[cairo] Road to 1.10

[Alexander Larsson]

On Tue, 2009-02-17 at 11:39 -0500, Kristian Høgsberg wrote:
> On Tue, Feb 17, 2009 at 5:58 AM, Alexander Larsson <alexl at redhat.com> wrote:
> > On Mon, 2009-02-16 at 15:23 -0500, Kristian Høgsberg wrote:
> >> On Mon, Feb 16, 2009 at 12:20 PM, Alexander Larsson <alexl at redhat.com> wrote:
> >> > Everything that scrolls use subwindows, plus GtkEventBox. Plus a bunch
> >> > of other widgets.
> >> >
> >> > We already allocate a pixmap when rendering double buffered, true, but
> >> > we only allocate one such pixmap per toplevel when exposing, so we still
> >> > need to clip in that pixmap when drawing multiple subwindows in that
> >> > toplevel.
> >>
> >> Yeah, what I meant was that for those subwindows we could just
> >> allocate more pixmaps, draw to them, then copy their contents back to
> >> the overall double buffer pixmap.
> >
> > Seems like a total waste of resources. Why not just clip. It already
> > works for essentially all apps, the clip_reset() case hasn't triggered
> > in any case I've seen yet.
> 
> I'm suggesting a transient allocation; you allocate the pixmap, render
> to it, copy it back, destroy it.  It uses more resources than the
> device clip idea, sure, but I don't think it's a bad approach.

I just don't understand why its even proposed. Cairo needs to handle
clipping anyway, so it won't save any code.