A shalfloop is a great circle on a sphere map. Figure 28.10 depicts the relationship between a shalfloop and its incident shalfloops, and sfaces on a sphere map. A shalfloop is an oriented sloop. It is always paired with a shalfloop whose supporting Sphere_circle is pointing in the opposite direction. The twin() member function returns this shalfloop of opposite orientation.
A sphere map having a shalfloop models the neighborhood of a vertex which is isolated on a facet. That facet is returned by the member function facet.
#include <CGAL/Nef_polyhedron_3.h>
The following types are the same as in Nef_polyhedron_3<Traits>.
There is no need for a user to create a SHalfloop explicitly. The class Nef_polyhedron_3<Traits> manages the needed shalfloops internally.
CGAL::Nef_polyhedron_3<Traits>::Halffacet
CGAL::Nef_polyhedron_3<Traits>::SFace
CGAL::Nef_polyhedron_S2<Traits>::Sphere_point