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No real changes, just remove wxIsDebuggerRunning() stub from wxOSX.
[wxWidgets.git] / src / png / pngwrite.c
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1
2/* pngwrite.c - general routines to write a PNG file
3 *
4 * Last changed in libpng 1.5.7 [December 15, 2011]
5 * Copyright (c) 1998-2011 Glenn Randers-Pehrson
6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
8 *
9 * This code is released under the libpng license.
10 * For conditions of distribution and use, see the disclaimer
11 * and license in png.h
12 */
13
14#include "pngpriv.h"
15
16#ifdef PNG_WRITE_SUPPORTED
17
18/* Writes all the PNG information. This is the suggested way to use the
19 * library. If you have a new chunk to add, make a function to write it,
20 * and put it in the correct location here. If you want the chunk written
21 * after the image data, put it in png_write_end(). I strongly encourage
22 * you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing
23 * the chunk, as that will keep the code from breaking if you want to just
24 * write a plain PNG file. If you have long comments, I suggest writing
25 * them in png_write_end(), and compressing them.
26 */
27void PNGAPI
28png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr)
29{
30 png_debug(1, "in png_write_info_before_PLTE");
31
32 if (png_ptr == NULL || info_ptr == NULL)
33 return;
34
35 if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
36 {
37 /* Write PNG signature */
38 png_write_sig(png_ptr);
39
40#ifdef PNG_MNG_FEATURES_SUPPORTED
41 if ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) && \
42 (png_ptr->mng_features_permitted))
43 {
44 png_warning(png_ptr, "MNG features are not allowed in a PNG datastream");
45 png_ptr->mng_features_permitted = 0;
46 }
47#endif
48
49 /* Write IHDR information. */
50 png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,
51 info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,
52 info_ptr->filter_type,
53#ifdef PNG_WRITE_INTERLACING_SUPPORTED
54 info_ptr->interlace_type);
55#else
56 0);
57#endif
58 /* The rest of these check to see if the valid field has the appropriate
59 * flag set, and if it does, writes the chunk.
60 */
61#ifdef PNG_WRITE_gAMA_SUPPORTED
62 if (info_ptr->valid & PNG_INFO_gAMA)
63 png_write_gAMA_fixed(png_ptr, info_ptr->gamma);
64#endif
65#ifdef PNG_WRITE_sRGB_SUPPORTED
66 if (info_ptr->valid & PNG_INFO_sRGB)
67 png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent);
68#endif
69
70#ifdef PNG_WRITE_iCCP_SUPPORTED
71 if (info_ptr->valid & PNG_INFO_iCCP)
72 png_write_iCCP(png_ptr, info_ptr->iccp_name, PNG_COMPRESSION_TYPE_BASE,
73 (png_charp)info_ptr->iccp_profile, (int)info_ptr->iccp_proflen);
74#endif
75#ifdef PNG_WRITE_sBIT_SUPPORTED
76 if (info_ptr->valid & PNG_INFO_sBIT)
77 png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
78#endif
79#ifdef PNG_WRITE_cHRM_SUPPORTED
80 if (info_ptr->valid & PNG_INFO_cHRM)
81 png_write_cHRM_fixed(png_ptr,
82 info_ptr->x_white, info_ptr->y_white,
83 info_ptr->x_red, info_ptr->y_red,
84 info_ptr->x_green, info_ptr->y_green,
85 info_ptr->x_blue, info_ptr->y_blue);
86#endif
87
88#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
89 if (info_ptr->unknown_chunks_num)
90 {
91 png_unknown_chunk *up;
92
93 png_debug(5, "writing extra chunks");
94
95 for (up = info_ptr->unknown_chunks;
96 up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
97 up++)
98 {
99 int keep = png_handle_as_unknown(png_ptr, up->name);
100
101 if (keep != PNG_HANDLE_CHUNK_NEVER &&
102 up->location &&
103 !(up->location & PNG_HAVE_PLTE) &&
104 !(up->location & PNG_HAVE_IDAT) &&
105 !(up->location & PNG_AFTER_IDAT) &&
106 ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
107 (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
108 {
109 if (up->size == 0)
110 png_warning(png_ptr, "Writing zero-length unknown chunk");
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");
129
130 if (png_ptr == NULL || info_ptr == NULL)
131 return;
132
133 png_write_info_before_PLTE(png_ptr, info_ptr);
134
135 if (info_ptr->valid & PNG_INFO_PLTE)
136 png_write_PLTE(png_ptr, info_ptr->palette,
137 (png_uint_32)info_ptr->num_palette);
138
139 else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
140 png_error(png_ptr, "Valid palette required for paletted images");
141
142#ifdef PNG_WRITE_tRNS_SUPPORTED
143 if (info_ptr->valid & PNG_INFO_tRNS)
144 {
145#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
146 /* Invert the alpha channel (in tRNS) */
147 if ((png_ptr->transformations & PNG_INVERT_ALPHA) &&
148 info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
149 {
150 int j;
151 for (j = 0; j<(int)info_ptr->num_trans; j++)
152 info_ptr->trans_alpha[j] =
153 (png_byte)(255 - info_ptr->trans_alpha[j]);
154 }
155#endif
156 png_write_tRNS(png_ptr, info_ptr->trans_alpha, &(info_ptr->trans_color),
157 info_ptr->num_trans, info_ptr->color_type);
158 }
159#endif
160#ifdef PNG_WRITE_bKGD_SUPPORTED
161 if (info_ptr->valid & PNG_INFO_bKGD)
162 png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
163#endif
164
165#ifdef PNG_WRITE_hIST_SUPPORTED
166 if (info_ptr->valid & PNG_INFO_hIST)
167 png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);
168#endif
169
170#ifdef PNG_WRITE_oFFs_SUPPORTED
171 if (info_ptr->valid & PNG_INFO_oFFs)
172 png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,
173 info_ptr->offset_unit_type);
174#endif
175
176#ifdef PNG_WRITE_pCAL_SUPPORTED
177 if (info_ptr->valid & PNG_INFO_pCAL)
178 png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0,
179 info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams,
180 info_ptr->pcal_units, info_ptr->pcal_params);
181#endif
182
183#ifdef PNG_WRITE_sCAL_SUPPORTED
184 if (info_ptr->valid & PNG_INFO_sCAL)
185 png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,
186 info_ptr->scal_s_width, info_ptr->scal_s_height);
187#endif /* sCAL */
188
189#ifdef 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 /* pHYs */
194
195#ifdef 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 /* tIME */
202
203#ifdef PNG_WRITE_sPLT_SUPPORTED
204 if (info_ptr->valid & PNG_INFO_sPLT)
205 for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
206 png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);
207#endif /* sPLT */
208
209#ifdef PNG_WRITE_TEXT_SUPPORTED
210 /* Check to see if we need to write text chunks */
211 for (i = 0; i < info_ptr->num_text; i++)
212 {
213 png_debug2(2, "Writing header text chunk %d, type %d", i,
214 info_ptr->text[i].compression);
215 /* An internationalized chunk? */
216 if (info_ptr->text[i].compression > 0)
217 {
218#ifdef PNG_WRITE_iTXt_SUPPORTED
219 /* Write international chunk */
220 png_write_iTXt(png_ptr,
221 info_ptr->text[i].compression,
222 info_ptr->text[i].key,
223 info_ptr->text[i].lang,
224 info_ptr->text[i].lang_key,
225 info_ptr->text[i].text);
226#else
227 png_warning(png_ptr, "Unable to write international text");
228#endif
229 /* Mark this chunk as written */
230 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
231 }
232
233 /* If we want a compressed text chunk */
234 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
235 {
236#ifdef PNG_WRITE_zTXt_SUPPORTED
237 /* Write compressed chunk */
238 png_write_zTXt(png_ptr, info_ptr->text[i].key,
239 info_ptr->text[i].text, 0,
240 info_ptr->text[i].compression);
241#else
242 png_warning(png_ptr, "Unable to write compressed text");
243#endif
244 /* Mark this chunk as written */
245 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
246 }
247
248 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
249 {
250#ifdef PNG_WRITE_tEXt_SUPPORTED
251 /* Write uncompressed chunk */
252 png_write_tEXt(png_ptr, info_ptr->text[i].key,
253 info_ptr->text[i].text,
254 0);
255 /* Mark this chunk as written */
256 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
257#else
258 /* Can't get here */
259 png_warning(png_ptr, "Unable to write uncompressed text");
260#endif
261 }
262 }
263#endif /* tEXt */
264
265#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
266 if (info_ptr->unknown_chunks_num)
267 {
268 png_unknown_chunk *up;
269
270 png_debug(5, "writing extra chunks");
271
272 for (up = info_ptr->unknown_chunks;
273 up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
274 up++)
275 {
276 int keep = png_handle_as_unknown(png_ptr, up->name);
277 if (keep != PNG_HANDLE_CHUNK_NEVER &&
278 up->location &&
279 (up->location & PNG_HAVE_PLTE) &&
280 !(up->location & PNG_HAVE_IDAT) &&
281 !(up->location & PNG_AFTER_IDAT) &&
282 ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
283 (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
284 {
285 png_write_chunk(png_ptr, up->name, up->data, up->size);
286 }
287 }
288 }
289#endif
290}
291
292/* Writes the end of the PNG file. If you don't want to write comments or
293 * time information, you can pass NULL for info. If you already wrote these
294 * in png_write_info(), do not write them again here. If you have long
295 * comments, I suggest writing them here, and compressing them.
296 */
297void PNGAPI
298png_write_end(png_structp png_ptr, png_infop info_ptr)
299{
300 png_debug(1, "in png_write_end");
301
302 if (png_ptr == NULL)
303 return;
304
305 if (!(png_ptr->mode & PNG_HAVE_IDAT))
306 png_error(png_ptr, "No IDATs written into file");
307
308 /* See if user wants us to write information chunks */
309 if (info_ptr != NULL)
310 {
311#ifdef PNG_WRITE_TEXT_SUPPORTED
312 int i; /* local index variable */
313#endif
314#ifdef PNG_WRITE_tIME_SUPPORTED
315 /* Check to see if user has supplied a time chunk */
316 if ((info_ptr->valid & PNG_INFO_tIME) &&
317 !(png_ptr->mode & PNG_WROTE_tIME))
318 png_write_tIME(png_ptr, &(info_ptr->mod_time));
319
320#endif
321#ifdef PNG_WRITE_TEXT_SUPPORTED
322 /* Loop through comment chunks */
323 for (i = 0; i < info_ptr->num_text; i++)
324 {
325 png_debug2(2, "Writing trailer text chunk %d, type %d", i,
326 info_ptr->text[i].compression);
327 /* An internationalized chunk? */
328 if (info_ptr->text[i].compression > 0)
329 {
330#ifdef PNG_WRITE_iTXt_SUPPORTED
331 /* Write international chunk */
332 png_write_iTXt(png_ptr,
333 info_ptr->text[i].compression,
334 info_ptr->text[i].key,
335 info_ptr->text[i].lang,
336 info_ptr->text[i].lang_key,
337 info_ptr->text[i].text);
338#else
339 png_warning(png_ptr, "Unable to write international text");
340#endif
341 /* Mark this chunk as written */
342 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
343 }
344
345 else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
346 {
347#ifdef PNG_WRITE_zTXt_SUPPORTED
348 /* Write compressed chunk */
349 png_write_zTXt(png_ptr, info_ptr->text[i].key,
350 info_ptr->text[i].text, 0,
351 info_ptr->text[i].compression);
352#else
353 png_warning(png_ptr, "Unable to write compressed text");
354#endif
355 /* Mark this chunk as written */
356 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
357 }
358
359 else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
360 {
361#ifdef PNG_WRITE_tEXt_SUPPORTED
362 /* Write uncompressed chunk */
363 png_write_tEXt(png_ptr, info_ptr->text[i].key,
364 info_ptr->text[i].text, 0);
365#else
366 png_warning(png_ptr, "Unable to write uncompressed text");
367#endif
368
369 /* Mark this chunk as written */
370 info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
371 }
372 }
373#endif
374#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED
375 if (info_ptr->unknown_chunks_num)
376 {
377 png_unknown_chunk *up;
378
379 png_debug(5, "writing extra chunks");
380
381 for (up = info_ptr->unknown_chunks;
382 up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
383 up++)
384 {
385 int keep = png_handle_as_unknown(png_ptr, up->name);
386 if (keep != PNG_HANDLE_CHUNK_NEVER &&
387 up->location &&
388 (up->location & PNG_AFTER_IDAT) &&
389 ((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
390 (png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
391 {
392 png_write_chunk(png_ptr, up->name, up->data, up->size);
393 }
394 }
395 }
396#endif
397 }
398
399 png_ptr->mode |= PNG_AFTER_IDAT;
400
401 /* Write end of PNG file */
402 png_write_IEND(png_ptr);
403 /* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03,
404 * and restored again in libpng-1.2.30, may cause some applications that
405 * do not set png_ptr->output_flush_fn to crash. If your application
406 * experiences a problem, please try building libpng with
407 * PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to
408 * png-mng-implement at lists.sf.net .
409 */
410#ifdef PNG_WRITE_FLUSH_SUPPORTED
411# ifdef PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED
412 png_flush(png_ptr);
413# endif
414#endif
415}
416
417#ifdef PNG_CONVERT_tIME_SUPPORTED
418/* "tm" structure is not supported on WindowsCE */
419void PNGAPI
420png_convert_from_struct_tm(png_timep ptime, PNG_CONST struct tm FAR * ttime)
421{
422 png_debug(1, "in png_convert_from_struct_tm");
423
424 ptime->year = (png_uint_16)(1900 + ttime->tm_year);
425 ptime->month = (png_byte)(ttime->tm_mon + 1);
426 ptime->day = (png_byte)ttime->tm_mday;
427 ptime->hour = (png_byte)ttime->tm_hour;
428 ptime->minute = (png_byte)ttime->tm_min;
429 ptime->second = (png_byte)ttime->tm_sec;
430}
431
432void PNGAPI
433png_convert_from_time_t(png_timep ptime, time_t ttime)
434{
435 struct tm *tbuf;
436
437 png_debug(1, "in png_convert_from_time_t");
438
439 tbuf = gmtime(&ttime);
440 png_convert_from_struct_tm(ptime, tbuf);
441}
442#endif
443
444/* Initialize png_ptr structure, and allocate any memory needed */
445PNG_FUNCTION(png_structp,PNGAPI
446png_create_write_struct,(png_const_charp user_png_ver, png_voidp error_ptr,
447 png_error_ptr error_fn, png_error_ptr warn_fn),PNG_ALLOCATED)
448{
449#ifdef PNG_USER_MEM_SUPPORTED
450 return (png_create_write_struct_2(user_png_ver, error_ptr, error_fn,
451 warn_fn, NULL, NULL, NULL));
452}
453
454/* Alternate initialize png_ptr structure, and allocate any memory needed */
455static void png_reset_filter_heuristics(png_structp png_ptr); /* forward decl */
456
457PNG_FUNCTION(png_structp,PNGAPI
458png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr,
459 png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
460 png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED)
461{
462#endif /* PNG_USER_MEM_SUPPORTED */
463 volatile int png_cleanup_needed = 0;
464#ifdef PNG_SETJMP_SUPPORTED
465 volatile
466#endif
467 png_structp png_ptr;
468#ifdef PNG_SETJMP_SUPPORTED
469#ifdef USE_FAR_KEYWORD
470 jmp_buf tmp_jmpbuf;
471#endif
472#endif
473
474 png_debug(1, "in png_create_write_struct");
475
476#ifdef PNG_USER_MEM_SUPPORTED
477 png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
478 (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);
479#else
480 png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
481#endif /* PNG_USER_MEM_SUPPORTED */
482 if (png_ptr == NULL)
483 return (NULL);
484
485 /* Added at libpng-1.2.6 */
486#ifdef PNG_SET_USER_LIMITS_SUPPORTED
487 png_ptr->user_width_max = PNG_USER_WIDTH_MAX;
488 png_ptr->user_height_max = PNG_USER_HEIGHT_MAX;
489#endif
490
491#ifdef PNG_SETJMP_SUPPORTED
492/* Applications that neglect to set up their own setjmp() and then
493 * encounter a png_error() will longjmp here. Since the jmpbuf is
494 * then meaningless we abort instead of returning.
495 */
496#ifdef USE_FAR_KEYWORD
497 if (setjmp(tmp_jmpbuf))
498#else
499 if (setjmp(png_jmpbuf(png_ptr))) /* sets longjmp to match setjmp */
500#endif
501#ifdef USE_FAR_KEYWORD
502 png_memcpy(png_jmpbuf(png_ptr), tmp_jmpbuf, png_sizeof(jmp_buf));
503#endif
504 PNG_ABORT();
505#endif
506
507#ifdef PNG_USER_MEM_SUPPORTED
508 png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
509#endif /* PNG_USER_MEM_SUPPORTED */
510 png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
511
512 if (!png_user_version_check(png_ptr, user_png_ver))
513 png_cleanup_needed = 1;
514
515 /* Initialize zbuf - compression buffer */
516 png_ptr->zbuf_size = PNG_ZBUF_SIZE;
517
518 if (!png_cleanup_needed)
519 {
520 png_ptr->zbuf = (png_bytep)png_malloc_warn(png_ptr,
521 png_ptr->zbuf_size);
522 if (png_ptr->zbuf == NULL)
523 png_cleanup_needed = 1;
524 }
525
526 if (png_cleanup_needed)
527 {
528 /* Clean up PNG structure and deallocate any memory. */
529 png_free(png_ptr, png_ptr->zbuf);
530 png_ptr->zbuf = NULL;
531#ifdef PNG_USER_MEM_SUPPORTED
532 png_destroy_struct_2((png_voidp)png_ptr,
533 (png_free_ptr)free_fn, (png_voidp)mem_ptr);
534#else
535 png_destroy_struct((png_voidp)png_ptr);
536#endif
537 return (NULL);
538 }
539
540 png_set_write_fn(png_ptr, NULL, NULL, NULL);
541
542#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
543 png_reset_filter_heuristics(png_ptr);
544#endif
545
546 return (png_ptr);
547}
548
549
550/* Write a few rows of image data. If the image is interlaced,
551 * either you will have to write the 7 sub images, or, if you
552 * have called png_set_interlace_handling(), you will have to
553 * "write" the image seven times.
554 */
555void PNGAPI
556png_write_rows(png_structp png_ptr, png_bytepp row,
557 png_uint_32 num_rows)
558{
559 png_uint_32 i; /* row counter */
560 png_bytepp rp; /* row pointer */
561
562 png_debug(1, "in png_write_rows");
563
564 if (png_ptr == NULL)
565 return;
566
567 /* Loop through the rows */
568 for (i = 0, rp = row; i < num_rows; i++, rp++)
569 {
570 png_write_row(png_ptr, *rp);
571 }
572}
573
574/* Write the image. You only need to call this function once, even
575 * if you are writing an interlaced image.
576 */
577void PNGAPI
578png_write_image(png_structp png_ptr, png_bytepp image)
579{
580 png_uint_32 i; /* row index */
581 int pass, num_pass; /* pass variables */
582 png_bytepp rp; /* points to current row */
583
584 if (png_ptr == NULL)
585 return;
586
587 png_debug(1, "in png_write_image");
588
589#ifdef PNG_WRITE_INTERLACING_SUPPORTED
590 /* Initialize interlace handling. If image is not interlaced,
591 * this will set pass to 1
592 */
593 num_pass = png_set_interlace_handling(png_ptr);
594#else
595 num_pass = 1;
596#endif
597 /* Loop through passes */
598 for (pass = 0; pass < num_pass; pass++)
599 {
600 /* Loop through image */
601 for (i = 0, rp = image; i < png_ptr->height; i++, rp++)
602 {
603 png_write_row(png_ptr, *rp);
604 }
605 }
606}
607
608/* Called by user to write a row of image data */
609void PNGAPI
610png_write_row(png_structp png_ptr, png_const_bytep row)
611{
612 /* 1.5.6: moved from png_struct to be a local structure: */
613 png_row_info row_info;
614
615 if (png_ptr == NULL)
616 return;
617
618 png_debug2(1, "in png_write_row (row %u, pass %d)",
619 png_ptr->row_number, png_ptr->pass);
620
621 /* Initialize transformations and other stuff if first time */
622 if (png_ptr->row_number == 0 && png_ptr->pass == 0)
623 {
624 /* Make sure we wrote the header info */
625 if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
626 png_error(png_ptr,
627 "png_write_info was never called before png_write_row");
628
629 /* Check for transforms that have been set but were defined out */
630#if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)
631 if (png_ptr->transformations & PNG_INVERT_MONO)
632 png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined");
633#endif
634
635#if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED)
636 if (png_ptr->transformations & PNG_FILLER)
637 png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined");
638#endif
639#if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && \
640 defined(PNG_READ_PACKSWAP_SUPPORTED)
641 if (png_ptr->transformations & PNG_PACKSWAP)
642 png_warning(png_ptr,
643 "PNG_WRITE_PACKSWAP_SUPPORTED is not defined");
644#endif
645
646#if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED)
647 if (png_ptr->transformations & PNG_PACK)
648 png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined");
649#endif
650
651#if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED)
652 if (png_ptr->transformations & PNG_SHIFT)
653 png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined");
654#endif
655
656#if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED)
657 if (png_ptr->transformations & PNG_BGR)
658 png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined");
659#endif
660
661#if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED)
662 if (png_ptr->transformations & PNG_SWAP_BYTES)
663 png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined");
664#endif
665
666 png_write_start_row(png_ptr);
667 }
668
669#ifdef PNG_WRITE_INTERLACING_SUPPORTED
670 /* If interlaced and not interested in row, return */
671 if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
672 {
673 switch (png_ptr->pass)
674 {
675 case 0:
676 if (png_ptr->row_number & 0x07)
677 {
678 png_write_finish_row(png_ptr);
679 return;
680 }
681 break;
682
683 case 1:
684 if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
685 {
686 png_write_finish_row(png_ptr);
687 return;
688 }
689 break;
690
691 case 2:
692 if ((png_ptr->row_number & 0x07) != 4)
693 {
694 png_write_finish_row(png_ptr);
695 return;
696 }
697 break;
698
699 case 3:
700 if ((png_ptr->row_number & 0x03) || png_ptr->width < 3)
701 {
702 png_write_finish_row(png_ptr);
703 return;
704 }
705 break;
706
707 case 4:
708 if ((png_ptr->row_number & 0x03) != 2)
709 {
710 png_write_finish_row(png_ptr);
711 return;
712 }
713 break;
714
715 case 5:
716 if ((png_ptr->row_number & 0x01) || png_ptr->width < 2)
717 {
718 png_write_finish_row(png_ptr);
719 return;
720 }
721 break;
722
723 case 6:
724 if (!(png_ptr->row_number & 0x01))
725 {
726 png_write_finish_row(png_ptr);
727 return;
728 }
729 break;
730
731 default: /* error: ignore it */
732 break;
733 }
734 }
735#endif
736
737 /* Set up row info for transformations */
738 row_info.color_type = png_ptr->color_type;
739 row_info.width = png_ptr->usr_width;
740 row_info.channels = png_ptr->usr_channels;
741 row_info.bit_depth = png_ptr->usr_bit_depth;
742 row_info.pixel_depth = (png_byte)(row_info.bit_depth * row_info.channels);
743 row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width);
744
745 png_debug1(3, "row_info->color_type = %d", row_info.color_type);
746 png_debug1(3, "row_info->width = %u", row_info.width);
747 png_debug1(3, "row_info->channels = %d", row_info.channels);
748 png_debug1(3, "row_info->bit_depth = %d", row_info.bit_depth);
749 png_debug1(3, "row_info->pixel_depth = %d", row_info.pixel_depth);
750 png_debug1(3, "row_info->rowbytes = %lu", (unsigned long)row_info.rowbytes);
751
752 /* Copy user's row into buffer, leaving room for filter byte. */
753 png_memcpy(png_ptr->row_buf + 1, row, row_info.rowbytes);
754
755#ifdef PNG_WRITE_INTERLACING_SUPPORTED
756 /* Handle interlacing */
757 if (png_ptr->interlaced && png_ptr->pass < 6 &&
758 (png_ptr->transformations & PNG_INTERLACE))
759 {
760 png_do_write_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass);
761 /* This should always get caught above, but still ... */
762 if (!(row_info.width))
763 {
764 png_write_finish_row(png_ptr);
765 return;
766 }
767 }
768#endif
769
770#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED
771 /* Handle other transformations */
772 if (png_ptr->transformations)
773 png_do_write_transformations(png_ptr, &row_info);
774#endif
775
776 /* At this point the row_info pixel depth must match the 'transformed' depth,
777 * which is also the output depth.
778 */
779 if (row_info.pixel_depth != png_ptr->pixel_depth ||
780 row_info.pixel_depth != png_ptr->transformed_pixel_depth)
781 png_error(png_ptr, "internal write transform logic error");
782
783#ifdef PNG_MNG_FEATURES_SUPPORTED
784 /* Write filter_method 64 (intrapixel differencing) only if
785 * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
786 * 2. Libpng did not write a PNG signature (this filter_method is only
787 * used in PNG datastreams that are embedded in MNG datastreams) and
788 * 3. The application called png_permit_mng_features with a mask that
789 * included PNG_FLAG_MNG_FILTER_64 and
790 * 4. The filter_method is 64 and
791 * 5. The color_type is RGB or RGBA
792 */
793 if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
794 (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
795 {
796 /* Intrapixel differencing */
797 png_do_write_intrapixel(&row_info, png_ptr->row_buf + 1);
798 }
799#endif
800
801 /* Find a filter if necessary, filter the row and write it out. */
802 png_write_find_filter(png_ptr, &row_info);
803
804 if (png_ptr->write_row_fn != NULL)
805 (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
806}
807
808#ifdef PNG_WRITE_FLUSH_SUPPORTED
809/* Set the automatic flush interval or 0 to turn flushing off */
810void PNGAPI
811png_set_flush(png_structp png_ptr, int nrows)
812{
813 png_debug(1, "in png_set_flush");
814
815 if (png_ptr == NULL)
816 return;
817
818 png_ptr->flush_dist = (nrows < 0 ? 0 : nrows);
819}
820
821/* Flush the current output buffers now */
822void PNGAPI
823png_write_flush(png_structp png_ptr)
824{
825 int wrote_IDAT;
826
827 png_debug(1, "in png_write_flush");
828
829 if (png_ptr == NULL)
830 return;
831
832 /* We have already written out all of the data */
833 if (png_ptr->row_number >= png_ptr->num_rows)
834 return;
835
836 do
837 {
838 int ret;
839
840 /* Compress the data */
841 ret = deflate(&png_ptr->zstream, Z_SYNC_FLUSH);
842 wrote_IDAT = 0;
843
844 /* Check for compression errors */
845 if (ret != Z_OK)
846 {
847 if (png_ptr->zstream.msg != NULL)
848 png_error(png_ptr, png_ptr->zstream.msg);
849
850 else
851 png_error(png_ptr, "zlib error");
852 }
853
854 if (!(png_ptr->zstream.avail_out))
855 {
856 /* Write the IDAT and reset the zlib output buffer */
857 png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
858 wrote_IDAT = 1;
859 }
860 } while (wrote_IDAT == 1);
861
862 /* If there is any data left to be output, write it into a new IDAT */
863 if (png_ptr->zbuf_size != png_ptr->zstream.avail_out)
864 {
865 /* Write the IDAT and reset the zlib output buffer */
866 png_write_IDAT(png_ptr, png_ptr->zbuf,
867 png_ptr->zbuf_size - png_ptr->zstream.avail_out);
868 }
869 png_ptr->flush_rows = 0;
870 png_flush(png_ptr);
871}
872#endif /* PNG_WRITE_FLUSH_SUPPORTED */
873
874/* Free all memory used by the write */
875void PNGAPI
876png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
877{
878 png_structp png_ptr = NULL;
879 png_infop info_ptr = NULL;
880#ifdef PNG_USER_MEM_SUPPORTED
881 png_free_ptr free_fn = NULL;
882 png_voidp mem_ptr = NULL;
883#endif
884
885 png_debug(1, "in png_destroy_write_struct");
886
887 if (png_ptr_ptr != NULL)
888 png_ptr = *png_ptr_ptr;
889
890#ifdef PNG_USER_MEM_SUPPORTED
891 if (png_ptr != NULL)
892 {
893 free_fn = png_ptr->free_fn;
894 mem_ptr = png_ptr->mem_ptr;
895 }
896#endif
897
898 if (info_ptr_ptr != NULL)
899 info_ptr = *info_ptr_ptr;
900
901 if (info_ptr != NULL)
902 {
903 if (png_ptr != NULL)
904 {
905 png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
906
907#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
908 if (png_ptr->num_chunk_list)
909 {
910 png_free(png_ptr, png_ptr->chunk_list);
911 png_ptr->num_chunk_list = 0;
912 }
913#endif
914 }
915
916#ifdef PNG_USER_MEM_SUPPORTED
917 png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
918 (png_voidp)mem_ptr);
919#else
920 png_destroy_struct((png_voidp)info_ptr);
921#endif
922 *info_ptr_ptr = NULL;
923 }
924
925 if (png_ptr != NULL)
926 {
927 png_write_destroy(png_ptr);
928#ifdef PNG_USER_MEM_SUPPORTED
929 png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
930 (png_voidp)mem_ptr);
931#else
932 png_destroy_struct((png_voidp)png_ptr);
933#endif
934 *png_ptr_ptr = NULL;
935 }
936}
937
938
939/* Free any memory used in png_ptr struct (old method) */
940void /* PRIVATE */
941png_write_destroy(png_structp png_ptr)
942{
943#ifdef PNG_SETJMP_SUPPORTED
944 jmp_buf tmp_jmp; /* Save jump buffer */
945#endif
946 png_error_ptr error_fn;
947#ifdef PNG_WARNINGS_SUPPORTED
948 png_error_ptr warning_fn;
949#endif
950 png_voidp error_ptr;
951#ifdef PNG_USER_MEM_SUPPORTED
952 png_free_ptr free_fn;
953#endif
954
955 png_debug(1, "in png_write_destroy");
956
957 /* Free any memory zlib uses */
958 if (png_ptr->zlib_state != PNG_ZLIB_UNINITIALIZED)
959 deflateEnd(&png_ptr->zstream);
960
961 /* Free our memory. png_free checks NULL for us. */
962 png_free(png_ptr, png_ptr->zbuf);
963 png_free(png_ptr, png_ptr->row_buf);
964#ifdef PNG_WRITE_FILTER_SUPPORTED
965 png_free(png_ptr, png_ptr->prev_row);
966 png_free(png_ptr, png_ptr->sub_row);
967 png_free(png_ptr, png_ptr->up_row);
968 png_free(png_ptr, png_ptr->avg_row);
969 png_free(png_ptr, png_ptr->paeth_row);
970#endif
971
972#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
973 /* Use this to save a little code space, it doesn't free the filter_costs */
974 png_reset_filter_heuristics(png_ptr);
975 png_free(png_ptr, png_ptr->filter_costs);
976 png_free(png_ptr, png_ptr->inv_filter_costs);
977#endif
978
979#ifdef PNG_SETJMP_SUPPORTED
980 /* Reset structure */
981 png_memcpy(tmp_jmp, png_ptr->longjmp_buffer, png_sizeof(jmp_buf));
982#endif
983
984 error_fn = png_ptr->error_fn;
985#ifdef PNG_WARNINGS_SUPPORTED
986 warning_fn = png_ptr->warning_fn;
987#endif
988 error_ptr = png_ptr->error_ptr;
989#ifdef PNG_USER_MEM_SUPPORTED
990 free_fn = png_ptr->free_fn;
991#endif
992
993 png_memset(png_ptr, 0, png_sizeof(png_struct));
994
995 png_ptr->error_fn = error_fn;
996#ifdef PNG_WARNINGS_SUPPORTED
997 png_ptr->warning_fn = warning_fn;
998#endif
999 png_ptr->error_ptr = error_ptr;
1000#ifdef PNG_USER_MEM_SUPPORTED
1001 png_ptr->free_fn = free_fn;
1002#endif
1003
1004#ifdef PNG_SETJMP_SUPPORTED
1005 png_memcpy(png_ptr->longjmp_buffer, tmp_jmp, png_sizeof(jmp_buf));
1006#endif
1007}
1008
1009/* Allow the application to select one or more row filters to use. */
1010void PNGAPI
1011png_set_filter(png_structp png_ptr, int method, int filters)
1012{
1013 png_debug(1, "in png_set_filter");
1014
1015 if (png_ptr == NULL)
1016 return;
1017
1018#ifdef PNG_MNG_FEATURES_SUPPORTED
1019 if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
1020 (method == PNG_INTRAPIXEL_DIFFERENCING))
1021 method = PNG_FILTER_TYPE_BASE;
1022
1023#endif
1024 if (method == PNG_FILTER_TYPE_BASE)
1025 {
1026 switch (filters & (PNG_ALL_FILTERS | 0x07))
1027 {
1028#ifdef PNG_WRITE_FILTER_SUPPORTED
1029 case 5:
1030 case 6:
1031 case 7: png_warning(png_ptr, "Unknown row filter for method 0");
1032#endif /* PNG_WRITE_FILTER_SUPPORTED */
1033 case PNG_FILTER_VALUE_NONE:
1034 png_ptr->do_filter = PNG_FILTER_NONE; break;
1035
1036#ifdef PNG_WRITE_FILTER_SUPPORTED
1037 case PNG_FILTER_VALUE_SUB:
1038 png_ptr->do_filter = PNG_FILTER_SUB; break;
1039
1040 case PNG_FILTER_VALUE_UP:
1041 png_ptr->do_filter = PNG_FILTER_UP; break;
1042
1043 case PNG_FILTER_VALUE_AVG:
1044 png_ptr->do_filter = PNG_FILTER_AVG; break;
1045
1046 case PNG_FILTER_VALUE_PAETH:
1047 png_ptr->do_filter = PNG_FILTER_PAETH; break;
1048
1049 default:
1050 png_ptr->do_filter = (png_byte)filters; break;
1051#else
1052 default:
1053 png_warning(png_ptr, "Unknown row filter for method 0");
1054#endif /* PNG_WRITE_FILTER_SUPPORTED */
1055 }
1056
1057 /* If we have allocated the row_buf, this means we have already started
1058 * with the image and we should have allocated all of the filter buffers
1059 * that have been selected. If prev_row isn't already allocated, then
1060 * it is too late to start using the filters that need it, since we
1061 * will be missing the data in the previous row. If an application
1062 * wants to start and stop using particular filters during compression,
1063 * it should start out with all of the filters, and then add and
1064 * remove them after the start of compression.
1065 */
1066 if (png_ptr->row_buf != NULL)
1067 {
1068#ifdef PNG_WRITE_FILTER_SUPPORTED
1069 if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL)
1070 {
1071 png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
1072 (png_ptr->rowbytes + 1));
1073 png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
1074 }
1075
1076 if ((png_ptr->do_filter & PNG_FILTER_UP) && png_ptr->up_row == NULL)
1077 {
1078 if (png_ptr->prev_row == NULL)
1079 {
1080 png_warning(png_ptr, "Can't add Up filter after starting");
1081 png_ptr->do_filter = (png_byte)(png_ptr->do_filter &
1082 ~PNG_FILTER_UP);
1083 }
1084
1085 else
1086 {
1087 png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
1088 (png_ptr->rowbytes + 1));
1089 png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
1090 }
1091 }
1092
1093 if ((png_ptr->do_filter & PNG_FILTER_AVG) && png_ptr->avg_row == NULL)
1094 {
1095 if (png_ptr->prev_row == NULL)
1096 {
1097 png_warning(png_ptr, "Can't add Average filter after starting");
1098 png_ptr->do_filter = (png_byte)(png_ptr->do_filter &
1099 ~PNG_FILTER_AVG);
1100 }
1101
1102 else
1103 {
1104 png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
1105 (png_ptr->rowbytes + 1));
1106 png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
1107 }
1108 }
1109
1110 if ((png_ptr->do_filter & PNG_FILTER_PAETH) &&
1111 png_ptr->paeth_row == NULL)
1112 {
1113 if (png_ptr->prev_row == NULL)
1114 {
1115 png_warning(png_ptr, "Can't add Paeth filter after starting");
1116 png_ptr->do_filter &= (png_byte)(~PNG_FILTER_PAETH);
1117 }
1118
1119 else
1120 {
1121 png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
1122 (png_ptr->rowbytes + 1));
1123 png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
1124 }
1125 }
1126
1127 if (png_ptr->do_filter == PNG_NO_FILTERS)
1128#endif /* PNG_WRITE_FILTER_SUPPORTED */
1129 png_ptr->do_filter = PNG_FILTER_NONE;
1130 }
1131 }
1132 else
1133 png_error(png_ptr, "Unknown custom filter method");
1134}
1135
1136/* This allows us to influence the way in which libpng chooses the "best"
1137 * filter for the current scanline. While the "minimum-sum-of-absolute-
1138 * differences metric is relatively fast and effective, there is some
1139 * question as to whether it can be improved upon by trying to keep the
1140 * filtered data going to zlib more consistent, hopefully resulting in
1141 * better compression.
1142 */
1143#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* GRR 970116 */
1144/* Convenience reset API. */
1145static void
1146png_reset_filter_heuristics(png_structp png_ptr)
1147{
1148 /* Clear out any old values in the 'weights' - this must be done because if
1149 * the app calls set_filter_heuristics multiple times with different
1150 * 'num_weights' values we would otherwise potentially have wrong sized
1151 * arrays.
1152 */
1153 png_ptr->num_prev_filters = 0;
1154 png_ptr->heuristic_method = PNG_FILTER_HEURISTIC_UNWEIGHTED;
1155 if (png_ptr->prev_filters != NULL)
1156 {
1157 png_bytep old = png_ptr->prev_filters;
1158 png_ptr->prev_filters = NULL;
1159 png_free(png_ptr, old);
1160 }
1161 if (png_ptr->filter_weights != NULL)
1162 {
1163 png_uint_16p old = png_ptr->filter_weights;
1164 png_ptr->filter_weights = NULL;
1165 png_free(png_ptr, old);
1166 }
1167
1168 if (png_ptr->inv_filter_weights != NULL)
1169 {
1170 png_uint_16p old = png_ptr->inv_filter_weights;
1171 png_ptr->inv_filter_weights = NULL;
1172 png_free(png_ptr, old);
1173 }
1174
1175 /* Leave the filter_costs - this array is fixed size. */
1176}
1177
1178static int
1179png_init_filter_heuristics(png_structp png_ptr, int heuristic_method,
1180 int num_weights)
1181{
1182 if (png_ptr == NULL)
1183 return 0;
1184
1185 /* Clear out the arrays */
1186 png_reset_filter_heuristics(png_ptr);
1187
1188 /* Check arguments; the 'reset' function makes the correct settings for the
1189 * unweighted case, but we must handle the weight case by initializing the
1190 * arrays for the caller.
1191 */
1192 if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
1193 {
1194 int i;
1195
1196 if (num_weights > 0)
1197 {
1198 png_ptr->prev_filters = (png_bytep)png_malloc(png_ptr,
1199 (png_uint_32)(png_sizeof(png_byte) * num_weights));
1200
1201 /* To make sure that the weighting starts out fairly */
1202 for (i = 0; i < num_weights; i++)
1203 {
1204 png_ptr->prev_filters[i] = 255;
1205 }
1206
1207 png_ptr->filter_weights = (png_uint_16p)png_malloc(png_ptr,
1208 (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
1209
1210 png_ptr->inv_filter_weights = (png_uint_16p)png_malloc(png_ptr,
1211 (png_uint_32)(png_sizeof(png_uint_16) * num_weights));
1212
1213 for (i = 0; i < num_weights; i++)
1214 {
1215 png_ptr->inv_filter_weights[i] =
1216 png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1217 }
1218
1219 /* Safe to set this now */
1220 png_ptr->num_prev_filters = (png_byte)num_weights;
1221 }
1222
1223 /* If, in the future, there are other filter methods, this would
1224 * need to be based on png_ptr->filter.
1225 */
1226 if (png_ptr->filter_costs == NULL)
1227 {
1228 png_ptr->filter_costs = (png_uint_16p)png_malloc(png_ptr,
1229 (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
1230
1231 png_ptr->inv_filter_costs = (png_uint_16p)png_malloc(png_ptr,
1232 (png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
1233 }
1234
1235 for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
1236 {
1237 png_ptr->inv_filter_costs[i] =
1238 png_ptr->filter_costs[i] = PNG_COST_FACTOR;
1239 }
1240
1241 /* All the arrays are inited, safe to set this: */
1242 png_ptr->heuristic_method = PNG_FILTER_HEURISTIC_WEIGHTED;
1243
1244 /* Return the 'ok' code. */
1245 return 1;
1246 }
1247 else if (heuristic_method == PNG_FILTER_HEURISTIC_DEFAULT ||
1248 heuristic_method == PNG_FILTER_HEURISTIC_UNWEIGHTED)
1249 {
1250 return 1;
1251 }
1252 else
1253 {
1254 png_warning(png_ptr, "Unknown filter heuristic method");
1255 return 0;
1256 }
1257}
1258
1259/* Provide floating and fixed point APIs */
1260#ifdef PNG_FLOATING_POINT_SUPPORTED
1261void PNGAPI
1262png_set_filter_heuristics(png_structp png_ptr, int heuristic_method,
1263 int num_weights, png_const_doublep filter_weights,
1264 png_const_doublep filter_costs)
1265{
1266 png_debug(1, "in png_set_filter_heuristics");
1267
1268 /* The internal API allocates all the arrays and ensures that the elements of
1269 * those arrays are set to the default value.
1270 */
1271 if (!png_init_filter_heuristics(png_ptr, heuristic_method, num_weights))
1272 return;
1273
1274 /* If using the weighted method copy in the weights. */
1275 if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
1276 {
1277 int i;
1278 for (i = 0; i < num_weights; i++)
1279 {
1280 if (filter_weights[i] <= 0.0)
1281 {
1282 png_ptr->inv_filter_weights[i] =
1283 png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1284 }
1285
1286 else
1287 {
1288 png_ptr->inv_filter_weights[i] =
1289 (png_uint_16)(PNG_WEIGHT_FACTOR*filter_weights[i]+.5);
1290
1291 png_ptr->filter_weights[i] =
1292 (png_uint_16)(PNG_WEIGHT_FACTOR/filter_weights[i]+.5);
1293 }
1294 }
1295
1296 /* Here is where we set the relative costs of the different filters. We
1297 * should take the desired compression level into account when setting
1298 * the costs, so that Paeth, for instance, has a high relative cost at low
1299 * compression levels, while it has a lower relative cost at higher
1300 * compression settings. The filter types are in order of increasing
1301 * relative cost, so it would be possible to do this with an algorithm.
1302 */
1303 for (i = 0; i < PNG_FILTER_VALUE_LAST; i++) if (filter_costs[i] >= 1.0)
1304 {
1305 png_ptr->inv_filter_costs[i] =
1306 (png_uint_16)(PNG_COST_FACTOR / filter_costs[i] + .5);
1307
1308 png_ptr->filter_costs[i] =
1309 (png_uint_16)(PNG_COST_FACTOR * filter_costs[i] + .5);
1310 }
1311 }
1312}
1313#endif /* FLOATING_POINT */
1314
1315#ifdef PNG_FIXED_POINT_SUPPORTED
1316void PNGAPI
1317png_set_filter_heuristics_fixed(png_structp png_ptr, int heuristic_method,
1318 int num_weights, png_const_fixed_point_p filter_weights,
1319 png_const_fixed_point_p filter_costs)
1320{
1321 png_debug(1, "in png_set_filter_heuristics_fixed");
1322
1323 /* The internal API allocates all the arrays and ensures that the elements of
1324 * those arrays are set to the default value.
1325 */
1326 if (!png_init_filter_heuristics(png_ptr, heuristic_method, num_weights))
1327 return;
1328
1329 /* If using the weighted method copy in the weights. */
1330 if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
1331 {
1332 int i;
1333 for (i = 0; i < num_weights; i++)
1334 {
1335 if (filter_weights[i] <= 0)
1336 {
1337 png_ptr->inv_filter_weights[i] =
1338 png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
1339 }
1340
1341 else
1342 {
1343 png_ptr->inv_filter_weights[i] = (png_uint_16)
1344 ((PNG_WEIGHT_FACTOR*filter_weights[i]+PNG_FP_HALF)/PNG_FP_1);
1345
1346 png_ptr->filter_weights[i] = (png_uint_16)((PNG_WEIGHT_FACTOR*
1347 PNG_FP_1+(filter_weights[i]/2))/filter_weights[i]);
1348 }
1349 }
1350
1351 /* Here is where we set the relative costs of the different filters. We
1352 * should take the desired compression level into account when setting
1353 * the costs, so that Paeth, for instance, has a high relative cost at low
1354 * compression levels, while it has a lower relative cost at higher
1355 * compression settings. The filter types are in order of increasing
1356 * relative cost, so it would be possible to do this with an algorithm.
1357 */
1358 for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
1359 if (filter_costs[i] >= PNG_FP_1)
1360 {
1361 png_uint_32 tmp;
1362
1363 /* Use a 32 bit unsigned temporary here because otherwise the
1364 * intermediate value will be a 32 bit *signed* integer (ANSI rules)
1365 * and this will get the wrong answer on division.
1366 */
1367 tmp = PNG_COST_FACTOR*PNG_FP_1 + (filter_costs[i]/2);
1368 tmp /= filter_costs[i];
1369
1370 png_ptr->inv_filter_costs[i] = (png_uint_16)tmp;
1371
1372 tmp = PNG_COST_FACTOR * filter_costs[i] + PNG_FP_HALF;
1373 tmp /= PNG_FP_1;
1374
1375 png_ptr->filter_costs[i] = (png_uint_16)tmp;
1376 }
1377 }
1378}
1379#endif /* FIXED_POINT */
1380#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
1381
1382void PNGAPI
1383png_set_compression_level(png_structp png_ptr, int level)
1384{
1385 png_debug(1, "in png_set_compression_level");
1386
1387 if (png_ptr == NULL)
1388 return;
1389
1390 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_LEVEL;
1391 png_ptr->zlib_level = level;
1392}
1393
1394void PNGAPI
1395png_set_compression_mem_level(png_structp png_ptr, int mem_level)
1396{
1397 png_debug(1, "in png_set_compression_mem_level");
1398
1399 if (png_ptr == NULL)
1400 return;
1401
1402 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL;
1403 png_ptr->zlib_mem_level = mem_level;
1404}
1405
1406void PNGAPI
1407png_set_compression_strategy(png_structp png_ptr, int strategy)
1408{
1409 png_debug(1, "in png_set_compression_strategy");
1410
1411 if (png_ptr == NULL)
1412 return;
1413
1414 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY;
1415 png_ptr->zlib_strategy = strategy;
1416}
1417
1418/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1419 * smaller value of window_bits if it can do so safely.
1420 */
1421void PNGAPI
1422png_set_compression_window_bits(png_structp png_ptr, int window_bits)
1423{
1424 if (png_ptr == NULL)
1425 return;
1426
1427 if (window_bits > 15)
1428 png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
1429
1430 else if (window_bits < 8)
1431 png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
1432
1433#ifndef WBITS_8_OK
1434 /* Avoid libpng bug with 256-byte windows */
1435 if (window_bits == 8)
1436 {
1437 png_warning(png_ptr, "Compression window is being reset to 512");
1438 window_bits = 9;
1439 }
1440
1441#endif
1442 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS;
1443 png_ptr->zlib_window_bits = window_bits;
1444}
1445
1446void PNGAPI
1447png_set_compression_method(png_structp png_ptr, int method)
1448{
1449 png_debug(1, "in png_set_compression_method");
1450
1451 if (png_ptr == NULL)
1452 return;
1453
1454 if (method != 8)
1455 png_warning(png_ptr, "Only compression method 8 is supported by PNG");
1456
1457 png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_METHOD;
1458 png_ptr->zlib_method = method;
1459}
1460
1461/* The following were added to libpng-1.5.4 */
1462#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
1463void PNGAPI
1464png_set_text_compression_level(png_structp png_ptr, int level)
1465{
1466 png_debug(1, "in png_set_text_compression_level");
1467
1468 if (png_ptr == NULL)
1469 return;
1470
1471 png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_LEVEL;
1472 png_ptr->zlib_text_level = level;
1473}
1474
1475void PNGAPI
1476png_set_text_compression_mem_level(png_structp png_ptr, int mem_level)
1477{
1478 png_debug(1, "in png_set_text_compression_mem_level");
1479
1480 if (png_ptr == NULL)
1481 return;
1482
1483 png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_MEM_LEVEL;
1484 png_ptr->zlib_text_mem_level = mem_level;
1485}
1486
1487void PNGAPI
1488png_set_text_compression_strategy(png_structp png_ptr, int strategy)
1489{
1490 png_debug(1, "in png_set_text_compression_strategy");
1491
1492 if (png_ptr == NULL)
1493 return;
1494
1495 png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_STRATEGY;
1496 png_ptr->zlib_text_strategy = strategy;
1497}
1498
1499/* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a
1500 * smaller value of window_bits if it can do so safely.
1501 */
1502void PNGAPI
1503png_set_text_compression_window_bits(png_structp png_ptr, int window_bits)
1504{
1505 if (png_ptr == NULL)
1506 return;
1507
1508 if (window_bits > 15)
1509 png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
1510
1511 else if (window_bits < 8)
1512 png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
1513
1514#ifndef WBITS_8_OK
1515 /* Avoid libpng bug with 256-byte windows */
1516 if (window_bits == 8)
1517 {
1518 png_warning(png_ptr, "Text compression window is being reset to 512");
1519 window_bits = 9;
1520 }
1521
1522#endif
1523 png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS;
1524 png_ptr->zlib_text_window_bits = window_bits;
1525}
1526
1527void PNGAPI
1528png_set_text_compression_method(png_structp png_ptr, int method)
1529{
1530 png_debug(1, "in png_set_text_compression_method");
1531
1532 if (png_ptr == NULL)
1533 return;
1534
1535 if (method != 8)
1536 png_warning(png_ptr, "Only compression method 8 is supported by PNG");
1537
1538 png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_METHOD;
1539 png_ptr->zlib_text_method = method;
1540}
1541#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */
1542/* end of API added to libpng-1.5.4 */
1543
1544void PNGAPI
1545png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn)
1546{
1547 if (png_ptr == NULL)
1548 return;
1549
1550 png_ptr->write_row_fn = write_row_fn;
1551}
1552
1553#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
1554void PNGAPI
1555png_set_write_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
1556 write_user_transform_fn)
1557{
1558 png_debug(1, "in png_set_write_user_transform_fn");
1559
1560 if (png_ptr == NULL)
1561 return;
1562
1563 png_ptr->transformations |= PNG_USER_TRANSFORM;
1564 png_ptr->write_user_transform_fn = write_user_transform_fn;
1565}
1566#endif
1567
1568
1569#ifdef PNG_INFO_IMAGE_SUPPORTED
1570void PNGAPI
1571png_write_png(png_structp png_ptr, png_infop info_ptr,
1572 int transforms, voidp params)
1573{
1574 if (png_ptr == NULL || info_ptr == NULL)
1575 return;
1576
1577 /* Write the file header information. */
1578 png_write_info(png_ptr, info_ptr);
1579
1580 /* ------ these transformations don't touch the info structure ------- */
1581
1582#ifdef PNG_WRITE_INVERT_SUPPORTED
1583 /* Invert monochrome pixels */
1584 if (transforms & PNG_TRANSFORM_INVERT_MONO)
1585 png_set_invert_mono(png_ptr);
1586#endif
1587
1588#ifdef PNG_WRITE_SHIFT_SUPPORTED
1589 /* Shift the pixels up to a legal bit depth and fill in
1590 * as appropriate to correctly scale the image.
1591 */
1592 if ((transforms & PNG_TRANSFORM_SHIFT)
1593 && (info_ptr->valid & PNG_INFO_sBIT))
1594 png_set_shift(png_ptr, &info_ptr->sig_bit);
1595#endif
1596
1597#ifdef PNG_WRITE_PACK_SUPPORTED
1598 /* Pack pixels into bytes */
1599 if (transforms & PNG_TRANSFORM_PACKING)
1600 png_set_packing(png_ptr);
1601#endif
1602
1603#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED
1604 /* Swap location of alpha bytes from ARGB to RGBA */
1605 if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
1606 png_set_swap_alpha(png_ptr);
1607#endif
1608
1609#ifdef PNG_WRITE_FILLER_SUPPORTED
1610 /* Pack XRGB/RGBX/ARGB/RGBA into RGB (4 channels -> 3 channels) */
1611 if (transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER)
1612 png_set_filler(png_ptr, 0, PNG_FILLER_AFTER);
1613
1614 else if (transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE)
1615 png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
1616#endif
1617
1618#ifdef PNG_WRITE_BGR_SUPPORTED
1619 /* Flip BGR pixels to RGB */
1620 if (transforms & PNG_TRANSFORM_BGR)
1621 png_set_bgr(png_ptr);
1622#endif
1623
1624#ifdef PNG_WRITE_SWAP_SUPPORTED
1625 /* Swap bytes of 16-bit files to most significant byte first */
1626 if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
1627 png_set_swap(png_ptr);
1628#endif
1629
1630#ifdef PNG_WRITE_PACKSWAP_SUPPORTED
1631 /* Swap bits of 1, 2, 4 bit packed pixel formats */
1632 if (transforms & PNG_TRANSFORM_PACKSWAP)
1633 png_set_packswap(png_ptr);
1634#endif
1635
1636#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED
1637 /* Invert the alpha channel from opacity to transparency */
1638 if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
1639 png_set_invert_alpha(png_ptr);
1640#endif
1641
1642 /* ----------------------- end of transformations ------------------- */
1643
1644 /* Write the bits */
1645 if (info_ptr->valid & PNG_INFO_IDAT)
1646 png_write_image(png_ptr, info_ptr->row_pointers);
1647
1648 /* It is REQUIRED to call this to finish writing the rest of the file */
1649 png_write_end(png_ptr, info_ptr);
1650
1651 PNG_UNUSED(transforms) /* Quiet compiler warnings */
1652 PNG_UNUSED(params)
1653}
1654#endif
1655#endif /* PNG_WRITE_SUPPORTED */
wxWidgets (Impactor)