined(PNG_READ_SHIFT_SUPPORTED)
3431 PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info, png_bytep row,
3432    png_color_8p sig_bits));
3433 #endif
3434 
3435 #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
3436 PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info, png_bytep row));
3437 #endif
3438 
3439 #if defined(PNG_READ_16_TO_8_SUPPORTED)
3440 PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info, png_bytep row));
3441 #endif
3442 
3443 #if defined(PNG_READ_DITHER_SUPPORTED)
3444 PNG_EXTERN void png_do_dither PNGARG((png_row_infop row_info,
3445    png_bytep row, png_bytep palette_lookup, png_bytep dither_lookup));
3446 
3447 #  if defined(PNG_CORRECT_PALETTE_SUPPORTED)
3448 PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr,
3449    png_colorp palette, int num_palette));
3450 #  endif
3451 #endif
3452 
3453 #if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED)
3454 PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info, png_bytep row));
3455 #endif
3456 
3457 #if defined(PNG_WRITE_PACK_SUPPORTED)
3458 PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info,
3459    png_bytep row, png_uint_32 bit_depth));
3460 #endif
3461 
3462 #if defined(PNG_WRITE_SHIFT_SUPPORTED)
3463 PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info, png_bytep row,
3464    png_color_8p bit_depth));
3465 #endif
3466 
3467 #if defined(PNG_READ_BACKGROUND_SUPPORTED)
3468 #if defined(PNG_READ_GAMMA_SUPPORTED)
3469 PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
3470    png_color_16p trans_values, png_color_16p background,
3471    png_color_16p background_1,
3472    png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,
3473    png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,
3474    png_uint_16pp gamma_16_to_1, int gamma_shift));
3475 #else
3476 PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
3477    png_color_16p trans_values, png_color_16p background));
3478 #endif
3479 #endif
3480 
3481 #if defined(PNG_READ_GAMMA_SUPPORTED)
3482 PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info, png_bytep row,
3483    png_bytep gamma_table, png_uint_16pp gamma_16_table,
3484    int gamma_shift));
3485 #endif
3486 
3487 #if defined(PNG_READ_EXPAND_SUPPORTED)
3488 PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info,
3489    png_bytep row, png_colorp palette, png_bytep trans, int num_trans));
3490 PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info,
3491    png_bytep row, png_color_16p trans_value));
3492 #endif
3493 
3494 /* The following decodes the appropriate chunks, and does error correction,
3495  * then calls the appropriate callback for the chunk if it is valid.
3496  */
3497 
3498 /* Decode the IHDR chunk */
3499 PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr,
3500    png_uint_32 length));
3501 PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr,
3502    png_uint_32 length));
3503 PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr,
3504    png_uint_32 length));
3505 
3506 #if defined(PNG_READ_bKGD_SUPPORTED)
3507 PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr,
3508    png_uint_32 length));
3509 #endif
3510 
3511 #if defined(PNG_READ_cHRM_SUPPORTED)
3512 PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr,
3513    png_uint_32 length));
3514 #endif
3515 
3516 #if defined(PNG_READ_gAMA_SUPPORTED)
3517 PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr,
3518    png_uint_32 length));
3519 #endif
3520 
3521 #if defined(PNG_READ_hIST_SUPPORTED)
3522 PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr,
3523    png_uint_32 length));
3524 #endif
3525 
3526 #if defined(PNG_READ_iCCP_SUPPORTED)
3527 extern void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr,
3528    png_uint_32 length));
3529 #endif /* PNG_READ_iCCP_SUPPORTED */
3530 
3531 #if defined(PNG_READ_iTXt_SUPPORTED)
3532 PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3533    png_uint_32 length));
3534 #endif
3535 
3536 #if defined(PNG_READ_oFFs_SUPPORTED)
3537 PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr,
3538    png_uint_32 length));
3539 #endif
3540 
3541 #if defined(PNG_READ_pCAL_SUPPORTED)
3542 PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
3543    png_uint_32 length));
3544 #endif
3545 
3546 #if defined(PNG_READ_pHYs_SUPPORTED)
3547 PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr,
3548    png_uint_32 length));
3549 #endif
3550 
3551 #if defined(PNG_READ_sBIT_SUPPORTED)
3552 PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr,
3553    png_uint_32 length));
3554 #endif
3555 
3556 #if defined(PNG_READ_sCAL_SUPPORTED)
3557 PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
3558    png_uint_32 length));
3559 #endif
3560 
3561 #if defined(PNG_READ_sPLT_SUPPORTED)
3562 extern void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr,
3563    png_uint_32 length));
3564 #endif /* PNG_READ_sPLT_SUPPORTED */
3565 
3566 #if defined(PNG_READ_sRGB_SUPPORTED)
3567 PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr,
3568    png_uint_32 length));
3569 #endif
3570 
3571 #if defined(PNG_READ_tEXt_SUPPORTED)
3572 PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3573    png_uint_32 length));
3574 #endif
3575 
3576 #if defined(PNG_READ_tIME_SUPPORTED)
3577 PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr,
3578    png_uint_32 length));
3579 #endif
3580 
3581 #if defined(PNG_READ_tRNS_SUPPORTED)
3582 PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr,
3583    png_uint_32 length));
3584 #endif
3585 
3586 #if defined(PNG_READ_zTXt_SUPPORTED)
3587 PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3588    png_uint_32 length));
3589 #endif
3590 
3591 PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
3592    png_infop info_ptr, png_uint_32 length));
3593 
3594 PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
3595    png_bytep chunk_name));
3596 
3597 /* Handle the transformations for reading and writing */
3598 PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr));
3599 PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr));
3600 
3601 PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr));
3602 
3603 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3604 PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
3605    png_infop info_ptr));
3606 PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr,
3607    png_infop info_ptr));
3608 PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr));
3609 PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr,
3610    png_uint_32 length));
3611 PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr));
3612 PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr));
3613 PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr,
3614    png_bytep buffer, png_size_t buffer_length));
3615 PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr));
3616 PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr,
3617    png_bytep buffer, png_size_t buffer_length));
3618 PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr));
3619 PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr,
3620    png_infop info_ptr, png_uint_32 length));
3621 PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr,
3622    png_infop info_ptr));
3623 PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr,
3624    png_infop info_ptr));
3625 PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr, png_bytep row));
3626 PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr,
3627    png_infop info_ptr));
3628 PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr,
3629    png_infop info_ptr));
3630 PNG_EXTERN void png_read_push_finish_row PNGARG((png_structp png_ptr));
3631 #if defined(PNG_READ_tEXt_SUPPORTED)
3632 PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr,
3633    png_infop info_ptr, png_uint_32 length));
3634 PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr,
3635    png_infop info_ptr));
3636 #endif
3637 #if defined(PNG_READ_zTXt_SUPPORTED)
3638 PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr,
3639    png_infop info_ptr, png_uint_32 length));
3640 PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr,
3641    png_infop info_ptr));
3642 #endif
3643 #if defined(PNG_READ_iTXt_SUPPORTED)
3644 PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr,
3645    png_infop info_ptr, png_uint_32 length));
3646 PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr,
3647    png_infop info_ptr));
3648 #endif
3649 
3650 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
3651 
3652 #ifdef PNG_MNG_FEATURES_SUPPORTED
3653 PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info,
3654    png_bytep row));
3655 PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info,
3656    png_bytep row));
3657 #endif
3658 
3659 #if defined(PNG_ASSEMBLER_CODE_SUPPORTED)
3660 #if defined(PNG_MMX_CODE_SUPPORTED)
3661 /* png.c */ /* PRIVATE */
3662 PNG_EXTERN void png_init_mmx_flags PNGARG((png_structp png_ptr));
3663 #endif
3664 #endif
3665 
3666 #if defined(PNG_INCH_CONVERSIONS) && defined(PNG_FLOATING_POINT_SUPPORTED)
3667 PNG_EXTERN png_uint_32 png_get_pixels_per_inch PNGARG((png_structp png_ptr,
3668 png_infop info_ptr));
3669 
3670 PNG_EXTERN png_uint_32 png_get_x_pixels_per_inch PNGARG((png_structp png_ptr,
3671 png_infop info_ptr));
3672 
3673 PNG_EXTERN png_uint_32 png_get_y_pixels_per_inch PNGARG((png_structp png_ptr,
3674 png_infop info_ptr));
3675 
3676 PNG_EXTERN float png_get_x_offset_inches PNGARG((png_structp png_ptr,
3677 png_infop info_ptr));
3678 
3679 PNG_EXTERN float png_get_y_offset_inches PNGARG((png_structp png_ptr,
3680 png_infop info_ptr));
3681 
3682 #if defined(PNG_pHYs_SUPPORTED)
3683 PNG_EXTERN png_uint_32 png_get_pHYs_dpi PNGARG((png_structp png_ptr,
3684 png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type));
3685 #endif /* PNG_pHYs_SUPPORTED */
3686 #endif  /* PNG_INCH_CONVERSIONS && PNG_FLOATING_POINT_SUPPORTED */
3687 
3688 /* Read the chunk header (length + type name) */
3689 PNG_EXTERN png_uint_32 png_read_chunk_header PNGARG((png_structp png_ptr));
3690 
3691 /* Added at libpng version 1.2.34 */
3692 #if defined(PNG_cHRM_SUPPORTED)
3693 PNG_EXTERN int png_check_cHRM_fixed  PNGARG((png_structp png_ptr,
3694    png_fixed_point int_white_x, png_fixed_point int_white_y,
3695    png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
3696    int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
3697    png_fixed_point int_blue_y));
3698 #endif
3699 
3700 /* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
3701 
3702 #endif /* PNG_INTERNAL */
3703 
3704 #ifdef __cplusplus
3705 }
3706 #endif
3707 
3708 #endif /* PNG_VERSION_INFO_ONLY */
3709 /* Do not put anything past this line */
3710 #endif /* PNG_H */
3711