src/mesa/main/texcompress_s3tc.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.1
   4  *
   5  * Copyright (C) 1999-2004  Brian Paul   All Rights Reserved.
   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  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25
  26 /**
  27  * \file texcompress_s3tc.c
  28  * GL_EXT_texture_compression_s3tc support.
  29  */
  30
  31 #ifndef USE_EXTERNAL_DXTN_LIB
  32 #define USE_EXTERNAL_DXTN_LIB 0
  33 #endif
  34
  35 #include "glheader.h"
  36 #include "imports.h"
  37 #include "colormac.h"
  38 #include "context.h"
  39 #include "convolve.h"
  40 #include "image.h"
  41 #include "texcompress.h"
  42 #include "texformat.h"
  43 #include "texstore.h"
  44
  45 #if USE_EXTERNAL_DXTN_LIB
  46 #ifdef __MINGW32__
  47 /* no dlopen */
  48 #define DXTN_EXT "dxtn.dll"
  49 #define DXTN_PREFIX ""
  50 #define dlopen(name, mode) LoadLibrary(name)
  51 #define dlsym(hndl, proc) GetProcAddress(hndl, proc)
  52 #define dlclose(hndl) FreeLibrary(hndl)
  53 #elif defined(__DJGPP__)
  54 /* has dlopen, but doesn't like the names */
  55 #include <dlfcn.h>
  56 #define DXTN_EXT "dxtn.dxe"
  57 #define DXTN_PREFIX "_"
  58 #else
  59 /* happiness */
  60 #include <dlfcn.h>
  61 #define DXTN_EXT "libtxc_dxtn.so"
  62 #define DXTN_PREFIX ""
  63 #endif
  64 #endif /* USE_EXTERNAL_DXTN_LIB */
  65
  66 typedef void (*dxtFetchTexelFuncExt)( GLint srcRowstride, GLubyte *pixdata, GLint col, GLint row, GLvoid *texelOut );
  67 dxtFetchTexelFuncExt fetch_ext_rgb_dxt1 = NULL;
  68 dxtFetchTexelFuncExt fetch_ext_rgba_dxt1 = NULL;
  69 dxtFetchTexelFuncExt fetch_ext_rgba_dxt3 = NULL;
  70 dxtFetchTexelFuncExt fetch_ext_rgba_dxt5 = NULL;
  71
  72 typedef void (*dxtCompressTexFuncExt)(GLint srccomps, GLint width, GLint height, const GLubyte *srcPixData, GLenum destformat, GLubyte *dest, GLint dstRowStride);
  73 dxtCompressTexFuncExt ext_tx_compress_dxtn = NULL;
  74
  75 void *dxtlibhandle = NULL;
  76
  77 void
  78 _mesa_init_texture_s3tc( GLcontext *ctx )
  79 {
  80    /* called during context initialization */
  81    ctx->Mesa_DXTn = GL_FALSE;
  82 #if USE_EXTERNAL_DXTN_LIB
  83    if (!dxtlibhandle) {
  84       dxtlibhandle = dlopen (DXTN_EXT, RTLD_LAZY | RTLD_GLOBAL);
  85       if (!dxtlibhandle) {
  86          _mesa_warning(ctx, "couldn't open " DXTN_EXT ", software DXTn "
  87             "compression/decompression unavailable\n");
  88       }
  89       else {
  90          /* the fetch functions are not per context! Might be problematic... */
  91          fetch_ext_rgb_dxt1 = (dxtFetchTexelFuncExt)dlsym(dxtlibhandle, DXTN_PREFIX "fetch_2d_texel_rgb_dxt1");
  92          if (fetch_ext_rgb_dxt1 != NULL) {
  93             fetch_ext_rgba_dxt1 = (dxtFetchTexelFuncExt)dlsym(dxtlibhandle, DXTN_PREFIX "fetch_2d_texel_rgba_dxt1");
  94          }
  95          if (fetch_ext_rgba_dxt1 != NULL) {
  96             fetch_ext_rgba_dxt3 = (dxtFetchTexelFuncExt)dlsym(dxtlibhandle, DXTN_PREFIX "fetch_2d_texel_rgba_dxt3");
  97          }
  98          if (fetch_ext_rgba_dxt3 != NULL) {
  99             fetch_ext_rgba_dxt5 = (dxtFetchTexelFuncExt)dlsym(dxtlibhandle, DXTN_PREFIX "fetch_2d_texel_rgba_dxt5");
 100          }
 101          if (fetch_ext_rgba_dxt5 != NULL) {
 102             ext_tx_compress_dxtn = (dxtCompressTexFuncExt)dlsym(dxtlibhandle, DXTN_PREFIX "tx_compress_dxtn");
 103          }
 104
 105          if (ext_tx_compress_dxtn == NULL) {
 106             _mesa_warning(ctx, "couldn't reference all symbols in "
 107                DXTN_EXT ", software DXTn compression/decompression "
 108                "unavailable\n");
 109             fetch_ext_rgb_dxt1 = NULL;
 110             fetch_ext_rgba_dxt1 = NULL;
 111             fetch_ext_rgba_dxt3 = NULL;
 112             fetch_ext_rgba_dxt5 = NULL;
 113             ext_tx_compress_dxtn = NULL;
 114             dlclose(dxtlibhandle);
 115             dxtlibhandle = NULL;
 116          }
 117       }
 118    }
 119    if (dxtlibhandle) {
 120       ctx->Mesa_DXTn = GL_TRUE;
 121       _mesa_warning(ctx, "software DXTn compression/decompression available\n");
 122    }
 123 #else
 124    (void) ctx;
 125 #endif
 126 }
 127
 128 /**
 129  * Called via TexFormat->StoreImage to store an RGB_DXT1 texture.
 130  */
 131 static GLboolean
 132 texstore_rgb_dxt1(STORE_PARAMS)
 133 {
 134    const GLchan *pixels;
 135    GLint srcRowStride;
 136    GLubyte *dst;
 137    const GLint texWidth = dstRowStride * 4 / 8; /* a bit of a hack */
 138    const GLchan *tempImage = NULL;
 139
 140    ASSERT(dstFormat == &_mesa_texformat_rgb_dxt1);
 141    ASSERT(dstXoffset % 4 == 0);
 142    ASSERT(dstYoffset % 4 == 0);
 143    ASSERT(dstZoffset % 4 == 0);
 144    (void) dstZoffset; (void) dstImageStride;
 145
 146    if (srcFormat != GL_RGB ||
 147        srcType != CHAN_TYPE ||
 148        ctx->_ImageTransferState ||
 149        srcPacking->SwapBytes) {
 150       /* convert image to RGB/GLchan */
 151       tempImage = _mesa_make_temp_chan_image(ctx, dims,
 152                                              baseInternalFormat,
 153                                              dstFormat->BaseFormat,
 154                                              srcWidth, srcHeight, srcDepth,
 155                                              srcFormat, srcType, srcAddr,
 156                                              srcPacking);
 157       if (!tempImage)
 158          return GL_FALSE; /* out of memory */
 159       _mesa_adjust_image_for_convolution(ctx, dims, &srcWidth, &srcHeight);
 160       pixels = tempImage;
 161       srcRowStride = 3 * srcWidth;
 162       srcFormat = GL_RGB;
 163    }
 164    else {
 165       pixels = (const GLchan *) srcAddr;
 166       srcRowStride = _mesa_image_row_stride(srcPacking, srcWidth, srcFormat,
 167                                             srcType) / sizeof(GLchan);
 168    }
 169
 170    dst = _mesa_compressed_image_address(dstXoffset, dstYoffset, 0,
 171                                         GL_COMPRESSED_RGB_S3TC_DXT1_EXT,
 172                                         texWidth, (GLubyte *) dstAddr);
 173
 174    if (ext_tx_compress_dxtn) {
 175       (*ext_tx_compress_dxtn)(3, srcWidth, srcHeight, pixels,  GL_COMPRESSED_RGB_S3TC_DXT1_EXT, dst, dstRowStride);
 176    }
 177    else {
 178       _mesa_problem(ctx, "external dxt library not available");
 179    }
 180
 181    if (tempImage)
 182       _mesa_free((void *) tempImage);
 183
 184    return GL_TRUE;
 185 }
 186
 187
 188 /**
 189  * Called via TexFormat->StoreImage to store an RGBA_DXT1 texture.
 190  */
 191 static GLboolean
 192 texstore_rgba_dxt1(STORE_PARAMS)
 193 {
 194    const GLchan *pixels;
 195    GLint srcRowStride;
 196    GLubyte *dst;
 197    const GLint texWidth = dstRowStride * 4 / 8; /* a bit of a hack */
 198    const GLchan *tempImage = NULL;
 199
 200    ASSERT(dstFormat == &_mesa_texformat_rgba_dxt1);
 201    ASSERT(dstXoffset % 4 == 0);
 202    ASSERT(dstYoffset % 4 == 0);
 203    ASSERT(dstZoffset % 4 == 0);
 204    (void) dstZoffset; (void) dstImageStride;
 205
 206    if (srcFormat != GL_RGBA ||
 207        srcType != CHAN_TYPE ||
 208        ctx->_ImageTransferState ||
 209        srcPacking->SwapBytes) {
 210       /* convert image to RGBA/GLchan */
 211       tempImage = _mesa_make_temp_chan_image(ctx, dims,
 212                                              baseInternalFormat,
 213                                              dstFormat->BaseFormat,
 214                                              srcWidth, srcHeight, srcDepth,
 215                                              srcFormat, srcType, srcAddr,
 216                                              srcPacking);
 217       if (!tempImage)
 218          return GL_FALSE; /* out of memory */
 219       _mesa_adjust_image_for_convolution(ctx, dims, &srcWidth, &srcHeight);
 220       pixels = tempImage;
 221       srcRowStride = 4 * srcWidth;
 222       srcFormat = GL_RGBA;
 223    }
 224    else {
 225       pixels = (const GLchan *) srcAddr;
 226       srcRowStride = _mesa_image_row_stride(srcPacking, srcWidth, srcFormat,
 227                                             srcType) / sizeof(GLchan);
 228    }
 229
 230    dst = _mesa_compressed_image_address(dstXoffset, dstYoffset, 0,
 231                                         GL_COMPRESSED_RGBA_S3TC_DXT1_EXT,
 232                                         texWidth, (GLubyte *) dstAddr);
 233    if (ext_tx_compress_dxtn) {
 234       (*ext_tx_compress_dxtn)(4, srcWidth, srcHeight, pixels,  GL_COMPRESSED_RGBA_S3TC_DXT1_EXT, dst, dstRowStride);
 235    }
 236    else {
 237       _mesa_problem(ctx, "external dxt library not available");
 238    }
 239
 240    if (tempImage)
 241       _mesa_free((void*) tempImage);
 242
 243    return GL_TRUE;
 244 }
 245
 246
 247 /**
 248  * Called via TexFormat->StoreImage to store an RGBA_DXT3 texture.
 249  */
 250 static GLboolean
 251 texstore_rgba_dxt3(STORE_PARAMS)
 252 {
 253    const GLchan *pixels;
 254    GLint srcRowStride;
 255    GLubyte *dst;
 256    const GLint texWidth = dstRowStride * 4 / 16; /* a bit of a hack */
 257    const GLchan *tempImage = NULL;
 258
 259    ASSERT(dstFormat == &_mesa_texformat_rgba_dxt3);
 260    ASSERT(dstXoffset % 4 == 0);
 261    ASSERT(dstYoffset % 4 == 0);
 262    ASSERT(dstZoffset % 4 == 0);
 263    (void) dstZoffset; (void) dstImageStride;
 264
 265    if (srcFormat != GL_RGBA ||
 266        srcType != CHAN_TYPE ||
 267        ctx->_ImageTransferState ||
 268        srcPacking->SwapBytes) {
 269       /* convert image to RGBA/GLchan */
 270       tempImage = _mesa_make_temp_chan_image(ctx, dims,
 271                                              baseInternalFormat,
 272                                              dstFormat->BaseFormat,
 273                                              srcWidth, srcHeight, srcDepth,
 274                                              srcFormat, srcType, srcAddr,
 275                                              srcPacking);
 276       if (!tempImage)
 277          return GL_FALSE; /* out of memory */
 278       _mesa_adjust_image_for_convolution(ctx, dims, &srcWidth, &srcHeight);
 279       pixels = tempImage;
 280       srcRowStride = 4 * srcWidth;
 281    }
 282    else {
 283       pixels = (const GLchan *) srcAddr;
 284       srcRowStride = _mesa_image_row_stride(srcPacking, srcWidth, srcFormat,
 285                                             srcType) / sizeof(GLchan);
 286    }
 287
 288    dst = _mesa_compressed_image_address(dstXoffset, dstYoffset, 0,
 289                                         GL_COMPRESSED_RGBA_S3TC_DXT3_EXT,
 290                                         texWidth, (GLubyte *) dstAddr);
 291    if (ext_tx_compress_dxtn) {
 292       (*ext_tx_compress_dxtn)(4, srcWidth, srcHeight, pixels,  GL_COMPRESSED_RGBA_S3TC_DXT3_EXT, dst, dstRowStride);
 293    }
 294    else {
 295       _mesa_problem(ctx, "external dxt library not available");
 296    }
 297
 298    if (tempImage)
 299       _mesa_free((void *) tempImage);
 300
 301    return GL_TRUE;
 302 }
 303
 304
 305 /**
 306  * Called via TexFormat->StoreImage to store an RGBA_DXT5 texture.
 307  */
 308 static GLboolean
 309 texstore_rgba_dxt5(STORE_PARAMS)
 310 {
 311    const GLchan *pixels;
 312    GLint srcRowStride;
 313    GLubyte *dst;
 314    const GLint texWidth = dstRowStride * 4 / 16; /* a bit of a hack */
 315    const GLchan *tempImage = NULL;
 316
 317    ASSERT(dstFormat == &_mesa_texformat_rgba_dxt5);
 318    ASSERT(dstXoffset % 4 == 0);
 319    ASSERT(dstYoffset % 4 == 0);
 320    ASSERT(dstZoffset % 4 == 0);
 321    (void) dstZoffset; (void) dstImageStride;
 322
 323    if (srcFormat != GL_RGBA ||
 324        srcType != CHAN_TYPE ||
 325        ctx->_ImageTransferState ||
 326        srcPacking->SwapBytes) {
 327       /* convert image to RGBA/GLchan */
 328       tempImage = _mesa_make_temp_chan_image(ctx, dims,
 329                                              baseInternalFormat,
 330                                              dstFormat->BaseFormat,
 331                                              srcWidth, srcHeight, srcDepth,
 332                                              srcFormat, srcType, srcAddr,
 333                                              srcPacking);
 334       if (!tempImage)
 335          return GL_FALSE; /* out of memory */
 336       _mesa_adjust_image_for_convolution(ctx, dims, &srcWidth, &srcHeight);
 337       pixels = tempImage;
 338       srcRowStride = 4 * srcWidth;
 339    }
 340    else {
 341       pixels = (const GLchan *) srcAddr;
 342       srcRowStride = _mesa_image_row_stride(srcPacking, srcWidth, srcFormat,
 343                                             srcType) / sizeof(GLchan);
 344    }
 345
 346    dst = _mesa_compressed_image_address(dstXoffset, dstYoffset, 0,
 347                                         GL_COMPRESSED_RGBA_S3TC_DXT5_EXT,
 348                                         texWidth, (GLubyte *) dstAddr);
 349    if (ext_tx_compress_dxtn) {
 350       (*ext_tx_compress_dxtn)(4, srcWidth, srcHeight, pixels,  GL_COMPRESSED_RGBA_S3TC_DXT5_EXT, dst, dstRowStride);
 351    }
 352    else {
 353       _mesa_problem(ctx, "external dxt library not available");
 354    }
 355
 356    if (tempImage)
 357       _mesa_free((void *) tempImage);
 358
 359    return GL_TRUE;
 360 }
 361
 362
 363 static void
 364 fetch_texel_2d_rgb_dxt1( const struct gl_texture_image *texImage,
 365                          GLint i, GLint j, GLint k, GLchan *texel )
 366 {
 367     (void) k;
 368     if (fetch_ext_rgb_dxt1) {
 369        ASSERT (sizeof(GLchan) == sizeof(GLubyte));
 370        (*fetch_ext_rgb_dxt1)((texImage)->RowStride, (GLubyte *)(texImage)->Data, i, j, texel);
 371     }
 372     else _mesa_debug(NULL, "attempted to decode s3tc texture without library available\n");
 373 }
 374
 375
 376 static void
 377 fetch_texel_2d_f_rgb_dxt1( const struct gl_texture_image *texImage,
 378                             GLint i, GLint j, GLint k, GLfloat *texel )
 379 {
 380    /* just sample as GLchan and convert to float here */
 381    GLchan rgba[4];
 382    fetch_texel_2d_rgb_dxt1(texImage, i, j, k, rgba);
 383    texel[RCOMP] = CHAN_TO_FLOAT(rgba[RCOMP]);
 384    texel[GCOMP] = CHAN_TO_FLOAT(rgba[GCOMP]);
 385    texel[BCOMP] = CHAN_TO_FLOAT(rgba[BCOMP]);
 386    texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);
 387 }
 388
 389
 390 static void
 391 fetch_texel_2d_rgba_dxt1( const struct gl_texture_image *texImage,
 392                           GLint i, GLint j, GLint k, GLchan *texel )
 393 {
 394    (void) k;
 395    if (fetch_ext_rgba_dxt1) {
 396        (*fetch_ext_rgba_dxt1)((texImage)->RowStride, (GLubyte *)(texImage)->Data, i, j, texel);
 397     }
 398     else _mesa_debug(NULL, "attempted to decode s3tc texture without library available\n");
 399 }
 400
 401
 402 static void
 403 fetch_texel_2d_f_rgba_dxt1( const struct gl_texture_image *texImage,
 404                             GLint i, GLint j, GLint k, GLfloat *texel )
 405 {
 406    /* just sample as GLchan and convert to float here */
 407    GLchan rgba[4];
 408    fetch_texel_2d_rgba_dxt1(texImage, i, j, k, rgba);
 409    texel[RCOMP] = CHAN_TO_FLOAT(rgba[RCOMP]);
 410    texel[GCOMP] = CHAN_TO_FLOAT(rgba[GCOMP]);
 411    texel[BCOMP] = CHAN_TO_FLOAT(rgba[BCOMP]);
 412    texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);
 413 }
 414
 415
 416 static void
 417 fetch_texel_2d_rgba_dxt3( const struct gl_texture_image *texImage,
 418                           GLint i, GLint j, GLint k, GLchan *texel )
 419 {
 420    (void) k;
 421    if (fetch_ext_rgba_dxt3) {
 422        ASSERT (sizeof(GLchan) == sizeof(GLubyte));
 423        (*fetch_ext_rgba_dxt3)((texImage)->RowStride, (GLubyte *)(texImage)->Data, i, j, texel);
 424     }
 425     else _mesa_debug(NULL, "attempted to decode s3tc texture without library available\n");
 426 }
 427
 428
 429 static void
 430 fetch_texel_2d_f_rgba_dxt3( const struct gl_texture_image *texImage,
 431                             GLint i, GLint j, GLint k, GLfloat *texel )
 432 {
 433    /* just sample as GLchan and convert to float here */
 434    GLchan rgba[4];
 435    fetch_texel_2d_rgba_dxt3(texImage, i, j, k, rgba);
 436    texel[RCOMP] = CHAN_TO_FLOAT(rgba[RCOMP]);
 437    texel[GCOMP] = CHAN_TO_FLOAT(rgba[GCOMP]);
 438    texel[BCOMP] = CHAN_TO_FLOAT(rgba[BCOMP]);
 439    texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);
 440 }
 441
 442
 443 static void
 444 fetch_texel_2d_rgba_dxt5( const struct gl_texture_image *texImage,
 445                           GLint i, GLint j, GLint k, GLchan *texel )
 446 {
 447    (void) k;
 448    if (fetch_ext_rgba_dxt5) {
 449        (*fetch_ext_rgba_dxt5)((texImage)->RowStride, (GLubyte *)(texImage)->Data, i, j, texel);
 450     }
 451     else _mesa_debug(NULL, "attempted to decode s3tc texture without library available\n");
 452 }
 453
 454
 455 static void
 456 fetch_texel_2d_f_rgba_dxt5( const struct gl_texture_image *texImage,
 457                             GLint i, GLint j, GLint k, GLfloat *texel )
 458 {
 459    /* just sample as GLchan and convert to float here */
 460    GLchan rgba[4];
 461    fetch_texel_2d_rgba_dxt5(texImage, i, j, k, rgba);
 462    texel[RCOMP] = CHAN_TO_FLOAT(rgba[RCOMP]);
 463    texel[GCOMP] = CHAN_TO_FLOAT(rgba[GCOMP]);
 464    texel[BCOMP] = CHAN_TO_FLOAT(rgba[BCOMP]);
 465    texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);
 466 }
 467
 468
 469 const struct gl_texture_format _mesa_texformat_rgb_dxt1 = {
 470    MESA_FORMAT_RGB_DXT1,                /* MesaFormat */
 471    GL_RGB,                              /* BaseFormat */
 472    GL_UNSIGNED_NORMALIZED_ARB,          /* DataType */
 473    4, /*approx*/                        /* RedBits */
 474    4, /*approx*/                        /* GreenBits */
 475    4, /*approx*/                        /* BlueBits */
 476    0,                                   /* AlphaBits */
 477    0,                                   /* LuminanceBits */
 478    0,                                   /* IntensityBits */
 479    0,                                   /* IndexBits */
 480    0,                                   /* DepthBits */
 481    0,                                   /* TexelBytes */
 482    texstore_rgb_dxt1,                   /* StoreTexImageFunc */
 483    NULL, /*impossible*/                 /* FetchTexel1D */
 484    fetch_texel_2d_rgb_dxt1,             /* FetchTexel2D */
 485    NULL, /*impossible*/                 /* FetchTexel3D */
 486    NULL, /*impossible*/                 /* FetchTexel1Df */
 487    fetch_texel_2d_f_rgb_dxt1,           /* FetchTexel2Df */
 488    NULL, /*impossible*/                 /* FetchTexel3Df */
 489 };
 490
 491 const struct gl_texture_format _mesa_texformat_rgba_dxt1 = {
 492    MESA_FORMAT_RGBA_DXT1,               /* MesaFormat */
 493    GL_RGBA,                             /* BaseFormat */
 494    GL_UNSIGNED_NORMALIZED_ARB,          /* DataType */
 495    4, /*approx*/                        /* RedBits */
 496    4, /*approx*/                        /* GreenBits */
 497    4, /*approx*/                        /* BlueBits */
 498    1, /*approx*/                        /* AlphaBits */
 499    0,                                   /* LuminanceBits */
 500    0,                                   /* IntensityBits */
 501    0,                                   /* IndexBits */
 502    0,                                   /* DepthBits */
 503    0,                                   /* TexelBytes */
 504    texstore_rgba_dxt1,                  /* StoreTexImageFunc */
 505    NULL, /*impossible*/                 /* FetchTexel1D */
 506    fetch_texel_2d_rgba_dxt1,            /* FetchTexel2D */
 507    NULL, /*impossible*/                 /* FetchTexel3D */
 508    NULL, /*impossible*/                 /* FetchTexel1Df */
 509    fetch_texel_2d_f_rgba_dxt1,          /* FetchTexel2Df */
 510    NULL, /*impossible*/                 /* FetchTexel3Df */
 511 };
 512
 513 const struct gl_texture_format _mesa_texformat_rgba_dxt3 = {
 514    MESA_FORMAT_RGBA_DXT3,               /* MesaFormat */
 515    GL_RGBA,                             /* BaseFormat */
 516    GL_UNSIGNED_NORMALIZED_ARB,          /* DataType */
 517    4, /*approx*/                        /* RedBits */
 518    4, /*approx*/                        /* GreenBits */
 519    4, /*approx*/                        /* BlueBits */
 520    4, /*approx*/                        /* AlphaBits */
 521    0,                                   /* LuminanceBits */
 522    0,                                   /* IntensityBits */
 523    0,                                   /* IndexBits */
 524    0,                                   /* DepthBits */
 525    0,                                   /* TexelBytes */
 526    texstore_rgba_dxt3,                  /* StoreTexImageFunc */
 527    NULL, /*impossible*/                 /* FetchTexel1D */
 528    fetch_texel_2d_rgba_dxt3,            /* FetchTexel2D */
 529    NULL, /*impossible*/                 /* FetchTexel3D */
 530    NULL, /*impossible*/                 /* FetchTexel1Df */
 531    fetch_texel_2d_f_rgba_dxt3,          /* FetchTexel2Df */
 532    NULL, /*impossible*/                 /* FetchTexel3Df */
 533 };
 534
 535 const struct gl_texture_format _mesa_texformat_rgba_dxt5 = {
 536    MESA_FORMAT_RGBA_DXT5,               /* MesaFormat */
 537    GL_RGBA,                             /* BaseFormat */
 538    GL_UNSIGNED_NORMALIZED_ARB,          /* DataType */
 539    4,/*approx*/                         /* RedBits */
 540    4,/*approx*/                         /* GreenBits */
 541    4,/*approx*/                         /* BlueBits */
 542    4,/*approx*/                         /* AlphaBits */
 543    0,                                   /* LuminanceBits */
 544    0,                                   /* IntensityBits */
 545    0,                                   /* IndexBits */
 546    0,                                   /* DepthBits */
 547    0,                                   /* TexelBytes */
 548    texstore_rgba_dxt5,                  /* StoreTexImageFunc */
 549    NULL, /*impossible*/                 /* FetchTexel1D */
 550    fetch_texel_2d_rgba_dxt5,            /* FetchTexel2D */
 551    NULL, /*impossible*/                 /* FetchTexel3D */
 552    NULL, /*impossible*/                 /* FetchTexel1Df */
 553    fetch_texel_2d_f_rgba_dxt5,          /* FetchTexel2Df */
 554    NULL, /*impossible*/                 /* FetchTexel3Df */
 555 };