CGAL users discussion list

[Bernhard Kornberger <>]

Here is a minimal example of a bug where I use exactly the
typedefs of one of the demo programs:

#include <istream>
#include <sstream>
#include <fstream>
#include <CGAL/Delaunay_triangulation_3.h>
#include <CGAL/Triangulation_hierarchy_3.h>
#include <CGAL/Triangulation_cell_base_with_circumcenter_3.h>
#include <CGAL/Exact_predicates_exact_constructions_kernel.h>


// exact constructions (circumcenter computations) are needed in this
// demo, not only predicates
typedef CGAL::Exact_predicates_exact_constructions_kernel K;
typedef CGAL::Triangulation_vertex_base_3<K>                 Vb;
typedef CGAL::Triangulation_cell_base_with_circumcenter_3<K> Cb;
typedef CGAL::Triangulation_data_structure_3<Vb, Cb>         TDS;
typedef CGAL::Delaunay_triangulation_3<K, TDS>               Triangulation;
typedef Triangulation::Finite_cells_iterator TFinite_cells_iterator;
typedef Triangulation::Point Point;



using namespace std;


int main(int argc, char *argv[])
{
        Triangulation T;

        ifstream in("badPoints.txt");
        vector<Point> surfacePoints;
        const int BUFSIZE=1024;
        char oneLine[BUFSIZE];
        while(in.getline(oneLine,BUFSIZE))
        {
                string buf=string(oneLine);
                istringstream buffer(buf.substr(0,buf.length()).c_str());
                double x,y,z;
                buffer>>x;
                buffer>>y;
                buffer>>z;
                Point p(x,y,z);
                T.insert(p);
                cout<<p<<endl;
        }

        for(TFinite_cells_iterator c_it=T.finite_cells_begin();
                c_it!=T.finite_cells_end();++c_it)
        {
                cout << "v=" <<T.dual(c_it)<<endl;
        }

}


You can download the source code and the badPoints.txt-File
here:  http://dist.ist.tugraz.at/mat2.tar.bz2

If it is started by the command "./mat" it inserts the points
from the badPoints.txt file into the traingulation. However,
when it comes to the computation of the dual voronoi vertices,
it outputs one time "nan nan nan".

...
v=72.4111 4.527 30.7071
v=nan nan nan
v=184950 26752.9 -71245.4
v=1.16208e+06 168117 -448105
v=1.29475e+06 187309 -499283
v=1.1143e+06 161204 -429666
...


g++ (GCC) 4.1.2 (Ubuntu 4.1.2-0ubuntu4)
CGAL 3.3

Best regards
Bernhard