> This requires some work describing geometry. Whether
> it is done with if/then/else or delta function or ...
> is probably not critical. The work is not just a bunch
> of programming of easy ideas.
"Le mieux est l'ennemi du bien." = The best is the enemy of the good.
There is nothing wrong with handling simple cases simply, just because
complicated cases are daunting. What I think is more important is
making sure that any answer we *do* give is correct: not giving an
answer is far better than giving an incorrect answer.
-s