MotionPlannerGraph*
MotionPlanner::init_graph(int island_idx)
{
if (this->graphs[island_idx + 1] == NULL) {
Polygons pp;
if (island_idx == -1) {
pp = this->outer;
} else {
pp = this->inner[island_idx];
}
MotionPlannerGraph* graph = this->graphs[island_idx + 1] = new MotionPlannerGraph();
// add polygon boundaries as edges
size_t node_idx = 0;
Lines lines;
for (Polygons::const_iterator polygon = pp.begin(); polygon != pp.end(); ++polygon) {
graph->nodes.push_back(polygon->points.back());
node_idx++;
for (Points::const_iterator p = polygon->points.begin(); p != polygon->points.end(); ++p) {
graph->nodes.push_back(*p);
double dist = graph->nodes[node_idx-1].distance_to(*p);
graph->add_edge(node_idx-1, node_idx, dist);
graph->add_edge(node_idx, node_idx-1, dist);
node_idx++;
}
polygon->lines(&lines);
}
// add Voronoi edges as internal edges
{
typedef voronoi_diagram<double> VD;
typedef std::map<const VD::vertex_type*,size_t> t_vd_vertices;
VD vd;
t_vd_vertices vd_vertices;
boost::polygon::construct_voronoi(lines.begin(), lines.end(), &vd);
for (VD::const_edge_iterator edge = vd.edges().begin(); edge != vd.edges().end(); ++edge) {
if (edge->is_infinite()) continue;
const VD::vertex_type* v0 = edge->vertex0();
const VD::vertex_type* v1 = edge->vertex1();
Point p0 = Point(v0->x(), v0->y());
Point p1 = Point(v1->x(), v1->y());
// contains() should probably be faster than contains(),
// and should it fail on any boundary points it's not a big problem
if (island_idx == -1) {
if (!this->outer.contains(p0) || !this->outer.contains(p1)) continue;
} else {
if (!this->inner[island_idx].contains(p0) || !this->inner[island_idx].contains(p1)) continue;
}
t_vd_vertices::const_iterator i_v0 = vd_vertices.find(v0);
size_t v0_idx;
if (i_v0 == vd_vertices.end()) {
graph->nodes.push_back(p0);
v0_idx = node_idx;
vd_vertices[v0] = node_idx;
node_idx++;
} else {
v0_idx = i_v0->second;
}
t_vd_vertices::const_iterator i_v1 = vd_vertices.find(v1);
size_t v1_idx;
if (i_v1 == vd_vertices.end()) {
graph->nodes.push_back(p1);
v1_idx = node_idx;
vd_vertices[v1] = node_idx;
node_idx++;
} else {
v1_idx = i_v1->second;
}
double dist = graph->nodes[v0_idx].distance_to(graph->nodes[v1_idx]);
graph->add_edge(v0_idx, v1_idx, dist);
}
}
return graph;
}
return this->graphs[island_idx + 1];
}
MotionPlannerGraph*
MotionPlanner::init_graph(int island_idx)
{
if (this->graphs[island_idx + 1] == NULL) {
// if this graph doesn't exist, initialize it
MotionPlannerGraph* graph = this->graphs[island_idx + 1] = new MotionPlannerGraph();
/* We don't add polygon boundaries as graph edges, because we'd need to connect
them to the Voronoi-generated edges by recognizing coinciding nodes. */
typedef voronoi_diagram<double> VD;
VD vd;
// mapping between Voronoi vertices and graph nodes
typedef std::map<const VD::vertex_type*,size_t> t_vd_vertices;
t_vd_vertices vd_vertices;
// get boundaries as lines
ExPolygonCollection env = this->get_env(island_idx);
Lines lines = env.lines();
boost::polygon::construct_voronoi(lines.begin(), lines.end(), &vd);
// traverse the Voronoi diagram and generate graph nodes and edges
for (VD::const_edge_iterator edge = vd.edges().begin(); edge != vd.edges().end(); ++edge) {
if (edge->is_infinite()) continue;
const VD::vertex_type* v0 = edge->vertex0();
const VD::vertex_type* v1 = edge->vertex1();
Point p0 = Point(v0->x(), v0->y());
Point p1 = Point(v1->x(), v1->y());
// skip edge if any of its endpoints is outside our configuration space
if (!env.contains_b(p0) || !env.contains_b(p1)) continue;
t_vd_vertices::const_iterator i_v0 = vd_vertices.find(v0);
size_t v0_idx;
if (i_v0 == vd_vertices.end()) {
graph->nodes.push_back(p0);
vd_vertices[v0] = v0_idx = graph->nodes.size()-1;
} else {
v0_idx = i_v0->second;
}
t_vd_vertices::const_iterator i_v1 = vd_vertices.find(v1);
size_t v1_idx;
if (i_v1 == vd_vertices.end()) {
graph->nodes.push_back(p1);
vd_vertices[v1] = v1_idx = graph->nodes.size()-1;
} else {
v1_idx = i_v1->second;
}
// Euclidean distance is used as weight for the graph edge
double dist = graph->nodes[v0_idx].distance_to(graph->nodes[v1_idx]);
graph->add_edge(v0_idx, v1_idx, dist);
}
return graph;
}
return this->graphs[island_idx + 1];
}