CGAL 4.7  2D Triangulation

#include <CGAL/Triangulation_2.h>
Inherited by CGAL::Triangulation_2< Traits, Tds >, and CGAL::Triangulation_2< Weighted_point_mapper_2< Traits >, Tds >.
The class Triangulation_cw_ccw_2
offers two functions int cw(int i)
and int ccw(int i)
which, given the index of a vertex in a face, compute the index of the next vertex of the same face in clockwise or counterclockwise order.
This works also for neighbor indexes. Thus, for example the neighbor neighbor(cw(i))
of a face f
is the neighbor which is next to neighbor(i)
turning clockwise around f
. The face neighbor(cw(i))
is also the first face encountered after f
when turning clockwise around vertex i
of f
.
Many of the classes in the triangulation package inherit from Triangulation_cw_ccw_2
. This is for instance the case for CGAL::Triangulation_2::Face
. Thus, for example the neighbor neighbor(cw(i))
of a face f
is the neighbor which is next to neighbor(i)
turning clockwise around f
. The face neighbor(cw(i))
is also the first face encountered after f
when turning clockwise around vertex i
of f
.
Creation  
Triangulation_cw_ccw_2 ()  
default constructor.  
Operations  
int  ccw (const int i) const 
returns the index of the neighbor or vertex that is next to the neighbor or vertex with index i in counterclockwise order around a face.  
int  cw (const int i) const 
returns the index of the neighbor or vertex that is next to the neighbor or vertex with index i in counterclockwise order around a face.  