Menelaos Karavelas and Mariette Yvinec
An Apollonius graph is the dual of the Apollonius diagram, also known as the additively weighted Voronoi diagram. It is essentially the Voronoi diagram of a set of disks, where the distance of a point of the plane from a disk is defined as the Euclidean distance of the point and the center of the circle, minus the radius of the disk.
Cgal provides the class CGAL::Apollonius_graph_2<Gt,Agds> for computing the 2D Apollonius graph. The two template parameters must be models of the ApolloniusGraphTraits_2 and ApolloniusGraphDataStructure_2 concepts. The first concept is related to the geometric objects and predicates associated with Apollonius graphs, whereas the second concept refers to the data structure used to represent the Apollonius graph. The classes Apollonius_graph_traits_2<K,Method_tag> and Triangulation_data_structure_2<Vb,Fb> are models of the aforementioned concepts.
ApolloniusGraphHierarchyVertexBase_2
CGAL::Apollonius_graph_hierarchy_2<Gt,Agds>
CGAL::Apollonius_graph_hierarchy_vertex_base_2<Agvb>