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 "pipe/p_screen.h"
  44 #include "st_context.h"
  45 #include "st_format.h"
  46
  47 static GLuint
  48 format_bits(
  49    pipe_format_rgbazs_t  info,
  50    GLuint comp )
  51 {
  52    GLuint   size;
  53
  54    if (pf_swizzle_x(info) == comp) {
  55       size = pf_size_x(info);
  56    }
  57    else if (pf_swizzle_y(info) == comp) {
  58       size = pf_size_y(info);
  59    }
  60    else if (pf_swizzle_z(info) == comp) {
  61       size = pf_size_z(info);
  62    }
  63    else if (pf_swizzle_w(info) == comp) {
  64       size = pf_size_w(info);
  65    }
  66    else {
  67       size = 0;
  68    }
  69    return size << (pf_exp8(info) * 3);
  70 }
  71
  72 static GLuint
  73 format_max_bits(
  74    pipe_format_rgbazs_t  info )
  75 {
  76    GLuint   size = format_bits( info, PIPE_FORMAT_COMP_R );
  77
  78    size = MAX2( size, format_bits( info, PIPE_FORMAT_COMP_G ) );
  79    size = MAX2( size, format_bits( info, PIPE_FORMAT_COMP_B ) );
  80    size = MAX2( size, format_bits( info, PIPE_FORMAT_COMP_A ) );
  81    size = MAX2( size, format_bits( info, PIPE_FORMAT_COMP_Z ) );
  82    size = MAX2( size, format_bits( info, PIPE_FORMAT_COMP_S ) );
  83    return size;
  84 }
  85
  86 static GLuint
  87 format_size(
  88    pipe_format_rgbazs_t  info )
  89 {
  90    return
  91       format_bits( info, PIPE_FORMAT_COMP_R ) +
  92       format_bits( info, PIPE_FORMAT_COMP_G ) +
  93       format_bits( info, PIPE_FORMAT_COMP_B ) +
  94       format_bits( info, PIPE_FORMAT_COMP_A ) +
  95       format_bits( info, PIPE_FORMAT_COMP_Z ) +
  96       format_bits( info, PIPE_FORMAT_COMP_S );
  97 }
  98
  99 /*
 100  * XXX temporary here
 101  */
 102 GLboolean
 103 st_get_format_info(enum pipe_format format, struct pipe_format_info *pinfo)
 104 {
 105    if (pf_layout(format) == PIPE_FORMAT_LAYOUT_RGBAZS) {
 106       pipe_format_rgbazs_t info;
 107
 108       info = format;
 109
 110 #if 0
 111       {
 112          char  fmtname[256];
 113
 114          pf_sprint_name( fmtname, format );
 115          printf(
 116             "%s\n",
 117             fmtname );
 118       }
 119 #endif
 120
 121       /* Data type */
 122       if (format == PIPE_FORMAT_A1R5G5B5_UNORM || format == PIPE_FORMAT_R5G6B5_UNORM) {
 123          pinfo->datatype = GL_UNSIGNED_SHORT;
 124       }
 125       else {
 126          GLuint size;
 127
 128          size = format_max_bits( info );
 129          if (size == 8) {
 130             if (pf_type(info) == PIPE_FORMAT_TYPE_UNORM)
 131                pinfo->datatype = GL_UNSIGNED_BYTE;
 132             else
 133                pinfo->datatype = GL_BYTE;
 134          }
 135          else if (size == 16) {
 136             if (pf_type(info) == PIPE_FORMAT_TYPE_UNORM)
 137                pinfo->datatype = GL_UNSIGNED_SHORT;
 138             else
 139                pinfo->datatype = GL_SHORT;
 140          }
 141          else {
 142             assert( size <= 32 );
 143             if (pf_type(info) == PIPE_FORMAT_TYPE_UNORM)
 144                pinfo->datatype = GL_UNSIGNED_INT;
 145             else
 146                pinfo->datatype = GL_INT;
 147          }
 148       }
 149
 150       /* Component bits */
 151       pinfo->red_bits = format_bits( info, PIPE_FORMAT_COMP_R );
 152       pinfo->green_bits = format_bits( info, PIPE_FORMAT_COMP_G );
 153       pinfo->blue_bits = format_bits( info, PIPE_FORMAT_COMP_B );
 154       pinfo->alpha_bits = format_bits( info, PIPE_FORMAT_COMP_A );
 155       pinfo->depth_bits = format_bits( info, PIPE_FORMAT_COMP_Z );
 156       pinfo->stencil_bits = format_bits( info, PIPE_FORMAT_COMP_S );
 157       pinfo->luminance_bits = 0;
 158       pinfo->intensity_bits = 0;
 159
 160       /* Format size */
 161       pinfo->size = format_size( info ) / 8;
 162
 163       /* Luminance & Intensity bits */
 164       if( pf_swizzle_x(info) == PIPE_FORMAT_COMP_R &&
 165           pf_swizzle_y(info) == PIPE_FORMAT_COMP_R &&
 166           pf_swizzle_z(info) == PIPE_FORMAT_COMP_R ) {
 167          if( pf_swizzle_w(info) == PIPE_FORMAT_COMP_R ) {
 168             pinfo->intensity_bits = pinfo->red_bits;
 169          }
 170          else {
 171             pinfo->luminance_bits = pinfo->red_bits;
 172          }
 173          pinfo->red_bits = 0;
 174       }
 175
 176       /* Base format */
 177       if (pinfo->depth_bits) {
 178          if (pinfo->stencil_bits) {
 179             pinfo->base_format = GL_DEPTH_STENCIL_EXT;
 180          }
 181          else {
 182             pinfo->base_format = GL_DEPTH_COMPONENT;
 183          }
 184       }
 185       else if (pinfo->stencil_bits) {
 186          pinfo->base_format = GL_STENCIL_INDEX;
 187       }
 188       else {
 189          pinfo->base_format = GL_RGBA;
 190       }
 191    }
 192    else {
 193       pipe_format_ycbcr_t info;
 194
 195       assert( pf_layout(format) == PIPE_FORMAT_LAYOUT_YCBCR );
 196
 197       info = format;
 198
 199       /* TODO */
 200       assert( 0 );
 201    }
 202
 203 #if 0
 204    printf(
 205       "ST_FORMAT: R(%u), G(%u), B(%u), A(%u), Z(%u), S(%u)\n",
 206       pinfo->red_bits,
 207       pinfo->green_bits,
 208       pinfo->blue_bits,
 209       pinfo->alpha_bits,
 210       pinfo->depth_bits,
 211       pinfo->stencil_bits );
 212 #endif
 213
 214    pinfo->format = format;
 215
 216    return GL_TRUE;
 217 }
 218
 219
 220 /**
 221  * Return bytes per pixel for the given format.
 222  */
 223 GLuint
 224 st_sizeof_format(enum pipe_format format)
 225 {
 226    struct pipe_format_info info;
 227    if (!st_get_format_info( format, &info )) {
 228       assert( 0 );
 229       return 0;
 230    }
 231    return info.size;
 232 }
 233
 234
 235 /**
 236  * Return bytes per pixel for the given format.
 237  */
 238 GLenum
 239 st_format_datatype(enum pipe_format format)
 240 {
 241    struct pipe_format_info info;
 242    if (!st_get_format_info( format, &info )) {
 243       assert( 0 );
 244       return 0;
 245    }
 246    return info.datatype;
 247 }
 248
 249
 250 enum pipe_format
 251 st_mesa_format_to_pipe_format(GLuint mesaFormat)
 252 {
 253    switch (mesaFormat) {
 254       /* fix this */
 255    case MESA_FORMAT_ARGB8888_REV:
 256    case MESA_FORMAT_ARGB8888:
 257       return PIPE_FORMAT_A8R8G8B8_UNORM;
 258    case MESA_FORMAT_ARGB1555:
 259       return PIPE_FORMAT_A1R5G5B5_UNORM;
 260    case MESA_FORMAT_ARGB4444:
 261       return PIPE_FORMAT_A4R4G4B4_UNORM;
 262    case MESA_FORMAT_RGB565:
 263       return PIPE_FORMAT_R5G6B5_UNORM;
 264    case MESA_FORMAT_AL88:
 265       return PIPE_FORMAT_U_A8_L8;
 266    case MESA_FORMAT_A8:
 267       return PIPE_FORMAT_U_A8;
 268    case MESA_FORMAT_L8:
 269       return PIPE_FORMAT_U_L8;
 270    case MESA_FORMAT_I8:
 271       return PIPE_FORMAT_U_I8;
 272    case MESA_FORMAT_Z16:
 273       return PIPE_FORMAT_Z16_UNORM;
 274    default:
 275       assert(0);
 276       return 0;
 277    }
 278 }
 279
 280 /**
 281  * Find an RGBA format supported by the context/winsys.
 282  */
 283 static GLuint
 284 default_rgba_format(struct pipe_context *pipe, uint type)
 285 {
 286    static const enum pipe_format colorFormats[] = {
 287       PIPE_FORMAT_A8R8G8B8_UNORM,
 288       PIPE_FORMAT_B8G8R8A8_UNORM,
 289       PIPE_FORMAT_R8G8B8A8_UNORM,
 290       PIPE_FORMAT_R5G6B5_UNORM
 291    };
 292    struct pipe_screen *screen = pipe->screen;
 293    uint i;
 294    for (i = 0; i < Elements(colorFormats); i++) {
 295       if (screen->is_format_supported( screen, colorFormats[i], type )) {
 296          return colorFormats[i];
 297       }
 298    }
 299    return PIPE_FORMAT_NONE;
 300 }
 301
 302
 303 /**
 304  * Search list of formats for first RGBA format with >8 bits/channel.
 305  */
 306 static GLuint
 307 default_deep_rgba_format(struct pipe_context *pipe, uint type)
 308 {
 309    struct pipe_screen *screen = pipe->screen;
 310    if (screen->is_format_supported(screen, PIPE_FORMAT_R16G16B16A16_SNORM, type)) {
 311       return PIPE_FORMAT_R16G16B16A16_SNORM;
 312    }
 313    return PIPE_FORMAT_NONE;
 314 }
 315
 316
 317 /**
 318  * Find an Z format supported by the context/winsys.
 319  */
 320 static GLuint
 321 default_depth_format(struct pipe_context *pipe, uint type)
 322 {
 323    static const enum pipe_format zFormats[] = {
 324       PIPE_FORMAT_Z16_UNORM,
 325       PIPE_FORMAT_Z32_UNORM,
 326       PIPE_FORMAT_S8Z24_UNORM,
 327       PIPE_FORMAT_Z24S8_UNORM
 328    };
 329    struct pipe_screen *screen = pipe->screen;
 330    uint i;
 331    for (i = 0; i < Elements(zFormats); i++) {
 332       if (screen->is_format_supported( screen, zFormats[i], type )) {
 333          return zFormats[i];
 334       }
 335    }
 336    return PIPE_FORMAT_NONE;
 337 }
 338
 339
 340 /**
 341  * Choose the PIPE_FORMAT_ to use for user-created renderbuffers.
 342  *
 343  * \return PIPE_FORMAT_NONE if error/problem.
 344  */
 345 enum pipe_format
 346 st_choose_renderbuffer_format(struct pipe_context *pipe, GLint internalFormat)
 347 {
 348    struct pipe_screen *screen = pipe->screen;
 349    uint surfType = PIPE_SURFACE;
 350
 351    switch (internalFormat) {
 352    case 4:
 353    case GL_RGBA:
 354    case GL_COMPRESSED_RGBA:
 355    case 3:
 356    case GL_RGB:
 357    case GL_COMPRESSED_RGB:
 358    case GL_RGBA8:
 359    case GL_RGB10_A2:
 360    case GL_RGBA12:
 361       return default_rgba_format( pipe, surfType );
 362    case GL_RGBA16:
 363       return default_deep_rgba_format( pipe, surfType );
 364
 365    case GL_RGBA4:
 366    case GL_RGBA2:
 367       if (screen->is_format_supported( screen, PIPE_FORMAT_A4R4G4B4_UNORM, surfType ))
 368          return PIPE_FORMAT_A4R4G4B4_UNORM;
 369       return default_rgba_format( pipe, surfType );
 370
 371    case GL_RGB5_A1:
 372       if (screen->is_format_supported( screen, PIPE_FORMAT_A1R5G5B5_UNORM, surfType ))
 373          return PIPE_FORMAT_A1R5G5B5_UNORM;
 374       return default_rgba_format( pipe, surfType );
 375
 376    case GL_RGB8:
 377    case GL_RGB10:
 378    case GL_RGB12:
 379    case GL_RGB16:
 380       return default_rgba_format( pipe, surfType );
 381
 382    case GL_RGB5:
 383    case GL_RGB4:
 384    case GL_R3_G3_B2:
 385       if (screen->is_format_supported( screen, PIPE_FORMAT_A1R5G5B5_UNORM, surfType ))
 386          return PIPE_FORMAT_A1R5G5B5_UNORM;
 387       if (screen->is_format_supported( screen, PIPE_FORMAT_R5G6B5_UNORM, surfType ))
 388          return PIPE_FORMAT_R5G6B5_UNORM;
 389       return default_rgba_format( pipe, surfType );
 390
 391    case GL_ALPHA:
 392    case GL_ALPHA4:
 393    case GL_ALPHA8:
 394    case GL_ALPHA12:
 395    case GL_ALPHA16:
 396    case GL_COMPRESSED_ALPHA:
 397       if (screen->is_format_supported( screen, PIPE_FORMAT_U_A8, surfType ))
 398          return PIPE_FORMAT_U_A8;
 399       return default_rgba_format( pipe, surfType );
 400
 401    case 1:
 402    case GL_LUMINANCE:
 403    case GL_LUMINANCE4:
 404    case GL_LUMINANCE8:
 405    case GL_LUMINANCE12:
 406    case GL_LUMINANCE16:
 407    case GL_COMPRESSED_LUMINANCE:
 408       if (screen->is_format_supported( screen, PIPE_FORMAT_U_L8, surfType ))
 409          return PIPE_FORMAT_U_A8;
 410       return default_rgba_format( pipe, surfType );
 411
 412    case 2:
 413    case GL_LUMINANCE_ALPHA:
 414    case GL_LUMINANCE4_ALPHA4:
 415    case GL_LUMINANCE6_ALPHA2:
 416    case GL_LUMINANCE8_ALPHA8:
 417    case GL_LUMINANCE12_ALPHA4:
 418    case GL_LUMINANCE12_ALPHA12:
 419    case GL_LUMINANCE16_ALPHA16:
 420    case GL_COMPRESSED_LUMINANCE_ALPHA:
 421       if (screen->is_format_supported( screen, PIPE_FORMAT_U_A8_L8, surfType ))
 422          return PIPE_FORMAT_U_A8_L8;
 423       return default_rgba_format( pipe, surfType );
 424
 425    case GL_INTENSITY:
 426    case GL_INTENSITY4:
 427    case GL_INTENSITY8:
 428    case GL_INTENSITY12:
 429    case GL_INTENSITY16:
 430    case GL_COMPRESSED_INTENSITY:
 431       if (screen->is_format_supported( screen, PIPE_FORMAT_U_I8, surfType ))
 432          return PIPE_FORMAT_U_I8;
 433       return default_rgba_format( pipe, surfType );
 434
 435 #if 0
 436    /* not supported for renderbuffers */
 437    case GL_YCBCR_MESA:
 438       return PIPE_FORMAT_NONE;
 439    case GL_COMPRESSED_RGB_FXT1_3DFX:
 440       return &_mesa_texformat_rgb_fxt1;
 441    case GL_COMPRESSED_RGBA_FXT1_3DFX:
 442       return &_mesa_texformat_rgba_fxt1;
 443
 444    case GL_RGB_S3TC:
 445    case GL_RGB4_S3TC:
 446    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
 447       return &_mesa_texformat_rgb_dxt1;
 448
 449    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
 450       return &_mesa_texformat_rgba_dxt1;
 451
 452    case GL_RGBA_S3TC:
 453    case GL_RGBA4_S3TC:
 454    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
 455       return &_mesa_texformat_rgba_dxt3;
 456
 457    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
 458       return &_mesa_texformat_rgba_dxt5;
 459 #endif
 460
 461    case GL_DEPTH_COMPONENT16:
 462       if (screen->is_format_supported( screen, PIPE_FORMAT_Z16_UNORM, surfType ))
 463          return PIPE_FORMAT_Z16_UNORM;
 464       /* fall-through */
 465    case GL_DEPTH_COMPONENT24:
 466       if (screen->is_format_supported( screen, PIPE_FORMAT_S8Z24_UNORM, surfType ))
 467          return PIPE_FORMAT_S8Z24_UNORM;
 468       if (screen->is_format_supported( screen, PIPE_FORMAT_Z24S8_UNORM, surfType ))
 469          return PIPE_FORMAT_Z24S8_UNORM;
 470       /* fall-through */
 471    case GL_DEPTH_COMPONENT32:
 472       if (screen->is_format_supported( screen, PIPE_FORMAT_Z32_UNORM, surfType ))
 473          return PIPE_FORMAT_Z32_UNORM;
 474       /* fall-through */
 475    case GL_DEPTH_COMPONENT:
 476       return default_depth_format( pipe, surfType );
 477
 478    case GL_STENCIL_INDEX:
 479    case GL_STENCIL_INDEX1_EXT:
 480    case GL_STENCIL_INDEX4_EXT:
 481    case GL_STENCIL_INDEX8_EXT:
 482    case GL_STENCIL_INDEX16_EXT:
 483       if (screen->is_format_supported( screen, PIPE_FORMAT_U_S8, surfType ))
 484          return PIPE_FORMAT_U_S8;
 485       if (screen->is_format_supported( screen, PIPE_FORMAT_S8Z24_UNORM, surfType ))
 486          return PIPE_FORMAT_S8Z24_UNORM;
 487       if (screen->is_format_supported( screen, PIPE_FORMAT_Z24S8_UNORM, surfType ))
 488          return PIPE_FORMAT_Z24S8_UNORM;
 489       return PIPE_FORMAT_NONE;
 490
 491    case GL_DEPTH_STENCIL_EXT:
 492    case GL_DEPTH24_STENCIL8_EXT:
 493       if (screen->is_format_supported( screen, PIPE_FORMAT_S8Z24_UNORM, surfType ))
 494          return PIPE_FORMAT_S8Z24_UNORM;
 495       if (screen->is_format_supported( screen, PIPE_FORMAT_Z24S8_UNORM, surfType ))
 496          return PIPE_FORMAT_Z24S8_UNORM;
 497       return PIPE_FORMAT_NONE;
 498
 499    default:
 500       return PIPE_FORMAT_NONE;
 501    }
 502 }
 503
 504
 505
 506 /* It works out that this function is fine for all the supported
 507  * hardware.  However, there is still a need to map the formats onto
 508  * hardware descriptors.
 509  */
 510 /* Note that the i915 can actually support many more formats than
 511  * these if we take the step of simply swizzling the colors
 512  * immediately after sampling...
 513  */
 514 const struct gl_texture_format *
 515 st_ChooseTextureFormat(GLcontext * ctx, GLint internalFormat,
 516                        GLenum format, GLenum type)
 517 {
 518 #if 0
 519    struct intel_context *intel = intel_context(ctx);
 520    const GLboolean do32bpt = (intel->intelScreen->front.cpp == 4);
 521 #else
 522    const GLboolean do32bpt = 1;
 523 #endif
 524
 525    (void) ctx;
 526
 527    switch (internalFormat) {
 528    case 4:
 529    case GL_RGBA:
 530    case GL_COMPRESSED_RGBA:
 531       if (format == GL_BGRA) {
 532          if (type == GL_UNSIGNED_BYTE || type == GL_UNSIGNED_INT_8_8_8_8_REV) {
 533             return &_mesa_texformat_argb8888;
 534          }
 535          else if (type == GL_UNSIGNED_SHORT_4_4_4_4_REV) {
 536             return &_mesa_texformat_argb4444;
 537          }
 538          else if (type == GL_UNSIGNED_SHORT_1_5_5_5_REV) {
 539             return &_mesa_texformat_argb1555;
 540          }
 541       }
 542       return do32bpt ? &_mesa_texformat_argb8888 : &_mesa_texformat_argb4444;
 543
 544    case 3:
 545    case GL_RGB:
 546    case GL_COMPRESSED_RGB:
 547       if (format == GL_RGB && type == GL_UNSIGNED_SHORT_5_6_5) {
 548          return &_mesa_texformat_rgb565;
 549       }
 550       return do32bpt ? &_mesa_texformat_argb8888 : &_mesa_texformat_rgb565;
 551
 552    case GL_RGBA8:
 553    case GL_RGB10_A2:
 554    case GL_RGBA12:
 555    case GL_RGBA16:
 556       return do32bpt ? &_mesa_texformat_argb8888 : &_mesa_texformat_argb4444;
 557
 558    case GL_RGBA4:
 559    case GL_RGBA2:
 560       return &_mesa_texformat_argb4444;
 561
 562    case GL_RGB5_A1:
 563       return &_mesa_texformat_argb1555;
 564
 565    case GL_RGB8:
 566    case GL_RGB10:
 567    case GL_RGB12:
 568    case GL_RGB16:
 569       return &_mesa_texformat_argb8888;
 570
 571    case GL_RGB5:
 572    case GL_RGB4:
 573    case GL_R3_G3_B2:
 574       return &_mesa_texformat_rgb565;
 575
 576    case GL_ALPHA:
 577    case GL_ALPHA4:
 578    case GL_ALPHA8:
 579    case GL_ALPHA12:
 580    case GL_ALPHA16:
 581    case GL_COMPRESSED_ALPHA:
 582       return &_mesa_texformat_a8;
 583
 584    case 1:
 585    case GL_LUMINANCE:
 586    case GL_LUMINANCE4:
 587    case GL_LUMINANCE8:
 588    case GL_LUMINANCE12:
 589    case GL_LUMINANCE16:
 590    case GL_COMPRESSED_LUMINANCE:
 591       return &_mesa_texformat_l8;
 592
 593    case 2:
 594    case GL_LUMINANCE_ALPHA:
 595    case GL_LUMINANCE4_ALPHA4:
 596    case GL_LUMINANCE6_ALPHA2:
 597    case GL_LUMINANCE8_ALPHA8:
 598    case GL_LUMINANCE12_ALPHA4:
 599    case GL_LUMINANCE12_ALPHA12:
 600    case GL_LUMINANCE16_ALPHA16:
 601    case GL_COMPRESSED_LUMINANCE_ALPHA:
 602       return &_mesa_texformat_al88;
 603
 604    case GL_INTENSITY:
 605    case GL_INTENSITY4:
 606    case GL_INTENSITY8:
 607    case GL_INTENSITY12:
 608    case GL_INTENSITY16:
 609    case GL_COMPRESSED_INTENSITY:
 610       return &_mesa_texformat_i8;
 611
 612    case GL_YCBCR_MESA:
 613       if (type == GL_UNSIGNED_SHORT_8_8_MESA || type == GL_UNSIGNED_BYTE)
 614          return &_mesa_texformat_ycbcr;
 615       else
 616          return &_mesa_texformat_ycbcr_rev;
 617
 618    case GL_COMPRESSED_RGB_FXT1_3DFX:
 619       return &_mesa_texformat_rgb_fxt1;
 620    case GL_COMPRESSED_RGBA_FXT1_3DFX:
 621       return &_mesa_texformat_rgba_fxt1;
 622
 623    case GL_RGB_S3TC:
 624    case GL_RGB4_S3TC:
 625    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
 626       return &_mesa_texformat_rgb_dxt1;
 627
 628    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
 629       return &_mesa_texformat_rgba_dxt1;
 630
 631    case GL_RGBA_S3TC:
 632    case GL_RGBA4_S3TC:
 633    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
 634       return &_mesa_texformat_rgba_dxt3;
 635
 636    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
 637       return &_mesa_texformat_rgba_dxt5;
 638
 639    case GL_DEPTH_COMPONENT:
 640    case GL_DEPTH_COMPONENT16:
 641    case GL_DEPTH_COMPONENT24:
 642    case GL_DEPTH_COMPONENT32:
 643       return &_mesa_texformat_z16;
 644
 645    case GL_DEPTH_STENCIL_EXT:
 646    case GL_DEPTH24_STENCIL8_EXT:
 647       return &_mesa_texformat_z24_s8;
 648
 649    default:
 650       fprintf(stderr, "unexpected texture format %s in %s\n",
 651               _mesa_lookup_enum_by_nr(internalFormat), __FUNCTION__);
 652       return NULL;
 653    }
 654
 655    return NULL;                 /* never get here */
 656 }