[cairo] Road to 1.10

[Chris Wilson]

On Mon, 2009-02-16 at 10:11 +0100, Alexander Larsson wrote:
> This is more of a feature request, since I've no time to implement this
> myself as things stand. But, after Gtk+ 2.16 is released (should be
> shortly now) we will try to merge the client side windows branch. The
> client side windows branch of gtk virtualizes all drawing to GdkWindows
> such that we can emulate the effects of subwindow clipping on the client
> side.

I agree that a form of device clipping is necessary to safely expose a
sub-surface to a direct rendering client, in particular I've been
thinking about this with regards to wayland.

So at the moment my thought is basically to add a clip extents to a
surface which may be smaller than its true extents. The biggest
difficultly lies in applying source clipping. Not too difficult for
cairo-drm where we can set up a sampler to a subset of a surface, but
for xlib support, I fear we may need to make a copy of the sub-surface
for the source.

Has anyone else had any thoughts about sub-surfaces?
-ickle