src/mesa/main/texcompress_s3tc.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.5
   4  *
   5  * Copyright (C) 1999-2005  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,
  73                                       GLint height, const GLchan *srcPixData,
  74                                       GLenum destformat, GLubyte *dest,
  75                                       GLint dstRowStride);
  76 static dxtCompressTexFuncExt ext_tx_compress_dxtn = NULL;
  77
  78 static void *dxtlibhandle = NULL;
  79
  80
  81 void
  82 _mesa_init_texture_s3tc( GLcontext *ctx )
  83 {
  84    /* called during context initialization */
  85    ctx->Mesa_DXTn = GL_FALSE;
  86 #if USE_EXTERNAL_DXTN_LIB
  87    if (!dxtlibhandle) {
  88       dxtlibhandle = dlopen (DXTN_EXT, RTLD_LAZY | RTLD_GLOBAL);
  89       if (!dxtlibhandle) {
  90          _mesa_warning(ctx, "couldn't open " DXTN_EXT ", software DXTn "
  91             "compression/decompression unavailable");
  92       }
  93       else {
  94          /* the fetch functions are not per context! Might be problematic... */
  95          fetch_ext_rgb_dxt1 = (dxtFetchTexelFuncExt)dlsym(dxtlibhandle, DXTN_PREFIX "fetch_2d_texel_rgb_dxt1");
  96          if (fetch_ext_rgb_dxt1 != NULL) {
  97             fetch_ext_rgba_dxt1 = (dxtFetchTexelFuncExt)dlsym(dxtlibhandle, DXTN_PREFIX "fetch_2d_texel_rgba_dxt1");
  98          }
  99          if (fetch_ext_rgba_dxt1 != NULL) {
 100             fetch_ext_rgba_dxt3 = (dxtFetchTexelFuncExt)dlsym(dxtlibhandle, DXTN_PREFIX "fetch_2d_texel_rgba_dxt3");
 101          }
 102          if (fetch_ext_rgba_dxt3 != NULL) {
 103             fetch_ext_rgba_dxt5 = (dxtFetchTexelFuncExt)dlsym(dxtlibhandle, DXTN_PREFIX "fetch_2d_texel_rgba_dxt5");
 104          }
 105          if (fetch_ext_rgba_dxt5 != NULL) {
 106             ext_tx_compress_dxtn = (dxtCompressTexFuncExt)dlsym(dxtlibhandle, DXTN_PREFIX "tx_compress_dxtn");
 107          }
 108
 109          if (ext_tx_compress_dxtn == NULL) {
 110             _mesa_warning(ctx, "couldn't reference all symbols in "
 111                DXTN_EXT ", software DXTn compression/decompression "
 112                "unavailable");
 113             fetch_ext_rgb_dxt1 = NULL;
 114             fetch_ext_rgba_dxt1 = NULL;
 115             fetch_ext_rgba_dxt3 = NULL;
 116             fetch_ext_rgba_dxt5 = NULL;
 117             ext_tx_compress_dxtn = NULL;
 118             dlclose(dxtlibhandle);
 119             dxtlibhandle = NULL;
 120          }
 121       }
 122    }
 123    if (dxtlibhandle) {
 124       ctx->Mesa_DXTn = GL_TRUE;
 125       _mesa_warning(ctx, "software DXTn compression/decompression available");
 126    }
 127 #else
 128    (void) ctx;
 129 #endif
 130 }
 131
 132 /**
 133  * Called via TexFormat->StoreImage to store an RGB_DXT1 texture.
 134  */
 135 static GLboolean
 136 texstore_rgb_dxt1(TEXSTORE_PARAMS)
 137 {
 138    const GLchan *pixels;
 139    GLint srcRowStride;
 140    GLubyte *dst;
 141    const GLint texWidth = dstRowStride * 4 / 8; /* a bit of a hack */
 142    const GLchan *tempImage = NULL;
 143
 144    ASSERT(dstFormat == &_mesa_texformat_rgb_dxt1);
 145    ASSERT(dstXoffset % 4 == 0);
 146    ASSERT(dstYoffset % 4 == 0);
 147    ASSERT(dstZoffset % 4 == 0);
 148    (void) dstZoffset;
 149    (void) dstImageOffsets;
 150
 151    if (srcFormat != GL_RGB ||
 152        srcType != CHAN_TYPE ||
 153        ctx->_ImageTransferState ||
 154        srcPacking->SwapBytes) {
 155       /* convert image to RGB/GLchan */
 156       tempImage = _mesa_make_temp_chan_image(ctx, dims,
 157                                              baseInternalFormat,
 158                                              dstFormat->BaseFormat,
 159                                              srcWidth, srcHeight, srcDepth,
 160                                              srcFormat, srcType, srcAddr,
 161                                              srcPacking);
 162       if (!tempImage)
 163          return GL_FALSE; /* out of memory */
 164       _mesa_adjust_image_for_convolution(ctx, dims, &srcWidth, &srcHeight);
 165       pixels = tempImage;
 166       srcRowStride = 3 * srcWidth;
 167       srcFormat = GL_RGB;
 168    }
 169    else {
 170       pixels = (const GLchan *) srcAddr;
 171       srcRowStride = _mesa_image_row_stride(srcPacking, srcWidth, srcFormat,
 172                                             srcType) / sizeof(GLchan);
 173    }
 174
 175    dst = _mesa_compressed_image_address(dstXoffset, dstYoffset, 0,
 176                                         dstFormat->MesaFormat,
 177                                         texWidth, (GLubyte *) dstAddr);
 178
 179    if (ext_tx_compress_dxtn) {
 180       (*ext_tx_compress_dxtn)(3, srcWidth, srcHeight, pixels,
 181                               GL_COMPRESSED_RGB_S3TC_DXT1_EXT,
 182                               dst, dstRowStride);
 183    }
 184    else {
 185       _mesa_problem(ctx, "external dxt library not available");
 186    }
 187
 188    if (tempImage)
 189       _mesa_free((void *) tempImage);
 190
 191    return GL_TRUE;
 192 }
 193
 194
 195 /**
 196  * Called via TexFormat->StoreImage to store an RGBA_DXT1 texture.
 197  */
 198 static GLboolean
 199 texstore_rgba_dxt1(TEXSTORE_PARAMS)
 200 {
 201    const GLchan *pixels;
 202    GLint srcRowStride;
 203    GLubyte *dst;
 204    const GLint texWidth = dstRowStride * 4 / 8; /* a bit of a hack */
 205    const GLchan *tempImage = NULL;
 206
 207    ASSERT(dstFormat == &_mesa_texformat_rgba_dxt1);
 208    ASSERT(dstXoffset % 4 == 0);
 209    ASSERT(dstYoffset % 4 == 0);
 210    ASSERT(dstZoffset % 4 == 0);
 211    (void) dstZoffset;
 212    (void) dstImageOffsets;
 213
 214    if (srcFormat != GL_RGBA ||
 215        srcType != CHAN_TYPE ||
 216        ctx->_ImageTransferState ||
 217        srcPacking->SwapBytes) {
 218       /* convert image to RGBA/GLchan */
 219       tempImage = _mesa_make_temp_chan_image(ctx, dims,
 220                                              baseInternalFormat,
 221                                              dstFormat->BaseFormat,
 222                                              srcWidth, srcHeight, srcDepth,
 223                                              srcFormat, srcType, srcAddr,
 224                                              srcPacking);
 225       if (!tempImage)
 226          return GL_FALSE; /* out of memory */
 227       _mesa_adjust_image_for_convolution(ctx, dims, &srcWidth, &srcHeight);
 228       pixels = tempImage;
 229       srcRowStride = 4 * srcWidth;
 230       srcFormat = GL_RGBA;
 231    }
 232    else {
 233       pixels = (const GLchan *) srcAddr;
 234       srcRowStride = _mesa_image_row_stride(srcPacking, srcWidth, srcFormat,
 235                                             srcType) / sizeof(GLchan);
 236    }
 237
 238    dst = _mesa_compressed_image_address(dstXoffset, dstYoffset, 0,
 239                                         dstFormat->MesaFormat,
 240                                         texWidth, (GLubyte *) dstAddr);
 241    if (ext_tx_compress_dxtn) {
 242       (*ext_tx_compress_dxtn)(4, srcWidth, srcHeight, pixels,
 243                               GL_COMPRESSED_RGBA_S3TC_DXT1_EXT,
 244                               dst, dstRowStride);
 245    }
 246    else {
 247       _mesa_problem(ctx, "external dxt library not available");
 248    }
 249
 250    if (tempImage)
 251       _mesa_free((void*) tempImage);
 252
 253    return GL_TRUE;
 254 }
 255
 256
 257 /**
 258  * Called via TexFormat->StoreImage to store an RGBA_DXT3 texture.
 259  */
 260 static GLboolean
 261 texstore_rgba_dxt3(TEXSTORE_PARAMS)
 262 {
 263    const GLchan *pixels;
 264    GLint srcRowStride;
 265    GLubyte *dst;
 266    const GLint texWidth = dstRowStride * 4 / 16; /* a bit of a hack */
 267    const GLchan *tempImage = NULL;
 268
 269    ASSERT(dstFormat == &_mesa_texformat_rgba_dxt3);
 270    ASSERT(dstXoffset % 4 == 0);
 271    ASSERT(dstYoffset % 4 == 0);
 272    ASSERT(dstZoffset % 4 == 0);
 273    (void) dstZoffset;
 274    (void) dstImageOffsets;
 275
 276    if (srcFormat != GL_RGBA ||
 277        srcType != CHAN_TYPE ||
 278        ctx->_ImageTransferState ||
 279        srcPacking->SwapBytes) {
 280       /* convert image to RGBA/GLchan */
 281       tempImage = _mesa_make_temp_chan_image(ctx, dims,
 282                                              baseInternalFormat,
 283                                              dstFormat->BaseFormat,
 284                                              srcWidth, srcHeight, srcDepth,
 285                                              srcFormat, srcType, srcAddr,
 286                                              srcPacking);
 287       if (!tempImage)
 288          return GL_FALSE; /* out of memory */
 289       _mesa_adjust_image_for_convolution(ctx, dims, &srcWidth, &srcHeight);
 290       pixels = tempImage;
 291       srcRowStride = 4 * srcWidth;
 292    }
 293    else {
 294       pixels = (const GLchan *) srcAddr;
 295       srcRowStride = _mesa_image_row_stride(srcPacking, srcWidth, srcFormat,
 296                                             srcType) / sizeof(GLchan);
 297    }
 298
 299    dst = _mesa_compressed_image_address(dstXoffset, dstYoffset, 0,
 300                                         dstFormat->MesaFormat,
 301                                         texWidth, (GLubyte *) dstAddr);
 302    if (ext_tx_compress_dxtn) {
 303       (*ext_tx_compress_dxtn)(4, srcWidth, srcHeight, pixels,
 304                               GL_COMPRESSED_RGBA_S3TC_DXT3_EXT,
 305                               dst, dstRowStride);
 306    }
 307    else {
 308       _mesa_problem(ctx, "external dxt library not available");
 309    }
 310
 311    if (tempImage)
 312       _mesa_free((void *) tempImage);
 313
 314    return GL_TRUE;
 315 }
 316
 317
 318 /**
 319  * Called via TexFormat->StoreImage to store an RGBA_DXT5 texture.
 320  */
 321 static GLboolean
 322 texstore_rgba_dxt5(TEXSTORE_PARAMS)
 323 {
 324    const GLchan *pixels;
 325    GLint srcRowStride;
 326    GLubyte *dst;
 327    const GLint texWidth = dstRowStride * 4 / 16; /* a bit of a hack */
 328    const GLchan *tempImage = NULL;
 329
 330    ASSERT(dstFormat == &_mesa_texformat_rgba_dxt5);
 331    ASSERT(dstXoffset % 4 == 0);
 332    ASSERT(dstYoffset % 4 == 0);
 333    ASSERT(dstZoffset % 4 == 0);
 334    (void) dstZoffset;
 335    (void) dstImageOffsets;
 336
 337    if (srcFormat != GL_RGBA ||
 338        srcType != CHAN_TYPE ||
 339        ctx->_ImageTransferState ||
 340        srcPacking->SwapBytes) {
 341       /* convert image to RGBA/GLchan */
 342       tempImage = _mesa_make_temp_chan_image(ctx, dims,
 343                                              baseInternalFormat,
 344                                              dstFormat->BaseFormat,
 345                                              srcWidth, srcHeight, srcDepth,
 346                                              srcFormat, srcType, srcAddr,
 347                                              srcPacking);
 348       if (!tempImage)
 349          return GL_FALSE; /* out of memory */
 350       _mesa_adjust_image_for_convolution(ctx, dims, &srcWidth, &srcHeight);
 351       pixels = tempImage;
 352       srcRowStride = 4 * srcWidth;
 353    }
 354    else {
 355       pixels = (const GLchan *) srcAddr;
 356       srcRowStride = _mesa_image_row_stride(srcPacking, srcWidth, srcFormat,
 357                                             srcType) / sizeof(GLchan);
 358    }
 359
 360    dst = _mesa_compressed_image_address(dstXoffset, dstYoffset, 0,
 361                                         dstFormat->MesaFormat,
 362                                         texWidth, (GLubyte *) dstAddr);
 363    if (ext_tx_compress_dxtn) {
 364       (*ext_tx_compress_dxtn)(4, srcWidth, srcHeight, pixels,
 365                               GL_COMPRESSED_RGBA_S3TC_DXT5_EXT,
 366                               dst, dstRowStride);
 367    }
 368    else {
 369       _mesa_problem(ctx, "external dxt library not available");
 370    }
 371
 372    if (tempImage)
 373       _mesa_free((void *) tempImage);
 374
 375    return GL_TRUE;
 376 }
 377
 378
 379 static void
 380 fetch_texel_2d_rgb_dxt1( const struct gl_texture_image *texImage,
 381                          GLint i, GLint j, GLint k, GLchan *texel )
 382 {
 383    (void) k;
 384    if (fetch_ext_rgb_dxt1) {
 385       ASSERT (sizeof(GLchan) == sizeof(GLubyte));
 386       fetch_ext_rgb_dxt1(texImage->RowStride,
 387                          (GLubyte *)(texImage)->Data, i, j, texel);
 388    }
 389    else
 390       _mesa_debug(NULL, "attempted to decode s3tc texture without library available\n");
 391 }
 392
 393
 394 static void
 395 fetch_texel_2d_f_rgb_dxt1( const struct gl_texture_image *texImage,
 396                             GLint i, GLint j, GLint k, GLfloat *texel )
 397 {
 398    /* just sample as GLchan and convert to float here */
 399    GLchan rgba[4];
 400    fetch_texel_2d_rgb_dxt1(texImage, i, j, k, rgba);
 401    texel[RCOMP] = CHAN_TO_FLOAT(rgba[RCOMP]);
 402    texel[GCOMP] = CHAN_TO_FLOAT(rgba[GCOMP]);
 403    texel[BCOMP] = CHAN_TO_FLOAT(rgba[BCOMP]);
 404    texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);
 405 }
 406
 407
 408 static void
 409 fetch_texel_2d_rgba_dxt1( const struct gl_texture_image *texImage,
 410                           GLint i, GLint j, GLint k, GLchan *texel )
 411 {
 412    (void) k;
 413    if (fetch_ext_rgba_dxt1) {
 414       fetch_ext_rgba_dxt1(texImage->RowStride,
 415                           (GLubyte *)(texImage)->Data, i, j, texel);
 416    }
 417    else
 418       _mesa_debug(NULL, "attempted to decode s3tc texture without library available\n");
 419 }
 420
 421
 422 static void
 423 fetch_texel_2d_f_rgba_dxt1( const struct gl_texture_image *texImage,
 424                             GLint i, GLint j, GLint k, GLfloat *texel )
 425 {
 426    /* just sample as GLchan and convert to float here */
 427    GLchan rgba[4];
 428    fetch_texel_2d_rgba_dxt1(texImage, i, j, k, rgba);
 429    texel[RCOMP] = CHAN_TO_FLOAT(rgba[RCOMP]);
 430    texel[GCOMP] = CHAN_TO_FLOAT(rgba[GCOMP]);
 431    texel[BCOMP] = CHAN_TO_FLOAT(rgba[BCOMP]);
 432    texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);
 433 }
 434
 435
 436 static void
 437 fetch_texel_2d_rgba_dxt3( const struct gl_texture_image *texImage,
 438                           GLint i, GLint j, GLint k, GLchan *texel )
 439 {
 440    (void) k;
 441    if (fetch_ext_rgba_dxt3) {
 442       ASSERT (sizeof(GLchan) == sizeof(GLubyte));
 443       fetch_ext_rgba_dxt3(texImage->RowStride, (GLubyte *)(texImage)->Data,
 444                           i, j, texel);
 445    }
 446    else
 447       _mesa_debug(NULL, "attempted to decode s3tc texture without library available\n");
 448 }
 449
 450
 451 static void
 452 fetch_texel_2d_f_rgba_dxt3( const struct gl_texture_image *texImage,
 453                             GLint i, GLint j, GLint k, GLfloat *texel )
 454 {
 455    /* just sample as GLchan and convert to float here */
 456    GLchan rgba[4];
 457    fetch_texel_2d_rgba_dxt3(texImage, i, j, k, rgba);
 458    texel[RCOMP] = CHAN_TO_FLOAT(rgba[RCOMP]);
 459    texel[GCOMP] = CHAN_TO_FLOAT(rgba[GCOMP]);
 460    texel[BCOMP] = CHAN_TO_FLOAT(rgba[BCOMP]);
 461    texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);
 462 }
 463
 464
 465 static void
 466 fetch_texel_2d_rgba_dxt5( const struct gl_texture_image *texImage,
 467                           GLint i, GLint j, GLint k, GLchan *texel )
 468 {
 469    (void) k;
 470    if (fetch_ext_rgba_dxt5) {
 471       fetch_ext_rgba_dxt5(texImage->RowStride, (GLubyte *)(texImage)->Data,
 472                           i, j, texel);
 473    }
 474    else
 475       _mesa_debug(NULL, "attempted to decode s3tc texture without library available\n");
 476 }
 477
 478
 479 static void
 480 fetch_texel_2d_f_rgba_dxt5( const struct gl_texture_image *texImage,
 481                             GLint i, GLint j, GLint k, GLfloat *texel )
 482 {
 483    /* just sample as GLchan and convert to float here */
 484    GLchan rgba[4];
 485    fetch_texel_2d_rgba_dxt5(texImage, i, j, k, rgba);
 486    texel[RCOMP] = CHAN_TO_FLOAT(rgba[RCOMP]);
 487    texel[GCOMP] = CHAN_TO_FLOAT(rgba[GCOMP]);
 488    texel[BCOMP] = CHAN_TO_FLOAT(rgba[BCOMP]);
 489    texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);
 490 }
 491
 492
 493 const struct gl_texture_format _mesa_texformat_rgb_dxt1 = {
 494    MESA_FORMAT_RGB_DXT1,                /* MesaFormat */
 495    GL_RGB,                              /* BaseFormat */
 496    GL_UNSIGNED_NORMALIZED_ARB,          /* DataType */
 497    4, /*approx*/                        /* RedBits */
 498    4, /*approx*/                        /* GreenBits */
 499    4, /*approx*/                        /* BlueBits */
 500    0,                                   /* AlphaBits */
 501    0,                                   /* LuminanceBits */
 502    0,                                   /* IntensityBits */
 503    0,                                   /* IndexBits */
 504    0,                                   /* DepthBits */
 505    0,                                   /* StencilBits */
 506    0,                                   /* TexelBytes */
 507    texstore_rgb_dxt1,                   /* StoreTexImageFunc */
 508    NULL, /*impossible*/                 /* FetchTexel1D */
 509    fetch_texel_2d_rgb_dxt1,             /* FetchTexel2D */
 510    NULL, /*impossible*/                 /* FetchTexel3D */
 511    NULL, /*impossible*/                 /* FetchTexel1Df */
 512    fetch_texel_2d_f_rgb_dxt1,           /* FetchTexel2Df */
 513    NULL, /*impossible*/                 /* FetchTexel3Df */
 514    NULL                                 /* StoreTexel */
 515 };
 516
 517 const struct gl_texture_format _mesa_texformat_rgba_dxt1 = {
 518    MESA_FORMAT_RGBA_DXT1,               /* MesaFormat */
 519    GL_RGBA,                             /* BaseFormat */
 520    GL_UNSIGNED_NORMALIZED_ARB,          /* DataType */
 521    4, /*approx*/                        /* RedBits */
 522    4, /*approx*/                        /* GreenBits */
 523    4, /*approx*/                        /* BlueBits */
 524    1, /*approx*/                        /* AlphaBits */
 525    0,                                   /* LuminanceBits */
 526    0,                                   /* IntensityBits */
 527    0,                                   /* IndexBits */
 528    0,                                   /* DepthBits */
 529    0,                                   /* StencilBits */
 530    0,                                   /* TexelBytes */
 531    texstore_rgba_dxt1,                  /* StoreTexImageFunc */
 532    NULL, /*impossible*/                 /* FetchTexel1D */
 533    fetch_texel_2d_rgba_dxt1,            /* FetchTexel2D */
 534    NULL, /*impossible*/                 /* FetchTexel3D */
 535    NULL, /*impossible*/                 /* FetchTexel1Df */
 536    fetch_texel_2d_f_rgba_dxt1,          /* FetchTexel2Df */
 537    NULL, /*impossible*/                 /* FetchTexel3Df */
 538    NULL                                 /* StoreTexel */
 539 };
 540
 541 const struct gl_texture_format _mesa_texformat_rgba_dxt3 = {
 542    MESA_FORMAT_RGBA_DXT3,               /* MesaFormat */
 543    GL_RGBA,                             /* BaseFormat */
 544    GL_UNSIGNED_NORMALIZED_ARB,          /* DataType */
 545    4, /*approx*/                        /* RedBits */
 546    4, /*approx*/                        /* GreenBits */
 547    4, /*approx*/                        /* BlueBits */
 548    4, /*approx*/                        /* AlphaBits */
 549    0,                                   /* LuminanceBits */
 550    0,                                   /* IntensityBits */
 551    0,                                   /* IndexBits */
 552    0,                                   /* DepthBits */
 553    0,                                   /* StencilBits */
 554    0,                                   /* TexelBytes */
 555    texstore_rgba_dxt3,                  /* StoreTexImageFunc */
 556    NULL, /*impossible*/                 /* FetchTexel1D */
 557    fetch_texel_2d_rgba_dxt3,            /* FetchTexel2D */
 558    NULL, /*impossible*/                 /* FetchTexel3D */
 559    NULL, /*impossible*/                 /* FetchTexel1Df */
 560    fetch_texel_2d_f_rgba_dxt3,          /* FetchTexel2Df */
 561    NULL, /*impossible*/                 /* FetchTexel3Df */
 562    NULL                                 /* StoreTexel */
 563 };
 564
 565 const struct gl_texture_format _mesa_texformat_rgba_dxt5 = {
 566    MESA_FORMAT_RGBA_DXT5,               /* MesaFormat */
 567    GL_RGBA,                             /* BaseFormat */
 568    GL_UNSIGNED_NORMALIZED_ARB,          /* DataType */
 569    4,/*approx*/                         /* RedBits */
 570    4,/*approx*/                         /* GreenBits */
 571    4,/*approx*/                         /* BlueBits */
 572    4,/*approx*/                         /* AlphaBits */
 573    0,                                   /* LuminanceBits */
 574    0,                                   /* IntensityBits */
 575    0,                                   /* IndexBits */
 576    0,                                   /* DepthBits */
 577    0,                                   /* StencilBits */
 578    0,                                   /* TexelBytes */
 579    texstore_rgba_dxt5,                  /* StoreTexImageFunc */
 580    NULL, /*impossible*/                 /* FetchTexel1D */
 581    fetch_texel_2d_rgba_dxt5,            /* FetchTexel2D */
 582    NULL, /*impossible*/                 /* FetchTexel3D */
 583    NULL, /*impossible*/                 /* FetchTexel1Df */
 584    fetch_texel_2d_f_rgba_dxt5,          /* FetchTexel2Df */
 585    NULL, /*impossible*/                 /* FetchTexel3Df */
 586    NULL                                 /* StoreTexel */
 587 };