Re: [Gzz] Re: [Gzz-commits] gzz/doc/gl irreg0.png irreg1.png

[Tuomas Lukka]

> Ok, yes, I wasn't thinking correctly. In your images, you need to draw 
> a border around the intersection of an irregular (defined by cs2) and a 
> regular (cs1) shape.
> 
> I.e., in the case where they partially intersect, part of the border is 
> the border of the visible area, and part of the border is the border of 
> the irregular shape.
> 
> So, how do you archieve that? Or, am I still not understanding right?

Well, in OpenGL to draw a stencil all I need to do is to figure a way to
draw exactly those fragments that will be in it. For this case, it's
pretty easy: just look at the edges ( there won't be too many of them,
especially if we assume that cs1 and cs2 are both upright. 

We adjust the texture coordinates / color (depending on how we set
the transparency), so that we get irregularity exactly where necessary.

        Tuomas