Resizing and scrolling very slow when running a compositing manager

[Brian Paul]

Matthias Hopf wrote:
> On Apr 25, 06 14:21:21 +0100, Ioannis Nousias wrote:
> 
>>>I have a Radeon 9200 Mobility and I'm running Xorg 7.0 with radeon driver.
>>>If I run a compositing manager like xcompmgr, scrolling and resizing
>>>windows is much slower, especially for applications like Firefox. I
> 
> 
> It's somehow a fundamental problem. AFAIR David has already thought
> quite a lot about it, there is no trivial fix for that right now,
> though. The problem is that the off-screen surfaces have to be resized,
> which is a costly operation. It's also expensive on higher end hardware,
> just not as noticable.
> 
> I think in the near future the resize plugin can do something about it
> (an intermediate off-screen surface during resizing, doing the final
> size in the very end), but nothing right now.

In another project I had to resize off-screen Pbuffers in response to 
window size changes.  I allocated my Pbuffers at a multiple of 32 
pixels.  Therefore, changing the size by a small amount didn't require 
reallocating the Pbuffer.  Seemed to work pretty well.

Is XGL doing anything like that?

-Brian