CGAL 5.1.3  2D Arrangements

#include <CGAL/Arrangement_2.h>
Face.
An object of the class Face
represents an arrangement face, namely, a \( 2\)dimensional arrangement cell.
An arrangement that supports only bounded curves contains exactly one unbounded face, and a number of bounded faces. An arrangement that supports also unbounded curves has one or more unbounded faces. Such an arrangement has also exactly one fictitious face, which does not correspond to a real twodimensional cell of the arrangement (and thus it is ignored in counting the number of faces of the arrangement.) Each bounded face has an outer boundary comprising a halfedge chain winding in counterclockwise orientation around it. Each unbounded face of an arrangement that has a fictitious face also has a boundary comprising a counterclockwise halfedgechain. The edges on the boundary of a face incident to the fictitious face are fictitious, as they do not correspond to real curves. A face may also contain holes, which are defined by clockwiseoriented halfedge chains, and isolated vertices.
Creation  
Face ()  
default constructor.  
Access Functions  
All nonconst methods listed below also have  
bool  is_fictitious () const 
returns a Boolean indicating whether this is the fictitious face, which contain the entire arrangement (and does not have an outer CCB). More...  
bool  is_unbounded () const 
returns a Boolean indicating whether the face is unbounded.  
bool  has_outer_ccb () const 
returns a Boolean indicating whether the face has an outer CCB. More...  
Ccb_halfedge_circulator  outer_ccb () 
returns a circulator that enables traversing the outer boundary of f . More...  
Hole_iterator  holes_begin () 
returns an iterator for traversing all the holes (inner CCBs) of f .  
Hole_iterator  holes_end () 
returns a pasttheend iterator for the holes of f .  
Isolated_vertex_iterator  isolated_vertices_begin () 
returns an iterator for traversing all the isolated vertices contained in the interior of f .  
Isolated_vertex_iterator  isolated_vertices_end () 
returns a pasttheend iterator for the isolated vertices contained inside f .  
bool CGAL::Arrangement_2< Traits, Dcel >::Face::has_outer_ccb  (  )  const 
returns a Boolean indicating whether the face has an outer CCB.
(The fictitious face and the unbounded face of an arrangement that does not have a fictitious face do not have outer CCBs.)
bool CGAL::Arrangement_2< Traits, Dcel >::Face::is_fictitious  (  )  const 
returns a Boolean indicating whether this is the fictitious face, which contain the entire arrangement (and does not have an outer CCB).
An arrangement that supports only bounded curves does not have a fictitious face at all.
Ccb_halfedge_circulator CGAL::Arrangement_2< Traits, Dcel >::Face::outer_ccb  (  ) 
returns a circulator that enables traversing the outer boundary of f
.
The edges along the CCB are traversed in a counterclockwise direction.
f
has an outer CCB.