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 "context.h"
  37 #include "formats.h"
  38 #include "image.h"
  39 #include "mipmap.h"
  40 #include "texcompress.h"
  41 #include "texstore.h"
  42
  43
  44 /**
  45  * Return list of (and count of) all specific texture compression
  46  * formats that are supported.
  47  *
  48  * \param ctx  the GL context
  49  * \param formats  the resulting format list (may be NULL).
  50  * \param all  if true return all formats, even those with  some kind
  51  *             of restrictions/limitations (See GL_ARB_texture_compression
  52  *             spec for more info).
  53  *
  54  * \return number of formats.
  55  */
  56 GLuint
  57 _mesa_get_compressed_formats(GLcontext *ctx, GLint *formats, GLboolean all)
  58 {
  59    GLuint n = 0;
  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    return n;
 113 }
 114
 115
 116 /**
 117  * Convert a compressed MESA_FORMAT_x to a GLenum.
 118  */
 119 gl_format
 120 _mesa_glenum_to_compressed_format(GLenum format)
 121 {
 122    switch (format) {
 123    case GL_COMPRESSED_RGB_FXT1_3DFX:
 124       return MESA_FORMAT_RGB_FXT1;
 125    case GL_COMPRESSED_RGBA_FXT1_3DFX:
 126       return MESA_FORMAT_RGBA_FXT1;
 127
 128    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
 129    case GL_RGB_S3TC:
 130       return MESA_FORMAT_RGB_DXT1;
 131    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
 132    case GL_RGB4_S3TC:
 133       return MESA_FORMAT_RGBA_DXT1;
 134    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
 135    case GL_RGBA_S3TC:
 136       return MESA_FORMAT_RGBA_DXT3;
 137    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
 138    case GL_RGBA4_S3TC:
 139       return MESA_FORMAT_RGBA_DXT5;
 140
 141    case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT:
 142       return MESA_FORMAT_SRGB_DXT1;
 143    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT:
 144       return MESA_FORMAT_SRGBA_DXT1;
 145    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT:
 146       return MESA_FORMAT_SRGBA_DXT3;
 147    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT:
 148       return MESA_FORMAT_SRGBA_DXT5;
 149
 150    default:
 151       return MESA_FORMAT_NONE;
 152    }
 153 }
 154
 155
 156 /**
 157  * Given a compressed MESA_FORMAT_x value, return the corresponding
 158  * GLenum for that format.
 159  * This is needed for glGetTexLevelParameter(GL_TEXTURE_INTERNAL_FORMAT)
 160  * which must return the specific texture format used when the user might
 161  * have originally specified a generic compressed format in their
 162  * glTexImage2D() call.
 163  * For non-compressed textures, we always return the user-specified
 164  * internal format unchanged.
 165  */
 166 GLenum
 167 _mesa_compressed_format_to_glenum(GLcontext *ctx, GLuint mesaFormat)
 168 {
 169    switch (mesaFormat) {
 170 #if FEATURE_texture_fxt1
 171    case MESA_FORMAT_RGB_FXT1:
 172       return GL_COMPRESSED_RGB_FXT1_3DFX;
 173    case MESA_FORMAT_RGBA_FXT1:
 174       return GL_COMPRESSED_RGBA_FXT1_3DFX;
 175 #endif
 176 #if FEATURE_texture_s3tc
 177    case MESA_FORMAT_RGB_DXT1:
 178       return GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
 179    case MESA_FORMAT_RGBA_DXT1:
 180       return GL_COMPRESSED_RGBA_S3TC_DXT1_EXT;
 181    case MESA_FORMAT_RGBA_DXT3:
 182       return GL_COMPRESSED_RGBA_S3TC_DXT3_EXT;
 183    case MESA_FORMAT_RGBA_DXT5:
 184       return GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
 185 #if FEATURE_EXT_texture_sRGB
 186    case MESA_FORMAT_SRGB_DXT1:
 187       return GL_COMPRESSED_SRGB_S3TC_DXT1_EXT;
 188    case MESA_FORMAT_SRGBA_DXT1:
 189       return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT;
 190    case MESA_FORMAT_SRGBA_DXT3:
 191       return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT;
 192    case MESA_FORMAT_SRGBA_DXT5:
 193       return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT;
 194 #endif
 195 #endif
 196    default:
 197       _mesa_problem(ctx, "Unexpected mesa texture format in"
 198                     " _mesa_compressed_format_to_glenum()");
 199       return 0;
 200    }
 201 }
 202
 203
 204 /*
 205  * Return the address of the pixel at (col, row, img) in a
 206  * compressed texture image.
 207  * \param col, row, img - image position (3D), should be a multiple of the
 208  *                        format's block size.
 209  * \param format - compressed image format
 210  * \param width - image width (stride) in pixels
 211  * \param image - the image address
 212  * \return address of pixel at (row, col, img)
 213  */
 214 GLubyte *
 215 _mesa_compressed_image_address(GLint col, GLint row, GLint img,
 216                                gl_format mesaFormat,
 217                                GLsizei width, const GLubyte *image)
 218 {
 219    /* XXX only 2D images implemented, not 3D */
 220    const GLuint blockSize = _mesa_get_format_bytes(mesaFormat);
 221    GLuint bw, bh;
 222    GLint offset;
 223
 224    _mesa_get_format_block_size(mesaFormat, &bw, &bh);
 225
 226    ASSERT(col % bw == 0);
 227    ASSERT(row % bh == 0);
 228
 229    offset = ((width + bw - 1) / bw) * (row / bh) + col / bw;
 230    offset *= blockSize;
 231
 232    return (GLubyte *) image + offset;
 233 }