This repository has been archived by the owner on Feb 11, 2021. It is now read-only.
SDL_pixels.c
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.
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 */
36
37
SDL_PixelFormatEnumToMasks(Uint32 format, int *bpp, Uint32 * Rmask,
Uint32 * Gmask, Uint32 * Bmask, Uint32 * Amask)
38
39
40
41
{
Uint32 masks[4];
/* Initialize the values here */
42
43
if (SDL_BITSPERPIXEL(format) == 24) {
*bpp = SDL_BYTESPERPIXEL(format) * 8;
45
*bpp = SDL_BITSPERPIXEL(format);
46
47
48
}
*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
/* Not a format that uses masks */
return SDL_TRUE;
}
56
switch (SDL_PIXELLAYOUT(format)) {
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
case SDL_PackedLayout_332:
masks[0] = 0x00000000;
masks[1] = 0x000000E0;
masks[2] = 0x0000001C;
masks[3] = 0x00000003;
break;
case SDL_PackedLayout_4444:
masks[0] = 0x0000F000;
masks[1] = 0x00000F00;
masks[2] = 0x000000F0;
masks[3] = 0x0000000F;
break;
case SDL_PackedLayout_1555:
masks[0] = 0x00008000;
masks[1] = 0x00007C00;
masks[2] = 0x000003E0;
masks[3] = 0x0000001F;
break;
case SDL_PackedLayout_565:
masks[0] = 0x00000000;
masks[1] = 0x0000F800;
masks[2] = 0x000007E0;
masks[3] = 0x0000001F;
break;
case SDL_PackedLayout_8888:
masks[0] = 0xFF000000;
masks[1] = 0x00FF0000;
masks[2] = 0x0000FF00;
masks[3] = 0x000000FF;
break;
case SDL_PackedLayout_2101010:
masks[0] = 0xC0000000;
masks[1] = 0x3FF00000;
masks[2] = 0x000FFC00;
masks[3] = 0x000003FF;
break;
default:
/* Unknown layout */
return SDL_FALSE;
}
98
switch (SDL_PIXELORDER(format)) {
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
case SDL_PackedOrder_XRGB:
*Rmask = masks[1];
*Gmask = masks[2];
*Bmask = masks[3];
break;
case SDL_PackedOrder_RGBX:
*Rmask = masks[0];
*Gmask = masks[1];
*Bmask = masks[2];
break;
case SDL_PackedOrder_ARGB:
*Amask = masks[0];
*Rmask = masks[1];
*Gmask = masks[2];
*Bmask = masks[3];
break;
case SDL_PackedOrder_RGBA:
*Rmask = masks[0];
*Gmask = masks[1];
*Bmask = masks[2];
*Amask = masks[3];
break;
case SDL_PackedOrder_XBGR:
*Bmask = masks[1];
*Gmask = masks[2];
*Rmask = masks[3];
break;
case SDL_PackedOrder_BGRX:
*Bmask = masks[0];
*Gmask = masks[1];
*Rmask = masks[2];
break;
case SDL_PackedOrder_BGRA:
*Bmask = masks[0];
*Gmask = masks[1];
*Rmask = masks[2];
*Amask = masks[3];
break;
case SDL_PackedOrder_ABGR:
*Amask = masks[0];
*Bmask = masks[1];
*Gmask = masks[2];
*Rmask = masks[3];
break;
default:
/* Unknown order */
return SDL_FALSE;
}
return SDL_TRUE;
}
Uint32
151
152
SDL_MasksToPixelFormatEnum(int bpp, Uint32 Rmask, Uint32 Gmask, Uint32 Bmask,
Uint32 Amask)
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
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
{
switch (bpp) {
case 8:
switch (Rmask) {
case 0:
return SDL_PixelFormat_Index8;
case 0xE0:
return SDL_PixelFormat_RGB332;
}
break;
case 12:
switch (Rmask) {
case 0x0F00:
return SDL_PixelFormat_RGB444;
}
break;
case 15:
switch (Rmask) {
case 0x7C00:
return SDL_PixelFormat_RGB555;
}
break;
case 16:
switch (Rmask) {
case 0x0F00:
return SDL_PixelFormat_ARGB4444;
case 0x7C00:
return SDL_PixelFormat_ARGB1555;
case 0xF800:
return SDL_PixelFormat_RGB565;
}
break;
case 32:
switch (Rmask) {
case 0xFF000000:
if (Amask == 0x000000FF) {
return SDL_PixelFormat_RGBA8888;
}
break;
case 0x00FF0000:
if (Amask == 0xFF000000) {
return SDL_PixelFormat_ARGB8888;
} else {
return SDL_PixelFormat_RGB888;
}
break;
case 0x0000FF00:
if (Amask == 0x000000FF) {
return SDL_PixelFormat_BGRA8888;
}
break;
case 0x000000FF:
if (Amask == 0xFF000000) {
return SDL_PixelFormat_ABGR8888;
} else {
return SDL_PixelFormat_BGR888;
}
break;
case 0x3FF00000:
return SDL_PixelFormat_ARGB2101010;
}
}
return SDL_PixelFormat_Unknown;
}
218
219
220
/*
* Allocate a pixel format structure and fill it according to the given info.
*/
221
SDL_PixelFormat *
222
223
SDL_AllocFormat(int bpp,
Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask)
224
{
225
226
227
228
SDL_PixelFormat *format;
Uint32 mask;
/* Allocate an empty pixel format structure */
229
format = SDL_malloc(sizeof(*format));
230
if (format == NULL) {
231
SDL_OutOfMemory();
232
233
return (NULL);
}
234
SDL_memset(format, 0, sizeof(*format));
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
format->alpha = SDL_ALPHA_OPAQUE;
/* Set up the format */
format->BitsPerPixel = bpp;
format->BytesPerPixel = (bpp + 7) / 8;
if (Rmask || Bmask || Gmask) { /* Packed pixels with custom mask */
format->palette = NULL;
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;
}
if (bpp <= 8) { /* Palettized mode */
int ncolors = 1 << bpp;
308
#ifdef DEBUG_PALETTE
309
fprintf(stderr, "bpp=%d ncolors=%d\n", bpp, ncolors);
311
format->palette = (SDL_Palette *) SDL_malloc(sizeof(SDL_Palette));
312
if (format->palette == NULL) {
313
314
SDL_FreeFormat(format);
SDL_OutOfMemory();
315
316
317
return (NULL);
}
(format->palette)->ncolors = ncolors;
318
319
320
321
322
(format->palette)->colors = (SDL_Color *) SDL_malloc((format->
palette)->
ncolors *
sizeof
(SDL_Color));
323
if ((format->palette)->colors == NULL) {
324
325
SDL_FreeFormat(format);
SDL_OutOfMemory();
326
327
328
329
330
331
332
return (NULL);
}
if (Rmask || Bmask || Gmask) {
/* create palette according to masks */
int i;
int Rm = 0, Gm = 0, Bm = 0;
int Rw = 0, Gw = 0, Bw = 0;
333
#ifdef ENABLE_PALETTE_ALPHA
334
int Am = 0, Aw = 0;
336
337
338
339
340
if (Rmask) {
Rw = 8 - format->Rloss;
for (i = format->Rloss; i > 0; i -= Rw)
Rm |= 1 << i;
}
341
#ifdef DEBUG_PALETTE
342
fprintf(stderr, "Rw=%d Rm=0x%02X\n", Rw, Rm);
344
345
346
347
348
if (Gmask) {
Gw = 8 - format->Gloss;
for (i = format->Gloss; i > 0; i -= Gw)
Gm |= 1 << i;
}
349
#ifdef DEBUG_PALETTE
350
fprintf(stderr, "Gw=%d Gm=0x%02X\n", Gw, Gm);
352
353
354
355
356
if (Bmask) {
Bw = 8 - format->Bloss;
for (i = format->Bloss; i > 0; i -= Bw)
Bm |= 1 << i;
}
357
#ifdef DEBUG_PALETTE
358
fprintf(stderr, "Bw=%d Bm=0x%02X\n", Bw, Bm);
359
360
#endif
#ifdef ENABLE_PALETTE_ALPHA
361
362
363
364
365
if (Amask) {
Aw = 8 - format->Aloss;
for (i = format->Aloss; i > 0; i -= Aw)
Am |= 1 << i;
}
366
# ifdef DEBUG_PALETTE
367
fprintf(stderr, "Aw=%d Am=0x%02X\n", Aw, Am);
368
369
# endif
#endif
370
371
372
373
374
for (i = 0; i < ncolors; ++i) {
int r, g, b;
r = (i & Rmask) >> format->Rshift;
r = (r << format->Rloss) | ((r * Rm) >> Rw);
format->palette->colors[i].r = r;
376
377
378
g = (i & Gmask) >> format->Gshift;
g = (g << format->Gloss) | ((g * Gm) >> Gw);
format->palette->colors[i].g = g;
380
381
382
b = (i & Bmask) >> format->Bshift;
b = (b << format->Bloss) | ((b * Bm) >> Bw);
format->palette->colors[i].b = b;
383
384
#ifdef ENABLE_PALETTE_ALPHA
385
386
387
a = (i & Amask) >> format->Ashift;
a = (a << format->Aloss) | ((a * Am) >> Aw);
format->palette->colors[i].unused = a;
389
format->palette->colors[i].unused = 0;
391
392
393
394
395
396
397
398
399
400
401
}
} else if (ncolors == 2) {
/* Create a black and white bitmap palette */
format->palette->colors[0].r = 0xFF;
format->palette->colors[0].g = 0xFF;
format->palette->colors[0].b = 0xFF;
format->palette->colors[1].r = 0x00;
format->palette->colors[1].g = 0x00;
format->palette->colors[1].b = 0x00;
} else {
/* Create an empty palette */
402
403
SDL_memset((format->palette)->colors, 0,
(format->palette)->ncolors * sizeof(SDL_Color));
404
405
406
}
}
return (format);
407
}
408
409
SDL_PixelFormat *
410
411
SDL_ReallocFormat(SDL_Surface * surface, int bpp,
Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask)
412
{
413
if (surface->format) {
414
415
SDL_FreeFormat(surface->format);
SDL_FormatChanged(surface);
417
surface->format = SDL_AllocFormat(bpp, Rmask, Gmask, Bmask, Amask);
418
return surface->format;
419
420
421
422
423
}
/*
* Change any previous mappings from/to the new surface format
*/
425
SDL_FormatChanged(SDL_Surface * surface)
426
{
427
428
429
430
431
432
static int format_version = 0;
++format_version;
if (format_version < 0) { /* It wrapped... */
format_version = 1;
}
surface->format_version = format_version;
433
SDL_InvalidateMap(surface->map);
434
}
436
437
438
/*
* Free a previously allocated format structure
*/
440
SDL_FreeFormat(SDL_PixelFormat * format)
441
{
442
443
444
if (format) {
if (format->palette) {
if (format->palette->colors) {
445
SDL_free(format->palette->colors);
447
SDL_free(format->palette);
449
SDL_free(format);
451
}
453
454
455
/*
* Calculate an 8-bit (3 red, 3 green, 2 blue) dithered palette of colors
*/
457
SDL_DitherColors(SDL_Color * colors, int bpp)
458
{
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
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;
}
478
}
480
481
482
/*
* Calculate the pad-aligned scanline width of a surface
*/
483
int
484
SDL_CalculatePitch(SDL_Surface * surface)
485
{
486
int pitch;
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
/* 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);
502
}
504
505
506
/*
* Match an RGB value to a particular palette index
*/
508
SDL_FindColor(SDL_Palette * pal, Uint8 r, Uint8 g, Uint8 b)
509
{
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
/* 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);
532
533
534
}
/* Find the opaque pixel value corresponding to an RGB triple */
536
SDL_MapRGB(SDL_PixelFormat * format, Uint8 r, Uint8 g, Uint8 b)
537
{
538
539
540
541
542
if (format->palette == NULL) {
return (r >> format->Rloss) << format->Rshift
| (g >> format->Gloss) << format->Gshift
| (b >> format->Bloss) << format->Bshift | format->Amask;
} else {
543
return SDL_FindColor(format->palette, r, g, b);
545
546
547
}
/* Find the pixel value corresponding to an RGBA quadruple */
549
SDL_MapRGBA(SDL_PixelFormat * format, Uint8 r, Uint8 g, Uint8 b, Uint8 a)
550
{
551
552
553
554
555
556
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 {
557
return SDL_FindColor(format->palette, r, g, b);
559
560
}
562
563
SDL_GetRGBA(Uint32 pixel, SDL_PixelFormat * fmt,
Uint8 * r, Uint8 * g, Uint8 * b, Uint8 * a)
564
{
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
if (fmt->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.
*/
unsigned v;
v = (pixel & fmt->Rmask) >> fmt->Rshift;
*r = (v << fmt->Rloss) + (v >> (8 - (fmt->Rloss << 1)));
v = (pixel & fmt->Gmask) >> fmt->Gshift;
*g = (v << fmt->Gloss) + (v >> (8 - (fmt->Gloss << 1)));
v = (pixel & fmt->Bmask) >> fmt->Bshift;
*b = (v << fmt->Bloss) + (v >> (8 - (fmt->Bloss << 1)));
if (fmt->Amask) {
v = (pixel & fmt->Amask) >> fmt->Ashift;
*a = (v << fmt->Aloss) + (v >> (8 - (fmt->Aloss << 1)));
} else {
*a = SDL_ALPHA_OPAQUE;
}
} else {
*r = fmt->palette->colors[pixel].r;
*g = fmt->palette->colors[pixel].g;
*b = fmt->palette->colors[pixel].b;
*a = SDL_ALPHA_OPAQUE;
}
594
595
}
597
598
SDL_GetRGB(Uint32 pixel, SDL_PixelFormat * fmt, Uint8 * r, Uint8 * g,
Uint8 * b)
599
{
600
601
602
603
604
605
606
607
608
609
610
611
612
613
if (fmt->palette == NULL) {
/* the note for SDL_GetRGBA above applies here too */
unsigned v;
v = (pixel & fmt->Rmask) >> fmt->Rshift;
*r = (v << fmt->Rloss) + (v >> (8 - (fmt->Rloss << 1)));
v = (pixel & fmt->Gmask) >> fmt->Gshift;
*g = (v << fmt->Gloss) + (v >> (8 - (fmt->Gloss << 1)));
v = (pixel & fmt->Bmask) >> fmt->Bshift;
*b = (v << fmt->Bloss) + (v >> (8 - (fmt->Bloss << 1)));
} else {
*r = fmt->palette->colors[pixel].r;
*g = fmt->palette->colors[pixel].g;
*b = fmt->palette->colors[pixel].b;
}
614
615
616
}
/* Apply gamma to a set of colors - this is easy. :) */
618
619
SDL_ApplyGamma(Uint16 * gamma, SDL_Color * colors, SDL_Color * output,
int ncolors)
620
{
623
624
625
626
627
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;
}
628
629
630
}
/* Map from Palette to Palette */
632
Map1to1(SDL_Palette * src, SDL_Palette * dst, int *identical)
633
{
634
635
636
637
638
639
Uint8 *map;
int i;
if (identical) {
if (src->ncolors <= dst->ncolors) {
/* If an identical palette, no need to map */
640
641
if (SDL_memcmp(src->colors, dst->colors, src->ncolors *
sizeof(SDL_Color)) == 0) {
642
643
644
645
646
647
*identical = 1;
return (NULL);
}
}
*identical = 0;
}
648
map = (Uint8 *) SDL_malloc(src->ncolors);
649
if (map == NULL) {
650
SDL_OutOfMemory();
651
652
653
return (NULL);
}
for (i = 0; i < src->ncolors; ++i) {
654
655
656
map[i] = SDL_FindColor(dst,
src->colors[i].r, src->colors[i].g,
src->colors[i].b);
657
658
}
return (map);
659
}
661
/* Map from Palette to BitField */
663
Map1toN(SDL_PixelFormat * src, SDL_PixelFormat * dst)
664
{
665
666
667
668
669
670
671
Uint8 *map;
int i;
int bpp;
unsigned alpha;
SDL_Palette *pal = src->palette;
bpp = ((dst->BytesPerPixel == 3) ? 4 : dst->BytesPerPixel);
672
map = (Uint8 *) SDL_malloc(pal->ncolors * bpp);
673
if (map == NULL) {
674
SDL_OutOfMemory();
675
676
677
678
679
680
return (NULL);
}
alpha = dst->Amask ? src->alpha : 0;
/* We memory copy to the pixel map so the endianness is preserved */
for (i = 0; i < pal->ncolors; ++i) {
681
682
683
ASSEMBLE_RGBA(&map[i * bpp], dst->BytesPerPixel, dst,
pal->colors[i].r, pal->colors[i].g,
pal->colors[i].b, alpha);
684
685
}
return (map);
686
}
688
/* Map from BitField to Dithered-Palette to Palette */
690
MapNto1(SDL_PixelFormat * src, SDL_PixelFormat * dst, int *identical)
691
{
692
693
694
695
696
697
698
/* Generate a 256 color dither palette */
SDL_Palette dithered;
SDL_Color colors[256];
SDL_Palette *pal = dst->palette;
/* SDL_DitherColors does not initialize the 'unused' component of colors,
but Map1to1 compares it against pal, so we should initialize it. */
699
SDL_memset(colors, 0, sizeof(colors));
700
701
dithered.ncolors = 256;
702
SDL_DitherColors(colors, 8);
703
dithered.colors = colors;
704
return (Map1to1(&dithered, pal, identical));
705
706
}
708
SDL_AllocBlitMap(void)
709
{
710
711
712
SDL_BlitMap *map;
/* Allocate the empty map */
713
map = (SDL_BlitMap *) SDL_malloc(sizeof(*map));
714
if (map == NULL) {
715
SDL_OutOfMemory();
716
717
return (NULL);
}
718
SDL_memset(map, 0, sizeof(*map));
719
720
721
/* Allocate the software blit data */
map->sw_data =
722
(struct private_swaccel *) SDL_malloc(sizeof(*map->sw_data));
723
if (map->sw_data == NULL) {
724
725
SDL_FreeBlitMap(map);
SDL_OutOfMemory();
726
727
return (NULL);
}
728
SDL_memset(map->sw_data, 0, sizeof(*map->sw_data));
729
730
731
/* It's ready to go */
return (map);
732
}
735
SDL_InvalidateMap(SDL_BlitMap * map)
736
{
737
738
739
740
741
742
if (!map) {
return;
}
map->dst = NULL;
map->format_version = (unsigned int) -1;
if (map->table) {
743
SDL_free(map->table);
744
745
map->table = NULL;
}
746
}
748
SDL_MapSurface(SDL_Surface * src, SDL_Surface * dst)
749
{
750
751
752
753
754
755
756
SDL_PixelFormat *srcfmt;
SDL_PixelFormat *dstfmt;
SDL_BlitMap *map;
/* Clear out any previous mapping */
map = src->map;
if ((src->flags & SDL_RLEACCEL) == SDL_RLEACCEL) {
757
SDL_UnRLESurface(src, 1);
759
SDL_InvalidateMap(map);
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
/* 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 */
/* If both SDL_HWSURFACE, assume have same palette */
if (((src->flags & SDL_HWSURFACE) == SDL_HWSURFACE) &&
((dst->flags & SDL_HWSURFACE) == SDL_HWSURFACE)) {
map->identity = 1;
} else {
775
776
map->table = Map1to1(srcfmt->palette,
dstfmt->palette, &map->identity);
777
778
779
780
781
782
783
784
785
786
787
788
}
if (!map->identity) {
if (map->table == NULL) {
return (-1);
}
}
if (srcfmt->BitsPerPixel != dstfmt->BitsPerPixel)
map->identity = 0;
break;
default:
/* Palette --> BitField */
789
map->table = Map1toN(srcfmt, dstfmt);
790
791
792
793
794
795
796
797
798
799
if (map->table == NULL) {
return (-1);
}
break;
}
break;
default:
switch (dstfmt->BytesPerPixel) {
case 1:
/* BitField --> Palette */
800
map->table = MapNto1(srcfmt, dstfmt, &map->identity);
801
802
803
804
805
806
807
808
809
if (!map->identity) {
if (map->table == NULL) {
return (-1);
}
}
map->identity = 0; /* Don't optimize to copy */
break;
default:
/* BitField --> BitField */
810
if (FORMAT_EQUAL(srcfmt, dstfmt))
811
812
813
814
815
816
817
818
819
820
map->identity = 1;
break;
}
break;
}
map->dst = dst;
map->format_version = dst->format_version;
/* Choose your blitters wisely */
821
return (SDL_CalculateBlit(src));
822
}
825
SDL_FreeBlitMap(SDL_BlitMap * map)
826
{
828
SDL_InvalidateMap(map);
829
if (map->sw_data != NULL) {
830
SDL_free(map->sw_data);
832
SDL_free(map);
834
}
835
836
/* vi: set ts=4 sw=4 expandtab: */