src/mesa/main/texfetch.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  7.7
   4  *
   5  * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
   6  * Copyright (c) 2009  VMware, Inc.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the "Software"),
  10  * to deal in the Software without restriction, including without limitation
  11  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12  * and/or sell copies of the Software, and to permit persons to whom the
  13  * Software is furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included
  16  * in all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  21  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  22  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  23  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  24  */
  25
  26
  27 /**
  28  * \file texfetch.c
  29  *
  30  * Texel fetch/store functions
  31  *
  32  * \author Gareth Hughes
  33  */
  34
  35
  36 #include "colormac.h"
  37 #include "context.h"
  38 #include "texcompress.h"
  39 #include "texcompress_fxt1.h"
  40 #include "texcompress_s3tc.h"
  41 #include "texfetch.h"
  42
  43
  44 /**
  45  * Convert an 8-bit sRGB value from non-linear space to a
  46  * linear RGB value in [0, 1].
  47  * Implemented with a 256-entry lookup table.
  48  */
  49 static INLINE GLfloat
  50 nonlinear_to_linear(GLubyte cs8)
  51 {
  52    static GLfloat table[256];
  53    static GLboolean tableReady = GL_FALSE;
  54    if (!tableReady) {
  55       /* compute lookup table now */
  56       GLuint i;
  57       for (i = 0; i < 256; i++) {
  58          const GLfloat cs = UBYTE_TO_FLOAT(i);
  59          if (cs <= 0.04045) {
  60             table[i] = cs / 12.92f;
  61          }
  62          else {
  63             table[i] = (GLfloat) _mesa_pow((cs + 0.055) / 1.055, 2.4);
  64          }
  65       }
  66       tableReady = GL_TRUE;
  67    }
  68    return table[cs8];
  69 }
  70
  71
  72
  73 /* Texel fetch routines for all supported formats
  74  */
  75 #define DIM 1
  76 #include "texfetch_tmp.h"
  77
  78 #define DIM 2
  79 #include "texfetch_tmp.h"
  80
  81 #define DIM 3
  82 #include "texfetch_tmp.h"
  83
  84 /**
  85  * Null texel fetch function.
  86  *
  87  * Have to have this so the FetchTexel function pointer is never NULL.
  88  */
  89 static void fetch_null_texelf( const struct gl_texture_image *texImage,
  90                                GLint i, GLint j, GLint k, GLfloat *texel )
  91 {
  92    (void) texImage; (void) i; (void) j; (void) k;
  93    texel[RCOMP] = 0.0;
  94    texel[GCOMP] = 0.0;
  95    texel[BCOMP] = 0.0;
  96    texel[ACOMP] = 0.0;
  97    _mesa_warning(NULL, "fetch_null_texelf() called!");
  98 }
  99
 100 static void store_null_texel(struct gl_texture_image *texImage,
 101                              GLint i, GLint j, GLint k, const void *texel)
 102 {
 103    (void) texImage;
 104    (void) i;
 105    (void) j;
 106    (void) k;
 107    (void) texel;
 108    /* no-op */
 109 }
 110
 111
 112
 113 /**
 114  * Table to map MESA_FORMAT_ to texel fetch/store funcs.
 115  * XXX this is somewhat temporary.
 116  */
 117 static struct {
 118    GLuint Name;
 119    FetchTexelFuncF Fetch1D;
 120    FetchTexelFuncF Fetch2D;
 121    FetchTexelFuncF Fetch3D;
 122    StoreTexelFunc StoreTexel;
 123 }
 124 texfetch_funcs[MESA_FORMAT_COUNT] =
 125 {
 126    {
 127       MESA_FORMAT_SRGB8,
 128       fetch_texel_1d_srgb8,
 129       fetch_texel_2d_srgb8,
 130       fetch_texel_3d_srgb8,
 131       store_texel_srgb8
 132    },
 133    {
 134       MESA_FORMAT_SRGBA8,
 135       fetch_texel_1d_srgba8,
 136       fetch_texel_2d_srgba8,
 137       fetch_texel_3d_srgba8,
 138       store_texel_srgba8
 139    },
 140    {
 141       MESA_FORMAT_SARGB8,
 142       fetch_texel_1d_sargb8,
 143       fetch_texel_2d_sargb8,
 144       fetch_texel_3d_sargb8,
 145       store_texel_sargb8
 146    },
 147    {
 148       MESA_FORMAT_SL8,
 149       fetch_texel_1d_sl8,
 150       fetch_texel_2d_sl8,
 151       fetch_texel_3d_sl8,
 152       store_texel_sl8
 153    },
 154    {
 155       MESA_FORMAT_SLA8,
 156       fetch_texel_1d_sla8,
 157       fetch_texel_2d_sla8,
 158       fetch_texel_3d_sla8,
 159       store_texel_sla8
 160    },
 161    {
 162       MESA_FORMAT_RGB_FXT1,
 163       NULL,
 164       _mesa_fetch_texel_2d_f_rgb_fxt1,
 165       NULL,
 166       NULL
 167    },
 168    {
 169       MESA_FORMAT_RGBA_FXT1,
 170       NULL,
 171       _mesa_fetch_texel_2d_f_rgba_fxt1,
 172       NULL,
 173       NULL
 174    },
 175    {
 176       MESA_FORMAT_RGB_DXT1,
 177       NULL,
 178       _mesa_fetch_texel_2d_f_rgb_dxt1,
 179       NULL,
 180       NULL
 181    },
 182    {
 183       MESA_FORMAT_RGBA_DXT1,
 184       NULL,
 185       _mesa_fetch_texel_2d_f_rgba_dxt1,
 186       NULL,
 187       NULL
 188    },
 189    {
 190       MESA_FORMAT_RGBA_DXT3,
 191       NULL,
 192       _mesa_fetch_texel_2d_f_rgba_dxt3,
 193       NULL,
 194       NULL
 195    },
 196    {
 197       MESA_FORMAT_RGBA_DXT5,
 198       NULL,
 199       _mesa_fetch_texel_2d_f_rgba_dxt5,
 200       NULL,
 201       NULL
 202    },
 203    {
 204       MESA_FORMAT_SRGB_DXT1,
 205       NULL,
 206       _mesa_fetch_texel_2d_f_srgb_dxt1,
 207       NULL,
 208       NULL
 209    },
 210    {
 211       MESA_FORMAT_SRGBA_DXT1,
 212       NULL,
 213       _mesa_fetch_texel_2d_f_srgba_dxt1,
 214       NULL,
 215       NULL
 216    },
 217    {
 218       MESA_FORMAT_SRGBA_DXT3,
 219       NULL,
 220       _mesa_fetch_texel_2d_f_srgba_dxt3,
 221       NULL,
 222       NULL
 223    },
 224    {
 225       MESA_FORMAT_SRGBA_DXT5,
 226       NULL,
 227       _mesa_fetch_texel_2d_f_srgba_dxt5,
 228       NULL,
 229       NULL
 230    },
 231    {
 232       MESA_FORMAT_RGBA_FLOAT32,
 233       fetch_texel_1d_f_rgba_f32,
 234       fetch_texel_2d_f_rgba_f32,
 235       fetch_texel_3d_f_rgba_f32,
 236       store_texel_rgba_f32
 237    },
 238    {
 239       MESA_FORMAT_RGBA_FLOAT16,
 240       fetch_texel_1d_f_rgba_f16,
 241       fetch_texel_2d_f_rgba_f16,
 242       fetch_texel_3d_f_rgba_f16,
 243       store_texel_rgba_f16
 244    },
 245    {
 246       MESA_FORMAT_RGB_FLOAT32,
 247       fetch_texel_1d_f_rgb_f32,
 248       fetch_texel_2d_f_rgb_f32,
 249       fetch_texel_3d_f_rgb_f32,
 250       store_texel_rgb_f32
 251    },
 252    {
 253       MESA_FORMAT_RGB_FLOAT16,
 254       fetch_texel_1d_f_rgb_f16,
 255       fetch_texel_2d_f_rgb_f16,
 256       fetch_texel_3d_f_rgb_f16,
 257       store_texel_rgb_f16
 258    },
 259    {
 260       MESA_FORMAT_ALPHA_FLOAT32,
 261       fetch_texel_1d_f_alpha_f32,
 262       fetch_texel_2d_f_alpha_f32,
 263       fetch_texel_3d_f_alpha_f32,
 264       store_texel_alpha_f32
 265    },
 266    {
 267       MESA_FORMAT_ALPHA_FLOAT16,
 268       fetch_texel_1d_f_alpha_f16,
 269       fetch_texel_2d_f_alpha_f16,
 270       fetch_texel_3d_f_alpha_f16,
 271       store_texel_alpha_f16
 272    },
 273    {
 274       MESA_FORMAT_LUMINANCE_FLOAT32,
 275       fetch_texel_1d_f_luminance_f32,
 276       fetch_texel_2d_f_luminance_f32,
 277       fetch_texel_3d_f_luminance_f32,
 278       store_texel_luminance_f32
 279    },
 280    {
 281       MESA_FORMAT_LUMINANCE_FLOAT16,
 282       fetch_texel_1d_f_luminance_f16,
 283       fetch_texel_2d_f_luminance_f16,
 284       fetch_texel_3d_f_luminance_f16,
 285       store_texel_luminance_f16
 286    },
 287    {
 288       MESA_FORMAT_LUMINANCE_ALPHA_FLOAT32,
 289       fetch_texel_1d_f_luminance_alpha_f32,
 290       fetch_texel_2d_f_luminance_alpha_f32,
 291       fetch_texel_3d_f_luminance_alpha_f32,
 292       store_texel_luminance_alpha_f32
 293    },
 294    {
 295       MESA_FORMAT_LUMINANCE_ALPHA_FLOAT16,
 296       fetch_texel_1d_f_luminance_alpha_f16,
 297       fetch_texel_2d_f_luminance_alpha_f16,
 298       fetch_texel_3d_f_luminance_alpha_f16,
 299       store_texel_luminance_alpha_f16
 300    },
 301    {
 302       MESA_FORMAT_INTENSITY_FLOAT32,
 303       fetch_texel_1d_f_intensity_f32,
 304       fetch_texel_2d_f_intensity_f32,
 305       fetch_texel_3d_f_intensity_f32,
 306       store_texel_intensity_f32
 307    },
 308    {
 309       MESA_FORMAT_INTENSITY_FLOAT16,
 310       fetch_texel_1d_f_intensity_f16,
 311       fetch_texel_2d_f_intensity_f16,
 312       fetch_texel_3d_f_intensity_f16,
 313       store_texel_intensity_f16
 314    },
 315    {
 316       MESA_FORMAT_DUDV8,
 317       fetch_texel_1d_dudv8,
 318       fetch_texel_2d_dudv8,
 319       fetch_texel_3d_dudv8,
 320       NULL
 321    },
 322    {
 323       MESA_FORMAT_SIGNED_RGBA8888,
 324       fetch_texel_1d_signed_rgba8888,
 325       fetch_texel_2d_signed_rgba8888,
 326       fetch_texel_3d_signed_rgba8888,
 327       store_texel_signed_rgba8888
 328    },
 329    {
 330       MESA_FORMAT_SIGNED_RGBA8888_REV,
 331       fetch_texel_1d_signed_rgba8888_rev,
 332       fetch_texel_2d_signed_rgba8888_rev,
 333       fetch_texel_3d_signed_rgba8888_rev,
 334       store_texel_signed_rgba8888_rev
 335    },
 336    {
 337       MESA_FORMAT_SIGNED_RGBA_16,
 338       NULL, /* XXX to do */
 339       NULL,
 340       NULL,
 341       NULL
 342    },
 343    {
 344       MESA_FORMAT_RGBA8888,
 345       fetch_texel_1d_f_rgba8888,
 346       fetch_texel_2d_f_rgba8888,
 347       fetch_texel_3d_f_rgba8888,
 348       store_texel_rgba8888
 349    },
 350    {
 351       MESA_FORMAT_RGBA8888_REV,
 352       fetch_texel_1d_f_rgba8888_rev,
 353       fetch_texel_2d_f_rgba8888_rev,
 354       fetch_texel_3d_f_rgba8888_rev,
 355       store_texel_rgba8888_rev
 356    },
 357    {
 358       MESA_FORMAT_ARGB8888,
 359       fetch_texel_1d_f_argb8888,
 360       fetch_texel_2d_f_argb8888,
 361       fetch_texel_3d_f_argb8888,
 362       store_texel_argb8888
 363    },
 364    {
 365       MESA_FORMAT_ARGB8888_REV,
 366       fetch_texel_1d_f_argb8888_rev,
 367       fetch_texel_2d_f_argb8888_rev,
 368       fetch_texel_3d_f_argb8888_rev,
 369       store_texel_argb8888_rev
 370    },
 371    {
 372       MESA_FORMAT_XRGB8888,
 373       fetch_texel_1d_f_xrgb8888,
 374       fetch_texel_2d_f_xrgb8888,
 375       fetch_texel_3d_f_xrgb8888,
 376       store_texel_xrgb8888
 377    },
 378    {
 379       MESA_FORMAT_XRGB8888_REV,
 380       fetch_texel_1d_f_xrgb8888_rev,
 381       fetch_texel_2d_f_xrgb8888_rev,
 382       fetch_texel_3d_f_xrgb8888_rev,
 383       store_texel_xrgb8888_rev,
 384    },
 385    {
 386       MESA_FORMAT_RGB888,
 387       fetch_texel_1d_f_rgb888,
 388       fetch_texel_2d_f_rgb888,
 389       fetch_texel_3d_f_rgb888,
 390       store_texel_rgb888
 391    },
 392    {
 393       MESA_FORMAT_BGR888,
 394       fetch_texel_1d_f_bgr888,
 395       fetch_texel_2d_f_bgr888,
 396       fetch_texel_3d_f_bgr888,
 397       store_texel_bgr888
 398    },
 399    {
 400       MESA_FORMAT_RGB565,
 401       fetch_texel_1d_f_rgb565,
 402       fetch_texel_2d_f_rgb565,
 403       fetch_texel_3d_f_rgb565,
 404       store_texel_rgb565
 405    },
 406    {
 407       MESA_FORMAT_RGB565_REV,
 408       fetch_texel_1d_f_rgb565_rev,
 409       fetch_texel_2d_f_rgb565_rev,
 410       fetch_texel_3d_f_rgb565_rev,
 411       store_texel_rgb565_rev
 412    },
 413    {
 414       MESA_FORMAT_ARGB4444,
 415       fetch_texel_1d_f_argb4444,
 416       fetch_texel_2d_f_argb4444,
 417       fetch_texel_3d_f_argb4444,
 418       store_texel_argb4444
 419    },
 420    {
 421       MESA_FORMAT_ARGB4444_REV,
 422       fetch_texel_1d_f_argb4444_rev,
 423       fetch_texel_2d_f_argb4444_rev,
 424       fetch_texel_3d_f_argb4444_rev,
 425       store_texel_argb4444_rev
 426    },
 427    {
 428       MESA_FORMAT_RGBA5551,
 429       fetch_texel_1d_f_rgba5551,
 430       fetch_texel_2d_f_rgba5551,
 431       fetch_texel_3d_f_rgba5551,
 432       store_texel_rgba5551
 433    },
 434    {
 435       MESA_FORMAT_ARGB1555,
 436       fetch_texel_1d_f_argb1555,
 437       fetch_texel_2d_f_argb1555,
 438       fetch_texel_3d_f_argb1555,
 439       store_texel_argb1555
 440    },
 441    {
 442       MESA_FORMAT_ARGB1555_REV,
 443       fetch_texel_1d_f_argb1555_rev,
 444       fetch_texel_2d_f_argb1555_rev,
 445       fetch_texel_3d_f_argb1555_rev,
 446       store_texel_argb1555_rev
 447    },
 448    {
 449       MESA_FORMAT_AL88,
 450       fetch_texel_1d_f_al88,
 451       fetch_texel_2d_f_al88,
 452       fetch_texel_3d_f_al88,
 453       store_texel_al88
 454    },
 455    {
 456       MESA_FORMAT_AL88_REV,
 457       fetch_texel_1d_f_al88_rev,
 458       fetch_texel_2d_f_al88_rev,
 459       fetch_texel_3d_f_al88_rev,
 460       store_texel_al88_rev
 461    },
 462    {
 463       MESA_FORMAT_AL1616,
 464       fetch_texel_1d_f_al1616,
 465       fetch_texel_2d_f_al1616,
 466       fetch_texel_3d_f_al1616,
 467       store_texel_al1616
 468    },
 469    {
 470       MESA_FORMAT_AL1616_REV,
 471       fetch_texel_1d_f_al1616_rev,
 472       fetch_texel_2d_f_al1616_rev,
 473       fetch_texel_3d_f_al1616_rev,
 474       store_texel_al1616_rev
 475    },
 476    {
 477       MESA_FORMAT_RGB332,
 478       fetch_texel_1d_f_rgb332,
 479       fetch_texel_2d_f_rgb332,
 480       fetch_texel_3d_f_rgb332,
 481       store_texel_rgb332
 482    },
 483    {
 484       MESA_FORMAT_A8,
 485       fetch_texel_1d_f_a8,
 486       fetch_texel_2d_f_a8,
 487       fetch_texel_3d_f_a8,
 488       store_texel_a8
 489    },
 490    {
 491       MESA_FORMAT_L8,
 492       fetch_texel_1d_f_l8,
 493       fetch_texel_2d_f_l8,
 494       fetch_texel_3d_f_l8,
 495       store_texel_l8
 496    },
 497    {
 498       MESA_FORMAT_I8,
 499       fetch_texel_1d_f_i8,
 500       fetch_texel_2d_f_i8,
 501       fetch_texel_3d_f_i8,
 502       store_texel_i8
 503    },
 504    {
 505       MESA_FORMAT_CI8,
 506       fetch_texel_1d_f_ci8,
 507       fetch_texel_2d_f_ci8,
 508       fetch_texel_3d_f_ci8,
 509       store_texel_ci8
 510    },
 511    {
 512       MESA_FORMAT_YCBCR,
 513       fetch_texel_1d_f_ycbcr,
 514       fetch_texel_2d_f_ycbcr,
 515       fetch_texel_3d_f_ycbcr,
 516       store_texel_ycbcr
 517    },
 518    {
 519       MESA_FORMAT_YCBCR_REV,
 520       fetch_texel_1d_f_ycbcr_rev,
 521       fetch_texel_2d_f_ycbcr_rev,
 522       fetch_texel_3d_f_ycbcr_rev,
 523       store_texel_ycbcr_rev
 524    },
 525    {
 526       MESA_FORMAT_Z24_S8,
 527       fetch_texel_1d_f_z24_s8,
 528       fetch_texel_2d_f_z24_s8,
 529       fetch_texel_3d_f_z24_s8,
 530       store_texel_z24_s8
 531    },
 532    {
 533       MESA_FORMAT_S8_Z24,
 534       fetch_texel_1d_f_s8_z24,
 535       fetch_texel_2d_f_s8_z24,
 536       fetch_texel_3d_f_s8_z24,
 537       store_texel_s8_z24
 538    },
 539    {
 540       MESA_FORMAT_Z16,
 541       fetch_texel_1d_f_z16,
 542       fetch_texel_2d_f_z16,
 543       fetch_texel_3d_f_z16,
 544       store_texel_z16
 545    },
 546    {
 547       MESA_FORMAT_X8_Z24,
 548       fetch_texel_1d_f_s8_z24,
 549       fetch_texel_2d_f_s8_z24,
 550       fetch_texel_3d_f_s8_z24,
 551       store_texel_s8_z24
 552    },
 553    {
 554       MESA_FORMAT_Z24_X8,
 555       fetch_texel_1d_f_z24_s8,
 556       fetch_texel_2d_f_z24_s8,
 557       fetch_texel_3d_f_z24_s8,
 558       store_texel_z24_s8
 559    },
 560    {
 561       MESA_FORMAT_Z32,
 562       fetch_texel_1d_f_z32,
 563       fetch_texel_2d_f_z32,
 564       fetch_texel_3d_f_z32,
 565       store_texel_z32
 566    }
 567 };
 568
 569
 570 static FetchTexelFuncF
 571 _mesa_get_texel_fetch_func(gl_format format, GLuint dims)
 572 {
 573    FetchTexelFuncF f = NULL;
 574    GLuint i;
 575    /* XXX replace loop with direct table lookup */
 576    for (i = 0; i < MESA_FORMAT_COUNT; i++) {
 577       if (texfetch_funcs[i].Name == format) {
 578          switch (dims) {
 579          case 1:
 580             f = texfetch_funcs[i].Fetch1D;
 581             break;
 582          case 2:
 583             f = texfetch_funcs[i].Fetch2D;
 584             break;
 585          case 3:
 586             f = texfetch_funcs[i].Fetch3D;
 587             break;
 588          }
 589          if (!f)
 590             f = fetch_null_texelf;
 591          return f;
 592       }
 593    }
 594    return NULL;
 595 }
 596
 597
 598 StoreTexelFunc
 599 _mesa_get_texel_store_func(gl_format format)
 600 {
 601    GLuint i;
 602    /* XXX replace loop with direct table lookup */
 603    for (i = 0; i < MESA_FORMAT_COUNT; i++) {
 604       if (texfetch_funcs[i].Name == format) {
 605          if (texfetch_funcs[i].StoreTexel)
 606             return texfetch_funcs[i].StoreTexel;
 607          else
 608             return store_null_texel;
 609       }
 610    }
 611    return NULL;
 612 }
 613
 614
 615
 616 /**
 617  * Adaptor for fetching a GLchan texel from a float-valued texture.
 618  */
 619 static void
 620 fetch_texel_float_to_chan(const struct gl_texture_image *texImage,
 621                           GLint i, GLint j, GLint k, GLchan *texelOut)
 622 {
 623    GLfloat temp[4];
 624    GLenum baseFormat = _mesa_get_format_base_format(texImage->TexFormat);
 625
 626    ASSERT(texImage->FetchTexelf);
 627    texImage->FetchTexelf(texImage, i, j, k, temp);
 628    if (baseFormat == GL_DEPTH_COMPONENT ||
 629        baseFormat == GL_DEPTH_STENCIL_EXT) {
 630       /* just one channel */
 631       UNCLAMPED_FLOAT_TO_CHAN(texelOut[0], temp[0]);
 632    }
 633    else {
 634       /* four channels */
 635       UNCLAMPED_FLOAT_TO_CHAN(texelOut[0], temp[0]);
 636       UNCLAMPED_FLOAT_TO_CHAN(texelOut[1], temp[1]);
 637       UNCLAMPED_FLOAT_TO_CHAN(texelOut[2], temp[2]);
 638       UNCLAMPED_FLOAT_TO_CHAN(texelOut[3], temp[3]);
 639    }
 640 }
 641
 642
 643 #if 0
 644 /**
 645  * Adaptor for fetching a float texel from a GLchan-valued texture.
 646  */
 647 static void
 648 fetch_texel_chan_to_float(const struct gl_texture_image *texImage,
 649                           GLint i, GLint j, GLint k, GLfloat *texelOut)
 650 {
 651    GLchan temp[4];
 652    GLenum baseFormat = _mesa_get_format_base_format(texImage->TexFormat);
 653
 654    ASSERT(texImage->FetchTexelc);
 655    texImage->FetchTexelc(texImage, i, j, k, temp);
 656    if (baseFormat == GL_DEPTH_COMPONENT ||
 657        baseFormat == GL_DEPTH_STENCIL_EXT) {
 658       /* just one channel */
 659       texelOut[0] = CHAN_TO_FLOAT(temp[0]);
 660    }
 661    else {
 662       /* four channels */
 663       texelOut[0] = CHAN_TO_FLOAT(temp[0]);
 664       texelOut[1] = CHAN_TO_FLOAT(temp[1]);
 665       texelOut[2] = CHAN_TO_FLOAT(temp[2]);
 666       texelOut[3] = CHAN_TO_FLOAT(temp[3]);
 667    }
 668 }
 669 #endif
 670
 671
 672 /**
 673  * Initialize the texture image's FetchTexelc and FetchTexelf methods.
 674  */
 675 void
 676 _mesa_set_fetch_functions(struct gl_texture_image *texImage, GLuint dims)
 677 {
 678    ASSERT(dims == 1 || dims == 2 || dims == 3);
 679    ASSERT(texImage->TexFormat);
 680
 681    if (!texImage->FetchTexelf) {
 682       texImage->FetchTexelf =
 683          _mesa_get_texel_fetch_func(texImage->TexFormat, dims);
 684    }
 685
 686    /* now check if we need to use a float/chan adaptor */
 687    if (!texImage->FetchTexelc) {
 688       texImage->FetchTexelc = fetch_texel_float_to_chan;
 689    }
 690
 691    ASSERT(texImage->FetchTexelc);
 692    ASSERT(texImage->FetchTexelf);
 693 }