This repository has been archived by the owner on Feb 11, 2021. It is now read-only.
/
SDL_pixels.c
865 lines (795 loc) · 23 KB
1
2
/*
SDL - Simple DirectMedia Layer
3
Copyright (C) 1997-2009 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
76
77
78
79
80
case SDL_PACKEDLAYOUT_5551:
masks[0] = 0x0000F800;
masks[1] = 0x000007C0;
masks[2] = 0x0000003E;
masks[3] = 0x00000001;
break;
81
case SDL_PACKEDLAYOUT_565:
82
83
84
85
86
masks[0] = 0x00000000;
masks[1] = 0x0000F800;
masks[2] = 0x000007E0;
masks[3] = 0x0000001F;
break;
87
case SDL_PACKEDLAYOUT_8888:
88
89
90
91
92
masks[0] = 0xFF000000;
masks[1] = 0x00FF0000;
masks[2] = 0x0000FF00;
masks[3] = 0x000000FF;
break;
93
case SDL_PACKEDLAYOUT_2101010:
94
95
96
97
98
masks[0] = 0xC0000000;
masks[1] = 0x3FF00000;
masks[2] = 0x000FFC00;
masks[3] = 0x000003FF;
break;
99
100
101
102
103
104
case SDL_PACKEDLAYOUT_1010102:
masks[0] = 0xFFC00000;
masks[1] = 0x003FF000;
masks[2] = 0x00000FFC;
masks[3] = 0x00000003;
break;
105
106
107
108
109
110
default:
/* Unknown layout */
return SDL_FALSE;
}
switch (SDL_PIXELORDER(format)) {
111
case SDL_PACKEDORDER_XRGB:
112
113
114
115
*Rmask = masks[1];
*Gmask = masks[2];
*Bmask = masks[3];
break;
116
case SDL_PACKEDORDER_RGBX:
117
118
119
120
*Rmask = masks[0];
*Gmask = masks[1];
*Bmask = masks[2];
break;
121
case SDL_PACKEDORDER_ARGB:
122
123
124
125
126
*Amask = masks[0];
*Rmask = masks[1];
*Gmask = masks[2];
*Bmask = masks[3];
break;
127
case SDL_PACKEDORDER_RGBA:
128
129
130
131
132
*Rmask = masks[0];
*Gmask = masks[1];
*Bmask = masks[2];
*Amask = masks[3];
break;
133
case SDL_PACKEDORDER_XBGR:
134
135
136
137
*Bmask = masks[1];
*Gmask = masks[2];
*Rmask = masks[3];
break;
138
case SDL_PACKEDORDER_BGRX:
139
140
141
142
*Bmask = masks[0];
*Gmask = masks[1];
*Rmask = masks[2];
break;
143
case SDL_PACKEDORDER_BGRA:
144
145
146
147
148
*Bmask = masks[0];
*Gmask = masks[1];
*Rmask = masks[2];
*Amask = masks[3];
break;
149
case SDL_PACKEDORDER_ABGR:
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
*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:
170
return SDL_PIXELFORMAT_INDEX8;
171
case 0xE0:
172
return SDL_PIXELFORMAT_RGB332;
173
174
175
176
177
}
break;
case 12:
switch (Rmask) {
case 0x0F00:
178
return SDL_PIXELFORMAT_RGB444;
179
180
181
182
}
break;
case 15:
switch (Rmask) {
183
184
case 0x001F:
return SDL_PIXELFORMAT_BGR555;
185
case 0x7C00:
186
return SDL_PIXELFORMAT_RGB555;
187
188
189
190
}
break;
case 16:
switch (Rmask) {
191
192
case 0x000F:
return SDL_PIXELFORMAT_ABGR4444;
193
case 0x001F:
194
195
196
if (Gmask == 0x07E0) {
return SDL_PIXELFORMAT_BGR565;
}
197
return SDL_PIXELFORMAT_ABGR1555;
198
case 0x0F00:
199
return SDL_PIXELFORMAT_ARGB4444;
200
case 0x7C00:
201
return SDL_PIXELFORMAT_ARGB1555;
202
case 0xF800:
203
return SDL_PIXELFORMAT_RGB565;
204
205
206
207
208
209
}
break;
case 32:
switch (Rmask) {
case 0xFF000000:
if (Amask == 0x000000FF) {
210
return SDL_PIXELFORMAT_RGBA8888;
211
212
213
214
}
break;
case 0x00FF0000:
if (Amask == 0xFF000000) {
215
return SDL_PIXELFORMAT_ARGB8888;
216
} else {
217
return SDL_PIXELFORMAT_RGB888;
218
219
220
221
}
break;
case 0x0000FF00:
if (Amask == 0x000000FF) {
222
return SDL_PIXELFORMAT_BGRA8888;
223
224
225
226
}
break;
case 0x000000FF:
if (Amask == 0xFF000000) {
227
return SDL_PIXELFORMAT_ABGR8888;
228
} else {
229
return SDL_PIXELFORMAT_BGR888;
230
231
232
}
break;
case 0x3FF00000:
233
return SDL_PIXELFORMAT_ARGB2101010;
234
235
}
}
236
return SDL_PIXELFORMAT_UNKNOWN;
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
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
}
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);
}
359
360
361
/*
* Allocate a pixel format structure and fill it according to the given info.
*/
362
363
364
SDL_PixelFormat *
SDL_AllocFormat(int bpp,
Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask)
365
{
366
367
368
SDL_PixelFormat *format;
/* Allocate an empty pixel format structure */
369
format = SDL_malloc(sizeof(*format));
370
371
372
373
374
375
if (format == NULL) {
SDL_OutOfMemory();
return (NULL);
}
/* Set up the format */
376
377
378
379
return SDL_InitFormat(format, bpp, Rmask, Gmask, Bmask, Amask);
}
SDL_PixelFormat *
380
381
SDL_InitFormat(SDL_PixelFormat * format, int bpp, Uint32 Rmask, Uint32 Gmask,
Uint32 Bmask, Uint32 Amask)
382
383
384
385
386
{
Uint32 mask;
/* Set up the format */
SDL_zerop(format);
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
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
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;
456
return format;
457
458
459
460
461
}
/*
* Change any previous mappings from/to the new surface format
*/
462
463
void
SDL_FormatChanged(SDL_Surface * surface)
464
{
465
466
467
468
469
470
471
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);
472
}
473
474
475
476
/*
* Free a previously allocated format structure
*/
477
478
void
SDL_FreeFormat(SDL_PixelFormat * format)
479
{
480
481
482
483
if (!format) {
return;
}
SDL_free(format);
484
}
485
486
487
488
/*
* Calculate an 8-bit (3 red, 3 green, 2 blue) dithered palette of colors
*/
489
490
void
SDL_DitherColors(SDL_Color * colors, int bpp)
491
{
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
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;
}
512
}
513
514
515
516
/*
* Calculate the pad-aligned scanline width of a surface
*/
517
518
int
SDL_CalculatePitch(SDL_Surface * surface)
519
{
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
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);
536
}
537
538
539
540
/*
* Match an RGB value to a particular palette index
*/
541
542
Uint8
SDL_FindColor(SDL_Palette * pal, Uint8 r, Uint8 g, Uint8 b)
543
{
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
/* 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);
566
567
568
}
/* Find the opaque pixel value corresponding to an RGB triple */
569
Uint32
570
SDL_MapRGB(const SDL_PixelFormat * format, Uint8 r, Uint8 g, Uint8 b)
571
{
572
573
574
575
576
577
578
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);
}
579
580
581
}
/* Find the pixel value corresponding to an RGBA quadruple */
582
Uint32
583
584
SDL_MapRGBA(const SDL_PixelFormat * format, Uint8 r, Uint8 g, Uint8 b,
Uint8 a)
585
{
586
587
588
589
590
591
592
593
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);
}
594
595
}
596
void
597
598
SDL_GetRGB(Uint32 pixel, const SDL_PixelFormat * format, Uint8 * r, Uint8 * g,
Uint8 * b)
599
{
600
if (format->palette == NULL) {
601
602
603
604
/*
* 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
605
* that white is indeed reported as (255, 255, 255).
606
607
608
609
* This only works for RGB bit fields at least 4 bit
* wide, which is almost always the case.
*/
unsigned v;
610
611
612
613
614
615
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)));
616
} else {
617
618
619
*r = format->palette->colors[pixel].r;
*g = format->palette->colors[pixel].g;
*b = format->palette->colors[pixel].b;
620
}
621
622
}
623
void
624
625
SDL_GetRGBA(Uint32 pixel, const SDL_PixelFormat * format,
Uint8 * r, Uint8 * g, Uint8 * b, Uint8 * a)
626
{
627
628
629
630
631
632
633
634
635
636
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.
*/
637
unsigned v;
638
639
640
641
642
643
644
645
646
647
648
649
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;
}
650
} else {
651
652
653
654
*r = format->palette->colors[pixel].r;
*g = format->palette->colors[pixel].g;
*b = format->palette->colors[pixel].b;
*a = SDL_ALPHA_OPAQUE;
655
}
656
657
658
}
/* Apply gamma to a set of colors - this is easy. :) */
659
660
661
void
SDL_ApplyGamma(Uint16 * gamma, SDL_Color * colors, SDL_Color * output,
int ncolors)
662
{
663
int i;
664
665
666
667
668
669
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;
}
670
671
672
}
/* Map from Palette to Palette */
673
674
static Uint8 *
Map1to1(SDL_Palette * src, SDL_Palette * dst, int *identical)
675
{
676
677
678
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
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);
704
}
705
706
/* Map from Palette to BitField */
707
static Uint8 *
708
709
Map1toN(SDL_PixelFormat * src, Uint8 Rmod, Uint8 Gmod, Uint8 Bmod, Uint8 Amod,
SDL_PixelFormat * dst)
710
{
711
712
713
714
715
716
717
718
719
720
721
722
723
724
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) {
725
Uint8 A = Amod;
726
727
728
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);
729
ASSEMBLE_RGBA(&map[i * bpp], dst->BytesPerPixel, dst, R, G, B, A);
730
731
}
return (map);
732
}
733
734
/* Map from BitField to Dithered-Palette to Palette */
735
736
static Uint8 *
MapNto1(SDL_PixelFormat * src, SDL_PixelFormat * dst, int *identical)
737
{
738
739
740
741
742
743
744
745
746
/* 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));
747
748
}
749
750
SDL_BlitMap *
SDL_AllocBlitMap(void)
751
{
752
753
754
SDL_BlitMap *map;
/* Allocate the empty map */
755
map = (SDL_BlitMap *) SDL_calloc(1, sizeof(*map));
756
757
758
759
if (map == NULL) {
SDL_OutOfMemory();
return (NULL);
}
760
761
762
763
map->info.r = 0xFF;
map->info.g = 0xFF;
map->info.b = 0xFF;
map->info.a = 0xFF;
764
765
766
/* It's ready to go */
return (map);
767
}
768
769
770
void
SDL_InvalidateMap(SDL_BlitMap * map)
771
{
772
773
774
775
776
if (!map) {
return;
}
map->dst = NULL;
map->format_version = (unsigned int) -1;
777
778
779
if (map->info.table) {
SDL_free(map->info.table);
map->info.table = NULL;
780
}
781
}
782
783
784
int
SDL_MapSurface(SDL_Surface * src, SDL_Surface * dst)
785
{
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
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 */
806
map->info.table =
807
808
Map1to1(srcfmt->palette, dstfmt->palette, &map->identity);
if (!map->identity) {
809
if (map->info.table == NULL) {
810
811
812
813
814
815
816
817
818
return (-1);
}
}
if (srcfmt->BitsPerPixel != dstfmt->BitsPerPixel)
map->identity = 0;
break;
default:
/* Palette --> BitField */
819
820
821
822
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) {
823
824
825
826
827
828
829
830
831
return (-1);
}
break;
}
break;
default:
switch (dstfmt->BytesPerPixel) {
case 1:
/* BitField --> Palette */
832
map->info.table = MapNto1(srcfmt, dstfmt, &map->identity);
833
if (!map->identity) {
834
if (map->info.table == NULL) {
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
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));
854
}
855
856
857
void
SDL_FreeBlitMap(SDL_BlitMap * map)
858
{
859
860
861
862
if (map) {
SDL_InvalidateMap(map);
SDL_free(map);
}
863
}
864
865
/* vi: set ts=4 sw=4 expandtab: */