TriangulationDataStructure_3::Cell Concept Reference

Definition

The concept TriangulationDataStructure_3::Cell stores four Vertex_handles to its four vertices and four Cell_handles to its four neighbors. The vertices are indexed 0, 1, 2, and 3 in consistent order. The neighbor indexed \( i\) lies opposite to vertex i.

In degenerate dimensions, cells are used to store faces of maximal dimension: in dimension 2, each cell represents only one facet of index 3, and 3 edges \( (0,1)\), \( (1,2)\) and \( (2,0)\); in dimension 1, each cell represents one edge \( (0,1)\). (See also Section Representation.)

Creation

In order to obtain new cells or destruct unused cells, the user must call the create_cell() and delete_cell() methods of the triangulation data structure.

See also

TriangulationDataStructure_3::Vertex

TriangulationDataStructure_3::Cell_data

Types
typedef TriangulationDataStructure_3	Triangulation_data_structure
typedef TriangulationDataStructure_3::Vertex_handle	Vertex_handle
typedef TriangulationDataStructure_3::Cell_handle	Cell_handle
typedef TriangulationDataStructure_3::Cell_data	TDS_data

Access Functions
Vertex_handle	vertex (int i) const
	Returns the vertex i of c.
int	index (Vertex_handle v) const
	Returns the index of vertex v in c.
bool	has_vertex (Vertex_handle v) const
	Returns true if v is a vertex of c.
bool	has_vertex (Vertex_handle v, int &i) const
	Returns true if v is a vertex of c, and computes its index i in c.
Cell_handle	neighbor (int i) const
	Returns the neighbor i of c.
int	index (Cell_handle n) const
	Returns the index corresponding to neighboring cell n.
bool	has_neighbor (Cell_handle n) const
	Returns true if n is a neighbor of c.
bool	has_neighbor (Cell_handle n, int &i) const
	Returns true if n is a neighbor of c, and computes its index i in c.

Setting
void	set_vertex (int i, Vertex_handle v)
	Sets vertex i to v.
void	set_vertices (Vertex_handle v0, Vertex_handle v1, Vertex_handle v2, Vertex_handle v3)
	Sets the vertex pointers.
void	set_neighbor (int i, Cell_handle n)
	Sets neighbor i to n.
void	set_neighbors (Cell_handle n0, Cell_handle n1, Cell_handle n2, Cell_handle n3)
	Sets the neighbors pointers.

Internal
Advanced These functions are used internally by the triangulation data structure. The user is not encouraged to use them directly as they may change in the future.
TDS_data &	tds_data ()
const TDS_data &	tds_data () const

Checking
bool	is_valid (bool verbose=false, int level=0) const
	This is a function for debugging purpose.

Member Function Documentation

index() [1/2]

int TriangulationDataStructure_3::Cell::index

(

Cell_handle

n

)

const

Returns the index corresponding to neighboring cell n.

Precondition

n is a neighbor of c.

index() [2/2]

int TriangulationDataStructure_3::Cell::index

(

Vertex_handle

v

)

const

Returns the index of vertex v in c.

Precondition

v is a vertex of c.

is_valid()

bool TriangulationDataStructure_3::Cell::is_valid	(	bool	verbose = false,
		int	level = 0
	)		const

This is a function for debugging purpose.

Debugging Support

User defined local validity checking function.

neighbor()

Cell_handle TriangulationDataStructure_3::Cell::neighbor

(

int

i

)

const

Returns the neighbor i of c.

Precondition

\( i \in\{0, 1, 2, 3\}\).

set_neighbor()

void TriangulationDataStructure_3::Cell::set_neighbor	(	int	i,
		Cell_handle	n
	)

Sets neighbor i to n.

Precondition

\( i \in\{0, 1, 2, 3\}\).

set_vertex()

void TriangulationDataStructure_3::Cell::set_vertex	(	int	i,
		Vertex_handle	v
	)

Sets vertex i to v.

Precondition

\( i \in\{0, 1, 2, 3\}\).

vertex()

Vertex_handle TriangulationDataStructure_3::Cell::vertex

(

int

i

)

const

Returns the vertex i of c.

Precondition

\( i \in\{0, 1, 2, 3\}\).