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/*
* Mesa 3-D graphics library
* Version: 6.5.1
*
* Copyright (C) 1999-2006 Brian Paul All Rights Reserved.
* Copyright (c) 2008 VMware, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
/**
* \file texcompress.c
* Helper functions for texture compression.
*/
#include "glheader.h"
#include "imports.h"
#include "colormac.h"
#include "context.h"
#include "formats.h"
#include "image.h"
#include "mipmap.h"
#include "texcompress.h"
#include "texstore.h"
/**
* Return list of (and count of) all specific texture compression
* formats that are supported.
*
* \param ctx the GL context
* \param formats the resulting format list (may be NULL).
* \param all if true return all formats, even those with some kind
* of restrictions/limitations (See GL_ARB_texture_compression
* spec for more info).
*
* \return number of formats.
*/
GLuint
_mesa_get_compressed_formats(GLcontext *ctx, GLint *formats, GLboolean all)
{
GLuint n = 0;
if (ctx->Extensions.TDFX_texture_compression_FXT1) {
if (formats) {
formats[n++] = GL_COMPRESSED_RGB_FXT1_3DFX;
formats[n++] = GL_COMPRESSED_RGBA_FXT1_3DFX;
}
else {
n += 2;
}
}
if (ctx->Extensions.EXT_texture_compression_s3tc) {
if (formats) {
formats[n++] = GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
/* This format has some restrictions/limitations and so should
* not be returned via the GL_COMPRESSED_TEXTURE_FORMATS query.
* Specifically, all transparent pixels become black. NVIDIA
* omits this format too.
*/
if (all)
formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT1_EXT;
formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT3_EXT;
formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
}
else {
n += 3;
if (all)
n += 1;
}
}
if (ctx->Extensions.S3_s3tc) {
if (formats) {
formats[n++] = GL_RGB_S3TC;
formats[n++] = GL_RGB4_S3TC;
formats[n++] = GL_RGBA_S3TC;
formats[n++] = GL_RGBA4_S3TC;
}
else {
n += 4;
}
}
#if FEATURE_EXT_texture_sRGB
if (ctx->Extensions.EXT_texture_sRGB) {
if (formats) {
formats[n++] = GL_COMPRESSED_SRGB_S3TC_DXT1_EXT;
formats[n++] = GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT;
formats[n++] = GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT;
formats[n++] = GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT;
}
else {
n += 4;
}
}
#endif /* FEATURE_EXT_texture_sRGB */
return n;
}
/**
* Convert a compressed MESA_FORMAT_x to a GLenum.
*/
gl_format
_mesa_glenum_to_compressed_format(GLenum format)
{
switch (format) {
case GL_COMPRESSED_RGB_FXT1_3DFX:
return MESA_FORMAT_RGB_FXT1;
case GL_COMPRESSED_RGBA_FXT1_3DFX:
return MESA_FORMAT_RGBA_FXT1;
case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
case GL_RGB_S3TC:
return MESA_FORMAT_RGB_DXT1;
case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
case GL_RGB4_S3TC:
return MESA_FORMAT_RGBA_DXT1;
case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
case GL_RGBA_S3TC:
return MESA_FORMAT_RGBA_DXT3;
case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
case GL_RGBA4_S3TC:
return MESA_FORMAT_RGBA_DXT5;
case GL_COMPRESSED_SRGB_S3TC_DXT1_EXT:
return MESA_FORMAT_SRGB_DXT1;
case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT:
return MESA_FORMAT_SRGBA_DXT1;
case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT:
return MESA_FORMAT_SRGBA_DXT3;
case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT:
return MESA_FORMAT_SRGBA_DXT5;
default:
return MESA_FORMAT_NONE;
}
}
/*
* Return the address of the pixel at (col, row, img) in a
* compressed texture image.
* \param col, row, img - image position (3D), should be a multiple of the
* format's block size.
* \param format - compressed image format
* \param width - image width (stride) in pixels
* \param image - the image address
* \return address of pixel at (row, col, img)
*/
GLubyte *
_mesa_compressed_image_address(GLint col, GLint row, GLint img,
gl_format mesaFormat,
GLsizei width, const GLubyte *image)
{
/* XXX only 2D images implemented, not 3D */
const GLuint blockSize = _mesa_get_format_bytes(mesaFormat);
GLuint bw, bh;
GLint offset;
_mesa_get_format_block_size(mesaFormat, &bw, &bh);
ASSERT(col % bw == 0);
ASSERT(row % bh == 0);
offset = ((width + bw - 1) / bw) * (row / bh) + col / bw;
offset *= blockSize;
return (GLubyte *) image + offset;
}
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