src/mesa/main/textureview.c

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 2013 LunarG, Inc.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included
  14  * in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  21  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  22  * DEALINGS IN THE SOFTWARE.
  23  *
  24  * Authors:
  25  *    Courtney Goeltzenleuchter <courtney@lunarg.com>
  26  */
  27
  28
  29 /**
  30  * \file textureview.c
  31  * GL_ARB_texture_view functions
  32  */
  33
  34 #include "glheader.h"
  35 #include "context.h"
  36 #include "enums.h"
  37 #include "imports.h"
  38 #include "macros.h"
  39 #include "teximage.h"
  40 #include "texobj.h"
  41 #include "mipmap.h"
  42 #include "texstorage.h"
  43 #include "textureview.h"
  44 #include "stdbool.h"
  45 #include "mtypes.h"
  46
  47 /* Table 3.X.2 (Compatible internal formats for TextureView)
  48     ---------------------------------------------------------------------------
  49     | Class                 | Internal formats                                |
  50     ---------------------------------------------------------------------------
  51     | VIEW_CLASS_128_BITS   | RGBA32F, RGBA32UI, RGBA32I                      |
  52     ---------------------------------------------------------------------------
  53     | VIEW_CLASS_96_BITS    | RGB32F, RGB32UI, RGB32I                         |
  54     ---------------------------------------------------------------------------
  55     | VIEW_CLASS_64_BITS    | RGBA16F, RG32F, RGBA16UI, RG32UI, RGBA16I,      |
  56     |                       | RG32I, RGBA16, RGBA16_SNORM                     |
  57     ---------------------------------------------------------------------------
  58     | VIEW_CLASS_48_BITS    | RGB16, RGB16_SNORM, RGB16F, RGB16UI, RGB16I     |
  59     ---------------------------------------------------------------------------
  60     | VIEW_CLASS_32_BITS    | RG16F, R11F_G11F_B10F, R32F,                    |
  61     |                       | RGB10_A2UI, RGBA8UI, RG16UI, R32UI,             |
  62     |                       | RGBA8I, RG16I, R32I, RGB10_A2, RGBA8, RG16,     |
  63     |                       | RGBA8_SNORM, RG16_SNORM, SRGB8_ALPHA8, RGB9_E5  |
  64     ---------------------------------------------------------------------------
  65     | VIEW_CLASS_24_BITS    | RGB8, RGB8_SNORM, SRGB8, RGB8UI, RGB8I          |
  66     ---------------------------------------------------------------------------
  67     | VIEW_CLASS_16_BITS    | R16F, RG8UI, R16UI, RG8I, R16I, RG8, R16,       |
  68     |                       | RG8_SNORM, R16_SNORM                            |
  69     ---------------------------------------------------------------------------
  70     | VIEW_CLASS_8_BITS     | R8UI, R8I, R8, R8_SNORM                         |
  71     ---------------------------------------------------------------------------
  72     | VIEW_CLASS_RGTC1_RED  | COMPRESSED_RED_RGTC1,                           |
  73     |                       | COMPRESSED_SIGNED_RED_RGTC1                     |
  74     ---------------------------------------------------------------------------
  75     | VIEW_CLASS_RGTC2_RG   | COMPRESSED_RG_RGTC2,                            |
  76     |                       | COMPRESSED_SIGNED_RG_RGTC2                      |
  77     ---------------------------------------------------------------------------
  78     | VIEW_CLASS_BPTC_UNORM | COMPRESSED_RGBA_BPTC_UNORM,                     |
  79     |                       | COMPRESSED_SRGB_ALPHA_BPTC_UNORM                |
  80     ---------------------------------------------------------------------------
  81     | VIEW_CLASS_BPTC_FLOAT | COMPRESSED_RGB_BPTC_SIGNED_FLOAT,               |
  82     |                       | COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT              |
  83     ---------------------------------------------------------------------------
  84  */
  85 struct internal_format_class_info {
  86    GLenum view_class;
  87    GLenum internal_format;
  88 };
  89 static const struct internal_format_class_info compatible_internal_formats[] = {
  90    {GL_VIEW_CLASS_128_BITS, GL_RGBA32F},
  91    {GL_VIEW_CLASS_128_BITS, GL_RGBA32UI},
  92    {GL_VIEW_CLASS_128_BITS, GL_RGBA32I},
  93    {GL_VIEW_CLASS_96_BITS, GL_RGB32F},
  94    {GL_VIEW_CLASS_96_BITS, GL_RGB32UI},
  95    {GL_VIEW_CLASS_96_BITS, GL_RGB32I},
  96    {GL_VIEW_CLASS_64_BITS, GL_RGBA16F},
  97    {GL_VIEW_CLASS_64_BITS, GL_RG32F},
  98    {GL_VIEW_CLASS_64_BITS, GL_RGBA16UI},
  99    {GL_VIEW_CLASS_64_BITS, GL_RG32UI},
 100    {GL_VIEW_CLASS_64_BITS, GL_RGBA16I},
 101    {GL_VIEW_CLASS_64_BITS, GL_RG32I},
 102    {GL_VIEW_CLASS_64_BITS, GL_RGBA16},
 103    {GL_VIEW_CLASS_64_BITS, GL_RGBA16_SNORM},
 104    {GL_VIEW_CLASS_48_BITS, GL_RGB16},
 105    {GL_VIEW_CLASS_48_BITS, GL_RGB16_SNORM},
 106    {GL_VIEW_CLASS_48_BITS, GL_RGB16F},
 107    {GL_VIEW_CLASS_48_BITS, GL_RGB16UI},
 108    {GL_VIEW_CLASS_48_BITS, GL_RGB16I},
 109    {GL_VIEW_CLASS_32_BITS, GL_RG16F},
 110    {GL_VIEW_CLASS_32_BITS, GL_R11F_G11F_B10F},
 111    {GL_VIEW_CLASS_32_BITS, GL_R32F},
 112    {GL_VIEW_CLASS_32_BITS, GL_RGB10_A2UI},
 113    {GL_VIEW_CLASS_32_BITS, GL_RGBA8UI},
 114    {GL_VIEW_CLASS_32_BITS, GL_RG16UI},
 115    {GL_VIEW_CLASS_32_BITS, GL_R32UI},
 116    {GL_VIEW_CLASS_32_BITS, GL_RGBA8I},
 117    {GL_VIEW_CLASS_32_BITS, GL_RG16I},
 118    {GL_VIEW_CLASS_32_BITS, GL_R32I},
 119    {GL_VIEW_CLASS_32_BITS, GL_RGB10_A2},
 120    {GL_VIEW_CLASS_32_BITS, GL_RGBA8},
 121    {GL_VIEW_CLASS_32_BITS, GL_RG16},
 122    {GL_VIEW_CLASS_32_BITS, GL_RGBA8_SNORM},
 123    {GL_VIEW_CLASS_32_BITS, GL_RG16_SNORM},
 124    {GL_VIEW_CLASS_32_BITS, GL_SRGB8_ALPHA8},
 125    {GL_VIEW_CLASS_32_BITS, GL_RGB9_E5},
 126    {GL_VIEW_CLASS_24_BITS, GL_RGB8},
 127    {GL_VIEW_CLASS_24_BITS, GL_RGB8_SNORM},
 128    {GL_VIEW_CLASS_24_BITS, GL_SRGB8},
 129    {GL_VIEW_CLASS_24_BITS, GL_RGB8UI},
 130    {GL_VIEW_CLASS_24_BITS, GL_RGB8I},
 131    {GL_VIEW_CLASS_16_BITS, GL_R16F},
 132    {GL_VIEW_CLASS_16_BITS, GL_RG8UI},
 133    {GL_VIEW_CLASS_16_BITS, GL_R16UI},
 134    {GL_VIEW_CLASS_16_BITS, GL_RG8I},
 135    {GL_VIEW_CLASS_16_BITS, GL_R16I},
 136    {GL_VIEW_CLASS_16_BITS, GL_RG8},
 137    {GL_VIEW_CLASS_16_BITS, GL_R16},
 138    {GL_VIEW_CLASS_16_BITS, GL_RG8_SNORM},
 139    {GL_VIEW_CLASS_16_BITS, GL_R16_SNORM},
 140    {GL_VIEW_CLASS_8_BITS, GL_R8UI},
 141    {GL_VIEW_CLASS_8_BITS, GL_R8I},
 142    {GL_VIEW_CLASS_8_BITS, GL_R8},
 143    {GL_VIEW_CLASS_8_BITS, GL_R8_SNORM},
 144    {GL_VIEW_CLASS_RGTC1_RED, GL_COMPRESSED_RED_RGTC1},
 145    {GL_VIEW_CLASS_RGTC1_RED, GL_COMPRESSED_SIGNED_RED_RGTC1},
 146    {GL_VIEW_CLASS_RGTC2_RG, GL_COMPRESSED_RG_RGTC2},
 147    {GL_VIEW_CLASS_RGTC2_RG, GL_COMPRESSED_SIGNED_RG_RGTC2},
 148    {GL_VIEW_CLASS_BPTC_UNORM, GL_COMPRESSED_RGBA_BPTC_UNORM_ARB},
 149    {GL_VIEW_CLASS_BPTC_UNORM, GL_COMPRESSED_SRGB_ALPHA_BPTC_UNORM_ARB},
 150    {GL_VIEW_CLASS_BPTC_FLOAT, GL_COMPRESSED_RGB_BPTC_SIGNED_FLOAT_ARB},
 151    {GL_VIEW_CLASS_BPTC_FLOAT, GL_COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT_ARB},
 152 };
 153
 154 static const struct internal_format_class_info s3tc_compatible_internal_formats[] = {
 155    {GL_VIEW_CLASS_S3TC_DXT1_RGB, GL_COMPRESSED_RGB_S3TC_DXT1_EXT},
 156    {GL_VIEW_CLASS_S3TC_DXT1_RGB, GL_COMPRESSED_SRGB_S3TC_DXT1_EXT},
 157    {GL_VIEW_CLASS_S3TC_DXT1_RGBA, GL_COMPRESSED_RGBA_S3TC_DXT1_EXT},
 158    {GL_VIEW_CLASS_S3TC_DXT1_RGBA, GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT},
 159    {GL_VIEW_CLASS_S3TC_DXT3_RGBA, GL_COMPRESSED_RGBA_S3TC_DXT3_EXT},
 160    {GL_VIEW_CLASS_S3TC_DXT3_RGBA, GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT},
 161    {GL_VIEW_CLASS_S3TC_DXT5_RGBA, GL_COMPRESSED_RGBA_S3TC_DXT5_EXT},
 162    {GL_VIEW_CLASS_S3TC_DXT5_RGBA, GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT},
 163 };
 164
 165 /**
 166  * Lookup format view class based on internalformat
 167  * \return VIEW_CLASS if internalformat found in table, false otherwise.
 168  */
 169 static GLenum
 170 lookup_view_class(struct gl_context *ctx, GLenum internalformat)
 171 {
 172    GLuint i;
 173
 174    for (i = 0; i < ARRAY_SIZE(compatible_internal_formats); i++) {
 175       if (compatible_internal_formats[i].internal_format == internalformat)
 176          return compatible_internal_formats[i].view_class;
 177    }
 178
 179    if (ctx->Extensions.EXT_texture_compression_s3tc && ctx->Extensions.EXT_texture_sRGB) {
 180       for (i = 0; i < ARRAY_SIZE(s3tc_compatible_internal_formats); i++) {
 181          if (s3tc_compatible_internal_formats[i].internal_format == internalformat)
 182             return s3tc_compatible_internal_formats[i].view_class;
 183       }
 184    }
 185    return GL_FALSE;
 186 }
 187
 188 /**
 189  * Initialize new texture's gl_texture_image structures. Will not call driver
 190  * to allocate new space, simply record relevant layer, face, format, etc.
 191  * \return GL_FALSE if any error, GL_TRUE otherwise.
 192  */
 193 static GLboolean
 194 initialize_texture_fields(struct gl_context *ctx,
 195                           GLenum target,
 196                           struct gl_texture_object *texObj,
 197                           GLint levels,
 198                           GLsizei width, GLsizei height, GLsizei depth,
 199                           GLenum internalFormat, gl_format texFormat)
 200 {
 201    const GLuint numFaces = _mesa_num_tex_faces(target);
 202    GLint level, levelWidth = width, levelHeight = height, levelDepth = depth;
 203    GLuint face;
 204
 205    /* Pretend we are bound to initialize the gl_texture_image structs */
 206    texObj->Target = target;
 207
 208    /* Set up all the texture object's gl_texture_images */
 209    for (level = 0; level < levels; level++) {
 210       for (face = 0; face < numFaces; face++) {
 211          struct gl_texture_image *texImage;
 212          GLenum faceTarget = target;
 213
 214          if (target == GL_TEXTURE_CUBE_MAP)
 215             faceTarget = GL_TEXTURE_CUBE_MAP_POSITIVE_X + face;
 216
 217          texImage = _mesa_get_tex_image(ctx, texObj, faceTarget, level);
 218
 219          if (!texImage) {
 220             _mesa_error(ctx, GL_OUT_OF_MEMORY, "glTexStorage");
 221             return GL_FALSE;
 222          }
 223
 224          _mesa_init_teximage_fields(ctx, texImage,
 225                                     levelWidth, levelHeight, levelDepth,
 226                                     0, internalFormat, texFormat);
 227       }
 228
 229       _mesa_next_mipmap_level_size(target, 0, levelWidth, levelHeight, levelDepth,
 230                                    &levelWidth, &levelHeight, &levelDepth);
 231    }
 232
 233    /* "unbind" */
 234    texObj->Target = 0;
 235
 236    return GL_TRUE;
 237 }
 238
 239 #define RETURN_IF_SUPPORTED(t) do {             \
 240    if (newTarget == GL_ ## t)                   \
 241       return true;                              \
 242 } while (0)
 243
 244 /**
 245  * Check for compatible target
 246  * If an error is found, record it with _mesa_error()
 247  * \return false if any error, true otherwise.
 248  */
 249 static bool
 250 target_valid(struct gl_context *ctx, GLenum origTarget, GLenum newTarget)
 251 {
 252    /*
 253     * From ARB_texture_view spec:
 254    ---------------------------------------------------------------------------------------------------------
 255    | Original target              | Valid new targets |
 256    ---------------------------------------------------------------------------------------------------------
 257    | TEXTURE_1D                   | TEXTURE_1D, TEXTURE_1D_ARRAY |
 258    | ------------------------------------------------------------------------------------------------------- |
 259    | TEXTURE_2D                   | TEXTURE_2D, TEXTURE_2D_ARRAY |
 260    | ------------------------------------------------------------------------------------------------------- |
 261    | TEXTURE_3D                   | TEXTURE_3D |
 262    | ------------------------------------------------------------------------------------------------------- |
 263    | TEXTURE_CUBE_MAP             | TEXTURE_CUBE_MAP, TEXTURE_2D, TEXTURE_2D_ARRAY, TEXTURE_CUBE_MAP_ARRAY |
 264    | ------------------------------------------------------------------------------------------------------- |
 265    | TEXTURE_RECTANGLE            | TEXTURE_RECTANGLE |
 266    | ------------------------------------------------------------------------------------------------------- |
 267    | TEXTURE_BUFFER               | <none> |
 268    | ------------------------------------------------------------------------------------------------------- |
 269    | TEXTURE_1D_ARRAY             | TEXTURE_1D_ARRAY, TEXTURE_1D |
 270    | ------------------------------------------------------------------------------------------------------- |
 271    | TEXTURE_2D_ARRAY             | TEXTURE_2D_ARRAY, TEXTURE_2D, TEXTURE_CUBE_MAP, TEXTURE_CUBE_MAP_ARRAY |
 272    | ------------------------------------------------------------------------------------------------------- |
 273    | TEXTURE_CUBE_MAP_ARRAY       | TEXTURE_CUBE_MAP_ARRAY, TEXTURE_2D_ARRAY, TEXTURE_2D, TEXTURE_CUBE_MAP |
 274    | ------------------------------------------------------------------------------------------------------- |
 275    | TEXTURE_2D_MULTISAMPLE       | TEXTURE_2D_MULTISAMPLE, TEXTURE_2D_MULTISAMPLE_ARRAY |
 276    | ------------------------------------------------------------------------------------------------------- |
 277    | TEXTURE_2D_MULTISAMPLE_ARRAY | TEXTURE_2D_MULTISAMPLE, TEXTURE_2D_MULTISAMPLE_ARRAY |
 278    ---------------------------------------------------------------------------------------------------------
 279     */
 280
 281    switch (origTarget) {
 282    case GL_TEXTURE_1D:
 283    case GL_TEXTURE_1D_ARRAY:
 284       RETURN_IF_SUPPORTED(TEXTURE_1D);
 285       RETURN_IF_SUPPORTED(TEXTURE_1D_ARRAY);
 286       break;
 287    case GL_TEXTURE_2D:
 288       RETURN_IF_SUPPORTED(TEXTURE_2D);
 289       RETURN_IF_SUPPORTED(TEXTURE_2D_ARRAY);
 290       break;
 291    case GL_TEXTURE_3D:
 292       RETURN_IF_SUPPORTED(TEXTURE_3D);
 293       break;
 294    case GL_TEXTURE_RECTANGLE:
 295       RETURN_IF_SUPPORTED(TEXTURE_RECTANGLE);
 296       break;
 297    case GL_TEXTURE_CUBE_MAP:
 298    case GL_TEXTURE_2D_ARRAY:
 299    case GL_TEXTURE_CUBE_MAP_ARRAY:
 300       RETURN_IF_SUPPORTED(TEXTURE_2D);
 301       RETURN_IF_SUPPORTED(TEXTURE_2D_ARRAY);
 302       RETURN_IF_SUPPORTED(TEXTURE_CUBE_MAP);
 303       RETURN_IF_SUPPORTED(TEXTURE_CUBE_MAP_ARRAY);
 304       break;
 305    case GL_TEXTURE_2D_MULTISAMPLE:
 306    case GL_TEXTURE_2D_MULTISAMPLE_ARRAY:
 307       RETURN_IF_SUPPORTED(TEXTURE_2D_MULTISAMPLE);
 308       RETURN_IF_SUPPORTED(TEXTURE_2D_MULTISAMPLE_ARRAY);
 309       break;
 310    }
 311    _mesa_error(ctx, GL_INVALID_OPERATION,
 312                "glTextureView(illegal target=%s)",
 313                _mesa_lookup_enum_by_nr(newTarget));
 314    return false;
 315 }
 316 #undef RETURN_IF_SUPPORTED
 317
 318 /**
 319  * Check for compatible format
 320  * If an error is found, record it with _mesa_error()
 321  * \return false if any error, true otherwise.
 322  */
 323 static bool
 324 compatible_format(struct gl_context *ctx, const struct gl_texture_object *origTexObj,
 325                   GLenum internalformat)
 326 {
 327    /* Level 0 of a texture created by glTextureStorage or glTextureView
 328     * is always defined.
 329     */
 330    struct gl_texture_image *texImage = origTexObj->Image[0][0];
 331    GLint origInternalFormat = texImage->InternalFormat;
 332    unsigned int origViewClass, newViewClass;
 333
 334    /* The two textures' internal formats must be compatible according to
 335     * Table 3.X.2 (Compatible internal formats for TextureView)
 336     * if the internal format exists in that table the view class must match.
 337     * The internal formats must be identical if not in that table,
 338     * or an INVALID_OPERATION error is generated.
 339     */
 340    if (origInternalFormat == internalformat)
 341       return true;
 342
 343    origViewClass = lookup_view_class(ctx, origInternalFormat);
 344    newViewClass = lookup_view_class(ctx, internalformat);
 345    if ((origViewClass == newViewClass) && origViewClass != false)
 346       return true;
 347
 348    _mesa_error(ctx, GL_INVALID_OPERATION,
 349                "glTextureView(internalformat %s not compatible with origtexture %s)",
 350                _mesa_lookup_enum_by_nr(internalformat),
 351                _mesa_lookup_enum_by_nr(origInternalFormat));
 352    return false;
 353 }
 354 /**
 355  * Helper function for TexStorage and teximagemultisample to set immutable
 356  * texture state needed by ARB_texture_view.
 357  */
 358 void
 359 _mesa_set_texture_view_state(struct gl_context *ctx,
 360                              struct gl_texture_object *texObj,
 361                              GLenum target, GLuint levels)
 362 {
 363    struct gl_texture_image *texImage;
 364
 365    /* Get a reference to what will become this View's base level */
 366    texImage = _mesa_select_tex_image(ctx, texObj, target, 0);
 367
 368    /* When an immutable texture is created via glTexStorage or glTexImageMultisample,
 369     * TEXTURE_IMMUTABLE_FORMAT becomes TRUE.
 370     * TEXTURE_IMMUTABLE_LEVELS and TEXTURE_VIEW_NUM_LEVELS become levels.
 371     * If the texture target is TEXTURE_1D_ARRAY then
 372     * TEXTURE_VIEW_NUM_LAYERS becomes height.
 373     * If the texture target is TEXTURE_2D_ARRAY, TEXTURE_CUBE_MAP_ARRAY,
 374     * or TEXTURE_2D_MULTISAMPLE_ARRAY then TEXTURE_VIEW_NUM_LAYERS becomes depth.
 375     * If the texture target is TEXTURE_CUBE_MAP, then
 376     * TEXTURE_VIEW_NUM_LAYERS becomes 6.
 377     * For any other texture target, TEXTURE_VIEW_NUM_LAYERS becomes 1.
 378     *
 379     * ARB_texture_multisample: Multisample textures do
 380     * not have multiple image levels.
 381     */
 382
 383    texObj->Immutable = GL_TRUE;
 384    texObj->ImmutableLevels = levels;
 385    texObj->MinLevel = 0;
 386    texObj->NumLevels = levels;
 387    texObj->MinLayer = 0;
 388    texObj->NumLayers = 1;
 389    switch (target) {
 390    case GL_TEXTURE_1D_ARRAY:
 391       texObj->NumLayers = texImage->Height;
 392       break;
 393
 394    case GL_TEXTURE_2D_MULTISAMPLE:
 395       texObj->NumLevels = 1;
 396       texObj->ImmutableLevels = 1;
 397       break;
 398
 399    case GL_TEXTURE_2D_MULTISAMPLE_ARRAY:
 400       texObj->NumLevels = 1;
 401       texObj->ImmutableLevels = 1;
 402       /* fall through to set NumLayers */
 403
 404    case GL_TEXTURE_2D_ARRAY:
 405    case GL_TEXTURE_CUBE_MAP_ARRAY:
 406       texObj->NumLayers = texImage->Depth;
 407       break;
 408
 409    case GL_TEXTURE_CUBE_MAP:
 410       texObj->NumLayers = 6;
 411       break;
 412
 413    }
 414 }
 415
 416 /**
 417  * glTextureView (ARB_texture_view)
 418  * If an error is found, record it with _mesa_error()
 419  * \return none.
 420  */
 421 void GLAPIENTRY
 422 _mesa_TextureView(GLuint texture, GLenum target, GLuint origtexture,
 423                   GLenum internalformat,
 424                   GLuint minlevel, GLuint numlevels,
 425                   GLuint minlayer, GLuint numlayers)
 426 {
 427    struct gl_texture_object *texObj;
 428    struct gl_texture_object *origTexObj;
 429    struct gl_texture_image *origTexImage;
 430    GLuint newViewMinLevel, newViewMinLayer;
 431    GLuint newViewNumLevels, newViewNumLayers;
 432    GLsizei width, height, depth;
 433    gl_format texFormat;
 434    GLboolean sizeOK, dimensionsOK;
 435    GLenum faceTarget;
 436
 437    GET_CURRENT_CONTEXT(ctx);
 438
 439    if (MESA_VERBOSE & (VERBOSE_API | VERBOSE_TEXTURE))
 440       _mesa_debug(ctx, "glTextureView %d %s %d %s %d %d %d %d\n",
 441                   texture, _mesa_lookup_enum_by_nr(target), origtexture,
 442                   _mesa_lookup_enum_by_nr(internalformat),
 443                   minlevel, numlevels, minlayer, numlayers);
 444
 445    if (origtexture == 0) {
 446       _mesa_error(ctx, GL_INVALID_VALUE, "glTextureView(origtexture = %u)", origtexture);
 447       return;
 448    }
 449
 450    /* Need original texture information to validate arguments */
 451    origTexObj = _mesa_lookup_texture(ctx, origtexture);
 452
 453    /* If <origtexture> is not the name of a texture, INVALID_VALUE is generated. */
 454    if (!origTexObj) {
 455       _mesa_error(ctx, GL_INVALID_VALUE, "glTextureView(origtexture = %u)", origtexture);
 456       return;
 457    }
 458
 459    /* If <origtexture>'s TEXTURE_IMMUTABLE_FORMAT value is not TRUE,
 460     * INVALID_OPERATION is generated.
 461     */
 462    if (!origTexObj->Immutable) {
 463       _mesa_error(ctx, GL_INVALID_OPERATION, "glTextureView(origtexture not immutable)");
 464       return;
 465    }
 466
 467    /* If <texture> is 0, INVALID_VALUE is generated. */
 468    if (texture == 0) {
 469       _mesa_error(ctx, GL_INVALID_VALUE, "glTextureView(texture = 0)");
 470       return;
 471    }
 472
 473    /* If <texture> is not a valid name returned by GenTextures,
 474     * the error INVALID_OPERATION is generated.
 475     */
 476    texObj = _mesa_lookup_texture(ctx, texture);
 477    if (texObj == NULL) {
 478       _mesa_error(ctx, GL_INVALID_OPERATION, "glTextureView(texture = %u non-gen name)", texture);
 479       return;
 480    }
 481
 482    /* If <texture> has already been bound and given a target, then
 483     * the error INVALID_OPERATION is generated.
 484     */
 485    if (texObj->Target) {
 486       _mesa_error(ctx, GL_INVALID_OPERATION, "glTextureView(texture = %u already bound)", texture);
 487       return;
 488    }
 489
 490    /* Check for compatible target */
 491    if (!target_valid(ctx, origTexObj->Target, target)) {
 492       return; /* error was recorded */
 493    }
 494
 495    /* minlevel and minlayer are relative to the view of origtexture
 496     * If minlevel or minlayer is greater than level or layer, respectively,
 497     * of origtexture return INVALID_VALUE.
 498     */
 499    newViewMinLevel = origTexObj->MinLevel + minlevel;
 500    newViewMinLayer = origTexObj->MinLayer + minlayer;
 501    if (newViewMinLevel >= (origTexObj->MinLevel + origTexObj->NumLevels)) {
 502       _mesa_error(ctx, GL_INVALID_VALUE,
 503                   "glTextureView(new minlevel (%d) > orig minlevel (%d) + orig numlevels (%d))",
 504                   newViewMinLevel, origTexObj->MinLevel, origTexObj->NumLevels);
 505       return;
 506    }
 507
 508    if (newViewMinLayer >= (origTexObj->MinLayer + origTexObj->NumLayers)) {
 509       _mesa_error(ctx, GL_INVALID_VALUE,
 510                   "glTextureView(new minlayer (%d) > orig minlayer (%d) + orig numlayers (%d))",
 511                   newViewMinLayer, origTexObj->MinLayer, origTexObj->NumLayers);
 512       return;
 513    }
 514
 515    if (!compatible_format(ctx, origTexObj, internalformat)) {
 516       return; /* Error logged */
 517    }
 518
 519    texFormat = _mesa_choose_texture_format(ctx, texObj, target, 0,
 520                                            internalformat, GL_NONE, GL_NONE);
 521    assert(texFormat != MESA_FORMAT_NONE);
 522    if (texFormat == MESA_FORMAT_NONE) return;
 523
 524    newViewNumLevels = MIN2(numlevels, origTexObj->NumLevels - minlevel);
 525    newViewNumLayers = MIN2(numlayers, origTexObj->NumLayers - minlayer);
 526
 527    faceTarget = origTexObj->Target;
 528    if (faceTarget == GL_TEXTURE_CUBE_MAP)
 529       faceTarget = GL_TEXTURE_CUBE_MAP_POSITIVE_X + minlayer;
 530
 531    /* Get a reference to what will become this View's base level */
 532    origTexImage = _mesa_select_tex_image(ctx, origTexObj,
 533                                          faceTarget, minlevel);
 534    width = origTexImage->Width;
 535    height = origTexImage->Height;
 536    depth = origTexImage->Depth;
 537
 538    /* Adjust width, height, depth to be appropriate for new target */
 539    switch (target) {
 540    case GL_TEXTURE_1D:
 541    case GL_TEXTURE_3D:
 542       break;
 543
 544    case GL_TEXTURE_1D_ARRAY:
 545       height = (GLsizei) newViewNumLayers;
 546       break;
 547
 548    case GL_TEXTURE_2D:
 549    case GL_TEXTURE_2D_MULTISAMPLE:
 550    case GL_TEXTURE_RECTANGLE:
 551    case GL_TEXTURE_CUBE_MAP:
 552       depth = 1;
 553       break;
 554
 555    case GL_TEXTURE_2D_ARRAY:
 556    case GL_TEXTURE_CUBE_MAP_ARRAY:
 557    case GL_TEXTURE_2D_MULTISAMPLE_ARRAY:
 558       depth = newViewNumLayers;
 559       break;
 560    }
 561
 562    /* If the dimensions of the original texture are larger than the maximum
 563     * supported dimensions of the new target, the error INVALID_OPERATION is
 564     * generated. For example, if the original texture has a TEXTURE_2D_ARRAY
 565     * target and its width is greater than MAX_CUBE_MAP_TEXTURE_SIZE, an error
 566     * will be generated if TextureView is called to create a TEXTURE_CUBE_MAP
 567     * view.
 568     */
 569    dimensionsOK = _mesa_legal_texture_dimensions(ctx, target, 0,
 570                                                  width, height, depth, 0);
 571    if (!dimensionsOK) {
 572       _mesa_error(ctx, GL_INVALID_OPERATION, "glTextureView(invalid width or height or depth)");
 573       return;
 574    }
 575
 576    sizeOK = ctx->Driver.TestProxyTexImage(ctx, target, 0, texFormat,
 577                                           width, height, depth, 0);
 578    if (!sizeOK) {
 579       _mesa_error(ctx, GL_INVALID_OPERATION, "glTextureView(invalid texture size)");
 580       return;
 581    }
 582
 583    /* If <target> is TEXTURE_1D, TEXTURE_2D, TEXTURE_3D, TEXTURE_RECTANGLE,
 584     * or TEXTURE_2D_MULTISAMPLE and <numlayers> does not equal 1, the error
 585     * INVALID_VALUE is generated.
 586     */
 587    switch (target) {
 588    case GL_TEXTURE_1D:
 589    case GL_TEXTURE_2D:
 590    case GL_TEXTURE_3D:
 591    case GL_TEXTURE_RECTANGLE:
 592    case GL_TEXTURE_2D_MULTISAMPLE:
 593       if (numlayers != 1) {
 594          _mesa_error(ctx, GL_INVALID_VALUE, "glTextureView(numlayers %d != 1)", numlayers);
 595          return;
 596       }
 597       break;
 598
 599    case GL_TEXTURE_CUBE_MAP:
 600       /* If the new texture's target is TEXTURE_CUBE_MAP, the clamped <numlayers>
 601        * must be equal to 6.
 602        */
 603       if (newViewNumLayers != 6) {
 604          _mesa_error(ctx, GL_INVALID_VALUE, "glTextureView(clamped numlayers %d != 6)",
 605                      newViewNumLayers);
 606          return;
 607       }
 608       break;
 609
 610    case GL_TEXTURE_CUBE_MAP_ARRAY:
 611       /* If the new texture's target is TEXTURE_CUBE_MAP_ARRAY,
 612        * then <numlayers> counts layer-faces rather than layers,
 613        * and the clamped <numlayers> must be a multiple of 6.
 614        * Otherwise, the error INVALID_VALUE is generated.
 615        */
 616       if ((newViewNumLayers % 6) != 0) {
 617          _mesa_error(ctx, GL_INVALID_VALUE,
 618                      "glTextureView(clamped numlayers %d is not a multiple of 6)",
 619                      newViewNumLayers);
 620          return;
 621       }
 622       break;
 623    }
 624
 625    /* If the new texture's target is TEXTURE_CUBE_MAP or
 626     * TEXTURE_CUBE_MAP_ARRAY, the width and height of the original texture's
 627     * levels must be equal otherwise the error INVALID_OPERATION is generated.
 628     */
 629    if ((target == GL_TEXTURE_CUBE_MAP || target == GL_TEXTURE_CUBE_MAP_ARRAY) &&
 630        (origTexImage->Width != origTexImage->Height)) {
 631       _mesa_error(ctx, GL_INVALID_OPERATION, "glTextureView(origtexture width (%d) != height (%d))",
 632                   origTexImage->Width, origTexImage->Height);
 633       return;
 634    }
 635
 636    /* When the original texture's target is TEXTURE_CUBE_MAP, the layer
 637     * parameters are interpreted in the same order as if it were a
 638     * TEXTURE_CUBE_MAP_ARRAY with 6 layer-faces.
 639     */
 640
 641    /* If the internal format does not exactly match the internal format of the
 642     * original texture, the contents of the memory are reinterpreted in the
 643     * same manner as for image bindings described in
 644     * section 3.9.20 (Texture Image Loads and Stores).
 645     */
 646
 647    /* TEXTURE_BASE_LEVEL and TEXTURE_MAX_LEVEL are interpreted
 648     * relative to the view and not relative to the original data store.
 649     */
 650
 651    if (!initialize_texture_fields(ctx, target, texObj, newViewNumLevels,
 652                                   width, height, depth,
 653                                   internalformat, texFormat)) {
 654       return; /* Already recorded error */
 655    }
 656
 657    texObj->MinLevel = newViewMinLevel;
 658    texObj->MinLayer = newViewMinLayer;
 659    texObj->NumLevels = newViewNumLevels;
 660    texObj->NumLayers = newViewNumLayers;
 661    texObj->Immutable = GL_TRUE;
 662    texObj->ImmutableLevels = origTexObj->ImmutableLevels;
 663    texObj->Target = target;
 664
 665    if (ctx->Driver.TextureView != NULL && !ctx->Driver.TextureView(ctx, texObj, origTexObj)) {
 666       return; /* driver recorded error */
 667    }
 668 }