Re: Vrooom

[Owen Taylor <otaylor redhat com>]

Pavel Machek <pavel ucw cz> writes:

> Hi!
> 
> > I'm about to commit the attached (quite large) patch. It's all about
> > accelerating alpha compositing of images with and without the RENDER
> > extension, though it has random bug fixes scattered in it.
> > 
> > How fast? It's pretty hard to quantify because it depends a lot on:
> > 
> >  - Whether RENDER is present or not
> >  - Whether RENDER is hardware accelerated
> >  - Whether the target drawable is in video ram or not
> >  - System details
> 
> I see comment about 2 roundtrips for older X servers. Will no this kill
> performance for remote displays? Think modem or internet...

I don't see the comments about "2 roundtrips". Yes, round alpha compositing
does involve a (single) round trip to the server when going over the
wire. 

People who find that unacceptable will probably want to upgrade to a
server supporting RENDER.

This is nothing new with my patch ... what my patch does is remove
round trips when RENDER is available.

Regards,
                                                  Owen