[Cairo] virtualizing the surface interface

[Carl Worth]

On Sep 26, Keith Packard wrote:
 > Around 2 o'clock on Sep 26, Jamey Sharp wrote:
 > 
 > > * Virtualize the backend interface so that the various backends can be
 > > compiled conditionally.
 >
 > Looks like you've made a good stab at this -- I do wonder how well this 
 > interface will support a PostScript backend though.

It should already be roughly at the low level you've proposed for a
PostScript backend. That is, it can generate PostScript with lists of
trapezoids rather than splines.

But certainly, when we actually implement the PostScript backend I'm
sure we'll find all kinds of things we want to change. One intentional
decision in the current framework is that the backend interface is not
exposed at all so we are free to gut and rewrite as much as needed.

-Carl

PS. Maybe if I add this to the TODO:

	* Write PostScript backend.

we can see another magic patch appear from another new Cairo
maintainer. :)

Thanks again, Jamey.