Constructions for Linear Cell Complex

Basic constructions.

Functions
template<class LCC>
LCC::Dart_descriptor	CGAL::read_plane_graph_in_lcc (LCC &lcc, std::istream &ais)
	Imports an embedded plane graph read from ais into lcc, a model of the LinearCellComplex concept.
template<class LCC>
LCC::Dart_descriptor	CGAL::import_from_plane_graph (LCC &lcc, std::istream &ais)
template<class LCC, class Polyhedron>
LCC::Dart_descriptor	CGAL::polyhedron_3_to_lcc (LCC &lcc, const Polyhedron &apoly)
	Imports apoly (a Polyhedron_3) into lcc, a model of the LinearCellComplex concept.
template<class LCC, class Triangulation_>
LCC::Dart_descriptor	CGAL::triangulation_3_to_lcc (LCC &lcc, const Triangulation_ &atr)
	Imports atr (a Triangulation_3) into lcc, a model of the LinearCellComplex concept.
template<class LCC, class PointRange, class TetraRange>
LCC::Dart_descriptor	CGAL::tetrahedron_soup_to_lcc (const PointRange &points, const TetraRange &tetras, LCC &lcc)
	imports a 3D tetrahedron soup into a linear cell complex.

Function Documentation

import_from_plane_graph()

template<class LCC>

LCC::Dart_descriptor CGAL::import_from_plane_graph	(	LCC &	lcc,
		std::istream &	ais )

#include <CGAL/Linear_cell_complex_constructors.h>

Deprecated

Use read_plane_graph_in_lcc() instead.

polyhedron_3_to_lcc()

template<class LCC, class Polyhedron>

LCC::Dart_descriptor CGAL::polyhedron_3_to_lcc	(	LCC &	lcc,
		const Polyhedron &	apoly )

#include <CGAL/Polyhedron_3_to_lcc.h>

Imports apoly (a Polyhedron_3) into lcc, a model of the LinearCellComplex concept.

Objects are added in lcc, existing darts are not modified. Returns a dart created during the import.

Precondition

LCC::dimension \( \geq\) 2 and LCC::ambient_dimension==3.

See also

CGAL::read_plane_graph_in_lcc<LCC>

CGAL::triangulation_3_to_lcc<LCC,Triangulation>

read_plane_graph_in_lcc()

template<class LCC>

LCC::Dart_descriptor CGAL::read_plane_graph_in_lcc	(	LCC &	lcc,
		std::istream &	ais )

#include <CGAL/Linear_cell_complex_constructors.h>

Imports an embedded plane graph read from ais into lcc, a model of the LinearCellComplex concept.

Objects are added in lcc, existing darts are not modified. Returns a dart created during the import.

Precondition

LCC::dimension \( \geq\) 2 and LCC::ambient_dimension==2.

File format

The file format must be the following. First the number of vertices and the number of edges of the planar graph. Then, for each vertex of the planar graph, the coordinates of the \( i^{\mbox{th}}\) vertex (two numbers for \( x\) and \( y\) coordinates). The first vertex index is 0. Then for each edge of the planar graph, the two indices of the two vertices (two numbers between 0 and the number of vertices minus 1).

Here a small example:

5 6
1.0 3.0 0.0 2.0 2.0 2.0 0.0 0.0 2.0 0.0
0 1 0 2 1 2 1 3 2 4 3 4

Example of import_graph reading the above file as istream, middle for combinatorial map as combinatorial data-structure, right for generalized maps.

Left: A planar graph embedded in the plane with P0=(1.0,3.0), P1=(0.0,2.0), P2=(2.0,2.0), P3=(0.0,0.0), P4=(2.0,0.0). Middle: the 2D linear cell complex reconstructed if combinatorial maps are the combinatorial data-structure. Right: the 2D linear cell complex reconstructed if generalized maps are the combinatorial data-structure.

See also

CGAL::triangulation_3_to_lcc<LCC,Triangulation>

CGAL::polyhedron_3_to_lcc<LCC,Polyhedron>

tetrahedron_soup_to_lcc()

template<class LCC, class PointRange, class TetraRange>

LCC::Dart_descriptor CGAL::tetrahedron_soup_to_lcc	(	const PointRange &	points,
		const TetraRange &	tetras,
		LCC &	lcc )

#include <CGAL/tetrahedron_soup_to_lcc.h>

imports a 3D tetrahedron soup into a linear cell complex.

Creates a 3D linear cell complex in lcc from a set of points and a range of tetrahedra defined by indices into points. The topological 3-combinatorial map is constructed by sewing adjacent 3-volumes (tetrahedra) along matching 2-faces.

Template Parameters

LCC	a model of the LinearCellComplex concept.
PointRange	a model of RandomAccessContainer with Point_3 as value type, being compatible with the point type of LCC.
TetraRange	a model of ConstRange where each element is a container of 4 point indices, accessible using operator[](int).

Parameters

points	range of 3D points.
tetras	range of tetrahedra, where each tetrahedron is represented by 4 indices corresponding to entries in points.
lcc	the target linear cell complex.

Returns

a descriptor to a dart of the created complex, or LCC::null_descriptor if the input is empty.

Precondition

LCC::dimension >= 3 and LCC::ambient_dimension == 3.

Indices in tetras must be valid 0-based indices into points.

See also

CGAL::triangulation_3_to_lcc()

triangulation_3_to_lcc()

template<class LCC, class Triangulation_>

LCC::Dart_descriptor CGAL::triangulation_3_to_lcc	(	LCC &	lcc,
		const Triangulation_ &	atr )

#include <CGAL/Triangulation_3_to_lcc.h>

Imports atr (a Triangulation_3) into lcc, a model of the LinearCellComplex concept.

Objects are added in lcc, existing darts are not modified. Returns a dart created during the import.

Precondition

LCC::dimension \( \geq\) 3 and LCC::ambient_dimension==3.

See also

CGAL::read_plane_graph_in_lcc<LCC>

CGAL::polyhedron_3_to_lcc<LCC,Polyhedron>