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/macros.h"
  37 #include "main/texcompress.h"
  38 #include "main/texcompress_fxt1.h"
  39 #include "main/texcompress_s3tc.h"
  40 #include "main/texcompress_rgtc.h"
  41 #include "main/texcompress_etc.h"
  42 #include "main/teximage.h"
  43 #include "main/samplerobj.h"
  44 #include "s_context.h"
  45 #include "s_texfetch.h"
  46 #include "../../gallium/auxiliary/util/u_format_rgb9e5.h"
  47 #include "../../gallium/auxiliary/util/u_format_r11g11b10f.h"
  48 #include "util/format_srgb.h"
  49
  50
  51 /* Texel fetch routines for all supported formats
  52  */
  53 #define DIM 1
  54 #include "s_texfetch_tmp.h"
  55
  56 #define DIM 2
  57 #include "s_texfetch_tmp.h"
  58
  59 #define DIM 3
  60 #include "s_texfetch_tmp.h"
  61
  62
  63 /**
  64  * All compressed texture texel fetching is done though this function.
  65  * Basically just call a core-Mesa texel fetch function.
  66  */
  67 static void
  68 fetch_compressed(const struct swrast_texture_image *swImage,
  69                  GLint i, GLint j, GLint k, GLfloat *texel)
  70 {
  71    /* The FetchCompressedTexel function takes an integer pixel rowstride,
  72     * while the image's rowstride is bytes per row of blocks.
  73     */
  74    GLuint bw, bh;
  75    GLuint texelBytes = _mesa_get_format_bytes(swImage->Base.TexFormat);
  76    _mesa_get_format_block_size(swImage->Base.TexFormat, &bw, &bh);
  77    assert(swImage->RowStride * bw % texelBytes == 0);
  78
  79    swImage->FetchCompressedTexel(swImage->ImageSlices[k],
  80                                  swImage->RowStride * bw / texelBytes,
  81                                  i, j, texel);
  82 }
  83
  84
  85
  86 /**
  87  * Null texel fetch function.
  88  *
  89  * Have to have this so the FetchTexel function pointer is never NULL.
  90  */
  91 static void fetch_null_texelf( const struct swrast_texture_image *texImage,
  92                                GLint i, GLint j, GLint k, GLfloat *texel )
  93 {
  94    (void) texImage; (void) i; (void) j; (void) k;
  95    texel[RCOMP] = 0.0;
  96    texel[GCOMP] = 0.0;
  97    texel[BCOMP] = 0.0;
  98    texel[ACOMP] = 0.0;
  99    _mesa_warning(NULL, "fetch_null_texelf() called!");
 100 }
 101
 102
 103 #define FETCH_FUNCS(NAME)       \
 104    {                            \
 105       MESA_FORMAT_ ## NAME,     \
 106       fetch_texel_1d_ ## NAME,  \
 107       fetch_texel_2d_ ## NAME,  \
 108       fetch_texel_3d_ ## NAME,  \
 109    }
 110
 111 #define FETCH_NULL(NAME)        \
 112    {                            \
 113       MESA_FORMAT_ ## NAME,     \
 114       NULL,                     \
 115       NULL,                     \
 116       NULL                      \
 117    }
 118
 119 /**
 120  * Table to map MESA_FORMAT_ to texel fetch/store funcs.
 121  */
 122 static struct {
 123    mesa_format Name;
 124    FetchTexelFunc Fetch1D;
 125    FetchTexelFunc Fetch2D;
 126    FetchTexelFunc Fetch3D;
 127 }
 128 texfetch_funcs[] =
 129 {
 130    {
 131       MESA_FORMAT_NONE,
 132       fetch_null_texelf,
 133       fetch_null_texelf,
 134       fetch_null_texelf
 135    },
 136
 137    /* Packed unorm formats */
 138    FETCH_FUNCS(A8B8G8R8_UNORM),
 139    FETCH_FUNCS(X8B8G8R8_UNORM),
 140    FETCH_FUNCS(R8G8B8A8_UNORM),
 141    FETCH_FUNCS(R8G8B8X8_UNORM),
 142    FETCH_FUNCS(B8G8R8A8_UNORM),
 143    FETCH_FUNCS(B8G8R8X8_UNORM),
 144    FETCH_FUNCS(A8R8G8B8_UNORM),
 145    FETCH_FUNCS(X8R8G8B8_UNORM),
 146    FETCH_FUNCS(L16A16_UNORM),
 147    FETCH_FUNCS(A16L16_UNORM),
 148    FETCH_FUNCS(B5G6R5_UNORM),
 149    FETCH_FUNCS(R5G6B5_UNORM),
 150    FETCH_FUNCS(B4G4R4A4_UNORM),
 151    FETCH_NULL(B4G4R4X4_UNORM),
 152    FETCH_FUNCS(A4R4G4B4_UNORM),
 153    FETCH_FUNCS(A1B5G5R5_UNORM),
 154    FETCH_FUNCS(B5G5R5A1_UNORM),
 155    FETCH_NULL(B5G5R5X1_UNORM),
 156    FETCH_FUNCS(A1R5G5B5_UNORM),
 157    FETCH_FUNCS(L8A8_UNORM),
 158    FETCH_FUNCS(A8L8_UNORM),
 159    FETCH_FUNCS(R8G8_UNORM),
 160    FETCH_FUNCS(G8R8_UNORM),
 161    FETCH_FUNCS(L4A4_UNORM),
 162    FETCH_FUNCS(B2G3R3_UNORM),
 163    FETCH_FUNCS(R16G16_UNORM),
 164    FETCH_FUNCS(G16R16_UNORM),
 165    FETCH_FUNCS(B10G10R10A2_UNORM),
 166    FETCH_NULL(B10G10R10X2_UNORM),
 167    FETCH_FUNCS(R10G10B10A2_UNORM),
 168    FETCH_NULL(R10G10B10X2_UNORM),
 169
 170    FETCH_FUNCS(S8_UINT_Z24_UNORM),
 171    {
 172       MESA_FORMAT_X8_UINT_Z24_UNORM,
 173       fetch_texel_1d_S8_UINT_Z24_UNORM,
 174       fetch_texel_2d_S8_UINT_Z24_UNORM,
 175       fetch_texel_3d_S8_UINT_Z24_UNORM
 176    },
 177    FETCH_FUNCS(Z24_UNORM_S8_UINT),
 178    {
 179       MESA_FORMAT_Z24_UNORM_X8_UINT,
 180       fetch_texel_1d_Z24_UNORM_S8_UINT,
 181       fetch_texel_2d_Z24_UNORM_S8_UINT,
 182       fetch_texel_3d_Z24_UNORM_S8_UINT
 183    },
 184    FETCH_NULL(R3G3B2_UNORM),
 185    FETCH_NULL(A4B4G4R4_UNORM),
 186    FETCH_NULL(R4G4B4A4_UNORM),
 187    FETCH_NULL(R5G5B5A1_UNORM),
 188    FETCH_NULL(A2B10G10R10_UNORM),
 189    FETCH_NULL(A2R10G10B10_UNORM),
 190
 191    FETCH_FUNCS(YCBCR),
 192    FETCH_FUNCS(YCBCR_REV),
 193
 194    /* Array unorm formats */
 195    FETCH_FUNCS(A_UNORM8),
 196    FETCH_FUNCS(A_UNORM16),
 197    FETCH_FUNCS(L_UNORM8),
 198    FETCH_FUNCS(L_UNORM16),
 199    FETCH_FUNCS(I_UNORM8),
 200    FETCH_FUNCS(I_UNORM16),
 201    FETCH_FUNCS(R_UNORM8),
 202    FETCH_FUNCS(R_UNORM16),
 203    FETCH_FUNCS(BGR_UNORM8),
 204    FETCH_FUNCS(RGB_UNORM8),
 205    FETCH_FUNCS(RGBA_UNORM16),
 206    FETCH_FUNCS(RGBX_UNORM16),
 207    FETCH_FUNCS(Z_UNORM16),
 208    FETCH_FUNCS(Z_UNORM32),
 209    FETCH_NULL(S_UINT8),
 210
 211    /* Packed signed/normalized formats */
 212    FETCH_FUNCS(A8B8G8R8_SNORM),
 213    FETCH_FUNCS(X8B8G8R8_SNORM),
 214    FETCH_FUNCS(R8G8B8A8_SNORM),
 215    FETCH_NULL(R8G8B8X8_SNORM),
 216    FETCH_FUNCS(R16G16_SNORM),
 217    FETCH_NULL(G16R16_SNORM),
 218    FETCH_FUNCS(R8G8_SNORM),
 219    FETCH_NULL(G8R8_SNORM),
 220    FETCH_FUNCS(L8A8_SNORM),
 221    FETCH_FUNCS(A8L8_SNORM),
 222
 223    /* Array signed/normalized formats */
 224    FETCH_FUNCS(A_SNORM8),
 225    FETCH_FUNCS(A_SNORM16),
 226    FETCH_FUNCS(L_SNORM8),
 227    FETCH_FUNCS(L_SNORM16),
 228    FETCH_FUNCS(I_SNORM8),
 229    FETCH_FUNCS(I_SNORM16),
 230    FETCH_FUNCS(R_SNORM8),
 231    FETCH_FUNCS(R_SNORM16),
 232    FETCH_FUNCS(LA_SNORM16),
 233    FETCH_FUNCS(RGB_SNORM16),
 234    FETCH_FUNCS(RGBA_SNORM16),
 235    FETCH_NULL(RGBX_SNORM16),
 236
 237    /* Packed sRGB formats */
 238    FETCH_FUNCS(A8B8G8R8_SRGB),
 239    FETCH_FUNCS(B8G8R8A8_SRGB),
 240    FETCH_FUNCS(A8R8G8B8_SRGB),
 241    FETCH_NULL(B8G8R8X8_SRGB),
 242    FETCH_NULL(X8R8G8B8_SRGB),
 243    FETCH_FUNCS(R8G8B8A8_SRGB),
 244    FETCH_FUNCS(R8G8B8X8_SRGB),
 245    FETCH_FUNCS(X8B8G8R8_SRGB),
 246    FETCH_FUNCS(L8A8_SRGB),
 247    FETCH_FUNCS(A8L8_SRGB),
 248
 249    /* Array sRGB formats */
 250    FETCH_FUNCS(L_SRGB8),
 251    FETCH_FUNCS(BGR_SRGB8),
 252
 253    /* Packed float formats */
 254    FETCH_FUNCS(R9G9B9E5_FLOAT),
 255    FETCH_FUNCS(R11G11B10_FLOAT),
 256    FETCH_FUNCS(Z32_FLOAT_S8X24_UINT),
 257
 258    /* Array float formats */
 259    FETCH_FUNCS(A_FLOAT16),
 260    FETCH_FUNCS(A_FLOAT32),
 261    FETCH_FUNCS(L_FLOAT16),
 262    FETCH_FUNCS(L_FLOAT32),
 263    FETCH_FUNCS(LA_FLOAT16),
 264    FETCH_FUNCS(LA_FLOAT32),
 265    FETCH_FUNCS(I_FLOAT16),
 266    FETCH_FUNCS(I_FLOAT32),
 267    FETCH_FUNCS(R_FLOAT16),
 268    FETCH_FUNCS(R_FLOAT32),
 269    FETCH_FUNCS(RG_FLOAT16),
 270    FETCH_FUNCS(RG_FLOAT32),
 271    FETCH_FUNCS(RGB_FLOAT16),
 272    FETCH_FUNCS(RGB_FLOAT32),
 273    FETCH_FUNCS(RGBA_FLOAT16),
 274    FETCH_FUNCS(RGBA_FLOAT32),
 275    FETCH_FUNCS(RGBX_FLOAT16),
 276    FETCH_FUNCS(RGBX_FLOAT32),
 277    {
 278       MESA_FORMAT_Z_FLOAT32,
 279       fetch_texel_1d_R_FLOAT32, /* Reuse the R32F functions. */
 280       fetch_texel_2d_R_FLOAT32,
 281       fetch_texel_3d_R_FLOAT32
 282    },
 283
 284    /* Packed signed/unsigned non-normalized integer formats */
 285    FETCH_NULL(B10G10R10A2_UINT),
 286    FETCH_NULL(R10G10B10A2_UINT),
 287    FETCH_NULL(A2B10G10R10_UINT),
 288    FETCH_NULL(A2R10G10B10_UINT),
 289
 290    /* Array signed/unsigned non-normalized integer formats */
 291    FETCH_NULL(A_UINT8),
 292    FETCH_NULL(A_UINT16),
 293    FETCH_NULL(A_UINT32),
 294    FETCH_NULL(A_SINT8),
 295    FETCH_NULL(A_SINT16),
 296    FETCH_NULL(A_SINT32),
 297    FETCH_NULL(I_UINT8),
 298    FETCH_NULL(I_UINT16),
 299    FETCH_NULL(I_UINT32),
 300    FETCH_NULL(I_SINT8),
 301    FETCH_NULL(I_SINT16),
 302    FETCH_NULL(I_SINT32),
 303    FETCH_NULL(L_UINT8),
 304    FETCH_NULL(L_UINT16),
 305    FETCH_NULL(L_UINT32),
 306    FETCH_NULL(L_SINT8),
 307    FETCH_NULL(L_SINT16),
 308    FETCH_NULL(L_SINT32),
 309    FETCH_NULL(LA_UINT8),
 310    FETCH_NULL(LA_UINT16),
 311    FETCH_NULL(LA_UINT32),
 312    FETCH_NULL(LA_SINT8),
 313    FETCH_NULL(LA_SINT16),
 314    FETCH_NULL(LA_SINT32),
 315    FETCH_NULL(R_UINT8),
 316    FETCH_NULL(R_UINT16),
 317    FETCH_NULL(R_UINT32),
 318    FETCH_NULL(R_SINT8),
 319    FETCH_NULL(R_SINT16),
 320    FETCH_NULL(R_SINT32),
 321    FETCH_NULL(RG_UINT8),
 322    FETCH_NULL(RG_UINT16),
 323    FETCH_NULL(RG_UINT32),
 324    FETCH_NULL(RG_SINT8),
 325    FETCH_NULL(RG_SINT16),
 326    FETCH_NULL(RG_SINT32),
 327    FETCH_NULL(RGB_UINT8),
 328    FETCH_NULL(RGB_UINT16),
 329    FETCH_NULL(RGB_UINT32),
 330    FETCH_NULL(RGB_SINT8),
 331    FETCH_NULL(RGB_SINT16),
 332    FETCH_NULL(RGB_SINT32),
 333    FETCH_FUNCS(RGBA_UINT8),
 334    FETCH_FUNCS(RGBA_UINT16),
 335    FETCH_FUNCS(RGBA_UINT32),
 336    FETCH_FUNCS(RGBA_SINT8),
 337    FETCH_FUNCS(RGBA_SINT16),
 338    FETCH_FUNCS(RGBA_SINT32),
 339    FETCH_NULL(RGBX_UINT8),
 340    FETCH_NULL(RGBX_UINT16),
 341    FETCH_NULL(RGBX_UINT32),
 342    FETCH_NULL(RGBX_SINT8),
 343    FETCH_NULL(RGBX_SINT16),
 344    FETCH_NULL(RGBX_SINT32),
 345
 346    /* DXT compressed formats */
 347    {
 348       MESA_FORMAT_RGB_DXT1,
 349       fetch_compressed,
 350       fetch_compressed,
 351       fetch_compressed
 352    },
 353    {
 354       MESA_FORMAT_RGBA_DXT1,
 355       fetch_compressed,
 356       fetch_compressed,
 357       fetch_compressed
 358    },
 359    {
 360       MESA_FORMAT_RGBA_DXT3,
 361       fetch_compressed,
 362       fetch_compressed,
 363       fetch_compressed
 364    },
 365    {
 366       MESA_FORMAT_RGBA_DXT5,
 367       fetch_compressed,
 368       fetch_compressed,
 369       fetch_compressed
 370    },
 371
 372    /* DXT sRGB compressed formats */
 373    {
 374       MESA_FORMAT_SRGB_DXT1,
 375       fetch_compressed,
 376       fetch_compressed,
 377       fetch_compressed
 378    },
 379    {
 380       MESA_FORMAT_SRGBA_DXT1,
 381       fetch_compressed,
 382       fetch_compressed,
 383       fetch_compressed
 384    },
 385    {
 386       MESA_FORMAT_SRGBA_DXT3,
 387       fetch_compressed,
 388       fetch_compressed,
 389       fetch_compressed
 390    },
 391    {
 392       MESA_FORMAT_SRGBA_DXT5,
 393       fetch_compressed,
 394       fetch_compressed,
 395       fetch_compressed
 396    },
 397
 398    /* FXT1 compressed formats */
 399    {
 400       MESA_FORMAT_RGB_FXT1,
 401       fetch_compressed,
 402       fetch_compressed,
 403       fetch_compressed
 404    },
 405    {
 406       MESA_FORMAT_RGBA_FXT1,
 407       fetch_compressed,
 408       fetch_compressed,
 409       fetch_compressed
 410    },
 411
 412    /* RGTC compressed formats */
 413    {
 414       MESA_FORMAT_R_RGTC1_UNORM,
 415       fetch_compressed,
 416       fetch_compressed,
 417       fetch_compressed
 418    },
 419    {
 420       MESA_FORMAT_R_RGTC1_SNORM,
 421       fetch_compressed,
 422       fetch_compressed,
 423       fetch_compressed
 424    },
 425    {
 426       MESA_FORMAT_RG_RGTC2_UNORM,
 427       fetch_compressed,
 428       fetch_compressed,
 429       fetch_compressed
 430    },
 431    {
 432       MESA_FORMAT_RG_RGTC2_SNORM,
 433       fetch_compressed,
 434       fetch_compressed,
 435       fetch_compressed
 436    },
 437
 438    /* LATC1/2 compressed formats */
 439    {
 440       MESA_FORMAT_L_LATC1_UNORM,
 441       fetch_compressed,
 442       fetch_compressed,
 443       fetch_compressed
 444    },
 445    {
 446       MESA_FORMAT_L_LATC1_SNORM,
 447       fetch_compressed,
 448       fetch_compressed,
 449       fetch_compressed
 450    },
 451    {
 452       MESA_FORMAT_LA_LATC2_UNORM,
 453       fetch_compressed,
 454       fetch_compressed,
 455       fetch_compressed
 456    },
 457    {
 458       MESA_FORMAT_LA_LATC2_SNORM,
 459       fetch_compressed,
 460       fetch_compressed,
 461       fetch_compressed
 462    },
 463
 464    /* ETC1/2 compressed formats */
 465    {
 466       MESA_FORMAT_ETC1_RGB8,
 467       fetch_compressed,
 468       fetch_compressed,
 469       fetch_compressed
 470    },
 471    {
 472       MESA_FORMAT_ETC2_RGB8,
 473       fetch_compressed,
 474       fetch_compressed,
 475       fetch_compressed
 476    },
 477    {
 478       MESA_FORMAT_ETC2_SRGB8,
 479       fetch_compressed,
 480       fetch_compressed,
 481       fetch_compressed
 482    },
 483    {
 484       MESA_FORMAT_ETC2_RGBA8_EAC,
 485       fetch_compressed,
 486       fetch_compressed,
 487       fetch_compressed
 488    },
 489    {
 490       MESA_FORMAT_ETC2_SRGB8_ALPHA8_EAC,
 491       fetch_compressed,
 492       fetch_compressed,
 493       fetch_compressed
 494    },
 495    {
 496       MESA_FORMAT_ETC2_R11_EAC,
 497       fetch_compressed,
 498       fetch_compressed,
 499       fetch_compressed
 500    },
 501    {
 502       MESA_FORMAT_ETC2_RG11_EAC,
 503       fetch_compressed,
 504       fetch_compressed,
 505       fetch_compressed
 506    },
 507    {
 508       MESA_FORMAT_ETC2_SIGNED_R11_EAC,
 509       fetch_compressed,
 510       fetch_compressed,
 511       fetch_compressed
 512    },
 513    {
 514       MESA_FORMAT_ETC2_SIGNED_RG11_EAC,
 515       fetch_compressed,
 516       fetch_compressed,
 517       fetch_compressed
 518    },
 519    {
 520       MESA_FORMAT_ETC2_RGB8_PUNCHTHROUGH_ALPHA1,
 521       fetch_compressed,
 522       fetch_compressed,
 523       fetch_compressed
 524    },
 525    {
 526       MESA_FORMAT_ETC2_SRGB8_PUNCHTHROUGH_ALPHA1,
 527       fetch_compressed,
 528       fetch_compressed,
 529       fetch_compressed
 530    },
 531    {
 532       MESA_FORMAT_BPTC_RGBA_UNORM,
 533       fetch_compressed,
 534       fetch_compressed,
 535       fetch_compressed
 536    },
 537    {
 538       MESA_FORMAT_BPTC_SRGB_ALPHA_UNORM,
 539       fetch_compressed,
 540       fetch_compressed,
 541       fetch_compressed
 542    },
 543    {
 544       MESA_FORMAT_BPTC_RGB_SIGNED_FLOAT,
 545       fetch_compressed,
 546       fetch_compressed,
 547       fetch_compressed
 548    },
 549    {
 550       MESA_FORMAT_BPTC_RGB_UNSIGNED_FLOAT,
 551       fetch_compressed,
 552       fetch_compressed,
 553       fetch_compressed
 554    }
 555 };
 556
 557
 558 /**
 559  * Initialize the texture image's FetchTexel methods.
 560  */
 561 static void
 562 set_fetch_functions(const struct gl_sampler_object *samp,
 563                     struct swrast_texture_image *texImage, GLuint dims)
 564 {
 565    mesa_format format = texImage->Base.TexFormat;
 566
 567 #ifdef DEBUG
 568    /* check that the table entries are sorted by format name */
 569    mesa_format fmt;
 570    for (fmt = 0; fmt < MESA_FORMAT_COUNT; fmt++) {
 571       assert(texfetch_funcs[fmt].Name == fmt);
 572    }
 573 #endif
 574
 575    STATIC_ASSERT(ARRAY_SIZE(texfetch_funcs) == MESA_FORMAT_COUNT);
 576
 577    if (samp->sRGBDecode == GL_SKIP_DECODE_EXT &&
 578        _mesa_get_format_color_encoding(format) == GL_SRGB) {
 579       format = _mesa_get_srgb_format_linear(format);
 580    }
 581
 582    assert(format < MESA_FORMAT_COUNT);
 583
 584    switch (dims) {
 585    case 1:
 586       texImage->FetchTexel = texfetch_funcs[format].Fetch1D;
 587       break;
 588    case 2:
 589       texImage->FetchTexel = texfetch_funcs[format].Fetch2D;
 590       break;
 591    case 3:
 592       texImage->FetchTexel = texfetch_funcs[format].Fetch3D;
 593       break;
 594    default:
 595       assert(!"Bad dims in set_fetch_functions()");
 596    }
 597
 598    texImage->FetchCompressedTexel = _mesa_get_compressed_fetch_func(format);
 599
 600    assert(texImage->FetchTexel);
 601 }
 602
 603 void
 604 _mesa_update_fetch_functions(struct gl_context *ctx, GLuint unit)
 605 {
 606    struct gl_texture_object *texObj = ctx->Texture.Unit[unit]._Current;
 607    struct gl_sampler_object *samp;
 608    GLuint face, i;
 609    GLuint dims;
 610
 611    if (!texObj)
 612       return;
 613
 614    samp = _mesa_get_samplerobj(ctx, unit);
 615
 616    dims = _mesa_get_texture_dimensions(texObj->Target);
 617
 618    for (face = 0; face < 6; face++) {
 619       for (i = 0; i < MAX_TEXTURE_LEVELS; i++) {
 620          if (texObj->Image[face][i]) {
 621             set_fetch_functions(samp,
 622                                 swrast_texture_image(texObj->Image[face][i]),
 623                                 dims);
 624          }
 625       }
 626    }
 627 }