mesa: fix GL_LUMINANCE handling in glGetTexImage

There are several cases in which we need to explicity "rebase" colors
(ex: set G=B=0) when getting GL_LUMINANCE textures:
1. If the luminance texture is actually stored as rgba
2. If getting a luminance texture, but returning rgba
3. If getting an rgba texture, but returning luminance

Fixes https://bugs.freedesktop.org/show_bug.cgi?id=46679

Also fixes the new piglit getteximage-luminance test.

Reviewed-by: José Fonseca <jfonseca@vmware.com>
This commit is contained in:
Brian Paul 2012-03-08 20:16:00 -07:00
parent 9917988223
commit f5d0ced242
1 changed files with 28 additions and 2 deletions

View File

@ -298,6 +298,8 @@ get_tex_rgba_uncompressed(struct gl_context *ctx, GLuint dimensions,
const gl_format texFormat =
_mesa_get_srgb_format_linear(texImage->TexFormat);
const GLuint width = texImage->Width;
const GLenum destBaseFormat = _mesa_base_tex_format(ctx, format);
GLenum rebaseFormat = GL_NONE;
GLuint height = texImage->Height;
GLuint depth = texImage->Depth;
GLuint img, row;
@ -318,6 +320,28 @@ get_tex_rgba_uncompressed(struct gl_context *ctx, GLuint dimensions,
height = 1;
}
if (texImage->_BaseFormat == GL_LUMINANCE ||
texImage->_BaseFormat == GL_INTENSITY ||
texImage->_BaseFormat == GL_LUMINANCE_ALPHA) {
/* If a luminance (or intensity) texture is read back as RGB(A), the
* returned value should be (L,0,0,1), not (L,L,L,1). Set rebaseFormat
* here to get G=B=0.
*/
rebaseFormat = texImage->_BaseFormat;
}
else if ((texImage->_BaseFormat == GL_RGBA ||
texImage->_BaseFormat == GL_RGB) &&
(destBaseFormat == GL_LUMINANCE ||
destBaseFormat == GL_LUMINANCE_ALPHA ||
destBaseFormat == GL_LUMINANCE_INTEGER_EXT ||
destBaseFormat == GL_LUMINANCE_ALPHA_INTEGER_EXT)) {
/* If we're reading back an RGB(A) texture as luminance then we need
* to return L=tex(R). Note, that's different from glReadPixels which
* returns L=R+G+B.
*/
rebaseFormat = GL_LUMINANCE_ALPHA; /* this covers GL_LUMINANCE too */
}
for (img = 0; img < depth; img++) {
GLubyte *srcMap;
GLint rowstride;
@ -335,12 +359,14 @@ get_tex_rgba_uncompressed(struct gl_context *ctx, GLuint dimensions,
if (is_integer) {
_mesa_unpack_uint_rgba_row(texFormat, width, src, rgba_uint);
_mesa_rebase_rgba_uint(width, rgba_uint, texImage->_BaseFormat);
if (rebaseFormat)
_mesa_rebase_rgba_uint(width, rgba_uint, rebaseFormat);
_mesa_pack_rgba_span_int(ctx, width, rgba_uint,
format, type, dest);
} else {
_mesa_unpack_rgba_row(texFormat, width, src, rgba);
_mesa_rebase_rgba_float(width, rgba, texImage->_BaseFormat);
if (rebaseFormat)
_mesa_rebase_rgba_float(width, rgba, rebaseFormat);
_mesa_pack_rgba_span_float(ctx, width, (GLfloat (*)[4]) rgba,
format, type, dest,
&ctx->Pack, transferOps);