summaryrefslogtreecommitdiff
path: root/src/mesa/state_tracker/st_format.c
blob: d5e8581b2157e6bc9db9b35a694f3456df8e240f (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
/**************************************************************************
 * 
 * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
 * 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/texformat.h"
#include "main/enums.h"
#include "main/macros.h"

#include "pipe/p_context.h"
#include "pipe/p_defines.h"
#include "st_context.h"
#include "st_format.h"

static GLuint
format_bits(
   struct pipe_format_rgbazs  info,
   GLuint comp )
{
   GLuint   size;

   if (info.swizzleX == comp) {
      size = info.sizeX;
   }
   else if (info.swizzleY == comp) {
      size = info.sizeY;
   }
   else if (info.swizzleZ == comp) {
      size = info.sizeZ;
   }
   else if (info.swizzleW == comp) {
      size = info.sizeW;
   }
   else {
      size = 0;
   }
   return size << (info.exp8 * 3);
}

static GLuint
format_max_bits(
   struct pipe_format_rgbazs  info )
{
   GLuint   size = format_bits( info, PIPE_FORMAT_COMP_R );

   size = MAX2( size, format_bits( info, PIPE_FORMAT_COMP_G ) );
   size = MAX2( size, format_bits( info, PIPE_FORMAT_COMP_B ) );
   size = MAX2( size, format_bits( info, PIPE_FORMAT_COMP_A ) );
   size = MAX2( size, format_bits( info, PIPE_FORMAT_COMP_Z ) );
   size = MAX2( size, format_bits( info, PIPE_FORMAT_COMP_S ) );
   return size;
}

static GLuint
format_size(
   struct pipe_format_rgbazs  info )
{
   return
      format_bits( info, PIPE_FORMAT_COMP_R ) +
      format_bits( info, PIPE_FORMAT_COMP_G ) +
      format_bits( info, PIPE_FORMAT_COMP_B ) +
      format_bits( info, PIPE_FORMAT_COMP_A ) +
      format_bits( info, PIPE_FORMAT_COMP_Z ) +
      format_bits( info, PIPE_FORMAT_COMP_S );
}

/*
 * XXX temporary here
 */
GLboolean
st_get_format_info(
   GLuint format,
   struct pipe_format_info *pinfo )
{
   union pipe_format fmt;

   fmt.value32 = format;
   if (fmt.header.layout == PIPE_FORMAT_LAYOUT_RGBAZS) {
      struct pipe_format_rgbazs  info;

      info = fmt.rgbazs;

#if 0
      printf(
         "PIPE_FORMAT: X(%u), Y(%u), Z(%u), W(%u)\n",
         info.sizeX,
         info.sizeY,
         info.sizeZ,
         info.sizeW );
#endif

      /* Data type */
      if (format == PIPE_FORMAT_U_A1_R5_G5_B5 || format == PIPE_FORMAT_U_R5_G6_B5) {
         pinfo->datatype = GL_UNSIGNED_SHORT;
      }
      else {
         GLuint size;

         size = format_max_bits( info );
         if (size == 8) {
            if (info.type == PIPE_FORMAT_TYPE_UNORM)
               pinfo->datatype = GL_UNSIGNED_BYTE;
            else
               pinfo->datatype = GL_BYTE;
         }
         else if (size == 16) {
            if (info.type == PIPE_FORMAT_TYPE_UNORM)
               pinfo->datatype = GL_UNSIGNED_SHORT;
            else
               pinfo->datatype = GL_SHORT;
         }
         else {
            assert( size <= 32 );
            if (info.type == PIPE_FORMAT_TYPE_UNORM)
               pinfo->datatype = GL_UNSIGNED_INT;
            else
               pinfo->datatype = GL_INT;
         }
      }

      /* Component bits */
      pinfo->red_bits = format_bits( info, PIPE_FORMAT_COMP_R );
      pinfo->green_bits = format_bits( info, PIPE_FORMAT_COMP_G );
      pinfo->blue_bits = format_bits( info, PIPE_FORMAT_COMP_B );
      pinfo->alpha_bits = format_bits( info, PIPE_FORMAT_COMP_A );
      pinfo->depth_bits = format_bits( info, PIPE_FORMAT_COMP_Z );
      pinfo->stencil_bits = format_bits( info, PIPE_FORMAT_COMP_S );

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

      /* Luminance & Intensity bits */
      if( info.swizzleX == PIPE_FORMAT_COMP_R && info.swizzleY == PIPE_FORMAT_COMP_R && info.swizzleZ == PIPE_FORMAT_COMP_R ) {
         if( info.swizzleW == PIPE_FORMAT_COMP_R ) {
            pinfo->luminance_bits = 0;
            pinfo->intensity_bits = pinfo->red_bits;
         }
         else {
            pinfo->luminance_bits = pinfo->red_bits;
            pinfo->intensity_bits = 0;
         }
         pinfo->red_bits = 0;
      }

      /* Base format */
      if (pinfo->depth_bits) {
         if (pinfo->stencil_bits) {
            pinfo->base_format = GL_DEPTH_STENCIL_EXT;
         }
         else {
            pinfo->base_format = GL_DEPTH_COMPONENT;
         }
      }
      else if (pinfo->stencil_bits) {
         pinfo->base_format = GL_STENCIL_INDEX;
      }
      else {
         pinfo->base_format = GL_RGBA;
      }
   }
   else {
      struct pipe_format_ycbcr   info;

      assert( fmt.header.layout == PIPE_FORMAT_LAYOUT_YCBCR );

      info = fmt.ycbcr;

      /* TODO */
      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(GLuint pipeFormat)
{
   struct pipe_format_info info;
   if (!st_get_format_info( pipeFormat, &info )) {
      assert( 0 );
      return 0;
   }
   return info.size;
}


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


GLuint
st_mesa_format_to_pipe_format(GLuint mesaFormat)
{
   switch (mesaFormat) {
      /* fix this */
   case MESA_FORMAT_ARGB8888_REV:
   case MESA_FORMAT_ARGB8888:
      return PIPE_FORMAT_U_A8_R8_G8_B8;
   case MESA_FORMAT_AL88:
      return PIPE_FORMAT_U_A8_L8;
   case MESA_FORMAT_A8:
      return PIPE_FORMAT_U_A8;
   case MESA_FORMAT_L8:
      return PIPE_FORMAT_U_L8;
   case MESA_FORMAT_I8:
      return PIPE_FORMAT_U_I8;
   case MESA_FORMAT_Z16:
      return PIPE_FORMAT_U_Z16;
   default:
      assert(0);
      return 0;
   }
}

/**
 * Search list of formats for first RGBA format.
 */
static GLuint
default_rgba_format(
   struct pipe_context *pipe )
{
   if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_R8_G8_B8_A8 )) {
      return PIPE_FORMAT_U_R8_G8_B8_A8;
   }
   if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_A8_R8_G8_B8 )) {
      return PIPE_FORMAT_U_A8_R8_G8_B8;
   }
   if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_R5_G6_B5 )) {
      return PIPE_FORMAT_U_R5_G6_B5;
   }
   return PIPE_FORMAT_NONE;
}


/**
 * Search list of formats for first RGBA format with >8 bits/channel.
 */
static GLuint
default_deep_rgba_format(
   struct pipe_context *pipe )
{
   if (pipe->is_format_supported( pipe, PIPE_FORMAT_S_R16_G16_B16_A16 )) {
      return PIPE_FORMAT_S_R16_G16_B16_A16;
   }
   return PIPE_FORMAT_NONE;
}


/**
 * Search list of formats for first depth/Z format.
 */
static GLuint
default_depth_format(
   struct pipe_context *pipe )
{
   if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_Z16 )) {
      return PIPE_FORMAT_U_Z16;
   }
   if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_Z32 )) {
      return PIPE_FORMAT_U_Z32;
   }
   if (pipe->is_format_supported( pipe, PIPE_FORMAT_S8_Z24 )) {
      return PIPE_FORMAT_S8_Z24;
   }
   return PIPE_FORMAT_NONE;
}

/**
 * Choose the PIPE_FORMAT_ to use for storing a texture image based
 * on the user's internalFormat, format and type parameters.
 * We query the pipe device for a list of formats which it supports
 * and choose from them.
 * If we find a device that needs a more intricate selection mechanism,
 * this function _could_ get pushed down into the pipe device.
 *
 * Note: also used for glRenderbufferStorageEXT()
 *
 * Note: format and type may be GL_NONE (see renderbuffers)
 *
 * \return PIPE_FORMAT_NONE if error/problem.
 */
GLuint
st_choose_pipe_format(struct pipe_context *pipe, GLint internalFormat,
                      GLenum format, GLenum type)
{
   switch (internalFormat) {
   case 4:
   case GL_RGBA:
   case GL_COMPRESSED_RGBA:
      if (format == GL_BGRA) {
         if (type == GL_UNSIGNED_BYTE || type == GL_UNSIGNED_INT_8_8_8_8_REV) {
            if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_A8_R8_G8_B8 ))
               return PIPE_FORMAT_U_A8_R8_G8_B8;
         }
         else if (type == GL_UNSIGNED_SHORT_4_4_4_4_REV) {
            if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_A4_R4_G4_B4 ))
               return PIPE_FORMAT_U_A4_R4_G4_B4;
         }
         else if (type == GL_UNSIGNED_SHORT_1_5_5_5_REV) {
            if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_A1_R5_G5_B5 ))
               return PIPE_FORMAT_U_A1_R5_G5_B5;
         }
      }
      return default_rgba_format( pipe );

   case 3:
   case GL_RGB:
   case GL_COMPRESSED_RGB:
      if (format == GL_RGB && type == GL_UNSIGNED_SHORT_5_6_5) {
         if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_R5_G6_B5 ))
            return PIPE_FORMAT_U_R5_G6_B5;
      }
      return default_rgba_format( pipe );

   case GL_RGBA8:
   case GL_RGB10_A2:
   case GL_RGBA12:
      return default_rgba_format( pipe );
   case GL_RGBA16:
      return default_deep_rgba_format( pipe );

   case GL_RGBA4:
   case GL_RGBA2:
      if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_A4_R4_G4_B4 ))
         return PIPE_FORMAT_U_A4_R4_G4_B4;
      return default_rgba_format( pipe );

   case GL_RGB5_A1:
      if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_A1_R5_G5_B5 ))
         return PIPE_FORMAT_U_A1_R5_G5_B5;
      return default_rgba_format( pipe );

   case GL_RGB8:
   case GL_RGB10:
   case GL_RGB12:
   case GL_RGB16:
      return default_rgba_format( pipe );

   case GL_RGB5:
   case GL_RGB4:
   case GL_R3_G3_B2:
      if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_A1_R5_G5_B5 ))
         return PIPE_FORMAT_U_A1_R5_G5_B5;
      return default_rgba_format( pipe );

   case GL_ALPHA:
   case GL_ALPHA4:
   case GL_ALPHA8:
   case GL_ALPHA12:
   case GL_ALPHA16:
   case GL_COMPRESSED_ALPHA:
      if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_A8 ))
         return PIPE_FORMAT_U_A8;
      return default_rgba_format( pipe );

   case 1:
   case GL_LUMINANCE:
   case GL_LUMINANCE4:
   case GL_LUMINANCE8:
   case GL_LUMINANCE12:
   case GL_LUMINANCE16:
   case GL_COMPRESSED_LUMINANCE:
      if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_A8 ))
         return PIPE_FORMAT_U_A8;
      return default_rgba_format( pipe );

   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 (pipe->is_format_supported( pipe, PIPE_FORMAT_U_A8_L8 ))
         return PIPE_FORMAT_U_A8_L8;
      return default_rgba_format( pipe );

   case GL_INTENSITY:
   case GL_INTENSITY4:
   case GL_INTENSITY8:
   case GL_INTENSITY12:
   case GL_INTENSITY16:
   case GL_COMPRESSED_INTENSITY:
      if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_I8 ))
         return PIPE_FORMAT_U_I8;
      return default_rgba_format( pipe );

   case GL_YCBCR_MESA:
      if (type == GL_UNSIGNED_SHORT_8_8_MESA || type == GL_UNSIGNED_BYTE) {
         if (pipe->is_format_supported( pipe, PIPE_FORMAT_YCBCR ))
            return PIPE_FORMAT_YCBCR;
      }
      else {
         if (pipe->is_format_supported( pipe, PIPE_FORMAT_YCBCR_REV ))
            return PIPE_FORMAT_YCBCR_REV;
      }
      return PIPE_FORMAT_NONE;

#if 0
   case GL_COMPRESSED_RGB_FXT1_3DFX:
      return &_mesa_texformat_rgb_fxt1;
   case GL_COMPRESSED_RGBA_FXT1_3DFX:
      return &_mesa_texformat_rgba_fxt1;

   case GL_RGB_S3TC:
   case GL_RGB4_S3TC:
   case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
      return &_mesa_texformat_rgb_dxt1;

   case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
      return &_mesa_texformat_rgba_dxt1;

   case GL_RGBA_S3TC:
   case GL_RGBA4_S3TC:
   case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
      return &_mesa_texformat_rgba_dxt3;

   case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
      return &_mesa_texformat_rgba_dxt5;
#endif

   case GL_DEPTH_COMPONENT16:
      if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_Z16 ))
         return PIPE_FORMAT_U_Z16;
      /* fall-through */
   case GL_DEPTH_COMPONENT24:
      if (pipe->is_format_supported( pipe, PIPE_FORMAT_S8_Z24 ))
         return PIPE_FORMAT_S8_Z24;
      /* fall-through */
   case GL_DEPTH_COMPONENT32:
      if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_Z32 ))
         return PIPE_FORMAT_U_Z32;
      /* fall-through */
   case GL_DEPTH_COMPONENT:
      return default_depth_format( pipe );

   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 (pipe->is_format_supported( pipe, PIPE_FORMAT_U_S8 ))
         return PIPE_FORMAT_U_S8;
      if (pipe->is_format_supported( pipe, PIPE_FORMAT_S8_Z24 ))
         return PIPE_FORMAT_S8_Z24;
      return PIPE_FORMAT_NONE;

   case GL_DEPTH_STENCIL_EXT:
   case GL_DEPTH24_STENCIL8_EXT:
      if (pipe->is_format_supported( pipe, PIPE_FORMAT_S8_Z24 ))
         return PIPE_FORMAT_S8_Z24;
      return PIPE_FORMAT_NONE;

   default:
      return PIPE_FORMAT_NONE;
   }
}



/* It works out that this function is fine for all the supported
 * hardware.  However, there is still a need to map the formats onto
 * hardware descriptors.
 */
/* Note that the i915 can actually support many more formats than
 * these if we take the step of simply swizzling the colors
 * immediately after sampling...
 */
const struct gl_texture_format *
st_ChooseTextureFormat(GLcontext * ctx, GLint internalFormat,
                         GLenum format, GLenum type)
{
#if 0
   struct intel_context *intel = intel_context(ctx);
   const GLboolean do32bpt = (intel->intelScreen->front.cpp == 4);
#else
   const GLboolean do32bpt = 1;
#endif

   switch (internalFormat) {
   case 4:
   case GL_RGBA:
   case GL_COMPRESSED_RGBA:
      if (format == GL_BGRA) {
         if (type == GL_UNSIGNED_BYTE || type == GL_UNSIGNED_INT_8_8_8_8_REV) {
            return &_mesa_texformat_argb8888;
         }
         else if (type == GL_UNSIGNED_SHORT_4_4_4_4_REV) {
            return &_mesa_texformat_argb4444;
         }
         else if (type == GL_UNSIGNED_SHORT_1_5_5_5_REV) {
            return &_mesa_texformat_argb1555;
         }
      }
      return do32bpt ? &_mesa_texformat_argb8888 : &_mesa_texformat_argb4444;

   case 3:
   case GL_RGB:
   case GL_COMPRESSED_RGB:
      if (format == GL_RGB && type == GL_UNSIGNED_SHORT_5_6_5) {
         return &_mesa_texformat_rgb565;
      }
      return do32bpt ? &_mesa_texformat_argb8888 : &_mesa_texformat_rgb565;

   case GL_RGBA8:
   case GL_RGB10_A2:
   case GL_RGBA12:
   case GL_RGBA16:
      return do32bpt ? &_mesa_texformat_argb8888 : &_mesa_texformat_argb4444;

   case GL_RGBA4:
   case GL_RGBA2:
      return &_mesa_texformat_argb4444;

   case GL_RGB5_A1:
      return &_mesa_texformat_argb1555;

   case GL_RGB8:
   case GL_RGB10:
   case GL_RGB12:
   case GL_RGB16:
      return &_mesa_texformat_argb8888;

   case GL_RGB5:
   case GL_RGB4:
   case GL_R3_G3_B2:
      return &_mesa_texformat_rgb565;

   case GL_ALPHA:
   case GL_ALPHA4:
   case GL_ALPHA8:
   case GL_ALPHA12:
   case GL_ALPHA16:
   case GL_COMPRESSED_ALPHA:
      return &_mesa_texformat_a8;

   case 1:
   case GL_LUMINANCE:
   case GL_LUMINANCE4:
   case GL_LUMINANCE8:
   case GL_LUMINANCE12:
   case GL_LUMINANCE16:
   case GL_COMPRESSED_LUMINANCE:
      return &_mesa_texformat_l8;

   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:
      return &_mesa_texformat_al88;

   case GL_INTENSITY:
   case GL_INTENSITY4:
   case GL_INTENSITY8:
   case GL_INTENSITY12:
   case GL_INTENSITY16:
   case GL_COMPRESSED_INTENSITY:
      return &_mesa_texformat_i8;

   case GL_YCBCR_MESA:
      if (type == GL_UNSIGNED_SHORT_8_8_MESA || type == GL_UNSIGNED_BYTE)
         return &_mesa_texformat_ycbcr;
      else
         return &_mesa_texformat_ycbcr_rev;

   case GL_COMPRESSED_RGB_FXT1_3DFX:
      return &_mesa_texformat_rgb_fxt1;
   case GL_COMPRESSED_RGBA_FXT1_3DFX:
      return &_mesa_texformat_rgba_fxt1;

   case GL_RGB_S3TC:
   case GL_RGB4_S3TC:
   case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
      return &_mesa_texformat_rgb_dxt1;

   case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
      return &_mesa_texformat_rgba_dxt1;

   case GL_RGBA_S3TC:
   case GL_RGBA4_S3TC:
   case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
      return &_mesa_texformat_rgba_dxt3;

   case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
      return &_mesa_texformat_rgba_dxt5;

   case GL_DEPTH_COMPONENT:
   case GL_DEPTH_COMPONENT16:
   case GL_DEPTH_COMPONENT24:
   case GL_DEPTH_COMPONENT32:
      return &_mesa_texformat_z16;

   case GL_DEPTH_STENCIL_EXT:
   case GL_DEPTH24_STENCIL8_EXT:
      return &_mesa_texformat_z24_s8;

   default:
      fprintf(stderr, "unexpected texture format %s in %s\n",
              _mesa_lookup_enum_by_nr(internalFormat), __FUNCTION__);
      return NULL;
   }

   return NULL;                 /* never get here */
}