Re: radeon 2d engine and alpha blending

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.  Although
thinking about it more, I guess the compositing manager could take
advantage of the render accel to accelerate alpha blending.

> Transparent bitblits are supported by XAA's normal bitblit functions,

how are these used?  are there any apps that use them?  render?


Alex

--- Thomas Winischhofer <[email protected]> wrote:
> Alex Deucher wrote:
> > According to marketing literature from ati, radeon hardware seems
> to
> > support alpha and transparent BLTs.  from the literature under 2D
> > graphics:
> > 
> > Support for Windows XP GDI extensions:
> > Alpha BLT
> > Transparent BLT
> > Gradient Fill
> > 
> > The databooks and DDKs also have several sections on doing
> transparent
> > BLTs.  is there any reason that this can't be used to accelerate
> alpha
> > blending in the xserver?  it seems like this has come up before and
> > there was a reason it wouldn't work, but from the looks of it I
> can't
> > see why it wouldn't.  I'd try to implement it myself, but I'm not
> > familiar enough if XAA to understand how it should be done.  In the
> > long run using the 3D engine is probably the way to go, but if it
> could
> > be hacked up quickly using the 2D engine it might give a nice boost
> in
> > the short term.
> 
> I'm almost too embarrased to say that (twice a day) - but as regards 
> alpha blended bitblits have a look at the sis (or mga) driver on how
> to 
> make use of this (keyword RENDER acceleration).
> 
> I can't think of a useful application for gradient fills (yes, sis 
> supports that, too).
> 
> Transparent bitblits are supported by XAA's normal bitblit functions,
> 
> hence this could be of some use.
> 
> Thomas
> 
>


__________________________________
Do you Yahoo!?
Protect your identity with Yahoo! Mail AddressGuard
http://antispam.yahoo.com/whatsnewfree