Re: radeon 2d engine and alpha blending

On Fri, 2003-11-21 at 04:39, Alex Deucher wrote:
> > > I realize that I could attempt to use it for render accel, but I was
> > > hoping to tie it into Keithp's compositing extension
> > > (http://www.freedesktop.org/Software/TranslucentWindows) to support
> > > alpha blended windows, not just hw accelerated AA text. 

What else would xcompmgr be using, if not RENDER?


> [...] I may need to use the 3d engine, 

'May'?

> which then gets into a whole new can of worms with regard to state and 
> locking.

I doubt it'll be all that bad, and anyway, you can worry about that once
you have something working...


> > >>Transparent bitblits are supported by XAA's normal bitblit
> > functions,
> > > 
> > > how are these used?  are there any apps that use them?  render?
> > 
> > Plain old ScreenToScreen copy. trans_color (the last argument to the 
> > SetupScreenToScreenCopy function) holds the (source) color which is 
> > handled to be transparent. It's as simple as that. (hint, hint: 
> > sis310_accel.c) And MD is right, it's not a plain "transparent"
> > bitblit, 
> > it's colorkeyed in fact (but only using one color key, not a range). 
> > Isn't used very often, though.
> 
> Thanks for the pointers.  I'll take a look.  It may not be worth the
> effort.

Colour-keyed blits have been implemented in the radeon driver for
ages... problem is, they're not what you'd like them to be. :)
(XDirectFB uses them for SHAPE quite nicely though)


-- 
Earthling Michel Dänzer      |     Debian (powerpc), X and DRI developer
Software libre enthusiast    |   http://svcs.affero.net/rm.php?r=daenzer