cgal/Polyhedron/demo/Polyhedron/One_ring_iterators.h

97 lines
3.2 KiB
C++

#ifndef ONE_RING_ITERATORS_H
#define ONE_RING_ITERATORS_H
/***************************************************************/
/* For iterating on one ring neighbor, sample usage:
Halfedge_handle h; //or Vertex_handle or Facet_handle
for(One_ring_iterator<Halfedge_handle> circ(h); circ; ++circ) {
Halfedge_handle h_neighbor = circ;
}
*/
template<typename Mesh, class T>
struct One_ring_iterator;
template<typename Mesh>
struct One_ring_iterator<Mesh, typename boost::graph_traits<Mesh>::vertex_descriptor> {
One_ring_iterator(typename boost::graph_traits<Mesh>::vertex_descriptor v, const Mesh& mesh)
: circ(v, mesh), end(circ), first(true), mesh(mesh) { }
operator bool() const { return first || circ != end; }
operator typename boost::graph_traits<Mesh>::vertex_descriptor() const { return target(opposite(*circ, mesh), mesh); }
One_ring_iterator& operator++() {
first = false;
++circ;
return *this;
}
CGAL::Halfedge_around_target_circulator<Mesh> circ;
CGAL::Halfedge_around_target_circulator<Mesh> end;
bool first;
const Mesh& mesh;
// to be used in One_ring_iterator<Halfedge_handle>
operator typename boost::graph_traits<Mesh>::halfedge_descriptor() const {
typename boost::graph_traits<Mesh>::halfedge_descriptor op =
opposite(*circ, mesh);
if ( &*circ < &op ) return *circ;
return op;
}
};
template<typename Mesh>
struct One_ring_iterator<Mesh, typename boost::graph_traits<Mesh>::face_descriptor> {
One_ring_iterator(typename boost::graph_traits<Mesh>::face_descriptor f, const Mesh& mesh)
: circ(halfedge(f, mesh), mesh), end(circ), first(true), mesh(mesh)
{
iterate_to_non_border(); // move it to valid location
}
operator bool() const { return first || circ != end; }
operator typename boost::graph_traits<Mesh>::face_descriptor() const {
CGAL_assertion(!is_border_edge(opposite(*circ, mesh), mesh));
return face(opposite(*circ, mesh), mesh);
}
One_ring_iterator& operator++() {
first = false;
++circ;
if(circ != end) { iterate_to_non_border(); }
return *this;
}
void iterate_to_non_border() {
while(is_border_edge(opposite(*circ, mesh), mesh)) {
first = false;
++circ;
if(circ == end) { break; }
}
}
CGAL::Halfedge_around_face_circulator<Mesh> circ;
CGAL::Halfedge_around_face_circulator<Mesh> end;
bool first;
const Mesh& mesh;
};
template<typename Mesh>
struct One_ring_iterator<Mesh, typename boost::graph_traits<Mesh>::edge_descriptor> {
One_ring_iterator(typename boost::graph_traits<Mesh>::edge_descriptor e, const Mesh& mesh)
: it_1(target(halfedge(e, mesh), mesh), mesh), it_2(target(opposite(halfedge(e, mesh), mesh), mesh), mesh),
mesh(mesh)
{ }
operator bool() const { return it_1 || it_2; }
operator typename boost::graph_traits<Mesh>::edge_descriptor() const {
Mesh tmp;
if(it_1) { return edge(it_1, tmp); }
return edge(it_2, tmp);
}
One_ring_iterator& operator++() {
it_1 ? ++it_1 : ++it_2;
return *this;
}
One_ring_iterator<Mesh, typename boost::graph_traits<Mesh>::vertex_descriptor> it_1;
One_ring_iterator<Mesh, typename boost::graph_traits<Mesh>::vertex_descriptor> it_2;
const Mesh& mesh;
};
#endif