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png.c@ 97

Last change on this file since 97 was 95, checked in by Rick van der Zwet, 15 years ago
Bad boy, improper move of directory
File size: 25.2 KB

Line
1
2	/* png.c - location for general purpose libpng functions
3	*
4	* Last changed in libpng 1.2.17 May 15, 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_18 Your_png_h_is_not_version_1_2_18;
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	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	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	const int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
60
61	/* offset to next interlace block */
62	const int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
63
64	/* start of interlace block in the y direction */
65	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	const int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
69
70	/* width of interlace block (used in assembler routines only) */
71	#ifdef PNG_HAVE_MMX_COMBINE_ROW
72	const int FARDATA png_pass_width[] = {8, 4, 4, 2, 2, 1, 1};
73	#endif
74
75	/* Height of interlace block. This is not currently used - if you need
76	* it, uncomment it here and in png.h
77	const int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
78	*/
79
80	/* Mask to determine which pixels are valid in a pass */
81	const int FARDATA png_pass_mask[] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff};
82
83	/* Mask to determine which pixels to overwrite while displaying */
84	const int FARDATA png_pass_dsp_mask[]
85	= {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
86
87	#endif /* PNG_READ_SUPPORTED */
88	#endif /* PNG_USE_GLOBAL_ARRAYS */
89
90	/* Tells libpng that we have already handled the first "num_bytes" bytes
91	* of the PNG file signature. If the PNG data is embedded into another
92	* stream we can set num_bytes = 8 so that libpng will not attempt to read
93	* or write any of the magic bytes before it starts on the IHDR.
94	*/
95
96	#ifdef PNG_READ_SUPPORTED
97	void PNGAPI
98	png_set_sig_bytes(png_structp png_ptr, int num_bytes)
99	{
100	if(png_ptr == NULL) return;
101	png_debug(1, "in png_set_sig_bytes\n");
102	if (num_bytes > 8)
103	png_error(png_ptr, "Too many bytes for PNG signature.");
104
105	png_ptr->sig_bytes = (png_byte)(num_bytes < 0 ? 0 : num_bytes);
106	}
107
108	/* Checks whether the supplied bytes match the PNG signature. We allow
109	* checking less than the full 8-byte signature so that those apps that
110	* already read the first few bytes of a file to determine the file type
111	* can simply check the remaining bytes for extra assurance. Returns
112	* an integer less than, equal to, or greater than zero if sig is found,
113	* respectively, to be less than, to match, or be greater than the correct
114	* PNG signature (this is the same behaviour as strcmp, memcmp, etc).
115	*/
116	int PNGAPI
117	png_sig_cmp(png_bytep sig, png_size_t start, png_size_t num_to_check)
118	{
119	png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
120	if (num_to_check > 8)
121	num_to_check = 8;
122	else if (num_to_check < 1)
123	return (-1);
124
125	if (start > 7)
126	return (-1);
127
128	if (start + num_to_check > 8)
129	num_to_check = 8 - start;
130
131	return ((int)(png_memcmp(&sig[start], &png_signature[start], num_to_check)));
132	}
133
134	#if defined(PNG_1_0_X) \|\| defined(PNG_1_2_X)
135	/* (Obsolete) function to check signature bytes. It does not allow one
136	* to check a partial signature. This function might be removed in the
137	* future - use png_sig_cmp(). Returns true (nonzero) if the file is a PNG.
138	*/
139	int PNGAPI
140	png_check_sig(png_bytep sig, int num)
141	{
142	return ((int)!png_sig_cmp(sig, (png_size_t)0, (png_size_t)num));
143	}
144	#endif
145	#endif /* PNG_READ_SUPPORTED */
146
147	#if defined(PNG_READ_SUPPORTED) \|\| defined(PNG_WRITE_SUPPORTED)
148	/* Function to allocate memory for zlib and clear it to 0. */
149	#ifdef PNG_1_0_X
150	voidpf PNGAPI
151	#else
152	voidpf /* private */
153	#endif
154	png_zalloc(voidpf png_ptr, uInt items, uInt size)
155	{
156	png_voidp ptr;
157	png_structp p=(png_structp)png_ptr;
158	png_uint_32 save_flags=p->flags;
159	png_uint_32 num_bytes;
160
161	if(png_ptr == NULL) return (NULL);
162	if (items > PNG_UINT_32_MAX/size)
163	{
164	png_warning (p, "Potential overflow in png_zalloc()");
165	return (NULL);
166	}
167	num_bytes = (png_uint_32)items * size;
168
169	p->flags\|=PNG_FLAG_MALLOC_NULL_MEM_OK;
170	ptr = (png_voidp)png_malloc((png_structp)png_ptr, num_bytes);
171	p->flags=save_flags;
172
173	#if defined(PNG_1_0_X) && !defined(PNG_NO_ZALLOC_ZERO)
174	if (ptr == NULL)
175	return ((voidpf)ptr);
176
177	if (num_bytes > (png_uint_32)0x8000L)
178	{
179	png_memset(ptr, 0, (png_size_t)0x8000L);
180	png_memset((png_bytep)ptr + (png_size_t)0x8000L, 0,
181	(png_size_t)(num_bytes - (png_uint_32)0x8000L));
182	}
183	else
184	{
185	png_memset(ptr, 0, (png_size_t)num_bytes);
186	}
187	#endif
188	return ((voidpf)ptr);
189	}
190
191	/* function to free memory for zlib */
192	#ifdef PNG_1_0_X
193	void PNGAPI
194	#else
195	void /* private */
196	#endif
197	png_zfree(voidpf png_ptr, voidpf ptr)
198	{
199	png_free((png_structp)png_ptr, (png_voidp)ptr);
200	}
201
202	/* Reset the CRC variable to 32 bits of 1's. Care must be taken
203	* in case CRC is > 32 bits to leave the top bits 0.
204	*/
205	void /* PRIVATE */
206	png_reset_crc(png_structp png_ptr)
207	{
208	png_ptr->crc = crc32(0, Z_NULL, 0);
209	}
210
211	/* Calculate the CRC over a section of data. We can only pass as
212	* much data to this routine as the largest single buffer size. We
213	* also check that this data will actually be used before going to the
214	* trouble of calculating it.
215	*/
216	void /* PRIVATE */
217	png_calculate_crc(png_structp png_ptr, png_bytep ptr, png_size_t length)
218	{
219	int need_crc = 1;
220
221	if (png_ptr->chunk_name[0] & 0x20) /* ancillary */
222	{
223	if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
224	(PNG_FLAG_CRC_ANCILLARY_USE \| PNG_FLAG_CRC_ANCILLARY_NOWARN))
225	need_crc = 0;
226	}
227	else /* critical */
228	{
229	if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE)
230	need_crc = 0;
231	}
232
233	if (need_crc)
234	png_ptr->crc = crc32(png_ptr->crc, ptr, (uInt)length);
235	}
236
237	/* Allocate the memory for an info_struct for the application. We don't
238	* really need the png_ptr, but it could potentially be useful in the
239	* future. This should be used in favour of malloc(png_sizeof(png_info))
240	* and png_info_init() so that applications that want to use a shared
241	* libpng don't have to be recompiled if png_info changes size.
242	*/
243	png_infop PNGAPI
244	png_create_info_struct(png_structp png_ptr)
245	{
246	png_infop info_ptr;
247
248	png_debug(1, "in png_create_info_struct\n");
249	if(png_ptr == NULL) return (NULL);
250	#ifdef PNG_USER_MEM_SUPPORTED
251	info_ptr = (png_infop)png_create_struct_2(PNG_STRUCT_INFO,
252	png_ptr->malloc_fn, png_ptr->mem_ptr);
253	#else
254	info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO);
255	#endif
256	if (info_ptr != NULL)
257	png_info_init_3(&info_ptr, png_sizeof(png_info));
258
259	return (info_ptr);
260	}
261
262	/* This function frees the memory associated with a single info struct.
263	* Normally, one would use either png_destroy_read_struct() or
264	* png_destroy_write_struct() to free an info struct, but this may be
265	* useful for some applications.
266	*/
267	void PNGAPI
268	png_destroy_info_struct(png_structp png_ptr, png_infopp info_ptr_ptr)
269	{
270	png_infop info_ptr = NULL;
271	if(png_ptr == NULL) return;
272
273	png_debug(1, "in png_destroy_info_struct\n");
274	if (info_ptr_ptr != NULL)
275	info_ptr = *info_ptr_ptr;
276
277	if (info_ptr != NULL)
278	{
279	png_info_destroy(png_ptr, info_ptr);
280
281	#ifdef PNG_USER_MEM_SUPPORTED
282	png_destroy_struct_2((png_voidp)info_ptr, png_ptr->free_fn,
283	png_ptr->mem_ptr);
284	#else
285	png_destroy_struct((png_voidp)info_ptr);
286	#endif
287	*info_ptr_ptr = NULL;
288	}
289	}
290
291	/* Initialize the info structure. This is now an internal function (0.89)
292	* and applications using it are urged to use png_create_info_struct()
293	* instead.
294	*/
295	#if defined(PNG_1_0_X) \|\| defined(PNG_1_2_X)
296	#undef png_info_init
297	void PNGAPI
298	png_info_init(png_infop info_ptr)
299	{
300	/* We only come here via pre-1.0.12-compiled applications */
301	png_info_init_3(&info_ptr, 0);
302	}
303	#endif
304
305	void PNGAPI
306	png_info_init_3(png_infopp ptr_ptr, png_size_t png_info_struct_size)
307	{
308	png_infop info_ptr = *ptr_ptr;
309
310	if(info_ptr == NULL) return;
311
312	png_debug(1, "in png_info_init_3\n");
313
314	if(png_sizeof(png_info) > png_info_struct_size)
315	{
316	png_destroy_struct(info_ptr);
317	info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO);
318	*ptr_ptr = info_ptr;
319	}
320
321	/* set everything to 0 */
322	png_memset(info_ptr, 0, png_sizeof (png_info));
323	}
324
325	#ifdef PNG_FREE_ME_SUPPORTED
326	void PNGAPI
327	png_data_freer(png_structp png_ptr, png_infop info_ptr,
328	int freer, png_uint_32 mask)
329	{
330	png_debug(1, "in png_data_freer\n");
331	if (png_ptr == NULL \|\| info_ptr == NULL)
332	return;
333	if(freer == PNG_DESTROY_WILL_FREE_DATA)
334	info_ptr->free_me \|= mask;
335	else if(freer == PNG_USER_WILL_FREE_DATA)
336	info_ptr->free_me &= ~mask;
337	else
338	png_warning(png_ptr,
339	"Unknown freer parameter in png_data_freer.");
340	}
341	#endif
342
343	void PNGAPI
344	png_free_data(png_structp png_ptr, png_infop info_ptr, png_uint_32 mask,
345	int num)
346	{
347	png_debug(1, "in png_free_data\n");
348	if (png_ptr == NULL \|\| info_ptr == NULL)
349	return;
350
351	#if defined(PNG_TEXT_SUPPORTED)
352	/* free text item num or (if num == -1) all text items */
353	#ifdef PNG_FREE_ME_SUPPORTED
354	if ((mask & PNG_FREE_TEXT) & info_ptr->free_me)
355	#else
356	if (mask & PNG_FREE_TEXT)
357	#endif
358	{
359	if (num != -1)
360	{
361	if (info_ptr->text && info_ptr->text[num].key)
362	{
363	png_free(png_ptr, info_ptr->text[num].key);
364	info_ptr->text[num].key = NULL;
365	}
366	}
367	else
368	{
369	int i;
370	for (i = 0; i < info_ptr->num_text; i++)
371	png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, i);
372	png_free(png_ptr, info_ptr->text);
373	info_ptr->text = NULL;
374	info_ptr->num_text=0;
375	}
376	}
377	#endif
378
379	#if defined(PNG_tRNS_SUPPORTED)
380	/* free any tRNS entry */
381	#ifdef PNG_FREE_ME_SUPPORTED
382	if ((mask & PNG_FREE_TRNS) & info_ptr->free_me)
383	#else
384	if ((mask & PNG_FREE_TRNS) && (png_ptr->flags & PNG_FLAG_FREE_TRNS))
385	#endif
386	{
387	png_free(png_ptr, info_ptr->trans);
388	info_ptr->valid &= ~PNG_INFO_tRNS;
389	#ifndef PNG_FREE_ME_SUPPORTED
390	png_ptr->flags &= ~PNG_FLAG_FREE_TRNS;
391	#endif
392	info_ptr->trans = NULL;
393	}
394	#endif
395
396	#if defined(PNG_sCAL_SUPPORTED)
397	/* free any sCAL entry */
398	#ifdef PNG_FREE_ME_SUPPORTED
399	if ((mask & PNG_FREE_SCAL) & info_ptr->free_me)
400	#else
401	if (mask & PNG_FREE_SCAL)
402	#endif
403	{
404	#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
405	png_free(png_ptr, info_ptr->scal_s_width);
406	png_free(png_ptr, info_ptr->scal_s_height);
407	info_ptr->scal_s_width = NULL;
408	info_ptr->scal_s_height = NULL;
409	#endif
410	info_ptr->valid &= ~PNG_INFO_sCAL;
411	}
412	#endif
413
414	#if defined(PNG_pCAL_SUPPORTED)
415	/* free any pCAL entry */
416	#ifdef PNG_FREE_ME_SUPPORTED
417	if ((mask & PNG_FREE_PCAL) & info_ptr->free_me)
418	#else
419	if (mask & PNG_FREE_PCAL)
420	#endif
421	{
422	png_free(png_ptr, info_ptr->pcal_purpose);
423	png_free(png_ptr, info_ptr->pcal_units);
424	info_ptr->pcal_purpose = NULL;
425	info_ptr->pcal_units = NULL;
426	if (info_ptr->pcal_params != NULL)
427	{
428	int i;
429	for (i = 0; i < (int)info_ptr->pcal_nparams; i++)
430	{
431	png_free(png_ptr, info_ptr->pcal_params[i]);
432	info_ptr->pcal_params[i]=NULL;
433	}
434	png_free(png_ptr, info_ptr->pcal_params);
435	info_ptr->pcal_params = NULL;
436	}
437	info_ptr->valid &= ~PNG_INFO_pCAL;
438	}
439	#endif
440
441	#if defined(PNG_iCCP_SUPPORTED)
442	/* free any iCCP entry */
443	#ifdef PNG_FREE_ME_SUPPORTED
444	if ((mask & PNG_FREE_ICCP) & info_ptr->free_me)
445	#else
446	if (mask & PNG_FREE_ICCP)
447	#endif
448	{
449	png_free(png_ptr, info_ptr->iccp_name);
450	png_free(png_ptr, info_ptr->iccp_profile);
451	info_ptr->iccp_name = NULL;
452	info_ptr->iccp_profile = NULL;
453	info_ptr->valid &= ~PNG_INFO_iCCP;
454	}
455	#endif
456
457	#if defined(PNG_sPLT_SUPPORTED)
458	/* free a given sPLT entry, or (if num == -1) all sPLT entries */
459	#ifdef PNG_FREE_ME_SUPPORTED
460	if ((mask & PNG_FREE_SPLT) & info_ptr->free_me)
461	#else
462	if (mask & PNG_FREE_SPLT)
463	#endif
464	{
465	if (num != -1)
466	{
467	if(info_ptr->splt_palettes)
468	{
469	png_free(png_ptr, info_ptr->splt_palettes[num].name);
470	png_free(png_ptr, info_ptr->splt_palettes[num].entries);
471	info_ptr->splt_palettes[num].name = NULL;
472	info_ptr->splt_palettes[num].entries = NULL;
473	}
474	}
475	else
476	{
477	if(info_ptr->splt_palettes_num)
478	{
479	int i;
480	for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
481	png_free_data(png_ptr, info_ptr, PNG_FREE_SPLT, i);
482
483	png_free(png_ptr, info_ptr->splt_palettes);
484	info_ptr->splt_palettes = NULL;
485	info_ptr->splt_palettes_num = 0;
486	}
487	info_ptr->valid &= ~PNG_INFO_sPLT;
488	}
489	}
490	#endif
491
492	#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
493	if(png_ptr->unknown_chunk.data)
494	{
495	png_free(png_ptr, png_ptr->unknown_chunk.data);
496	png_ptr->unknown_chunk.data = NULL;
497	}
498	#ifdef PNG_FREE_ME_SUPPORTED
499	if ((mask & PNG_FREE_UNKN) & info_ptr->free_me)
500	#else
501	if (mask & PNG_FREE_UNKN)
502	#endif
503	{
504	if (num != -1)
505	{
506	if(info_ptr->unknown_chunks)
507	{
508	png_free(png_ptr, info_ptr->unknown_chunks[num].data);
509	info_ptr->unknown_chunks[num].data = NULL;
510	}
511	}
512	else
513	{
514	int i;
515
516	if(info_ptr->unknown_chunks_num)
517	{
518	for (i = 0; i < (int)info_ptr->unknown_chunks_num; i++)
519	png_free_data(png_ptr, info_ptr, PNG_FREE_UNKN, i);
520
521	png_free(png_ptr, info_ptr->unknown_chunks);
522	info_ptr->unknown_chunks = NULL;
523	info_ptr->unknown_chunks_num = 0;
524	}
525	}
526	}
527	#endif
528
529	#if defined(PNG_hIST_SUPPORTED)
530	/* free any hIST entry */
531	#ifdef PNG_FREE_ME_SUPPORTED
532	if ((mask & PNG_FREE_HIST) & info_ptr->free_me)
533	#else
534	if ((mask & PNG_FREE_HIST) && (png_ptr->flags & PNG_FLAG_FREE_HIST))
535	#endif
536	{
537	png_free(png_ptr, info_ptr->hist);
538	info_ptr->hist = NULL;
539	info_ptr->valid &= ~PNG_INFO_hIST;
540	#ifndef PNG_FREE_ME_SUPPORTED
541	png_ptr->flags &= ~PNG_FLAG_FREE_HIST;
542	#endif
543	}
544	#endif
545
546	/* free any PLTE entry that was internally allocated */
547	#ifdef PNG_FREE_ME_SUPPORTED
548	if ((mask & PNG_FREE_PLTE) & info_ptr->free_me)
549	#else
550	if ((mask & PNG_FREE_PLTE) && (png_ptr->flags & PNG_FLAG_FREE_PLTE))
551	#endif
552	{
553	png_zfree(png_ptr, info_ptr->palette);
554	info_ptr->palette = NULL;
555	info_ptr->valid &= ~PNG_INFO_PLTE;
556	#ifndef PNG_FREE_ME_SUPPORTED
557	png_ptr->flags &= ~PNG_FLAG_FREE_PLTE;
558	#endif
559	info_ptr->num_palette = 0;
560	}
561
562	#if defined(PNG_INFO_IMAGE_SUPPORTED)
563	/* free any image bits attached to the info structure */
564	#ifdef PNG_FREE_ME_SUPPORTED
565	if ((mask & PNG_FREE_ROWS) & info_ptr->free_me)
566	#else
567	if (mask & PNG_FREE_ROWS)
568	#endif
569	{
570	if(info_ptr->row_pointers)
571	{
572	int row;
573	for (row = 0; row < (int)info_ptr->height; row++)
574	{
575	png_free(png_ptr, info_ptr->row_pointers[row]);
576	info_ptr->row_pointers[row]=NULL;
577	}
578	png_free(png_ptr, info_ptr->row_pointers);
579	info_ptr->row_pointers=NULL;
580	}
581	info_ptr->valid &= ~PNG_INFO_IDAT;
582	}
583	#endif
584
585	#ifdef PNG_FREE_ME_SUPPORTED
586	if(num == -1)
587	info_ptr->free_me &= ~mask;
588	else
589	info_ptr->free_me &= ~(mask & ~PNG_FREE_MUL);
590	#endif
591	}
592
593	/* This is an internal routine to free any memory that the info struct is
594	* pointing to before re-using it or freeing the struct itself. Recall
595	* that png_free() checks for NULL pointers for us.
596	*/
597	void /* PRIVATE */
598	png_info_destroy(png_structp png_ptr, png_infop info_ptr)
599	{
600	png_debug(1, "in png_info_destroy\n");
601
602	png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
603
604	#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
605	if (png_ptr->num_chunk_list)
606	{
607	png_free(png_ptr, png_ptr->chunk_list);
608	png_ptr->chunk_list=NULL;
609	png_ptr->num_chunk_list=0;
610	}
611	#endif
612
613	png_info_init_3(&info_ptr, png_sizeof(png_info));
614	}
615	#endif /* defined(PNG_READ_SUPPORTED) \|\| defined(PNG_WRITE_SUPPORTED) */
616
617	/* This function returns a pointer to the io_ptr associated with the user
618	* functions. The application should free any memory associated with this
619	* pointer before png_write_destroy() or png_read_destroy() are called.
620	*/
621	png_voidp PNGAPI
622	png_get_io_ptr(png_structp png_ptr)
623	{
624	if(png_ptr == NULL) return (NULL);
625	return (png_ptr->io_ptr);
626	}
627
628	#if defined(PNG_READ_SUPPORTED) \|\| defined(PNG_WRITE_SUPPORTED)
629	#if !defined(PNG_NO_STDIO)
630	/* Initialize the default input/output functions for the PNG file. If you
631	* use your own read or write routines, you can call either png_set_read_fn()
632	* or png_set_write_fn() instead of png_init_io(). If you have defined
633	* PNG_NO_STDIO, you must use a function of your own because "FILE *" isn't
634	* necessarily available.
635	*/
636	void PNGAPI
637	png_init_io(png_structp png_ptr, png_FILE_p fp)
638	{
639	png_debug(1, "in png_init_io\n");
640	if(png_ptr == NULL) return;
641	png_ptr->io_ptr = (png_voidp)fp;
642	}
643	#endif
644
645	#if defined(PNG_TIME_RFC1123_SUPPORTED)
646	/* Convert the supplied time into an RFC 1123 string suitable for use in
647	* a "Creation Time" or other text-based time string.
648	*/
649	png_charp PNGAPI
650	png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime)
651	{
652	static PNG_CONST char short_months[12][4] =
653	{"Jan", "Feb", "Mar", "Apr", "May", "Jun",
654	"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
655
656	if(png_ptr == NULL) return (NULL);
657	if (png_ptr->time_buffer == NULL)
658	{
659	png_ptr->time_buffer = (png_charp)png_malloc(png_ptr, (png_uint_32)(29*
660	png_sizeof(char)));
661	}
662
663	#if defined(_WIN32_WCE)
664	{
665	wchar_t time_buf[29];
666	wsprintf(time_buf, TEXT("%d %S %d %02d:%02d:%02d +0000"),
667	ptime->day % 32, short_months[(ptime->month - 1) % 12],
668	ptime->year, ptime->hour % 24, ptime->minute % 60,
669	ptime->second % 61);
670	WideCharToMultiByte(CP_ACP, 0, time_buf, -1, png_ptr->time_buffer, 29,
671	NULL, NULL);
672	}
673	#else
674	#ifdef USE_FAR_KEYWORD
675	{
676	char near_time_buf[29];
677	sprintf(near_time_buf, "%d %s %d %02d:%02d:%02d +0000",
678	ptime->day % 32, short_months[(ptime->month - 1) % 12],
679	ptime->year, ptime->hour % 24, ptime->minute % 60,
680	ptime->second % 61);
681	png_memcpy(png_ptr->time_buffer, near_time_buf,
682	29*png_sizeof(char));
683	}
684	#else
685	sprintf(png_ptr->time_buffer, "%d %s %d %02d:%02d:%02d +0000",
686	ptime->day % 32, short_months[(ptime->month - 1) % 12],
687	ptime->year, ptime->hour % 24, ptime->minute % 60,
688	ptime->second % 61);
689	#endif
690	#endif /* _WIN32_WCE */
691	return ((png_charp)png_ptr->time_buffer);
692	}
693	#endif /* PNG_TIME_RFC1123_SUPPORTED */
694
695	#if 0
696	/* Signature string for a PNG file. */
697	png_bytep PNGAPI
698	png_sig_bytes(void)
699	{
700	return ((png_bytep)"\211\120\116\107\015\012\032\012");
701	}
702	#endif
703	#endif /* defined(PNG_READ_SUPPORTED) \|\| defined(PNG_WRITE_SUPPORTED) */
704
705	png_charp PNGAPI
706	png_get_copyright(png_structp png_ptr)
707	{
708	if (&png_ptr != NULL) /* silence compiler warning about unused png_ptr */
709	return ((png_charp) "\n libpng version 1.2.18 - May 15, 2007\n\
710	Copyright (c) 1998-2007 Glenn Randers-Pehrson\n\
711	Copyright (c) 1996-1997 Andreas Dilger\n\
712	Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.\n");
713	return ((png_charp) "");
714	}
715
716	/* The following return the library version as a short string in the
717	* format 1.0.0 through 99.99.99zz. To get the version of *.h files
718	* used with your application, print out PNG_LIBPNG_VER_STRING, which
719	* is defined in png.h.
720	* Note: now there is no difference between png_get_libpng_ver() and
721	* png_get_header_ver(). Due to the version_nn_nn_nn typedef guard,
722	* it is guaranteed that png.c uses the correct version of png.h.
723	*/
724	png_charp PNGAPI
725	png_get_libpng_ver(png_structp png_ptr)
726	{
727	/* Version of .c files used when building libpng /
728	if (&png_ptr != NULL) /* silence compiler warning about unused png_ptr */
729	return ((png_charp) PNG_LIBPNG_VER_STRING);
730	return ((png_charp) "");
731	}
732
733	png_charp PNGAPI
734	png_get_header_ver(png_structp png_ptr)
735	{
736	/* Version of .h files used when building libpng /
737	if (&png_ptr != NULL) /* silence compiler warning about unused png_ptr */
738	return ((png_charp) PNG_LIBPNG_VER_STRING);
739	return ((png_charp) "");
740	}
741
742	png_charp PNGAPI
743	png_get_header_version(png_structp png_ptr)
744	{
745	/* Returns longer string containing both version and date */
746	if (&png_ptr != NULL) /* silence compiler warning about unused png_ptr */
747	return ((png_charp) PNG_HEADER_VERSION_STRING);
748	return ((png_charp) "");
749	}
750
751	#if defined(PNG_READ_SUPPORTED) \|\| defined(PNG_WRITE_SUPPORTED)
752	#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
753	int PNGAPI
754	png_handle_as_unknown(png_structp png_ptr, png_bytep chunk_name)
755	{
756	/* check chunk_name and return "keep" value if it's on the list, else 0 */
757	int i;
758	png_bytep p;
759	if((png_ptr == NULL && chunk_name == NULL) \|\| png_ptr->num_chunk_list<=0)
760	return 0;
761	p=png_ptr->chunk_list+png_ptr->num_chunk_list*5-5;
762	for (i = png_ptr->num_chunk_list; i; i--, p-=5)
763	if (!png_memcmp(chunk_name, p, 4))
764	return ((int)*(p+4));
765	return 0;
766	}
767	#endif
768
769	/* This function, added to libpng-1.0.6g, is untested. */
770	int PNGAPI
771	png_reset_zstream(png_structp png_ptr)
772	{
773	if (png_ptr == NULL) return Z_STREAM_ERROR;
774	return (inflateReset(&png_ptr->zstream));
775	}
776	#endif /* defined(PNG_READ_SUPPORTED) \|\| defined(PNG_WRITE_SUPPORTED) */
777
778	/* This function was added to libpng-1.0.7 */
779	png_uint_32 PNGAPI
780	png_access_version_number(void)
781	{
782	/* Version of .c files used when building libpng /
783	return((png_uint_32) PNG_LIBPNG_VER);
784	}
785
786
787	#if defined(PNG_READ_SUPPORTED) && defined(PNG_ASSEMBLER_CODE_SUPPORTED)
788	#if !defined(PNG_1_0_X)
789	#if defined(PNG_MMX_CODE_SUPPORTED)
790	/* this INTERNAL function was added to libpng 1.2.0 */
791	void /* PRIVATE */
792	png_init_mmx_flags (png_structp png_ptr)
793	{
794	if(png_ptr == NULL) return;
795	png_ptr->mmx_rowbytes_threshold = 0;
796	png_ptr->mmx_bitdepth_threshold = 0;
797
798	# if (defined(PNG_USE_PNGVCRD) \|\| defined(PNG_USE_PNGGCCRD))
799
800	png_ptr->asm_flags \|= PNG_ASM_FLAG_MMX_SUPPORT_COMPILED;
801
802	if (png_mmx_support() > 0) {
803	png_ptr->asm_flags \|= PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU
804	# ifdef PNG_HAVE_MMX_COMBINE_ROW
805	\| PNG_ASM_FLAG_MMX_READ_COMBINE_ROW
806	# endif
807	# ifdef PNG_HAVE_MMX_READ_INTERLACE
808	\| PNG_ASM_FLAG_MMX_READ_INTERLACE
809	# endif
810	# ifndef PNG_HAVE_MMX_READ_FILTER_ROW
811	;
812	# else
813	\| PNG_ASM_FLAG_MMX_READ_FILTER_SUB
814	\| PNG_ASM_FLAG_MMX_READ_FILTER_UP
815	\| PNG_ASM_FLAG_MMX_READ_FILTER_AVG
816	\| PNG_ASM_FLAG_MMX_READ_FILTER_PAETH ;
817
818	png_ptr->mmx_rowbytes_threshold = PNG_MMX_ROWBYTES_THRESHOLD_DEFAULT;
819	png_ptr->mmx_bitdepth_threshold = PNG_MMX_BITDEPTH_THRESHOLD_DEFAULT;
820	# endif
821	} else {
822	png_ptr->asm_flags &= ~( PNG_ASM_FLAG_MMX_SUPPORT_IN_CPU
823	\| PNG_MMX_READ_FLAGS
824	\| PNG_MMX_WRITE_FLAGS );
825	}
826
827	# else /* !(PNGVCRD \|\| PNGGCCRD) */
828
829	/* clear all MMX flags; no support is compiled in */
830	png_ptr->asm_flags &= ~( PNG_MMX_FLAGS );
831
832	# endif /* ?(PNGVCRD \|\| PNGGCCRD) */
833	}
834
835	#endif /* !(PNG_MMX_CODE_SUPPORTED) */
836
837	/* this function was added to libpng 1.2.0 */
838	#if !defined(PNG_USE_PNGGCCRD) && \
839	!(defined(PNG_MMX_CODE_SUPPORTED) && defined(PNG_USE_PNGVCRD))
840	int PNGAPI
841	png_mmx_support(void)
842	{
843	return -1;
844	}
845	#endif
846	#endif /* PNG_1_0_X && PNG_ASSEMBLER_CODE_SUPPORTED */
847	#endif /* PNG_READ_SUPPORTED */
848
849	#if defined(PNG_READ_SUPPORTED) \|\| defined(PNG_WRITE_SUPPORTED)
850	#ifdef PNG_SIZE_T
851	/* Added at libpng version 1.2.6 */
852	PNG_EXTERN png_size_t PNGAPI png_convert_size PNGARG((size_t size));
853	png_size_t PNGAPI
854	png_convert_size(size_t size)
855	{
856	if (size > (png_size_t)-1)
857	PNG_ABORT(); /* We haven't got access to png_ptr, so no png_error() */
858	return ((png_size_t)size);
859	}
860	#endif /* PNG_SIZE_T */
861	#endif /* defined(PNG_READ_SUPPORTED) \|\| defined(PNG_WRITE_SUPPORTED) */

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source: liacs/MIR2010/SourceCode/cximage/png/png.c@ 97

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