[compiz] Using glitz directly vs using XRender

[Mike Hearn]

> Looks correct. I highly recommend using xrender. Any filter support
> being added to cairo should be able to use the existing filter interface
> that is part of xrender and already accelerated by Xgl. Using glitz
> backend shouldn't give you anything extra. Using it will just add some
> overhead from creating an additional GL context instead of having Xgl
> use its core GL context.

Huh. So does that mean the XRender protocol will be extended as time 
goes by to simply have whatever effects are added to Cairo? What if my 
app wants to do something like draw some shapes with Cairo then do a 
hardware blur ... with GL I'd use a pixel shader, but how is that 
expressed in XRender? It knows about each effect individually?

I dunno ... it just seems odd to have two protocols to talk to the 
graphics hardware, GLX and XRender, when GLX presumably has so many more 
features. I know I've seen debate on the xorg lists before on whether 
incrementally extending XRender is a good idea or whether it'd just turn 
into a GL clone eventually.

What are your thoughts on that?

thanks -mike