IMG_bmp.c
2
SDL_image: An example image loading library for use with SDL
3
Copyright (C) 1997-2013 Sam Lantinga <slouken@libsdl.org>
5
6
7
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.
9
10
11
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:
13
14
15
16
17
18
19
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
#if (!defined(__APPLE__) || defined(SDL_IMAGE_USE_COMMON_BACKEND)) || !defined(BMP_USES_IMAGEIO)
24
/* This is a BMP image file loading framework */
25
26
/* ICO/CUR file support is here as well since it uses similar internal
* representation */
27
28
29
30
31
32
33
34
35
36
37
#include <stdio.h>
#include <string.h>
#include "SDL_image.h"
#ifdef LOAD_BMP
/* See if an image is contained in a data source */
int IMG_isBMP(SDL_RWops *src)
{
39
40
41
int is_BMP;
char magic[2];
42
43
if ( !src )
return 0;
44
start = SDL_RWtell(src);
45
is_BMP = 0;
46
if ( SDL_RWread(src, magic, sizeof(magic), 1) ) {
47
if ( SDL_strncmp(magic, "BM", 2) == 0 ) {
48
49
50
is_BMP = 1;
}
}
51
SDL_RWseek(src, start, RW_SEEK_SET);
52
53
54
return(is_BMP);
}
55
56
static int IMG_isICOCUR(SDL_RWops *src, int type)
{
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
int is_ICOCUR;
/* The Win32 ICO file header (14 bytes) */
Uint16 bfReserved;
Uint16 bfType;
Uint16 bfCount;
if ( !src )
return 0;
start = SDL_RWtell(src);
is_ICOCUR = 0;
bfReserved = SDL_ReadLE16(src);
bfType = SDL_ReadLE16(src);
bfCount = SDL_ReadLE16(src);
if ((bfReserved == 0) && (bfType == type) && (bfCount != 0))
is_ICOCUR = 1;
74
SDL_RWseek(src, start, RW_SEEK_SET);
75
76
77
78
79
80
81
82
83
84
85
86
87
88
return (is_ICOCUR);
}
int IMG_isICO(SDL_RWops *src)
{
return IMG_isICOCUR(src, 1);
}
int IMG_isCUR(SDL_RWops *src)
{
return IMG_isICOCUR(src, 2);
}
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
#include "SDL_error.h"
#include "SDL_video.h"
#include "SDL_endian.h"
/* Compression encodings for BMP files */
#ifndef BI_RGB
#define BI_RGB 0
#define BI_RLE8 1
#define BI_RLE4 2
#define BI_BITFIELDS 3
#endif
static int readRlePixels(SDL_Surface * surface, SDL_RWops * src, int isRle8)
{
/*
| Sets the surface pixels from src. A bmp image is upside down.
*/
int pitch = surface->pitch;
int height = surface->h;
108
109
110
Uint8 *start = (Uint8 *)surface->pixels;
Uint8 *end = start + (height*pitch);
Uint8 *bits = end-pitch, *spot;
111
112
113
114
int ofs = 0;
Uint8 ch;
Uint8 needsPad;
115
116
#define COPY_PIXEL(x) spot = &bits[ofs++]; if(spot >= start && spot < end) *spot = (x)
117
118
119
120
121
122
123
124
125
126
127
for (;;) {
if ( !SDL_RWread(src, &ch, 1, 1) ) return 1;
/*
| encoded mode starts with a run length, and then a byte
| with two colour indexes to alternate between for the run
*/
if ( ch ) {
Uint8 pixel;
if ( !SDL_RWread(src, &pixel, 1, 1) ) return 1;
if ( isRle8 ) { /* 256-color bitmap, compressed */
do {
128
COPY_PIXEL(pixel);
129
} while (--ch);
130
} else { /* 16-color bitmap, compressed */
131
132
133
Uint8 pixel0 = pixel >> 4;
Uint8 pixel1 = pixel & 0x0F;
for (;;) {
134
COPY_PIXEL(pixel0); /* even count, high nibble */
135
if (!--ch) break;
136
COPY_PIXEL(pixel1); /* odd count, low nibble */
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
if (!--ch) break;
}
}
} else {
/*
| A leading zero is an escape; it may signal the end of the bitmap,
| a cursor move, or some absolute data.
| zero tag may be absolute mode or an escape
*/
if ( !SDL_RWread(src, &ch, 1, 1) ) return 1;
switch (ch) {
case 0: /* end of line */
ofs = 0;
bits -= pitch; /* go to previous */
break;
case 1: /* end of bitmap */
return 0; /* success! */
case 2: /* delta */
if ( !SDL_RWread(src, &ch, 1, 1) ) return 1;
ofs += ch;
if ( !SDL_RWread(src, &ch, 1, 1) ) return 1;
bits -= (ch * pitch);
break;
default: /* no compression */
if (isRle8) {
needsPad = ( ch & 1 );
do {
164
165
166
Uint8 pixel;
if ( !SDL_RWread(src, &pixel, 1, 1) ) return 1;
COPY_PIXEL(pixel);
167
168
169
170
171
172
} while (--ch);
} else {
needsPad = ( ((ch+1)>>1) & 1 ); /* (ch+1)>>1: bytes size */
for (;;) {
Uint8 pixel;
if ( !SDL_RWread(src, &pixel, 1, 1) ) return 1;
173
COPY_PIXEL(pixel >> 4);
174
if (!--ch) break;
175
COPY_PIXEL(pixel & 0x0F);
176
177
178
179
180
181
182
183
184
185
186
187
188
if (!--ch) break;
}
}
/* pad at even boundary */
if ( needsPad && !SDL_RWread(src, &ch, 1, 1) ) return 1;
break;
}
}
}
}
static SDL_Surface *LoadBMP_RW (SDL_RWops *src, int freesrc)
{
189
SDL_bool was_error;
190
Sint64 fp_offset;
191
192
193
194
195
196
int bmpPitch;
int i, pad;
SDL_Surface *surface;
Uint32 Rmask;
Uint32 Gmask;
Uint32 Bmask;
197
Uint32 Amask;
198
199
SDL_Palette *palette;
Uint8 *bits;
200
201
Uint8 *top, *end;
SDL_bool topDown;
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
int ExpandBMP;
/* The Win32 BMP file header (14 bytes) */
char magic[2];
Uint32 bfSize;
Uint16 bfReserved1;
Uint16 bfReserved2;
Uint32 bfOffBits;
/* The Win32 BITMAPINFOHEADER struct (40 bytes) */
Uint32 biSize;
Sint32 biWidth;
Sint32 biHeight;
Uint16 biPlanes;
Uint16 biBitCount;
Uint32 biCompression;
Uint32 biSizeImage;
Sint32 biXPelsPerMeter;
Sint32 biYPelsPerMeter;
Uint32 biClrUsed;
Uint32 biClrImportant;
/* Make sure we are passed a valid data source */
surface = NULL;
226
was_error = SDL_FALSE;
227
if ( src == NULL ) {
228
was_error = SDL_TRUE;
229
230
231
232
233
234
235
236
goto done;
}
/* Read in the BMP file header */
fp_offset = SDL_RWtell(src);
SDL_ClearError();
if ( SDL_RWread(src, magic, 1, 2) != 2 ) {
SDL_Error(SDL_EFREAD);
237
was_error = SDL_TRUE;
238
239
goto done;
}
240
if ( SDL_strncmp(magic, "BM", 2) != 0 ) {
241
IMG_SetError("File is not a Windows BMP file");
242
was_error = SDL_TRUE;
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
goto done;
}
bfSize = SDL_ReadLE32(src);
bfReserved1 = SDL_ReadLE16(src);
bfReserved2 = SDL_ReadLE16(src);
bfOffBits = SDL_ReadLE32(src);
/* Read the Win32 BITMAPINFOHEADER */
biSize = SDL_ReadLE32(src);
if ( biSize == 12 ) {
biWidth = (Uint32)SDL_ReadLE16(src);
biHeight = (Uint32)SDL_ReadLE16(src);
biPlanes = SDL_ReadLE16(src);
biBitCount = SDL_ReadLE16(src);
biCompression = BI_RGB;
biSizeImage = 0;
biXPelsPerMeter = 0;
biYPelsPerMeter = 0;
biClrUsed = 0;
biClrImportant = 0;
} else {
biWidth = SDL_ReadLE32(src);
biHeight = SDL_ReadLE32(src);
biPlanes = SDL_ReadLE16(src);
biBitCount = SDL_ReadLE16(src);
biCompression = SDL_ReadLE32(src);
biSizeImage = SDL_ReadLE32(src);
biXPelsPerMeter = SDL_ReadLE32(src);
biYPelsPerMeter = SDL_ReadLE32(src);
biClrUsed = SDL_ReadLE32(src);
biClrImportant = SDL_ReadLE32(src);
}
275
276
277
278
279
280
if (biHeight < 0) {
topDown = SDL_TRUE;
biHeight = -biHeight;
} else {
topDown = SDL_FALSE;
}
281
282
283
/* Check for read error */
if ( strcmp(SDL_GetError(), "") != 0 ) {
284
was_error = SDL_TRUE;
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
goto done;
}
/* Expand 1 and 4 bit bitmaps to 8 bits per pixel */
switch (biBitCount) {
case 1:
case 4:
ExpandBMP = biBitCount;
biBitCount = 8;
break;
default:
ExpandBMP = 0;
break;
}
/* RLE4 and RLE8 BMP compression is supported */
301
Rmask = Gmask = Bmask = Amask = 0;
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
switch (biCompression) {
case BI_RGB:
/* If there are no masks, use the defaults */
if ( bfOffBits == (14+biSize) ) {
/* Default values for the BMP format */
switch (biBitCount) {
case 15:
case 16:
Rmask = 0x7C00;
Gmask = 0x03E0;
Bmask = 0x001F;
break;
case 24:
#if SDL_BYTEORDER == SDL_BIG_ENDIAN
Rmask = 0x000000FF;
Gmask = 0x0000FF00;
Bmask = 0x00FF0000;
319
320
321
322
#else
Rmask = 0x00FF0000;
Gmask = 0x0000FF00;
Bmask = 0x000000FF;
326
Amask = 0xFF000000;
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
Rmask = 0x00FF0000;
Gmask = 0x0000FF00;
Bmask = 0x000000FF;
break;
default:
break;
}
break;
}
/* Fall through -- read the RGB masks */
default:
switch (biBitCount) {
case 15:
case 16:
342
343
344
345
Rmask = SDL_ReadLE32(src);
Gmask = SDL_ReadLE32(src);
Bmask = SDL_ReadLE32(src);
break;
346
347
348
349
case 32:
Rmask = SDL_ReadLE32(src);
Gmask = SDL_ReadLE32(src);
Bmask = SDL_ReadLE32(src);
350
Amask = SDL_ReadLE32(src);
351
352
353
354
355
356
357
358
359
break;
default:
break;
}
break;
}
/* Create a compatible surface, note that the colors are RGB ordered */
surface = SDL_CreateRGBSurface(SDL_SWSURFACE,
360
biWidth, biHeight, biBitCount, Rmask, Gmask, Bmask, Amask);
361
if ( surface == NULL ) {
362
was_error = SDL_TRUE;
363
364
365
366
367
368
goto done;
}
/* Load the palette, if any */
palette = (surface->format)->palette;
if ( palette ) {
369
if ( SDL_RWseek(src, fp_offset+14+biSize, RW_SEEK_SET) < 0 ) {
370
SDL_Error(SDL_EFSEEK);
371
was_error = SDL_TRUE;
372
373
374
goto done;
}
375
376
377
378
379
380
381
382
383
384
385
386
/*
| guich: always use 1<<bpp b/c some bitmaps can bring wrong information
| for colorsUsed
*/
/* if ( biClrUsed == 0 ) { */
biClrUsed = 1 << biBitCount;
/* } */
if ( biSize == 12 ) {
for ( i = 0; i < (int)biClrUsed; ++i ) {
SDL_RWread(src, &palette->colors[i].b, 1, 1);
SDL_RWread(src, &palette->colors[i].g, 1, 1);
SDL_RWread(src, &palette->colors[i].r, 1, 1);
387
palette->colors[i].a = SDL_ALPHA_OPAQUE;
388
389
390
391
392
393
}
} else {
for ( i = 0; i < (int)biClrUsed; ++i ) {
SDL_RWread(src, &palette->colors[i].b, 1, 1);
SDL_RWread(src, &palette->colors[i].g, 1, 1);
SDL_RWread(src, &palette->colors[i].r, 1, 1);
394
SDL_RWread(src, &palette->colors[i].a, 1, 1);
395
396
397
398
399
400
/* According to Microsoft documentation, the fourth element
is reserved and must be zero, so we shouldn't treat it as
alpha.
*/
palette->colors[i].a = SDL_ALPHA_OPAQUE;
401
402
403
404
405
406
}
}
palette->ncolors = biClrUsed;
}
/* Read the surface pixels. Note that the bmp image is upside down */
407
if ( SDL_RWseek(src, fp_offset+bfOffBits, RW_SEEK_SET) < 0 ) {
408
SDL_Error(SDL_EFSEEK);
409
was_error = SDL_TRUE;
410
411
412
goto done;
}
if ((biCompression == BI_RLE4) || (biCompression == BI_RLE8)) {
413
was_error = (SDL_bool)readRlePixels(surface, src, biCompression == BI_RLE8);
414
if (was_error) IMG_SetError("Error reading from BMP");
415
416
goto done;
}
417
418
top = (Uint8 *)surface->pixels;
end = (Uint8 *)surface->pixels+(surface->h*surface->pitch);
419
420
421
422
423
424
425
426
427
428
429
430
431
432
switch (ExpandBMP) {
case 1:
bmpPitch = (biWidth + 7) >> 3;
pad = (((bmpPitch)%4) ? (4-((bmpPitch)%4)) : 0);
break;
case 4:
bmpPitch = (biWidth + 1) >> 1;
pad = (((bmpPitch)%4) ? (4-((bmpPitch)%4)) : 0);
break;
default:
pad = ((surface->pitch%4) ?
(4-(surface->pitch%4)) : 0);
break;
}
433
434
435
436
437
438
if ( topDown ) {
bits = top;
} else {
bits = end - surface->pitch;
}
while ( bits >= top && bits < end ) {
439
440
441
442
443
444
445
446
switch (ExpandBMP) {
case 1:
case 4: {
Uint8 pixel = 0;
int shift = (8-ExpandBMP);
for ( i=0; i<surface->w; ++i ) {
if ( i%(8/ExpandBMP) == 0 ) {
if ( !SDL_RWread(src, &pixel, 1, 1) ) {
447
IMG_SetError(
448
"Error reading from BMP");
449
was_error = SDL_TRUE;
450
451
452
453
454
455
456
457
458
459
460
461
goto done;
}
}
*(bits+i) = (pixel>>shift);
pixel <<= ExpandBMP;
} }
break;
default:
if ( SDL_RWread(src, bits, 1, surface->pitch)
!= surface->pitch ) {
SDL_Error(SDL_EFREAD);
462
was_error = SDL_TRUE;
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
goto done;
}
#if SDL_BYTEORDER == SDL_BIG_ENDIAN
/* Byte-swap the pixels if needed. Note that the 24bpp
case has already been taken care of above. */
switch(biBitCount) {
case 15:
case 16: {
Uint16 *pix = (Uint16 *)bits;
for(i = 0; i < surface->w; i++)
pix[i] = SDL_Swap16(pix[i]);
break;
}
case 32: {
Uint32 *pix = (Uint32 *)bits;
for(i = 0; i < surface->w; i++)
pix[i] = SDL_Swap32(pix[i]);
break;
}
}
#endif
break;
}
/* Skip padding bytes, ugh */
if ( pad ) {
Uint8 padbyte;
for ( i=0; i<pad; ++i ) {
SDL_RWread(src, &padbyte, 1, 1);
}
}
494
495
496
497
498
if ( topDown ) {
bits += surface->pitch;
} else {
bits -= surface->pitch;
}
499
500
501
}
done:
if ( was_error ) {
503
SDL_RWseek(src, fp_offset, RW_SEEK_SET);
505
506
507
508
509
510
511
512
513
514
515
if ( surface ) {
SDL_FreeSurface(surface);
}
surface = NULL;
}
if ( freesrc && src ) {
SDL_RWclose(src);
}
return(surface);
}
516
517
518
519
520
521
522
523
524
525
526
527
static Uint8
SDL_Read8(SDL_RWops * src)
{
Uint8 value;
SDL_RWread(src, &value, 1, 1);
return (value);
}
static SDL_Surface *
LoadICOCUR_RW(SDL_RWops * src, int type, int freesrc)
{
528
SDL_bool was_error;
529
Sint64 fp_offset;
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
int bmpPitch;
int i, pad;
SDL_Surface *surface;
Uint32 Rmask;
Uint32 Gmask;
Uint32 Bmask;
Uint8 *bits;
int ExpandBMP;
int maxCol = 0;
int icoOfs = 0;
Uint32 palette[256];
/* The Win32 ICO file header (14 bytes) */
Uint16 bfReserved;
Uint16 bfType;
Uint16 bfCount;
/* The Win32 BITMAPINFOHEADER struct (40 bytes) */
Uint32 biSize;
Sint32 biWidth;
Sint32 biHeight;
Uint16 biPlanes;
Uint16 biBitCount;
Uint32 biCompression;
Uint32 biSizeImage;
Sint32 biXPelsPerMeter;
Sint32 biYPelsPerMeter;
Uint32 biClrUsed;
Uint32 biClrImportant;
/* Make sure we are passed a valid data source */
surface = NULL;
562
was_error = SDL_FALSE;
563
if (src == NULL) {
564
was_error = SDL_TRUE;
565
566
567
568
569
570
571
572
573
574
575
goto done;
}
/* Read in the ICO file header */
fp_offset = SDL_RWtell(src);
SDL_ClearError();
bfReserved = SDL_ReadLE16(src);
bfType = SDL_ReadLE16(src);
bfCount = SDL_ReadLE16(src);
if ((bfReserved != 0) || (bfType != type) || (bfCount == 0)) {
576
IMG_SetError("File is not a Windows %s file", type == 1 ? "ICO" : "CUR");
577
was_error = SDL_TRUE;
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
goto done;
}
/* Read the Win32 Icon Directory */
for (i = 0; i < bfCount; i++) {
/* Icon Directory Entries */
int bWidth = SDL_Read8(src); /* Uint8, but 0 = 256 ! */
int bHeight = SDL_Read8(src); /* Uint8, but 0 = 256 ! */
int bColorCount = SDL_Read8(src); /* Uint8, but 0 = 256 ! */
Uint8 bReserved = SDL_Read8(src);
Uint16 wPlanes = SDL_ReadLE16(src);
Uint16 wBitCount = SDL_ReadLE16(src);
Uint32 dwBytesInRes = SDL_ReadLE32(src);
Uint32 dwImageOffset = SDL_ReadLE32(src);
if (!bWidth)
bWidth = 256;
if (!bHeight)
bHeight = 256;
if (!bColorCount)
bColorCount = 256;
//printf("%dx%d@%d - %08x\n", bWidth, bHeight, bColorCount, dwImageOffset);
if (bColorCount > maxCol) {
maxCol = bColorCount;
icoOfs = dwImageOffset;
//printf("marked\n");
}
}
/* Advance to the DIB Data */
if (SDL_RWseek(src, icoOfs, RW_SEEK_SET) < 0) {
SDL_Error(SDL_EFSEEK);
611
was_error = SDL_TRUE;
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
goto done;
}
/* Read the Win32 BITMAPINFOHEADER */
biSize = SDL_ReadLE32(src);
if (biSize == 40) {
biWidth = SDL_ReadLE32(src);
biHeight = SDL_ReadLE32(src);
biPlanes = SDL_ReadLE16(src);
biBitCount = SDL_ReadLE16(src);
biCompression = SDL_ReadLE32(src);
biSizeImage = SDL_ReadLE32(src);
biXPelsPerMeter = SDL_ReadLE32(src);
biYPelsPerMeter = SDL_ReadLE32(src);
biClrUsed = SDL_ReadLE32(src);
biClrImportant = SDL_ReadLE32(src);
} else {
629
IMG_SetError("Unsupported ICO bitmap format");
630
was_error = SDL_TRUE;
631
632
633
634
635
goto done;
}
/* Check for read error */
if (SDL_strcmp(SDL_GetError(), "") != 0) {
636
was_error = SDL_TRUE;
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
goto done;
}
/* We don't support any BMP compression right now */
switch (biCompression) {
case BI_RGB:
/* Default values for the BMP format */
switch (biBitCount) {
case 1:
case 4:
ExpandBMP = biBitCount;
biBitCount = 8;
break;
case 8:
ExpandBMP = 8;
break;
case 32:
Rmask = 0x00FF0000;
Gmask = 0x0000FF00;
Bmask = 0x000000FF;
ExpandBMP = 0;
break;
default:
660
IMG_SetError("ICO file with unsupported bit count");
661
was_error = SDL_TRUE;
662
663
664
665
goto done;
}
break;
default:
666
IMG_SetError("Compressed ICO files not supported");
667
was_error = SDL_TRUE;
668
669
670
671
672
673
674
675
676
677
goto done;
}
/* Create a RGBA surface */
biHeight = biHeight >> 1;
//printf("%d x %d\n", biWidth, biHeight);
surface =
SDL_CreateRGBSurface(0, biWidth, biHeight, 32, 0x00FF0000,
0x0000FF00, 0x000000FF, 0xFF000000);
if (surface == NULL) {
678
was_error = SDL_TRUE;
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
goto done;
}
/* Load the palette, if any */
//printf("bc %d bused %d\n", biBitCount, biClrUsed);
if (biBitCount <= 8) {
if (biClrUsed == 0) {
biClrUsed = 1 << biBitCount;
}
for (i = 0; i < (int) biClrUsed; ++i) {
SDL_RWread(src, &palette[i], 4, 1);
}
}
/* Read the surface pixels. Note that the bmp image is upside down */
bits = (Uint8 *) surface->pixels + (surface->h * surface->pitch);
switch (ExpandBMP) {
case 1:
bmpPitch = (biWidth + 7) >> 3;
pad = (((bmpPitch) % 4) ? (4 - ((bmpPitch) % 4)) : 0);
break;
case 4:
bmpPitch = (biWidth + 1) >> 1;
pad = (((bmpPitch) % 4) ? (4 - ((bmpPitch) % 4)) : 0);
break;
case 8:
bmpPitch = biWidth;
pad = (((bmpPitch) % 4) ? (4 - ((bmpPitch) % 4)) : 0);
break;
default:
bmpPitch = biWidth * 4;
pad = 0;
break;
}
while (bits > (Uint8 *) surface->pixels) {
bits -= surface->pitch;
switch (ExpandBMP) {
case 1:
case 4:
case 8:
{
Uint8 pixel = 0;
int shift = (8 - ExpandBMP);
for (i = 0; i < surface->w; ++i) {
if (i % (8 / ExpandBMP) == 0) {
if (!SDL_RWread(src, &pixel, 1, 1)) {
725
IMG_SetError("Error reading from ICO");
726
was_error = SDL_TRUE;
727
728
729
730
731
732
733
734
735
736
737
738
739
goto done;
}
}
*((Uint32 *) bits + i) = (palette[pixel >> shift]);
pixel <<= ExpandBMP;
}
}
break;
default:
if (SDL_RWread(src, bits, 1, surface->pitch)
!= surface->pitch) {
SDL_Error(SDL_EFREAD);
740
was_error = SDL_TRUE;
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
goto done;
}
break;
}
/* Skip padding bytes, ugh */
if (pad) {
Uint8 padbyte;
for (i = 0; i < pad; ++i) {
SDL_RWread(src, &padbyte, 1, 1);
}
}
}
/* Read the mask pixels. Note that the bmp image is upside down */
bits = (Uint8 *) surface->pixels + (surface->h * surface->pitch);
ExpandBMP = 1;
bmpPitch = (biWidth + 7) >> 3;
pad = (((bmpPitch) % 4) ? (4 - ((bmpPitch) % 4)) : 0);
while (bits > (Uint8 *) surface->pixels) {
Uint8 pixel = 0;
int shift = (8 - ExpandBMP);
bits -= surface->pitch;
for (i = 0; i < surface->w; ++i) {
if (i % (8 / ExpandBMP) == 0) {
if (!SDL_RWread(src, &pixel, 1, 1)) {
766
IMG_SetError("Error reading from ICO");
767
was_error = SDL_TRUE;
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
goto done;
}
}
*((Uint32 *) bits + i) |= ((pixel >> shift) ? 0 : 0xFF000000);
pixel <<= ExpandBMP;
}
/* Skip padding bytes, ugh */
if (pad) {
Uint8 padbyte;
for (i = 0; i < pad; ++i) {
SDL_RWread(src, &padbyte, 1, 1);
}
}
}
done:
if (was_error) {
if (src) {
SDL_RWseek(src, fp_offset, RW_SEEK_SET);
}
if (surface) {
SDL_FreeSurface(surface);
}
surface = NULL;
}
if (freesrc && src) {
SDL_RWclose(src);
}
return (surface);
}
798
799
800
/* Load a BMP type image from an SDL datasource */
SDL_Surface *IMG_LoadBMP_RW(SDL_RWops *src)
{
801
return(LoadBMP_RW(src, 0));
802
803
}
804
805
806
807
808
809
810
811
812
813
814
815
/* Load a ICO type image from an SDL datasource */
SDL_Surface *IMG_LoadICO_RW(SDL_RWops *src)
{
return(LoadICOCUR_RW(src, 1, 0));
}
/* Load a CUR type image from an SDL datasource */
SDL_Surface *IMG_LoadCUR_RW(SDL_RWops *src)
{
return(LoadICOCUR_RW(src, 2, 0));
}
816
817
818
819
820
821
822
823
#else
/* See if an image is contained in a data source */
int IMG_isBMP(SDL_RWops *src)
{
return(0);
}
824
825
826
827
828
829
830
831
832
833
int IMG_isICO(SDL_RWops *src)
{
return(0);
}
int IMG_isCUR(SDL_RWops *src)
{
return(0);
}
834
835
836
837
838
839
/* Load a BMP type image from an SDL datasource */
SDL_Surface *IMG_LoadBMP_RW(SDL_RWops *src)
{
return(NULL);
}
840
841
842
843
844
845
846
847
848
849
850
851
/* Load a BMP type image from an SDL datasource */
SDL_Surface *IMG_LoadCUR_RW(SDL_RWops *src)
{
return(NULL);
}
/* Load a BMP type image from an SDL datasource */
SDL_Surface *IMG_LoadICO_RW(SDL_RWops *src)
{
return(NULL);
}
852
#endif /* LOAD_BMP */
853
854
#endif /* !defined(__APPLE__) || defined(SDL_IMAGE_USE_COMMON_BACKEND) */