RGBA opaque regions

[Cody Russell <bratsche gnome org>]

I would like to re-propose a new hint for the ewmh spec, with the changes that were suggested by Fredrik Höglund.

_NET_WM_OPAQUE_REGION

As I would like to change gtk+ to be able to support RGBA colormaps by default, we would like some mechanism to allow the compositing manager to be optimized by knowing the regions of the window that are opaque.  Matthias Clasen would like to only enable RGBA-by-default in gtk+ if this proposed hint is available in _NET_SUPPORTED.  The toolkit would store the region as a list of rectangles which represent regions that are known to be opaque.

If nobody disagrees, I will try to prepare a patch against the spec and file that.

Thanks,

   Cody