Re: [Qemu-devel] [PATCH] opengl rendering in the sdl window

["François Revol" <revol@free.fr>]

> On Mon, Sep 08, 2008 at 11:53:57AM +0100, Stefano Stabellini wrote:
> > Daniel P. Berrange wrote:
> >
> > > On Mon, Sep 08, 2008 at 11:30:09AM +0100, Stefano Stabellini
> > > wrote:
> > >> I completely agree with Avi: Opengl has been around since 1992,
> > > > and now
> > >> you tell me that it is better not to use it because it breaks
> > > > Compiz?!
> > >> To say the least it would be a bad long term engineering
> > > > decision.
> > >
> > > It would be a bad decision *if* OpenGL were the only technical
> > > solution
> > > to the problem. There are a variety of possible solutions with
> > > various
> > > pluses & minuses. If it is possible to do an implementation which
> > > uses
> > > hardware acceleration for scaling to get the same level of
> > > performance
> > > as the OpenGL proposal, it is good sense to evaluate it. Blindly
> > > going
> > > for OpenGL when it has known problems without evaluating
> > > alternatives
> > > would be the bad engineering  decision.
> >
> >
> > You are right that we have a variety of possible solution each one
> > with
> > its own pros and cons.
> > I think removing SDL(+Opengl) for Gtk and Cairo is not a good idea
> > *but*
> > we could add another Gtk based fronted.
>
> Sorry, I wasn't being entirely clear in my suggestion. Cairo itself
> is not
> tied to any toolkit - its dependancy is on libX11 / the RENDER
> extension.
> So, use of Cairo is rather tangential to question of GTK vs SDL - you
> can
> use Cairo with either of them. That said, it may turn out that SDL
> does
> not expose enough of its X11 internals to allow an efficient use of
> Cairo.
> It would need some experimentation to determine for sure, because the
> docs
> aren't entirely clear on this question.

It would definitely make things much less portable...
Cairo itself is quite a beast to port I heard... (not everyone uses
X11...)

François.