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1
2/* pngwrite.c - general routines to write a PNG file
3 *
4 * libpng 1.2.5rc3 - September 18, 2002
5 * For conditions of distribution and use, see copyright notice in png.h
6 * Copyright (c) 1998-2002 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 */
25void PNGAPI
26png_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 != HANDLE_CHUNK_NEVER &&
108 up->location && (!(up->location & PNG_HAVE_PLTE)) &&
109 ((up->name[3] & 0x20) || keep == HANDLE_CHUNK_ALWAYS ||
110 (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
111 {
112 png_write_chunk(png_ptr, up->name, up->data, up->size);
113 }
114 }
115 }
116#endif
117 png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;
118 }
119}
120
121void PNGAPI
122png_write_info(png_structp png_ptr, png_infop info_ptr)
123{
124#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
125 int i;
126#endif
127
128 png_debug(1, "in png_write_info\n");
129
130 png_write_info_before_PLTE(png_ptr, info_ptr);
131
132 if (info_ptr->valid & PNG_INFO_PLTE)
133 png_write_PLTE(png_ptr, info_ptr->palette,
134 (png_uint_32)info_ptr->num_palette);
135 else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
136 png_error(png_ptr, "Valid palette required for paletted images\n");
137
138#if defined(PNG_WRITE_tRNS_SUPPORTED)
139 if (info_ptr->valid & PNG_INFO_tRNS)
140 {
141#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
142 /* invert the alpha channel (in tRNS) */
143 if ((png_ptr->transformations & PNG_INVERT_ALPHA) &&
144 info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
145 {
146 int j;
147 for (j=0; j<(int)info_ptr->num_trans; j++)
148 info_ptr->trans[j] = (png_byte)(255 - info_ptr->trans[j]);
149 }
150#endif
151 png_write_tRNS(png_ptr, info_ptr->trans, &(info_ptr->trans_values),
152 info_ptr->num_trans, info_ptr->color_type);
153 }
154#endif
155#if defined(PNG_WRITE_bKGD_SUPPORTED)
156 if (info_ptr->valid & PNG_INFO_bKGD)
157 png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
158#endif
159#if defined(PNG_WRITE_hIST_SUPPORTED)
160 if (info_ptr->valid & PNG_INFO_hIST)
161 png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);
162#endif
163#if defined(PNG_WRITE_oFFs_SUPPORTED)
164 if (info_ptr->valid & PNG_INFO_oFFs)
165 png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,
166 info_ptr->offset_unit_type);
167#endif
168#if defined(PNG_WRITE_pCAL_SUPPORTED)
169 if (info_ptr->valid & PNG_INFO_pCAL)
170 png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0,
171 info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams,
172 info_ptr->pcal_units, info_ptr->pcal_params);
173#endif
174#if defined(PNG_WRITE_sCAL_SUPPORTED)
175 if (info_ptr->valid & PNG_INFO_sCAL)
176#if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
177 png_write_sCAL(png_ptr, (int)info_ptr->scal_unit,
178 info_ptr->scal_pixel_width, info_ptr->scal_pixel_height);
179#else
180#ifdef PNG_FIXED_POINT_SUPPORTED
181 png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,
182 info_ptr->scal_s_width, info_ptr->scal_s_height);
183#else
184 png_warning(png_ptr,
185 "png_write_sCAL not supported; sCAL chunk not written.\n");
186#endif
187#endif
188#endif
189#if defined(PNG_WRITE_pHYs_SUPPORTED)
190 if (info_ptr->valid & PNG_INFO_pHYs)
191 png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,
192 info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type);
193#endif
194#if defined(PNG_WRITE_tIME_SUPPORTED)
195 if (info_ptr->valid & PNG_INFO_tIME)
196 {
197 png_write_tIME(png_ptr, &(info_ptr->mod_time));
198 png_ptr->mode |= PNG_WROTE_tIME;
199 }
200#endif
201#if defined(PNG_WRITE_sPLT_SUPPORTED)
202 if (info_ptr->valid & PNG_INFO_sPLT)
203 for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
204 png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);
205#endif
206#if defined(PNG_WRITE_TEXT_SUPPORTED)
207 /* Check to see if we need to write text chunks */
208 for (i = 0; i < info_ptr->num_text; i++)
209 {
210 png_debug2(2, "Writing header text chunk %d, type %d\n", i,
211 info_ptr->text[i].compression);
212 /* an internationalized chunk? */
213 if (info_ptr->text[i].compression > 0)
214 {
215#if defined(PNG_WRITE_iTXt_SUPPORTED)
216 /* write international chunk */
217 png_write_iTXt(png_ptr,
218 info_ptr->text[i].compression,
219 info_ptr->text[i].key,
220 info_ptr->text[i].lang,
221 info_ptr->text[i].lang_key,
222 info_ptr->text[i].text);
223#else
224 png_warning(png_ptr, "Unable to write international text\n");
225#endif
226 /* Mark this chunk as written */
227 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
228 }
229 /* If we want a compressed text chunk */
230 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
231 {
232#if defined(PNG_WRITE_zTXt_SUPPORTED)
233 /* write compressed chunk */
234 png_write_zTXt(png_ptr, info_ptr->text[i].key,
235 info_ptr->text[i].text, 0,
236 info_ptr->text[i].compression);
237#else
238 png_warning(png_ptr, "Unable to write compressed text\n");
239#endif
240 /* Mark this chunk as written */
241 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
242 }
243 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
244 {
245#if defined(PNG_WRITE_tEXt_SUPPORTED)
246 /* write uncompressed chunk */
247 png_write_tEXt(png_ptr, info_ptr->text[i].key,
248 info_ptr->text[i].text,
249 0);
250#else
251 png_warning(png_ptr, "Unable to write uncompressed text\n");
252#endif
253 /* Mark this chunk as written */
254 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
255 }
256 }
257#endif
258#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
259 if (info_ptr->unknown_chunks_num)
260 {
261 png_unknown_chunk *up;
262
263 png_debug(5, "writing extra chunks\n");
264
265 for (up = info_ptr->unknown_chunks;
266 up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
267 up++)
268 {
269 int keep=png_handle_as_unknown(png_ptr, up->name);
270 if (keep != HANDLE_CHUNK_NEVER &&
271 up->location && (up->location & PNG_HAVE_PLTE) &&
272 !(up->location & PNG_HAVE_IDAT) &&
273 ((up->name[3] & 0x20) || keep == HANDLE_CHUNK_ALWAYS ||
274 (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
275 {
276 png_write_chunk(png_ptr, up->name, up->data, up->size);
277 }
278 }
279 }
280#endif
281}
282
283/* Writes the end of the PNG file. If you don't want to write comments or
284 * time information, you can pass NULL for info. If you already wrote these
285 * in png_write_info(), do not write them again here. If you have long
286 * comments, I suggest writing them here, and compressing them.
287 */
288void PNGAPI
289png_write_end(png_structp png_ptr, png_infop info_ptr)
290{
291 png_debug(1, "in png_write_end\n");
292 if (!(png_ptr->mode & PNG_HAVE_IDAT))
293 png_error(png_ptr, "No IDATs written into file");
294
295 /* see if user wants us to write information chunks */
296 if (info_ptr != NULL)
297 {
298#if defined(PNG_WRITE_TEXT_SUPPORTED)
299 int i; /* local index variable */
300#endif
301#if defined(PNG_WRITE_tIME_SUPPORTED)
302 /* check to see if user has supplied a time chunk */
303 if ((info_ptr->valid & PNG_INFO_tIME) &&
304 !(png_ptr->mode & PNG_WROTE_tIME))
305 png_write_tIME(png_ptr, &(info_ptr->mod_time));
306#endif
307#if defined(PNG_WRITE_TEXT_SUPPORTED)
308 /* loop through comment chunks */
309 for (i = 0; i < info_ptr->num_text; i++)
310 {
311 png_debug2(2, "Writing trailer text chunk %d, type %d\n", i,
312 info_ptr->text[i].compression);
313 /* an internationalized chunk? */
314 if (info_ptr->text[i].compression > 0)
315 {
316#if defined(PNG_WRITE_iTXt_SUPPORTED)
317 /* write international chunk */
318 png_write_iTXt(png_ptr,
319 info_ptr->text[i].compression,
320 info_ptr->text[i].key,
321 info_ptr->text[i].lang,
322 info_ptr->text[i].lang_key,
323 info_ptr->text[i].text);
324#else
325 png_warning(png_ptr, "Unable to write international text\n");
326#endif
327 /* Mark this chunk as written */
328 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
329 }
330 else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
331 {
332#if defined(PNG_WRITE_zTXt_SUPPORTED)
333 /* write compressed chunk */
334 png_write_zTXt(png_ptr, info_ptr->text[i].key,
335 info_ptr->text[i].text, 0,
336 info_ptr->text[i].compression);
337#else
338 png_warning(png_ptr, "Unable to write compressed text\n");
339#endif
340 /* Mark this chunk as written */
341 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
342 }
343 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
344 {
345#if defined(PNG_WRITE_tEXt_SUPPORTED)
346 /* write uncompressed chunk */
347 png_write_tEXt(png_ptr, info_ptr->text[i].key,
348 info_ptr->text[i].text, 0);
349#else
350 png_warning(png_ptr, "Unable to write uncompressed text\n");
351#endif
352
353 /* Mark this chunk as written */
354 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
355 }
356 }
357#endif
358#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
359 if (info_ptr->unknown_chunks_num)
360 {
361 png_unknown_chunk *up;
362
363 png_debug(5, "writing extra chunks\n");
364
365 for (up = info_ptr->unknown_chunks;
366 up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
367 up++)
368 {
369 int keep=png_handle_as_unknown(png_ptr, up->name);
370 if (keep != HANDLE_CHUNK_NEVER &&
371 up->location && (up->location & PNG_AFTER_IDAT) &&
372 ((up->name[3] & 0x20) || keep == HANDLE_CHUNK_ALWAYS ||
373 (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
374 {
375 png_write_chunk(png_ptr, up->name, up->data, up->size);
376 }
377 }
378 }
379#endif
380 }
381
382 png_ptr->mode |= PNG_AFTER_IDAT;
383
384 /* write end of PNG file */
385 png_write_IEND(png_ptr);
386#if 0
387/* This flush, added in libpng-1.0.8, causes some applications to crash
388 because they do not set png_ptr->output_flush_fn */
389 png_flush(png_ptr);
390#endif
391}
392
393#if defined(PNG_WRITE_tIME_SUPPORTED)
394#if !defined(_WIN32_WCE)
395/* "time.h" functions are not supported on WindowsCE */
396void PNGAPI
397png_convert_from_struct_tm(png_timep ptime, struct tm FAR * ttime)
398{
399 png_debug(1, "in png_convert_from_struct_tm\n");
400 ptime->year = (png_uint_16)(1900 + ttime->tm_year);
401 ptime->month = (png_byte)(ttime->tm_mon + 1);
402 ptime->day = (png_byte)ttime->tm_mday;
403 ptime->hour = (png_byte)ttime->tm_hour;
404 ptime->minute = (png_byte)ttime->tm_min;
405 ptime->second = (png_byte)ttime->tm_sec;
406}
407
408void PNGAPI
409png_convert_from_time_t(png_timep ptime, time_t ttime)
410{
411 struct tm *tbuf;
412
413 png_debug(1, "in png_convert_from_time_t\n");
414 tbuf = gmtime(&ttime);
415 png_convert_from_struct_tm(ptime, tbuf);
416}
417#endif
418#endif
419
420/* Initialize png_ptr structure, and allocate any memory needed */
421png_structp PNGAPI
422png_create_write_struct(png_const_charp user_png_ver, png_voidp error_ptr,
423 png_error_ptr error_fn, png_error_ptr warn_fn)
424{
425#ifdef PNG_USER_MEM_SUPPORTED
426 return (png_create_write_struct_2(user_png_ver, error_ptr, error_fn,
427 warn_fn, png_voidp_NULL, png_malloc_ptr_NULL, png_free_ptr_NULL));
428}
429
430/* Alternate initialize png_ptr structure, and allocate any memory needed */
431png_structp PNGAPI
432png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
433 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
434 png_malloc_ptr malloc_fn, png_free_ptr free_fn)
435{
436#endif /* PNG_USER_MEM_SUPPORTED */
437 png_structp png_ptr;
438#ifdef PNG_SETJMP_SUPPORTED
439#ifdef USE_FAR_KEYWORD
440 jmp_buf jmpbuf;
441#endif
442#endif
443 int i;
444 png_debug(1, "in png_create_write_struct\n");
445#ifdef PNG_USER_MEM_SUPPORTED
446 png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
447 (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);
448#else
449 png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
450#endif /* PNG_USER_MEM_SUPPORTED */
451 if (png_ptr == NULL)
452 return (NULL);
453
454#if !defined(PNG_1_0_X)
455#ifdef PNG_ASSEMBLER_CODE_SUPPORTED
456 png_init_mmx_flags(png_ptr); /* 1.2.0 addition */
457#endif
458#endif /* PNG_1_0_X */
459
460#ifdef PNG_SETJMP_SUPPORTED
461#ifdef USE_FAR_KEYWORD
462 if (setjmp(jmpbuf))
463#else
464 if (setjmp(png_ptr->jmpbuf))
465#endif
466 {
467 png_free(png_ptr, png_ptr->zbuf);
468 png_ptr->zbuf=NULL;
469 png_destroy_struct(png_ptr);
470 return (NULL);
471 }
472#ifdef USE_FAR_KEYWORD
473 png_memcpy(png_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf));
474#endif
475#endif
476
477#ifdef PNG_USER_MEM_SUPPORTED
478 png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
479#endif /* PNG_USER_MEM_SUPPORTED */
480 png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
481
482 i=0;
483 do
484 {
485 if(user_png_ver[i] != png_libpng_ver[i])
486 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
487 } while (png_libpng_ver[i++]);
488
489 if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
490 {
491 /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
492 * we must recompile any applications that use any older library version.
493 * For versions after libpng 1.0, we will be compatible, so we need
494 * only check the first digit.
495 */
496 if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
497 (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
498 (user_png_ver[0] == '0' && user_png_ver[2] < '9'))
499 {
500#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
501 char msg[80];
502 if (user_png_ver)
503 {
504 sprintf(msg, "Application was compiled with png.h from libpng-%.20s",
505 user_png_ver);
506 png_warning(png_ptr, msg);
507 }
508 sprintf(msg, "Application is running with png.c from libpng-%.20s",
509 png_libpng_ver);
510 png_warning(png_ptr, msg);
511#endif
512#ifdef PNG_ERROR_NUMBERS_SUPPORTED
513 png_ptr->flags=0;
514#endif
515 png_error(png_ptr,
516 "Incompatible libpng version in application and library");
517 }
518 }
519
520 /* initialize zbuf - compression buffer */
521 png_ptr->zbuf_size = PNG_ZBUF_SIZE;
522 png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
523 (png_uint_32)png_ptr->zbuf_size);
524
525 png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
526 png_flush_ptr_NULL);
527
528#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
529 png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
530 1, png_doublep_NULL, png_doublep_NULL);
531#endif
532
533#ifdef PNG_SETJMP_SUPPORTED
534/* Applications that neglect to set up their own setjmp() and then encounter
535 a png_error() will longjmp here. Since the jmpbuf is then meaningless we
536 abort instead of returning. */
537#ifdef USE_FAR_KEYWORD
538 if (setjmp(jmpbuf))
539 PNG_ABORT();
540 png_memcpy(png_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf));
541#else
542 if (setjmp(png_ptr->jmpbuf))
543 PNG_ABORT();
544#endif
545#endif
546 return (png_ptr);
547}
548
549/* Initialize png_ptr structure, and allocate any memory needed */
550#undef png_write_init
551void PNGAPI
552png_write_init(png_structp png_ptr)
553{
554 /* We only come here via pre-1.0.7-compiled applications */
555 png_write_init_2(png_ptr, "1.0.6 or earlier", 0, 0);
556}
557
558void PNGAPI
559png_write_init_2(png_structp png_ptr, png_const_charp user_png_ver,
560 png_size_t png_struct_size, png_size_t png_info_size)
561{
562 /* We only come here via pre-1.0.12-compiled applications */
563#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
564 if(sizeof(png_struct) > png_struct_size || sizeof(png_info) > png_info_size)
565 {
566 char msg[80];
567 png_ptr->warning_fn=NULL;
568 if (user_png_ver)
569 {
570 sprintf(msg, "Application was compiled with png.h from libpng-%.20s",
571 user_png_ver);
572 png_warning(png_ptr, msg);
573 }
574 sprintf(msg, "Application is running with png.c from libpng-%.20s",
575 png_libpng_ver);
576 png_warning(png_ptr, msg);
577 }
578#endif
579 if(sizeof(png_struct) > png_struct_size)
580 {
581 png_ptr->error_fn=NULL;
582#ifdef PNG_ERROR_NUMBERS_SUPPORTED
583 png_ptr->flags=0;
584#endif
585 png_error(png_ptr,
586 "The png struct allocated by the application for writing is too small.");
587 }
588 if(sizeof(png_info) > png_info_size)
589 {
590 png_ptr->error_fn=NULL;
591#ifdef PNG_ERROR_NUMBERS_SUPPORTED
592 png_ptr->flags=0;
593#endif
594 png_error(png_ptr,
595 "The info struct allocated by the application for writing is too small.");
596 }
597 png_write_init_3(&png_ptr, user_png_ver, png_struct_size);
598}
599
600
601void PNGAPI
602png_write_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
603 png_size_t png_struct_size)
604{
605 png_structp png_ptr=*ptr_ptr;
606#ifdef PNG_SETJMP_SUPPORTED
607 jmp_buf tmp_jmp; /* to save current jump buffer */
608#endif
609 int i = 0;
610 do
611 {
612 if (user_png_ver[i] != png_libpng_ver[i])
613 {
614#ifdef PNG_LEGACY_SUPPORTED
615 png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
616#else
617 png_ptr->warning_fn=NULL;
618 png_warning(png_ptr,
619 "Application uses deprecated png_write_init() and should be recompiled.");
620 break;
621#endif
622 }
623 } while (png_libpng_ver[i++]);
624
625 png_debug(1, "in png_write_init_3\n");
626
627#ifdef PNG_SETJMP_SUPPORTED
628 /* save jump buffer and error functions */
629 png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf));
630#endif
631
632 if (sizeof(png_struct) > png_struct_size)
633 {
634 png_destroy_struct(png_ptr);
635 png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
636 *ptr_ptr = png_ptr;
637 }
638
639 /* reset all variables to 0 */
640 png_memset(png_ptr, 0, sizeof (png_struct));
641
642#if !defined(PNG_1_0_X)
643#ifdef PNG_ASSEMBLER_CODE_SUPPORTED
644 png_init_mmx_flags(png_ptr); /* 1.2.0 addition */
645#endif
646#endif /* PNG_1_0_X */
647
648#ifdef PNG_SETJMP_SUPPORTED
649 /* restore jump buffer */
650 png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf));
651#endif
652
653 png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
654 png_flush_ptr_NULL);
655
656 /* initialize zbuf - compression buffer */
657 png_ptr->zbuf_size = PNG_ZBUF_SIZE;
658 png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
659 (png_uint_32)png_ptr->zbuf_size);
660
661#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
662 png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
663 1, png_doublep_NULL, png_doublep_NULL);
664#endif
665}
666
667/* Write a few rows of image data. If the image is interlaced,
668 * either you will have to write the 7 sub images, or, if you
669 * have called png_set_interlace_handling(), you will have to
670 * "write" the image seven times.
671 */
672void PNGAPI
673png_write_rows(png_structp png_ptr, png_bytepp row,
674 png_uint_32 num_rows)
675{
676 png_uint_32 i; /* row counter */
677 png_bytepp rp; /* row pointer */
678
679 png_debug(1, "in png_write_rows\n");
680 /* loop through the rows */
681 for (i = 0, rp = row; i < num_rows; i++, rp++)
682 {
683 png_write_row(png_ptr, *rp);
684 }
685}
686
687/* Write the image. You only need to call this function once, even
688 * if you are writing an interlaced image.
689 */
690void PNGAPI
691png_write_image(png_structp png_ptr, png_bytepp image)
692{
693 png_uint_32 i; /* row index */
694 int pass, num_pass; /* pass variables */
695 png_bytepp rp; /* points to current row */
696
697 png_debug(1, "in png_write_image\n");
698#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
699 /* intialize interlace handling. If image is not interlaced,
700 this will set pass to 1 */
701 num_pass = png_set_interlace_handling(png_ptr);
702#else
703 num_pass = 1;
704#endif
705 /* loop through passes */
706 for (pass = 0; pass < num_pass; pass++)
707 {
708 /* loop through image */
709 for (i = 0, rp = image; i < png_ptr->height; i++, rp++)
710 {
711 png_write_row(png_ptr, *rp);
712 }
713 }
714}
715
716/* called by user to write a row of image data */
717void PNGAPI
718png_write_row(png_structp png_ptr, png_bytep row)
719{
720 png_debug2(1, "in png_write_row (row %ld, pass %d)\n",
721 png_ptr->row_number, png_ptr->pass);
722 /* initialize transformations and other stuff if first time */
723 if (png_ptr->row_number == 0 && png_ptr->pass == 0)
724 {
725 /* make sure we wrote the header info */
726 if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
727 png_error(png_ptr,
728 "png_write_info was never called before png_write_row.");
729
730 /* check for transforms that have been set but were defined out */
731#if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)
732 if (png_ptr->transformations & PNG_INVERT_MONO)
733 png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined.");
734#endif
735#if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED)
736 if (png_ptr->transformations & PNG_FILLER)
737 png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined.");
738#endif
739#if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && defined(PNG_READ_PACKSWAP_SUPPORTED)
740 if (png_ptr->transformations & PNG_PACKSWAP)
741 png_warning(png_ptr, "PNG_WRITE_PACKSWAP_SUPPORTED is not defined.");
742#endif
743#if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED)
744 if (png_ptr->transformations & PNG_PACK)
745 png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined.");
746#endif
747#if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED)
748 if (png_ptr->transformations & PNG_SHIFT)
749 png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined.");
750#endif
751#if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED)
752 if (png_ptr->transformations & PNG_BGR)
753 png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined.");
754#endif
755#if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED)
756 if (png_ptr->transformations & PNG_SWAP_BYTES)
757 png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined.");
758#endif
759
760 png_write_start_row(png_ptr);
761 }
762
763#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
764 /* if interlaced and not interested in row, return */
765 if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
766 {
767 switch (png_ptr->pass)
768 {
769 case 0:
770 if (png_ptr->row_number & 0x07)
771 {
772 png_write_finish_row(png_ptr);
773 return;
774 }
775 break;
776 case 1:
777 if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
778 {
779 png_write_finish_row(png_ptr);
780 return;
781 }
782 break;
783 case 2:
784 if ((png_ptr->row_number & 0x07) != 4)
785 {
786 png_write_finish_row(png_ptr);
787 return;
788 }
789 break;
790 case 3:
791 if ((png_ptr->row_number & 0x03) || png_ptr->width < 3)
792 {
793 png_write_finish_row(png_ptr);
794 return;
795 }
796 break;
797 case 4:
798 if ((png_ptr->row_number & 0x03) != 2)
799 {
800 png_write_finish_row(png_ptr);
801 return;
802 }
803 break;
804 case 5:
805 if ((png_ptr->row_number & 0x01) || png_ptr->width < 2)
806 {
807 png_write_finish_row(png_ptr);
808 return;
809 }
810 break;
811 case 6:
812 if (!(png_ptr->row_number & 0x01))
813 {
814 png_write_finish_row(png_ptr);
815 return;
816 }
817 break;
818 }
819 }
820#endif
821
822 /* set up row info for transformations */
823 png_ptr->row_info.color_type = png_ptr->color_type;
824 png_ptr->row_info.width = png_ptr->usr_width;
825 png_ptr->row_info.channels = png_ptr->usr_channels;
826 png_ptr->row_info.bit_depth = png_ptr->usr_bit_depth;
827 png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth *
828 png_ptr->row_info.channels);
829
830 png_ptr->row_info.rowbytes = ((png_ptr->row_info.width *
831 (png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3);
832
833 png_debug1(3, "row_info->color_type = %d\n", png_ptr->row_info.color_type);
834 png_debug1(3, "row_info->width = %lu\n", png_ptr->row_info.width);
835 png_debug1(3, "row_info->channels = %d\n", png_ptr->row_info.channels);
836 png_debug1(3, "row_info->bit_depth = %d\n", png_ptr->row_info.bit_depth);
837 png_debug1(3, "row_info->pixel_depth = %d\n", png_ptr->row_info.pixel_depth);
838 png_debug1(3, "row_info->rowbytes = %lu\n", png_ptr->row_info.rowbytes);
839
840 /* Copy user's row into buffer, leaving room for filter byte. */
841 png_memcpy_check(png_ptr, png_ptr->row_buf + 1, row,
842 png_ptr->row_info.rowbytes);
843
844#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
845 /* handle interlacing */
846 if (png_ptr->interlaced && png_ptr->pass < 6 &&
847 (png_ptr->transformations & PNG_INTERLACE))
848 {
849 png_do_write_interlace(&(png_ptr->row_info),
850 png_ptr->row_buf + 1, png_ptr->pass);
851 /* this should always get caught above, but still ... */
852 if (!(png_ptr->row_info.width))
853 {
854 png_write_finish_row(png_ptr);
855 return;
856 }
857 }
858#endif
859
860 /* handle other transformations */
861 if (png_ptr->transformations)
862 png_do_write_transformations(png_ptr);
863
864#if defined(PNG_MNG_FEATURES_SUPPORTED)
865 /* Write filter_method 64 (intrapixel differencing) only if
866 * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
867 * 2. Libpng did not write a PNG signature (this filter_method is only
868 * used in PNG datastreams that are embedded in MNG datastreams) and
869 * 3. The application called png_permit_mng_features with a mask that
870 * included PNG_FLAG_MNG_FILTER_64 and
871 * 4. The filter_method is 64 and
872 * 5. The color_type is RGB or RGBA
873 */
874 if((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
875 (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
876 {
877 /* Intrapixel differencing */
878 png_do_write_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
879 }
880#endif
881
882 /* Find a filter if necessary, filter the row and write it out. */
883 png_write_find_filter(png_ptr, &(png_ptr->row_info));
884
885 if (png_ptr->write_row_fn != NULL)
886 (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
887}
888
889#if defined(PNG_WRITE_FLUSH_SUPPORTED)
890/* Set the automatic flush interval or 0 to turn flushing off */
891void PNGAPI
892png_set_flush(png_structp png_ptr, int nrows)
893{
894 png_debug(1, "in png_set_flush\n");
895 png_ptr->flush_dist = (nrows < 0 ? 0 : nrows);
896}
897
898/* flush the current output buffers now */
899void PNGAPI
900png_write_flush(png_structp png_ptr)
901{
902 int wrote_IDAT;
903
904 png_debug(1, "in png_write_flush\n");
905 /* We have already written out all of the data */
906 if (png_ptr->row_number >= png_ptr->num_rows)
907 return;
908
909 do
910 {
911 int ret;
912
913 /* compress the data */
914 ret = deflate(&png_ptr->zstream, Z_SYNC_FLUSH);
915 wrote_IDAT = 0;
916
917 /* check for compression errors */
918 if (ret != Z_OK)
919 {
920 if (png_ptr->zstream.msg != NULL)
921 png_error(png_ptr, png_ptr->zstream.msg);
922 else
923 png_error(png_ptr, "zlib error");
924 }
925
926 if (!(png_ptr->zstream.avail_out))
927 {
928 /* write the IDAT and reset the zlib output buffer */
929 png_write_IDAT(png_ptr, png_ptr->zbuf,
930 png_ptr->zbuf_size);
931 png_ptr->zstream.next_out = png_ptr->zbuf;
932 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
933 wrote_IDAT = 1;
934 }
935 } while(wrote_IDAT == 1);
936
937 /* If there is any data left to be output, write it into a new IDAT */
938 if (png_ptr->zbuf_size != png_ptr->zstream.avail_out)
939 {
940 /* write the IDAT and reset the zlib output buffer */
941 png_write_IDAT(png_ptr, png_ptr->zbuf,
942 png_ptr->zbuf_size - png_ptr->zstream.avail_out);
943 png_ptr->zstream.next_out = png_ptr->zbuf;
944 png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
945 }
946 png_ptr->flush_rows = 0;
947 png_flush(png_ptr);
948}
949#endif /* PNG_WRITE_FLUSH_SUPPORTED */
950
951/* free all memory used by the write */
952void PNGAPI
953png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
954{
955 png_structp png_ptr = NULL;
956 png_infop info_ptr = NULL;
957#ifdef PNG_USER_MEM_SUPPORTED
958 png_free_ptr free_fn = NULL;
959 png_voidp mem_ptr = NULL;
960#endif
961
962 png_debug(1, "in png_destroy_write_struct\n");
963 if (png_ptr_ptr != NULL)
964 {
965 png_ptr = *png_ptr_ptr;
966#ifdef PNG_USER_MEM_SUPPORTED
967 free_fn = png_ptr->free_fn;
968 mem_ptr = png_ptr->mem_ptr;
969#endif
970 }
971
972 if (info_ptr_ptr != NULL)
973 info_ptr = *info_ptr_ptr;
974
975 if (info_ptr != NULL)
976 {
977 png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
978
979#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
980 if (png_ptr->num_chunk_list)
981 {
982 png_free(png_ptr, png_ptr->chunk_list);
983 png_ptr->chunk_list=NULL;
984 png_ptr->num_chunk_list=0;
985 }
986#endif
987
988#ifdef PNG_USER_MEM_SUPPORTED
989 png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
990 (png_voidp)mem_ptr);
991#else
992 png_destroy_struct((png_voidp)info_ptr);
993#endif
994 *info_ptr_ptr = NULL;
995 }
996
997 if (png_ptr != NULL)
998 {
999 png_write_destroy(png_ptr);
1000#ifdef PNG_USER_MEM_SUPPORTED
1001 png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
1002 (png_voidp)mem_ptr);
1003#else
1004 png_destroy_struct((png_voidp)png_ptr);
1005#endif
1006 *png_ptr_ptr = NULL;
1007 }
1008}
1009
1010
1011/* Free any memory used in png_ptr struct (old method) */
1012void /* PRIVATE */
1013png_write_destroy(png_structp png_ptr)
1014{
1015#ifdef PNG_SETJMP_SUPPORTED
1016 jmp_buf tmp_jmp; /* save jump buffer */
1017#endif
1018 png_error_ptr error_fn;
1019 png_error_ptr warning_fn;
1020 png_voidp error_ptr;
1021#ifdef PNG_USER_MEM_SUPPORTED
1022 png_free_ptr free_fn;
1023#endif
1024
1025 png_debug(1, "in png_write_destroy\n");
1026 /* free any memory zlib uses */
1027 deflateEnd(&png_ptr->zstream);
1028
1029 /* free our memory. png_free checks NULL for us. */
1030 png_free(png_ptr, png_ptr->zbuf);
1031 png_free(png_ptr, png_ptr->row_buf);
1032 png_free(png_ptr, png_ptr->prev_row);
1033 png_free(png_ptr, png_ptr->sub_row);
1034 png_free(png_ptr, png_ptr->up_row);
1035 png_free(png_ptr, png_ptr->avg_row);
1036 png_free(png_ptr, png_ptr->paeth_row);
1037
1038#if defined(PNG_TIME_RFC1123_SUPPORTED)
1039 png_free(png_ptr, png_ptr->time_buffer);
1040#endif
1041
1042#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
1043 png_free(png_ptr, png_ptr->prev_filters);
1044 png_free(png_ptr, png_ptr->filter_weights);
1045 png_free(png_ptr, png_ptr->inv_filter_weights);
1046 png_free(png_ptr, png_ptr->filter_costs);
1047 png_free(png_ptr, png_ptr->inv_filter_costs);
1048#endif
1049
1050#ifdef PNG_SETJMP_SUPPORTED
1051 /* reset structure */
1052 png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf));
1053#endif
1054
1055 error_fn = png_ptr->error_fn;
1056 warning_fn = png_ptr->warning_fn;
1057 error_ptr = png_ptr->error_ptr;
1058#ifdef PNG_USER_MEM_SUPPORTED
1059 free_fn = png_ptr->free_fn;
1060#endif
1061
1062 png_memset(png_ptr, 0, sizeof (png_struct));
1063
1064 png_ptr->error_fn = error_fn;
1065 png_ptr->warning_fn = warning_fn;
1066 png_ptr->error_ptr = error_ptr;
1067#ifdef PNG_USER_MEM_SUPPORTED
1068 png_ptr->free_fn = free_fn;
1069#endif
1070
1071#ifdef PNG_SETJMP_SUPPORTED
1072 png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf));
1073#endif
1074}
1075
1076/* Allow the application to select one or more row filters to use. */
1077void PNGAPI
1078png_set_filter(png_structp png_ptr, int method, int filters)
1079{
1080 png_debug(1, "in png_set_filter\n");
1081#if defined(PNG_MNG_FEATURES_SUPPORTED)
1082 if((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
1083 (method == PNG_INTRAPIXEL_DIFFERENCING))
1084 method = PNG_FILTER_TYPE_BASE;
1085#endif
1086 if (method == PNG_FILTER_TYPE_BASE)
1087 {
1088 switch (filters & (PNG_ALL_FILTERS | 0x07))
1089 {
1090 case 5:
1091 case 6:
1092 case 7: png_warning(png_ptr, "Unknown row filter for method 0");
1093 case PNG_FILTER_VALUE_NONE: png_ptr->do_filter=PNG_FILTER_NONE; break;
1094 case PNG_FILTER_VALUE_SUB: png_ptr->do_filter=PNG_FILTER_SUB; break;
1095 case PNG_FILTER_VALUE_UP: png_ptr->do_filter=PNG_FILTER_UP; break;
1096 case PNG_FILTER_VALUE_AVG: png_ptr->do_filter=PNG_FILTER_AVG; break;
1097 case PNG_FILTER_VALUE_PAETH: png_ptr->do_filter=PNG_FILTER_PAETH;break;
1098 default: png_ptr->do_filter = (png_byte)filters; break;
1099 }
1100
1101 /* If we have allocated the row_buf, this means we have already started
1102 * with the image and we should have allocated all of the filter buffers
1103 * that have been selected. If prev_row isn't already allocated, then
1104 * it is too late to start using the filters that need it, since we
1105 * will be missing the data in the previous row. If an application
1106 * wants to start and stop using particular filters during compression,
1107 * it should start out with all of the filters, and then add and
1108 * remove them after the start of compression.
1109 */
1110 if (png_ptr->row_buf != NULL)
1111 {
1112 if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL)
1113 {
1114 png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
1115 (png_ptr->rowbytes + 1));
1116 png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
1117 }
1118
1119 if ((png_ptr->do_filter & PNG_FILTER_UP) && png_ptr->up_row == NULL)
1120 {
1121 if (png_ptr->prev_row == NULL)
1122 {
1123 png_warning(png_ptr, "Can't add Up filter after starting");
1124 png_ptr->do_filter &= ~PNG_FILTER_UP;
1125 }
1126 else
1127 {
1128 png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
1129 (png_ptr->rowbytes + 1));
1130 png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
1131 }
1132 }
1133
1134 if ((png_ptr->do_filter & PNG_FILTER_AVG) && png_ptr->avg_row == NULL)
1135 {
1136 if (png_ptr->prev_row == NULL)
1137 {
1138 png_warning(png_ptr, "Can't add Average filter after starting");
1139 png_ptr->do_filter &= ~PNG_FILTER_AVG;
1140 }
1141 else
1142 {
1143 png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
1144 (png_ptr->rowbytes + 1));
1145 png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
1146 }
1147 }
1148
1149 if ((png_ptr->do_filter & PNG_FILTER_PAETH) &&
1150 png_ptr->paeth_row == NULL)
1151 {
1152 if (png_ptr->prev_row == NULL)
1153 {
1154 png_warning(png_ptr, "Can't add Paeth filter after starting");
1155 png_ptr->do_filter &= (png_byte)(~PNG_FILTER_PAETH);
1156 }
1157 else
1158 {
1159 png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
1160 (png_ptr->rowbytes + 1));
1161 png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
1162 }
1163 }
1164
1165 if (png_ptr->do_filter == PNG_NO_FILTERS)
1166 png_ptr->do_filter = PNG_FILTER_NONE;
1167 }
1168 }
1169 else
1170 png_error(png_ptr, "Unknown custom filter method");
1171}
1172
1173/* This allows us to influence the way in which libpng chooses the "best"
1174 * filter for the current scanline. While the "minimum-sum-of-absolute-
1175 * differences metric is relatively fast and effective, there is some
1176 * question as to whether it can be improved upon by trying to keep the
1177 * filtered data going to zlib more consistent, hopefully resulting in
1178 * better compression.
1179 */
1180#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* GRR 970116 */
1181void PNGAPI
1182png_set_filter_heuristics(png_structp png_ptr, int heuristic_method,
1183 int num_weights, png_doublep filter_weights,
1184 png_doublep filter_costs)
1185{
1186 int i;
1187
1188 png_debug(1, "in png_set_filter_heuristics\n");
1189 if (heuristic_method >= PNG_FILTER_HEURISTIC_LAST)
1190 {
1191 png_warning(png_ptr, "Unknown filter heuristic method");
1192 return;
1193 }
1194
1195 if (heuristic_method == PNG_FILTER_HEURISTIC_DEFAULT)
1196 {
1197 heuristic_method = PNG_FILTER_HEURISTIC_UNWEIGHTED;
1198 }
1199
1200 if (num_weights < 0 || filter_weights == NULL ||
1201 heuristic_method == PNG_FILTER_HEURISTIC_UNWEIGHTED)
1202 {
1203 num_weights = 0;
1204 }
1205
1206 png_ptr->num_prev_filters = (png_byte)num_weights;
1207 png_ptr->heuristic_method = (png_byte)heuristic_method;
1208
1209 if (num_weights > 0)
1210 {
1211 if (png_ptr->prev_filters == NULL)
1212 {
1213 png_ptr->prev_filters = (png_bytep)png_malloc(png_ptr,
1214 (png_uint_32)(sizeof(png_byte) * num_weights));
1215
1216 /* To make sure that the weighting starts out fairly */
1217 for (i = 0; i < num_weights; i++)
1218 {
1219 png_ptr->prev_filters[i] = 255;
1220 }
1221 }
1222
1223 if (png_ptr->filter_weights == NULL)
1224 {
1225 png_ptr->filter_weights = (png_uint_16p)png_malloc(png_ptr,
1226 (png_uint_32)(sizeof(png_uint_16) * num_weights));
1227
1228 png_ptr->inv_filter_weights = (png_uint_16p)png_malloc(png_ptr,
1229 (png_uint_32)(sizeof(png_uint_16) * num_weights));
1230 for (i = 0; i < num_weights; i++)
1231 {
1232 png_ptr->inv_filter_weights[i] =
1233 png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1234 }
1235 }
1236
1237 for (i = 0; i < num_weights; i++)
1238 {
1239 if (filter_weights[i] < 0.0)
1240 {
1241 png_ptr->inv_filter_weights[i] =
1242 png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1243 }
1244 else
1245 {
1246 png_ptr->inv_filter_weights[i] =
1247 (png_uint_16)((double)PNG_WEIGHT_FACTOR*filter_weights[i]+0.5);
1248 png_ptr->filter_weights[i] =
1249 (png_uint_16)((double)PNG_WEIGHT_FACTOR/filter_weights[i]+0.5);
1250 }
1251 }
1252 }
1253
1254 /* If, in the future, there are other filter methods, this would
1255 * need to be based on png_ptr->filter.
1256 */
1257 if (png_ptr->filter_costs == NULL)
1258 {
1259 png_ptr->filter_costs = (png_uint_16p)png_malloc(png_ptr,
1260 (png_uint_32)(sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
1261
1262 png_ptr->inv_filter_costs = (png_uint_16p)png_malloc(png_ptr,
1263 (png_uint_32)(sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
1264
1265 for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
1266 {
1267 png_ptr->inv_filter_costs[i] =
1268 png_ptr->filter_costs[i] = PNG_COST_FACTOR;
1269 }
1270 }
1271
1272 /* Here is where we set the relative costs of the different filters. We
1273 * should take the desired compression level into account when setting
1274 * the costs, so that Paeth, for instance, has a high relative cost at low
1275 * compression levels, while it has a lower relative cost at higher
1276 * compression settings. The filter types are in order of increasing
1277 * relative cost, so it would be possible to do this with an algorithm.
1278 */
1279 for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
1280 {
1281 if (filter_costs == NULL || filter_costs[i] < 0.0)
1282 {
1283 png_ptr->inv_filter_costs[i] =
1284 png_ptr->filter_costs[i] = PNG_COST_FACTOR;
1285 }
1286 else if (filter_costs[i] >= 1.0)
1287 {
1288 png_ptr->inv_filter_costs[i] =
1289 (png_uint_16)((double)PNG_COST_FACTOR / filter_costs[i] + 0.5);
1290 png_ptr->filter_costs[i] =
1291 (png_uint_16)((double)PNG_COST_FACTOR * filter_costs[i] + 0.5);
1292 }
1293 }
1294}
1295#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1296
1297void PNGAPI
1298png_set_compression_level(png_structp png_ptr, int level)
1299{
1300 png_debug(1, "in png_set_compression_level\n");
1301 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_LEVEL;
1302 png_ptr->zlib_level = level;
1303}
1304
1305void PNGAPI
1306png_set_compression_mem_level(png_structp png_ptr, int mem_level)
1307{
1308 png_debug(1, "in png_set_compression_mem_level\n");
1309 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL;
1310 png_ptr->zlib_mem_level = mem_level;
1311}
1312
1313void PNGAPI
1314png_set_compression_strategy(png_structp png_ptr, int strategy)
1315{
1316 png_debug(1, "in png_set_compression_strategy\n");
1317 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY;
1318 png_ptr->zlib_strategy = strategy;
1319}
1320
1321void PNGAPI
1322png_set_compression_window_bits(png_structp png_ptr, int window_bits)
1323{
1324 if (window_bits > 15)
1325 png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
1326 else if (window_bits < 8)
1327 png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
1328#ifndef WBITS_8_OK
1329 /* avoid libpng bug with 256-byte windows */
1330 if (window_bits == 8)
1331 {
1332 png_warning(png_ptr, "Compression window is being reset to 512");
1333 window_bits=9;
1334 }
1335#endif
1336 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS;
1337 png_ptr->zlib_window_bits = window_bits;
1338}
1339
1340void PNGAPI
1341png_set_compression_method(png_structp png_ptr, int method)
1342{
1343 png_debug(1, "in png_set_compression_method\n");
1344 if (method != 8)
1345 png_warning(png_ptr, "Only compression method 8 is supported by PNG");
1346 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_METHOD;
1347 png_ptr->zlib_method = method;
1348}
1349
1350void PNGAPI
1351png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn)
1352{
1353 png_ptr->write_row_fn = write_row_fn;
1354}
1355
1356#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
1357void PNGAPI
1358png_set_write_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
1359 write_user_transform_fn)
1360{
1361 png_debug(1, "in png_set_write_user_transform_fn\n");
1362 png_ptr->transformations |= PNG_USER_TRANSFORM;
1363 png_ptr->write_user_transform_fn = write_user_transform_fn;
1364}
1365#endif
1366
1367
1368#if defined(PNG_INFO_IMAGE_SUPPORTED)
1369void PNGAPI
1370png_write_png(png_structp png_ptr, png_infop info_ptr,
1371 int transforms, voidp params)
1372{
1373#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
1374 /* invert the alpha channel from opacity to transparency */
1375 if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
1376 png_set_invert_alpha(png_ptr);
1377#endif
1378
1379 /* Write the file header information. */
1380 png_write_info(png_ptr, info_ptr);
1381
1382 /* ------ these transformations don't touch the info structure ------- */
1383
1384#if defined(PNG_WRITE_INVERT_SUPPORTED)
1385 /* invert monochrome pixels */
1386 if (transforms & PNG_TRANSFORM_INVERT_MONO)
1387 png_set_invert_mono(png_ptr);
1388#endif
1389
1390#if defined(PNG_WRITE_SHIFT_SUPPORTED)
1391 /* Shift the pixels up to a legal bit depth and fill in
1392 * as appropriate to correctly scale the image.
1393 */
1394 if ((transforms & PNG_TRANSFORM_SHIFT)
1395 && (info_ptr->valid & PNG_INFO_sBIT))
1396 png_set_shift(png_ptr, &info_ptr->sig_bit);
1397#endif
1398
1399#if defined(PNG_WRITE_PACK_SUPPORTED)
1400 /* pack pixels into bytes */
1401 if (transforms & PNG_TRANSFORM_PACKING)
1402 png_set_packing(png_ptr);
1403#endif
1404
1405#if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
1406 /* swap location of alpha bytes from ARGB to RGBA */
1407 if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
1408 png_set_swap_alpha(png_ptr);
1409#endif
1410
1411#if defined(PNG_WRITE_FILLER_SUPPORTED)
1412 /* Get rid of filler (OR ALPHA) bytes, pack XRGB/RGBX/ARGB/RGBA into
1413 * RGB (4 channels -> 3 channels). The second parameter is not used.
1414 */
1415 if (transforms & PNG_TRANSFORM_STRIP_FILLER)
1416 png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
1417#endif
1418
1419#if defined(PNG_WRITE_BGR_SUPPORTED)
1420 /* flip BGR pixels to RGB */
1421 if (transforms & PNG_TRANSFORM_BGR)
1422 png_set_bgr(png_ptr);
1423#endif
1424
1425#if defined(PNG_WRITE_SWAP_SUPPORTED)
1426 /* swap bytes of 16-bit files to most significant byte first */
1427 if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
1428 png_set_swap(png_ptr);
1429#endif
1430
1431#if defined(PNG_WRITE_PACKSWAP_SUPPORTED)
1432 /* swap bits of 1, 2, 4 bit packed pixel formats */
1433 if (transforms & PNG_TRANSFORM_PACKSWAP)
1434 png_set_packswap(png_ptr);
1435#endif
1436
1437 /* ----------------------- end of transformations ------------------- */
1438
1439 /* write the bits */
1440 if (info_ptr->valid & PNG_INFO_IDAT)
1441 png_write_image(png_ptr, info_ptr->row_pointers);
1442
1443 /* It is REQUIRED to call this to finish writing the rest of the file */
1444 png_write_end(png_ptr, info_ptr);
1445
1446 if(transforms == 0 || params == NULL)
1447 /* quiet compiler warnings */ return;
1448}
1449#endif
1450#endif /* PNG_WRITE_SUPPORTED */
wxWidgets (Impactor)