[Xorg] XComposite, XDamage Extension with Xvideo or GL

Alan Cox alan at lxorguk.ukuu.org.uk
Sat Aug 7 10:10:04 PDT 2004

On Sad, 2004-08-07 at 18:59, Amir Bukhari wrote:
> What confuse me is the end (2D) image (after doing all 3D rendering) must be
> draw to the OpenGL Window. This surely the job of X Server DDX Layer -

For performance reasons the OpenGL direct render layer does the 2D blit
itself while holding the X lock so that its window rectangle lists don't
change under it. What you say is correct for a server side GL

The DRI client really doesn't care whether its drawing to the window or
offscreen. The problems is the memory allocation, the mechanism for
indicating that such behaviour should begin/end and the way in which the
server finds out if the area has been damaged. (Especially as for
most games the answer will always be "yes")

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