CGAL users discussion list

[KHartmann <>]

Hi Efi,

Thanks!  My code compiles and runs now!

But there is one problem.  The point containment test doesn't work as I had 
hoped.  When I test a point that is inside a hole of a
Gen_Polygon_with_holes_2,
 the result is "yes, it hits a face".  I would like to be able to test if 
that face is a hole, so I can say "no, it does not hit a face."  Is there a 
way for me to know (in constant time) that the face is actually a hole in
the original
polygon?

I got the gist of the code below from an example int the documentation.

Thanks,
Kevin

void ContainmentTest( Gen_Polygon_with_holes_2* currPWHC, 
                      bool strict,
                      std::vector< std::pair< Point*, bool > >& containments
)
{
  Gen_Polygon_set_2 gps( *currPWHC );

  Arrangement_2& arr = gps.arrangement();

  std::vector<Arr_Point_2> points;
  for ( size_t pCount = 0; pCount < containments.size(); pCount++ )
  {
    Point* currPoint = containments[ pCount ].first;
    points.push_back( Arr_Point_2( currPoint->GetX(), currPoint->GetY() ) );
  }

  std::vector<Query_result> results;
  CGAL::locate( arr, points.begin(), points.end(), std::back_inserter(
results ));

  for (size_t pCount = 0; pCount < points.size(); pCount++)
  {
    Query_result result = results[ pCount ];
    std::pair< Point*, bool >& containment = containments[ pCount ];

    Point* currPoint = containment.first;

    bool onFace = false;
    bool onEdge = false;
    bool onVertex = false;

    if (const Arrangement_2::Face_const_handle* f = 
      boost::get<Arrangement_2::Face_const_handle>(&(result.second)))
      if (!(*f)->is_unbounded())
        onFace = true;

    if (const Arrangement_2::Halfedge_const_handle* e = 
      boost::get<Arrangement_2::Halfedge_const_handle>(&(result.second)))
      onEdge = true;

    if (const Arrangement_2::Vertex_const_handle*   v = 
      boost::get<Arrangement_2::Vertex_const_handle>(&(result.second)))
      onVertex = true;

    if (strict)
      containment.second = onFace;
    else
      containment.second = onFace || onEdge || onVertex;
  }
}




--
View this message in context: 
http://cgal-discuss.949826.n4.nabble.com/Test-for-General-polygon-with-holes-2-containment-of-a-Point-2-tp4661702p4661711.html
Sent from the cgal-discuss mailing list archive at Nabble.com.