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#include <CGAL/Linear_cell_complex_for_combinatorial_map.h>
#include <CGAL/Delaunay_triangulation_3.h>
#include <CGAL/Triangulation_3_to_lcc.h>
#include <iostream>
#include <fstream>
#include <cassert>
/* // If you want to use exact constructions.
#include <CGAL/Exact_predicates_exact_constructions_kernel.h>
typedef CGAL::Linear_cell_complex<3,3,
CGAL::Linear_cell_complex_traits<3, CGAL::Exact_predicates_exact_constructions_kernel> > LCC_3;
*/
typedef CGAL::Linear_cell_complex_for_combinatorial_map<3> LCC_3;
typedef LCC_3::Dart_descriptor Dart_descriptor;
typedef LCC_3::Point Point;
typedef CGAL::Delaunay_triangulation_3<LCC_3::Traits> Triangulation;
// Function used to display the voronoi diagram.
void display_voronoi(LCC_3& alcc, Dart_descriptor adart)
{
// We remove the infinite volume plus all the volumes adjacent to it.
// Indeed, we cannot view these volumes since they do not have
// a "correct geometry".
std::stack<Dart_descriptor> toremove;
LCC_3::size_type mark_toremove=alcc.get_new_mark();
// adart belongs to the infinite volume.
toremove.push(adart);
CGAL::mark_cell<LCC_3,3>(alcc, adart, mark_toremove);
// Now we get all the volumes adjacent to the infinite volume.
for (LCC_3::Dart_of_cell_range<3>::iterator
it=alcc.darts_of_cell<3>(adart).begin(),
itend=alcc.darts_of_cell<3>(adart).end(); it!=itend; ++it)
{
if ( !alcc.is_marked(alcc.beta(it,3), mark_toremove) )
{
CGAL::mark_cell<LCC_3,3>(alcc, alcc.beta(it,3), mark_toremove);
toremove.push(alcc.beta(it,3));
}
}
while( !toremove.empty() )
{
alcc.remove_cell<3>(toremove.top());
toremove.pop();
}
assert(alcc.is_without_boundary(1) && alcc.is_without_boundary(2));
std::cout<<"Voronoi subdvision, only finite volumes:"<<std::endl<<" ";
alcc.display_characteristics(std::cout) << ", valid="
<< alcc.is_valid()
<< std::endl;
}
template<typename LCC, typename TR>
void transform_dart_to_their_dual(LCC& alcc, LCC& adual,
std::map<typename TR::Cell_handle,
typename LCC::Dart_descriptor>& assoc)
{
typename LCC::Dart_range::iterator it1=alcc.darts().begin();
typename LCC::Dart_range::iterator it2=adual.darts().begin();
std::map<typename LCC::Dart_descriptor, typename LCC::Dart_descriptor> dual;
for ( ; it1!=alcc.darts().end(); ++it1, ++it2 )
{
dual[it1]=it2;
}
for ( typename std::map<typename TR::Cell_handle, typename LCC::Dart_descriptor>
::iterator it=assoc.begin(), itend=assoc.end(); it!=itend; ++it)
{
assoc[it->first]=dual[it->second];
}
}
template<typename LCC, typename TR>
void set_geometry_of_dual(LCC& alcc, TR& tr,
std::map<typename TR::Cell_handle,
typename LCC::Dart_descriptor>& assoc)
{
for ( typename std::map<typename TR::Cell_handle, typename LCC::Dart_descriptor>
::iterator it=assoc.begin(), itend=assoc.end(); it!=itend; ++it)
{
if ( !tr.is_infinite(it->first) )
alcc.set_vertex_attribute
(it->second,alcc.create_vertex_attribute(tr.dual(it->first)));
else
alcc.set_vertex_attribute(it->second,alcc.create_vertex_attribute());
}
}
int main(int narg, char** argv)
{
if (narg>1 && (!strcmp(argv[1],"-h") || !strcmp(argv[1],"-?")) )
{
std::cout<<"Usage : voronoi_3 filename"<<std::endl
<<" filename being a fine containing 3D points used to "
<<" compute the Delaunay_triangulation_3."<<std::endl;
return EXIT_FAILURE;
}
std::string filename;
if ( narg==1 )
{
filename=std::string("data/points_3");
std::cout<<"No filename given: use data/points_3 by default."<<std::endl;
}
else
filename=std::string(argv[1]);
// 1) Compute the Delaunay_triangulation_3.
Triangulation T;
std::ifstream iFile(filename.c_str());
if (!iFile)
{
std::cout << "Problem reading file " << filename << std::endl;
return EXIT_FAILURE;
}
std::istream_iterator<Point> begin(iFile), end;
T.insert(begin, end);
assert(T.is_valid(false));
// 2) Convert the triangulation into a 3D lcc.
LCC_3 lcc;
std::map<Triangulation::Cell_handle,
LCC_3::Dart_descriptor > vol_to_dart;
Dart_descriptor d=CGAL::import_from_triangulation_3<LCC_3, Triangulation>
(lcc, T, &vol_to_dart);
std::cout<<"Delaunay triangulation :"<<std::endl<<" ";
lcc.display_characteristics(std::cout) << ", valid="
<< lcc.is_valid() << std::endl;
// 3) Compute the dual lcc.
LCC_3 dual_lcc;
Dart_descriptor dd=lcc.dual(dual_lcc, d);
// Here, dual_lcc is the 3D Voronoi diagram.
assert(dual_lcc.is_without_boundary());
// 4) We update the geometry of dual_lcc by using the std::map
// face_to_dart.
transform_dart_to_their_dual<LCC_3,Triangulation>
(lcc, dual_lcc, vol_to_dart);
set_geometry_of_dual<LCC_3,Triangulation>(dual_lcc, T, vol_to_dart);
// 5) Display the dual_lcc characteristics.
std::cout<<"Voronoi subdvision :"<<std::endl<<" ";
dual_lcc.display_characteristics(std::cout) << ", valid="
<< dual_lcc.is_valid()
<< std::endl;
display_voronoi(dual_lcc, dd);
return EXIT_SUCCESS;
}
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