ArrangementTopologyTraits Concept Reference

Definition

A geometry traits class encapsulates the definitions of the geometric entities and implements the geometric predicates and constructions needed by instances of the CGAL::Arrangement_on_surface_2 class template and by the peripheral algorithms that operate on objects of such instances. Essentially, it maintains the doubly-connected connected edge list (DCEL) used by the arrangement.

The package contains three topology traits, as follows:

• CGAL::Arr_spherical_topology_traits_2—can serve as a topology traits for an arrangement of planar bounded curves.
• CGAL::Arr_bounded_planar_topology_traits_2—can serve as a topology traits for an arrangement of planar unbounded curves.
• CGAL::Arr_unb_planar_topology_traits_2—can serve as a topology traits for an arrangement of arcs of great circles embedded on a sphere.

At this point we do not expose all the requirements of this concept.

Has models

CGAL::Arr_bounded_planar_topology_traits_2<GeometryTraits_2,Dcel>

CGAL::Arr_unb_planar_topology_traits_2<GeometryTraits_2,Dcel>

CGAL::Arr_spherical_topology_traits_2<GeometryTraits_2,Dcel>

See also

Arrangement_on_surface_2<GeometryTraits_2,TopologyTraits>

Types
typedef unspecified_type	Geometry_traits_2

Creation
	Arr_topology_traits ()
	constructs default.
	Arr_topology_traits (const Geometry_traits_2 *geometry_traits)
	constructs from a geometry-traits object.

Access Functions
const Dcel &	dcel () const
	obtains the (const) DCEL.
Dcel &	dcel ()
	obtains the (non-const) DCEL.