Edit: /usr/include/boost/graph/make_maximal_planar.hpp (7578B)
//=======================================================================
// Copyright 2007 Aaron Windsor
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//=======================================================================
#ifndef __MAKE_MAXIMAL_PLANAR_HPP__
#define __MAKE_MAXIMAL_PLANAR_HPP__
#include
#include //for tie
#include
#include
#include
#include
#include
#include
#include
namespace boost
{
template < typename Graph, typename VertexIndexMap, typename AddEdgeVisitor >
struct triangulation_visitor : public planar_face_traversal_visitor
{
typedef typename graph_traits< Graph >::vertex_descriptor vertex_t;
typedef typename graph_traits< Graph >::edge_descriptor edge_t;
typedef typename graph_traits< Graph >::vertices_size_type v_size_t;
typedef typename graph_traits< Graph >::degree_size_type degree_size_t;
typedef typename graph_traits< Graph >::edge_iterator edge_iterator_t;
typedef typename graph_traits< Graph >::vertex_iterator vertex_iterator_t;
typedef
typename graph_traits< Graph >::adjacency_iterator adjacency_iterator_t;
typedef typename std::vector< vertex_t > vertex_vector_t;
typedef typename std::vector< v_size_t > v_size_vector_t;
typedef typename std::vector< degree_size_t > degree_size_vector_t;
typedef iterator_property_map< typename v_size_vector_t::iterator,
VertexIndexMap >
vertex_to_v_size_map_t;
typedef iterator_property_map< typename degree_size_vector_t::iterator,
VertexIndexMap >
vertex_to_degree_size_map_t;
typedef typename vertex_vector_t::iterator face_iterator;
triangulation_visitor(Graph& arg_g, VertexIndexMap arg_vm,
AddEdgeVisitor arg_add_edge_visitor)
: g(arg_g)
, vm(arg_vm)
, add_edge_visitor(arg_add_edge_visitor)
, timestamp(0)
, marked_vector(num_vertices(g), timestamp)
, degree_vector(num_vertices(g), 0)
, marked(marked_vector.begin(), vm)
, degree(degree_vector.begin(), vm)
{
vertex_iterator_t vi, vi_end;
for (boost::tie(vi, vi_end) = vertices(g); vi != vi_end; ++vi)
put(degree, *vi, out_degree(*vi, g));
}
template < typename Vertex > void next_vertex(Vertex v)
{
// Self-loops will appear as consecutive vertices in the list of
// vertices on a face. We want to skip these.
if (!vertices_on_face.empty()
&& (vertices_on_face.back() == v || vertices_on_face.front() == v))
return;
vertices_on_face.push_back(v);
}
void end_face()
{
++timestamp;
if (vertices_on_face.size() <= 3)
{
// At most three vertices on this face - don't need to triangulate
vertices_on_face.clear();
return;
}
// Find vertex on face of minimum degree
degree_size_t min_degree = num_vertices(g);
typename vertex_vector_t::iterator min_degree_vertex_itr;
face_iterator fi_end = vertices_on_face.end();
for (face_iterator fi = vertices_on_face.begin(); fi != fi_end; ++fi)
{
degree_size_t deg = get(degree, *fi);
if (deg < min_degree)
{
min_degree_vertex_itr = fi;
min_degree = deg;
}
}
// To simplify some of the manipulations, we'll re-arrange
// vertices_on_face so that it still contains the same
// (counter-clockwise) order of the vertices on this face, but now the
// min_degree_vertex is the first element in vertices_on_face.
vertex_vector_t temp_vector;
std::copy(min_degree_vertex_itr, vertices_on_face.end(),
std::back_inserter(temp_vector));
std::copy(vertices_on_face.begin(), min_degree_vertex_itr,
std::back_inserter(temp_vector));
vertices_on_face.swap(temp_vector);
// Mark all of the min degree vertex's neighbors
adjacency_iterator_t ai, ai_end;
for (boost::tie(ai, ai_end)
= adjacent_vertices(vertices_on_face.front(), g);
ai != ai_end; ++ai)
{
put(marked, *ai, timestamp);
}
typename vertex_vector_t::iterator marked_neighbor
= vertices_on_face.end();
// The iterator manipulations on the next two lines are safe because
// vertices_on_face.size() > 3 (from the first test in this function)
fi_end = prior(vertices_on_face.end());
for (face_iterator fi
= boost::next(boost::next(vertices_on_face.begin()));
fi != fi_end; ++fi)
{
if (get(marked, *fi) == timestamp)
{
marked_neighbor = fi;
break;
}
}
if (marked_neighbor == vertices_on_face.end())
{
add_edge_range(vertices_on_face[0],
boost::next(boost::next(vertices_on_face.begin())),
prior(vertices_on_face.end()));
}
else
{
add_edge_range(vertices_on_face[1], boost::next(marked_neighbor),
vertices_on_face.end());
add_edge_range(*boost::next(marked_neighbor),
boost::next(boost::next(vertices_on_face.begin())),
marked_neighbor);
}
// reset for the next face
vertices_on_face.clear();
}
private:
void add_edge_range(vertex_t anchor, face_iterator fi, face_iterator fi_end)
{
for (; fi != fi_end; ++fi)
{
vertex_t v(*fi);
add_edge_visitor.visit_vertex_pair(anchor, v, g);
put(degree, anchor, get(degree, anchor) + 1);
put(degree, v, get(degree, v) + 1);
}
}
Graph& g;
VertexIndexMap vm;
AddEdgeVisitor add_edge_visitor;
v_size_t timestamp;
vertex_vector_t vertices_on_face;
v_size_vector_t marked_vector;
degree_size_vector_t degree_vector;
vertex_to_v_size_map_t marked;
vertex_to_degree_size_map_t degree;
};
template < typename Graph, typename PlanarEmbedding, typename VertexIndexMap,
typename EdgeIndexMap, typename AddEdgeVisitor >
void make_maximal_planar(Graph& g, PlanarEmbedding embedding, VertexIndexMap vm,
EdgeIndexMap em, AddEdgeVisitor& vis)
{
triangulation_visitor< Graph, VertexIndexMap, AddEdgeVisitor > visitor(
g, vm, vis);
planar_face_traversal(g, embedding, visitor, em);
}
template < typename Graph, typename PlanarEmbedding, typename VertexIndexMap,
typename EdgeIndexMap >
void make_maximal_planar(
Graph& g, PlanarEmbedding embedding, VertexIndexMap vm, EdgeIndexMap em)
{
default_add_edge_visitor vis;
make_maximal_planar(g, embedding, vm, em, vis);
}
template < typename Graph, typename PlanarEmbedding, typename VertexIndexMap >
void make_maximal_planar(Graph& g, PlanarEmbedding embedding, VertexIndexMap vm)
{
make_maximal_planar(g, embedding, vm, get(edge_index, g));
}
template < typename Graph, typename PlanarEmbedding >
void make_maximal_planar(Graph& g, PlanarEmbedding embedding)
{
make_maximal_planar(g, embedding, get(vertex_index, g));
}
} // namespace boost
#endif //__MAKE_MAXIMAL_PLANAR_HPP__