[cairo] path storage optimizations ( was: how to propose a change? )

[Vladimir Vukicevic]

ionous wrote:
> all, re: is it worth it?
> 
> i think so.  whether things like a tad fewer allocs and a tad less 
> memory used trump code maintenance is a definitely an important 
> question.  in this case, i think the new code is just different than the 
> old code, not less maintainable.  previously you had to understand the 
> why of checking for flags like "current point" and peeks for "move tos" 
> -- now you have to grok a small state machine, and a null terminated 
> list of draw commands.  neither is particularly problematic, tho both 
> require some thought.

Does this actually show up in real-world preformance, though?  I 
understand that there are serious memory fragmentation and other issues 
on consoles, but it doesn't look like these changes would actually help 
with any of that: they would just achieve a very modest memory savings 
but still keep the exact same current allocation scheme.  The 
LINE_SEGMENT/CURVE_SEGMENT suggestion in particular seems like an 
optimization for disjoint lines/curves, which I think are fairly 
uncommon in paths.

> once i get back from my trip - i will figure out the build issues, make 
> patches against latest, and re-post so y'all can take a closer look-see.

I've got updated win32 makefiles for pixman and for cairo that I'll be 
checking in shortly; you'll need to grab a win32 build of libpng and 
zlib and make them available in $INCLUDE/$LIB, but other than that it 
should build cleanly then.

     - Vlad