mirror of https://github.com/CGAL/cgal
46 lines
1.4 KiB
C++
46 lines
1.4 KiB
C++
#ifndef _COMPUTE_NORMAL_
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#define _COMPUTE_NORMAL_
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template <class Facet, class Kernel>
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typename Kernel::Vector_3 compute_facet_normal(Facet& f)
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{
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typedef typename Kernel::Point_3 Point;
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typedef typename Kernel::Vector_3 Vector;
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typedef typename Facet::Halfedge_around_facet_circulator HF_circulator;
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Vector normal = CGAL::NULL_VECTOR;
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HF_circulator he = f.facet_begin();
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HF_circulator end = he;
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CGAL_For_all(he,end)
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{
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const Point& prev = he->prev()->vertex()->point();
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const Point& curr = he->vertex()->point();
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const Point& next = he->next()->vertex()->point();
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Vector n = CGAL::cross_product(next-curr,prev-curr);
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normal = normal + (n / std::sqrt(n*n));
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}
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return normal / std::sqrt(normal * normal);
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}
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template <class Vertex, class Kernel>
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typename Kernel::Vector_3 compute_vertex_normal(Vertex& v)
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{
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typedef typename Kernel::Point_3 Point;
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typedef typename Kernel::Vector_3 Vector;
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typedef typename Vertex::Halfedge_around_vertex_circulator HV_circulator;
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typedef typename Vertex::Facet Facet;
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Vector normal = CGAL::NULL_VECTOR;
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HV_circulator he = v.vertex_begin();
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HV_circulator end = he;
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CGAL_For_all(he,end)
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{
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if(!he->is_border())
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{
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Vector n = compute_facet_normal<Facet,Kernel>(*he->facet());
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normal = normal + (n / std::sqrt(n*n));
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}
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}
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return normal / std::sqrt(normal * normal);
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}
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#endif // _COMPUTE_NORMAL_
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