#define GRID_MAX_XI ((unsigned int) floor(GRID_WIDTH / GRID)) // min is 0
#define GRID_MAX_YI ((unsigned int) floor(GRID_HEIGHT / GRID)) // min is 0
-// ext7
-#define MAX_DIM 2
+/*! \brief Use k-d tree data structure to store RRT nodes.
+
+This approach speeds up the search process for the nearest neighbor and
+the near vertices procedures. This extension implements 3D K-d tree.
+
+\see https://en.wikipedia.org/wiki/K-d_tree
+*/
+class RRTExt8 : public virtual RRTS {
+ private:
+ class KdNode {
+ private:
+ RRTNode *node_ = nullptr;
+ KdNode *left_ = nullptr;
+ KdNode *right_ = nullptr;
+ public:
+ // getter, setter
+ RRTNode *node() const { return this->node_; }
+ KdNode *&left() { return this->left_; }
+ KdNode *&right() { return this->right_; }
+ KdNode(RRTNode *n);
+ };
+ KdNode *kdroot_ = nullptr;
+ void delete_kd_nodes(KdNode *n);
+ void store_node(RRTNode *n, KdNode *&r, int l);
+ void nn(RRTNode *&n, RRTNode &t, KdNode *r, int l, double &d);
+ public:
+ void init();
+ void deinit();
+ void store_node(RRTNode n);
+ RRTNode *nn(RRTNode &t);
+ std::vector<RRTNode *> nv(RRTNode &t);
+};
/*! \brief Use k-d tree data structure to store RRT nodes.
--- /dev/null
+#include "rrtext.h"
+
+RRTExt8::KdNode::KdNode(RRTNode *n)
+ : node_(n)
+ , left_(nullptr)
+ , right_(nullptr)
+{
+}
+
+void RRTExt8::delete_kd_nodes(KdNode *n)
+{
+ if (!n)
+ return;
+ if (n->left() != nullptr)
+ delete_kd_nodes(n->left());
+ if (n->right() != nullptr)
+ delete_kd_nodes(n->right());
+ delete n;
+}
+
+void RRTExt8::store_node(RRTNode *n, KdNode *&r, int l)
+{
+ if (r == nullptr)
+ r = new KdNode(n);
+ else if (l % 2 == 0 && n->x() < r->node()->x())
+ store_node(n, r->left(), l + 1);
+ else if (l % 2 == 0)
+ store_node(n, r->right(), l + 1);
+ else if (l % 2 == 1 && n->y() < r->node()->y())
+ store_node(n, r->left(), l + 1);
+ else
+ store_node(n, r->right(), l + 1);
+}
+
+void RRTExt8::nn(RRTNode *&n, RRTNode &t, KdNode *r, int l, double &d)
+{
+ if (r == nullptr)
+ return;
+ if (this->cost_search(*r->node(), t) < d) {
+ n = r->node();
+ d = this->cost_search(*r->node(), t);
+ }
+ if (l % 2 == 0 && t.x() < r->node()->x()) {
+ nn(n, t, r->left(), l + 1, d);
+ if (r->node()->x() - t.x() < d)
+ nn(n, t, r->right(), l + 1, d);
+ } else if (l % 2 == 0) {
+ nn(n, t, r->right(), l + 1, d);
+ if (t.x() - r->node()->x() < d)
+ nn(n, t, r->left(), l + 1, d);
+ } else if (l % 2 == 1 && t.y() < r->node()->y()) {
+ nn(n, t, r->left(), l + 1, d);
+ if (r->node()->y() - t.y() < d)
+ nn(n, t, r->right(), l + 1, d);
+ } else {
+ nn(n, t, r->right(), l + 1, d);
+ if (t.y() - r->node()->y() < d)
+ nn(n, t, r->left(), l + 1, d);
+ }
+}
+
+// API
+void RRTExt8::init()
+{
+}
+
+void RRTExt8::deinit()
+{
+ this->delete_kd_nodes(this->kdroot_);
+}
+
+void RRTExt8::store_node(RRTNode n)
+{
+ RRTS::store_node(n);
+ RRTNode *sn = &this->nodes().back();
+ this->store_node(sn, this->kdroot_, 0);
+}
+
+RRTNode *RRTExt8::nn(RRTNode &t)
+{
+ RRTNode *n = &this->nodes().front();
+ double d = 9999;
+ this->nn(n, t, this->kdroot_, 0, d);
+ return n;
+}
+
+std::vector<RRTNode *> RRTExt8::nv(RRTNode &t)
+{
+ std::vector<RRTNode *> nv;
+ return nv;
+}