Re: radeon 2d engine and alpha blending

--- Michel D�nzer <[email protected]> wrote:
> 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 dunno... I just never really looked at render too much.  As I recall
back when it was first everyone wanted to do compositing with it and
the general reponse was that it was only for AA text.  I guess we were
just lacking the compmgr and damage extention at the time...

> 
> > [...] 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...

Yeah I know.  I doubt it'll be that bad.  It's just that I've gotten to
understand the 2d engine pretty well (or at least I think I do) and the
3D engine seems like this daunting "thing" out there.  However looking
at the code and databooks it doesn't look that complicated, I just need
to sit down and do it some day.  I'm just trying to get the most bang
from my limited time...

> 
> 
> > > >>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)
> 
> 

Yeah, I'm starting to understand how all this stuff fits together now. 
Is there anyway xfree86 could use them for the shape extension? or does
it already? 

Alex


__________________________________
Do you Yahoo!?
Free Pop-Up Blocker - Get it now
http://companion.yahoo.com/