/** Insert an item into the quadtree this is the root of. */
public void insert(Envelope itemEnv, Object item) {
int index = getSubnodeIndex(itemEnv, origin);
// if index is -1, itemEnv must cross the X or Y axis.
if (index == -1) {
add(item);
return;
}
/**
* the item must be contained in one quadrant, so insert it into the tree for that quadrant
* (which may not yet exist)
*/
ExitEarlyNode node = subnode[index];
/**
* If the subquad doesn't exist or this item is not contained in it, have to expand the tree
* upward to contain the item.
*/
if (node == null || !node.getEnvelope().contains(itemEnv)) {
ExitEarlyNode largerNode = ExitEarlyNode.createExpanded(node, itemEnv);
subnode[index] = largerNode;
}
/**
* At this point we have a subquad which exists and must contain contains the env for the item.
* Insert the item into the tree.
*/
insertContained(subnode[index], itemEnv, item);
// System.out.println("depth = " + root.depth() + " size = " + root.size());
// System.out.println(" size = " + size());
}
/**
* insert an item which is known to be contained in the tree rooted at the given QuadNode root.
* Lower levels of the tree will be created if necessary to hold the item.
*/
private void insertContained(ExitEarlyNode tree, Envelope itemEnv, Object item) {
Assert.isTrue(tree.getEnvelope().contains(itemEnv));
/**
* Do NOT create a new quad for zero-area envelopes - this would lead to infinite recursion.
* Instead, use a heuristic of simply returning the smallest existing quad containing the query
*/
boolean isZeroX = IntervalSize.isZeroWidth(itemEnv.getMinX(), itemEnv.getMaxX());
boolean isZeroY = IntervalSize.isZeroWidth(itemEnv.getMinY(), itemEnv.getMaxY());
ExitEarlyNodeBase node;
if (isZeroX || isZeroY) node = tree.find(itemEnv);
else node = tree.getNode(itemEnv);
node.add(item);
}