[maemo-developers] Clutter in Fremantle (Alpha SDK)

[From: Henrik Hedberg]

Kimmo Hämäläinen wrote:
> On Tue, 2009-03-17 at 08:37 +0100, ext Henrik Hedberg wrote:

>>     Is this somehow related to this statement: "It is assumed that we 
>> will have only one OpenGL drawing context, and thus a single process 
>> running in the system will be using Clutter at a time. This process will 
>> be the window manager and the implementor of all challenging graphical 
>> UI effects on the screen." [2]
> 
> This we have assumed in the design, but it does not mean that multi-
> context does not work. As Kate has already proven, multi-context works.
> But as long as you have hildon-desktop running in the background, you
> will not render directly to the screen even if you use
> Clutter/QtGraphicsView/EGL+OpenGLES2.0/whatnot in your application. When
> hildon-desktop is running, it is the only one drawing on the screen
> (with the exception of XVideo). So, killing hildon-desktop is the only
> way to get direct rendering to the screen at the moment. (We might have
> something more elegant for this in the future...)

    Could you clarify what does this mean in practice? Is the 
performance of 3D rendering significantly slower in applications, for 
example? I suppose that even if off-screen rendering is used it is still 
hardware accelerated. Thus, compositing in window manager level should 
not be a big issue, and we can live with that (for now) if everything 
just work fast enough. Who needs direct rendering anyway. :)

    BR,

    Henrik

-- 
    Henrik Hedberg  -  http://www.henrikhedberg.net/