[cairo] Pixman Performance Regressions

[Chris Wilson]

On Fri, 2009-08-07 at 00:07 +0200, Soeren Sandmann wrote:
> The glyph regresssion for the image backend is because the image
> backend unlike the X backend is drawing glyphs in a way that doesn't
> have fast path support in pixman. This means many calls to the general
> path with small images. In master this is inherently slower because we
> now do proper clipping instead of relying on region calculus. I'm not
> sure there is a general fix for this, but we can fix the concrete
> symptom by writing fast paths for glyph rendering.

More fast paths for glyphs is always good news! Can you explain what the
difference is between doing proper clipping and using regions? Is this
something that cairo can take advantage of?
-ickle