CSGeometry* NGInterface::loadCSG(string data)
{
strstream in;
CSGeometry *geom;
Point<3> pmin(minX,minY,minZ),
pmax(maxX,maxY,maxZ);
Box<3> box(pmin,pmax);
in << data;
try
{
geom = ParseCSG(in);
}
catch(...)
{
cerr << "Problem in CSG-file!" << endl;
return NULL;
}
if (!geom)
{
cout << "geo-file should start with 'algebraic3d'" << endl;
return NULL;
}
else
geom->FindIdenticSurfaces(1e-8*geom->MaxSize());
geom->SetBoundingBox(box);
geom->CalcTriangleApproximation(detail,facets);
return (CSGeometry*)(geometry = geom);
}
int main()
{
std::ifstream geometry_file;
geometry_file.open("../data/half-trigate.geo");
CSGeometry * geom = ParseCSG( geometry_file );
geom->FindIdenticSurfaces(1e-8 * geom->MaxSize());
Mesh * netgen_mesh = new Mesh();
netgen::MeshingParameters mparams;
geom->GenerateMesh(netgen_mesh, mparams, 1, 5);
{
typedef viennagrid::tetrahedral_3d_mesh MeshType;
typedef viennagrid::tetrahedral_3d_segmentation SegmentationType;
MeshType mesh;
SegmentationType segmentation(mesh);
typedef viennagrid::result_of::point<MeshType>::type PointType;
typedef viennagrid::result_of::vertex_handle<MeshType>::type VertexHandleType;
typedef SegmentationType::segment_handle_type SegmentType;
int num_points = netgen_mesh->GetNP();
int num_tets = netgen_mesh->GetNE();
std::cout << "Num Points: " << num_points << std::endl;
std::cout << "Num Tets: " << num_tets << std::endl;
std::vector<VertexHandleType> vertex_handles( num_points );
for (int i = 1; i <= num_points; ++i)
{
PointType vgrid_point(netgen_mesh->Point(i)[0], netgen_mesh->Point(i)[1], netgen_mesh->Point(i)[2]);
vertex_handles[i-1] = viennagrid::make_vertex( mesh, vgrid_point );
}
for (int i = 0; i < num_tets; ++i)
{
ElementIndex ei = i;
SegmentType segment = segmentation.get_make_segment( (*netgen_mesh)[ei].GetIndex() );
viennagrid::make_tetrahedron( segment, vertex_handles[(*netgen_mesh)[ei][0]-1], vertex_handles[(*netgen_mesh)[ei][1]-1],
vertex_handles[(*netgen_mesh)[ei][2]-1], vertex_handles[(*netgen_mesh)[ei][3]-1]);
}
viennagrid::io::vtk_writer<MeshType, SegmentationType> writer;
writer(mesh, segmentation, "out");
}
}
