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 "mtypes.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(struct gl_context *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 #if FEATURE_ES1 || FEATURE_ES2
 112    if (formats) {
 113       formats[n++] = GL_PALETTE4_RGB8_OES;
 114       formats[n++] = GL_PALETTE4_RGBA8_OES;
 115       formats[n++] = GL_PALETTE4_R5_G6_B5_OES;
 116       formats[n++] = GL_PALETTE4_RGBA4_OES;
 117       formats[n++] = GL_PALETTE4_RGB5_A1_OES;
 118       formats[n++] = GL_PALETTE8_RGB8_OES;
 119       formats[n++] = GL_PALETTE8_RGBA8_OES;
 120       formats[n++] = GL_PALETTE8_R5_G6_B5_OES;
 121       formats[n++] = GL_PALETTE8_RGBA4_OES;
 122       formats[n++] = GL_PALETTE8_RGB5_A1_OES;
 123    }
 124    else {
 125       n += 10;
 126    }
 127 #endif
 128 }
 129
 130
 131 /**
 132  * Convert a compressed MESA_FORMAT_x to a GLenum.
 133  */
 134 gl_format
 135 _mesa_glenum_to_compressed_format(GLenum format)
 136 {
 137    switch (format) {
 138    case GL_COMPRESSED_RGB_FXT1_3DFX:
 139       return MESA_FORMAT_RGB_FXT1;
 140    case GL_COMPRESSED_RGBA_FXT1_3DFX:
 141       return MESA_FORMAT_RGBA_FXT1;
 142
 143    case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
 144    case GL_RGB_S3TC:
 145       return MESA_FORMAT_RGB_DXT1;
 146    case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
 147    case GL_RGB4_S3TC:
 148       return MESA_FORMAT_RGBA_DXT1;
 149    case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
 150    case GL_RGBA_S3TC:
 151       return MESA_FORMAT_RGBA_DXT3;
 152    case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
 153    case GL_RGBA4_S3TC:
 154       return MESA_FORMAT_RGBA_DXT5;
 155
 156    case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT:
 157       return MESA_FORMAT_SRGB_DXT1;
 158    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT:
 159       return MESA_FORMAT_SRGBA_DXT1;
 160    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT:
 161       return MESA_FORMAT_SRGBA_DXT3;
 162    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT:
 163       return MESA_FORMAT_SRGBA_DXT5;
 164
 165    default:
 166       return MESA_FORMAT_NONE;
 167    }
 168 }
 169
 170
 171 /**
 172  * Given a compressed MESA_FORMAT_x value, return the corresponding
 173  * GLenum for that format.
 174  * This is needed for glGetTexLevelParameter(GL_TEXTURE_INTERNAL_FORMAT)
 175  * which must return the specific texture format used when the user might
 176  * have originally specified a generic compressed format in their
 177  * glTexImage2D() call.
 178  * For non-compressed textures, we always return the user-specified
 179  * internal format unchanged.
 180  */
 181 GLenum
 182 _mesa_compressed_format_to_glenum(struct gl_context *ctx, GLuint mesaFormat)
 183 {
 184    switch (mesaFormat) {
 185 #if FEATURE_texture_fxt1
 186    case MESA_FORMAT_RGB_FXT1:
 187       return GL_COMPRESSED_RGB_FXT1_3DFX;
 188    case MESA_FORMAT_RGBA_FXT1:
 189       return GL_COMPRESSED_RGBA_FXT1_3DFX;
 190 #endif
 191 #if FEATURE_texture_s3tc
 192    case MESA_FORMAT_RGB_DXT1:
 193       return GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
 194    case MESA_FORMAT_RGBA_DXT1:
 195       return GL_COMPRESSED_RGBA_S3TC_DXT1_EXT;
 196    case MESA_FORMAT_RGBA_DXT3:
 197       return GL_COMPRESSED_RGBA_S3TC_DXT3_EXT;
 198    case MESA_FORMAT_RGBA_DXT5:
 199       return GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
 200 #if FEATURE_EXT_texture_sRGB
 201    case MESA_FORMAT_SRGB_DXT1:
 202       return GL_COMPRESSED_SRGB_S3TC_DXT1_EXT;
 203    case MESA_FORMAT_SRGBA_DXT1:
 204       return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT;
 205    case MESA_FORMAT_SRGBA_DXT3:
 206       return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT;
 207    case MESA_FORMAT_SRGBA_DXT5:
 208       return GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT;
 209 #endif
 210 #endif
 211    default:
 212       _mesa_problem(ctx, "Unexpected mesa texture format in"
 213                     " _mesa_compressed_format_to_glenum()");
 214       return 0;
 215    }
 216 }
 217
 218
 219 /*
 220  * Return the address of the pixel at (col, row, img) in a
 221  * compressed texture image.
 222  * \param col, row, img - image position (3D), should be a multiple of the
 223  *                        format's block size.
 224  * \param format - compressed image format
 225  * \param width - image width (stride) in pixels
 226  * \param image - the image address
 227  * \return address of pixel at (row, col, img)
 228  */
 229 GLubyte *
 230 _mesa_compressed_image_address(GLint col, GLint row, GLint img,
 231                                gl_format mesaFormat,
 232                                GLsizei width, const GLubyte *image)
 233 {
 234    /* XXX only 2D images implemented, not 3D */
 235    const GLuint blockSize = _mesa_get_format_bytes(mesaFormat);
 236    GLuint bw, bh;
 237    GLint offset;
 238
 239    _mesa_get_format_block_size(mesaFormat, &bw, &bh);
 240
 241    ASSERT(col % bw == 0);
 242    ASSERT(row % bh == 0);
 243
 244    offset = ((width + bw - 1) / bw) * (row / bh) + col / bw;
 245    offset *= blockSize;
 246
 247    return (GLubyte *) image + offset;
 248 }