src/mesa/main/copyimage.c

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 2014 Intel Corporation.  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 "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
  17  * OR 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
  20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  22  * OTHER DEALINGS IN THE SOFTWARE.
  23  *
  24  * Authors:
  25  *    Jason Ekstrand <jason.ekstrand@intel.com>
  26  */
  27
  28 #include "context.h"
  29 #include "glheader.h"
  30 #include "errors.h"
  31 #include "enums.h"
  32 #include "copyimage.h"
  33 #include "teximage.h"
  34 #include "texobj.h"
  35 #include "fbobject.h"
  36 #include "textureview.h"
  37 #include "glformats.h"
  38
  39 enum mesa_block_class {
  40    BLOCK_CLASS_128_BITS,
  41    BLOCK_CLASS_64_BITS
  42 };
  43
  44 /**
  45  * Prepare the source or destination resource.  This involves error
  46  * checking and returning the relevant gl_texture_image or gl_renderbuffer.
  47  * Note that one of the resulting tex_image or renderbuffer pointers will be
  48  * NULL and the other will be non-null.
  49  *
  50  * \param name  the texture or renderbuffer name
  51  * \param target  One of GL_TEXTURE_x target or GL_RENDERBUFFER
  52  * \param level  mipmap level
  53  * \param z  src or dest Z
  54  * \param depth  number of slices/faces/layers to copy
  55  * \param tex_image  returns a pointer to a texture image
  56  * \param renderbuffer  returns a pointer to a renderbuffer
  57  * \return true if success, false if error
  58  */
  59 static bool
  60 prepare_target_err(struct gl_context *ctx, GLuint name, GLenum target,
  61                    int level, int z, int depth,
  62                    struct gl_texture_image **tex_image,
  63                    struct gl_renderbuffer **renderbuffer,
  64                    mesa_format *format,
  65                    GLenum *internalFormat,
  66                    GLuint *width,
  67                    GLuint *height,
  68                    GLuint *num_samples,
  69                    const char *dbg_prefix)
  70 {
  71    if (name == 0) {
  72       _mesa_error(ctx, GL_INVALID_VALUE,
  73                   "glCopyImageSubData(%sName = %d)", dbg_prefix, name);
  74       return false;
  75    }
  76
  77    /*
  78     * INVALID_ENUM is generated
  79     *  * if either <srcTarget> or <dstTarget>
  80     *   - is not RENDERBUFFER or a valid non-proxy texture target
  81     *   - is TEXTURE_BUFFER, or
  82     *   - is one of the cubemap face selectors described in table 3.17,
  83     */
  84    switch (target) {
  85    case GL_RENDERBUFFER:
  86       /* Not a texture target, but valid */
  87    case GL_TEXTURE_1D:
  88    case GL_TEXTURE_1D_ARRAY:
  89    case GL_TEXTURE_2D:
  90    case GL_TEXTURE_3D:
  91    case GL_TEXTURE_CUBE_MAP:
  92    case GL_TEXTURE_RECTANGLE:
  93    case GL_TEXTURE_2D_ARRAY:
  94    case GL_TEXTURE_CUBE_MAP_ARRAY:
  95    case GL_TEXTURE_2D_MULTISAMPLE:
  96    case GL_TEXTURE_2D_MULTISAMPLE_ARRAY:
  97       /* These are all valid */
  98       break;
  99    case GL_TEXTURE_EXTERNAL_OES:
 100       /* Only exists in ES */
 101    case GL_TEXTURE_BUFFER:
 102    default:
 103       _mesa_error(ctx, GL_INVALID_ENUM,
 104                   "glCopyImageSubData(%sTarget = %s)", dbg_prefix,
 105                   _mesa_enum_to_string(target));
 106       return false;
 107    }
 108
 109    if (target == GL_RENDERBUFFER) {
 110       struct gl_renderbuffer *rb = _mesa_lookup_renderbuffer(ctx, name);
 111
 112       if (!rb) {
 113          _mesa_error(ctx, GL_INVALID_VALUE,
 114                      "glCopyImageSubData(%sName = %u)", dbg_prefix, name);
 115          return false;
 116       }
 117
 118       if (!rb->Name) {
 119          _mesa_error(ctx, GL_INVALID_OPERATION,
 120                      "glCopyImageSubData(%sName incomplete)", dbg_prefix);
 121          return false;
 122       }
 123
 124       if (level != 0) {
 125          _mesa_error(ctx, GL_INVALID_VALUE,
 126                      "glCopyImageSubData(%sLevel = %u)", dbg_prefix, level);
 127          return false;
 128       }
 129
 130       *renderbuffer = rb;
 131       *format = rb->Format;
 132       *internalFormat = rb->InternalFormat;
 133       *width = rb->Width;
 134       *height = rb->Height;
 135       *num_samples = rb->NumSamples;
 136       *tex_image = NULL;
 137    } else {
 138       struct gl_texture_object *texObj = _mesa_lookup_texture(ctx, name);
 139
 140       if (!texObj) {
 141          /*
 142           * From GL_ARB_copy_image specification:
 143           * "INVALID_VALUE is generated if either <srcName> or <dstName> does
 144           * not correspond to a valid renderbuffer or texture object according
 145           * to the corresponding target parameter."
 146           */
 147          _mesa_error(ctx, GL_INVALID_VALUE,
 148                      "glCopyImageSubData(%sName = %u)", dbg_prefix, name);
 149          return false;
 150       }
 151
 152       _mesa_test_texobj_completeness(ctx, texObj);
 153       if (!texObj->_BaseComplete ||
 154           (level != 0 && !texObj->_MipmapComplete)) {
 155          _mesa_error(ctx, GL_INVALID_OPERATION,
 156                      "glCopyImageSubData(%sName incomplete)", dbg_prefix);
 157          return false;
 158       }
 159
 160       /* Note that target will not be a cube face name */
 161       if (texObj->Target != target) {
 162          /*
 163           * From GL_ARB_copy_image_specification:
 164           * "INVALID_ENUM is generated if the target does not match the type
 165           * of the object."
 166           */
 167          _mesa_error(ctx, GL_INVALID_ENUM,
 168                      "glCopyImageSubData(%sTarget = %s)", dbg_prefix,
 169                      _mesa_enum_to_string(target));
 170          return false;
 171       }
 172
 173       if (level < 0 || level >= MAX_TEXTURE_LEVELS) {
 174          _mesa_error(ctx, GL_INVALID_VALUE,
 175                      "glCopyImageSubData(%sLevel = %d)", dbg_prefix, level);
 176          return false;
 177       }
 178
 179       if (target == GL_TEXTURE_CUBE_MAP) {
 180          int i;
 181
 182          assert(z < MAX_FACES);  /* should have been caught earlier */
 183
 184          /* make sure all the cube faces are present */
 185          for (i = 0; i < depth; i++) {
 186             if (!texObj->Image[z+i][level]) {
 187                /* missing cube face */
 188                _mesa_error(ctx, GL_INVALID_VALUE,
 189                            "glCopyImageSubData(missing cube face)");
 190                return false;
 191             }
 192          }
 193
 194          *tex_image = texObj->Image[z][level];
 195       }
 196       else {
 197          *tex_image = _mesa_select_tex_image(texObj, target, level);
 198       }
 199
 200       if (!*tex_image) {
 201          _mesa_error(ctx, GL_INVALID_VALUE,
 202                      "glCopyImageSubData(%sLevel = %u)", dbg_prefix, level);
 203          return false;
 204       }
 205
 206       *renderbuffer = NULL;
 207       *format = (*tex_image)->TexFormat;
 208       *internalFormat = (*tex_image)->InternalFormat;
 209       *width = (*tex_image)->Width;
 210       *height = (*tex_image)->Height;
 211       *num_samples = (*tex_image)->NumSamples;
 212    }
 213
 214    return true;
 215 }
 216
 217 static void
 218 prepare_target(struct gl_context *ctx, GLuint name, GLenum target,
 219                int level, int z,
 220                struct gl_texture_image **texImage,
 221                struct gl_renderbuffer **renderbuffer)
 222 {
 223    if (target == GL_RENDERBUFFER) {
 224       struct gl_renderbuffer *rb = _mesa_lookup_renderbuffer(ctx, name);
 225
 226       *renderbuffer = rb;
 227       *texImage = NULL;
 228    } else {
 229       struct gl_texture_object *texObj = _mesa_lookup_texture(ctx, name);
 230
 231       if (target == GL_TEXTURE_CUBE_MAP) {
 232          *texImage = texObj->Image[z][level];
 233       }
 234       else {
 235          *texImage = _mesa_select_tex_image(texObj, target, level);
 236       }
 237
 238       *renderbuffer = NULL;
 239    }
 240 }
 241
 242 /**
 243  * Check that the x,y,z,width,height,region is within the texture image
 244  * dimensions.
 245  * \return true if bounds OK, false if regions is out of bounds
 246  */
 247 static bool
 248 check_region_bounds(struct gl_context *ctx,
 249                     GLenum target,
 250                     const struct gl_texture_image *tex_image,
 251                     const struct gl_renderbuffer *renderbuffer,
 252                     int x, int y, int z, int width, int height, int depth,
 253                     const char *dbg_prefix)
 254 {
 255    int surfWidth, surfHeight, surfDepth;
 256
 257    if (width < 0 || height < 0 || depth < 0) {
 258       _mesa_error(ctx, GL_INVALID_VALUE,
 259                   "glCopyImageSubData(%sWidth, %sHeight, or %sDepth is negative)",
 260                   dbg_prefix, dbg_prefix, dbg_prefix);
 261       return false;
 262    }
 263
 264    if (x < 0 || y < 0 || z < 0) {
 265       _mesa_error(ctx, GL_INVALID_VALUE,
 266                   "glCopyImageSubData(%sX, %sY, or %sZ is negative)",
 267                   dbg_prefix, dbg_prefix, dbg_prefix);
 268       return false;
 269    }
 270
 271    /* Check X direction */
 272    if (target == GL_RENDERBUFFER) {
 273       surfWidth = renderbuffer->Width;
 274    }
 275    else {
 276       surfWidth = tex_image->Width;
 277    }
 278
 279    if (x + width > surfWidth) {
 280       _mesa_error(ctx, GL_INVALID_VALUE,
 281                   "glCopyImageSubData(%sX or %sWidth exceeds image bounds)",
 282                   dbg_prefix, dbg_prefix);
 283       return false;
 284    }
 285
 286    /* Check Y direction */
 287    switch (target) {
 288    case GL_RENDERBUFFER:
 289       surfHeight = renderbuffer->Height;
 290       break;
 291    case GL_TEXTURE_1D:
 292    case GL_TEXTURE_1D_ARRAY:
 293       surfHeight = 1;
 294       break;
 295    default:
 296       surfHeight = tex_image->Height;
 297    }
 298
 299    if (y + height > surfHeight) {
 300       _mesa_error(ctx, GL_INVALID_VALUE,
 301                   "glCopyImageSubData(%sY or %sHeight exceeds image bounds)",
 302                   dbg_prefix, dbg_prefix);
 303       return false;
 304    }
 305
 306    /* Check Z direction */
 307    switch (target) {
 308    case GL_RENDERBUFFER:
 309    case GL_TEXTURE_1D:
 310    case GL_TEXTURE_2D:
 311    case GL_TEXTURE_2D_MULTISAMPLE:
 312    case GL_TEXTURE_RECTANGLE:
 313       surfDepth = 1;
 314       break;
 315    case GL_TEXTURE_CUBE_MAP:
 316       surfDepth = 6;
 317       break;
 318    case GL_TEXTURE_1D_ARRAY:
 319       surfDepth = tex_image->Height;
 320       break;
 321    default:
 322       surfDepth = tex_image->Depth;
 323    }
 324
 325    if (z < 0 || z + depth > surfDepth) {
 326       _mesa_error(ctx, GL_INVALID_VALUE,
 327                   "glCopyImageSubData(%sZ or %sDepth exceeds image bounds)",
 328                   dbg_prefix, dbg_prefix);
 329       return false;
 330    }
 331
 332    return true;
 333 }
 334
 335 static bool
 336 compressed_format_compatible(const struct gl_context *ctx,
 337                              GLenum compressedFormat, GLenum otherFormat)
 338 {
 339    enum mesa_block_class compressedClass, otherClass;
 340
 341    /* Two view-incompatible compressed formats are never compatible. */
 342    if (_mesa_is_compressed_format(ctx, otherFormat)) {
 343       return false;
 344    }
 345
 346    /*
 347     * From ARB_copy_image spec:
 348     *    Table 4.X.1 (Compatible internal formats for copying between
 349     *                 compressed and uncompressed internal formats)
 350     *    ---------------------------------------------------------------------
 351     *    | Texel / | Uncompressed      |                                     |
 352     *    | Block   | internal format   | Compressed internal format          |
 353     *    | size    |                   |                                     |
 354     *    ---------------------------------------------------------------------
 355     *    | 128-bit | RGBA32UI,         | COMPRESSED_RGBA_S3TC_DXT3_EXT,      |
 356     *    |         | RGBA32I,          | COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT,|
 357     *    |         | RGBA32F           | COMPRESSED_RGBA_S3TC_DXT5_EXT,      |
 358     *    |         |                   | COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT,|
 359     *    |         |                   | COMPRESSED_RG_RGTC2,                |
 360     *    |         |                   | COMPRESSED_SIGNED_RG_RGTC2,         |
 361     *    |         |                   | COMPRESSED_RGBA_BPTC_UNORM,         |
 362     *    |         |                   | COMPRESSED_SRGB_ALPHA_BPTC_UNORM,   |
 363     *    |         |                   | COMPRESSED_RGB_BPTC_SIGNED_FLOAT,   |
 364     *    |         |                   | COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT  |
 365     *    ---------------------------------------------------------------------
 366     *    | 64-bit  | RGBA16F, RG32F,   | COMPRESSED_RGB_S3TC_DXT1_EXT,       |
 367     *    |         | RGBA16UI, RG32UI, | COMPRESSED_SRGB_S3TC_DXT1_EXT,      |
 368     *    |         | RGBA16I, RG32I,   | COMPRESSED_RGBA_S3TC_DXT1_EXT,      |
 369     *    |         | RGBA16,           | COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT,|
 370     *    |         | RGBA16_SNORM      | COMPRESSED_RED_RGTC1,               |
 371     *    |         |                   | COMPRESSED_SIGNED_RED_RGTC1         |
 372     *    ---------------------------------------------------------------------
 373     */
 374
 375    switch (compressedFormat) {
 376       case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
 377       case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT:
 378       case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
 379       case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT:
 380       case GL_COMPRESSED_RG_RGTC2:
 381       case GL_COMPRESSED_SIGNED_RG_RGTC2:
 382       case GL_COMPRESSED_RGBA_BPTC_UNORM:
 383       case GL_COMPRESSED_SRGB_ALPHA_BPTC_UNORM:
 384       case GL_COMPRESSED_RGB_BPTC_SIGNED_FLOAT:
 385       case GL_COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT:
 386          compressedClass = BLOCK_CLASS_128_BITS;
 387          break;
 388       case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
 389       case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT:
 390       case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
 391       case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT:
 392       case GL_COMPRESSED_RED_RGTC1:
 393       case GL_COMPRESSED_SIGNED_RED_RGTC1:
 394          compressedClass = BLOCK_CLASS_64_BITS;
 395          break;
 396       case GL_COMPRESSED_RGBA8_ETC2_EAC:
 397       case GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC:
 398       case GL_COMPRESSED_RG11_EAC:
 399       case GL_COMPRESSED_SIGNED_RG11_EAC:
 400          if (_mesa_is_gles(ctx))
 401             compressedClass = BLOCK_CLASS_128_BITS;
 402          else
 403             return false;
 404          break;
 405       case GL_COMPRESSED_RGB8_ETC2:
 406       case GL_COMPRESSED_SRGB8_ETC2:
 407       case GL_COMPRESSED_R11_EAC:
 408       case GL_COMPRESSED_SIGNED_R11_EAC:
 409       case GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2:
 410       case GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2:
 411          if (_mesa_is_gles(ctx))
 412             compressedClass = BLOCK_CLASS_64_BITS;
 413          else
 414             return false;
 415          break;
 416       default:
 417          if (_mesa_is_gles(ctx) && _mesa_is_astc_format(compressedFormat))
 418             compressedClass = BLOCK_CLASS_128_BITS;
 419          else
 420             return false;
 421          break;
 422    }
 423
 424    switch (otherFormat) {
 425       case GL_RGBA32UI:
 426       case GL_RGBA32I:
 427       case GL_RGBA32F:
 428          otherClass = BLOCK_CLASS_128_BITS;
 429          break;
 430       case GL_RGBA16F:
 431       case GL_RG32F:
 432       case GL_RGBA16UI:
 433       case GL_RG32UI:
 434       case GL_RGBA16I:
 435       case GL_RG32I:
 436       case GL_RGBA16:
 437       case GL_RGBA16_SNORM:
 438          otherClass = BLOCK_CLASS_64_BITS;
 439          break;
 440       default:
 441          return false;
 442    }
 443
 444    return compressedClass == otherClass;
 445 }
 446
 447 static bool
 448 copy_format_compatible(const struct gl_context *ctx,
 449                        GLenum srcFormat, GLenum dstFormat)
 450 {
 451    /*
 452     * From ARB_copy_image spec:
 453     *    For the purposes of CopyImageSubData, two internal formats
 454     *    are considered compatible if any of the following conditions are
 455     *    met:
 456     *    * the formats are the same,
 457     *    * the formats are considered compatible according to the
 458     *      compatibility rules used for texture views as defined in
 459     *      section 3.9.X. In particular, if both internal formats are listed
 460     *      in the same entry of Table 3.X.2, they are considered compatible, or
 461     *    * one format is compressed and the other is uncompressed and
 462     *      Table 4.X.1 lists the two formats in the same row.
 463     */
 464
 465    if (_mesa_texture_view_compatible_format(ctx, srcFormat, dstFormat)) {
 466       /* Also checks if formats are equal. */
 467       return true;
 468    } else if (_mesa_is_compressed_format(ctx, srcFormat)) {
 469       return compressed_format_compatible(ctx, srcFormat, dstFormat);
 470    } else if (_mesa_is_compressed_format(ctx, dstFormat)) {
 471       return compressed_format_compatible(ctx, dstFormat, srcFormat);
 472    }
 473
 474    return false;
 475 }
 476
 477 void GLAPIENTRY
 478 _mesa_CopyImageSubData(GLuint srcName, GLenum srcTarget, GLint srcLevel,
 479                        GLint srcX, GLint srcY, GLint srcZ,
 480                        GLuint dstName, GLenum dstTarget, GLint dstLevel,
 481                        GLint dstX, GLint dstY, GLint dstZ,
 482                        GLsizei srcWidth, GLsizei srcHeight, GLsizei srcDepth)
 483 {
 484    GET_CURRENT_CONTEXT(ctx);
 485    struct gl_texture_image *srcTexImage, *dstTexImage;
 486    struct gl_renderbuffer *srcRenderbuffer, *dstRenderbuffer;
 487    mesa_format srcFormat, dstFormat;
 488    GLenum srcIntFormat, dstIntFormat;
 489    GLuint src_w, src_h, dst_w, dst_h;
 490    GLuint src_bw, src_bh, dst_bw, dst_bh;
 491    GLuint src_num_samples, dst_num_samples;
 492    int dstWidth, dstHeight, dstDepth;
 493    int i;
 494
 495    if (MESA_VERBOSE & VERBOSE_API)
 496       _mesa_debug(ctx, "glCopyImageSubData(%u, %s, %d, %d, %d, %d, "
 497                                           "%u, %s, %d, %d, %d, %d, "
 498                                           "%d, %d, %d)\n",
 499                   srcName, _mesa_enum_to_string(srcTarget), srcLevel,
 500                   srcX, srcY, srcZ,
 501                   dstName, _mesa_enum_to_string(dstTarget), dstLevel,
 502                   dstX, dstY, dstZ,
 503                   srcWidth, srcHeight, srcDepth);
 504
 505    if (!ctx->Extensions.ARB_copy_image) {
 506       _mesa_error(ctx, GL_INVALID_OPERATION,
 507                   "glCopyImageSubData(extension not available)");
 508       return;
 509    }
 510
 511    if (!prepare_target_err(ctx, srcName, srcTarget, srcLevel, srcZ, srcDepth,
 512                            &srcTexImage, &srcRenderbuffer, &srcFormat,
 513                            &srcIntFormat, &src_w, &src_h, &src_num_samples,
 514                            "src"))
 515       return;
 516
 517    if (!prepare_target_err(ctx, dstName, dstTarget, dstLevel, dstZ, srcDepth,
 518                            &dstTexImage, &dstRenderbuffer, &dstFormat,
 519                            &dstIntFormat, &dst_w, &dst_h, &dst_num_samples,
 520                            "dst"))
 521       return;
 522
 523    _mesa_get_format_block_size(srcFormat, &src_bw, &src_bh);
 524
 525    /* Section 18.3.2 (Copying Between Images) of the OpenGL 4.5 Core Profile
 526     * spec says:
 527     *
 528     *    An INVALID_VALUE error is generated if the dimensions of either
 529     *    subregion exceeds the boundaries of the corresponding image object,
 530     *    or if the image format is compressed and the dimensions of the
 531     *    subregion fail to meet the alignment constraints of the format.
 532     *
 533     * and Section 8.7 (Compressed Texture Images) says:
 534     *
 535     *    An INVALID_OPERATION error is generated if any of the following
 536     *    conditions occurs:
 537     *
 538     *      * width is not a multiple of four, and width + xoffset is not
 539     *        equal to the value of TEXTURE_WIDTH.
 540     *      * height is not a multiple of four, and height + yoffset is not
 541     *        equal to the value of TEXTURE_HEIGHT.
 542     *
 543     * so we take that to mean that you can copy the "last" block of a
 544     * compressed texture image even if it's smaller than the minimum block
 545     * dimensions.
 546     */
 547    if ((srcX % src_bw != 0) || (srcY % src_bh != 0) ||
 548        (srcWidth % src_bw != 0 && (srcX + srcWidth) != src_w) ||
 549        (srcHeight % src_bh != 0 && (srcY + srcHeight) != src_h)) {
 550       _mesa_error(ctx, GL_INVALID_VALUE,
 551                   "glCopyImageSubData(unaligned src rectangle)");
 552       return;
 553    }
 554
 555    _mesa_get_format_block_size(dstFormat, &dst_bw, &dst_bh);
 556    if ((dstX % dst_bw != 0) || (dstY % dst_bh != 0)) {
 557       _mesa_error(ctx, GL_INVALID_VALUE,
 558                   "glCopyImageSubData(unaligned dst rectangle)");
 559       return;
 560    }
 561
 562    /* From the GL_ARB_copy_image spec:
 563     *
 564     * "The dimensions are always specified in texels, even for compressed
 565     * texture formats. But it should be noted that if only one of the
 566     * source and destination textures is compressed then the number of
 567     * texels touched in the compressed image will be a factor of the
 568     * block size larger than in the uncompressed image."
 569     *
 570     * So, if copying from compressed to uncompressed, the dest region is
 571     * shrunk by the src block size factor.  If copying from uncompressed
 572     * to compressed, the dest region is grown by the dest block size factor.
 573     * Note that we're passed the _source_ width, height, depth and those
 574     * dimensions are never changed.
 575     */
 576    dstWidth = srcWidth * dst_bw / src_bw;
 577    dstHeight = srcHeight * dst_bh / src_bh;
 578    dstDepth = srcDepth;
 579
 580    if (!check_region_bounds(ctx, srcTarget, srcTexImage, srcRenderbuffer,
 581                             srcX, srcY, srcZ, srcWidth, srcHeight, srcDepth,
 582                             "src"))
 583       return;
 584
 585    if (!check_region_bounds(ctx, dstTarget, dstTexImage, dstRenderbuffer,
 586                             dstX, dstY, dstZ, dstWidth, dstHeight, dstDepth,
 587                             "dst"))
 588       return;
 589
 590    /* Section 18.3.2 (Copying Between Images) of the OpenGL 4.5 Core Profile
 591     * spec says:
 592     *
 593     *    An INVALID_OPERATION error is generated if either object is a texture
 594     *    and the texture is not complete, if the source and destination internal
 595     *    formats are not compatible, or if the number of samples do not match.
 596     */
 597    if (!copy_format_compatible(ctx, srcIntFormat, dstIntFormat)) {
 598       _mesa_error(ctx, GL_INVALID_OPERATION,
 599                   "glCopyImageSubData(internalFormat mismatch)");
 600       return;
 601    }
 602
 603    if (src_num_samples != dst_num_samples) {
 604       _mesa_error(ctx, GL_INVALID_OPERATION,
 605                   "glCopyImageSubData(number of samples mismatch)");
 606       return;
 607    }
 608
 609    /* loop over 2D slices/faces/layers */
 610    for (i = 0; i < srcDepth; ++i) {
 611       int newSrcZ = srcZ + i;
 612       int newDstZ = dstZ + i;
 613
 614       if (srcTexImage &&
 615           srcTexImage->TexObject->Target == GL_TEXTURE_CUBE_MAP) {
 616          /* need to update srcTexImage pointer for the cube face */
 617          assert(srcZ + i < MAX_FACES);
 618          srcTexImage = srcTexImage->TexObject->Image[srcZ + i][srcLevel];
 619          assert(srcTexImage);
 620          newSrcZ = 0;
 621       }
 622
 623       if (dstTexImage &&
 624           dstTexImage->TexObject->Target == GL_TEXTURE_CUBE_MAP) {
 625          /* need to update dstTexImage pointer for the cube face */
 626          assert(dstZ + i < MAX_FACES);
 627          dstTexImage = dstTexImage->TexObject->Image[dstZ + i][dstLevel];
 628          assert(dstTexImage);
 629          newDstZ = 0;
 630       }
 631
 632       ctx->Driver.CopyImageSubData(ctx,
 633                                    srcTexImage, srcRenderbuffer,
 634                                    srcX, srcY, newSrcZ,
 635                                    dstTexImage, dstRenderbuffer,
 636                                    dstX, dstY, newDstZ,
 637                                    srcWidth, srcHeight);
 638    }
 639 }