private void condenseTree(Node <T> l)
{
// CT1 [Initialize] Set n=l. Set the list of eliminated
// nodes to be empty.
Node <T> n = l;
Node <T> parent = null;
int parentEntry = 0;
//TIntStack eliminatedNodeIds = new TIntStack();
Stack <int> eliminatedNodeIds = new Stack <int>();
// CT2 [Find parent entry] If N is the root, go to CT6. Otherwise
// let P be the parent of N, and let En be N's entry in P
while (n.level != treeHeight)
{
parent = getNode(parents.Pop());
parentEntry = parentsEntry.Pop();
// CT3 [Eliminiate under-full node] If N has too few entries,
// delete En from P and add N to the list of eliminated nodes
if (n.entryCount < minNodeEntries)
{
parent.deleteEntry(parentEntry, minNodeEntries);
eliminatedNodeIds.Push(n.nodeId);
}
else
{
// CT4 [Adjust covering rectangle] If N has not been eliminated,
// adjust EnI to tightly contain all entries in N
if (!n.mbr.Equals(parent.entries[parentEntry]))
{
oldRectangle.set(parent.entries[parentEntry].min, parent.entries[parentEntry].max);
parent.entries[parentEntry].set(n.mbr.min, n.mbr.max);
parent.recalculateMBR(oldRectangle);
}
}
// CT5 [Move up one level in tree] Set N=P and repeat from CT2
n = parent;
}
// CT6 [Reinsert orphaned entries] Reinsert all entries of nodes in set Q.
// Entries from eliminated leaf nodes are reinserted in tree leaves as in
// Insert(), but entries from higher level nodes must be placed higher in
// the tree, so that leaves of their dependent subtrees will be on the same
// level as leaves of the main tree
while (eliminatedNodeIds.Count > 0)
{
Node <T> e = getNode(eliminatedNodeIds.Pop());
for (int j = 0; j < e.entryCount; j++)
{
add(e.entries[j], e.ids[j], e.level);
e.entries[j] = null;
}
e.entryCount = 0;
deletedNodeIds.Push(e.nodeId);
}
}
