[cairo] Pixman refactoring

[Jeff Muizelaar]

On Tue, May 19, 2009 at 05:42:02PM +0200, Soeren Sandmann wrote:
> An implementation has a reference to another implementation that it
> can use for fallbacks. For example, the sse2 implementation knows
> about an mmx implementation, which knows about a "C fast path"
> implementation, which knows about a "general" implementation.
> 
> An implementation can optionally implement accelerated combiners,
> which will be used from the general implementation. To make this work,
> each implementation also knows about the toplevel implementation in
> the stack, so that when it calls a lower level virtual function, it
> can get the best implementation available.

I'm wondering about the benefit of the indirection to the delegate
implementation. I can't think of any situations where an implementation
wouldn't know it's delegate statically. Any thoughts?

-Jeff