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simplifying alpha, adding commented part for high-res screens
[wxWidgets.git] / src / png / pngread.c
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75b6e0a0
GD		 1
2/* pngread.c - read a PNG file
3 *
706b8807 4 * libpng 1.2.7 - September 12, 2004
75b6e0a0 5 * For conditions of distribution and use, see copyright notice in png.h
5b02c8a1 6 * Copyright (c) 1998-2004 Glenn Randers-Pehrson
4946a942
GD		 7 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
8 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
75b6e0a0
GD		 9 *
10 * This file contains routines that an application calls directly to
11 * read a PNG file or stream.
12 */
13
14#define PNG_INTERNAL
15#include "png.h"
16
17/* Create a PNG structure for reading, and allocate any memory needed. */
4946a942 18png_structp PNGAPI
75b6e0a0
GD		 19png_create_read_struct(png_const_charp user_png_ver, png_voidp error_ptr,
20 png_error_ptr error_fn, png_error_ptr warn_fn)
21{
22
23#ifdef PNG_USER_MEM_SUPPORTED
24 return (png_create_read_struct_2(user_png_ver, error_ptr, error_fn,
4946a942 25 warn_fn, png_voidp_NULL, png_malloc_ptr_NULL, png_free_ptr_NULL));
75b6e0a0
GD		 26}
27
28/* Alternate create PNG structure for reading, and allocate any memory needed. */
4946a942 29png_structp PNGAPI
75b6e0a0
GD		 30png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
31 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
32 png_malloc_ptr malloc_fn, png_free_ptr free_fn)
33{
34#endif /* PNG_USER_MEM_SUPPORTED */
35
36 png_structp png_ptr;
4946a942
GD		 37
38#ifdef PNG_SETJMP_SUPPORTED
75b6e0a0
GD		 39#ifdef USE_FAR_KEYWORD
40 jmp_buf jmpbuf;
41#endif
4946a942
GD		 42#endif
43
44 int i;
45
75b6e0a0
GD		 46 png_debug(1, "in png_create_read_struct\n");
47#ifdef PNG_USER_MEM_SUPPORTED
4946a942
GD		 48 png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
49 (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);
75b6e0a0 50#else
4946a942 51 png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
75b6e0a0 52#endif
4946a942
GD		 53 if (png_ptr == NULL)
54 return (NULL);
55
56#if !defined(PNG_1_0_X)
57#ifdef PNG_ASSEMBLER_CODE_SUPPORTED
58 png_init_mmx_flags(png_ptr); /* 1.2.0 addition */
59#endif
60#endif /* PNG_1_0_X */
61
5b02c8a1
VS		 62 /* added at libpng-1.2.6 */
63#ifdef PNG_SET_USER_LIMITS_SUPPORTED
64 png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
65 png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
66#endif
67
4946a942 68#ifdef PNG_SETJMP_SUPPORTED
75b6e0a0
GD		 69#ifdef USE_FAR_KEYWORD
70 if (setjmp(jmpbuf))
71#else
72 if (setjmp(png_ptr->jmpbuf))
73#endif
74 {
75 png_free(png_ptr, png_ptr->zbuf);
4946a942
GD		 76 png_ptr->zbuf=NULL;
77#ifdef PNG_USER_MEM_SUPPORTED
78 png_destroy_struct_2((png_voidp)png_ptr,
79 (png_free_ptr)free_fn, (png_voidp)mem_ptr);
80#else
81 png_destroy_struct((png_voidp)png_ptr);
82#endif
83 return (NULL);
75b6e0a0
GD		 84 }
85#ifdef USE_FAR_KEYWORD
5b02c8a1 86 png_memcpy(png_ptr->jmpbuf,jmpbuf,png_sizeof(jmp_buf));
75b6e0a0 87#endif
4946a942 88#endif
75b6e0a0
GD		 89
90#ifdef PNG_USER_MEM_SUPPORTED
91 png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
4946a942 92#endif
75b6e0a0
GD		 93
94 png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
95
4946a942
GD		 96 i=0;
97 do
75b6e0a0 98 {
4946a942
GD		 99 if(user_png_ver[i] != png_libpng_ver[i])
100 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
101 } while (png_libpng_ver[i++]);
102
103 if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
104 {
105 /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
106 * we must recompile any applications that use any older library version.
107 * For versions after libpng 1.0, we will be compatible, so we need
108 * only check the first digit.
109 */
110 if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
111 (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
112 (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
113 {
114#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
115 char msg[80];
116 if (user_png_ver)
117 {
118 sprintf(msg, "Application was compiled with png.h from libpng-%.20s",
119 user_png_ver);
120 png_warning(png_ptr, msg);
121 }
122 sprintf(msg, "Application is running with png.c from libpng-%.20s",
123 png_libpng_ver);
124 png_warning(png_ptr, msg);
125#endif
126#ifdef PNG_ERROR_NUMBERS_SUPPORTED
127 png_ptr->flags=0;
128#endif
129 png_error(png_ptr,
130 "Incompatible libpng version in application and library");
131 }
75b6e0a0
GD		 132 }
133
134 /* initialize zbuf - compression buffer */
135 png_ptr->zbuf_size = PNG_ZBUF_SIZE;
136 png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
137 (png_uint_32)png_ptr->zbuf_size);
138 png_ptr->zstream.zalloc = png_zalloc;
139 png_ptr->zstream.zfree = png_zfree;
140 png_ptr->zstream.opaque = (voidpf)png_ptr;
141
142 switch (inflateInit(&png_ptr->zstream))
143 {
144 case Z_OK: /* Do nothing */ break;
145 case Z_MEM_ERROR:
146 case Z_STREAM_ERROR: png_error(png_ptr, "zlib memory error"); break;
147 case Z_VERSION_ERROR: png_error(png_ptr, "zlib version error"); break;
148 default: png_error(png_ptr, "Unknown zlib error");
149 }
150
151 png_ptr->zstream.next_out = png_ptr->zbuf;
152 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
153
4946a942 154 png_set_read_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL);
75b6e0a0 155
4946a942
GD		 156#ifdef PNG_SETJMP_SUPPORTED
157/* Applications that neglect to set up their own setjmp() and then encounter
158 a png_error() will longjmp here. Since the jmpbuf is then meaningless we
159 abort instead of returning. */
160#ifdef USE_FAR_KEYWORD
161 if (setjmp(jmpbuf))
162 PNG_ABORT();
5b02c8a1 163 png_memcpy(png_ptr->jmpbuf,jmpbuf,png_sizeof(jmp_buf));
4946a942
GD		 164#else
165 if (setjmp(png_ptr->jmpbuf))
166 PNG_ABORT();
167#endif
168#endif
75b6e0a0
GD		 169 return (png_ptr);
170}
171
172/* Initialize PNG structure for reading, and allocate any memory needed.
173 This interface is deprecated in favour of the png_create_read_struct(),
174 and it will eventually disappear. */
4946a942
GD		 175#undef png_read_init
176void PNGAPI
75b6e0a0
GD		 177png_read_init(png_structp png_ptr)
178{
4946a942
GD		 179 /* We only come here via pre-1.0.7-compiled applications */
180 png_read_init_2(png_ptr, "1.0.6 or earlier", 0, 0);
181}
182
183void PNGAPI
184png_read_init_2(png_structp png_ptr, png_const_charp user_png_ver,
185 png_size_t png_struct_size, png_size_t png_info_size)
186{
187 /* We only come here via pre-1.0.12-compiled applications */
188#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
5b02c8a1
VS		 189 if(png_sizeof(png_struct) > png_struct_size ||
190 png_sizeof(png_info) > png_info_size)
4946a942
GD		 191 {
192 char msg[80];
193 png_ptr->warning_fn=NULL;
194 if (user_png_ver)
195 {
196 sprintf(msg, "Application was compiled with png.h from libpng-%.20s",
197 user_png_ver);
198 png_warning(png_ptr, msg);
199 }
200 sprintf(msg, "Application is running with png.c from libpng-%.20s",
201 png_libpng_ver);
202 png_warning(png_ptr, msg);
203 }
204#endif
5b02c8a1 205 if(png_sizeof(png_struct) > png_struct_size)
4946a942
GD		 206 {
207 png_ptr->error_fn=NULL;
208#ifdef PNG_ERROR_NUMBERS_SUPPORTED
209 png_ptr->flags=0;
210#endif
211 png_error(png_ptr,
212 "The png struct allocated by the application for reading is too small.");
213 }
5b02c8a1 214 if(png_sizeof(png_info) > png_info_size)
4946a942
GD		 215 {
216 png_ptr->error_fn=NULL;
217#ifdef PNG_ERROR_NUMBERS_SUPPORTED
218 png_ptr->flags=0;
219#endif
220 png_error(png_ptr,
221 "The info struct allocated by application for reading is too small.");
222 }
223 png_read_init_3(&png_ptr, user_png_ver, png_struct_size);
224}
225
226void PNGAPI
227png_read_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
228 png_size_t png_struct_size)
229{
230#ifdef PNG_SETJMP_SUPPORTED
75b6e0a0 231 jmp_buf tmp_jmp; /* to save current jump buffer */
4946a942
GD		 232#endif
233
234 int i=0;
75b6e0a0 235
4946a942
GD		 236 png_structp png_ptr=*ptr_ptr;
237
238 do
239 {
240 if(user_png_ver[i] != png_libpng_ver[i])
241 {
242#ifdef PNG_LEGACY_SUPPORTED
243 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
244#else
245 png_ptr->warning_fn=NULL;
246 png_warning(png_ptr,
247 "Application uses deprecated png_read_init() and should be recompiled.");
248 break;
249#endif
250 }
251 } while (png_libpng_ver[i++]);
252
253 png_debug(1, "in png_read_init_3\n");
254
255#ifdef PNG_SETJMP_SUPPORTED
75b6e0a0 256 /* save jump buffer and error functions */
5b02c8a1 257 png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof (jmp_buf));
4946a942
GD		 258#endif
259
5b02c8a1 260 if(png_sizeof(png_struct) > png_struct_size)
4946a942
GD		 261 {
262 png_destroy_struct(png_ptr);
263 *ptr_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
264 png_ptr = *ptr_ptr;
265 }
75b6e0a0
GD		 266
267 /* reset all variables to 0 */
5b02c8a1 268 png_memset(png_ptr, 0, png_sizeof (png_struct));
75b6e0a0 269
4946a942 270#ifdef PNG_SETJMP_SUPPORTED
75b6e0a0 271 /* restore jump buffer */
5b02c8a1
VS		 272 png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof (jmp_buf));
273#endif
274
275 /* added at libpng-1.2.6 */
276#ifdef PNG_SET_USER_LIMITS_SUPPORTED
277 png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
278 png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
4946a942 279#endif
75b6e0a0
GD		 280
281 /* initialize zbuf - compression buffer */
282 png_ptr->zbuf_size = PNG_ZBUF_SIZE;
283 png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
284 (png_uint_32)png_ptr->zbuf_size);
285 png_ptr->zstream.zalloc = png_zalloc;
286 png_ptr->zstream.zfree = png_zfree;
287 png_ptr->zstream.opaque = (voidpf)png_ptr;
288
289 switch (inflateInit(&png_ptr->zstream))
290 {
291 case Z_OK: /* Do nothing */ break;
292 case Z_MEM_ERROR:
293 case Z_STREAM_ERROR: png_error(png_ptr, "zlib memory"); break;
294 case Z_VERSION_ERROR: png_error(png_ptr, "zlib version"); break;
295 default: png_error(png_ptr, "Unknown zlib error");
296 }
297
298 png_ptr->zstream.next_out = png_ptr->zbuf;
299 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
300
4946a942 301 png_set_read_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL);
75b6e0a0
GD		 302}
303
5b02c8a1 304#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
75b6e0a0
GD		 305/* Read the information before the actual image data. This has been
306 * changed in v0.90 to allow reading a file that already has the magic
307 * bytes read from the stream. You can tell libpng how many bytes have
308 * been read from the beginning of the stream (up to the maximum of 8)
309 * via png_set_sig_bytes(), and we will only check the remaining bytes
310 * here. The application can then have access to the signature bytes we
311 * read if it is determined that this isn't a valid PNG file.
312 */
4946a942 313void PNGAPI
75b6e0a0
GD		 314png_read_info(png_structp png_ptr, png_infop info_ptr)
315{
316 png_debug(1, "in png_read_info\n");
75b6e0a0
GD		 317 /* If we haven't checked all of the PNG signature bytes, do so now. */
318 if (png_ptr->sig_bytes < 8)
319 {
320 png_size_t num_checked = png_ptr->sig_bytes,
321 num_to_check = 8 - num_checked;
322
323 png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check);
324 png_ptr->sig_bytes = 8;
325
326 if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
327 {
328 if (num_checked < 4 &&
329 png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
330 png_error(png_ptr, "Not a PNG file");
331 else
332 png_error(png_ptr, "PNG file corrupted by ASCII conversion");
333 }
4946a942
GD		 334 if (num_checked < 3)
335 png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
75b6e0a0
GD		 336 }
337
338 for(;;)
339 {
4946a942
GD		 340#ifdef PNG_USE_LOCAL_ARRAYS
341 PNG_IHDR;
342 PNG_IDAT;
343 PNG_IEND;
344 PNG_PLTE;
345#if defined(PNG_READ_bKGD_SUPPORTED)
346 PNG_bKGD;
347#endif
348#if defined(PNG_READ_cHRM_SUPPORTED)
349 PNG_cHRM;
350#endif
351#if defined(PNG_READ_gAMA_SUPPORTED)
352 PNG_gAMA;
353#endif
354#if defined(PNG_READ_hIST_SUPPORTED)
355 PNG_hIST;
356#endif
357#if defined(PNG_READ_iCCP_SUPPORTED)
358 PNG_iCCP;
359#endif
360#if defined(PNG_READ_iTXt_SUPPORTED)
361 PNG_iTXt;
362#endif
363#if defined(PNG_READ_oFFs_SUPPORTED)
364 PNG_oFFs;
365#endif
366#if defined(PNG_READ_pCAL_SUPPORTED)
367 PNG_pCAL;
368#endif
369#if defined(PNG_READ_pHYs_SUPPORTED)
370 PNG_pHYs;
371#endif
372#if defined(PNG_READ_sBIT_SUPPORTED)
373 PNG_sBIT;
374#endif
375#if defined(PNG_READ_sCAL_SUPPORTED)
376 PNG_sCAL;
377#endif
378#if defined(PNG_READ_sPLT_SUPPORTED)
379 PNG_sPLT;
380#endif
381#if defined(PNG_READ_sRGB_SUPPORTED)
382 PNG_sRGB;
383#endif
384#if defined(PNG_READ_tEXt_SUPPORTED)
385 PNG_tEXt;
386#endif
387#if defined(PNG_READ_tIME_SUPPORTED)
388 PNG_tIME;
389#endif
390#if defined(PNG_READ_tRNS_SUPPORTED)
391 PNG_tRNS;
392#endif
393#if defined(PNG_READ_zTXt_SUPPORTED)
394 PNG_zTXt;
395#endif
396#endif /* PNG_GLOBAL_ARRAYS */
75b6e0a0
GD		 397 png_byte chunk_length[4];
398 png_uint_32 length;
399
400 png_read_data(png_ptr, chunk_length, 4);
5b02c8a1 401 length = png_get_uint_31(png_ptr,chunk_length);
75b6e0a0
GD		 402
403 png_reset_crc(png_ptr);
404 png_crc_read(png_ptr, png_ptr->chunk_name, 4);
405
4946a942
GD		 406 png_debug2(0, "Reading %s chunk, length=%lu.\n", png_ptr->chunk_name,
407 length);
408
75b6e0a0
GD		 409 /* This should be a binary subdivision search or a hash for
410 * matching the chunk name rather than a linear search.
411 */
412 if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
413 png_handle_IHDR(png_ptr, info_ptr, length);
75b6e0a0
GD		 414 else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
415 png_handle_IEND(png_ptr, info_ptr, length);
4946a942
GD		 416#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
417 else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
418 {
419 if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
420 png_ptr->mode |= PNG_HAVE_IDAT;
421 png_handle_unknown(png_ptr, info_ptr, length);
422 if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
423 png_ptr->mode |= PNG_HAVE_PLTE;
424 else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
425 {
426 if (!(png_ptr->mode & PNG_HAVE_IHDR))
427 png_error(png_ptr, "Missing IHDR before IDAT");
428 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
429 !(png_ptr->mode & PNG_HAVE_PLTE))
430 png_error(png_ptr, "Missing PLTE before IDAT");
431 break;
432 }
433 }
434#endif
435 else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
436 png_handle_PLTE(png_ptr, info_ptr, length);
75b6e0a0
GD		 437 else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
438 {
439 if (!(png_ptr->mode & PNG_HAVE_IHDR))
440 png_error(png_ptr, "Missing IHDR before IDAT");
441 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
442 !(png_ptr->mode & PNG_HAVE_PLTE))
443 png_error(png_ptr, "Missing PLTE before IDAT");
444
445 png_ptr->idat_size = length;
446 png_ptr->mode |= PNG_HAVE_IDAT;
447 break;
448 }
449#if defined(PNG_READ_bKGD_SUPPORTED)
450 else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
451 png_handle_bKGD(png_ptr, info_ptr, length);
452#endif
453#if defined(PNG_READ_cHRM_SUPPORTED)
454 else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
455 png_handle_cHRM(png_ptr, info_ptr, length);
456#endif
457#if defined(PNG_READ_gAMA_SUPPORTED)
458 else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
459 png_handle_gAMA(png_ptr, info_ptr, length);
460#endif
461#if defined(PNG_READ_hIST_SUPPORTED)
462 else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
463 png_handle_hIST(png_ptr, info_ptr, length);
464#endif
465#if defined(PNG_READ_oFFs_SUPPORTED)
466 else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
467 png_handle_oFFs(png_ptr, info_ptr, length);
468#endif
469#if defined(PNG_READ_pCAL_SUPPORTED)
470 else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
471 png_handle_pCAL(png_ptr, info_ptr, length);
472#endif
4946a942
GD		 473#if defined(PNG_READ_sCAL_SUPPORTED)
474 else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
475 png_handle_sCAL(png_ptr, info_ptr, length);
476#endif
75b6e0a0
GD		 477#if defined(PNG_READ_pHYs_SUPPORTED)
478 else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
479 png_handle_pHYs(png_ptr, info_ptr, length);
480#endif
481#if defined(PNG_READ_sBIT_SUPPORTED)
482 else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
483 png_handle_sBIT(png_ptr, info_ptr, length);
484#endif
485#if defined(PNG_READ_sRGB_SUPPORTED)
486 else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
487 png_handle_sRGB(png_ptr, info_ptr, length);
488#endif
4946a942
GD		 489#if defined(PNG_READ_iCCP_SUPPORTED)
490 else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
491 png_handle_iCCP(png_ptr, info_ptr, length);
492#endif
493#if defined(PNG_READ_sPLT_SUPPORTED)
494 else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
495 png_handle_sPLT(png_ptr, info_ptr, length);
496#endif
75b6e0a0
GD		 497#if defined(PNG_READ_tEXt_SUPPORTED)
498 else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
499 png_handle_tEXt(png_ptr, info_ptr, length);
500#endif
501#if defined(PNG_READ_tIME_SUPPORTED)
502 else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
503 png_handle_tIME(png_ptr, info_ptr, length);
504#endif
505#if defined(PNG_READ_tRNS_SUPPORTED)
506 else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
507 png_handle_tRNS(png_ptr, info_ptr, length);
508#endif
509#if defined(PNG_READ_zTXt_SUPPORTED)
510 else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
511 png_handle_zTXt(png_ptr, info_ptr, length);
4946a942
GD		 512#endif
513#if defined(PNG_READ_iTXt_SUPPORTED)
514 else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
515 png_handle_iTXt(png_ptr, info_ptr, length);
75b6e0a0
GD		 516#endif
517 else
518 png_handle_unknown(png_ptr, info_ptr, length);
519 }
520}
5b02c8a1 521#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
75b6e0a0
GD		 522
523/* optional call to update the users info_ptr structure */
4946a942 524void PNGAPI
75b6e0a0
GD		 525png_read_update_info(png_structp png_ptr, png_infop info_ptr)
526{
527 png_debug(1, "in png_read_update_info\n");
75b6e0a0
GD		 528 if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
529 png_read_start_row(png_ptr);
4946a942
GD		 530 else
531 png_warning(png_ptr,
532 "Ignoring extra png_read_update_info() call; row buffer not reallocated");
75b6e0a0
GD		 533 png_read_transform_info(png_ptr, info_ptr);
534}
535
5b02c8a1 536#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
75b6e0a0
GD		 537/* Initialize palette, background, etc, after transformations
538 * are set, but before any reading takes place. This allows
539 * the user to obtain a gamma-corrected palette, for example.
540 * If the user doesn't call this, we will do it ourselves.
541 */
4946a942 542void PNGAPI
75b6e0a0
GD		 543png_start_read_image(png_structp png_ptr)
544{
545 png_debug(1, "in png_start_read_image\n");
75b6e0a0
GD		 546 if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
547 png_read_start_row(png_ptr);
548}
5b02c8a1 549#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
75b6e0a0 550
5b02c8a1 551#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
4946a942 552void PNGAPI
75b6e0a0
GD		 553png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row)
554{
4946a942
GD		 555#ifdef PNG_USE_LOCAL_ARRAYS
556 PNG_IDAT;
557 const int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
558 const int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
559#endif
75b6e0a0 560 int ret;
4946a942 561 png_debug2(1, "in png_read_row (row %lu, pass %d)\n",
75b6e0a0 562 png_ptr->row_number, png_ptr->pass);
75b6e0a0
GD		 563 if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
564 png_read_start_row(png_ptr);
565 if (png_ptr->row_number == 0 && png_ptr->pass == 0)
566 {
567 /* check for transforms that have been set but were defined out */
568#if defined(PNG_WRITE_INVERT_SUPPORTED) && !defined(PNG_READ_INVERT_SUPPORTED)
569 if (png_ptr->transformations & PNG_INVERT_MONO)
570 png_warning(png_ptr, "PNG_READ_INVERT_SUPPORTED is not defined.");
571#endif
572#if defined(PNG_WRITE_FILLER_SUPPORTED) && !defined(PNG_READ_FILLER_SUPPORTED)
573 if (png_ptr->transformations & PNG_FILLER)
574 png_warning(png_ptr, "PNG_READ_FILLER_SUPPORTED is not defined.");
575#endif
576#if defined(PNG_WRITE_PACKSWAP_SUPPORTED) && !defined(PNG_READ_PACKSWAP_SUPPORTED)
577 if (png_ptr->transformations & PNG_PACKSWAP)
578 png_warning(png_ptr, "PNG_READ_PACKSWAP_SUPPORTED is not defined.");
579#endif
580#if defined(PNG_WRITE_PACK_SUPPORTED) && !defined(PNG_READ_PACK_SUPPORTED)
581 if (png_ptr->transformations & PNG_PACK)
582 png_warning(png_ptr, "PNG_READ_PACK_SUPPORTED is not defined.");
583#endif
584#if defined(PNG_WRITE_SHIFT_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED)
585 if (png_ptr->transformations & PNG_SHIFT)
586 png_warning(png_ptr, "PNG_READ_SHIFT_SUPPORTED is not defined.");
587#endif
588#if defined(PNG_WRITE_BGR_SUPPORTED) && !defined(PNG_READ_BGR_SUPPORTED)
589 if (png_ptr->transformations & PNG_BGR)
590 png_warning(png_ptr, "PNG_READ_BGR_SUPPORTED is not defined.");
591#endif
592#if defined(PNG_WRITE_SWAP_SUPPORTED) && !defined(PNG_READ_SWAP_SUPPORTED)
593 if (png_ptr->transformations & PNG_SWAP_BYTES)
594 png_warning(png_ptr, "PNG_READ_SWAP_SUPPORTED is not defined.");
595#endif
596 }
597
598#if defined(PNG_READ_INTERLACING_SUPPORTED)
599 /* if interlaced and we do not need a new row, combine row and return */
600 if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
601 {
602 switch (png_ptr->pass)
603 {
604 case 0:
4946a942 605 if (png_ptr->row_number & 0x07)
75b6e0a0
GD		 606 {
607 if (dsp_row != NULL)
608 png_combine_row(png_ptr, dsp_row,
609 png_pass_dsp_mask[png_ptr->pass]);
610 png_read_finish_row(png_ptr);
611 return;
612 }
613 break;
614 case 1:
4946a942 615 if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
75b6e0a0
GD		 616 {
617 if (dsp_row != NULL)
618 png_combine_row(png_ptr, dsp_row,
619 png_pass_dsp_mask[png_ptr->pass]);
620 png_read_finish_row(png_ptr);
621 return;
622 }
623 break;
624 case 2:
4946a942 625 if ((png_ptr->row_number & 0x07) != 4)
75b6e0a0
GD		 626 {
627 if (dsp_row != NULL && (png_ptr->row_number & 4))
628 png_combine_row(png_ptr, dsp_row,
629 png_pass_dsp_mask[png_ptr->pass]);
630 png_read_finish_row(png_ptr);
631 return;
632 }
633 break;
634 case 3:
635 if ((png_ptr->row_number & 3) || png_ptr->width < 3)
636 {
637 if (dsp_row != NULL)
638 png_combine_row(png_ptr, dsp_row,
639 png_pass_dsp_mask[png_ptr->pass]);
640 png_read_finish_row(png_ptr);
641 return;
642 }
643 break;
644 case 4:
645 if ((png_ptr->row_number & 3) != 2)
646 {
647 if (dsp_row != NULL && (png_ptr->row_number & 2))
648 png_combine_row(png_ptr, dsp_row,
649 png_pass_dsp_mask[png_ptr->pass]);
650 png_read_finish_row(png_ptr);
651 return;
652 }
653 break;
654 case 5:
655 if ((png_ptr->row_number & 1) || png_ptr->width < 2)
656 {
657 if (dsp_row != NULL)
658 png_combine_row(png_ptr, dsp_row,
659 png_pass_dsp_mask[png_ptr->pass]);
660 png_read_finish_row(png_ptr);
661 return;
662 }
663 break;
664 case 6:
665 if (!(png_ptr->row_number & 1))
666 {
667 png_read_finish_row(png_ptr);
668 return;
669 }
670 break;
671 }
672 }
673#endif
674
675 if (!(png_ptr->mode & PNG_HAVE_IDAT))
676 png_error(png_ptr, "Invalid attempt to read row data");
677
678 png_ptr->zstream.next_out = png_ptr->row_buf;
679 png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
680 do
681 {
682 if (!(png_ptr->zstream.avail_in))
683 {
684 while (!png_ptr->idat_size)
685 {
686 png_byte chunk_length[4];
687
688 png_crc_finish(png_ptr, 0);
689
690 png_read_data(png_ptr, chunk_length, 4);
5b02c8a1 691 png_ptr->idat_size = png_get_uint_31(png_ptr,chunk_length);
4946a942 692
75b6e0a0
GD		 693 png_reset_crc(png_ptr);
694 png_crc_read(png_ptr, png_ptr->chunk_name, 4);
695 if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
696 png_error(png_ptr, "Not enough image data");
697 }
698 png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size;
699 png_ptr->zstream.next_in = png_ptr->zbuf;
700 if (png_ptr->zbuf_size > png_ptr->idat_size)
701 png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size;
702 png_crc_read(png_ptr, png_ptr->zbuf,
703 (png_size_t)png_ptr->zstream.avail_in);
704 png_ptr->idat_size -= png_ptr->zstream.avail_in;
705 }
706 ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
707 if (ret == Z_STREAM_END)
708 {
709 if (png_ptr->zstream.avail_out || png_ptr->zstream.avail_in ||
710 png_ptr->idat_size)
711 png_error(png_ptr, "Extra compressed data");
712 png_ptr->mode |= PNG_AFTER_IDAT;
713 png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
714 break;
715 }
716 if (ret != Z_OK)
717 png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg :
718 "Decompression error");
719
720 } while (png_ptr->zstream.avail_out);
721
722 png_ptr->row_info.color_type = png_ptr->color_type;
723 png_ptr->row_info.width = png_ptr->iwidth;
724 png_ptr->row_info.channels = png_ptr->channels;
725 png_ptr->row_info.bit_depth = png_ptr->bit_depth;
726 png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
5b02c8a1
VS		 727 png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
728 png_ptr->row_info.width);
75b6e0a0 729
4946a942 730 if(png_ptr->row_buf[0])
75b6e0a0
GD		 731 png_read_filter_row(png_ptr, &(png_ptr->row_info),
732 png_ptr->row_buf + 1, png_ptr->prev_row + 1,
733 (int)(png_ptr->row_buf[0]));
734
735 png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf,
736 png_ptr->rowbytes + 1);
4946a942
GD		 737
738#if defined(PNG_MNG_FEATURES_SUPPORTED)
739 if((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
740 (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
741 {
742 /* Intrapixel differencing */
743 png_do_read_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
744 }
745#endif
75b6e0a0
GD		 746
747 if (png_ptr->transformations)
748 png_do_read_transformations(png_ptr);
749
750#if defined(PNG_READ_INTERLACING_SUPPORTED)
751 /* blow up interlaced rows to full size */
752 if (png_ptr->interlaced &&
753 (png_ptr->transformations & PNG_INTERLACE))
754 {
755 if (png_ptr->pass < 6)
4946a942 756/* old interface (pre-1.0.9):
75b6e0a0
GD		 757 png_do_read_interlace(&(png_ptr->row_info),
758 png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
4946a942
GD		 759 */
760 png_do_read_interlace(png_ptr);
75b6e0a0
GD		 761
762 if (dsp_row != NULL)
763 png_combine_row(png_ptr, dsp_row,
764 png_pass_dsp_mask[png_ptr->pass]);
765 if (row != NULL)
766 png_combine_row(png_ptr, row,
767 png_pass_mask[png_ptr->pass]);
768 }
769 else
770#endif
771 {
772 if (row != NULL)
773 png_combine_row(png_ptr, row, 0xff);
774 if (dsp_row != NULL)
775 png_combine_row(png_ptr, dsp_row, 0xff);
776 }
777 png_read_finish_row(png_ptr);
778
779 if (png_ptr->read_row_fn != NULL)
780 (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
781}
5b02c8a1 782#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
75b6e0a0 783
5b02c8a1 784#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
75b6e0a0
GD		 785/* Read one or more rows of image data. If the image is interlaced,
786 * and png_set_interlace_handling() has been called, the rows need to
787 * contain the contents of the rows from the previous pass. If the
788 * image has alpha or transparency, and png_handle_alpha()[*] has been
789 * called, the rows contents must be initialized to the contents of the
790 * screen.
791 *
792 * "row" holds the actual image, and pixels are placed in it
793 * as they arrive. If the image is displayed after each pass, it will
794 * appear to "sparkle" in. "display_row" can be used to display a
795 * "chunky" progressive image, with finer detail added as it becomes
796 * available. If you do not want this "chunky" display, you may pass
797 * NULL for display_row. If you do not want the sparkle display, and
798 * you have not called png_handle_alpha(), you may pass NULL for rows.
799 * If you have called png_handle_alpha(), and the image has either an
800 * alpha channel or a transparency chunk, you must provide a buffer for
801 * rows. In this case, you do not have to provide a display_row buffer
802 * also, but you may. If the image is not interlaced, or if you have
803 * not called png_set_interlace_handling(), the display_row buffer will
804 * be ignored, so pass NULL to it.
805 *
706b8807 806 * [*] png_handle_alpha() does not exist yet, as of libpng version 1.2.7
75b6e0a0
GD		 807 */
808
4946a942 809void PNGAPI
75b6e0a0
GD		 810png_read_rows(png_structp png_ptr, png_bytepp row,
811 png_bytepp display_row, png_uint_32 num_rows)
812{
813 png_uint_32 i;
814 png_bytepp rp;
815 png_bytepp dp;
816
817 png_debug(1, "in png_read_rows\n");
75b6e0a0
GD		 818 rp = row;
819 dp = display_row;
820 if (rp != NULL && dp != NULL)
821 for (i = 0; i < num_rows; i++)
822 {
823 png_bytep rptr = *rp++;
824 png_bytep dptr = *dp++;
825
826 png_read_row(png_ptr, rptr, dptr);
827 }
828 else if(rp != NULL)
829 for (i = 0; i < num_rows; i++)
830 {
831 png_bytep rptr = *rp;
4946a942 832 png_read_row(png_ptr, rptr, png_bytep_NULL);
75b6e0a0
GD		 833 rp++;
834 }
835 else if(dp != NULL)
836 for (i = 0; i < num_rows; i++)
837 {
838 png_bytep dptr = *dp;
4946a942 839 png_read_row(png_ptr, png_bytep_NULL, dptr);
75b6e0a0
GD		 840 dp++;
841 }
842}
5b02c8a1 843#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
75b6e0a0 844
5b02c8a1 845#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
75b6e0a0
GD		 846/* Read the entire image. If the image has an alpha channel or a tRNS
847 * chunk, and you have called png_handle_alpha()[*], you will need to
848 * initialize the image to the current image that PNG will be overlaying.
849 * We set the num_rows again here, in case it was incorrectly set in
850 * png_read_start_row() by a call to png_read_update_info() or
851 * png_start_read_image() if png_set_interlace_handling() wasn't called
852 * prior to either of these functions like it should have been. You can
853 * only call this function once. If you desire to have an image for
854 * each pass of a interlaced image, use png_read_rows() instead.
855 *
706b8807 856 * [*] png_handle_alpha() does not exist yet, as of libpng version 1.2.7
75b6e0a0 857 */
4946a942 858void PNGAPI
75b6e0a0
GD		 859png_read_image(png_structp png_ptr, png_bytepp image)
860{
861 png_uint_32 i,image_height;
862 int pass, j;
863 png_bytepp rp;
864
865 png_debug(1, "in png_read_image\n");
4946a942
GD		 866
867#ifdef PNG_READ_INTERLACING_SUPPORTED
75b6e0a0 868 pass = png_set_interlace_handling(png_ptr);
4946a942
GD		 869#else
870 if (png_ptr->interlaced)
871 png_error(png_ptr,
872 "Cannot read interlaced image -- interlace handler disabled.");
873 pass = 1;
874#endif
875
75b6e0a0
GD		 876
877 image_height=png_ptr->height;
878 png_ptr->num_rows = image_height; /* Make sure this is set correctly */
879
880 for (j = 0; j < pass; j++)
881 {
882 rp = image;
883 for (i = 0; i < image_height; i++)
884 {
4946a942 885 png_read_row(png_ptr, *rp, png_bytep_NULL);
75b6e0a0
GD		 886 rp++;
887 }
888 }
889}
5b02c8a1 890#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
75b6e0a0 891
5b02c8a1 892#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
75b6e0a0
GD		 893/* Read the end of the PNG file. Will not read past the end of the
894 * file, will verify the end is accurate, and will read any comments
895 * or time information at the end of the file, if info is not NULL.
896 */
4946a942 897void PNGAPI
75b6e0a0
GD		 898png_read_end(png_structp png_ptr, png_infop info_ptr)
899{
900 png_byte chunk_length[4];
901 png_uint_32 length;
902
903 png_debug(1, "in png_read_end\n");
75b6e0a0
GD		 904 png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */
905
906 do
907 {
4946a942
GD		 908#ifdef PNG_USE_LOCAL_ARRAYS
909 PNG_IHDR;
910 PNG_IDAT;
911 PNG_IEND;
912 PNG_PLTE;
913#if defined(PNG_READ_bKGD_SUPPORTED)
914 PNG_bKGD;
915#endif
916#if defined(PNG_READ_cHRM_SUPPORTED)
917 PNG_cHRM;
918#endif
919#if defined(PNG_READ_gAMA_SUPPORTED)
920 PNG_gAMA;
921#endif
922#if defined(PNG_READ_hIST_SUPPORTED)
923 PNG_hIST;
924#endif
925#if defined(PNG_READ_iCCP_SUPPORTED)
926 PNG_iCCP;
927#endif
928#if defined(PNG_READ_iTXt_SUPPORTED)
929 PNG_iTXt;
930#endif
931#if defined(PNG_READ_oFFs_SUPPORTED)
932 PNG_oFFs;
933#endif
934#if defined(PNG_READ_pCAL_SUPPORTED)
935 PNG_pCAL;
936#endif
937#if defined(PNG_READ_pHYs_SUPPORTED)
938 PNG_pHYs;
939#endif
940#if defined(PNG_READ_sBIT_SUPPORTED)
941 PNG_sBIT;
942#endif
943#if defined(PNG_READ_sCAL_SUPPORTED)
944 PNG_sCAL;
945#endif
946#if defined(PNG_READ_sPLT_SUPPORTED)
947 PNG_sPLT;
948#endif
949#if defined(PNG_READ_sRGB_SUPPORTED)
950 PNG_sRGB;
951#endif
952#if defined(PNG_READ_tEXt_SUPPORTED)
953 PNG_tEXt;
954#endif
955#if defined(PNG_READ_tIME_SUPPORTED)
956 PNG_tIME;
957#endif
958#if defined(PNG_READ_tRNS_SUPPORTED)
959 PNG_tRNS;
960#endif
961#if defined(PNG_READ_zTXt_SUPPORTED)
962 PNG_zTXt;
963#endif
964#endif /* PNG_GLOBAL_ARRAYS */
965
75b6e0a0 966 png_read_data(png_ptr, chunk_length, 4);
5b02c8a1 967 length = png_get_uint_31(png_ptr,chunk_length);
75b6e0a0
GD		 968
969 png_reset_crc(png_ptr);
970 png_crc_read(png_ptr, png_ptr->chunk_name, 4);
971
972 png_debug1(0, "Reading %s chunk.\n", png_ptr->chunk_name);
973
974 if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
975 png_handle_IHDR(png_ptr, info_ptr, length);
4946a942
GD		 976 else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
977 png_handle_IEND(png_ptr, info_ptr, length);
978#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
979 else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
980 {
981 if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
982 {
983 if (length > 0 || png_ptr->mode & PNG_AFTER_IDAT)
984 png_error(png_ptr, "Too many IDAT's found");
985 }
986 else
987 png_ptr->mode |= PNG_AFTER_IDAT;
988 png_handle_unknown(png_ptr, info_ptr, length);
989 if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
990 png_ptr->mode |= PNG_HAVE_PLTE;
991 }
992#endif
75b6e0a0
GD		 993 else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
994 {
995 /* Zero length IDATs are legal after the last IDAT has been
996 * read, but not after other chunks have been read.
997 */
998 if (length > 0 || png_ptr->mode & PNG_AFTER_IDAT)
999 png_error(png_ptr, "Too many IDAT's found");
4946a942 1000 png_crc_finish(png_ptr, length);
75b6e0a0
GD		 1001 }
1002 else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
1003 png_handle_PLTE(png_ptr, info_ptr, length);
75b6e0a0
GD		 1004#if defined(PNG_READ_bKGD_SUPPORTED)
1005 else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
1006 png_handle_bKGD(png_ptr, info_ptr, length);
1007#endif
1008#if defined(PNG_READ_cHRM_SUPPORTED)
1009 else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
1010 png_handle_cHRM(png_ptr, info_ptr, length);
1011#endif
1012#if defined(PNG_READ_gAMA_SUPPORTED)
1013 else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
1014 png_handle_gAMA(png_ptr, info_ptr, length);
1015#endif
1016#if defined(PNG_READ_hIST_SUPPORTED)
1017 else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
1018 png_handle_hIST(png_ptr, info_ptr, length);
1019#endif
1020#if defined(PNG_READ_oFFs_SUPPORTED)
1021 else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
1022 png_handle_oFFs(png_ptr, info_ptr, length);
1023#endif
1024#if defined(PNG_READ_pCAL_SUPPORTED)
1025 else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
1026 png_handle_pCAL(png_ptr, info_ptr, length);
1027#endif
4946a942
GD		 1028#if defined(PNG_READ_sCAL_SUPPORTED)
1029 else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
1030 png_handle_sCAL(png_ptr, info_ptr, length);
1031#endif
75b6e0a0
GD		 1032#if defined(PNG_READ_pHYs_SUPPORTED)
1033 else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
1034 png_handle_pHYs(png_ptr, info_ptr, length);
1035#endif
1036#if defined(PNG_READ_sBIT_SUPPORTED)
1037 else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
1038 png_handle_sBIT(png_ptr, info_ptr, length);
1039#endif
1040#if defined(PNG_READ_sRGB_SUPPORTED)
1041 else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
1042 png_handle_sRGB(png_ptr, info_ptr, length);
1043#endif
4946a942
GD		 1044#if defined(PNG_READ_iCCP_SUPPORTED)
1045 else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
1046 png_handle_iCCP(png_ptr, info_ptr, length);
1047#endif
1048#if defined(PNG_READ_sPLT_SUPPORTED)
1049 else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
1050 png_handle_sPLT(png_ptr, info_ptr, length);
1051#endif
75b6e0a0
GD		 1052#if defined(PNG_READ_tEXt_SUPPORTED)
1053 else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
1054 png_handle_tEXt(png_ptr, info_ptr, length);
1055#endif
1056#if defined(PNG_READ_tIME_SUPPORTED)
1057 else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
1058 png_handle_tIME(png_ptr, info_ptr, length);
1059#endif
1060#if defined(PNG_READ_tRNS_SUPPORTED)
1061 else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
1062 png_handle_tRNS(png_ptr, info_ptr, length);
1063#endif
1064#if defined(PNG_READ_zTXt_SUPPORTED)
1065 else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
1066 png_handle_zTXt(png_ptr, info_ptr, length);
4946a942
GD		 1067#endif
1068#if defined(PNG_READ_iTXt_SUPPORTED)
1069 else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
1070 png_handle_iTXt(png_ptr, info_ptr, length);
75b6e0a0
GD		 1071#endif
1072 else
1073 png_handle_unknown(png_ptr, info_ptr, length);
1074 } while (!(png_ptr->mode & PNG_HAVE_IEND));
1075}
5b02c8a1 1076#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
75b6e0a0
GD		 1077
1078/* free all memory used by the read */
4946a942 1079void PNGAPI
75b6e0a0
GD		 1080png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
1081 png_infopp end_info_ptr_ptr)
1082{
1083 png_structp png_ptr = NULL;
1084 png_infop info_ptr = NULL, end_info_ptr = NULL;
1085#ifdef PNG_USER_MEM_SUPPORTED
5b02c8a1
VS		 1086 png_free_ptr free_fn;
1087 png_voidp mem_ptr;
4946a942 1088#endif
75b6e0a0
GD		 1089
1090 png_debug(1, "in png_destroy_read_struct\n");
75b6e0a0
GD		 1091 if (png_ptr_ptr != NULL)
1092 png_ptr = *png_ptr_ptr;
1093
1094 if (info_ptr_ptr != NULL)
1095 info_ptr = *info_ptr_ptr;
1096
1097 if (end_info_ptr_ptr != NULL)
1098 end_info_ptr = *end_info_ptr_ptr;
1099
1100#ifdef PNG_USER_MEM_SUPPORTED
1101 free_fn = png_ptr->free_fn;
4946a942 1102 mem_ptr = png_ptr->mem_ptr;
75b6e0a0
GD		 1103#endif
1104
1105 png_read_destroy(png_ptr, info_ptr, end_info_ptr);
1106
1107 if (info_ptr != NULL)
1108 {
4946a942
GD		 1109#if defined(PNG_TEXT_SUPPORTED)
1110 png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, -1);
75b6e0a0
GD		 1111#endif
1112
1113#ifdef PNG_USER_MEM_SUPPORTED
4946a942
GD		 1114 png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
1115 (png_voidp)mem_ptr);
75b6e0a0
GD		 1116#else
1117 png_destroy_struct((png_voidp)info_ptr);
1118#endif
4946a942 1119 *info_ptr_ptr = NULL;
75b6e0a0
GD		 1120 }
1121
1122 if (end_info_ptr != NULL)
1123 {
4946a942
GD		 1124#if defined(PNG_READ_TEXT_SUPPORTED)
1125 png_free_data(png_ptr, end_info_ptr, PNG_FREE_TEXT, -1);
75b6e0a0
GD		 1126#endif
1127#ifdef PNG_USER_MEM_SUPPORTED
4946a942
GD		 1128 png_destroy_struct_2((png_voidp)end_info_ptr, (png_free_ptr)free_fn,
1129 (png_voidp)mem_ptr);
75b6e0a0
GD		 1130#else
1131 png_destroy_struct((png_voidp)end_info_ptr);
1132#endif
4946a942 1133 *end_info_ptr_ptr = NULL;
75b6e0a0
GD		 1134 }
1135
1136 if (png_ptr != NULL)
1137 {
1138#ifdef PNG_USER_MEM_SUPPORTED
4946a942
GD		 1139 png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
1140 (png_voidp)mem_ptr);
75b6e0a0
GD		 1141#else
1142 png_destroy_struct((png_voidp)png_ptr);
1143#endif
4946a942 1144 *png_ptr_ptr = NULL;
75b6e0a0
GD		 1145 }
1146}
1147
1148/* free all memory used by the read (old method) */
4946a942 1149void /* PRIVATE */
75b6e0a0
GD		 1150png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr)
1151{
4946a942 1152#ifdef PNG_SETJMP_SUPPORTED
75b6e0a0 1153 jmp_buf tmp_jmp;
4946a942 1154#endif
75b6e0a0
GD		 1155 png_error_ptr error_fn;
1156 png_error_ptr warning_fn;
1157 png_voidp error_ptr;
1158#ifdef PNG_USER_MEM_SUPPORTED
1159 png_free_ptr free_fn;
1160#endif
1161
1162 png_debug(1, "in png_read_destroy\n");
75b6e0a0
GD		 1163 if (info_ptr != NULL)
1164 png_info_destroy(png_ptr, info_ptr);
1165
1166 if (end_info_ptr != NULL)
1167 png_info_destroy(png_ptr, end_info_ptr);
1168
1169 png_free(png_ptr, png_ptr->zbuf);
4946a942 1170 png_free(png_ptr, png_ptr->big_row_buf);
75b6e0a0
GD		 1171 png_free(png_ptr, png_ptr->prev_row);
1172#if defined(PNG_READ_DITHER_SUPPORTED)
1173 png_free(png_ptr, png_ptr->palette_lookup);
1174 png_free(png_ptr, png_ptr->dither_index);
1175#endif
1176#if defined(PNG_READ_GAMMA_SUPPORTED)
1177 png_free(png_ptr, png_ptr->gamma_table);
1178#endif
1179#if defined(PNG_READ_BACKGROUND_SUPPORTED)
1180 png_free(png_ptr, png_ptr->gamma_from_1);
1181 png_free(png_ptr, png_ptr->gamma_to_1);
1182#endif
4946a942
GD		 1183#ifdef PNG_FREE_ME_SUPPORTED
1184 if (png_ptr->free_me & PNG_FREE_PLTE)
75b6e0a0 1185 png_zfree(png_ptr, png_ptr->palette);
4946a942
GD		 1186 png_ptr->free_me &= ~PNG_FREE_PLTE;
1187#else
1188 if (png_ptr->flags & PNG_FLAG_FREE_PLTE)
1189 png_zfree(png_ptr, png_ptr->palette);
1190 png_ptr->flags &= ~PNG_FLAG_FREE_PLTE;
1191#endif
1192#if defined(PNG_tRNS_SUPPORTED) || \
1193 defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
1194#ifdef PNG_FREE_ME_SUPPORTED
1195 if (png_ptr->free_me & PNG_FREE_TRNS)
75b6e0a0 1196 png_free(png_ptr, png_ptr->trans);
4946a942
GD		 1197 png_ptr->free_me &= ~PNG_FREE_TRNS;
1198#else
1199 if (png_ptr->flags & PNG_FLAG_FREE_TRNS)
1200 png_free(png_ptr, png_ptr->trans);
1201 png_ptr->flags &= ~PNG_FLAG_FREE_TRNS;
1202#endif
1203#endif
75b6e0a0 1204#if defined(PNG_READ_hIST_SUPPORTED)
4946a942
GD		 1205#ifdef PNG_FREE_ME_SUPPORTED
1206 if (png_ptr->free_me & PNG_FREE_HIST)
1207 png_free(png_ptr, png_ptr->hist);
1208 png_ptr->free_me &= ~PNG_FREE_HIST;
1209#else
75b6e0a0
GD		 1210 if (png_ptr->flags & PNG_FLAG_FREE_HIST)
1211 png_free(png_ptr, png_ptr->hist);
4946a942
GD		 1212 png_ptr->flags &= ~PNG_FLAG_FREE_HIST;
1213#endif
75b6e0a0
GD		 1214#endif
1215#if defined(PNG_READ_GAMMA_SUPPORTED)
1216 if (png_ptr->gamma_16_table != NULL)
1217 {
1218 int i;
1219 int istop = (1 << (8 - png_ptr->gamma_shift));
1220 for (i = 0; i < istop; i++)
1221 {
1222 png_free(png_ptr, png_ptr->gamma_16_table[i]);
1223 }
1224 png_free(png_ptr, png_ptr->gamma_16_table);
1225 }
1226#if defined(PNG_READ_BACKGROUND_SUPPORTED)
1227 if (png_ptr->gamma_16_from_1 != NULL)
1228 {
1229 int i;
1230 int istop = (1 << (8 - png_ptr->gamma_shift));
1231 for (i = 0; i < istop; i++)
1232 {
1233 png_free(png_ptr, png_ptr->gamma_16_from_1[i]);
1234 }
1235 png_free(png_ptr, png_ptr->gamma_16_from_1);
1236 }
1237 if (png_ptr->gamma_16_to_1 != NULL)
1238 {
1239 int i;
1240 int istop = (1 << (8 - png_ptr->gamma_shift));
1241 for (i = 0; i < istop; i++)
1242 {
1243 png_free(png_ptr, png_ptr->gamma_16_to_1[i]);
1244 }
1245 png_free(png_ptr, png_ptr->gamma_16_to_1);
1246 }
1247#endif
1248#endif
1249#if defined(PNG_TIME_RFC1123_SUPPORTED)
1250 png_free(png_ptr, png_ptr->time_buffer);
4946a942 1251#endif
75b6e0a0
GD		 1252
1253 inflateEnd(&png_ptr->zstream);
1254#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1255 png_free(png_ptr, png_ptr->save_buffer);
1256#endif
1257
4946a942
GD		 1258#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
1259#ifdef PNG_TEXT_SUPPORTED
1260 png_free(png_ptr, png_ptr->current_text);
1261#endif /* PNG_TEXT_SUPPORTED */
1262#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
1263
75b6e0a0
GD		 1264 /* Save the important info out of the png_struct, in case it is
1265 * being used again.
1266 */
4946a942 1267#ifdef PNG_SETJMP_SUPPORTED
5b02c8a1 1268 png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof (jmp_buf));
4946a942 1269#endif
75b6e0a0
GD		 1270
1271 error_fn = png_ptr->error_fn;
1272 warning_fn = png_ptr->warning_fn;
1273 error_ptr = png_ptr->error_ptr;
1274#ifdef PNG_USER_MEM_SUPPORTED
1275 free_fn = png_ptr->free_fn;
1276#endif
1277
5b02c8a1 1278 png_memset(png_ptr, 0, png_sizeof (png_struct));
75b6e0a0
GD		 1279
1280 png_ptr->error_fn = error_fn;
1281 png_ptr->warning_fn = warning_fn;
1282 png_ptr->error_ptr = error_ptr;
1283#ifdef PNG_USER_MEM_SUPPORTED
1284 png_ptr->free_fn = free_fn;
1285#endif
1286
4946a942 1287#ifdef PNG_SETJMP_SUPPORTED
5b02c8a1 1288 png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof (jmp_buf));
4946a942
GD		 1289#endif
1290
75b6e0a0
GD		 1291}
1292
4946a942 1293void PNGAPI
75b6e0a0
GD		 1294png_set_read_status_fn(png_structp png_ptr, png_read_status_ptr read_row_fn)
1295{
1296 png_ptr->read_row_fn = read_row_fn;
1297}
4946a942 1298
5b02c8a1
VS		 1299
1300#ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED
4946a942
GD		 1301#if defined(PNG_INFO_IMAGE_SUPPORTED)
1302void PNGAPI
1303png_read_png(png_structp png_ptr, png_infop info_ptr,
1304 int transforms,
1305 voidp params)
1306{
1307 int row;
1308
1309#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
5b02c8a1
VS		 1310 /* invert the alpha channel from opacity to transparency
1311 */
4946a942
GD		 1312 if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
1313 png_set_invert_alpha(png_ptr);
1314#endif
1315
5b02c8a1 1316 /* png_read_info() gives us all of the information from the
4946a942
GD		 1317 * PNG file before the first IDAT (image data chunk).
1318 */
1319 png_read_info(png_ptr, info_ptr);
5b02c8a1
VS		 1320 if (info_ptr->height > PNG_UINT_32_MAX/png_sizeof(png_bytep))
1321 png_error(png_ptr,"Image is too high to process with png_read_png()");
4946a942
GD		 1322
1323 /* -------------- image transformations start here ------------------- */
1324
1325#if defined(PNG_READ_16_TO_8_SUPPORTED)
5b02c8a1
VS		 1326 /* tell libpng to strip 16 bit/color files down to 8 bits per color
1327 */
4946a942
GD		 1328 if (transforms & PNG_TRANSFORM_STRIP_16)
1329 png_set_strip_16(png_ptr);
1330#endif
1331
1332#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
5b02c8a1
VS		 1333 /* Strip alpha bytes from the input data without combining with
1334 * the background (not recommended).
4946a942
GD		 1335 */
1336 if (transforms & PNG_TRANSFORM_STRIP_ALPHA)
1337 png_set_strip_alpha(png_ptr);
1338#endif
1339
1340#if defined(PNG_READ_PACK_SUPPORTED) && !defined(PNG_READ_EXPAND_SUPPORTED)
5b02c8a1 1341 /* Extract multiple pixels with bit depths of 1, 2, or 4 from a single
4946a942
GD		 1342 * byte into separate bytes (useful for paletted and grayscale images).
1343 */
1344 if (transforms & PNG_TRANSFORM_PACKING)
1345 png_set_packing(png_ptr);
1346#endif
1347
1348#if defined(PNG_READ_PACKSWAP_SUPPORTED)
1349 /* Change the order of packed pixels to least significant bit first
5b02c8a1
VS		 1350 * (not useful if you are using png_set_packing).
1351 */
4946a942
GD		 1352 if (transforms & PNG_TRANSFORM_PACKSWAP)
1353 png_set_packswap(png_ptr);
1354#endif
1355
1356#if defined(PNG_READ_EXPAND_SUPPORTED)
1357 /* Expand paletted colors into true RGB triplets
1358 * Expand grayscale images to full 8 bits from 1, 2, or 4 bits/pixel
1359 * Expand paletted or RGB images with transparency to full alpha
1360 * channels so the data will be available as RGBA quartets.
1361 */
1362 if (transforms & PNG_TRANSFORM_EXPAND)
1363 if ((png_ptr->bit_depth < 8) ||
1364 (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ||
1365 (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)))
1366 png_set_expand(png_ptr);
1367#endif
1368
5b02c8a1
VS		 1369 /* We don't handle background color or gamma transformation or dithering.
1370 */
4946a942
GD		 1371
1372#if defined(PNG_READ_INVERT_SUPPORTED)
5b02c8a1
VS		 1373 /* invert monochrome files to have 0 as white and 1 as black
1374 */
4946a942
GD		 1375 if (transforms & PNG_TRANSFORM_INVERT_MONO)
1376 png_set_invert_mono(png_ptr);
1377#endif
1378
1379#if defined(PNG_READ_SHIFT_SUPPORTED)
1380 /* If you want to shift the pixel values from the range [0,255] or
1381 * [0,65535] to the original [0,7] or [0,31], or whatever range the
1382 * colors were originally in:
1383 */
1384 if ((transforms & PNG_TRANSFORM_SHIFT)
1385 && png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT))
1386 {
1387 png_color_8p sig_bit;
1388
1389 png_get_sBIT(png_ptr, info_ptr, &sig_bit);
1390 png_set_shift(png_ptr, sig_bit);
1391 }
1392#endif
1393
1394#if defined(PNG_READ_BGR_SUPPORTED)
5b02c8a1
VS		 1395 /* flip the RGB pixels to BGR (or RGBA to BGRA)
1396 */
4946a942
GD		 1397 if (transforms & PNG_TRANSFORM_BGR)
1398 png_set_bgr(png_ptr);
1399#endif
1400
1401#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
5b02c8a1
VS		 1402 /* swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR)
1403 */
4946a942
GD		 1404 if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
1405 png_set_swap_alpha(png_ptr);
1406#endif
1407
1408#if defined(PNG_READ_SWAP_SUPPORTED)
5b02c8a1
VS		 1409 /* swap bytes of 16 bit files to least significant byte first
1410 */
4946a942
GD		 1411 if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
1412 png_set_swap(png_ptr);
1413#endif
1414
1415 /* We don't handle adding filler bytes */
1416
1417 /* Optional call to gamma correct and add the background to the palette
1418 * and update info structure. REQUIRED if you are expecting libpng to
1419 * update the palette for you (i.e., you selected such a transform above).
1420 */
1421 png_read_update_info(png_ptr, info_ptr);
1422
1423 /* -------------- image transformations end here ------------------- */
1424
1425#ifdef PNG_FREE_ME_SUPPORTED
1426 png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0);
1427#endif
1428 if(info_ptr->row_pointers == NULL)
1429 {
1430 info_ptr->row_pointers = (png_bytepp)png_malloc(png_ptr,
5b02c8a1 1431 info_ptr->height * png_sizeof(png_bytep));
4946a942
GD		 1432#ifdef PNG_FREE_ME_SUPPORTED
1433 info_ptr->free_me |= PNG_FREE_ROWS;
1434#endif
1435 for (row = 0; row < (int)info_ptr->height; row++)
1436 {
1437 info_ptr->row_pointers[row] = (png_bytep)png_malloc(png_ptr,
1438 png_get_rowbytes(png_ptr, info_ptr));
1439 }
1440 }
1441
1442 png_read_image(png_ptr, info_ptr->row_pointers);
1443 info_ptr->valid |= PNG_INFO_IDAT;
1444
1445 /* read rest of file, and get additional chunks in info_ptr - REQUIRED */
1446 png_read_end(png_ptr, info_ptr);
1447
1448 if(transforms == 0 || params == NULL)
1449 /* quiet compiler warnings */ return;
1450
1451}
1452#endif
5b02c8a1 1453#endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */
wxWidgets (Impactor)