Composite and damage status

[Egbert Eich]

Keith Packard writes:
 > 
 > Around 11 o'clock on May 11, Egbert Eich wrote:
 > 
 > > - Does that mean we don't have to 'fix' XAA any more for composite?
 > 
 > Correct.  "fixing" XAA would still be a good idea, but it's not required.
 > Using the 'shim' layer causes duplicate allocation of GCs, Pictures and a 
 > lot of extra region manipulation.  Functional, but sub-optimal.
 > 

:-((( 

 > > - Will we 'automatically' get offscreen fb storage of COMPOSITE
 > >   windows doing this? XAA can do offscreen pixmaps. If a wrapping
 > >   layer makes a lower layer believe that these windows are really
 > >   pixmaps it should work. (I have to admit I've never looked at
 > >   the BS code).
 > 
 > That would have happened in any case as the rendering is directed at 
 > pixmaps.  The shim, however, eliminates the window entirely from the DDX's 
 > viewpoint, so rendering appears to be directed solely at pixmaps.
 > 

OK. Then you have to tell the DDX in some way what is 'on screen' and
what is 'off screen'  I suppose. I don't see how this will work
with the XAA implementation as this uses the drawable type to decide
where the data goes. Windows - from an XAA point of view - are always
'on screen' Pixmaps can either live in offscreen fb memory or in main
memory at the XAA level's discretion.

Egbert.