/**
* Descend Tree and insert particle. We're at a cell so
* we need to move down the tree.
*
* @param p the body to insert into the tree
* @param xpic
* @param l
* @param tree the root of the tree
* @return the subtree with the new body inserted
*/
public override Cell loadTree(Body p, MathVector xpic, int l, BTree tree)
{
// move down one level
int si = Node.oldSubindex(xpic, l);
Node rt = subp [si];
if (rt != null)
{
subp [si] = rt.loadTree(p, xpic, l >> 1, tree);
}
else
{
subp [si] = p;
}
return(this);
}
/**
* Descend Tree and insert particle. We're at a body so we need to
* create a cell and attach this body to the cell.
*
* @param p the body to insert
* @param xpic
* @param l
* @param tree the root of the data structure
* @return the subtree with the new body inserted
*/
public override Cell loadTree(Body p, MathVector xpic, int l, BTree tree)
{
// create a Cell
Cell retval = Cell.makeCell();
int si = subindex(tree, l);
// attach this Body node to the cell
retval.subp [si] = this;
// move down one level
si = Node.oldSubindex(xpic, l);
Node rt = retval.subp [si];
if (rt != null)
{
retval.subp [si] = rt.loadTree(p, xpic, l >> 1, tree);
}
else
{
retval.subp [si] = p;
}
return(retval);
}