CGAL users discussion list

[Marc Glisse <>]

On Mon, 27 Feb 2012, Zohar wrote:

> I read this faq already, and I'm aware that the double is less robust, but I
> thought that only for complicated algorithm, I need more than it.

Anything that involves computations (like, say, an addition) is 
complicated.

> Frankly I
> expected the double to be able to intersect two segments with common edge.
> Otherwise I think this should be emphasized (this specific point regarding
> intersection) in the intersection / Cartesian / faq (which is too mild IMO
> on this point).

FAQ: never use Cartesian<double>. If you insist on shooting yourself in 
the foot, at least use Simple_cartesian<double> instead.

> Anyway I tried the exact_exact and it's terribly slow.

There is a price to pay...

If you only need to check whether 2 objects intersect and not know their 
intersection, use a predicate (do_intersect I think) and not a 
construction (intersection?), so the Epick kernel might be enough.


--
Marc Glisse