| 1 | // Copyright 2004 The Trustees of Indiana University. |
|---|---|
| 2 | |
| 3 | // Distributed under the Boost Software License, Version 1.0. |
| 4 | // (See accompanying file LICENSE_1_0.txt or copy at |
| 5 | // http://www.boost.org/LICENSE_1_0.txt) |
| 6 | |
| 7 | // Authors: Douglas Gregor |
| 8 | // Andrew Lumsdaine |
| 9 | #ifndef BOOST_GRAPH_CIRCLE_LAYOUT_HPP |
| 10 | #define BOOST_GRAPH_CIRCLE_LAYOUT_HPP |
| 11 | #include <boost/config/no_tr1/cmath.hpp> |
| 12 | #include <boost/math/constants/constants.hpp> |
| 13 | #include <utility> |
| 14 | #include <boost/graph/graph_traits.hpp> |
| 15 | #include <boost/graph/iteration_macros.hpp> |
| 16 | #include <boost/graph/topology.hpp> |
| 17 | #include <boost/static_assert.hpp> |
| 18 | |
| 19 | namespace boost { |
| 20 | /** |
| 21 | * \brief Layout the graph with the vertices at the points of a regular |
| 22 | * n-polygon. |
| 23 | * |
| 24 | * The distance from the center of the polygon to each point is |
| 25 | * determined by the @p radius parameter. The @p position parameter |
| 26 | * must be an Lvalue Property Map whose value type is a class type |
| 27 | * containing @c x and @c y members that will be set to the @c x and |
| 28 | * @c y coordinates. |
| 29 | */ |
| 30 | template<typename VertexListGraph, typename PositionMap, typename Radius> |
| 31 | void |
| 32 | circle_graph_layout(const VertexListGraph& g, PositionMap position, |
| 33 | Radius radius) |
| 34 | { |
| 35 | BOOST_STATIC_ASSERT (property_traits<PositionMap>::value_type::dimensions >= 2); |
| 36 | const double pi = boost::math::constants::pi<double>(); |
| 37 | |
| 38 | #ifndef BOOST_NO_STDC_NAMESPACE |
| 39 | using std::sin; |
| 40 | using std::cos; |
| 41 | #endif // BOOST_NO_STDC_NAMESPACE |
| 42 | |
| 43 | typedef typename graph_traits<VertexListGraph>::vertices_size_type |
| 44 | vertices_size_type; |
| 45 | |
| 46 | vertices_size_type n = num_vertices(g); |
| 47 | |
| 48 | vertices_size_type i = 0; |
| 49 | double two_pi_over_n = 2. * pi / n; |
| 50 | BGL_FORALL_VERTICES_T(v, g, VertexListGraph) { |
| 51 | position[v][0] = radius * cos(i * two_pi_over_n); |
| 52 | position[v][1] = radius * sin(i * two_pi_over_n); |
| 53 | ++i; |
| 54 | } |
| 55 | } |
| 56 | } // end namespace boost |
| 57 | |
| 58 | #endif // BOOST_GRAPH_CIRCLE_LAYOUT_HPP |
| 59 |