Compositing GL

[Stefan Dösinger]

Am Mittwoch, 22. August 2007 20:57 schrieb H. Verbeet:
> > This solution is the best way to go. Luckily Microsoft made similar
> > changes in Vista.
>
> Conceptually its probably correct, but I think the speed hit is pretty
> large, and it's not like we've got a lot of performance to spare. As
> for the Vista comparison... Vista isn't exactly well known for it's
> OpenGL performance either. What is the performance hit for something
> like the CSS stress test? That should be a bit more representative
> than dx9 swapchains.
>
> I'm certainly not saying it's not a good idea, but I do think the
> performance hit shouldn't be quite as noticeable.
I think for applications like css, we shouldn't activate that code at all. css 
renders to a top level window, so it doesn't have any clipping problems. The 
pixel format problem should be fixed in other ways, like making it safe to 
recreate X11 windows, as it seems to be needed for other things too.

I have tested this with a few apps. Simple d3d8 and d3d7 demos work nicely, 
but the mfctex and mfcfog samples crash with a GLXBadDrawable in 
X_GLXMakeCurrent. Wine also complains about missing GLX_MESA_copy_sub_buffer, 
but it does that in both working and broken demos. I also tried the warcraft 
3 map editor, it fails with the bad drawable error too, and windows media 
player 10. The alchemy visualization doesn't crash, but it doesn't update the 
screen either.

But it looks very promising. The apps that work look nice now :-)