src/mesa/swrast/s_texfetch.c

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
   5  * Copyright (c) 2009  VMware, Inc.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  21  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  22  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  23  * OTHER DEALINGS IN THE SOFTWARE.
  24  */
  25
  26
  27 /**
  28  * \file s_texfetch.c
  29  *
  30  * Texel fetch/store functions
  31  *
  32  * \author Gareth Hughes
  33  */
  34
  35
  36 #include "main/colormac.h"
  37 #include "main/macros.h"
  38 #include "main/texcompress.h"
  39 #include "main/texcompress_fxt1.h"
  40 #include "main/texcompress_s3tc.h"
  41 #include "main/texcompress_rgtc.h"
  42 #include "main/texcompress_etc.h"
  43 #include "main/teximage.h"
  44 #include "main/samplerobj.h"
  45 #include "s_context.h"
  46 #include "s_texfetch.h"
  47 #include "../../gallium/auxiliary/util/u_format_rgb9e5.h"
  48 #include "../../gallium/auxiliary/util/u_format_r11g11b10f.h"
  49 #include "util/format_srgb.h"
  50
  51
  52 /* Texel fetch routines for all supported formats
  53  */
  54 #define DIM 1
  55 #include "s_texfetch_tmp.h"
  56
  57 #define DIM 2
  58 #include "s_texfetch_tmp.h"
  59
  60 #define DIM 3
  61 #include "s_texfetch_tmp.h"
  62
  63
  64 /**
  65  * All compressed texture texel fetching is done though this function.
  66  * Basically just call a core-Mesa texel fetch function.
  67  */
  68 static void
  69 fetch_compressed(const struct swrast_texture_image *swImage,
  70                  GLint i, GLint j, GLint k, GLfloat *texel)
  71 {
  72    /* The FetchCompressedTexel function takes an integer pixel rowstride,
  73     * while the image's rowstride is bytes per row of blocks.
  74     */
  75    GLuint bw, bh;
  76    GLuint texelBytes = _mesa_get_format_bytes(swImage->Base.TexFormat);
  77    _mesa_get_format_block_size(swImage->Base.TexFormat, &bw, &bh);
  78    assert(swImage->RowStride * bw % texelBytes == 0);
  79
  80    swImage->FetchCompressedTexel(swImage->ImageSlices[k],
  81                                  swImage->RowStride * bw / texelBytes,
  82                                  i, j, texel);
  83 }
  84
  85
  86
  87 /**
  88  * Null texel fetch function.
  89  *
  90  * Have to have this so the FetchTexel function pointer is never NULL.
  91  */
  92 static void fetch_null_texelf( const struct swrast_texture_image *texImage,
  93                                GLint i, GLint j, GLint k, GLfloat *texel )
  94 {
  95    (void) texImage; (void) i; (void) j; (void) k;
  96    texel[RCOMP] = 0.0;
  97    texel[GCOMP] = 0.0;
  98    texel[BCOMP] = 0.0;
  99    texel[ACOMP] = 0.0;
 100    _mesa_warning(NULL, "fetch_null_texelf() called!");
 101 }
 102
 103
 104 #define FETCH_FUNCS(NAME)       \
 105    {                            \
 106       MESA_FORMAT_ ## NAME,     \
 107       fetch_texel_1d_ ## NAME,  \
 108       fetch_texel_2d_ ## NAME,  \
 109       fetch_texel_3d_ ## NAME,  \
 110    }
 111
 112 #define FETCH_NULL(NAME)        \
 113    {                            \
 114       MESA_FORMAT_ ## NAME,     \
 115       NULL,                     \
 116       NULL,                     \
 117       NULL                      \
 118    }
 119
 120 /**
 121  * Table to map MESA_FORMAT_ to texel fetch/store funcs.
 122  */
 123 static struct {
 124    mesa_format Name;
 125    FetchTexelFunc Fetch1D;
 126    FetchTexelFunc Fetch2D;
 127    FetchTexelFunc Fetch3D;
 128 }
 129 texfetch_funcs[] =
 130 {
 131    {
 132       MESA_FORMAT_NONE,
 133       fetch_null_texelf,
 134       fetch_null_texelf,
 135       fetch_null_texelf
 136    },
 137
 138    /* Packed unorm formats */
 139    FETCH_FUNCS(A8B8G8R8_UNORM),
 140    FETCH_FUNCS(X8B8G8R8_UNORM),
 141    FETCH_FUNCS(R8G8B8A8_UNORM),
 142    FETCH_FUNCS(R8G8B8X8_UNORM),
 143    FETCH_FUNCS(B8G8R8A8_UNORM),
 144    FETCH_FUNCS(B8G8R8X8_UNORM),
 145    FETCH_FUNCS(A8R8G8B8_UNORM),
 146    FETCH_FUNCS(X8R8G8B8_UNORM),
 147    FETCH_FUNCS(L16A16_UNORM),
 148    FETCH_FUNCS(A16L16_UNORM),
 149    FETCH_FUNCS(B5G6R5_UNORM),
 150    FETCH_FUNCS(R5G6B5_UNORM),
 151    FETCH_FUNCS(B4G4R4A4_UNORM),
 152    FETCH_NULL(B4G4R4X4_UNORM),
 153    FETCH_FUNCS(A4R4G4B4_UNORM),
 154    FETCH_FUNCS(A1B5G5R5_UNORM),
 155    FETCH_FUNCS(B5G5R5A1_UNORM),
 156    FETCH_NULL(B5G5R5X1_UNORM),
 157    FETCH_FUNCS(A1R5G5B5_UNORM),
 158    FETCH_FUNCS(L8A8_UNORM),
 159    FETCH_FUNCS(A8L8_UNORM),
 160    FETCH_FUNCS(R8G8_UNORM),
 161    FETCH_FUNCS(G8R8_UNORM),
 162    FETCH_FUNCS(L4A4_UNORM),
 163    FETCH_FUNCS(B2G3R3_UNORM),
 164    FETCH_FUNCS(R16G16_UNORM),
 165    FETCH_FUNCS(G16R16_UNORM),
 166    FETCH_FUNCS(B10G10R10A2_UNORM),
 167    FETCH_NULL(B10G10R10X2_UNORM),
 168    FETCH_FUNCS(R10G10B10A2_UNORM),
 169    FETCH_FUNCS(S8_UINT_Z24_UNORM),
 170    {
 171       MESA_FORMAT_X8_UINT_Z24_UNORM,
 172       fetch_texel_1d_S8_UINT_Z24_UNORM,
 173       fetch_texel_2d_S8_UINT_Z24_UNORM,
 174       fetch_texel_3d_S8_UINT_Z24_UNORM
 175    },
 176    FETCH_FUNCS(Z24_UNORM_S8_UINT),
 177    {
 178       MESA_FORMAT_Z24_UNORM_X8_UINT,
 179       fetch_texel_1d_Z24_UNORM_S8_UINT,
 180       fetch_texel_2d_Z24_UNORM_S8_UINT,
 181       fetch_texel_3d_Z24_UNORM_S8_UINT
 182    },
 183    FETCH_NULL(R3G3B2_UNORM),
 184    FETCH_NULL(A4B4G4R4_UNORM),
 185    FETCH_NULL(R4G4B4A4_UNORM),
 186    FETCH_NULL(R1G5B5A5_UNORM),
 187    FETCH_NULL(R5G5B5A1_UNORM),
 188    FETCH_NULL(A5B5G5R1_UNORM),
 189    FETCH_NULL(A2B10G10R10_UNORM),
 190    FETCH_NULL(A2R10G10B10_UNORM),
 191    FETCH_NULL(R2G10B10A10_UNORM),
 192    FETCH_NULL(A10B10G10R2_UNORM),
 193
 194    FETCH_FUNCS(YCBCR),
 195    FETCH_FUNCS(YCBCR_REV),
 196
 197    /* Array unorm formats */
 198    FETCH_FUNCS(A_UNORM8),
 199    FETCH_FUNCS(A_UNORM16),
 200    FETCH_FUNCS(L_UNORM8),
 201    FETCH_FUNCS(L_UNORM16),
 202    FETCH_FUNCS(I_UNORM8),
 203    FETCH_FUNCS(I_UNORM16),
 204    FETCH_FUNCS(R_UNORM8),
 205    FETCH_FUNCS(R_UNORM16),
 206    FETCH_FUNCS(BGR_UNORM8),
 207    FETCH_FUNCS(RGB_UNORM8),
 208    FETCH_FUNCS(RGBA_UNORM16),
 209    FETCH_FUNCS(RGBX_UNORM16),
 210    FETCH_FUNCS(Z_UNORM16),
 211    FETCH_FUNCS(Z_UNORM32),
 212    FETCH_NULL(S_UINT8),
 213
 214    /* Packed signed/normalized formats */
 215    FETCH_FUNCS(A8B8G8R8_SNORM),
 216    FETCH_FUNCS(X8B8G8R8_SNORM),
 217    FETCH_FUNCS(R8G8B8A8_SNORM),
 218    FETCH_NULL(R8G8B8X8_SNORM),
 219    FETCH_FUNCS(R16G16_SNORM),
 220    FETCH_NULL(G16R16_SNORM),
 221    FETCH_FUNCS(R8G8_SNORM),
 222    FETCH_NULL(G8R8_SNORM),
 223    FETCH_FUNCS(L8A8_SNORM),
 224    FETCH_FUNCS(A8L8_SNORM),
 225
 226    /* Array signed/normalized formats */
 227    FETCH_FUNCS(A_SNORM8),
 228    FETCH_FUNCS(A_SNORM16),
 229    FETCH_FUNCS(L_SNORM8),
 230    FETCH_FUNCS(L_SNORM16),
 231    FETCH_FUNCS(I_SNORM8),
 232    FETCH_FUNCS(I_SNORM16),
 233    FETCH_FUNCS(R_SNORM8),
 234    FETCH_FUNCS(R_SNORM16),
 235    FETCH_FUNCS(LA_SNORM16),
 236    FETCH_FUNCS(RGB_SNORM16),
 237    FETCH_FUNCS(RGBA_SNORM16),
 238    FETCH_NULL(RGBX_SNORM16),
 239
 240    /* Packed sRGB formats */
 241    FETCH_FUNCS(A8B8G8R8_SRGB),
 242    FETCH_FUNCS(B8G8R8A8_SRGB),
 243    FETCH_FUNCS(A8R8G8B8_SRGB),
 244    FETCH_NULL(B8G8R8X8_SRGB),
 245    FETCH_NULL(X8R8G8B8_SRGB),
 246    FETCH_FUNCS(R8G8B8A8_SRGB),
 247    FETCH_FUNCS(R8G8B8X8_SRGB),
 248    FETCH_FUNCS(X8B8G8R8_SRGB),
 249    FETCH_FUNCS(L8A8_SRGB),
 250    FETCH_FUNCS(A8L8_SRGB),
 251
 252    /* Array sRGB formats */
 253    FETCH_FUNCS(L_SRGB8),
 254    FETCH_FUNCS(BGR_SRGB8),
 255
 256    /* Packed float formats */
 257    FETCH_FUNCS(R9G9B9E5_FLOAT),
 258    FETCH_FUNCS(R11G11B10_FLOAT),
 259    FETCH_FUNCS(Z32_FLOAT_S8X24_UINT),
 260
 261    /* Array float formats */
 262    FETCH_FUNCS(A_FLOAT16),
 263    FETCH_FUNCS(A_FLOAT32),
 264    FETCH_FUNCS(L_FLOAT16),
 265    FETCH_FUNCS(L_FLOAT32),
 266    FETCH_FUNCS(LA_FLOAT16),
 267    FETCH_FUNCS(LA_FLOAT32),
 268    FETCH_FUNCS(I_FLOAT16),
 269    FETCH_FUNCS(I_FLOAT32),
 270    FETCH_FUNCS(R_FLOAT16),
 271    FETCH_FUNCS(R_FLOAT32),
 272    FETCH_FUNCS(RG_FLOAT16),
 273    FETCH_FUNCS(RG_FLOAT32),
 274    FETCH_FUNCS(RGB_FLOAT16),
 275    FETCH_FUNCS(RGB_FLOAT32),
 276    FETCH_FUNCS(RGBA_FLOAT16),
 277    FETCH_FUNCS(RGBA_FLOAT32),
 278    FETCH_FUNCS(RGBX_FLOAT16),
 279    FETCH_FUNCS(RGBX_FLOAT32),
 280    {
 281       MESA_FORMAT_Z_FLOAT32,
 282       fetch_texel_1d_R_FLOAT32, /* Reuse the R32F functions. */
 283       fetch_texel_2d_R_FLOAT32,
 284       fetch_texel_3d_R_FLOAT32
 285    },
 286
 287    /* Packed signed/unsigned non-normalized integer formats */
 288    FETCH_NULL(B10G10R10A2_UINT),
 289    FETCH_NULL(R10G10B10A2_UINT),
 290    FETCH_NULL(A2B10G10R10_UINT),
 291    FETCH_NULL(A2R10G10B10_UINT),
 292
 293    /* Array signed/unsigned non-normalized integer formats */
 294    FETCH_NULL(A_UINT8),
 295    FETCH_NULL(A_UINT16),
 296    FETCH_NULL(A_UINT32),
 297    FETCH_NULL(A_SINT8),
 298    FETCH_NULL(A_SINT16),
 299    FETCH_NULL(A_SINT32),
 300    FETCH_NULL(I_UINT8),
 301    FETCH_NULL(I_UINT16),
 302    FETCH_NULL(I_UINT32),
 303    FETCH_NULL(I_SINT8),
 304    FETCH_NULL(I_SINT16),
 305    FETCH_NULL(I_SINT32),
 306    FETCH_NULL(L_UINT8),
 307    FETCH_NULL(L_UINT16),
 308    FETCH_NULL(L_UINT32),
 309    FETCH_NULL(L_SINT8),
 310    FETCH_NULL(L_SINT16),
 311    FETCH_NULL(L_SINT32),
 312    FETCH_NULL(LA_UINT8),
 313    FETCH_NULL(LA_UINT16),
 314    FETCH_NULL(LA_UINT32),
 315    FETCH_NULL(LA_SINT8),
 316    FETCH_NULL(LA_SINT16),
 317    FETCH_NULL(LA_SINT32),
 318    FETCH_NULL(R_UINT8),
 319    FETCH_NULL(R_UINT16),
 320    FETCH_NULL(R_UINT32),
 321    FETCH_NULL(R_SINT8),
 322    FETCH_NULL(R_SINT16),
 323    FETCH_NULL(R_SINT32),
 324    FETCH_NULL(RG_UINT8),
 325    FETCH_NULL(RG_UINT16),
 326    FETCH_NULL(RG_UINT32),
 327    FETCH_NULL(RG_SINT8),
 328    FETCH_NULL(RG_SINT16),
 329    FETCH_NULL(RG_SINT32),
 330    FETCH_NULL(RGB_UINT8),
 331    FETCH_NULL(RGB_UINT16),
 332    FETCH_NULL(RGB_UINT32),
 333    FETCH_NULL(RGB_SINT8),
 334    FETCH_NULL(RGB_SINT16),
 335    FETCH_NULL(RGB_SINT32),
 336    FETCH_FUNCS(RGBA_UINT8),
 337    FETCH_FUNCS(RGBA_UINT16),
 338    FETCH_FUNCS(RGBA_UINT32),
 339    FETCH_FUNCS(RGBA_SINT8),
 340    FETCH_FUNCS(RGBA_SINT16),
 341    FETCH_FUNCS(RGBA_SINT32),
 342    FETCH_NULL(RGBX_UINT8),
 343    FETCH_NULL(RGBX_UINT16),
 344    FETCH_NULL(RGBX_UINT32),
 345    FETCH_NULL(RGBX_SINT8),
 346    FETCH_NULL(RGBX_SINT16),
 347    FETCH_NULL(RGBX_SINT32),
 348
 349    /* DXT compressed formats */
 350    {
 351       MESA_FORMAT_RGB_DXT1,
 352       fetch_compressed,
 353       fetch_compressed,
 354       fetch_compressed
 355    },
 356    {
 357       MESA_FORMAT_RGBA_DXT1,
 358       fetch_compressed,
 359       fetch_compressed,
 360       fetch_compressed
 361    },
 362    {
 363       MESA_FORMAT_RGBA_DXT3,
 364       fetch_compressed,
 365       fetch_compressed,
 366       fetch_compressed
 367    },
 368    {
 369       MESA_FORMAT_RGBA_DXT5,
 370       fetch_compressed,
 371       fetch_compressed,
 372       fetch_compressed
 373    },
 374
 375    /* DXT sRGB compressed formats */
 376    {
 377       MESA_FORMAT_SRGB_DXT1,
 378       fetch_compressed,
 379       fetch_compressed,
 380       fetch_compressed
 381    },
 382    {
 383       MESA_FORMAT_SRGBA_DXT1,
 384       fetch_compressed,
 385       fetch_compressed,
 386       fetch_compressed
 387    },
 388    {
 389       MESA_FORMAT_SRGBA_DXT3,
 390       fetch_compressed,
 391       fetch_compressed,
 392       fetch_compressed
 393    },
 394    {
 395       MESA_FORMAT_SRGBA_DXT5,
 396       fetch_compressed,
 397       fetch_compressed,
 398       fetch_compressed
 399    },
 400
 401    /* FXT1 compressed formats */
 402    {
 403       MESA_FORMAT_RGB_FXT1,
 404       fetch_compressed,
 405       fetch_compressed,
 406       fetch_compressed
 407    },
 408    {
 409       MESA_FORMAT_RGBA_FXT1,
 410       fetch_compressed,
 411       fetch_compressed,
 412       fetch_compressed
 413    },
 414
 415    /* RGTC compressed formats */
 416    {
 417       MESA_FORMAT_R_RGTC1_UNORM,
 418       fetch_compressed,
 419       fetch_compressed,
 420       fetch_compressed
 421    },
 422    {
 423       MESA_FORMAT_R_RGTC1_SNORM,
 424       fetch_compressed,
 425       fetch_compressed,
 426       fetch_compressed
 427    },
 428    {
 429       MESA_FORMAT_RG_RGTC2_UNORM,
 430       fetch_compressed,
 431       fetch_compressed,
 432       fetch_compressed
 433    },
 434    {
 435       MESA_FORMAT_RG_RGTC2_SNORM,
 436       fetch_compressed,
 437       fetch_compressed,
 438       fetch_compressed
 439    },
 440
 441    /* LATC1/2 compressed formats */
 442    {
 443       MESA_FORMAT_L_LATC1_UNORM,
 444       fetch_compressed,
 445       fetch_compressed,
 446       fetch_compressed
 447    },
 448    {
 449       MESA_FORMAT_L_LATC1_SNORM,
 450       fetch_compressed,
 451       fetch_compressed,
 452       fetch_compressed
 453    },
 454    {
 455       MESA_FORMAT_LA_LATC2_UNORM,
 456       fetch_compressed,
 457       fetch_compressed,
 458       fetch_compressed
 459    },
 460    {
 461       MESA_FORMAT_LA_LATC2_SNORM,
 462       fetch_compressed,
 463       fetch_compressed,
 464       fetch_compressed
 465    },
 466
 467    /* ETC1/2 compressed formats */
 468    {
 469       MESA_FORMAT_ETC1_RGB8,
 470       fetch_compressed,
 471       fetch_compressed,
 472       fetch_compressed
 473    },
 474    {
 475       MESA_FORMAT_ETC2_RGB8,
 476       fetch_compressed,
 477       fetch_compressed,
 478       fetch_compressed
 479    },
 480    {
 481       MESA_FORMAT_ETC2_SRGB8,
 482       fetch_compressed,
 483       fetch_compressed,
 484       fetch_compressed
 485    },
 486    {
 487       MESA_FORMAT_ETC2_RGBA8_EAC,
 488       fetch_compressed,
 489       fetch_compressed,
 490       fetch_compressed
 491    },
 492    {
 493       MESA_FORMAT_ETC2_SRGB8_ALPHA8_EAC,
 494       fetch_compressed,
 495       fetch_compressed,
 496       fetch_compressed
 497    },
 498    {
 499       MESA_FORMAT_ETC2_R11_EAC,
 500       fetch_compressed,
 501       fetch_compressed,
 502       fetch_compressed
 503    },
 504    {
 505       MESA_FORMAT_ETC2_RG11_EAC,
 506       fetch_compressed,
 507       fetch_compressed,
 508       fetch_compressed
 509    },
 510    {
 511       MESA_FORMAT_ETC2_SIGNED_R11_EAC,
 512       fetch_compressed,
 513       fetch_compressed,
 514       fetch_compressed
 515    },
 516    {
 517       MESA_FORMAT_ETC2_SIGNED_RG11_EAC,
 518       fetch_compressed,
 519       fetch_compressed,
 520       fetch_compressed
 521    },
 522    {
 523       MESA_FORMAT_ETC2_RGB8_PUNCHTHROUGH_ALPHA1,
 524       fetch_compressed,
 525       fetch_compressed,
 526       fetch_compressed
 527    },
 528    {
 529       MESA_FORMAT_ETC2_SRGB8_PUNCHTHROUGH_ALPHA1,
 530       fetch_compressed,
 531       fetch_compressed,
 532       fetch_compressed
 533    },
 534    {
 535       MESA_FORMAT_BPTC_RGBA_UNORM,
 536       fetch_compressed,
 537       fetch_compressed,
 538       fetch_compressed
 539    },
 540    {
 541       MESA_FORMAT_BPTC_SRGB_ALPHA_UNORM,
 542       fetch_compressed,
 543       fetch_compressed,
 544       fetch_compressed
 545    },
 546    {
 547       MESA_FORMAT_BPTC_RGB_SIGNED_FLOAT,
 548       fetch_compressed,
 549       fetch_compressed,
 550       fetch_compressed
 551    },
 552    {
 553       MESA_FORMAT_BPTC_RGB_UNSIGNED_FLOAT,
 554       fetch_compressed,
 555       fetch_compressed,
 556       fetch_compressed
 557    }
 558 };
 559
 560
 561 /**
 562  * Initialize the texture image's FetchTexel methods.
 563  */
 564 static void
 565 set_fetch_functions(const struct gl_sampler_object *samp,
 566                     struct swrast_texture_image *texImage, GLuint dims)
 567 {
 568    mesa_format format = texImage->Base.TexFormat;
 569
 570 #ifdef DEBUG
 571    /* check that the table entries are sorted by format name */
 572    mesa_format fmt;
 573    for (fmt = 0; fmt < MESA_FORMAT_COUNT; fmt++) {
 574       assert(texfetch_funcs[fmt].Name == fmt);
 575    }
 576 #endif
 577
 578    STATIC_ASSERT(Elements(texfetch_funcs) == MESA_FORMAT_COUNT);
 579
 580    if (samp->sRGBDecode == GL_SKIP_DECODE_EXT &&
 581        _mesa_get_format_color_encoding(format) == GL_SRGB) {
 582       format = _mesa_get_srgb_format_linear(format);
 583    }
 584
 585    assert(format < MESA_FORMAT_COUNT);
 586
 587    switch (dims) {
 588    case 1:
 589       texImage->FetchTexel = texfetch_funcs[format].Fetch1D;
 590       break;
 591    case 2:
 592       texImage->FetchTexel = texfetch_funcs[format].Fetch2D;
 593       break;
 594    case 3:
 595       texImage->FetchTexel = texfetch_funcs[format].Fetch3D;
 596       break;
 597    default:
 598       assert(!"Bad dims in set_fetch_functions()");
 599    }
 600
 601    texImage->FetchCompressedTexel = _mesa_get_compressed_fetch_func(format);
 602
 603    ASSERT(texImage->FetchTexel);
 604 }
 605
 606 void
 607 _mesa_update_fetch_functions(struct gl_context *ctx, GLuint unit)
 608 {
 609    struct gl_texture_object *texObj = ctx->Texture.Unit[unit]._Current;
 610    struct gl_sampler_object *samp;
 611    GLuint face, i;
 612    GLuint dims;
 613
 614    if (!texObj)
 615       return;
 616
 617    samp = _mesa_get_samplerobj(ctx, unit);
 618
 619    dims = _mesa_get_texture_dimensions(texObj->Target);
 620
 621    for (face = 0; face < 6; face++) {
 622       for (i = 0; i < MAX_TEXTURE_LEVELS; i++) {
 623          if (texObj->Image[face][i]) {
 624             set_fetch_functions(samp,
 625                                 swrast_texture_image(texObj->Image[face][i]),
 626                                 dims);
 627          }
 628       }
 629    }
 630 }