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/errors.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 "util/format_rgb9e5.h"
  48 #include "util/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 #define FETCH_COMPRESSED(NAME)  \
 121    {                            \
 122       MESA_FORMAT_ ## NAME,     \
 123       fetch_compressed,         \
 124       fetch_compressed,         \
 125       fetch_compressed          \
 126    }
 127
 128 /**
 129  * Table to map MESA_FORMAT_ to texel fetch/store funcs.
 130  */
 131 static struct {
 132    mesa_format Name;
 133    FetchTexelFunc Fetch1D;
 134    FetchTexelFunc Fetch2D;
 135    FetchTexelFunc Fetch3D;
 136 }
 137 texfetch_funcs[] =
 138 {
 139    {
 140       MESA_FORMAT_NONE,
 141       fetch_null_texelf,
 142       fetch_null_texelf,
 143       fetch_null_texelf
 144    },
 145
 146    /* Packed unorm formats */
 147    FETCH_FUNCS(A8B8G8R8_UNORM),
 148    FETCH_FUNCS(X8B8G8R8_UNORM),
 149    FETCH_FUNCS(R8G8B8A8_UNORM),
 150    FETCH_FUNCS(R8G8B8X8_UNORM),
 151    FETCH_FUNCS(B8G8R8A8_UNORM),
 152    FETCH_FUNCS(B8G8R8X8_UNORM),
 153    FETCH_FUNCS(A8R8G8B8_UNORM),
 154    FETCH_FUNCS(X8R8G8B8_UNORM),
 155    FETCH_FUNCS(L16A16_UNORM),
 156    FETCH_FUNCS(A16L16_UNORM),
 157    FETCH_FUNCS(B5G6R5_UNORM),
 158    FETCH_FUNCS(R5G6B5_UNORM),
 159    FETCH_FUNCS(B4G4R4A4_UNORM),
 160    FETCH_NULL(B4G4R4X4_UNORM),
 161    FETCH_FUNCS(A4R4G4B4_UNORM),
 162    FETCH_FUNCS(A1B5G5R5_UNORM),
 163    FETCH_NULL(X1B5G5R5_UNORM),
 164    FETCH_FUNCS(B5G5R5A1_UNORM),
 165    FETCH_NULL(B5G5R5X1_UNORM),
 166    FETCH_FUNCS(A1R5G5B5_UNORM),
 167    FETCH_FUNCS(L8A8_UNORM),
 168    FETCH_FUNCS(A8L8_UNORM),
 169    FETCH_FUNCS(R8G8_UNORM),
 170    FETCH_FUNCS(G8R8_UNORM),
 171    FETCH_FUNCS(L4A4_UNORM),
 172    FETCH_FUNCS(B2G3R3_UNORM),
 173    FETCH_FUNCS(R16G16_UNORM),
 174    FETCH_FUNCS(G16R16_UNORM),
 175    FETCH_FUNCS(B10G10R10A2_UNORM),
 176    FETCH_NULL(B10G10R10X2_UNORM),
 177    FETCH_FUNCS(R10G10B10A2_UNORM),
 178    FETCH_NULL(R10G10B10X2_UNORM),
 179
 180    FETCH_FUNCS(S8_UINT_Z24_UNORM),
 181    {
 182       MESA_FORMAT_X8_UINT_Z24_UNORM,
 183       fetch_texel_1d_S8_UINT_Z24_UNORM,
 184       fetch_texel_2d_S8_UINT_Z24_UNORM,
 185       fetch_texel_3d_S8_UINT_Z24_UNORM
 186    },
 187    FETCH_FUNCS(Z24_UNORM_S8_UINT),
 188    {
 189       MESA_FORMAT_Z24_UNORM_X8_UINT,
 190       fetch_texel_1d_Z24_UNORM_S8_UINT,
 191       fetch_texel_2d_Z24_UNORM_S8_UINT,
 192       fetch_texel_3d_Z24_UNORM_S8_UINT
 193    },
 194    FETCH_NULL(R3G3B2_UNORM),
 195    FETCH_NULL(A4B4G4R4_UNORM),
 196    FETCH_NULL(R4G4B4A4_UNORM),
 197    FETCH_NULL(R5G5B5A1_UNORM),
 198    FETCH_NULL(A2B10G10R10_UNORM),
 199    FETCH_NULL(A2R10G10B10_UNORM),
 200
 201    FETCH_FUNCS(YCBCR),
 202    FETCH_FUNCS(YCBCR_REV),
 203
 204    /* Array unorm formats */
 205    FETCH_FUNCS(A_UNORM8),
 206    FETCH_FUNCS(A_UNORM16),
 207    FETCH_FUNCS(L_UNORM8),
 208    FETCH_FUNCS(L_UNORM16),
 209    FETCH_FUNCS(I_UNORM8),
 210    FETCH_FUNCS(I_UNORM16),
 211    FETCH_FUNCS(R_UNORM8),
 212    FETCH_FUNCS(R_UNORM16),
 213    FETCH_FUNCS(BGR_UNORM8),
 214    FETCH_FUNCS(RGB_UNORM8),
 215    FETCH_FUNCS(RGBA_UNORM16),
 216    FETCH_FUNCS(RGBX_UNORM16),
 217    FETCH_FUNCS(Z_UNORM16),
 218    FETCH_FUNCS(Z_UNORM32),
 219    FETCH_NULL(S_UINT8),
 220
 221    /* Packed signed/normalized formats */
 222    FETCH_FUNCS(A8B8G8R8_SNORM),
 223    FETCH_FUNCS(X8B8G8R8_SNORM),
 224    FETCH_FUNCS(R8G8B8A8_SNORM),
 225    FETCH_NULL(R8G8B8X8_SNORM),
 226    FETCH_FUNCS(R16G16_SNORM),
 227    FETCH_NULL(G16R16_SNORM),
 228    FETCH_FUNCS(R8G8_SNORM),
 229    FETCH_NULL(G8R8_SNORM),
 230    FETCH_FUNCS(L8A8_SNORM),
 231    FETCH_FUNCS(A8L8_SNORM),
 232
 233    /* Array signed/normalized formats */
 234    FETCH_FUNCS(A_SNORM8),
 235    FETCH_FUNCS(A_SNORM16),
 236    FETCH_FUNCS(L_SNORM8),
 237    FETCH_FUNCS(L_SNORM16),
 238    FETCH_FUNCS(I_SNORM8),
 239    FETCH_FUNCS(I_SNORM16),
 240    FETCH_FUNCS(R_SNORM8),
 241    FETCH_FUNCS(R_SNORM16),
 242    FETCH_FUNCS(LA_SNORM16),
 243    FETCH_FUNCS(RGB_SNORM16),
 244    FETCH_FUNCS(RGBA_SNORM16),
 245    FETCH_NULL(RGBX_SNORM16),
 246
 247    /* Packed sRGB formats */
 248    FETCH_FUNCS(A8B8G8R8_SRGB),
 249    FETCH_FUNCS(B8G8R8A8_SRGB),
 250    FETCH_FUNCS(A8R8G8B8_SRGB),
 251    FETCH_NULL(B8G8R8X8_SRGB),
 252    FETCH_NULL(X8R8G8B8_SRGB),
 253    FETCH_FUNCS(R8G8B8A8_SRGB),
 254    FETCH_FUNCS(R8G8B8X8_SRGB),
 255    FETCH_FUNCS(X8B8G8R8_SRGB),
 256    FETCH_FUNCS(L8A8_SRGB),
 257    FETCH_FUNCS(A8L8_SRGB),
 258
 259    /* Array sRGB formats */
 260    FETCH_FUNCS(R_SRGB8),
 261    FETCH_FUNCS(L_SRGB8),
 262    FETCH_FUNCS(BGR_SRGB8),
 263
 264    /* Packed float formats */
 265    FETCH_FUNCS(R9G9B9E5_FLOAT),
 266    FETCH_FUNCS(R11G11B10_FLOAT),
 267    FETCH_FUNCS(Z32_FLOAT_S8X24_UINT),
 268
 269    /* Array float formats */
 270    FETCH_FUNCS(A_FLOAT16),
 271    FETCH_FUNCS(A_FLOAT32),
 272    FETCH_FUNCS(L_FLOAT16),
 273    FETCH_FUNCS(L_FLOAT32),
 274    FETCH_FUNCS(LA_FLOAT16),
 275    FETCH_FUNCS(LA_FLOAT32),
 276    FETCH_FUNCS(I_FLOAT16),
 277    FETCH_FUNCS(I_FLOAT32),
 278    FETCH_FUNCS(R_FLOAT16),
 279    FETCH_FUNCS(R_FLOAT32),
 280    FETCH_FUNCS(RG_FLOAT16),
 281    FETCH_FUNCS(RG_FLOAT32),
 282    FETCH_FUNCS(RGB_FLOAT16),
 283    FETCH_FUNCS(RGB_FLOAT32),
 284    FETCH_FUNCS(RGBA_FLOAT16),
 285    FETCH_FUNCS(RGBA_FLOAT32),
 286    FETCH_FUNCS(RGBX_FLOAT16),
 287    FETCH_FUNCS(RGBX_FLOAT32),
 288    {
 289       MESA_FORMAT_Z_FLOAT32,
 290       fetch_texel_1d_R_FLOAT32, /* Reuse the R32F functions. */
 291       fetch_texel_2d_R_FLOAT32,
 292       fetch_texel_3d_R_FLOAT32
 293    },
 294
 295    /* Packed signed/unsigned non-normalized integer formats */
 296    FETCH_NULL(A8B8G8R8_UINT),
 297    FETCH_NULL(A8R8G8B8_UINT),
 298    FETCH_NULL(R8G8B8A8_UINT),
 299    FETCH_NULL(B8G8R8A8_UINT),
 300    FETCH_NULL(B10G10R10A2_UINT),
 301    FETCH_NULL(R10G10B10A2_UINT),
 302    FETCH_NULL(A2B10G10R10_UINT),
 303    FETCH_NULL(A2R10G10B10_UINT),
 304    FETCH_NULL(B5G6R5_UINT),
 305    FETCH_NULL(R5G6B5_UINT),
 306    FETCH_NULL(B2G3R3_UINT),
 307    FETCH_NULL(R3G3B2_UINT),
 308    FETCH_NULL(A4B4G4R4_UINT),
 309    FETCH_NULL(R4G4B4A4_UINT),
 310    FETCH_NULL(B4G4R4A4_UINT),
 311    FETCH_NULL(A4R4G4B4_UINT),
 312    FETCH_NULL(A1B5G5R5_UINT),
 313    FETCH_NULL(B5G5R5A1_UINT),
 314    FETCH_NULL(A1R5G5B5_UINT),
 315    FETCH_NULL(R5G5B5A1_UINT),
 316
 317    /* Array signed/unsigned non-normalized integer formats */
 318    FETCH_NULL(A_UINT8),
 319    FETCH_NULL(A_UINT16),
 320    FETCH_NULL(A_UINT32),
 321    FETCH_NULL(A_SINT8),
 322    FETCH_NULL(A_SINT16),
 323    FETCH_NULL(A_SINT32),
 324    FETCH_NULL(I_UINT8),
 325    FETCH_NULL(I_UINT16),
 326    FETCH_NULL(I_UINT32),
 327    FETCH_NULL(I_SINT8),
 328    FETCH_NULL(I_SINT16),
 329    FETCH_NULL(I_SINT32),
 330    FETCH_NULL(L_UINT8),
 331    FETCH_NULL(L_UINT16),
 332    FETCH_NULL(L_UINT32),
 333    FETCH_NULL(L_SINT8),
 334    FETCH_NULL(L_SINT16),
 335    FETCH_NULL(L_SINT32),
 336    FETCH_NULL(LA_UINT8),
 337    FETCH_NULL(LA_UINT16),
 338    FETCH_NULL(LA_UINT32),
 339    FETCH_NULL(LA_SINT8),
 340    FETCH_NULL(LA_SINT16),
 341    FETCH_NULL(LA_SINT32),
 342    FETCH_NULL(R_UINT8),
 343    FETCH_NULL(R_UINT16),
 344    FETCH_NULL(R_UINT32),
 345    FETCH_NULL(R_SINT8),
 346    FETCH_NULL(R_SINT16),
 347    FETCH_NULL(R_SINT32),
 348    FETCH_NULL(RG_UINT8),
 349    FETCH_NULL(RG_UINT16),
 350    FETCH_NULL(RG_UINT32),
 351    FETCH_NULL(RG_SINT8),
 352    FETCH_NULL(RG_SINT16),
 353    FETCH_NULL(RG_SINT32),
 354    FETCH_NULL(RGB_UINT8),
 355    FETCH_NULL(RGB_UINT16),
 356    FETCH_NULL(RGB_UINT32),
 357    FETCH_NULL(RGB_SINT8),
 358    FETCH_NULL(RGB_SINT16),
 359    FETCH_NULL(RGB_SINT32),
 360    FETCH_FUNCS(RGBA_UINT8),
 361    FETCH_FUNCS(RGBA_UINT16),
 362    FETCH_FUNCS(RGBA_UINT32),
 363    FETCH_FUNCS(RGBA_SINT8),
 364    FETCH_FUNCS(RGBA_SINT16),
 365    FETCH_FUNCS(RGBA_SINT32),
 366    FETCH_NULL(RGBX_UINT8),
 367    FETCH_NULL(RGBX_UINT16),
 368    FETCH_NULL(RGBX_UINT32),
 369    FETCH_NULL(RGBX_SINT8),
 370    FETCH_NULL(RGBX_SINT16),
 371    FETCH_NULL(RGBX_SINT32),
 372
 373    /* DXT compressed formats */
 374    FETCH_COMPRESSED(RGB_DXT1),
 375    FETCH_COMPRESSED(RGBA_DXT1),
 376    FETCH_COMPRESSED(RGBA_DXT3),
 377    FETCH_COMPRESSED(RGBA_DXT5),
 378
 379    /* DXT sRGB compressed formats */
 380    FETCH_COMPRESSED(SRGB_DXT1),
 381    FETCH_COMPRESSED(SRGBA_DXT1),
 382    FETCH_COMPRESSED(SRGBA_DXT3),
 383    FETCH_COMPRESSED(SRGBA_DXT5),
 384
 385    /* FXT1 compressed formats */
 386    FETCH_COMPRESSED(RGB_FXT1),
 387    FETCH_COMPRESSED(RGBA_FXT1),
 388
 389    /* RGTC compressed formats */
 390    FETCH_COMPRESSED(R_RGTC1_UNORM),
 391    FETCH_COMPRESSED(R_RGTC1_SNORM),
 392    FETCH_COMPRESSED(RG_RGTC2_UNORM),
 393    FETCH_COMPRESSED(RG_RGTC2_SNORM),
 394
 395    /* LATC1/2 compressed formats */
 396    FETCH_COMPRESSED(L_LATC1_UNORM),
 397    FETCH_COMPRESSED(L_LATC1_SNORM),
 398    FETCH_COMPRESSED(LA_LATC2_UNORM),
 399    FETCH_COMPRESSED(LA_LATC2_SNORM),
 400
 401    /* ETC1/2 compressed formats */
 402    FETCH_COMPRESSED(ETC1_RGB8),
 403    FETCH_COMPRESSED(ETC2_RGB8),
 404    FETCH_COMPRESSED(ETC2_SRGB8),
 405    FETCH_COMPRESSED(ETC2_RGBA8_EAC),
 406    FETCH_COMPRESSED(ETC2_SRGB8_ALPHA8_EAC),
 407    FETCH_COMPRESSED(ETC2_R11_EAC),
 408    FETCH_COMPRESSED(ETC2_RG11_EAC),
 409    FETCH_COMPRESSED(ETC2_SIGNED_R11_EAC),
 410    FETCH_COMPRESSED(ETC2_SIGNED_RG11_EAC),
 411    FETCH_COMPRESSED(ETC2_RGB8_PUNCHTHROUGH_ALPHA1),
 412    FETCH_COMPRESSED(ETC2_SRGB8_PUNCHTHROUGH_ALPHA1),
 413    FETCH_COMPRESSED(BPTC_RGBA_UNORM),
 414    FETCH_COMPRESSED(BPTC_SRGB_ALPHA_UNORM),
 415    FETCH_COMPRESSED(BPTC_RGB_SIGNED_FLOAT),
 416    FETCH_COMPRESSED(BPTC_RGB_UNSIGNED_FLOAT),
 417
 418    /* ASTC compressed formats */
 419    FETCH_NULL(RGBA_ASTC_4x4),
 420    FETCH_NULL(RGBA_ASTC_5x4),
 421    FETCH_NULL(RGBA_ASTC_5x5),
 422    FETCH_NULL(RGBA_ASTC_6x5),
 423    FETCH_NULL(RGBA_ASTC_6x6),
 424    FETCH_NULL(RGBA_ASTC_8x5),
 425    FETCH_NULL(RGBA_ASTC_8x6),
 426    FETCH_NULL(RGBA_ASTC_8x8),
 427    FETCH_NULL(RGBA_ASTC_10x5),
 428    FETCH_NULL(RGBA_ASTC_10x6),
 429    FETCH_NULL(RGBA_ASTC_10x8),
 430    FETCH_NULL(RGBA_ASTC_10x10),
 431    FETCH_NULL(RGBA_ASTC_12x10),
 432    FETCH_NULL(RGBA_ASTC_12x12),
 433    FETCH_NULL(SRGB8_ALPHA8_ASTC_4x4),
 434    FETCH_NULL(SRGB8_ALPHA8_ASTC_5x4),
 435    FETCH_NULL(SRGB8_ALPHA8_ASTC_5x5),
 436    FETCH_NULL(SRGB8_ALPHA8_ASTC_6x5),
 437    FETCH_NULL(SRGB8_ALPHA8_ASTC_6x6),
 438    FETCH_NULL(SRGB8_ALPHA8_ASTC_8x5),
 439    FETCH_NULL(SRGB8_ALPHA8_ASTC_8x6),
 440    FETCH_NULL(SRGB8_ALPHA8_ASTC_8x8),
 441    FETCH_NULL(SRGB8_ALPHA8_ASTC_10x5),
 442    FETCH_NULL(SRGB8_ALPHA8_ASTC_10x6),
 443    FETCH_NULL(SRGB8_ALPHA8_ASTC_10x8),
 444    FETCH_NULL(SRGB8_ALPHA8_ASTC_10x10),
 445    FETCH_NULL(SRGB8_ALPHA8_ASTC_12x10),
 446    FETCH_NULL(SRGB8_ALPHA8_ASTC_12x12),
 447
 448    FETCH_NULL(RGBA_ASTC_3x3x3),
 449    FETCH_NULL(RGBA_ASTC_4x3x3),
 450    FETCH_NULL(RGBA_ASTC_4x4x3),
 451    FETCH_NULL(RGBA_ASTC_4x4x4),
 452    FETCH_NULL(RGBA_ASTC_5x4x4),
 453    FETCH_NULL(RGBA_ASTC_5x5x4),
 454    FETCH_NULL(RGBA_ASTC_5x5x5),
 455    FETCH_NULL(RGBA_ASTC_6x5x5),
 456    FETCH_NULL(RGBA_ASTC_6x6x5),
 457    FETCH_NULL(RGBA_ASTC_6x6x6),
 458    FETCH_NULL(SRGB8_ALPHA8_ASTC_3x3x3),
 459    FETCH_NULL(SRGB8_ALPHA8_ASTC_4x3x3),
 460    FETCH_NULL(SRGB8_ALPHA8_ASTC_4x4x3),
 461    FETCH_NULL(SRGB8_ALPHA8_ASTC_4x4x4),
 462    FETCH_NULL(SRGB8_ALPHA8_ASTC_5x4x4),
 463    FETCH_NULL(SRGB8_ALPHA8_ASTC_5x5x4),
 464    FETCH_NULL(SRGB8_ALPHA8_ASTC_5x5x5),
 465    FETCH_NULL(SRGB8_ALPHA8_ASTC_6x5x5),
 466    FETCH_NULL(SRGB8_ALPHA8_ASTC_6x6x5),
 467    FETCH_NULL(SRGB8_ALPHA8_ASTC_6x6x6),
 468
 469    FETCH_NULL(ATC_RGB),
 470    FETCH_NULL(ATC_RGBA_EXPLICIT),
 471    FETCH_NULL(ATC_RGBA_INTERPOLATED)
 472 };
 473
 474
 475 /**
 476  * Initialize the texture image's FetchTexel methods.
 477  */
 478 static void
 479 set_fetch_functions(const struct gl_sampler_object *samp,
 480                     struct swrast_texture_image *texImage, GLuint dims)
 481 {
 482    mesa_format format = texImage->Base.TexFormat;
 483
 484 #ifdef DEBUG
 485    /* check that the table entries are sorted by format name */
 486    mesa_format fmt;
 487    for (fmt = 0; fmt < MESA_FORMAT_COUNT; fmt++) {
 488       assert(texfetch_funcs[fmt].Name == fmt);
 489    }
 490 #endif
 491
 492    STATIC_ASSERT(ARRAY_SIZE(texfetch_funcs) == MESA_FORMAT_COUNT);
 493
 494    if (samp->sRGBDecode == GL_SKIP_DECODE_EXT &&
 495        _mesa_get_format_color_encoding(format) == GL_SRGB) {
 496       format = _mesa_get_srgb_format_linear(format);
 497    }
 498
 499    assert(format < MESA_FORMAT_COUNT);
 500
 501    switch (dims) {
 502    case 1:
 503       texImage->FetchTexel = texfetch_funcs[format].Fetch1D;
 504       break;
 505    case 2:
 506       texImage->FetchTexel = texfetch_funcs[format].Fetch2D;
 507       break;
 508    case 3:
 509       texImage->FetchTexel = texfetch_funcs[format].Fetch3D;
 510       break;
 511    default:
 512       assert(!"Bad dims in set_fetch_functions()");
 513    }
 514
 515    texImage->FetchCompressedTexel = _mesa_get_compressed_fetch_func(format);
 516
 517    assert(texImage->FetchTexel);
 518 }
 519
 520 void
 521 _mesa_update_fetch_functions(struct gl_context *ctx, GLuint unit)
 522 {
 523    struct gl_texture_object *texObj = ctx->Texture.Unit[unit]._Current;
 524    struct gl_sampler_object *samp;
 525    GLuint face, i;
 526    GLuint dims;
 527
 528    if (!texObj)
 529       return;
 530
 531    samp = _mesa_get_samplerobj(ctx, unit);
 532
 533    dims = _mesa_get_texture_dimensions(texObj->Target);
 534
 535    for (face = 0; face < 6; face++) {
 536       for (i = 0; i < MAX_TEXTURE_LEVELS; i++) {
 537          if (texObj->Image[face][i]) {
 538             set_fetch_functions(samp,
 539                                 swrast_texture_image(texObj->Image[face][i]),
 540                                 dims);
 541          }
 542       }
 543    }
 544 }