CGAL users discussion list

[James Le Cuirot <>]

On Thu, 1 Apr 2010 23:53:01 +0200
"Laurent Rineau (GeometryFactory)"
<>
 wrote:

> > The Ray_2 class has a function called supporting_line(). It sounds
> > useful but I'm not quite sure what it does. The docs say it returns
> > the line supporting r which has the same direction. What is a
> > supporting line exactly?  
> 
> Given a (non-degenerated) ray, there is exactly one line that
> contains it. That is the supporting line of the ray.
> 
> Another example: given a triangle in 3D there is exactly one plane
> that contains it, that the supporting plane.
> 
> I think you get the point, now.

Hmm I wish I did. I'm lacking some background here. Doesn't a ray extend
to infinity in one direction? How can a line "contain" that?

James