This repository has been archived by the owner on Feb 11, 2021. It is now read-only.
/
SDL_pixels.c
833 lines (766 loc) · 22.2 KB
1
2
/*
SDL - Simple DirectMedia Layer
3
Copyright (C) 1997-2006 Sam Lantinga
4
5
This library is free software; you can redistribute it and/or
6
modify it under the terms of the GNU Lesser General Public
7
License as published by the Free Software Foundation; either
8
version 2.1 of the License, or (at your option) any later version.
9
10
11
12
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
13
Lesser General Public License for more details.
14
15
16
17
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18
19
Sam Lantinga
20
slouken@libsdl.org
21
*/
22
#include "SDL_config.h"
23
24
25
26
27
28
29
30
31
32
33
/* General (mostly internal) pixel/color manipulation routines for SDL */
#include "SDL_endian.h"
#include "SDL_video.h"
#include "SDL_sysvideo.h"
#include "SDL_blit.h"
#include "SDL_pixels_c.h"
#include "SDL_RLEaccel_c.h"
/* Helper functions */
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
SDL_bool
SDL_PixelFormatEnumToMasks(Uint32 format, int *bpp, Uint32 * Rmask,
Uint32 * Gmask, Uint32 * Bmask, Uint32 * Amask)
{
Uint32 masks[4];
/* Initialize the values here */
if (SDL_BITSPERPIXEL(format) == 24) {
*bpp = SDL_BYTESPERPIXEL(format) * 8;
} else {
*bpp = SDL_BITSPERPIXEL(format);
}
*Rmask = *Gmask = *Bmask = *Amask = 0;
49
50
51
if (SDL_PIXELTYPE(format) != SDL_PIXELTYPE_PACKED8 &&
SDL_PIXELTYPE(format) != SDL_PIXELTYPE_PACKED16 &&
SDL_PIXELTYPE(format) != SDL_PIXELTYPE_PACKED32) {
52
53
54
55
56
/* Not a format that uses masks */
return SDL_TRUE;
}
switch (SDL_PIXELLAYOUT(format)) {
57
case SDL_PACKEDLAYOUT_332:
58
59
60
61
62
masks[0] = 0x00000000;
masks[1] = 0x000000E0;
masks[2] = 0x0000001C;
masks[3] = 0x00000003;
break;
63
case SDL_PACKEDLAYOUT_4444:
64
65
66
67
68
masks[0] = 0x0000F000;
masks[1] = 0x00000F00;
masks[2] = 0x000000F0;
masks[3] = 0x0000000F;
break;
69
case SDL_PACKEDLAYOUT_1555:
70
71
72
73
74
masks[0] = 0x00008000;
masks[1] = 0x00007C00;
masks[2] = 0x000003E0;
masks[3] = 0x0000001F;
break;
75
case SDL_PACKEDLAYOUT_565:
76
77
78
79
80
masks[0] = 0x00000000;
masks[1] = 0x0000F800;
masks[2] = 0x000007E0;
masks[3] = 0x0000001F;
break;
81
case SDL_PACKEDLAYOUT_8888:
82
83
84
85
86
masks[0] = 0xFF000000;
masks[1] = 0x00FF0000;
masks[2] = 0x0000FF00;
masks[3] = 0x000000FF;
break;
87
case SDL_PACKEDLAYOUT_2101010:
88
89
90
91
92
93
94
95
96
97
98
masks[0] = 0xC0000000;
masks[1] = 0x3FF00000;
masks[2] = 0x000FFC00;
masks[3] = 0x000003FF;
break;
default:
/* Unknown layout */
return SDL_FALSE;
}
switch (SDL_PIXELORDER(format)) {
99
case SDL_PACKEDORDER_XRGB:
100
101
102
103
*Rmask = masks[1];
*Gmask = masks[2];
*Bmask = masks[3];
break;
104
case SDL_PACKEDORDER_RGBX:
105
106
107
108
*Rmask = masks[0];
*Gmask = masks[1];
*Bmask = masks[2];
break;
109
case SDL_PACKEDORDER_ARGB:
110
111
112
113
114
*Amask = masks[0];
*Rmask = masks[1];
*Gmask = masks[2];
*Bmask = masks[3];
break;
115
case SDL_PACKEDORDER_RGBA:
116
117
118
119
120
*Rmask = masks[0];
*Gmask = masks[1];
*Bmask = masks[2];
*Amask = masks[3];
break;
121
case SDL_PACKEDORDER_XBGR:
122
123
124
125
*Bmask = masks[1];
*Gmask = masks[2];
*Rmask = masks[3];
break;
126
case SDL_PACKEDORDER_BGRX:
127
128
129
130
*Bmask = masks[0];
*Gmask = masks[1];
*Rmask = masks[2];
break;
131
case SDL_PACKEDORDER_BGRA:
132
133
134
135
136
*Bmask = masks[0];
*Gmask = masks[1];
*Rmask = masks[2];
*Amask = masks[3];
break;
137
case SDL_PACKEDORDER_ABGR:
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
*Amask = masks[0];
*Bmask = masks[1];
*Gmask = masks[2];
*Rmask = masks[3];
break;
default:
/* Unknown order */
return SDL_FALSE;
}
return SDL_TRUE;
}
Uint32
SDL_MasksToPixelFormatEnum(int bpp, Uint32 Rmask, Uint32 Gmask, Uint32 Bmask,
Uint32 Amask)
{
switch (bpp) {
case 8:
switch (Rmask) {
case 0:
158
return SDL_PIXELFORMAT_INDEX8;
159
case 0xE0:
160
return SDL_PIXELFORMAT_RGB332;
161
162
163
164
165
}
break;
case 12:
switch (Rmask) {
case 0x0F00:
166
return SDL_PIXELFORMAT_RGB444;
167
168
169
170
171
}
break;
case 15:
switch (Rmask) {
case 0x7C00:
172
return SDL_PIXELFORMAT_RGB555;
173
174
175
176
177
}
break;
case 16:
switch (Rmask) {
case 0x0F00:
178
return SDL_PIXELFORMAT_ARGB4444;
179
case 0x7C00:
180
return SDL_PIXELFORMAT_ARGB1555;
181
case 0xF800:
182
return SDL_PIXELFORMAT_RGB565;
183
184
185
186
187
188
}
break;
case 32:
switch (Rmask) {
case 0xFF000000:
if (Amask == 0x000000FF) {
189
return SDL_PIXELFORMAT_RGBA8888;
190
191
192
193
}
break;
case 0x00FF0000:
if (Amask == 0xFF000000) {
194
return SDL_PIXELFORMAT_ARGB8888;
195
} else {
196
return SDL_PIXELFORMAT_RGB888;
197
198
199
200
}
break;
case 0x0000FF00:
if (Amask == 0x000000FF) {
201
return SDL_PIXELFORMAT_BGRA8888;
202
203
204
205
}
break;
case 0x000000FF:
if (Amask == 0xFF000000) {
206
return SDL_PIXELFORMAT_ABGR8888;
207
} else {
208
return SDL_PIXELFORMAT_BGR888;
209
210
211
}
break;
case 0x3FF00000:
212
return SDL_PIXELFORMAT_ARGB2101010;
213
214
}
}
215
return SDL_PIXELFORMAT_UNKNOWN;
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
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
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
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
}
SDL_Palette *
SDL_AllocPalette(int ncolors)
{
SDL_Palette *palette;
palette = (SDL_Palette *) SDL_malloc(sizeof(*palette));
if (!palette) {
SDL_OutOfMemory();
return NULL;
}
palette->colors =
(SDL_Color *) SDL_malloc(ncolors * sizeof(*palette->colors));
if (!palette->colors) {
SDL_free(palette);
return NULL;
}
palette->ncolors = ncolors;
palette->watch = NULL;
palette->refcount = 1;
SDL_memset(palette->colors, 0xFF, ncolors * sizeof(*palette->colors));
return palette;
}
int
SDL_AddPaletteWatch(SDL_Palette * palette, SDL_PaletteChangedFunc callback,
void *userdata)
{
SDL_PaletteWatch *watch;
if (!palette) {
return -1;
}
watch = (SDL_PaletteWatch *) SDL_malloc(sizeof(*watch));
if (!watch) {
SDL_OutOfMemory();
return -1;
}
watch->callback = callback;
watch->userdata = userdata;
watch->next = palette->watch;
palette->watch = watch;
++palette->refcount;
return 0;
}
void
SDL_DelPaletteWatch(SDL_Palette * palette, SDL_PaletteChangedFunc callback,
void *userdata)
{
SDL_PaletteWatch *prev, *watch;
if (!palette) {
return;
}
for (prev = NULL, watch = palette->watch; watch;
prev = watch, watch = watch->next) {
if (watch->callback == callback && watch->userdata == userdata) {
if (prev) {
prev->next = watch->next;
} else {
palette->watch = watch->next;
}
SDL_free(watch);
SDL_FreePalette(palette);
return;
}
}
}
int
SDL_SetPaletteColors(SDL_Palette * palette, const SDL_Color * colors,
int firstcolor, int ncolors)
{
SDL_PaletteWatch *watch;
int status = 0;
/* Verify the parameters */
if (!palette) {
return -1;
}
if (ncolors > (palette->ncolors - firstcolor)) {
ncolors = (palette->ncolors - firstcolor);
status = -1;
}
if (colors != (palette->colors + firstcolor)) {
SDL_memcpy(palette->colors + firstcolor, colors,
ncolors * sizeof(*colors));
}
for (watch = palette->watch; watch; watch = watch->next) {
if (watch->callback(watch->userdata, palette) < 0) {
status = -1;
}
}
return status;
}
void
SDL_FreePalette(SDL_Palette * palette)
{
if (!palette) {
return;
}
if (--palette->refcount > 0) {
return;
}
if (palette->colors) {
SDL_free(palette->colors);
}
SDL_free(palette);
}
338
339
340
/*
* Allocate a pixel format structure and fill it according to the given info.
*/
341
342
343
SDL_PixelFormat *
SDL_AllocFormat(int bpp,
Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask)
344
{
345
346
347
348
SDL_PixelFormat *format;
Uint32 mask;
/* Allocate an empty pixel format structure */
349
format = SDL_calloc(1, sizeof(*format));
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
if (format == NULL) {
SDL_OutOfMemory();
return (NULL);
}
/* Set up the format */
format->BitsPerPixel = bpp;
format->BytesPerPixel = (bpp + 7) / 8;
if (Rmask || Bmask || Gmask) { /* Packed pixels with custom mask */
format->Rshift = 0;
format->Rloss = 8;
if (Rmask) {
for (mask = Rmask; !(mask & 0x01); mask >>= 1)
++format->Rshift;
for (; (mask & 0x01); mask >>= 1)
--format->Rloss;
}
format->Gshift = 0;
format->Gloss = 8;
if (Gmask) {
for (mask = Gmask; !(mask & 0x01); mask >>= 1)
++format->Gshift;
for (; (mask & 0x01); mask >>= 1)
--format->Gloss;
}
format->Bshift = 0;
format->Bloss = 8;
if (Bmask) {
for (mask = Bmask; !(mask & 0x01); mask >>= 1)
++format->Bshift;
for (; (mask & 0x01); mask >>= 1)
--format->Bloss;
}
format->Ashift = 0;
format->Aloss = 8;
if (Amask) {
for (mask = Amask; !(mask & 0x01); mask >>= 1)
++format->Ashift;
for (; (mask & 0x01); mask >>= 1)
--format->Aloss;
}
format->Rmask = Rmask;
format->Gmask = Gmask;
format->Bmask = Bmask;
format->Amask = Amask;
} else if (bpp > 8) { /* Packed pixels with standard mask */
/* R-G-B */
if (bpp > 24)
bpp = 24;
format->Rloss = 8 - (bpp / 3);
format->Gloss = 8 - (bpp / 3) - (bpp % 3);
format->Bloss = 8 - (bpp / 3);
format->Rshift = ((bpp / 3) + (bpp % 3)) + (bpp / 3);
format->Gshift = (bpp / 3);
format->Bshift = 0;
format->Rmask = ((0xFF >> format->Rloss) << format->Rshift);
format->Gmask = ((0xFF >> format->Gloss) << format->Gshift);
format->Bmask = ((0xFF >> format->Bloss) << format->Bshift);
} else {
/* Palettized formats have no mask info */
format->Rloss = 8;
format->Gloss = 8;
format->Bloss = 8;
format->Aloss = 8;
format->Rshift = 0;
format->Gshift = 0;
format->Bshift = 0;
format->Ashift = 0;
format->Rmask = 0;
format->Gmask = 0;
format->Bmask = 0;
format->Amask = 0;
}
format->palette = NULL;
return (format);
426
427
428
429
430
}
/*
* Change any previous mappings from/to the new surface format
*/
431
432
void
SDL_FormatChanged(SDL_Surface * surface)
433
{
434
435
436
437
438
439
440
static int format_version = 0;
++format_version;
if (format_version < 0) { /* It wrapped... */
format_version = 1;
}
surface->format_version = format_version;
SDL_InvalidateMap(surface->map);
441
}
442
443
444
445
/*
* Free a previously allocated format structure
*/
446
447
void
SDL_FreeFormat(SDL_PixelFormat * format)
448
{
449
450
451
452
if (!format) {
return;
}
SDL_free(format);
453
}
454
455
456
457
/*
* Calculate an 8-bit (3 red, 3 green, 2 blue) dithered palette of colors
*/
458
459
void
SDL_DitherColors(SDL_Color * colors, int bpp)
460
{
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
int i;
if (bpp != 8)
return; /* only 8bpp supported right now */
for (i = 0; i < 256; i++) {
int r, g, b;
/* map each bit field to the full [0, 255] interval,
so 0 is mapped to (0, 0, 0) and 255 to (255, 255, 255) */
r = i & 0xe0;
r |= r >> 3 | r >> 6;
colors[i].r = r;
g = (i << 3) & 0xe0;
g |= g >> 3 | g >> 6;
colors[i].g = g;
b = i & 0x3;
b |= b << 2;
b |= b << 4;
colors[i].b = b;
colors[i].unused = SDL_ALPHA_OPAQUE;
}
481
}
482
483
484
485
/*
* Calculate the pad-aligned scanline width of a surface
*/
486
487
int
SDL_CalculatePitch(SDL_Surface * surface)
488
{
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
int pitch;
/* Surface should be 4-byte aligned for speed */
pitch = surface->w * surface->format->BytesPerPixel;
switch (surface->format->BitsPerPixel) {
case 1:
pitch = (pitch + 7) / 8;
break;
case 4:
pitch = (pitch + 1) / 2;
break;
default:
break;
}
pitch = (pitch + 3) & ~3; /* 4-byte aligning */
return (pitch);
505
}
506
507
508
509
/*
* Match an RGB value to a particular palette index
*/
510
511
Uint8
SDL_FindColor(SDL_Palette * pal, Uint8 r, Uint8 g, Uint8 b)
512
{
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
/* Do colorspace distance matching */
unsigned int smallest;
unsigned int distance;
int rd, gd, bd;
int i;
Uint8 pixel = 0;
smallest = ~0;
for (i = 0; i < pal->ncolors; ++i) {
rd = pal->colors[i].r - r;
gd = pal->colors[i].g - g;
bd = pal->colors[i].b - b;
distance = (rd * rd) + (gd * gd) + (bd * bd);
if (distance < smallest) {
pixel = i;
if (distance == 0) { /* Perfect match! */
break;
}
smallest = distance;
}
}
return (pixel);
535
536
537
}
/* Find the opaque pixel value corresponding to an RGB triple */
538
Uint32
539
SDL_MapRGB(const SDL_PixelFormat * format, Uint8 r, Uint8 g, Uint8 b)
540
{
541
542
543
544
545
546
547
if (format->palette == NULL) {
return (r >> format->Rloss) << format->Rshift
| (g >> format->Gloss) << format->Gshift
| (b >> format->Bloss) << format->Bshift | format->Amask;
} else {
return SDL_FindColor(format->palette, r, g, b);
}
548
549
550
}
/* Find the pixel value corresponding to an RGBA quadruple */
551
Uint32
552
553
SDL_MapRGBA(const SDL_PixelFormat * format, Uint8 r, Uint8 g, Uint8 b,
Uint8 a)
554
{
555
556
557
558
559
560
561
562
if (format->palette == NULL) {
return (r >> format->Rloss) << format->Rshift
| (g >> format->Gloss) << format->Gshift
| (b >> format->Bloss) << format->Bshift
| ((a >> format->Aloss) << format->Ashift & format->Amask);
} else {
return SDL_FindColor(format->palette, r, g, b);
}
563
564
}
565
void
566
567
SDL_GetRGB(Uint32 pixel, const SDL_PixelFormat * format, Uint8 * r, Uint8 * g,
Uint8 * b)
568
{
569
if (format->palette == NULL) {
570
571
572
573
/*
* This makes sure that the result is mapped to the
* interval [0..255], and the maximum value for each
* component is 255. This is important to make sure
574
* that white is indeed reported as (255, 255, 255).
575
576
577
578
* This only works for RGB bit fields at least 4 bit
* wide, which is almost always the case.
*/
unsigned v;
579
580
581
582
583
584
v = (pixel & format->Rmask) >> format->Rshift;
*r = (v << format->Rloss) + (v >> (8 - (format->Rloss << 1)));
v = (pixel & format->Gmask) >> format->Gshift;
*g = (v << format->Gloss) + (v >> (8 - (format->Gloss << 1)));
v = (pixel & format->Bmask) >> format->Bshift;
*b = (v << format->Bloss) + (v >> (8 - (format->Bloss << 1)));
585
} else {
586
587
588
*r = format->palette->colors[pixel].r;
*g = format->palette->colors[pixel].g;
*b = format->palette->colors[pixel].b;
589
}
590
591
}
592
void
593
594
SDL_GetRGBA(Uint32 pixel, const SDL_PixelFormat * format,
Uint8 * r, Uint8 * g, Uint8 * b, Uint8 * a)
595
{
596
597
598
599
600
601
602
603
604
605
if (format->palette == NULL) {
/*
* This makes sure that the result is mapped to the
* interval [0..255], and the maximum value for each
* component is 255. This is important to make sure
* that white is indeed reported as (255, 255, 255),
* and that opaque alpha is 255.
* This only works for RGB bit fields at least 4 bit
* wide, which is almost always the case.
*/
606
unsigned v;
607
608
609
610
611
612
613
614
615
616
617
618
v = (pixel & format->Rmask) >> format->Rshift;
*r = (v << format->Rloss) + (v >> (8 - (format->Rloss << 1)));
v = (pixel & format->Gmask) >> format->Gshift;
*g = (v << format->Gloss) + (v >> (8 - (format->Gloss << 1)));
v = (pixel & format->Bmask) >> format->Bshift;
*b = (v << format->Bloss) + (v >> (8 - (format->Bloss << 1)));
if (format->Amask) {
v = (pixel & format->Amask) >> format->Ashift;
*a = (v << format->Aloss) + (v >> (8 - (format->Aloss << 1)));
} else {
*a = SDL_ALPHA_OPAQUE;
}
619
} else {
620
621
622
623
*r = format->palette->colors[pixel].r;
*g = format->palette->colors[pixel].g;
*b = format->palette->colors[pixel].b;
*a = SDL_ALPHA_OPAQUE;
624
}
625
626
627
}
/* Apply gamma to a set of colors - this is easy. :) */
628
629
630
void
SDL_ApplyGamma(Uint16 * gamma, SDL_Color * colors, SDL_Color * output,
int ncolors)
631
{
632
int i;
633
634
635
636
637
638
for (i = 0; i < ncolors; ++i) {
output[i].r = gamma[0 * 256 + colors[i].r] >> 8;
output[i].g = gamma[1 * 256 + colors[i].g] >> 8;
output[i].b = gamma[2 * 256 + colors[i].b] >> 8;
}
639
640
641
}
/* Map from Palette to Palette */
642
643
static Uint8 *
Map1to1(SDL_Palette * src, SDL_Palette * dst, int *identical)
644
{
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
Uint8 *map;
int i;
if (identical) {
if (src->ncolors <= dst->ncolors) {
/* If an identical palette, no need to map */
if (src == dst
||
(SDL_memcmp
(src->colors, dst->colors,
src->ncolors * sizeof(SDL_Color)) == 0)) {
*identical = 1;
return (NULL);
}
}
*identical = 0;
}
map = (Uint8 *) SDL_malloc(src->ncolors);
if (map == NULL) {
SDL_OutOfMemory();
return (NULL);
}
for (i = 0; i < src->ncolors; ++i) {
map[i] = SDL_FindColor(dst,
src->colors[i].r, src->colors[i].g,
src->colors[i].b);
}
return (map);
673
}
674
675
/* Map from Palette to BitField */
676
static Uint8 *
677
678
Map1toN(SDL_PixelFormat * src, Uint8 Rmod, Uint8 Gmod, Uint8 Bmod, Uint8 Amod,
SDL_PixelFormat * dst)
679
{
680
681
682
683
684
685
686
687
688
689
690
691
692
693
Uint8 *map;
int i;
int bpp;
SDL_Palette *pal = src->palette;
bpp = ((dst->BytesPerPixel == 3) ? 4 : dst->BytesPerPixel);
map = (Uint8 *) SDL_malloc(pal->ncolors * bpp);
if (map == NULL) {
SDL_OutOfMemory();
return (NULL);
}
/* We memory copy to the pixel map so the endianness is preserved */
for (i = 0; i < pal->ncolors; ++i) {
694
Uint8 A = Amod;
695
696
697
Uint8 R = (Uint8) ((pal->colors[i].r * Rmod) / 255);
Uint8 G = (Uint8) ((pal->colors[i].g * Gmod) / 255);
Uint8 B = (Uint8) ((pal->colors[i].b * Bmod) / 255);
698
ASSEMBLE_RGBA(&map[i * bpp], dst->BytesPerPixel, dst, R, G, B, A);
699
700
}
return (map);
701
}
702
703
/* Map from BitField to Dithered-Palette to Palette */
704
705
static Uint8 *
MapNto1(SDL_PixelFormat * src, SDL_PixelFormat * dst, int *identical)
706
{
707
708
709
710
711
712
713
714
715
/* Generate a 256 color dither palette */
SDL_Palette dithered;
SDL_Color colors[256];
SDL_Palette *pal = dst->palette;
dithered.ncolors = 256;
SDL_DitherColors(colors, 8);
dithered.colors = colors;
return (Map1to1(&dithered, pal, identical));
716
717
}
718
719
SDL_BlitMap *
SDL_AllocBlitMap(void)
720
{
721
722
723
SDL_BlitMap *map;
/* Allocate the empty map */
724
map = (SDL_BlitMap *) SDL_calloc(1, sizeof(*map));
725
726
727
728
if (map == NULL) {
SDL_OutOfMemory();
return (NULL);
}
729
730
731
732
map->info.r = 0xFF;
map->info.g = 0xFF;
map->info.b = 0xFF;
map->info.a = 0xFF;
733
734
735
/* It's ready to go */
return (map);
736
}
737
738
739
void
SDL_InvalidateMap(SDL_BlitMap * map)
740
{
741
742
743
744
745
if (!map) {
return;
}
map->dst = NULL;
map->format_version = (unsigned int) -1;
746
747
748
if (map->info.table) {
SDL_free(map->info.table);
map->info.table = NULL;
749
}
750
}
751
752
int
SDL_MapSurface(SDL_Surface * src, SDL_Surface * dst)
753
{
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
SDL_PixelFormat *srcfmt;
SDL_PixelFormat *dstfmt;
SDL_BlitMap *map;
/* Clear out any previous mapping */
map = src->map;
if ((src->flags & SDL_RLEACCEL) == SDL_RLEACCEL) {
SDL_UnRLESurface(src, 1);
}
SDL_InvalidateMap(map);
/* Figure out what kind of mapping we're doing */
map->identity = 0;
srcfmt = src->format;
dstfmt = dst->format;
switch (srcfmt->BytesPerPixel) {
case 1:
switch (dstfmt->BytesPerPixel) {
case 1:
/* Palette --> Palette */
774
map->info.table =
775
776
Map1to1(srcfmt->palette, dstfmt->palette, &map->identity);
if (!map->identity) {
777
if (map->info.table == NULL) {
778
779
780
781
782
783
784
785
786
return (-1);
}
}
if (srcfmt->BitsPerPixel != dstfmt->BitsPerPixel)
map->identity = 0;
break;
default:
/* Palette --> BitField */
787
788
789
790
map->info.table =
Map1toN(srcfmt, src->map->info.r, src->map->info.g,
src->map->info.b, src->map->info.a, dstfmt);
if (map->info.table == NULL) {
791
792
793
794
795
796
797
798
799
return (-1);
}
break;
}
break;
default:
switch (dstfmt->BytesPerPixel) {
case 1:
/* BitField --> Palette */
800
map->info.table = MapNto1(srcfmt, dstfmt, &map->identity);
801
if (!map->identity) {
802
if (map->info.table == NULL) {
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
return (-1);
}
}
map->identity = 0; /* Don't optimize to copy */
break;
default:
/* BitField --> BitField */
if (FORMAT_EQUAL(srcfmt, dstfmt))
map->identity = 1;
break;
}
break;
}
map->dst = dst;
map->format_version = dst->format_version;
/* Choose your blitters wisely */
return (SDL_CalculateBlit(src));
822
}
823
824
825
void
SDL_FreeBlitMap(SDL_BlitMap * map)
826
{
827
828
829
830
if (map) {
SDL_InvalidateMap(map);
SDL_free(map);
}
831
}
832
833
/* vi: set ts=4 sw=4 expandtab: */