59 lines
2.0 KiB
C++
59 lines
2.0 KiB
C++
// 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
|