CGAL 6.0  2D Arrangements

#include <CGAL/Arrangement_on_surface_2.h>
typename Dcel::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.
Types inherited from the base Dcel::Face  
typedef Base::Inner_ccb_iterator  Inner_ccb_iterator 
a bidirectional iterator over the inner CCBs of the face.  
typedef Base::Outer_ccb_iterator  Outer_ccb_iterator 
a bidirectional iterator over the outer CCBs of the face.  
typedef Base::Hole_iterator  Hole_iterator 
a bidirectional iterator over the holes (i.e., inner CCBs) contained inside the face.  
typedef Base::Isolated_vertex_iterator  Isolated_vertex_iterator 
a bidirectional iterator over the isolated vertices contained inside the face.  
Creation  
Face ()  
default constructor.  
Access Functions  
All nonconst methods listed below also have  
bool  is_fictitious () const 
obtains a Boolean indicating whether this is the fictitious face, which contain the entire arrangement (and does not have an outer CCB).  
bool  is_unbounded () const 
obtains a Boolean indicating whether the face is unbounded.  
Size  number_of_outer_ccbs () const 
obtains the number of outer CCBs of the face.  
Outer_ccb_iterator  outer_ccbs_begin () 
obtains a begin iterator for the outer CCBs of the face.  
Outer_ccb_iterator  outer_ccbs_end () 
obtains a pasttheend iterator for the outer CCBs.  
Size  number_of_inner_ccbs () const 
obtains the number of inner CCBs of the face.  
Inner_ccb_iterator  inner_ccbs_begin () 
obtains a begin iterator for the inner CCBs of the face.  
Inner_ccb_iterator  inner_ccbs_end () 
obtains a pasttheend iterator for the inner CCBs.  
bool  has_outer_ccb () const 
indicates whether the face has an outer CCB.  
Ccb_halfedge_circulator  outer_ccb () 
obtains a circulator that enables traversing the outer boundary of f .  
Size  number_of_holes () const 
obtains the number of holes (inner CCBs) inside the face.  
Hole_iterator  holes_begin () 
obtains an iterator for traversing all the holes (inner CCBs) of f .  
Hole_iterator  holes_end () 
obtains a pasttheend iterator for the holes of f .  
Isolated_vertex_iterator  isolated_vertices_begin () 
obtains an iterator for traversing all the isolated vertices contained in the interior of f .  
Isolated_vertex_iterator  isolated_vertices_end () 
obtains a pasttheend iterator for the isolated vertices contained inside f .  
typedef Base::Hole_iterator CGAL::Arrangement_on_surface_2< GeometryTraits, TopologyTraits >::Face::Hole_iterator 
a bidirectional iterator over the holes (i.e., inner CCBs) contained inside the face.
Its value type is Ccb_halfedge_circulator
.
typedef Base::Inner_ccb_iterator CGAL::Arrangement_on_surface_2< GeometryTraits, TopologyTraits >::Face::Inner_ccb_iterator 
a bidirectional iterator over the inner CCBs of the face.
Its value type is Ccb_halfedge_circulator
.
typedef Base::Isolated_vertex_iterator CGAL::Arrangement_on_surface_2< GeometryTraits, TopologyTraits >::Face::Isolated_vertex_iterator 
a bidirectional iterator over the isolated vertices contained inside the face.
Its value type is Vertex
.
typedef Base::Outer_ccb_iterator CGAL::Arrangement_on_surface_2< GeometryTraits, TopologyTraits >::Face::Outer_ccb_iterator 
a bidirectional iterator over the outer CCBs of the face.
Its value type is Ccb_halfedge_circulator
.
bool CGAL::Arrangement_on_surface_2< GeometryTraits, TopologyTraits >::Face::has_outer_ccb  (  )  const 
indicates 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_on_surface_2< GeometryTraits, TopologyTraits >::Face::is_fictitious  (  )  const 
obtains 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_on_surface_2< GeometryTraits, TopologyTraits >::Face::outer_ccb  (  ) 
obtains 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.