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

[Benja Fallenstein]

Tuomas Lukka wrote:

> On Wed, Sep 11, 2002 at 05:30:44PM +0200, Benja Fallenstein wrote:
>  
>
> > Tuomas Lukka wrote:
> >
> >    
> >
> > > On Wed, Sep 11, 2002 at 10:00:04AM +0200, Benja Fallenstein wrote:
> > >
> > >
> > >      
> > >
> > > > Remember that the difficult part in these is how to draw the border 
> > > > correctly (or so I think)-- any ideas on that, yet?
> > > >
> > > >        
> > > Try "make runirregu" ;) ;) ;)
> > >
> > >
> > >      
> > Hm, are you saying that you've already implemented it? How?
> >    
>
> A simple trick, which jvk suggested. (I had used it somewhere before
> but had forgotten it in the meantime)
>
>         First, draw the shape 4 times in black, shifted 2 pixels up,
>         down, left, right respectively.
>
>         Then, draw the shape in white.
>  

I don't really understand: The problem I was refering to is that you 
need to draw the border around the *intersection* of two irregular 
shapes-- how do you do that? Does the algorithm above solve that? If so, 
how? If not, what *does* it solve? ;-)

- Benja