CGAL 4.7 - 2D Triangulation
ConstrainedTriangulationFaceBase_2 Concept Reference

## Definition

In a constrained triangulation, the information about constrained edges is stored in the faces of the triangulation. The base face of a constrained triangulation has to be a model of the concept ConstrainedTriangulationFaceBase_2 which refines the concept TriangulationFaceBase_2 providing functionalities to deal with constraints.

Refines:
TriangulationFaceBase_2

Types

Defines the same types as the TriangulationFaceBase_2 concept

Has Models:
CGAL::Constrained_triangulation_face_base_2<Traits>
TriangulationFaceBase_2
CGAL::Constrained_triangulation_2<Traits,Tds>
CGAL::Constrained_triangulation_face_base_2<Traits>

## Access Functions

bool is_constrained (int i)
returns true if the edge between the face and its neighbor neighbor(i) is constrained. More...

## Modifiers

void set_constraint (int i, bool b)
This is an advanced function. More...

void set_constraints (bool c0, bool c1, bool c2)
This is an advanced function. More...

void reorient ()
This is an advanced function. More...

void ccw_permute ()
This is an advanced function. More...

void cw_permute ()
This is an advanced function. More...

## Miscellaneous

bool is_valid ()
This is an advanced function. More...

## Member Function Documentation

 void ConstrainedTriangulationFaceBase_2::ccw_permute ( )

performs a counterclockwise permutation of the vertices, neighbors and constrained status of the face.

 void ConstrainedTriangulationFaceBase_2::cw_permute ( )

performs a clockwise permutation of the vertices and neighbors and constrained status of the face.

 bool ConstrainedTriangulationFaceBase_2::is_constrained ( int i)

returns true if the edge between the face and its neighbor neighbor(i) is constrained.

Precondition
$$0\leq i \leq2$$.
 bool ConstrainedTriangulationFaceBase_2::is_valid ( )

tests the validity of the face as a face of a plain triangulation and additionally checks if the edges of the face are consistently marked as constrained or unconstrained edges in the face and its neighbors.

 void ConstrainedTriangulationFaceBase_2::reorient ( )

changes the orientation of the face by exchanging vertex(0) with vertex(1) and neighbor(0) with neighbor(1) and the corresponding constrained status.

 void ConstrainedTriangulationFaceBase_2::set_constraint ( int i, bool b )

sets the edge between the face and its neighbor neighbor(i) as a constrained or unconstrained edge according to b.