[Gzz] Tjl(10th)

[Tuomas Lukka]

Stencil stuff, discovering a nasty NVIDIA driver bug: depth and stencil tests
affect each other really badly. So we'll have to use stencils without depth for 
now;
luckily, for the demos this can probably be done.

Also, thinking about drawing the cutaway shapes (Jvk: please read carefully,
I'd like you to think about this one a little). What we want is to use a texture
to define the stencil shape as a square with two irregular edges. This is simple
with e.g. three quads, using (alpha - texture alpha ) as the alpha through
register combiners and then using alpha_test to discard some fragments. However,
the problem is that I want to draw an about two-pixel thick edge for the whole 
shape.
It *should* be doable by just drawing approx. the same quads but getting the 
border
right for the irregular parts is difficult. Do we need to create a special 
texture with
some extra info in a different component? At least that way it *can* be done.


        Tuomas