reactos/dll/opengl/mesa/src/mesa/main/texcompress.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.5.1
   4  *
   5  * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
   6  * Copyright (c) 2008 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 texcompress.c
  29  * Helper functions for texture compression.
  30  */
  31
  32
  33 #include "glheader.h"
  34 #include "imports.h"
  35 #include "colormac.h"
  36 #include "formats.h"
  37 #include "mfeatures.h"
  38 #include "mtypes.h"
  39 #include "texcompress.h"
  40 #include "texcompress_fxt1.h"
  41 #include "texcompress_rgtc.h"
  42 #include "texcompress_s3tc.h"
  43 #include "texcompress_etc.h"
  44 #include "swrast/s_context.h"
  45
  46
  47 /**
  48  * Get the GL base format of a specified GL compressed texture format
  49  *
  50  * From page 232 of the OpenGL 3.3 (Compatiblity Profile) spec:
  51  *
  52  *     "Compressed Internal Format      Base Internal Format    Type
  53  *     ---------------------------     --------------------    ---------
  54  *     COMPRESSED_ALPHA                ALPHA                   Generic
  55  *     COMPRESSED_LUMINANCE            LUMINANCE               Generic
  56  *     COMPRESSED_LUMINANCE_ALPHA      LUMINANCE_ALPHA         Generic
  57  *     COMPRESSED_INTENSITY            INTENSITY               Generic
  58  *     COMPRESSED_RED                  RED                     Generic
  59  *     COMPRESSED_RG                   RG                      Generic
  60  *     COMPRESSED_RGB                  RGB                     Generic
  61  *     COMPRESSED_RGBA                 RGBA                    Generic
  62  *     COMPRESSED_SRGB                 RGB                     Generic
  63  *     COMPRESSED_SRGB_ALPHA           RGBA                    Generic
  64  *     COMPRESSED_SLUMINANCE           LUMINANCE               Generic
  65  *     COMPRESSED_SLUMINANCE_ALPHA     LUMINANCE_ALPHA         Generic
  66  *     COMPRESSED_RED_RGTC1            RED                     Specific
  67  *     COMPRESSED_SIGNED_RED_RGTC1     RED                     Specific
  68  *     COMPRESSED_RG_RGTC2             RG                      Specific
  69  *     COMPRESSED_SIGNED_RG_RGTC2      RG                      Specific"
  70  *
  71  * \return
  72  * The base format of \c format if \c format is a compressed format (either
  73  * generic or specific.  Otherwise 0 is returned.
  74  */
  75 GLenum
  76 _mesa_gl_compressed_format_base_format(GLenum format)
  77 {
  78    switch (format) {
  79    case GL_COMPRESSED_RED:
  80    case GL_COMPRESSED_RED_RGTC1:
  81    case GL_COMPRESSED_SIGNED_RED_RGTC1:
  82       return GL_RED;
  83
  84    case GL_COMPRESSED_RG:
  85    case GL_COMPRESSED_RG_RGTC2:
  86    case GL_COMPRESSED_SIGNED_RG_RGTC2:
  87       return GL_RG;
  88
  89    case GL_COMPRESSED_RGB:
  90    case GL_COMPRESSED_SRGB:
  91    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
  92    case GL_COMPRESSED_RGB_FXT1_3DFX:
  93    case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT:
  94    case GL_ETC1_RGB8_OES:
  95       return GL_RGB;
  96
  97    case GL_COMPRESSED_RGBA:
  98    case GL_COMPRESSED_SRGB_ALPHA:
  99    case GL_COMPRESSED_RGBA_BPTC_UNORM_ARB:
 100    case GL_COMPRESSED_SRGB_ALPHA_BPTC_UNORM_ARB:
 101    case GL_COMPRESSED_RGB_BPTC_SIGNED_FLOAT_ARB:
 102    case GL_COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT_ARB:
 103    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
 104    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
 105    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
 106    case GL_COMPRESSED_RGBA_FXT1_3DFX:
 107    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT:
 108    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT:
 109    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT:
 110       return GL_RGBA;
 111
 112    case GL_COMPRESSED_ALPHA:
 113       return GL_ALPHA;
 114
 115    case GL_COMPRESSED_LUMINANCE:
 116    case GL_COMPRESSED_SLUMINANCE:
 117    case GL_COMPRESSED_LUMINANCE_LATC1_EXT:
 118    case GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT:
 119       return GL_LUMINANCE;
 120
 121    case GL_COMPRESSED_LUMINANCE_ALPHA:
 122    case GL_COMPRESSED_SLUMINANCE_ALPHA:
 123    case GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT:
 124    case GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT:
 125    case GL_COMPRESSED_LUMINANCE_ALPHA_3DC_ATI:
 126       return GL_LUMINANCE_ALPHA;
 127
 128    case GL_COMPRESSED_INTENSITY:
 129       return GL_INTENSITY;
 130
 131    default:
 132       return 0;
 133    }
 134 }
 135
 136 /**
 137  * Return list of (and count of) all specific texture compression
 138  * formats that are supported.
 139  *
 140  * Some formats are \b not returned by this function.  The
 141  * \c GL_COMPRESSED_TEXTURE_FORMATS query only returns formats that are
 142  * "suitable for general-purpose usage."  All texture compression extensions
 143  * have taken this to mean either linear RGB or linear RGBA.
 144  *
 145  * The GL_ARB_texture_compress_rgtc spec says:
 146  *
 147  *    "19) Should the GL_NUM_COMPRESSED_TEXTURE_FORMATS and
 148  *        GL_COMPRESSED_TEXTURE_FORMATS queries return the RGTC formats?
 149  *
 150  *        RESOLVED:  No.
 151  *
 152  *        The OpenGL 2.1 specification says "The only values returned
 153  *        by this query [GL_COMPRESSED_TEXTURE_FORMATS"] are those
 154  *        corresponding to formats suitable for general-purpose usage.
 155  *        The renderer will not enumerate formats with restrictions that
 156  *        need to be specifically understood prior to use."
 157  *
 158  *        Compressed textures with just red or red-green components are
 159  *        not general-purpose so should not be returned by these queries
 160  *        because they have restrictions.
 161  *
 162  *        Applications that seek to use the RGTC formats should do so
 163  *        by looking for this extension's name in the string returned by
 164  *        glGetString(GL_EXTENSIONS) rather than
 165  *        what GL_NUM_COMPRESSED_TEXTURE_FORMATS and
 166  *        GL_COMPRESSED_TEXTURE_FORMATS return."
 167  *
 168  * There is nearly identical wording in the GL_EXT_texture_compression_rgtc
 169  * spec.
 170  *
 171  * The GL_EXT_texture_rRGB spec says:
 172  *
 173  *    "22) Should the new COMPRESSED_SRGB_* formats be listed in an
 174  *        implementation's GL_COMPRESSED_TEXTURE_FORMATS list?
 175  *
 176  *        RESOLVED:  No.  Section 3.8.1 says formats listed by
 177  *        GL_COMPRESSED_TEXTURE_FORMATS are "suitable for general-purpose
 178  *        usage."  The non-linear distribution of red, green, and
 179  *        blue for these sRGB compressed formats makes them not really
 180  *        general-purpose."
 181  *
 182  * The GL_EXT_texture_compression_latc spec says:
 183  *
 184  *    "16) Should the GL_NUM_COMPRESSED_TEXTURE_FORMATS and
 185  *        GL_COMPRESSED_TEXTURE_FORMATS queries return the LATC formats?
 186  *
 187  *        RESOLVED:  No.
 188  *
 189  *        The OpenGL 2.1 specification says "The only values returned
 190  *        by this query [GL_COMPRESSED_TEXTURE_FORMATS"] are those
 191  *        corresponding to formats suitable for general-purpose usage.
 192  *        The renderer will not enumerate formats with restrictions that
 193  *        need to be specifically understood prior to use."
 194  *
 195  *        Historically, OpenGL implementation have advertised the RGB and
 196  *        RGBA versions of the S3TC extensions compressed format tokens
 197  *        through this mechanism.
 198  *
 199  *        The specification is not sufficiently clear about what "suitable
 200  *        for general-purpose usage" means.  Historically that seems to mean
 201  *        unsigned RGB or unsigned RGBA.  The DXT1 format supporting alpha
 202  *        (GL_COMPRESSED_RGBA_S3TC_DXT1_EXT) is not exposed in the list (at
 203  *        least for NVIDIA drivers) because the alpha is always 1.0 expect
 204  *        when it is 0.0 when RGB is required to be black.  NVIDIA's even
 205  *        limits itself to true linear RGB or RGBA formats, specifically
 206  *        not including EXT_texture_sRGB's sRGB S3TC compressed formats.
 207  *
 208  *        Adding luminance and luminance-alpha texture formats (and
 209  *        certainly signed versions of luminance and luminance-alpha
 210  *        formats!) invites potential comptaibility problems with old
 211  *        applications using this mechanism since old applications are
 212  *        unlikely to expect non-RGB or non-RGBA formats to be advertised
 213  *        through this mechanism.  However no specific misinteractions
 214  *        with old applications is known.
 215  *
 216  *        Applications that seek to use the LATC formats should do so
 217  *        by looking for this extension's name in the string returned by
 218  *        glGetString(GL_EXTENSIONS) rather than
 219  *        what GL_NUM_COMPRESSED_TEXTURE_FORMATS and
 220  *        GL_COMPRESSED_TEXTURE_FORMATS return."
 221  *
 222  * There is no formal spec for GL_ATI_texture_compression_3dc.  Since the
 223  * formats added by this extension are luminance-alpha formats, it is
 224  * reasonable to expect them to follow the same rules as
 225  * GL_EXT_texture_compression_latc.  At the very least, Catalyst 11.6 does not
 226  * expose the 3dc formats through this mechanism.
 227  *
 228  * \param ctx  the GL context
 229  * \param formats  the resulting format list (may be NULL).
 230  *
 231  * \return number of formats.
 232  */
 233 GLuint
 234 _mesa_get_compressed_formats(struct gl_context *ctx, GLint *formats)
 235 {
 236    GLuint n = 0;
 237    if (ctx->Extensions.TDFX_texture_compression_FXT1) {
 238       if (formats) {
 239          formats[n++] = GL_COMPRESSED_RGB_FXT1_3DFX;
 240          formats[n++] = GL_COMPRESSED_RGBA_FXT1_3DFX;
 241       }
 242       else {
 243          n += 2;
 244       }
 245    }
 246
 247    if (ctx->Extensions.EXT_texture_compression_s3tc) {
 248       if (formats) {
 249          formats[n++] = GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
 250          formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT3_EXT;
 251          formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
 252       }
 253       else {
 254          n += 3;
 255       }
 256    }
 257    if (ctx->Extensions.S3_s3tc) {
 258       if (formats) {
 259          formats[n++] = GL_RGB_S3TC;
 260          formats[n++] = GL_RGB4_S3TC;
 261          formats[n++] = GL_RGBA_S3TC;
 262          formats[n++] = GL_RGBA4_S3TC;
 263       }
 264       else {
 265          n += 4;
 266       }
 267    }
 268
 269    if (ctx->Extensions.OES_compressed_ETC1_RGB8_texture) {
 270       if (formats) {
 271          formats[n++] = GL_ETC1_RGB8_OES;
 272       }
 273       else {
 274          n += 1;
 275       }
 276    }
 277
 278 #if FEATURE_ES1
 279    if (ctx->API == API_OPENGLES) {
 280       if (formats) {
 281          formats[n++] = GL_PALETTE4_RGB8_OES;
 282          formats[n++] = GL_PALETTE4_RGBA8_OES;
 283          formats[n++] = GL_PALETTE4_R5_G6_B5_OES;
 284          formats[n++] = GL_PALETTE4_RGBA4_OES;
 285          formats[n++] = GL_PALETTE4_RGB5_A1_OES;
 286          formats[n++] = GL_PALETTE8_RGB8_OES;
 287          formats[n++] = GL_PALETTE8_RGBA8_OES;
 288          formats[n++] = GL_PALETTE8_R5_G6_B5_OES;
 289          formats[n++] = GL_PALETTE8_RGBA4_OES;
 290          formats[n++] = GL_PALETTE8_RGB5_A1_OES;
 291       }
 292       else {
 293          n += 10;
 294       }
 295    }
 296 #endif
 297
 298    return n;
 299 }
 300
 301
 302 /**
 303  * Convert a compressed MESA_FORMAT_x to a GLenum.
 304  */
 305 gl_format
 306 _mesa_glenum_to_compressed_format(GLenum format)
 307 {
 308    switch (format) {
 309    case GL_COMPRESSED_RGB_FXT1_3DFX:
 310       return MESA_FORMAT_RGB_FXT1;
 311    case GL_COMPRESSED_RGBA_FXT1_3DFX:
 312       return MESA_FORMAT_RGBA_FXT1;
 313
 314    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
 315    case GL_RGB_S3TC:
 316       return MESA_FORMAT_RGB_DXT1;
 317    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
 318    case GL_RGB4_S3TC:
 319       return MESA_FORMAT_RGBA_DXT1;
 320    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
 321    case GL_RGBA_S3TC:
 322       return MESA_FORMAT_RGBA_DXT3;
 323    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
 324    case GL_RGBA4_S3TC:
 325       return MESA_FORMAT_RGBA_DXT5;
 326
 327    case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT:
 328       return MESA_FORMAT_SRGB_DXT1;
 329    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT:
 330       return MESA_FORMAT_SRGBA_DXT1;
 331    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT:
 332       return MESA_FORMAT_SRGBA_DXT3;
 333    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT:
 334       return MESA_FORMAT_SRGBA_DXT5;
 335
 336    case GL_COMPRESSED_RED_RGTC1:
 337       return MESA_FORMAT_RED_RGTC1;
 338    case GL_COMPRESSED_SIGNED_RED_RGTC1:
 339       return MESA_FORMAT_SIGNED_RED_RGTC1;
 340    case GL_COMPRESSED_RG_RGTC2:
 341       return MESA_FORMAT_RG_RGTC2;
 342    case GL_COMPRESSED_SIGNED_RG_RGTC2:
 343       return MESA_FORMAT_SIGNED_RG_RGTC2;
 344
 345    case GL_COMPRESSED_LUMINANCE_LATC1_EXT:
 346       return MESA_FORMAT_L_LATC1;
 347    case GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT:
 348       return MESA_FORMAT_SIGNED_L_LATC1;
 349    case GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT:
 350    case GL_COMPRESSED_LUMINANCE_ALPHA_3DC_ATI:
 351       return MESA_FORMAT_LA_LATC2;
 352    case GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT:
 353       return MESA_FORMAT_SIGNED_LA_LATC2;
 354
 355    case GL_ETC1_RGB8_OES:
 356       return MESA_FORMAT_ETC1_RGB8;
 357
 358    default:
 359       return MESA_FORMAT_NONE;
 360    }
 361 }
 362
 363
 364 /**
 365  * Given a compressed MESA_FORMAT_x value, return the corresponding
 366  * GLenum for that format.
 367  * This is needed for glGetTexLevelParameter(GL_TEXTURE_INTERNAL_FORMAT)
 368  * which must return the specific texture format used when the user might
 369  * have originally specified a generic compressed format in their
 370  * glTexImage2D() call.
 371  * For non-compressed textures, we always return the user-specified
 372  * internal format unchanged.
 373  */
 374 GLenum
 375 _mesa_compressed_format_to_glenum(struct gl_context *ctx, GLuint mesaFormat)
 376 {
 377    switch (mesaFormat) {
 378 #if FEATURE_texture_fxt1
 379    case MESA_FORMAT_RGB_FXT1:
 380       return GL_COMPRESSED_RGB_FXT1_3DFX;
 381    case MESA_FORMAT_RGBA_FXT1:
 382       return GL_COMPRESSED_RGBA_FXT1_3DFX;
 383 #endif
 384 #if FEATURE_texture_s3tc
 385    case MESA_FORMAT_RGB_DXT1:
 386       return GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
 387    case MESA_FORMAT_RGBA_DXT1:
 388       return GL_COMPRESSED_RGBA_S3TC_DXT1_EXT;
 389    case MESA_FORMAT_RGBA_DXT3:
 390       return GL_COMPRESSED_RGBA_S3TC_DXT3_EXT;
 391    case MESA_FORMAT_RGBA_DXT5:
 392       return GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
 393 #if FEATURE_EXT_texture_sRGB
 394    case MESA_FORMAT_SRGB_DXT1:
 395       return GL_COMPRESSED_SRGB_S3TC_DXT1_EXT;
 396    case MESA_FORMAT_SRGBA_DXT1:
 397       return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT;
 398    case MESA_FORMAT_SRGBA_DXT3:
 399       return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT;
 400    case MESA_FORMAT_SRGBA_DXT5:
 401       return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT;
 402 #endif
 403 #endif
 404
 405    case MESA_FORMAT_RED_RGTC1:
 406       return GL_COMPRESSED_RED_RGTC1;
 407    case MESA_FORMAT_SIGNED_RED_RGTC1:
 408       return GL_COMPRESSED_SIGNED_RED_RGTC1;
 409    case MESA_FORMAT_RG_RGTC2:
 410       return GL_COMPRESSED_RG_RGTC2;
 411    case MESA_FORMAT_SIGNED_RG_RGTC2:
 412       return GL_COMPRESSED_SIGNED_RG_RGTC2;
 413
 414    case MESA_FORMAT_L_LATC1:
 415       return GL_COMPRESSED_LUMINANCE_LATC1_EXT;
 416    case MESA_FORMAT_SIGNED_L_LATC1:
 417       return GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT;
 418    case MESA_FORMAT_LA_LATC2:
 419       return GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT;
 420    case MESA_FORMAT_SIGNED_LA_LATC2:
 421       return GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT;
 422
 423    case MESA_FORMAT_ETC1_RGB8:
 424       return GL_ETC1_RGB8_OES;
 425
 426    default:
 427       _mesa_problem(ctx, "Unexpected mesa texture format in"
 428                     " _mesa_compressed_format_to_glenum()");
 429       return 0;
 430    }
 431 }
 432
 433
 434 /*
 435  * Return the address of the pixel at (col, row, img) in a
 436  * compressed texture image.
 437  * \param col, row, img - image position (3D), should be a multiple of the
 438  *                        format's block size.
 439  * \param format - compressed image format
 440  * \param width - image width (stride) in pixels
 441  * \param image - the image address
 442  * \return address of pixel at (row, col, img)
 443  */
 444 GLubyte *
 445 _mesa_compressed_image_address(GLint col, GLint row, GLint img,
 446                                gl_format mesaFormat,
 447                                GLsizei width, const GLubyte *image)
 448 {
 449    /* XXX only 2D images implemented, not 3D */
 450    const GLuint blockSize = _mesa_get_format_bytes(mesaFormat);
 451    GLuint bw, bh;
 452    GLint offset;
 453
 454    _mesa_get_format_block_size(mesaFormat, &bw, &bh);
 455
 456    ASSERT(col % bw == 0);
 457    ASSERT(row % bh == 0);
 458
 459    offset = ((width + bw - 1) / bw) * (row / bh) + col / bw;
 460    offset *= blockSize;
 461
 462    return (GLubyte *) image + offset;
 463 }
 464
 465
 466 /**
 467  * Decompress a compressed texture image, returning a GL_RGBA/GL_FLOAT image.
 468  */
 469 void
 470 _mesa_decompress_image(gl_format format, GLuint width, GLuint height,
 471                        const GLubyte *src, GLint srcRowStride,
 472                        GLfloat *dest)
 473 {
 474    void (*fetch)(const struct swrast_texture_image *texImage,
 475                  GLint i, GLint j, GLint k, GLfloat *texel);
 476    struct swrast_texture_image texImage;  /* dummy teximage */
 477    GLuint i, j;
 478
 479    /* setup dummy texture image info */
 480    memset(&texImage, 0, sizeof(texImage));
 481    texImage.Map = (void *) src;
 482    texImage.RowStride = srcRowStride;
 483
 484    switch (format) {
 485    /* DXT formats */
 486    case MESA_FORMAT_RGB_DXT1:
 487       fetch = _mesa_fetch_texel_2d_f_rgb_dxt1;
 488       break;
 489    case MESA_FORMAT_RGBA_DXT1:
 490       fetch = _mesa_fetch_texel_2d_f_rgba_dxt1;
 491       break;
 492    case MESA_FORMAT_RGBA_DXT3:
 493       fetch = _mesa_fetch_texel_2d_f_rgba_dxt3;
 494       break;
 495    case MESA_FORMAT_RGBA_DXT5:
 496       fetch = _mesa_fetch_texel_2d_f_rgba_dxt5;
 497       break;
 498
 499    /* FXT1 formats */
 500    case MESA_FORMAT_RGB_FXT1:
 501       fetch = _mesa_fetch_texel_2d_f_rgb_fxt1;
 502       break;
 503    case MESA_FORMAT_RGBA_FXT1:
 504       fetch = _mesa_fetch_texel_2d_f_rgba_fxt1;
 505       break;
 506
 507    /* Red/RG formats */
 508    case MESA_FORMAT_RED_RGTC1:
 509       fetch = _mesa_fetch_texel_2d_f_red_rgtc1;
 510       break;
 511    case MESA_FORMAT_SIGNED_RED_RGTC1:
 512       fetch = _mesa_fetch_texel_2d_f_signed_red_rgtc1;
 513       break;
 514    case MESA_FORMAT_RG_RGTC2:
 515       fetch = _mesa_fetch_texel_2d_f_rg_rgtc2;
 516       break;
 517    case MESA_FORMAT_SIGNED_RG_RGTC2:
 518       fetch = _mesa_fetch_texel_2d_f_signed_rg_rgtc2;
 519       break;
 520
 521    /* L/LA formats */
 522    case MESA_FORMAT_L_LATC1:
 523       fetch = _mesa_fetch_texel_2d_f_l_latc1;
 524       break;
 525    case MESA_FORMAT_SIGNED_L_LATC1:
 526       fetch = _mesa_fetch_texel_2d_f_signed_l_latc1;
 527       break;
 528    case MESA_FORMAT_LA_LATC2:
 529       fetch = _mesa_fetch_texel_2d_f_la_latc2;
 530       break;
 531    case MESA_FORMAT_SIGNED_LA_LATC2:
 532       fetch = _mesa_fetch_texel_2d_f_signed_la_latc2;
 533       break;
 534
 535    /* ETC1 formats */
 536    case MESA_FORMAT_ETC1_RGB8:
 537       fetch = _mesa_fetch_texel_2d_f_etc1_rgb8;
 538       break;
 539
 540    default:
 541       _mesa_problem(NULL, "Unexpected format in _mesa_decompress_image()");
 542       return;
 543    }
 544
 545    for (j = 0; j < height; j++) {
 546       for (i = 0; i < width; i++) {
 547          fetch(&texImage, i, j, 0, dest);
 548          dest += 4;
 549       }
 550    }
 551 }