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 "texcompress.h"
  39
  40
  41 /**
  42  * Return list of (and count of) all specific texture compression
  43  * formats that are supported.
  44  *
  45  * \param ctx  the GL context
  46  * \param formats  the resulting format list (may be NULL).
  47  * \param all  if true return all formats, even those with  some kind
  48  *             of restrictions/limitations (See GL_ARB_texture_compression
  49  *             spec for more info).
  50  *
  51  * \return number of formats.
  52  */
  53 GLuint
  54 _mesa_get_compressed_formats(GLcontext *ctx, GLint *formats, GLboolean all)
  55 {
  56    GLuint n = 0;
  57    if (ctx->Extensions.TDFX_texture_compression_FXT1) {
  58       if (formats) {
  59          formats[n++] = GL_COMPRESSED_RGB_FXT1_3DFX;
  60          formats[n++] = GL_COMPRESSED_RGBA_FXT1_3DFX;
  61       }
  62       else {
  63          n += 2;
  64       }
  65    }
  66    if (ctx->Extensions.EXT_texture_compression_s3tc) {
  67       if (formats) {
  68          formats[n++] = GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
  69          /* This format has some restrictions/limitations and so should
  70           * not be returned via the GL_COMPRESSED_TEXTURE_FORMATS query.
  71           * Specifically, all transparent pixels become black.  NVIDIA
  72           * omits this format too.
  73           */
  74          if (all)
  75              formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT1_EXT;
  76          formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT3_EXT;
  77          formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
  78       }
  79       else {
  80          n += 3;
  81          if (all)
  82              n += 1;
  83       }
  84    }
  85    if (ctx->Extensions.S3_s3tc) {
  86       if (formats) {
  87          formats[n++] = GL_RGB_S3TC;
  88          formats[n++] = GL_RGB4_S3TC;
  89          formats[n++] = GL_RGBA_S3TC;
  90          formats[n++] = GL_RGBA4_S3TC;
  91       }
  92       else {
  93          n += 4;
  94       }
  95    }
  96 #if FEATURE_EXT_texture_sRGB
  97    if (ctx->Extensions.EXT_texture_sRGB) {
  98       if (formats) {
  99          formats[n++] = GL_COMPRESSED_SRGB_S3TC_DXT1_EXT;
 100          formats[n++] = GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT;
 101          formats[n++] = GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT;
 102          formats[n++] = GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT;
 103       }
 104       else {
 105          n += 4;
 106       }
 107    }
 108 #endif /* FEATURE_EXT_texture_sRGB */
 109    return n;
 110 }
 111
 112
 113 /**
 114  * Convert a compressed MESA_FORMAT_x to a GLenum.
 115  */
 116 gl_format
 117 _mesa_glenum_to_compressed_format(GLenum format)
 118 {
 119    switch (format) {
 120    case GL_COMPRESSED_RGB_FXT1_3DFX:
 121       return MESA_FORMAT_RGB_FXT1;
 122    case GL_COMPRESSED_RGBA_FXT1_3DFX:
 123       return MESA_FORMAT_RGBA_FXT1;
 124
 125    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
 126    case GL_RGB_S3TC:
 127       return MESA_FORMAT_RGB_DXT1;
 128    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
 129    case GL_RGB4_S3TC:
 130       return MESA_FORMAT_RGBA_DXT1;
 131    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
 132    case GL_RGBA_S3TC:
 133       return MESA_FORMAT_RGBA_DXT3;
 134    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
 135    case GL_RGBA4_S3TC:
 136       return MESA_FORMAT_RGBA_DXT5;
 137
 138    case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT:
 139       return MESA_FORMAT_SRGB_DXT1;
 140    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT:
 141       return MESA_FORMAT_SRGBA_DXT1;
 142    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT:
 143       return MESA_FORMAT_SRGBA_DXT3;
 144    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT:
 145       return MESA_FORMAT_SRGBA_DXT5;
 146
 147    default:
 148       return MESA_FORMAT_NONE;
 149    }
 150 }
 151
 152
 153 /**
 154  * Given a compressed MESA_FORMAT_x value, return the corresponding
 155  * GLenum for that format.
 156  * This is needed for glGetTexLevelParameter(GL_TEXTURE_INTERNAL_FORMAT)
 157  * which must return the specific texture format used when the user might
 158  * have originally specified a generic compressed format in their
 159  * glTexImage2D() call.
 160  * For non-compressed textures, we always return the user-specified
 161  * internal format unchanged.
 162  */
 163 GLenum
 164 _mesa_compressed_format_to_glenum(GLcontext *ctx, GLuint mesaFormat)
 165 {
 166    switch (mesaFormat) {
 167 #if FEATURE_texture_fxt1
 168    case MESA_FORMAT_RGB_FXT1:
 169       return GL_COMPRESSED_RGB_FXT1_3DFX;
 170    case MESA_FORMAT_RGBA_FXT1:
 171       return GL_COMPRESSED_RGBA_FXT1_3DFX;
 172 #endif
 173 #if FEATURE_texture_s3tc
 174    case MESA_FORMAT_RGB_DXT1:
 175       return GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
 176    case MESA_FORMAT_RGBA_DXT1:
 177       return GL_COMPRESSED_RGBA_S3TC_DXT1_EXT;
 178    case MESA_FORMAT_RGBA_DXT3:
 179       return GL_COMPRESSED_RGBA_S3TC_DXT3_EXT;
 180    case MESA_FORMAT_RGBA_DXT5:
 181       return GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
 182 #if FEATURE_EXT_texture_sRGB
 183    case MESA_FORMAT_SRGB_DXT1:
 184       return GL_COMPRESSED_SRGB_S3TC_DXT1_EXT;
 185    case MESA_FORMAT_SRGBA_DXT1:
 186       return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT;
 187    case MESA_FORMAT_SRGBA_DXT3:
 188       return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT;
 189    case MESA_FORMAT_SRGBA_DXT5:
 190       return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT;
 191 #endif
 192 #endif
 193    default:
 194       _mesa_problem(ctx, "Unexpected mesa texture format in"
 195                     " _mesa_compressed_format_to_glenum()");
 196       return 0;
 197    }
 198 }
 199
 200
 201 /*
 202  * Return the address of the pixel at (col, row, img) in a
 203  * compressed texture image.
 204  * \param col, row, img - image position (3D), should be a multiple of the
 205  *                        format's block size.
 206  * \param format - compressed image format
 207  * \param width - image width (stride) in pixels
 208  * \param image - the image address
 209  * \return address of pixel at (row, col, img)
 210  */
 211 GLubyte *
 212 _mesa_compressed_image_address(GLint col, GLint row, GLint img,
 213                                gl_format mesaFormat,
 214                                GLsizei width, const GLubyte *image)
 215 {
 216    /* XXX only 2D images implemented, not 3D */
 217    const GLuint blockSize = _mesa_get_format_bytes(mesaFormat);
 218    GLuint bw, bh;
 219    GLint offset;
 220
 221    _mesa_get_format_block_size(mesaFormat, &bw, &bh);
 222
 223    ASSERT(col % bw == 0);
 224    ASSERT(row % bh == 0);
 225
 226    offset = ((width + bw - 1) / bw) * (row / bh) + col / bw;
 227    offset *= blockSize;
 228
 229    return (GLubyte *) image + offset;
 230 }