// 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 |