EXA

[Lars Knoll]

On Wednesday 12 October 2005 06:32, Eric Anholt wrote:
> On Wed, 2005-10-12 at 01:54 +0200, Thomas Winischhofer wrote:
> > -----BEGIN PGP SIGNED MESSAGE-----
> > Hash: SHA1
> >
> >
> > EXA is getting close to the point where it is entirely useless on
> > hardware that doesn't accelerate render/composite.
> >
> > On my (admittedly slow, 400Mhz) testbox, I can actually watch KDE paint
> > its default blue background.
> >
> > Adding some logging into the EXA hooks reveals that the driver receives
> > millions (yes, millions) of calls of copy commands with a width and
> > height of 1. Yes, 1. It fills the screen with 1x1 copy commands.
>
> Sounds like KDE is using a 1x1 pixmap for the window background, rather
> than setting a solid color.  Lame.  We'll just need to do something
> similar to what exaComposite does for 1x1 repeating pictures -- read out
> the one pixel and solid-fill it over the whole thing.

No, it's not KDE. In many cases the only way to set do solid fills in Render 
is to setup a 1x1 pixmap with Repeat (at least it was up to 3 months ago). 
Xft uses exactly the same scheme, feel free to check XftDrawSrcPicture in 
xftdraw.c.

Using 1x1 pictures with repeat has been a standard idiom in Render to do solid 
fills for years. The software code in fb/ has optimised code paths for this 
case. So should exa.

Lars