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view libs/libpng/png.c @ 17:aef7f51f6397
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| author | John Tsiombikas <nuclear@member.fsf.org> |
|---|---|
| date | Wed, 10 Jun 2015 06:56:27 +0300 |
| parents | |
| children |
line source
2 /* png.c - location for general purpose libpng functions
3 *
4 * Last changed in libpng 1.2.30 [August 15, 2008]
5 * For conditions of distribution and use, see copyright notice in png.h
6 * Copyright (c) 1998-2008 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 */
11 #define PNG_INTERNAL
12 #define PNG_NO_EXTERN
13 #include "png.h"
15 /* Generate a compiler error if there is an old png.h in the search path. */
16 typedef version_1_2_33 Your_png_h_is_not_version_1_2_33;
18 /* Version information for C files. This had better match the version
19 * string defined in png.h. */
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;
25 #ifdef PNG_READ_SUPPORTED
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 */
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;
55 #ifdef PNG_READ_SUPPORTED
56 /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
58 /* start of interlace block */
59 PNG_CONST int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
61 /* offset to next interlace block */
62 PNG_CONST int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
64 /* start of interlace block in the y direction */
65 PNG_CONST int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
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};
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 */
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};
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};
82 #endif /* PNG_READ_SUPPORTED */
83 #endif /* PNG_USE_GLOBAL_ARRAYS */
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 */
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.");
100 png_ptr->sig_bytes = (png_byte)(num_bytes < 0 ? 0 : num_bytes);
101 }
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);
120 if (start > 7)
121 return (-1);
123 if (start + num_to_check > 8)
124 num_to_check = 8 - start;
126 return ((int)(png_memcmp(&sig[start], &png_signature[start], num_to_check)));
127 }
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 */
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;
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;
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;
168 #if defined(PNG_1_0_X) && !defined(PNG_NO_ZALLOC_ZERO)
169 if (ptr == NULL)
170 return ((voidpf)ptr);
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 }
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 }
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 }
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;
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 }
228 if (need_crc)
229 png_ptr->crc = crc32(png_ptr->crc, ptr, (uInt)length);
230 }
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;
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));
254 return (info_ptr);
255 }
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;
268 png_debug(1, "in png_destroy_info_struct\n");
269 if (info_ptr_ptr != NULL)
270 info_ptr = *info_ptr_ptr;
272 if (info_ptr != NULL)
273 {
274 png_info_destroy(png_ptr, info_ptr);
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 }
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
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;
305 if (info_ptr == NULL) return;
307 png_debug(1, "in png_info_init_3\n");
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 }
316 /* set everything to 0 */
317 png_memset(info_ptr, 0, png_sizeof(png_info));
318 }
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
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;
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
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->trans = NULL;
384 info_ptr->valid &= ~PNG_INFO_tRNS;
385 #ifndef PNG_FREE_ME_SUPPORTED
386 png_ptr->flags &= ~PNG_FLAG_FREE_TRNS;
387 #endif
388 }
389 #endif
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
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
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
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);
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
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 }
494 #ifdef PNG_FREE_ME_SUPPORTED
495 if ((mask & PNG_FREE_UNKN) & info_ptr->free_me)
496 #else
497 if (mask & PNG_FREE_UNKN)
498 #endif
499 {
500 if (num != -1)
501 {
502 if (info_ptr->unknown_chunks)
503 {
504 png_free(png_ptr, info_ptr->unknown_chunks[num].data);
505 info_ptr->unknown_chunks[num].data = NULL;
506 }
507 }
508 else
509 {
510 int i;
512 if (info_ptr->unknown_chunks_num)
513 {
514 for (i = 0; i < (int)info_ptr->unknown_chunks_num; i++)
515 png_free_data(png_ptr, info_ptr, PNG_FREE_UNKN, i);
517 png_free(png_ptr, info_ptr->unknown_chunks);
518 info_ptr->unknown_chunks = NULL;
519 info_ptr->unknown_chunks_num = 0;
520 }
521 }
522 }
523 #endif
525 #if defined(PNG_hIST_SUPPORTED)
526 /* free any hIST entry */
527 #ifdef PNG_FREE_ME_SUPPORTED
528 if ((mask & PNG_FREE_HIST) & info_ptr->free_me)
529 #else
530 if ((mask & PNG_FREE_HIST) && (png_ptr->flags & PNG_FLAG_FREE_HIST))
531 #endif
532 {
533 png_free(png_ptr, info_ptr->hist);
534 info_ptr->hist = NULL;
535 info_ptr->valid &= ~PNG_INFO_hIST;
536 #ifndef PNG_FREE_ME_SUPPORTED
537 png_ptr->flags &= ~PNG_FLAG_FREE_HIST;
538 #endif
539 }
540 #endif
542 /* free any PLTE entry that was internally allocated */
543 #ifdef PNG_FREE_ME_SUPPORTED
544 if ((mask & PNG_FREE_PLTE) & info_ptr->free_me)
545 #else
546 if ((mask & PNG_FREE_PLTE) && (png_ptr->flags & PNG_FLAG_FREE_PLTE))
547 #endif
548 {
549 png_zfree(png_ptr, info_ptr->palette);
550 info_ptr->palette = NULL;
551 info_ptr->valid &= ~PNG_INFO_PLTE;
552 #ifndef PNG_FREE_ME_SUPPORTED
553 png_ptr->flags &= ~PNG_FLAG_FREE_PLTE;
554 #endif
555 info_ptr->num_palette = 0;
556 }
558 #if defined(PNG_INFO_IMAGE_SUPPORTED)
559 /* free any image bits attached to the info structure */
560 #ifdef PNG_FREE_ME_SUPPORTED
561 if ((mask & PNG_FREE_ROWS) & info_ptr->free_me)
562 #else
563 if (mask & PNG_FREE_ROWS)
564 #endif
565 {
566 if (info_ptr->row_pointers)
567 {
568 int row;
569 for (row = 0; row < (int)info_ptr->height; row++)
570 {
571 png_free(png_ptr, info_ptr->row_pointers[row]);
572 info_ptr->row_pointers[row]=NULL;
573 }
574 png_free(png_ptr, info_ptr->row_pointers);
575 info_ptr->row_pointers=NULL;
576 }
577 info_ptr->valid &= ~PNG_INFO_IDAT;
578 }
579 #endif
581 #ifdef PNG_FREE_ME_SUPPORTED
582 if (num == -1)
583 info_ptr->free_me &= ~mask;
584 else
585 info_ptr->free_me &= ~(mask & ~PNG_FREE_MUL);
586 #endif
587 }
589 /* This is an internal routine to free any memory that the info struct is
590 * pointing to before re-using it or freeing the struct itself. Recall
591 * that png_free() checks for NULL pointers for us.
592 */
593 void /* PRIVATE */
594 png_info_destroy(png_structp png_ptr, png_infop info_ptr)
595 {
596 png_debug(1, "in png_info_destroy\n");
598 png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
600 #if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
601 if (png_ptr->num_chunk_list)
602 {
603 png_free(png_ptr, png_ptr->chunk_list);
604 png_ptr->chunk_list=NULL;
605 png_ptr->num_chunk_list = 0;
606 }
607 #endif
609 png_info_init_3(&info_ptr, png_sizeof(png_info));
610 }
611 #endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
613 /* This function returns a pointer to the io_ptr associated with the user
614 * functions. The application should free any memory associated with this
615 * pointer before png_write_destroy() or png_read_destroy() are called.
616 */
617 png_voidp PNGAPI
618 png_get_io_ptr(png_structp png_ptr)
619 {
620 if (png_ptr == NULL) return (NULL);
621 return (png_ptr->io_ptr);
622 }
624 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
625 #if !defined(PNG_NO_STDIO)
626 /* Initialize the default input/output functions for the PNG file. If you
627 * use your own read or write routines, you can call either png_set_read_fn()
628 * or png_set_write_fn() instead of png_init_io(). If you have defined
629 * PNG_NO_STDIO, you must use a function of your own because "FILE *" isn't
630 * necessarily available.
631 */
632 void PNGAPI
633 png_init_io(png_structp png_ptr, png_FILE_p fp)
634 {
635 png_debug(1, "in png_init_io\n");
636 if (png_ptr == NULL) return;
637 png_ptr->io_ptr = (png_voidp)fp;
638 }
639 #endif
641 #if defined(PNG_TIME_RFC1123_SUPPORTED)
642 /* Convert the supplied time into an RFC 1123 string suitable for use in
643 * a "Creation Time" or other text-based time string.
644 */
645 png_charp PNGAPI
646 png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime)
647 {
648 static PNG_CONST char short_months[12][4] =
649 {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
650 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
652 if (png_ptr == NULL) return (NULL);
653 if (png_ptr->time_buffer == NULL)
654 {
655 png_ptr->time_buffer = (png_charp)png_malloc(png_ptr, (png_uint_32)(29*
656 png_sizeof(char)));
657 }
659 #if defined(_WIN32_WCE)
660 {
661 wchar_t time_buf[29];
662 wsprintf(time_buf, TEXT("%d %S %d %02d:%02d:%02d +0000"),
663 ptime->day % 32, short_months[(ptime->month - 1) % 12],
664 ptime->year, ptime->hour % 24, ptime->minute % 60,
665 ptime->second % 61);
666 WideCharToMultiByte(CP_ACP, 0, time_buf, -1, png_ptr->time_buffer, 29,
667 NULL, NULL);
668 }
669 #else
670 #ifdef USE_FAR_KEYWORD
671 {
672 char near_time_buf[29];
673 png_snprintf6(near_time_buf, 29, "%d %s %d %02d:%02d:%02d +0000",
674 ptime->day % 32, short_months[(ptime->month - 1) % 12],
675 ptime->year, ptime->hour % 24, ptime->minute % 60,
676 ptime->second % 61);
677 png_memcpy(png_ptr->time_buffer, near_time_buf,
678 29*png_sizeof(char));
679 }
680 #else
681 png_snprintf6(png_ptr->time_buffer, 29, "%d %s %d %02d:%02d:%02d +0000",
682 ptime->day % 32, short_months[(ptime->month - 1) % 12],
683 ptime->year, ptime->hour % 24, ptime->minute % 60,
684 ptime->second % 61);
685 #endif
686 #endif /* _WIN32_WCE */
687 return ((png_charp)png_ptr->time_buffer);
688 }
689 #endif /* PNG_TIME_RFC1123_SUPPORTED */
691 #endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
693 png_charp PNGAPI
694 png_get_copyright(png_structp png_ptr)
695 {
696 png_ptr = png_ptr; /* silence compiler warning about unused png_ptr */
697 return ((png_charp) "\n libpng version 1.2.33 - October 31, 2008\n\
698 Copyright (c) 1998-2008 Glenn Randers-Pehrson\n\
699 Copyright (c) 1996-1997 Andreas Dilger\n\
700 Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.\n");
701 }
703 /* The following return the library version as a short string in the
704 * format 1.0.0 through 99.99.99zz. To get the version of *.h files
705 * used with your application, print out PNG_LIBPNG_VER_STRING, which
706 * is defined in png.h.
707 * Note: now there is no difference between png_get_libpng_ver() and
708 * png_get_header_ver(). Due to the version_nn_nn_nn typedef guard,
709 * it is guaranteed that png.c uses the correct version of png.h.
710 */
711 png_charp PNGAPI
712 png_get_libpng_ver(png_structp png_ptr)
713 {
714 /* Version of *.c files used when building libpng */
715 png_ptr = png_ptr; /* silence compiler warning about unused png_ptr */
716 return ((png_charp) PNG_LIBPNG_VER_STRING);
717 }
719 png_charp PNGAPI
720 png_get_header_ver(png_structp png_ptr)
721 {
722 /* Version of *.h files used when building libpng */
723 png_ptr = png_ptr; /* silence compiler warning about unused png_ptr */
724 return ((png_charp) PNG_LIBPNG_VER_STRING);
725 }
727 png_charp PNGAPI
728 png_get_header_version(png_structp png_ptr)
729 {
730 /* Returns longer string containing both version and date */
731 png_ptr = png_ptr; /* silence compiler warning about unused png_ptr */
732 return ((png_charp) PNG_HEADER_VERSION_STRING
733 #ifndef PNG_READ_SUPPORTED
734 " (NO READ SUPPORT)"
735 #endif
736 "\n");
737 }
739 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
740 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
741 int PNGAPI
742 png_handle_as_unknown(png_structp png_ptr, png_bytep chunk_name)
743 {
744 /* check chunk_name and return "keep" value if it's on the list, else 0 */
745 int i;
746 png_bytep p;
747 if (png_ptr == NULL || chunk_name == NULL || png_ptr->num_chunk_list<=0)
748 return 0;
749 p = png_ptr->chunk_list + png_ptr->num_chunk_list*5 - 5;
750 for (i = png_ptr->num_chunk_list; i; i--, p -= 5)
751 if (!png_memcmp(chunk_name, p, 4))
752 return ((int)*(p + 4));
753 return 0;
754 }
755 #endif
757 /* This function, added to libpng-1.0.6g, is untested. */
758 int PNGAPI
759 png_reset_zstream(png_structp png_ptr)
760 {
761 if (png_ptr == NULL) return Z_STREAM_ERROR;
762 return (inflateReset(&png_ptr->zstream));
763 }
764 #endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */
766 /* This function was added to libpng-1.0.7 */
767 png_uint_32 PNGAPI
768 png_access_version_number(void)
769 {
770 /* Version of *.c files used when building libpng */
771 return((png_uint_32) PNG_LIBPNG_VER);
772 }
775 #if defined(PNG_READ_SUPPORTED) && defined(PNG_ASSEMBLER_CODE_SUPPORTED)
776 #if !defined(PNG_1_0_X)
777 /* this function was added to libpng 1.2.0 */
778 int PNGAPI
779 png_mmx_support(void)
780 {
781 /* obsolete, to be removed from libpng-1.4.0 */
782 return -1;
783 }
784 #endif /* PNG_1_0_X */
785 #endif /* PNG_READ_SUPPORTED && PNG_ASSEMBLER_CODE_SUPPORTED */
787 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
788 #ifdef PNG_SIZE_T
789 /* Added at libpng version 1.2.6 */
790 PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size));
791 png_size_t PNGAPI
792 png_convert_size(size_t size)
793 {
794 if (size > (png_size_t)-1)
795 PNG_ABORT(); /* We haven't got access to png_ptr, so no png_error() */
796 return ((png_size_t)size);
797 }
798 #endif /* PNG_SIZE_T */
799 #endif /* defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) */