pngwrite.c@ 27325

最後變更在這個檔案從27325是 6393,由 vboxsync 提交於 17 年前
export libpng and zlib so Windows and OS/2 builds cleanly.
屬性 svn:eol-style 設為 `native`
檔案大小: 46.8 KB

行
1
2	/* pngwrite.c - general routines to write a PNG file
3	*
4	* libpng 1.2.8 - December 3, 2004
5	* For conditions of distribution and use, see copyright notice in png.h
6	* Copyright (c) 1998-2004 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	/* get internal access to png.h */
12	#define PNG_INTERNAL
13	#include "png.h"
14	#ifdef PNG_WRITE_SUPPORTED
15
16	/* Writes all the PNG information. This is the suggested way to use the
17	* library. If you have a new chunk to add, make a function to write it,
18	* and put it in the correct location here. If you want the chunk written
19	* after the image data, put it in png_write_end(). I strongly encourage
20	* you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing
21	* the chunk, as that will keep the code from breaking if you want to just
22	* write a plain PNG file. If you have long comments, I suggest writing
23	* them in png_write_end(), and compressing them.
24	*/
25	void PNGAPI
26	png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr)
27	{
28	png_debug(1, "in png_write_info_before_PLTE\n");
29	if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
30	{
31	png_write_sig(png_ptr); /* write PNG signature */
32	#if defined(PNG_MNG_FEATURES_SUPPORTED)
33	if((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE)&&(png_ptr->mng_features_permitted))
34	{
35	png_warning(png_ptr,"MNG features are not allowed in a PNG datastream\n");
36	png_ptr->mng_features_permitted=0;
37	}
38	#endif
39	/* write IHDR information. */
40	png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,
41	info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,
42	info_ptr->filter_type,
43	#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
44	info_ptr->interlace_type);
45	#else
46	0);
47	#endif
48	/* the rest of these check to see if the valid field has the appropriate
49	flag set, and if it does, writes the chunk. */
50	#if defined(PNG_WRITE_gAMA_SUPPORTED)
51	if (info_ptr->valid & PNG_INFO_gAMA)
52	{
53	# ifdef PNG_FLOATING_POINT_SUPPORTED
54	png_write_gAMA(png_ptr, info_ptr->gamma);
55	#else
56	#ifdef PNG_FIXED_POINT_SUPPORTED
57	png_write_gAMA_fixed(png_ptr, info_ptr->int_gamma);
58	# endif
59	#endif
60	}
61	#endif
62	#if defined(PNG_WRITE_sRGB_SUPPORTED)
63	if (info_ptr->valid & PNG_INFO_sRGB)
64	png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent);
65	#endif
66	#if defined(PNG_WRITE_iCCP_SUPPORTED)
67	if (info_ptr->valid & PNG_INFO_iCCP)
68	png_write_iCCP(png_ptr, info_ptr->iccp_name, PNG_COMPRESSION_TYPE_BASE,
69	info_ptr->iccp_profile, (int)info_ptr->iccp_proflen);
70	#endif
71	#if defined(PNG_WRITE_sBIT_SUPPORTED)
72	if (info_ptr->valid & PNG_INFO_sBIT)
73	png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
74	#endif
75	#if defined(PNG_WRITE_cHRM_SUPPORTED)
76	if (info_ptr->valid & PNG_INFO_cHRM)
77	{
78	#ifdef PNG_FLOATING_POINT_SUPPORTED
79	png_write_cHRM(png_ptr,
80	info_ptr->x_white, info_ptr->y_white,
81	info_ptr->x_red, info_ptr->y_red,
82	info_ptr->x_green, info_ptr->y_green,
83	info_ptr->x_blue, info_ptr->y_blue);
84	#else
85	# ifdef PNG_FIXED_POINT_SUPPORTED
86	png_write_cHRM_fixed(png_ptr,
87	info_ptr->int_x_white, info_ptr->int_y_white,
88	info_ptr->int_x_red, info_ptr->int_y_red,
89	info_ptr->int_x_green, info_ptr->int_y_green,
90	info_ptr->int_x_blue, info_ptr->int_y_blue);
91	# endif
92	#endif
93	}
94	#endif
95	#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
96	if (info_ptr->unknown_chunks_num)
97	{
98	png_unknown_chunk *up;
99
100	png_debug(5, "writing extra chunks\n");
101
102	for (up = info_ptr->unknown_chunks;
103	up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
104	up++)
105	{
106	int keep=png_handle_as_unknown(png_ptr, up->name);
107	if (keep != PNG_HANDLE_CHUNK_NEVER &&
108	up->location && !(up->location & PNG_HAVE_PLTE) &&
109	!(up->location & PNG_HAVE_IDAT) &&
110	((up->name[3] & 0x20) \|\| keep == PNG_HANDLE_CHUNK_ALWAYS \|\|
111	(png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
112	{
113	png_write_chunk(png_ptr, up->name, up->data, up->size);
114	}
115	}
116	}
117	#endif
118	png_ptr->mode \|= PNG_WROTE_INFO_BEFORE_PLTE;
119	}
120	}
121
122	void PNGAPI
123	png_write_info(png_structp png_ptr, png_infop info_ptr)
124	{
125	#if defined(PNG_WRITE_TEXT_SUPPORTED) \|\| defined(PNG_WRITE_sPLT_SUPPORTED)
126	int i;
127	#endif
128
129	png_debug(1, "in png_write_info\n");
130
131	png_write_info_before_PLTE(png_ptr, info_ptr);
132
133	if (info_ptr->valid & PNG_INFO_PLTE)
134	png_write_PLTE(png_ptr, info_ptr->palette,
135	(png_uint_32)info_ptr->num_palette);
136	else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
137	png_error(png_ptr, "Valid palette required for paletted images\n");
138
139	#if defined(PNG_WRITE_tRNS_SUPPORTED)
140	if (info_ptr->valid & PNG_INFO_tRNS)
141	{
142	#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
143	/* invert the alpha channel (in tRNS) */
144	if ((png_ptr->transformations & PNG_INVERT_ALPHA) &&
145	info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
146	{
147	int j;
148	for (j=0; j<(int)info_ptr->num_trans; j++)
149	info_ptr->trans[j] = (png_byte)(255 - info_ptr->trans[j]);
150	}
151	#endif
152	png_write_tRNS(png_ptr, info_ptr->trans, &(info_ptr->trans_values),
153	info_ptr->num_trans, info_ptr->color_type);
154	}
155	#endif
156	#if defined(PNG_WRITE_bKGD_SUPPORTED)
157	if (info_ptr->valid & PNG_INFO_bKGD)
158	png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
159	#endif
160	#if defined(PNG_WRITE_hIST_SUPPORTED)
161	if (info_ptr->valid & PNG_INFO_hIST)
162	png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);
163	#endif
164	#if defined(PNG_WRITE_oFFs_SUPPORTED)
165	if (info_ptr->valid & PNG_INFO_oFFs)
166	png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,
167	info_ptr->offset_unit_type);
168	#endif
169	#if defined(PNG_WRITE_pCAL_SUPPORTED)
170	if (info_ptr->valid & PNG_INFO_pCAL)
171	png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0,
172	info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams,
173	info_ptr->pcal_units, info_ptr->pcal_params);
174	#endif
175	#if defined(PNG_WRITE_sCAL_SUPPORTED)
176	if (info_ptr->valid & PNG_INFO_sCAL)
177	#if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
178	png_write_sCAL(png_ptr, (int)info_ptr->scal_unit,
179	info_ptr->scal_pixel_width, info_ptr->scal_pixel_height);
180	#else
181	#ifdef PNG_FIXED_POINT_SUPPORTED
182	png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,
183	info_ptr->scal_s_width, info_ptr->scal_s_height);
184	#else
185	png_warning(png_ptr,
186	"png_write_sCAL not supported; sCAL chunk not written.\n");
187	#endif
188	#endif
189	#endif
190	#if defined(PNG_WRITE_pHYs_SUPPORTED)
191	if (info_ptr->valid & PNG_INFO_pHYs)
192	png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,
193	info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type);
194	#endif
195	#if defined(PNG_WRITE_tIME_SUPPORTED)
196	if (info_ptr->valid & PNG_INFO_tIME)
197	{
198	png_write_tIME(png_ptr, &(info_ptr->mod_time));
199	png_ptr->mode \|= PNG_WROTE_tIME;
200	}
201	#endif
202	#if defined(PNG_WRITE_sPLT_SUPPORTED)
203	if (info_ptr->valid & PNG_INFO_sPLT)
204	for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
205	png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);
206	#endif
207	#if defined(PNG_WRITE_TEXT_SUPPORTED)
208	/* Check to see if we need to write text chunks */
209	for (i = 0; i < info_ptr->num_text; i++)
210	{
211	png_debug2(2, "Writing header text chunk %d, type %d\n", i,
212	info_ptr->text[i].compression);
213	/* an internationalized chunk? */
214	if (info_ptr->text[i].compression > 0)
215	{
216	#if defined(PNG_WRITE_iTXt_SUPPORTED)
217	/* write international chunk */
218	png_write_iTXt(png_ptr,
219	info_ptr->text[i].compression,
220	info_ptr->text[i].key,
221	info_ptr->text[i].lang,
222	info_ptr->text[i].lang_key,
223	info_ptr->text[i].text);
224	#else
225	png_warning(png_ptr, "Unable to write international text\n");
226	#endif
227	/* Mark this chunk as written */
228	info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
229	}
230	/* If we want a compressed text chunk */
231	else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
232	{
233	#if defined(PNG_WRITE_zTXt_SUPPORTED)
234	/* write compressed chunk */
235	png_write_zTXt(png_ptr, info_ptr->text[i].key,
236	info_ptr->text[i].text, 0,
237	info_ptr->text[i].compression);
238	#else
239	png_warning(png_ptr, "Unable to write compressed text\n");
240	#endif
241	/* Mark this chunk as written */
242	info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
243	}
244	else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
245	{
246	#if defined(PNG_WRITE_tEXt_SUPPORTED)
247	/* write uncompressed chunk */
248	png_write_tEXt(png_ptr, info_ptr->text[i].key,
249	info_ptr->text[i].text,
250	0);
251	#else
252	png_warning(png_ptr, "Unable to write uncompressed text\n");
253	#endif
254	/* Mark this chunk as written */
255	info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
256	}
257	}
258	#endif
259	#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
260	if (info_ptr->unknown_chunks_num)
261	{
262	png_unknown_chunk *up;
263
264	png_debug(5, "writing extra chunks\n");
265
266	for (up = info_ptr->unknown_chunks;
267	up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
268	up++)
269	{
270	int keep=png_handle_as_unknown(png_ptr, up->name);
271	if (keep != PNG_HANDLE_CHUNK_NEVER &&
272	up->location && (up->location & PNG_HAVE_PLTE) &&
273	!(up->location & PNG_HAVE_IDAT) &&
274	((up->name[3] & 0x20) \|\| keep == PNG_HANDLE_CHUNK_ALWAYS \|\|
275	(png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
276	{
277	png_write_chunk(png_ptr, up->name, up->data, up->size);
278	}
279	}
280	}
281	#endif
282	}
283
284	/* Writes the end of the PNG file. If you don't want to write comments or
285	* time information, you can pass NULL for info. If you already wrote these
286	* in png_write_info(), do not write them again here. If you have long
287	* comments, I suggest writing them here, and compressing them.
288	*/
289	void PNGAPI
290	png_write_end(png_structp png_ptr, png_infop info_ptr)
291	{
292	png_debug(1, "in png_write_end\n");
293	if (!(png_ptr->mode & PNG_HAVE_IDAT))
294	png_error(png_ptr, "No IDATs written into file");
295
296	/* see if user wants us to write information chunks */
297	if (info_ptr != NULL)
298	{
299	#if defined(PNG_WRITE_TEXT_SUPPORTED)
300	int i; /* local index variable */
301	#endif
302	#if defined(PNG_WRITE_tIME_SUPPORTED)
303	/* check to see if user has supplied a time chunk */
304	if ((info_ptr->valid & PNG_INFO_tIME) &&
305	!(png_ptr->mode & PNG_WROTE_tIME))
306	png_write_tIME(png_ptr, &(info_ptr->mod_time));
307	#endif
308	#if defined(PNG_WRITE_TEXT_SUPPORTED)
309	/* loop through comment chunks */
310	for (i = 0; i < info_ptr->num_text; i++)
311	{
312	png_debug2(2, "Writing trailer text chunk %d, type %d\n", i,
313	info_ptr->text[i].compression);
314	/* an internationalized chunk? */
315	if (info_ptr->text[i].compression > 0)
316	{
317	#if defined(PNG_WRITE_iTXt_SUPPORTED)
318	/* write international chunk */
319	png_write_iTXt(png_ptr,
320	info_ptr->text[i].compression,
321	info_ptr->text[i].key,
322	info_ptr->text[i].lang,
323	info_ptr->text[i].lang_key,
324	info_ptr->text[i].text);
325	#else
326	png_warning(png_ptr, "Unable to write international text\n");
327	#endif
328	/* Mark this chunk as written */
329	info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
330	}
331	else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
332	{
333	#if defined(PNG_WRITE_zTXt_SUPPORTED)
334	/* write compressed chunk */
335	png_write_zTXt(png_ptr, info_ptr->text[i].key,
336	info_ptr->text[i].text, 0,
337	info_ptr->text[i].compression);
338	#else
339	png_warning(png_ptr, "Unable to write compressed text\n");
340	#endif
341	/* Mark this chunk as written */
342	info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
343	}
344	else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
345	{
346	#if defined(PNG_WRITE_tEXt_SUPPORTED)
347	/* write uncompressed chunk */
348	png_write_tEXt(png_ptr, info_ptr->text[i].key,
349	info_ptr->text[i].text, 0);
350	#else
351	png_warning(png_ptr, "Unable to write uncompressed text\n");
352	#endif
353
354	/* Mark this chunk as written */
355	info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
356	}
357	}
358	#endif
359	#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
360	if (info_ptr->unknown_chunks_num)
361	{
362	png_unknown_chunk *up;
363
364	png_debug(5, "writing extra chunks\n");
365
366	for (up = info_ptr->unknown_chunks;
367	up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
368	up++)
369	{
370	int keep=png_handle_as_unknown(png_ptr, up->name);
371	if (keep != PNG_HANDLE_CHUNK_NEVER &&
372	up->location && (up->location & PNG_AFTER_IDAT) &&
373	((up->name[3] & 0x20) \|\| keep == PNG_HANDLE_CHUNK_ALWAYS \|\|
374	(png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
375	{
376	png_write_chunk(png_ptr, up->name, up->data, up->size);
377	}
378	}
379	}
380	#endif
381	}
382
383	png_ptr->mode \|= PNG_AFTER_IDAT;
384
385	/* write end of PNG file */
386	png_write_IEND(png_ptr);
387	#if 0
388	/* This flush, added in libpng-1.0.8, causes some applications to crash
389	because they do not set png_ptr->output_flush_fn */
390	png_flush(png_ptr);
391	#endif
392	}
393
394	#if defined(PNG_WRITE_tIME_SUPPORTED)
395	#if !defined(_WIN32_WCE)
396	/* "time.h" functions are not supported on WindowsCE */
397	void PNGAPI
398	png_convert_from_struct_tm(png_timep ptime, struct tm FAR * ttime)
399	{
400	png_debug(1, "in png_convert_from_struct_tm\n");
401	ptime->year = (png_uint_16)(1900 + ttime->tm_year);
402	ptime->month = (png_byte)(ttime->tm_mon + 1);
403	ptime->day = (png_byte)ttime->tm_mday;
404	ptime->hour = (png_byte)ttime->tm_hour;
405	ptime->minute = (png_byte)ttime->tm_min;
406	ptime->second = (png_byte)ttime->tm_sec;
407	}
408
409	void PNGAPI
410	png_convert_from_time_t(png_timep ptime, time_t ttime)
411	{
412	struct tm *tbuf;
413
414	png_debug(1, "in png_convert_from_time_t\n");
415	tbuf = gmtime(&ttime);
416	png_convert_from_struct_tm(ptime, tbuf);
417	}
418	#endif
419	#endif
420
421	/* Initialize png_ptr structure, and allocate any memory needed */
422	png_structp PNGAPI
423	png_create_write_struct(png_const_charp user_png_ver, png_voidp error_ptr,
424	png_error_ptr error_fn, png_error_ptr warn_fn)
425	{
426	#ifdef PNG_USER_MEM_SUPPORTED
427	return (png_create_write_struct_2(user_png_ver, error_ptr, error_fn,
428	warn_fn, png_voidp_NULL, png_malloc_ptr_NULL, png_free_ptr_NULL));
429	}
430
431	/* Alternate initialize png_ptr structure, and allocate any memory needed */
432	png_structp PNGAPI
433	png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
434	png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
435	png_malloc_ptr malloc_fn, png_free_ptr free_fn)
436	{
437	#endif /* PNG_USER_MEM_SUPPORTED */
438	png_structp png_ptr;
439	#ifdef PNG_SETJMP_SUPPORTED
440	#ifdef USE_FAR_KEYWORD
441	jmp_buf jmpbuf;
442	#endif
443	#endif
444	int i;
445	png_debug(1, "in png_create_write_struct\n");
446	#ifdef PNG_USER_MEM_SUPPORTED
447	png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
448	(png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);
449	#else
450	png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
451	#endif /* PNG_USER_MEM_SUPPORTED */
452	if (png_ptr == NULL)
453	return (NULL);
454
455	#if !defined(PNG_1_0_X)
456	#ifdef PNG_ASSEMBLER_CODE_SUPPORTED
457	png_init_mmx_flags(png_ptr); /* 1.2.0 addition */
458	#endif
459	#endif /* PNG_1_0_X */
460
461	/* added at libpng-1.2.6 */
462	#ifdef PNG_SET_USER_LIMITS_SUPPORTED
463	png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
464	png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
465	#endif
466
467	#ifdef PNG_SETJMP_SUPPORTED
468	#ifdef USE_FAR_KEYWORD
469	if (setjmp(jmpbuf))
470	#else
471	if (setjmp(png_ptr->jmpbuf))
472	#endif
473	{
474	png_free(png_ptr, png_ptr->zbuf);
475	png_ptr->zbuf=NULL;
476	png_destroy_struct(png_ptr);
477	return (NULL);
478	}
479	#ifdef USE_FAR_KEYWORD
480	png_memcpy(png_ptr->jmpbuf,jmpbuf,png_sizeof(jmp_buf));
481	#endif
482	#endif
483
484	#ifdef PNG_USER_MEM_SUPPORTED
485	png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
486	#endif /* PNG_USER_MEM_SUPPORTED */
487	png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
488
489	i=0;
490	do
491	{
492	if(user_png_ver[i] != png_libpng_ver[i])
493	png_ptr->flags \|= PNG_FLAG_LIBRARY_MISMATCH;
494	} while (png_libpng_ver[i++]);
495
496	if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
497	{
498	/* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
499	* we must recompile any applications that use any older library version.
500	* For versions after libpng 1.0, we will be compatible, so we need
501	* only check the first digit.
502	*/
503	if (user_png_ver == NULL \|\| user_png_ver[0] != png_libpng_ver[0] \|\|
504	(user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) \|\|
505	(user_png_ver[0] == '0' && user_png_ver[2] < '9'))
506	{
507	#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
508	char msg[80];
509	if (user_png_ver)
510	{
511	sprintf(msg, "Application was compiled with png.h from libpng-%.20s",
512	user_png_ver);
513	png_warning(png_ptr, msg);
514	}
515	sprintf(msg, "Application is running with png.c from libpng-%.20s",
516	png_libpng_ver);
517	png_warning(png_ptr, msg);
518	#endif
519	#ifdef PNG_ERROR_NUMBERS_SUPPORTED
520	png_ptr->flags=0;
521	#endif
522	png_error(png_ptr,
523	"Incompatible libpng version in application and library");
524	}
525	}
526
527	/* initialize zbuf - compression buffer */
528	png_ptr->zbuf_size = PNG_ZBUF_SIZE;
529	png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
530	(png_uint_32)png_ptr->zbuf_size);
531
532	png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
533	png_flush_ptr_NULL);
534
535	#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
536	png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
537	1, png_doublep_NULL, png_doublep_NULL);
538	#endif
539
540	#ifdef PNG_SETJMP_SUPPORTED
541	/* Applications that neglect to set up their own setjmp() and then encounter
542	a png_error() will longjmp here. Since the jmpbuf is then meaningless we
543	abort instead of returning. */
544	#ifdef USE_FAR_KEYWORD
545	if (setjmp(jmpbuf))
546	PNG_ABORT();
547	png_memcpy(png_ptr->jmpbuf,jmpbuf,png_sizeof(jmp_buf));
548	#else
549	if (setjmp(png_ptr->jmpbuf))
550	PNG_ABORT();
551	#endif
552	#endif
553	return (png_ptr);
554	}
555
556	/* Initialize png_ptr structure, and allocate any memory needed */
557	#undef png_write_init
558	void PNGAPI
559	png_write_init(png_structp png_ptr)
560	{
561	/* We only come here via pre-1.0.7-compiled applications */
562	png_write_init_2(png_ptr, "1.0.6 or earlier", 0, 0);
563	}
564
565	void PNGAPI
566	png_write_init_2(png_structp png_ptr, png_const_charp user_png_ver,
567	png_size_t png_struct_size, png_size_t png_info_size)
568	{
569	/* We only come here via pre-1.0.12-compiled applications */
570	#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
571	if(png_sizeof(png_struct) > png_struct_size \|\|
572	png_sizeof(png_info) > png_info_size)
573	{
574	char msg[80];
575	png_ptr->warning_fn=NULL;
576	if (user_png_ver)
577	{
578	sprintf(msg, "Application was compiled with png.h from libpng-%.20s",
579	user_png_ver);
580	png_warning(png_ptr, msg);
581	}
582	sprintf(msg, "Application is running with png.c from libpng-%.20s",
583	png_libpng_ver);
584	png_warning(png_ptr, msg);
585	}
586	#endif
587	if(png_sizeof(png_struct) > png_struct_size)
588	{
589	png_ptr->error_fn=NULL;
590	#ifdef PNG_ERROR_NUMBERS_SUPPORTED
591	png_ptr->flags=0;
592	#endif
593	png_error(png_ptr,
594	"The png struct allocated by the application for writing is too small.");
595	}
596	if(png_sizeof(png_info) > png_info_size)
597	{
598	png_ptr->error_fn=NULL;
599	#ifdef PNG_ERROR_NUMBERS_SUPPORTED
600	png_ptr->flags=0;
601	#endif
602	png_error(png_ptr,
603	"The info struct allocated by the application for writing is too small.");
604	}
605	png_write_init_3(&png_ptr, user_png_ver, png_struct_size);
606	}
607
608
609	void PNGAPI
610	png_write_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
611	png_size_t png_struct_size)
612	{
613	png_structp png_ptr=*ptr_ptr;
614	#ifdef PNG_SETJMP_SUPPORTED
615	jmp_buf tmp_jmp; /* to save current jump buffer */
616	#endif
617	int i = 0;
618	do
619	{
620	if (user_png_ver[i] != png_libpng_ver[i])
621	{
622	#ifdef PNG_LEGACY_SUPPORTED
623	png_ptr->flags \|= PNG_FLAG_LIBRARY_MISMATCH;
624	#else
625	png_ptr->warning_fn=NULL;
626	png_warning(png_ptr,
627	"Application uses deprecated png_write_init() and should be recompiled.");
628	break;
629	#endif
630	}
631	} while (png_libpng_ver[i++]);
632
633	png_debug(1, "in png_write_init_3\n");
634
635	#ifdef PNG_SETJMP_SUPPORTED
636	/* save jump buffer and error functions */
637	png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof (jmp_buf));
638	#endif
639
640	if (png_sizeof(png_struct) > png_struct_size)
641	{
642	png_destroy_struct(png_ptr);
643	png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
644	*ptr_ptr = png_ptr;
645	}
646
647	/* reset all variables to 0 */
648	png_memset(png_ptr, 0, png_sizeof (png_struct));
649
650	/* added at libpng-1.2.6 */
651	#ifdef PNG_SET_USER_LIMITS_SUPPORTED
652	png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
653	png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
654	#endif
655
656	#if !defined(PNG_1_0_X)
657	#ifdef PNG_ASSEMBLER_CODE_SUPPORTED
658	png_init_mmx_flags(png_ptr); /* 1.2.0 addition */
659	#endif
660	#endif /* PNG_1_0_X */
661
662	#ifdef PNG_SETJMP_SUPPORTED
663	/* restore jump buffer */
664	png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof (jmp_buf));
665	#endif
666
667	png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
668	png_flush_ptr_NULL);
669
670	/* initialize zbuf - compression buffer */
671	png_ptr->zbuf_size = PNG_ZBUF_SIZE;
672	png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
673	(png_uint_32)png_ptr->zbuf_size);
674
675	#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
676	png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
677	1, png_doublep_NULL, png_doublep_NULL);
678	#endif
679	}
680
681	/* Write a few rows of image data. If the image is interlaced,
682	* either you will have to write the 7 sub images, or, if you
683	* have called png_set_interlace_handling(), you will have to
684	* "write" the image seven times.
685	*/
686	void PNGAPI
687	png_write_rows(png_structp png_ptr, png_bytepp row,
688	png_uint_32 num_rows)
689	{
690	png_uint_32 i; /* row counter */
691	png_bytepp rp; /* row pointer */
692
693	png_debug(1, "in png_write_rows\n");
694	/* loop through the rows */
695	for (i = 0, rp = row; i < num_rows; i++, rp++)
696	{
697	png_write_row(png_ptr, *rp);
698	}
699	}
700
701	/* Write the image. You only need to call this function once, even
702	* if you are writing an interlaced image.
703	*/
704	void PNGAPI
705	png_write_image(png_structp png_ptr, png_bytepp image)
706	{
707	png_uint_32 i; /* row index */
708	int pass, num_pass; /* pass variables */
709	png_bytepp rp; /* points to current row */
710
711	png_debug(1, "in png_write_image\n");
712	#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
713	/* intialize interlace handling. If image is not interlaced,
714	this will set pass to 1 */
715	num_pass = png_set_interlace_handling(png_ptr);
716	#else
717	num_pass = 1;
718	#endif
719	/* loop through passes */
720	for (pass = 0; pass < num_pass; pass++)
721	{
722	/* loop through image */
723	for (i = 0, rp = image; i < png_ptr->height; i++, rp++)
724	{
725	png_write_row(png_ptr, *rp);
726	}
727	}
728	}
729
730	/* called by user to write a row of image data */
731	void PNGAPI
732	png_write_row(png_structp png_ptr, png_bytep row)
733	{
734	png_debug2(1, "in png_write_row (row %ld, pass %d)\n",
735	png_ptr->row_number, png_ptr->pass);
736	/* initialize transformations and other stuff if first time */
737	if (png_ptr->row_number == 0 && png_ptr->pass == 0)
738	{
739	/* make sure we wrote the header info */
740	if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
741	png_error(png_ptr,
742	"png_write_info was never called before png_write_row.");
743
744	/* check for transforms that have been set but were defined out */
745	#if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)
746	if (png_ptr->transformations & PNG_INVERT_MONO)
747	png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined.");
748	#endif
749	#if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED)
750	if (png_ptr->transformations & PNG_FILLER)
751	png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined.");
752	#endif
753	#if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && defined(PNG_READ_PACKSWAP_SUPPORTED)
754	if (png_ptr->transformations & PNG_PACKSWAP)
755	png_warning(png_ptr, "PNG_WRITE_PACKSWAP_SUPPORTED is not defined.");
756	#endif
757	#if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED)
758	if (png_ptr->transformations & PNG_PACK)
759	png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined.");
760	#endif
761	#if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED)
762	if (png_ptr->transformations & PNG_SHIFT)
763	png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined.");
764	#endif
765	#if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED)
766	if (png_ptr->transformations & PNG_BGR)
767	png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined.");
768	#endif
769	#if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED)
770	if (png_ptr->transformations & PNG_SWAP_BYTES)
771	png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined.");
772	#endif
773
774	png_write_start_row(png_ptr);
775	}
776
777	#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
778	/* if interlaced and not interested in row, return */
779	if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
780	{
781	switch (png_ptr->pass)
782	{
783	case 0:
784	if (png_ptr->row_number & 0x07)
785	{
786	png_write_finish_row(png_ptr);
787	return;
788	}
789	break;
790	case 1:
791	if ((png_ptr->row_number & 0x07) \|\| png_ptr->width < 5)
792	{
793	png_write_finish_row(png_ptr);
794	return;
795	}
796	break;
797	case 2:
798	if ((png_ptr->row_number & 0x07) != 4)
799	{
800	png_write_finish_row(png_ptr);
801	return;
802	}
803	break;
804	case 3:
805	if ((png_ptr->row_number & 0x03) \|\| png_ptr->width < 3)
806	{
807	png_write_finish_row(png_ptr);
808	return;
809	}
810	break;
811	case 4:
812	if ((png_ptr->row_number & 0x03) != 2)
813	{
814	png_write_finish_row(png_ptr);
815	return;
816	}
817	break;
818	case 5:
819	if ((png_ptr->row_number & 0x01) \|\| png_ptr->width < 2)
820	{
821	png_write_finish_row(png_ptr);
822	return;
823	}
824	break;
825	case 6:
826	if (!(png_ptr->row_number & 0x01))
827	{
828	png_write_finish_row(png_ptr);
829	return;
830	}
831	break;
832	}
833	}
834	#endif
835
836	/* set up row info for transformations */
837	png_ptr->row_info.color_type = png_ptr->color_type;
838	png_ptr->row_info.width = png_ptr->usr_width;
839	png_ptr->row_info.channels = png_ptr->usr_channels;
840	png_ptr->row_info.bit_depth = png_ptr->usr_bit_depth;
841	png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth *
842	png_ptr->row_info.channels);
843
844	png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
845	png_ptr->row_info.width);
846
847	png_debug1(3, "row_info->color_type = %d\n", png_ptr->row_info.color_type);
848	png_debug1(3, "row_info->width = %lu\n", png_ptr->row_info.width);
849	png_debug1(3, "row_info->channels = %d\n", png_ptr->row_info.channels);
850	png_debug1(3, "row_info->bit_depth = %d\n", png_ptr->row_info.bit_depth);
851	png_debug1(3, "row_info->pixel_depth = %d\n", png_ptr->row_info.pixel_depth);
852	png_debug1(3, "row_info->rowbytes = %lu\n", png_ptr->row_info.rowbytes);
853
854	/* Copy user's row into buffer, leaving room for filter byte. */
855	png_memcpy_check(png_ptr, png_ptr->row_buf + 1, row,
856	png_ptr->row_info.rowbytes);
857
858	#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
859	/* handle interlacing */
860	if (png_ptr->interlaced && png_ptr->pass < 6 &&
861	(png_ptr->transformations & PNG_INTERLACE))
862	{
863	png_do_write_interlace(&(png_ptr->row_info),
864	png_ptr->row_buf + 1, png_ptr->pass);
865	/* this should always get caught above, but still ... */
866	if (!(png_ptr->row_info.width))
867	{
868	png_write_finish_row(png_ptr);
869	return;
870	}
871	}
872	#endif
873
874	/* handle other transformations */
875	if (png_ptr->transformations)
876	png_do_write_transformations(png_ptr);
877
878	#if defined(PNG_MNG_FEATURES_SUPPORTED)
879	/* Write filter_method 64 (intrapixel differencing) only if
880	* 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
881	* 2. Libpng did not write a PNG signature (this filter_method is only
882	* used in PNG datastreams that are embedded in MNG datastreams) and
883	* 3. The application called png_permit_mng_features with a mask that
884	* included PNG_FLAG_MNG_FILTER_64 and
885	* 4. The filter_method is 64 and
886	* 5. The color_type is RGB or RGBA
887	*/
888	if((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
889	(png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
890	{
891	/* Intrapixel differencing */
892	png_do_write_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
893	}
894	#endif
895
896	/* Find a filter if necessary, filter the row and write it out. */
897	png_write_find_filter(png_ptr, &(png_ptr->row_info));
898
899	if (png_ptr->write_row_fn != NULL)
900	(*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
901	}
902
903	#if defined(PNG_WRITE_FLUSH_SUPPORTED)
904	/* Set the automatic flush interval or 0 to turn flushing off */
905	void PNGAPI
906	png_set_flush(png_structp png_ptr, int nrows)
907	{
908	png_debug(1, "in png_set_flush\n");
909	png_ptr->flush_dist = (nrows < 0 ? 0 : nrows);
910	}
911
912	/* flush the current output buffers now */
913	void PNGAPI
914	png_write_flush(png_structp png_ptr)
915	{
916	int wrote_IDAT;
917
918	png_debug(1, "in png_write_flush\n");
919	/* We have already written out all of the data */
920	if (png_ptr->row_number >= png_ptr->num_rows)
921	return;
922
923	do
924	{
925	int ret;
926
927	/* compress the data */
928	ret = deflate(&png_ptr->zstream, Z_SYNC_FLUSH);
929	wrote_IDAT = 0;
930
931	/* check for compression errors */
932	if (ret != Z_OK)
933	{
934	if (png_ptr->zstream.msg != NULL)
935	png_error(png_ptr, png_ptr->zstream.msg);
936	else
937	png_error(png_ptr, "zlib error");
938	}
939
940	if (!(png_ptr->zstream.avail_out))
941	{
942	/* write the IDAT and reset the zlib output buffer */
943	png_write_IDAT(png_ptr, png_ptr->zbuf,
944	png_ptr->zbuf_size);
945	png_ptr->zstream.next_out = png_ptr->zbuf;
946	png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
947	wrote_IDAT = 1;
948	}
949	} while(wrote_IDAT == 1);
950
951	/* If there is any data left to be output, write it into a new IDAT */
952	if (png_ptr->zbuf_size != png_ptr->zstream.avail_out)
953	{
954	/* write the IDAT and reset the zlib output buffer */
955	png_write_IDAT(png_ptr, png_ptr->zbuf,
956	png_ptr->zbuf_size - png_ptr->zstream.avail_out);
957	png_ptr->zstream.next_out = png_ptr->zbuf;
958	png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
959	}
960	png_ptr->flush_rows = 0;
961	png_flush(png_ptr);
962	}
963	#endif /* PNG_WRITE_FLUSH_SUPPORTED */
964
965	/* free all memory used by the write */
966	void PNGAPI
967	png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
968	{
969	png_structp png_ptr = NULL;
970	png_infop info_ptr = NULL;
971	#ifdef PNG_USER_MEM_SUPPORTED
972	png_free_ptr free_fn = NULL;
973	png_voidp mem_ptr = NULL;
974	#endif
975
976	png_debug(1, "in png_destroy_write_struct\n");
977	if (png_ptr_ptr != NULL)
978	{
979	png_ptr = *png_ptr_ptr;
980	#ifdef PNG_USER_MEM_SUPPORTED
981	free_fn = png_ptr->free_fn;
982	mem_ptr = png_ptr->mem_ptr;
983	#endif
984	}
985
986	if (info_ptr_ptr != NULL)
987	info_ptr = *info_ptr_ptr;
988
989	if (info_ptr != NULL)
990	{
991	png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
992
993	#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
994	if (png_ptr->num_chunk_list)
995	{
996	png_free(png_ptr, png_ptr->chunk_list);
997	png_ptr->chunk_list=NULL;
998	png_ptr->num_chunk_list=0;
999	}
1000	#endif
1001
1002	#ifdef PNG_USER_MEM_SUPPORTED
1003	png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
1004	(png_voidp)mem_ptr);
1005	#else
1006	png_destroy_struct((png_voidp)info_ptr);
1007	#endif
1008	*info_ptr_ptr = NULL;
1009	}
1010
1011	if (png_ptr != NULL)
1012	{
1013	png_write_destroy(png_ptr);
1014	#ifdef PNG_USER_MEM_SUPPORTED
1015	png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
1016	(png_voidp)mem_ptr);
1017	#else
1018	png_destroy_struct((png_voidp)png_ptr);
1019	#endif
1020	*png_ptr_ptr = NULL;
1021	}
1022	}
1023
1024
1025	/* Free any memory used in png_ptr struct (old method) */
1026	void /* PRIVATE */
1027	png_write_destroy(png_structp png_ptr)
1028	{
1029	#ifdef PNG_SETJMP_SUPPORTED
1030	jmp_buf tmp_jmp; /* save jump buffer */
1031	#endif
1032	png_error_ptr error_fn;
1033	png_error_ptr warning_fn;
1034	png_voidp error_ptr;
1035	#ifdef PNG_USER_MEM_SUPPORTED
1036	png_free_ptr free_fn;
1037	#endif
1038
1039	png_debug(1, "in png_write_destroy\n");
1040	/* free any memory zlib uses */
1041	deflateEnd(&png_ptr->zstream);
1042
1043	/* free our memory. png_free checks NULL for us. */
1044	png_free(png_ptr, png_ptr->zbuf);
1045	png_free(png_ptr, png_ptr->row_buf);
1046	png_free(png_ptr, png_ptr->prev_row);
1047	png_free(png_ptr, png_ptr->sub_row);
1048	png_free(png_ptr, png_ptr->up_row);
1049	png_free(png_ptr, png_ptr->avg_row);
1050	png_free(png_ptr, png_ptr->paeth_row);
1051
1052	#if defined(PNG_TIME_RFC1123_SUPPORTED)
1053	png_free(png_ptr, png_ptr->time_buffer);
1054	#endif
1055
1056	#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
1057	png_free(png_ptr, png_ptr->prev_filters);
1058	png_free(png_ptr, png_ptr->filter_weights);
1059	png_free(png_ptr, png_ptr->inv_filter_weights);
1060	png_free(png_ptr, png_ptr->filter_costs);
1061	png_free(png_ptr, png_ptr->inv_filter_costs);
1062	#endif
1063
1064	#ifdef PNG_SETJMP_SUPPORTED
1065	/* reset structure */
1066	png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof (jmp_buf));
1067	#endif
1068
1069	error_fn = png_ptr->error_fn;
1070	warning_fn = png_ptr->warning_fn;
1071	error_ptr = png_ptr->error_ptr;
1072	#ifdef PNG_USER_MEM_SUPPORTED
1073	free_fn = png_ptr->free_fn;
1074	#endif
1075
1076	png_memset(png_ptr, 0, png_sizeof (png_struct));
1077
1078	png_ptr->error_fn = error_fn;
1079	png_ptr->warning_fn = warning_fn;
1080	png_ptr->error_ptr = error_ptr;
1081	#ifdef PNG_USER_MEM_SUPPORTED
1082	png_ptr->free_fn = free_fn;
1083	#endif
1084
1085	#ifdef PNG_SETJMP_SUPPORTED
1086	png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof (jmp_buf));
1087	#endif
1088	}
1089
1090	/* Allow the application to select one or more row filters to use. */
1091	void PNGAPI
1092	png_set_filter(png_structp png_ptr, int method, int filters)
1093	{
1094	png_debug(1, "in png_set_filter\n");
1095	#if defined(PNG_MNG_FEATURES_SUPPORTED)
1096	if((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
1097	(method == PNG_INTRAPIXEL_DIFFERENCING))
1098	method = PNG_FILTER_TYPE_BASE;
1099	#endif
1100	if (method == PNG_FILTER_TYPE_BASE)
1101	{
1102	switch (filters & (PNG_ALL_FILTERS \| 0x07))
1103	{
1104	case 5:
1105	case 6:
1106	case 7: png_warning(png_ptr, "Unknown row filter for method 0");
1107	case PNG_FILTER_VALUE_NONE: png_ptr->do_filter=PNG_FILTER_NONE; break;
1108	case PNG_FILTER_VALUE_SUB: png_ptr->do_filter=PNG_FILTER_SUB; break;
1109	case PNG_FILTER_VALUE_UP: png_ptr->do_filter=PNG_FILTER_UP; break;
1110	case PNG_FILTER_VALUE_AVG: png_ptr->do_filter=PNG_FILTER_AVG; break;
1111	case PNG_FILTER_VALUE_PAETH: png_ptr->do_filter=PNG_FILTER_PAETH;break;
1112	default: png_ptr->do_filter = (png_byte)filters; break;
1113	}
1114
1115	/* If we have allocated the row_buf, this means we have already started
1116	* with the image and we should have allocated all of the filter buffers
1117	* that have been selected. If prev_row isn't already allocated, then
1118	* it is too late to start using the filters that need it, since we
1119	* will be missing the data in the previous row. If an application
1120	* wants to start and stop using particular filters during compression,
1121	* it should start out with all of the filters, and then add and
1122	* remove them after the start of compression.
1123	*/
1124	if (png_ptr->row_buf != NULL)
1125	{
1126	if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL)
1127	{
1128	png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
1129	(png_ptr->rowbytes + 1));
1130	png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
1131	}
1132
1133	if ((png_ptr->do_filter & PNG_FILTER_UP) && png_ptr->up_row == NULL)
1134	{
1135	if (png_ptr->prev_row == NULL)
1136	{
1137	png_warning(png_ptr, "Can't add Up filter after starting");
1138	png_ptr->do_filter &= ~PNG_FILTER_UP;
1139	}
1140	else
1141	{
1142	png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
1143	(png_ptr->rowbytes + 1));
1144	png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
1145	}
1146	}
1147
1148	if ((png_ptr->do_filter & PNG_FILTER_AVG) && png_ptr->avg_row == NULL)
1149	{
1150	if (png_ptr->prev_row == NULL)
1151	{
1152	png_warning(png_ptr, "Can't add Average filter after starting");
1153	png_ptr->do_filter &= ~PNG_FILTER_AVG;
1154	}
1155	else
1156	{
1157	png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
1158	(png_ptr->rowbytes + 1));
1159	png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
1160	}
1161	}
1162
1163	if ((png_ptr->do_filter & PNG_FILTER_PAETH) &&
1164	png_ptr->paeth_row == NULL)
1165	{
1166	if (png_ptr->prev_row == NULL)
1167	{
1168	png_warning(png_ptr, "Can't add Paeth filter after starting");
1169	png_ptr->do_filter &= (png_byte)(~PNG_FILTER_PAETH);
1170	}
1171	else
1172	{
1173	png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
1174	(png_ptr->rowbytes + 1));
1175	png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
1176	}
1177	}
1178
1179	if (png_ptr->do_filter == PNG_NO_FILTERS)
1180	png_ptr->do_filter = PNG_FILTER_NONE;
1181	}
1182	}
1183	else
1184	png_error(png_ptr, "Unknown custom filter method");
1185	}
1186
1187	/* This allows us to influence the way in which libpng chooses the "best"
1188	* filter for the current scanline. While the "minimum-sum-of-absolute-
1189	* differences metric is relatively fast and effective, there is some
1190	* question as to whether it can be improved upon by trying to keep the
1191	* filtered data going to zlib more consistent, hopefully resulting in
1192	* better compression.
1193	*/
1194	#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* GRR 970116 */
1195	void PNGAPI
1196	png_set_filter_heuristics(png_structp png_ptr, int heuristic_method,
1197	int num_weights, png_doublep filter_weights,
1198	png_doublep filter_costs)
1199	{
1200	int i;
1201
1202	png_debug(1, "in png_set_filter_heuristics\n");
1203	if (heuristic_method >= PNG_FILTER_HEURISTIC_LAST)
1204	{
1205	png_warning(png_ptr, "Unknown filter heuristic method");
1206	return;
1207	}
1208
1209	if (heuristic_method == PNG_FILTER_HEURISTIC_DEFAULT)
1210	{
1211	heuristic_method = PNG_FILTER_HEURISTIC_UNWEIGHTED;
1212	}
1213
1214	if (num_weights < 0 \|\| filter_weights == NULL \|\|
1215	heuristic_method == PNG_FILTER_HEURISTIC_UNWEIGHTED)
1216	{
1217	num_weights = 0;
1218	}
1219
1220	png_ptr->num_prev_filters = (png_byte)num_weights;
1221	png_ptr->heuristic_method = (png_byte)heuristic_method;
1222
1223	if (num_weights > 0)
1224	{
1225	if (png_ptr->prev_filters == NULL)
1226	{
1227	png_ptr->prev_filters = (png_bytep)png_malloc(png_ptr,
1228	(png_uint_32)(png_sizeof(png_byte) * num_weights));
1229
1230	/* To make sure that the weighting starts out fairly */
1231	for (i = 0; i < num_weights; i++)
1232	{
1233	png_ptr->prev_filters[i] = 255;
1234	}
1235	}
1236
1237	if (png_ptr->filter_weights == NULL)
1238	{
1239	png_ptr->filter_weights = (png_uint_16p)png_malloc(png_ptr,
1240	(png_uint_32)(png_sizeof(png_uint_16) * num_weights));
1241
1242	png_ptr->inv_filter_weights = (png_uint_16p)png_malloc(png_ptr,
1243	(png_uint_32)(png_sizeof(png_uint_16) * num_weights));
1244	for (i = 0; i < num_weights; i++)
1245	{
1246	png_ptr->inv_filter_weights[i] =
1247	png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1248	}
1249	}
1250
1251	for (i = 0; i < num_weights; i++)
1252	{
1253	if (filter_weights[i] < 0.0)
1254	{
1255	png_ptr->inv_filter_weights[i] =
1256	png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1257	}
1258	else
1259	{
1260	png_ptr->inv_filter_weights[i] =
1261	(png_uint_16)((double)PNG_WEIGHT_FACTOR*filter_weights[i]+0.5);
1262	png_ptr->filter_weights[i] =
1263	(png_uint_16)((double)PNG_WEIGHT_FACTOR/filter_weights[i]+0.5);
1264	}
1265	}
1266	}
1267
1268	/* If, in the future, there are other filter methods, this would
1269	* need to be based on png_ptr->filter.
1270	*/
1271	if (png_ptr->filter_costs == NULL)
1272	{
1273	png_ptr->filter_costs = (png_uint_16p)png_malloc(png_ptr,
1274	(png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
1275
1276	png_ptr->inv_filter_costs = (png_uint_16p)png_malloc(png_ptr,
1277	(png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
1278
1279	for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
1280	{
1281	png_ptr->inv_filter_costs[i] =
1282	png_ptr->filter_costs[i] = PNG_COST_FACTOR;
1283	}
1284	}
1285
1286	/* Here is where we set the relative costs of the different filters. We
1287	* should take the desired compression level into account when setting
1288	* the costs, so that Paeth, for instance, has a high relative cost at low
1289	* compression levels, while it has a lower relative cost at higher
1290	* compression settings. The filter types are in order of increasing
1291	* relative cost, so it would be possible to do this with an algorithm.
1292	*/
1293	for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
1294	{
1295	if (filter_costs == NULL \|\| filter_costs[i] < 0.0)
1296	{
1297	png_ptr->inv_filter_costs[i] =
1298	png_ptr->filter_costs[i] = PNG_COST_FACTOR;
1299	}
1300	else if (filter_costs[i] >= 1.0)
1301	{
1302	png_ptr->inv_filter_costs[i] =
1303	(png_uint_16)((double)PNG_COST_FACTOR / filter_costs[i] + 0.5);
1304	png_ptr->filter_costs[i] =
1305	(png_uint_16)((double)PNG_COST_FACTOR * filter_costs[i] + 0.5);
1306	}
1307	}
1308	}
1309	#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1310
1311	void PNGAPI
1312	png_set_compression_level(png_structp png_ptr, int level)
1313	{
1314	png_debug(1, "in png_set_compression_level\n");
1315	png_ptr->flags \|= PNG_FLAG_ZLIB_CUSTOM_LEVEL;
1316	png_ptr->zlib_level = level;
1317	}
1318
1319	void PNGAPI
1320	png_set_compression_mem_level(png_structp png_ptr, int mem_level)
1321	{
1322	png_debug(1, "in png_set_compression_mem_level\n");
1323	png_ptr->flags \|= PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL;
1324	png_ptr->zlib_mem_level = mem_level;
1325	}
1326
1327	void PNGAPI
1328	png_set_compression_strategy(png_structp png_ptr, int strategy)
1329	{
1330	png_debug(1, "in png_set_compression_strategy\n");
1331	png_ptr->flags \|= PNG_FLAG_ZLIB_CUSTOM_STRATEGY;
1332	png_ptr->zlib_strategy = strategy;
1333	}
1334
1335	void PNGAPI
1336	png_set_compression_window_bits(png_structp png_ptr, int window_bits)
1337	{
1338	if (window_bits > 15)
1339	png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
1340	else if (window_bits < 8)
1341	png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
1342	#ifndef WBITS_8_OK
1343	/* avoid libpng bug with 256-byte windows */
1344	if (window_bits == 8)
1345	{
1346	png_warning(png_ptr, "Compression window is being reset to 512");
1347	window_bits=9;
1348	}
1349	#endif
1350	png_ptr->flags \|= PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS;
1351	png_ptr->zlib_window_bits = window_bits;
1352	}
1353
1354	void PNGAPI
1355	png_set_compression_method(png_structp png_ptr, int method)
1356	{
1357	png_debug(1, "in png_set_compression_method\n");
1358	if (method != 8)
1359	png_warning(png_ptr, "Only compression method 8 is supported by PNG");
1360	png_ptr->flags \|= PNG_FLAG_ZLIB_CUSTOM_METHOD;
1361	png_ptr->zlib_method = method;
1362	}
1363
1364	void PNGAPI
1365	png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn)
1366	{
1367	png_ptr->write_row_fn = write_row_fn;
1368	}
1369
1370	#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1371	void PNGAPI
1372	png_set_write_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
1373	write_user_transform_fn)
1374	{
1375	png_debug(1, "in png_set_write_user_transform_fn\n");
1376	png_ptr->transformations \|= PNG_USER_TRANSFORM;
1377	png_ptr->write_user_transform_fn = write_user_transform_fn;
1378	}
1379	#endif
1380
1381
1382	#if defined(PNG_INFO_IMAGE_SUPPORTED)
1383	void PNGAPI
1384	png_write_png(png_structp png_ptr, png_infop info_ptr,
1385	int transforms, voidp params)
1386	{
1387	#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1388	/* invert the alpha channel from opacity to transparency */
1389	if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
1390	png_set_invert_alpha(png_ptr);
1391	#endif
1392
1393	/* Write the file header information. */
1394	png_write_info(png_ptr, info_ptr);
1395
1396	/* ------ these transformations don't touch the info structure ------- */
1397
1398	#if defined(PNG_WRITE_INVERT_SUPPORTED)
1399	/* invert monochrome pixels */
1400	if (transforms & PNG_TRANSFORM_INVERT_MONO)
1401	png_set_invert_mono(png_ptr);
1402	#endif
1403
1404	#if defined(PNG_WRITE_SHIFT_SUPPORTED)
1405	/* Shift the pixels up to a legal bit depth and fill in
1406	* as appropriate to correctly scale the image.
1407	*/
1408	if ((transforms & PNG_TRANSFORM_SHIFT)
1409	&& (info_ptr->valid & PNG_INFO_sBIT))
1410	png_set_shift(png_ptr, &info_ptr->sig_bit);
1411	#endif
1412
1413	#if defined(PNG_WRITE_PACK_SUPPORTED)
1414	/* pack pixels into bytes */
1415	if (transforms & PNG_TRANSFORM_PACKING)
1416	png_set_packing(png_ptr);
1417	#endif
1418
1419	#if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1420	/* swap location of alpha bytes from ARGB to RGBA */
1421	if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
1422	png_set_swap_alpha(png_ptr);
1423	#endif
1424
1425	#if defined(PNG_WRITE_FILLER_SUPPORTED)
1426	/* Get rid of filler (OR ALPHA) bytes, pack XRGB/RGBX/ARGB/RGBA into
1427	* RGB (4 channels -> 3 channels). The second parameter is not used.
1428	*/
1429	if (transforms & PNG_TRANSFORM_STRIP_FILLER)
1430	png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
1431	#endif
1432
1433	#if defined(PNG_WRITE_BGR_SUPPORTED)
1434	/* flip BGR pixels to RGB */
1435	if (transforms & PNG_TRANSFORM_BGR)
1436	png_set_bgr(png_ptr);
1437	#endif
1438
1439	#if defined(PNG_WRITE_SWAP_SUPPORTED)
1440	/* swap bytes of 16-bit files to most significant byte first */
1441	if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
1442	png_set_swap(png_ptr);
1443	#endif
1444
1445	#if defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1446	/* swap bits of 1, 2, 4 bit packed pixel formats */
1447	if (transforms & PNG_TRANSFORM_PACKSWAP)
1448	png_set_packswap(png_ptr);
1449	#endif
1450
1451	/* ----------------------- end of transformations ------------------- */
1452
1453	/* write the bits */
1454	if (info_ptr->valid & PNG_INFO_IDAT)
1455	png_write_image(png_ptr, info_ptr->row_pointers);
1456
1457	/* It is REQUIRED to call this to finish writing the rest of the file */
1458	png_write_end(png_ptr, info_ptr);
1459
1460	if(transforms == 0 \|\| params == NULL)
1461	/* quiet compiler warnings */ return;
1462	}
1463	#endif
1464	#endif /* PNG_WRITE_SUPPORTED */

注意: 瀏覽 TracBrowser 來幫助您使用儲存庫瀏覽器

source: vbox/trunk/src/libs/libpng-1.2.8/pngwrite.c@ 27325

以其他格式下載: