williamr@2: // Copyright 2004 The Trustees of Indiana University.
williamr@2:
williamr@2: // Distributed under the Boost Software License, Version 1.0.
williamr@2: // (See accompanying file LICENSE_1_0.txt or copy at
williamr@2: // http://www.boost.org/LICENSE_1_0.txt)
williamr@2:
williamr@2: // Authors: Jeremiah Willcock
williamr@2: // Douglas Gregor
williamr@2: // Andrew Lumsdaine
williamr@2: #ifndef BOOST_GRAPH_GURSOY_ATUN_LAYOUT_HPP
williamr@2: #define BOOST_GRAPH_GURSOY_ATUN_LAYOUT_HPP
williamr@2:
williamr@2: // Gursoy-Atun graph layout, based on:
williamr@2: // "Neighbourhood Preserving Load Balancing: A Self-Organizing Approach"
williamr@2: // in EuroPar 2000, p. 234 of LNCS 1900
williamr@2: // http://springerlink.metapress.com/link.asp?id=pcu07ew5rhexp9yt
williamr@2:
williamr@2: #include <cmath>
williamr@2: #include <vector>
williamr@2: #include <exception>
williamr@2: #include <algorithm>
williamr@2:
williamr@2: #include <boost/graph/visitors.hpp>
williamr@2: #include <boost/graph/properties.hpp>
williamr@2: #include <boost/random/uniform_01.hpp>
williamr@2: #include <boost/random/linear_congruential.hpp>
williamr@2: #include <boost/shared_ptr.hpp>
williamr@2: #include <boost/graph/breadth_first_search.hpp>
williamr@2: #include <boost/graph/dijkstra_shortest_paths.hpp>
williamr@2: #include <boost/graph/named_function_params.hpp>
williamr@2:
williamr@2: namespace boost {
williamr@2:
williamr@2: namespace detail {
williamr@2:
williamr@2: struct over_distance_limit : public std::exception {};
williamr@2:
williamr@2: template <typename PositionMap, typename NodeDistanceMap, typename Topology,
williamr@2: typename Graph>
williamr@2: struct update_position_visitor {
williamr@2: typedef typename Topology::point_type Point;
williamr@2: PositionMap position_map;
williamr@2: NodeDistanceMap node_distance;
williamr@2: const Topology& space;
williamr@2: Point input_vector;
williamr@2: double distance_limit;
williamr@2: double learning_constant;
williamr@2: double falloff_ratio;
williamr@2:
williamr@2: typedef boost::on_examine_vertex event_filter;
williamr@2:
williamr@2: typedef typename graph_traits<Graph>::vertex_descriptor
williamr@2: vertex_descriptor;
williamr@2:
williamr@2: update_position_visitor(PositionMap position_map,
williamr@2: NodeDistanceMap node_distance,
williamr@2: const Topology& space,
williamr@2: const Point& input_vector,
williamr@2: double distance_limit,
williamr@2: double learning_constant,
williamr@2: double falloff_ratio):
williamr@2: position_map(position_map), node_distance(node_distance),
williamr@2: space(space),
williamr@2: input_vector(input_vector), distance_limit(distance_limit),
williamr@2: learning_constant(learning_constant), falloff_ratio(falloff_ratio) {}
williamr@2:
williamr@2: void operator()(vertex_descriptor v, const Graph&) const
williamr@2: {
williamr@2: #ifndef BOOST_NO_STDC_NAMESPACE
williamr@2: using std::pow;
williamr@2: #endif
williamr@2:
williamr@2: if (get(node_distance, v) > distance_limit)
williamr@2: throw over_distance_limit();
williamr@2: Point old_position = get(position_map, v);
williamr@2: double distance = get(node_distance, v);
williamr@2: double fraction =
williamr@2: learning_constant * pow(falloff_ratio, distance * distance);
williamr@2: put(position_map, v,
williamr@2: space.move_position_toward(old_position, fraction, input_vector));
williamr@2: }
williamr@2: };
williamr@2:
williamr@2: template<typename EdgeWeightMap>
williamr@2: struct gursoy_shortest
williamr@2: {
williamr@2: template<typename Graph, typename NodeDistanceMap, typename UpdatePosition>
williamr@2: static inline void
williamr@2: run(const Graph& g, typename graph_traits<Graph>::vertex_descriptor s,
williamr@2: NodeDistanceMap node_distance, UpdatePosition& update_position,
williamr@2: EdgeWeightMap weight)
williamr@2: {
williamr@2: boost::dijkstra_shortest_paths(g, s, weight_map(weight).
williamr@2: visitor(boost::make_dijkstra_visitor(std::make_pair(
williamr@2: boost::record_distances(node_distance, boost::on_edge_relaxed()),
williamr@2: update_position))));
williamr@2: }
williamr@2: };
williamr@2:
williamr@2: template<>
williamr@2: struct gursoy_shortest<dummy_property_map>
williamr@2: {
williamr@2: template<typename Graph, typename NodeDistanceMap, typename UpdatePosition>
williamr@2: static inline void
williamr@2: run(const Graph& g, typename graph_traits<Graph>::vertex_descriptor s,
williamr@2: NodeDistanceMap node_distance, UpdatePosition& update_position,
williamr@2: dummy_property_map)
williamr@2: {
williamr@2: boost::breadth_first_search(g, s,
williamr@2: visitor(boost::make_bfs_visitor(std::make_pair(
williamr@2: boost::record_distances(node_distance, boost::on_tree_edge()),
williamr@2: update_position))));
williamr@2: }
williamr@2: };
williamr@2:
williamr@2: } // namespace detail
williamr@2:
williamr@2: template <typename VertexListAndIncidenceGraph, typename Topology,
williamr@2: typename PositionMap, typename Diameter, typename VertexIndexMap,
williamr@2: typename EdgeWeightMap>
williamr@2: void
williamr@2: gursoy_atun_step
williamr@2: (const VertexListAndIncidenceGraph& graph,
williamr@2: const Topology& space,
williamr@2: PositionMap position,
williamr@2: Diameter diameter,
williamr@2: double learning_constant,
williamr@2: VertexIndexMap vertex_index_map,
williamr@2: EdgeWeightMap weight)
williamr@2: {
williamr@2: #ifndef BOOST_NO_STDC_NAMESPACE
williamr@2: using std::pow;
williamr@2: using std::exp;
williamr@2: #endif
williamr@2:
williamr@2: typedef typename graph_traits<VertexListAndIncidenceGraph>::vertex_iterator
williamr@2: vertex_iterator;
williamr@2: typedef typename graph_traits<VertexListAndIncidenceGraph>::vertex_descriptor
williamr@2: vertex_descriptor;
williamr@2: typedef typename Topology::point_type point_type;
williamr@2: vertex_iterator i, iend;
williamr@2: std::vector<double> distance_from_input_vector(num_vertices(graph));
williamr@2: typedef boost::iterator_property_map<std::vector<double>::iterator,
williamr@2: VertexIndexMap,
williamr@2: double, double&>
williamr@2: DistanceFromInputMap;
williamr@2: DistanceFromInputMap distance_from_input(distance_from_input_vector.begin(),
williamr@2: vertex_index_map);
williamr@2: std::vector<double> node_distance_map_vector(num_vertices(graph));
williamr@2: typedef boost::iterator_property_map<std::vector<double>::iterator,
williamr@2: VertexIndexMap,
williamr@2: double, double&>
williamr@2: NodeDistanceMap;
williamr@2: NodeDistanceMap node_distance(node_distance_map_vector.begin(),
williamr@2: vertex_index_map);
williamr@2: point_type input_vector = space.random_point();
williamr@2: vertex_descriptor min_distance_loc
williamr@2: = graph_traits<VertexListAndIncidenceGraph>::null_vertex();
williamr@2: double min_distance = 0.0;
williamr@2: bool min_distance_unset = true;
williamr@2: for (boost::tie(i, iend) = vertices(graph); i != iend; ++i) {
williamr@2: double this_distance = space.distance(get(position, *i), input_vector);
williamr@2: put(distance_from_input, *i, this_distance);
williamr@2: if (min_distance_unset || this_distance < min_distance) {
williamr@2: min_distance = this_distance;
williamr@2: min_distance_loc = *i;
williamr@2: }
williamr@2: min_distance_unset = false;
williamr@2: }
williamr@2: assert (!min_distance_unset); // Graph must have at least one vertex
williamr@2: boost::detail::update_position_visitor<
williamr@2: PositionMap, NodeDistanceMap, Topology,
williamr@2: VertexListAndIncidenceGraph>
williamr@2: update_position(position, node_distance, space,
williamr@2: input_vector, diameter, learning_constant,
williamr@2: exp(-1. / (2 * diameter * diameter)));
williamr@2: std::fill(node_distance_map_vector.begin(), node_distance_map_vector.end(), 0);
williamr@2: try {
williamr@2: typedef detail::gursoy_shortest<EdgeWeightMap> shortest;
williamr@2: shortest::run(graph, min_distance_loc, node_distance, update_position,
williamr@2: weight);
williamr@2: } catch (detail::over_distance_limit) {
williamr@2: /* Thrown to break out of BFS or Dijkstra early */
williamr@2: }
williamr@2: }
williamr@2:
williamr@2: template <typename VertexListAndIncidenceGraph, typename Topology,
williamr@2: typename PositionMap, typename VertexIndexMap,
williamr@2: typename EdgeWeightMap>
williamr@2: void gursoy_atun_refine(const VertexListAndIncidenceGraph& graph,
williamr@2: const Topology& space,
williamr@2: PositionMap position,
williamr@2: int nsteps,
williamr@2: double diameter_initial,
williamr@2: double diameter_final,
williamr@2: double learning_constant_initial,
williamr@2: double learning_constant_final,
williamr@2: VertexIndexMap vertex_index_map,
williamr@2: EdgeWeightMap weight)
williamr@2: {
williamr@2: #ifndef BOOST_NO_STDC_NAMESPACE
williamr@2: using std::pow;
williamr@2: using std::exp;
williamr@2: #endif
williamr@2:
williamr@2: typedef typename graph_traits<VertexListAndIncidenceGraph>::vertex_iterator
williamr@2: vertex_iterator;
williamr@2: typedef typename graph_traits<VertexListAndIncidenceGraph>::vertex_descriptor
williamr@2: vertex_descriptor;
williamr@2: typedef typename Topology::point_type point_type;
williamr@2: vertex_iterator i, iend;
williamr@2: double diameter_ratio = (double)diameter_final / diameter_initial;
williamr@2: double learning_constant_ratio =
williamr@2: learning_constant_final / learning_constant_initial;
williamr@2: std::vector<double> distance_from_input_vector(num_vertices(graph));
williamr@2: typedef boost::iterator_property_map<std::vector<double>::iterator,
williamr@2: VertexIndexMap,
williamr@2: double, double&>
williamr@2: DistanceFromInputMap;
williamr@2: DistanceFromInputMap distance_from_input(distance_from_input_vector.begin(),
williamr@2: vertex_index_map);
williamr@2: std::vector<int> node_distance_map_vector(num_vertices(graph));
williamr@2: typedef boost::iterator_property_map<std::vector<int>::iterator,
williamr@2: VertexIndexMap, double, double&>
williamr@2: NodeDistanceMap;
williamr@2: NodeDistanceMap node_distance(node_distance_map_vector.begin(),
williamr@2: vertex_index_map);
williamr@2: for (int round = 0; round < nsteps; ++round) {
williamr@2: double part_done = (double)round / (nsteps - 1);
williamr@2: int diameter = (int)(diameter_initial * pow(diameter_ratio, part_done));
williamr@2: double learning_constant =
williamr@2: learning_constant_initial * pow(learning_constant_ratio, part_done);
williamr@2: gursoy_atun_step(graph, space, position, diameter, learning_constant,
williamr@2: vertex_index_map, weight);
williamr@2: }
williamr@2: }
williamr@2:
williamr@2: template <typename VertexListAndIncidenceGraph, typename Topology,
williamr@2: typename PositionMap, typename VertexIndexMap,
williamr@2: typename EdgeWeightMap>
williamr@2: void gursoy_atun_layout(const VertexListAndIncidenceGraph& graph,
williamr@2: const Topology& space,
williamr@2: PositionMap position,
williamr@2: int nsteps,
williamr@2: double diameter_initial,
williamr@2: double diameter_final,
williamr@2: double learning_constant_initial,
williamr@2: double learning_constant_final,
williamr@2: VertexIndexMap vertex_index_map,
williamr@2: EdgeWeightMap weight)
williamr@2: {
williamr@2: typedef typename graph_traits<VertexListAndIncidenceGraph>::vertex_iterator
williamr@2: vertex_iterator;
williamr@2: vertex_iterator i, iend;
williamr@2: for (boost::tie(i, iend) = vertices(graph); i != iend; ++i) {
williamr@2: put(position, *i, space.random_point());
williamr@2: }
williamr@2: gursoy_atun_refine(graph, space,
williamr@2: position, nsteps,
williamr@2: diameter_initial, diameter_final,
williamr@2: learning_constant_initial, learning_constant_final,
williamr@2: vertex_index_map, weight);
williamr@2: }
williamr@2:
williamr@2: template <typename VertexListAndIncidenceGraph, typename Topology,
williamr@2: typename PositionMap, typename VertexIndexMap>
williamr@2: void gursoy_atun_layout(const VertexListAndIncidenceGraph& graph,
williamr@2: const Topology& space,
williamr@2: PositionMap position,
williamr@2: int nsteps,
williamr@2: double diameter_initial,
williamr@2: double diameter_final,
williamr@2: double learning_constant_initial,
williamr@2: double learning_constant_final,
williamr@2: VertexIndexMap vertex_index_map)
williamr@2: {
williamr@2: gursoy_atun_layout(graph, space, position, nsteps,
williamr@2: diameter_initial, diameter_final,
williamr@2: learning_constant_initial, learning_constant_final,
williamr@2: vertex_index_map, dummy_property_map());
williamr@2: }
williamr@2:
williamr@2: template <typename VertexListAndIncidenceGraph, typename Topology,
williamr@2: typename PositionMap>
williamr@2: void gursoy_atun_layout(const VertexListAndIncidenceGraph& graph,
williamr@2: const Topology& space,
williamr@2: PositionMap position,
williamr@2: int nsteps,
williamr@2: double diameter_initial,
williamr@2: double diameter_final = 1.0,
williamr@2: double learning_constant_initial = 0.8,
williamr@2: double learning_constant_final = 0.2)
williamr@2: {
williamr@2: gursoy_atun_layout(graph, space, position, nsteps, diameter_initial,
williamr@2: diameter_final, learning_constant_initial,
williamr@2: learning_constant_final, get(vertex_index, graph));
williamr@2: }
williamr@2:
williamr@2: template <typename VertexListAndIncidenceGraph, typename Topology,
williamr@2: typename PositionMap>
williamr@2: void gursoy_atun_layout(const VertexListAndIncidenceGraph& graph,
williamr@2: const Topology& space,
williamr@2: PositionMap position,
williamr@2: int nsteps)
williamr@2: {
williamr@2: #ifndef BOOST_NO_STDC_NAMESPACE
williamr@2: using std::sqrt;
williamr@2: #endif
williamr@2:
williamr@2: gursoy_atun_layout(graph, space, position, nsteps,
williamr@2: sqrt((double)num_vertices(graph)));
williamr@2: }
williamr@2:
williamr@2: template <typename VertexListAndIncidenceGraph, typename Topology,
williamr@2: typename PositionMap>
williamr@2: void gursoy_atun_layout(const VertexListAndIncidenceGraph& graph,
williamr@2: const Topology& space,
williamr@2: PositionMap position)
williamr@2: {
williamr@2: gursoy_atun_layout(graph, space, position, num_vertices(graph));
williamr@2: }
williamr@2:
williamr@2: template<typename VertexListAndIncidenceGraph, typename Topology,
williamr@2: typename PositionMap, typename P, typename T, typename R>
williamr@2: void
williamr@2: gursoy_atun_layout(const VertexListAndIncidenceGraph& graph,
williamr@2: const Topology& space,
williamr@2: PositionMap position,
williamr@2: const bgl_named_params<P,T,R>& params)
williamr@2: {
williamr@2: #ifndef BOOST_NO_STDC_NAMESPACE
williamr@2: using std::sqrt;
williamr@2: #endif
williamr@2:
williamr@2: std::pair<double, double> diam(sqrt(double(num_vertices(graph))), 1.0);
williamr@2: std::pair<double, double> learn(0.8, 0.2);
williamr@2: gursoy_atun_layout(graph, space, position,
williamr@2: choose_param(get_param(params, iterations_t()),
williamr@2: num_vertices(graph)),
williamr@2: choose_param(get_param(params, diameter_range_t()),
williamr@2: diam).first,
williamr@2: choose_param(get_param(params, diameter_range_t()),
williamr@2: diam).second,
williamr@2: choose_param(get_param(params, learning_constant_range_t()),
williamr@2: learn).first,
williamr@2: choose_param(get_param(params, learning_constant_range_t()),
williamr@2: learn).second,
williamr@2: choose_const_pmap(get_param(params, vertex_index), graph,
williamr@2: vertex_index),
williamr@2: choose_param(get_param(params, edge_weight),
williamr@2: dummy_property_map()));
williamr@2: }
williamr@2:
williamr@2: /***********************************************************
williamr@2: * Topologies *
williamr@2: ***********************************************************/
williamr@2: template<std::size_t Dims>
williamr@2: class convex_topology
williamr@2: {
williamr@2: struct point
williamr@2: {
williamr@2: point() { }
williamr@2: double& operator[](std::size_t i) {return values[i];}
williamr@2: const double& operator[](std::size_t i) const {return values[i];}
williamr@2:
williamr@2: private:
williamr@2: double values[Dims];
williamr@2: };
williamr@2:
williamr@2: public:
williamr@2: typedef point point_type;
williamr@2:
williamr@2: double distance(point a, point b) const
williamr@2: {
williamr@2: double dist = 0;
williamr@2: for (std::size_t i = 0; i < Dims; ++i) {
williamr@2: double diff = b[i] - a[i];
williamr@2: dist += diff * diff;
williamr@2: }
williamr@2: // Exact properties of the distance are not important, as long as
williamr@2: // < on what this returns matches real distances
williamr@2: return dist;
williamr@2: }
williamr@2:
williamr@2: point move_position_toward(point a, double fraction, point b) const
williamr@2: {
williamr@2: point result;
williamr@2: for (std::size_t i = 0; i < Dims; ++i)
williamr@2: result[i] = a[i] + (b[i] - a[i]) * fraction;
williamr@2: return result;
williamr@2: }
williamr@2: };
williamr@2:
williamr@2: template<std::size_t Dims,
williamr@2: typename RandomNumberGenerator = minstd_rand>
williamr@2: class hypercube_topology : public convex_topology<Dims>
williamr@2: {
williamr@2: typedef uniform_01<RandomNumberGenerator, double> rand_t;
williamr@2:
williamr@2: public:
williamr@2: typedef typename convex_topology<Dims>::point_type point_type;
williamr@2:
williamr@2: explicit hypercube_topology(double scaling = 1.0)
williamr@2: : gen_ptr(new RandomNumberGenerator), rand(new rand_t(*gen_ptr)),
williamr@2: scaling(scaling)
williamr@2: { }
williamr@2:
williamr@2: hypercube_topology(RandomNumberGenerator& gen, double scaling = 1.0)
williamr@2: : gen_ptr(), rand(new rand_t(gen)), scaling(scaling) { }
williamr@2:
williamr@2: point_type random_point() const
williamr@2: {
williamr@2: point_type p;
williamr@2: for (std::size_t i = 0; i < Dims; ++i)
williamr@2: p[i] = (*rand)() * scaling;
williamr@2: return p;
williamr@2: }
williamr@2:
williamr@2: private:
williamr@2: shared_ptr<RandomNumberGenerator> gen_ptr;
williamr@2: shared_ptr<rand_t> rand;
williamr@2: double scaling;
williamr@2: };
williamr@2:
williamr@2: template<typename RandomNumberGenerator = minstd_rand>
williamr@2: class square_topology : public hypercube_topology<2, RandomNumberGenerator>
williamr@2: {
williamr@2: typedef hypercube_topology<2, RandomNumberGenerator> inherited;
williamr@2:
williamr@2: public:
williamr@2: explicit square_topology(double scaling = 1.0) : inherited(scaling) { }
williamr@2:
williamr@2: square_topology(RandomNumberGenerator& gen, double scaling = 1.0)
williamr@2: : inherited(gen, scaling) { }
williamr@2: };
williamr@2:
williamr@2: template<typename RandomNumberGenerator = minstd_rand>
williamr@2: class cube_topology : public hypercube_topology<3, RandomNumberGenerator>
williamr@2: {
williamr@2: typedef hypercube_topology<3, RandomNumberGenerator> inherited;
williamr@2:
williamr@2: public:
williamr@2: explicit cube_topology(double scaling = 1.0) : inherited(scaling) { }
williamr@2:
williamr@2: cube_topology(RandomNumberGenerator& gen, double scaling = 1.0)
williamr@2: : inherited(gen, scaling) { }
williamr@2: };
williamr@2:
williamr@2: template<std::size_t Dims,
williamr@2: typename RandomNumberGenerator = minstd_rand>
williamr@2: class ball_topology : public convex_topology<Dims>
williamr@2: {
williamr@2: typedef uniform_01<RandomNumberGenerator, double> rand_t;
williamr@2:
williamr@2: public:
williamr@2: typedef typename convex_topology<Dims>::point_type point_type;
williamr@2:
williamr@2: explicit ball_topology(double radius = 1.0)
williamr@2: : gen_ptr(new RandomNumberGenerator), rand(new rand_t(*gen_ptr)),
williamr@2: radius(radius)
williamr@2: { }
williamr@2:
williamr@2: ball_topology(RandomNumberGenerator& gen, double radius = 1.0)
williamr@2: : gen_ptr(), rand(new rand_t(gen)), radius(radius) { }
williamr@2:
williamr@2: point_type random_point() const
williamr@2: {
williamr@2: point_type p;
williamr@2: double dist_sum;
williamr@2: do {
williamr@2: dist_sum = 0.0;
williamr@2: for (std::size_t i = 0; i < Dims; ++i) {
williamr@2: double x = (*rand)() * 2*radius - radius;
williamr@2: p[i] = x;
williamr@2: dist_sum += x * x;
williamr@2: }
williamr@2: } while (dist_sum > radius*radius);
williamr@2: return p;
williamr@2: }
williamr@2:
williamr@2: private:
williamr@2: shared_ptr<RandomNumberGenerator> gen_ptr;
williamr@2: shared_ptr<rand_t> rand;
williamr@2: double radius;
williamr@2: };
williamr@2:
williamr@2: template<typename RandomNumberGenerator = minstd_rand>
williamr@2: class circle_topology : public ball_topology<2, RandomNumberGenerator>
williamr@2: {
williamr@2: typedef ball_topology<2, RandomNumberGenerator> inherited;
williamr@2:
williamr@2: public:
williamr@2: explicit circle_topology(double radius = 1.0) : inherited(radius) { }
williamr@2:
williamr@2: circle_topology(RandomNumberGenerator& gen, double radius = 1.0)
williamr@2: : inherited(gen, radius) { }
williamr@2: };
williamr@2:
williamr@2: template<typename RandomNumberGenerator = minstd_rand>
williamr@2: class sphere_topology : public ball_topology<3, RandomNumberGenerator>
williamr@2: {
williamr@2: typedef ball_topology<3, RandomNumberGenerator> inherited;
williamr@2:
williamr@2: public:
williamr@2: explicit sphere_topology(double radius = 1.0) : inherited(radius) { }
williamr@2:
williamr@2: sphere_topology(RandomNumberGenerator& gen, double radius = 1.0)
williamr@2: : inherited(gen, radius) { }
williamr@2: };
williamr@2:
williamr@2: template<typename RandomNumberGenerator = minstd_rand>
williamr@2: class heart_topology
williamr@2: {
williamr@2: // Heart is defined as the union of three shapes:
williamr@2: // Square w/ corners (+-1000, -1000), (0, 0), (0, -2000)
williamr@2: // Circle centered at (-500, -500) radius 500*sqrt(2)
williamr@2: // Circle centered at (500, -500) radius 500*sqrt(2)
williamr@2: // Bounding box (-1000, -2000) - (1000, 500*(sqrt(2) - 1))
williamr@2:
williamr@2: struct point
williamr@2: {
williamr@2: point() { values[0] = 0.0; values[1] = 0.0; }
williamr@2: point(double x, double y) { values[0] = x; values[1] = y; }
williamr@2:
williamr@2: double& operator[](std::size_t i) { return values[i]; }
williamr@2: double operator[](std::size_t i) const { return values[i]; }
williamr@2:
williamr@2: private:
williamr@2: double values[2];
williamr@2: };
williamr@2:
williamr@2: bool in_heart(point p) const
williamr@2: {
williamr@2: #ifndef BOOST_NO_STDC_NAMESPACE
williamr@2: using std::abs;
williamr@2: using std::pow;
williamr@2: #endif
williamr@2:
williamr@2: if (p[1] < abs(p[0]) - 2000) return false; // Bottom
williamr@2: if (p[1] <= -1000) return true; // Diagonal of square
williamr@2: if (pow(p[0] - -500, 2) + pow(p[1] - -500, 2) <= 500000)
williamr@2: return true; // Left circle
williamr@2: if (pow(p[0] - 500, 2) + pow(p[1] - -500, 2) <= 500000)
williamr@2: return true; // Right circle
williamr@2: return false;
williamr@2: }
williamr@2:
williamr@2: bool segment_within_heart(point p1, point p2) const
williamr@2: {
williamr@2: // Assumes that p1 and p2 are within the heart
williamr@2: if ((p1[0] < 0) == (p2[0] < 0)) return true; // Same side of symmetry line
williamr@2: if (p1[0] == p2[0]) return true; // Vertical
williamr@2: double slope = (p2[1] - p1[1]) / (p2[0] - p1[0]);
williamr@2: double intercept = p1[1] - p1[0] * slope;
williamr@2: if (intercept > 0) return false; // Crosses between circles
williamr@2: return true;
williamr@2: }
williamr@2:
williamr@2: typedef uniform_01<RandomNumberGenerator, double> rand_t;
williamr@2:
williamr@2: public:
williamr@2: typedef point point_type;
williamr@2:
williamr@2: heart_topology()
williamr@2: : gen_ptr(new RandomNumberGenerator), rand(new rand_t(*gen_ptr)) { }
williamr@2:
williamr@2: heart_topology(RandomNumberGenerator& gen)
williamr@2: : gen_ptr(), rand(new rand_t(gen)) { }
williamr@2:
williamr@2: point random_point() const
williamr@2: {
williamr@2: #ifndef BOOST_NO_STDC_NAMESPACE
williamr@2: using std::sqrt;
williamr@2: #endif
williamr@2:
williamr@2: point result;
williamr@2: double sqrt2 = sqrt(2.);
williamr@2: do {
williamr@2: result[0] = (*rand)() * (1000 + 1000 * sqrt2) - (500 + 500 * sqrt2);
williamr@2: result[1] = (*rand)() * (2000 + 500 * (sqrt2 - 1)) - 2000;
williamr@2: } while (!in_heart(result));
williamr@2: return result;
williamr@2: }
williamr@2:
williamr@2: double distance(point a, point b) const
williamr@2: {
williamr@2: #ifndef BOOST_NO_STDC_NAMESPACE
williamr@2: using std::sqrt;
williamr@2: #endif
williamr@2: if (segment_within_heart(a, b)) {
williamr@2: // Straight line
williamr@2: return sqrt((b[0] - a[0]) * (b[0] - a[0]) + (b[1] - a[1]) * (b[1] - a[1]));
williamr@2: } else {
williamr@2: // Straight line bending around (0, 0)
williamr@2: return sqrt(a[0] * a[0] + a[1] * a[1]) + sqrt(b[0] * b[0] + b[1] * b[1]);
williamr@2: }
williamr@2: }
williamr@2:
williamr@2: point move_position_toward(point a, double fraction, point b) const
williamr@2: {
williamr@2: #ifndef BOOST_NO_STDC_NAMESPACE
williamr@2: using std::sqrt;
williamr@2: #endif
williamr@2:
williamr@2: if (segment_within_heart(a, b)) {
williamr@2: // Straight line
williamr@2: return point(a[0] + (b[0] - a[0]) * fraction,
williamr@2: a[1] + (b[1] - a[1]) * fraction);
williamr@2: } else {
williamr@2: double distance_to_point_a = sqrt(a[0] * a[0] + a[1] * a[1]);
williamr@2: double distance_to_point_b = sqrt(b[0] * b[0] + b[1] * b[1]);
williamr@2: double location_of_point = distance_to_point_a /
williamr@2: (distance_to_point_a + distance_to_point_b);
williamr@2: if (fraction < location_of_point)
williamr@2: return point(a[0] * (1 - fraction / location_of_point),
williamr@2: a[1] * (1 - fraction / location_of_point));
williamr@2: else
williamr@2: return point(
williamr@2: b[0] * ((fraction - location_of_point) / (1 - location_of_point)),
williamr@2: b[1] * ((fraction - location_of_point) / (1 - location_of_point)));
williamr@2: }
williamr@2: }
williamr@2:
williamr@2: private:
williamr@2: shared_ptr<RandomNumberGenerator> gen_ptr;
williamr@2: shared_ptr<rand_t> rand;
williamr@2: };
williamr@2:
williamr@2: } // namespace boost
williamr@2:
williamr@2: #endif // BOOST_GRAPH_GURSOY_ATUN_LAYOUT_HPP