CGAL 5.4 - 2D Apollonius Graphs (Delaunay Graphs of Disks)
ApolloniusGraphHierarchyVertexBase_2 Concept Reference

## Definition

The vertex of an Apollonius graph included in an Apollonius graph hierarchy has to provide some pointers to the corresponding vertices in the graphs of the next and preceding levels. Therefore, the concept ApolloniusGraphHierarchyVertexBase_2 refines the concept ApolloniusGraphVertexBase_2, by adding two vertex handles to the corresponding vertices for the next and previous level graphs.

Refines:
ApolloniusGraphVertexBase_2

Types

ApolloniusGraphHierarchyVertexBase_2 does not introduce any types in addition to those of ApolloniusGraphVertexBase_2.

Has Models:
CGAL::Apollonius_graph_hierarchy_vertex_base_2<CGAL::Apollonius_graph_vertex_base_2<Gt,StoreHidden> >
ApolloniusGraphDataStructure_2
CGAL::Apollonius_graph_hierarchy_2<Gt,Agds>
CGAL::Triangulation_data_structure_2<Vb,Fb>

## Creation

ApolloniusGraphHierarchyVertexBase_2 ()
Default constructor.

ApolloniusGraphHierarchyVertexBase_2 (Site_2 s).
Constructs a vertex associated with the site s and embedded at the center of s.

ApolloniusGraphHierarchyVertexBase_2 (Site_2 s, Face_handle f).
Constructs a vertex associated with the site s, embedded at the center of s, and pointing to face f.

## Operations

Vertex_handle up ()
Returns a handle to the corresponding vertex of the next level Apollonius graph. More...

Vertex_handle down ()
Returns a handle to the corresponding vertex of the previous level Apollonius graph.

void set_up (Vertex_handle u)
Sets the handle for the vertex of the next level Apollonius graph.

void set_down (Vertex_handle d)
Sets the handle for the vertex of the previous level Apollonius graph;.

## ◆ up()

 Vertex_handle ApolloniusGraphHierarchyVertexBase_2::up ( )

Returns a handle to the corresponding vertex of the next level Apollonius graph.

If such a vertex does not exist Vertex_handle(nullptr) is returned.