[cairo] Road to 1.10

Kristian Høgsberg krh at bitplanet.net
Tue Feb 17 08:39:49 PST 2009


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.

cheers,
Kristian


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