SDL  2.0
SDL_pixels.c
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1 /*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2018 Sam Lantinga <slouken@libsdl.org>
4 
5  This software is provided 'as-is', without any express or implied
6  warranty. In no event will the authors be held liable for any damages
7  arising from the use of this software.
8 
9  Permission is granted to anyone to use this software for any purpose,
10  including commercial applications, and to alter it and redistribute it
11  freely, subject to the following restrictions:
12 
13  1. The origin of this software must not be misrepresented; you must not
14  claim that you wrote the original software. If you use this software
15  in a product, an acknowledgment in the product documentation would be
16  appreciated but is not required.
17  2. Altered source versions must be plainly marked as such, and must not be
18  misrepresented as being the original software.
19  3. This notice may not be removed or altered from any source distribution.
20 */
21 #include "../SDL_internal.h"
22 
23 /* General (mostly internal) pixel/color manipulation routines for SDL */
24 
25 #include "SDL_endian.h"
26 #include "SDL_video.h"
27 #include "SDL_sysvideo.h"
28 #include "SDL_blit.h"
29 #include "SDL_pixels_c.h"
30 #include "SDL_RLEaccel_c.h"
31 
32 
33 /* Lookup tables to expand partial bytes to the full 0..255 range */
34 
35 static Uint8 lookup_0[] = {
36 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 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, 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, 98, 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, 151, 152, 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, 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
37 };
38 
39 static Uint8 lookup_1[] = {
40 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 255
41 };
42 
43 static Uint8 lookup_2[] = {
44 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60, 64, 68, 72, 76, 80, 85, 89, 93, 97, 101, 105, 109, 113, 117, 121, 125, 129, 133, 137, 141, 145, 149, 153, 157, 161, 165, 170, 174, 178, 182, 186, 190, 194, 198, 202, 206, 210, 214, 218, 222, 226, 230, 234, 238, 242, 246, 250, 255
45 };
46 
47 static Uint8 lookup_3[] = {
48 0, 8, 16, 24, 32, 41, 49, 57, 65, 74, 82, 90, 98, 106, 115, 123, 131, 139, 148, 156, 164, 172, 180, 189, 197, 205, 213, 222, 230, 238, 246, 255
49 };
50 
51 static Uint8 lookup_4[] = {
52 0, 17, 34, 51, 68, 85, 102, 119, 136, 153, 170, 187, 204, 221, 238, 255
53 };
54 
55 static Uint8 lookup_5[] = {
56 0, 36, 72, 109, 145, 182, 218, 255
57 };
58 
59 static Uint8 lookup_6[] = {
60 0, 85, 170, 255
61 };
62 
63 static Uint8 lookup_7[] = {
64 0, 255
65 };
66 
67 static Uint8 lookup_8[] = {
68 255
69 };
70 
72  lookup_0,
73  lookup_1,
74  lookup_2,
75  lookup_3,
76  lookup_4,
77  lookup_5,
78  lookup_6,
79  lookup_7,
80  lookup_8
81 };
82 
83 /* Helper functions */
84 
85 const char*
87 {
88  switch (format) {
89 #define CASE(X) case X: return #X;
127 #undef CASE
128  default:
129  return "SDL_PIXELFORMAT_UNKNOWN";
130  }
131 }
132 
133 SDL_bool
135  Uint32 * Gmask, Uint32 * Bmask, Uint32 * Amask)
136 {
137  Uint32 masks[4];
138 
139  /* This function doesn't work with FourCC pixel formats */
140  if (SDL_ISPIXELFORMAT_FOURCC(format)) {
141  SDL_SetError("FOURCC pixel formats are not supported");
142  return SDL_FALSE;
143  }
144 
145  /* Initialize the values here */
146  if (SDL_BYTESPERPIXEL(format) <= 2) {
147  *bpp = SDL_BITSPERPIXEL(format);
148  } else {
149  *bpp = SDL_BYTESPERPIXEL(format) * 8;
150  }
151  *Rmask = *Gmask = *Bmask = *Amask = 0;
152 
153  if (format == SDL_PIXELFORMAT_RGB24) {
154 #if SDL_BYTEORDER == SDL_BIG_ENDIAN
155  *Rmask = 0x00FF0000;
156  *Gmask = 0x0000FF00;
157  *Bmask = 0x000000FF;
158 #else
159  *Rmask = 0x000000FF;
160  *Gmask = 0x0000FF00;
161  *Bmask = 0x00FF0000;
162 #endif
163  return SDL_TRUE;
164  }
165 
166  if (format == SDL_PIXELFORMAT_BGR24) {
167 #if SDL_BYTEORDER == SDL_BIG_ENDIAN
168  *Rmask = 0x000000FF;
169  *Gmask = 0x0000FF00;
170  *Bmask = 0x00FF0000;
171 #else
172  *Rmask = 0x00FF0000;
173  *Gmask = 0x0000FF00;
174  *Bmask = 0x000000FF;
175 #endif
176  return SDL_TRUE;
177  }
178 
179  if (SDL_PIXELTYPE(format) != SDL_PIXELTYPE_PACKED8 &&
182  /* Not a format that uses masks */
183  return SDL_TRUE;
184  }
185 
186  switch (SDL_PIXELLAYOUT(format)) {
188  masks[0] = 0x00000000;
189  masks[1] = 0x000000E0;
190  masks[2] = 0x0000001C;
191  masks[3] = 0x00000003;
192  break;
194  masks[0] = 0x0000F000;
195  masks[1] = 0x00000F00;
196  masks[2] = 0x000000F0;
197  masks[3] = 0x0000000F;
198  break;
200  masks[0] = 0x00008000;
201  masks[1] = 0x00007C00;
202  masks[2] = 0x000003E0;
203  masks[3] = 0x0000001F;
204  break;
206  masks[0] = 0x0000F800;
207  masks[1] = 0x000007C0;
208  masks[2] = 0x0000003E;
209  masks[3] = 0x00000001;
210  break;
212  masks[0] = 0x00000000;
213  masks[1] = 0x0000F800;
214  masks[2] = 0x000007E0;
215  masks[3] = 0x0000001F;
216  break;
218  masks[0] = 0xFF000000;
219  masks[1] = 0x00FF0000;
220  masks[2] = 0x0000FF00;
221  masks[3] = 0x000000FF;
222  break;
224  masks[0] = 0xC0000000;
225  masks[1] = 0x3FF00000;
226  masks[2] = 0x000FFC00;
227  masks[3] = 0x000003FF;
228  break;
230  masks[0] = 0xFFC00000;
231  masks[1] = 0x003FF000;
232  masks[2] = 0x00000FFC;
233  masks[3] = 0x00000003;
234  break;
235  default:
236  SDL_SetError("Unknown pixel format");
237  return SDL_FALSE;
238  }
239 
240  switch (SDL_PIXELORDER(format)) {
242  *Rmask = masks[1];
243  *Gmask = masks[2];
244  *Bmask = masks[3];
245  break;
247  *Rmask = masks[0];
248  *Gmask = masks[1];
249  *Bmask = masks[2];
250  break;
252  *Amask = masks[0];
253  *Rmask = masks[1];
254  *Gmask = masks[2];
255  *Bmask = masks[3];
256  break;
258  *Rmask = masks[0];
259  *Gmask = masks[1];
260  *Bmask = masks[2];
261  *Amask = masks[3];
262  break;
264  *Bmask = masks[1];
265  *Gmask = masks[2];
266  *Rmask = masks[3];
267  break;
269  *Bmask = masks[0];
270  *Gmask = masks[1];
271  *Rmask = masks[2];
272  break;
274  *Bmask = masks[0];
275  *Gmask = masks[1];
276  *Rmask = masks[2];
277  *Amask = masks[3];
278  break;
280  *Amask = masks[0];
281  *Bmask = masks[1];
282  *Gmask = masks[2];
283  *Rmask = masks[3];
284  break;
285  default:
286  SDL_SetError("Unknown pixel format");
287  return SDL_FALSE;
288  }
289  return SDL_TRUE;
290 }
291 
292 Uint32
293 SDL_MasksToPixelFormatEnum(int bpp, Uint32 Rmask, Uint32 Gmask, Uint32 Bmask,
294  Uint32 Amask)
295 {
296  switch (bpp) {
297  case 1:
298  /* SDL defaults to MSB ordering */
300  case 4:
301  /* SDL defaults to MSB ordering */
303  case 8:
304  if (Rmask == 0) {
305  return SDL_PIXELFORMAT_INDEX8;
306  }
307  if (Rmask == 0xE0 &&
308  Gmask == 0x1C &&
309  Bmask == 0x03 &&
310  Amask == 0x00) {
311  return SDL_PIXELFORMAT_RGB332;
312  }
313  break;
314  case 12:
315  if (Rmask == 0) {
316  return SDL_PIXELFORMAT_RGB444;
317  }
318  if (Rmask == 0x0F00 &&
319  Gmask == 0x00F0 &&
320  Bmask == 0x000F &&
321  Amask == 0x0000) {
322  return SDL_PIXELFORMAT_RGB444;
323  }
324  break;
325  case 15:
326  if (Rmask == 0) {
327  return SDL_PIXELFORMAT_RGB555;
328  }
329  /* fallthrough */
330  case 16:
331  if (Rmask == 0) {
332  return SDL_PIXELFORMAT_RGB565;
333  }
334  if (Rmask == 0x7C00 &&
335  Gmask == 0x03E0 &&
336  Bmask == 0x001F &&
337  Amask == 0x0000) {
338  return SDL_PIXELFORMAT_RGB555;
339  }
340  if (Rmask == 0x001F &&
341  Gmask == 0x03E0 &&
342  Bmask == 0x7C00 &&
343  Amask == 0x0000) {
344  return SDL_PIXELFORMAT_BGR555;
345  }
346  if (Rmask == 0x0F00 &&
347  Gmask == 0x00F0 &&
348  Bmask == 0x000F &&
349  Amask == 0xF000) {
351  }
352  if (Rmask == 0xF000 &&
353  Gmask == 0x0F00 &&
354  Bmask == 0x00F0 &&
355  Amask == 0x000F) {
357  }
358  if (Rmask == 0x000F &&
359  Gmask == 0x00F0 &&
360  Bmask == 0x0F00 &&
361  Amask == 0xF000) {
363  }
364  if (Rmask == 0x00F0 &&
365  Gmask == 0x0F00 &&
366  Bmask == 0xF000 &&
367  Amask == 0x000F) {
369  }
370  if (Rmask == 0x7C00 &&
371  Gmask == 0x03E0 &&
372  Bmask == 0x001F &&
373  Amask == 0x8000) {
375  }
376  if (Rmask == 0xF800 &&
377  Gmask == 0x07C0 &&
378  Bmask == 0x003E &&
379  Amask == 0x0001) {
381  }
382  if (Rmask == 0x001F &&
383  Gmask == 0x03E0 &&
384  Bmask == 0x7C00 &&
385  Amask == 0x8000) {
387  }
388  if (Rmask == 0x003E &&
389  Gmask == 0x07C0 &&
390  Bmask == 0xF800 &&
391  Amask == 0x0001) {
393  }
394  if (Rmask == 0xF800 &&
395  Gmask == 0x07E0 &&
396  Bmask == 0x001F &&
397  Amask == 0x0000) {
398  return SDL_PIXELFORMAT_RGB565;
399  }
400  if (Rmask == 0x001F &&
401  Gmask == 0x07E0 &&
402  Bmask == 0xF800 &&
403  Amask == 0x0000) {
404  return SDL_PIXELFORMAT_BGR565;
405  }
406  if (Rmask == 0x003F &&
407  Gmask == 0x07C0 &&
408  Bmask == 0xF800 &&
409  Amask == 0x0000) {
410  /* Technically this would be BGR556, but Witek says this works in bug 3158 */
411  return SDL_PIXELFORMAT_RGB565;
412  }
413  break;
414  case 24:
415  switch (Rmask) {
416  case 0:
417  case 0x00FF0000:
418 #if SDL_BYTEORDER == SDL_BIG_ENDIAN
419  return SDL_PIXELFORMAT_RGB24;
420 #else
421  return SDL_PIXELFORMAT_BGR24;
422 #endif
423  case 0x000000FF:
424 #if SDL_BYTEORDER == SDL_BIG_ENDIAN
425  return SDL_PIXELFORMAT_BGR24;
426 #else
427  return SDL_PIXELFORMAT_RGB24;
428 #endif
429  }
430  case 32:
431  if (Rmask == 0) {
432  return SDL_PIXELFORMAT_RGB888;
433  }
434  if (Rmask == 0x00FF0000 &&
435  Gmask == 0x0000FF00 &&
436  Bmask == 0x000000FF &&
437  Amask == 0x00000000) {
438  return SDL_PIXELFORMAT_RGB888;
439  }
440  if (Rmask == 0xFF000000 &&
441  Gmask == 0x00FF0000 &&
442  Bmask == 0x0000FF00 &&
443  Amask == 0x00000000) {
445  }
446  if (Rmask == 0x000000FF &&
447  Gmask == 0x0000FF00 &&
448  Bmask == 0x00FF0000 &&
449  Amask == 0x00000000) {
450  return SDL_PIXELFORMAT_BGR888;
451  }
452  if (Rmask == 0x0000FF00 &&
453  Gmask == 0x00FF0000 &&
454  Bmask == 0xFF000000 &&
455  Amask == 0x00000000) {
457  }
458  if (Rmask == 0x00FF0000 &&
459  Gmask == 0x0000FF00 &&
460  Bmask == 0x000000FF &&
461  Amask == 0xFF000000) {
463  }
464  if (Rmask == 0xFF000000 &&
465  Gmask == 0x00FF0000 &&
466  Bmask == 0x0000FF00 &&
467  Amask == 0x000000FF) {
469  }
470  if (Rmask == 0x000000FF &&
471  Gmask == 0x0000FF00 &&
472  Bmask == 0x00FF0000 &&
473  Amask == 0xFF000000) {
475  }
476  if (Rmask == 0x0000FF00 &&
477  Gmask == 0x00FF0000 &&
478  Bmask == 0xFF000000 &&
479  Amask == 0x000000FF) {
481  }
482  if (Rmask == 0x3FF00000 &&
483  Gmask == 0x000FFC00 &&
484  Bmask == 0x000003FF &&
485  Amask == 0xC0000000) {
487  }
488  }
490 }
491 
494 
496 SDL_AllocFormat(Uint32 pixel_format)
497 {
499 
501 
502  /* Look it up in our list of previously allocated formats */
503  for (format = formats; format; format = format->next) {
504  if (pixel_format == format->format) {
505  ++format->refcount;
507  return format;
508  }
509  }
510 
511  /* Allocate an empty pixel format structure, and initialize it */
512  format = SDL_malloc(sizeof(*format));
513  if (format == NULL) {
515  SDL_OutOfMemory();
516  return NULL;
517  }
518  if (SDL_InitFormat(format, pixel_format) < 0) {
520  SDL_free(format);
521  SDL_InvalidParamError("format");
522  return NULL;
523  }
524 
525  if (!SDL_ISPIXELFORMAT_INDEXED(pixel_format)) {
526  /* Cache the RGB formats */
527  format->next = formats;
528  formats = format;
529  }
530 
532 
533  return format;
534 }
535 
536 int
538 {
539  int bpp;
540  Uint32 Rmask, Gmask, Bmask, Amask;
541  Uint32 mask;
542 
543  if (!SDL_PixelFormatEnumToMasks(pixel_format, &bpp,
544  &Rmask, &Gmask, &Bmask, &Amask)) {
545  return -1;
546  }
547 
548  /* Set up the format */
549  SDL_zerop(format);
550  format->format = pixel_format;
551  format->BitsPerPixel = bpp;
552  format->BytesPerPixel = (bpp + 7) / 8;
553 
554  format->Rmask = Rmask;
555  format->Rshift = 0;
556  format->Rloss = 8;
557  if (Rmask) {
558  for (mask = Rmask; !(mask & 0x01); mask >>= 1)
559  ++format->Rshift;
560  for (; (mask & 0x01); mask >>= 1)
561  --format->Rloss;
562  }
563 
564  format->Gmask = Gmask;
565  format->Gshift = 0;
566  format->Gloss = 8;
567  if (Gmask) {
568  for (mask = Gmask; !(mask & 0x01); mask >>= 1)
569  ++format->Gshift;
570  for (; (mask & 0x01); mask >>= 1)
571  --format->Gloss;
572  }
573 
574  format->Bmask = Bmask;
575  format->Bshift = 0;
576  format->Bloss = 8;
577  if (Bmask) {
578  for (mask = Bmask; !(mask & 0x01); mask >>= 1)
579  ++format->Bshift;
580  for (; (mask & 0x01); mask >>= 1)
581  --format->Bloss;
582  }
583 
584  format->Amask = Amask;
585  format->Ashift = 0;
586  format->Aloss = 8;
587  if (Amask) {
588  for (mask = Amask; !(mask & 0x01); mask >>= 1)
589  ++format->Ashift;
590  for (; (mask & 0x01); mask >>= 1)
591  --format->Aloss;
592  }
593 
594  format->palette = NULL;
595  format->refcount = 1;
596  format->next = NULL;
597 
598  return 0;
599 }
600 
601 void
603 {
604  SDL_PixelFormat *prev;
605 
606  if (!format) {
607  SDL_InvalidParamError("format");
608  return;
609  }
610 
612 
613  if (--format->refcount > 0) {
615  return;
616  }
617 
618  /* Remove this format from our list */
619  if (format == formats) {
620  formats = format->next;
621  } else if (formats) {
622  for (prev = formats; prev->next; prev = prev->next) {
623  if (prev->next == format) {
624  prev->next = format->next;
625  break;
626  }
627  }
628  }
629 
631 
632  if (format->palette) {
633  SDL_FreePalette(format->palette);
634  }
635  SDL_free(format);
636 }
637 
638 SDL_Palette *
639 SDL_AllocPalette(int ncolors)
640 {
641  SDL_Palette *palette;
642 
643  /* Input validation */
644  if (ncolors < 1) {
645  SDL_InvalidParamError("ncolors");
646  return NULL;
647  }
648 
649  palette = (SDL_Palette *) SDL_malloc(sizeof(*palette));
650  if (!palette) {
651  SDL_OutOfMemory();
652  return NULL;
653  }
654  palette->colors =
655  (SDL_Color *) SDL_malloc(ncolors * sizeof(*palette->colors));
656  if (!palette->colors) {
657  SDL_free(palette);
658  return NULL;
659  }
660  palette->ncolors = ncolors;
661  palette->version = 1;
662  palette->refcount = 1;
663 
664  SDL_memset(palette->colors, 0xFF, ncolors * sizeof(*palette->colors));
665 
666  return palette;
667 }
668 
669 int
671 {
672  if (!format) {
673  return SDL_SetError("SDL_SetPixelFormatPalette() passed NULL format");
674  }
675 
676  if (palette && palette->ncolors > (1 << format->BitsPerPixel)) {
677  return SDL_SetError("SDL_SetPixelFormatPalette() passed a palette that doesn't match the format");
678  }
679 
680  if (format->palette == palette) {
681  return 0;
682  }
683 
684  if (format->palette) {
685  SDL_FreePalette(format->palette);
686  }
687 
688  format->palette = palette;
689 
690  if (format->palette) {
691  ++format->palette->refcount;
692  }
693 
694  return 0;
695 }
696 
697 int
699  int firstcolor, int ncolors)
700 {
701  int status = 0;
702 
703  /* Verify the parameters */
704  if (!palette) {
705  return -1;
706  }
707  if (ncolors > (palette->ncolors - firstcolor)) {
708  ncolors = (palette->ncolors - firstcolor);
709  status = -1;
710  }
711 
712  if (colors != (palette->colors + firstcolor)) {
713  SDL_memcpy(palette->colors + firstcolor, colors,
714  ncolors * sizeof(*colors));
715  }
716  ++palette->version;
717  if (!palette->version) {
718  palette->version = 1;
719  }
720 
721  return status;
722 }
723 
724 void
726 {
727  if (!palette) {
728  SDL_InvalidParamError("palette");
729  return;
730  }
731  if (--palette->refcount > 0) {
732  return;
733  }
734  SDL_free(palette->colors);
735  SDL_free(palette);
736 }
737 
738 /*
739  * Calculate an 8-bit (3 red, 3 green, 2 blue) dithered palette of colors
740  */
741 void
743 {
744  int i;
745  if (bpp != 8)
746  return; /* only 8bpp supported right now */
747 
748  for (i = 0; i < 256; i++) {
749  int r, g, b;
750  /* map each bit field to the full [0, 255] interval,
751  so 0 is mapped to (0, 0, 0) and 255 to (255, 255, 255) */
752  r = i & 0xe0;
753  r |= r >> 3 | r >> 6;
754  colors[i].r = r;
755  g = (i << 3) & 0xe0;
756  g |= g >> 3 | g >> 6;
757  colors[i].g = g;
758  b = i & 0x3;
759  b |= b << 2;
760  b |= b << 4;
761  colors[i].b = b;
762  colors[i].a = SDL_ALPHA_OPAQUE;
763  }
764 }
765 
766 /*
767  * Match an RGB value to a particular palette index
768  */
769 Uint8
771 {
772  /* Do colorspace distance matching */
773  unsigned int smallest;
774  unsigned int distance;
775  int rd, gd, bd, ad;
776  int i;
777  Uint8 pixel = 0;
778 
779  smallest = ~0;
780  for (i = 0; i < pal->ncolors; ++i) {
781  rd = pal->colors[i].r - r;
782  gd = pal->colors[i].g - g;
783  bd = pal->colors[i].b - b;
784  ad = pal->colors[i].a - a;
785  distance = (rd * rd) + (gd * gd) + (bd * bd) + (ad * ad);
786  if (distance < smallest) {
787  pixel = i;
788  if (distance == 0) { /* Perfect match! */
789  break;
790  }
791  smallest = distance;
792  }
793  }
794  return (pixel);
795 }
796 
797 /* Find the opaque pixel value corresponding to an RGB triple */
798 Uint32
800 {
801  if (format->palette == NULL) {
802  return (r >> format->Rloss) << format->Rshift
803  | (g >> format->Gloss) << format->Gshift
804  | (b >> format->Bloss) << format->Bshift | format->Amask;
805  } else {
806  return SDL_FindColor(format->palette, r, g, b, SDL_ALPHA_OPAQUE);
807  }
808 }
809 
810 /* Find the pixel value corresponding to an RGBA quadruple */
811 Uint32
813  Uint8 a)
814 {
815  if (format->palette == NULL) {
816  return (r >> format->Rloss) << format->Rshift
817  | (g >> format->Gloss) << format->Gshift
818  | (b >> format->Bloss) << format->Bshift
819  | ((a >> format->Aloss) << format->Ashift & format->Amask);
820  } else {
821  return SDL_FindColor(format->palette, r, g, b, a);
822  }
823 }
824 
825 void
827  Uint8 * b)
828 {
829  if (format->palette == NULL) {
830  unsigned v;
831  v = (pixel & format->Rmask) >> format->Rshift;
832  *r = SDL_expand_byte[format->Rloss][v];
833  v = (pixel & format->Gmask) >> format->Gshift;
834  *g = SDL_expand_byte[format->Gloss][v];
835  v = (pixel & format->Bmask) >> format->Bshift;
836  *b = SDL_expand_byte[format->Bloss][v];
837  } else {
838  if (pixel < (unsigned)format->palette->ncolors) {
839  *r = format->palette->colors[pixel].r;
840  *g = format->palette->colors[pixel].g;
841  *b = format->palette->colors[pixel].b;
842  } else {
843  *r = *g = *b = 0;
844  }
845  }
846 }
847 
848 void
850  Uint8 * r, Uint8 * g, Uint8 * b, Uint8 * a)
851 {
852  if (format->palette == NULL) {
853  unsigned v;
854  v = (pixel & format->Rmask) >> format->Rshift;
855  *r = SDL_expand_byte[format->Rloss][v];
856  v = (pixel & format->Gmask) >> format->Gshift;
857  *g = SDL_expand_byte[format->Gloss][v];
858  v = (pixel & format->Bmask) >> format->Bshift;
859  *b = SDL_expand_byte[format->Bloss][v];
860  v = (pixel & format->Amask) >> format->Ashift;
861  *a = SDL_expand_byte[format->Aloss][v];
862  } else {
863  if (pixel < (unsigned)format->palette->ncolors) {
864  *r = format->palette->colors[pixel].r;
865  *g = format->palette->colors[pixel].g;
866  *b = format->palette->colors[pixel].b;
867  *a = format->palette->colors[pixel].a;
868  } else {
869  *r = *g = *b = *a = 0;
870  }
871  }
872 }
873 
874 /* Map from Palette to Palette */
875 static Uint8 *
876 Map1to1(SDL_Palette * src, SDL_Palette * dst, int *identical)
877 {
878  Uint8 *map;
879  int i;
880 
881  if (identical) {
882  if (src->ncolors <= dst->ncolors) {
883  /* If an identical palette, no need to map */
884  if (src == dst
885  ||
886  (SDL_memcmp
887  (src->colors, dst->colors,
888  src->ncolors * sizeof(SDL_Color)) == 0)) {
889  *identical = 1;
890  return (NULL);
891  }
892  }
893  *identical = 0;
894  }
895  map = (Uint8 *) SDL_malloc(src->ncolors);
896  if (map == NULL) {
897  SDL_OutOfMemory();
898  return (NULL);
899  }
900  for (i = 0; i < src->ncolors; ++i) {
901  map[i] = SDL_FindColor(dst,
902  src->colors[i].r, src->colors[i].g,
903  src->colors[i].b, src->colors[i].a);
904  }
905  return (map);
906 }
907 
908 /* Map from Palette to BitField */
909 static Uint8 *
910 Map1toN(SDL_PixelFormat * src, Uint8 Rmod, Uint8 Gmod, Uint8 Bmod, Uint8 Amod,
912 {
913  Uint8 *map;
914  int i;
915  int bpp;
916  SDL_Palette *pal = src->palette;
917 
918  bpp = ((dst->BytesPerPixel == 3) ? 4 : dst->BytesPerPixel);
919  map = (Uint8 *) SDL_malloc(pal->ncolors * bpp);
920  if (map == NULL) {
921  SDL_OutOfMemory();
922  return (NULL);
923  }
924 
925  /* We memory copy to the pixel map so the endianness is preserved */
926  for (i = 0; i < pal->ncolors; ++i) {
927  Uint8 R = (Uint8) ((pal->colors[i].r * Rmod) / 255);
928  Uint8 G = (Uint8) ((pal->colors[i].g * Gmod) / 255);
929  Uint8 B = (Uint8) ((pal->colors[i].b * Bmod) / 255);
930  Uint8 A = (Uint8) ((pal->colors[i].a * Amod) / 255);
931  ASSEMBLE_RGBA(&map[i * bpp], dst->BytesPerPixel, dst, R, G, B, A);
932  }
933  return (map);
934 }
935 
936 /* Map from BitField to Dithered-Palette to Palette */
937 static Uint8 *
939 {
940  /* Generate a 256 color dither palette */
941  SDL_Palette dithered;
942  SDL_Color colors[256];
943  SDL_Palette *pal = dst->palette;
944 
945  dithered.ncolors = 256;
946  SDL_DitherColors(colors, 8);
947  dithered.colors = colors;
948  return (Map1to1(&dithered, pal, identical));
949 }
950 
951 SDL_BlitMap *
953 {
954  SDL_BlitMap *map;
955 
956  /* Allocate the empty map */
957  map = (SDL_BlitMap *) SDL_calloc(1, sizeof(*map));
958  if (map == NULL) {
959  SDL_OutOfMemory();
960  return (NULL);
961  }
962  map->info.r = 0xFF;
963  map->info.g = 0xFF;
964  map->info.b = 0xFF;
965  map->info.a = 0xFF;
966 
967  /* It's ready to go */
968  return (map);
969 }
970 
971 void
973 {
974  if (!map) {
975  return;
976  }
977  if (map->dst) {
978  /* Release our reference to the surface - see the note below */
979  if (--map->dst->refcount <= 0) {
980  SDL_FreeSurface(map->dst);
981  }
982  }
983  map->dst = NULL;
984  map->src_palette_version = 0;
985  map->dst_palette_version = 0;
986  SDL_free(map->info.table);
987  map->info.table = NULL;
988 }
989 
990 int
992 {
993  SDL_PixelFormat *srcfmt;
994  SDL_PixelFormat *dstfmt;
995  SDL_BlitMap *map;
996 
997  /* Clear out any previous mapping */
998  map = src->map;
999  if ((src->flags & SDL_RLEACCEL) == SDL_RLEACCEL) {
1000  SDL_UnRLESurface(src, 1);
1001  }
1002  SDL_InvalidateMap(map);
1003 
1004  /* Figure out what kind of mapping we're doing */
1005  map->identity = 0;
1006  srcfmt = src->format;
1007  dstfmt = dst->format;
1008  if (SDL_ISPIXELFORMAT_INDEXED(srcfmt->format)) {
1009  if (SDL_ISPIXELFORMAT_INDEXED(dstfmt->format)) {
1010  /* Palette --> Palette */
1011  map->info.table =
1012  Map1to1(srcfmt->palette, dstfmt->palette, &map->identity);
1013  if (!map->identity) {
1014  if (map->info.table == NULL) {
1015  return (-1);
1016  }
1017  }
1018  if (srcfmt->BitsPerPixel != dstfmt->BitsPerPixel)
1019  map->identity = 0;
1020  } else {
1021  /* Palette --> BitField */
1022  map->info.table =
1023  Map1toN(srcfmt, src->map->info.r, src->map->info.g,
1024  src->map->info.b, src->map->info.a, dstfmt);
1025  if (map->info.table == NULL) {
1026  return (-1);
1027  }
1028  }
1029  } else {
1030  if (SDL_ISPIXELFORMAT_INDEXED(dstfmt->format)) {
1031  /* BitField --> Palette */
1032  map->info.table = MapNto1(srcfmt, dstfmt, &map->identity);
1033  if (!map->identity) {
1034  if (map->info.table == NULL) {
1035  return (-1);
1036  }
1037  }
1038  map->identity = 0; /* Don't optimize to copy */
1039  } else {
1040  /* BitField --> BitField */
1041  if (srcfmt == dstfmt) {
1042  map->identity = 1;
1043  }
1044  }
1045  }
1046 
1047  map->dst = dst;
1048 
1049  if (map->dst) {
1050  /* Keep a reference to this surface so it doesn't get deleted
1051  while we're still pointing at it.
1052 
1053  A better method would be for the destination surface to keep
1054  track of surfaces that are mapped to it and automatically
1055  invalidate them when it is freed, but this will do for now.
1056  */
1057  ++map->dst->refcount;
1058  }
1059 
1060  if (dstfmt->palette) {
1061  map->dst_palette_version = dstfmt->palette->version;
1062  } else {
1063  map->dst_palette_version = 0;
1064  }
1065 
1066  if (srcfmt->palette) {
1067  map->src_palette_version = srcfmt->palette->version;
1068  } else {
1069  map->src_palette_version = 0;
1070  }
1071 
1072  /* Choose your blitters wisely */
1073  return (SDL_CalculateBlit(src));
1074 }
1075 
1076 void
1078 {
1079  if (map) {
1080  SDL_InvalidateMap(map);
1081  SDL_free(map);
1082  }
1083 }
1084 
1085 void
1086 SDL_CalculateGammaRamp(float gamma, Uint16 * ramp)
1087 {
1088  int i;
1089 
1090  /* Input validation */
1091  if (gamma < 0.0f ) {
1092  SDL_InvalidParamError("gamma");
1093  return;
1094  }
1095  if (ramp == NULL) {
1096  SDL_InvalidParamError("ramp");
1097  return;
1098  }
1099 
1100  /* 0.0 gamma is all black */
1101  if (gamma == 0.0f) {
1102  SDL_memset(ramp, 0, 256 * sizeof(Uint16));
1103  return;
1104  } else if (gamma == 1.0f) {
1105  /* 1.0 gamma is identity */
1106  for (i = 0; i < 256; ++i) {
1107  ramp[i] = (i << 8) | i;
1108  }
1109  return;
1110  } else {
1111  /* Calculate a real gamma ramp */
1112  int value;
1113  gamma = 1.0f / gamma;
1114  for (i = 0; i < 256; ++i) {
1115  value =
1116  (int) (SDL_pow((double) i / 256.0, gamma) * 65535.0 + 0.5);
1117  if (value > 65535) {
1118  value = 65535;
1119  }
1120  ramp[i] = (Uint16) value;
1121  }
1122  }
1123 }
1124 
1125 /* vi: set ts=4 sw=4 expandtab: */
static Uint8 lookup_5[]
Definition: SDL_pixels.c:55
Uint8 * table
Definition: SDL_blit.h:67
Uint8 r
Definition: SDL_blit.h:70
GLdouble GLdouble GLdouble r
Definition: SDL_opengl.h:2079
Uint32 version
Definition: SDL_pixels.h:308
Uint8 b
Definition: SDL_blit.h:70
void SDL_DitherColors(SDL_Color *colors, int bpp)
Definition: SDL_pixels.c:742
void SDL_GetRGB(Uint32 pixel, const SDL_PixelFormat *format, Uint8 *r, Uint8 *g, Uint8 *b)
Get the RGB components from a pixel of the specified format.
Definition: SDL_pixels.c:826
Uint8 g
Definition: SDL_pixels.h:298
const GLdouble * v
Definition: SDL_opengl.h:2064
GLenum GLenum dst
#define SDL_AtomicLock
#define SDL_PIXELLAYOUT(X)
Definition: SDL_pixels.h:126
#define SDL_ISPIXELFORMAT_INDEXED(format)
Definition: SDL_pixels.h:134
static SDL_PixelFormat * formats
Definition: SDL_pixels.c:492
Uint32 SDL_MapRGBA(const SDL_PixelFormat *format, Uint8 r, Uint8 g, Uint8 b, Uint8 a)
Maps an RGBA quadruple to a pixel value for a given pixel format.
Definition: SDL_pixels.c:812
Uint8 BytesPerPixel
Definition: SDL_pixels.h:320
Uint8 g
Definition: SDL_blit.h:70
void SDL_GetRGBA(Uint32 pixel, const SDL_PixelFormat *format, Uint8 *r, Uint8 *g, Uint8 *b, Uint8 *a)
Get the RGBA components from a pixel of the specified format.
Definition: SDL_pixels.c:849
static Uint8 lookup_0[]
Definition: SDL_pixels.c:35
SDL_bool SDL_PixelFormatEnumToMasks(Uint32 format, int *bpp, Uint32 *Rmask, Uint32 *Gmask, Uint32 *Bmask, Uint32 *Amask)
Convert one of the enumerated pixel formats to a bpp and RGBA masks.
Definition: SDL_pixels.c:134
#define ASSEMBLE_RGBA(buf, bpp, fmt, r, g, b, a)
Definition: SDL_blit.h:402
A collection of pixels used in software blitting.
Definition: SDL_surface.h:69
Uint32 SDL_MasksToPixelFormatEnum(int bpp, Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask)
Convert a bpp and RGBA masks to an enumerated pixel format.
Definition: SDL_pixels.c:293
void SDL_UnRLESurface(SDL_Surface *surface, int recode)
GLfloat f
#define SDL_BYTESPERPIXEL(X)
Definition: SDL_pixels.h:128
Uint32 dst_palette_version
Definition: SDL_blit.h:96
Uint8 b
Definition: SDL_pixels.h:299
static Uint8 lookup_4[]
Definition: SDL_pixels.c:51
uint32_t Uint32
Definition: SDL_stdinc.h:181
#define SDL_InvalidParamError(param)
Definition: SDL_error.h:54
GLenum src
static Uint8 lookup_2[]
Definition: SDL_pixels.c:43
static Uint8 lookup_7[]
Definition: SDL_pixels.c:63
#define SDL_zerop(x)
Definition: SDL_stdinc.h:417
GLsizei GLsizei GLfloat distance
Uint32 flags
Definition: SDL_surface.h:71
Uint32 src_palette_version
Definition: SDL_blit.h:97
#define SDL_AtomicUnlock
void SDL_InvalidateMap(SDL_BlitMap *map)
Definition: SDL_pixels.c:972
GLint GLint GLsizei GLsizei GLsizei GLint GLenum format
Definition: SDL_opengl.h:1572
int SDL_SetPaletteColors(SDL_Palette *palette, const SDL_Color *colors, int firstcolor, int ncolors)
Set a range of colors in a palette.
Definition: SDL_pixels.c:698
static Uint8 lookup_1[]
Definition: SDL_pixels.c:39
struct SDL_BlitMap * map
Definition: SDL_surface.h:88
void SDL_FreeFormat(SDL_PixelFormat *format)
Free an SDL_PixelFormat structure.
Definition: SDL_pixels.c:602
static SDL_SpinLock formats_lock
Definition: SDL_pixels.c:493
#define SDL_memcpy
Uint8 r
Definition: SDL_pixels.h:297
static Uint8 * Map1to1(SDL_Palette *src, SDL_Palette *dst, int *identical)
Definition: SDL_pixels.c:876
static Uint8 lookup_8[]
Definition: SDL_pixels.c:67
int SDL_MapSurface(SDL_Surface *src, SDL_Surface *dst)
Definition: SDL_pixels.c:991
#define SDL_FreeSurface
Uint8 a
Definition: SDL_pixels.h:300
uint8_t Uint8
Definition: SDL_stdinc.h:157
#define SDL_free
Uint8 BitsPerPixel
Definition: SDL_pixels.h:319
SDL_PixelFormat * SDL_AllocFormat(Uint32 pixel_format)
Create an SDL_PixelFormat structure from a pixel format enum.
Definition: SDL_pixels.c:496
int SDL_SetPixelFormatPalette(SDL_PixelFormat *format, SDL_Palette *palette)
Set the palette for a pixel format structure.
Definition: SDL_pixels.c:670
Uint32 SDL_MapRGB(const SDL_PixelFormat *format, Uint8 r, Uint8 g, Uint8 b)
Maps an RGB triple to an opaque pixel value for a given pixel format.
Definition: SDL_pixels.c:799
Uint8 SDL_FindColor(SDL_Palette *pal, Uint8 r, Uint8 g, Uint8 b, Uint8 a)
Definition: SDL_pixels.c:770
#define SDL_pow
#define SDL_memcmp
GLenum GLint GLuint mask
void SDL_FreePalette(SDL_Palette *palette)
Free a palette created with SDL_AllocPalette().
Definition: SDL_pixels.c:725
#define SDL_PIXELORDER(X)
Definition: SDL_pixels.h:125
GLsizei const GLfloat * value
void SDL_CalculateGammaRamp(float gamma, Uint16 *ramp)
Calculate a 256 entry gamma ramp for a gamma value.
Definition: SDL_pixels.c:1086
Uint8 * SDL_expand_byte[9]
Definition: SDL_pixels.c:71
int SDL_CalculateBlit(SDL_Surface *surface)
Definition: SDL_blit.c:216
int SDL_InitFormat(SDL_PixelFormat *format, Uint32 pixel_format)
Definition: SDL_pixels.c:537
static Uint8 * MapNto1(SDL_PixelFormat *src, SDL_PixelFormat *dst, int *identical)
Definition: SDL_pixels.c:938
#define SDL_PIXELTYPE(X)
Definition: SDL_pixels.h:124
return Display return Display Bool Bool int int int return Display XEvent Bool(*) XPointer return Display return Display Drawable _Xconst char unsigned int unsigned int return Display Pixmap Pixmap XColor XColor unsigned int unsigned int return Display _Xconst char char int char return Display Visual unsigned int int int char unsigned int unsigned int in i)
Definition: SDL_x11sym.h:50
SDL_Palette * SDL_AllocPalette(int ncolors)
Create a palette structure with the specified number of color entries.
Definition: SDL_pixels.c:639
SDL_Surface * dst
Definition: SDL_blit.h:88
#define NULL
Definition: begin_code.h:164
#define SDL_OutOfMemory()
Definition: SDL_error.h:52
SDL_bool
Definition: SDL_stdinc.h:139
SDL_Color * colors
Definition: SDL_pixels.h:307
SDL_PixelFormat * format
Definition: SDL_surface.h:72
#define SDL_SetError
#define SDL_calloc
static Uint8 * Map1toN(SDL_PixelFormat *src, Uint8 Rmod, Uint8 Gmod, Uint8 Bmod, Uint8 Amod, SDL_PixelFormat *dst)
Definition: SDL_pixels.c:910
#define G(x, y, z)
Definition: SDL_test_md5.c:74
SDL_BlitMap * SDL_AllocBlitMap(void)
Definition: SDL_pixels.c:952
uint16_t Uint16
Definition: SDL_stdinc.h:169
#define SDL_malloc
SDL_Palette * palette
Definition: SDL_pixels.h:318
#define SDL_ISPIXELFORMAT_FOURCC(format)
Definition: SDL_pixels.h:167
int SDL_SpinLock
Definition: SDL_atomic.h:89
const GLubyte GLuint GLuint GLuint GLuint alpha GLboolean GLboolean GLboolean GLboolean alpha GLint GLint GLsizei GLsizei GLenum type GLenum GLint GLenum GLint GLint GLsizei GLsizei GLint border GLenum GLint GLint GLint GLint GLint GLsizei GLsizei height GLsizei GLsizei GLenum GLenum const GLvoid *pixels GLenum GLint GLint GLint GLint j2 GLdouble GLdouble GLdouble GLdouble GLdouble GLdouble zFar GLenum GLenum GLint *params GLenum GLenum GLint *params GLenum GLenum GLint *params GLenum GLenum GLfloat *params GLenum GLint GLenum GLenum GLvoid *pixels GLenum GLint GLenum GLint *params GLenum GLenum GLint *params GLenum GLsizei const GLvoid *pointer GLenum GLenum const GLint *params GLenum GLfloat GLfloat GLint GLint const GLfloat *points GLenum GLfloat GLfloat GLint GLint GLfloat GLfloat GLint GLint const GLfloat *points GLint GLfloat GLfloat GLint GLfloat GLfloat v2 GLenum GLenum const GLint *params GLdouble GLdouble GLdouble GLdouble GLdouble GLdouble zFar GLenum map
Definition: SDL_glfuncs.h:290
static Uint8 lookup_3[]
Definition: SDL_pixels.c:47
static int colors[7]
Definition: testgesture.c:39
GLboolean GLboolean GLboolean GLboolean a
#define SDL_ALPHA_OPAQUE
Definition: SDL_pixels.h:46
const char * SDL_GetPixelFormatName(Uint32 format)
Get the human readable name of a pixel format.
Definition: SDL_pixels.c:86
GLboolean GLboolean g
GLboolean GLboolean GLboolean b
void SDL_FreeBlitMap(SDL_BlitMap *map)
Definition: SDL_pixels.c:1077
int identity
Definition: SDL_blit.h:89
#define SDL_BITSPERPIXEL(X)
Definition: SDL_pixels.h:127
struct SDL_PixelFormat * next
Definition: SDL_pixels.h:335
SDL_BlitInfo info
Definition: SDL_blit.h:92
static Uint8 lookup_6[]
Definition: SDL_pixels.c:59
#define CASE(X)
#define SDL_memset
#define SDL_RLEACCEL
Definition: SDL_surface.h:54
Uint8 a
Definition: SDL_blit.h:70