CGAL 5.5.2 - 2D Hyperbolic Delaunay Triangulations
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The concept HyperbolicDelaunayTriangulationTraits_2
describes the set of requirements to be fulfilled by any class used to instantiate the first template parameter of the class CGAL::Hyperbolic_Delaunay_triangulation_2<Traits, Tds>
. It defines the geometric objects (points, segments...) forming the triangulation together with geometric predicates and constructions on these objects.
This concept refines DelaunayTriangulationTraits_2
because the class CGAL::Hyperbolic_Delaunay_triangulation_2
internally relies on the class CGAL::Delaunay_triangulation_2
.
Types | |
typedef unspecified_type | FT |
Field number type. | |
typedef unspecified_type | Hyperbolic_point_2 |
Represents a point in the Poincaré disk or on the (unit) circle at infinity. | |
typedef unspecified_type | Hyperbolic_Voronoi_point_2 |
Represents the dual object of a triangle in the hyperbolic Delaunay triangulation. More... | |
typedef unspecified_type | Hyperbolic_segment_2 |
Represents a hyperbolic segment defined by two points. More... | |
typedef unspecified_type | Hyperbolic_triangle_2 |
Represents a triangle in the hyperbolic plane defined by three hyperbolic points. | |
Predicate Types | |
typedef unspecified_type | Side_of_oriented_circle_2 |
A predicate object. More... | |
typedef unspecified_type | Side_of_oriented_hyperbolic_segment_2 |
A predicate object. More... | |
typedef unspecified_type | Is_Delaunay_hyperbolic |
A predicate object. More... | |
Construction Types | |
typedef unspecified_type | Construct_hyperbolic_segment_2 |
A constructor object. More... | |
typedef unspecified_type | Construct_hyperbolic_circumcenter_2 |
A constructor object. More... | |
typedef unspecified_type | Construct_hyperbolic_bisector_2 |
A constructor object. More... | |
Operations | |
The following functions give access to the predicate objects. | |
Orientation_2 | orientation_2_object () |
Side_of_oriented_circle_2 | side_of_oriented_circle_2_object () |
Side_of_oriented_hyperbolic_segment_2 | side_of_oriented_hyperbolic_segment_2_object () |
Is_Delaunay_hyperbolic | is_Delaunay_hyperbolic_object () |
The following functions must be provided only if the methods of | |
Construct_hyperbolic_segment_2 | construct_hyperbolic_segment_2_object () |
Construct_hyperbolic_circumcenter_2 | construct_hyperbolic_circumcenter_2_object () |
Construct_hyperbolic_bisector_2 | construct_hyperbolic_bisector_2_object () |
A constructor object.
Must provide the function operator
Hyperbolic_segment_2 operator()(Hyperbolic_point_2 p, Hyperbolic_point_2 q),
which constructs the hyperbolic bisector of two points p
and q
lying in the Poincaré disk. The endpoints of the resulting hyperbolic segment lie on the circle at infinity. It must also provide the function operator
Hyperbolic_segment_2 operator()(Hyperbolic_point_2 p, Hyperbolic_point_2 q, Hyperbolic_point_2 r),
where the points p, q
, and r
lie in the Poincaré disk. This overloaded version constructs the hyperbolic bisector of the segment [p,q] limited by the hyperbolic circumcenter of p, q, r
on one side and the circle at infinity on the other. Moreover, it must provide the function operator
Hyperbolic_segment_2 operator()(Hyperbolic_point_2 p, Hyperbolic_point_2 q, Hyperbolic_point_2 r, Hyperbolic_point_2 s),
where the points p, q, r
, and s
lie in the Poincaré disk. This overloaded version constructs the hyperbolic bisector of the segment [p,q] limited by the hyperbolic circumcenter of p, q, r
on one side, and the hyperbolic circumcenter of p, s, q
on the other side.
typedef unspecified_type HyperbolicDelaunayTriangulationTraits_2::Construct_hyperbolic_circumcenter_2 |
A constructor object.
Must provide the function operator
Hyperbolic_Voronoi_point_2 operator()(Hyperbolic_point_2 p, Hyperbolic_point_2 q, Hyperbolic_point_2 r),
which constructs the hyperbolic circumcenter of the triangle with vertices p, q
, and r
.
A constructor object.
Must provide the function operator
Hyperbolic_segment_2 operator()(Hyperbolic_point_2 p, Hyperbolic_point_2 q),
which constructs a hyperbolic segment from two points p
and q
. Note that p
and q
may also lie on the circle at infinity.
Represents a hyperbolic segment defined by two points.
In the Poincaré disk model, a hyperbolic segment is supported either by the Euclidean circle that passes through the two points and is perpendicular to the circle at infinity, or by the Euclidean line that passes through the two points and the origin. Abusively, we allow one or both endpoints of the segment to lie on the circle at infinity, so a hyperbolic segment can actually represent a hyperbolic ray or a hyperbolic line.
Represents the dual object of a triangle in the hyperbolic Delaunay triangulation.
The dual of a Delaunay triangle is the hyperbolic center of the circle circumscribing it.
A predicate object.
Must provide the function operator
bool operator()(Hyperbolic_point_2 p0, Hyperbolic_point_2 p1, Hyperbolic_point_2 p2),
which returns a boolean indicating whether the triangle defined by the points p0, p1,
and p2
is hyperbolic (i.e., if its circumscribing disk is contained in the unit disk). It must also provide the function operator
bool operator() (Hyperbolic_point_2 p0, Hyperbolic_point_2 p1, Hyperbolic_point_2 p2, int& ind),
which returns whether the triangle is hyperbolic, and if not stores in ind
the index of the non-hyperbolic edge of the triangle, as defined in [1]. The edge of the triangle opposite to pj
for j = 0,1,2
is considered to have index j
.
A predicate object.
Must provide the function operator
Oriented_side operator()(Hyperbolic_point_2 p, Hyperbolic_point_2 q, Hyperbolic_point_2 r, Hyperbolic_point_2 t),
which returns the position of the point t
relative to the oriented circle defined by the points p, q
, and r
.
typedef unspecified_type HyperbolicDelaunayTriangulationTraits_2::Side_of_oriented_hyperbolic_segment_2 |
A predicate object.
Must provide the function operator
Oriented_side operator()(Hyperbolic_point_2 p, Hyperbolic_point_2 q, Hyperbolic_point_2 query),
which returns the position of the point query
relative to the oriented hyperbolic segment with vertices p
and q
.