aboutsummaryrefslogtreecommitdiffstats
path: root/src/mesa/state_tracker/st_format.c
blob: 3ffc2aee2a2b8d011abc08338531a211b7c56b29 (plain)
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
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
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
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
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
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
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
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
673
674
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
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
/**************************************************************************
 * 
 * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
 * Copyright (c) 2008 VMware, Inc.
 * All Rights Reserved.
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 * 
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
 * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 * 
 **************************************************************************/


/**
 * Texture Image-related functions.
 * \author Brian Paul
 */

#include "main/imports.h"
#include "main/context.h"
#include "main/texstore.h"
#include "main/enums.h"
#include "main/macros.h"

#include "pipe/p_context.h"
#include "pipe/p_defines.h"
#include "pipe/p_screen.h"
#include "util/u_format.h"
#include "st_context.h"
#include "st_format.h"


static GLuint
format_max_bits(enum pipe_format format)
{
   GLuint size = util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_RGB, 0);

   size = MAX2(size, util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_RGB, 1));
   size = MAX2(size, util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_RGB, 2));
   size = MAX2(size, util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_RGB, 3));
   size = MAX2(size, util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_ZS, 0));
   size = MAX2(size, util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_ZS, 1));
   return size;
}

static GLuint
format_size(enum pipe_format format)
{
   return
      util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_RGB, 0) +
      util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_RGB, 1) +
      util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_RGB, 2) +
      util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_RGB, 3) +
      util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_ZS, 0) +
      util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_ZS, 1);
}

/*
 * XXX temporary here
 */
GLboolean
st_get_format_info(enum pipe_format format, struct pipe_format_info *pinfo)
{
   const struct util_format_description *desc;

   desc = util_format_description(format);
   assert(desc);

   if (desc->layout == UTIL_FORMAT_LAYOUT_ARITH ||
       desc->layout == UTIL_FORMAT_LAYOUT_ARRAY) {
#if 0
      printf("%s\n", pf_name( format ) );
#endif

      /* Data type */
      if (format == PIPE_FORMAT_A1R5G5B5_UNORM || format == PIPE_FORMAT_R5G6B5_UNORM) {
         pinfo->datatype = GL_UNSIGNED_SHORT;
      }
      else if (format == PIPE_FORMAT_S8Z24_UNORM ||
               format == PIPE_FORMAT_Z24S8_UNORM) {
         pinfo->datatype = GL_UNSIGNED_INT_24_8;
      }
      else {
         const GLuint size = format_max_bits(format);
         if (size == 8) {
            if (desc->channel[0].type == UTIL_FORMAT_TYPE_UNSIGNED)
               pinfo->datatype = GL_UNSIGNED_BYTE;
            else
               pinfo->datatype = GL_BYTE;
         }
         else if (size == 16) {
            if (desc->channel[0].type == UTIL_FORMAT_TYPE_UNSIGNED)
               pinfo->datatype = GL_UNSIGNED_SHORT;
            else
               pinfo->datatype = GL_SHORT;
         }
         else {
            assert( size <= 32 );
            if (desc->channel[0].type == UTIL_FORMAT_TYPE_UNSIGNED)
               pinfo->datatype = GL_UNSIGNED_INT;
            else
               pinfo->datatype = GL_INT;
         }
      }

      /* Component bits */
      pinfo->red_bits = util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_RGB, 0);
      pinfo->green_bits = util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_RGB, 1);
      pinfo->blue_bits = util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_RGB, 2);
      pinfo->alpha_bits = util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_RGB, 3);
      pinfo->depth_bits = util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_ZS, 0);
      pinfo->stencil_bits = util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_ZS, 1);
      pinfo->luminance_bits = 0;
      pinfo->intensity_bits = 0;

      /* Format size */
      pinfo->size = format_size(format) / 8;

      /* Luminance & Intensity bits */
      if (desc->swizzle[0] == UTIL_FORMAT_SWIZZLE_X &&
          desc->swizzle[1] == UTIL_FORMAT_SWIZZLE_X &&
          desc->swizzle[2] == UTIL_FORMAT_SWIZZLE_X) {
         if (desc->swizzle[3] == UTIL_FORMAT_SWIZZLE_X) {
            pinfo->intensity_bits = pinfo->red_bits;
         }
         else {
            pinfo->luminance_bits = pinfo->red_bits;
         }
         pinfo->red_bits = 0;
      }

      pinfo->mesa_format = st_pipe_format_to_mesa_format(format);
   }
   else if (desc->layout == UTIL_FORMAT_LAYOUT_YUV) {
      pinfo->mesa_format = MESA_FORMAT_YCBCR;
      pinfo->datatype = GL_UNSIGNED_SHORT;
      pinfo->size = 2; /* two bytes per "texel" */
   }
   else {
      /* compressed format? */
      assert(0);
   }

#if 0
   printf(
      "ST_FORMAT: R(%u), G(%u), B(%u), A(%u), Z(%u), S(%u)\n",
      pinfo->red_bits,
      pinfo->green_bits,
      pinfo->blue_bits,
      pinfo->alpha_bits,
      pinfo->depth_bits,
      pinfo->stencil_bits );
#endif

   pinfo->format = format;

   return GL_TRUE;
}


/**
 * Return bytes per pixel for the given format.
 */
GLuint
st_sizeof_format(enum pipe_format format)
{
   struct pipe_format_info info;
   if (!st_get_format_info( format, &info )) {
      assert( 0 );
      return 0;
   }
   return info.size;
}


/**
 * Return bytes per pixel for the given format.
 */
GLenum
st_format_datatype(enum pipe_format format)
{
   struct pipe_format_info info;
   if (!st_get_format_info( format, &info )) {
      assert( 0 );
      return 0;
   }
   return info.datatype;
}


enum pipe_format
st_mesa_format_to_pipe_format(gl_format mesaFormat)
{
   switch (mesaFormat) {
      /* fix this */
   case MESA_FORMAT_ARGB8888_REV:
   case MESA_FORMAT_ARGB8888:
      return PIPE_FORMAT_A8R8G8B8_UNORM;
   case MESA_FORMAT_XRGB8888:
      return PIPE_FORMAT_X8R8G8B8_UNORM;
   case MESA_FORMAT_ARGB1555:
      return PIPE_FORMAT_A1R5G5B5_UNORM;
   case MESA_FORMAT_ARGB4444:
      return PIPE_FORMAT_A4R4G4B4_UNORM;
   case MESA_FORMAT_RGB565:
      return PIPE_FORMAT_R5G6B5_UNORM;
   case MESA_FORMAT_AL88:
      return PIPE_FORMAT_A8L8_UNORM;
   case MESA_FORMAT_A8:
      return PIPE_FORMAT_A8_UNORM;
   case MESA_FORMAT_L8:
      return PIPE_FORMAT_L8_UNORM;
   case MESA_FORMAT_I8:
      return PIPE_FORMAT_I8_UNORM;
   case MESA_FORMAT_Z16:
      return PIPE_FORMAT_Z16_UNORM;
   case MESA_FORMAT_Z32:
      return PIPE_FORMAT_Z32_UNORM;
   case MESA_FORMAT_Z24_S8:
      return PIPE_FORMAT_Z24S8_UNORM;
   case MESA_FORMAT_S8_Z24:
      return PIPE_FORMAT_S8Z24_UNORM;
   case MESA_FORMAT_YCBCR:
      return PIPE_FORMAT_YCBCR;
#if FEATURE_texture_s3tc
   case MESA_FORMAT_RGB_DXT1:
      return PIPE_FORMAT_DXT1_RGB;
   case MESA_FORMAT_RGBA_DXT1:
      return PIPE_FORMAT_DXT1_RGBA;
   case MESA_FORMAT_RGBA_DXT3:
      return PIPE_FORMAT_DXT3_RGBA;
   case MESA_FORMAT_RGBA_DXT5:
      return PIPE_FORMAT_DXT5_RGBA;
#if FEATURE_EXT_texture_sRGB
   case MESA_FORMAT_SRGB_DXT1:
      return PIPE_FORMAT_DXT1_SRGB;
   case MESA_FORMAT_SRGBA_DXT1:
      return PIPE_FORMAT_DXT1_SRGBA;
   case MESA_FORMAT_SRGBA_DXT3:
      return PIPE_FORMAT_DXT3_SRGBA;
   case MESA_FORMAT_SRGBA_DXT5:
      return PIPE_FORMAT_DXT5_SRGBA;
#endif
#endif
#if FEATURE_EXT_texture_sRGB
   case MESA_FORMAT_SLA8:
      return PIPE_FORMAT_A8L8_SRGB;
   case MESA_FORMAT_SL8:
      return PIPE_FORMAT_L8_SRGB;
   case MESA_FORMAT_SRGB8:
      return PIPE_FORMAT_R8G8B8_SRGB;
   case MESA_FORMAT_SRGBA8:
      return PIPE_FORMAT_R8G8B8A8_SRGB;
   case MESA_FORMAT_SARGB8:
      return PIPE_FORMAT_A8R8G8B8_SRGB;
#endif
   default:
      assert(0);
      return 0;
   }
}


gl_format
st_pipe_format_to_mesa_format(enum pipe_format pipeFormat)
{
   switch (pipeFormat) {
   case PIPE_FORMAT_A8R8G8B8_UNORM:
      return MESA_FORMAT_ARGB8888;
   case PIPE_FORMAT_X8R8G8B8_UNORM:
      return MESA_FORMAT_XRGB8888;
   case PIPE_FORMAT_B8G8R8A8_UNORM:
      return MESA_FORMAT_ARGB8888_REV;
   case PIPE_FORMAT_B8G8R8X8_UNORM:
      return MESA_FORMAT_XRGB8888_REV;
   case PIPE_FORMAT_A1R5G5B5_UNORM:
      return MESA_FORMAT_ARGB1555;
   case PIPE_FORMAT_A4R4G4B4_UNORM:
      return MESA_FORMAT_ARGB4444;
   case PIPE_FORMAT_R5G6B5_UNORM:
      return MESA_FORMAT_RGB565;
   case PIPE_FORMAT_A8L8_UNORM:
      return MESA_FORMAT_AL88;
   case PIPE_FORMAT_A8_UNORM:
      return MESA_FORMAT_A8;
   case PIPE_FORMAT_L8_UNORM:
      return MESA_FORMAT_L8;
   case PIPE_FORMAT_I8_UNORM:
      return MESA_FORMAT_I8;
   case PIPE_FORMAT_Z16_UNORM:
      return MESA_FORMAT_Z16;
   case PIPE_FORMAT_Z32_UNORM:
      return MESA_FORMAT_Z32;
   case PIPE_FORMAT_Z24X8_UNORM:
      return MESA_FORMAT_Z24_X8;
   case PIPE_FORMAT_Z24S8_UNORM:
      return MESA_FORMAT_Z24_S8;
   case PIPE_FORMAT_X8Z24_UNORM:
      return MESA_FORMAT_X8_Z24;
   case PIPE_FORMAT_S8Z24_UNORM:
      return MESA_FORMAT_S8_Z24;
   case PIPE_FORMAT_S8_UNORM:
      return MESA_FORMAT_S8;

   case PIPE_FORMAT_YCBCR:
      return MESA_FORMAT_YCBCR;
   case PIPE_FORMAT_R16G16B16A16_SNORM:
      return MESA_FORMAT_SIGNED_RGBA_16;

#if FEATURE_texture_s3tc
   case PIPE_FORMAT_DXT1_RGB:
      return MESA_FORMAT_RGB_DXT1;
   case PIPE_FORMAT_DXT1_RGBA:
      return MESA_FORMAT_RGBA_DXT1;
   case PIPE_FORMAT_DXT3_RGBA:
      return MESA_FORMAT_RGBA_DXT3;
   case PIPE_FORMAT_DXT5_RGBA:
      return MESA_FORMAT_RGBA_DXT5;
#if FEATURE_EXT_texture_sRGB
   case PIPE_FORMAT_DXT1_SRGB:
      return MESA_FORMAT_SRGB_DXT1;
   case PIPE_FORMAT_DXT1_SRGBA:
      return MESA_FORMAT_SRGBA_DXT1;
   case PIPE_FORMAT_DXT3_SRGBA:
      return MESA_FORMAT_SRGBA_DXT3;
   case PIPE_FORMAT_DXT5_SRGBA:
      return MESA_FORMAT_SRGBA_DXT5;
#endif
#endif
#if FEATURE_EXT_texture_sRGB
   case PIPE_FORMAT_A8L8_SRGB:
      return MESA_FORMAT_SLA8;
   case PIPE_FORMAT_L8_SRGB:
      return MESA_FORMAT_SL8;
   case PIPE_FORMAT_R8G8B8_SRGB:
      return MESA_FORMAT_SRGB8;
   case PIPE_FORMAT_R8G8B8A8_SRGB:
      return MESA_FORMAT_SRGBA8;
   case PIPE_FORMAT_A8R8G8B8_SRGB:
      return MESA_FORMAT_SARGB8;
#endif
   default:
      assert(0);
      return 0;
   }
}


/**
 * Find an RGBA format supported by the context/winsys.
 */
static enum pipe_format
default_rgba_format(struct pipe_screen *screen, 
                    enum pipe_texture_target target,
                    unsigned tex_usage, 
                    unsigned geom_flags)
{
   static const enum pipe_format colorFormats[] = {
      PIPE_FORMAT_A8R8G8B8_UNORM,
      PIPE_FORMAT_B8G8R8A8_UNORM,
      PIPE_FORMAT_R8G8B8A8_UNORM,
      PIPE_FORMAT_R5G6B5_UNORM
   };
   uint i;
   for (i = 0; i < Elements(colorFormats); i++) {
      if (screen->is_format_supported( screen, colorFormats[i], target, tex_usage, geom_flags )) {
         return colorFormats[i];
      }
   }
   return PIPE_FORMAT_NONE;
}

/**
 * Find an RGB format supported by the context/winsys.
 */
static enum pipe_format
default_rgb_format(struct pipe_screen *screen, 
                   enum pipe_texture_target target,
                   unsigned tex_usage, 
                   unsigned geom_flags)
{
   static const enum pipe_format colorFormats[] = {
      PIPE_FORMAT_X8R8G8B8_UNORM,
      PIPE_FORMAT_B8G8R8X8_UNORM,
      PIPE_FORMAT_R8G8B8X8_UNORM,
      PIPE_FORMAT_A8R8G8B8_UNORM,
      PIPE_FORMAT_B8G8R8A8_UNORM,
      PIPE_FORMAT_R8G8B8A8_UNORM,
      PIPE_FORMAT_R5G6B5_UNORM
   };
   uint i;
   for (i = 0; i < Elements(colorFormats); i++) {
      if (screen->is_format_supported( screen, colorFormats[i], target, tex_usage, geom_flags )) {
         return colorFormats[i];
      }
   }
   return PIPE_FORMAT_NONE;
}

/**
 * Find an sRGBA format supported by the context/winsys.
 */
static enum pipe_format
default_srgba_format(struct pipe_screen *screen, 
                    enum pipe_texture_target target,
                    unsigned tex_usage, 
                    unsigned geom_flags)
{
   static const enum pipe_format colorFormats[] = {
      PIPE_FORMAT_A8R8G8B8_SRGB,
      PIPE_FORMAT_B8G8R8A8_SRGB,
      PIPE_FORMAT_R8G8B8A8_SRGB,
   };
   uint i;
   for (i = 0; i < Elements(colorFormats); i++) {
      if (screen->is_format_supported( screen, colorFormats[i], target, tex_usage, geom_flags )) {
         return colorFormats[i];
      }
   }
   return PIPE_FORMAT_NONE;
}

/**
 * Search list of formats for first RGBA format with >8 bits/channel.
 */
static enum pipe_format
default_deep_rgba_format(struct pipe_screen *screen, 
                         enum pipe_texture_target target,
                         unsigned tex_usage, 
                         unsigned geom_flags)
{
   if (screen->is_format_supported(screen, PIPE_FORMAT_R16G16B16A16_SNORM, target, tex_usage, geom_flags)) {
      return PIPE_FORMAT_R16G16B16A16_SNORM;
   }
   if (tex_usage & PIPE_TEXTURE_USAGE_RENDER_TARGET)
      return default_rgba_format(screen, target, tex_usage, geom_flags);
   else
      return PIPE_FORMAT_NONE;
}


/**
 * Find an Z format supported by the context/winsys.
 */
static enum pipe_format
default_depth_format(struct pipe_screen *screen, 
                     enum pipe_texture_target target,
                     unsigned tex_usage, 
                     unsigned geom_flags)
{
   static const enum pipe_format zFormats[] = {
      PIPE_FORMAT_Z16_UNORM,
      PIPE_FORMAT_Z32_UNORM,
      PIPE_FORMAT_S8Z24_UNORM,
      PIPE_FORMAT_Z24S8_UNORM
   };
   uint i;
   for (i = 0; i < Elements(zFormats); i++) {
      if (screen->is_format_supported( screen, zFormats[i], target, tex_usage, geom_flags )) {
         return zFormats[i];
      }
   }
   return PIPE_FORMAT_NONE;
}


/**
 * Given an OpenGL internalFormat value for a texture or surface, return
 * the best matching PIPE_FORMAT_x, or PIPE_FORMAT_NONE if there's no match.
 * \param target  one of PIPE_TEXTURE_x
 * \param tex_usage  either PIPE_TEXTURE_USAGE_RENDER_TARGET
 *                   or PIPE_TEXTURE_USAGE_SAMPLER
 */
enum pipe_format
st_choose_format(struct pipe_screen *screen, GLenum internalFormat,
                 enum pipe_texture_target target, unsigned tex_usage)
{
   unsigned geom_flags = 0;

   switch (internalFormat) {
   case 4:
   case GL_RGBA:
   case GL_COMPRESSED_RGBA:
   case GL_RGBA8:
   case GL_RGB10_A2:
   case GL_RGBA12:
      return default_rgba_format( screen, target, tex_usage, geom_flags );
   case 3:
   case GL_RGB:
   case GL_COMPRESSED_RGB:
      return default_rgb_format( screen, target, tex_usage, geom_flags );
   case GL_RGBA16:
      if (tex_usage & PIPE_TEXTURE_USAGE_RENDER_TARGET)
         return default_deep_rgba_format( screen, target, tex_usage, geom_flags );
      else
         return default_rgba_format( screen, target, tex_usage, geom_flags );

   case GL_RGBA4:
   case GL_RGBA2:
      if (screen->is_format_supported( screen, PIPE_FORMAT_A4R4G4B4_UNORM, target, tex_usage, geom_flags ))
         return PIPE_FORMAT_A4R4G4B4_UNORM;
      return default_rgba_format( screen, target, tex_usage, geom_flags );

   case GL_RGB5_A1:
      if (screen->is_format_supported( screen, PIPE_FORMAT_A1R5G5B5_UNORM, target, tex_usage, geom_flags ))
         return PIPE_FORMAT_A1R5G5B5_UNORM;
      return default_rgba_format( screen, target, tex_usage, geom_flags );

   case GL_RGB8:
   case GL_RGB10:
   case GL_RGB12:
   case GL_RGB16:
      return default_rgb_format( screen, target, tex_usage, geom_flags );

   case GL_RGB5:
   case GL_RGB4:
   case GL_R3_G3_B2:
      if (screen->is_format_supported( screen, PIPE_FORMAT_R5G6B5_UNORM, target, tex_usage, geom_flags ))
         return PIPE_FORMAT_R5G6B5_UNORM;
      if (screen->is_format_supported( screen, PIPE_FORMAT_A1R5G5B5_UNORM, target, tex_usage, geom_flags ))
         return PIPE_FORMAT_A1R5G5B5_UNORM;
      return default_rgba_format( screen, target, tex_usage, geom_flags );

   case GL_ALPHA:
   case GL_ALPHA4:
   case GL_ALPHA8:
   case GL_ALPHA12:
   case GL_ALPHA16:
   case GL_COMPRESSED_ALPHA:
      if (screen->is_format_supported( screen, PIPE_FORMAT_A8_UNORM, target, tex_usage, geom_flags ))
         return PIPE_FORMAT_A8_UNORM;
      return default_rgba_format( screen, target, tex_usage, geom_flags );

   case 1:
   case GL_LUMINANCE:
   case GL_LUMINANCE4:
   case GL_LUMINANCE8:
   case GL_LUMINANCE12:
   case GL_LUMINANCE16:
   case GL_COMPRESSED_LUMINANCE:
      if (screen->is_format_supported( screen, PIPE_FORMAT_L8_UNORM, target, tex_usage, geom_flags ))
         return PIPE_FORMAT_L8_UNORM;
      return default_rgba_format( screen, target, tex_usage, geom_flags );

   case 2:
   case GL_LUMINANCE_ALPHA:
   case GL_LUMINANCE4_ALPHA4:
   case GL_LUMINANCE6_ALPHA2:
   case GL_LUMINANCE8_ALPHA8:
   case GL_LUMINANCE12_ALPHA4:
   case GL_LUMINANCE12_ALPHA12:
   case GL_LUMINANCE16_ALPHA16:
   case GL_COMPRESSED_LUMINANCE_ALPHA:
      if (screen->is_format_supported( screen, PIPE_FORMAT_A8L8_UNORM, target, tex_usage, geom_flags ))
         return PIPE_FORMAT_A8L8_UNORM;
      return default_rgba_format( screen, target, tex_usage, geom_flags );

   case GL_INTENSITY:
   case GL_INTENSITY4:
   case GL_INTENSITY8:
   case GL_INTENSITY12:
   case GL_INTENSITY16:
   case GL_COMPRESSED_INTENSITY:
      if (screen->is_format_supported( screen, PIPE_FORMAT_I8_UNORM, target, tex_usage, geom_flags ))
         return PIPE_FORMAT_I8_UNORM;
      return default_rgba_format( screen, target, tex_usage, geom_flags );

   case GL_YCBCR_MESA:
      if (screen->is_format_supported(screen, PIPE_FORMAT_YCBCR,
                                      target, tex_usage, geom_flags)) {
         return PIPE_FORMAT_YCBCR;
      }
      if (screen->is_format_supported(screen, PIPE_FORMAT_YCBCR_REV,
                                      target, tex_usage, geom_flags)) {
         return PIPE_FORMAT_YCBCR_REV;
      }
      return PIPE_FORMAT_NONE;

   case GL_RGB_S3TC:
   case GL_RGB4_S3TC:
   case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
      return PIPE_FORMAT_DXT1_RGB;

   case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
      return PIPE_FORMAT_DXT1_RGBA;

   case GL_RGBA_S3TC:
   case GL_RGBA4_S3TC:
   case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
      return PIPE_FORMAT_DXT3_RGBA;

   case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
      return PIPE_FORMAT_DXT5_RGBA;

#if 0
   case GL_COMPRESSED_RGB_FXT1_3DFX:
      return PIPE_FORMAT_RGB_FXT1;
   case GL_COMPRESSED_RGBA_FXT1_3DFX:
      return PIPE_FORMAT_RGB_FXT1;
#endif

   case GL_DEPTH_COMPONENT16:
      if (screen->is_format_supported( screen, PIPE_FORMAT_Z16_UNORM, target, tex_usage, geom_flags ))
         return PIPE_FORMAT_Z16_UNORM;
      /* fall-through */
   case GL_DEPTH_COMPONENT24:
      if (screen->is_format_supported( screen, PIPE_FORMAT_S8Z24_UNORM, target, tex_usage, geom_flags ))
         return PIPE_FORMAT_S8Z24_UNORM;
      if (screen->is_format_supported( screen, PIPE_FORMAT_Z24S8_UNORM, target, tex_usage, geom_flags ))
         return PIPE_FORMAT_Z24S8_UNORM;
      /* fall-through */
   case GL_DEPTH_COMPONENT32:
      if (screen->is_format_supported( screen, PIPE_FORMAT_Z32_UNORM, target, tex_usage, geom_flags ))
         return PIPE_FORMAT_Z32_UNORM;
      /* fall-through */
   case GL_DEPTH_COMPONENT:
      return default_depth_format( screen, target, tex_usage, geom_flags );

   case GL_STENCIL_INDEX:
   case GL_STENCIL_INDEX1_EXT:
   case GL_STENCIL_INDEX4_EXT:
   case GL_STENCIL_INDEX8_EXT:
   case GL_STENCIL_INDEX16_EXT:
      if (screen->is_format_supported( screen, PIPE_FORMAT_S8_UNORM, target, tex_usage, geom_flags ))
         return PIPE_FORMAT_S8_UNORM;
      if (screen->is_format_supported( screen, PIPE_FORMAT_S8Z24_UNORM, target, tex_usage, geom_flags ))
         return PIPE_FORMAT_S8Z24_UNORM;
      if (screen->is_format_supported( screen, PIPE_FORMAT_Z24S8_UNORM, target, tex_usage, geom_flags ))
         return PIPE_FORMAT_Z24S8_UNORM;
      return PIPE_FORMAT_NONE;

   case GL_DEPTH_STENCIL_EXT:
   case GL_DEPTH24_STENCIL8_EXT:
      if (screen->is_format_supported( screen, PIPE_FORMAT_S8Z24_UNORM, target, tex_usage, geom_flags ))
         return PIPE_FORMAT_S8Z24_UNORM;
      if (screen->is_format_supported( screen, PIPE_FORMAT_Z24S8_UNORM, target, tex_usage, geom_flags ))
         return PIPE_FORMAT_Z24S8_UNORM;
      return PIPE_FORMAT_NONE;

   case GL_SRGB_EXT:
   case GL_SRGB8_EXT:
   case GL_COMPRESSED_SRGB_EXT:
   case GL_COMPRESSED_SRGB_ALPHA_EXT:
   case GL_SRGB_ALPHA_EXT:
   case GL_SRGB8_ALPHA8_EXT:
      return default_srgba_format( screen, target, tex_usage, geom_flags );
   case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT:
      return PIPE_FORMAT_DXT1_SRGB;
   case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT:
      return PIPE_FORMAT_DXT1_SRGBA;
   case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT:
      return PIPE_FORMAT_DXT3_SRGBA;
   case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT:
      return PIPE_FORMAT_DXT5_SRGBA;

   case GL_SLUMINANCE_ALPHA_EXT:
   case GL_SLUMINANCE8_ALPHA8_EXT:
   case GL_COMPRESSED_SLUMINANCE_EXT:
   case GL_COMPRESSED_SLUMINANCE_ALPHA_EXT:
      if (screen->is_format_supported( screen, PIPE_FORMAT_A8L8_SRGB, target, tex_usage, geom_flags ))
         return PIPE_FORMAT_A8L8_SRGB;
      return default_srgba_format( screen, target, tex_usage, geom_flags );

   case GL_SLUMINANCE_EXT:
   case GL_SLUMINANCE8_EXT:
      if (screen->is_format_supported( screen, PIPE_FORMAT_L8_SRGB, target, tex_usage, geom_flags ))
         return PIPE_FORMAT_L8_SRGB;
      return default_srgba_format( screen, target, tex_usage, geom_flags );

   default:
      return PIPE_FORMAT_NONE;
   }
}


static GLboolean
is_depth_or_stencil_format(GLenum internalFormat)
{
   switch (internalFormat) {
   case GL_DEPTH_COMPONENT:
   case GL_DEPTH_COMPONENT16:
   case GL_DEPTH_COMPONENT24:
   case GL_DEPTH_COMPONENT32:
   case GL_STENCIL_INDEX:
   case GL_STENCIL_INDEX1_EXT:
   case GL_STENCIL_INDEX4_EXT:
   case GL_STENCIL_INDEX8_EXT:
   case GL_STENCIL_INDEX16_EXT:
   case GL_DEPTH_STENCIL_EXT:
   case GL_DEPTH24_STENCIL8_EXT:
      return GL_TRUE;
   default:
      return GL_FALSE;
   }
}

/**
 * Called by FBO code to choose a PIPE_FORMAT_ for drawing surfaces.
 */
enum pipe_format
st_choose_renderbuffer_format(struct pipe_screen *screen,
                              GLenum internalFormat)
{
   uint usage;
   if (is_depth_or_stencil_format(internalFormat))
      usage = PIPE_TEXTURE_USAGE_DEPTH_STENCIL;
   else
      usage = PIPE_TEXTURE_USAGE_RENDER_TARGET;
   return st_choose_format(screen, internalFormat, PIPE_TEXTURE_2D, usage);
}


static gl_format
translate_gallium_format_to_mesa_format(enum pipe_format format)
{
   switch (format) {
   case PIPE_FORMAT_A8R8G8B8_UNORM:
      return MESA_FORMAT_ARGB8888;
   case PIPE_FORMAT_X8R8G8B8_UNORM:
      return MESA_FORMAT_XRGB8888;
   case PIPE_FORMAT_A1R5G5B5_UNORM:
      return MESA_FORMAT_ARGB1555;
   case PIPE_FORMAT_A4R4G4B4_UNORM:
      return MESA_FORMAT_ARGB4444;
   case PIPE_FORMAT_R5G6B5_UNORM:
      return MESA_FORMAT_RGB565;
   case PIPE_FORMAT_A8L8_UNORM:
      return MESA_FORMAT_AL88;
   case PIPE_FORMAT_A8_UNORM:
      return MESA_FORMAT_A8;
   case PIPE_FORMAT_L8_UNORM:
      return MESA_FORMAT_L8;
   case PIPE_FORMAT_I8_UNORM:
      return MESA_FORMAT_I8;
   case PIPE_FORMAT_Z16_UNORM:
      return MESA_FORMAT_Z16;
   case PIPE_FORMAT_Z32_UNORM:
      return MESA_FORMAT_Z32;
   case PIPE_FORMAT_Z24S8_UNORM:
      return MESA_FORMAT_Z24_S8;
   case PIPE_FORMAT_X8Z24_UNORM:
      return MESA_FORMAT_X8_Z24;
   case PIPE_FORMAT_S8Z24_UNORM:
      return MESA_FORMAT_S8_Z24;
   case PIPE_FORMAT_YCBCR:
      return MESA_FORMAT_YCBCR;
   case PIPE_FORMAT_YCBCR_REV:
      return MESA_FORMAT_YCBCR_REV;
#if FEATURE_texture_s3tc
   case PIPE_FORMAT_DXT1_RGB:
      return MESA_FORMAT_RGB_DXT1;
   case PIPE_FORMAT_DXT1_RGBA:
      return MESA_FORMAT_RGBA_DXT1;
   case PIPE_FORMAT_DXT3_RGBA:
      return MESA_FORMAT_RGBA_DXT3;
   case PIPE_FORMAT_DXT5_RGBA:
      return MESA_FORMAT_RGBA_DXT5;
#if FEATURE_EXT_texture_sRGB
   case PIPE_FORMAT_DXT1_SRGB:
      return MESA_FORMAT_SRGB_DXT1;
   case PIPE_FORMAT_DXT1_SRGBA:
      return MESA_FORMAT_SRGBA_DXT1;
   case PIPE_FORMAT_DXT3_SRGBA:
      return MESA_FORMAT_SRGBA_DXT3;
   case PIPE_FORMAT_DXT5_SRGBA:
      return MESA_FORMAT_SRGBA_DXT5;
#endif
#endif
#if FEATURE_EXT_texture_sRGB
   case PIPE_FORMAT_A8L8_SRGB:
      return MESA_FORMAT_SLA8;
   case PIPE_FORMAT_L8_SRGB:
      return MESA_FORMAT_SL8;
   case PIPE_FORMAT_R8G8B8_SRGB:
      return MESA_FORMAT_SRGB8;
   case PIPE_FORMAT_R8G8B8A8_SRGB:
      return MESA_FORMAT_SRGBA8;
   case PIPE_FORMAT_A8R8G8B8_SRGB:
      return MESA_FORMAT_SARGB8;
#endif
   /* XXX add additional cases */
   default:
      assert(0);
      return MESA_FORMAT_NONE;
   }
}


/**
 * Called via ctx->Driver.chooseTextureFormat().
 */
gl_format
st_ChooseTextureFormat(GLcontext *ctx, GLint internalFormat,
                       GLenum format, GLenum type)
{
   enum pipe_format pFormat;

   (void) format;
   (void) type;

   pFormat = st_choose_format(ctx->st->pipe->screen, internalFormat,
                              PIPE_TEXTURE_2D, PIPE_TEXTURE_USAGE_SAMPLER);
   if (pFormat == PIPE_FORMAT_NONE)
      return MESA_FORMAT_NONE;

   return translate_gallium_format_to_mesa_format(pFormat);
}


/**
 * Test if a gallium format is equivalent to a GL format/type.
 */
GLboolean
st_equal_formats(enum pipe_format pFormat, GLenum format, GLenum type)
{
   switch (pFormat) {
   case PIPE_FORMAT_R8G8B8A8_UNORM:
      return format == GL_RGBA && type == GL_UNSIGNED_BYTE;
   case PIPE_FORMAT_B8G8R8A8_UNORM:
      return format == GL_BGRA && type == GL_UNSIGNED_BYTE;
   case PIPE_FORMAT_R5G6B5_UNORM:
      return format == GL_RGB && type == GL_UNSIGNED_SHORT_5_6_5;
   /* XXX more combos... */
   default:
      return GL_FALSE;
   }
}