/
IMG_png.c
852 lines (766 loc) · 28.9 KB
1
/*
2
SDL_image: An example image loading library for use with SDL
3
Copyright (C) 1997-2017 Sam Lantinga <slouken@libsdl.org>
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
20
21
22
23
24
25
*/
/* This is a PNG image file loading framework */
#include "SDL_image.h"
26
#if !(defined(__APPLE__) || defined(SDL_IMAGE_USE_WIC_BACKEND)) || defined(SDL_IMAGE_USE_COMMON_BACKEND)
27
28
29
#ifdef LOAD_PNG
30
31
#define USE_LIBPNG
32
33
/*=============================================================================
File: SDL_png.c
34
35
Purpose: A PNG loader and saver for the SDL library
Revision:
36
37
Created by: Philippe Lavoie (2 November 1998)
lavoie@zeus.genie.uottawa.ca
38
Modified by:
39
40
41
Copyright notice:
Copyright (C) 1998 Philippe Lavoie
42
43
44
45
46
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
47
48
49
50
51
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free
Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
Comments: The load and save routine are basically the ones you can find
in the example.c file from the libpng distribution.
Changes:
5/17/99 - Modified to use the new SDL data sources - Sam Lantinga
=============================================================================*/
#include "SDL_endian.h"
67
68
69
#ifdef macintosh
#define MACOS
#endif
70
71
#include <png.h>
72
/* Check for the older version of libpng */
73
#if (PNG_LIBPNG_VER_MAJOR == 1)
74
#if (PNG_LIBPNG_VER_MINOR < 5)
75
#define LIBPNG_VERSION_12
76
typedef png_bytep png_const_bytep;
77
78
#endif
#if (PNG_LIBPNG_VER_MINOR < 6)
79
80
typedef png_structp png_const_structrp;
typedef png_infop png_const_inforp;
81
#endif
82
#endif
83
84
static struct {
85
86
int loaded;
void *handle;
87
png_infop (*png_create_info_struct) (png_const_structrp png_ptr);
88
89
png_structp (*png_create_read_struct) (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warn_fn);
void (*png_destroy_read_struct) (png_structpp png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr);
90
91
92
93
94
95
png_uint_32 (*png_get_IHDR) (png_const_structrp png_ptr, png_const_inforp info_ptr, png_uint_32 *width, png_uint_32 *height, int *bit_depth, int *color_type, int *interlace_method, int *compression_method, int *filter_method);
png_voidp (*png_get_io_ptr) (png_const_structrp png_ptr);
png_byte (*png_get_channels) (png_const_structrp png_ptr, png_const_inforp info_ptr);
png_uint_32 (*png_get_PLTE) (png_const_structrp png_ptr, png_infop info_ptr, png_colorp *palette, int *num_palette);
png_uint_32 (*png_get_tRNS) (png_const_structrp png_ptr, png_infop info_ptr, png_bytep *trans, int *num_trans, png_color_16p *trans_values);
png_uint_32 (*png_get_valid) (png_const_structrp png_ptr, png_const_inforp info_ptr, png_uint_32 flag);
96
97
98
99
100
101
102
103
void (*png_read_image) (png_structp png_ptr, png_bytepp image);
void (*png_read_info) (png_structp png_ptr, png_infop info_ptr);
void (*png_read_update_info) (png_structp png_ptr, png_infop info_ptr);
void (*png_set_expand) (png_structp png_ptr);
void (*png_set_gray_to_rgb) (png_structp png_ptr);
void (*png_set_packing) (png_structp png_ptr);
void (*png_set_read_fn) (png_structp png_ptr, png_voidp io_ptr, png_rw_ptr read_data_fn);
void (*png_set_strip_16) (png_structp png_ptr);
104
int (*png_sig_cmp) (png_const_bytep sig, png_size_t start, png_size_t num_to_check);
105
#ifndef LIBPNG_VERSION_12
106
jmp_buf* (*png_set_longjmp_fn) (png_structp, png_longjmp_ptr, size_t);
107
#endif
108
109
110
111
112
113
114
115
png_structp (*png_create_write_struct) (png_const_charp user_png_ver, png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warn_fn);
void (*png_destroy_write_struct) (png_structpp png_ptr_ptr, png_infopp info_ptr_ptr);
void (*png_set_write_fn) (png_structp png_ptr, png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn);
void (*png_set_IHDR) (png_structp png_ptr, png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth, int color_type, int interlace_type, int compression_type, int filter_type);
void (*png_write_info) (png_structp png_ptr, png_infop info_ptr);
void (*png_set_rows) (png_structp png_ptr, png_infop info_ptr, png_bytepp row_pointers);
void (*png_write_png) (png_structp png_ptr, png_infop info_ptr, int transforms, png_voidp params);
void (*png_set_PLTE) (png_structp png_ptr, png_infop info_ptr, png_colorp palette, int num_palette);
116
117
118
} lib;
#ifdef LOAD_PNG_DYNAMIC
119
int IMG_InitPNG()
120
{
121
122
123
124
125
126
if ( lib.loaded == 0 ) {
lib.handle = SDL_LoadObject(LOAD_PNG_DYNAMIC);
if ( lib.handle == NULL ) {
return -1;
}
lib.png_create_info_struct =
127
(png_infop (*) (png_const_structrp))
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
SDL_LoadFunction(lib.handle, "png_create_info_struct");
if ( lib.png_create_info_struct == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_create_read_struct =
(png_structp (*) (png_const_charp, png_voidp, png_error_ptr, png_error_ptr))
SDL_LoadFunction(lib.handle, "png_create_read_struct");
if ( lib.png_create_read_struct == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_destroy_read_struct =
(void (*) (png_structpp, png_infopp, png_infopp))
SDL_LoadFunction(lib.handle, "png_destroy_read_struct");
if ( lib.png_destroy_read_struct == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_get_IHDR =
148
(png_uint_32 (*) (png_const_structrp, png_const_inforp, png_uint_32 *, png_uint_32 *, int *, int *, int *, int *, int *))
149
150
151
152
153
154
SDL_LoadFunction(lib.handle, "png_get_IHDR");
if ( lib.png_get_IHDR == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_get_channels =
155
(png_byte (*) (png_const_structrp, png_const_inforp))
156
157
158
159
160
161
SDL_LoadFunction(lib.handle, "png_get_channels");
if ( lib.png_get_channels == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_get_io_ptr =
162
(png_voidp (*) (png_const_structrp))
163
164
165
166
167
168
SDL_LoadFunction(lib.handle, "png_get_io_ptr");
if ( lib.png_get_io_ptr == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_get_PLTE =
169
(png_uint_32 (*) (png_const_structrp, png_infop, png_colorp *, int *))
170
171
172
173
174
175
SDL_LoadFunction(lib.handle, "png_get_PLTE");
if ( lib.png_get_PLTE == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_get_tRNS =
176
(png_uint_32 (*) (png_const_structrp, png_infop, png_bytep *, int *, png_color_16p *))
177
178
179
180
181
182
SDL_LoadFunction(lib.handle, "png_get_tRNS");
if ( lib.png_get_tRNS == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_get_valid =
183
(png_uint_32 (*) (png_const_structrp, png_const_inforp, png_uint_32))
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
SDL_LoadFunction(lib.handle, "png_get_valid");
if ( lib.png_get_valid == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_read_image =
(void (*) (png_structp, png_bytepp))
SDL_LoadFunction(lib.handle, "png_read_image");
if ( lib.png_read_image == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_read_info =
(void (*) (png_structp, png_infop))
SDL_LoadFunction(lib.handle, "png_read_info");
if ( lib.png_read_info == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_read_update_info =
(void (*) (png_structp, png_infop))
SDL_LoadFunction(lib.handle, "png_read_update_info");
if ( lib.png_read_update_info == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_set_expand =
(void (*) (png_structp))
SDL_LoadFunction(lib.handle, "png_set_expand");
if ( lib.png_set_expand == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_set_gray_to_rgb =
(void (*) (png_structp))
SDL_LoadFunction(lib.handle, "png_set_gray_to_rgb");
if ( lib.png_set_gray_to_rgb == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_set_packing =
(void (*) (png_structp))
SDL_LoadFunction(lib.handle, "png_set_packing");
if ( lib.png_set_packing == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_set_read_fn =
(void (*) (png_structp, png_voidp, png_rw_ptr))
SDL_LoadFunction(lib.handle, "png_set_read_fn");
if ( lib.png_set_read_fn == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_set_strip_16 =
(void (*) (png_structp))
SDL_LoadFunction(lib.handle, "png_set_strip_16");
if ( lib.png_set_strip_16 == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_sig_cmp =
246
(int (*) (png_const_bytep, png_size_t, png_size_t))
247
248
249
250
251
SDL_LoadFunction(lib.handle, "png_sig_cmp");
if ( lib.png_sig_cmp == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
252
#ifndef LIBPNG_VERSION_12
253
254
255
256
257
258
259
lib.png_set_longjmp_fn =
(jmp_buf * (*) (png_structp, png_longjmp_ptr, size_t))
SDL_LoadFunction(lib.handle, "png_set_longjmp_fn");
if ( lib.png_set_longjmp_fn == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
260
#endif
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
lib.png_create_write_struct =
(png_structp (*) (png_const_charp, png_voidp, png_error_ptr, png_error_ptr))
SDL_LoadFunction(lib.handle, "png_create_write_struct");
if ( lib.png_create_write_struct == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_destroy_write_struct =
(void (*) (png_structpp, png_infopp))
SDL_LoadFunction(lib.handle, "png_destroy_write_struct");
if ( lib.png_destroy_write_struct == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_set_write_fn =
(void (*) (png_structp, png_voidp, png_rw_ptr, png_flush_ptr))
SDL_LoadFunction(lib.handle, "png_set_write_fn");
if ( lib.png_set_write_fn == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_set_IHDR =
(void (*) (png_structp, png_infop, png_uint_32, png_uint_32, int, int, int, int, int))
SDL_LoadFunction(lib.handle, "png_set_IHDR");
if ( lib.png_set_IHDR == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_write_info =
(void (*) (png_structp, png_infop))
SDL_LoadFunction(lib.handle, "png_write_info");
if ( lib.png_write_info == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_set_rows =
(void (*) (png_structp, png_infop, png_bytepp))
SDL_LoadFunction(lib.handle, "png_set_rows");
if ( lib.png_set_rows == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_write_png =
(void (*) (png_structp, png_infop, int, png_voidp))
SDL_LoadFunction(lib.handle, "png_write_png");
if ( lib.png_write_png == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_set_PLTE =
(void (*) (png_structp, png_infop, png_colorp, int))
SDL_LoadFunction(lib.handle, "png_set_PLTE");
if ( lib.png_set_PLTE == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
317
318
}
++lib.loaded;
319
320
return 0;
321
}
322
void IMG_QuitPNG()
323
{
324
325
326
327
328
329
330
if ( lib.loaded == 0 ) {
return;
}
if ( lib.loaded == 1 ) {
SDL_UnloadObject(lib.handle);
}
--lib.loaded;
331
332
}
#else
333
int IMG_InitPNG()
334
{
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
if ( lib.loaded == 0 ) {
lib.png_create_info_struct = png_create_info_struct;
lib.png_create_read_struct = png_create_read_struct;
lib.png_destroy_read_struct = png_destroy_read_struct;
lib.png_get_IHDR = png_get_IHDR;
lib.png_get_channels = png_get_channels;
lib.png_get_io_ptr = png_get_io_ptr;
lib.png_get_PLTE = png_get_PLTE;
lib.png_get_tRNS = png_get_tRNS;
lib.png_get_valid = png_get_valid;
lib.png_read_image = png_read_image;
lib.png_read_info = png_read_info;
lib.png_read_update_info = png_read_update_info;
lib.png_set_expand = png_set_expand;
lib.png_set_gray_to_rgb = png_set_gray_to_rgb;
lib.png_set_packing = png_set_packing;
lib.png_set_read_fn = png_set_read_fn;
lib.png_set_strip_16 = png_set_strip_16;
lib.png_sig_cmp = png_sig_cmp;
354
#ifndef LIBPNG_VERSION_12
355
lib.png_set_longjmp_fn = png_set_longjmp_fn;
356
#endif
357
358
359
360
361
362
363
364
lib.png_create_write_struct = png_create_write_struct;
lib.png_destroy_write_struct = png_destroy_write_struct;
lib.png_set_write_fn = png_set_write_fn;
lib.png_set_IHDR = png_set_IHDR;
lib.png_write_info = png_write_info;
lib.png_set_rows = png_set_rows;
lib.png_write_png = png_write_png;
lib.png_set_PLTE = png_set_PLTE;
365
366
}
++lib.loaded;
367
368
return 0;
369
}
370
void IMG_QuitPNG()
371
{
372
373
374
375
376
377
if ( lib.loaded == 0 ) {
return;
}
if ( lib.loaded == 1 ) {
}
--lib.loaded;
378
379
380
}
#endif /* LOAD_PNG_DYNAMIC */
381
382
383
/* See if an image is contained in a data source */
int IMG_isPNG(SDL_RWops *src)
{
384
385
386
387
Sint64 start;
int is_PNG;
Uint8 magic[4];
388
if ( !src ) {
389
return 0;
390
391
}
392
393
394
start = SDL_RWtell(src);
is_PNG = 0;
if ( SDL_RWread(src, magic, 1, sizeof(magic)) == sizeof(magic) ) {
395
396
397
398
if ( magic[0] == 0x89 &&
magic[1] == 'P' &&
magic[2] == 'N' &&
magic[3] == 'G' ) {
399
400
401
402
403
is_PNG = 1;
}
}
SDL_RWseek(src, start, RW_SEEK_SET);
return(is_PNG);
404
405
406
407
408
}
/* Load a PNG type image from an SDL datasource */
static void png_read_data(png_structp ctx, png_bytep area, png_size_t size)
{
409
SDL_RWops *src;
410
411
412
src = (SDL_RWops *)lib.png_get_io_ptr(ctx);
SDL_RWread(src, area, size, 1);
413
414
415
}
SDL_Surface *IMG_LoadPNG_RW(SDL_RWops *src)
{
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
Sint64 start;
const char *error;
SDL_Surface *volatile surface;
png_structp png_ptr;
png_infop info_ptr;
png_uint_32 width, height;
int bit_depth, color_type, interlace_type, num_channels;
Uint32 Rmask;
Uint32 Gmask;
Uint32 Bmask;
Uint32 Amask;
SDL_Palette *palette;
png_bytep *volatile row_pointers;
int row, i;
int ckey = -1;
png_color_16 *transv;
if ( !src ) {
/* The error message has been set in SDL_RWFromFile */
return NULL;
}
start = SDL_RWtell(src);
439
if ( (IMG_Init(IMG_INIT_PNG) & IMG_INIT_PNG) == 0 ) {
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
return NULL;
}
/* Initialize the data we will clean up when we're done */
error = NULL;
png_ptr = NULL; info_ptr = NULL; row_pointers = NULL; surface = NULL;
/* Create the PNG loading context structure */
png_ptr = lib.png_create_read_struct(PNG_LIBPNG_VER_STRING,
NULL,NULL,NULL);
if (png_ptr == NULL){
error = "Couldn't allocate memory for PNG file or incompatible PNG dll";
goto done;
}
/* Allocate/initialize the memory for image information. REQUIRED. */
info_ptr = lib.png_create_info_struct(png_ptr);
if (info_ptr == NULL) {
error = "Couldn't create image information for PNG file";
goto done;
}
/* Set error handling if you are using setjmp/longjmp method (this is
* the normal method of doing things with libpng). REQUIRED unless you
* set up your own error handlers in png_create_read_struct() earlier.
*/
466
#ifndef LIBPNG_VERSION_12
467
if ( setjmp(*lib.png_set_longjmp_fn(png_ptr, longjmp, sizeof (jmp_buf))) )
468
#else
469
if ( setjmp(png_ptr->jmpbuf) )
470
#endif
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
{
error = "Error reading the PNG file.";
goto done;
}
/* Set up the input control */
lib.png_set_read_fn(png_ptr, src, png_read_data);
/* Read PNG header info */
lib.png_read_info(png_ptr, info_ptr);
lib.png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth,
&color_type, &interlace_type, NULL, NULL);
/* tell libpng to strip 16 bit/color files down to 8 bits/color */
lib.png_set_strip_16(png_ptr) ;
/* Extract multiple pixels with bit depths of 1, 2, and 4 from a single
* byte into separate bytes (useful for paletted and grayscale images).
*/
lib.png_set_packing(png_ptr);
/* scale greyscale values to the range 0..255 */
if (color_type == PNG_COLOR_TYPE_GRAY)
lib.png_set_expand(png_ptr);
/* For images with a single "transparent colour", set colour key;
if more than one index has transparency, or if partially transparent
entries exist, use full alpha channel */
if (lib.png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) {
500
int num_trans;
501
Uint8 *trans;
502
lib.png_get_tRNS(png_ptr, info_ptr, &trans, &num_trans, &transv);
503
504
505
506
if (color_type == PNG_COLOR_TYPE_PALETTE) {
/* Check if all tRNS entries are opaque except one */
int j, t = -1;
for (j = 0; j < num_trans; j++) {
507
508
509
if (trans[j] == 0) {
if (t >= 0) {
break;
510
}
511
512
513
514
515
t = j;
} else if (trans[j] != 255) {
break;
}
}
516
if (j == num_trans) {
517
518
/* exactly one transparent index */
ckey = t;
519
} else {
520
521
/* more than one transparent index, or translucency */
lib.png_set_expand(png_ptr);
522
}
523
} else {
524
ckey = 0; /* actual value will be set later */
525
}
526
527
528
529
530
531
532
533
534
535
536
537
538
539
}
if ( color_type == PNG_COLOR_TYPE_GRAY_ALPHA )
lib.png_set_gray_to_rgb(png_ptr);
lib.png_read_update_info(png_ptr, info_ptr);
lib.png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth,
&color_type, &interlace_type, NULL, NULL);
/* Allocate the SDL surface to hold the image */
Rmask = Gmask = Bmask = Amask = 0 ;
num_channels = lib.png_get_channels(png_ptr, info_ptr);
if ( num_channels >= 3 ) {
540
#if SDL_BYTEORDER == SDL_LIL_ENDIAN
541
542
543
544
Rmask = 0x000000FF;
Gmask = 0x0000FF00;
Bmask = 0x00FF0000;
Amask = (num_channels == 4) ? 0xFF000000 : 0;
545
#else
546
547
548
549
550
int s = (num_channels == 4) ? 0 : 8;
Rmask = 0xFF000000 >> s;
Gmask = 0x00FF0000 >> s;
Bmask = 0x0000FF00 >> s;
Amask = 0x000000FF >> s;
551
#endif
552
553
554
555
556
557
558
559
560
}
surface = SDL_CreateRGBSurface(SDL_SWSURFACE, width, height,
bit_depth*num_channels, Rmask,Gmask,Bmask,Amask);
if ( surface == NULL ) {
error = SDL_GetError();
goto done;
}
if (ckey != -1) {
561
if (color_type != PNG_COLOR_TYPE_PALETTE) {
562
/* FIXME: Should these be truncated or shifted down? */
563
564
565
566
567
568
ckey = SDL_MapRGB(surface->format,
(Uint8)transv->red,
(Uint8)transv->green,
(Uint8)transv->blue);
}
SDL_SetColorKey(surface, SDL_TRUE, ckey);
569
570
571
572
}
/* Create the array of pointers to image data */
row_pointers = (png_bytep*) SDL_malloc(sizeof(png_bytep)*height);
573
if (!row_pointers) {
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
error = "Out of memory";
goto done;
}
for (row = 0; row < (int)height; row++) {
row_pointers[row] = (png_bytep)
(Uint8 *)surface->pixels + row*surface->pitch;
}
/* Read the entire image in one go */
lib.png_read_image(png_ptr, row_pointers);
/* and we're done! (png_read_end() can be omitted if no processing of
* post-IDAT text/time/etc. is desired)
* In some cases it can't read PNG's created by some popular programs (ACDSEE),
* we do not want to process comments, so we omit png_read_end
lib.png_read_end(png_ptr, info_ptr);
*/
/* Load the palette, if any */
palette = surface->format->palette;
if ( palette ) {
int png_num_palette;
png_colorp png_palette;
lib.png_get_PLTE(png_ptr, info_ptr, &png_palette, &png_num_palette);
if (color_type == PNG_COLOR_TYPE_GRAY) {
600
601
602
603
604
605
palette->ncolors = 256;
for (i = 0; i < 256; i++) {
palette->colors[i].r = i;
palette->colors[i].g = i;
palette->colors[i].b = i;
}
606
} else if (png_num_palette > 0 ) {
607
608
609
610
611
612
palette->ncolors = png_num_palette;
for ( i=0; i<png_num_palette; ++i ) {
palette->colors[i].b = png_palette[i].blue;
palette->colors[i].g = png_palette[i].green;
palette->colors[i].r = png_palette[i].red;
}
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
}
}
done: /* Clean up and return */
if ( png_ptr ) {
lib.png_destroy_read_struct(&png_ptr,
info_ptr ? &info_ptr : (png_infopp)0,
(png_infopp)0);
}
if ( row_pointers ) {
SDL_free(row_pointers);
}
if ( error ) {
SDL_RWseek(src, start, RW_SEEK_SET);
if ( surface ) {
SDL_FreeSurface(surface);
surface = NULL;
}
631
IMG_SetError("%s", error);
632
633
}
return(surface);
634
635
636
637
}
#else
638
639
int IMG_InitPNG()
{
640
641
IMG_SetError("PNG images are not supported");
return(-1);
642
643
644
645
646
647
}
void IMG_QuitPNG()
{
}
648
649
650
/* See if an image is contained in a data source */
int IMG_isPNG(SDL_RWops *src)
{
651
return(0);
652
653
654
655
656
}
/* Load a PNG type image from an SDL datasource */
SDL_Surface *IMG_LoadPNG_RW(SDL_RWops *src)
{
657
return(NULL);
658
659
660
}
#endif /* LOAD_PNG */
661
662
#endif /* !defined(__APPLE__) || defined(SDL_IMAGE_USE_COMMON_BACKEND) */
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
/* We'll always have PNG save support */
#define SAVE_PNG
#ifdef SAVE_PNG
int IMG_SavePNG(SDL_Surface *surface, const char *file)
{
SDL_RWops *dst = SDL_RWFromFile(file, "wb");
if (dst) {
return IMG_SavePNG_RW(surface, dst, 1);
} else {
return -1;
}
}
679
680
681
682
683
684
685
686
687
#if SDL_BYTEORDER == SDL_LIL_ENDIAN
static const Uint32 png_format = SDL_PIXELFORMAT_ABGR8888;
#else
static const Uint32 png_format = SDL_PIXELFORMAT_RGBA8888;
#endif
#ifdef USE_LIBPNG
static void png_write_data(png_structp png_ptr, png_bytep src, png_size_t size)
688
{
689
690
691
692
693
694
695
SDL_RWops *dst = (SDL_RWops *)lib.png_get_io_ptr(png_ptr);
SDL_RWwrite(dst, src, size, 1);
}
static void png_flush_data(png_structp png_ptr)
{
}
696
697
698
static int IMG_SavePNG_RW_libpng(SDL_Surface *surface, SDL_RWops *dst, int freedst)
{
699
if (dst) {
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
png_structp png_ptr;
png_infop info_ptr;
png_colorp color_ptr = NULL;
SDL_Surface *source = surface;
SDL_Palette *palette;
int png_color_type = PNG_COLOR_TYPE_RGB_ALPHA;
png_ptr = lib.png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (png_ptr == NULL) {
SDL_SetError("Couldn't allocate memory for PNG file or incompatible PNG dll");
return -1;
}
info_ptr = lib.png_create_info_struct(png_ptr);
if (info_ptr == NULL) {
lib.png_destroy_write_struct(&png_ptr, NULL);
SDL_SetError("Couldn't create image information for PNG file");
return -1;
}
#ifndef LIBPNG_VERSION_12
if (setjmp(*lib.png_set_longjmp_fn(png_ptr, longjmp, sizeof (jmp_buf))))
722
#else
723
if (setjmp(png_ptr->jmpbuf))
724
#endif
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
{
lib.png_destroy_write_struct(&png_ptr, &info_ptr);
SDL_SetError("Error writing the PNG file.");
return -1;
}
palette = surface->format->palette;
if (palette) {
const int ncolors = palette->ncolors;
int i;
color_ptr = SDL_malloc(sizeof(png_colorp) * ncolors);
if (color_ptr == NULL)
{
lib.png_destroy_write_struct(&png_ptr, &info_ptr);
SDL_SetError("Couldn't create palette for PNG file");
return -1;
}
for (i = 0; i < ncolors; i++) {
color_ptr[i].red = palette->colors[i].r;
color_ptr[i].green = palette->colors[i].g;
color_ptr[i].blue = palette->colors[i].b;
}
lib.png_set_PLTE(png_ptr, info_ptr, color_ptr, ncolors);
png_color_type = PNG_COLOR_TYPE_PALETTE;
}
else if (surface->format->format != png_format) {
source = SDL_ConvertSurfaceFormat(surface, png_format, 0);
}
lib.png_set_write_fn(png_ptr, dst, png_write_data, png_flush_data);
lib.png_set_IHDR(png_ptr, info_ptr, surface->w, surface->h,
8, png_color_type, PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
if (source) {
png_bytep *row_pointers;
int row;
row_pointers = (png_bytep *) SDL_malloc(sizeof(png_bytep) * source->h);
if (!row_pointers) {
lib.png_destroy_write_struct(&png_ptr, &info_ptr);
SDL_SetError("Out of memory");
return -1;
}
for (row = 0; row < (int)source->h; row++) {
row_pointers[row] = (png_bytep) (Uint8 *) source->pixels + row * source->pitch;
}
lib.png_set_rows(png_ptr, info_ptr, row_pointers);
lib.png_write_png(png_ptr, info_ptr, PNG_TRANSFORM_IDENTITY, NULL);
SDL_free(row_pointers);
if (source != surface) {
SDL_FreeSurface(source);
}
}
lib.png_destroy_write_struct(&png_ptr, &info_ptr);
if (color_ptr) {
SDL_free(color_ptr);
}
if (freedst) {
SDL_RWclose(dst);
}
} else {
SDL_SetError("Passed NULL dst");
return -1;
}
return 0;
}
#endif /* USE_LIBPNG */
#include "miniz.h"
static int IMG_SavePNG_RW_miniz(SDL_Surface *surface, SDL_RWops *dst, int freedst)
{
int result = -1;
if (dst) {
806
size_t size;
807
void *png = NULL;
808
809
if (surface->format->format == png_format) {
810
png = tdefl_write_image_to_png_file_in_memory(surface->pixels, surface->w, surface->h, surface->format->BytesPerPixel, surface->pitch, &size);
811
812
813
} else {
SDL_Surface *cvt = SDL_ConvertSurfaceFormat(surface, png_format, 0);
if (cvt) {
814
png = tdefl_write_image_to_png_file_in_memory(cvt->pixels, cvt->w, cvt->h, cvt->format->BytesPerPixel, cvt->pitch, &size);
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
SDL_FreeSurface(cvt);
}
}
if (png) {
if (SDL_RWwrite(dst, png, size, 1)) {
result = 0;
}
SDL_free(png);
} else {
SDL_SetError("Failed to convert and save image");
}
if (freedst) {
SDL_RWclose(dst);
}
} else {
SDL_SetError("Passed NULL dst");
}
return result;
}
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
int IMG_SavePNG_RW(SDL_Surface *surface, SDL_RWops *dst, int freedst)
{
static int (*rw_func)(SDL_Surface *surface, SDL_RWops *dst, int freedst);
if (!rw_func)
{
#ifdef USE_LIBPNG
if (IMG_Init(IMG_INIT_PNG)) {
rw_func = IMG_SavePNG_RW_libpng;
} else
#endif
rw_func = IMG_SavePNG_RW_miniz;
}
return rw_func(surface, dst, freedst);
}
852
#endif /* SAVE_PNG */