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_NULL(R10G10B10X2_UNORM),
 170
 171    FETCH_FUNCS(S8_UINT_Z24_UNORM),
 172    {
 173       MESA_FORMAT_X8_UINT_Z24_UNORM,
 174       fetch_texel_1d_S8_UINT_Z24_UNORM,
 175       fetch_texel_2d_S8_UINT_Z24_UNORM,
 176       fetch_texel_3d_S8_UINT_Z24_UNORM
 177    },
 178    FETCH_FUNCS(Z24_UNORM_S8_UINT),
 179    {
 180       MESA_FORMAT_Z24_UNORM_X8_UINT,
 181       fetch_texel_1d_Z24_UNORM_S8_UINT,
 182       fetch_texel_2d_Z24_UNORM_S8_UINT,
 183       fetch_texel_3d_Z24_UNORM_S8_UINT
 184    },
 185    FETCH_NULL(R3G3B2_UNORM),
 186    FETCH_NULL(A4B4G4R4_UNORM),
 187    FETCH_NULL(R4G4B4A4_UNORM),
 188    FETCH_NULL(R5G5B5A1_UNORM),
 189    FETCH_NULL(A2B10G10R10_UNORM),
 190    FETCH_NULL(A2R10G10B10_UNORM),
 191
 192    FETCH_FUNCS(YCBCR),
 193    FETCH_FUNCS(YCBCR_REV),
 194
 195    /* Array unorm formats */
 196    FETCH_FUNCS(A_UNORM8),
 197    FETCH_FUNCS(A_UNORM16),
 198    FETCH_FUNCS(L_UNORM8),
 199    FETCH_FUNCS(L_UNORM16),
 200    FETCH_FUNCS(I_UNORM8),
 201    FETCH_FUNCS(I_UNORM16),
 202    FETCH_FUNCS(R_UNORM8),
 203    FETCH_FUNCS(R_UNORM16),
 204    FETCH_FUNCS(BGR_UNORM8),
 205    FETCH_FUNCS(RGB_UNORM8),
 206    FETCH_FUNCS(RGBA_UNORM16),
 207    FETCH_FUNCS(RGBX_UNORM16),
 208    FETCH_FUNCS(Z_UNORM16),
 209    FETCH_FUNCS(Z_UNORM32),
 210    FETCH_NULL(S_UINT8),
 211
 212    /* Packed signed/normalized formats */
 213    FETCH_FUNCS(A8B8G8R8_SNORM),
 214    FETCH_FUNCS(X8B8G8R8_SNORM),
 215    FETCH_FUNCS(R8G8B8A8_SNORM),
 216    FETCH_NULL(R8G8B8X8_SNORM),
 217    FETCH_FUNCS(R16G16_SNORM),
 218    FETCH_NULL(G16R16_SNORM),
 219    FETCH_FUNCS(R8G8_SNORM),
 220    FETCH_NULL(G8R8_SNORM),
 221    FETCH_FUNCS(L8A8_SNORM),
 222    FETCH_FUNCS(A8L8_SNORM),
 223
 224    /* Array signed/normalized formats */
 225    FETCH_FUNCS(A_SNORM8),
 226    FETCH_FUNCS(A_SNORM16),
 227    FETCH_FUNCS(L_SNORM8),
 228    FETCH_FUNCS(L_SNORM16),
 229    FETCH_FUNCS(I_SNORM8),
 230    FETCH_FUNCS(I_SNORM16),
 231    FETCH_FUNCS(R_SNORM8),
 232    FETCH_FUNCS(R_SNORM16),
 233    FETCH_FUNCS(LA_SNORM16),
 234    FETCH_FUNCS(RGB_SNORM16),
 235    FETCH_FUNCS(RGBA_SNORM16),
 236    FETCH_NULL(RGBX_SNORM16),
 237
 238    /* Packed sRGB formats */
 239    FETCH_FUNCS(A8B8G8R8_SRGB),
 240    FETCH_FUNCS(B8G8R8A8_SRGB),
 241    FETCH_FUNCS(A8R8G8B8_SRGB),
 242    FETCH_NULL(B8G8R8X8_SRGB),
 243    FETCH_NULL(X8R8G8B8_SRGB),
 244    FETCH_FUNCS(R8G8B8A8_SRGB),
 245    FETCH_FUNCS(R8G8B8X8_SRGB),
 246    FETCH_FUNCS(X8B8G8R8_SRGB),
 247    FETCH_FUNCS(L8A8_SRGB),
 248    FETCH_FUNCS(A8L8_SRGB),
 249
 250    /* Array sRGB formats */
 251    FETCH_FUNCS(L_SRGB8),
 252    FETCH_FUNCS(BGR_SRGB8),
 253
 254    /* Packed float formats */
 255    FETCH_FUNCS(R9G9B9E5_FLOAT),
 256    FETCH_FUNCS(R11G11B10_FLOAT),
 257    FETCH_FUNCS(Z32_FLOAT_S8X24_UINT),
 258
 259    /* Array float formats */
 260    FETCH_FUNCS(A_FLOAT16),
 261    FETCH_FUNCS(A_FLOAT32),
 262    FETCH_FUNCS(L_FLOAT16),
 263    FETCH_FUNCS(L_FLOAT32),
 264    FETCH_FUNCS(LA_FLOAT16),
 265    FETCH_FUNCS(LA_FLOAT32),
 266    FETCH_FUNCS(I_FLOAT16),
 267    FETCH_FUNCS(I_FLOAT32),
 268    FETCH_FUNCS(R_FLOAT16),
 269    FETCH_FUNCS(R_FLOAT32),
 270    FETCH_FUNCS(RG_FLOAT16),
 271    FETCH_FUNCS(RG_FLOAT32),
 272    FETCH_FUNCS(RGB_FLOAT16),
 273    FETCH_FUNCS(RGB_FLOAT32),
 274    FETCH_FUNCS(RGBA_FLOAT16),
 275    FETCH_FUNCS(RGBA_FLOAT32),
 276    FETCH_FUNCS(RGBX_FLOAT16),
 277    FETCH_FUNCS(RGBX_FLOAT32),
 278    {
 279       MESA_FORMAT_Z_FLOAT32,
 280       fetch_texel_1d_R_FLOAT32, /* Reuse the R32F functions. */
 281       fetch_texel_2d_R_FLOAT32,
 282       fetch_texel_3d_R_FLOAT32
 283    },
 284
 285    /* Packed signed/unsigned non-normalized integer formats */
 286    FETCH_NULL(B10G10R10A2_UINT),
 287    FETCH_NULL(R10G10B10A2_UINT),
 288    FETCH_NULL(A2B10G10R10_UINT),
 289    FETCH_NULL(A2R10G10B10_UINT),
 290
 291    /* Array signed/unsigned non-normalized integer formats */
 292    FETCH_NULL(A_UINT8),
 293    FETCH_NULL(A_UINT16),
 294    FETCH_NULL(A_UINT32),
 295    FETCH_NULL(A_SINT8),
 296    FETCH_NULL(A_SINT16),
 297    FETCH_NULL(A_SINT32),
 298    FETCH_NULL(I_UINT8),
 299    FETCH_NULL(I_UINT16),
 300    FETCH_NULL(I_UINT32),
 301    FETCH_NULL(I_SINT8),
 302    FETCH_NULL(I_SINT16),
 303    FETCH_NULL(I_SINT32),
 304    FETCH_NULL(L_UINT8),
 305    FETCH_NULL(L_UINT16),
 306    FETCH_NULL(L_UINT32),
 307    FETCH_NULL(L_SINT8),
 308    FETCH_NULL(L_SINT16),
 309    FETCH_NULL(L_SINT32),
 310    FETCH_NULL(LA_UINT8),
 311    FETCH_NULL(LA_UINT16),
 312    FETCH_NULL(LA_UINT32),
 313    FETCH_NULL(LA_SINT8),
 314    FETCH_NULL(LA_SINT16),
 315    FETCH_NULL(LA_SINT32),
 316    FETCH_NULL(R_UINT8),
 317    FETCH_NULL(R_UINT16),
 318    FETCH_NULL(R_UINT32),
 319    FETCH_NULL(R_SINT8),
 320    FETCH_NULL(R_SINT16),
 321    FETCH_NULL(R_SINT32),
 322    FETCH_NULL(RG_UINT8),
 323    FETCH_NULL(RG_UINT16),
 324    FETCH_NULL(RG_UINT32),
 325    FETCH_NULL(RG_SINT8),
 326    FETCH_NULL(RG_SINT16),
 327    FETCH_NULL(RG_SINT32),
 328    FETCH_NULL(RGB_UINT8),
 329    FETCH_NULL(RGB_UINT16),
 330    FETCH_NULL(RGB_UINT32),
 331    FETCH_NULL(RGB_SINT8),
 332    FETCH_NULL(RGB_SINT16),
 333    FETCH_NULL(RGB_SINT32),
 334    FETCH_FUNCS(RGBA_UINT8),
 335    FETCH_FUNCS(RGBA_UINT16),
 336    FETCH_FUNCS(RGBA_UINT32),
 337    FETCH_FUNCS(RGBA_SINT8),
 338    FETCH_FUNCS(RGBA_SINT16),
 339    FETCH_FUNCS(RGBA_SINT32),
 340    FETCH_NULL(RGBX_UINT8),
 341    FETCH_NULL(RGBX_UINT16),
 342    FETCH_NULL(RGBX_UINT32),
 343    FETCH_NULL(RGBX_SINT8),
 344    FETCH_NULL(RGBX_SINT16),
 345    FETCH_NULL(RGBX_SINT32),
 346
 347    /* DXT compressed formats */
 348    {
 349       MESA_FORMAT_RGB_DXT1,
 350       fetch_compressed,
 351       fetch_compressed,
 352       fetch_compressed
 353    },
 354    {
 355       MESA_FORMAT_RGBA_DXT1,
 356       fetch_compressed,
 357       fetch_compressed,
 358       fetch_compressed
 359    },
 360    {
 361       MESA_FORMAT_RGBA_DXT3,
 362       fetch_compressed,
 363       fetch_compressed,
 364       fetch_compressed
 365    },
 366    {
 367       MESA_FORMAT_RGBA_DXT5,
 368       fetch_compressed,
 369       fetch_compressed,
 370       fetch_compressed
 371    },
 372
 373    /* DXT sRGB compressed formats */
 374    {
 375       MESA_FORMAT_SRGB_DXT1,
 376       fetch_compressed,
 377       fetch_compressed,
 378       fetch_compressed
 379    },
 380    {
 381       MESA_FORMAT_SRGBA_DXT1,
 382       fetch_compressed,
 383       fetch_compressed,
 384       fetch_compressed
 385    },
 386    {
 387       MESA_FORMAT_SRGBA_DXT3,
 388       fetch_compressed,
 389       fetch_compressed,
 390       fetch_compressed
 391    },
 392    {
 393       MESA_FORMAT_SRGBA_DXT5,
 394       fetch_compressed,
 395       fetch_compressed,
 396       fetch_compressed
 397    },
 398
 399    /* FXT1 compressed formats */
 400    {
 401       MESA_FORMAT_RGB_FXT1,
 402       fetch_compressed,
 403       fetch_compressed,
 404       fetch_compressed
 405    },
 406    {
 407       MESA_FORMAT_RGBA_FXT1,
 408       fetch_compressed,
 409       fetch_compressed,
 410       fetch_compressed
 411    },
 412
 413    /* RGTC compressed formats */
 414    {
 415       MESA_FORMAT_R_RGTC1_UNORM,
 416       fetch_compressed,
 417       fetch_compressed,
 418       fetch_compressed
 419    },
 420    {
 421       MESA_FORMAT_R_RGTC1_SNORM,
 422       fetch_compressed,
 423       fetch_compressed,
 424       fetch_compressed
 425    },
 426    {
 427       MESA_FORMAT_RG_RGTC2_UNORM,
 428       fetch_compressed,
 429       fetch_compressed,
 430       fetch_compressed
 431    },
 432    {
 433       MESA_FORMAT_RG_RGTC2_SNORM,
 434       fetch_compressed,
 435       fetch_compressed,
 436       fetch_compressed
 437    },
 438
 439    /* LATC1/2 compressed formats */
 440    {
 441       MESA_FORMAT_L_LATC1_UNORM,
 442       fetch_compressed,
 443       fetch_compressed,
 444       fetch_compressed
 445    },
 446    {
 447       MESA_FORMAT_L_LATC1_SNORM,
 448       fetch_compressed,
 449       fetch_compressed,
 450       fetch_compressed
 451    },
 452    {
 453       MESA_FORMAT_LA_LATC2_UNORM,
 454       fetch_compressed,
 455       fetch_compressed,
 456       fetch_compressed
 457    },
 458    {
 459       MESA_FORMAT_LA_LATC2_SNORM,
 460       fetch_compressed,
 461       fetch_compressed,
 462       fetch_compressed
 463    },
 464
 465    /* ETC1/2 compressed formats */
 466    {
 467       MESA_FORMAT_ETC1_RGB8,
 468       fetch_compressed,
 469       fetch_compressed,
 470       fetch_compressed
 471    },
 472    {
 473       MESA_FORMAT_ETC2_RGB8,
 474       fetch_compressed,
 475       fetch_compressed,
 476       fetch_compressed
 477    },
 478    {
 479       MESA_FORMAT_ETC2_SRGB8,
 480       fetch_compressed,
 481       fetch_compressed,
 482       fetch_compressed
 483    },
 484    {
 485       MESA_FORMAT_ETC2_RGBA8_EAC,
 486       fetch_compressed,
 487       fetch_compressed,
 488       fetch_compressed
 489    },
 490    {
 491       MESA_FORMAT_ETC2_SRGB8_ALPHA8_EAC,
 492       fetch_compressed,
 493       fetch_compressed,
 494       fetch_compressed
 495    },
 496    {
 497       MESA_FORMAT_ETC2_R11_EAC,
 498       fetch_compressed,
 499       fetch_compressed,
 500       fetch_compressed
 501    },
 502    {
 503       MESA_FORMAT_ETC2_RG11_EAC,
 504       fetch_compressed,
 505       fetch_compressed,
 506       fetch_compressed
 507    },
 508    {
 509       MESA_FORMAT_ETC2_SIGNED_R11_EAC,
 510       fetch_compressed,
 511       fetch_compressed,
 512       fetch_compressed
 513    },
 514    {
 515       MESA_FORMAT_ETC2_SIGNED_RG11_EAC,
 516       fetch_compressed,
 517       fetch_compressed,
 518       fetch_compressed
 519    },
 520    {
 521       MESA_FORMAT_ETC2_RGB8_PUNCHTHROUGH_ALPHA1,
 522       fetch_compressed,
 523       fetch_compressed,
 524       fetch_compressed
 525    },
 526    {
 527       MESA_FORMAT_ETC2_SRGB8_PUNCHTHROUGH_ALPHA1,
 528       fetch_compressed,
 529       fetch_compressed,
 530       fetch_compressed
 531    },
 532    {
 533       MESA_FORMAT_BPTC_RGBA_UNORM,
 534       fetch_compressed,
 535       fetch_compressed,
 536       fetch_compressed
 537    },
 538    {
 539       MESA_FORMAT_BPTC_SRGB_ALPHA_UNORM,
 540       fetch_compressed,
 541       fetch_compressed,
 542       fetch_compressed
 543    },
 544    {
 545       MESA_FORMAT_BPTC_RGB_SIGNED_FLOAT,
 546       fetch_compressed,
 547       fetch_compressed,
 548       fetch_compressed
 549    },
 550    {
 551       MESA_FORMAT_BPTC_RGB_UNSIGNED_FLOAT,
 552       fetch_compressed,
 553       fetch_compressed,
 554       fetch_compressed
 555    }
 556 };
 557
 558
 559 /**
 560  * Initialize the texture image's FetchTexel methods.
 561  */
 562 static void
 563 set_fetch_functions(const struct gl_sampler_object *samp,
 564                     struct swrast_texture_image *texImage, GLuint dims)
 565 {
 566    mesa_format format = texImage->Base.TexFormat;
 567
 568 #ifdef DEBUG
 569    /* check that the table entries are sorted by format name */
 570    mesa_format fmt;
 571    for (fmt = 0; fmt < MESA_FORMAT_COUNT; fmt++) {
 572       assert(texfetch_funcs[fmt].Name == fmt);
 573    }
 574 #endif
 575
 576    STATIC_ASSERT(Elements(texfetch_funcs) == MESA_FORMAT_COUNT);
 577
 578    if (samp->sRGBDecode == GL_SKIP_DECODE_EXT &&
 579        _mesa_get_format_color_encoding(format) == GL_SRGB) {
 580       format = _mesa_get_srgb_format_linear(format);
 581    }
 582
 583    assert(format < MESA_FORMAT_COUNT);
 584
 585    switch (dims) {
 586    case 1:
 587       texImage->FetchTexel = texfetch_funcs[format].Fetch1D;
 588       break;
 589    case 2:
 590       texImage->FetchTexel = texfetch_funcs[format].Fetch2D;
 591       break;
 592    case 3:
 593       texImage->FetchTexel = texfetch_funcs[format].Fetch3D;
 594       break;
 595    default:
 596       assert(!"Bad dims in set_fetch_functions()");
 597    }
 598
 599    texImage->FetchCompressedTexel = _mesa_get_compressed_fetch_func(format);
 600
 601    ASSERT(texImage->FetchTexel);
 602 }
 603
 604 void
 605 _mesa_update_fetch_functions(struct gl_context *ctx, GLuint unit)
 606 {
 607    struct gl_texture_object *texObj = ctx->Texture.Unit[unit]._Current;
 608    struct gl_sampler_object *samp;
 609    GLuint face, i;
 610    GLuint dims;
 611
 612    if (!texObj)
 613       return;
 614
 615    samp = _mesa_get_samplerobj(ctx, unit);
 616
 617    dims = _mesa_get_texture_dimensions(texObj->Target);
 618
 619    for (face = 0; face < 6; face++) {
 620       for (i = 0; i < MAX_TEXTURE_LEVELS; i++) {
 621          if (texObj->Image[face][i]) {
 622             set_fetch_functions(samp,
 623                                 swrast_texture_image(texObj->Image[face][i]),
 624                                 dims);
 625          }
 626       }
 627    }
 628 }