[cairo] Compositing benchmarks

[jose_ogp at juno.com]

> > Obviously there's a reason for this seeming disparity
> > -- possibly it's the desire to have a single unified method for
> > dealing with transforms... But I would say that this is an area
> > that could use more looking into.
> 
> I think the reason is simply that we haven't gotten around to
> fixing it yet. I'd love to see someone implement a software
> "mipmap"-like approach for image scaling. It would eliminate one
> of the few visual-quality warts still left in cairo.
> 
> -Carl

	Mipmapping approaches seem to have some 'issues'...
In order to obtaing something close to full sampling (and thus 'good'
results), one needs more than just (1/2,1/2) factors.. which means
a somewhat more complex 'mipmapping' approach. But perhaps one could
make this work satisfactory.

	Again, it's odd that such an important aspect of comp gfx
hasn't been covered in great detail before, with some (maybe many)
satisfactory solution to 'high quality' image transforms being well
known in the field.

   jose.