CGAL 5.3 - 2D Triangulation Data Structure
TriangulationDataStructure_2::Vertex Concept Reference

## Definition

The concept TriangulationDataStructure_2::Vertex describes the type used by a TriangulationDataStructure_2 to store the vertices.

Some of the requirements listed below are of geometric nature and are optional when using the triangulation data structure class alone. They became required when the triangulation data structure is plugged into a triangulation.

Creation

In order to obtain new vertices or destruct unused vertices, the user must call the create_vertex() and delete_vertex() methods of the triangulation data structure.

Has Models:
CGAL::Triangulation_ds_vertex_base_2<Tds>
TriangulationDSVertexBase_2
TriangulationDataStructure_2::Face
TriangulationDataStructure_2

## Types

The class TriangulationDataStructure_2::Vertex defines the same types as the triangulation data structure except the iterators.

typedef unspecified_type Point
Optional for the triangulation data structure used alone.

## Access Functions

Point point () const
returns the geometric information of the vertex.

Face_handle face () const
returns a face of the triangulation having *this as a vertex.

## Setting

void set_point (const Point &p)
This is an advanced function. More...

void set_face (Face_handle f)
This is an advanced function. More...

## Checking

bool is_valid (bool verbose=false) const
Checks the validity of the vertex. More...

std::istream & operator>> (std::istream &is, TriangulationDataStructure_2::Vertex &v)
Inputs the non-combinatorial information possibly stored in the vertex.

std::ostream & operator<< (std::ostream &os, const TriangulationDataStructure_2::Vertex &v)
Outputs the non combinatorial operation possibly stored in the vertex.

## ◆ is_valid()

 bool TriangulationDataStructure_2::Vertex::is_valid ( bool verbose = false ) const

Checks the validity of the vertex.

Must check that its incident face has this vertex. The validity of the base vertex is also checked.

When verbose is set to true, messages are printed to give a precise indication on the kind of invalidity encountered.

## ◆ set_face()

 void TriangulationDataStructure_2::Vertex::set_face ( Face_handle f )

sets the incident face to f.
sets the geometric information to p.