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    (void) size;
 141
 142    switch (mesaFormat) {
 143 #if FEATURE_texture_fxt1
 144    case MESA_FORMAT_RGB_FXT1:
 145    case MESA_FORMAT_RGBA_FXT1:
 146       /* round up width to next multiple of 8, height to next multiple of 4 */
 147       width = (width + 7) & ~7;
 148       height = (height + 3) & ~3;
 149       /* 16 bytes per 8x4 tile of RGB[A] texels */
 150       size = width * height / 2;
 151       /* Textures smaller than 8x4 will effectively be made into 8x4 and
 152        * take 16 bytes.
 153        */
 154       return size;
 155 #endif
 156 #if FEATURE_texture_s3tc
 157    case MESA_FORMAT_RGB_DXT1:
 158    case MESA_FORMAT_RGBA_DXT1:
 159       /* round up width, height to next multiple of 4 */
 160       width = (width + 3) & ~3;
 161       height = (height + 3) & ~3;
 162       /* 8 bytes per 4x4 tile of RGB[A] texels */
 163       size = width * height / 2;
 164       /* Textures smaller than 4x4 will effectively be made into 4x4 and
 165        * take 8 bytes.
 166        */
 167       return size;
 168    case MESA_FORMAT_RGBA_DXT3:
 169    case MESA_FORMAT_RGBA_DXT5:
 170       /* round up width, height to next multiple of 4 */
 171       width = (width + 3) & ~3;
 172       height = (height + 3) & ~3;
 173       /* 16 bytes per 4x4 tile of RGBA texels */
 174       size = width * height; /* simple! */
 175       /* Textures smaller than 4x4 will effectively be made into 4x4 and
 176        * take 16 bytes.
 177        */
 178       return size;
 179 #endif
 180    default:
 181       _mesa_problem(ctx, "bad mesaFormat in _mesa_compressed_texture_size");
 182       return 0;
 183    }
 184 }
 185
 186
 187 /**
 188  * As above, but format is specified by a GLenum (GL_COMPRESSED_*) token.
 189  *
 190  * Note: This function CAN NOT return a padded hardware texture size.
 191  * That's why we don't call the ctx->Driver.CompressedTextureSize() function.
 192  *
 193  * We use this function to validate the <imageSize> parameter
 194  * of glCompressedTex[Sub]Image1/2/3D(), which must be an exact match.
 195  */
 196 GLuint
 197 _mesa_compressed_texture_size_glenum(GLcontext *ctx,
 198                                      GLsizei width, GLsizei height,
 199                                      GLsizei depth, GLenum glformat)
 200 {
 201    GLuint mesaFormat;
 202
 203    switch (glformat) {
 204 #if FEATURE_texture_fxt1
 205    case GL_COMPRESSED_RGB_FXT1_3DFX:
 206       mesaFormat = MESA_FORMAT_RGB_FXT1;
 207       break;
 208    case GL_COMPRESSED_RGBA_FXT1_3DFX:
 209       mesaFormat = MESA_FORMAT_RGBA_FXT1;
 210       break;
 211 #endif
 212 #if FEATURE_texture_s3tc
 213    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
 214    case GL_RGB_S3TC:
 215       mesaFormat = MESA_FORMAT_RGB_DXT1;
 216       break;
 217    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
 218    case GL_RGB4_S3TC:
 219       mesaFormat = MESA_FORMAT_RGBA_DXT1;
 220       break;
 221    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
 222    case GL_RGBA_S3TC:
 223       mesaFormat = MESA_FORMAT_RGBA_DXT3;
 224       break;
 225    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
 226    case GL_RGBA4_S3TC:
 227       mesaFormat = MESA_FORMAT_RGBA_DXT5;
 228       break;
 229 #endif
 230    default:
 231       return 0;
 232    }
 233
 234    return _mesa_compressed_texture_size(ctx, width, height, depth, mesaFormat);
 235 }
 236
 237
 238 /*
 239  * Compute the bytes per row in a compressed texture image.
 240  * We use this for computing the destination address for sub-texture updates.
 241  * \param mesaFormat  one of the MESA_FORMAT_* compressed formats
 242  * \param width  image width in pixels
 243  * \return stride, in bytes, between rows for compressed image
 244  */
 245 GLint
 246 _mesa_compressed_row_stride(GLuint mesaFormat, GLsizei width)
 247 {
 248    GLint stride;
 249
 250    switch (mesaFormat) {
 251 #if FEATURE_texture_fxt1
 252    case MESA_FORMAT_RGB_FXT1:
 253    case MESA_FORMAT_RGBA_FXT1:
 254       stride = ((width + 7) / 8) * 16; /* 16 bytes per 8x4 tile */
 255       break;
 256 #endif
 257 #if FEATURE_texture_s3tc
 258    case MESA_FORMAT_RGB_DXT1:
 259    case MESA_FORMAT_RGBA_DXT1:
 260       stride = ((width + 3) / 4) * 8; /* 8 bytes per 4x4 tile */
 261       break;
 262    case MESA_FORMAT_RGBA_DXT3:
 263    case MESA_FORMAT_RGBA_DXT5:
 264       stride = ((width + 3) / 4) * 16; /* 16 bytes per 4x4 tile */
 265       break;
 266 #endif
 267    default:
 268       _mesa_problem(NULL, "bad mesaFormat in _mesa_compressed_row_stride");
 269       return 0;
 270    }
 271
 272    return stride;
 273 }
 274
 275
 276 /*
 277  * Return the address of the pixel at (col, row, img) in a
 278  * compressed texture image.
 279  * \param col, row, img - image position (3D)
 280  * \param format - compressed image format
 281  * \param width - image width
 282  * \param image - the image address
 283  * \return address of pixel at (row, col)
 284  */
 285 GLubyte *
 286 _mesa_compressed_image_address(GLint col, GLint row, GLint img,
 287                                GLuint mesaFormat,
 288                                GLsizei width, const GLubyte *image)
 289 {
 290    GLubyte *addr;
 291
 292    (void) img;
 293
 294    /* We try to spot a "complete" subtexture "above" ROW, COL;
 295     * this texture is given by appropriate rounding of WIDTH x ROW.
 296     * Then we just add the amount left (usually on the left).
 297     *
 298     * Example for X*Y microtiles (Z bytes each)
 299     * offset = Z * (((width + X - 1) / X) * (row / Y) + col / X);
 300     */
 301
 302    switch (mesaFormat) {
 303 #if FEATURE_texture_fxt1
 304    case MESA_FORMAT_RGB_FXT1:
 305    case MESA_FORMAT_RGBA_FXT1:
 306       addr = (GLubyte *) image + 16 * (((width + 7) / 8) * (row / 4) + col / 8);
 307       break;
 308 #endif
 309 #if FEATURE_texture_s3tc
 310    case MESA_FORMAT_RGB_DXT1:
 311    case MESA_FORMAT_RGBA_DXT1:
 312       addr = (GLubyte *) image + 8 * (((width + 3) / 4) * (row / 4) + col / 4);
 313       break;
 314    case MESA_FORMAT_RGBA_DXT3:
 315    case MESA_FORMAT_RGBA_DXT5:
 316       addr = (GLubyte *) image + 16 * (((width + 3) / 4) * (row / 4) + col / 4);
 317       break;
 318 #endif
 319    default:
 320       _mesa_problem(NULL, "bad mesaFormat in _mesa_compressed_image_address");
 321       addr = NULL;
 322    }
 323
 324    return addr;
 325 }