>From the GLX spec:
"GLX_X_RENDERABLE is a boolean indicating whether X can be used to
render into a drawable created with the GLXFBConfig. This attribute
is True if the GLXFBConfig supports GLX windows and/or pixmaps."
Every backend was setting this to true unconditionally, and then the
core ignored that value and sent true unconditionally on its own. This
is broken for ARB_fbconfig_float and EXT_fbconfig_packed_float, which
only apply to pbuffers, which are not renderable from non-GLX APIs.
Instead compute GLX_X_RENDERABLE from the supported drawable types. The
dri backends were getting _that_ wrong too, so fix that as well.
This is not a functional change, as there are no mesa drivers that claim
to support __DRI_ATTRIB_{UNSIGNED_,}FLOAT_BIT yet.
Signed-off-by: Adam Jackson <ajax@redhat.com>
Reviewed-by: Eric Anholt <eric@anholt.net>