| // Copyright 2004 The Trustees of Indiana University. |
| |
| // 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) |
| |
| // Authors: Douglas Gregor |
| // Andrew Lumsdaine |
| #ifndef BOOST_GRAPH_CIRCLE_LAYOUT_HPP |
| #define BOOST_GRAPH_CIRCLE_LAYOUT_HPP |
| #include <boost/config/no_tr1/cmath.hpp> |
| #include <boost/math/constants/constants.hpp> |
| #include <utility> |
| #include <boost/graph/graph_traits.hpp> |
| #include <boost/graph/iteration_macros.hpp> |
| #include <boost/graph/topology.hpp> |
| #include <boost/static_assert.hpp> |
| |
| namespace boost { |
| /** |
| * \brief Layout the graph with the vertices at the points of a regular |
| * n-polygon. |
| * |
| * The distance from the center of the polygon to each point is |
| * determined by the @p radius parameter. The @p position parameter |
| * must be an Lvalue Property Map whose value type is a class type |
| * containing @c x and @c y members that will be set to the @c x and |
| * @c y coordinates. |
| */ |
| template<typename VertexListGraph, typename PositionMap, typename Radius> |
| void |
| circle_graph_layout(const VertexListGraph& g, PositionMap position, |
| Radius radius) |
| { |
| BOOST_STATIC_ASSERT (property_traits<PositionMap>::value_type::dimensions >= 2); |
| const double pi = boost::math::constants::pi<double>(); |
| |
| #ifndef BOOST_NO_STDC_NAMESPACE |
| using std::sin; |
| using std::cos; |
| #endif // BOOST_NO_STDC_NAMESPACE |
| |
| typedef typename graph_traits<VertexListGraph>::vertices_size_type |
| vertices_size_type; |
| |
| vertices_size_type n = num_vertices(g); |
| |
| vertices_size_type i = 0; |
| double two_pi_over_n = 2. * pi / n; |
| BGL_FORALL_VERTICES_T(v, g, VertexListGraph) { |
| position[v][0] = radius * cos(i * two_pi_over_n); |
| position[v][1] = radius * sin(i * two_pi_over_n); |
| ++i; |
| } |
| } |
| } // end namespace boost |
| |
| #endif // BOOST_GRAPH_CIRCLE_LAYOUT_HPP |