src/mesa/main/texcompress.c

   1 /**
   2  * \file texcompress.c
   3  * Compressed textures functions.
   4  */
   5
   6 /*
   7  * Mesa 3-D graphics library
   8  * Version:  5.1
   9  *
  10  * Copyright (C) 1999-2003  Brian Paul   All Rights Reserved.
  11  *
  12  * Permission is hereby granted, free of charge, to any person obtaining a
  13  * copy of this software and associated documentation files (the "Software"),
  14  * to deal in the Software without restriction, including without limitation
  15  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  16  * and/or sell copies of the Software, and to permit persons to whom the
  17  * Software is furnished to do so, subject to the following conditions:
  18  *
  19  * The above copyright notice and this permission notice shall be included
  20  * in all copies or substantial portions of the Software.
  21  *
  22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  23  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  25  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  26  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  27  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  28  */
  29
  30
  31 #include "glheader.h"
  32 #include "imports.h"
  33 #include "context.h"
  34 #include "image.h"
  35 #include "texcompress.h"
  36 #include "texformat.h"
  37
  38
  39 /**
  40  * Get the list of supported internal compression formats.
  41  *
  42  * \param ctx GL context.
  43  * \param formats the resulting format list (may be NULL).
  44  *
  45  * \return number of formats.
  46  */
  47 GLuint
  48 _mesa_get_compressed_formats( GLcontext *ctx, GLint *formats )
  49 {
  50    GLuint n = 0;
  51    if (ctx->Extensions.ARB_texture_compression) {
  52       if (ctx->Extensions.TDFX_texture_compression_FXT1) {
  53          if (formats) {
  54             formats[n++] = GL_COMPRESSED_RGB_FXT1_3DFX;
  55             formats[n++] = GL_COMPRESSED_RGBA_FXT1_3DFX;
  56          }
  57          else {
  58             n += 2;
  59          }
  60       }
  61       if (ctx->Extensions.EXT_texture_compression_s3tc) {
  62          if (formats) {
  63             formats[n++] = GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
  64             /* Skip this one because it has a restriction (all transparent
  65              * pixels become black).  See the texture compressions spec for
  66              * a detailed explanation.  This is what NVIDIA does.
  67             formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT1_EXT;
  68             */
  69             formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT3_EXT;
  70             formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
  71          }
  72          else {
  73             n += 3;
  74          }
  75       }
  76       if (ctx->Extensions.S3_s3tc) {
  77          if (formats) {
  78             formats[n++] = GL_RGB_S3TC;
  79             formats[n++] = GL_RGB4_S3TC;
  80             formats[n++] = GL_RGBA_S3TC;
  81             formats[n++] = GL_RGBA4_S3TC;
  82          }
  83          else {
  84             n += 4;
  85          }
  86       }
  87    }
  88    return n;
  89 }
  90
  91
  92 /**
  93  * Return bytes of storage needed for the given texture size and
  94  * compressed format.
  95  *
  96  * \param width texture width in texels.
  97  * \param height texture height in texels.
  98  * \param depth texture depth in texels.
  99  * \param texFormat one of the compressed format enums
 100  *
 101  * \return size in bytes, or zero if bad \p texFormat.
 102  */
 103 GLuint
 104 _mesa_compressed_texture_size( GLcontext *ctx,
 105                                GLsizei width, GLsizei height, GLsizei depth,
 106                                GLenum format )
 107 {
 108    GLuint size;
 109
 110    if (ctx->Driver.CompressedTextureSize) {
 111       return ctx->Driver.CompressedTextureSize(ctx, width, height, depth, format);
 112    }
 113
 114    ASSERT(depth == 1);
 115
 116    switch (format) {
 117    case GL_COMPRESSED_RGB_FXT1_3DFX:
 118    case GL_COMPRESSED_RGBA_FXT1_3DFX:
 119       /* round up width to next multiple of 8, height to next multiple of 4 */
 120       width = (width + 7) & ~7;
 121       height = (height + 3) & ~3;
 122       /* 16 bytes per 8x4 tile of RGB[A] texels */
 123       size = width * height / 2;
 124       /* Textures smaller than 8x4 will effectively be made into 8x4 and
 125        * take 16 bytes.
 126        */
 127       if (size < 16)
 128          size = 16;
 129       return size;
 130    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
 131    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
 132    case GL_RGB_S3TC:
 133    case GL_RGB4_S3TC:
 134       /* round up width, height to next multiple of 4 */
 135       width = (width + 3) & ~3;
 136       height = (height + 3) & ~3;
 137       /* 8 bytes per 4x4 tile of RGB[A] texels */
 138       size = width * height / 2;
 139       /* Textures smaller than 4x4 will effectively be made into 4x4 and
 140        * take 8 bytes.
 141        */
 142       if (size < 8)
 143          size = 8;
 144       return size;
 145    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
 146    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
 147    case GL_RGBA_S3TC:
 148    case GL_RGBA4_S3TC:
 149       /* round up width, height to next multiple of 4 */
 150       width = (width + 3) & ~3;
 151       height = (height + 3) & ~3;
 152       /* 16 bytes per 4x4 tile of RGBA texels */
 153       size = width * height; /* simple! */
 154       /* Textures smaller than 4x4 will effectively be made into 4x4 and
 155        * take 16 bytes.
 156        */
 157       if (size < 16)
 158          size = 16;
 159       return size;
 160    default:
 161       _mesa_problem(ctx, "bad texformat in compressed_texture_size");
 162       return 0;
 163    }
 164 }
 165
 166
 167 /**
 168  * Compute the bytes per row in a compressed texture image.
 169  * We use this for computing the destination address for sub-texture updates.
 170  * \param format  one of the specific texture compression formats
 171  * \param width  image width in pixels
 172  * \return stride, in bytes, between rows for compressed image
 173  */
 174 GLint
 175 _mesa_compressed_row_stride(GLenum format, GLsizei width)
 176 {
 177    GLint stride;
 178
 179    switch (format) {
 180    case GL_COMPRESSED_RGB_FXT1_3DFX:
 181    case GL_COMPRESSED_RGBA_FXT1_3DFX:
 182       stride = ((width + 7) / 8) * 16; /* 16 bytes per 8x4 tile */
 183       break;
 184    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
 185    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
 186    case GL_RGB_S3TC:
 187    case GL_RGB4_S3TC:
 188       stride = ((width + 3) / 4) * 8; /* 8 bytes per 4x4 tile */
 189       break;
 190    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
 191    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
 192    case GL_RGBA_S3TC:
 193    case GL_RGBA4_S3TC:
 194       stride = ((width + 3) / 4) * 16; /* 16 bytes per 4x4 tile */
 195       break;
 196    default:
 197       return 0;
 198    }
 199
 200    return stride;
 201 }
 202
 203
 204 /**
 205  * Return the address of the pixel at (col, row, img) in a
 206  * compressed texture image.
 207  *
 208  * \param col image position.
 209  * \param row image position.
 210  * \param img image position.
 211  * \param format compressed image format.
 212  * \param width image width.
 213  * \param image the image address.
 214  *
 215  * \return address of pixel at (row, col).
 216  */
 217 GLubyte *
 218 _mesa_compressed_image_address(GLint col, GLint row, GLint img,
 219                                GLenum format,
 220                                GLsizei width, const GLubyte *image)
 221 {
 222    GLubyte *addr;
 223
 224    (void) img;
 225
 226    /* We try to spot a "complete" subtexture "above" ROW, COL;
 227     * this texture is given by appropriate rounding of WIDTH x ROW.
 228     * Then we just add the amount left (usually on the left).
 229     *
 230     * Example for X*Y microtiles (Z bytes each)
 231     * offset = Z * (((width + X - 1) / X) * (row / Y) + col / X);
 232     */
 233
 234    switch (format) {
 235    case GL_COMPRESSED_RGB_FXT1_3DFX:
 236    case GL_COMPRESSED_RGBA_FXT1_3DFX:
 237       addr = (GLubyte *) image + 16 * (((width + 7) / 8) * (row / 4) + col / 8);
 238       break;
 239    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
 240    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
 241    case GL_RGB_S3TC:
 242    case GL_RGB4_S3TC:
 243       addr = (GLubyte *) image + 8 * (((width + 3) / 4) * (row / 4) + col / 4);
 244       break;
 245    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
 246    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
 247    case GL_RGBA_S3TC:
 248    case GL_RGBA4_S3TC:
 249       addr = (GLubyte *) image + 16 * (((width + 3) / 4) * (row / 4) + col / 4);
 250       break;
 251    default:
 252       return 0;
 253    }
 254
 255    return addr;
 256 }
 257
 258
 259 /**
 260  * \param srcRowStride source stride, in pixels
 261  */
 262 void
 263 _mesa_compress_teximage( GLcontext *ctx, GLsizei width, GLsizei height,
 264                          GLenum srcFormat, const GLchan *source,
 265                          GLint srcRowStride,
 266                          const struct gl_texture_format *dstFormat,
 267                          GLubyte *dest, GLint dstRowStride )
 268 {
 269    switch (dstFormat->MesaFormat) {
 270    default:
 271       _mesa_problem(ctx, "Bad dstFormat in _mesa_compress_teximage()");
 272       return;
 273    }
 274 }