Re: [Mesa3d-dev] [mesa patch 1/3] dri2: Event driven buffer validation.

[Michel D. <mi...@da...>]

On Sat, 2010-01-16 at 23:01 +0100, Francisco Jerez wrote: 
> When a buffer invalidation event is received from the X server, the
> "invalidate" hook of the DRI2 flush extension is executed: A generic
> implementation (dri2InvalidateDrawable) is provided that just bumps
> the "pStamp" sequence number in __DRIdrawableRec.
> 
> For old servers not supporting buffer invalidation events, the
> invalidate hook will be called after flushing the fake front/back
> buffer (that's typically once per frame -- not a lot worse than the
> situation we were in before).

When the invalidate event is available, IMO the buffers should also only
be invalidated after a buffer swap / front buffer flush, not 'in the
middle of a frame'.


> No effort has been made on preserving backwards compatibility with
> version 2 of the flush extension, but I think it's acceptable because
> AFAIK no released stack is making use of it.

IIRC it was added for a released but proprietary driver.


> @@ -378,17 +394,14 @@ dri2SwapBuffers(__GLXDRIdrawable *pdraw, int64_t target_msc, int64_t divisor,
>      /* Old servers can't handle swapbuffers */
>      if (!pdp->swapAvailable) {
>         dri2CopySubBuffer(pdraw, 0, 0, priv->width, priv->height);
> +       dri2LegacyInvalidate(pdraw);
> +
>         return 0;
>      }
>  

Doesn't this also need to call dri2LegacyInvalidate() if
(pdp->swapAvailable) but (!pdp->invalidateAvailable)?


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