src/mesa/main/texcompress.c

   1 /* $Id: texcompress.c,v 1.3 2002/10/24 23:57:21 brianp Exp $ */
   2
   3 /*
   4  * Mesa 3-D graphics library
   5  * Version:  4.1
   6  *
   7  * Copyright (C) 1999-2002  Brian Paul   All Rights Reserved.
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a
  10  * copy of this software and associated documentation files (the "Software"),
  11  * to deal in the Software without restriction, including without limitation
  12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  13  * and/or sell copies of the Software, and to permit persons to whom the
  14  * Software is furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be included
  17  * in all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  20  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  22  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  23  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  24  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  */
  26
  27
  28 #include "glheader.h"
  29 #include "imports.h"
  30 #include "context.h"
  31 #include "image.h"
  32 #include "texcompress.h"
  33 #include "texformat.h"
  34
  35
  36 /**
  37  * Get the list of supported internal compression formats.
  38  * \param formats - the results list (may be NULL)
  39  * \return number of formats.
  40  */
  41 GLuint
  42 _mesa_get_compressed_formats( GLcontext *ctx, GLint *formats )
  43 {
  44    GLuint n = 0;
  45    if (ctx->Extensions.ARB_texture_compression) {
  46       if (ctx->Extensions.TDFX_texture_compression_FXT1) {
  47          if (formats) {
  48             formats[n++] = GL_COMPRESSED_RGB_FXT1_3DFX;
  49             formats[n++] = GL_COMPRESSED_RGBA_FXT1_3DFX;
  50          }
  51          else {
  52             n += 4;
  53          }
  54       }
  55    }
  56    return n;
  57 }
  58
  59
  60
  61 /**
  62  * Return bytes of storage needed for the given texture size and compressed
  63  * format.
  64  * \param width, height, depth - texture size in texels
  65  * \param texFormat - one of the compressed format enums
  66  * \return size in bytes, or zero if bad texFormat
  67  */
  68 GLuint
  69 _mesa_compressed_texture_size( GLcontext *ctx,
  70                                GLsizei width, GLsizei height, GLsizei depth,
  71                                GLenum format )
  72 {
  73    GLuint size;
  74
  75    switch (format) {
  76    case GL_COMPRESSED_RGB_FXT1_3DFX:
  77    case GL_COMPRESSED_RGBA_FXT1_3DFX:
  78       /* round up to multiple of 4 */
  79       size = ((width + 7) / 8) * ((height + 3) / 4) * 16;
  80       return size;
  81    default:
  82       _mesa_problem(ctx, "bad texformat in compressed_texture_size");
  83       return 0;
  84    }
  85 }
  86
  87
  88 /*
  89  * Compute the bytes per row in a compressed texture image.
  90  */
  91 GLint
  92 _mesa_compressed_row_stride(GLenum format, GLsizei width)
  93 {
  94    GLint bytesPerTile, stride;
  95
  96    switch (format) {
  97    default:
  98       return 0;
  99    }
 100
 101    stride = ((width + 3) / 4) * bytesPerTile;
 102    return stride;
 103 }
 104
 105
 106 /*
 107  * Return the address of the pixel at (col, row, img) in a
 108  * compressed texture image.
 109  * \param col, row, img - image position (3D)
 110  * \param format - compressed image format
 111  * \param width - image width
 112  * \param image - the image address
 113  * \return address of pixel at (row, col)
 114  */
 115 GLubyte *
 116 _mesa_compressed_image_address(GLint col, GLint row, GLint img,
 117                                GLenum format,
 118                                GLsizei width, const GLubyte *image)
 119 {
 120    GLint bytesPerTile, stride;
 121    GLubyte *addr;
 122
 123    ASSERT((row & 3) == 0);
 124    ASSERT((col & 3) == 0);
 125    (void) img;
 126
 127    switch (format) {
 128    default:
 129       return 0;
 130    }
 131
 132    stride = ((width + 3) / 4) * bytesPerTile;
 133
 134    addr = (GLubyte *) image + (row / 4) * stride + (col / 4) * bytesPerTile;
 135    return addr;
 136 }
 137
 138
 139
 140 /*
 141  * \param srcRowStride - source stride, in pixels
 142  */
 143 void
 144 _mesa_compress_teximage( GLcontext *ctx, GLsizei width, GLsizei height,
 145                          GLenum srcFormat, const GLchan *source,
 146                          GLint srcRowStride,
 147                          const struct gl_texture_format *dstFormat,
 148                          GLubyte *dest, GLint dstRowStride )
 149 {
 150    switch (dstFormat->MesaFormat) {
 151    default:
 152       _mesa_problem(ctx, "Bad dstFormat in _mesa_compress_teximage()");
 153       return;
 154    }
 155 }