input transformations

[David Reveman]

On Mon, 2007-02-05 at 11:11 -0800, Deron Johnson wrote:
> It's hard for me to evaluate this without some higher level context.
> What sort of window transformations are you aiming to support
> 3D perspective affine transformations? What sort of 3D objects will the
> windows be mapped onto? There are a variety of possibilities:
> a quad of infinite thinness, a flat slab (rectangular parallelipiped) or
> any arbitrarily shaped 3D object. And, do you want to permit interaction
> with transformed windows or use transformation only for transitional 
> effects?

I'd like us to be able to support an arbitrarily shaped 3D object even
though I don't have any good use cases for that yet. The most important
use cases right now are scaling, translating and duplicating windows but
we'll definitely use this for more complex transformations soon.

> If you want the former you will need to perform mouse-over picking with
> input pointer events. If you merely want the latter then it simplifies the
> problem considerably. If you can give me a brief summary of what
> effects you are trying to achieve I can be in a better position to
> help evaluate this proposal. Thanks.

We've been doing the later in compiz for quite a while now. You can
check out some of the videos here:
http://www.go-compiz.org/index.php?title=Video
if you want to get up to date on the kind of window transformations that
compiz is currently doing. However, I'm not just interested in solving
the current cases but providing a solution that will work for years to
come.

- David