/**
* Decompress a compressed texture image, returning a GL_RGBA/GL_FLOAT image.
* \param srcRowStride stride in bytes between rows of blocks in the
* compressed source image.
*/
void
_mesa_decompress_image(mesa_format format, GLuint width, GLuint height,
const GLubyte *src, GLint srcRowStride,
GLfloat *dest)
{
compressed_fetch_func fetch;
GLuint i, j;
GLuint bytes, bw, bh;
GLint stride;
bytes = _mesa_get_format_bytes(format);
_mesa_get_format_block_size(format, &bw, &bh);
fetch = _mesa_get_compressed_fetch_func(format);
if (!fetch) {
_mesa_problem(NULL, "Unexpected format in _mesa_decompress_image()");
return;
}
stride = srcRowStride * bh / bytes;
for (j = 0; j < height; j++) {
for (i = 0; i < width; i++) {
fetch(src, stride, i, j, dest);
dest += 4;
}
}
}
/**
* Initialize the texture image's FetchTexel methods.
*/
static void
set_fetch_functions(const struct gl_sampler_object *samp,
struct swrast_texture_image *texImage, GLuint dims)
{
gl_format format = texImage->Base.TexFormat;
#ifdef DEBUG
/* check that the table entries are sorted by format name */
gl_format fmt;
for (fmt = 0; fmt < MESA_FORMAT_COUNT; fmt++) {
assert(texfetch_funcs[fmt].Name == fmt);
}
#endif
STATIC_ASSERT(Elements(texfetch_funcs) == MESA_FORMAT_COUNT);
if (samp->sRGBDecode == GL_SKIP_DECODE_EXT &&
_mesa_get_format_color_encoding(format) == GL_SRGB) {
format = _mesa_get_srgb_format_linear(format);
}
assert(format < MESA_FORMAT_COUNT);
switch (dims) {
case 1:
texImage->FetchTexel = texfetch_funcs[format].Fetch1D;
break;
case 2:
texImage->FetchTexel = texfetch_funcs[format].Fetch2D;
break;
case 3:
texImage->FetchTexel = texfetch_funcs[format].Fetch3D;
break;
default:
assert(!"Bad dims in set_fetch_functions()");
}
texImage->FetchCompressedTexel = _mesa_get_compressed_fetch_func(format);
ASSERT(texImage->FetchTexel);
}
