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)
 341       return GL_FALSE;
 342
 343    _mesa_test_texobj_completeness(ctx, t);
 344
 345    if (u->Level < t->BaseLevel ||
 346        u->Level > t->_MaxLevel ||
 347        (u->Level == t->BaseLevel && !t->_BaseComplete) ||
 348        (u->Level != t->BaseLevel && !t->_MipmapComplete))
 349       return GL_FALSE;
 350
 351    if (_mesa_tex_target_is_layered(t->Target) &&
 352        u->Layer >= _mesa_get_texture_layers(t, u->Level))
 353       return GL_FALSE;
 354
 355    if (t->Target == GL_TEXTURE_BUFFER) {
 356       tex_format = t->_BufferObjectFormat;
 357
 358    } else {
 359       struct gl_texture_image *img = (t->Target == GL_TEXTURE_CUBE_MAP ?
 360                                       t->Image[u->Layer][u->Level] :
 361                                       t->Image[0][u->Level]);
 362
 363       if (!img || img->Border || img->NumSamples > ctx->Const.MaxImageSamples)
 364          return GL_FALSE;
 365
 366       tex_format = img->TexFormat;
 367    }
 368
 369    if (get_image_format_class(tex_format) == IMAGE_FORMAT_CLASS_NONE)
 370       return GL_FALSE;
 371
 372    switch (t->ImageFormatCompatibilityType) {
 373    case GL_IMAGE_FORMAT_COMPATIBILITY_BY_SIZE:
 374       if (_mesa_get_format_bytes(tex_format) !=
 375           _mesa_get_format_bytes(u->_ActualFormat))
 376          return GL_FALSE;
 377       break;
 378
 379    case GL_IMAGE_FORMAT_COMPATIBILITY_BY_CLASS:
 380       if (get_image_format_class(tex_format) !=
 381           get_image_format_class(u->_ActualFormat))
 382          return GL_FALSE;
 383       break;
 384
 385    default:
 386       assert(!"Unexpected image format compatibility type");
 387    }
 388
 389    return GL_TRUE;
 390 }
 391
 392 void
 393 _mesa_validate_image_units(struct gl_context *ctx)
 394 {
 395    unsigned i;
 396
 397    for (i = 0; i < ctx->Const.MaxImageUnits; ++i) {
 398       struct gl_image_unit *u = &ctx->ImageUnits[i];
 399       u->_Valid = validate_image_unit(ctx, u);
 400    }
 401 }
 402
 403 static GLboolean
 404 validate_bind_image_texture(struct gl_context *ctx, GLuint unit,
 405                             GLuint texture, GLint level, GLboolean layered,
 406                             GLint layer, GLenum access, GLenum format)
 407 {
 408    assert(ctx->Const.MaxImageUnits <= MAX_IMAGE_UNITS);
 409
 410    if (unit >= ctx->Const.MaxImageUnits) {
 411       _mesa_error(ctx, GL_INVALID_VALUE, "glBindImageTexture(unit)");
 412       return GL_FALSE;
 413    }
 414
 415    if (level < 0) {
 416       _mesa_error(ctx, GL_INVALID_VALUE, "glBindImageTexture(level)");
 417       return GL_FALSE;
 418    }
 419
 420    if (layer < 0) {
 421       _mesa_error(ctx, GL_INVALID_VALUE, "glBindImageTexture(layer)");
 422       return GL_FALSE;
 423    }
 424
 425    if (access != GL_READ_ONLY &&
 426        access != GL_WRITE_ONLY &&
 427        access != GL_READ_WRITE) {
 428       _mesa_error(ctx, GL_INVALID_VALUE, "glBindImageTexture(access)");
 429       return GL_FALSE;
 430    }
 431
 432    if (!_mesa_get_shader_image_format(format)) {
 433       _mesa_error(ctx, GL_INVALID_VALUE, "glBindImageTexture(format)");
 434       return GL_FALSE;
 435    }
 436
 437    return GL_TRUE;
 438 }
 439
 440 void GLAPIENTRY
 441 _mesa_BindImageTexture(GLuint unit, GLuint texture, GLint level,
 442                        GLboolean layered, GLint layer, GLenum access,
 443                        GLenum format)
 444 {
 445    GET_CURRENT_CONTEXT(ctx);
 446    struct gl_texture_object *t = NULL;
 447    struct gl_image_unit *u;
 448
 449    if (!validate_bind_image_texture(ctx, unit, texture, level,
 450                                     layered, layer, access, format))
 451       return;
 452
 453    u = &ctx->ImageUnits[unit];
 454
 455    FLUSH_VERTICES(ctx, 0);
 456    ctx->NewDriverState |= ctx->DriverFlags.NewImageUnits;
 457
 458    if (texture) {
 459       t = _mesa_lookup_texture(ctx, texture);
 460       if (!t) {
 461          _mesa_error(ctx, GL_INVALID_VALUE, "glBindImageTexture(texture)");
 462          return;
 463       }
 464
 465       _mesa_reference_texobj(&u->TexObj, t);
 466       u->Level = level;
 467       u->Access = access;
 468       u->Format = format;
 469       u->_ActualFormat = _mesa_get_shader_image_format(format);
 470
 471       if (_mesa_tex_target_is_layered(t->Target)) {
 472          u->Layered = layered;
 473          u->Layer = (layered ? 0 : layer);
 474       } else {
 475          u->Layered = GL_FALSE;
 476          u->Layer = 0;
 477       }
 478
 479    } else {
 480       _mesa_reference_texobj(&u->TexObj, NULL);
 481    }
 482
 483    u->_Valid = validate_image_unit(ctx, u);
 484
 485    if (ctx->Driver.BindImageTexture)
 486       ctx->Driver.BindImageTexture(ctx, u, t, level, layered,
 487                                    layer, access, format);
 488 }
 489
 490 void GLAPIENTRY
 491 _mesa_BindImageTextures(GLuint first, GLsizei count, const GLuint *textures)
 492 {
 493    GET_CURRENT_CONTEXT(ctx);
 494    int i;
 495
 496    if (!ctx->Extensions.ARB_shader_image_load_store) {
 497       _mesa_error(ctx, GL_INVALID_OPERATION, "glBindImageTextures()");
 498       return;
 499    }
 500
 501    if (first + count > ctx->Const.MaxImageUnits) {
 502       /* The ARB_multi_bind spec says:
 503        *
 504        *    "An INVALID_OPERATION error is generated if <first> + <count>
 505        *     is greater than the number of image units supported by
 506        *     the implementation."
 507        */
 508       _mesa_error(ctx, GL_INVALID_OPERATION,
 509                   "glBindImageTextures(first=%u + count=%d > the value of "
 510                   "GL_MAX_IMAGE_UNITS=%u)",
 511                   first, count, ctx->Const.MaxImageUnits);
 512       return;
 513    }
 514
 515    /* Assume that at least one binding will be changed */
 516    FLUSH_VERTICES(ctx, 0);
 517    ctx->NewDriverState |= ctx->DriverFlags.NewImageUnits;
 518
 519    /* Note that the error semantics for multi-bind commands differ from
 520     * those of other GL commands.
 521     *
 522     * The Issues section in the ARB_multi_bind spec says:
 523     *
 524     *    "(11) Typically, OpenGL specifies that if an error is generated by
 525     *          a command, that command has no effect.  This is somewhat
 526     *          unfortunate for multi-bind commands, because it would require
 527     *          a first pass to scan the entire list of bound objects for
 528     *          errors and then a second pass to actually perform the
 529     *          bindings.  Should we have different error semantics?
 530     *
 531     *       RESOLVED:  Yes.  In this specification, when the parameters for
 532     *       one of the <count> binding points are invalid, that binding
 533     *       point is not updated and an error will be generated.  However,
 534     *       other binding points in the same command will be updated if
 535     *       their parameters are valid and no other error occurs."
 536     */
 537
 538    _mesa_begin_texture_lookups(ctx);
 539
 540    for (i = 0; i < count; i++) {
 541       struct gl_image_unit *u = &ctx->ImageUnits[first + i];
 542       const GLuint texture = textures ? textures[i] : 0;
 543
 544       if (texture != 0) {
 545          struct gl_texture_object *texObj;
 546          GLenum tex_format;
 547
 548          if (!u->TexObj || u->TexObj->Name != texture) {
 549             texObj = _mesa_lookup_texture_locked(ctx, texture);
 550             if (!texObj) {
 551                /* The ARB_multi_bind spec says:
 552                 *
 553                 *    "An INVALID_OPERATION error is generated if any value
 554                 *     in <textures> is not zero or the name of an existing
 555                 *     texture object (per binding)."
 556                 */
 557                _mesa_error(ctx, GL_INVALID_OPERATION,
 558                            "glBindImageTextures(textures[%d]=%u "
 559                            "is not zero or the name of an existing texture "
 560                            "object)", i, texture);
 561                continue;
 562             }
 563          } else {
 564             texObj = u->TexObj;
 565          }
 566
 567          if (texObj->Target == GL_TEXTURE_BUFFER) {
 568             tex_format = texObj->BufferObjectFormat;
 569          } else {
 570             struct gl_texture_image *image = texObj->Image[0][0];
 571
 572             if (!image || image->Width == 0 || image->Height == 0 ||
 573                 image->Depth == 0) {
 574                /* The ARB_multi_bind spec says:
 575                 *
 576                 *    "An INVALID_OPERATION error is generated if the width,
 577                 *     height, or depth of the level zero texture image of
 578                 *     any texture in <textures> is zero (per binding)."
 579                 */
 580                _mesa_error(ctx, GL_INVALID_OPERATION,
 581                            "glBindImageTextures(the width, height or depth "
 582                            "of the level zero texture image of "
 583                            "textures[%d]=%u is zero)", i, texture);
 584                continue;
 585             }
 586
 587             tex_format = image->InternalFormat;
 588          }
 589
 590          if (_mesa_get_shader_image_format(tex_format) == MESA_FORMAT_NONE) {
 591             /* The ARB_multi_bind spec says:
 592              *
 593              *   "An INVALID_OPERATION error is generated if the internal
 594              *    format of the level zero texture image of any texture
 595              *    in <textures> is not found in table 8.33 (per binding)."
 596              */
 597             _mesa_error(ctx, GL_INVALID_OPERATION,
 598                         "glBindImageTextures(the internal format %s of "
 599                         "the level zero texture image of textures[%d]=%u "
 600                         "is not supported)",
 601                         _mesa_lookup_enum_by_nr(tex_format),
 602                         i, texture);
 603             continue;
 604          }
 605
 606          /* Update the texture binding */
 607          _mesa_reference_texobj(&u->TexObj, texObj);
 608          u->Level = 0;
 609          u->Layered = _mesa_tex_target_is_layered(texObj->Target);
 610          u->Layer = 0;
 611          u->Access = GL_READ_WRITE;
 612          u->Format = tex_format;
 613          u->_ActualFormat = _mesa_get_shader_image_format(tex_format);
 614          u->_Valid = validate_image_unit(ctx, u);
 615       } else {
 616          /* Unbind the texture from the unit */
 617          _mesa_reference_texobj(&u->TexObj, NULL);
 618          u->Level = 0;
 619          u->Layered = GL_FALSE;
 620          u->Layer = 0;
 621          u->Access = GL_READ_ONLY;
 622          u->Format = GL_R8;
 623          u->_ActualFormat = MESA_FORMAT_R_UNORM8;
 624          u->_Valid = GL_FALSE;
 625       }
 626
 627       /* Pass the BindImageTexture call down to the device driver */
 628       if (ctx->Driver.BindImageTexture)
 629          ctx->Driver.BindImageTexture(ctx, u, u->TexObj, u->Level, u->Layered,
 630                                       u->Layer, u->Access, u->Format);
 631    }
 632
 633    _mesa_end_texture_lookups(ctx);
 634 }
 635
 636 void GLAPIENTRY
 637 _mesa_MemoryBarrier(GLbitfield barriers)
 638 {
 639    GET_CURRENT_CONTEXT(ctx);
 640
 641    if (ctx->Driver.MemoryBarrier)
 642       ctx->Driver.MemoryBarrier(ctx, barriers);
 643 }