pixmaps are offscreen and don't have alpha maps. It is the last case
checked before going to software fallback
- Use the new Composite hook in the ati driver to implement acceleration of
most Composites that get done in an xcompmgr environment on r100 series
cards. It is only available when using the DRM. There are still some
corruption issues, but the DRI is still non-default and I need to get
this into version control.