[cairo] Compositing benchmarks

[jose_ogp at juno.com]

	Bill Spitzak wrote:

> The more immediate and useful solution for Cairo is to do filtered
> sampling of more than 4 pixels of the source image. I believe that
> for Cairo, a pixel-aligned box filter is quite sufficient, and has
> the advantage of blending smoothly with how cairo enlarges images.
> The following will do it, there is just a small matter of optimizing
> it  :-)
> 
> ....
> ....

	Seems like a reasonable start. :)
	It might take some work, but if you could write out an actual
working sample implementation, I'm sure optimizations could be made
to follow.

   jose.