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comparison ext/libpng-1.2.29/png.c @ 0:4a0efb7baf70

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* Datasets becomes the new trunk and retires after that :-)
author mvbarracuda@33b003aa-7bff-0310-803a-e67f0ece8222
date Sun, 29 Jun 2008 18:44:17 +0000
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-1:000000000000 0:4a0efb7baf70
1
2 /* png.c - location for general purpose libpng functions
3 *
4 * Last changed in libpng 1.2.21 October 4, 2007
5 * For conditions of distribution and use, see copyright notice in png.h
6 * Copyright (c) 1998-2007 Glenn Randers-Pehrson
7 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
8 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
9 */
10
11 #define PNG_INTERNAL
12 #define PNG_NO_EXTERN
13 #include "png.h"
14
15 /* Generate a compiler error if there is an old png.h in the search path. */
16 typedef version_1_2_29 Your_png_h_is_not_version_1_2_29;
17
18 /* Version information for C files. This had better match the version
19 * string defined in png.h. */
20
21 #ifdef PNG_USE_GLOBAL_ARRAYS
22 /* png_libpng_ver was changed to a function in version 1.0.5c */
23 PNG_CONST char png_libpng_ver[18] = PNG_LIBPNG_VER_STRING;
24
25 #ifdef PNG_READ_SUPPORTED
26
27 /* png_sig was changed to a function in version 1.0.5c */
28 /* Place to hold the signature string for a PNG file. */
29 PNG_CONST png_byte FARDATA png_sig[8] = {137, 80, 78, 71, 13, 10, 26, 10};
30 #endif /* PNG_READ_SUPPORTED */
31
32 /* Invoke global declarations for constant strings for known chunk types */
33 PNG_IHDR;
34 PNG_IDAT;
35 PNG_IEND;
36 PNG_PLTE;
37 PNG_bKGD;
38 PNG_cHRM;
39 PNG_gAMA;
40 PNG_hIST;
41 PNG_iCCP;
42 PNG_iTXt;
43 PNG_oFFs;
44 PNG_pCAL;
45 PNG_sCAL;
46 PNG_pHYs;
47 PNG_sBIT;
48 PNG_sPLT;
49 PNG_sRGB;
50 PNG_tEXt;
51 PNG_tIME;
52 PNG_tRNS;
53 PNG_zTXt;
54
55 #ifdef PNG_READ_SUPPORTED
56 /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
57
58 /* start of interlace block */
59 PNG_CONST int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
60
61 /* offset to next interlace block */
62 PNG_CONST int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
63
64 /* start of interlace block in the y direction */
65 PNG_CONST int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
66
67 /* offset to next interlace block in the y direction */
68 PNG_CONST int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
69
70 /* Height of interlace block. This is not currently used - if you need
71 * it, uncomment it here and in png.h
72 PNG_CONST int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
73 */
74
75 /* Mask to determine which pixels are valid in a pass */
76 PNG_CONST int FARDATA png_pass_mask[] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
77
78 /* Mask to determine which pixels to overwrite while displaying */
79 PNG_CONST int FARDATA png_pass_dsp_mask[]
80 = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
81
82 #endif /* PNG_READ_SUPPORTED */
83 #endif /* PNG_USE_GLOBAL_ARRAYS */
84
85 /* Tells libpng that we have already handled the first "num_bytes" bytes
86 * of the PNG file signature. If the PNG data is embedded into another
87 * stream we can set num_bytes = 8 so that libpng will not attempt to read
88 * or write any of the magic bytes before it starts on the IHDR.
89 */
90
91 #ifdef PNG_READ_SUPPORTED
92 void PNGAPI
93 png_set_sig_bytes(png_structp png_ptr, int num_bytes)
94 {
95 if(png_ptr == NULL) return;
96 png_debug(1, "in png_set_sig_bytes\n");
97 if (num_bytes > 8)
98 png_error(png_ptr, "Too many bytes for PNG signature.");
99
100 png_ptr->sig_bytes = (png_byte)(num_bytes < 0 ? 0 : num_bytes);
101 }
102
103 /* Checks whether the supplied bytes match the PNG signature. We allow
104 * checking less than the full 8-byte signature so that those apps that
105 * already read the first few bytes of a file to determine the file type
106 * can simply check the remaining bytes for extra assurance. Returns
107 * an integer less than, equal to, or greater than zero if sig is found,
108 * respectively, to be less than, to match, or be greater than the correct
109 * PNG signature (this is the same behaviour as strcmp, memcmp, etc).
110 */
111 int PNGAPI
112 png_sig_cmp(png_bytep sig, png_size_t start, png_size_t num_to_check)
113 {
114 png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
115 if (num_to_check > 8)
116 num_to_check = 8;
117 else if (num_to_check < 1)
118 return (-1);
119
120 if (start > 7)
121 return (-1);
122
123 if (start + num_to_check > 8)
124 num_to_check = 8 - start;
125
126 return ((int)(png_memcmp(&sig[start], &png_signature[start], num_to_check)));
127 }
128
129 #if defined(PNG_1_0_X) || defined(PNG_1_2_X)
130 /* (Obsolete) function to check signature bytes. It does not allow one
131 * to check a partial signature. This function might be removed in the
132 * future - use png_sig_cmp(). Returns true (nonzero) if the file is PNG.
133 */
134 int PNGAPI
135 png_check_sig(png_bytep sig, int num)
136 {
137 return ((int)!png_sig_cmp(sig, (png_size_t)0, (png_size_t)num));
138 }
139 #endif
140 #endif /* PNG_READ_SUPPORTED */
141
142 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
143 /* Function to allocate memory for zlib and clear it to 0. */
144 #ifdef PNG_1_0_X
145 voidpf PNGAPI
146 #else
147 voidpf /* private */
148 #endif
149 png_zalloc(voidpf png_ptr, uInt items, uInt size)
150 {
151 png_voidp ptr;
152 png_structp p=(png_structp)png_ptr;
153 png_uint_32 save_flags=p->flags;
154 png_uint_32 num_bytes;
155
156 if(png_ptr == NULL) return (NULL);
157 if (items > PNG_UINT_32_MAX/size)
158 {
159 png_warning (p, "Potential overflow in png_zalloc()");
160 return (NULL);
161 }
162 num_bytes = (png_uint_32)items * size;
163
164 p->flags|=PNG_FLAG_MALLOC_NULL_MEM_OK;
165 ptr = (png_voidp)png_malloc((png_structp)png_ptr, num_bytes);
166 p->flags=save_flags;
167
168 #if defined(PNG_1_0_X) && !defined(PNG_NO_ZALLOC_ZERO)
169 if (ptr == NULL)
170 return ((voidpf)ptr);
171
172 if (num_bytes > (png_uint_32)0x8000L)
173 {
174 png_memset(ptr, 0, (png_size_t)0x8000L);
175 png_memset((png_bytep)ptr + (png_size_t)0x8000L, 0,
176 (png_size_t)(num_bytes - (png_uint_32)0x8000L));
177 }
178 else
179 {
180 png_memset(ptr, 0, (png_size_t)num_bytes);
181 }
182 #endif
183 return ((voidpf)ptr);
184 }
185
186 /* function to free memory for zlib */
187 #ifdef PNG_1_0_X
188 void PNGAPI
189 #else
190 void /* private */
191 #endif
192 png_zfree(voidpf png_ptr, voidpf ptr)
193 {
194 png_free((png_structp)png_ptr, (png_voidp)ptr);
195 }
196
197 /* Reset the CRC variable to 32 bits of 1's. Care must be taken
198 * in case CRC is > 32 bits to leave the top bits 0.
199 */
200 void /* PRIVATE */
201 png_reset_crc(png_structp png_ptr)
202 {
203 png_ptr->crc = crc32(0, Z_NULL, 0);
204 }
205
206 /* Calculate the CRC over a section of data. We can only pass as
207 * much data to this routine as the largest single buffer size. We
208 * also check that this data will actually be used before going to the
209 * trouble of calculating it.
210 */
211 void /* PRIVATE */
212 png_calculate_crc(png_structp png_ptr, png_bytep ptr, png_size_t length)
213 {
214 int need_crc = 1;
215
216 if (png_ptr->chunk_name[0] & 0x20) /* ancillary */
217 {
218 if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
219 (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
220 need_crc = 0;
221 }
222 else /* critical */
223 {
224 if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE)
225 need_crc = 0;
226 }
227
228 if (need_crc)
229 png_ptr->crc = crc32(png_ptr->crc, ptr, (uInt)length);
230 }
231
232 /* Allocate the memory for an info_struct for the application. We don't
233 * really need the png_ptr, but it could potentially be useful in the
234 * future. This should be used in favour of malloc(png_sizeof(png_info))
235 * and png_info_init() so that applications that want to use a shared
236 * libpng don't have to be recompiled if png_info changes size.
237 */
238 png_infop PNGAPI
239 png_create_info_struct(png_structp png_ptr)
240 {
241 png_infop info_ptr;
242
243 png_debug(1, "in png_create_info_struct\n");
244 if(png_ptr == NULL) return (NULL);
245 #ifdef PNG_USER_MEM_SUPPORTED
246 info_ptr = (png_infop)png_create_struct_2(PNG_STRUCT_INFO,
247 png_ptr->malloc_fn, png_ptr->mem_ptr);
248 #else
249 info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO);
250 #endif
251 if (info_ptr != NULL)
252 png_info_init_3(&info_ptr, png_sizeof(png_info));
253
254 return (info_ptr);
255 }
256
257 /* This function frees the memory associated with a single info struct.
258 * Normally, one would use either png_destroy_read_struct() or
259 * png_destroy_write_struct() to free an info struct, but this may be
260 * useful for some applications.
261 */
262 void PNGAPI
263 png_destroy_info_struct(png_structp png_ptr, png_infopp info_ptr_ptr)
264 {
265 png_infop info_ptr = NULL;
266 if(png_ptr == NULL) return;
267
268 png_debug(1, "in png_destroy_info_struct\n");
269 if (info_ptr_ptr != NULL)
270 info_ptr = *info_ptr_ptr;
271
272 if (info_ptr != NULL)
273 {
274 png_info_destroy(png_ptr, info_ptr);
275
276 #ifdef PNG_USER_MEM_SUPPORTED
277 png_destroy_struct_2((png_voidp)info_ptr, png_ptr->free_fn,
278 png_ptr->mem_ptr);
279 #else
280 png_destroy_struct((png_voidp)info_ptr);
281 #endif
282 *info_ptr_ptr = NULL;
283 }
284 }
285
286 /* Initialize the info structure. This is now an internal function (0.89)
287 * and applications using it are urged to use png_create_info_struct()
288 * instead.
289 */
290 #if defined(PNG_1_0_X) || defined(PNG_1_2_X)
291 #undef png_info_init
292 void PNGAPI
293 png_info_init(png_infop info_ptr)
294 {
295 /* We only come here via pre-1.0.12-compiled applications */
296 png_info_init_3(&info_ptr, 0);
297 }
298 #endif
299
300 void PNGAPI
301 png_info_init_3(png_infopp ptr_ptr, png_size_t png_info_struct_size)
302 {
303 png_infop info_ptr = *ptr_ptr;
304
305 if(info_ptr == NULL) return;
306
307 png_debug(1, "in png_info_init_3\n");
308
309 if(png_sizeof(png_info) > png_info_struct_size)
310 {
311 png_destroy_struct(info_ptr);
312 info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO);
313 *ptr_ptr = info_ptr;
314 }
315
316 /* set everything to 0 */
317 png_memset(info_ptr, 0, png_sizeof (png_info));
318 }
319
320 #ifdef PNG_FREE_ME_SUPPORTED
321 void PNGAPI
322 png_data_freer(png_structp png_ptr, png_infop info_ptr,
323 int freer, png_uint_32 mask)
324 {
325 png_debug(1, "in png_data_freer\n");
326 if (png_ptr == NULL || info_ptr == NULL)
327 return;
328 if(freer == PNG_DESTROY_WILL_FREE_DATA)
329 info_ptr->free_me |= mask;
330 else if(freer == PNG_USER_WILL_FREE_DATA)
331 info_ptr->free_me &= ~mask;
332 else
333 png_warning(png_ptr,
334 "Unknown freer parameter in png_data_freer.");
335 }
336 #endif
337
338 void PNGAPI
339 png_free_data(png_structp png_ptr, png_infop info_ptr, png_uint_32 mask,
340 int num)
341 {
342 png_debug(1, "in png_free_data\n");
343 if (png_ptr == NULL || info_ptr == NULL)
344 return;
345
346 #if defined(PNG_TEXT_SUPPORTED)
347 /* free text item num or (if num == -1) all text items */
348 #ifdef PNG_FREE_ME_SUPPORTED
349 if ((mask & PNG_FREE_TEXT) & info_ptr->free_me)
350 #else
351 if (mask & PNG_FREE_TEXT)
352 #endif
353 {
354 if (num != -1)
355 {
356 if (info_ptr->text && info_ptr->text[num].key)
357 {
358 png_free(png_ptr, info_ptr->text[num].key);
359 info_ptr->text[num].key = NULL;
360 }
361 }
362 else
363 {
364 int i;
365 for (i = 0; i < info_ptr->num_text; i++)
366 png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, i);
367 png_free(png_ptr, info_ptr->text);
368 info_ptr->text = NULL;
369 info_ptr->num_text=0;
370 }
371 }
372 #endif
373
374 #if defined(PNG_tRNS_SUPPORTED)
375 /* free any tRNS entry */
376 #ifdef PNG_FREE_ME_SUPPORTED
377 if ((mask & PNG_FREE_TRNS) & info_ptr->free_me)
378 #else
379 if ((mask & PNG_FREE_TRNS) && (png_ptr->flags & PNG_FLAG_FREE_TRNS))
380 #endif
381 {
382 png_free(png_ptr, info_ptr->trans);
383 info_ptr->valid &= ~PNG_INFO_tRNS;
384 #ifndef PNG_FREE_ME_SUPPORTED
385 png_ptr->flags &= ~PNG_FLAG_FREE_TRNS;
386 #endif
387 info_ptr->trans = NULL;
388 }
389 #endif
390
391 #if defined(PNG_sCAL_SUPPORTED)
392 /* free any sCAL entry */
393 #ifdef PNG_FREE_ME_SUPPORTED
394 if ((mask & PNG_FREE_SCAL) & info_ptr->free_me)
395 #else
396 if (mask & PNG_FREE_SCAL)
397 #endif
398 {
399 #if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
400 png_free(png_ptr, info_ptr->scal_s_width);
401 png_free(png_ptr, info_ptr->scal_s_height);
402 info_ptr->scal_s_width = NULL;
403 info_ptr->scal_s_height = NULL;
404 #endif
405 info_ptr->valid &= ~PNG_INFO_sCAL;
406 }
407 #endif
408
409 #if defined(PNG_pCAL_SUPPORTED)
410 /* free any pCAL entry */
411 #ifdef PNG_FREE_ME_SUPPORTED
412 if ((mask & PNG_FREE_PCAL) & info_ptr->free_me)
413 #else
414 if (mask & PNG_FREE_PCAL)
415 #endif
416 {
417 png_free(png_ptr, info_ptr->pcal_purpose);
418 png_free(png_ptr, info_ptr->pcal_units);
419 info_ptr->pcal_purpose = NULL;
420 info_ptr->pcal_units = NULL;
421 if (info_ptr->pcal_params != NULL)
422 {
423 int i;
424 for (i = 0; i < (int)info_ptr->pcal_nparams; i++)
425 {
426 png_free(png_ptr, info_ptr->pcal_params[i]);
427 info_ptr->pcal_params[i]=NULL;
428 }
429 png_free(png_ptr, info_ptr->pcal_params);
430 info_ptr->pcal_params = NULL;
431 }
432 info_ptr->valid &= ~PNG_INFO_pCAL;
433 }
434 #endif
435
436 #if defined(PNG_iCCP_SUPPORTED)
437 /* free any iCCP entry */
438 #ifdef PNG_FREE_ME_SUPPORTED
439 if ((mask & PNG_FREE_ICCP) & info_ptr->free_me)
440 #else
441 if (mask & PNG_FREE_ICCP)
442 #endif
443 {
444 png_free(png_ptr, info_ptr->iccp_name);
445 png_free(png_ptr, info_ptr->iccp_profile);
446 info_ptr->iccp_name = NULL;
447 info_ptr->iccp_profile = NULL;
448 info_ptr->valid &= ~PNG_INFO_iCCP;
449 }
450 #endif
451
452 #if defined(PNG_sPLT_SUPPORTED)
453 /* free a given sPLT entry, or (if num == -1) all sPLT entries */
454 #ifdef PNG_FREE_ME_SUPPORTED
455 if ((mask & PNG_FREE_SPLT) & info_ptr->free_me)
456 #else
457 if (mask & PNG_FREE_SPLT)
458 #endif
459 {
460 if (num != -1)
461 {
462 if(info_ptr->splt_palettes)
463 {
464 png_free(png_ptr, info_ptr->splt_palettes[num].name);
465 png_free(png_ptr, info_ptr->splt_palettes[num].entries);
466 info_ptr->splt_palettes[num].name = NULL;
467 info_ptr->splt_palettes[num].entries = NULL;
468 }
469 }
470 else
471 {
472 if(info_ptr->splt_palettes_num)
473 {
474 int i;
475 for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
476 png_free_data(png_ptr, info_ptr, PNG_FREE_SPLT, i);
477
478 png_free(png_ptr, info_ptr->splt_palettes);
479 info_ptr->splt_palettes = NULL;
480 info_ptr->splt_palettes_num = 0;
481 }
482 info_ptr->valid &= ~PNG_INFO_sPLT;
483 }
484 }
485 #endif
486
487 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
488 if(png_ptr->unknown_chunk.data)
489 {
490 png_free(png_ptr, png_ptr->unknown_chunk.data);
491 png_ptr->unknown_chunk.data = NULL;
492 }
493 #ifdef PNG_FREE_ME_SUPPORTED
494 if ((mask & PNG_FREE_UNKN) & info_ptr->free_me)
495 #else
496 if (mask & PNG_FREE_UNKN)
497 #endif
498 {
499 if (num != -1)
500 {
501 if(info_ptr->unknown_chunks)
502 {
503 png_free(png_ptr, info_ptr->unknown_chunks[num].data);
504 info_ptr->unknown_chunks[num].data = NULL;
505 }
506 }
507 else
508 {
509 int i;
510
511 if(info_ptr->unknown_chunks_num)
512 {
513 for (i = 0; i < (int)info_ptr->unknown_chunks_num; i++)
514 png_free_data(png_ptr, info_ptr, PNG_FREE_UNKN, i);
515
516 png_free(png_ptr, info_ptr->unknown_chunks);
517 info_ptr->unknown_chunks = NULL;
518 info_ptr->unknown_chunks_num = 0;
519 }
520 }
521 }
522 #endif
523
524 #if defined(PNG_hIST_SUPPORTED)
525 /* free any hIST entry */
526 #ifdef PNG_FREE_ME_SUPPORTED
527 if ((mask & PNG_FREE_HIST) & info_ptr->free_me)
528 #else
529 if ((mask & PNG_FREE_HIST) && (png_ptr->flags & PNG_FLAG_FREE_HIST))
530 #endif
531 {
532 png_free(png_ptr, info_ptr->hist);
533 info_ptr->hist = NULL;
534 info_ptr->valid &= ~PNG_INFO_hIST;
535 #ifndef PNG_FREE_ME_SUPPORTED
536 png_ptr->flags &= ~PNG_FLAG_FREE_HIST;
537 #endif
538 }
539 #endif
540
541 /* free any PLTE entry that was internally allocated */
542 #ifdef PNG_FREE_ME_SUPPORTED
543 if ((mask & PNG_FREE_PLTE) & info_ptr->free_me)
544 #else
545 if ((mask & PNG_FREE_PLTE) && (png_ptr->flags & PNG_FLAG_FREE_PLTE))
546 #endif
547 {
548 png_zfree(png_ptr, info_ptr->palette);
549 info_ptr->palette = NULL;
550 info_ptr->valid &= ~PNG_INFO_PLTE;
551 #ifndef PNG_FREE_ME_SUPPORTED
552 png_ptr->flags &= ~PNG_FLAG_FREE_PLTE;
553 #endif
554 info_ptr->num_palette = 0;
555 }
556
557 #if defined(PNG_INFO_IMAGE_SUPPORTED)
558 /* free any image bits attached to the info structure */
559 #ifdef PNG_FREE_ME_SUPPORTED
560 if ((mask & PNG_FREE_ROWS) & info_ptr->free_me)
561 #else
562 if (mask & PNG_FREE_ROWS)
563 #endif
564 {
565 if(info_ptr->row_pointers)
566 {
567 int row;
568 for (row = 0; row < (int)info_ptr->height; row++)
569 {
570 png_free(png_ptr, info_ptr->row_pointers[row]);
571 info_ptr->row_pointers[row]=NULL;
572 }
573 png_free(png_ptr, info_ptr->row_pointers);
574 info_ptr->row_pointers=NULL;
575 }
576 info_ptr->valid &= ~PNG_INFO_IDAT;
577 }
578 #endif
579
580 #ifdef PNG_FREE_ME_SUPPORTED
581 if(num == -1)
582 info_ptr->free_me &= ~mask;
583 else
584 info_ptr->free_me &= ~(mask & ~PNG_FREE_MUL);
585 #endif
586 }
587
588 /* This is an internal routine to free any memory that the info struct is
589 * pointing to before re-using it or freeing the struct itself. Recall
590 * that png_free() checks for NULL pointers for us.
591 */
592 void /* PRIVATE */
593 png_info_destroy(png_structp png_ptr, png_infop info_ptr)
594 {
595 png_debug(1, "in png_info_destroy\n");
596
597 png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
598
599 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
600 if (png_ptr->num_chunk_list)
601 {
602 png_free(png_ptr, png_ptr->chunk_list);
603 png_ptr->chunk_list=NULL;
604 png_ptr->num_chunk_list=0;
605 }
606 #endif
607
608 png_info_init_3(&info_ptr, png_sizeof(png_info));
609 }
610 #endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
611
612 /* This function returns a pointer to the io_ptr associated with the user
613 * functions. The application should free any memory associated with this
614 * pointer before png_write_destroy() or png_read_destroy() are called.
615 */
616 png_voidp PNGAPI
617 png_get_io_ptr(png_structp png_ptr)
618 {
619 if(png_ptr == NULL) return (NULL);
620 return (png_ptr->io_ptr);
621 }
622
623 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
624 #if !defined(PNG_NO_STDIO)
625 /* Initialize the default input/output functions for the PNG file. If you
626 * use your own read or write routines, you can call either png_set_read_fn()
627 * or png_set_write_fn() instead of png_init_io(). If you have defined
628 * PNG_NO_STDIO, you must use a function of your own because "FILE *" isn't
629 * necessarily available.
630 */
631 void PNGAPI
632 png_init_io(png_structp png_ptr, png_FILE_p fp)
633 {
634 png_debug(1, "in png_init_io\n");
635 if(png_ptr == NULL) return;
636 png_ptr->io_ptr = (png_voidp)fp;
637 }
638 #endif
639
640 #if defined(PNG_TIME_RFC1123_SUPPORTED)
641 /* Convert the supplied time into an RFC 1123 string suitable for use in
642 * a "Creation Time" or other text-based time string.
643 */
644 png_charp PNGAPI
645 png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime)
646 {
647 static PNG_CONST char short_months[12][4] =
648 {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
649 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
650
651 if(png_ptr == NULL) return (NULL);
652 if (png_ptr->time_buffer == NULL)
653 {
654 png_ptr->time_buffer = (png_charp)png_malloc(png_ptr, (png_uint_32)(29*
655 png_sizeof(char)));
656 }
657
658 #if defined(_WIN32_WCE)
659 {
660 wchar_t time_buf[29];
661 wsprintf(time_buf, TEXT("%d %S %d %02d:%02d:%02d +0000"),
662 ptime->day % 32, short_months[(ptime->month - 1) % 12],
663 ptime->year, ptime->hour % 24, ptime->minute % 60,
664 ptime->second % 61);
665 WideCharToMultiByte(CP_ACP, 0, time_buf, -1, png_ptr->time_buffer, 29,
666 NULL, NULL);
667 }
668 #else
669 #ifdef USE_FAR_KEYWORD
670 {
671 char near_time_buf[29];
672 png_snprintf6(near_time_buf,29,"%d %s %d %02d:%02d:%02d +0000",
673 ptime->day % 32, short_months[(ptime->month - 1) % 12],
674 ptime->year, ptime->hour % 24, ptime->minute % 60,
675 ptime->second % 61);
676 png_memcpy(png_ptr->time_buffer, near_time_buf,
677 29*png_sizeof(char));
678 }
679 #else
680 png_snprintf6(png_ptr->time_buffer,29,"%d %s %d %02d:%02d:%02d +0000",
681 ptime->day % 32, short_months[(ptime->month - 1) % 12],
682 ptime->year, ptime->hour % 24, ptime->minute % 60,
683 ptime->second % 61);
684 #endif
685 #endif /* _WIN32_WCE */
686 return ((png_charp)png_ptr->time_buffer);
687 }
688 #endif /* PNG_TIME_RFC1123_SUPPORTED */
689
690 #endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
691
692 png_charp PNGAPI
693 png_get_copyright(png_structp png_ptr)
694 {
695 png_ptr = png_ptr; /* silence compiler warning about unused png_ptr */
696 return ((png_charp) "\n libpng version 1.2.29 - May 8, 2008\n\
697 Copyright (c) 1998-2008 Glenn Randers-Pehrson\n\
698 Copyright (c) 1996-1997 Andreas Dilger\n\
699 Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.\n");
700 }
701
702 /* The following return the library version as a short string in the
703 * format 1.0.0 through 99.99.99zz. To get the version of *.h files
704 * used with your application, print out PNG_LIBPNG_VER_STRING, which
705 * is defined in png.h.
706 * Note: now there is no difference between png_get_libpng_ver() and
707 * png_get_header_ver(). Due to the version_nn_nn_nn typedef guard,
708 * it is guaranteed that png.c uses the correct version of png.h.
709 */
710 png_charp PNGAPI
711 png_get_libpng_ver(png_structp png_ptr)
712 {
713 /* Version of *.c files used when building libpng */
714 png_ptr = png_ptr; /* silence compiler warning about unused png_ptr */
715 return ((png_charp) PNG_LIBPNG_VER_STRING);
716 }
717
718 png_charp PNGAPI
719 png_get_header_ver(png_structp png_ptr)
720 {
721 /* Version of *.h files used when building libpng */
722 png_ptr = png_ptr; /* silence compiler warning about unused png_ptr */
723 return ((png_charp) PNG_LIBPNG_VER_STRING);
724 }
725
726 png_charp PNGAPI
727 png_get_header_version(png_structp png_ptr)
728 {
729 /* Returns longer string containing both version and date */
730 png_ptr = png_ptr; /* silence compiler warning about unused png_ptr */
731 return ((png_charp) PNG_HEADER_VERSION_STRING
732 #ifndef PNG_READ_SUPPORTED
733 " (NO READ SUPPORT)"
734 #endif
735 "\n");
736 }
737
738 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
739 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
740 int PNGAPI
741 png_handle_as_unknown(png_structp png_ptr, png_bytep chunk_name)
742 {
743 /* check chunk_name and return "keep" value if it's on the list, else 0 */
744 int i;
745 png_bytep p;
746 if(png_ptr == NULL || chunk_name == NULL || png_ptr->num_chunk_list<=0)
747 return 0;
748 p=png_ptr->chunk_list+png_ptr->num_chunk_list*5-5;
749 for (i = png_ptr->num_chunk_list; i; i--, p-=5)
750 if (!png_memcmp(chunk_name, p, 4))
751 return ((int)*(p+4));
752 return 0;
753 }
754 #endif
755
756 /* This function, added to libpng-1.0.6g, is untested. */
757 int PNGAPI
758 png_reset_zstream(png_structp png_ptr)
759 {
760 if (png_ptr == NULL) return Z_STREAM_ERROR;
761 return (inflateReset(&png_ptr->zstream));
762 }
763 #endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
764
765 /* This function was added to libpng-1.0.7 */
766 png_uint_32 PNGAPI
767 png_access_version_number(void)
768 {
769 /* Version of *.c files used when building libpng */
770 return((png_uint_32) PNG_LIBPNG_VER);
771 }
772
773
774 #if defined(PNG_READ_SUPPORTED) && defined(PNG_ASSEMBLER_CODE_SUPPORTED)
775 #if !defined(PNG_1_0_X)
776 /* this function was added to libpng 1.2.0 */
777 int PNGAPI
778 png_mmx_support(void)
779 {
780 /* obsolete, to be removed from libpng-1.4.0 */
781 return -1;
782 }
783 #endif /* PNG_1_0_X */
784 #endif /* PNG_READ_SUPPORTED && PNG_ASSEMBLER_CODE_SUPPORTED */
785
786 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
787 #ifdef PNG_SIZE_T
788 /* Added at libpng version 1.2.6 */
789 PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size));
790 png_size_t PNGAPI
791 png_convert_size(size_t size)
792 {
793 if (size > (png_size_t)-1)
794 PNG_ABORT(); /* We haven't got access to png_ptr, so no png_error() */
795 return ((png_size_t)size);
796 }
797 #endif /* PNG_SIZE_T */
798 #endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */