png.h@ 58324

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libpng 1.2.53 export fix
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1	/* png.h - header file for PNG reference library
2	*
3	* libpng version 1.2.53 - February 26, 2015
4	* Copyright (c) 1998-2015 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 1.2.53 - February 26, 2015: 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	* 1.0.45 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	* 1.2.39beta01-05 13 10239 12.so.0.39[.0]
241	* 1.2.39rc01 13 10239 12.so.0.39[.0]
242	* 1.0.48 10 10048 10.so.0.48[.0]
243	* 1.2.39 13 10239 12.so.0.39[.0]
244	* 1.2.40beta01 13 10240 12.so.0.40[.0]
245	* 1.2.40rc01 13 10240 12.so.0.40[.0]
246	* 1.0.49 10 10049 10.so.0.49[.0]
247	* 1.2.40 13 10240 12.so.0.40[.0]
248	* 1.2.41beta01-18 13 10241 12.so.0.41[.0]
249	* 1.0.51rc01 10 10051 10.so.0.51[.0]
250	* 1.2.41rc01-03 13 10241 12.so.0.41[.0]
251	* 1.0.51 10 10051 10.so.0.51[.0]
252	* 1.2.41 13 10241 12.so.0.41[.0]
253	* 1.2.42beta01-02 13 10242 12.so.0.42[.0]
254	* 1.2.42rc01-05 13 10242 12.so.0.42[.0]
255	* 1.0.52 10 10052 10.so.0.52[.0]
256	* 1.2.42 13 10242 12.so.0.42[.0]
257	* 1.2.43beta01-05 13 10243 12.so.0.43[.0]
258	* 1.0.53rc01-02 10 10053 10.so.0.53[.0]
259	* 1.2.43rc01-02 13 10243 12.so.0.43[.0]
260	* 1.0.53 10 10053 10.so.0.53[.0]
261	* 1.2.43 13 10243 12.so.0.43[.0]
262	* 1.2.44beta01-03 13 10244 12.so.0.44[.0]
263	* 1.2.44rc01-03 13 10244 12.so.0.44[.0]
264	* 1.2.44 13 10244 12.so.0.44[.0]
265	* 1.2.45beta01-03 13 10245 12.so.0.45[.0]
266	* 1.0.55rc01 10 10055 10.so.0.55[.0]
267	* 1.2.45rc01 13 10245 12.so.0.45[.0]
268	* 1.0.55 10 10055 10.so.0.55[.0]
269	* 1.2.45 13 10245 12.so.0.45[.0]
270	* 1.2.46rc01-02 13 10246 12.so.0.46[.0]
271	* 1.0.56 10 10056 10.so.0.56[.0]
272	* 1.2.46 13 10246 12.so.0.46[.0]
273	* 1.2.47beta01 13 10247 12.so.0.47[.0]
274	* 1.2.47rc01 13 10247 12.so.0.47[.0]
275	* 1.0.57rc01 10 10057 10.so.0.57[.0]
276	* 1.2.47 13 10247 12.so.0.47[.0]
277	* 1.0.57 10 10057 10.so.0.57[.0]
278	* 1.2.48beta01 13 10248 12.so.0.48[.0]
279	* 1.2.48rc01-02 13 10248 12.so.0.48[.0]
280	* 1.0.58 10 10058 10.so.0.58[.0]
281	* 1.2.48 13 10248 12.so.0.48[.0]
282	* 1.2.49rc01 13 10249 12.so.0.49[.0]
283	* 1.0.59 10 10059 10.so.0.59[.0]
284	* 1.2.49 13 10249 12.so.0.49[.0]
285	* 1.0.60 10 10060 10.so.0.60[.0]
286	* 1.2.50 13 10250 12.so.0.50[.0]
287	* 1.2.51beta01-05 13 10251 12.so.0.51[.0]
288	* 1.2.51rc01-04 13 10251 12.so.0.51[.0]
289	* 1.0.61 10 10061 10.so.0.61[.0]
290	* 1.2.51 13 10251 12.so.0.51[.0]
291	* 1.2.52beta01 13 10252 12.so.0.52[.0]
292	* 1.2.52rc01-02 13 10252 12.so.0.52[.0]
293	* 1.0.62 10 10062 10.so.0.62[.0]
294	* 1.2.52 13 10252 12.so.0.52[.0]
295	* 1.2.53beta01-02 13 10253 12.so.0.53[.0]
296	* 1.2.53rc01-03 13 10253 12.so.0.53[.0]
297	* 1.0.63 10 10063 10.so.0.63[.0]
298	* 1.2.53 13 10253 12.so.0.53[.0]
299	*
300	* Henceforth the source version will match the shared-library major
301	* and minor numbers; the shared-library major version number will be
302	* used for changes in backward compatibility, as it is intended. The
303	* PNG_LIBPNG_VER macro, which is not used within libpng but is available
304	* for applications, is an unsigned integer of the form xyyzz corresponding
305	* to the source version x.y.z (leading zeros in y and z). Beta versions
306	* were given the previous public release number plus a letter, until
307	* version 1.0.6j; from then on they were given the upcoming public
308	* release number plus "betaNN" or "rcNN".
309	*
310	* Binary incompatibility exists only when applications make direct access
311	* to the info_ptr or png_ptr members through png.h, and the compiled
312	* application is loaded with a different version of the library.
313	*
314	* DLLNUM will change each time there are forward or backward changes
315	* in binary compatibility (e.g., when a new feature is added).
316	*
317	* See libpng.txt or libpng.3 for more information. The PNG specification
318	* is available as a W3C Recommendation and as an ISO Specification,
319	* <http://www.w3.org/TR/2003/REC-PNG-20031110/
320	*/
321
322	/*
323	* COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
324	*
325	* If you modify libpng you may insert additional notices immediately following
326	* this sentence.
327	*
328	* This code is released under the libpng license.
329	*
330	* libpng versions 1.2.6, August 15, 2004, through 1.2.53, February 26, 2015, are
331	* Copyright (c) 2004, 2006-2015 Glenn Randers-Pehrson, and are
332	* distributed according to the same disclaimer and license as libpng-1.2.5
333	* with the following individual added to the list of Contributing Authors:
334	*
335	* Cosmin Truta
336	*
337	* libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are
338	* Copyright (c) 2000-2002 Glenn Randers-Pehrson, and are
339	* distributed according to the same disclaimer and license as libpng-1.0.6
340	* with the following individuals added to the list of Contributing Authors:
341	*
342	* Simon-Pierre Cadieux
343	* Eric S. Raymond
344	* Gilles Vollant
345	*
346	* and with the following additions to the disclaimer:
347	*
348	* There is no warranty against interference with your enjoyment of the
349	* library or against infringement. There is no warranty that our
350	* efforts or the library will fulfill any of your particular purposes
351	* or needs. This library is provided with all faults, and the entire
352	* risk of satisfactory quality, performance, accuracy, and effort is with
353	* the user.
354	*
355	* libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
356	* Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are
357	* distributed according to the same disclaimer and license as libpng-0.96,
358	* with the following individuals added to the list of Contributing Authors:
359	*
360	* Tom Lane
361	* Glenn Randers-Pehrson
362	* Willem van Schaik
363	*
364	* libpng versions 0.89, June 1996, through 0.96, May 1997, are
365	* Copyright (c) 1996, 1997 Andreas Dilger
366	* Distributed according to the same disclaimer and license as libpng-0.88,
367	* with the following individuals added to the list of Contributing Authors:
368	*
369	* John Bowler
370	* Kevin Bracey
371	* Sam Bushell
372	* Magnus Holmgren
373	* Greg Roelofs
374	* Tom Tanner
375	*
376	* libpng versions 0.5, May 1995, through 0.88, January 1996, are
377	* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
378	*
379	* For the purposes of this copyright and license, "Contributing Authors"
380	* is defined as the following set of individuals:
381	*
382	* Andreas Dilger
383	* Dave Martindale
384	* Guy Eric Schalnat
385	* Paul Schmidt
386	* Tim Wegner
387	*
388	* The PNG Reference Library is supplied "AS IS". The Contributing Authors
389	* and Group 42, Inc. disclaim all warranties, expressed or implied,
390	* including, without limitation, the warranties of merchantability and of
391	* fitness for any purpose. The Contributing Authors and Group 42, Inc.
392	* assume no liability for direct, indirect, incidental, special, exemplary,
393	* or consequential damages, which may result from the use of the PNG
394	* Reference Library, even if advised of the possibility of such damage.
395	*
396	* Permission is hereby granted to use, copy, modify, and distribute this
397	* source code, or portions hereof, for any purpose, without fee, subject
398	* to the following restrictions:
399	*
400	* 1. The origin of this source code must not be misrepresented.
401	*
402	* 2. Altered versions must be plainly marked as such and
403	* must not be misrepresented as being the original source.
404	*
405	* 3. This Copyright notice may not be removed or altered from
406	* any source or altered source distribution.
407	*
408	* The Contributing Authors and Group 42, Inc. specifically permit, without
409	* fee, and encourage the use of this source code as a component to
410	* supporting the PNG file format in commercial products. If you use this
411	* source code in a product, acknowledgment is not required but would be
412	* appreciated.
413	*/
414
415	/*
416	* A "png_get_copyright" function is available, for convenient use in "about"
417	* boxes and the like:
418	*
419	* printf("%s",png_get_copyright(NULL));
420	*
421	* Also, the PNG logo (in PNG format, of course) is supplied in the
422	* files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31).
423	*/
424
425	/*
426	* Libpng is OSI Certified Open Source Software. OSI Certified is a
427	* certification mark of the Open Source Initiative.
428	*/
429
430	/*
431	* The contributing authors would like to thank all those who helped
432	* with testing, bug fixes, and patience. This wouldn't have been
433	* possible without all of you.
434	*
435	* Thanks to Frank J. T. Wojcik for helping with the documentation.
436	*/
437
438	/*
439	* Y2K compliance in libpng:
440	* =========================
441	*
442	* February 26, 2015
443	*
444	* Since the PNG Development group is an ad-hoc body, we can't make
445	* an official declaration.
446	*
447	* This is your unofficial assurance that libpng from version 0.71 and
448	* upward through 1.2.53 are Y2K compliant. It is my belief that earlier
449	* versions were also Y2K compliant.
450	*
451	* Libpng only has three year fields. One is a 2-byte unsigned integer
452	* that will hold years up to 65535. The other two hold the date in text
453	* format, and will hold years up to 9999.
454	*
455	* The integer is
456	* "png_uint_16 year" in png_time_struct.
457	*
458	* The strings are
459	* "png_charp time_buffer" in png_struct and
460	* "near_time_buffer", which is a local character string in png.c.
461	*
462	* There are seven time-related functions:
463	* png.c: png_convert_to_rfc_1123() in png.c
464	* (formerly png_convert_to_rfc_1152() in error)
465	* png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
466	* png_convert_from_time_t() in pngwrite.c
467	* png_get_tIME() in pngget.c
468	* png_handle_tIME() in pngrutil.c, called in pngread.c
469	* png_set_tIME() in pngset.c
470	* png_write_tIME() in pngwutil.c, called in pngwrite.c
471	*
472	* All handle dates properly in a Y2K environment. The
473	* png_convert_from_time_t() function calls gmtime() to convert from system
474	* clock time, which returns (year - 1900), which we properly convert to
475	* the full 4-digit year. There is a possibility that applications using
476	* libpng are not passing 4-digit years into the png_convert_to_rfc_1123()
477	* function, or that they are incorrectly passing only a 2-digit year
478	* instead of "year - 1900" into the png_convert_from_struct_tm() function,
479	* but this is not under our control. The libpng documentation has always
480	* stated that it works with 4-digit years, and the APIs have been
481	* documented as such.
482	*
483	* The tIME chunk itself is also Y2K compliant. It uses a 2-byte unsigned
484	* integer to hold the year, and can hold years as large as 65535.
485	*
486	* zlib, upon which libpng depends, is also Y2K compliant. It contains
487	* no date-related code.
488	*
489	* Glenn Randers-Pehrson
490	* libpng maintainer
491	* PNG Development Group
492	*/
493
494	#ifndef PNG_H
495	#define PNG_H
496
497	/* This is not the place to learn how to use libpng. The file libpng.txt
498	* describes how to use libpng, and the file example.c summarizes it
499	* with some code on which to build. This file is useful for looking
500	* at the actual function definitions and structure components.
501	*/
502
503	/* Version information for png.h - this should match the version in png.c */
504	#define PNG_LIBPNG_VER_STRING "1.2.53"
505	#define PNG_HEADER_VERSION_STRING \
506	" libpng version 1.2.53 - February 26, 2015\n"
507
508	#define PNG_LIBPNG_VER_SONUM 0
509	#define PNG_LIBPNG_VER_DLLNUM 13
510
511	/* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
512	#define PNG_LIBPNG_VER_MAJOR 1
513	#define PNG_LIBPNG_VER_MINOR 2
514	#define PNG_LIBPNG_VER_RELEASE 53
515	/* This should match the numeric part of the final component of
516	* PNG_LIBPNG_VER_STRING, omitting any leading zero:
517	*/
518
519	#define PNG_LIBPNG_VER_BUILD 0
520
521	/* Release Status */
522	#define PNG_LIBPNG_BUILD_ALPHA 1
523	#define PNG_LIBPNG_BUILD_BETA 2
524	#define PNG_LIBPNG_BUILD_RC 3
525	#define PNG_LIBPNG_BUILD_STABLE 4
526	#define PNG_LIBPNG_BUILD_RELEASE_STATUS_MASK 7
527
528	/* Release-Specific Flags */
529	#define PNG_LIBPNG_BUILD_PATCH 8 /* Can be OR'ed with
530	PNG_LIBPNG_BUILD_STABLE only */
531	#define PNG_LIBPNG_BUILD_PRIVATE 16 /* Cannot be OR'ed with
532	PNG_LIBPNG_BUILD_SPECIAL */
533	#define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
534	PNG_LIBPNG_BUILD_PRIVATE */
535
536	#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
537
538	/* Careful here. At one time, Guy wanted to use 082, but that would be octal.
539	* We must not include leading zeros.
540	* Versions 0.7 through 1.0.0 were in the range 0 to 100 here (only
541	* version 1.0.0 was mis-numbered 100 instead of 10000). From
542	* version 1.0.1 it's xxyyzz, where x=major, y=minor, z=release
543	*/
544	#define PNG_LIBPNG_VER 10253 /* 1.2.53 */
545
546	#ifndef PNG_VERSION_INFO_ONLY
547	/* Include the compression library's header */
548	#include "zlib.h"
549	#endif
550
551	/* Include all user configurable info, including optional assembler routines */
552	#include "pngconf.h"
553
554	/*
555	* Added at libpng-1.2.8 */
556	/* Ref MSDN: Private as priority over Special
557	* VS_FF_PRIVATEBUILD File was not built using standard release
558	* procedures. If this value is given, the StringFileInfo block must
559	* contain a PrivateBuild string.
560	*
561	* VS_FF_SPECIALBUILD File was built by the original company using
562	* standard release procedures but is a variation of the standard
563	* file of the same version number. If this value is given, the
564	* StringFileInfo block must contain a SpecialBuild string.
565	*/
566
567	#ifdef PNG_USER_PRIVATEBUILD
568	# define PNG_LIBPNG_BUILD_TYPE \
569	(PNG_LIBPNG_BUILD_BASE_TYPE \| PNG_LIBPNG_BUILD_PRIVATE)
570	#else
571	# ifdef PNG_LIBPNG_SPECIALBUILD
572	# define PNG_LIBPNG_BUILD_TYPE \
573	(PNG_LIBPNG_BUILD_BASE_TYPE \| PNG_LIBPNG_BUILD_SPECIAL)
574	# else
575	# define PNG_LIBPNG_BUILD_TYPE (PNG_LIBPNG_BUILD_BASE_TYPE)
576	# endif
577	#endif
578
579	#ifndef PNG_VERSION_INFO_ONLY
580
581	/* Inhibit C++ name-mangling for libpng functions but not for system calls. */
582	#ifdef __cplusplus
583	extern "C" {
584	#endif /* __cplusplus */
585
586	/* This file is arranged in several sections. The first section contains
587	* structure and type definitions. The second section contains the external
588	* library functions, while the third has the internal library functions,
589	* which applications aren't expected to use directly.
590	*/
591
592	#ifndef PNG_NO_TYPECAST_NULL
593	#define int_p_NULL (int *)NULL
594	#define png_bytep_NULL (png_bytep)NULL
595	#define png_bytepp_NULL (png_bytepp)NULL
596	#define png_doublep_NULL (png_doublep)NULL
597	#define png_error_ptr_NULL (png_error_ptr)NULL
598	#define png_flush_ptr_NULL (png_flush_ptr)NULL
599	#define png_free_ptr_NULL (png_free_ptr)NULL
600	#define png_infopp_NULL (png_infopp)NULL
601	#define png_malloc_ptr_NULL (png_malloc_ptr)NULL
602	#define png_read_status_ptr_NULL (png_read_status_ptr)NULL
603	#define png_rw_ptr_NULL (png_rw_ptr)NULL
604	#define png_structp_NULL (png_structp)NULL
605	#define png_uint_16p_NULL (png_uint_16p)NULL
606	#define png_voidp_NULL (png_voidp)NULL
607	#define png_write_status_ptr_NULL (png_write_status_ptr)NULL
608	#else
609	#define int_p_NULL NULL
610	#define png_bytep_NULL NULL
611	#define png_bytepp_NULL NULL
612	#define png_doublep_NULL NULL
613	#define png_error_ptr_NULL NULL
614	#define png_flush_ptr_NULL NULL
615	#define png_free_ptr_NULL NULL
616	#define png_infopp_NULL NULL
617	#define png_malloc_ptr_NULL NULL
618	#define png_read_status_ptr_NULL NULL
619	#define png_rw_ptr_NULL NULL
620	#define png_structp_NULL NULL
621	#define png_uint_16p_NULL NULL
622	#define png_voidp_NULL NULL
623	#define png_write_status_ptr_NULL NULL
624	#endif
625
626	/* Variables declared in png.c - only it needs to define PNG_NO_EXTERN */
627	#if !defined(PNG_NO_EXTERN) \|\| defined(PNG_ALWAYS_EXTERN)
628	/* Version information for C files, stored in png.c. This had better match
629	* the version above.
630	*/
631	#ifdef PNG_USE_GLOBAL_ARRAYS
632	PNG_EXPORT_VAR (PNG_CONST char) png_libpng_ver[18];
633	/* Need room for 99.99.99beta99z */
634	#else
635	#define png_libpng_ver png_get_header_ver(NULL)
636	#endif
637
638	#ifdef PNG_USE_GLOBAL_ARRAYS
639	/* This was removed in version 1.0.5c */
640	/* Structures to facilitate easy interlacing. See png.c for more details */
641	PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_start[7];
642	PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_inc[7];
643	PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_ystart[7];
644	PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_yinc[7];
645	PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_mask[7];
646	PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_dsp_mask[7];
647	/* This isn't currently used. If you need it, see png.c for more details.
648	PNG_EXPORT_VAR (PNG_CONST int FARDATA) png_pass_height[7];
649	*/
650	#endif
651
652	#endif /* PNG_NO_EXTERN */
653
654	/* Three color definitions. The order of the red, green, and blue, (and the
655	* exact size) is not important, although the size of the fields need to
656	* be png_byte or png_uint_16 (as defined below).
657	*/
658	typedef struct png_color_struct
659	{
660	png_byte red;
661	png_byte green;
662	png_byte blue;
663	} png_color;
664	typedef png_color FAR * png_colorp;
665	typedef png_color FAR * FAR * png_colorpp;
666
667	typedef struct png_color_16_struct
668	{
669	png_byte index; /* used for palette files */
670	png_uint_16 red; /* for use in red green blue files */
671	png_uint_16 green;
672	png_uint_16 blue;
673	png_uint_16 gray; /* for use in grayscale files */
674	} png_color_16;
675	typedef png_color_16 FAR * png_color_16p;
676	typedef png_color_16 FAR * FAR * png_color_16pp;
677
678	typedef struct png_color_8_struct
679	{
680	png_byte red; /* for use in red green blue files */
681	png_byte green;
682	png_byte blue;
683	png_byte gray; /* for use in grayscale files */
684	png_byte alpha; /* for alpha channel files */
685	} png_color_8;
686	typedef png_color_8 FAR * png_color_8p;
687	typedef png_color_8 FAR * FAR * png_color_8pp;
688
689	/*
690	* The following two structures are used for the in-core representation
691	* of sPLT chunks.
692	*/
693	typedef struct png_sPLT_entry_struct
694	{
695	png_uint_16 red;
696	png_uint_16 green;
697	png_uint_16 blue;
698	png_uint_16 alpha;
699	png_uint_16 frequency;
700	} png_sPLT_entry;
701	typedef png_sPLT_entry FAR * png_sPLT_entryp;
702	typedef png_sPLT_entry FAR * FAR * png_sPLT_entrypp;
703
704	/* When the depth of the sPLT palette is 8 bits, the color and alpha samples
705	* occupy the LSB of their respective members, and the MSB of each member
706	* is zero-filled. The frequency member always occupies the full 16 bits.
707	*/
708
709	typedef struct png_sPLT_struct
710	{
711	png_charp name; /* palette name */
712	png_byte depth; /* depth of palette samples */
713	png_sPLT_entryp entries; /* palette entries */
714	png_int_32 nentries; /* number of palette entries */
715	} png_sPLT_t;
716	typedef png_sPLT_t FAR * png_sPLT_tp;
717	typedef png_sPLT_t FAR * FAR * png_sPLT_tpp;
718
719	#ifdef PNG_TEXT_SUPPORTED
720	/* png_text holds the contents of a text/ztxt/itxt chunk in a PNG file,
721	* and whether that contents is compressed or not. The "key" field
722	* points to a regular zero-terminated C string. The "text", "lang", and
723	* "lang_key" fields can be regular C strings, empty strings, or NULL pointers.
724	* However, the * structure returned by png_get_text() will always contain
725	* regular zero-terminated C strings (possibly empty), never NULL pointers,
726	* so they can be safely used in printf() and other string-handling functions.
727	*/
728	typedef struct png_text_struct
729	{
730	int compression; /* compression value:
731	-1: tEXt, none
732	0: zTXt, deflate
733	1: iTXt, none
734	2: iTXt, deflate */
735	png_charp key; /* keyword, 1-79 character description of "text" */
736	png_charp text; /* comment, may be an empty string (ie "")
737	or a NULL pointer */
738	png_size_t text_length; /* length of the text string */
739	#ifdef PNG_iTXt_SUPPORTED
740	png_size_t itxt_length; /* length of the itxt string */
741	png_charp lang; /* language code, 0-79 characters
742	or a NULL pointer */
743	png_charp lang_key; /* keyword translated UTF-8 string, 0 or more
744	chars or a NULL pointer */
745	#endif
746	} png_text;
747	typedef png_text FAR * png_textp;
748	typedef png_text FAR * FAR * png_textpp;
749	#endif
750
751	/* Supported compression types for text in PNG files (tEXt, and zTXt).
752	* The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed.
753	*/
754	#define PNG_TEXT_COMPRESSION_NONE_WR -3
755	#define PNG_TEXT_COMPRESSION_zTXt_WR -2
756	#define PNG_TEXT_COMPRESSION_NONE -1
757	#define PNG_TEXT_COMPRESSION_zTXt 0
758	#define PNG_ITXT_COMPRESSION_NONE 1
759	#define PNG_ITXT_COMPRESSION_zTXt 2
760	#define PNG_TEXT_COMPRESSION_LAST 3 /* Not a valid value */
761
762	/* png_time is a way to hold the time in an machine independent way.
763	* Two conversions are provided, both from time_t and struct tm. There
764	* is no portable way to convert to either of these structures, as far
765	* as I know. If you know of a portable way, send it to me. As a side
766	* note - PNG has always been Year 2000 compliant!
767	*/
768	typedef struct png_time_struct
769	{
770	png_uint_16 year; /* full year, as in, 1995 */
771	png_byte month; /* month of year, 1 - 12 */
772	png_byte day; /* day of month, 1 - 31 */
773	png_byte hour; /* hour of day, 0 - 23 */
774	png_byte minute; /* minute of hour, 0 - 59 */
775	png_byte second; /* second of minute, 0 - 60 (for leap seconds) */
776	} png_time;
777	typedef png_time FAR * png_timep;
778	typedef png_time FAR * FAR * png_timepp;
779
780	#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) \|\| \
781	defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
782	/* png_unknown_chunk is a structure to hold queued chunks for which there is
783	* no specific support. The idea is that we can use this to queue
784	* up private chunks for output even though the library doesn't actually
785	* know about their semantics.
786	*/
787	#define PNG_CHUNK_NAME_LENGTH 5
788	typedef struct png_unknown_chunk_t
789	{
790	png_byte name[PNG_CHUNK_NAME_LENGTH];
791	png_byte *data;
792	png_size_t size;
793
794	/* libpng-using applications should NOT directly modify this byte. */
795	png_byte location; /* mode of operation at read time */
796	}
797	png_unknown_chunk;
798	typedef png_unknown_chunk FAR * png_unknown_chunkp;
799	typedef png_unknown_chunk FAR * FAR * png_unknown_chunkpp;
800	#endif
801
802	/* png_info is a structure that holds the information in a PNG file so
803	* that the application can find out the characteristics of the image.
804	* If you are reading the file, this structure will tell you what is
805	* in the PNG file. If you are writing the file, fill in the information
806	* you want to put into the PNG file, then call png_write_info().
807	* The names chosen should be very close to the PNG specification, so
808	* consult that document for information about the meaning of each field.
809	*
810	* With libpng < 0.95, it was only possible to directly set and read the
811	* the values in the png_info_struct, which meant that the contents and
812	* order of the values had to remain fixed. With libpng 0.95 and later,
813	* however, there are now functions that abstract the contents of
814	* png_info_struct from the application, so this makes it easier to use
815	* libpng with dynamic libraries, and even makes it possible to use
816	* libraries that don't have all of the libpng ancillary chunk-handing
817	* functionality.
818	*
819	* In any case, the order of the parameters in png_info_struct should NOT
820	* be changed for as long as possible to keep compatibility with applications
821	* that use the old direct-access method with png_info_struct.
822	*
823	* The following members may have allocated storage attached that should be
824	* cleaned up before the structure is discarded: palette, trans, text,
825	* pcal_purpose, pcal_units, pcal_params, hist, iccp_name, iccp_profile,
826	* splt_palettes, scal_unit, row_pointers, and unknowns. By default, these
827	* are automatically freed when the info structure is deallocated, if they were
828	* allocated internally by libpng. This behavior can be changed by means
829	* of the png_data_freer() function.
830	*
831	* More allocation details: all the chunk-reading functions that
832	* change these members go through the corresponding png_set_*
833	* functions. A function to clear these members is available: see
834	* png_free_data(). The png_set_* functions do not depend on being
835	* able to point info structure members to any of the storage they are
836	* passed (they make their own copies), EXCEPT that the png_set_text
837	* functions use the same storage passed to them in the text_ptr or
838	* itxt_ptr structure argument, and the png_set_rows and png_set_unknowns
839	* functions do not make their own copies.
840	*/
841	typedef struct png_info_struct
842	{
843	/* The following are necessary for every PNG file */
844	png_uint_32 width PNG_DEPSTRUCT; /* width of image in pixels (from IHDR) */
845	png_uint_32 height PNG_DEPSTRUCT; /* height of image in pixels (from IHDR) */
846	png_uint_32 valid PNG_DEPSTRUCT; /* valid chunk data (see PNG_INFO_ below) */
847	png_uint_32 rowbytes PNG_DEPSTRUCT; /* bytes needed to hold an untransformed row */
848	png_colorp palette PNG_DEPSTRUCT; /* array of color values (valid & PNG_INFO_PLTE) */
849	png_uint_16 num_palette PNG_DEPSTRUCT; /* number of color entries in "palette" (PLTE) */
850	png_uint_16 num_trans PNG_DEPSTRUCT; /* number of transparent palette color (tRNS) */
851	png_byte bit_depth PNG_DEPSTRUCT; /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */
852	png_byte color_type PNG_DEPSTRUCT; /* see PNG_COLOR_TYPE_ below (from IHDR) */
853	/* The following three should have been named _method not _type */
854	png_byte compression_type PNG_DEPSTRUCT; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */
855	png_byte filter_type PNG_DEPSTRUCT; /* must be PNG_FILTER_TYPE_BASE (from IHDR) */
856	png_byte interlace_type PNG_DEPSTRUCT; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
857
858	/* The following is informational only on read, and not used on writes. */
859	png_byte channels PNG_DEPSTRUCT; /* number of data channels per pixel (1, 2, 3, 4) */
860	png_byte pixel_depth PNG_DEPSTRUCT; /* number of bits per pixel */
861	png_byte spare_byte PNG_DEPSTRUCT; /* to align the data, and for future use */
862	png_byte signature[8] PNG_DEPSTRUCT; /* magic bytes read by libpng from start of file */
863
864	/* The rest of the data is optional. If you are reading, check the
865	* valid field to see if the information in these are valid. If you
866	* are writing, set the valid field to those chunks you want written,
867	* and initialize the appropriate fields below.
868	*/
869
870	#if defined(PNG_gAMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
871	/* The gAMA chunk describes the gamma characteristics of the system
872	* on which the image was created, normally in the range [1.0, 2.5].
873	* Data is valid if (valid & PNG_INFO_gAMA) is non-zero.
874	*/
875	float gamma PNG_DEPSTRUCT; /* gamma value of image, if (valid & PNG_INFO_gAMA) */
876	#endif
877
878	#ifdef PNG_sRGB_SUPPORTED
879	/* GR-P, 0.96a */
880	/* Data valid if (valid & PNG_INFO_sRGB) non-zero. */
881	png_byte srgb_intent PNG_DEPSTRUCT; /* sRGB rendering intent [0, 1, 2, or 3] */
882	#endif
883
884	#ifdef PNG_TEXT_SUPPORTED
885	/* The tEXt, and zTXt chunks contain human-readable textual data in
886	* uncompressed, compressed, and optionally compressed forms, respectively.
887	* The data in "text" is an array of pointers to uncompressed,
888	* null-terminated C strings. Each chunk has a keyword that describes the
889	* textual data contained in that chunk. Keywords are not required to be
890	* unique, and the text string may be empty. Any number of text chunks may
891	* be in an image.
892	*/
893	int num_text PNG_DEPSTRUCT; /* number of comments read/to write */
894	int max_text PNG_DEPSTRUCT; /* current size of text array */
895	png_textp text PNG_DEPSTRUCT; /* array of comments read/to write */
896	#endif /* PNG_TEXT_SUPPORTED */
897
898	#ifdef PNG_tIME_SUPPORTED
899	/* The tIME chunk holds the last time the displayed image data was
900	* modified. See the png_time struct for the contents of this struct.
901	*/
902	png_time mod_time PNG_DEPSTRUCT;
903	#endif
904
905	#ifdef PNG_sBIT_SUPPORTED
906	/* The sBIT chunk specifies the number of significant high-order bits
907	* in the pixel data. Values are in the range [1, bit_depth], and are
908	* only specified for the channels in the pixel data. The contents of
909	* the low-order bits is not specified. Data is valid if
910	* (valid & PNG_INFO_sBIT) is non-zero.
911	*/
912	png_color_8 sig_bit PNG_DEPSTRUCT; /* significant bits in color channels */
913	#endif
914
915	#if defined(PNG_tRNS_SUPPORTED) \|\| defined(PNG_READ_EXPAND_SUPPORTED) \|\| \
916	defined(PNG_READ_BACKGROUND_SUPPORTED)
917	/* The tRNS chunk supplies transparency data for paletted images and
918	* other image types that don't need a full alpha channel. There are
919	* "num_trans" transparency values for a paletted image, stored in the
920	* same order as the palette colors, starting from index 0. Values
921	* for the data are in the range [0, 255], ranging from fully transparent
922	* to fully opaque, respectively. For non-paletted images, there is a
923	* single color specified that should be treated as fully transparent.
924	* Data is valid if (valid & PNG_INFO_tRNS) is non-zero.
925	*/
926	png_bytep trans PNG_DEPSTRUCT; /* transparent values for paletted image */
927	png_color_16 trans_values PNG_DEPSTRUCT; /* transparent color for non-palette image */
928	#endif
929
930	#if defined(PNG_bKGD_SUPPORTED) \|\| defined(PNG_READ_BACKGROUND_SUPPORTED)
931	/* The bKGD chunk gives the suggested image background color if the
932	* display program does not have its own background color and the image
933	* is needs to composited onto a background before display. The colors
934	* in "background" are normally in the same color space/depth as the
935	* pixel data. Data is valid if (valid & PNG_INFO_bKGD) is non-zero.
936	*/
937	png_color_16 background PNG_DEPSTRUCT;
938	#endif
939
940	#ifdef PNG_oFFs_SUPPORTED
941	/* The oFFs chunk gives the offset in "offset_unit_type" units rightwards
942	* and downwards from the top-left corner of the display, page, or other
943	* application-specific co-ordinate space. See the PNG_OFFSET_ defines
944	* below for the unit types. Valid if (valid & PNG_INFO_oFFs) non-zero.
945	*/
946	png_int_32 x_offset PNG_DEPSTRUCT; /* x offset on page */
947	png_int_32 y_offset PNG_DEPSTRUCT; /* y offset on page */
948	png_byte offset_unit_type PNG_DEPSTRUCT; /* offset units type */
949	#endif
950
951	#ifdef PNG_pHYs_SUPPORTED
952	/* The pHYs chunk gives the physical pixel density of the image for
953	* display or printing in "phys_unit_type" units (see PNG_RESOLUTION_
954	* defines below). Data is valid if (valid & PNG_INFO_pHYs) is non-zero.
955	*/
956	png_uint_32 x_pixels_per_unit PNG_DEPSTRUCT; /* horizontal pixel density */
957	png_uint_32 y_pixels_per_unit PNG_DEPSTRUCT; /* vertical pixel density */
958	png_byte phys_unit_type PNG_DEPSTRUCT; /* resolution type (see PNG_RESOLUTION_ below) */
959	#endif
960
961	#ifdef PNG_hIST_SUPPORTED
962	/* The hIST chunk contains the relative frequency or importance of the
963	* various palette entries, so that a viewer can intelligently select a
964	* reduced-color palette, if required. Data is an array of "num_palette"
965	* values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST)
966	* is non-zero.
967	*/
968	png_uint_16p hist PNG_DEPSTRUCT;
969	#endif
970
971	#ifdef PNG_cHRM_SUPPORTED
972	/* The cHRM chunk describes the CIE color characteristics of the monitor
973	* on which the PNG was created. This data allows the viewer to do gamut
974	* mapping of the input image to ensure that the viewer sees the same
975	* colors in the image as the creator. Values are in the range
976	* [0.0, 0.8]. Data valid if (valid & PNG_INFO_cHRM) non-zero.
977	*/
978	#ifdef PNG_FLOATING_POINT_SUPPORTED
979	float x_white PNG_DEPSTRUCT;
980	float y_white PNG_DEPSTRUCT;
981	float x_red PNG_DEPSTRUCT;
982	float y_red PNG_DEPSTRUCT;
983	float x_green PNG_DEPSTRUCT;
984	float y_green PNG_DEPSTRUCT;
985	float x_blue PNG_DEPSTRUCT;
986	float y_blue PNG_DEPSTRUCT;
987	#endif
988	#endif
989
990	#ifdef PNG_pCAL_SUPPORTED
991	/* The pCAL chunk describes a transformation between the stored pixel
992	* values and original physical data values used to create the image.
993	* The integer range [0, 2^bit_depth - 1] maps to the floating-point
994	* range given by [pcal_X0, pcal_X1], and are further transformed by a
995	* (possibly non-linear) transformation function given by "pcal_type"
996	* and "pcal_params" into "pcal_units". Please see the PNG_EQUATION_
997	* defines below, and the PNG-Group's PNG extensions document for a
998	* complete description of the transformations and how they should be
999	* implemented, and for a description of the ASCII parameter strings.
1000	* Data values are valid if (valid & PNG_INFO_pCAL) non-zero.
1001	*/
1002	png_charp pcal_purpose PNG_DEPSTRUCT; /* pCAL chunk description string */
1003	png_int_32 pcal_X0 PNG_DEPSTRUCT; /* minimum value */
1004	png_int_32 pcal_X1 PNG_DEPSTRUCT; /* maximum value */
1005	png_charp pcal_units PNG_DEPSTRUCT; /* Latin-1 string giving physical units */
1006	png_charpp pcal_params PNG_DEPSTRUCT; /* ASCII strings containing parameter values */
1007	png_byte pcal_type PNG_DEPSTRUCT; /* equation type (see PNG_EQUATION_ below) */
1008	png_byte pcal_nparams PNG_DEPSTRUCT; /* number of parameters given in pcal_params */
1009	#endif
1010
1011	/* New members added in libpng-1.0.6 */
1012	#ifdef PNG_FREE_ME_SUPPORTED
1013	png_uint_32 free_me PNG_DEPSTRUCT; /* flags items libpng is responsible for freeing */
1014	#endif
1015
1016	#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED) \|\| \
1017	defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
1018	/* Storage for unknown chunks that the library doesn't recognize. */
1019	png_unknown_chunkp unknown_chunks PNG_DEPSTRUCT;
1020	png_size_t unknown_chunks_num PNG_DEPSTRUCT;
1021	#endif
1022
1023	#ifdef PNG_iCCP_SUPPORTED
1024	/* iCCP chunk data. */
1025	png_charp iccp_name PNG_DEPSTRUCT; /* profile name */
1026	png_charp iccp_profile PNG_DEPSTRUCT; /* International Color Consortium profile data */
1027	/* Note to maintainer: should be png_bytep */
1028	png_uint_32 iccp_proflen PNG_DEPSTRUCT; /* ICC profile data length */
1029	png_byte iccp_compression PNG_DEPSTRUCT; /* Always zero */
1030	#endif
1031
1032	#ifdef PNG_sPLT_SUPPORTED
1033	/* Data on sPLT chunks (there may be more than one). */
1034	png_sPLT_tp splt_palettes PNG_DEPSTRUCT;
1035	png_uint_32 splt_palettes_num PNG_DEPSTRUCT;
1036	#endif
1037
1038	#ifdef PNG_sCAL_SUPPORTED
1039	/* The sCAL chunk describes the actual physical dimensions of the
1040	* subject matter of the graphic. The chunk contains a unit specification
1041	* a byte value, and two ASCII strings representing floating-point
1042	* values. The values are width and height corresponsing to one pixel
1043	* in the image. This external representation is converted to double
1044	* here. Data values are valid if (valid & PNG_INFO_sCAL) is non-zero.
1045	*/
1046	png_byte scal_unit PNG_DEPSTRUCT; /* unit of physical scale */
1047	#ifdef PNG_FLOATING_POINT_SUPPORTED
1048	double scal_pixel_width PNG_DEPSTRUCT; /* width of one pixel */
1049	double scal_pixel_height PNG_DEPSTRUCT; /* height of one pixel */
1050	#endif
1051	#ifdef PNG_FIXED_POINT_SUPPORTED
1052	png_charp scal_s_width PNG_DEPSTRUCT; /* string containing height */
1053	png_charp scal_s_height PNG_DEPSTRUCT; /* string containing width */
1054	#endif
1055	#endif
1056
1057	#ifdef PNG_INFO_IMAGE_SUPPORTED
1058	/* Memory has been allocated if (valid & PNG_ALLOCATED_INFO_ROWS) non-zero */
1059	/* Data valid if (valid & PNG_INFO_IDAT) non-zero */
1060	png_bytepp row_pointers PNG_DEPSTRUCT; /* the image bits */
1061	#endif
1062
1063	#if defined(PNG_FIXED_POINT_SUPPORTED) && defined(PNG_gAMA_SUPPORTED)
1064	png_fixed_point int_gamma PNG_DEPSTRUCT; /* gamma of image, if (valid & PNG_INFO_gAMA) */
1065	#endif
1066
1067	#if defined(PNG_cHRM_SUPPORTED) && defined(PNG_FIXED_POINT_SUPPORTED)
1068	png_fixed_point int_x_white PNG_DEPSTRUCT;
1069	png_fixed_point int_y_white PNG_DEPSTRUCT;
1070	png_fixed_point int_x_red PNG_DEPSTRUCT;
1071	png_fixed_point int_y_red PNG_DEPSTRUCT;
1072	png_fixed_point int_x_green PNG_DEPSTRUCT;
1073	png_fixed_point int_y_green PNG_DEPSTRUCT;
1074	png_fixed_point int_x_blue PNG_DEPSTRUCT;
1075	png_fixed_point int_y_blue PNG_DEPSTRUCT;
1076	#endif
1077
1078	} png_info;
1079
1080	typedef png_info FAR * png_infop;
1081	typedef png_info FAR * FAR * png_infopp;
1082
1083	/* Maximum positive integer used in PNG is (2^31)-1 */
1084	#define PNG_UINT_31_MAX ((png_uint_32)0x7fffffffL)
1085	#define PNG_UINT_32_MAX ((png_uint_32)(-1))
1086	#define PNG_SIZE_MAX ((png_size_t)(-1))
1087	#if defined(PNG_1_0_X) \|\| defined (PNG_1_2_X)
1088	/* PNG_MAX_UINT is deprecated; use PNG_UINT_31_MAX instead. */
1089	#define PNG_MAX_UINT PNG_UINT_31_MAX
1090	#endif
1091
1092	/* These describe the color_type field in png_info. */
1093	/* color type masks */
1094	#define PNG_COLOR_MASK_PALETTE 1
1095	#define PNG_COLOR_MASK_COLOR 2
1096	#define PNG_COLOR_MASK_ALPHA 4
1097
1098	/* color types. Note that not all combinations are legal */
1099	#define PNG_COLOR_TYPE_GRAY 0
1100	#define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR \| PNG_COLOR_MASK_PALETTE)
1101	#define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR)
1102	#define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR \| PNG_COLOR_MASK_ALPHA)
1103	#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA)
1104	/* aliases */
1105	#define PNG_COLOR_TYPE_RGBA PNG_COLOR_TYPE_RGB_ALPHA
1106	#define PNG_COLOR_TYPE_GA PNG_COLOR_TYPE_GRAY_ALPHA
1107
1108	/* This is for compression type. PNG 1.0-1.2 only define the single type. */
1109	#define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */
1110	#define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE
1111
1112	/* This is for filter type. PNG 1.0-1.2 only define the single type. */
1113	#define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */
1114	#define PNG_INTRAPIXEL_DIFFERENCING 64 /* Used only in MNG datastreams */
1115	#define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE
1116
1117	/* These are for the interlacing type. These values should NOT be changed. */
1118	#define PNG_INTERLACE_NONE 0 /* Non-interlaced image */
1119	#define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */
1120	#define PNG_INTERLACE_LAST 2 /* Not a valid value */
1121
1122	/* These are for the oFFs chunk. These values should NOT be changed. */
1123	#define PNG_OFFSET_PIXEL 0 /* Offset in pixels */
1124	#define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */
1125	#define PNG_OFFSET_LAST 2 /* Not a valid value */
1126
1127	/* These are for the pCAL chunk. These values should NOT be changed. */
1128	#define PNG_EQUATION_LINEAR 0 /* Linear transformation */
1129	#define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */
1130	#define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */
1131	#define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */
1132	#define PNG_EQUATION_LAST 4 /* Not a valid value */
1133
1134	/* These are for the sCAL chunk. These values should NOT be changed. */
1135	#define PNG_SCALE_UNKNOWN 0 /* unknown unit (image scale) */
1136	#define PNG_SCALE_METER 1 /* meters per pixel */
1137	#define PNG_SCALE_RADIAN 2 /* radians per pixel */
1138	#define PNG_SCALE_LAST 3 /* Not a valid value */
1139
1140	/* These are for the pHYs chunk. These values should NOT be changed. */
1141	#define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */
1142	#define PNG_RESOLUTION_METER 1 /* pixels/meter */
1143	#define PNG_RESOLUTION_LAST 2 /* Not a valid value */
1144
1145	/* These are for the sRGB chunk. These values should NOT be changed. */
1146	#define PNG_sRGB_INTENT_PERCEPTUAL 0
1147	#define PNG_sRGB_INTENT_RELATIVE 1
1148	#define PNG_sRGB_INTENT_SATURATION 2
1149	#define PNG_sRGB_INTENT_ABSOLUTE 3
1150	#define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */
1151
1152	/* This is for text chunks */
1153	#define PNG_KEYWORD_MAX_LENGTH 79
1154
1155	/* Maximum number of entries in PLTE/sPLT/tRNS arrays */
1156	#define PNG_MAX_PALETTE_LENGTH 256
1157
1158	/* These determine if an ancillary chunk's data has been successfully read
1159	* from the PNG header, or if the application has filled in the corresponding
1160	* data in the info_struct to be written into the output file. The values
1161	* of the PNG_INFO_<chunk> defines should NOT be changed.
1162	*/
1163	#define PNG_INFO_gAMA 0x0001
1164	#define PNG_INFO_sBIT 0x0002
1165	#define PNG_INFO_cHRM 0x0004
1166	#define PNG_INFO_PLTE 0x0008
1167	#define PNG_INFO_tRNS 0x0010
1168	#define PNG_INFO_bKGD 0x0020
1169	#define PNG_INFO_hIST 0x0040
1170	#define PNG_INFO_pHYs 0x0080
1171	#define PNG_INFO_oFFs 0x0100
1172	#define PNG_INFO_tIME 0x0200
1173	#define PNG_INFO_pCAL 0x0400
1174	#define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */
1175	#define PNG_INFO_iCCP 0x1000 /* ESR, 1.0.6 */
1176	#define PNG_INFO_sPLT 0x2000 /* ESR, 1.0.6 */
1177	#define PNG_INFO_sCAL 0x4000 /* ESR, 1.0.6 */
1178	#define PNG_INFO_IDAT 0x8000L /* ESR, 1.0.6 */
1179
1180	/* This is used for the transformation routines, as some of them
1181	* change these values for the row. It also should enable using
1182	* the routines for other purposes.
1183	*/
1184	typedef struct png_row_info_struct
1185	{
1186	png_uint_32 width; /* width of row */
1187	png_uint_32 rowbytes; /* number of bytes in row */
1188	png_byte color_type; /* color type of row */
1189	png_byte bit_depth; /* bit depth of row */
1190	png_byte channels; /* number of channels (1, 2, 3, or 4) */
1191	png_byte pixel_depth; /* bits per pixel (depth * channels) */
1192	} png_row_info;
1193
1194	typedef png_row_info FAR * png_row_infop;
1195	typedef png_row_info FAR * FAR * png_row_infopp;
1196
1197	/* These are the function types for the I/O functions and for the functions
1198	* that allow the user to override the default I/O functions with his or her
1199	* own. The png_error_ptr type should match that of user-supplied warning
1200	* and error functions, while the png_rw_ptr type should match that of the
1201	* user read/write data functions.
1202	*/
1203	typedef struct png_struct_def png_struct;
1204	typedef png_struct FAR * png_structp;
1205
1206	typedef void (PNGAPI *png_error_ptr) PNGARG((png_structp, png_const_charp));
1207	typedef void (PNGAPI *png_rw_ptr) PNGARG((png_structp, png_bytep, png_size_t));
1208	typedef void (PNGAPI *png_flush_ptr) PNGARG((png_structp));
1209	typedef void (PNGAPI *png_read_status_ptr) PNGARG((png_structp, png_uint_32,
1210	int));
1211	typedef void (PNGAPI *png_write_status_ptr) PNGARG((png_structp, png_uint_32,
1212	int));
1213
1214	#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1215	typedef void (PNGAPI *png_progressive_info_ptr) PNGARG((png_structp, png_infop));
1216	typedef void (PNGAPI *png_progressive_end_ptr) PNGARG((png_structp, png_infop));
1217	typedef void (PNGAPI *png_progressive_row_ptr) PNGARG((png_structp, png_bytep,
1218	png_uint_32, int));
1219	#endif
1220
1221	#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) \|\| \
1222	defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) \|\| \
1223	defined(PNG_LEGACY_SUPPORTED)
1224	typedef void (PNGAPI *png_user_transform_ptr) PNGARG((png_structp,
1225	png_row_infop, png_bytep));
1226	#endif
1227
1228	#ifdef PNG_USER_CHUNKS_SUPPORTED
1229	typedef int (PNGAPI *png_user_chunk_ptr) PNGARG((png_structp, png_unknown_chunkp));
1230	#endif
1231	#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
1232	typedef void (PNGAPI *png_unknown_chunk_ptr) PNGARG((png_structp));
1233	#endif
1234
1235	/* Transform masks for the high-level interface */
1236	#define PNG_TRANSFORM_IDENTITY 0x0000 /* read and write */
1237	#define PNG_TRANSFORM_STRIP_16 0x0001 /* read only */
1238	#define PNG_TRANSFORM_STRIP_ALPHA 0x0002 /* read only */
1239	#define PNG_TRANSFORM_PACKING 0x0004 /* read and write */
1240	#define PNG_TRANSFORM_PACKSWAP 0x0008 /* read and write */
1241	#define PNG_TRANSFORM_EXPAND 0x0010 /* read only */
1242	#define PNG_TRANSFORM_INVERT_MONO 0x0020 /* read and write */
1243	#define PNG_TRANSFORM_SHIFT 0x0040 /* read and write */
1244	#define PNG_TRANSFORM_BGR 0x0080 /* read and write */
1245	#define PNG_TRANSFORM_SWAP_ALPHA 0x0100 /* read and write */
1246	#define PNG_TRANSFORM_SWAP_ENDIAN 0x0200 /* read and write */
1247	#define PNG_TRANSFORM_INVERT_ALPHA 0x0400 /* read and write */
1248	#define PNG_TRANSFORM_STRIP_FILLER 0x0800 /* write only, deprecated */
1249	/* Added to libpng-1.2.34 */
1250	#define PNG_TRANSFORM_STRIP_FILLER_BEFORE 0x0800 /* write only */
1251	#define PNG_TRANSFORM_STRIP_FILLER_AFTER 0x1000 /* write only */
1252	/* Added to libpng-1.2.41 */
1253	#define PNG_TRANSFORM_GRAY_TO_RGB 0x2000 /* read only */
1254
1255	/* Flags for MNG supported features */
1256	#define PNG_FLAG_MNG_EMPTY_PLTE 0x01
1257	#define PNG_FLAG_MNG_FILTER_64 0x04
1258	#define PNG_ALL_MNG_FEATURES 0x05
1259
1260	typedef png_voidp (*png_malloc_ptr) PNGARG((png_structp, png_size_t));
1261	typedef void (*png_free_ptr) PNGARG((png_structp, png_voidp));
1262
1263	/* The structure that holds the information to read and write PNG files.
1264	* The only people who need to care about what is inside of this are the
1265	* people who will be modifying the library for their own special needs.
1266	* It should NOT be accessed directly by an application, except to store
1267	* the jmp_buf.
1268	*/
1269
1270	struct png_struct_def
1271	{
1272	#ifdef PNG_SETJMP_SUPPORTED
1273	jmp_buf jmpbuf; /* used in png_error */
1274	#endif
1275	png_error_ptr error_fn PNG_DEPSTRUCT; /* function for printing errors and aborting */
1276	png_error_ptr warning_fn PNG_DEPSTRUCT; /* function for printing warnings */
1277	png_voidp error_ptr PNG_DEPSTRUCT; /* user supplied struct for error functions */
1278	png_rw_ptr write_data_fn PNG_DEPSTRUCT; /* function for writing output data */
1279	png_rw_ptr read_data_fn PNG_DEPSTRUCT; /* function for reading input data */
1280	png_voidp io_ptr PNG_DEPSTRUCT; /* ptr to application struct for I/O functions */
1281
1282	#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
1283	png_user_transform_ptr read_user_transform_fn PNG_DEPSTRUCT; /* user read transform */
1284	#endif
1285
1286	#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1287	png_user_transform_ptr write_user_transform_fn PNG_DEPSTRUCT; /* user write transform */
1288	#endif
1289
1290	/* These were added in libpng-1.0.2 */
1291	#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
1292	#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) \|\| \
1293	defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1294	png_voidp user_transform_ptr PNG_DEPSTRUCT; /* user supplied struct for user transform */
1295	png_byte user_transform_depth PNG_DEPSTRUCT; /* bit depth of user transformed pixels */
1296	png_byte user_transform_channels PNG_DEPSTRUCT; /* channels in user transformed pixels */
1297	#endif
1298	#endif
1299
1300	png_uint_32 mode PNG_DEPSTRUCT; /* tells us where we are in the PNG file */
1301	png_uint_32 flags PNG_DEPSTRUCT; /* flags indicating various things to libpng */
1302	png_uint_32 transformations PNG_DEPSTRUCT; /* which transformations to perform */
1303
1304	z_stream zstream PNG_DEPSTRUCT; /* pointer to decompression structure (below) */
1305	png_bytep zbuf PNG_DEPSTRUCT; /* buffer for zlib */
1306	png_size_t zbuf_size PNG_DEPSTRUCT; /* size of zbuf */
1307	int zlib_level PNG_DEPSTRUCT; /* holds zlib compression level */
1308	int zlib_method PNG_DEPSTRUCT; /* holds zlib compression method */
1309	int zlib_window_bits PNG_DEPSTRUCT; /* holds zlib compression window bits */
1310	int zlib_mem_level PNG_DEPSTRUCT; /* holds zlib compression memory level */
1311	int zlib_strategy PNG_DEPSTRUCT; /* holds zlib compression strategy */
1312
1313	png_uint_32 width PNG_DEPSTRUCT; /* width of image in pixels */
1314	png_uint_32 height PNG_DEPSTRUCT; /* height of image in pixels */
1315	png_uint_32 num_rows PNG_DEPSTRUCT; /* number of rows in current pass */
1316	png_uint_32 usr_width PNG_DEPSTRUCT; /* width of row at start of write */
1317	png_uint_32 rowbytes PNG_DEPSTRUCT; /* size of row in bytes */
1318	#if 0 /* Replaced with the following in libpng-1.2.43 */
1319	png_size_t irowbytes PNG_DEPSTRUCT;
1320	#endif
1321	/* Added in libpng-1.2.43 */
1322	#ifdef PNG_USER_LIMITS_SUPPORTED
1323	/* Added in libpng-1.4.0: Total number of sPLT, text, and unknown
1324	* chunks that can be stored (0 means unlimited).
1325	*/
1326	png_uint_32 user_chunk_cache_max PNG_DEPSTRUCT;
1327	#endif
1328	png_uint_32 iwidth PNG_DEPSTRUCT; /* width of current interlaced row in pixels */
1329	png_uint_32 row_number PNG_DEPSTRUCT; /* current row in interlace pass */
1330	png_bytep prev_row PNG_DEPSTRUCT; /* buffer to save previous (unfiltered) row */
1331	png_bytep row_buf PNG_DEPSTRUCT; /* buffer to save current (unfiltered) row */
1332	#ifndef PNG_NO_WRITE_FILTER
1333	png_bytep sub_row PNG_DEPSTRUCT; /* buffer to save "sub" row when filtering */
1334	png_bytep up_row PNG_DEPSTRUCT; /* buffer to save "up" row when filtering */
1335	png_bytep avg_row PNG_DEPSTRUCT; /* buffer to save "avg" row when filtering */
1336	png_bytep paeth_row PNG_DEPSTRUCT; /* buffer to save "Paeth" row when filtering */
1337	#endif
1338	png_row_info row_info PNG_DEPSTRUCT; /* used for transformation routines */
1339
1340	png_uint_32 idat_size PNG_DEPSTRUCT; /* current IDAT size for read */
1341	png_uint_32 crc PNG_DEPSTRUCT; /* current chunk CRC value */
1342	png_colorp palette PNG_DEPSTRUCT; /* palette from the input file */
1343	png_uint_16 num_palette PNG_DEPSTRUCT; /* number of color entries in palette */
1344	png_uint_16 num_trans PNG_DEPSTRUCT; /* number of transparency values */
1345	png_byte chunk_name[5] PNG_DEPSTRUCT; /* null-terminated name of current chunk */
1346	png_byte compression PNG_DEPSTRUCT; /* file compression type (always 0) */
1347	png_byte filter PNG_DEPSTRUCT; /* file filter type (always 0) */
1348	png_byte interlaced PNG_DEPSTRUCT; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
1349	png_byte pass PNG_DEPSTRUCT; /* current interlace pass (0 - 6) */
1350	png_byte do_filter PNG_DEPSTRUCT; /* row filter flags (see PNG_FILTER_ below ) */
1351	png_byte color_type PNG_DEPSTRUCT; /* color type of file */
1352	png_byte bit_depth PNG_DEPSTRUCT; /* bit depth of file */
1353	png_byte usr_bit_depth PNG_DEPSTRUCT; /* bit depth of users row */
1354	png_byte pixel_depth PNG_DEPSTRUCT; /* number of bits per pixel */
1355	png_byte channels PNG_DEPSTRUCT; /* number of channels in file */
1356	png_byte usr_channels PNG_DEPSTRUCT; /* channels at start of write */
1357	png_byte sig_bytes PNG_DEPSTRUCT; /* magic bytes read/written from start of file */
1358
1359	#if defined(PNG_READ_FILLER_SUPPORTED) \|\| defined(PNG_WRITE_FILLER_SUPPORTED)
1360	#ifdef PNG_LEGACY_SUPPORTED
1361	png_byte filler PNG_DEPSTRUCT; /* filler byte for pixel expansion */
1362	#else
1363	png_uint_16 filler PNG_DEPSTRUCT; /* filler bytes for pixel expansion */
1364	#endif
1365	#endif
1366
1367	#ifdef PNG_bKGD_SUPPORTED
1368	png_byte background_gamma_type PNG_DEPSTRUCT;
1369	# ifdef PNG_FLOATING_POINT_SUPPORTED
1370	float background_gamma PNG_DEPSTRUCT;
1371	# endif
1372	png_color_16 background PNG_DEPSTRUCT; /* background color in screen gamma space */
1373	#ifdef PNG_READ_GAMMA_SUPPORTED
1374	png_color_16 background_1 PNG_DEPSTRUCT; /* background normalized to gamma 1.0 */
1375	#endif
1376	#endif /* PNG_bKGD_SUPPORTED */
1377
1378	#ifdef PNG_WRITE_FLUSH_SUPPORTED
1379	png_flush_ptr output_flush_fn PNG_DEPSTRUCT; /* Function for flushing output */
1380	png_uint_32 flush_dist PNG_DEPSTRUCT; /* how many rows apart to flush, 0 - no flush */
1381	png_uint_32 flush_rows PNG_DEPSTRUCT; /* number of rows written since last flush */
1382	#endif
1383
1384	#if defined(PNG_READ_GAMMA_SUPPORTED) \|\| defined(PNG_READ_BACKGROUND_SUPPORTED)
1385	int gamma_shift PNG_DEPSTRUCT; /* number of "insignificant" bits 16-bit gamma */
1386	#ifdef PNG_FLOATING_POINT_SUPPORTED
1387	float gamma PNG_DEPSTRUCT; /* file gamma value */
1388	float screen_gamma PNG_DEPSTRUCT; /* screen gamma value (display_exponent) */
1389	#endif
1390	#endif
1391
1392	#if defined(PNG_READ_GAMMA_SUPPORTED) \|\| defined(PNG_READ_BACKGROUND_SUPPORTED)
1393	png_bytep gamma_table PNG_DEPSTRUCT; /* gamma table for 8-bit depth files */
1394	png_bytep gamma_from_1 PNG_DEPSTRUCT; /* converts from 1.0 to screen */
1395	png_bytep gamma_to_1 PNG_DEPSTRUCT; /* converts from file to 1.0 */
1396	png_uint_16pp gamma_16_table PNG_DEPSTRUCT; /* gamma table for 16-bit depth files */
1397	png_uint_16pp gamma_16_from_1 PNG_DEPSTRUCT; /* converts from 1.0 to screen */
1398	png_uint_16pp gamma_16_to_1 PNG_DEPSTRUCT; /* converts from file to 1.0 */
1399	#endif
1400
1401	#if defined(PNG_READ_GAMMA_SUPPORTED) \|\| defined(PNG_sBIT_SUPPORTED)
1402	png_color_8 sig_bit PNG_DEPSTRUCT; /* significant bits in each available channel */
1403	#endif
1404
1405	#if defined(PNG_READ_SHIFT_SUPPORTED) \|\| defined(PNG_WRITE_SHIFT_SUPPORTED)
1406	png_color_8 shift PNG_DEPSTRUCT; /* shift for significant bit tranformation */
1407	#endif
1408
1409	#if defined(PNG_tRNS_SUPPORTED) \|\| defined(PNG_READ_BACKGROUND_SUPPORTED) \
1410	\|\| defined(PNG_READ_EXPAND_SUPPORTED) \|\| defined(PNG_READ_BACKGROUND_SUPPORTED)
1411	png_bytep trans PNG_DEPSTRUCT; /* transparency values for paletted files */
1412	png_color_16 trans_values PNG_DEPSTRUCT; /* transparency values for non-paletted files */
1413	#endif
1414
1415	png_read_status_ptr read_row_fn PNG_DEPSTRUCT; /* called after each row is decoded */
1416	png_write_status_ptr write_row_fn PNG_DEPSTRUCT; /* called after each row is encoded */
1417	#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1418	png_progressive_info_ptr info_fn PNG_DEPSTRUCT; /* called after header data fully read */
1419	png_progressive_row_ptr row_fn PNG_DEPSTRUCT; /* called after each prog. row is decoded */
1420	png_progressive_end_ptr end_fn PNG_DEPSTRUCT; /* called after image is complete */
1421	png_bytep save_buffer_ptr PNG_DEPSTRUCT; /* current location in save_buffer */
1422	png_bytep save_buffer PNG_DEPSTRUCT; /* buffer for previously read data */
1423	png_bytep current_buffer_ptr PNG_DEPSTRUCT; /* current location in current_buffer */
1424	png_bytep current_buffer PNG_DEPSTRUCT; /* buffer for recently used data */
1425	png_uint_32 push_length PNG_DEPSTRUCT; /* size of current input chunk */
1426	png_uint_32 skip_length PNG_DEPSTRUCT; /* bytes to skip in input data */
1427	png_size_t save_buffer_size PNG_DEPSTRUCT; /* amount of data now in save_buffer */
1428	png_size_t save_buffer_max PNG_DEPSTRUCT; /* total size of save_buffer */
1429	png_size_t buffer_size PNG_DEPSTRUCT; /* total amount of available input data */
1430	png_size_t current_buffer_size PNG_DEPSTRUCT; /* amount of data now in current_buffer */
1431	int process_mode PNG_DEPSTRUCT; /* what push library is currently doing */
1432	int cur_palette PNG_DEPSTRUCT; /* current push library palette index */
1433
1434	# ifdef PNG_TEXT_SUPPORTED
1435	png_size_t current_text_size PNG_DEPSTRUCT; /* current size of text input data */
1436	png_size_t current_text_left PNG_DEPSTRUCT; /* how much text left to read in input */
1437	png_charp current_text PNG_DEPSTRUCT; /* current text chunk buffer */
1438	png_charp current_text_ptr PNG_DEPSTRUCT; /* current location in current_text */
1439	# endif /* PNG_TEXT_SUPPORTED */
1440	#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1441
1442	#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
1443	/* for the Borland special 64K segment handler */
1444	png_bytepp offset_table_ptr PNG_DEPSTRUCT;
1445	png_bytep offset_table PNG_DEPSTRUCT;
1446	png_uint_16 offset_table_number PNG_DEPSTRUCT;
1447	png_uint_16 offset_table_count PNG_DEPSTRUCT;
1448	png_uint_16 offset_table_count_free PNG_DEPSTRUCT;
1449	#endif
1450
1451	#ifdef PNG_READ_DITHER_SUPPORTED
1452	png_bytep palette_lookup PNG_DEPSTRUCT; /* lookup table for dithering */
1453	png_bytep dither_index PNG_DEPSTRUCT; /* index translation for palette files */
1454	#endif
1455
1456	#if defined(PNG_READ_DITHER_SUPPORTED) \|\| defined(PNG_hIST_SUPPORTED)
1457	png_uint_16p hist PNG_DEPSTRUCT; /* histogram */
1458	#endif
1459
1460	#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
1461	png_byte heuristic_method PNG_DEPSTRUCT; /* heuristic for row filter selection */
1462	png_byte num_prev_filters PNG_DEPSTRUCT; /* number of weights for previous rows */
1463	png_bytep prev_filters PNG_DEPSTRUCT; /* filter type(s) of previous row(s) */
1464	png_uint_16p filter_weights PNG_DEPSTRUCT; /* weight(s) for previous line(s) */
1465	png_uint_16p inv_filter_weights PNG_DEPSTRUCT; /* 1/weight(s) for previous line(s) */
1466	png_uint_16p filter_costs PNG_DEPSTRUCT; /* relative filter calculation cost */
1467	png_uint_16p inv_filter_costs PNG_DEPSTRUCT; /* 1/relative filter calculation cost */
1468	#endif
1469
1470	#ifdef PNG_TIME_RFC1123_SUPPORTED
1471	png_charp time_buffer PNG_DEPSTRUCT; /* String to hold RFC 1123 time text */
1472	#endif
1473
1474	/* New members added in libpng-1.0.6 */
1475
1476	#ifdef PNG_FREE_ME_SUPPORTED
1477	png_uint_32 free_me PNG_DEPSTRUCT; /* flags items libpng is responsible for freeing */
1478	#endif
1479
1480	#ifdef PNG_USER_CHUNKS_SUPPORTED
1481	png_voidp user_chunk_ptr PNG_DEPSTRUCT;
1482	png_user_chunk_ptr read_user_chunk_fn PNG_DEPSTRUCT; /* user read chunk handler */
1483	#endif
1484
1485	#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
1486	int num_chunk_list PNG_DEPSTRUCT;
1487	png_bytep chunk_list PNG_DEPSTRUCT;
1488	#endif
1489
1490	/* New members added in libpng-1.0.3 */
1491	#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1492	png_byte rgb_to_gray_status PNG_DEPSTRUCT;
1493	/* These were changed from png_byte in libpng-1.0.6 */
1494	png_uint_16 rgb_to_gray_red_coeff PNG_DEPSTRUCT;
1495	png_uint_16 rgb_to_gray_green_coeff PNG_DEPSTRUCT;
1496	png_uint_16 rgb_to_gray_blue_coeff PNG_DEPSTRUCT;
1497	#endif
1498
1499	/* New member added in libpng-1.0.4 (renamed in 1.0.9) */
1500	#if defined(PNG_MNG_FEATURES_SUPPORTED) \|\| \
1501	defined(PNG_READ_EMPTY_PLTE_SUPPORTED) \|\| \
1502	defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1503	/* Changed from png_byte to png_uint_32 at version 1.2.0 */
1504	#ifdef PNG_1_0_X
1505	png_byte mng_features_permitted PNG_DEPSTRUCT;
1506	#else
1507	png_uint_32 mng_features_permitted PNG_DEPSTRUCT;
1508	#endif /* PNG_1_0_X */
1509	#endif
1510
1511	/* New member added in libpng-1.0.7 */
1512	#if defined(PNG_READ_GAMMA_SUPPORTED) \|\| defined(PNG_READ_BACKGROUND_SUPPORTED)
1513	png_fixed_point int_gamma PNG_DEPSTRUCT;
1514	#endif
1515
1516	/* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
1517	#ifdef PNG_MNG_FEATURES_SUPPORTED
1518	png_byte filter_type PNG_DEPSTRUCT;
1519	#endif
1520
1521	#ifdef PNG_1_0_X
1522	/* New member added in libpng-1.0.10, ifdef'ed out in 1.2.0 */
1523	png_uint_32 row_buf_size PNG_DEPSTRUCT;
1524	#endif
1525
1526	/* New members added in libpng-1.2.0 */
1527	#ifdef PNG_ASSEMBLER_CODE_SUPPORTED
1528	# ifndef PNG_1_0_X
1529	# ifdef PNG_MMX_CODE_SUPPORTED
1530	png_byte mmx_bitdepth_threshold PNG_DEPSTRUCT;
1531	png_uint_32 mmx_rowbytes_threshold PNG_DEPSTRUCT;
1532	# endif
1533	png_uint_32 asm_flags PNG_DEPSTRUCT;
1534	# endif
1535	#endif
1536
1537	/* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
1538	#ifdef PNG_USER_MEM_SUPPORTED
1539	png_voidp mem_ptr PNG_DEPSTRUCT; /* user supplied struct for mem functions */
1540	png_malloc_ptr malloc_fn PNG_DEPSTRUCT; /* function for allocating memory */
1541	png_free_ptr free_fn PNG_DEPSTRUCT; /* function for freeing memory */
1542	#endif
1543
1544	/* New member added in libpng-1.0.13 and 1.2.0 */
1545	png_bytep big_row_buf PNG_DEPSTRUCT; /* buffer to save current (unfiltered) row */
1546
1547	#ifdef PNG_READ_DITHER_SUPPORTED
1548	/* The following three members were added at version 1.0.14 and 1.2.4 */
1549	png_bytep dither_sort PNG_DEPSTRUCT; /* working sort array */
1550	png_bytep index_to_palette PNG_DEPSTRUCT; /* where the original index currently is */
1551	/* in the palette */
1552	png_bytep palette_to_index PNG_DEPSTRUCT; /* which original index points to this */
1553	/* palette color */
1554	#endif
1555
1556	/* New members added in libpng-1.0.16 and 1.2.6 */
1557	png_byte compression_type PNG_DEPSTRUCT;
1558
1559	#ifdef PNG_USER_LIMITS_SUPPORTED
1560	png_uint_32 user_width_max PNG_DEPSTRUCT;
1561	png_uint_32 user_height_max PNG_DEPSTRUCT;
1562	#endif
1563
1564	/* New member added in libpng-1.0.25 and 1.2.17 */
1565	#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
1566	/* Storage for unknown chunk that the library doesn't recognize. */
1567	png_unknown_chunk unknown_chunk PNG_DEPSTRUCT;
1568	#endif
1569
1570	/* New members added in libpng-1.2.26 */
1571	png_uint_32 old_big_row_buf_size PNG_DEPSTRUCT;
1572	png_uint_32 old_prev_row_size PNG_DEPSTRUCT;
1573
1574	/* New member added in libpng-1.2.30 */
1575	png_charp chunkdata PNG_DEPSTRUCT; /* buffer for reading chunk data */
1576
1577
1578	};
1579
1580
1581	/* This triggers a compiler error in png.c, if png.c and png.h
1582	* do not agree upon the version number.
1583	*/
1584	typedef png_structp version_1_2_53;
1585
1586	typedef png_struct FAR * FAR * png_structpp;
1587
1588	/* Here are the function definitions most commonly used. This is not
1589	* the place to find out how to use libpng. See libpng.txt for the
1590	* full explanation, see example.c for the summary. This just provides
1591	* a simple one line description of the use of each function.
1592	*/
1593
1594	/* Returns the version number of the library */
1595	extern PNG_EXPORT(png_uint_32,png_access_version_number) PNGARG((void));
1596
1597	/* Tell lib we have already handled the first <num_bytes> magic bytes.
1598	* Handling more than 8 bytes from the beginning of the file is an error.
1599	*/
1600	extern PNG_EXPORT(void,png_set_sig_bytes) PNGARG((png_structp png_ptr,
1601	int num_bytes));
1602
1603	/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a
1604	* PNG file. Returns zero if the supplied bytes match the 8-byte PNG
1605	* signature, and non-zero otherwise. Having num_to_check == 0 or
1606	* start > 7 will always fail (ie return non-zero).
1607	*/
1608	extern PNG_EXPORT(int,png_sig_cmp) PNGARG((png_bytep sig, png_size_t start,
1609	png_size_t num_to_check));
1610
1611	/* Simple signature checking function. This is the same as calling
1612	* png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n).
1613	*/
1614	extern PNG_EXPORT(int,png_check_sig) PNGARG((png_bytep sig, int num)) PNG_DEPRECATED;
1615
1616	/* Allocate and initialize png_ptr struct for reading, and any other memory. */
1617	extern PNG_EXPORT(png_structp,png_create_read_struct)
1618	PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1619	png_error_ptr error_fn, png_error_ptr warn_fn)) PNG_ALLOCATED;
1620
1621	/* Allocate and initialize png_ptr struct for writing, and any other memory */
1622	extern PNG_EXPORT(png_structp,png_create_write_struct)
1623	PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1624	png_error_ptr error_fn, png_error_ptr warn_fn)) PNG_ALLOCATED;
1625
1626	#ifdef PNG_WRITE_SUPPORTED
1627	extern PNG_EXPORT(png_uint_32,png_get_compression_buffer_size)
1628	PNGARG((png_structp png_ptr));
1629	#endif
1630
1631	#ifdef PNG_WRITE_SUPPORTED
1632	extern PNG_EXPORT(void,png_set_compression_buffer_size)
1633	PNGARG((png_structp png_ptr, png_uint_32 size));
1634	#endif
1635
1636	/* Reset the compression stream */
1637	extern PNG_EXPORT(int,png_reset_zstream) PNGARG((png_structp png_ptr));
1638
1639	/* New functions added in libpng-1.0.2 (not enabled by default until 1.2.0) */
1640	#ifdef PNG_USER_MEM_SUPPORTED
1641	extern PNG_EXPORT(png_structp,png_create_read_struct_2)
1642	PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1643	png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1644	png_malloc_ptr malloc_fn, png_free_ptr free_fn)) PNG_ALLOCATED;
1645	extern PNG_EXPORT(png_structp,png_create_write_struct_2)
1646	PNGARG((png_const_charp user_png_ver, png_voidp error_ptr,
1647	png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
1648	png_malloc_ptr malloc_fn, png_free_ptr free_fn)) PNG_ALLOCATED;
1649	#endif
1650
1651	/* Write a PNG chunk - size, type, (optional) data, CRC. */
1652	extern PNG_EXPORT(void,png_write_chunk) PNGARG((png_structp png_ptr,
1653	png_bytep chunk_name, png_bytep data, png_size_t length));
1654
1655	/* Write the start of a PNG chunk - length and chunk name. */
1656	extern PNG_EXPORT(void,png_write_chunk_start) PNGARG((png_structp png_ptr,
1657	png_bytep chunk_name, png_uint_32 length));
1658
1659	/* Write the data of a PNG chunk started with png_write_chunk_start(). */
1660	extern PNG_EXPORT(void,png_write_chunk_data) PNGARG((png_structp png_ptr,
1661	png_bytep data, png_size_t length));
1662
1663	/* Finish a chunk started with png_write_chunk_start() (includes CRC). */
1664	extern PNG_EXPORT(void,png_write_chunk_end) PNGARG((png_structp png_ptr));
1665
1666	/* Allocate and initialize the info structure */
1667	extern PNG_EXPORT(png_infop,png_create_info_struct)
1668	PNGARG((png_structp png_ptr)) PNG_ALLOCATED;
1669
1670	#if defined(PNG_1_0_X) \|\| defined (PNG_1_2_X)
1671	/* Initialize the info structure (old interface - DEPRECATED) */
1672	extern PNG_EXPORT(void,png_info_init) PNGARG((png_infop info_ptr))
1673	PNG_DEPRECATED;
1674	#undef png_info_init
1675	#define png_info_init(info_ptr) png_info_init_3(&info_ptr,\
1676	png_sizeof(png_info));
1677	#endif
1678
1679	extern PNG_EXPORT(void,png_info_init_3) PNGARG((png_infopp info_ptr,
1680	png_size_t png_info_struct_size));
1681
1682	/* Writes all the PNG information before the image. */
1683	extern PNG_EXPORT(void,png_write_info_before_PLTE) PNGARG((png_structp png_ptr,
1684	png_infop info_ptr));
1685	extern PNG_EXPORT(void,png_write_info) PNGARG((png_structp png_ptr,
1686	png_infop info_ptr));
1687
1688	#ifdef PNG_SEQUENTIAL_READ_SUPPORTED
1689	/* Read the information before the actual image data. */
1690	extern PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr,
1691	png_infop info_ptr));
1692	#endif
1693
1694	#ifdef PNG_TIME_RFC1123_SUPPORTED
1695	extern PNG_EXPORT(png_charp,png_convert_to_rfc1123)
1696	PNGARG((png_structp png_ptr, png_timep ptime));
1697	#endif
1698
1699	#ifdef PNG_CONVERT_tIME_SUPPORTED
1700	/* Convert from a struct tm to png_time */
1701	extern PNG_EXPORT(void,png_convert_from_struct_tm) PNGARG((png_timep ptime,
1702	struct tm FAR * ttime));
1703
1704	/* Convert from time_t to png_time. Uses gmtime() */
1705	extern PNG_EXPORT(void,png_convert_from_time_t) PNGARG((png_timep ptime,
1706	time_t ttime));
1707	#endif /* PNG_CONVERT_tIME_SUPPORTED */
1708
1709	#ifdef PNG_READ_EXPAND_SUPPORTED
1710	/* Expand data to 24-bit RGB, or 8-bit grayscale, with alpha if available. */
1711	extern PNG_EXPORT(void,png_set_expand) PNGARG((png_structp png_ptr));
1712	#ifndef PNG_1_0_X
1713	extern PNG_EXPORT(void,png_set_expand_gray_1_2_4_to_8) PNGARG((png_structp
1714	png_ptr));
1715	#endif
1716	extern PNG_EXPORT(void,png_set_palette_to_rgb) PNGARG((png_structp png_ptr));
1717	extern PNG_EXPORT(void,png_set_tRNS_to_alpha) PNGARG((png_structp png_ptr));
1718	#if defined(PNG_1_0_X) \|\| defined (PNG_1_2_X)
1719	/* Deprecated */
1720	extern PNG_EXPORT(void,png_set_gray_1_2_4_to_8) PNGARG((png_structp
1721	png_ptr)) PNG_DEPRECATED;
1722	#endif
1723	#endif
1724
1725	#if defined(PNG_READ_BGR_SUPPORTED) \|\| defined(PNG_WRITE_BGR_SUPPORTED)
1726	/* Use blue, green, red order for pixels. */
1727	extern PNG_EXPORT(void,png_set_bgr) PNGARG((png_structp png_ptr));
1728	#endif
1729
1730	#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1731	/* Expand the grayscale to 24-bit RGB if necessary. */
1732	extern PNG_EXPORT(void,png_set_gray_to_rgb) PNGARG((png_structp png_ptr));
1733	#endif
1734
1735	#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1736	/* Reduce RGB to grayscale. */
1737	#ifdef PNG_FLOATING_POINT_SUPPORTED
1738	extern PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr,
1739	int error_action, double red, double green ));
1740	#endif
1741	extern PNG_EXPORT(void,png_set_rgb_to_gray_fixed) PNGARG((png_structp png_ptr,
1742	int error_action, png_fixed_point red, png_fixed_point green ));
1743	extern PNG_EXPORT(png_byte,png_get_rgb_to_gray_status) PNGARG((png_structp
1744	png_ptr));
1745	#endif
1746
1747	extern PNG_EXPORT(void,png_build_grayscale_palette) PNGARG((int bit_depth,
1748	png_colorp palette));
1749
1750	#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1751	extern PNG_EXPORT(void,png_set_strip_alpha) PNGARG((png_structp png_ptr));
1752	#endif
1753
1754	#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) \|\| \
1755	defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1756	extern PNG_EXPORT(void,png_set_swap_alpha) PNGARG((png_structp png_ptr));
1757	#endif
1758
1759	#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) \|\| \
1760	defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1761	extern PNG_EXPORT(void,png_set_invert_alpha) PNGARG((png_structp png_ptr));
1762	#endif
1763
1764	#if defined(PNG_READ_FILLER_SUPPORTED) \|\| defined(PNG_WRITE_FILLER_SUPPORTED)
1765	/* Add a filler byte to 8-bit Gray or 24-bit RGB images. */
1766	extern PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr,
1767	png_uint_32 filler, int flags));
1768	/* The values of the PNG_FILLER_ defines should NOT be changed */
1769	#define PNG_FILLER_BEFORE 0
1770	#define PNG_FILLER_AFTER 1
1771	/* Add an alpha byte to 8-bit Gray or 24-bit RGB images. */
1772	#ifndef PNG_1_0_X
1773	extern PNG_EXPORT(void,png_set_add_alpha) PNGARG((png_structp png_ptr,
1774	png_uint_32 filler, int flags));
1775	#endif
1776	#endif /* PNG_READ_FILLER_SUPPORTED \|\| PNG_WRITE_FILLER_SUPPORTED */
1777
1778	#if defined(PNG_READ_SWAP_SUPPORTED) \|\| defined(PNG_WRITE_SWAP_SUPPORTED)
1779	/* Swap bytes in 16-bit depth files. */
1780	extern PNG_EXPORT(void,png_set_swap) PNGARG((png_structp png_ptr));
1781	#endif
1782
1783	#if defined(PNG_READ_PACK_SUPPORTED) \|\| defined(PNG_WRITE_PACK_SUPPORTED)
1784	/* Use 1 byte per pixel in 1, 2, or 4-bit depth files. */
1785	extern PNG_EXPORT(void,png_set_packing) PNGARG((png_structp png_ptr));
1786	#endif
1787
1788	#if defined(PNG_READ_PACKSWAP_SUPPORTED) \|\| defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1789	/* Swap packing order of pixels in bytes. */
1790	extern PNG_EXPORT(void,png_set_packswap) PNGARG((png_structp png_ptr));
1791	#endif
1792
1793	#if defined(PNG_READ_SHIFT_SUPPORTED) \|\| defined(PNG_WRITE_SHIFT_SUPPORTED)
1794	/* Converts files to legal bit depths. */
1795	extern PNG_EXPORT(void,png_set_shift) PNGARG((png_structp png_ptr,
1796	png_color_8p true_bits));
1797	#endif
1798
1799	#if defined(PNG_READ_INTERLACING_SUPPORTED) \|\| \
1800	defined(PNG_WRITE_INTERLACING_SUPPORTED)
1801	/* Have the code handle the interlacing. Returns the number of passes. */
1802	extern PNG_EXPORT(int,png_set_interlace_handling) PNGARG((png_structp png_ptr));
1803	#endif
1804
1805	#if defined(PNG_READ_INVERT_SUPPORTED) \|\| defined(PNG_WRITE_INVERT_SUPPORTED)
1806	/* Invert monochrome files */
1807	extern PNG_EXPORT(void,png_set_invert_mono) PNGARG((png_structp png_ptr));
1808	#endif
1809
1810	#ifdef PNG_READ_BACKGROUND_SUPPORTED
1811	/* Handle alpha and tRNS by replacing with a background color. */
1812	#ifdef PNG_FLOATING_POINT_SUPPORTED
1813	extern PNG_EXPORT(void,png_set_background) PNGARG((png_structp png_ptr,
1814	png_color_16p background_color, int background_gamma_code,
1815	int need_expand, double background_gamma));
1816	#endif
1817	#define PNG_BACKGROUND_GAMMA_UNKNOWN 0
1818	#define PNG_BACKGROUND_GAMMA_SCREEN 1
1819	#define PNG_BACKGROUND_GAMMA_FILE 2
1820	#define PNG_BACKGROUND_GAMMA_UNIQUE 3
1821	#endif
1822
1823	#ifdef PNG_READ_16_TO_8_SUPPORTED
1824	/* Strip the second byte of information from a 16-bit depth file. */
1825	extern PNG_EXPORT(void,png_set_strip_16) PNGARG((png_structp png_ptr));
1826	#endif
1827
1828	#ifdef PNG_READ_DITHER_SUPPORTED
1829	/* Turn on dithering, and reduce the palette to the number of colors available. */
1830	extern PNG_EXPORT(void,png_set_dither) PNGARG((png_structp png_ptr,
1831	png_colorp palette, int num_palette, int maximum_colors,
1832	png_uint_16p histogram, int full_dither));
1833	#endif
1834
1835	#ifdef PNG_READ_GAMMA_SUPPORTED
1836	/* Handle gamma correction. Screen_gamma=(display_exponent) */
1837	#ifdef PNG_FLOATING_POINT_SUPPORTED
1838	extern PNG_EXPORT(void,png_set_gamma) PNGARG((png_structp png_ptr,
1839	double screen_gamma, double default_file_gamma));
1840	#endif
1841	#endif
1842
1843	#if defined(PNG_1_0_X) \|\| defined (PNG_1_2_X)
1844	#if defined(PNG_READ_EMPTY_PLTE_SUPPORTED) \|\| \
1845	defined(PNG_WRITE_EMPTY_PLTE_SUPPORTED)
1846	/* Permit or disallow empty PLTE (0: not permitted, 1: permitted) */
1847	/* Deprecated and will be removed. Use png_permit_mng_features() instead. */
1848	extern PNG_EXPORT(void,png_permit_empty_plte) PNGARG((png_structp png_ptr,
1849	int empty_plte_permitted)) PNG_DEPRECATED;
1850	#endif
1851	#endif
1852
1853	#ifdef PNG_WRITE_FLUSH_SUPPORTED
1854	/* Set how many lines between output flushes - 0 for no flushing */
1855	extern PNG_EXPORT(void,png_set_flush) PNGARG((png_structp png_ptr, int nrows));
1856	/* Flush the current PNG output buffer */
1857	extern PNG_EXPORT(void,png_write_flush) PNGARG((png_structp png_ptr));
1858	#endif
1859
1860	/* Optional update palette with requested transformations */
1861	extern PNG_EXPORT(void,png_start_read_image) PNGARG((png_structp png_ptr));
1862
1863	/* Optional call to update the users info structure */
1864	extern PNG_EXPORT(void,png_read_update_info) PNGARG((png_structp png_ptr,
1865	png_infop info_ptr));
1866
1867	#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1868	/* Read one or more rows of image data. */
1869	extern PNG_EXPORT(void,png_read_rows) PNGARG((png_structp png_ptr,
1870	png_bytepp row, png_bytepp display_row, png_uint_32 num_rows));
1871	#endif
1872
1873	#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1874	/* Read a row of data. */
1875	extern PNG_EXPORT(void,png_read_row) PNGARG((png_structp png_ptr,
1876	png_bytep row,
1877	png_bytep display_row));
1878	#endif
1879
1880	#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1881	/* Read the whole image into memory at once. */
1882	extern PNG_EXPORT(void,png_read_image) PNGARG((png_structp png_ptr,
1883	png_bytepp image));
1884	#endif
1885
1886	/* Write a row of image data */
1887	extern PNG_EXPORT(void,png_write_row) PNGARG((png_structp png_ptr,
1888	png_bytep row));
1889
1890	/* Write a few rows of image data */
1891	extern PNG_EXPORT(void,png_write_rows) PNGARG((png_structp png_ptr,
1892	png_bytepp row, png_uint_32 num_rows));
1893
1894	/* Write the image data */
1895	extern PNG_EXPORT(void,png_write_image) PNGARG((png_structp png_ptr,
1896	png_bytepp image));
1897
1898	/* Writes the end of the PNG file. */
1899	extern PNG_EXPORT(void,png_write_end) PNGARG((png_structp png_ptr,
1900	png_infop info_ptr));
1901
1902	#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
1903	/* Read the end of the PNG file. */
1904	extern PNG_EXPORT(void,png_read_end) PNGARG((png_structp png_ptr,
1905	png_infop info_ptr));
1906	#endif
1907
1908	/* Free any memory associated with the png_info_struct */
1909	extern PNG_EXPORT(void,png_destroy_info_struct) PNGARG((png_structp png_ptr,
1910	png_infopp info_ptr_ptr));
1911
1912	/* Free any memory associated with the png_struct and the png_info_structs */
1913	extern PNG_EXPORT(void,png_destroy_read_struct) PNGARG((png_structpp
1914	png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr));
1915
1916	/* Free all memory used by the read (old method - NOT DLL EXPORTED) */
1917	extern void png_read_destroy PNGARG((png_structp png_ptr, png_infop info_ptr,
1918	png_infop end_info_ptr)) PNG_DEPRECATED;
1919
1920	/* Free any memory associated with the png_struct and the png_info_structs */
1921	extern PNG_EXPORT(void,png_destroy_write_struct)
1922	PNGARG((png_structpp png_ptr_ptr, png_infopp info_ptr_ptr));
1923
1924	/* Free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */
1925	extern void png_write_destroy PNGARG((png_structp png_ptr)) PNG_DEPRECATED;
1926
1927	/* Set the libpng method of handling chunk CRC errors */
1928	extern PNG_EXPORT(void,png_set_crc_action) PNGARG((png_structp png_ptr,
1929	int crit_action, int ancil_action));
1930
1931	/* Values for png_set_crc_action() to say how to handle CRC errors in
1932	* ancillary and critical chunks, and whether to use the data contained
1933	* therein. Note that it is impossible to "discard" data in a critical
1934	* chunk. For versions prior to 0.90, the action was always error/quit,
1935	* whereas in version 0.90 and later, the action for CRC errors in ancillary
1936	* chunks is warn/discard. These values should NOT be changed.
1937	*
1938	* value action:critical action:ancillary
1939	*/
1940	#define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */
1941	#define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */
1942	#define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */
1943	#define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */
1944	#define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */
1945	#define PNG_CRC_NO_CHANGE 5 /* use current value use current value */
1946
1947	/* These functions give the user control over the scan-line filtering in
1948	* libpng and the compression methods used by zlib. These functions are
1949	* mainly useful for testing, as the defaults should work with most users.
1950	* Those users who are tight on memory or want faster performance at the
1951	* expense of compression can modify them. See the compression library
1952	* header file (zlib.h) for an explination of the compression functions.
1953	*/
1954
1955	/* Set the filtering method(s) used by libpng. Currently, the only valid
1956	* value for "method" is 0.
1957	*/
1958	extern PNG_EXPORT(void,png_set_filter) PNGARG((png_structp png_ptr, int method,
1959	int filters));
1960
1961	/* Flags for png_set_filter() to say which filters to use. The flags
1962	* are chosen so that they don't conflict with real filter types
1963	* below, in case they are supplied instead of the #defined constants.
1964	* These values should NOT be changed.
1965	*/
1966	#define PNG_NO_FILTERS 0x00
1967	#define PNG_FILTER_NONE 0x08
1968	#define PNG_FILTER_SUB 0x10
1969	#define PNG_FILTER_UP 0x20
1970	#define PNG_FILTER_AVG 0x40
1971	#define PNG_FILTER_PAETH 0x80
1972	#define PNG_ALL_FILTERS (PNG_FILTER_NONE \| PNG_FILTER_SUB \| PNG_FILTER_UP \| \
1973	PNG_FILTER_AVG \| PNG_FILTER_PAETH)
1974
1975	/* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now.
1976	* These defines should NOT be changed.
1977	*/
1978	#define PNG_FILTER_VALUE_NONE 0
1979	#define PNG_FILTER_VALUE_SUB 1
1980	#define PNG_FILTER_VALUE_UP 2
1981	#define PNG_FILTER_VALUE_AVG 3
1982	#define PNG_FILTER_VALUE_PAETH 4
1983	#define PNG_FILTER_VALUE_LAST 5
1984
1985	#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* EXPERIMENTAL */
1986	/* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_
1987	* defines, either the default (minimum-sum-of-absolute-differences), or
1988	* the experimental method (weighted-minimum-sum-of-absolute-differences).
1989	*
1990	* Weights are factors >= 1.0, indicating how important it is to keep the
1991	* filter type consistent between rows. Larger numbers mean the current
1992	* filter is that many times as likely to be the same as the "num_weights"
1993	* previous filters. This is cumulative for each previous row with a weight.
1994	* There needs to be "num_weights" values in "filter_weights", or it can be
1995	* NULL if the weights aren't being specified. Weights have no influence on
1996	* the selection of the first row filter. Well chosen weights can (in theory)
1997	* improve the compression for a given image.
1998	*
1999	* Costs are factors >= 1.0 indicating the relative decoding costs of a
2000	* filter type. Higher costs indicate more decoding expense, and are
2001	* therefore less likely to be selected over a filter with lower computational
2002	* costs. There needs to be a value in "filter_costs" for each valid filter
2003	* type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't
2004	* setting the costs. Costs try to improve the speed of decompression without
2005	* unduly increasing the compressed image size.
2006	*
2007	* A negative weight or cost indicates the default value is to be used, and
2008	* values in the range [0.0, 1.0) indicate the value is to remain unchanged.
2009	* The default values for both weights and costs are currently 1.0, but may
2010	* change if good general weighting/cost heuristics can be found. If both
2011	* the weights and costs are set to 1.0, this degenerates the WEIGHTED method
2012	* to the UNWEIGHTED method, but with added encoding time/computation.
2013	*/
2014	#ifdef PNG_FLOATING_POINT_SUPPORTED
2015	extern PNG_EXPORT(void,png_set_filter_heuristics) PNGARG((png_structp png_ptr,
2016	int heuristic_method, int num_weights, png_doublep filter_weights,
2017	png_doublep filter_costs));
2018	#endif
2019	#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
2020
2021	/* Heuristic used for row filter selection. These defines should NOT be
2022	* changed.
2023	*/
2024	#define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */
2025	#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */
2026	#define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */
2027	#define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */
2028
2029	/* Set the library compression level. Currently, valid values range from
2030	* 0 - 9, corresponding directly to the zlib compression levels 0 - 9
2031	* (0 - no compression, 9 - "maximal" compression). Note that tests have
2032	* shown that zlib compression levels 3-6 usually perform as well as level 9
2033	* for PNG images, and do considerably fewer caclulations. In the future,
2034	* these values may not correspond directly to the zlib compression levels.
2035	*/
2036	extern PNG_EXPORT(void,png_set_compression_level) PNGARG((png_structp png_ptr,
2037	int level));
2038
2039	extern PNG_EXPORT(void,png_set_compression_mem_level)
2040	PNGARG((png_structp png_ptr, int mem_level));
2041
2042	extern PNG_EXPORT(void,png_set_compression_strategy)
2043	PNGARG((png_structp png_ptr, int strategy));
2044
2045	extern PNG_EXPORT(void,png_set_compression_window_bits)
2046	PNGARG((png_structp png_ptr, int window_bits));
2047
2048	extern PNG_EXPORT(void,png_set_compression_method) PNGARG((png_structp png_ptr,
2049	int method));
2050
2051	/* These next functions are called for input/output, memory, and error
2052	* handling. They are in the file pngrio.c, pngwio.c, and pngerror.c,
2053	* and call standard C I/O routines such as fread(), fwrite(), and
2054	* fprintf(). These functions can be made to use other I/O routines
2055	* at run time for those applications that need to handle I/O in a
2056	* different manner by calling png_set_???_fn(). See libpng.txt for
2057	* more information.
2058	*/
2059
2060	#ifdef PNG_STDIO_SUPPORTED
2061	/* Initialize the input/output for the PNG file to the default functions. */
2062	extern PNG_EXPORT(void,png_init_io) PNGARG((png_structp png_ptr, png_FILE_p fp));
2063	#endif
2064
2065	/* Replace the (error and abort), and warning functions with user
2066	* supplied functions. If no messages are to be printed you must still
2067	* write and use replacement functions. The replacement error_fn should
2068	* still do a longjmp to the last setjmp location if you are using this
2069	* method of error handling. If error_fn or warning_fn is NULL, the
2070	* default function will be used.
2071	*/
2072
2073	extern PNG_EXPORT(void,png_set_error_fn) PNGARG((png_structp png_ptr,
2074	png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn));
2075
2076	/* Return the user pointer associated with the error functions */
2077	extern PNG_EXPORT(png_voidp,png_get_error_ptr) PNGARG((png_structp png_ptr));
2078
2079	/* Replace the default data output functions with a user supplied one(s).
2080	* If buffered output is not used, then output_flush_fn can be set to NULL.
2081	* If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time
2082	* output_flush_fn will be ignored (and thus can be NULL).
2083	* It is probably a mistake to use NULL for output_flush_fn if
2084	* write_data_fn is not also NULL unless you have built libpng with
2085	* PNG_WRITE_FLUSH_SUPPORTED undefined, because in this case libpng's
2086	* default flush function, which uses the standard *FILE structure, will
2087	* be used.
2088	*/
2089	extern PNG_EXPORT(void,png_set_write_fn) PNGARG((png_structp png_ptr,
2090	png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn));
2091
2092	/* Replace the default data input function with a user supplied one. */
2093	extern PNG_EXPORT(void,png_set_read_fn) PNGARG((png_structp png_ptr,
2094	png_voidp io_ptr, png_rw_ptr read_data_fn));
2095
2096	/* Return the user pointer associated with the I/O functions */
2097	extern PNG_EXPORT(png_voidp,png_get_io_ptr) PNGARG((png_structp png_ptr));
2098
2099	extern PNG_EXPORT(void,png_set_read_status_fn) PNGARG((png_structp png_ptr,
2100	png_read_status_ptr read_row_fn));
2101
2102	extern PNG_EXPORT(void,png_set_write_status_fn) PNGARG((png_structp png_ptr,
2103	png_write_status_ptr write_row_fn));
2104
2105	#ifdef PNG_USER_MEM_SUPPORTED
2106	/* Replace the default memory allocation functions with user supplied one(s). */
2107	extern PNG_EXPORT(void,png_set_mem_fn) PNGARG((png_structp png_ptr,
2108	png_voidp mem_ptr, png_malloc_ptr malloc_fn, png_free_ptr free_fn));
2109	/* Return the user pointer associated with the memory functions */
2110	extern PNG_EXPORT(png_voidp,png_get_mem_ptr) PNGARG((png_structp png_ptr));
2111	#endif
2112
2113	#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) \|\| \
2114	defined(PNG_LEGACY_SUPPORTED)
2115	extern PNG_EXPORT(void,png_set_read_user_transform_fn) PNGARG((png_structp
2116	png_ptr, png_user_transform_ptr read_user_transform_fn));
2117	#endif
2118
2119	#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) \|\| \
2120	defined(PNG_LEGACY_SUPPORTED)
2121	extern PNG_EXPORT(void,png_set_write_user_transform_fn) PNGARG((png_structp
2122	png_ptr, png_user_transform_ptr write_user_transform_fn));
2123	#endif
2124
2125	#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) \|\| \
2126	defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) \|\| \
2127	defined(PNG_LEGACY_SUPPORTED)
2128	extern PNG_EXPORT(void,png_set_user_transform_info) PNGARG((png_structp
2129	png_ptr, png_voidp user_transform_ptr, int user_transform_depth,
2130	int user_transform_channels));
2131	/* Return the user pointer associated with the user transform functions */
2132	extern PNG_EXPORT(png_voidp,png_get_user_transform_ptr)
2133	PNGARG((png_structp png_ptr));
2134	#endif
2135
2136	#ifdef PNG_USER_CHUNKS_SUPPORTED
2137	extern PNG_EXPORT(void,png_set_read_user_chunk_fn) PNGARG((png_structp png_ptr,
2138	png_voidp user_chunk_ptr, png_user_chunk_ptr read_user_chunk_fn));
2139	extern PNG_EXPORT(png_voidp,png_get_user_chunk_ptr) PNGARG((png_structp
2140	png_ptr));
2141	#endif
2142
2143	#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
2144	/* Sets the function callbacks for the push reader, and a pointer to a
2145	* user-defined structure available to the callback functions.
2146	*/
2147	extern PNG_EXPORT(void,png_set_progressive_read_fn) PNGARG((png_structp png_ptr,
2148	png_voidp progressive_ptr,
2149	png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
2150	png_progressive_end_ptr end_fn));
2151
2152	/* Returns the user pointer associated with the push read functions */
2153	extern PNG_EXPORT(png_voidp,png_get_progressive_ptr)
2154	PNGARG((png_structp png_ptr));
2155
2156	/* Function to be called when data becomes available */
2157	extern PNG_EXPORT(void,png_process_data) PNGARG((png_structp png_ptr,
2158	png_infop info_ptr, png_bytep buffer, png_size_t buffer_size));
2159
2160	/* Function that combines rows. Not very much different than the
2161	* png_combine_row() call. Is this even used?????
2162	*/
2163	extern PNG_EXPORT(void,png_progressive_combine_row) PNGARG((png_structp png_ptr,
2164	png_bytep old_row, png_bytep new_row));
2165	#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
2166
2167	extern PNG_EXPORT(png_voidp,png_malloc) PNGARG((png_structp png_ptr,
2168	png_uint_32 size)) PNG_ALLOCATED;
2169
2170	#ifdef PNG_1_0_X
2171	# define png_malloc_warn png_malloc
2172	#else
2173	/* Added at libpng version 1.2.4 */
2174	extern PNG_EXPORT(png_voidp,png_malloc_warn) PNGARG((png_structp png_ptr,
2175	png_uint_32 size)) PNG_ALLOCATED;
2176	#endif
2177
2178	/* Frees a pointer allocated by png_malloc() */
2179	extern PNG_EXPORT(void,png_free) PNGARG((png_structp png_ptr, png_voidp ptr));
2180
2181	#ifdef PNG_1_0_X
2182	/* Function to allocate memory for zlib. */
2183	extern PNG_EXPORT(voidpf,png_zalloc) PNGARG((voidpf png_ptr, uInt items,
2184	uInt size));
2185
2186	/* Function to free memory for zlib */
2187	extern PNG_EXPORT(void,png_zfree) PNGARG((voidpf png_ptr, voidpf ptr));
2188	#endif
2189
2190	/* Free data that was allocated internally */
2191	extern PNG_EXPORT(void,png_free_data) PNGARG((png_structp png_ptr,
2192	png_infop info_ptr, png_uint_32 free_me, int num));
2193	#ifdef PNG_FREE_ME_SUPPORTED
2194	/* Reassign responsibility for freeing existing data, whether allocated
2195	* by libpng or by the application
2196	*/
2197	extern PNG_EXPORT(void,png_data_freer) PNGARG((png_structp png_ptr,
2198	png_infop info_ptr, int freer, png_uint_32 mask));
2199	#endif
2200	/* Assignments for png_data_freer */
2201	#define PNG_DESTROY_WILL_FREE_DATA 1
2202	#define PNG_SET_WILL_FREE_DATA 1
2203	#define PNG_USER_WILL_FREE_DATA 2
2204	/* Flags for png_ptr->free_me and info_ptr->free_me */
2205	#define PNG_FREE_HIST 0x0008
2206	#define PNG_FREE_ICCP 0x0010
2207	#define PNG_FREE_SPLT 0x0020
2208	#define PNG_FREE_ROWS 0x0040
2209	#define PNG_FREE_PCAL 0x0080
2210	#define PNG_FREE_SCAL 0x0100
2211	#define PNG_FREE_UNKN 0x0200
2212	#define PNG_FREE_LIST 0x0400
2213	#define PNG_FREE_PLTE 0x1000
2214	#define PNG_FREE_TRNS 0x2000
2215	#define PNG_FREE_TEXT 0x4000
2216	#define PNG_FREE_ALL 0x7fff
2217	#define PNG_FREE_MUL 0x4220 /* PNG_FREE_SPLT\|PNG_FREE_TEXT\|PNG_FREE_UNKN */
2218
2219	#ifdef PNG_USER_MEM_SUPPORTED
2220	extern PNG_EXPORT(png_voidp,png_malloc_default) PNGARG((png_structp png_ptr,
2221	png_uint_32 size)) PNG_ALLOCATED;
2222	extern PNG_EXPORT(void,png_free_default) PNGARG((png_structp png_ptr,
2223	png_voidp ptr));
2224	#endif
2225
2226	extern PNG_EXPORT(png_voidp,png_memcpy_check) PNGARG((png_structp png_ptr,
2227	png_voidp s1, png_voidp s2, png_uint_32 size)) PNG_DEPRECATED;
2228
2229	extern PNG_EXPORT(png_voidp,png_memset_check) PNGARG((png_structp png_ptr,
2230	png_voidp s1, int value, png_uint_32 size)) PNG_DEPRECATED;
2231
2232	#if defined(USE_FAR_KEYWORD) /* memory model conversion function */
2233	extern void *png_far_to_near PNGARG((png_structp png_ptr,png_voidp ptr,
2234	int check));
2235	#endif /* USE_FAR_KEYWORD */
2236
2237	#ifndef PNG_NO_ERROR_TEXT
2238	/* Fatal error in PNG image of libpng - can't continue */
2239	extern PNG_EXPORT(void,png_error) PNGARG((png_structp png_ptr,
2240	png_const_charp error_message)) PNG_NORETURN;
2241
2242	/* The same, but the chunk name is prepended to the error string. */
2243	extern PNG_EXPORT(void,png_chunk_error) PNGARG((png_structp png_ptr,
2244	png_const_charp error_message)) PNG_NORETURN;
2245	#else
2246	/* Fatal error in PNG image of libpng - can't continue */
2247	extern PNG_EXPORT(void,png_err) PNGARG((png_structp png_ptr)) PNG_NORETURN;
2248	#endif
2249
2250	#ifndef PNG_NO_WARNINGS
2251	/* Non-fatal error in libpng. Can continue, but may have a problem. */
2252	extern PNG_EXPORT(void,png_warning) PNGARG((png_structp png_ptr,
2253	png_const_charp warning_message));
2254
2255	#ifdef PNG_READ_SUPPORTED
2256	/* Non-fatal error in libpng, chunk name is prepended to message. */
2257	extern PNG_EXPORT(void,png_chunk_warning) PNGARG((png_structp png_ptr,
2258	png_const_charp warning_message));
2259	#endif /* PNG_READ_SUPPORTED */
2260	#endif /* PNG_NO_WARNINGS */
2261
2262	/* The png_set_<chunk> functions are for storing values in the png_info_struct.
2263	* Similarly, the png_get_<chunk> calls are used to read values from the
2264	* png_info_struct, either storing the parameters in the passed variables, or
2265	* setting pointers into the png_info_struct where the data is stored. The
2266	* png_get_<chunk> functions return a non-zero value if the data was available
2267	* in info_ptr, or return zero and do not change any of the parameters if the
2268	* data was not available.
2269	*
2270	* These functions should be used instead of directly accessing png_info
2271	* to avoid problems with future changes in the size and internal layout of
2272	* png_info_struct.
2273	*/
2274	/* Returns "flag" if chunk data is valid in info_ptr. */
2275	extern PNG_EXPORT(png_uint_32,png_get_valid) PNGARG((png_structp png_ptr,
2276	png_infop info_ptr, png_uint_32 flag));
2277
2278	/* Returns number of bytes needed to hold a transformed row. */
2279	extern PNG_EXPORT(png_uint_32,png_get_rowbytes) PNGARG((png_structp png_ptr,
2280	png_infop info_ptr));
2281
2282	#ifdef PNG_INFO_IMAGE_SUPPORTED
2283	/* Returns row_pointers, which is an array of pointers to scanlines that was
2284	* returned from png_read_png().
2285	*/
2286	extern PNG_EXPORT(png_bytepp,png_get_rows) PNGARG((png_structp png_ptr,
2287	png_infop info_ptr));
2288	/* Set row_pointers, which is an array of pointers to scanlines for use
2289	* by png_write_png().
2290	*/
2291	extern PNG_EXPORT(void,png_set_rows) PNGARG((png_structp png_ptr,
2292	png_infop info_ptr, png_bytepp row_pointers));
2293	#endif
2294
2295	/* Returns number of color channels in image. */
2296	extern PNG_EXPORT(png_byte,png_get_channels) PNGARG((png_structp png_ptr,
2297	png_infop info_ptr));
2298
2299	#ifdef PNG_EASY_ACCESS_SUPPORTED
2300	/* Returns image width in pixels. */
2301	extern PNG_EXPORT(png_uint_32, png_get_image_width) PNGARG((png_structp
2302	png_ptr, png_infop info_ptr));
2303
2304	/* Returns image height in pixels. */
2305	extern PNG_EXPORT(png_uint_32, png_get_image_height) PNGARG((png_structp
2306	png_ptr, png_infop info_ptr));
2307
2308	/* Returns image bit_depth. */
2309	extern PNG_EXPORT(png_byte, png_get_bit_depth) PNGARG((png_structp
2310	png_ptr, png_infop info_ptr));
2311
2312	/* Returns image color_type. */
2313	extern PNG_EXPORT(png_byte, png_get_color_type) PNGARG((png_structp
2314	png_ptr, png_infop info_ptr));
2315
2316	/* Returns image filter_type. */
2317	extern PNG_EXPORT(png_byte, png_get_filter_type) PNGARG((png_structp
2318	png_ptr, png_infop info_ptr));
2319
2320	/* Returns image interlace_type. */
2321	extern PNG_EXPORT(png_byte, png_get_interlace_type) PNGARG((png_structp
2322	png_ptr, png_infop info_ptr));
2323
2324	/* Returns image compression_type. */
2325	extern PNG_EXPORT(png_byte, png_get_compression_type) PNGARG((png_structp
2326	png_ptr, png_infop info_ptr));
2327
2328	/* Returns image resolution in pixels per meter, from pHYs chunk data. */
2329	extern PNG_EXPORT(png_uint_32, png_get_pixels_per_meter) PNGARG((png_structp
2330	png_ptr, png_infop info_ptr));
2331	extern PNG_EXPORT(png_uint_32, png_get_x_pixels_per_meter) PNGARG((png_structp
2332	png_ptr, png_infop info_ptr));
2333	extern PNG_EXPORT(png_uint_32, png_get_y_pixels_per_meter) PNGARG((png_structp
2334	png_ptr, png_infop info_ptr));
2335
2336	/* Returns pixel aspect ratio, computed from pHYs chunk data. */
2337	#ifdef PNG_FLOATING_POINT_SUPPORTED
2338	extern PNG_EXPORT(float, png_get_pixel_aspect_ratio) PNGARG((png_structp
2339	png_ptr, png_infop info_ptr));
2340	#endif
2341
2342	/* Returns image x, y offset in pixels or microns, from oFFs chunk data. */
2343	extern PNG_EXPORT(png_int_32, png_get_x_offset_pixels) PNGARG((png_structp
2344	png_ptr, png_infop info_ptr));
2345	extern PNG_EXPORT(png_int_32, png_get_y_offset_pixels) PNGARG((png_structp
2346	png_ptr, png_infop info_ptr));
2347	extern PNG_EXPORT(png_int_32, png_get_x_offset_microns) PNGARG((png_structp
2348	png_ptr, png_infop info_ptr));
2349	extern PNG_EXPORT(png_int_32, png_get_y_offset_microns) PNGARG((png_structp
2350	png_ptr, png_infop info_ptr));
2351
2352	#endif /* PNG_EASY_ACCESS_SUPPORTED */
2353
2354	/* Returns pointer to signature string read from PNG header */
2355	extern PNG_EXPORT(png_bytep,png_get_signature) PNGARG((png_structp png_ptr,
2356	png_infop info_ptr));
2357
2358	#ifdef PNG_bKGD_SUPPORTED
2359	extern PNG_EXPORT(png_uint_32,png_get_bKGD) PNGARG((png_structp png_ptr,
2360	png_infop info_ptr, png_color_16p *background));
2361	#endif
2362
2363	#ifdef PNG_bKGD_SUPPORTED
2364	extern PNG_EXPORT(void,png_set_bKGD) PNGARG((png_structp png_ptr,
2365	png_infop info_ptr, png_color_16p background));
2366	#endif
2367
2368	#ifdef PNG_cHRM_SUPPORTED
2369	#ifdef PNG_FLOATING_POINT_SUPPORTED
2370	extern PNG_EXPORT(png_uint_32,png_get_cHRM) PNGARG((png_structp png_ptr,
2371	png_infop info_ptr, double white_x, double white_y, double *red_x,
2372	double red_y, double green_x, double green_y, double blue_x,
2373	double *blue_y));
2374	#endif
2375	#ifdef PNG_FIXED_POINT_SUPPORTED
2376	extern PNG_EXPORT(png_uint_32,png_get_cHRM_fixed) PNGARG((png_structp png_ptr,
2377	png_infop info_ptr, png_fixed_point *int_white_x, png_fixed_point
2378	int_white_y, png_fixed_point int_red_x, png_fixed_point *int_red_y,
2379	png_fixed_point int_green_x, png_fixed_point int_green_y, png_fixed_point
2380	int_blue_x, png_fixed_point int_blue_y));
2381	#endif
2382	#endif
2383
2384	#ifdef PNG_cHRM_SUPPORTED
2385	#ifdef PNG_FLOATING_POINT_SUPPORTED
2386	extern PNG_EXPORT(void,png_set_cHRM) PNGARG((png_structp png_ptr,
2387	png_infop info_ptr, double white_x, double white_y, double red_x,
2388	double red_y, double green_x, double green_y, double blue_x, double blue_y));
2389	#endif
2390	#ifdef PNG_FIXED_POINT_SUPPORTED
2391	extern PNG_EXPORT(void,png_set_cHRM_fixed) PNGARG((png_structp png_ptr,
2392	png_infop info_ptr, png_fixed_point int_white_x, png_fixed_point int_white_y,
2393	png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
2394	int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
2395	png_fixed_point int_blue_y));
2396	#endif
2397	#endif
2398
2399	#ifdef PNG_gAMA_SUPPORTED
2400	#ifdef PNG_FLOATING_POINT_SUPPORTED
2401	extern PNG_EXPORT(png_uint_32,png_get_gAMA) PNGARG((png_structp png_ptr,
2402	png_infop info_ptr, double *file_gamma));
2403	#endif
2404	extern PNG_EXPORT(png_uint_32,png_get_gAMA_fixed) PNGARG((png_structp png_ptr,
2405	png_infop info_ptr, png_fixed_point *int_file_gamma));
2406	#endif
2407
2408	#ifdef PNG_gAMA_SUPPORTED
2409	#ifdef PNG_FLOATING_POINT_SUPPORTED
2410	extern PNG_EXPORT(void,png_set_gAMA) PNGARG((png_structp png_ptr,
2411	png_infop info_ptr, double file_gamma));
2412	#endif
2413	extern PNG_EXPORT(void,png_set_gAMA_fixed) PNGARG((png_structp png_ptr,
2414	png_infop info_ptr, png_fixed_point int_file_gamma));
2415	#endif
2416
2417	#ifdef PNG_hIST_SUPPORTED
2418	extern PNG_EXPORT(png_uint_32,png_get_hIST) PNGARG((png_structp png_ptr,
2419	png_infop info_ptr, png_uint_16p *hist));
2420	#endif
2421
2422	#ifdef PNG_hIST_SUPPORTED
2423	extern PNG_EXPORT(void,png_set_hIST) PNGARG((png_structp png_ptr,
2424	png_infop info_ptr, png_uint_16p hist));
2425	#endif
2426
2427	extern PNG_EXPORT(png_uint_32,png_get_IHDR) PNGARG((png_structp png_ptr,
2428	png_infop info_ptr, png_uint_32 width, png_uint_32 height,
2429	int bit_depth, int color_type, int *interlace_method,
2430	int compression_method, int filter_method));
2431
2432	extern PNG_EXPORT(void,png_set_IHDR) PNGARG((png_structp png_ptr,
2433	png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth,
2434	int color_type, int interlace_method, int compression_method,
2435	int filter_method));
2436
2437	#ifdef PNG_oFFs_SUPPORTED
2438	extern PNG_EXPORT(png_uint_32,png_get_oFFs) PNGARG((png_structp png_ptr,
2439	png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2440	int *unit_type));
2441	#endif
2442
2443	#ifdef PNG_oFFs_SUPPORTED
2444	extern PNG_EXPORT(void,png_set_oFFs) PNGARG((png_structp png_ptr,
2445	png_infop info_ptr, png_int_32 offset_x, png_int_32 offset_y,
2446	int unit_type));
2447	#endif
2448
2449	#ifdef PNG_pCAL_SUPPORTED
2450	extern PNG_EXPORT(png_uint_32,png_get_pCAL) PNGARG((png_structp png_ptr,
2451	png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 *X1,
2452	int type, int nparams, png_charp units, png_charpp params));
2453	#endif
2454
2455	#ifdef PNG_pCAL_SUPPORTED
2456	extern PNG_EXPORT(void,png_set_pCAL) PNGARG((png_structp png_ptr,
2457	png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1,
2458	int type, int nparams, png_charp units, png_charpp params));
2459	#endif
2460
2461	#ifdef PNG_pHYs_SUPPORTED
2462	extern PNG_EXPORT(png_uint_32,png_get_pHYs) PNGARG((png_structp png_ptr,
2463	png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int *unit_type));
2464	#endif
2465
2466	#ifdef PNG_pHYs_SUPPORTED
2467	extern PNG_EXPORT(void,png_set_pHYs) PNGARG((png_structp png_ptr,
2468	png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type));
2469	#endif
2470
2471	extern PNG_EXPORT(png_uint_32,png_get_PLTE) PNGARG((png_structp png_ptr,
2472	png_infop info_ptr, png_colorp palette, int num_palette));
2473
2474	extern PNG_EXPORT(void,png_set_PLTE) PNGARG((png_structp png_ptr,
2475	png_infop info_ptr, png_colorp palette, int num_palette));
2476
2477	#ifdef PNG_sBIT_SUPPORTED
2478	extern PNG_EXPORT(png_uint_32,png_get_sBIT) PNGARG((png_structp png_ptr,
2479	png_infop info_ptr, png_color_8p *sig_bit));
2480	#endif
2481
2482	#ifdef PNG_sBIT_SUPPORTED
2483	extern PNG_EXPORT(void,png_set_sBIT) PNGARG((png_structp png_ptr,
2484	png_infop info_ptr, png_color_8p sig_bit));
2485	#endif
2486
2487	#ifdef PNG_sRGB_SUPPORTED
2488	extern PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr,
2489	png_infop info_ptr, int *intent));
2490	#endif
2491
2492	#ifdef PNG_sRGB_SUPPORTED
2493	extern PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr,
2494	png_infop info_ptr, int intent));
2495	extern PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr,
2496	png_infop info_ptr, int intent));
2497	#endif
2498
2499	#ifdef PNG_iCCP_SUPPORTED
2500	extern PNG_EXPORT(png_uint_32,png_get_iCCP) PNGARG((png_structp png_ptr,
2501	png_infop info_ptr, png_charpp name, int *compression_type,
2502	png_charpp profile, png_uint_32 *proflen));
2503	/* Note to maintainer: profile should be png_bytepp */
2504	#endif
2505
2506	#ifdef PNG_iCCP_SUPPORTED
2507	extern PNG_EXPORT(void,png_set_iCCP) PNGARG((png_structp png_ptr,
2508	png_infop info_ptr, png_charp name, int compression_type,
2509	png_charp profile, png_uint_32 proflen));
2510	/* Note to maintainer: profile should be png_bytep */
2511	#endif
2512
2513	#ifdef PNG_sPLT_SUPPORTED
2514	extern PNG_EXPORT(png_uint_32,png_get_sPLT) PNGARG((png_structp png_ptr,
2515	png_infop info_ptr, png_sPLT_tpp entries));
2516	#endif
2517
2518	#ifdef PNG_sPLT_SUPPORTED
2519	extern PNG_EXPORT(void,png_set_sPLT) PNGARG((png_structp png_ptr,
2520	png_infop info_ptr, png_sPLT_tp entries, int nentries));
2521	#endif
2522
2523	#ifdef PNG_TEXT_SUPPORTED
2524	/* png_get_text also returns the number of text chunks in num_text /
2525	extern PNG_EXPORT(png_uint_32,png_get_text) PNGARG((png_structp png_ptr,
2526	png_infop info_ptr, png_textp text_ptr, int num_text));
2527	#endif
2528
2529	/*
2530	* Note while png_set_text() will accept a structure whose text,
2531	* language, and translated keywords are NULL pointers, the structure
2532	* returned by png_get_text will always contain regular
2533	* zero-terminated C strings. They might be empty strings but
2534	* they will never be NULL pointers.
2535	*/
2536
2537	#ifdef PNG_TEXT_SUPPORTED
2538	extern PNG_EXPORT(void,png_set_text) PNGARG((png_structp png_ptr,
2539	png_infop info_ptr, png_textp text_ptr, int num_text));
2540	#endif
2541
2542	#ifdef PNG_tIME_SUPPORTED
2543	extern PNG_EXPORT(png_uint_32,png_get_tIME) PNGARG((png_structp png_ptr,
2544	png_infop info_ptr, png_timep *mod_time));
2545	#endif
2546
2547	#ifdef PNG_tIME_SUPPORTED
2548	extern PNG_EXPORT(void,png_set_tIME) PNGARG((png_structp png_ptr,
2549	png_infop info_ptr, png_timep mod_time));
2550	#endif
2551
2552	#ifdef PNG_tRNS_SUPPORTED
2553	extern PNG_EXPORT(png_uint_32,png_get_tRNS) PNGARG((png_structp png_ptr,
2554	png_infop info_ptr, png_bytep trans, int num_trans,
2555	png_color_16p *trans_values));
2556	#endif
2557
2558	#ifdef PNG_tRNS_SUPPORTED
2559	extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
2560	png_infop info_ptr, png_bytep trans, int num_trans,
2561	png_color_16p trans_values));
2562	#endif
2563
2564	#ifdef PNG_tRNS_SUPPORTED
2565	#endif
2566
2567	#ifdef PNG_sCAL_SUPPORTED
2568	#ifdef PNG_FLOATING_POINT_SUPPORTED
2569	extern PNG_EXPORT(png_uint_32,png_get_sCAL) PNGARG((png_structp png_ptr,
2570	png_infop info_ptr, int unit, double width, double *height));
2571	#else
2572	#ifdef PNG_FIXED_POINT_SUPPORTED
2573	extern PNG_EXPORT(png_uint_32,png_get_sCAL_s) PNGARG((png_structp png_ptr,
2574	png_infop info_ptr, int *unit, png_charpp swidth, png_charpp sheight));
2575	#endif
2576	#endif
2577	#endif /* PNG_sCAL_SUPPORTED */
2578
2579	#ifdef PNG_sCAL_SUPPORTED
2580	#ifdef PNG_FLOATING_POINT_SUPPORTED
2581	extern PNG_EXPORT(void,png_set_sCAL) PNGARG((png_structp png_ptr,
2582	png_infop info_ptr, int unit, double width, double height));
2583	#else
2584	#ifdef PNG_FIXED_POINT_SUPPORTED
2585	extern PNG_EXPORT(void,png_set_sCAL_s) PNGARG((png_structp png_ptr,
2586	png_infop info_ptr, int unit, png_charp swidth, png_charp sheight));
2587	#endif
2588	#endif
2589	#endif /* PNG_sCAL_SUPPORTED \|\| PNG_WRITE_sCAL_SUPPORTED */
2590
2591	#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
2592	/* Provide a list of chunks and how they are to be handled, if the built-in
2593	handling or default unknown chunk handling is not desired. Any chunks not
2594	listed will be handled in the default manner. The IHDR and IEND chunks
2595	must not be listed.
2596	keep = 0: follow default behaviour
2597	= 1: do not keep
2598	= 2: keep only if safe-to-copy
2599	= 3: keep even if unsafe-to-copy
2600	*/
2601	extern PNG_EXPORT(void, png_set_keep_unknown_chunks) PNGARG((png_structp
2602	png_ptr, int keep, png_bytep chunk_list, int num_chunks));
2603	PNG_EXPORT(int,png_handle_as_unknown) PNGARG((png_structp png_ptr, png_bytep
2604	chunk_name));
2605	#endif
2606	#ifdef PNG_UNKNOWN_CHUNKS_SUPPORTED
2607	extern PNG_EXPORT(void, png_set_unknown_chunks) PNGARG((png_structp png_ptr,
2608	png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns));
2609	extern PNG_EXPORT(void, png_set_unknown_chunk_location)
2610	PNGARG((png_structp png_ptr, png_infop info_ptr, int chunk, int location));
2611	extern PNG_EXPORT(png_uint_32,png_get_unknown_chunks) PNGARG((png_structp
2612	png_ptr, png_infop info_ptr, png_unknown_chunkpp entries));
2613	#endif
2614
2615	/* Png_free_data() will turn off the "valid" flag for anything it frees.
2616	* If you need to turn it off for a chunk that your application has freed,
2617	* you can use png_set_invalid(png_ptr, info_ptr, PNG_INFO_CHNK);
2618	*/
2619	extern PNG_EXPORT(void, png_set_invalid) PNGARG((png_structp png_ptr,
2620	png_infop info_ptr, int mask));
2621
2622	#ifdef PNG_INFO_IMAGE_SUPPORTED
2623	/* The "params" pointer is currently not used and is for future expansion. */
2624	extern PNG_EXPORT(void, png_read_png) PNGARG((png_structp png_ptr,
2625	png_infop info_ptr,
2626	int transforms,
2627	png_voidp params));
2628	extern PNG_EXPORT(void, png_write_png) PNGARG((png_structp png_ptr,
2629	png_infop info_ptr,
2630	int transforms,
2631	png_voidp params));
2632	#endif
2633
2634	/* Define PNG_DEBUG at compile time for debugging information. Higher
2635	* numbers for PNG_DEBUG mean more debugging information. This has
2636	* only been added since version 0.95 so it is not implemented throughout
2637	* libpng yet, but more support will be added as needed.
2638	*/
2639	#ifdef PNG_DEBUG
2640	#if (PNG_DEBUG > 0)
2641	#if !defined(PNG_DEBUG_FILE) && defined(_MSC_VER)
2642	#include <crtdbg.h>
2643	#if (PNG_DEBUG > 1)
2644	#ifndef _DEBUG
2645	# define _DEBUG
2646	#endif
2647	#ifndef png_debug
2648	#define png_debug(l,m) _RPT0(_CRT_WARN,m PNG_STRING_NEWLINE)
2649	#endif
2650	#ifndef png_debug1
2651	#define png_debug1(l,m,p1) _RPT1(_CRT_WARN,m PNG_STRING_NEWLINE,p1)
2652	#endif
2653	#ifndef png_debug2
2654	#define png_debug2(l,m,p1,p2) _RPT2(_CRT_WARN,m PNG_STRING_NEWLINE,p1,p2)
2655	#endif
2656	#endif
2657	#else /* PNG_DEBUG_FILE \|\| !_MSC_VER */
2658	#ifndef PNG_DEBUG_FILE
2659	#define PNG_DEBUG_FILE stderr
2660	#endif /* PNG_DEBUG_FILE */
2661
2662	#if (PNG_DEBUG > 1)
2663	/* Note: ["%s"m PNG_STRING_NEWLINE] probably does not work on non-ISO
2664	* compilers.
2665	*/
2666	# ifdef __STDC__
2667	# ifndef png_debug
2668	# define png_debug(l,m) \
2669	{ \
2670	int num_tabs=l; \
2671	fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
2672	(num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":"")))); \
2673	}
2674	# endif
2675	# ifndef png_debug1
2676	# define png_debug1(l,m,p1) \
2677	{ \
2678	int num_tabs=l; \
2679	fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
2680	(num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1); \
2681	}
2682	# endif
2683	# ifndef png_debug2
2684	# define png_debug2(l,m,p1,p2) \
2685	{ \
2686	int num_tabs=l; \
2687	fprintf(PNG_DEBUG_FILE,"%s" m PNG_STRING_NEWLINE,(num_tabs==1 ? "\t" : \
2688	(num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))),p1,p2); \
2689	}
2690	# endif
2691	# else /* __STDC __ */
2692	# ifndef png_debug
2693	# define png_debug(l,m) \
2694	{ \
2695	int num_tabs=l; \
2696	char format[256]; \
2697	snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
2698	(num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
2699	m,PNG_STRING_NEWLINE); \
2700	fprintf(PNG_DEBUG_FILE,format); \
2701	}
2702	# endif
2703	# ifndef png_debug1
2704	# define png_debug1(l,m,p1) \
2705	{ \
2706	int num_tabs=l; \
2707	char format[256]; \
2708	snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
2709	(num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
2710	m,PNG_STRING_NEWLINE); \
2711	fprintf(PNG_DEBUG_FILE,format,p1); \
2712	}
2713	# endif
2714	# ifndef png_debug2
2715	# define png_debug2(l,m,p1,p2) \
2716	{ \
2717	int num_tabs=l; \
2718	char format[256]; \
2719	snprintf(format,256,"%s%s%s",(num_tabs==1 ? "\t" : \
2720	(num_tabs==2 ? "\t\t":(num_tabs>2 ? "\t\t\t":""))), \
2721	m,PNG_STRING_NEWLINE); \
2722	fprintf(PNG_DEBUG_FILE,format,p1,p2); \
2723	}
2724	# endif
2725	# endif /* __STDC __ */
2726	#endif /* (PNG_DEBUG > 1) */
2727
2728	#endif /* _MSC_VER */
2729	#endif /* (PNG_DEBUG > 0) */
2730	#endif /* PNG_DEBUG */
2731	#ifndef png_debug
2732	#define png_debug(l, m)
2733	#endif
2734	#ifndef png_debug1
2735	#define png_debug1(l, m, p1)
2736	#endif
2737	#ifndef png_debug2
2738	#define png_debug2(l, m, p1, p2)
2739	#endif
2740
2741	extern PNG_EXPORT(png_charp,png_get_copyright) PNGARG((png_structp png_ptr));
2742	extern PNG_EXPORT(png_charp,png_get_header_ver) PNGARG((png_structp png_ptr));
2743	extern PNG_EXPORT(png_charp,png_get_header_version) PNGARG((png_structp png_ptr));
2744	extern PNG_EXPORT(png_charp,png_get_libpng_ver) PNGARG((png_structp png_ptr));
2745
2746	#ifdef PNG_MNG_FEATURES_SUPPORTED
2747	extern PNG_EXPORT(png_uint_32,png_permit_mng_features) PNGARG((png_structp
2748	png_ptr, png_uint_32 mng_features_permitted));
2749	#endif
2750
2751	/* For use in png_set_keep_unknown, added to version 1.2.6 */
2752	#define PNG_HANDLE_CHUNK_AS_DEFAULT 0
2753	#define PNG_HANDLE_CHUNK_NEVER 1
2754	#define PNG_HANDLE_CHUNK_IF_SAFE 2
2755	#define PNG_HANDLE_CHUNK_ALWAYS 3
2756
2757	/* Added to version 1.2.0 */
2758	#ifdef PNG_ASSEMBLER_CODE_SUPPORTED
2759	#ifdef PNG_MMX_CODE_SUPPORTED
2760	#define PNG_ASM_FLAG_MMX_SUPPORT_COMPILED 0x01 /* not user-settable */
2761	#define PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU 0x02 /* not user-settable */
2762	#define PNG_ASM_FLAG_MMX_READ_COMBINE_ROW 0x04
2763	#define PNG_ASM_FLAG_MMX_READ_INTERLACE 0x08
2764	#define PNG_ASM_FLAG_MMX_READ_FILTER_SUB 0x10
2765	#define PNG_ASM_FLAG_MMX_READ_FILTER_UP 0x20
2766	#define PNG_ASM_FLAG_MMX_READ_FILTER_AVG 0x40
2767	#define PNG_ASM_FLAG_MMX_READ_FILTER_PAETH 0x80
2768	#define PNG_ASM_FLAGS_INITIALIZED 0x80000000 /* not user-settable */
2769
2770	#define PNG_MMX_READ_FLAGS ( PNG_ASM_FLAG_MMX_READ_COMBINE_ROW \
2771	\| PNG_ASM_FLAG_MMX_READ_INTERLACE \
2772	\| PNG_ASM_FLAG_MMX_READ_FILTER_SUB \
2773	\| PNG_ASM_FLAG_MMX_READ_FILTER_UP \
2774	\| PNG_ASM_FLAG_MMX_READ_FILTER_AVG \
2775	\| PNG_ASM_FLAG_MMX_READ_FILTER_PAETH )
2776	#define PNG_MMX_WRITE_FLAGS ( 0 )
2777
2778	#define PNG_MMX_FLAGS ( PNG_ASM_FLAG_MMX_SUPPORT_COMPILED \
2779	\| PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU \
2780	\| PNG_MMX_READ_FLAGS \
2781	\| PNG_MMX_WRITE_FLAGS )
2782
2783	#define PNG_SELECT_READ 1
2784	#define PNG_SELECT_WRITE 2
2785	#endif /* PNG_MMX_CODE_SUPPORTED */
2786
2787	#ifndef PNG_1_0_X
2788	/* pngget.c */
2789	extern PNG_EXPORT(png_uint_32,png_get_mmx_flagmask)
2790	PNGARG((int flag_select, int *compilerID));
2791
2792	/* pngget.c */
2793	extern PNG_EXPORT(png_uint_32,png_get_asm_flagmask)
2794	PNGARG((int flag_select));
2795
2796	/* pngget.c */
2797	extern PNG_EXPORT(png_uint_32,png_get_asm_flags)
2798	PNGARG((png_structp png_ptr));
2799
2800	/* pngget.c */
2801	extern PNG_EXPORT(png_byte,png_get_mmx_bitdepth_threshold)
2802	PNGARG((png_structp png_ptr));
2803
2804	/* pngget.c */
2805	extern PNG_EXPORT(png_uint_32,png_get_mmx_rowbytes_threshold)
2806	PNGARG((png_structp png_ptr));
2807
2808	/* pngset.c */
2809	extern PNG_EXPORT(void,png_set_asm_flags)
2810	PNGARG((png_structp png_ptr, png_uint_32 asm_flags));
2811
2812	/* pngset.c */
2813	extern PNG_EXPORT(void,png_set_mmx_thresholds)
2814	PNGARG((png_structp png_ptr, png_byte mmx_bitdepth_threshold,
2815	png_uint_32 mmx_rowbytes_threshold));
2816
2817	#endif /* PNG_1_0_X */
2818
2819	#ifndef PNG_1_0_X
2820	/* png.c, pnggccrd.c, or pngvcrd.c */
2821	extern PNG_EXPORT(int,png_mmx_support) PNGARG((void));
2822	#endif /* PNG_1_0_X */
2823	#endif /* PNG_ASSEMBLER_CODE_SUPPORTED */
2824
2825	/* Strip the prepended error numbers ("#nnn ") from error and warning
2826	* messages before passing them to the error or warning handler.
2827	*/
2828	#ifdef PNG_ERROR_NUMBERS_SUPPORTED
2829	extern PNG_EXPORT(void,png_set_strip_error_numbers) PNGARG((png_structp
2830	png_ptr, png_uint_32 strip_mode));
2831	#endif
2832
2833	/* Added at libpng-1.2.6 */
2834	#ifdef PNG_SET_USER_LIMITS_SUPPORTED
2835	extern PNG_EXPORT(void,png_set_user_limits) PNGARG((png_structp
2836	png_ptr, png_uint_32 user_width_max, png_uint_32 user_height_max));
2837	extern PNG_EXPORT(png_uint_32,png_get_user_width_max) PNGARG((png_structp
2838	png_ptr));
2839	extern PNG_EXPORT(png_uint_32,png_get_user_height_max) PNGARG((png_structp
2840	png_ptr));
2841	#endif
2842	/* Maintainer: Put new public prototypes here ^, in libpng.3, and in
2843	* project defs
2844	*/
2845
2846	#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED
2847	/* With these routines we avoid an integer divide, which will be slower on
2848	* most machines. However, it does take more operations than the corresponding
2849	* divide method, so it may be slower on a few RISC systems. There are two
2850	* shifts (by 8 or 16 bits) and an addition, versus a single integer divide.
2851	*
2852	* Note that the rounding factors are NOT supposed to be the same! 128 and
2853	* 32768 are correct for the NODIV code; 127 and 32767 are correct for the
2854	* standard method.
2855	*
2856	* [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ]
2857	*/
2858
2859	/* fg and bg should be in `gamma 1.0' space; alpha is the opacity */
2860
2861	# define png_composite(composite, fg, alpha, bg) \
2862	{ png_uint_16 temp = (png_uint_16)((png_uint_16)(fg) * (png_uint_16)(alpha) \
2863	+ (png_uint_16)(bg)*(png_uint_16)(255 - \
2864	(png_uint_16)(alpha)) + (png_uint_16)128); \
2865	(composite) = (png_byte)((temp + (temp >> 8)) >> 8); }
2866
2867	# define png_composite_16(composite, fg, alpha, bg) \
2868	{ png_uint_32 temp = (png_uint_32)((png_uint_32)(fg) * (png_uint_32)(alpha) \
2869	+ (png_uint_32)(bg)*(png_uint_32)(65535L - \
2870	(png_uint_32)(alpha)) + (png_uint_32)32768L); \
2871	(composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); }
2872
2873	#else /* Standard method using integer division */
2874
2875	# define png_composite(composite, fg, alpha, bg) \
2876	(composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \
2877	(png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \
2878	(png_uint_16)127) / 255)
2879
2880	# define png_composite_16(composite, fg, alpha, bg) \
2881	(composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \
2882	(png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) + \
2883	(png_uint_32)32767) / (png_uint_32)65535L)
2884
2885	#endif /* PNG_READ_COMPOSITE_NODIV_SUPPORTED */
2886
2887	/* Inline macros to do direct reads of bytes from the input buffer. These
2888	* require that you are using an architecture that uses PNG byte ordering
2889	* (MSB first) and supports unaligned data storage. I think that PowerPC
2890	* in big-endian mode and 680x0 are the only ones that will support this.
2891	* The x86 line of processors definitely do not. The png_get_int_32()
2892	* routine also assumes we are using two's complement format for negative
2893	* values, which is almost certainly true.
2894	*/
2895	#ifdef PNG_READ_BIG_ENDIAN_SUPPORTED
2896	# define png_get_uint_32(buf) ( *((png_uint_32p) (buf)))
2897	# define png_get_uint_16(buf) ( *((png_uint_16p) (buf)))
2898	# define png_get_int_32(buf) ( *((png_int_32p) (buf)))
2899	#else
2900	extern PNG_EXPORT(png_uint_32,png_get_uint_32) PNGARG((png_bytep buf));
2901	extern PNG_EXPORT(png_uint_16,png_get_uint_16) PNGARG((png_bytep buf));
2902	extern PNG_EXPORT(png_int_32,png_get_int_32) PNGARG((png_bytep buf));
2903	#endif /* !PNG_READ_BIG_ENDIAN_SUPPORTED */
2904	extern PNG_EXPORT(png_uint_32,png_get_uint_31)
2905	PNGARG((png_structp png_ptr, png_bytep buf));
2906	/* No png_get_int_16 -- may be added if there's a real need for it. */
2907
2908	/* Place a 32-bit number into a buffer in PNG byte order (big-endian).
2909	*/
2910	extern PNG_EXPORT(void,png_save_uint_32)
2911	PNGARG((png_bytep buf, png_uint_32 i));
2912	extern PNG_EXPORT(void,png_save_int_32)
2913	PNGARG((png_bytep buf, png_int_32 i));
2914
2915	/* Place a 16-bit number into a buffer in PNG byte order.
2916	* The parameter is declared unsigned int, not png_uint_16,
2917	* just to avoid potential problems on pre-ANSI C compilers.
2918	*/
2919	extern PNG_EXPORT(void,png_save_uint_16)
2920	PNGARG((png_bytep buf, unsigned int i));
2921	/* No png_save_int_16 -- may be added if there's a real need for it. */
2922
2923	/* ************************************************************************* */
2924
2925	/* These next functions are used internally in the code. They generally
2926	* shouldn't be used unless you are writing code to add or replace some
2927	* functionality in libpng. More information about most functions can
2928	* be found in the files where the functions are located.
2929	*/
2930
2931
2932	/* Various modes of operation, that are visible to applications because
2933	* they are used for unknown chunk location.
2934	*/
2935	#define PNG_HAVE_IHDR 0x01
2936	#define PNG_HAVE_PLTE 0x02
2937	#define PNG_HAVE_IDAT 0x04
2938	#define PNG_AFTER_IDAT 0x08 /* Have complete zlib datastream */
2939	#define PNG_HAVE_IEND 0x10
2940
2941	#ifdef PNG_INTERNAL
2942
2943	/* More modes of operation. Note that after an init, mode is set to
2944	* zero automatically when the structure is created.
2945	*/
2946	#define PNG_HAVE_gAMA 0x20
2947	#define PNG_HAVE_cHRM 0x40
2948	#define PNG_HAVE_sRGB 0x80
2949	#define PNG_HAVE_CHUNK_HEADER 0x100
2950	#define PNG_WROTE_tIME 0x200
2951	#define PNG_WROTE_INFO_BEFORE_PLTE 0x400
2952	#define PNG_BACKGROUND_IS_GRAY 0x800
2953	#define PNG_HAVE_PNG_SIGNATURE 0x1000
2954	#define PNG_HAVE_CHUNK_AFTER_IDAT 0x2000 /* Have another chunk after IDAT */
2955
2956	/* Flags for the transformations the PNG library does on the image data */
2957	#define PNG_BGR 0x0001
2958	#define PNG_INTERLACE 0x0002
2959	#define PNG_PACK 0x0004
2960	#define PNG_SHIFT 0x0008
2961	#define PNG_SWAP_BYTES 0x0010
2962	#define PNG_INVERT_MONO 0x0020
2963	#define PNG_DITHER 0x0040
2964	#define PNG_BACKGROUND 0x0080
2965	#define PNG_BACKGROUND_EXPAND 0x0100
2966	/* 0x0200 unused */
2967	#define PNG_16_TO_8 0x0400
2968	#define PNG_RGBA 0x0800
2969	#define PNG_EXPAND 0x1000
2970	#define PNG_GAMMA 0x2000
2971	#define PNG_GRAY_TO_RGB 0x4000
2972	#define PNG_FILLER 0x8000L
2973	#define PNG_PACKSWAP 0x10000L
2974	#define PNG_SWAP_ALPHA 0x20000L
2975	#define PNG_STRIP_ALPHA 0x40000L
2976	#define PNG_INVERT_ALPHA 0x80000L
2977	#define PNG_USER_TRANSFORM 0x100000L
2978	#define PNG_RGB_TO_GRAY_ERR 0x200000L
2979	#define PNG_RGB_TO_GRAY_WARN 0x400000L
2980	#define PNG_RGB_TO_GRAY 0x600000L /* two bits, RGB_TO_GRAY_ERR\|WARN */
2981	/* 0x800000L Unused */
2982	#define PNG_ADD_ALPHA 0x1000000L /* Added to libpng-1.2.7 */
2983	#define PNG_EXPAND_tRNS 0x2000000L /* Added to libpng-1.2.9 */
2984	#define PNG_PREMULTIPLY_ALPHA 0x4000000L /* Added to libpng-1.2.41 */
2985	/* by volker */
2986	/* 0x8000000L unused */
2987	/* 0x10000000L unused */
2988	/* 0x20000000L unused */
2989	/* 0x40000000L unused */
2990
2991	/* Flags for png_create_struct */
2992	#define PNG_STRUCT_PNG 0x0001
2993	#define PNG_STRUCT_INFO 0x0002
2994
2995	/* Scaling factor for filter heuristic weighting calculations */
2996	#define PNG_WEIGHT_SHIFT 8
2997	#define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT))
2998	#define PNG_COST_SHIFT 3
2999	#define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT))
3000
3001	/* Flags for the png_ptr->flags rather than declaring a byte for each one */
3002	#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001
3003	#define PNG_FLAG_ZLIB_CUSTOM_LEVEL 0x0002
3004	#define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL 0x0004
3005	#define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS 0x0008
3006	#define PNG_FLAG_ZLIB_CUSTOM_METHOD 0x0010
3007	#define PNG_FLAG_ZLIB_FINISHED 0x0020
3008	#define PNG_FLAG_ROW_INIT 0x0040
3009	#define PNG_FLAG_FILLER_AFTER 0x0080
3010	#define PNG_FLAG_CRC_ANCILLARY_USE 0x0100
3011	#define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200
3012	#define PNG_FLAG_CRC_CRITICAL_USE 0x0400
3013	#define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800
3014	#define PNG_FLAG_FREE_PLTE 0x1000
3015	#define PNG_FLAG_FREE_TRNS 0x2000
3016	#define PNG_FLAG_FREE_HIST 0x4000
3017	#define PNG_FLAG_KEEP_UNKNOWN_CHUNKS 0x8000L
3018	#define PNG_FLAG_KEEP_UNSAFE_CHUNKS 0x10000L
3019	#define PNG_FLAG_LIBRARY_MISMATCH 0x20000L
3020	#define PNG_FLAG_STRIP_ERROR_NUMBERS 0x40000L
3021	#define PNG_FLAG_STRIP_ERROR_TEXT 0x80000L
3022	#define PNG_FLAG_MALLOC_NULL_MEM_OK 0x100000L
3023	#define PNG_FLAG_ADD_ALPHA 0x200000L /* Added to libpng-1.2.8 */
3024	#define PNG_FLAG_STRIP_ALPHA 0x400000L /* Added to libpng-1.2.8 */
3025	/* 0x800000L unused */
3026	/* 0x1000000L unused */
3027	/* 0x2000000L unused */
3028	/* 0x4000000L unused */
3029	/* 0x8000000L unused */
3030	/* 0x10000000L unused */
3031	/* 0x20000000L unused */
3032	/* 0x40000000L unused */
3033
3034	#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE \| \
3035	PNG_FLAG_CRC_ANCILLARY_NOWARN)
3036
3037	#define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE \| \
3038	PNG_FLAG_CRC_CRITICAL_IGNORE)
3039
3040	#define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK \| \
3041	PNG_FLAG_CRC_CRITICAL_MASK)
3042
3043	/* Save typing and make code easier to understand */
3044
3045	#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \
3046	abs((int)((c1).green) - (int)((c2).green)) + \
3047	abs((int)((c1).blue) - (int)((c2).blue)))
3048
3049	/* Added to libpng-1.2.6 JB */
3050	#define PNG_ROWBYTES(pixel_bits, width) \
3051	((pixel_bits) >= 8 ? \
3052	((width) * (((png_uint_32)(pixel_bits)) >> 3)) : \
3053	(( ((width) * ((png_uint_32)(pixel_bits))) + 7) >> 3) )
3054
3055	/* PNG_OUT_OF_RANGE returns true if value is outside the range
3056	* ideal-delta..ideal+delta. Each argument is evaluated twice.
3057	* "ideal" and "delta" should be constants, normally simple
3058	* integers, "value" a variable. Added to libpng-1.2.6 JB
3059	*/
3060	#define PNG_OUT_OF_RANGE(value, ideal, delta) \
3061	( (value) < (ideal)-(delta) \|\| (value) > (ideal)+(delta) )
3062
3063	/* Variables declared in png.c - only it needs to define PNG_NO_EXTERN */
3064	#if !defined(PNG_NO_EXTERN) \|\| defined(PNG_ALWAYS_EXTERN)
3065	/* Place to hold the signature string for a PNG file. */
3066	#ifdef PNG_USE_GLOBAL_ARRAYS
3067	PNG_EXPORT_VAR (PNG_CONST png_byte FARDATA) png_sig[8];
3068	#else
3069	#endif
3070	#endif /* PNG_NO_EXTERN */
3071
3072	/* Constant strings for known chunk types. If you need to add a chunk,
3073	* define the name here, and add an invocation of the macro in png.c and
3074	* wherever it's needed.
3075	*/
3076	#define PNG_IHDR png_byte png_IHDR[5] = { 73, 72, 68, 82, '\0'}
3077	#define PNG_IDAT png_byte png_IDAT[5] = { 73, 68, 65, 84, '\0'}
3078	#define PNG_IEND png_byte png_IEND[5] = { 73, 69, 78, 68, '\0'}
3079	#define PNG_PLTE png_byte png_PLTE[5] = { 80, 76, 84, 69, '\0'}
3080	#define PNG_bKGD png_byte png_bKGD[5] = { 98, 75, 71, 68, '\0'}
3081	#define PNG_cHRM png_byte png_cHRM[5] = { 99, 72, 82, 77, '\0'}
3082	#define PNG_gAMA png_byte png_gAMA[5] = {103, 65, 77, 65, '\0'}
3083	#define PNG_hIST png_byte png_hIST[5] = {104, 73, 83, 84, '\0'}
3084	#define PNG_iCCP png_byte png_iCCP[5] = {105, 67, 67, 80, '\0'}
3085	#define PNG_iTXt png_byte png_iTXt[5] = {105, 84, 88, 116, '\0'}
3086	#define PNG_oFFs png_byte png_oFFs[5] = {111, 70, 70, 115, '\0'}
3087	#define PNG_pCAL png_byte png_pCAL[5] = {112, 67, 65, 76, '\0'}
3088	#define PNG_sCAL png_byte png_sCAL[5] = {115, 67, 65, 76, '\0'}
3089	#define PNG_pHYs png_byte png_pHYs[5] = {112, 72, 89, 115, '\0'}
3090	#define PNG_sBIT png_byte png_sBIT[5] = {115, 66, 73, 84, '\0'}
3091	#define PNG_sPLT png_byte png_sPLT[5] = {115, 80, 76, 84, '\0'}
3092	#define PNG_sRGB png_byte png_sRGB[5] = {115, 82, 71, 66, '\0'}
3093	#define PNG_tEXt png_byte png_tEXt[5] = {116, 69, 88, 116, '\0'}
3094	#define PNG_tIME png_byte png_tIME[5] = {116, 73, 77, 69, '\0'}
3095	#define PNG_tRNS png_byte png_tRNS[5] = {116, 82, 78, 83, '\0'}
3096	#define PNG_zTXt png_byte png_zTXt[5] = {122, 84, 88, 116, '\0'}
3097
3098	#ifdef PNG_USE_GLOBAL_ARRAYS
3099	PNG_EXPORT_VAR (png_byte FARDATA) png_IHDR[5];
3100	PNG_EXPORT_VAR (png_byte FARDATA) png_IDAT[5];
3101	PNG_EXPORT_VAR (png_byte FARDATA) png_IEND[5];
3102	PNG_EXPORT_VAR (png_byte FARDATA) png_PLTE[5];
3103	PNG_EXPORT_VAR (png_byte FARDATA) png_bKGD[5];
3104	PNG_EXPORT_VAR (png_byte FARDATA) png_cHRM[5];
3105	PNG_EXPORT_VAR (png_byte FARDATA) png_gAMA[5];
3106	PNG_EXPORT_VAR (png_byte FARDATA) png_hIST[5];
3107	PNG_EXPORT_VAR (png_byte FARDATA) png_iCCP[5];
3108	PNG_EXPORT_VAR (png_byte FARDATA) png_iTXt[5];
3109	PNG_EXPORT_VAR (png_byte FARDATA) png_oFFs[5];
3110	PNG_EXPORT_VAR (png_byte FARDATA) png_pCAL[5];
3111	PNG_EXPORT_VAR (png_byte FARDATA) png_sCAL[5];
3112	PNG_EXPORT_VAR (png_byte FARDATA) png_pHYs[5];
3113	PNG_EXPORT_VAR (png_byte FARDATA) png_sBIT[5];
3114	PNG_EXPORT_VAR (png_byte FARDATA) png_sPLT[5];
3115	PNG_EXPORT_VAR (png_byte FARDATA) png_sRGB[5];
3116	PNG_EXPORT_VAR (png_byte FARDATA) png_tEXt[5];
3117	PNG_EXPORT_VAR (png_byte FARDATA) png_tIME[5];
3118	PNG_EXPORT_VAR (png_byte FARDATA) png_tRNS[5];
3119	PNG_EXPORT_VAR (png_byte FARDATA) png_zTXt[5];
3120	#endif /* PNG_USE_GLOBAL_ARRAYS */
3121
3122	#if defined(PNG_1_0_X) \|\| defined (PNG_1_2_X)
3123	/* Initialize png_ptr struct for reading, and allocate any other memory.
3124	* (old interface - DEPRECATED - use png_create_read_struct instead).
3125	*/
3126	extern PNG_EXPORT(void,png_read_init) PNGARG((png_structp png_ptr))
3127	PNG_DEPRECATED;
3128	#undef png_read_init
3129	#define png_read_init(png_ptr) png_read_init_3(&png_ptr, \
3130	PNG_LIBPNG_VER_STRING, png_sizeof(png_struct));
3131	#endif
3132
3133	extern PNG_EXPORT(void,png_read_init_3) PNGARG((png_structpp ptr_ptr,
3134	png_const_charp user_png_ver, png_size_t png_struct_size));
3135	#if defined(PNG_1_0_X) \|\| defined (PNG_1_2_X)
3136	extern PNG_EXPORT(void,png_read_init_2) PNGARG((png_structp png_ptr,
3137	png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
3138	png_info_size));
3139	#endif
3140
3141	#if defined(PNG_1_0_X) \|\| defined (PNG_1_2_X)
3142	/* Initialize png_ptr struct for writing, and allocate any other memory.
3143	* (old interface - DEPRECATED - use png_create_write_struct instead).
3144	*/
3145	extern PNG_EXPORT(void,png_write_init) PNGARG((png_structp png_ptr))
3146	PNG_DEPRECATED;
3147	#undef png_write_init
3148	#define png_write_init(png_ptr) png_write_init_3(&png_ptr, \
3149	PNG_LIBPNG_VER_STRING, png_sizeof(png_struct));
3150	#endif
3151
3152	extern PNG_EXPORT(void,png_write_init_3) PNGARG((png_structpp ptr_ptr,
3153	png_const_charp user_png_ver, png_size_t png_struct_size));
3154	extern PNG_EXPORT(void,png_write_init_2) PNGARG((png_structp png_ptr,
3155	png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t
3156	png_info_size));
3157
3158	/* Allocate memory for an internal libpng struct */
3159	PNG_EXTERN png_voidp png_create_struct PNGARG((int type)) PNG_PRIVATE;
3160
3161	/* Free memory from internal libpng struct */
3162	PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr)) PNG_PRIVATE;
3163
3164	PNG_EXTERN png_voidp png_create_struct_2 PNGARG((int type, png_malloc_ptr
3165	malloc_fn, png_voidp mem_ptr)) PNG_PRIVATE;
3166	PNG_EXTERN void png_destroy_struct_2 PNGARG((png_voidp struct_ptr,
3167	png_free_ptr free_fn, png_voidp mem_ptr)) PNG_PRIVATE;
3168
3169	/* Free any memory that info_ptr points to and reset struct. */
3170	PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr,
3171	png_infop info_ptr)) PNG_PRIVATE;
3172
3173	#ifndef PNG_1_0_X
3174	/* Function to allocate memory for zlib. */
3175	PNG_EXTERN voidpf png_zalloc PNGARG((voidpf png_ptr, uInt items,
3176	uInt size)) PNG_PRIVATE;
3177
3178	/* Function to free memory for zlib */
3179	PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr)) PNG_PRIVATE;
3180
3181	#ifdef PNG_SIZE_T
3182	/* Function to convert a sizeof an item to png_sizeof item */
3183	PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size))
3184	PNG_PRIVATE;
3185	#endif
3186
3187	/* Next four functions are used internally as callbacks. PNGAPI is required
3188	* but not PNG_EXPORT. PNGAPI added at libpng version 1.2.3.
3189	*/
3190
3191	PNG_EXTERN void PNGAPI png_default_read_data PNGARG((png_structp png_ptr,
3192	png_bytep data, png_size_t length)) PNG_PRIVATE;
3193
3194	#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3195	PNG_EXTERN void PNGAPI png_push_fill_buffer PNGARG((png_structp png_ptr,
3196	png_bytep buffer, png_size_t length)) PNG_PRIVATE;
3197	#endif
3198
3199	PNG_EXTERN void PNGAPI png_default_write_data PNGARG((png_structp png_ptr,
3200	png_bytep data, png_size_t length)) PNG_PRIVATE;
3201
3202	#ifdef PNG_WRITE_FLUSH_SUPPORTED
3203	#ifdef PNG_STDIO_SUPPORTED
3204	PNG_EXTERN void PNGAPI png_default_flush PNGARG((png_structp png_ptr))
3205	PNG_PRIVATE;
3206	#endif
3207	#endif
3208	#else /* PNG_1_0_X */
3209	#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3210	PNG_EXTERN void png_push_fill_buffer PNGARG((png_structp png_ptr,
3211	png_bytep buffer, png_size_t length)) PNG_PRIVATE;
3212	#endif
3213	#endif /* PNG_1_0_X */
3214
3215	/* Reset the CRC variable */
3216	PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3217
3218	/* Write the "data" buffer to whatever output you are using. */
3219	PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr, png_bytep data,
3220	png_size_t length)) PNG_PRIVATE;
3221
3222	/* Read data from whatever input you are using into the "data" buffer */
3223	PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data,
3224	png_size_t length)) PNG_PRIVATE;
3225
3226	/* Read bytes into buf, and update png_ptr->crc */
3227	PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf,
3228	png_size_t length)) PNG_PRIVATE;
3229
3230	/* Decompress data in a chunk that uses compression */
3231	#if defined(PNG_zTXt_SUPPORTED) \|\| defined(PNG_iTXt_SUPPORTED) \|\| \
3232	defined(PNG_iCCP_SUPPORTED) \|\| defined(PNG_sPLT_SUPPORTED)
3233	PNG_EXTERN void png_decompress_chunk PNGARG((png_structp png_ptr,
3234	int comp_type, png_size_t chunklength,
3235	png_size_t prefix_length, png_size_t *data_length)) PNG_PRIVATE;
3236	#endif
3237
3238	/* Read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */
3239	PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip)
3240	PNG_PRIVATE);
3241
3242	/* Read the CRC from the file and compare it to the libpng calculated CRC */
3243	PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3244
3245	/* Calculate the CRC over a section of data. Note that we are only
3246	* passing a maximum of 64K on systems that have this as a memory limit,
3247	* since this is the maximum buffer size we can specify.
3248	*/
3249	PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr, png_bytep ptr,
3250	png_size_t length)) PNG_PRIVATE;
3251
3252	#ifdef PNG_WRITE_FLUSH_SUPPORTED
3253	PNG_EXTERN void png_flush PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3254	#endif
3255
3256	/* Simple function to write the signature */
3257	PNG_EXTERN void png_write_sig PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3258
3259	/* Write various chunks */
3260
3261	/* Write the IHDR chunk, and update the png_struct with the necessary
3262	* information.
3263	*/
3264	PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width,
3265	png_uint_32 height,
3266	int bit_depth, int color_type, int compression_method, int filter_method,
3267	int interlace_method)) PNG_PRIVATE;
3268
3269	PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr, png_colorp palette,
3270	png_uint_32 num_pal)) PNG_PRIVATE;
3271
3272	PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data,
3273	png_size_t length)) PNG_PRIVATE;
3274
3275	PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3276
3277	#ifdef PNG_WRITE_gAMA_SUPPORTED
3278	#ifdef PNG_FLOATING_POINT_SUPPORTED
3279	PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma))
3280	PNG_PRIVATE;
3281	#endif
3282	#ifdef PNG_FIXED_POINT_SUPPORTED
3283	PNG_EXTERN void png_write_gAMA_fixed PNGARG((png_structp png_ptr,
3284	png_fixed_point file_gamma)) PNG_PRIVATE;
3285	#endif
3286	#endif
3287
3288	#ifdef PNG_WRITE_sBIT_SUPPORTED
3289	PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr, png_color_8p sbit,
3290	int color_type)) PNG_PRIVATE;
3291	#endif
3292
3293	#ifdef PNG_WRITE_cHRM_SUPPORTED
3294	#ifdef PNG_FLOATING_POINT_SUPPORTED
3295	PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr,
3296	double white_x, double white_y,
3297	double red_x, double red_y, double green_x, double green_y,
3298	double blue_x, double blue_y)) PNG_PRIVATE;
3299	#endif
3300	#ifdef PNG_FIXED_POINT_SUPPORTED
3301	PNG_EXTERN void png_write_cHRM_fixed PNGARG((png_structp png_ptr,
3302	png_fixed_point int_white_x, png_fixed_point int_white_y,
3303	png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
3304	int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
3305	png_fixed_point int_blue_y)) PNG_PRIVATE;
3306	#endif
3307	#endif
3308
3309	#ifdef PNG_WRITE_sRGB_SUPPORTED
3310	PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
3311	int intent)) PNG_PRIVATE;
3312	#endif
3313
3314	#ifdef PNG_WRITE_iCCP_SUPPORTED
3315	PNG_EXTERN void png_write_iCCP PNGARG((png_structp png_ptr,
3316	png_charp name, int compression_type,
3317	png_charp profile, int proflen)) PNG_PRIVATE;
3318	/* Note to maintainer: profile should be png_bytep */
3319	#endif
3320
3321	#ifdef PNG_WRITE_sPLT_SUPPORTED
3322	PNG_EXTERN void png_write_sPLT PNGARG((png_structp png_ptr,
3323	png_sPLT_tp palette)) PNG_PRIVATE;
3324	#endif
3325
3326	#ifdef PNG_WRITE_tRNS_SUPPORTED
3327	PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr, png_bytep trans,
3328	png_color_16p values, int number, int color_type)) PNG_PRIVATE;
3329	#endif
3330
3331	#ifdef PNG_WRITE_bKGD_SUPPORTED
3332	PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr,
3333	png_color_16p values, int color_type)) PNG_PRIVATE;
3334	#endif
3335
3336	#ifdef PNG_WRITE_hIST_SUPPORTED
3337	PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, png_uint_16p hist,
3338	int num_hist)) PNG_PRIVATE;
3339	#endif
3340
3341	#if defined(PNG_WRITE_TEXT_SUPPORTED) \|\| defined(PNG_WRITE_pCAL_SUPPORTED) \|\| \
3342	defined(PNG_WRITE_iCCP_SUPPORTED) \|\| defined(PNG_WRITE_sPLT_SUPPORTED)
3343	PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr,
3344	png_charp key, png_charpp new_key)) PNG_PRIVATE;
3345	#endif
3346
3347	#ifdef PNG_WRITE_tEXt_SUPPORTED
3348	PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_charp key,
3349	png_charp text, png_size_t text_len)) PNG_PRIVATE;
3350	#endif
3351
3352	#ifdef PNG_WRITE_zTXt_SUPPORTED
3353	PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_charp key,
3354	png_charp text, png_size_t text_len, int compression)) PNG_PRIVATE;
3355	#endif
3356
3357	#ifdef PNG_WRITE_iTXt_SUPPORTED
3358	PNG_EXTERN void png_write_iTXt PNGARG((png_structp png_ptr,
3359	int compression, png_charp key, png_charp lang, png_charp lang_key,
3360	png_charp text)) PNG_PRIVATE;
3361	#endif
3362
3363	#ifdef PNG_TEXT_SUPPORTED /* Added at version 1.0.14 and 1.2.4 */
3364	PNG_EXTERN int png_set_text_2 PNGARG((png_structp png_ptr,
3365	png_infop info_ptr, png_textp text_ptr, int num_text)) PNG_PRIVATE;
3366	#endif
3367
3368	#ifdef PNG_WRITE_oFFs_SUPPORTED
3369	PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr,
3370	png_int_32 x_offset, png_int_32 y_offset, int unit_type)) PNG_PRIVATE;
3371	#endif
3372
3373	#ifdef PNG_WRITE_pCAL_SUPPORTED
3374	PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose,
3375	png_int_32 X0, png_int_32 X1, int type, int nparams,
3376	png_charp units, png_charpp params)) PNG_PRIVATE;
3377	#endif
3378
3379	#ifdef PNG_WRITE_pHYs_SUPPORTED
3380	PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr,
3381	png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit,
3382	int unit_type)) PNG_PRIVATE;
3383	#endif
3384
3385	#ifdef PNG_WRITE_tIME_SUPPORTED
3386	PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr,
3387	png_timep mod_time)) PNG_PRIVATE;
3388	#endif
3389
3390	#ifdef PNG_WRITE_sCAL_SUPPORTED
3391	#if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
3392	PNG_EXTERN void png_write_sCAL PNGARG((png_structp png_ptr,
3393	int unit, double width, double height)) PNG_PRIVATE;
3394	#else
3395	#ifdef PNG_FIXED_POINT_SUPPORTED
3396	PNG_EXTERN void png_write_sCAL_s PNGARG((png_structp png_ptr,
3397	int unit, png_charp width, png_charp height)) PNG_PRIVATE;
3398	#endif
3399	#endif
3400	#endif
3401
3402	/* Called when finished processing a row of data */
3403	PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3404
3405	/* Internal use only. Called before first row of data */
3406	PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3407
3408	#ifdef PNG_READ_GAMMA_SUPPORTED
3409	PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3410	#endif
3411
3412	/* Combine a row of data, dealing with alpha, etc. if requested */
3413	PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row,
3414	int mask)) PNG_PRIVATE;
3415
3416	#ifdef PNG_READ_INTERLACING_SUPPORTED
3417	/* Expand an interlaced row */
3418	/* OLD pre-1.0.9 interface:
3419	PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info,
3420	png_bytep row, int pass, png_uint_32 transformations)) PNG_PRIVATE;
3421	*/
3422	PNG_EXTERN void png_do_read_interlace PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3423	#endif
3424
3425	/* GRR TO DO (2.0 or whenever): simplify other internal calling interfaces */
3426
3427	#ifdef PNG_WRITE_INTERLACING_SUPPORTED
3428	/* Grab pixels out of a row for an interlaced pass */
3429	PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info,
3430	png_bytep row, int pass)) PNG_PRIVATE;
3431	#endif
3432
3433	/* Unfilter a row */
3434	PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr,
3435	png_row_infop row_info, png_bytep row, png_bytep prev_row,
3436	int filter)) PNG_PRIVATE;
3437
3438	/* Choose the best filter to use and filter the row data */
3439	PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr,
3440	png_row_infop row_info)) PNG_PRIVATE;
3441
3442	/* Write out the filtered row. */
3443	PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr,
3444	png_bytep filtered_row)) PNG_PRIVATE;
3445	/* Finish a row while reading, dealing with interlacing passes, etc. */
3446	PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr));
3447
3448	/* Initialize the row buffers, etc. */
3449	PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3450	/* Optional call to update the users info structure */
3451	PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr,
3452	png_infop info_ptr)) PNG_PRIVATE;
3453
3454	/* These are the functions that do the transformations */
3455	#ifdef PNG_READ_FILLER_SUPPORTED
3456	PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info,
3457	png_bytep row, png_uint_32 filler, png_uint_32 flags)) PNG_PRIVATE;
3458	#endif
3459
3460	#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
3461	PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info,
3462	png_bytep row)) PNG_PRIVATE;
3463	#endif
3464
3465	#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
3466	PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info,
3467	png_bytep row)) PNG_PRIVATE;
3468	#endif
3469
3470	#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
3471	PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info,
3472	png_bytep row)) PNG_PRIVATE;
3473	#endif
3474
3475	#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
3476	PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info,
3477	png_bytep row)) PNG_PRIVATE;
3478	#endif
3479
3480	#if defined(PNG_WRITE_FILLER_SUPPORTED) \|\| \
3481	defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
3482	PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info,
3483	png_bytep row, png_uint_32 flags)) PNG_PRIVATE;
3484	#endif
3485
3486	#if defined(PNG_READ_SWAP_SUPPORTED) \|\| defined(PNG_WRITE_SWAP_SUPPORTED)
3487	PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info,
3488	png_bytep row)) PNG_PRIVATE;
3489	#endif
3490
3491	#if defined(PNG_READ_PACKSWAP_SUPPORTED) \|\| defined(PNG_WRITE_PACKSWAP_SUPPORTED)
3492	PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info,
3493	png_bytep row)) PNG_PRIVATE;
3494	#endif
3495
3496	#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
3497	PNG_EXTERN int png_do_rgb_to_gray PNGARG((png_structp png_ptr, png_row_infop
3498	row_info, png_bytep row)) PNG_PRIVATE;
3499	#endif
3500
3501	#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
3502	PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info,
3503	png_bytep row)) PNG_PRIVATE;
3504	#endif
3505
3506	#ifdef PNG_READ_PACK_SUPPORTED
3507	PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info,
3508	png_bytep row)) PNG_PRIVATE;
3509	#endif
3510
3511	#ifdef PNG_READ_SHIFT_SUPPORTED
3512	PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info, png_bytep row,
3513	png_color_8p sig_bits)) PNG_PRIVATE;
3514	#endif
3515
3516	#if defined(PNG_READ_INVERT_SUPPORTED) \|\| defined(PNG_WRITE_INVERT_SUPPORTED)
3517	PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info,
3518	png_bytep row)) PNG_PRIVATE;
3519	#endif
3520
3521	#ifdef PNG_READ_16_TO_8_SUPPORTED
3522	PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info,
3523	png_bytep row)) PNG_PRIVATE;
3524	#endif
3525
3526	#ifdef PNG_READ_DITHER_SUPPORTED
3527	PNG_EXTERN void png_do_dither PNGARG((png_row_infop row_info,
3528	png_bytep row, png_bytep palette_lookup,
3529	png_bytep dither_lookup)) PNG_PRIVATE;
3530
3531	# ifdef PNG_CORRECT_PALETTE_SUPPORTED
3532	PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr,
3533	png_colorp palette, int num_palette)) PNG_PRIVATE;
3534	# endif
3535	#endif
3536
3537	#if defined(PNG_READ_BGR_SUPPORTED) \|\| defined(PNG_WRITE_BGR_SUPPORTED)
3538	PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info,
3539	png_bytep row)) PNG_PRIVATE;
3540	#endif
3541
3542	#ifdef PNG_WRITE_PACK_SUPPORTED
3543	PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info,
3544	png_bytep row, png_uint_32 bit_depth)) PNG_PRIVATE;
3545	#endif
3546
3547	#ifdef PNG_WRITE_SHIFT_SUPPORTED
3548	PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info, png_bytep row,
3549	png_color_8p bit_depth)) PNG_PRIVATE;
3550	#endif
3551
3552	#ifdef PNG_READ_BACKGROUND_SUPPORTED
3553	#ifdef PNG_READ_GAMMA_SUPPORTED
3554	PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
3555	png_color_16p trans_values, png_color_16p background,
3556	png_color_16p background_1,
3557	png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,
3558	png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,
3559	png_uint_16pp gamma_16_to_1, int gamma_shift)) PNG_PRIVATE;
3560	#else
3561	PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row,
3562	png_color_16p trans_values, png_color_16p background)) PNG_PRIVATE;
3563	#endif
3564	#endif
3565
3566	#ifdef PNG_READ_GAMMA_SUPPORTED
3567	PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info, png_bytep row,
3568	png_bytep gamma_table, png_uint_16pp gamma_16_table,
3569	int gamma_shift)) PNG_PRIVATE;
3570	#endif
3571
3572	#ifdef PNG_READ_EXPAND_SUPPORTED
3573	PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info,
3574	png_bytep row, png_colorp palette, png_bytep trans,
3575	int num_trans)) PNG_PRIVATE;
3576	PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info,
3577	png_bytep row, png_color_16p trans_value)) PNG_PRIVATE;
3578	#endif
3579
3580	/* The following decodes the appropriate chunks, and does error correction,
3581	* then calls the appropriate callback for the chunk if it is valid.
3582	*/
3583
3584	/* Decode the IHDR chunk */
3585	PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr,
3586	png_uint_32 length)) PNG_PRIVATE;
3587	PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr,
3588	png_uint_32 length));
3589	PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr,
3590	png_uint_32 length));
3591
3592	#ifdef PNG_READ_bKGD_SUPPORTED
3593	PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr,
3594	png_uint_32 length)) PNG_PRIVATE;
3595	#endif
3596
3597	#ifdef PNG_READ_cHRM_SUPPORTED
3598	PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr,
3599	png_uint_32 length)) PNG_PRIVATE;
3600	#endif
3601
3602	#ifdef PNG_READ_gAMA_SUPPORTED
3603	PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr,
3604	png_uint_32 length)) PNG_PRIVATE;
3605	#endif
3606
3607	#ifdef PNG_READ_hIST_SUPPORTED
3608	PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr,
3609	png_uint_32 length)) PNG_PRIVATE;
3610	#endif
3611
3612	#ifdef PNG_READ_iCCP_SUPPORTED
3613	extern void png_handle_iCCP PNGARG((png_structp png_ptr, png_infop info_ptr,
3614	png_uint_32 length));
3615	#endif /* PNG_READ_iCCP_SUPPORTED */
3616
3617	#ifdef PNG_READ_iTXt_SUPPORTED
3618	PNG_EXTERN void png_handle_iTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3619	png_uint_32 length)) PNG_PRIVATE;
3620	#endif
3621
3622	#ifdef PNG_READ_oFFs_SUPPORTED
3623	PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr,
3624	png_uint_32 length)) PNG_PRIVATE;
3625	#endif
3626
3627	#ifdef PNG_READ_pCAL_SUPPORTED
3628	PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
3629	png_uint_32 length)) PNG_PRIVATE;
3630	#endif
3631
3632	#ifdef PNG_READ_pHYs_SUPPORTED
3633	PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr,
3634	png_uint_32 length)) PNG_PRIVATE;
3635	#endif
3636
3637	#ifdef PNG_READ_sBIT_SUPPORTED
3638	PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr,
3639	png_uint_32 length)) PNG_PRIVATE;
3640	#endif
3641
3642	#ifdef PNG_READ_sCAL_SUPPORTED
3643	PNG_EXTERN void png_handle_sCAL PNGARG((png_structp png_ptr, png_infop info_ptr,
3644	png_uint_32 length)) PNG_PRIVATE;
3645	#endif
3646
3647	#ifdef PNG_READ_sPLT_SUPPORTED
3648	extern void png_handle_sPLT PNGARG((png_structp png_ptr, png_infop info_ptr,
3649	png_uint_32 length)) PNG_PRIVATE;
3650	#endif /* PNG_READ_sPLT_SUPPORTED */
3651
3652	#ifdef PNG_READ_sRGB_SUPPORTED
3653	PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr,
3654	png_uint_32 length)) PNG_PRIVATE;
3655	#endif
3656
3657	#ifdef PNG_READ_tEXt_SUPPORTED
3658	PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3659	png_uint_32 length)) PNG_PRIVATE;
3660	#endif
3661
3662	#ifdef PNG_READ_tIME_SUPPORTED
3663	PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr,
3664	png_uint_32 length)) PNG_PRIVATE;
3665	#endif
3666
3667	#ifdef PNG_READ_tRNS_SUPPORTED
3668	PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr,
3669	png_uint_32 length)) PNG_PRIVATE;
3670	#endif
3671
3672	#ifdef PNG_READ_zTXt_SUPPORTED
3673	PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr,
3674	png_uint_32 length)) PNG_PRIVATE;
3675	#endif
3676
3677	PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr,
3678	png_infop info_ptr, png_uint_32 length)) PNG_PRIVATE;
3679
3680	PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr,
3681	png_bytep chunk_name)) PNG_PRIVATE;
3682
3683	/* Handle the transformations for reading and writing */
3684	PNG_EXTERN void png_do_read_transformations
3685	PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3686	PNG_EXTERN void png_do_write_transformations
3687	PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3688
3689	PNG_EXTERN void png_init_read_transformations
3690	PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3691
3692	#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
3693	PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr,
3694	png_infop info_ptr)) PNG_PRIVATE;
3695	PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr,
3696	png_infop info_ptr)) PNG_PRIVATE;
3697	PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3698	PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr,
3699	png_uint_32 length)) PNG_PRIVATE;
3700	PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3701	PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3702	PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr,
3703	png_bytep buffer, png_size_t buffer_length)) PNG_PRIVATE;
3704	PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3705	PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr,
3706	png_bytep buffer, png_size_t buffer_length)) PNG_PRIVATE;
3707	PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3708	PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr,
3709	png_infop info_ptr, png_uint_32 length)) PNG_PRIVATE;
3710	PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr,
3711	png_infop info_ptr)) PNG_PRIVATE;
3712	PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr,
3713	png_infop info_ptr)) PNG_PRIVATE;
3714	PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr,
3715	png_bytep row)) PNG_PRIVATE;
3716	PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr,
3717	png_infop info_ptr)) PNG_PRIVATE;
3718	PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr,
3719	png_infop info_ptr)) PNG_PRIVATE;
3720	PNG_EXTERN void png_read_push_finish_row
3721	PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3722	#ifdef PNG_READ_tEXt_SUPPORTED
3723	PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr,
3724	png_infop info_ptr, png_uint_32 length)) PNG_PRIVATE;
3725	PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr,
3726	png_infop info_ptr)) PNG_PRIVATE;
3727	#endif
3728	#ifdef PNG_READ_zTXt_SUPPORTED
3729	PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr,
3730	png_infop info_ptr, png_uint_32 length)) PNG_PRIVATE;
3731	PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr,
3732	png_infop info_ptr)) PNG_PRIVATE;
3733	#endif
3734	#ifdef PNG_READ_iTXt_SUPPORTED
3735	PNG_EXTERN void png_push_handle_iTXt PNGARG((png_structp png_ptr,
3736	png_infop info_ptr, png_uint_32 length)) PNG_PRIVATE;
3737	PNG_EXTERN void png_push_read_iTXt PNGARG((png_structp png_ptr,
3738	png_infop info_ptr)) PNG_PRIVATE;
3739	#endif
3740
3741	#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
3742
3743	#ifdef PNG_MNG_FEATURES_SUPPORTED
3744	PNG_EXTERN void png_do_read_intrapixel PNGARG((png_row_infop row_info,
3745	png_bytep row)) PNG_PRIVATE;
3746	PNG_EXTERN void png_do_write_intrapixel PNGARG((png_row_infop row_info,
3747	png_bytep row)) PNG_PRIVATE;
3748	#endif
3749
3750	#ifdef PNG_ASSEMBLER_CODE_SUPPORTED
3751	#ifdef PNG_MMX_CODE_SUPPORTED
3752	/* png.c / / PRIVATE */
3753	PNG_EXTERN void png_init_mmx_flags PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3754	#endif
3755	#endif
3756
3757
3758	/* The following six functions will be exported in libpng-1.4.0. */
3759	#if defined(PNG_INCH_CONVERSIONS) && defined(PNG_FLOATING_POINT_SUPPORTED)
3760	PNG_EXTERN png_uint_32 png_get_pixels_per_inch PNGARG((png_structp png_ptr,
3761	png_infop info_ptr));
3762
3763	PNG_EXTERN png_uint_32 png_get_x_pixels_per_inch PNGARG((png_structp png_ptr,
3764	png_infop info_ptr));
3765
3766	PNG_EXTERN png_uint_32 png_get_y_pixels_per_inch PNGARG((png_structp png_ptr,
3767	png_infop info_ptr));
3768
3769	PNG_EXTERN float png_get_x_offset_inches PNGARG((png_structp png_ptr,
3770	png_infop info_ptr));
3771
3772	PNG_EXTERN float png_get_y_offset_inches PNGARG((png_structp png_ptr,
3773	png_infop info_ptr));
3774
3775	#ifdef PNG_pHYs_SUPPORTED
3776	PNG_EXTERN png_uint_32 png_get_pHYs_dpi PNGARG((png_structp png_ptr,
3777	png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int *unit_type));
3778	#endif /* PNG_pHYs_SUPPORTED */
3779	#endif /* PNG_INCH_CONVERSIONS && PNG_FLOATING_POINT_SUPPORTED */
3780
3781	/* Read the chunk header (length + type name) */
3782	PNG_EXTERN png_uint_32 png_read_chunk_header
3783	PNGARG((png_structp png_ptr)) PNG_PRIVATE;
3784
3785	/* Added at libpng version 1.2.34 */
3786	#ifdef PNG_cHRM_SUPPORTED
3787	PNG_EXTERN int png_check_cHRM_fixed PNGARG((png_structp png_ptr,
3788	png_fixed_point int_white_x, png_fixed_point int_white_y,
3789	png_fixed_point int_red_x, png_fixed_point int_red_y, png_fixed_point
3790	int_green_x, png_fixed_point int_green_y, png_fixed_point int_blue_x,
3791	png_fixed_point int_blue_y)) PNG_PRIVATE;
3792	#endif
3793
3794	#ifdef PNG_cHRM_SUPPORTED
3795	#ifdef PNG_CHECK_cHRM_SUPPORTED
3796	/* Added at libpng version 1.2.34 */
3797	PNG_EXTERN void png_64bit_product PNGARG((long v1, long v2,
3798	unsigned long hi_product, unsigned long lo_product)) PNG_PRIVATE;
3799	#endif
3800	#endif
3801
3802	/* Added at libpng version 1.2.41 */
3803	PNG_EXTERN void png_check_IHDR PNGARG((png_structp png_ptr,
3804	png_uint_32 width, png_uint_32 height, int bit_depth,
3805	int color_type, int interlace_type, int compression_type,
3806	int filter_type)) PNG_PRIVATE;
3807
3808	/* Added at libpng version 1.2.41 */
3809	PNG_EXTERN png_voidp png_calloc PNGARG((png_structp png_ptr,
3810	png_uint_32 size));
3811
3812	/* Maintainer: Put new private prototypes here ^ and in libpngpf.3 */
3813
3814	#endif /* PNG_INTERNAL */
3815
3816	#ifdef __cplusplus
3817	}
3818	#endif
3819
3820	#endif /* PNG_VERSION_INFO_ONLY */
3821	/* Do not put anything past this line */
3822	#endif /* PNG_H */

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