[PATCH] remove damagePostOp() from DamageDamageRegion()

Michel Dänzer michel at tungstengraphics.com
Fri Aug 29 02:58:32 PDT 2008

On Wed, 2008-08-27 at 15:10 -0700, Aaron Plattner wrote:
> For implementing 5:
>     It seems like it would be possible to add a new request that's similar
> to DamageSubtract but that also inserts a sync marker into X's channel and
> returns the counter value to the client.  The client would then use some
> new extension to insert a waitSync on that counter value into its own
> channel before continuing.  This would ensure that the client's rendering
> happens after X's, while allowing both X and the client to continue to
> enqueue more commands.

It occurred to me that this description sounds similar to a possible
implementation of glXWaitX(). Maybe that could be used at least as an
initial solution for the problem until a potential better solution is
worked out.

Aaron, you opined on IRC that glXWaitX isn't sufficient, but from my
reading of the GLX spec, I don't understand why not. In particular, the
spec says:

        X rendering calls made prior to glXWaitX are guaranteed to be
        executed before OpenGL rendering calls made after glXWaitX.

How do others interpret this?

Earthling Michel Dänzer           |          http://tungstengraphics.com
Libre software enthusiast         |          Debian, X and DRI developer

More information about the xorg mailing list