Requirements for a Vertex

Definition

A vertex optionally stores a point and a pointer to an incident halfedge that points to the vertex. Type tags indicate whether these member functions are supported. Figure  depicts the relationship between a halfedge and its incident halfedges, vertices, and facets.

Types

Vertex::Vertex
	self.
Vertex::Halfedge
	corresponding halfedge type.
Vertex::Facet
	corresponding facet type.

Type for (optionally) associated geometry. If a point is not supported the type is void*.

Vertex::Point
	point type stored in vertices.

Operations

Halfedge*	v.halfedge ()	an incident halfedge pointing to v.
const Halfedge*	v.halfedge ()
Point&	v.point ()	the point.
Point	v.point ()
void	v.set_halfedge ( Halfedge* h)
		set incident halfedge.

Types for Tagging Optional Features

The nested types below are either equal to Tag_true or Tag_false, depending on whether the named member function is supported or not.

Vertex::Supports_vertex_halfedge
	halfedge().
Vertex::Supports_vertex_point
	point().