src/mesa/main/texcompress.c

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
   5  * Copyright (c) 2008 VMware, Inc.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  21  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  22  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  23  * OTHER DEALINGS IN THE SOFTWARE.
  24  */
  25
  26
  27 /**
  28  * \file texcompress.c
  29  * Helper functions for texture compression.
  30  */
  31
  32
  33 #include "glheader.h"
  34
  35 #include "context.h"
  36 #include "formats.h"
  37 #include "mtypes.h"
  38 #include "context.h"
  39 #include "texcompress.h"
  40 #include "texcompress_fxt1.h"
  41 #include "texcompress_rgtc.h"
  42 #include "texcompress_s3tc.h"
  43 #include "texcompress_etc.h"
  44 #include "texcompress_bptc.h"
  45
  46
  47 /**
  48  * Get the GL base format of a specified GL compressed texture format
  49  *
  50  * From page 232 of the OpenGL 3.3 (Compatiblity Profile) spec:
  51  *
  52  *     "Compressed Internal Format      Base Internal Format    Type
  53  *     ---------------------------     --------------------    ---------
  54  *     COMPRESSED_ALPHA                ALPHA                   Generic
  55  *     COMPRESSED_LUMINANCE            LUMINANCE               Generic
  56  *     COMPRESSED_LUMINANCE_ALPHA      LUMINANCE_ALPHA         Generic
  57  *     COMPRESSED_INTENSITY            INTENSITY               Generic
  58  *     COMPRESSED_RED                  RED                     Generic
  59  *     COMPRESSED_RG                   RG                      Generic
  60  *     COMPRESSED_RGB                  RGB                     Generic
  61  *     COMPRESSED_RGBA                 RGBA                    Generic
  62  *     COMPRESSED_SRGB                 RGB                     Generic
  63  *     COMPRESSED_SRGB_ALPHA           RGBA                    Generic
  64  *     COMPRESSED_SLUMINANCE           LUMINANCE               Generic
  65  *     COMPRESSED_SLUMINANCE_ALPHA     LUMINANCE_ALPHA         Generic
  66  *     COMPRESSED_RED_RGTC1            RED                     Specific
  67  *     COMPRESSED_SIGNED_RED_RGTC1     RED                     Specific
  68  *     COMPRESSED_RG_RGTC2             RG                      Specific
  69  *     COMPRESSED_SIGNED_RG_RGTC2      RG                      Specific"
  70  *
  71  * \return
  72  * The base format of \c format if \c format is a compressed format (either
  73  * generic or specific.  Otherwise 0 is returned.
  74  */
  75 GLenum
  76 _mesa_gl_compressed_format_base_format(GLenum format)
  77 {
  78    switch (format) {
  79    case GL_COMPRESSED_RED:
  80    case GL_COMPRESSED_R11_EAC:
  81    case GL_COMPRESSED_RED_RGTC1:
  82    case GL_COMPRESSED_SIGNED_R11_EAC:
  83    case GL_COMPRESSED_SIGNED_RED_RGTC1:
  84       return GL_RED;
  85
  86    case GL_COMPRESSED_RG:
  87    case GL_COMPRESSED_RG11_EAC:
  88    case GL_COMPRESSED_RG_RGTC2:
  89    case GL_COMPRESSED_SIGNED_RG11_EAC:
  90    case GL_COMPRESSED_SIGNED_RG_RGTC2:
  91       return GL_RG;
  92
  93    case GL_COMPRESSED_RGB:
  94    case GL_COMPRESSED_SRGB:
  95    case GL_COMPRESSED_RGB_BPTC_SIGNED_FLOAT_ARB:
  96    case GL_COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT_ARB:
  97    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
  98    case GL_COMPRESSED_RGB_FXT1_3DFX:
  99    case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT:
 100    case GL_ETC1_RGB8_OES:
 101    case GL_COMPRESSED_RGB8_ETC2:
 102    case GL_COMPRESSED_SRGB8_ETC2:
 103    case GL_RGB_S3TC:
 104    case GL_RGB4_S3TC:
 105    case GL_PALETTE4_RGB8_OES:
 106    case GL_PALETTE4_R5_G6_B5_OES:
 107    case GL_PALETTE8_RGB8_OES:
 108    case GL_PALETTE8_R5_G6_B5_OES:
 109    case GL_ATC_RGB_AMD:
 110       return GL_RGB;
 111
 112    case GL_COMPRESSED_RGBA:
 113    case GL_COMPRESSED_SRGB_ALPHA:
 114    case GL_COMPRESSED_RGBA_BPTC_UNORM_ARB:
 115    case GL_COMPRESSED_SRGB_ALPHA_BPTC_UNORM_ARB:
 116    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
 117    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
 118    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
 119    case GL_COMPRESSED_RGBA_FXT1_3DFX:
 120    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT:
 121    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT:
 122    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT:
 123    case GL_COMPRESSED_RGBA8_ETC2_EAC:
 124    case GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC:
 125    case GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2:
 126    case GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2:
 127    case GL_RGBA_S3TC:
 128    case GL_RGBA4_S3TC:
 129    case GL_PALETTE4_RGBA8_OES:
 130    case GL_PALETTE8_RGB5_A1_OES:
 131    case GL_PALETTE4_RGBA4_OES:
 132    case GL_PALETTE4_RGB5_A1_OES:
 133    case GL_PALETTE8_RGBA8_OES:
 134    case GL_PALETTE8_RGBA4_OES:
 135    case GL_ATC_RGBA_EXPLICIT_ALPHA_AMD:
 136    case GL_ATC_RGBA_INTERPOLATED_ALPHA_AMD:
 137       return GL_RGBA;
 138
 139    case GL_COMPRESSED_ALPHA:
 140       return GL_ALPHA;
 141
 142    case GL_COMPRESSED_LUMINANCE:
 143    case GL_COMPRESSED_SLUMINANCE:
 144    case GL_COMPRESSED_LUMINANCE_LATC1_EXT:
 145    case GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT:
 146       return GL_LUMINANCE;
 147
 148    case GL_COMPRESSED_LUMINANCE_ALPHA:
 149    case GL_COMPRESSED_SLUMINANCE_ALPHA:
 150    case GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT:
 151    case GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT:
 152    case GL_COMPRESSED_LUMINANCE_ALPHA_3DC_ATI:
 153       return GL_LUMINANCE_ALPHA;
 154
 155    case GL_COMPRESSED_INTENSITY:
 156       return GL_INTENSITY;
 157
 158    default:
 159       return 0;
 160    }
 161 }
 162
 163 /**
 164  * Return list of (and count of) all specific texture compression
 165  * formats that are supported.
 166  *
 167  * Some formats are \b not returned by this function.  The
 168  * \c GL_COMPRESSED_TEXTURE_FORMATS query only returns formats that are
 169  * "suitable for general-purpose usage."  All texture compression extensions
 170  * have taken this to mean either linear RGB or linear RGBA.
 171  *
 172  * The GL_ARB_texture_compress_rgtc spec says:
 173  *
 174  *    "19) Should the GL_NUM_COMPRESSED_TEXTURE_FORMATS and
 175  *        GL_COMPRESSED_TEXTURE_FORMATS queries return the RGTC formats?
 176  *
 177  *        RESOLVED:  No.
 178  *
 179  *        The OpenGL 2.1 specification says "The only values returned
 180  *        by this query [GL_COMPRESSED_TEXTURE_FORMATS"] are those
 181  *        corresponding to formats suitable for general-purpose usage.
 182  *        The renderer will not enumerate formats with restrictions that
 183  *        need to be specifically understood prior to use."
 184  *
 185  *        Compressed textures with just red or red-green components are
 186  *        not general-purpose so should not be returned by these queries
 187  *        because they have restrictions.
 188  *
 189  *        Applications that seek to use the RGTC formats should do so
 190  *        by looking for this extension's name in the string returned by
 191  *        glGetString(GL_EXTENSIONS) rather than
 192  *        what GL_NUM_COMPRESSED_TEXTURE_FORMATS and
 193  *        GL_COMPRESSED_TEXTURE_FORMATS return."
 194  *
 195  * There is nearly identical wording in the GL_EXT_texture_compression_rgtc
 196  * spec.
 197  *
 198  * The GL_EXT_texture_rRGB spec says:
 199  *
 200  *    "22) Should the new COMPRESSED_SRGB_* formats be listed in an
 201  *        implementation's GL_COMPRESSED_TEXTURE_FORMATS list?
 202  *
 203  *        RESOLVED:  No.  Section 3.8.1 says formats listed by
 204  *        GL_COMPRESSED_TEXTURE_FORMATS are "suitable for general-purpose
 205  *        usage."  The non-linear distribution of red, green, and
 206  *        blue for these sRGB compressed formats makes them not really
 207  *        general-purpose."
 208  *
 209  * The GL_EXT_texture_compression_latc spec says:
 210  *
 211  *    "16) Should the GL_NUM_COMPRESSED_TEXTURE_FORMATS and
 212  *        GL_COMPRESSED_TEXTURE_FORMATS queries return the LATC formats?
 213  *
 214  *        RESOLVED:  No.
 215  *
 216  *        The OpenGL 2.1 specification says "The only values returned
 217  *        by this query [GL_COMPRESSED_TEXTURE_FORMATS"] are those
 218  *        corresponding to formats suitable for general-purpose usage.
 219  *        The renderer will not enumerate formats with restrictions that
 220  *        need to be specifically understood prior to use."
 221  *
 222  *        Historically, OpenGL implementation have advertised the RGB and
 223  *        RGBA versions of the S3TC extensions compressed format tokens
 224  *        through this mechanism.
 225  *
 226  *        The specification is not sufficiently clear about what "suitable
 227  *        for general-purpose usage" means.  Historically that seems to mean
 228  *        unsigned RGB or unsigned RGBA.  The DXT1 format supporting alpha
 229  *        (GL_COMPRESSED_RGBA_S3TC_DXT1_EXT) is not exposed in the list (at
 230  *        least for NVIDIA drivers) because the alpha is always 1.0 expect
 231  *        when it is 0.0 when RGB is required to be black.  NVIDIA's even
 232  *        limits itself to true linear RGB or RGBA formats, specifically
 233  *        not including EXT_texture_sRGB's sRGB S3TC compressed formats.
 234  *
 235  *        Adding luminance and luminance-alpha texture formats (and
 236  *        certainly signed versions of luminance and luminance-alpha
 237  *        formats!) invites potential comptaibility problems with old
 238  *        applications using this mechanism since old applications are
 239  *        unlikely to expect non-RGB or non-RGBA formats to be advertised
 240  *        through this mechanism.  However no specific misinteractions
 241  *        with old applications is known.
 242  *
 243  *        Applications that seek to use the LATC formats should do so
 244  *        by looking for this extension's name in the string returned by
 245  *        glGetString(GL_EXTENSIONS) rather than
 246  *        what GL_NUM_COMPRESSED_TEXTURE_FORMATS and
 247  *        GL_COMPRESSED_TEXTURE_FORMATS return."
 248  *
 249  * There is no formal spec for GL_ATI_texture_compression_3dc.  Since the
 250  * formats added by this extension are luminance-alpha formats, it is
 251  * reasonable to expect them to follow the same rules as
 252  * GL_EXT_texture_compression_latc.  At the very least, Catalyst 11.6 does not
 253  * expose the 3dc formats through this mechanism.
 254  *
 255  * The spec for GL_ARB_texture_compression_bptc doesn't mention whether it
 256  * should be included in GL_COMPRESSED_TEXTURE_FORMATS. However as it takes a
 257  * very long time to compress the textures in this format it's probably not
 258  * very useful as a general format where the GL will have to compress it on
 259  * the fly.
 260  *
 261  * \param ctx  the GL context
 262  * \param formats  the resulting format list (may be NULL).
 263  *
 264  * \return number of formats.
 265  */
 266 GLuint
 267 _mesa_get_compressed_formats(struct gl_context *ctx, GLint *formats)
 268 {
 269    GLint discard_formats[100];
 270    GLuint n = 0;
 271
 272    if (!formats) {
 273       formats = discard_formats;
 274    }
 275
 276    if (_mesa_is_desktop_gl(ctx) &&
 277        ctx->Extensions.TDFX_texture_compression_FXT1) {
 278       formats[n++] = GL_COMPRESSED_RGB_FXT1_3DFX;
 279       formats[n++] = GL_COMPRESSED_RGBA_FXT1_3DFX;
 280    }
 281
 282    if (ctx->Extensions.EXT_texture_compression_s3tc) {
 283       formats[n++] = GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
 284       formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT3_EXT;
 285       formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
 286
 287       /* The ES and desktop GL specs diverge here.
 288        *
 289        * In desktop OpenGL, the driver can perform online compression of
 290        * uncompressed texture data.  GL_NUM_COMPRESSED_TEXTURE_FORMATS and
 291        * GL_COMPRESSED_TEXTURE_FORMATS give the application a list of
 292        * formats that it could ask the driver to compress with some
 293        * expectation of quality.  The GL_ARB_texture_compression spec
 294        * calls this "suitable for general-purpose usage."  As noted
 295        * above, this means GL_COMPRESSED_RGBA_S3TC_DXT1_EXT is not
 296        * included in the list.
 297        *
 298        * In OpenGL ES, the driver never performs compression.
 299        * GL_NUM_COMPRESSED_TEXTURE_FORMATS and
 300        * GL_COMPRESSED_TEXTURE_FORMATS give the application a list of
 301        * formats that the driver can receive from the application.  It
 302        * is the *complete* list of formats.  The
 303        * GL_EXT_texture_compression_s3tc spec says:
 304        *
 305        *     "New State for OpenGL ES 2.0.25 and 3.0.2 Specifications
 306        *
 307        *         The queries for NUM_COMPRESSED_TEXTURE_FORMATS and
 308        *         COMPRESSED_TEXTURE_FORMATS include
 309        *         COMPRESSED_RGB_S3TC_DXT1_EXT,
 310        *         COMPRESSED_RGBA_S3TC_DXT1_EXT,
 311        *         COMPRESSED_RGBA_S3TC_DXT3_EXT, and
 312        *         COMPRESSED_RGBA_S3TC_DXT5_EXT."
 313        *
 314        * Note that the addition is only to the OpenGL ES specification!
 315        */
 316       if (_mesa_is_gles(ctx)) {
 317          formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT1_EXT;
 318       }
 319    }
 320
 321    /* The GL_OES_compressed_ETC1_RGB8_texture spec says:
 322     *
 323     *     "New State
 324     *
 325     *         The queries for NUM_COMPRESSED_TEXTURE_FORMATS and
 326     *         COMPRESSED_TEXTURE_FORMATS include ETC1_RGB8_OES."
 327     */
 328    if (_mesa_is_gles(ctx)
 329        && ctx->Extensions.OES_compressed_ETC1_RGB8_texture) {
 330       formats[n++] = GL_ETC1_RGB8_OES;
 331    }
 332
 333    /* Required by EXT_texture_compression_bptc in GLES. */
 334    if (_mesa_has_EXT_texture_compression_bptc(ctx)) {
 335       formats[n++] = GL_COMPRESSED_RGBA_BPTC_UNORM;
 336       formats[n++] = GL_COMPRESSED_SRGB_ALPHA_BPTC_UNORM;
 337       formats[n++] = GL_COMPRESSED_RGB_BPTC_SIGNED_FLOAT;
 338       formats[n++] = GL_COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT;
 339    }
 340
 341    /* Required by EXT_texture_compression_rgtc in GLES. */
 342    if (_mesa_is_gles3(ctx) &&
 343        _mesa_has_EXT_texture_compression_rgtc(ctx)) {
 344       formats[n++] = GL_COMPRESSED_RED_RGTC1_EXT;
 345       formats[n++] = GL_COMPRESSED_SIGNED_RED_RGTC1_EXT;
 346       formats[n++] = GL_COMPRESSED_RED_GREEN_RGTC2_EXT;
 347       formats[n++] = GL_COMPRESSED_SIGNED_RED_GREEN_RGTC2_EXT;
 348    }
 349
 350    if (ctx->API == API_OPENGLES) {
 351       formats[n++] = GL_PALETTE4_RGB8_OES;
 352       formats[n++] = GL_PALETTE4_RGBA8_OES;
 353       formats[n++] = GL_PALETTE4_R5_G6_B5_OES;
 354       formats[n++] = GL_PALETTE4_RGBA4_OES;
 355       formats[n++] = GL_PALETTE4_RGB5_A1_OES;
 356       formats[n++] = GL_PALETTE8_RGB8_OES;
 357       formats[n++] = GL_PALETTE8_RGBA8_OES;
 358       formats[n++] = GL_PALETTE8_R5_G6_B5_OES;
 359       formats[n++] = GL_PALETTE8_RGBA4_OES;
 360       formats[n++] = GL_PALETTE8_RGB5_A1_OES;
 361    }
 362
 363    if (_mesa_is_gles3(ctx) || ctx->Extensions.ARB_ES3_compatibility) {
 364       formats[n++] = GL_COMPRESSED_RGB8_ETC2;
 365       formats[n++] = GL_COMPRESSED_RGBA8_ETC2_EAC;
 366       formats[n++] = GL_COMPRESSED_R11_EAC;
 367       formats[n++] = GL_COMPRESSED_RG11_EAC;
 368       formats[n++] = GL_COMPRESSED_SIGNED_R11_EAC;
 369       formats[n++] = GL_COMPRESSED_SIGNED_RG11_EAC;
 370       formats[n++] = GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2;
 371    }
 372
 373    if (_mesa_is_gles3(ctx)) {
 374       formats[n++] = GL_COMPRESSED_SRGB8_ETC2;
 375       formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC;
 376       formats[n++] = GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2;
 377    }
 378
 379    /* The KHR_texture_compression_astc_hdr spec says:
 380     *
 381     *    "Interactions with OpenGL 4.2
 382     *
 383     *        OpenGL 4.2 supports the feature that compressed textures can be
 384     *        compressed online, by passing the compressed texture format enum
 385     *        as the internal format when uploading a texture using TexImage1D,
 386     *        TexImage2D or TexImage3D (see Section 3.9.3, Texture Image
 387     *        Specification, subsection Encoding of Special Internal Formats).
 388     *
 389     *        Due to the complexity of the ASTC compression algorithm, it is
 390     *        not usually suitable for online use, and therefore ASTC support
 391     *        will be limited to pre-compressed textures only. Where on-device
 392     *        compression is required, a domain-specific limited compressor
 393     *        will typically be used, and this is therefore not suitable for
 394     *        implementation in the driver.
 395     *
 396     *        In particular, the ASTC format specifiers will not be added to
 397     *        Table 3.14, and thus will not be accepted by the TexImage*D
 398     *        functions, and will not be returned by the (already deprecated)
 399     *        COMPRESSED_TEXTURE_FORMATS query."
 400     *
 401     * The ES and the desktop specs diverge here. In OpenGL ES, the
 402     * COMPRESSED_TEXTURE_FORMATS query returns the set of supported specific
 403     * compressed formats.
 404     */
 405    if (ctx->API == API_OPENGLES2 &&
 406        ctx->Extensions.KHR_texture_compression_astc_ldr) {
 407       formats[n++] = GL_COMPRESSED_RGBA_ASTC_4x4_KHR;
 408       formats[n++] = GL_COMPRESSED_RGBA_ASTC_5x4_KHR;
 409       formats[n++] = GL_COMPRESSED_RGBA_ASTC_5x5_KHR;
 410       formats[n++] = GL_COMPRESSED_RGBA_ASTC_6x5_KHR;
 411       formats[n++] = GL_COMPRESSED_RGBA_ASTC_6x6_KHR;
 412       formats[n++] = GL_COMPRESSED_RGBA_ASTC_8x5_KHR;
 413       formats[n++] = GL_COMPRESSED_RGBA_ASTC_8x6_KHR;
 414       formats[n++] = GL_COMPRESSED_RGBA_ASTC_8x8_KHR;
 415       formats[n++] = GL_COMPRESSED_RGBA_ASTC_10x5_KHR;
 416       formats[n++] = GL_COMPRESSED_RGBA_ASTC_10x6_KHR;
 417       formats[n++] = GL_COMPRESSED_RGBA_ASTC_10x8_KHR;
 418       formats[n++] = GL_COMPRESSED_RGBA_ASTC_10x10_KHR;
 419       formats[n++] = GL_COMPRESSED_RGBA_ASTC_12x10_KHR;
 420       formats[n++] = GL_COMPRESSED_RGBA_ASTC_12x12_KHR;
 421       formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x4_KHR;
 422       formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x4_KHR;
 423       formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x5_KHR;
 424       formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x5_KHR;
 425       formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x6_KHR;
 426       formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8x5_KHR;
 427       formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8x6_KHR;
 428       formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8x8_KHR;
 429       formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x5_KHR;
 430       formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x6_KHR;
 431       formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x8_KHR;
 432       formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x10_KHR;
 433       formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_12x10_KHR;
 434       formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_12x12_KHR;
 435    }
 436
 437    if (_mesa_is_gles3(ctx) &&
 438        ctx->Extensions.OES_texture_compression_astc) {
 439       formats[n++] = GL_COMPRESSED_RGBA_ASTC_3x3x3_OES;
 440       formats[n++] = GL_COMPRESSED_RGBA_ASTC_4x3x3_OES;
 441       formats[n++] = GL_COMPRESSED_RGBA_ASTC_4x4x3_OES;
 442       formats[n++] = GL_COMPRESSED_RGBA_ASTC_4x4x4_OES;
 443       formats[n++] = GL_COMPRESSED_RGBA_ASTC_5x4x4_OES;
 444       formats[n++] = GL_COMPRESSED_RGBA_ASTC_5x5x4_OES;
 445       formats[n++] = GL_COMPRESSED_RGBA_ASTC_5x5x5_OES;
 446       formats[n++] = GL_COMPRESSED_RGBA_ASTC_6x5x5_OES;
 447       formats[n++] = GL_COMPRESSED_RGBA_ASTC_6x6x5_OES;
 448       formats[n++] = GL_COMPRESSED_RGBA_ASTC_6x6x6_OES;
 449       formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_3x3x3_OES;
 450       formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x3x3_OES;
 451       formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x4x3_OES;
 452       formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x4x4_OES;
 453       formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x4x4_OES;
 454       formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x5x4_OES;
 455       formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x5x5_OES;
 456       formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x5x5_OES;
 457       formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x6x5_OES;
 458       formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x6x6_OES;
 459    }
 460
 461    /* The GL_AMD_compressed_ATC_texture spec says:
 462     *
 463     *     "New State
 464     *
 465     *         The queries for NUM_COMPRESSED_TEXTURE_FORMATS and
 466     *         COMPRESSED_TEXTURE_FORMATS include ATC_RGB_AMD,
 467     *         ATC_RGBA_EXPLICIT_ALPHA_AMD, and ATC_RGBA_INTERPOLATED_ALPHA_AMD."
 468     */
 469    if (_mesa_has_AMD_compressed_ATC_texture(ctx)) {
 470       formats[n++] = GL_ATC_RGB_AMD;
 471       formats[n++] = GL_ATC_RGBA_EXPLICIT_ALPHA_AMD;
 472       formats[n++] = GL_ATC_RGBA_INTERPOLATED_ALPHA_AMD;
 473    }
 474
 475    assert(n <= ARRAY_SIZE(discard_formats));
 476
 477    return n;
 478 }
 479
 480
 481 /**
 482  * Convert GLenum to a compressed MESA_FORMAT_x.
 483  */
 484 mesa_format
 485 _mesa_glenum_to_compressed_format(GLenum format)
 486 {
 487    switch (format) {
 488    case GL_COMPRESSED_RGB_FXT1_3DFX:
 489       return MESA_FORMAT_RGB_FXT1;
 490    case GL_COMPRESSED_RGBA_FXT1_3DFX:
 491       return MESA_FORMAT_RGBA_FXT1;
 492
 493    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
 494    case GL_RGB_S3TC:
 495    case GL_RGB4_S3TC:
 496       return MESA_FORMAT_RGB_DXT1;
 497    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
 498       return MESA_FORMAT_RGBA_DXT1;
 499    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
 500    case GL_RGBA_S3TC:
 501    case GL_RGBA4_S3TC:
 502       return MESA_FORMAT_RGBA_DXT3;
 503    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
 504       return MESA_FORMAT_RGBA_DXT5;
 505
 506    case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT:
 507       return MESA_FORMAT_SRGB_DXT1;
 508    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT:
 509       return MESA_FORMAT_SRGBA_DXT1;
 510    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT:
 511       return MESA_FORMAT_SRGBA_DXT3;
 512    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT:
 513       return MESA_FORMAT_SRGBA_DXT5;
 514
 515    case GL_COMPRESSED_RED_RGTC1:
 516       return MESA_FORMAT_R_RGTC1_UNORM;
 517    case GL_COMPRESSED_SIGNED_RED_RGTC1:
 518       return MESA_FORMAT_R_RGTC1_SNORM;
 519    case GL_COMPRESSED_RG_RGTC2:
 520       return MESA_FORMAT_RG_RGTC2_UNORM;
 521    case GL_COMPRESSED_SIGNED_RG_RGTC2:
 522       return MESA_FORMAT_RG_RGTC2_SNORM;
 523
 524    case GL_COMPRESSED_LUMINANCE_LATC1_EXT:
 525       return MESA_FORMAT_L_LATC1_UNORM;
 526    case GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT:
 527       return MESA_FORMAT_L_LATC1_SNORM;
 528    case GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT:
 529    case GL_COMPRESSED_LUMINANCE_ALPHA_3DC_ATI:
 530       return MESA_FORMAT_LA_LATC2_UNORM;
 531    case GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT:
 532       return MESA_FORMAT_LA_LATC2_SNORM;
 533
 534    case GL_ETC1_RGB8_OES:
 535       return MESA_FORMAT_ETC1_RGB8;
 536    case GL_COMPRESSED_RGB8_ETC2:
 537       return MESA_FORMAT_ETC2_RGB8;
 538    case GL_COMPRESSED_SRGB8_ETC2:
 539       return MESA_FORMAT_ETC2_SRGB8;
 540    case GL_COMPRESSED_RGBA8_ETC2_EAC:
 541       return MESA_FORMAT_ETC2_RGBA8_EAC;
 542    case GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC:
 543       return MESA_FORMAT_ETC2_SRGB8_ALPHA8_EAC;
 544    case GL_COMPRESSED_R11_EAC:
 545       return MESA_FORMAT_ETC2_R11_EAC;
 546    case GL_COMPRESSED_RG11_EAC:
 547       return MESA_FORMAT_ETC2_RG11_EAC;
 548    case GL_COMPRESSED_SIGNED_R11_EAC:
 549       return MESA_FORMAT_ETC2_SIGNED_R11_EAC;
 550    case GL_COMPRESSED_SIGNED_RG11_EAC:
 551       return MESA_FORMAT_ETC2_SIGNED_RG11_EAC;
 552    case GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2:
 553       return MESA_FORMAT_ETC2_RGB8_PUNCHTHROUGH_ALPHA1;
 554    case GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2:
 555       return MESA_FORMAT_ETC2_SRGB8_PUNCHTHROUGH_ALPHA1;
 556
 557    case GL_COMPRESSED_RGBA_BPTC_UNORM:
 558       return MESA_FORMAT_BPTC_RGBA_UNORM;
 559    case GL_COMPRESSED_SRGB_ALPHA_BPTC_UNORM:
 560       return MESA_FORMAT_BPTC_SRGB_ALPHA_UNORM;
 561    case GL_COMPRESSED_RGB_BPTC_SIGNED_FLOAT:
 562       return MESA_FORMAT_BPTC_RGB_SIGNED_FLOAT;
 563    case GL_COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT:
 564       return MESA_FORMAT_BPTC_RGB_UNSIGNED_FLOAT;
 565
 566    case GL_COMPRESSED_RGBA_ASTC_4x4_KHR:
 567       return MESA_FORMAT_RGBA_ASTC_4x4;
 568    case GL_COMPRESSED_RGBA_ASTC_5x4_KHR:
 569       return MESA_FORMAT_RGBA_ASTC_5x4;
 570    case GL_COMPRESSED_RGBA_ASTC_5x5_KHR:
 571       return MESA_FORMAT_RGBA_ASTC_5x5;
 572    case GL_COMPRESSED_RGBA_ASTC_6x5_KHR:
 573       return MESA_FORMAT_RGBA_ASTC_6x5;
 574    case GL_COMPRESSED_RGBA_ASTC_6x6_KHR:
 575       return MESA_FORMAT_RGBA_ASTC_6x6;
 576    case GL_COMPRESSED_RGBA_ASTC_8x5_KHR:
 577       return MESA_FORMAT_RGBA_ASTC_8x5;
 578    case GL_COMPRESSED_RGBA_ASTC_8x6_KHR:
 579       return MESA_FORMAT_RGBA_ASTC_8x6;
 580    case GL_COMPRESSED_RGBA_ASTC_8x8_KHR:
 581       return MESA_FORMAT_RGBA_ASTC_8x8;
 582    case GL_COMPRESSED_RGBA_ASTC_10x5_KHR:
 583       return MESA_FORMAT_RGBA_ASTC_10x5;
 584    case GL_COMPRESSED_RGBA_ASTC_10x6_KHR:
 585       return MESA_FORMAT_RGBA_ASTC_10x6;
 586    case GL_COMPRESSED_RGBA_ASTC_10x8_KHR:
 587       return MESA_FORMAT_RGBA_ASTC_10x8;
 588    case GL_COMPRESSED_RGBA_ASTC_10x10_KHR:
 589       return MESA_FORMAT_RGBA_ASTC_10x10;
 590    case GL_COMPRESSED_RGBA_ASTC_12x10_KHR:
 591       return MESA_FORMAT_RGBA_ASTC_12x10;
 592    case GL_COMPRESSED_RGBA_ASTC_12x12_KHR:
 593       return MESA_FORMAT_RGBA_ASTC_12x12;
 594    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x4_KHR:
 595       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_4x4;
 596    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x4_KHR:
 597       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_5x4;
 598    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x5_KHR:
 599       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_5x5;
 600    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x5_KHR:
 601       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_6x5;
 602    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x6_KHR:
 603       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_6x6;
 604    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8x5_KHR:
 605       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_8x5;
 606    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8x6_KHR:
 607       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_8x6;
 608    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8x8_KHR:
 609       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_8x8;
 610    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x5_KHR:
 611       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_10x5;
 612    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x6_KHR:
 613       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_10x6;
 614    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x8_KHR:
 615       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_10x8;
 616    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x10_KHR:
 617       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_10x10;
 618    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_12x10_KHR:
 619       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_12x10;
 620    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_12x12_KHR:
 621       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_12x12;
 622    case GL_COMPRESSED_RGBA_ASTC_3x3x3_OES:
 623       return MESA_FORMAT_RGBA_ASTC_3x3x3;
 624    case GL_COMPRESSED_RGBA_ASTC_4x3x3_OES:
 625       return MESA_FORMAT_RGBA_ASTC_4x3x3;
 626    case GL_COMPRESSED_RGBA_ASTC_4x4x3_OES:
 627       return MESA_FORMAT_RGBA_ASTC_4x4x3;
 628    case GL_COMPRESSED_RGBA_ASTC_4x4x4_OES:
 629       return MESA_FORMAT_RGBA_ASTC_4x4x4;
 630    case GL_COMPRESSED_RGBA_ASTC_5x4x4_OES:
 631       return MESA_FORMAT_RGBA_ASTC_5x4x4;
 632    case GL_COMPRESSED_RGBA_ASTC_5x5x4_OES:
 633       return MESA_FORMAT_RGBA_ASTC_5x5x4;
 634    case GL_COMPRESSED_RGBA_ASTC_5x5x5_OES:
 635       return MESA_FORMAT_RGBA_ASTC_5x5x5;
 636    case GL_COMPRESSED_RGBA_ASTC_6x5x5_OES:
 637       return MESA_FORMAT_RGBA_ASTC_6x5x5;
 638    case GL_COMPRESSED_RGBA_ASTC_6x6x5_OES:
 639       return MESA_FORMAT_RGBA_ASTC_6x6x5;
 640    case GL_COMPRESSED_RGBA_ASTC_6x6x6_OES:
 641       return MESA_FORMAT_RGBA_ASTC_6x6x6;
 642    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_3x3x3_OES:
 643       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_3x3x3;
 644    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x3x3_OES:
 645       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_4x3x3;
 646    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x4x3_OES:
 647       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_4x4x3;
 648    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x4x4_OES:
 649       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_4x4x4;
 650    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x4x4_OES:
 651       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_5x4x4;
 652    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x5x4_OES:
 653       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_5x5x4;
 654    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x5x5_OES:
 655       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_5x5x5;
 656    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x5x5_OES:
 657       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_6x5x5;
 658    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x6x5_OES:
 659       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_6x6x5;
 660    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x6x6_OES:
 661       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_6x6x6;
 662
 663    case GL_ATC_RGB_AMD:
 664       return MESA_FORMAT_ATC_RGB;
 665    case GL_ATC_RGBA_EXPLICIT_ALPHA_AMD:
 666       return MESA_FORMAT_ATC_RGBA_EXPLICIT;
 667    case GL_ATC_RGBA_INTERPOLATED_ALPHA_AMD:
 668       return MESA_FORMAT_ATC_RGBA_INTERPOLATED;
 669
 670    default:
 671       return MESA_FORMAT_NONE;
 672    }
 673 }
 674
 675
 676 /**
 677  * Given a compressed MESA_FORMAT_x value, return the corresponding
 678  * GLenum for that format.
 679  * This is needed for glGetTexLevelParameter(GL_TEXTURE_INTERNAL_FORMAT)
 680  * which must return the specific texture format used when the user might
 681  * have originally specified a generic compressed format in their
 682  * glTexImage2D() call.
 683  * For non-compressed textures, we always return the user-specified
 684  * internal format unchanged.
 685  */
 686 GLenum
 687 _mesa_compressed_format_to_glenum(struct gl_context *ctx,
 688                                   mesa_format mesaFormat)
 689 {
 690    switch (mesaFormat) {
 691    case MESA_FORMAT_RGB_FXT1:
 692       return GL_COMPRESSED_RGB_FXT1_3DFX;
 693    case MESA_FORMAT_RGBA_FXT1:
 694       return GL_COMPRESSED_RGBA_FXT1_3DFX;
 695    case MESA_FORMAT_RGB_DXT1:
 696       return GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
 697    case MESA_FORMAT_RGBA_DXT1:
 698       return GL_COMPRESSED_RGBA_S3TC_DXT1_EXT;
 699    case MESA_FORMAT_RGBA_DXT3:
 700       return GL_COMPRESSED_RGBA_S3TC_DXT3_EXT;
 701    case MESA_FORMAT_RGBA_DXT5:
 702       return GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
 703    case MESA_FORMAT_SRGB_DXT1:
 704       return GL_COMPRESSED_SRGB_S3TC_DXT1_EXT;
 705    case MESA_FORMAT_SRGBA_DXT1:
 706       return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT;
 707    case MESA_FORMAT_SRGBA_DXT3:
 708       return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT;
 709    case MESA_FORMAT_SRGBA_DXT5:
 710       return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT;
 711    case MESA_FORMAT_R_RGTC1_UNORM:
 712       return GL_COMPRESSED_RED_RGTC1;
 713    case MESA_FORMAT_R_RGTC1_SNORM:
 714       return GL_COMPRESSED_SIGNED_RED_RGTC1;
 715    case MESA_FORMAT_RG_RGTC2_UNORM:
 716       return GL_COMPRESSED_RG_RGTC2;
 717    case MESA_FORMAT_RG_RGTC2_SNORM:
 718       return GL_COMPRESSED_SIGNED_RG_RGTC2;
 719
 720    case MESA_FORMAT_L_LATC1_UNORM:
 721       return GL_COMPRESSED_LUMINANCE_LATC1_EXT;
 722    case MESA_FORMAT_L_LATC1_SNORM:
 723       return GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT;
 724    case MESA_FORMAT_LA_LATC2_UNORM:
 725       return GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT;
 726    case MESA_FORMAT_LA_LATC2_SNORM:
 727       return GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT;
 728
 729    case MESA_FORMAT_ETC1_RGB8:
 730       return GL_ETC1_RGB8_OES;
 731    case MESA_FORMAT_ETC2_RGB8:
 732       return GL_COMPRESSED_RGB8_ETC2;
 733    case MESA_FORMAT_ETC2_SRGB8:
 734       return GL_COMPRESSED_SRGB8_ETC2;
 735    case MESA_FORMAT_ETC2_RGBA8_EAC:
 736       return GL_COMPRESSED_RGBA8_ETC2_EAC;
 737    case MESA_FORMAT_ETC2_SRGB8_ALPHA8_EAC:
 738       return GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC;
 739    case MESA_FORMAT_ETC2_R11_EAC:
 740       return GL_COMPRESSED_R11_EAC;
 741    case MESA_FORMAT_ETC2_RG11_EAC:
 742       return GL_COMPRESSED_RG11_EAC;
 743    case MESA_FORMAT_ETC2_SIGNED_R11_EAC:
 744       return GL_COMPRESSED_SIGNED_R11_EAC;
 745    case MESA_FORMAT_ETC2_SIGNED_RG11_EAC:
 746       return GL_COMPRESSED_SIGNED_RG11_EAC;
 747    case MESA_FORMAT_ETC2_RGB8_PUNCHTHROUGH_ALPHA1:
 748       return GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2;
 749    case MESA_FORMAT_ETC2_SRGB8_PUNCHTHROUGH_ALPHA1:
 750       return GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2;
 751
 752    case MESA_FORMAT_BPTC_RGBA_UNORM:
 753       return GL_COMPRESSED_RGBA_BPTC_UNORM;
 754    case MESA_FORMAT_BPTC_SRGB_ALPHA_UNORM:
 755       return GL_COMPRESSED_SRGB_ALPHA_BPTC_UNORM;
 756    case MESA_FORMAT_BPTC_RGB_SIGNED_FLOAT:
 757       return GL_COMPRESSED_RGB_BPTC_SIGNED_FLOAT;
 758    case MESA_FORMAT_BPTC_RGB_UNSIGNED_FLOAT:
 759       return GL_COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT;
 760
 761    case MESA_FORMAT_RGBA_ASTC_4x4:
 762       return GL_COMPRESSED_RGBA_ASTC_4x4_KHR;
 763    case MESA_FORMAT_RGBA_ASTC_5x4:
 764       return GL_COMPRESSED_RGBA_ASTC_5x4_KHR;
 765    case MESA_FORMAT_RGBA_ASTC_5x5:
 766       return GL_COMPRESSED_RGBA_ASTC_5x5_KHR;
 767    case MESA_FORMAT_RGBA_ASTC_6x5:
 768       return GL_COMPRESSED_RGBA_ASTC_6x5_KHR;
 769    case MESA_FORMAT_RGBA_ASTC_6x6:
 770       return GL_COMPRESSED_RGBA_ASTC_6x6_KHR;
 771    case MESA_FORMAT_RGBA_ASTC_8x5:
 772       return GL_COMPRESSED_RGBA_ASTC_8x5_KHR;
 773    case MESA_FORMAT_RGBA_ASTC_8x6:
 774       return GL_COMPRESSED_RGBA_ASTC_8x6_KHR;
 775    case MESA_FORMAT_RGBA_ASTC_8x8:
 776       return GL_COMPRESSED_RGBA_ASTC_8x8_KHR;
 777    case MESA_FORMAT_RGBA_ASTC_10x5:
 778       return GL_COMPRESSED_RGBA_ASTC_10x5_KHR;
 779    case MESA_FORMAT_RGBA_ASTC_10x6:
 780       return GL_COMPRESSED_RGBA_ASTC_10x6_KHR;
 781    case MESA_FORMAT_RGBA_ASTC_10x8:
 782       return GL_COMPRESSED_RGBA_ASTC_10x8_KHR;
 783    case MESA_FORMAT_RGBA_ASTC_10x10:
 784       return GL_COMPRESSED_RGBA_ASTC_10x10_KHR;
 785    case MESA_FORMAT_RGBA_ASTC_12x10:
 786       return GL_COMPRESSED_RGBA_ASTC_12x10_KHR;
 787    case MESA_FORMAT_RGBA_ASTC_12x12:
 788       return GL_COMPRESSED_RGBA_ASTC_12x12_KHR;
 789    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_4x4:
 790       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x4_KHR;
 791    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_5x4:
 792       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x4_KHR;
 793    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_5x5:
 794       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x5_KHR;
 795    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_6x5:
 796       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x5_KHR;
 797    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_6x6:
 798       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x6_KHR;
 799    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_8x5:
 800       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8x5_KHR;
 801    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_8x6:
 802       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8x6_KHR;
 803    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_8x8:
 804       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8x8_KHR;
 805    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_10x5:
 806       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x5_KHR;
 807    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_10x6:
 808       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x6_KHR;
 809    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_10x8:
 810       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x8_KHR;
 811    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_10x10:
 812       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x10_KHR;
 813    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_12x10:
 814       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_12x10_KHR;
 815    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_12x12:
 816       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_12x12_KHR;
 817
 818    case MESA_FORMAT_RGBA_ASTC_3x3x3:
 819       return GL_COMPRESSED_RGBA_ASTC_3x3x3_OES;
 820    case MESA_FORMAT_RGBA_ASTC_4x3x3:
 821       return GL_COMPRESSED_RGBA_ASTC_4x3x3_OES;
 822    case MESA_FORMAT_RGBA_ASTC_4x4x3:
 823       return GL_COMPRESSED_RGBA_ASTC_4x4x3_OES;
 824    case MESA_FORMAT_RGBA_ASTC_4x4x4:
 825       return GL_COMPRESSED_RGBA_ASTC_4x4x4_OES;
 826    case MESA_FORMAT_RGBA_ASTC_5x4x4:
 827       return GL_COMPRESSED_RGBA_ASTC_5x4x4_OES;
 828    case MESA_FORMAT_RGBA_ASTC_5x5x4:
 829       return GL_COMPRESSED_RGBA_ASTC_5x5x4_OES;
 830    case MESA_FORMAT_RGBA_ASTC_5x5x5:
 831       return GL_COMPRESSED_RGBA_ASTC_5x5x5_OES;
 832    case MESA_FORMAT_RGBA_ASTC_6x5x5:
 833       return GL_COMPRESSED_RGBA_ASTC_6x5x5_OES;
 834    case MESA_FORMAT_RGBA_ASTC_6x6x5:
 835       return GL_COMPRESSED_RGBA_ASTC_6x6x5_OES;
 836    case MESA_FORMAT_RGBA_ASTC_6x6x6:
 837       return GL_COMPRESSED_RGBA_ASTC_6x6x6_OES;
 838    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_3x3x3:
 839       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_3x3x3_OES;
 840    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_4x3x3:
 841       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x3x3_OES;
 842    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_4x4x3:
 843       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x4x3_OES;
 844    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_4x4x4:
 845       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x4x4_OES;
 846    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_5x4x4:
 847       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x4x4_OES;
 848    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_5x5x4:
 849       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x5x4_OES;
 850    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_5x5x5:
 851       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x5x5_OES;
 852    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_6x5x5:
 853       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x5x5_OES;
 854    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_6x6x5:
 855       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x6x5_OES;
 856    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_6x6x6:
 857       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x6x6_OES;
 858
 859    case MESA_FORMAT_ATC_RGB:
 860       return GL_ATC_RGB_AMD;
 861    case MESA_FORMAT_ATC_RGBA_EXPLICIT:
 862       return GL_ATC_RGBA_EXPLICIT_ALPHA_AMD;
 863    case MESA_FORMAT_ATC_RGBA_INTERPOLATED:
 864       return GL_ATC_RGBA_INTERPOLATED_ALPHA_AMD;
 865
 866    default:
 867       _mesa_problem(ctx, "Unexpected mesa texture format in"
 868                     " _mesa_compressed_format_to_glenum()");
 869       return 0;
 870    }
 871 }
 872
 873
 874 /*
 875  * Return the address of the pixel at (col, row, img) in a
 876  * compressed texture image.
 877  * \param col, row, img - image position (3D), should be a multiple of the
 878  *                        format's block size.
 879  * \param format - compressed image format
 880  * \param width - image width (stride) in pixels
 881  * \param image - the image address
 882  * \return address of pixel at (row, col, img)
 883  */
 884 GLubyte *
 885 _mesa_compressed_image_address(GLint col, GLint row, GLint img,
 886                                mesa_format mesaFormat,
 887                                GLsizei width, const GLubyte *image)
 888 {
 889    /* XXX only 2D images implemented, not 3D */
 890    const GLuint blockSize = _mesa_get_format_bytes(mesaFormat);
 891    GLuint bw, bh;
 892    GLint offset;
 893
 894    _mesa_get_format_block_size(mesaFormat, &bw, &bh);
 895
 896    assert(col % bw == 0);
 897    assert(row % bh == 0);
 898
 899    offset = ((width + bw - 1) / bw) * (row / bh) + col / bw;
 900    offset *= blockSize;
 901
 902    return (GLubyte *) image + offset;
 903 }
 904
 905
 906 /**
 907  * Return a texel-fetch function for the given format, or NULL if
 908  * invalid format.
 909  */
 910 compressed_fetch_func
 911 _mesa_get_compressed_fetch_func(mesa_format format)
 912 {
 913    switch (_mesa_get_format_layout(format)) {
 914    case MESA_FORMAT_LAYOUT_S3TC:
 915       return _mesa_get_dxt_fetch_func(format);
 916    case MESA_FORMAT_LAYOUT_FXT1:
 917       return _mesa_get_fxt_fetch_func(format);
 918    case MESA_FORMAT_LAYOUT_RGTC:
 919    case MESA_FORMAT_LAYOUT_LATC:
 920       return _mesa_get_compressed_rgtc_func(format);
 921    case MESA_FORMAT_LAYOUT_ETC1:
 922       return _mesa_get_etc_fetch_func(format);
 923    case MESA_FORMAT_LAYOUT_BPTC:
 924       return _mesa_get_bptc_fetch_func(format);
 925    default:
 926       return NULL;
 927    }
 928 }
 929
 930
 931 /**
 932  * Decompress a compressed texture image, returning a GL_RGBA/GL_FLOAT image.
 933  * \param srcRowStride  stride in bytes between rows of blocks in the
 934  *                      compressed source image.
 935  */
 936 void
 937 _mesa_decompress_image(mesa_format format, GLuint width, GLuint height,
 938                        const GLubyte *src, GLint srcRowStride,
 939                        GLfloat *dest)
 940 {
 941    compressed_fetch_func fetch;
 942    GLuint i, j;
 943    GLuint bytes, bw, bh;
 944    GLint stride;
 945
 946    bytes = _mesa_get_format_bytes(format);
 947    _mesa_get_format_block_size(format, &bw, &bh);
 948
 949    fetch = _mesa_get_compressed_fetch_func(format);
 950    if (!fetch) {
 951       _mesa_problem(NULL, "Unexpected format in _mesa_decompress_image()");
 952       return;
 953    }
 954
 955    stride = srcRowStride * bh / bytes;
 956
 957    for (j = 0; j < height; j++) {
 958       for (i = 0; i < width; i++) {
 959          fetch(src, stride, i, j, dest);
 960          dest += 4;
 961       }
 962    }
 963 }