CGAL users discussion list

[Ashwin Nanjappa <>]

Bill Conan wrote:
> i'm a little confused with the Edge. is there any Edge data structure
> that is explicitly implemented in the CGAL?

No.

> my problem is i need to add some attribute to the Edge like this:
[...]
> but i'm wondering, if i travel all the edges in this way, and give
> each edge a color
[...]
> then is that true that only half of the half-edges are assigned the color red?

Yes.

> and which half-edge of the two half-edges of an Edge can be visited by
> the edge iterator? is there any rule behind?

If the half edges are {0, 1, 2, 3, 4, 5}, the edge iterator visits {0, 2, 
4}. The edge iterator and the half edge iterator access the same half edge 
data structure. The edge iterator just skips 2 items instead of 1 when you 
 apply the ++ operator to it.

> say if at the beginning i let all the edges in red. and then i split
> some random edges of the geometry.
> and i assign the all the splitted edge to be in red too.
>
> and now i if i travel all the edges again,
[...]
> can i make sure all the edges i traveled are in red?

I couldn't understand your query.

~ash