Experimenting with beta pointers in LCC associated with infinite vertex.

experimentWithBeta.cpp

#include <iostream>
#include <map>
#include <CGAL/Delaunay_triangulation_3.h>
#include <CGAL/Linear_cell_complex.h>
#include <CGAL/Linear_cell_complex_constructors.h>

using namespace std;
using namespace CGAL;

typedef Exact_predicates_inexact_constructions_kernel K;
typedef Linear_cell_complex_traits<3, K> Traits;
typedef Linear_cell_complex<3,3, Traits> LCC;
typedef Delaunay_triangulation_3<K> Delaunay;
typedef Point_3<K> Point;

LCC lcc;
static size_t nDarts = 0;
int infiniteVertexMark;

void markInfiniteVertexDart(LCC::Dart_handle d)
{
	if (!lcc.is_marked(d, infiniteVertexMark))
	{
		lcc.mark(d, infiniteVertexMark);
		nDarts++;
	
		d = lcc.beta(d, 2, 1);
		markInfiniteVertexDart(d);

		d = lcc.beta(d, 3, 1);
		markInfiniteVertexDart(d);
	}

	return;
}


/*! \fn int main()
 *  \brief Main procedure
 */
int main()
{
	vector<Point> ptVector;
	
	// create a cube
	ptVector.push_back(Point(0, 0, 0));
	ptVector.push_back(Point(0, 0, 1));
	ptVector.push_back(Point(0, 1, 0));
	ptVector.push_back(Point(0, 1, 1));

	ptVector.push_back(Point(1, 0, 0));
	ptVector.push_back(Point(1, 0, 1));
	ptVector.push_back(Point(1, 1, 0));
	ptVector.push_back(Point(1, 1, 1));

	// compute Delaunay triangulation
	Delaunay DT;
	DT.insert(ptVector.begin(), ptVector.end());
	
	map<Delaunay::Cell_handle, LCC::Dart_handle>* DTToLCCMap = NULL;
	
	// import DT to LCC
	LCC::Dart_handle dartToInfiniteVertex = import_from_triangulation_3(lcc, DT, DTToLCCMap);

	// mark all darts defining infinite vertex
	infiniteVertexMark = lcc.get_new_mark();
	
	if (infiniteVertexMark == -1)
		exit(0);

	// Marking all darts associated with segments incident on the infinite vertex.
	size_t nSegments = 0;
	for (LCC::One_dart_per_incident_cell_range<1, 0>::iterator segIter = lcc.one_dart_per_incident_cell<1, 0>(dartToInfiniteVertex).begin(), segIterEnd = lcc.one_dart_per_incident_cell<1, 0>(dartToInfiniteVertex).end(); segIter != segIterEnd; segIter++)
	{
		lcc.mark(segIter, infiniteVertexMark);
		nSegments++;
	}
	cout << "Number of segments incident on the infinite vertex: " << nSegments << "\n";


	// reuse the mark
	lcc.free_mark(infiniteVertexMark);
	infiniteVertexMark = lcc.get_new_mark();
	if (infiniteVertexMark == -1)
		exit(0);

	// Marking all darts associated with the infinite vertex.
	markInfiniteVertexDart(dartToInfiniteVertex);
	cout << "Number of darts associated with the infinite vertex: " << nDarts << "\n";

	return 0;
}