[Openchrome-users] Accelerated Rotation?

[Thomas Hellström]

Dan Sandberg wrote:

> > No. The OpenChrome driver does not support accelerated rotation at all.
> > The CN400 chip has hardware 2D support for accelerated rotation,
> > the CLE266 chip can probably do it using the 3D engine, but none of 
> this is supported in the
> > driver.
>
> How difficult would it be to add support for this?
>
> Thanks,
>
> -Dan

It's done in the intel driver, but I've never looked at the code.

The 3D api you need to access the texture engines is in via_3d.c.
This is probably the slower part but will be compatible with earlier
unichromes and unichrome pros that don't have the 2D rotation support.

For the (probably faster) 2D engine and Xv rotation support, you need
the unichrome pro programming manual from VIA, and probably a good bit
of trial-and-error to make it work.

It might be possible to have someone extend a compositing manager to use
EXA to rotate the screen in a non driver-specific way.  Try and ask on
the xorg list. If that's possible, it would be supported in hardware by
the openChrome driver.

/Thomas