[compiz] Using glitz directly vs using XRender

[Mike Hearn]

Hi,

In the past I've found that using the glitz backend to Cairo with Xorg 
made some simple animation tests I wrote go much faster. I haven't yet 
tried them with Xgl but I was wondering which backend is theoretically 
'best' in this configuration?

My understanding is that Xgl feeds everything drawn to the screen via 
OpenGL - a bit like Quartz 2D Extreme will when Apple get it stable 
enough to enable by default. So the paths would look like:

app -> cairo -> xrender backend -> [xgl  xrender -> glitz -> gl]

   and

app -> cairo -> glitz backend -> glx -> [xgl -> gl]

Does that look right? Which makes more sense to use within a Compiz 
plugin? Can the second pipeline offer more acceleration for things like 
some of the SVG filter effects that are being moved into Cairo?

thanks -mike