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  *
   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  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25
  26 /**
  27  * \file texcompress.c
  28  * Helper functions for texture compression.
  29  */
  30
  31
  32 #include "glheader.h"
  33 #include "imports.h"
  34 #include "colormac.h"
  35 #include "context.h"
  36 #include "image.h"
  37 #include "mipmap.h"
  38 #include "texcompress.h"
  39 #include "texformat.h"
  40 #include "texstore.h"
  41
  42
  43 /**
  44  * Return list of (and count of) all specific texture compression
  45  * formats that are supported.
  46  *
  47  * \param ctx  the GL context
  48  * \param formats  the resulting format list (may be NULL).
  49  * \param all  if true return all formats, even those with  some kind
  50  *             of restrictions/limitations (See GL_ARB_texture_compression
  51  *             spec for more info).
  52  *
  53  * \return number of formats.
  54  */
  55 GLuint
  56 _mesa_get_compressed_formats(GLcontext *ctx, GLint *formats, GLboolean all)
  57 {
  58    GLuint n = 0;
  59    if (ctx->Extensions.ARB_texture_compression) {
  60       if (ctx->Extensions.TDFX_texture_compression_FXT1) {
  61          if (formats) {
  62             formats[n++] = GL_COMPRESSED_RGB_FXT1_3DFX;
  63             formats[n++] = GL_COMPRESSED_RGBA_FXT1_3DFX;
  64          }
  65          else {
  66             n += 2;
  67          }
  68       }
  69       if (ctx->Extensions.EXT_texture_compression_s3tc) {
  70          if (formats) {
  71             formats[n++] = GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
  72             /* This format has some restrictions/limitations and so should
  73              * not be returned via the GL_COMPRESSED_TEXTURE_FORMATS query.
  74              * Specifically, all transparent pixels become black.  NVIDIA
  75              * omits this format too.
  76              */
  77             if (all)
  78                formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT1_EXT;
  79             formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT3_EXT;
  80             formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
  81          }
  82          else {
  83             n += 3;
  84             if (all)
  85                n += 1;
  86          }
  87       }
  88       if (ctx->Extensions.S3_s3tc) {
  89          if (formats) {
  90             formats[n++] = GL_RGB_S3TC;
  91             formats[n++] = GL_RGB4_S3TC;
  92             formats[n++] = GL_RGBA_S3TC;
  93             formats[n++] = GL_RGBA4_S3TC;
  94          }
  95          else {
  96             n += 4;
  97          }
  98       }
  99 #if FEATURE_EXT_texture_sRGB
 100       if (ctx->Extensions.EXT_texture_sRGB) {
 101          if (formats) {
 102             formats[n++] = GL_COMPRESSED_SRGB_S3TC_DXT1_EXT;
 103             formats[n++] = GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT;
 104             formats[n++] = GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT;
 105             formats[n++] = GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT;
 106          }
 107          else {
 108             n += 4;
 109          }
 110       }
 111 #endif /* FEATURE_EXT_texture_sRGB */
 112    }
 113    return n;
 114 }
 115
 116
 117
 118 /**
 119  * Return number of bytes needed to store a texture of the given size
 120  * using the specified compressed format.
 121  * This is called via the ctx->Driver.CompressedTextureSize function,
 122  * unless a device driver overrides it.
 123  *
 124  * \param width texture width in texels.
 125  * \param height texture height in texels.
 126  * \param depth texture depth in texels.
 127  * \param mesaFormat  one of the MESA_FORMAT_* compressed formats
 128  *
 129  * \return size in bytes, or zero if bad format
 130  */
 131 GLuint
 132 _mesa_compressed_texture_size( GLcontext *ctx,
 133                                GLsizei width, GLsizei height, GLsizei depth,
 134                                GLuint mesaFormat )
 135 {
 136    GLuint size;
 137
 138    ASSERT(depth == 1);
 139    (void) depth;
 140
 141    switch (mesaFormat) {
 142    case MESA_FORMAT_RGB_FXT1:
 143    case MESA_FORMAT_RGBA_FXT1:
 144       /* round up width to next multiple of 8, height to next multiple of 4 */
 145       width = (width + 7) & ~7;
 146       height = (height + 3) & ~3;
 147       /* 16 bytes per 8x4 tile of RGB[A] texels */
 148       size = width * height / 2;
 149       /* Textures smaller than 8x4 will effectively be made into 8x4 and
 150        * take 16 bytes.
 151        */
 152       return size;
 153    case MESA_FORMAT_RGB_DXT1:
 154    case MESA_FORMAT_RGBA_DXT1:
 155       /* round up width, height to next multiple of 4 */
 156       width = (width + 3) & ~3;
 157       height = (height + 3) & ~3;
 158       /* 8 bytes per 4x4 tile of RGB[A] texels */
 159       size = width * height / 2;
 160       /* Textures smaller than 4x4 will effectively be made into 4x4 and
 161        * take 8 bytes.
 162        */
 163       return size;
 164    case MESA_FORMAT_RGBA_DXT3:
 165    case MESA_FORMAT_RGBA_DXT5:
 166       /* round up width, height to next multiple of 4 */
 167       width = (width + 3) & ~3;
 168       height = (height + 3) & ~3;
 169       /* 16 bytes per 4x4 tile of RGBA texels */
 170       size = width * height; /* simple! */
 171       /* Textures smaller than 4x4 will effectively be made into 4x4 and
 172        * take 16 bytes.
 173        */
 174       return size;
 175    default:
 176       _mesa_problem(ctx, "bad mesaFormat in _mesa_compressed_texture_size");
 177       return 0;
 178    }
 179 }
 180
 181
 182 /**
 183  * As above, but format is specified by a GLenum (GL_COMPRESSED_*) token.
 184  *
 185  * Note: This function CAN NOT return a padded hardware texture size.
 186  * That's why we don't call the ctx->Driver.CompressedTextureSize() function.
 187  *
 188  * We use this function to validate the <imageSize> parameter
 189  * of glCompressedTex[Sub]Image1/2/3D(), which must be an exact match.
 190  */
 191 GLuint
 192 _mesa_compressed_texture_size_glenum(GLcontext *ctx,
 193                                      GLsizei width, GLsizei height,
 194                                      GLsizei depth, GLenum glformat)
 195 {
 196    GLuint mesaFormat;
 197
 198    switch (glformat) {
 199    case GL_COMPRESSED_RGB_FXT1_3DFX:
 200       mesaFormat = MESA_FORMAT_RGB_FXT1;
 201       break;
 202    case GL_COMPRESSED_RGBA_FXT1_3DFX:
 203       mesaFormat = MESA_FORMAT_RGBA_FXT1;
 204       break;
 205    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
 206    case GL_RGB_S3TC:
 207       mesaFormat = MESA_FORMAT_RGB_DXT1;
 208       break;
 209    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
 210    case GL_RGB4_S3TC:
 211       mesaFormat = MESA_FORMAT_RGBA_DXT1;
 212       break;
 213    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
 214    case GL_RGBA_S3TC:
 215       mesaFormat = MESA_FORMAT_RGBA_DXT3;
 216       break;
 217    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
 218    case GL_RGBA4_S3TC:
 219       mesaFormat = MESA_FORMAT_RGBA_DXT5;
 220       break;
 221    default:
 222       return 0;
 223    }
 224
 225    return _mesa_compressed_texture_size(ctx, width, height, depth, mesaFormat);
 226 }
 227
 228
 229 /*
 230  * Compute the bytes per row in a compressed texture image.
 231  * We use this for computing the destination address for sub-texture updates.
 232  * \param mesaFormat  one of the MESA_FORMAT_* compressed formats
 233  * \param width  image width in pixels
 234  * \return stride, in bytes, between rows for compressed image
 235  */
 236 GLint
 237 _mesa_compressed_row_stride(GLuint mesaFormat, GLsizei width)
 238 {
 239    GLint stride;
 240
 241    switch (mesaFormat) {
 242    case MESA_FORMAT_RGB_FXT1:
 243    case MESA_FORMAT_RGBA_FXT1:
 244       stride = ((width + 7) / 8) * 16; /* 16 bytes per 8x4 tile */
 245       break;
 246    case MESA_FORMAT_RGB_DXT1:
 247    case MESA_FORMAT_RGBA_DXT1:
 248       stride = ((width + 3) / 4) * 8; /* 8 bytes per 4x4 tile */
 249       break;
 250    case MESA_FORMAT_RGBA_DXT3:
 251    case MESA_FORMAT_RGBA_DXT5:
 252       stride = ((width + 3) / 4) * 16; /* 16 bytes per 4x4 tile */
 253       break;
 254    default:
 255       _mesa_problem(NULL, "bad mesaFormat in _mesa_compressed_row_stride");
 256       return 0;
 257    }
 258
 259    return stride;
 260 }
 261
 262
 263 /*
 264  * Return the address of the pixel at (col, row, img) in a
 265  * compressed texture image.
 266  * \param col, row, img - image position (3D)
 267  * \param format - compressed image format
 268  * \param width - image width
 269  * \param image - the image address
 270  * \return address of pixel at (row, col)
 271  */
 272 GLubyte *
 273 _mesa_compressed_image_address(GLint col, GLint row, GLint img,
 274                                GLuint mesaFormat,
 275                                GLsizei width, const GLubyte *image)
 276 {
 277    GLubyte *addr;
 278
 279    (void) img;
 280
 281    /* We try to spot a "complete" subtexture "above" ROW, COL;
 282     * this texture is given by appropriate rounding of WIDTH x ROW.
 283     * Then we just add the amount left (usually on the left).
 284     *
 285     * Example for X*Y microtiles (Z bytes each)
 286     * offset = Z * (((width + X - 1) / X) * (row / Y) + col / X);
 287     */
 288
 289    switch (mesaFormat) {
 290    case MESA_FORMAT_RGB_FXT1:
 291    case MESA_FORMAT_RGBA_FXT1:
 292       addr = (GLubyte *) image + 16 * (((width + 7) / 8) * (row / 4) + col / 8);
 293       break;
 294    case MESA_FORMAT_RGB_DXT1:
 295    case MESA_FORMAT_RGBA_DXT1:
 296       addr = (GLubyte *) image + 8 * (((width + 3) / 4) * (row / 4) + col / 4);
 297       break;
 298    case MESA_FORMAT_RGBA_DXT3:
 299    case MESA_FORMAT_RGBA_DXT5:
 300       addr = (GLubyte *) image + 16 * (((width + 3) / 4) * (row / 4) + col / 4);
 301       break;
 302    default:
 303       _mesa_problem(NULL, "bad mesaFormat in _mesa_compressed_image_address");
 304       addr = NULL;
 305    }
 306
 307    return addr;
 308 }