[Xcb] double buffering

[Thomas Hunger]

Hello,

I am a bit confused about double buffering in the new Xorg. 

As I understand, the composite enabled servers will give me a drawable 
which I can draw to. Then I "Damage" the drawable and it will be 
composited onto the screen, making double buffering unnecessary?

Is that the reason why there is no double buffering extension (dbe) in 
XCB any more?

If my X server does not have compositing enabled, how would I 
implement double buffering in XCB? Using pixmap as a back buffer?

rather confused thanks,
Tom