src/mesa/main/shaderimage.c

   1 /*
   2  * Copyright 2013 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  *    Francisco Jerez <currojerez@riseup.net>
  25  */
  26
  27 #include <assert.h>
  28
  29 #include "shaderimage.h"
  30 #include "mtypes.h"
  31 #include "formats.h"
  32 #include "errors.h"
  33 #include "context.h"
  34 #include "texobj.h"
  35 #include "teximage.h"
  36 #include "enums.h"
  37
  38 /*
  39  * Define endian-invariant aliases for some mesa formats that are
  40  * defined in terms of their channel layout from LSB to MSB in a
  41  * 32-bit word.  The actual byte offsets matter here because the user
  42  * is allowed to bit-cast one format into another and get predictable
  43  * results.
  44  */
  45 #ifdef MESA_BIG_ENDIAN
  46 # define MESA_FORMAT_RGBA_8 MESA_FORMAT_A8B8G8R8_UNORM
  47 # define MESA_FORMAT_RG_16 MESA_FORMAT_G16R16_UNORM
  48 # define MESA_FORMAT_RG_8 MESA_FORMAT_G8R8_UNORM
  49 # define MESA_FORMAT_SIGNED_RGBA_8 MESA_FORMAT_A8B8G8R8_SNORM
  50 # define MESA_FORMAT_SIGNED_RG_16 MESA_FORMAT_G16R16_SNORM
  51 # define MESA_FORMAT_SIGNED_RG_8 MESA_FORMAT_G8R8_SNORM
  52 #else
  53 # define MESA_FORMAT_RGBA_8 MESA_FORMAT_R8G8B8A8_UNORM
  54 # define MESA_FORMAT_RG_16 MESA_FORMAT_R16G16_UNORM
  55 # define MESA_FORMAT_RG_8 MESA_FORMAT_R8G8_UNORM
  56 # define MESA_FORMAT_SIGNED_RGBA_8 MESA_FORMAT_R8G8B8A8_SNORM
  57 # define MESA_FORMAT_SIGNED_RG_16 MESA_FORMAT_R16G16_SNORM
  58 # define MESA_FORMAT_SIGNED_RG_8 MESA_FORMAT_R8G8_SNORM
  59 #endif
  60
  61 mesa_format
  62 _mesa_get_shader_image_format(GLenum format)
  63 {
  64    switch (format) {
  65    case GL_RGBA32F:
  66       return MESA_FORMAT_RGBA_FLOAT32;
  67
  68    case GL_RGBA16F:
  69       return MESA_FORMAT_RGBA_FLOAT16;
  70
  71    case GL_RG32F:
  72       return MESA_FORMAT_RG_FLOAT32;
  73
  74    case GL_RG16F:
  75       return MESA_FORMAT_RG_FLOAT16;
  76
  77    case GL_R11F_G11F_B10F:
  78       return MESA_FORMAT_R11G11B10_FLOAT;
  79
  80    case GL_R32F:
  81       return MESA_FORMAT_R_FLOAT32;
  82
  83    case GL_R16F:
  84       return MESA_FORMAT_R_FLOAT16;
  85
  86    case GL_RGBA32UI:
  87       return MESA_FORMAT_RGBA_UINT32;
  88
  89    case GL_RGBA16UI:
  90       return MESA_FORMAT_RGBA_UINT16;
  91
  92    case GL_RGB10_A2UI:
  93       return MESA_FORMAT_R10G10B10A2_UINT;
  94
  95    case GL_RGBA8UI:
  96       return MESA_FORMAT_RGBA_UINT8;
  97
  98    case GL_RG32UI:
  99       return MESA_FORMAT_RG_UINT32;
 100
 101    case GL_RG16UI:
 102       return MESA_FORMAT_RG_UINT16;
 103
 104    case GL_RG8UI:
 105       return MESA_FORMAT_RG_UINT8;
 106
 107    case GL_R32UI:
 108       return MESA_FORMAT_R_UINT32;
 109
 110    case GL_R16UI:
 111       return MESA_FORMAT_R_UINT16;
 112
 113    case GL_R8UI:
 114       return MESA_FORMAT_R_UINT8;
 115
 116    case GL_RGBA32I:
 117       return MESA_FORMAT_RGBA_SINT32;
 118
 119    case GL_RGBA16I:
 120       return MESA_FORMAT_RGBA_SINT16;
 121
 122    case GL_RGBA8I:
 123       return MESA_FORMAT_RGBA_SINT8;
 124
 125    case GL_RG32I:
 126       return MESA_FORMAT_RG_SINT32;
 127
 128    case GL_RG16I:
 129       return MESA_FORMAT_RG_SINT16;
 130
 131    case GL_RG8I:
 132       return MESA_FORMAT_RG_SINT8;
 133
 134    case GL_R32I:
 135       return MESA_FORMAT_R_SINT32;
 136
 137    case GL_R16I:
 138       return MESA_FORMAT_R_SINT16;
 139
 140    case GL_R8I:
 141       return MESA_FORMAT_R_SINT8;
 142
 143    case GL_RGBA16:
 144       return MESA_FORMAT_RGBA_UNORM16;
 145
 146    case GL_RGB10_A2:
 147       return MESA_FORMAT_R10G10B10A2_UNORM;
 148
 149    case GL_RGBA8:
 150       return MESA_FORMAT_RGBA_8;
 151
 152    case GL_RG16:
 153       return MESA_FORMAT_RG_16;
 154
 155    case GL_RG8:
 156       return MESA_FORMAT_RG_8;
 157
 158    case GL_R16:
 159       return MESA_FORMAT_R_UNORM16;
 160
 161    case GL_R8:
 162       return MESA_FORMAT_R_UNORM8;
 163
 164    case GL_RGBA16_SNORM:
 165       return MESA_FORMAT_RGBA_SNORM16;
 166
 167    case GL_RGBA8_SNORM:
 168       return MESA_FORMAT_SIGNED_RGBA_8;
 169
 170    case GL_RG16_SNORM:
 171       return MESA_FORMAT_SIGNED_RG_16;
 172
 173    case GL_RG8_SNORM:
 174       return MESA_FORMAT_SIGNED_RG_8;
 175
 176    case GL_R16_SNORM:
 177       return MESA_FORMAT_R_SNORM16;
 178
 179    case GL_R8_SNORM:
 180       return MESA_FORMAT_R_SNORM8;
 181
 182    default:
 183       return MESA_FORMAT_NONE;
 184    }
 185 }
 186
 187 enum image_format_class
 188 {
 189    /** Not a valid image format. */
 190    IMAGE_FORMAT_CLASS_NONE = 0,
 191
 192    /** Classes of image formats you can cast into each other. */
 193    /** \{ */
 194    IMAGE_FORMAT_CLASS_1X8,
 195    IMAGE_FORMAT_CLASS_1X16,
 196    IMAGE_FORMAT_CLASS_1X32,
 197    IMAGE_FORMAT_CLASS_2X8,
 198    IMAGE_FORMAT_CLASS_2X16,
 199    IMAGE_FORMAT_CLASS_2X32,
 200    IMAGE_FORMAT_CLASS_10_11_11,
 201    IMAGE_FORMAT_CLASS_4X8,
 202    IMAGE_FORMAT_CLASS_4X16,
 203    IMAGE_FORMAT_CLASS_4X32,
 204    IMAGE_FORMAT_CLASS_2_10_10_10
 205    /** \} */
 206 };
 207
 208 static enum image_format_class
 209 get_image_format_class(mesa_format format)
 210 {
 211    switch (format) {
 212    case MESA_FORMAT_RGBA_FLOAT32:
 213       return IMAGE_FORMAT_CLASS_4X32;
 214
 215    case MESA_FORMAT_RGBA_FLOAT16:
 216       return IMAGE_FORMAT_CLASS_4X16;
 217
 218    case MESA_FORMAT_RG_FLOAT32:
 219       return IMAGE_FORMAT_CLASS_2X32;
 220
 221    case MESA_FORMAT_RG_FLOAT16:
 222       return IMAGE_FORMAT_CLASS_2X16;
 223
 224    case MESA_FORMAT_R11G11B10_FLOAT:
 225       return IMAGE_FORMAT_CLASS_10_11_11;
 226
 227    case MESA_FORMAT_R_FLOAT32:
 228       return IMAGE_FORMAT_CLASS_1X32;
 229
 230    case MESA_FORMAT_R_FLOAT16:
 231       return IMAGE_FORMAT_CLASS_1X16;
 232
 233    case MESA_FORMAT_RGBA_UINT32:
 234       return IMAGE_FORMAT_CLASS_4X32;
 235
 236    case MESA_FORMAT_RGBA_UINT16:
 237       return IMAGE_FORMAT_CLASS_4X16;
 238
 239    case MESA_FORMAT_R10G10B10A2_UINT:
 240       return IMAGE_FORMAT_CLASS_2_10_10_10;
 241
 242    case MESA_FORMAT_RGBA_UINT8:
 243       return IMAGE_FORMAT_CLASS_4X8;
 244
 245    case MESA_FORMAT_RG_UINT32:
 246       return IMAGE_FORMAT_CLASS_2X32;
 247
 248    case MESA_FORMAT_RG_UINT16:
 249       return IMAGE_FORMAT_CLASS_2X16;
 250
 251    case MESA_FORMAT_RG_UINT8:
 252       return IMAGE_FORMAT_CLASS_2X8;
 253
 254    case MESA_FORMAT_R_UINT32:
 255       return IMAGE_FORMAT_CLASS_1X32;
 256
 257    case MESA_FORMAT_R_UINT16:
 258       return IMAGE_FORMAT_CLASS_1X16;
 259
 260    case MESA_FORMAT_R_UINT8:
 261       return IMAGE_FORMAT_CLASS_1X8;
 262
 263    case MESA_FORMAT_RGBA_SINT32:
 264       return IMAGE_FORMAT_CLASS_4X32;
 265
 266    case MESA_FORMAT_RGBA_SINT16:
 267       return IMAGE_FORMAT_CLASS_4X16;
 268
 269    case MESA_FORMAT_RGBA_SINT8:
 270       return IMAGE_FORMAT_CLASS_4X8;
 271
 272    case MESA_FORMAT_RG_SINT32:
 273       return IMAGE_FORMAT_CLASS_2X32;
 274
 275    case MESA_FORMAT_RG_SINT16:
 276       return IMAGE_FORMAT_CLASS_2X16;
 277
 278    case MESA_FORMAT_RG_SINT8:
 279       return IMAGE_FORMAT_CLASS_2X8;
 280
 281    case MESA_FORMAT_R_SINT32:
 282       return IMAGE_FORMAT_CLASS_1X32;
 283
 284    case MESA_FORMAT_R_SINT16:
 285       return IMAGE_FORMAT_CLASS_1X16;
 286
 287    case MESA_FORMAT_R_SINT8:
 288       return IMAGE_FORMAT_CLASS_1X8;
 289
 290    case MESA_FORMAT_RGBA_UNORM16:
 291       return IMAGE_FORMAT_CLASS_4X16;
 292
 293    case MESA_FORMAT_R10G10B10A2_UNORM:
 294       return IMAGE_FORMAT_CLASS_2_10_10_10;
 295
 296    case MESA_FORMAT_RGBA_8:
 297       return IMAGE_FORMAT_CLASS_4X8;
 298
 299    case MESA_FORMAT_RG_16:
 300       return IMAGE_FORMAT_CLASS_2X16;
 301
 302    case MESA_FORMAT_RG_8:
 303       return IMAGE_FORMAT_CLASS_2X8;
 304
 305    case MESA_FORMAT_R_UNORM16:
 306       return IMAGE_FORMAT_CLASS_1X16;
 307
 308    case MESA_FORMAT_R_UNORM8:
 309       return IMAGE_FORMAT_CLASS_1X8;
 310
 311    case MESA_FORMAT_RGBA_SNORM16:
 312       return IMAGE_FORMAT_CLASS_4X16;
 313
 314    case MESA_FORMAT_SIGNED_RGBA_8:
 315       return IMAGE_FORMAT_CLASS_4X8;
 316
 317    case MESA_FORMAT_SIGNED_RG_16:
 318       return IMAGE_FORMAT_CLASS_2X16;
 319
 320    case MESA_FORMAT_SIGNED_RG_8:
 321       return IMAGE_FORMAT_CLASS_2X8;
 322
 323    case MESA_FORMAT_R_SNORM16:
 324       return IMAGE_FORMAT_CLASS_1X16;
 325
 326    case MESA_FORMAT_R_SNORM8:
 327       return IMAGE_FORMAT_CLASS_1X8;
 328
 329    default:
 330       return IMAGE_FORMAT_CLASS_NONE;
 331    }
 332 }
 333
 334 static GLboolean
 335 validate_image_unit(struct gl_context *ctx, struct gl_image_unit *u)
 336 {
 337    struct gl_texture_object *t = u->TexObj;
 338    mesa_format tex_format;
 339
 340    if (!t || u->Level < t->BaseLevel ||
 341        u->Level > t->_MaxLevel)
 342       return GL_FALSE;
 343
 344    _mesa_test_texobj_completeness(ctx, t);
 345
 346    if ((u->Level == t->BaseLevel && !t->_BaseComplete) ||
 347        (u->Level != t->BaseLevel && !t->_MipmapComplete))
 348       return GL_FALSE;
 349
 350    if (_mesa_tex_target_is_layered(t->Target) &&
 351        u->Layer >= _mesa_get_texture_layers(t, u->Level))
 352       return GL_FALSE;
 353
 354    if (t->Target == GL_TEXTURE_BUFFER) {
 355       tex_format = t->_BufferObjectFormat;
 356
 357    } else {
 358       struct gl_texture_image *img = (t->Target == GL_TEXTURE_CUBE_MAP ?
 359                                       t->Image[u->Layer][u->Level] :
 360                                       t->Image[0][u->Level]);
 361
 362       if (!img || img->Border || img->NumSamples > ctx->Const.MaxImageSamples)
 363          return GL_FALSE;
 364
 365       tex_format = img->TexFormat;
 366    }
 367
 368    if (get_image_format_class(tex_format) == IMAGE_FORMAT_CLASS_NONE)
 369       return GL_FALSE;
 370
 371    switch (t->ImageFormatCompatibilityType) {
 372    case GL_IMAGE_FORMAT_COMPATIBILITY_BY_SIZE:
 373       if (_mesa_get_format_bytes(tex_format) !=
 374           _mesa_get_format_bytes(u->_ActualFormat))
 375          return GL_FALSE;
 376       break;
 377
 378    case GL_IMAGE_FORMAT_COMPATIBILITY_BY_CLASS:
 379       if (get_image_format_class(tex_format) !=
 380           get_image_format_class(u->_ActualFormat))
 381          return GL_FALSE;
 382       break;
 383
 384    default:
 385       assert(!"Unexpected image format compatibility type");
 386    }
 387
 388    return GL_TRUE;
 389 }
 390
 391 void
 392 _mesa_validate_image_units(struct gl_context *ctx)
 393 {
 394    unsigned i;
 395
 396    for (i = 0; i < ctx->Const.MaxImageUnits; ++i) {
 397       struct gl_image_unit *u = &ctx->ImageUnits[i];
 398       u->_Valid = validate_image_unit(ctx, u);
 399    }
 400 }
 401
 402 static GLboolean
 403 validate_bind_image_texture(struct gl_context *ctx, GLuint unit,
 404                             GLuint texture, GLint level, GLboolean layered,
 405                             GLint layer, GLenum access, GLenum format)
 406 {
 407    assert(ctx->Const.MaxImageUnits <= MAX_IMAGE_UNITS);
 408
 409    if (unit >= ctx->Const.MaxImageUnits) {
 410       _mesa_error(ctx, GL_INVALID_VALUE, "glBindImageTexture(unit)");
 411       return GL_FALSE;
 412    }
 413
 414    if (level < 0) {
 415       _mesa_error(ctx, GL_INVALID_VALUE, "glBindImageTexture(level)");
 416       return GL_FALSE;
 417    }
 418
 419    if (layer < 0) {
 420       _mesa_error(ctx, GL_INVALID_VALUE, "glBindImageTexture(layer)");
 421       return GL_FALSE;
 422    }
 423
 424    if (access != GL_READ_ONLY &&
 425        access != GL_WRITE_ONLY &&
 426        access != GL_READ_WRITE) {
 427       _mesa_error(ctx, GL_INVALID_VALUE, "glBindImageTexture(access)");
 428       return GL_FALSE;
 429    }
 430
 431    if (!_mesa_get_shader_image_format(format)) {
 432       _mesa_error(ctx, GL_INVALID_VALUE, "glBindImageTexture(format)");
 433       return GL_FALSE;
 434    }
 435
 436    return GL_TRUE;
 437 }
 438
 439 void GLAPIENTRY
 440 _mesa_BindImageTexture(GLuint unit, GLuint texture, GLint level,
 441                        GLboolean layered, GLint layer, GLenum access,
 442                        GLenum format)
 443 {
 444    GET_CURRENT_CONTEXT(ctx);
 445    struct gl_texture_object *t = NULL;
 446    struct gl_image_unit *u;
 447
 448    if (!validate_bind_image_texture(ctx, unit, texture, level,
 449                                     layered, layer, access, format))
 450       return;
 451
 452    u = &ctx->ImageUnits[unit];
 453
 454    FLUSH_VERTICES(ctx, 0);
 455    ctx->NewDriverState |= ctx->DriverFlags.NewImageUnits;
 456
 457    if (texture) {
 458       t = _mesa_lookup_texture(ctx, texture);
 459       if (!t) {
 460          _mesa_error(ctx, GL_INVALID_VALUE, "glBindImageTexture(texture)");
 461          return;
 462       }
 463
 464       _mesa_reference_texobj(&u->TexObj, t);
 465       u->Level = level;
 466       u->Access = access;
 467       u->Format = format;
 468       u->_ActualFormat = _mesa_get_shader_image_format(format);
 469
 470       if (_mesa_tex_target_is_layered(t->Target)) {
 471          u->Layered = layered;
 472          u->Layer = (layered ? 0 : layer);
 473       } else {
 474          u->Layered = GL_FALSE;
 475          u->Layer = 0;
 476       }
 477
 478    } else {
 479       _mesa_reference_texobj(&u->TexObj, NULL);
 480    }
 481
 482    u->_Valid = validate_image_unit(ctx, u);
 483
 484    if (ctx->Driver.BindImageTexture)
 485       ctx->Driver.BindImageTexture(ctx, u, t, level, layered,
 486                                    layer, access, format);
 487 }
 488
 489 void GLAPIENTRY
 490 _mesa_BindImageTextures(GLuint first, GLsizei count, const GLuint *textures)
 491 {
 492    GET_CURRENT_CONTEXT(ctx);
 493    int i;
 494
 495    if (!ctx->Extensions.ARB_shader_image_load_store) {
 496       _mesa_error(ctx, GL_INVALID_OPERATION, "glBindImageTextures()");
 497       return;
 498    }
 499
 500    if (first + count > ctx->Const.MaxImageUnits) {
 501       /* The ARB_multi_bind spec says:
 502        *
 503        *    "An INVALID_OPERATION error is generated if <first> + <count>
 504        *     is greater than the number of image units supported by
 505        *     the implementation."
 506        */
 507       _mesa_error(ctx, GL_INVALID_OPERATION,
 508                   "glBindImageTextures(first=%u + count=%d > the value of "
 509                   "GL_MAX_IMAGE_UNITS=%u)",
 510                   first, count, ctx->Const.MaxImageUnits);
 511       return;
 512    }
 513
 514    /* Assume that at least one binding will be changed */
 515    FLUSH_VERTICES(ctx, 0);
 516    ctx->NewDriverState |= ctx->DriverFlags.NewImageUnits;
 517
 518    /* Note that the error semantics for multi-bind commands differ from
 519     * those of other GL commands.
 520     *
 521     * The Issues section in the ARB_multi_bind spec says:
 522     *
 523     *    "(11) Typically, OpenGL specifies that if an error is generated by
 524     *          a command, that command has no effect.  This is somewhat
 525     *          unfortunate for multi-bind commands, because it would require
 526     *          a first pass to scan the entire list of bound objects for
 527     *          errors and then a second pass to actually perform the
 528     *          bindings.  Should we have different error semantics?
 529     *
 530     *       RESOLVED:  Yes.  In this specification, when the parameters for
 531     *       one of the <count> binding points are invalid, that binding
 532     *       point is not updated and an error will be generated.  However,
 533     *       other binding points in the same command will be updated if
 534     *       their parameters are valid and no other error occurs."
 535     */
 536
 537    _mesa_begin_texture_lookups(ctx);
 538
 539    for (i = 0; i < count; i++) {
 540       struct gl_image_unit *u = &ctx->ImageUnits[first + i];
 541       const GLuint texture = textures ? textures[i] : 0;
 542
 543       if (texture != 0) {
 544          struct gl_texture_object *texObj;
 545          GLenum tex_format;
 546
 547          if (!u->TexObj || u->TexObj->Name != texture) {
 548             texObj = _mesa_lookup_texture_locked(ctx, texture);
 549             if (!texObj) {
 550                /* The ARB_multi_bind spec says:
 551                 *
 552                 *    "An INVALID_OPERATION error is generated if any value
 553                 *     in <textures> is not zero or the name of an existing
 554                 *     texture object (per binding)."
 555                 */
 556                _mesa_error(ctx, GL_INVALID_OPERATION,
 557                            "glBindImageTextures(textures[%d]=%u "
 558                            "is not zero or the name of an existing texture "
 559                            "object)", i, texture);
 560                continue;
 561             }
 562          } else {
 563             texObj = u->TexObj;
 564          }
 565
 566          if (texObj->Target == GL_TEXTURE_BUFFER) {
 567             tex_format = texObj->BufferObjectFormat;
 568          } else {
 569             struct gl_texture_image *image = texObj->Image[0][0];
 570
 571             if (!image || image->Width == 0 || image->Height == 0 ||
 572                 image->Depth == 0) {
 573                /* The ARB_multi_bind spec says:
 574                 *
 575                 *    "An INVALID_OPERATION error is generated if the width,
 576                 *     height, or depth of the level zero texture image of
 577                 *     any texture in <textures> is zero (per binding)."
 578                 */
 579                _mesa_error(ctx, GL_INVALID_OPERATION,
 580                            "glBindImageTextures(the width, height or depth "
 581                            "of the level zero texture image of "
 582                            "textures[%d]=%u is zero)", i, texture);
 583                continue;
 584             }
 585
 586             tex_format = image->InternalFormat;
 587          }
 588
 589          if (_mesa_get_shader_image_format(tex_format) == MESA_FORMAT_NONE) {
 590             /* The ARB_multi_bind spec says:
 591              *
 592              *   "An INVALID_OPERATION error is generated if the internal
 593              *    format of the level zero texture image of any texture
 594              *    in <textures> is not found in table 8.33 (per binding)."
 595              */
 596             _mesa_error(ctx, GL_INVALID_OPERATION,
 597                         "glBindImageTextures(the internal format %s of "
 598                         "the level zero texture image of textures[%d]=%u "
 599                         "is not supported)",
 600                         _mesa_lookup_enum_by_nr(tex_format),
 601                         i, texture);
 602             continue;
 603          }
 604
 605          /* Update the texture binding */
 606          _mesa_reference_texobj(&u->TexObj, texObj);
 607          u->Level = 0;
 608          u->Layered = _mesa_tex_target_is_layered(texObj->Target);
 609          u->Layer = 0;
 610          u->Access = GL_READ_WRITE;
 611          u->Format = tex_format;
 612          u->_ActualFormat = _mesa_get_shader_image_format(tex_format);
 613          u->_Valid = validate_image_unit(ctx, u);
 614       } else {
 615          /* Unbind the texture from the unit */
 616          _mesa_reference_texobj(&u->TexObj, NULL);
 617          u->Level = 0;
 618          u->Layered = GL_FALSE;
 619          u->Layer = 0;
 620          u->Access = GL_READ_ONLY;
 621          u->Format = GL_R8;
 622          u->_ActualFormat = MESA_FORMAT_R_UNORM8;
 623          u->_Valid = GL_FALSE;
 624       }
 625
 626       /* Pass the BindImageTexture call down to the device driver */
 627       if (ctx->Driver.BindImageTexture)
 628          ctx->Driver.BindImageTexture(ctx, u, u->TexObj, u->Level, u->Layered,
 629                                       u->Layer, u->Access, u->Format);
 630    }
 631
 632    _mesa_end_texture_lookups(ctx);
 633 }
 634
 635 void GLAPIENTRY
 636 _mesa_MemoryBarrier(GLbitfield barriers)
 637 {
 638    GET_CURRENT_CONTEXT(ctx);
 639
 640    if (ctx->Driver.MemoryBarrier)
 641       ctx->Driver.MemoryBarrier(ctx, barriers);
 642 }