ceph/src/boost/libs/graph/example/planar_face_traversal.cpp

   1 //=======================================================================
   2 // Copyright 2007 Aaron Windsor
   3 //
   4 // Distributed under the Boost Software License, Version 1.0. (See
   5 // accompanying file LICENSE_1_0.txt or copy at
   6 // http://www.boost.org/LICENSE_1_0.txt)
   7 //=======================================================================
   8 #include <iostream>
   9 #include <boost/graph/adjacency_list.hpp>
  10 #include <boost/graph/properties.hpp>
  11 #include <boost/graph/graph_traits.hpp>
  12 #include <boost/property_map/property_map.hpp>
  13 #include <boost/ref.hpp>
  14 #include <vector>
  15
  16 #include <boost/graph/planar_face_traversal.hpp>
  17 #include <boost/graph/boyer_myrvold_planar_test.hpp>
  18
  19
  20 using namespace boost;
  21
  22
  23
  24 // Some planar face traversal visitors that will
  25 // print the vertices and edges on the faces
  26
  27 struct output_visitor : public planar_face_traversal_visitor
  28 {
  29   void begin_face() { std::cout << "New face: "; }
  30   void end_face() { std::cout << std::endl; }
  31 };
  32
  33
  34
  35 struct vertex_output_visitor : public output_visitor
  36 {
  37   template <typename Vertex>
  38   void next_vertex(Vertex v)
  39   {
  40     std::cout << v << " ";
  41   }
  42 };
  43
  44
  45
  46 struct edge_output_visitor : public output_visitor
  47 {
  48   template <typename Edge>
  49   void next_edge(Edge e)
  50   {
  51     std::cout << e << " ";
  52   }
  53 };
  54
  55
  56 int main(int argc, char** argv)
  57 {
  58
  59   typedef adjacency_list
  60     < vecS,
  61       vecS,
  62       undirectedS,
  63       property<vertex_index_t, int>,
  64       property<edge_index_t, int>
  65     >
  66     graph;
  67
  68   // Create a graph - this is a biconnected, 3 x 3 grid.
  69   // It should have four small (four vertex/four edge) faces and
  70   // one large face that contains all but the interior vertex
  71   graph g(9);
  72
  73   add_edge(0,1,g);
  74   add_edge(1,2,g);
  75
  76   add_edge(3,4,g);
  77   add_edge(4,5,g);
  78
  79   add_edge(6,7,g);
  80   add_edge(7,8,g);
  81
  82
  83   add_edge(0,3,g);
  84   add_edge(3,6,g);
  85
  86   add_edge(1,4,g);
  87   add_edge(4,7,g);
  88
  89   add_edge(2,5,g);
  90   add_edge(5,8,g);
  91
  92
  93   // Initialize the interior edge index
  94   property_map<graph, edge_index_t>::type e_index = get(edge_index, g);
  95   graph_traits<graph>::edges_size_type edge_count = 0;
  96   graph_traits<graph>::edge_iterator ei, ei_end;
  97   for(boost::tie(ei, ei_end) = edges(g); ei != ei_end; ++ei)
  98     put(e_index, *ei, edge_count++);
  99
 100
 101   // Test for planarity - we know it is planar, we just want to
 102   // compute the planar embedding as a side-effect
 103   typedef std::vector< graph_traits<graph>::edge_descriptor > vec_t;
 104   std::vector<vec_t> embedding(num_vertices(g));
 105   if (boyer_myrvold_planarity_test(boyer_myrvold_params::graph = g,
 106                                    boyer_myrvold_params::embedding =
 107                                        &embedding[0]
 108                                    )
 109       )
 110     std::cout << "Input graph is planar" << std::endl;
 111   else
 112     std::cout << "Input graph is not planar" << std::endl;
 113
 114
 115   std::cout << std::endl << "Vertices on the faces: " << std::endl;
 116   vertex_output_visitor v_vis;
 117   planar_face_traversal(g, &embedding[0], v_vis);
 118
 119   std::cout << std::endl << "Edges on the faces: " << std::endl;
 120   edge_output_visitor e_vis;
 121   planar_face_traversal(g, &embedding[0], e_vis);
 122
 123   return 0;
 124 }