/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2001-2006 Vivid Solutions
* (C) 2001-2008, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
package org.geotools.geometry.iso.index.quadtree;
import org.geotools.geometry.iso.topograph2D.Coordinate;
import org.geotools.geometry.iso.topograph2D.Envelope;
import org.geotools.geometry.iso.util.Assert;
/**
* QuadRoot is the root of a single Quadtree. It is centred at the origin, and
* does not have a defined extent.
*
*
*
*
* @source $URL$
* @version 1.7.2
*/
public class Root extends NodeBase {
// the singleton root quad is centred at the origin.
private static final Coordinate origin = new Coordinate(0.0, 0.0);
public Root() {
}
/**
* 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)
*/
Node 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)) {
Node largerNode = Node.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(Node 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.getMinX(), itemEnv
.getMaxX());
NodeBase node;
if (isZeroX || isZeroY)
node = tree.find(itemEnv);
else
node = tree.getNode(itemEnv);
node.add(item);
}
protected boolean isSearchMatch(Envelope searchEnv) {
return true;
}
}