#include "BarnesHutTree.hpp"
#include "Node.hpp"
#include <iostream>
namespace nbody {
using namespace std;
BarnesHutTree::BarnesHutTree() {
this->control.maxLeafBodies = 16;
this->control.tree = this;
this->control.processedNodes = 0;
pthread_rwlock_init(&this->control.lock, NULL);
}
BarnesHutTree::~BarnesHutTree() {
pthread_rwlock_destroy(&this->control.lock);
}
vector<Box> BarnesHutTree::splitBB(Node* node) {
return node->getBB().octreeSplit();
}
int BarnesHutTree::numberOfChildren() {
return 8;
}
void BarnesHutTree::update() {
//iterate for updating representatives
Node* current = this->nodes->prev;
while (current != this->nodes) {
current->representative.mass = 0.0;
current->representative.position[0] = 0.0;
current->representative.position[1] = 0.0;
current->representative.position[2] = 0.0;
if (current->leaf) {
for (unsigned int i = 0; i < current->bodies.size(); i++) {
current->representative.mass += current->bodies[i].mass;
for (int j = 0; j < 3; j++) {
current->representative.position[j] += current->bodies[i].position[j] * current->bodies[i].mass;
}
}
} else {
Node* child = current->next;
do {
current->representative.mass += child->representative.mass;
for (int j = 0; j < 3; j++) {
current->representative.position[j] += child->representative.position[j] * child->representative.mass;
}
child = child->nextSibling;
} while (child != NULL);
}
for (int j = 0; j < 3; j++) {
current->representative.position[j] /= current->representative.mass;
}
current = current->prev;
}
}
void BarnesHutTree::splitNode(Node* current) {
if (current->isSplitable(&this->control)) {
vector<Box> subboxes = this->splitBB(current);
current->leaf = false;
Node* after = current->next;
for (vector<Box>::iterator it = subboxes.begin(); it != subboxes.end(); it++) {
Node* child = new Node(this);
child->parent = current;
child->bb = *it;
child->bodies = it->copyBodies(current->bodies);
child->nextSibling = NULL;
child->prevSibling = NULL;
after->insertBefore(child);
if (it != subboxes.begin()) {
child->prev->nextSibling = child;
child->prevSibling = child->prev;
child->prev->afterSubtree = child;
}
}
after->prev->afterSubtree = current->afterSubtree;
current->bodies.clear();
}
}
void BarnesHutTree::build(vector<Body> bodies, Box domain) {
Node* current;
this->clean();
if (bodies.empty()) return;
//insert root node
this->nodes->insertAfter(new Node(this));
current = this->nodes->next;
//assign bodies to root node
current->bodies = bodies;
//setup proper bounding box
current->bb = domain;
current->extendBBforBodies();
current->extendBBtoCube();
current->afterSubtree = current->next;
//iterate over existing boxes and split if it contains too much bodies
while (current != this->nodes) {
this->splitNode(current);
current = current->next;
}
this->update();
}
void BarnesHutTree::build(vector<Body> bodies) {
Box bb;
bb.extendForBodies(bodies);
this->build(bodies, bb);
}
void BarnesHutTree::mergeLET(vector<Body> bodies) {
for (vector<Body>::iterator it = bodies.begin(); it != bodies.end(); it++) {
Node* current = this->nodes->next;
while (!current->leaf) {
Node* child = current->next;
while (child != NULL && !child->getBB().contained(it->position)) {
child = child->nextSibling;
}
if (child == NULL) {
cout << it - bodies.begin() << " Error: not contained: " << it->position[0] << " " << it->position[1] << " " << it->position[2] << endl;
} else {
current = child;
}
}
current->bodies.push_back(*it);
current->bodies.back().refinement = true;
this->splitNode(current);
}
this->update();
}
}