Render spec clarification

[Adam Jackson]

On Mon, 2008-10-13 at 11:19 -0700, Keith Packard wrote:
> On Mon, 2008-10-13 at 13:50 -0400, Adam Jackson wrote:
> > "like a copy" semantics of Option B to make
> > the results predictable.
> 
> The core protocol uses 'like a copy' for CopyArea/CopyPlane. Actually
> creating a copy would be fairly simple inside the Render code -- just
> make a copy of the destination and use that as whichever source operands
> match the destination.

Either or both source operands, remember.

> > The other possibly unpleasant bit about Option B is it introduces more
> > cases where the server will need to do significant allocation to satisfy
> > rendering.  Probably not a huge deal, but worth noting.
> 
> A pain, to be sure.
> 
> If we do this, we would want to make sure the driver could recognize
> scrolling cases and make those work correctly. And, make GraphicsExpose
> events actually work too.

My thinking there was that we'd just smash onto the CopyArea path like
we do already.  Technically (a SRC b) is more general than a plain blit
since they can be different Picture formats pointing to the same Pixmap,
but that seems like something we should just not allow for the scrolling
loophole.

I get what GraphicsExpose events are supposed to be for, but not really
how the region is defined.  It does seem like CopyArea's returned region
is approximately the same thing though.

- ajax
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 197 bytes
Desc: This is a digitally signed message part
URL: <http://lists.x.org/archives/xorg/attachments/20081013/84327c4a/attachment.pgp>