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 "formats.h"
  37 #include "texcompress.h"
  38
  39
  40 /**
  41  * Return list of (and count of) all specific texture compression
  42  * formats that are supported.
  43  *
  44  * \param ctx  the GL context
  45  * \param formats  the resulting format list (may be NULL).
  46  * \param all  if true return all formats, even those with  some kind
  47  *             of restrictions/limitations (See GL_ARB_texture_compression
  48  *             spec for more info).
  49  *
  50  * \return number of formats.
  51  */
  52 GLuint
  53 _mesa_get_compressed_formats(struct gl_context *ctx, GLint *formats, GLboolean all)
  54 {
  55    GLuint n = 0;
  56    if (ctx->Extensions.TDFX_texture_compression_FXT1) {
  57       if (formats) {
  58          formats[n++] = GL_COMPRESSED_RGB_FXT1_3DFX;
  59          formats[n++] = GL_COMPRESSED_RGBA_FXT1_3DFX;
  60       }
  61       else {
  62          n += 2;
  63       }
  64    }
  65    if (ctx->Extensions.EXT_texture_compression_s3tc) {
  66       if (formats) {
  67          formats[n++] = GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
  68          /* This format has some restrictions/limitations and so should
  69           * not be returned via the GL_COMPRESSED_TEXTURE_FORMATS query.
  70           * Specifically, all transparent pixels become black.  NVIDIA
  71           * omits this format too.
  72           */
  73          if (all)
  74              formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT1_EXT;
  75          formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT3_EXT;
  76          formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
  77       }
  78       else {
  79          n += 3;
  80          if (all)
  81              n += 1;
  82       }
  83    }
  84    if (ctx->Extensions.S3_s3tc) {
  85       if (formats) {
  86          formats[n++] = GL_RGB_S3TC;
  87          formats[n++] = GL_RGB4_S3TC;
  88          formats[n++] = GL_RGBA_S3TC;
  89          formats[n++] = GL_RGBA4_S3TC;
  90       }
  91       else {
  92          n += 4;
  93       }
  94    }
  95 #if FEATURE_EXT_texture_sRGB
  96    if (ctx->Extensions.EXT_texture_sRGB) {
  97       if (formats) {
  98          formats[n++] = GL_COMPRESSED_SRGB_S3TC_DXT1_EXT;
  99          formats[n++] = GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT;
 100          formats[n++] = GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT;
 101          formats[n++] = GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT;
 102       }
 103       else {
 104          n += 4;
 105       }
 106    }
 107 #endif /* FEATURE_EXT_texture_sRGB */
 108    return n;
 109
 110 #if FEATURE_ES1 || FEATURE_ES2
 111    if (formats) {
 112       formats[n++] = GL_PALETTE4_RGB8_OES;
 113       formats[n++] = GL_PALETTE4_RGBA8_OES;
 114       formats[n++] = GL_PALETTE4_R5_G6_B5_OES;
 115       formats[n++] = GL_PALETTE4_RGBA4_OES;
 116       formats[n++] = GL_PALETTE4_RGB5_A1_OES;
 117       formats[n++] = GL_PALETTE8_RGB8_OES;
 118       formats[n++] = GL_PALETTE8_RGBA8_OES;
 119       formats[n++] = GL_PALETTE8_R5_G6_B5_OES;
 120       formats[n++] = GL_PALETTE8_RGBA4_OES;
 121       formats[n++] = GL_PALETTE8_RGB5_A1_OES;
 122    }
 123    else {
 124       n += 10;
 125    }
 126 #endif
 127 }
 128
 129
 130 /**
 131  * Convert a compressed MESA_FORMAT_x to a GLenum.
 132  */
 133 gl_format
 134 _mesa_glenum_to_compressed_format(GLenum format)
 135 {
 136    switch (format) {
 137    case GL_COMPRESSED_RGB_FXT1_3DFX:
 138       return MESA_FORMAT_RGB_FXT1;
 139    case GL_COMPRESSED_RGBA_FXT1_3DFX:
 140       return MESA_FORMAT_RGBA_FXT1;
 141
 142    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
 143    case GL_RGB_S3TC:
 144       return MESA_FORMAT_RGB_DXT1;
 145    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
 146    case GL_RGB4_S3TC:
 147       return MESA_FORMAT_RGBA_DXT1;
 148    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
 149    case GL_RGBA_S3TC:
 150       return MESA_FORMAT_RGBA_DXT3;
 151    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
 152    case GL_RGBA4_S3TC:
 153       return MESA_FORMAT_RGBA_DXT5;
 154
 155    case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT:
 156       return MESA_FORMAT_SRGB_DXT1;
 157    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT:
 158       return MESA_FORMAT_SRGBA_DXT1;
 159    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT:
 160       return MESA_FORMAT_SRGBA_DXT3;
 161    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT:
 162       return MESA_FORMAT_SRGBA_DXT5;
 163
 164    default:
 165       return MESA_FORMAT_NONE;
 166    }
 167 }
 168
 169
 170 /**
 171  * Given a compressed MESA_FORMAT_x value, return the corresponding
 172  * GLenum for that format.
 173  * This is needed for glGetTexLevelParameter(GL_TEXTURE_INTERNAL_FORMAT)
 174  * which must return the specific texture format used when the user might
 175  * have originally specified a generic compressed format in their
 176  * glTexImage2D() call.
 177  * For non-compressed textures, we always return the user-specified
 178  * internal format unchanged.
 179  */
 180 GLenum
 181 _mesa_compressed_format_to_glenum(struct gl_context *ctx, GLuint mesaFormat)
 182 {
 183    switch (mesaFormat) {
 184 #if FEATURE_texture_fxt1
 185    case MESA_FORMAT_RGB_FXT1:
 186       return GL_COMPRESSED_RGB_FXT1_3DFX;
 187    case MESA_FORMAT_RGBA_FXT1:
 188       return GL_COMPRESSED_RGBA_FXT1_3DFX;
 189 #endif
 190 #if FEATURE_texture_s3tc
 191    case MESA_FORMAT_RGB_DXT1:
 192       return GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
 193    case MESA_FORMAT_RGBA_DXT1:
 194       return GL_COMPRESSED_RGBA_S3TC_DXT1_EXT;
 195    case MESA_FORMAT_RGBA_DXT3:
 196       return GL_COMPRESSED_RGBA_S3TC_DXT3_EXT;
 197    case MESA_FORMAT_RGBA_DXT5:
 198       return GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
 199 #if FEATURE_EXT_texture_sRGB
 200    case MESA_FORMAT_SRGB_DXT1:
 201       return GL_COMPRESSED_SRGB_S3TC_DXT1_EXT;
 202    case MESA_FORMAT_SRGBA_DXT1:
 203       return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT;
 204    case MESA_FORMAT_SRGBA_DXT3:
 205       return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT;
 206    case MESA_FORMAT_SRGBA_DXT5:
 207       return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT;
 208 #endif
 209 #endif
 210    default:
 211       _mesa_problem(ctx, "Unexpected mesa texture format in"
 212                     " _mesa_compressed_format_to_glenum()");
 213       return 0;
 214    }
 215 }
 216
 217
 218 /*
 219  * Return the address of the pixel at (col, row, img) in a
 220  * compressed texture image.
 221  * \param col, row, img - image position (3D), should be a multiple of the
 222  *                        format's block size.
 223  * \param format - compressed image format
 224  * \param width - image width (stride) in pixels
 225  * \param image - the image address
 226  * \return address of pixel at (row, col, img)
 227  */
 228 GLubyte *
 229 _mesa_compressed_image_address(GLint col, GLint row, GLint img,
 230                                gl_format mesaFormat,
 231                                GLsizei width, const GLubyte *image)
 232 {
 233    /* XXX only 2D images implemented, not 3D */
 234    const GLuint blockSize = _mesa_get_format_bytes(mesaFormat);
 235    GLuint bw, bh;
 236    GLint offset;
 237
 238    _mesa_get_format_block_size(mesaFormat, &bw, &bh);
 239
 240    ASSERT(col % bw == 0);
 241    ASSERT(row % bh == 0);
 242
 243    offset = ((width + bw - 1) / bw) * (row / bh) + col / bw;
 244    offset *= blockSize;
 245
 246    return (GLubyte *) image + offset;
 247 }