CGAL 5.6 - 2D Periodic Hyperbolic Triangulations
CGAL::Periodic_4_hyperbolic_triangulation_2< GT, TDS > Class Template Reference

#include <CGAL/Periodic_4_hyperbolic_triangulation_2.h>

Inherited by CGAL::Periodic_4_hyperbolic_Delaunay_triangulation_2< GT, TDS >.

Definition

The class Periodic_4_hyperbolic_triangulation_2 offers base functionalities needed by Periodic_4_hyperbolic_Delaunay_triangulation_2.

Note that this class does not support modification of the triangulation (insertion or removal).

The class expects two template parameters.

Template Parameters
GTGeometric traits parameter. Must be a model of the concept Periodic_4HyperbolicTriangulationTraits_2. This parameter has no default value.
TDSTriangulation data structure parameter. Must be a model of the concept TriangulationDataStructure_2 with some additional functionality in the vertices and faces, following the concepts Periodic_4HyperbolicTriangulationVertexBase_2 and Periodic_4HyperbolicTriangulationFaceBase_2, respectively. The default value for this parameter is
CGAL::Periodic_4_hyperbolic_triangulation_vertex_base_2<GT>,

Types

typedef GT Geometric_traits
 
typedef TDS Triangulation_data_structure
 

The following types represent geometric objects.

typedef Triangulation_data_structure::Vertex::Point Point
 Represents a point in the hyperbolic plane. More...
 
typedef Geometric_traits::Hyperbolic_segment_2 Hyperbolic_segment
 Represents a hyperbolic segment in the hyperbolic plane.
 
typedef Geometric_traits::Hyperbolic_triangle_2 Hyperbolic_triangle
 Represents a triangle contained in the Poincaré disk.
 

The following type represents hyperbolic translations specific for the Bolza surface.

typedef Geometric_traits::Hyperbolic_translation Hyperbolic_translation
 

The following types represent images of points, segments, and triangles under the action of hyperbolic translations.

typedef std::pair< Point, Hyperbolic_translationPeriodic_point
 Represents a periodic point, i.e., a pair of a point in the original octagon and a hyperbolic translation.
 
typedef std::array< std::pair< Point, Hyperbolic_translation >, 2 > Periodic_segment
 Represents a periodic segment, defined by two periodic points.
 
typedef std::array< std::pair< Point, Hyperbolic_translation >, 3 > Periodic_triangle
 Represents a periodic triangle, defined by three periodic points.
 

The following types give access to the elements of the triangulation.

typedef Triangulation_data_structure::Edge Edge
 
typedef Triangulation_data_structure::Face Face
 
typedef Triangulation_data_structure::Vertex_handle Vertex_handle
 
typedef Triangulation_data_structure::Face_handle Face_handle
 

The following iterator and circulator types are defined to give access over the vertices, edges, and faces of the triangulation.

typedef Triangulation_data_structure::Face_iterator Face_iterator
 
typedef Triangulation_data_structure::Edge_iterator Edge_iterator
 
typedef Triangulation_data_structure::Vertex_iterator Vertex_iterator
 
typedef Triangulation_data_structure::Face_circulator Face_circulator
 
typedef Triangulation_data_structure::Edge_circulator Edge_circulator
 
typedef Triangulation_data_structure::Vertex_circulator Vertex_circulator
 

Enums

The following enumeration type indicates where a point is located in the triangulation.

enum  Locate_type { VERTEX = 0, EDGE, FACE }
 

Creation

 Periodic_4_hyperbolic_triangulation_2 (const Geometric_traits &gt=Geometric_traits())
 Default constructor, with an optional parameter for the geometric traits object.
 
 Periodic_4_hyperbolic_triangulation_2 (const Periodic_4_hyperbolic_triangulation_2 &tr)
 Copy constructor.
 

Assignment

Periodic_4_hyperbolic_triangulation_2operator= (Periodic_4_hyperbolic_triangulation_2 tr)
 The triangulation tr is duplicated, and modifying the copy after the duplication does not modify the original.
 
void swap (Periodic_4_hyperbolic_triangulation_2 &tr)
 The triangulation is swapped with tr.
 
void clear ()
 Deletes all faces and vertices of the triangulation.
 

Access functions

const Geometric_traitsgeom_traits () const
 Returns a const reference to the geometric traits object.
 
const Triangulation_data_structuretds () const
 Returns a const reference to the triangulation data structure.
 
Triangulation_data_structuretds ()
 Returns a reference to the triangulation data structure.
 
size_type number_of_vertices () const
 Returns the number of vertices in the triangulation.
 
size_type number_of_edges () const
 Returns the number of edges in the triangulation.
 
size_type number_of_faces () const
 Returns the number of faces in the triangulation.
 

Geometric access functions

The functions below return periodic points, segments, and triangles.

Periodic_point periodic_point (const Face_handle f, int i) const
 Returns the periodic point given by the i-th vertex of face f, that is the point in the original domain and the translation of the vertex in f. More...
 
Periodic_segment periodic_segment (const Point &p1, const Point &p2, const Hyperbolic_translation &tr1, const Hyperbolic_translation &tr2) const
 Returns the periodic segment formed by the two point-translation pairs (p1, tr1) and (p2, tr2).
 
Periodic_segment periodic_segment (const Point &p1, const Point &p2) const
 Returns the periodic segment formed by the two point-translation pairs (p1, Id) and (p2, Id), where Id is the identity translation.
 
Periodic_segment periodic_segment (const Face_handle c, int i, int j) const
 Returns the periodic segment formed by the endpoints of edge (f,i,j). More...
 
Periodic_segment periodic_segment (const Edge &e) const
 Returns the periodic segment formed by the endpoints of edge e. More...
 
Periodic_segment periodic_segment (const Edge &e, const Hyperbolic_translation &tr) const
 Returns the periodic segment formed by the endpoints of edge e translated by tr. More...
 
Periodic_triangle periodic_triangle (const Face &f) const
 Returns the periodic triangle formed by the pairs of points and translations corresponding to each vertex of f.
 
Periodic_triangle periodic_triangle (const Face &f, const Hyperbolic_translation &tr) const
 Returns the periodic triangle formed by the pairs of points and translations corresponding to each vertex of f, translated by tr.
 

The functions below return non-periodic points, segments and triangles.

Point construct_point (const Periodic_point &pp) const
 Converts the periodic point pp into a point in the hyperbolic plane by applying pp.second to pp.first.
 
Hyperbolic_segment construct_hyperbolic_segment (const Face_handle &fh, int idx) const
 Constructs the hyperbolic segment formed by the endpoints of edge (fh, idx). More...
 
Hyperbolic_segment construct_hyperbolic_segment (const Point &p1, const Point &p2) const
 Returns the hyperbolic segment with endpoints p1 and p2.
 
Hyperbolic_segment construct_hyperbolic_segment (const pair< Face_handle, int > &e) const
 Returns the hyperbolic segment formed by the endpoints of e.
 
Hyperbolic_segment construct_hyperbolic_segment (const Periodic_segment &ps) const
 Returns the hyperbolic segment formed by the endpoints of ps.
 
Triangle construct_triangle (const Face_handle &fh) const
 Returns the triangle formed by the vertices of fh.
 
Triangle construct_triangle (const Periodic_triangle &pt) const
 Returns the triangle formed by the vertices of pt.
 

Point location

Face_handle hyperbolic_periodic_locate (const Point &p, Hyperbolic_translation &lo, const Face_handle start=Face_handle()) const
 Returns the face rf for which the periodic triangle (rf, lo) contains the query point p. More...
 
Face_handle hyperbolic_periodic_locate (const Point &p, Locate_type &lt, int &li, Hyperbolic_translation &lo, const Face_handle start=Face_handle()) const
 Same as above. More...
 
Face_handle hyperbolic_locate (const Point &p, Face_handle start=Face_handle()) const
 Returns the canonical representative of the face that contains the query point p. More...
 
Face_handle hyperbolic_locate (const Point &p, Locate_type &lt, int &li, Face_handle start=Face_handle()) const
 Same as above. More...
 

Predicate functions

Orientation orientation (const Point &p1, const Point &p2, const Point &p3) const
 Returns the Orientation of the points p1, p2, p3. More...
 
Orientation orientation (const Point &p1, const Point &p2, const Point &p3, const Hyperbolic_translation &tr1, const Hyperbolic_translation &tr2, const Hyperbolic_translation &tr3) const
 Returns the Orientation of the three periodic points (p1, tr1), (p2, tr2) and (p3, tr3).
 
Oriented_side side_of_oriented_circle (const Point &p1, const Point &p2, const Point &p3, const Point &q) const
 Returns the Oriented_side on which q is located with respect to the circle defined by the points p1,p2,p3. More...
 
Oriented_side side_of_oriented_circle (const Point &p1, const Point &p2, const Point &p3, const Point &q, const Hyperbolic_translation &tr1, const Hyperbolic_translation &tr2, const Hyperbolic_translation &tr3, const Hyperbolic_translation &trq) const
 Returns the Oriented_side on which the periodic point (q, trq) is located with respect to the circle defined by the periodic points (p1, tr1), (p2, tr2) and (p3, tr3).
 

Queries

bool is_vertex (Vertex_handle v) const
 Tests whether v is a vertex of the triangulation.
 
bool is_edge (Vertex_handle u, Vertex_handle v, Face_handle &fh, int &i) const
 Tests whether (u, v) is an edge of the triangulation. More...
 
bool is_face (Vertex_handle u, Vertex_handle v, Vertex_handle w, Face_handle &fh) const
 Tests whether there exists a face in the triangulation with vertices u, v and w. More...
 
bool has_vertex (const Face_handle f, const Vertex_handle v, const int i) const
 Tests whether face f has v as a vertex. More...
 

Vertex, Edge, and Face iterators

Vertex_iterator vertices_begin () const
 Starts at an arbitrary vertex. More...
 
Vertex_iterator vertices_end () const
 Past-the-end iterator.
 
Edge_iterator edges_begin () const
 Starts at an arbitrary edge. More...
 
Edge_iterator edges_end () const
 Past-the-end iterator.
 
Face_iterator faces_begin () const
 Starts at an arbitrary face. More...
 
Face_iterator faces_end () const
 Past-the-end iterator.
 

Vertex, Edge and Face circulators

Vertex_circulator adjacent_vertices (Vertex_handle v) const
 Starts at an arbitrary vertex incident to v.
 
Vertex_circulator adjacent_vertices (Vertex_handle v, Face_handle f) const
 Starts at the first vertex of f adjacent to v in counterclockwise order around v.
 
Edge_circulator incident_edges (Vertex_handle v) const
 Starts at an arbitrary edge incident to v.
 
Edge_circulator incident_edges (Vertex_handle v, Face_handle f) const
 Starts at the first edge of f incident to v, in counterclockwise order around v.
 
Face_circulator incident_faces (Vertex_handle v) const
 Starts at an arbitrary face incident to v.
 
Face_circulator incident_faces (Vertex_handle v, Face_handle f) const
 Starts at face f.
 

Traversal of the Vertices, Edges and Faces incident to a vertex

template<class OutputIterator >
OutputIterator incident_faces (Vertex_handle v, OutputIterator faces) const
 Copies the faces incident to v into the output iterator faces.
 
template<class OutputIterator >
OutputIterator incident_edges (Vertex_handle v, OutputIterator edges) const
 Copies the edges incident to v into the output iterator edges.
 
template<class OutputIterator >
OutputIterator adjacent_vertices (Vertex_handle v, OutputIterator vertices) const
 Copies the vertices incident to v into the output iterator vertices.
 
size_type degree (Vertex_handle v) const
 Returns the degree of v, i.e., the number of edges incident to v.
 

Traversal between adjacent faces

int mirror_index (Face_handle f, int i) const
 Returns the index of f in its i-th neighbor.
 
Vertex_handle mirror_vertex (Face_handle f, int i) const
 Returns the vertex of the i-th neighbor of f that is opposite to f.
 
Edge mirror_edge (Edge e) const
 Returns the same edge seen from the other adjacent face.
 
Hyperbolic_translation neighbor_translation (const Face_handle fh, int i) const
 Returns the hyperbolic translation for which the i-th neighbor of fh is adjacent to (the canonical representative of) fh in the hyperbolic plane.
 

Validity checking

bool is_valid (bool verbose=false) const
 Checks the combinatorial validity of the triangulation, and also the validity of its geometric embedding.
 
bool is_valid (Face_handle f, bool verbose=false) const
 Checks the combinatorial validity of face f.
 

Member Typedef Documentation

◆ Point

template<class GT , class TDS >
typedef Triangulation_data_structure::Vertex::Point CGAL::Periodic_4_hyperbolic_triangulation_2< GT, TDS >::Point

Represents a point in the hyperbolic plane.

Note that for Delaunay triangulations of the Bolza surface, all points must lie inside the original hyperbolic octagon.

Member Enumeration Documentation

◆ Locate_type

template<class GT , class TDS >
enum CGAL::Periodic_4_hyperbolic_triangulation_2::Locate_type
Enumerator
VERTEX 

the located point coincides with a vertex of the triangulation

EDGE 

the point is in the relative interior of an edge

FACE 

the point is in the interior of a facet

Member Function Documentation

◆ construct_hyperbolic_segment()

template<class GT , class TDS >
Hyperbolic_segment CGAL::Periodic_4_hyperbolic_triangulation_2< GT, TDS >::construct_hyperbolic_segment ( const Face_handle fh,
int  idx 
) const

Constructs the hyperbolic segment formed by the endpoints of edge (fh, idx).

Precondition
\( 0 \leq idx \leq 2 \)

◆ edges_begin()

template<class GT , class TDS >
Edge_iterator CGAL::Periodic_4_hyperbolic_triangulation_2< GT, TDS >::edges_begin ( ) const

Starts at an arbitrary edge.

Iterates over all the edges in the triangulation.

◆ faces_begin()

template<class GT , class TDS >
Face_iterator CGAL::Periodic_4_hyperbolic_triangulation_2< GT, TDS >::faces_begin ( ) const

Starts at an arbitrary face.

Iterates over all the faces of the triangulation.

◆ has_vertex()

template<class GT , class TDS >
bool CGAL::Periodic_4_hyperbolic_triangulation_2< GT, TDS >::has_vertex ( const Face_handle  f,
const Vertex_handle  v,
const int  i 
) const

Tests whether face f has v as a vertex.

If the answer is true, then i contains the index of v in f.

◆ hyperbolic_locate() [1/2]

template<class GT , class TDS >
Face_handle CGAL::Periodic_4_hyperbolic_triangulation_2< GT, TDS >::hyperbolic_locate ( const Point p,
Face_handle  start = Face_handle() 
) const

Returns the canonical representative of the face that contains the query point p.

The parameter start, if provided, is used as a starting point for the location.

◆ hyperbolic_locate() [2/2]

template<class GT , class TDS >
Face_handle CGAL::Periodic_4_hyperbolic_triangulation_2< GT, TDS >::hyperbolic_locate ( const Point p,
Locate_type lt,
int &  li,
Face_handle  start = Face_handle() 
) const

Same as above.

The value of the variable lt indicates whether p has been located inside the canonical representative, on one of its sides, or on one of its vertices. If p is located on a side or on a vertex, then li contains the index of the corresponding edge or vertex in the returned face. The parameter start, if provided, is used as a starting point for the location.

◆ hyperbolic_periodic_locate() [1/2]

template<class GT , class TDS >
Face_handle CGAL::Periodic_4_hyperbolic_triangulation_2< GT, TDS >::hyperbolic_periodic_locate ( const Point p,
Hyperbolic_translation lo,
const Face_handle  start = Face_handle() 
) const

Returns the face rf for which the periodic triangle (rf, lo) contains the query point p.

The parameter start, if provided, is used as a starting point for the location.

◆ hyperbolic_periodic_locate() [2/2]

template<class GT , class TDS >
Face_handle CGAL::Periodic_4_hyperbolic_triangulation_2< GT, TDS >::hyperbolic_periodic_locate ( const Point p,
Locate_type lt,
int &  li,
Hyperbolic_translation lo,
const Face_handle  start = Face_handle() 
) const

Same as above.

The value of the variable lt indicates whether p has been located inside the hyperbolic triangle, on one of its sides, or on one of its vertices. If p is located on a side or on a vertex, then li contains the index of the corresponding edge or vertex in the returned face. The parameter start, if provided, is used as a starting point for the location.

◆ is_edge()

template<class GT , class TDS >
bool CGAL::Periodic_4_hyperbolic_triangulation_2< GT, TDS >::is_edge ( Vertex_handle  u,
Vertex_handle  v,
Face_handle fh,
int &  i 
) const

Tests whether (u, v) is an edge of the triangulation.

If the edge is found, then it is the i-th edge of fh.

◆ is_face()

template<class GT , class TDS >
bool CGAL::Periodic_4_hyperbolic_triangulation_2< GT, TDS >::is_face ( Vertex_handle  u,
Vertex_handle  v,
Vertex_handle  w,
Face_handle fh 
) const

Tests whether there exists a face in the triangulation with vertices u, v and w.

If the face is found, then it is returned as fh.

◆ orientation()

template<class GT , class TDS >
Orientation CGAL::Periodic_4_hyperbolic_triangulation_2< GT, TDS >::orientation ( const Point p1,
const Point p2,
const Point p3 
) const

Returns the Orientation of the points p1, p2, p3.

See also
CGAL::orientation()

◆ periodic_point()

template<class GT , class TDS >
Periodic_point CGAL::Periodic_4_hyperbolic_triangulation_2< GT, TDS >::periodic_point ( const Face_handle  f,
int  i 
) const

Returns the periodic point given by the i-th vertex of face f, that is the point in the original domain and the translation of the vertex in f.

Precondition
\(0 \leq i \leq 2\)

◆ periodic_segment() [1/3]

template<class GT , class TDS >
Periodic_segment CGAL::Periodic_4_hyperbolic_triangulation_2< GT, TDS >::periodic_segment ( const Face_handle  c,
int  i,
int  j 
) const

Returns the periodic segment formed by the endpoints of edge (f,i,j).

Precondition
\( 0 \leq i,j \leq 2, \qquad i \neq j \)

◆ periodic_segment() [2/3]

template<class GT , class TDS >
Periodic_segment CGAL::Periodic_4_hyperbolic_triangulation_2< GT, TDS >::periodic_segment ( const Edge e) const

Returns the periodic segment formed by the endpoints of edge e.

Note that the translations in the resulting periodic segment are determined by e.first.

◆ periodic_segment() [3/3]

template<class GT , class TDS >
Periodic_segment CGAL::Periodic_4_hyperbolic_triangulation_2< GT, TDS >::periodic_segment ( const Edge e,
const Hyperbolic_translation tr 
) const

Returns the periodic segment formed by the endpoints of edge e translated by tr.

Note that the translations in the resulting segment are determined by the translations in e.first, multiplied on the left by tr.

◆ side_of_oriented_circle()

template<class GT , class TDS >
Oriented_side CGAL::Periodic_4_hyperbolic_triangulation_2< GT, TDS >::side_of_oriented_circle ( const Point p1,
const Point p2,
const Point p3,
const Point q 
) const

Returns the Oriented_side on which q is located with respect to the circle defined by the points p1,p2,p3.

See also
CGAL::side_of_oriented_circle()

◆ vertices_begin()

template<class GT , class TDS >
Vertex_iterator CGAL::Periodic_4_hyperbolic_triangulation_2< GT, TDS >::vertices_begin ( ) const

Starts at an arbitrary vertex.

Iterates over all the vertices in the triangulation.