src/mesa/state_tracker/st_format.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * 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
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28
  29 /**
  30  * Texture Image-related functions.
  31  * \author Brian Paul
  32  */
  33
  34 #include "main/imports.h"
  35 #include "main/context.h"
  36 #include "main/texstore.h"
  37 #include "main/texformat.h"
  38 #include "main/enums.h"
  39 #include "main/macros.h"
  40
  41 #include "pipe/p_context.h"
  42 #include "pipe/p_defines.h"
  43 #include "st_context.h"
  44 #include "st_format.h"
  45
  46 static GLuint
  47 format_bits(
  48    pipe_format_rgbazs_t  info,
  49    GLuint comp )
  50 {
  51    GLuint   size;
  52
  53    if (pf_swizzle_x(info) == comp) {
  54       size = pf_size_x(info);
  55    }
  56    else if (pf_swizzle_y(info) == comp) {
  57       size = pf_size_y(info);
  58    }
  59    else if (pf_swizzle_z(info) == comp) {
  60       size = pf_size_z(info);
  61    }
  62    else if (pf_swizzle_w(info) == comp) {
  63       size = pf_size_w(info);
  64    }
  65    else {
  66       size = 0;
  67    }
  68    return size << (pf_exp8(info) * 3);
  69 }
  70
  71 static GLuint
  72 format_max_bits(
  73    pipe_format_rgbazs_t  info )
  74 {
  75    GLuint   size = format_bits( info, PIPE_FORMAT_COMP_R );
  76
  77    size = MAX2( size, format_bits( info, PIPE_FORMAT_COMP_G ) );
  78    size = MAX2( size, format_bits( info, PIPE_FORMAT_COMP_B ) );
  79    size = MAX2( size, format_bits( info, PIPE_FORMAT_COMP_A ) );
  80    size = MAX2( size, format_bits( info, PIPE_FORMAT_COMP_Z ) );
  81    size = MAX2( size, format_bits( info, PIPE_FORMAT_COMP_S ) );
  82    return size;
  83 }
  84
  85 static GLuint
  86 format_size(
  87    pipe_format_rgbazs_t  info )
  88 {
  89    return
  90       format_bits( info, PIPE_FORMAT_COMP_R ) +
  91       format_bits( info, PIPE_FORMAT_COMP_G ) +
  92       format_bits( info, PIPE_FORMAT_COMP_B ) +
  93       format_bits( info, PIPE_FORMAT_COMP_A ) +
  94       format_bits( info, PIPE_FORMAT_COMP_Z ) +
  95       format_bits( info, PIPE_FORMAT_COMP_S );
  96 }
  97
  98 /*
  99  * XXX temporary here
 100  */
 101 GLboolean
 102 st_get_format_info(enum pipe_format format, struct pipe_format_info *pinfo)
 103 {
 104    if (pf_layout(format) == PIPE_FORMAT_LAYOUT_RGBAZS) {
 105       pipe_format_rgbazs_t info;
 106
 107       info = format;
 108
 109 #if 0
 110       {
 111          char  fmtname[256];
 112
 113          pf_sprint_name( fmtname, format );
 114          printf(
 115             "%s\n",
 116             fmtname );
 117       }
 118 #endif
 119
 120       /* Data type */
 121       if (format == PIPE_FORMAT_A1R5G5B5_UNORM || format == PIPE_FORMAT_R5G6B5_UNORM) {
 122          pinfo->datatype = GL_UNSIGNED_SHORT;
 123       }
 124       else {
 125          GLuint size;
 126
 127          size = format_max_bits( info );
 128          if (size == 8) {
 129             if (pf_type(info) == PIPE_FORMAT_TYPE_UNORM)
 130                pinfo->datatype = GL_UNSIGNED_BYTE;
 131             else
 132                pinfo->datatype = GL_BYTE;
 133          }
 134          else if (size == 16) {
 135             if (pf_type(info) == PIPE_FORMAT_TYPE_UNORM)
 136                pinfo->datatype = GL_UNSIGNED_SHORT;
 137             else
 138                pinfo->datatype = GL_SHORT;
 139          }
 140          else {
 141             assert( size <= 32 );
 142             if (pf_type(info) == PIPE_FORMAT_TYPE_UNORM)
 143                pinfo->datatype = GL_UNSIGNED_INT;
 144             else
 145                pinfo->datatype = GL_INT;
 146          }
 147       }
 148
 149       /* Component bits */
 150       pinfo->red_bits = format_bits( info, PIPE_FORMAT_COMP_R );
 151       pinfo->green_bits = format_bits( info, PIPE_FORMAT_COMP_G );
 152       pinfo->blue_bits = format_bits( info, PIPE_FORMAT_COMP_B );
 153       pinfo->alpha_bits = format_bits( info, PIPE_FORMAT_COMP_A );
 154       pinfo->depth_bits = format_bits( info, PIPE_FORMAT_COMP_Z );
 155       pinfo->stencil_bits = format_bits( info, PIPE_FORMAT_COMP_S );
 156       pinfo->luminance_bits = 0;
 157       pinfo->intensity_bits = 0;
 158
 159       /* Format size */
 160       pinfo->size = format_size( info ) / 8;
 161
 162       /* Luminance & Intensity bits */
 163       if( pf_swizzle_x(info) == PIPE_FORMAT_COMP_R &&
 164           pf_swizzle_y(info) == PIPE_FORMAT_COMP_R &&
 165           pf_swizzle_z(info) == PIPE_FORMAT_COMP_R ) {
 166          if( pf_swizzle_w(info) == PIPE_FORMAT_COMP_R ) {
 167             pinfo->intensity_bits = pinfo->red_bits;
 168          }
 169          else {
 170             pinfo->luminance_bits = pinfo->red_bits;
 171          }
 172          pinfo->red_bits = 0;
 173       }
 174
 175       /* Base format */
 176       if (pinfo->depth_bits) {
 177          if (pinfo->stencil_bits) {
 178             pinfo->base_format = GL_DEPTH_STENCIL_EXT;
 179          }
 180          else {
 181             pinfo->base_format = GL_DEPTH_COMPONENT;
 182          }
 183       }
 184       else if (pinfo->stencil_bits) {
 185          pinfo->base_format = GL_STENCIL_INDEX;
 186       }
 187       else {
 188          pinfo->base_format = GL_RGBA;
 189       }
 190    }
 191    else {
 192       pipe_format_ycbcr_t info;
 193
 194       assert( pf_layout(format) == PIPE_FORMAT_LAYOUT_YCBCR );
 195
 196       info = format;
 197
 198       /* TODO */
 199       assert( 0 );
 200    }
 201
 202 #if 0
 203    printf(
 204       "ST_FORMAT: R(%u), G(%u), B(%u), A(%u), Z(%u), S(%u)\n",
 205       pinfo->red_bits,
 206       pinfo->green_bits,
 207       pinfo->blue_bits,
 208       pinfo->alpha_bits,
 209       pinfo->depth_bits,
 210       pinfo->stencil_bits );
 211 #endif
 212
 213    pinfo->format = format;
 214
 215    return GL_TRUE;
 216 }
 217
 218
 219 /**
 220  * Return bytes per pixel for the given format.
 221  */
 222 GLuint
 223 st_sizeof_format(enum pipe_format format)
 224 {
 225    struct pipe_format_info info;
 226    if (!st_get_format_info( format, &info )) {
 227       assert( 0 );
 228       return 0;
 229    }
 230    return info.size;
 231 }
 232
 233
 234 /**
 235  * Return bytes per pixel for the given format.
 236  */
 237 GLenum
 238 st_format_datatype(enum pipe_format format)
 239 {
 240    struct pipe_format_info info;
 241    if (!st_get_format_info( format, &info )) {
 242       assert( 0 );
 243       return 0;
 244    }
 245    return info.datatype;
 246 }
 247
 248
 249 enum pipe_format
 250 st_mesa_format_to_pipe_format(GLuint mesaFormat)
 251 {
 252    switch (mesaFormat) {
 253       /* fix this */
 254    case MESA_FORMAT_ARGB8888_REV:
 255    case MESA_FORMAT_ARGB8888:
 256       return PIPE_FORMAT_A8R8G8B8_UNORM;
 257    case MESA_FORMAT_ARGB1555:
 258       return PIPE_FORMAT_A1R5G5B5_UNORM;
 259    case MESA_FORMAT_ARGB4444:
 260       return PIPE_FORMAT_A4R4G4B4_UNORM;
 261    case MESA_FORMAT_RGB565:
 262       return PIPE_FORMAT_R5G6B5_UNORM;
 263    case MESA_FORMAT_AL88:
 264       return PIPE_FORMAT_U_A8_L8;
 265    case MESA_FORMAT_A8:
 266       return PIPE_FORMAT_U_A8;
 267    case MESA_FORMAT_L8:
 268       return PIPE_FORMAT_U_L8;
 269    case MESA_FORMAT_I8:
 270       return PIPE_FORMAT_U_I8;
 271    case MESA_FORMAT_Z16:
 272       return PIPE_FORMAT_Z16_UNORM;
 273    default:
 274       assert(0);
 275       return 0;
 276    }
 277 }
 278
 279 /**
 280  * Find an RGBA format supported by the context/winsys.
 281  */
 282 static GLuint
 283 default_rgba_format(struct pipe_context *pipe, uint type)
 284 {
 285    static const enum pipe_format colorFormats[] = {
 286       PIPE_FORMAT_A8R8G8B8_UNORM,
 287       PIPE_FORMAT_B8G8R8A8_UNORM,
 288       PIPE_FORMAT_R8G8B8A8_UNORM,
 289       PIPE_FORMAT_R5G6B5_UNORM
 290    };
 291    uint i;
 292    for (i = 0; i < Elements(colorFormats); i++) {
 293       if (pipe->is_format_supported( pipe, colorFormats[i], type )) {
 294          return colorFormats[i];
 295       }
 296    }
 297    return PIPE_FORMAT_NONE;
 298 }
 299
 300
 301 /**
 302  * Search list of formats for first RGBA format with >8 bits/channel.
 303  */
 304 static GLuint
 305 default_deep_rgba_format(struct pipe_context *pipe, uint type)
 306 {
 307    if (pipe->is_format_supported(pipe, PIPE_FORMAT_R16G16B16A16_SNORM, type)) {
 308       return PIPE_FORMAT_R16G16B16A16_SNORM;
 309    }
 310    return PIPE_FORMAT_NONE;
 311 }
 312
 313
 314 /**
 315  * Find an Z format supported by the context/winsys.
 316  */
 317 static GLuint
 318 default_depth_format(struct pipe_context *pipe, uint type)
 319 {
 320    static const enum pipe_format zFormats[] = {
 321       PIPE_FORMAT_Z16_UNORM,
 322       PIPE_FORMAT_Z32_UNORM,
 323       PIPE_FORMAT_S8Z24_UNORM,
 324       PIPE_FORMAT_Z24S8_UNORM
 325    };
 326    uint i;
 327    for (i = 0; i < Elements(zFormats); i++) {
 328       if (pipe->is_format_supported( pipe, zFormats[i], type )) {
 329          return zFormats[i];
 330       }
 331    }
 332    return PIPE_FORMAT_NONE;
 333 }
 334
 335
 336 /**
 337  * Choose the PIPE_FORMAT_ to use for user-created renderbuffers.
 338  *
 339  * \return PIPE_FORMAT_NONE if error/problem.
 340  */
 341 enum pipe_format
 342 st_choose_renderbuffer_format(struct pipe_context *pipe, GLint internalFormat)
 343 {
 344    uint surfType = PIPE_SURFACE;
 345
 346    switch (internalFormat) {
 347    case 4:
 348    case GL_RGBA:
 349    case GL_COMPRESSED_RGBA:
 350    case 3:
 351    case GL_RGB:
 352    case GL_COMPRESSED_RGB:
 353    case GL_RGBA8:
 354    case GL_RGB10_A2:
 355    case GL_RGBA12:
 356       return default_rgba_format( pipe, surfType );
 357    case GL_RGBA16:
 358       return default_deep_rgba_format( pipe, surfType );
 359
 360    case GL_RGBA4:
 361    case GL_RGBA2:
 362       if (pipe->is_format_supported( pipe, PIPE_FORMAT_A4R4G4B4_UNORM, surfType ))
 363          return PIPE_FORMAT_A4R4G4B4_UNORM;
 364       return default_rgba_format( pipe, surfType );
 365
 366    case GL_RGB5_A1:
 367       if (pipe->is_format_supported( pipe, PIPE_FORMAT_A1R5G5B5_UNORM, surfType ))
 368          return PIPE_FORMAT_A1R5G5B5_UNORM;
 369       return default_rgba_format( pipe, surfType );
 370
 371    case GL_RGB8:
 372    case GL_RGB10:
 373    case GL_RGB12:
 374    case GL_RGB16:
 375       return default_rgba_format( pipe, surfType );
 376
 377    case GL_RGB5:
 378    case GL_RGB4:
 379    case GL_R3_G3_B2:
 380       if (pipe->is_format_supported( pipe, PIPE_FORMAT_A1R5G5B5_UNORM, surfType ))
 381          return PIPE_FORMAT_A1R5G5B5_UNORM;
 382       if (pipe->is_format_supported( pipe, PIPE_FORMAT_R5G6B5_UNORM, surfType ))
 383          return PIPE_FORMAT_R5G6B5_UNORM;
 384       return default_rgba_format( pipe, surfType );
 385
 386    case GL_ALPHA:
 387    case GL_ALPHA4:
 388    case GL_ALPHA8:
 389    case GL_ALPHA12:
 390    case GL_ALPHA16:
 391    case GL_COMPRESSED_ALPHA:
 392       if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_A8, surfType ))
 393          return PIPE_FORMAT_U_A8;
 394       return default_rgba_format( pipe, surfType );
 395
 396    case 1:
 397    case GL_LUMINANCE:
 398    case GL_LUMINANCE4:
 399    case GL_LUMINANCE8:
 400    case GL_LUMINANCE12:
 401    case GL_LUMINANCE16:
 402    case GL_COMPRESSED_LUMINANCE:
 403       if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_L8, surfType ))
 404          return PIPE_FORMAT_U_A8;
 405       return default_rgba_format( pipe, surfType );
 406
 407    case 2:
 408    case GL_LUMINANCE_ALPHA:
 409    case GL_LUMINANCE4_ALPHA4:
 410    case GL_LUMINANCE6_ALPHA2:
 411    case GL_LUMINANCE8_ALPHA8:
 412    case GL_LUMINANCE12_ALPHA4:
 413    case GL_LUMINANCE12_ALPHA12:
 414    case GL_LUMINANCE16_ALPHA16:
 415    case GL_COMPRESSED_LUMINANCE_ALPHA:
 416       if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_A8_L8, surfType ))
 417          return PIPE_FORMAT_U_A8_L8;
 418       return default_rgba_format( pipe, surfType );
 419
 420    case GL_INTENSITY:
 421    case GL_INTENSITY4:
 422    case GL_INTENSITY8:
 423    case GL_INTENSITY12:
 424    case GL_INTENSITY16:
 425    case GL_COMPRESSED_INTENSITY:
 426       if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_I8, surfType ))
 427          return PIPE_FORMAT_U_I8;
 428       return default_rgba_format( pipe, surfType );
 429
 430 #if 0
 431    /* not supported for renderbuffers */
 432    case GL_YCBCR_MESA:
 433       return PIPE_FORMAT_NONE;
 434    case GL_COMPRESSED_RGB_FXT1_3DFX:
 435       return &_mesa_texformat_rgb_fxt1;
 436    case GL_COMPRESSED_RGBA_FXT1_3DFX:
 437       return &_mesa_texformat_rgba_fxt1;
 438
 439    case GL_RGB_S3TC:
 440    case GL_RGB4_S3TC:
 441    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
 442       return &_mesa_texformat_rgb_dxt1;
 443
 444    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
 445       return &_mesa_texformat_rgba_dxt1;
 446
 447    case GL_RGBA_S3TC:
 448    case GL_RGBA4_S3TC:
 449    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
 450       return &_mesa_texformat_rgba_dxt3;
 451
 452    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
 453       return &_mesa_texformat_rgba_dxt5;
 454 #endif
 455
 456    case GL_DEPTH_COMPONENT16:
 457       if (pipe->is_format_supported( pipe, PIPE_FORMAT_Z16_UNORM, surfType ))
 458          return PIPE_FORMAT_Z16_UNORM;
 459       /* fall-through */
 460    case GL_DEPTH_COMPONENT24:
 461       if (pipe->is_format_supported( pipe, PIPE_FORMAT_S8Z24_UNORM, surfType ))
 462          return PIPE_FORMAT_S8Z24_UNORM;
 463       if (pipe->is_format_supported( pipe, PIPE_FORMAT_Z24S8_UNORM, surfType ))
 464          return PIPE_FORMAT_Z24S8_UNORM;
 465       /* fall-through */
 466    case GL_DEPTH_COMPONENT32:
 467       if (pipe->is_format_supported( pipe, PIPE_FORMAT_Z32_UNORM, surfType ))
 468          return PIPE_FORMAT_Z32_UNORM;
 469       /* fall-through */
 470    case GL_DEPTH_COMPONENT:
 471       return default_depth_format( pipe, surfType );
 472
 473    case GL_STENCIL_INDEX:
 474    case GL_STENCIL_INDEX1_EXT:
 475    case GL_STENCIL_INDEX4_EXT:
 476    case GL_STENCIL_INDEX8_EXT:
 477    case GL_STENCIL_INDEX16_EXT:
 478       if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_S8, surfType ))
 479          return PIPE_FORMAT_U_S8;
 480       if (pipe->is_format_supported( pipe, PIPE_FORMAT_S8Z24_UNORM, surfType ))
 481          return PIPE_FORMAT_S8Z24_UNORM;
 482       if (pipe->is_format_supported( pipe, PIPE_FORMAT_Z24S8_UNORM, surfType ))
 483          return PIPE_FORMAT_Z24S8_UNORM;
 484       return PIPE_FORMAT_NONE;
 485
 486    case GL_DEPTH_STENCIL_EXT:
 487    case GL_DEPTH24_STENCIL8_EXT:
 488       if (pipe->is_format_supported( pipe, PIPE_FORMAT_S8Z24_UNORM, surfType ))
 489          return PIPE_FORMAT_S8Z24_UNORM;
 490       if (pipe->is_format_supported( pipe, PIPE_FORMAT_Z24S8_UNORM, surfType ))
 491          return PIPE_FORMAT_Z24S8_UNORM;
 492       return PIPE_FORMAT_NONE;
 493
 494    default:
 495       return PIPE_FORMAT_NONE;
 496    }
 497 }
 498
 499
 500
 501 /* It works out that this function is fine for all the supported
 502  * hardware.  However, there is still a need to map the formats onto
 503  * hardware descriptors.
 504  */
 505 /* Note that the i915 can actually support many more formats than
 506  * these if we take the step of simply swizzling the colors
 507  * immediately after sampling...
 508  */
 509 const struct gl_texture_format *
 510 st_ChooseTextureFormat(GLcontext * ctx, GLint internalFormat,
 511                        GLenum format, GLenum type)
 512 {
 513 #if 0
 514    struct intel_context *intel = intel_context(ctx);
 515    const GLboolean do32bpt = (intel->intelScreen->front.cpp == 4);
 516 #else
 517    const GLboolean do32bpt = 1;
 518 #endif
 519
 520    (void) ctx;
 521
 522    switch (internalFormat) {
 523    case 4:
 524    case GL_RGBA:
 525    case GL_COMPRESSED_RGBA:
 526       if (format == GL_BGRA) {
 527          if (type == GL_UNSIGNED_BYTE || type == GL_UNSIGNED_INT_8_8_8_8_REV) {
 528             return &_mesa_texformat_argb8888;
 529          }
 530          else if (type == GL_UNSIGNED_SHORT_4_4_4_4_REV) {
 531             return &_mesa_texformat_argb4444;
 532          }
 533          else if (type == GL_UNSIGNED_SHORT_1_5_5_5_REV) {
 534             return &_mesa_texformat_argb1555;
 535          }
 536       }
 537       return do32bpt ? &_mesa_texformat_argb8888 : &_mesa_texformat_argb4444;
 538
 539    case 3:
 540    case GL_RGB:
 541    case GL_COMPRESSED_RGB:
 542       if (format == GL_RGB && type == GL_UNSIGNED_SHORT_5_6_5) {
 543          return &_mesa_texformat_rgb565;
 544       }
 545       return do32bpt ? &_mesa_texformat_argb8888 : &_mesa_texformat_rgb565;
 546
 547    case GL_RGBA8:
 548    case GL_RGB10_A2:
 549    case GL_RGBA12:
 550    case GL_RGBA16:
 551       return do32bpt ? &_mesa_texformat_argb8888 : &_mesa_texformat_argb4444;
 552
 553    case GL_RGBA4:
 554    case GL_RGBA2:
 555       return &_mesa_texformat_argb4444;
 556
 557    case GL_RGB5_A1:
 558       return &_mesa_texformat_argb1555;
 559
 560    case GL_RGB8:
 561    case GL_RGB10:
 562    case GL_RGB12:
 563    case GL_RGB16:
 564       return &_mesa_texformat_argb8888;
 565
 566    case GL_RGB5:
 567    case GL_RGB4:
 568    case GL_R3_G3_B2:
 569       return &_mesa_texformat_rgb565;
 570
 571    case GL_ALPHA:
 572    case GL_ALPHA4:
 573    case GL_ALPHA8:
 574    case GL_ALPHA12:
 575    case GL_ALPHA16:
 576    case GL_COMPRESSED_ALPHA:
 577       return &_mesa_texformat_a8;
 578
 579    case 1:
 580    case GL_LUMINANCE:
 581    case GL_LUMINANCE4:
 582    case GL_LUMINANCE8:
 583    case GL_LUMINANCE12:
 584    case GL_LUMINANCE16:
 585    case GL_COMPRESSED_LUMINANCE:
 586       return &_mesa_texformat_l8;
 587
 588    case 2:
 589    case GL_LUMINANCE_ALPHA:
 590    case GL_LUMINANCE4_ALPHA4:
 591    case GL_LUMINANCE6_ALPHA2:
 592    case GL_LUMINANCE8_ALPHA8:
 593    case GL_LUMINANCE12_ALPHA4:
 594    case GL_LUMINANCE12_ALPHA12:
 595    case GL_LUMINANCE16_ALPHA16:
 596    case GL_COMPRESSED_LUMINANCE_ALPHA:
 597       return &_mesa_texformat_al88;
 598
 599    case GL_INTENSITY:
 600    case GL_INTENSITY4:
 601    case GL_INTENSITY8:
 602    case GL_INTENSITY12:
 603    case GL_INTENSITY16:
 604    case GL_COMPRESSED_INTENSITY:
 605       return &_mesa_texformat_i8;
 606
 607    case GL_YCBCR_MESA:
 608       if (type == GL_UNSIGNED_SHORT_8_8_MESA || type == GL_UNSIGNED_BYTE)
 609          return &_mesa_texformat_ycbcr;
 610       else
 611          return &_mesa_texformat_ycbcr_rev;
 612
 613    case GL_COMPRESSED_RGB_FXT1_3DFX:
 614       return &_mesa_texformat_rgb_fxt1;
 615    case GL_COMPRESSED_RGBA_FXT1_3DFX:
 616       return &_mesa_texformat_rgba_fxt1;
 617
 618    case GL_RGB_S3TC:
 619    case GL_RGB4_S3TC:
 620    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
 621       return &_mesa_texformat_rgb_dxt1;
 622
 623    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
 624       return &_mesa_texformat_rgba_dxt1;
 625
 626    case GL_RGBA_S3TC:
 627    case GL_RGBA4_S3TC:
 628    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
 629       return &_mesa_texformat_rgba_dxt3;
 630
 631    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
 632       return &_mesa_texformat_rgba_dxt5;
 633
 634    case GL_DEPTH_COMPONENT:
 635    case GL_DEPTH_COMPONENT16:
 636    case GL_DEPTH_COMPONENT24:
 637    case GL_DEPTH_COMPONENT32:
 638       return &_mesa_texformat_z16;
 639
 640    case GL_DEPTH_STENCIL_EXT:
 641    case GL_DEPTH24_STENCIL8_EXT:
 642       return &_mesa_texformat_z24_s8;
 643
 644    default:
 645       fprintf(stderr, "unexpected texture format %s in %s\n",
 646               _mesa_lookup_enum_by_nr(internalFormat), __FUNCTION__);
 647       return NULL;
 648    }
 649
 650    return NULL;                 /* never get here */
 651 }