TriangulationDataStructure_3::Cell

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 32.1.)

Types

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.

Operations

Access Functions

Vertex_handle	c.vertex ( int i)	Returns the vertex i of c. Precondition:  $$i {0, 1, 2, 3}.
int	c.index ( Vertex_handle v)	Returns the index of vertex v in c. Precondition:  v is a vertex of c.
bool	c.has_vertex ( Vertex_handle v)	Returns true if v is a vertex of c.
bool	c.has_vertex ( Vertex_handle v, int & i)
		Returns true if v is a vertex of c, and computes its index i in c.
Cell_handle	c.neighbor ( int i)	Returns the neighbor i of c. Precondition:  $$i {0, 1, 2, 3}.
int	c.index ( Cell_handle n)	Returns the index corresponding to neighboring cell n. Precondition:  n is a neighbor of c.
bool	c.has_neighbor ( Cell_handle n)	Returns true if n is a neighbor of c.
bool	c.has_neighbor ( Cell_handle n, int & i)
		Returns true if n is a neighbor of c, and computes its index i in c.

Setting

void	c.set_vertex ( int i, Vertex_handle v)
		Sets vertex i to v. Precondition:  $$i {0, 1, 2, 3}.
void	c.set_vertices ( Vertex_handle v0, Vertex_handle v1, Vertex_handle v2, Vertex_handle v3)
		Sets the vertex pointers.
void	c.set_neighbor ( int i, Cell_handle n)
		Sets neighbor i to n. Precondition:  $$i {0, 1, 2, 3}.
void	c.set_neighbors ( Cell_handle n0, Cell_handle n1, Cell_handle n2, Cell_handle n3)
		Sets the neighbors pointers.

Checking

See Also

TriangulationDataStructure_3::Vertex.