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 #include "imports.h"
  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       return GL_RGB;
 104
 105    case GL_COMPRESSED_RGBA:
 106    case GL_COMPRESSED_SRGB_ALPHA:
 107    case GL_COMPRESSED_RGBA_BPTC_UNORM_ARB:
 108    case GL_COMPRESSED_SRGB_ALPHA_BPTC_UNORM_ARB:
 109    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
 110    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
 111    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
 112    case GL_COMPRESSED_RGBA_FXT1_3DFX:
 113    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT:
 114    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT:
 115    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT:
 116    case GL_COMPRESSED_RGBA8_ETC2_EAC:
 117    case GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC:
 118    case GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2:
 119    case GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2:
 120       return GL_RGBA;
 121
 122    case GL_COMPRESSED_ALPHA:
 123       return GL_ALPHA;
 124
 125    case GL_COMPRESSED_LUMINANCE:
 126    case GL_COMPRESSED_SLUMINANCE:
 127    case GL_COMPRESSED_LUMINANCE_LATC1_EXT:
 128    case GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT:
 129       return GL_LUMINANCE;
 130
 131    case GL_COMPRESSED_LUMINANCE_ALPHA:
 132    case GL_COMPRESSED_SLUMINANCE_ALPHA:
 133    case GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT:
 134    case GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT:
 135    case GL_COMPRESSED_LUMINANCE_ALPHA_3DC_ATI:
 136       return GL_LUMINANCE_ALPHA;
 137
 138    case GL_COMPRESSED_INTENSITY:
 139       return GL_INTENSITY;
 140
 141    default:
 142       return 0;
 143    }
 144 }
 145
 146 /**
 147  * Return list of (and count of) all specific texture compression
 148  * formats that are supported.
 149  *
 150  * Some formats are \b not returned by this function.  The
 151  * \c GL_COMPRESSED_TEXTURE_FORMATS query only returns formats that are
 152  * "suitable for general-purpose usage."  All texture compression extensions
 153  * have taken this to mean either linear RGB or linear RGBA.
 154  *
 155  * The GL_ARB_texture_compress_rgtc spec says:
 156  *
 157  *    "19) Should the GL_NUM_COMPRESSED_TEXTURE_FORMATS and
 158  *        GL_COMPRESSED_TEXTURE_FORMATS queries return the RGTC formats?
 159  *
 160  *        RESOLVED:  No.
 161  *
 162  *        The OpenGL 2.1 specification says "The only values returned
 163  *        by this query [GL_COMPRESSED_TEXTURE_FORMATS"] are those
 164  *        corresponding to formats suitable for general-purpose usage.
 165  *        The renderer will not enumerate formats with restrictions that
 166  *        need to be specifically understood prior to use."
 167  *
 168  *        Compressed textures with just red or red-green components are
 169  *        not general-purpose so should not be returned by these queries
 170  *        because they have restrictions.
 171  *
 172  *        Applications that seek to use the RGTC formats should do so
 173  *        by looking for this extension's name in the string returned by
 174  *        glGetString(GL_EXTENSIONS) rather than
 175  *        what GL_NUM_COMPRESSED_TEXTURE_FORMATS and
 176  *        GL_COMPRESSED_TEXTURE_FORMATS return."
 177  *
 178  * There is nearly identical wording in the GL_EXT_texture_compression_rgtc
 179  * spec.
 180  *
 181  * The GL_EXT_texture_rRGB spec says:
 182  *
 183  *    "22) Should the new COMPRESSED_SRGB_* formats be listed in an
 184  *        implementation's GL_COMPRESSED_TEXTURE_FORMATS list?
 185  *
 186  *        RESOLVED:  No.  Section 3.8.1 says formats listed by
 187  *        GL_COMPRESSED_TEXTURE_FORMATS are "suitable for general-purpose
 188  *        usage."  The non-linear distribution of red, green, and
 189  *        blue for these sRGB compressed formats makes them not really
 190  *        general-purpose."
 191  *
 192  * The GL_EXT_texture_compression_latc spec says:
 193  *
 194  *    "16) Should the GL_NUM_COMPRESSED_TEXTURE_FORMATS and
 195  *        GL_COMPRESSED_TEXTURE_FORMATS queries return the LATC formats?
 196  *
 197  *        RESOLVED:  No.
 198  *
 199  *        The OpenGL 2.1 specification says "The only values returned
 200  *        by this query [GL_COMPRESSED_TEXTURE_FORMATS"] are those
 201  *        corresponding to formats suitable for general-purpose usage.
 202  *        The renderer will not enumerate formats with restrictions that
 203  *        need to be specifically understood prior to use."
 204  *
 205  *        Historically, OpenGL implementation have advertised the RGB and
 206  *        RGBA versions of the S3TC extensions compressed format tokens
 207  *        through this mechanism.
 208  *
 209  *        The specification is not sufficiently clear about what "suitable
 210  *        for general-purpose usage" means.  Historically that seems to mean
 211  *        unsigned RGB or unsigned RGBA.  The DXT1 format supporting alpha
 212  *        (GL_COMPRESSED_RGBA_S3TC_DXT1_EXT) is not exposed in the list (at
 213  *        least for NVIDIA drivers) because the alpha is always 1.0 expect
 214  *        when it is 0.0 when RGB is required to be black.  NVIDIA's even
 215  *        limits itself to true linear RGB or RGBA formats, specifically
 216  *        not including EXT_texture_sRGB's sRGB S3TC compressed formats.
 217  *
 218  *        Adding luminance and luminance-alpha texture formats (and
 219  *        certainly signed versions of luminance and luminance-alpha
 220  *        formats!) invites potential comptaibility problems with old
 221  *        applications using this mechanism since old applications are
 222  *        unlikely to expect non-RGB or non-RGBA formats to be advertised
 223  *        through this mechanism.  However no specific misinteractions
 224  *        with old applications is known.
 225  *
 226  *        Applications that seek to use the LATC formats should do so
 227  *        by looking for this extension's name in the string returned by
 228  *        glGetString(GL_EXTENSIONS) rather than
 229  *        what GL_NUM_COMPRESSED_TEXTURE_FORMATS and
 230  *        GL_COMPRESSED_TEXTURE_FORMATS return."
 231  *
 232  * The KHR_texture_compression_astc_hdr spec says:
 233  *
 234  *    "Interactions with OpenGL 4.2
 235  *
 236  *        OpenGL 4.2 supports the feature that compressed textures can be
 237  *        compressed online, by passing the compressed texture format enum as
 238  *        the internal format when uploading a texture using TexImage1D,
 239  *        TexImage2D or TexImage3D (see Section 3.9.3, Texture Image
 240  *        Specification, subsection Encoding of Special Internal Formats).
 241  *
 242  *        Due to the complexity of the ASTC compression algorithm, it is not
 243  *        usually suitable for online use, and therefore ASTC support will be
 244  *        limited to pre-compressed textures only. Where on-device compression
 245  *        is required, a domain-specific limited compressor will typically
 246  *        be used, and this is therefore not suitable for implementation in
 247  *        the driver.
 248  *
 249  *        In particular, the ASTC format specifiers will not be added to
 250  *        Table 3.14, and thus will not be accepted by the TexImage*D
 251  *        functions, and will not be returned by the (already deprecated)
 252  *        COMPRESSED_TEXTURE_FORMATS query."
 253  *
 254  * There is no formal spec for GL_ATI_texture_compression_3dc.  Since the
 255  * formats added by this extension are luminance-alpha formats, it is
 256  * reasonable to expect them to follow the same rules as
 257  * GL_EXT_texture_compression_latc.  At the very least, Catalyst 11.6 does not
 258  * expose the 3dc formats through this mechanism.
 259  *
 260  * The spec for GL_ARB_texture_compression_bptc doesn't mention whether it
 261  * should be included in GL_COMPRESSED_TEXTURE_FORMATS. However as it takes a
 262  * very long time to compress the textures in this format it's probably not
 263  * very useful as a general format where the GL will have to compress it on
 264  * the fly.
 265  *
 266  * \param ctx  the GL context
 267  * \param formats  the resulting format list (may be NULL).
 268  *
 269  * \return number of formats.
 270  */
 271 GLuint
 272 _mesa_get_compressed_formats(struct gl_context *ctx, GLint *formats)
 273 {
 274    GLuint n = 0;
 275    if (ctx->Extensions.TDFX_texture_compression_FXT1) {
 276       if (formats) {
 277          formats[n++] = GL_COMPRESSED_RGB_FXT1_3DFX;
 278          formats[n++] = GL_COMPRESSED_RGBA_FXT1_3DFX;
 279       }
 280       else {
 281          n += 2;
 282       }
 283    }
 284
 285    if (ctx->Extensions.EXT_texture_compression_s3tc) {
 286       if (formats) {
 287          formats[n++] = GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
 288          formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT3_EXT;
 289          formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
 290       }
 291       else {
 292          n += 3;
 293       }
 294
 295       /* The ES and desktop GL specs diverge here.
 296        *
 297        * In desktop OpenGL, the driver can perform online compression of
 298        * uncompressed texture data.  GL_NUM_COMPRESSED_TEXTURE_FORMATS and
 299        * GL_COMPRESSED_TEXTURE_FORMATS give the application a list of
 300        * formats that it could ask the driver to compress with some
 301        * expectation of quality.  The GL_ARB_texture_compression spec
 302        * calls this "suitable for general-purpose usage."  As noted
 303        * above, this means GL_COMPRESSED_RGBA_S3TC_DXT1_EXT is not
 304        * included in the list.
 305        *
 306        * In OpenGL ES, the driver never performs compression.
 307        * GL_NUM_COMPRESSED_TEXTURE_FORMATS and
 308        * GL_COMPRESSED_TEXTURE_FORMATS give the application a list of
 309        * formats that the driver can receive from the application.  It
 310        * is the *complete* list of formats.  The
 311        * GL_EXT_texture_compression_s3tc spec says:
 312        *
 313        *     "New State for OpenGL ES 2.0.25 and 3.0.2 Specifications
 314        *
 315        *         The queries for NUM_COMPRESSED_TEXTURE_FORMATS and
 316        *         COMPRESSED_TEXTURE_FORMATS include
 317        *         COMPRESSED_RGB_S3TC_DXT1_EXT,
 318        *         COMPRESSED_RGBA_S3TC_DXT1_EXT,
 319        *         COMPRESSED_RGBA_S3TC_DXT3_EXT, and
 320        *         COMPRESSED_RGBA_S3TC_DXT5_EXT."
 321        *
 322        * Note that the addition is only to the OpenGL ES specification!
 323        */
 324       if (_mesa_is_gles(ctx)) {
 325          if (formats) {
 326             formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT1_EXT;
 327          } else {
 328             n += 1;
 329          }
 330       }
 331    }
 332
 333    /* The GL_OES_compressed_ETC1_RGB8_texture spec says:
 334     *
 335     *     "New State
 336     *
 337     *         The queries for NUM_COMPRESSED_TEXTURE_FORMATS and
 338     *         COMPRESSED_TEXTURE_FORMATS include ETC1_RGB8_OES."
 339     */
 340    if (_mesa_is_gles(ctx)
 341        && ctx->Extensions.OES_compressed_ETC1_RGB8_texture) {
 342       if (formats) {
 343          formats[n++] = GL_ETC1_RGB8_OES;
 344       }
 345       else {
 346          n += 1;
 347       }
 348    }
 349
 350    if (ctx->API == API_OPENGLES) {
 351       if (formats) {
 352          formats[n++] = GL_PALETTE4_RGB8_OES;
 353          formats[n++] = GL_PALETTE4_RGBA8_OES;
 354          formats[n++] = GL_PALETTE4_R5_G6_B5_OES;
 355          formats[n++] = GL_PALETTE4_RGBA4_OES;
 356          formats[n++] = GL_PALETTE4_RGB5_A1_OES;
 357          formats[n++] = GL_PALETTE8_RGB8_OES;
 358          formats[n++] = GL_PALETTE8_RGBA8_OES;
 359          formats[n++] = GL_PALETTE8_R5_G6_B5_OES;
 360          formats[n++] = GL_PALETTE8_RGBA4_OES;
 361          formats[n++] = GL_PALETTE8_RGB5_A1_OES;
 362       }
 363       else {
 364          n += 10;
 365       }
 366    }
 367
 368    if (_mesa_is_gles3(ctx)) {
 369       if (formats) {
 370          formats[n++] = GL_COMPRESSED_RGB8_ETC2;
 371          formats[n++] = GL_COMPRESSED_SRGB8_ETC2;
 372          formats[n++] = GL_COMPRESSED_RGBA8_ETC2_EAC;
 373          formats[n++] = GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC;
 374          formats[n++] = GL_COMPRESSED_R11_EAC;
 375          formats[n++] = GL_COMPRESSED_RG11_EAC;
 376          formats[n++] = GL_COMPRESSED_SIGNED_R11_EAC;
 377          formats[n++] = GL_COMPRESSED_SIGNED_RG11_EAC;
 378          formats[n++] = GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2;
 379          formats[n++] = GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2;
 380       }
 381       else {
 382          n += 10;
 383       }
 384    }
 385    return n;
 386 }
 387
 388
 389 /**
 390  * Convert a compressed MESA_FORMAT_x to a GLenum.
 391  */
 392 mesa_format
 393 _mesa_glenum_to_compressed_format(GLenum format)
 394 {
 395    switch (format) {
 396    case GL_COMPRESSED_RGB_FXT1_3DFX:
 397       return MESA_FORMAT_RGB_FXT1;
 398    case GL_COMPRESSED_RGBA_FXT1_3DFX:
 399       return MESA_FORMAT_RGBA_FXT1;
 400
 401    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
 402    case GL_RGB_S3TC:
 403    case GL_RGB4_S3TC:
 404       return MESA_FORMAT_RGB_DXT1;
 405    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
 406       return MESA_FORMAT_RGBA_DXT1;
 407    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
 408    case GL_RGBA_S3TC:
 409    case GL_RGBA4_S3TC:
 410       return MESA_FORMAT_RGBA_DXT3;
 411    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
 412       return MESA_FORMAT_RGBA_DXT5;
 413
 414    case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT:
 415       return MESA_FORMAT_SRGB_DXT1;
 416    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT:
 417       return MESA_FORMAT_SRGBA_DXT1;
 418    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT:
 419       return MESA_FORMAT_SRGBA_DXT3;
 420    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT:
 421       return MESA_FORMAT_SRGBA_DXT5;
 422
 423    case GL_COMPRESSED_RED_RGTC1:
 424       return MESA_FORMAT_R_RGTC1_UNORM;
 425    case GL_COMPRESSED_SIGNED_RED_RGTC1:
 426       return MESA_FORMAT_R_RGTC1_SNORM;
 427    case GL_COMPRESSED_RG_RGTC2:
 428       return MESA_FORMAT_RG_RGTC2_UNORM;
 429    case GL_COMPRESSED_SIGNED_RG_RGTC2:
 430       return MESA_FORMAT_RG_RGTC2_SNORM;
 431
 432    case GL_COMPRESSED_LUMINANCE_LATC1_EXT:
 433       return MESA_FORMAT_L_LATC1_UNORM;
 434    case GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT:
 435       return MESA_FORMAT_L_LATC1_SNORM;
 436    case GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT:
 437    case GL_COMPRESSED_LUMINANCE_ALPHA_3DC_ATI:
 438       return MESA_FORMAT_LA_LATC2_UNORM;
 439    case GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT:
 440       return MESA_FORMAT_LA_LATC2_SNORM;
 441
 442    case GL_ETC1_RGB8_OES:
 443       return MESA_FORMAT_ETC1_RGB8;
 444    case GL_COMPRESSED_RGB8_ETC2:
 445       return MESA_FORMAT_ETC2_RGB8;
 446    case GL_COMPRESSED_SRGB8_ETC2:
 447       return MESA_FORMAT_ETC2_SRGB8;
 448    case GL_COMPRESSED_RGBA8_ETC2_EAC:
 449       return MESA_FORMAT_ETC2_RGBA8_EAC;
 450    case GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC:
 451       return MESA_FORMAT_ETC2_SRGB8_ALPHA8_EAC;
 452    case GL_COMPRESSED_R11_EAC:
 453       return MESA_FORMAT_ETC2_R11_EAC;
 454    case GL_COMPRESSED_RG11_EAC:
 455       return MESA_FORMAT_ETC2_RG11_EAC;
 456    case GL_COMPRESSED_SIGNED_R11_EAC:
 457       return MESA_FORMAT_ETC2_SIGNED_R11_EAC;
 458    case GL_COMPRESSED_SIGNED_RG11_EAC:
 459       return MESA_FORMAT_ETC2_SIGNED_RG11_EAC;
 460    case GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2:
 461       return MESA_FORMAT_ETC2_RGB8_PUNCHTHROUGH_ALPHA1;
 462    case GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2:
 463       return MESA_FORMAT_ETC2_SRGB8_PUNCHTHROUGH_ALPHA1;
 464
 465    case GL_COMPRESSED_RGBA_BPTC_UNORM:
 466       return MESA_FORMAT_BPTC_RGBA_UNORM;
 467    case GL_COMPRESSED_SRGB_ALPHA_BPTC_UNORM:
 468       return MESA_FORMAT_BPTC_SRGB_ALPHA_UNORM;
 469    case GL_COMPRESSED_RGB_BPTC_SIGNED_FLOAT:
 470       return MESA_FORMAT_BPTC_RGB_SIGNED_FLOAT;
 471    case GL_COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT:
 472       return MESA_FORMAT_BPTC_RGB_UNSIGNED_FLOAT;
 473
 474    case GL_COMPRESSED_RGBA_ASTC_4x4_KHR:
 475       return MESA_FORMAT_RGBA_ASTC_4x4;
 476    case GL_COMPRESSED_RGBA_ASTC_5x4_KHR:
 477       return MESA_FORMAT_RGBA_ASTC_5x4;
 478    case GL_COMPRESSED_RGBA_ASTC_5x5_KHR:
 479       return MESA_FORMAT_RGBA_ASTC_5x5;
 480    case GL_COMPRESSED_RGBA_ASTC_6x5_KHR:
 481       return MESA_FORMAT_RGBA_ASTC_6x5;
 482    case GL_COMPRESSED_RGBA_ASTC_6x6_KHR:
 483       return MESA_FORMAT_RGBA_ASTC_6x6;
 484    case GL_COMPRESSED_RGBA_ASTC_8x5_KHR:
 485       return MESA_FORMAT_RGBA_ASTC_8x5;
 486    case GL_COMPRESSED_RGBA_ASTC_8x6_KHR:
 487       return MESA_FORMAT_RGBA_ASTC_8x6;
 488    case GL_COMPRESSED_RGBA_ASTC_8x8_KHR:
 489       return MESA_FORMAT_RGBA_ASTC_8x8;
 490    case GL_COMPRESSED_RGBA_ASTC_10x5_KHR:
 491       return MESA_FORMAT_RGBA_ASTC_10x5;
 492    case GL_COMPRESSED_RGBA_ASTC_10x6_KHR:
 493       return MESA_FORMAT_RGBA_ASTC_10x6;
 494    case GL_COMPRESSED_RGBA_ASTC_10x8_KHR:
 495       return MESA_FORMAT_RGBA_ASTC_10x8;
 496    case GL_COMPRESSED_RGBA_ASTC_10x10_KHR:
 497       return MESA_FORMAT_RGBA_ASTC_10x10;
 498    case GL_COMPRESSED_RGBA_ASTC_12x10_KHR:
 499       return MESA_FORMAT_RGBA_ASTC_12x10;
 500    case GL_COMPRESSED_RGBA_ASTC_12x12_KHR:
 501       return MESA_FORMAT_RGBA_ASTC_12x12;
 502    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x4_KHR:
 503       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_4x4;
 504    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x4_KHR:
 505       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_5x4;
 506    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x5_KHR:
 507       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_5x5;
 508    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x5_KHR:
 509       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_6x5;
 510    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x6_KHR:
 511       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_6x6;
 512    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8x5_KHR:
 513       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_8x5;
 514    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8x6_KHR:
 515       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_8x6;
 516    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8x8_KHR:
 517       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_8x8;
 518    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x5_KHR:
 519       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_10x5;
 520    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x6_KHR:
 521       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_10x6;
 522    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x8_KHR:
 523       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_10x8;
 524    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x10_KHR:
 525       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_10x10;
 526    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_12x10_KHR:
 527       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_12x10;
 528    case GL_COMPRESSED_SRGB8_ALPHA8_ASTC_12x12_KHR:
 529       return MESA_FORMAT_SRGB8_ALPHA8_ASTC_12x12;
 530
 531    default:
 532       return MESA_FORMAT_NONE;
 533    }
 534 }
 535
 536
 537 /**
 538  * Given a compressed MESA_FORMAT_x value, return the corresponding
 539  * GLenum for that format.
 540  * This is needed for glGetTexLevelParameter(GL_TEXTURE_INTERNAL_FORMAT)
 541  * which must return the specific texture format used when the user might
 542  * have originally specified a generic compressed format in their
 543  * glTexImage2D() call.
 544  * For non-compressed textures, we always return the user-specified
 545  * internal format unchanged.
 546  */
 547 GLenum
 548 _mesa_compressed_format_to_glenum(struct gl_context *ctx, mesa_format mesaFormat)
 549 {
 550    switch (mesaFormat) {
 551    case MESA_FORMAT_RGB_FXT1:
 552       return GL_COMPRESSED_RGB_FXT1_3DFX;
 553    case MESA_FORMAT_RGBA_FXT1:
 554       return GL_COMPRESSED_RGBA_FXT1_3DFX;
 555    case MESA_FORMAT_RGB_DXT1:
 556       return GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
 557    case MESA_FORMAT_RGBA_DXT1:
 558       return GL_COMPRESSED_RGBA_S3TC_DXT1_EXT;
 559    case MESA_FORMAT_RGBA_DXT3:
 560       return GL_COMPRESSED_RGBA_S3TC_DXT3_EXT;
 561    case MESA_FORMAT_RGBA_DXT5:
 562       return GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
 563    case MESA_FORMAT_SRGB_DXT1:
 564       return GL_COMPRESSED_SRGB_S3TC_DXT1_EXT;
 565    case MESA_FORMAT_SRGBA_DXT1:
 566       return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT;
 567    case MESA_FORMAT_SRGBA_DXT3:
 568       return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT;
 569    case MESA_FORMAT_SRGBA_DXT5:
 570       return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT;
 571    case MESA_FORMAT_R_RGTC1_UNORM:
 572       return GL_COMPRESSED_RED_RGTC1;
 573    case MESA_FORMAT_R_RGTC1_SNORM:
 574       return GL_COMPRESSED_SIGNED_RED_RGTC1;
 575    case MESA_FORMAT_RG_RGTC2_UNORM:
 576       return GL_COMPRESSED_RG_RGTC2;
 577    case MESA_FORMAT_RG_RGTC2_SNORM:
 578       return GL_COMPRESSED_SIGNED_RG_RGTC2;
 579
 580    case MESA_FORMAT_L_LATC1_UNORM:
 581       return GL_COMPRESSED_LUMINANCE_LATC1_EXT;
 582    case MESA_FORMAT_L_LATC1_SNORM:
 583       return GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT;
 584    case MESA_FORMAT_LA_LATC2_UNORM:
 585       return GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT;
 586    case MESA_FORMAT_LA_LATC2_SNORM:
 587       return GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT;
 588
 589    case MESA_FORMAT_ETC1_RGB8:
 590       return GL_ETC1_RGB8_OES;
 591    case MESA_FORMAT_ETC2_RGB8:
 592       return GL_COMPRESSED_RGB8_ETC2;
 593    case MESA_FORMAT_ETC2_SRGB8:
 594       return GL_COMPRESSED_SRGB8_ETC2;
 595    case MESA_FORMAT_ETC2_RGBA8_EAC:
 596       return GL_COMPRESSED_RGBA8_ETC2_EAC;
 597    case MESA_FORMAT_ETC2_SRGB8_ALPHA8_EAC:
 598       return GL_COMPRESSED_SRGB8_ALPHA8_ETC2_EAC;
 599    case MESA_FORMAT_ETC2_R11_EAC:
 600       return GL_COMPRESSED_R11_EAC;
 601    case MESA_FORMAT_ETC2_RG11_EAC:
 602       return GL_COMPRESSED_RG11_EAC;
 603    case MESA_FORMAT_ETC2_SIGNED_R11_EAC:
 604       return GL_COMPRESSED_SIGNED_R11_EAC;
 605    case MESA_FORMAT_ETC2_SIGNED_RG11_EAC:
 606       return GL_COMPRESSED_SIGNED_RG11_EAC;
 607    case MESA_FORMAT_ETC2_RGB8_PUNCHTHROUGH_ALPHA1:
 608       return GL_COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2;
 609    case MESA_FORMAT_ETC2_SRGB8_PUNCHTHROUGH_ALPHA1:
 610       return GL_COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2;
 611
 612    case MESA_FORMAT_BPTC_RGBA_UNORM:
 613       return GL_COMPRESSED_RGBA_BPTC_UNORM;
 614    case MESA_FORMAT_BPTC_SRGB_ALPHA_UNORM:
 615       return GL_COMPRESSED_SRGB_ALPHA_BPTC_UNORM;
 616    case MESA_FORMAT_BPTC_RGB_SIGNED_FLOAT:
 617       return GL_COMPRESSED_RGB_BPTC_SIGNED_FLOAT;
 618    case MESA_FORMAT_BPTC_RGB_UNSIGNED_FLOAT:
 619       return GL_COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT;
 620
 621    case MESA_FORMAT_RGBA_ASTC_4x4:
 622       return GL_COMPRESSED_RGBA_ASTC_4x4_KHR;
 623    case MESA_FORMAT_RGBA_ASTC_5x4:
 624       return GL_COMPRESSED_RGBA_ASTC_5x4_KHR;
 625    case MESA_FORMAT_RGBA_ASTC_5x5:
 626       return GL_COMPRESSED_RGBA_ASTC_5x5_KHR;
 627    case MESA_FORMAT_RGBA_ASTC_6x5:
 628       return GL_COMPRESSED_RGBA_ASTC_6x5_KHR;
 629    case MESA_FORMAT_RGBA_ASTC_6x6:
 630       return GL_COMPRESSED_RGBA_ASTC_6x6_KHR;
 631    case MESA_FORMAT_RGBA_ASTC_8x5:
 632       return GL_COMPRESSED_RGBA_ASTC_8x5_KHR;
 633    case MESA_FORMAT_RGBA_ASTC_8x6:
 634       return GL_COMPRESSED_RGBA_ASTC_8x6_KHR;
 635    case MESA_FORMAT_RGBA_ASTC_8x8:
 636       return GL_COMPRESSED_RGBA_ASTC_8x8_KHR;
 637    case MESA_FORMAT_RGBA_ASTC_10x5:
 638       return GL_COMPRESSED_RGBA_ASTC_10x5_KHR;
 639    case MESA_FORMAT_RGBA_ASTC_10x6:
 640       return GL_COMPRESSED_RGBA_ASTC_10x6_KHR;
 641    case MESA_FORMAT_RGBA_ASTC_10x8:
 642       return GL_COMPRESSED_RGBA_ASTC_10x8_KHR;
 643    case MESA_FORMAT_RGBA_ASTC_10x10:
 644       return GL_COMPRESSED_RGBA_ASTC_10x10_KHR;
 645    case MESA_FORMAT_RGBA_ASTC_12x10:
 646       return GL_COMPRESSED_RGBA_ASTC_12x10_KHR;
 647    case MESA_FORMAT_RGBA_ASTC_12x12:
 648       return GL_COMPRESSED_RGBA_ASTC_12x12_KHR;
 649    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_4x4:
 650       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_4x4_KHR;
 651    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_5x4:
 652       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x4_KHR;
 653    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_5x5:
 654       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_5x5_KHR;
 655    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_6x5:
 656       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x5_KHR;
 657    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_6x6:
 658       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_6x6_KHR;
 659    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_8x5:
 660       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8x5_KHR;
 661    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_8x6:
 662       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8x6_KHR;
 663    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_8x8:
 664       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_8x8_KHR;
 665    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_10x5:
 666       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x5_KHR;
 667    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_10x6:
 668       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x6_KHR;
 669    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_10x8:
 670       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x8_KHR;
 671    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_10x10:
 672       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_10x10_KHR;
 673    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_12x10:
 674       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_12x10_KHR;
 675    case MESA_FORMAT_SRGB8_ALPHA8_ASTC_12x12:
 676       return GL_COMPRESSED_SRGB8_ALPHA8_ASTC_12x12_KHR;
 677
 678    default:
 679       _mesa_problem(ctx, "Unexpected mesa texture format in"
 680                     " _mesa_compressed_format_to_glenum()");
 681       return 0;
 682    }
 683 }
 684
 685
 686 /*
 687  * Return the address of the pixel at (col, row, img) in a
 688  * compressed texture image.
 689  * \param col, row, img - image position (3D), should be a multiple of the
 690  *                        format's block size.
 691  * \param format - compressed image format
 692  * \param width - image width (stride) in pixels
 693  * \param image - the image address
 694  * \return address of pixel at (row, col, img)
 695  */
 696 GLubyte *
 697 _mesa_compressed_image_address(GLint col, GLint row, GLint img,
 698                                mesa_format mesaFormat,
 699                                GLsizei width, const GLubyte *image)
 700 {
 701    /* XXX only 2D images implemented, not 3D */
 702    const GLuint blockSize = _mesa_get_format_bytes(mesaFormat);
 703    GLuint bw, bh;
 704    GLint offset;
 705
 706    _mesa_get_format_block_size(mesaFormat, &bw, &bh);
 707
 708    assert(col % bw == 0);
 709    assert(row % bh == 0);
 710
 711    offset = ((width + bw - 1) / bw) * (row / bh) + col / bw;
 712    offset *= blockSize;
 713
 714    return (GLubyte *) image + offset;
 715 }
 716
 717
 718 /**
 719  * Return a texel-fetch function for the given format, or NULL if
 720  * invalid format.
 721  */
 722 compressed_fetch_func
 723 _mesa_get_compressed_fetch_func(mesa_format format)
 724 {
 725    switch (_mesa_get_format_layout(format)) {
 726    case MESA_FORMAT_LAYOUT_S3TC:
 727       return _mesa_get_dxt_fetch_func(format);
 728    case MESA_FORMAT_LAYOUT_FXT1:
 729       return _mesa_get_fxt_fetch_func(format);
 730    case MESA_FORMAT_LAYOUT_RGTC:
 731       return _mesa_get_compressed_rgtc_func(format);
 732    case MESA_FORMAT_LAYOUT_ETC1:
 733       return _mesa_get_etc_fetch_func(format);
 734    case MESA_FORMAT_LAYOUT_BPTC:
 735       return _mesa_get_bptc_fetch_func(format);
 736    default:
 737       return NULL;
 738    }
 739 }
 740
 741
 742 /**
 743  * Decompress a compressed texture image, returning a GL_RGBA/GL_FLOAT image.
 744  * \param srcRowStride  stride in bytes between rows of blocks in the
 745  *                      compressed source image.
 746  */
 747 void
 748 _mesa_decompress_image(mesa_format format, GLuint width, GLuint height,
 749                        const GLubyte *src, GLint srcRowStride,
 750                        GLfloat *dest)
 751 {
 752    compressed_fetch_func fetch;
 753    GLuint i, j;
 754    GLuint bytes, bw, bh;
 755    GLint stride;
 756
 757    bytes = _mesa_get_format_bytes(format);
 758    _mesa_get_format_block_size(format, &bw, &bh);
 759
 760    fetch = _mesa_get_compressed_fetch_func(format);
 761    if (!fetch) {
 762       _mesa_problem(NULL, "Unexpected format in _mesa_decompress_image()");
 763       return;
 764    }
 765
 766    stride = srcRowStride * bh / bytes;
 767
 768    for (j = 0; j < height; j++) {
 769       for (i = 0; i < width; i++) {
 770          fetch(src, stride, i, j, dest);
 771          dest += 4;
 772       }
 773    }
 774 }