input transformations

[David Reveman]

On Wed, 2007-02-07 at 00:01 -0800, Keith Packard wrote:
> On Wed, 2007-02-07 at 00:25 -0500, David Reveman wrote:
> 
> > It's just pairs of triangles, one triangle in parent space paired with a
> > triangle in child space. Basic uv-mapping is used to transform a
> > coordinate from parent -> child or child -> parent.
> 
> How are you doing picking? Using the original stacking order? Or is
> there a tag on each triangle in the mapping which indicates whether that
> space is mapped to visible window pixels?

Using the original stacking order. Just making a triangle map all
coordinates outside the border clip of the window will give you the same
result as such a tag.

- David