void addBem(){
signal(SIGALRM,SIG_IGN);
if(reverse==0)
insertBody(Tail->prev,Tail);
else
insertBody(Head,Head->next);
signal(SIGALRM,whileBem);
}
void BHTree::insertBody(BHTree& node, const Body& b)
{
if(!node.hasBody && !node.isInternalNode) {//empty node
node.body = b;
node.hasBody = true;
updateTotalAndCenterMass(node, b);
}
else if(node.isInternalNode) {//internal node
//update total and center of mass
updateTotalAndCenterMass(node, b);
//recursively insert into correct quadrant
BHTree& correctQuad = getCorrectQuadForBody(node, b);
insertBody(correctQuad, b);
}
else { //external node that already contains a body
//In order to avoid stack overflow when 2 bodies happen to be extrememly close to each other,
//we will not try to subdivide a node further if the tree is already too deep. Instead we will simply update
//the lowest nodes mass and center of mass with the new body (essentially just 'cramming' more than one body
//into a single node)
if(node.treeDepth < MAX_TREE_DEPTH)
{
node.subdivide();
Body& existingBody = node.body;
node.hasBody = false;
BHTree& correctQuadForNewBody = getCorrectQuadForBody(node, b);
BHTree& correctQuadForExistingBody = getCorrectQuadForBody(node, existingBody);
insertBody(correctQuadForNewBody, b);
insertBody(correctQuadForExistingBody, existingBody);
}
else
{
std::cout << "MAX_TREE_DEPTH reached" << std::endl;
}
//update total and center of mass
updateTotalAndCenterMass(node, b);
}
}
void BarnesHutTree::insertBody(const Body& body)
{
//If there's not a body there already, put the body there.
if (m_bodyInTree.mass() == 0)
{
m_bodyInTree.set_mass(body.mass());
m_bodyInTree.set_xPosition(body.xPosition());
m_bodyInTree.set_yPosition(body.yPosition());
m_bodyInTree.set_zPosition(body.zPosition());
}
//If there's already a body there, but it's not an external node
//combine the two bodies and figure out which quadrant of the
//tree it should be located in. Then recursively update the nodes below it.
else if (isExternal() == false)
{
double newMass = m_bodyInTree.mass() + body.mass();
m_bodyInTree.set_xPosition((m_bodyInTree.xPosition()*m_bodyInTree.mass() + body.xPosition()*body.mass()) / newMass);
m_bodyInTree.set_yPosition((m_bodyInTree.yPosition()*m_bodyInTree.mass() + body.yPosition()*body.mass()) / newMass);
m_bodyInTree.set_zPosition((m_bodyInTree.zPosition()*m_bodyInTree.mass() + body.zPosition()*body.mass()) / newMass);
m_bodyInTree.set_mass(m_bodyInTree.mass() + body.mass());
if (body.isInQuadrant(m_Quadrant.NWQuad()))
{
if (!m_NW)
{
m_NW = new BarnesHutTree(m_Quadrant.NWQuad());
}
m_NW->insertBody(body);
}
else if (body.isInQuadrant(m_Quadrant.NEQuad()))
{
if (!m_NE)
{
m_NE = new BarnesHutTree(m_Quadrant.NEQuad());
}
m_NE->insertBody(body);
}
else if (body.isInQuadrant(m_Quadrant.SWQuad()))
{
if (!m_SW)
{
m_SW = new BarnesHutTree(m_Quadrant.SWQuad());
}
m_SW->insertBody(body);
}
else if (body.isInQuadrant(m_Quadrant.SEQuad()))
{
if (!m_SE)
{
m_SE = new BarnesHutTree(m_Quadrant.SEQuad());
};
m_SE->insertBody(body);
};
}
//If the node is external and contains one other body, create BHTrees
//where the bodies should go, update the node, and end
//(do not do anything recursively)
else if (isExternal() == true)
{
//there is only one body in this tree
if (m_bodyInTree.isInQuadrant(m_Quadrant.NWQuad()))
{
if (!m_NW)
{
m_NW = new BarnesHutTree(m_Quadrant.NWQuad());
};
m_NW->insertBody(m_bodyInTree);
}
else if (m_bodyInTree.isInQuadrant(m_Quadrant.NEQuad()))
{
if (!m_NE)
{
m_NE = new BarnesHutTree(m_Quadrant.NEQuad());
};
m_NE->insertBody(m_bodyInTree);
}
else if (m_bodyInTree.isInQuadrant(m_Quadrant.SWQuad()))
{
if (!m_SW)
{
m_SW = new BarnesHutTree(m_Quadrant.SWQuad());
};
m_SW->insertBody(m_bodyInTree);
}
else if (m_bodyInTree.isInQuadrant(m_Quadrant.SEQuad()))
{
if (!m_SE)
{
m_SE = new BarnesHutTree(m_Quadrant.SEQuad());
};
m_SE->insertBody(m_bodyInTree);
}
insertBody(body);
}
};
