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(
 103    GLuint format,
 104    struct pipe_format_info *pinfo )
 105 {
 106    if (pf_layout(format) == PIPE_FORMAT_LAYOUT_RGBAZS) {
 107       pipe_format_rgbazs_t info;
 108
 109       info = format;
 110
 111 #if 0
 112       printf(
 113          "PIPE_FORMAT: X(%u), Y(%u), Z(%u), W(%u)\n",
 114          info.sizeX,
 115          info.sizeY,
 116          info.sizeZ,
 117          info.sizeW );
 118 #endif
 119
 120       /* Data type */
 121       if (format == PIPE_FORMAT_U_A1_R5_G5_B5 || format == PIPE_FORMAT_U_R5_G6_B5) {
 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(GLuint pipeFormat)
 224 {
 225    struct pipe_format_info info;
 226    if (!st_get_format_info( pipeFormat, &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(GLuint pipeFormat)
 239 {
 240    struct pipe_format_info info;
 241    if (!st_get_format_info( pipeFormat, &info )) {
 242       assert( 0 );
 243       return 0;
 244    }
 245    return info.datatype;
 246 }
 247
 248
 249 GLuint
 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_U_A8_R8_G8_B8;
 257    case MESA_FORMAT_AL88:
 258       return PIPE_FORMAT_U_A8_L8;
 259    case MESA_FORMAT_A8:
 260       return PIPE_FORMAT_U_A8;
 261    case MESA_FORMAT_L8:
 262       return PIPE_FORMAT_U_L8;
 263    case MESA_FORMAT_I8:
 264       return PIPE_FORMAT_U_I8;
 265    case MESA_FORMAT_Z16:
 266       return PIPE_FORMAT_U_Z16;
 267    default:
 268       assert(0);
 269       return 0;
 270    }
 271 }
 272
 273 /**
 274  * Search list of formats for first RGBA format.
 275  */
 276 static GLuint
 277 default_rgba_format(
 278    struct pipe_context *pipe )
 279 {
 280    if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_R8_G8_B8_A8 )) {
 281       return PIPE_FORMAT_U_R8_G8_B8_A8;
 282    }
 283    if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_A8_R8_G8_B8 )) {
 284       return PIPE_FORMAT_U_A8_R8_G8_B8;
 285    }
 286    if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_R5_G6_B5 )) {
 287       return PIPE_FORMAT_U_R5_G6_B5;
 288    }
 289    return PIPE_FORMAT_NONE;
 290 }
 291
 292
 293 /**
 294  * Search list of formats for first RGBA format with >8 bits/channel.
 295  */
 296 static GLuint
 297 default_deep_rgba_format(
 298    struct pipe_context *pipe )
 299 {
 300    if (pipe->is_format_supported( pipe, PIPE_FORMAT_S_R16_G16_B16_A16 )) {
 301       return PIPE_FORMAT_S_R16_G16_B16_A16;
 302    }
 303    return PIPE_FORMAT_NONE;
 304 }
 305
 306
 307 /**
 308  * Search list of formats for first depth/Z format.
 309  */
 310 static GLuint
 311 default_depth_format(
 312    struct pipe_context *pipe )
 313 {
 314    if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_Z16 )) {
 315       return PIPE_FORMAT_U_Z16;
 316    }
 317    if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_Z32 )) {
 318       return PIPE_FORMAT_U_Z32;
 319    }
 320    if (pipe->is_format_supported( pipe, PIPE_FORMAT_S8_Z24 )) {
 321       return PIPE_FORMAT_S8_Z24;
 322    }
 323    if (pipe->is_format_supported( pipe, PIPE_FORMAT_Z24_S8 )) {
 324       return PIPE_FORMAT_Z24_S8;
 325    }
 326    return PIPE_FORMAT_NONE;
 327 }
 328
 329 /**
 330  * Choose the PIPE_FORMAT_ to use for storing a texture image based
 331  * on the user's internalFormat, format and type parameters.
 332  * We query the pipe device for a list of formats which it supports
 333  * and choose from them.
 334  * If we find a device that needs a more intricate selection mechanism,
 335  * this function _could_ get pushed down into the pipe device.
 336  *
 337  * Note: also used for glRenderbufferStorageEXT()
 338  *
 339  * Note: format and type may be GL_NONE (see renderbuffers)
 340  *
 341  * \return PIPE_FORMAT_NONE if error/problem.
 342  */
 343 GLuint
 344 st_choose_pipe_format(struct pipe_context *pipe, GLint internalFormat,
 345                       GLenum format, GLenum type)
 346 {
 347    switch (internalFormat) {
 348    case 4:
 349    case GL_RGBA:
 350    case GL_COMPRESSED_RGBA:
 351       if (format == GL_BGRA) {
 352          if (type == GL_UNSIGNED_BYTE || type == GL_UNSIGNED_INT_8_8_8_8_REV) {
 353             if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_A8_R8_G8_B8 ))
 354                return PIPE_FORMAT_U_A8_R8_G8_B8;
 355          }
 356          else if (type == GL_UNSIGNED_SHORT_4_4_4_4_REV) {
 357             if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_A4_R4_G4_B4 ))
 358                return PIPE_FORMAT_U_A4_R4_G4_B4;
 359          }
 360          else if (type == GL_UNSIGNED_SHORT_1_5_5_5_REV) {
 361             if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_A1_R5_G5_B5 ))
 362                return PIPE_FORMAT_U_A1_R5_G5_B5;
 363          }
 364       }
 365       return default_rgba_format( pipe );
 366
 367    case 3:
 368    case GL_RGB:
 369    case GL_COMPRESSED_RGB:
 370       if (format == GL_RGB && type == GL_UNSIGNED_SHORT_5_6_5) {
 371          if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_R5_G6_B5 ))
 372             return PIPE_FORMAT_U_R5_G6_B5;
 373       }
 374       return default_rgba_format( pipe );
 375
 376    case GL_RGBA8:
 377    case GL_RGB10_A2:
 378    case GL_RGBA12:
 379       return default_rgba_format( pipe );
 380    case GL_RGBA16:
 381       return default_deep_rgba_format( pipe );
 382
 383    case GL_RGBA4:
 384    case GL_RGBA2:
 385       if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_A4_R4_G4_B4 ))
 386          return PIPE_FORMAT_U_A4_R4_G4_B4;
 387       return default_rgba_format( pipe );
 388
 389    case GL_RGB5_A1:
 390       if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_A1_R5_G5_B5 ))
 391          return PIPE_FORMAT_U_A1_R5_G5_B5;
 392       return default_rgba_format( pipe );
 393
 394    case GL_RGB8:
 395    case GL_RGB10:
 396    case GL_RGB12:
 397    case GL_RGB16:
 398       return default_rgba_format( pipe );
 399
 400    case GL_RGB5:
 401    case GL_RGB4:
 402    case GL_R3_G3_B2:
 403       if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_A1_R5_G5_B5 ))
 404          return PIPE_FORMAT_U_A1_R5_G5_B5;
 405       return default_rgba_format( pipe );
 406
 407    case GL_ALPHA:
 408    case GL_ALPHA4:
 409    case GL_ALPHA8:
 410    case GL_ALPHA12:
 411    case GL_ALPHA16:
 412    case GL_COMPRESSED_ALPHA:
 413       if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_A8 ))
 414          return PIPE_FORMAT_U_A8;
 415       return default_rgba_format( pipe );
 416
 417    case 1:
 418    case GL_LUMINANCE:
 419    case GL_LUMINANCE4:
 420    case GL_LUMINANCE8:
 421    case GL_LUMINANCE12:
 422    case GL_LUMINANCE16:
 423    case GL_COMPRESSED_LUMINANCE:
 424       if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_A8 ))
 425          return PIPE_FORMAT_U_A8;
 426       return default_rgba_format( pipe );
 427
 428    case 2:
 429    case GL_LUMINANCE_ALPHA:
 430    case GL_LUMINANCE4_ALPHA4:
 431    case GL_LUMINANCE6_ALPHA2:
 432    case GL_LUMINANCE8_ALPHA8:
 433    case GL_LUMINANCE12_ALPHA4:
 434    case GL_LUMINANCE12_ALPHA12:
 435    case GL_LUMINANCE16_ALPHA16:
 436    case GL_COMPRESSED_LUMINANCE_ALPHA:
 437       if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_A8_L8 ))
 438          return PIPE_FORMAT_U_A8_L8;
 439       return default_rgba_format( pipe );
 440
 441    case GL_INTENSITY:
 442    case GL_INTENSITY4:
 443    case GL_INTENSITY8:
 444    case GL_INTENSITY12:
 445    case GL_INTENSITY16:
 446    case GL_COMPRESSED_INTENSITY:
 447       if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_I8 ))
 448          return PIPE_FORMAT_U_I8;
 449       return default_rgba_format( pipe );
 450
 451    case GL_YCBCR_MESA:
 452       if (type == GL_UNSIGNED_SHORT_8_8_MESA || type == GL_UNSIGNED_BYTE) {
 453          if (pipe->is_format_supported( pipe, PIPE_FORMAT_YCBCR ))
 454             return PIPE_FORMAT_YCBCR;
 455       }
 456       else {
 457          if (pipe->is_format_supported( pipe, PIPE_FORMAT_YCBCR_REV ))
 458             return PIPE_FORMAT_YCBCR_REV;
 459       }
 460       return PIPE_FORMAT_NONE;
 461
 462 #if 0
 463    case GL_COMPRESSED_RGB_FXT1_3DFX:
 464       return &_mesa_texformat_rgb_fxt1;
 465    case GL_COMPRESSED_RGBA_FXT1_3DFX:
 466       return &_mesa_texformat_rgba_fxt1;
 467
 468    case GL_RGB_S3TC:
 469    case GL_RGB4_S3TC:
 470    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
 471       return &_mesa_texformat_rgb_dxt1;
 472
 473    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
 474       return &_mesa_texformat_rgba_dxt1;
 475
 476    case GL_RGBA_S3TC:
 477    case GL_RGBA4_S3TC:
 478    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
 479       return &_mesa_texformat_rgba_dxt3;
 480
 481    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
 482       return &_mesa_texformat_rgba_dxt5;
 483 #endif
 484
 485    case GL_DEPTH_COMPONENT16:
 486       if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_Z16 ))
 487          return PIPE_FORMAT_U_Z16;
 488       /* fall-through */
 489    case GL_DEPTH_COMPONENT24:
 490       if (pipe->is_format_supported( pipe, PIPE_FORMAT_S8_Z24 ))
 491          return PIPE_FORMAT_S8_Z24;
 492       if (pipe->is_format_supported( pipe, PIPE_FORMAT_Z24_S8 ))
 493          return PIPE_FORMAT_Z24_S8;
 494       /* fall-through */
 495    case GL_DEPTH_COMPONENT32:
 496       if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_Z32 ))
 497          return PIPE_FORMAT_U_Z32;
 498       /* fall-through */
 499    case GL_DEPTH_COMPONENT:
 500       return default_depth_format( pipe );
 501
 502    case GL_STENCIL_INDEX:
 503    case GL_STENCIL_INDEX1_EXT:
 504    case GL_STENCIL_INDEX4_EXT:
 505    case GL_STENCIL_INDEX8_EXT:
 506    case GL_STENCIL_INDEX16_EXT:
 507       if (pipe->is_format_supported( pipe, PIPE_FORMAT_U_S8 ))
 508          return PIPE_FORMAT_U_S8;
 509       if (pipe->is_format_supported( pipe, PIPE_FORMAT_S8_Z24 ))
 510          return PIPE_FORMAT_S8_Z24;
 511       if (pipe->is_format_supported( pipe, PIPE_FORMAT_Z24_S8 ))
 512          return PIPE_FORMAT_Z24_S8;
 513       return PIPE_FORMAT_NONE;
 514
 515    case GL_DEPTH_STENCIL_EXT:
 516    case GL_DEPTH24_STENCIL8_EXT:
 517       if (pipe->is_format_supported( pipe, PIPE_FORMAT_S8_Z24 ))
 518          return PIPE_FORMAT_S8_Z24;
 519       if (pipe->is_format_supported( pipe, PIPE_FORMAT_Z24_S8 ))
 520          return PIPE_FORMAT_Z24_S8;
 521       return PIPE_FORMAT_NONE;
 522
 523    default:
 524       return PIPE_FORMAT_NONE;
 525    }
 526 }
 527
 528
 529
 530 /* It works out that this function is fine for all the supported
 531  * hardware.  However, there is still a need to map the formats onto
 532  * hardware descriptors.
 533  */
 534 /* Note that the i915 can actually support many more formats than
 535  * these if we take the step of simply swizzling the colors
 536  * immediately after sampling...
 537  */
 538 const struct gl_texture_format *
 539 st_ChooseTextureFormat(GLcontext * ctx, GLint internalFormat,
 540                          GLenum format, GLenum type)
 541 {
 542 #if 0
 543    struct intel_context *intel = intel_context(ctx);
 544    const GLboolean do32bpt = (intel->intelScreen->front.cpp == 4);
 545 #else
 546    const GLboolean do32bpt = 1;
 547 #endif
 548
 549    switch (internalFormat) {
 550    case 4:
 551    case GL_RGBA:
 552    case GL_COMPRESSED_RGBA:
 553       if (format == GL_BGRA) {
 554          if (type == GL_UNSIGNED_BYTE || type == GL_UNSIGNED_INT_8_8_8_8_REV) {
 555             return &_mesa_texformat_argb8888;
 556          }
 557          else if (type == GL_UNSIGNED_SHORT_4_4_4_4_REV) {
 558             return &_mesa_texformat_argb4444;
 559          }
 560          else if (type == GL_UNSIGNED_SHORT_1_5_5_5_REV) {
 561             return &_mesa_texformat_argb1555;
 562          }
 563       }
 564       return do32bpt ? &_mesa_texformat_argb8888 : &_mesa_texformat_argb4444;
 565
 566    case 3:
 567    case GL_RGB:
 568    case GL_COMPRESSED_RGB:
 569       if (format == GL_RGB && type == GL_UNSIGNED_SHORT_5_6_5) {
 570          return &_mesa_texformat_rgb565;
 571       }
 572       return do32bpt ? &_mesa_texformat_argb8888 : &_mesa_texformat_rgb565;
 573
 574    case GL_RGBA8:
 575    case GL_RGB10_A2:
 576    case GL_RGBA12:
 577    case GL_RGBA16:
 578       return do32bpt ? &_mesa_texformat_argb8888 : &_mesa_texformat_argb4444;
 579
 580    case GL_RGBA4:
 581    case GL_RGBA2:
 582       return &_mesa_texformat_argb4444;
 583
 584    case GL_RGB5_A1:
 585       return &_mesa_texformat_argb1555;
 586
 587    case GL_RGB8:
 588    case GL_RGB10:
 589    case GL_RGB12:
 590    case GL_RGB16:
 591       return &_mesa_texformat_argb8888;
 592
 593    case GL_RGB5:
 594    case GL_RGB4:
 595    case GL_R3_G3_B2:
 596       return &_mesa_texformat_rgb565;
 597
 598    case GL_ALPHA:
 599    case GL_ALPHA4:
 600    case GL_ALPHA8:
 601    case GL_ALPHA12:
 602    case GL_ALPHA16:
 603    case GL_COMPRESSED_ALPHA:
 604       return &_mesa_texformat_a8;
 605
 606    case 1:
 607    case GL_LUMINANCE:
 608    case GL_LUMINANCE4:
 609    case GL_LUMINANCE8:
 610    case GL_LUMINANCE12:
 611    case GL_LUMINANCE16:
 612    case GL_COMPRESSED_LUMINANCE:
 613       return &_mesa_texformat_l8;
 614
 615    case 2:
 616    case GL_LUMINANCE_ALPHA:
 617    case GL_LUMINANCE4_ALPHA4:
 618    case GL_LUMINANCE6_ALPHA2:
 619    case GL_LUMINANCE8_ALPHA8:
 620    case GL_LUMINANCE12_ALPHA4:
 621    case GL_LUMINANCE12_ALPHA12:
 622    case GL_LUMINANCE16_ALPHA16:
 623    case GL_COMPRESSED_LUMINANCE_ALPHA:
 624       return &_mesa_texformat_al88;
 625
 626    case GL_INTENSITY:
 627    case GL_INTENSITY4:
 628    case GL_INTENSITY8:
 629    case GL_INTENSITY12:
 630    case GL_INTENSITY16:
 631    case GL_COMPRESSED_INTENSITY:
 632       return &_mesa_texformat_i8;
 633
 634    case GL_YCBCR_MESA:
 635       if (type == GL_UNSIGNED_SHORT_8_8_MESA || type == GL_UNSIGNED_BYTE)
 636          return &_mesa_texformat_ycbcr;
 637       else
 638          return &_mesa_texformat_ycbcr_rev;
 639
 640    case GL_COMPRESSED_RGB_FXT1_3DFX:
 641       return &_mesa_texformat_rgb_fxt1;
 642    case GL_COMPRESSED_RGBA_FXT1_3DFX:
 643       return &_mesa_texformat_rgba_fxt1;
 644
 645    case GL_RGB_S3TC:
 646    case GL_RGB4_S3TC:
 647    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
 648       return &_mesa_texformat_rgb_dxt1;
 649
 650    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
 651       return &_mesa_texformat_rgba_dxt1;
 652
 653    case GL_RGBA_S3TC:
 654    case GL_RGBA4_S3TC:
 655    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
 656       return &_mesa_texformat_rgba_dxt3;
 657
 658    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
 659       return &_mesa_texformat_rgba_dxt5;
 660
 661    case GL_DEPTH_COMPONENT:
 662    case GL_DEPTH_COMPONENT16:
 663    case GL_DEPTH_COMPONENT24:
 664    case GL_DEPTH_COMPONENT32:
 665       return &_mesa_texformat_z16;
 666
 667    case GL_DEPTH_STENCIL_EXT:
 668    case GL_DEPTH24_STENCIL8_EXT:
 669       return &_mesa_texformat_z24_s8;
 670
 671    default:
 672       fprintf(stderr, "unexpected texture format %s in %s\n",
 673               _mesa_lookup_enum_by_nr(internalFormat), __FUNCTION__);
 674       return NULL;
 675    }
 676
 677    return NULL;                 /* never get here */
 678 }