summaryrefslogtreecommitdiffstats
path: root/src/mesa/main/texrender.c
blob: 8cec24c3e247ccae5a9ad7d6068ba791cdc55fca (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

#include "context.h"
#include "colormac.h"
#include "macros.h"
#include "texfetch.h"
#include "teximage.h"
#include "texrender.h"
#include "renderbuffer.h"


/*
 * Render-to-texture code for GL_EXT_framebuffer_object
 */


/**
 * Derived from gl_renderbuffer class
 */
struct texture_renderbuffer
{
   struct gl_renderbuffer Base;   /**< Base class object */
   struct gl_texture_image *TexImage;
   StoreTexelFunc Store;
   FetchTexelFuncF Fetchf;
   GLint Yoffset;                 /**< Layer for 1D array textures. */
   GLint Zoffset;                 /**< Layer for 2D array textures, or slice
				   * for 3D textures
				   */
};


/**
 * Get row of values from the renderbuffer that wraps a texture image.
 */
static void
texture_get_row(struct gl_context *ctx, struct gl_renderbuffer *rb, GLuint count,
                GLint x, GLint y, void *values)
{
   const struct texture_renderbuffer *trb
      = (const struct texture_renderbuffer *) rb;
   const GLint z = trb->Zoffset;
   GLuint i;

   ASSERT(trb->TexImage->Width == rb->Width);
   ASSERT(trb->TexImage->Height == rb->Height);

   y += trb->Yoffset;

   if (rb->DataType == CHAN_TYPE) {
      GLchan *rgbaOut = (GLchan *) values;
      for (i = 0; i < count; i++) {
         GLfloat rgba[4];
         trb->Fetchf(trb->TexImage, x + i, y, z, rgba);
         UNCLAMPED_FLOAT_TO_RGBA_CHAN(rgbaOut + 4 * i, rgba);
      }
   }
   else if (rb->DataType == GL_UNSIGNED_SHORT) {
      GLushort *zValues = (GLushort *) values;
      for (i = 0; i < count; i++) {
         GLfloat flt;
         trb->Fetchf(trb->TexImage, x + i, y, z, &flt);
         zValues[i] = (GLushort) (flt * 0xffff);
      }
   }
   else if (rb->DataType == GL_UNSIGNED_INT) {
      GLuint *zValues = (GLuint *) values;
      /*
      const GLdouble scale = (GLdouble) 0xffffffff;
      */
      for (i = 0; i < count; i++) {
         GLfloat flt;
         trb->Fetchf(trb->TexImage, x + i, y, z, &flt);
#if 0
         /* this should work, but doesn't (overflow due to low precision) */
         zValues[i] = (GLuint) (flt * scale);
#else
         /* temporary hack */
         zValues[i] = ((GLuint) (flt * 0xffffff)) << 8;
#endif
      }
   }
   else if (rb->DataType == GL_UNSIGNED_INT_24_8_EXT) {
      GLuint *zValues = (GLuint *) values;
      for (i = 0; i < count; i++) {
         GLfloat flt;
         trb->Fetchf(trb->TexImage, x + i, y, z, &flt);
         zValues[i] = ((GLuint) (flt * 0xffffff)) << 8;
      }
   }
   else if (rb->DataType == GL_UNSIGNED_INT_8_24_REV_MESA) {
      GLuint *zValues = (GLuint *) values;
      for (i = 0; i < count; i++) {
         GLfloat flt;
         trb->Fetchf(trb->TexImage, x + i, y, z, &flt);
         zValues[i] = (GLuint) (flt * 0xffffff);
      }
   }
   else {
      _mesa_problem(ctx, "invalid rb->DataType in texture_get_row");
   }
}


static void
texture_get_values(struct gl_context *ctx, struct gl_renderbuffer *rb, GLuint count,
                   const GLint x[], const GLint y[], void *values)
{
   const struct texture_renderbuffer *trb
      = (const struct texture_renderbuffer *) rb;
   const GLint z = trb->Zoffset;
   GLuint i;

   if (rb->DataType == CHAN_TYPE) {
      GLchan *rgbaOut = (GLchan *) values;
      for (i = 0; i < count; i++) {
         GLfloat rgba[4];
         trb->Fetchf(trb->TexImage, x[i], y[i] + trb->Yoffset,
				    z, rgba);
         UNCLAMPED_FLOAT_TO_RGBA_CHAN(rgbaOut + 4 * i, rgba);
      }
   }
   else if (rb->DataType == GL_UNSIGNED_SHORT) {
      GLushort *zValues = (GLushort *) values;
      for (i = 0; i < count; i++) {
         GLfloat flt;
         trb->Fetchf(trb->TexImage, x[i], y[i] + trb->Yoffset,
				    z, &flt);
         zValues[i] = (GLushort) (flt * 0xffff);
      }
   }
   else if (rb->DataType == GL_UNSIGNED_INT) {
      GLuint *zValues = (GLuint *) values;
      for (i = 0; i < count; i++) {
         GLfloat flt;
         trb->Fetchf(trb->TexImage, x[i], y[i] + trb->Yoffset,
				    z, &flt);
#if 0
         zValues[i] = (GLuint) (flt * 0xffffffff);
#else
         zValues[i] = ((GLuint) (flt * 0xffffff)) << 8;
#endif
      }
   }
   else if (rb->DataType == GL_UNSIGNED_INT_24_8_EXT) {
      GLuint *zValues = (GLuint *) values;
      for (i = 0; i < count; i++) {
         GLfloat flt;
         trb->Fetchf(trb->TexImage, x[i], y[i] + trb->Yoffset,
				    z, &flt);
         zValues[i] = ((GLuint) (flt * 0xffffff)) << 8;
      }
   }
   else if (rb->DataType == GL_UNSIGNED_INT_8_24_REV_MESA) {
      GLuint *zValues = (GLuint *) values;
      for (i = 0; i < count; i++) {
         GLfloat flt;
         trb->Fetchf(trb->TexImage, x[i], y[i] + trb->Yoffset,
				    z, &flt);
         zValues[i] = (GLuint) (flt * 0xffffff);
      }
   }
   else {
      _mesa_problem(ctx, "invalid rb->DataType in texture_get_values");
   }
}


/**
 * Put row of values into a renderbuffer that wraps a texture image.
 */
static void
texture_put_row(struct gl_context *ctx, struct gl_renderbuffer *rb, GLuint count,
                GLint x, GLint y, const void *values, const GLubyte *mask)
{
   const struct texture_renderbuffer *trb
      = (const struct texture_renderbuffer *) rb;
   const GLint z = trb->Zoffset;
   GLuint i;

   y += trb->Yoffset;

   if (rb->DataType == CHAN_TYPE) {
      const GLchan *rgba = (const GLchan *) values;
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            trb->Store(trb->TexImage, x + i, y, z, rgba);
         }
         rgba += 4;
      }
   }
   else if (rb->DataType == GL_UNSIGNED_SHORT) {
      const GLushort *zValues = (const GLushort *) values;
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            trb->Store(trb->TexImage, x + i, y, z, zValues + i);
         }
      }
   }
   else if (rb->DataType == GL_UNSIGNED_INT) {
      const GLuint *zValues = (const GLuint *) values;
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            trb->Store(trb->TexImage, x + i, y, z, zValues + i);
         }
      }
   }
   else if (rb->DataType == GL_UNSIGNED_INT_24_8_EXT) {
      const GLuint *zValues = (const GLuint *) values;
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            GLfloat flt = (GLfloat) ((zValues[i] >> 8) * (1.0 / 0xffffff));
            trb->Store(trb->TexImage, x + i, y, z, &flt);
         }
      }
   }
   else if (rb->DataType == GL_UNSIGNED_INT_8_24_REV_MESA) {
      const GLuint *zValues = (const GLuint *) values;
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            GLfloat flt = (GLfloat) ((zValues[i] & 0xffffff) * (1.0 / 0xffffff));
            trb->Store(trb->TexImage, x + i, y, z, &flt);
         }
      }
   }
   else {
      _mesa_problem(ctx, "invalid rb->DataType in texture_put_row");
   }
}

/**
 * Put row of RGB values into a renderbuffer that wraps a texture image.
 */
static void
texture_put_row_rgb(struct gl_context *ctx, struct gl_renderbuffer *rb, GLuint count,
                GLint x, GLint y, const void *values, const GLubyte *mask)
{
   const struct texture_renderbuffer *trb
      = (const struct texture_renderbuffer *) rb;
   const GLint z = trb->Zoffset;
   GLuint i;

   y += trb->Yoffset;

   if (rb->DataType == CHAN_TYPE) {
      const GLchan *rgb = (const GLchan *) values;
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            trb->Store(trb->TexImage, x + i, y, z, rgb);
         }
         rgb += 3;
      }
   }
   else if (rb->DataType == GL_UNSIGNED_SHORT) {
      const GLushort *zValues = (const GLushort *) values;
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            trb->Store(trb->TexImage, x + i, y, z, zValues + i);
         }
      }
   }
   else if (rb->DataType == GL_UNSIGNED_INT) {
      const GLuint *zValues = (const GLuint *) values;
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            trb->Store(trb->TexImage, x + i, y, z, zValues + i);
         }
      }
   }
   else if (rb->DataType == GL_UNSIGNED_INT_24_8_EXT) {
      const GLuint *zValues = (const GLuint *) values;
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            GLfloat flt = (GLfloat) ((zValues[i] >> 8) * (1.0 / 0xffffff));
            trb->Store(trb->TexImage, x + i, y, z, &flt);
         }
      }
   }
   else if (rb->DataType == GL_UNSIGNED_INT_8_24_REV_MESA) {
      const GLuint *zValues = (const GLuint *) values;
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            GLfloat flt = (GLfloat) ((zValues[i] & 0xffffff) * (1.0 / 0xffffff));
            trb->Store(trb->TexImage, x + i, y, z, &flt);
         }
      }
   }
   else {
      _mesa_problem(ctx, "invalid rb->DataType in texture_put_row");
   }
}


static void
texture_put_mono_row(struct gl_context *ctx, struct gl_renderbuffer *rb, GLuint count,
                     GLint x, GLint y, const void *value, const GLubyte *mask)
{
   const struct texture_renderbuffer *trb
      = (const struct texture_renderbuffer *) rb;
   const GLint z = trb->Zoffset;
   GLuint i;

   y += trb->Yoffset;

   if (rb->DataType == CHAN_TYPE) {
      const GLchan *rgba = (const GLchan *) value;
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            trb->Store(trb->TexImage, x + i, y, z, rgba);
         }
      }
   }
   else if (rb->DataType == GL_UNSIGNED_SHORT) {
      const GLushort zValue = *((const GLushort *) value);
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            trb->Store(trb->TexImage, x + i, y, z, &zValue);
         }
      }
   }
   else if (rb->DataType == GL_UNSIGNED_INT) {
      const GLuint zValue = *((const GLuint *) value);
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            trb->Store(trb->TexImage, x + i, y, z, &zValue);
         }
      }
   }
   else if (rb->DataType == GL_UNSIGNED_INT_24_8_EXT) {
      const GLuint zValue = *((const GLuint *) value);
      const GLfloat flt = (GLfloat) ((zValue >> 8) * (1.0 / 0xffffff));
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            trb->Store(trb->TexImage, x + i, y, z, &flt);
         }
      }
   }
   else if (rb->DataType == GL_UNSIGNED_INT_8_24_REV_MESA) {
      const GLuint zValue = *((const GLuint *) value);
      const GLfloat flt = (GLfloat) ((zValue & 0xffffff) * (1.0 / 0xffffff));
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            trb->Store(trb->TexImage, x + i, y, z, &flt);
         }
      }
   }
   else {
      _mesa_problem(ctx, "invalid rb->DataType in texture_put_mono_row");
   }
}


static void
texture_put_values(struct gl_context *ctx, struct gl_renderbuffer *rb, GLuint count,
                   const GLint x[], const GLint y[], const void *values,
                   const GLubyte *mask)
{
   const struct texture_renderbuffer *trb
      = (const struct texture_renderbuffer *) rb;
   const GLint z = trb->Zoffset;
   GLuint i;

   if (rb->DataType == CHAN_TYPE) {
      const GLchan *rgba = (const GLchan *) values;
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            trb->Store(trb->TexImage, x[i], y[i] + trb->Yoffset, z, rgba);
         }
         rgba += 4;
      }
   }
   else if (rb->DataType == GL_UNSIGNED_SHORT) {
      const GLushort *zValues = (const GLushort *) values;
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            trb->Store(trb->TexImage, x[i], y[i] + trb->Yoffset, z, zValues + i);
         }
      }
   }
   else if (rb->DataType == GL_UNSIGNED_INT) {
      const GLuint *zValues = (const GLuint *) values;
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            trb->Store(trb->TexImage, x[i], y[i] + trb->Yoffset, z, zValues + i);
         }
      }
   }
   else if (rb->DataType == GL_UNSIGNED_INT_24_8_EXT) {
      const GLuint *zValues = (const GLuint *) values;
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            GLfloat flt = (GLfloat) ((zValues[i] >> 8) * (1.0 / 0xffffff));
            trb->Store(trb->TexImage, x[i], y[i] + trb->Yoffset, z, &flt);
         }
      }
   }
   else if (rb->DataType == GL_UNSIGNED_INT_8_24_REV_MESA) {
      const GLuint *zValues = (const GLuint *) values;
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            GLfloat flt = (GLfloat) ((zValues[i] & 0xffffff) * (1.0 / 0xffffff));
            trb->Store(trb->TexImage, x[i], y[i] + trb->Yoffset, z, &flt);
         }
      }
   }
   else {
      _mesa_problem(ctx, "invalid rb->DataType in texture_put_values");
   }
}


static void
texture_put_mono_values(struct gl_context *ctx, struct gl_renderbuffer *rb,
                        GLuint count, const GLint x[], const GLint y[],
                        const void *value, const GLubyte *mask)
{
   const struct texture_renderbuffer *trb
      = (const struct texture_renderbuffer *) rb;
   const GLint z = trb->Zoffset;
   GLuint i;

   if (rb->DataType == CHAN_TYPE) {
      const GLchan *rgba = (const GLchan *) value;
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            trb->Store(trb->TexImage, x[i], y[i] + trb->Yoffset, z, rgba);
         }
      }
   }
   else if (rb->DataType == GL_UNSIGNED_INT) {
      const GLuint zValue = *((const GLuint *) value);
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            trb->Store(trb->TexImage, x[i], y[i] + trb->Yoffset, z, &zValue);
         }
      }
   }
   else if (rb->DataType == GL_UNSIGNED_SHORT) {
      const GLushort zValue = *((const GLushort *) value);
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            trb->Store(trb->TexImage, x[i], y[i] + trb->Yoffset, z, &zValue);
         }
      }
   }
   else if (rb->DataType == GL_UNSIGNED_INT_24_8_EXT) {
      const GLuint zValue = *((const GLuint *) value);
      const GLfloat flt = (GLfloat) ((zValue >> 8) * (1.0 / 0xffffff));
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            trb->Store(trb->TexImage, x[i], y[i] + trb->Yoffset, z, &flt);
         }
      }
   }
   else if (rb->DataType == GL_UNSIGNED_INT_8_24_REV_MESA) {
      const GLuint zValue = *((const GLuint *) value);
      const GLfloat flt = (GLfloat) ((zValue & 0xffffff) * (1.0 / 0xffffff));
      for (i = 0; i < count; i++) {
         if (!mask || mask[i]) {
            trb->Store(trb->TexImage, x[i], y[i] + trb->Yoffset, z, &flt);
         }
      }
   }
   else {
      _mesa_problem(ctx, "invalid rb->DataType in texture_put_mono_values");
   }
}


static void
store_nop(struct gl_texture_image *texImage,
          GLint col, GLint row, GLint img,
          const void *texel)
{
}


static void
delete_texture_wrapper(struct gl_renderbuffer *rb)
{
   ASSERT(rb->RefCount == 0);
   free(rb);
}


/**
 * This function creates a renderbuffer object which wraps a texture image.
 * The new renderbuffer is plugged into the given attachment point.
 * This allows rendering into the texture as if it were a renderbuffer.
 */
static void
wrap_texture(struct gl_context *ctx, struct gl_renderbuffer_attachment *att)
{
   struct texture_renderbuffer *trb;
   const GLuint name = 0;

   ASSERT(att->Type == GL_TEXTURE);
   ASSERT(att->Renderbuffer == NULL);

   trb = CALLOC_STRUCT(texture_renderbuffer);
   if (!trb) {
      _mesa_error(ctx, GL_OUT_OF_MEMORY, "wrap_texture");
      return;
   }

   /* init base gl_renderbuffer fields */
   _mesa_init_renderbuffer(&trb->Base, name);
   /* plug in our texture_renderbuffer-specific functions */
   trb->Base.Delete = delete_texture_wrapper;
   trb->Base.AllocStorage = NULL; /* illegal! */
   trb->Base.GetRow = texture_get_row;
   trb->Base.GetValues = texture_get_values;
   trb->Base.PutRow = texture_put_row;
   trb->Base.PutRowRGB = texture_put_row_rgb;
   trb->Base.PutMonoRow = texture_put_mono_row;
   trb->Base.PutValues = texture_put_values;
   trb->Base.PutMonoValues = texture_put_mono_values;

   /* update attachment point */
   _mesa_reference_renderbuffer(&att->Renderbuffer, &(trb->Base));
}

/**
 * Update the renderbuffer wrapper for rendering to a texture.
 * For example, update the width, height of the RB based on the texture size,
 * update the internal format info, etc.
 */
static void
update_wrapper(struct gl_context *ctx, const struct gl_renderbuffer_attachment *att)
{
   struct texture_renderbuffer *trb
      = (struct texture_renderbuffer *) att->Renderbuffer;

   (void) ctx;
   ASSERT(trb);

   trb->TexImage = att->Texture->Image[att->CubeMapFace][att->TextureLevel];
   ASSERT(trb->TexImage);

   trb->Store = _mesa_get_texel_store_func(trb->TexImage->TexFormat);
   if (!trb->Store) {
      /* we'll never draw into some textures (compressed formats) */
      trb->Store = store_nop;
   }

   trb->Fetchf = trb->TexImage->FetchTexelf;

   if (att->Texture->Target == GL_TEXTURE_1D_ARRAY_EXT) {
      trb->Yoffset = att->Zoffset;
      trb->Zoffset = 0;
   }
   else {
      trb->Yoffset = 0;
      trb->Zoffset = att->Zoffset;
   }

   trb->Base.Width = trb->TexImage->Width;
   trb->Base.Height = trb->TexImage->Height;
   trb->Base.InternalFormat = trb->TexImage->InternalFormat;
   trb->Base.Format = trb->TexImage->TexFormat;

   /* XXX may need more special cases here */
   switch (trb->TexImage->TexFormat) {
   case MESA_FORMAT_Z24_S8:
      trb->Base.DataType = GL_UNSIGNED_INT_24_8_EXT;
      trb->Base._BaseFormat = GL_DEPTH_STENCIL;
      break;
   case MESA_FORMAT_S8_Z24:
      trb->Base.DataType = GL_UNSIGNED_INT_8_24_REV_MESA;
      trb->Base._BaseFormat = GL_DEPTH_STENCIL;
      break;
   case MESA_FORMAT_Z24_X8:
      trb->Base.DataType = GL_UNSIGNED_INT_24_8_EXT;
      trb->Base._BaseFormat = GL_DEPTH_COMPONENT;
      break;
   case MESA_FORMAT_X8_Z24:
      trb->Base.DataType = GL_UNSIGNED_INT_8_24_REV_MESA;
      trb->Base._BaseFormat = GL_DEPTH_COMPONENT;
      break;
   case MESA_FORMAT_Z16:
      trb->Base.DataType = GL_UNSIGNED_SHORT;
      trb->Base._BaseFormat = GL_DEPTH_COMPONENT;
      break;
   case MESA_FORMAT_Z32:
      trb->Base.DataType = GL_UNSIGNED_INT;
      trb->Base._BaseFormat = GL_DEPTH_COMPONENT;
      break;
   /* SRGB formats pre EXT_framebuffer_sRGB don't do sRGB translations on FBO readback */
   case MESA_FORMAT_SRGB8:
      trb->Fetchf = _mesa_get_texel_fetch_func(MESA_FORMAT_RGB888, _mesa_get_texture_dimensions(att->Texture->Target));
      trb->Base.DataType = CHAN_TYPE;
      trb->Base._BaseFormat = GL_RGBA;
      break;
   case MESA_FORMAT_SRGBA8:
      trb->Fetchf = _mesa_get_texel_fetch_func(MESA_FORMAT_RGBA8888, _mesa_get_texture_dimensions(att->Texture->Target));
      trb->Base.DataType = CHAN_TYPE;
      trb->Base._BaseFormat = GL_RGBA;
      break;
   case MESA_FORMAT_SARGB8:
      trb->Fetchf = _mesa_get_texel_fetch_func(MESA_FORMAT_ARGB8888, _mesa_get_texture_dimensions(att->Texture->Target));
      trb->Base.DataType = CHAN_TYPE;
      trb->Base._BaseFormat = GL_RGBA;
      break;
   default:
      trb->Base.DataType = CHAN_TYPE;
      trb->Base._BaseFormat = GL_RGBA;
   }
   trb->Base.Data = trb->TexImage->Data;
}



/**
 * Called when rendering to a texture image begins, or when changing
 * the dest mipmap level, cube face, etc.
 * This is a fallback routine for software render-to-texture.
 *
 * Called via the glRenderbufferTexture1D/2D/3D() functions
 * and elsewhere (such as glTexImage2D).
 *
 * The image we're rendering into is
 * att->Texture->Image[att->CubeMapFace][att->TextureLevel];
 * It'll never be NULL.
 *
 * \param fb  the framebuffer object the texture is being bound to
 * \param att  the fb attachment point of the texture
 *
 * \sa _mesa_framebuffer_renderbuffer
 */
void
_mesa_render_texture(struct gl_context *ctx,
                     struct gl_framebuffer *fb,
                     struct gl_renderbuffer_attachment *att)
{
   (void) fb;

   if (!att->Renderbuffer) {
      wrap_texture(ctx, att);
   }
   update_wrapper(ctx, att);
}


void
_mesa_finish_render_texture(struct gl_context *ctx,
                            struct gl_renderbuffer_attachment *att)
{
   /* do nothing */
   /* The renderbuffer texture wrapper will get deleted by the
    * normal mechanism for deleting renderbuffers.
    */
   (void) ctx;
   (void) att;
}