src/mesa/main/texcompress.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.5.1
   4  *
   5  * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
   6  * Copyright (c) 2008 VMware, Inc.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the "Software"),
  10  * to deal in the Software without restriction, including without limitation
  11  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12  * and/or sell copies of the Software, and to permit persons to whom the
  13  * Software is furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included
  16  * in all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  21  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  22  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  23  * CONNECTION WITH THE SOFTWARE OR THE USE OR 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 "colormac.h"
  36 #include "formats.h"
  37 #include "mfeatures.h"
  38 #include "mtypes.h"
  39 #include "texcompress.h"
  40
  41
  42 /**
  43  * Get the GL base format of a specified GL compressed texture format
  44  *
  45  * From page 232 of the OpenGL 3.3 (Compatiblity Profile) spec:
  46  *
  47  *     "Compressed Internal Format      Base Internal Format    Type
  48  *     ---------------------------     --------------------    ---------
  49  *     COMPRESSED_ALPHA                ALPHA                   Generic
  50  *     COMPRESSED_LUMINANCE            LUMINANCE               Generic
  51  *     COMPRESSED_LUMINANCE_ALPHA      LUMINANCE_ALPHA         Generic
  52  *     COMPRESSED_INTENSITY            INTENSITY               Generic
  53  *     COMPRESSED_RED                  RED                     Generic
  54  *     COMPRESSED_RG                   RG                      Generic
  55  *     COMPRESSED_RGB                  RGB                     Generic
  56  *     COMPRESSED_RGBA                 RGBA                    Generic
  57  *     COMPRESSED_SRGB                 RGB                     Generic
  58  *     COMPRESSED_SRGB_ALPHA           RGBA                    Generic
  59  *     COMPRESSED_SLUMINANCE           LUMINANCE               Generic
  60  *     COMPRESSED_SLUMINANCE_ALPHA     LUMINANCE_ALPHA         Generic
  61  *     COMPRESSED_RED_RGTC1            RED                     Specific
  62  *     COMPRESSED_SIGNED_RED_RGTC1     RED                     Specific
  63  *     COMPRESSED_RG_RGTC2             RG                      Specific
  64  *     COMPRESSED_SIGNED_RG_RGTC2      RG                      Specific"
  65  *
  66  * \return
  67  * The base format of \c format if \c format is a compressed format (either
  68  * generic or specific.  Otherwise 0 is returned.
  69  */
  70 GLenum
  71 _mesa_gl_compressed_format_base_format(GLenum format)
  72 {
  73    switch (format) {
  74    case GL_COMPRESSED_RED:
  75    case GL_COMPRESSED_RED_RGTC1:
  76    case GL_COMPRESSED_SIGNED_RED_RGTC1:
  77       return GL_RED;
  78
  79    case GL_COMPRESSED_RG:
  80    case GL_COMPRESSED_RG_RGTC2:
  81    case GL_COMPRESSED_SIGNED_RG_RGTC2:
  82       return GL_RG;
  83
  84    case GL_COMPRESSED_RGB:
  85    case GL_COMPRESSED_SRGB:
  86    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
  87    case GL_COMPRESSED_RGB_FXT1_3DFX:
  88    case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT:
  89       return GL_RGB;
  90
  91    case GL_COMPRESSED_RGBA:
  92    case GL_COMPRESSED_SRGB_ALPHA:
  93    case GL_COMPRESSED_RGBA_BPTC_UNORM_ARB:
  94    case GL_COMPRESSED_SRGB_ALPHA_BPTC_UNORM_ARB:
  95    case GL_COMPRESSED_RGB_BPTC_SIGNED_FLOAT_ARB:
  96    case GL_COMPRESSED_RGB_BPTC_UNSIGNED_FLOAT_ARB:
  97    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
  98    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
  99    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
 100    case GL_COMPRESSED_RGBA_FXT1_3DFX:
 101    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT:
 102    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT:
 103    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT:
 104       return GL_RGBA;
 105
 106    case GL_COMPRESSED_ALPHA:
 107       return GL_ALPHA;
 108
 109    case GL_COMPRESSED_LUMINANCE:
 110    case GL_COMPRESSED_SLUMINANCE:
 111    case GL_COMPRESSED_LUMINANCE_LATC1_EXT:
 112    case GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT:
 113       return GL_LUMINANCE;
 114
 115    case GL_COMPRESSED_LUMINANCE_ALPHA:
 116    case GL_COMPRESSED_SLUMINANCE_ALPHA:
 117    case GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT:
 118    case GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT:
 119    case GL_COMPRESSED_LUMINANCE_ALPHA_3DC_ATI:
 120       return GL_LUMINANCE_ALPHA;
 121
 122    case GL_COMPRESSED_INTENSITY:
 123       return GL_INTENSITY;
 124
 125    default:
 126       return 0;
 127    }
 128 }
 129
 130 /**
 131  * Return list of (and count of) all specific texture compression
 132  * formats that are supported.
 133  *
 134  * Some formats are \b not returned by this function.  The
 135  * \c GL_COMPRESSED_TEXTURE_FORMATS query only returns formats that are
 136  * "suitable for general-purpose usage."  All texture compression extensions
 137  * have taken this to mean either linear RGB or linear RGBA.
 138  *
 139  * The GL_ARB_texture_compress_rgtc spec says:
 140  *
 141  *    "19) Should the GL_NUM_COMPRESSED_TEXTURE_FORMATS and
 142  *        GL_COMPRESSED_TEXTURE_FORMATS queries return the RGTC formats?
 143  *
 144  *        RESOLVED:  No.
 145  *
 146  *        The OpenGL 2.1 specification says "The only values returned
 147  *        by this query [GL_COMPRESSED_TEXTURE_FORMATS"] are those
 148  *        corresponding to formats suitable for general-purpose usage.
 149  *        The renderer will not enumerate formats with restrictions that
 150  *        need to be specifically understood prior to use."
 151  *
 152  *        Compressed textures with just red or red-green components are
 153  *        not general-purpose so should not be returned by these queries
 154  *        because they have restrictions.
 155  *
 156  *        Applications that seek to use the RGTC formats should do so
 157  *        by looking for this extension's name in the string returned by
 158  *        glGetString(GL_EXTENSIONS) rather than
 159  *        what GL_NUM_COMPRESSED_TEXTURE_FORMATS and
 160  *        GL_COMPRESSED_TEXTURE_FORMATS return."
 161  *
 162  * There is nearly identical wording in the GL_EXT_texture_compression_rgtc
 163  * spec.
 164  *
 165  * The GL_EXT_texture_rRGB spec says:
 166  *
 167  *    "22) Should the new COMPRESSED_SRGB_* formats be listed in an
 168  *        implementation's GL_COMPRESSED_TEXTURE_FORMATS list?
 169  *
 170  *        RESOLVED:  No.  Section 3.8.1 says formats listed by
 171  *        GL_COMPRESSED_TEXTURE_FORMATS are "suitable for general-purpose
 172  *        usage."  The non-linear distribution of red, green, and
 173  *        blue for these sRGB compressed formats makes them not really
 174  *        general-purpose."
 175  *
 176  * The GL_EXT_texture_compression_latc spec says:
 177  *
 178  *    "16) Should the GL_NUM_COMPRESSED_TEXTURE_FORMATS and
 179  *        GL_COMPRESSED_TEXTURE_FORMATS queries return the LATC formats?
 180  *
 181  *        RESOLVED:  No.
 182  *
 183  *        The OpenGL 2.1 specification says "The only values returned
 184  *        by this query [GL_COMPRESSED_TEXTURE_FORMATS"] are those
 185  *        corresponding to formats suitable for general-purpose usage.
 186  *        The renderer will not enumerate formats with restrictions that
 187  *        need to be specifically understood prior to use."
 188  *
 189  *        Historically, OpenGL implementation have advertised the RGB and
 190  *        RGBA versions of the S3TC extensions compressed format tokens
 191  *        through this mechanism.
 192  *
 193  *        The specification is not sufficiently clear about what "suitable
 194  *        for general-purpose usage" means.  Historically that seems to mean
 195  *        unsigned RGB or unsigned RGBA.  The DXT1 format supporting alpha
 196  *        (GL_COMPRESSED_RGBA_S3TC_DXT1_EXT) is not exposed in the list (at
 197  *        least for NVIDIA drivers) because the alpha is always 1.0 expect
 198  *        when it is 0.0 when RGB is required to be black.  NVIDIA's even
 199  *        limits itself to true linear RGB or RGBA formats, specifically
 200  *        not including EXT_texture_sRGB's sRGB S3TC compressed formats.
 201  *
 202  *        Adding luminance and luminance-alpha texture formats (and
 203  *        certainly signed versions of luminance and luminance-alpha
 204  *        formats!) invites potential comptaibility problems with old
 205  *        applications using this mechanism since old applications are
 206  *        unlikely to expect non-RGB or non-RGBA formats to be advertised
 207  *        through this mechanism.  However no specific misinteractions
 208  *        with old applications is known.
 209  *
 210  *        Applications that seek to use the LATC formats should do so
 211  *        by looking for this extension's name in the string returned by
 212  *        glGetString(GL_EXTENSIONS) rather than
 213  *        what GL_NUM_COMPRESSED_TEXTURE_FORMATS and
 214  *        GL_COMPRESSED_TEXTURE_FORMATS return."
 215  *
 216  * There is no formal spec for GL_ATI_texture_compression_3dc.  Since the
 217  * formats added by this extension are luminance-alpha formats, it is
 218  * reasonable to expect them to follow the same rules as
 219  * GL_EXT_texture_compression_latc.  At the very least, Catalyst 11.6 does not
 220  * expose the 3dc formats through this mechanism.
 221  *
 222  * \param ctx  the GL context
 223  * \param formats  the resulting format list (may be NULL).
 224  *
 225  * \return number of formats.
 226  */
 227 GLuint
 228 _mesa_get_compressed_formats(struct gl_context *ctx, GLint *formats)
 229 {
 230    GLuint n = 0;
 231    if (ctx->Extensions.TDFX_texture_compression_FXT1) {
 232       if (formats) {
 233          formats[n++] = GL_COMPRESSED_RGB_FXT1_3DFX;
 234          formats[n++] = GL_COMPRESSED_RGBA_FXT1_3DFX;
 235       }
 236       else {
 237          n += 2;
 238       }
 239    }
 240
 241    if (ctx->Extensions.EXT_texture_compression_s3tc) {
 242       if (formats) {
 243          formats[n++] = GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
 244          formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT3_EXT;
 245          formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
 246       }
 247       else {
 248          n += 3;
 249       }
 250    }
 251    if (ctx->Extensions.S3_s3tc) {
 252       if (formats) {
 253          formats[n++] = GL_RGB_S3TC;
 254          formats[n++] = GL_RGB4_S3TC;
 255          formats[n++] = GL_RGBA_S3TC;
 256          formats[n++] = GL_RGBA4_S3TC;
 257       }
 258       else {
 259          n += 4;
 260       }
 261    }
 262    return n;
 263
 264 #if FEATURE_ES1 || FEATURE_ES2
 265    if (formats) {
 266       formats[n++] = GL_PALETTE4_RGB8_OES;
 267       formats[n++] = GL_PALETTE4_RGBA8_OES;
 268       formats[n++] = GL_PALETTE4_R5_G6_B5_OES;
 269       formats[n++] = GL_PALETTE4_RGBA4_OES;
 270       formats[n++] = GL_PALETTE4_RGB5_A1_OES;
 271       formats[n++] = GL_PALETTE8_RGB8_OES;
 272       formats[n++] = GL_PALETTE8_RGBA8_OES;
 273       formats[n++] = GL_PALETTE8_R5_G6_B5_OES;
 274       formats[n++] = GL_PALETTE8_RGBA4_OES;
 275       formats[n++] = GL_PALETTE8_RGB5_A1_OES;
 276    }
 277    else {
 278       n += 10;
 279    }
 280 #endif
 281 }
 282
 283
 284 /**
 285  * Convert a compressed MESA_FORMAT_x to a GLenum.
 286  */
 287 gl_format
 288 _mesa_glenum_to_compressed_format(GLenum format)
 289 {
 290    switch (format) {
 291    case GL_COMPRESSED_RGB_FXT1_3DFX:
 292       return MESA_FORMAT_RGB_FXT1;
 293    case GL_COMPRESSED_RGBA_FXT1_3DFX:
 294       return MESA_FORMAT_RGBA_FXT1;
 295
 296    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
 297    case GL_RGB_S3TC:
 298       return MESA_FORMAT_RGB_DXT1;
 299    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
 300    case GL_RGB4_S3TC:
 301       return MESA_FORMAT_RGBA_DXT1;
 302    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
 303    case GL_RGBA_S3TC:
 304       return MESA_FORMAT_RGBA_DXT3;
 305    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
 306    case GL_RGBA4_S3TC:
 307       return MESA_FORMAT_RGBA_DXT5;
 308
 309    case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT:
 310       return MESA_FORMAT_SRGB_DXT1;
 311    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT:
 312       return MESA_FORMAT_SRGBA_DXT1;
 313    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT:
 314       return MESA_FORMAT_SRGBA_DXT3;
 315    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT:
 316       return MESA_FORMAT_SRGBA_DXT5;
 317
 318    case GL_COMPRESSED_RED_RGTC1:
 319       return MESA_FORMAT_RED_RGTC1;
 320    case GL_COMPRESSED_SIGNED_RED_RGTC1:
 321       return MESA_FORMAT_SIGNED_RED_RGTC1;
 322    case GL_COMPRESSED_RG_RGTC2:
 323       return MESA_FORMAT_RG_RGTC2;
 324    case GL_COMPRESSED_SIGNED_RG_RGTC2:
 325       return MESA_FORMAT_SIGNED_RG_RGTC2;
 326
 327    case GL_COMPRESSED_LUMINANCE_LATC1_EXT:
 328       return MESA_FORMAT_L_LATC1;
 329    case GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT:
 330       return MESA_FORMAT_SIGNED_L_LATC1;
 331    case GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT:
 332    case GL_COMPRESSED_LUMINANCE_ALPHA_3DC_ATI:
 333       return MESA_FORMAT_LA_LATC2;
 334    case GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT:
 335       return MESA_FORMAT_SIGNED_LA_LATC2;
 336
 337    default:
 338       return MESA_FORMAT_NONE;
 339    }
 340 }
 341
 342
 343 /**
 344  * Given a compressed MESA_FORMAT_x value, return the corresponding
 345  * GLenum for that format.
 346  * This is needed for glGetTexLevelParameter(GL_TEXTURE_INTERNAL_FORMAT)
 347  * which must return the specific texture format used when the user might
 348  * have originally specified a generic compressed format in their
 349  * glTexImage2D() call.
 350  * For non-compressed textures, we always return the user-specified
 351  * internal format unchanged.
 352  */
 353 GLenum
 354 _mesa_compressed_format_to_glenum(struct gl_context *ctx, GLuint mesaFormat)
 355 {
 356    switch (mesaFormat) {
 357 #if FEATURE_texture_fxt1
 358    case MESA_FORMAT_RGB_FXT1:
 359       return GL_COMPRESSED_RGB_FXT1_3DFX;
 360    case MESA_FORMAT_RGBA_FXT1:
 361       return GL_COMPRESSED_RGBA_FXT1_3DFX;
 362 #endif
 363 #if FEATURE_texture_s3tc
 364    case MESA_FORMAT_RGB_DXT1:
 365       return GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
 366    case MESA_FORMAT_RGBA_DXT1:
 367       return GL_COMPRESSED_RGBA_S3TC_DXT1_EXT;
 368    case MESA_FORMAT_RGBA_DXT3:
 369       return GL_COMPRESSED_RGBA_S3TC_DXT3_EXT;
 370    case MESA_FORMAT_RGBA_DXT5:
 371       return GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
 372 #if FEATURE_EXT_texture_sRGB
 373    case MESA_FORMAT_SRGB_DXT1:
 374       return GL_COMPRESSED_SRGB_S3TC_DXT1_EXT;
 375    case MESA_FORMAT_SRGBA_DXT1:
 376       return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT;
 377    case MESA_FORMAT_SRGBA_DXT3:
 378       return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT;
 379    case MESA_FORMAT_SRGBA_DXT5:
 380       return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT;
 381 #endif
 382 #endif
 383
 384    case MESA_FORMAT_RED_RGTC1:
 385       return GL_COMPRESSED_RED_RGTC1;
 386    case MESA_FORMAT_SIGNED_RED_RGTC1:
 387       return GL_COMPRESSED_SIGNED_RED_RGTC1;
 388    case MESA_FORMAT_RG_RGTC2:
 389       return GL_COMPRESSED_RG_RGTC2;
 390    case MESA_FORMAT_SIGNED_RG_RGTC2:
 391       return GL_COMPRESSED_SIGNED_RG_RGTC2;
 392
 393    case MESA_FORMAT_L_LATC1:
 394       return GL_COMPRESSED_LUMINANCE_LATC1_EXT;
 395    case MESA_FORMAT_SIGNED_L_LATC1:
 396       return GL_COMPRESSED_SIGNED_LUMINANCE_LATC1_EXT;
 397    case MESA_FORMAT_LA_LATC2:
 398       return GL_COMPRESSED_LUMINANCE_ALPHA_LATC2_EXT;
 399    case MESA_FORMAT_SIGNED_LA_LATC2:
 400       return GL_COMPRESSED_SIGNED_LUMINANCE_ALPHA_LATC2_EXT;
 401
 402    default:
 403       _mesa_problem(ctx, "Unexpected mesa texture format in"
 404                     " _mesa_compressed_format_to_glenum()");
 405       return 0;
 406    }
 407 }
 408
 409
 410 /*
 411  * Return the address of the pixel at (col, row, img) in a
 412  * compressed texture image.
 413  * \param col, row, img - image position (3D), should be a multiple of the
 414  *                        format's block size.
 415  * \param format - compressed image format
 416  * \param width - image width (stride) in pixels
 417  * \param image - the image address
 418  * \return address of pixel at (row, col, img)
 419  */
 420 GLubyte *
 421 _mesa_compressed_image_address(GLint col, GLint row, GLint img,
 422                                gl_format mesaFormat,
 423                                GLsizei width, const GLubyte *image)
 424 {
 425    /* XXX only 2D images implemented, not 3D */
 426    const GLuint blockSize = _mesa_get_format_bytes(mesaFormat);
 427    GLuint bw, bh;
 428    GLint offset;
 429
 430    _mesa_get_format_block_size(mesaFormat, &bw, &bh);
 431
 432    ASSERT(col % bw == 0);
 433    ASSERT(row % bh == 0);
 434
 435    offset = ((width + bw - 1) / bw) * (row / bh) + col / bw;
 436    offset *= blockSize;
 437
 438    return (GLubyte *) image + offset;
 439 }