[cairo] GSoC: Scan converting rasteriser update

[Carl Worth]

On Wed, 2008-10-01 at 15:19 -0400, Jeff Muizelaar wrote:
> Overall comments:
> - I don't really like the make_span_renderer interface. It might be better if
>   instead of relying on the fallback surface, we had helpers that would be called from
>   the image surface's fill and stroke methods.

Agreed.

This approach is a general one that could be applied liberally to
cairo's code base to clean it up considerably. That is, it would be nice
to have explicit code in each backend for each interface, calling into
specific helper functions, rather than just returning UNSUPPORTED and
relying on the fallback code to do something, (which might not be
optimal across all backends). And even if the fallback code doesn't
perform poorly, it makes the code much harder to read.

We've had that idea for a long time, but haven't gotten around to
cleaning up any existing interfaces to make the switch. But I definitely
agree that I'd like to see new interfaces added with this new style.

> I'll probably have more comments but let's start with these.

Thanks for the code review, Jeff!

-Carl

PS. I do love git branches and the ability to do things like "git fetch
joonas" to track all the latest code branches that Joonas has done. But
at the same time, I really love having code come across my email inbox.
Code in my inbox basically forces me to take a look at it, while code in
a git tree, (even with a nice "please review this branch" mail in my
inbox), waits for me to go looking for it.

So anyone, (Adrian, Joonas, Chris), that's been waiting for me to review
some branch of cairo work, please feel free to send it to the list. I'm
fine with a patch series as one long message, (but binary attachments
put me back in the position of having to do extra steps to go read the
code).