comparison DEPENDENCIES/generic/include/boost/graph/planar_face_traversal.hpp @ 16:2665513ce2d3

Add boost headers

+//=======================================================================
+// Copyright (c) Aaron Windsor 2007
+//
+// 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 __PLANAR_FACE_TRAVERSAL_HPP__
+#define __PLANAR_FACE_TRAVERSAL_HPP__
+
+#include <vector>
+#include <set>
+#include <map>
+#include <boost/next_prior.hpp>
+#include <boost/graph/graph_traits.hpp>
+#include <boost/graph/properties.hpp>
+
+
+namespace boost
+{
+
+
+
+
+  struct planar_face_traversal_visitor
+  {
+    void begin_traversal()
+    {}
+
+    void begin_face()
+    {}
+
+    template <typename Edge>
+    void next_edge(Edge)
+    {}
+
+    template <typename Vertex>
+    void next_vertex(Vertex)
+    {}
+
+    void end_face()
+    {}
+
+    void end_traversal()
+    {}
+
+  };
+
+
+
+
+
+  template<typename Graph, 
+           typename PlanarEmbedding, 
+           typename Visitor, 
+           typename EdgeIndexMap>
+  void planar_face_traversal(const Graph& g, 
+                             PlanarEmbedding embedding, 
+                             Visitor& visitor, EdgeIndexMap em
+                             )
+  {
+    typedef typename graph_traits<Graph>::vertex_descriptor vertex_t;
+    typedef typename graph_traits<Graph>::edge_descriptor edge_t;
+    typedef typename graph_traits<Graph>::vertex_iterator vertex_iterator_t;
+    typedef typename graph_traits<Graph>::edge_iterator edge_iterator_t;
+    typedef typename 
+      property_traits<PlanarEmbedding>::value_type embedding_value_t;
+    typedef typename embedding_value_t::const_iterator embedding_iterator_t;
+
+    typedef typename 
+      std::vector< std::set<vertex_t> > distinguished_edge_storage_t;
+    typedef typename 
+      std::vector< std::map<vertex_t, edge_t> > 
+      distinguished_edge_to_edge_storage_t;
+
+    typedef typename 
+      boost::iterator_property_map
+        <typename distinguished_edge_storage_t::iterator, EdgeIndexMap>
+      distinguished_edge_map_t;
+
+    typedef typename 
+      boost::iterator_property_map
+        <typename distinguished_edge_to_edge_storage_t::iterator, EdgeIndexMap>
+      distinguished_edge_to_edge_map_t;
+
+    distinguished_edge_storage_t visited_vector(num_edges(g));
+    distinguished_edge_to_edge_storage_t next_edge_vector(num_edges(g));
+
+    distinguished_edge_map_t visited(visited_vector.begin(), em);
+    distinguished_edge_to_edge_map_t next_edge(next_edge_vector.begin(), em);
+
+    vertex_iterator_t vi, vi_end;
+    typename std::vector<edge_t>::iterator ei, ei_end;
+    edge_iterator_t fi, fi_end;
+    embedding_iterator_t pi, pi_begin, pi_end;
+
+    visitor.begin_traversal();
+
+    // Initialize the next_edge property map. This map is initialized from the
+    // PlanarEmbedding so that get(next_edge, e)[v] is the edge that comes
+    // after e in the clockwise embedding around vertex v.
+
+    for(boost::tie(vi,vi_end) = vertices(g); vi != vi_end; ++vi)
+      {
+        vertex_t v(*vi);
+        pi_begin = embedding[v].begin();
+        pi_end = embedding[v].end();
+        for(pi = pi_begin; pi != pi_end; ++pi)
+          {
+            edge_t e(*pi);
+            std::map<vertex_t, edge_t> m = get(next_edge, e);
+            m[v] = boost::next(pi) == pi_end ? *pi_begin : *boost::next(pi);
+            put(next_edge, e, m);
+          } 
+      }
+
+    // Take a copy of the edges in the graph here, since we want to accomodate
+    // face traversals that add edges to the graph (for triangulation, in 
+    // particular) and don't want to use invalidated edge iterators.
+    // Also, while iterating over all edges in the graph, we single out
+    // any self-loops, which need some special treatment in the face traversal.
+
+    std::vector<edge_t> self_loops;
+    std::vector<edge_t> edges_cache;
+    std::vector<vertex_t> vertices_in_edge;
+
+    for(boost::tie(fi,fi_end) = edges(g); fi != fi_end; ++fi)
+      {
+        edge_t e(*fi);
+        edges_cache.push_back(e);
+        if (source(e,g) == target(e,g))
+          self_loops.push_back(e);
+      }
+
+
+    // Iterate over all edges in the graph
+    ei_end = edges_cache.end();
+    for(ei = edges_cache.begin(); ei != ei_end; ++ei)
+      {
+
+        edge_t e(*ei);
+        vertices_in_edge.clear();
+        vertices_in_edge.push_back(source(e,g));
+        vertices_in_edge.push_back(target(e,g));
+
+        typename std::vector<vertex_t>::iterator vi, vi_end;
+        vi_end = vertices_in_edge.end();
+        
+        //Iterate over both vertices in the current edge
+        for(vi = vertices_in_edge.begin(); vi != vi_end; ++vi)
+          {
+
+            vertex_t v(*vi);
+            std::set<vertex_t> e_visited = get(visited, e);
+            typename std::set<vertex_t>::iterator e_visited_found 
+              = e_visited.find(v);
+            
+            if (e_visited_found == e_visited.end())
+              visitor.begin_face();
+            
+            while (e_visited.find(v) == e_visited.end())
+              {
+                visitor.next_vertex(v);
+                visitor.next_edge(e);
+                e_visited.insert(v);
+                put(visited, e, e_visited);
+                v = source(e,g) == v ? target(e,g) : source(e,g);
+                e = get(next_edge, e)[v];
+                e_visited = get(visited, e);
+              }
+            
+            if (e_visited_found == e_visited.end())
+              visitor.end_face();
+            
+          }
+
+      }
+
+    // Iterate over all self-loops, visiting them once separately
+    // (they've already been visited once, this visitation is for
+    // the "inside" of the self-loop)
+    
+    ei_end = self_loops.end();
+    for(ei = self_loops.begin(); ei != ei_end; ++ei)
+      {
+        visitor.begin_face();
+        visitor.next_edge(*ei);
+        visitor.next_vertex(source(*ei,g));
+        visitor.end_face();
+      }
+
+    visitor.end_traversal();
+
+  }
+
+
+
+  template<typename Graph, typename PlanarEmbedding, typename Visitor>
+  inline void planar_face_traversal(const Graph& g, 
+                                    PlanarEmbedding embedding, 
+                                    Visitor& visitor
+                                    )
+  {
+    planar_face_traversal(g, embedding, visitor, get(edge_index, g));
+  }
+
+
+
+
+} //namespace boost
+
+#endif //__PLANAR_FACE_TRAVERSAL_HPP__