/
IMG_png.c
599 lines (541 loc) · 18.1 KB
1
/*
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
SDL_image: An example image loading library for use with SDL
Copyright (C) 1997-2012 Sam Lantinga <slouken@libsdl.org>
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
#if !defined(__APPLE__) || defined(SDL_IMAGE_USE_COMMON_BACKEND)
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
/* This is a PNG image file loading framework */
#include <stdlib.h>
#include <stdio.h>
#include "SDL_image.h"
#ifdef LOAD_PNG
/*=============================================================================
File: SDL_png.c
Purpose: A PNG loader and saver for the SDL library
Revision:
Created by: Philippe Lavoie (2 November 1998)
lavoie@zeus.genie.uottawa.ca
Modified by:
Copyright notice:
Copyright (C) 1998 Philippe Lavoie
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.
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.
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"
68
69
70
#ifdef macintosh
#define MACOS
#endif
71
72
#include <png.h>
73
/* Check for the older version of libpng */
74
75
#if (PNG_LIBPNG_VER_MAJOR == 1)
#if (PNG_LIBPNG_VER_MINOR < 5)
76
#define LIBPNG_VERSION_12
77
78
79
80
81
82
83
84
typedef png_bytep png_const_bytep;
#endif
#if (PNG_LIBPNG_VER_MINOR < 6)
typedef png_structp png_const_structrp;
typedef png_infop png_const_inforp;
typedef png_structp png_structrp;
typedef png_infop png_inforp;
#endif
85
#endif
86
87
88
89
static struct {
int loaded;
void *handle;
90
png_infop (*png_create_info_struct) (png_const_structrp png_ptr);
91
92
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);
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
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_inforp info_ptr, png_colorp *palette, int *num_palette);
png_uint_32 (*png_get_tRNS) (png_const_structrp png_ptr, png_inforp 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);
void (*png_read_image) (png_structrp png_ptr, png_bytepp image);
void (*png_read_info) (png_structrp png_ptr, png_inforp info_ptr);
void (*png_read_update_info) (png_structrp png_ptr, png_inforp info_ptr);
void (*png_set_expand) (png_structrp png_ptr);
void (*png_set_gray_to_rgb) (png_structrp png_ptr);
void (*png_set_packing) (png_structrp png_ptr);
void (*png_set_read_fn) (png_structrp png_ptr, png_voidp io_ptr, png_rw_ptr read_data_fn);
void (*png_set_strip_16) (png_structrp png_ptr);
int (*png_set_interlace_handling) (png_structp png_ptr);
int (*png_sig_cmp) (png_const_bytep sig, png_size_t start, png_size_t num_to_check);
109
#ifndef LIBPNG_VERSION_12
110
jmp_buf* (*png_set_longjmp_fn) (png_structrp, png_longjmp_ptr, size_t);
111
#endif
112
113
114
} lib;
#ifdef LOAD_PNG_DYNAMIC
115
int IMG_InitPNG()
116
117
118
119
120
121
122
{
if ( lib.loaded == 0 ) {
lib.handle = SDL_LoadObject(LOAD_PNG_DYNAMIC);
if ( lib.handle == NULL ) {
return -1;
}
lib.png_create_info_struct =
123
(png_infop (*) (png_const_structrp))
124
125
126
127
128
129
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 =
130
(png_structrp (*) (png_const_charp, png_voidp, png_error_ptr, png_error_ptr))
131
132
133
134
135
136
137
138
139
140
141
142
143
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 =
144
(png_uint_32 (*) (png_const_structrp, png_const_inforp, png_uint_32 *, png_uint_32 *, int *, int *, int *, int *, int *))
145
146
147
148
149
SDL_LoadFunction(lib.handle, "png_get_IHDR");
if ( lib.png_get_IHDR == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
150
lib.png_get_channels =
151
(png_byte (*) (png_const_structrp, png_const_inforp))
152
153
154
155
156
SDL_LoadFunction(lib.handle, "png_get_channels");
if ( lib.png_get_channels == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
157
lib.png_get_io_ptr =
158
(png_voidp (*) (png_const_structrp))
159
160
161
162
163
SDL_LoadFunction(lib.handle, "png_get_io_ptr");
if ( lib.png_get_io_ptr == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
164
lib.png_get_PLTE =
165
(png_uint_32 (*) (png_const_structrp, png_inforp, png_colorp *, int *))
166
167
168
169
170
SDL_LoadFunction(lib.handle, "png_get_PLTE");
if ( lib.png_get_PLTE == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
171
lib.png_get_tRNS =
172
(png_uint_32 (*) (png_const_structrp, png_inforp, png_bytep *, int *, png_color_16p *))
173
174
175
176
177
178
SDL_LoadFunction(lib.handle, "png_get_tRNS");
if ( lib.png_get_tRNS == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_get_valid =
179
(png_uint_32 (*) (png_const_structrp, png_const_inforp, png_uint_32))
180
181
182
183
184
185
SDL_LoadFunction(lib.handle, "png_get_valid");
if ( lib.png_get_valid == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_read_image =
186
(void (*) (png_structrp, png_bytepp))
187
188
189
190
191
192
SDL_LoadFunction(lib.handle, "png_read_image");
if ( lib.png_read_image == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_read_info =
193
(void (*) (png_structrp, png_inforp))
194
195
196
197
198
199
SDL_LoadFunction(lib.handle, "png_read_info");
if ( lib.png_read_info == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_read_update_info =
200
(void (*) (png_structrp, png_inforp))
201
202
203
204
205
206
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 =
207
(void (*) (png_structrp))
208
209
210
211
212
213
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 =
214
(void (*) (png_structrp))
215
216
217
218
219
220
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 =
221
(void (*) (png_structrp))
222
223
224
225
226
227
SDL_LoadFunction(lib.handle, "png_set_packing");
if ( lib.png_set_packing == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
lib.png_set_read_fn =
228
(void (*) (png_structrp, png_voidp, png_rw_ptr))
229
230
231
232
233
234
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 =
235
(void (*) (png_structrp))
236
237
238
239
240
SDL_LoadFunction(lib.handle, "png_set_strip_16");
if ( lib.png_set_strip_16 == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
241
242
243
244
245
246
247
lib.png_set_interlace_handling =
(void (*) (png_structp))
SDL_LoadFunction(lib.handle, "png_set_interlace_handling");
if ( lib.png_set_interlace_handling == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
248
lib.png_sig_cmp =
249
(int (*) (png_const_bytep, png_size_t, png_size_t))
250
251
252
253
254
SDL_LoadFunction(lib.handle, "png_sig_cmp");
if ( lib.png_sig_cmp == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
255
#ifndef LIBPNG_VERSION_12
256
lib.png_set_longjmp_fn =
257
(jmp_buf * (*) (png_structrp, png_longjmp_ptr, size_t))
258
259
260
261
262
SDL_LoadFunction(lib.handle, "png_set_longjmp_fn");
if ( lib.png_set_longjmp_fn == NULL ) {
SDL_UnloadObject(lib.handle);
return -1;
}
263
#endif
264
265
266
267
268
}
++lib.loaded;
return 0;
}
269
void IMG_QuitPNG()
270
271
272
273
274
275
276
277
278
279
{
if ( lib.loaded == 0 ) {
return;
}
if ( lib.loaded == 1 ) {
SDL_UnloadObject(lib.handle);
}
--lib.loaded;
}
#else
280
int IMG_InitPNG()
281
282
283
284
285
286
{
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;
287
lib.png_get_channels = png_get_channels;
288
lib.png_get_io_ptr = png_get_io_ptr;
289
lib.png_get_PLTE = png_get_PLTE;
290
291
292
293
294
295
296
297
298
299
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;
300
lib.png_set_interlace_handling = png_set_interlace_handling;
301
lib.png_sig_cmp = png_sig_cmp;
302
303
304
#ifndef LIBPNG_VERSION_12
lib.png_set_longjmp_fn = png_set_longjmp_fn;
#endif
305
306
}
++lib.loaded;
307
308
return 0;
309
}
310
void IMG_QuitPNG()
311
312
313
314
315
316
317
318
319
320
{
if ( lib.loaded == 0 ) {
return;
}
if ( lib.loaded == 1 ) {
}
--lib.loaded;
}
#endif /* LOAD_PNG_DYNAMIC */
321
322
323
/* See if an image is contained in a data source */
int IMG_isPNG(SDL_RWops *src)
{
324
325
int start;
int is_PNG;
326
Uint8 magic[4];
327
328
329
if ( !src )
return 0;
330
331
start = SDL_RWtell(src);
is_PNG = 0;
332
333
334
335
336
if ( SDL_RWread(src, magic, 1, sizeof(magic)) == sizeof(magic) ) {
if ( magic[0] == 0x89 &&
magic[1] == 'P' &&
magic[2] == 'N' &&
magic[3] == 'G' ) {
337
338
is_PNG = 1;
}
339
}
340
SDL_RWseek(src, start, RW_SEEK_SET);
341
return(is_PNG);
342
343
344
345
346
347
348
}
/* Load a PNG type image from an SDL datasource */
static void png_read_data(png_structp ctx, png_bytep area, png_size_t size)
{
SDL_RWops *src;
349
src = (SDL_RWops *)lib.png_get_io_ptr(ctx);
350
351
352
353
SDL_RWread(src, area, size, 1);
}
SDL_Surface *IMG_LoadPNG_RW(SDL_RWops *src)
{
354
355
int start;
const char *error;
356
SDL_Surface *volatile surface;
357
358
359
png_structp png_ptr;
png_infop info_ptr;
png_uint_32 width, height;
360
int bit_depth, color_type, interlace_type, num_channels;
361
362
363
364
365
Uint32 Rmask;
Uint32 Gmask;
Uint32 Bmask;
Uint32 Amask;
SDL_Palette *palette;
366
png_bytep *volatile row_pointers;
367
int row, i;
368
volatile int ckey = -1;
369
370
png_color_16 *transv;
371
372
373
374
if ( !src ) {
/* The error message has been set in SDL_RWFromFile */
return NULL;
}
375
start = SDL_RWtell(src);
376
377
if ( !IMG_Init(IMG_INIT_PNG) ) {
378
379
380
return NULL;
}
381
/* Initialize the data we will clean up when we're done */
382
error = NULL;
383
384
385
png_ptr = NULL; info_ptr = NULL; row_pointers = NULL; surface = NULL;
/* Create the PNG loading context structure */
386
png_ptr = lib.png_create_read_struct(PNG_LIBPNG_VER_STRING,
387
388
NULL,NULL,NULL);
if (png_ptr == NULL){
389
error = "Couldn't allocate memory for PNG file or incompatible PNG dll";
390
391
392
393
goto done;
}
/* Allocate/initialize the memory for image information. REQUIRED. */
394
info_ptr = lib.png_create_info_struct(png_ptr);
395
if (info_ptr == NULL) {
396
error = "Couldn't create image information for PNG file";
397
398
399
400
401
402
403
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.
*/
404
405
406
407
408
409
#ifndef LIBPNG_VERSION_12
if ( setjmp(*lib.png_set_longjmp_fn(png_ptr, longjmp, sizeof (jmp_buf))) )
#else
if ( setjmp(png_ptr->jmpbuf) )
#endif
{
410
error = "Error reading the PNG file.";
411
412
413
414
goto done;
}
/* Set up the input control */
415
lib.png_set_read_fn(png_ptr, src, png_read_data);
416
417
/* Read PNG header info */
418
419
lib.png_read_info(png_ptr, info_ptr);
lib.png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth,
420
421
422
&color_type, &interlace_type, NULL, NULL);
/* tell libpng to strip 16 bit/color files down to 8 bits/color */
423
lib.png_set_strip_16(png_ptr) ;
424
425
426
427
/* tell libpng to de-interlace (if the image is interlaced) */
lib.png_set_interlace_handling(png_ptr) ;
428
429
430
/* Extract multiple pixels with bit depths of 1, 2, and 4 from a single
* byte into separate bytes (useful for paletted and grayscale images).
*/
431
lib.png_set_packing(png_ptr);
432
433
434
/* scale greyscale values to the range 0..255 */
if(color_type == PNG_COLOR_TYPE_GRAY)
435
lib.png_set_expand(png_ptr);
436
437
/* For images with a single "transparent colour", set colour key;
438
439
if more than one index has transparency, or if partially transparent
entries exist, use full alpha channel */
440
if (lib.png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) {
441
442
int num_trans;
Uint8 *trans;
443
lib.png_get_tRNS(png_ptr, info_ptr, &trans, &num_trans,
444
445
&transv);
if(color_type == PNG_COLOR_TYPE_PALETTE) {
446
447
448
449
450
451
452
453
454
455
456
457
458
459
/* Check if all tRNS entries are opaque except one */
int i, t = -1;
for(i = 0; i < num_trans; i++)
if(trans[i] == 0) {
if(t >= 0)
break;
t = i;
} else if(trans[i] != 255)
break;
if(i == num_trans) {
/* exactly one transparent index */
ckey = t;
} else {
/* more than one transparent index, or translucency */
460
lib.png_set_expand(png_ptr);
461
}
462
463
464
465
} else
ckey = 0; /* actual value will be set later */
}
466
if ( color_type == PNG_COLOR_TYPE_GRAY_ALPHA )
467
lib.png_set_gray_to_rgb(png_ptr);
468
469
lib.png_read_update_info(png_ptr, info_ptr);
470
471
lib.png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth,
472
473
474
&color_type, &interlace_type, NULL, NULL);
/* Allocate the SDL surface to hold the image */
475
476
Rmask = Gmask = Bmask = Amask = 0 ;
num_channels = lib.png_get_channels(png_ptr, info_ptr);
477
478
479
480
481
if ( color_type != PNG_COLOR_TYPE_PALETTE ) {
if ( SDL_BYTEORDER == SDL_LIL_ENDIAN ) {
Rmask = 0x000000FF;
Gmask = 0x0000FF00;
Bmask = 0x00FF0000;
482
Amask = (num_channels == 4) ? 0xFF000000 : 0;
483
} else {
484
int s = (num_channels == 4) ? 0 : 8;
485
486
487
488
489
490
491
Rmask = 0xFF000000 >> s;
Gmask = 0x00FF0000 >> s;
Bmask = 0x0000FF00 >> s;
Amask = 0x000000FF >> s;
}
}
surface = SDL_AllocSurface(SDL_SWSURFACE, width, height,
492
bit_depth*num_channels, Rmask,Gmask,Bmask,Amask);
493
if ( surface == NULL ) {
494
error = "Out of memory";
495
496
497
498
499
goto done;
}
if(ckey != -1) {
if(color_type != PNG_COLOR_TYPE_PALETTE)
500
501
502
503
504
/* FIXME: Should these be truncated or shifted down? */
ckey = SDL_MapRGB(surface->format,
(Uint8)transv->red,
(Uint8)transv->green,
(Uint8)transv->blue);
505
506
507
508
509
510
SDL_SetColorKey(surface, SDL_SRCCOLORKEY, ckey);
}
/* Create the array of pointers to image data */
row_pointers = (png_bytep*) malloc(sizeof(png_bytep)*height);
if ( (row_pointers == NULL) ) {
511
error = "Out of memory";
512
513
goto done;
}
514
for (row = 0; row < (int)height; row++) {
515
516
517
518
519
row_pointers[row] = (png_bytep)
(Uint8 *)surface->pixels + row*surface->pitch;
}
/* Read the entire image in one go */
520
lib.png_read_image(png_ptr, row_pointers);
521
522
523
524
525
526
/* 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
527
lib.png_read_end(png_ptr, info_ptr);
528
*/
529
530
531
/* Load the palette, if any */
palette = surface->format->palette;
532
if ( palette ) {
533
534
535
int png_num_palette;
png_colorp png_palette;
lib.png_get_PLTE(png_ptr, info_ptr, &png_palette, &png_num_palette);
536
537
538
if(color_type == PNG_COLOR_TYPE_GRAY) {
palette->ncolors = 256;
for(i = 0; i < 256; i++) {
539
540
541
palette->colors[i].r = (Uint8)i;
palette->colors[i].g = (Uint8)i;
palette->colors[i].b = (Uint8)i;
542
}
543
} else if (png_num_palette > 0 ) {
544
palette->ncolors = png_num_palette;
545
546
547
548
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;
549
}
550
}
551
552
553
}
done: /* Clean up and return */
554
if ( png_ptr ) {
555
lib.png_destroy_read_struct(&png_ptr,
556
info_ptr ? &info_ptr : (png_infopp)0,
557
(png_infopp)0);
558
}
559
560
561
if ( row_pointers ) {
free(row_pointers);
}
562
if ( error ) {
563
SDL_RWseek(src, start, RW_SEEK_SET);
564
565
566
567
568
569
if ( surface ) {
SDL_FreeSurface(surface);
surface = NULL;
}
IMG_SetError(error);
}
570
571
572
573
574
return(surface);
}
#else
575
576
577
578
579
580
581
582
583
584
int IMG_InitPNG()
{
IMG_SetError("PNG images are not supported");
return(-1);
}
void IMG_QuitPNG()
{
}
585
586
587
588
589
590
591
592
593
594
595
596
597
/* See if an image is contained in a data source */
int IMG_isPNG(SDL_RWops *src)
{
return(0);
}
/* Load a PNG type image from an SDL datasource */
SDL_Surface *IMG_LoadPNG_RW(SDL_RWops *src)
{
return(NULL);
}
#endif /* LOAD_PNG */
598
599
#endif /* !defined(__APPLE__) || defined(SDL_IMAGE_USE_COMMON_BACKEND) */