/* * The JTS Topology Suite is a collection of Java classes that * implement the fundamental operations required to validate a given * geo-spatial data set to a known topological specification. * * Copyright (C) 2001 Vivid Solutions * * 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; either * version 2.1 of the License, or (at your option) any later version. * * 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. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * For more information, contact: * * Vivid Solutions * Suite #1A * 2328 Government Street * Victoria BC V8T 5G5 * Canada * * (250)385-6040 * www.vividsolutions.com */ package com.revolsys.geometry.index.bintree; import com.revolsys.geometry.index.IntervalSize; import com.revolsys.geometry.util.Assert; /** * The root node of a single {@link Bintree}. * It is centred at the origin, * and does not have a defined extent. * * @version 1.7 */ public class Root extends NodeBase { // the singleton root node is centred at the origin. private static final double origin = 0.0; public Root() { } /** * Insert an item into the tree this is the root of. */ public void insert(final Interval itemInterval, final Object item) { final int index = getSubnodeIndex(itemInterval, origin); // if index is -1, itemEnv must contain the origin. if (index == -1) { add(item); return; } /** * the item must be contained in one interval, so insert it into the * tree for that interval (which may not yet exist) */ final Node node = this.subnode[index]; /** * If the subnode 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.getInterval().contains(itemInterval)) { final Node largerNode = Node.newNodeExpanded(node, itemInterval); this.subnode[index] = largerNode; } /** * At this point we have a subnode which exists and must contain * contains the env for the item. Insert the item into the tree. */ insertContained(this.subnode[index], itemInterval, item); // System.out.println("depth = " + root.depth() + " size = " + root.size()); } /** * insert an item which is known to be contained in the tree rooted at * the given Node. Lower levels of the tree will be created * if necessary to hold the item. */ private void insertContained(final Node tree, final Interval itemInterval, final Object item) { Assert.isTrue(tree.getInterval().contains(itemInterval)); /** * Do NOT Construct a new new node for zero-area intervals - this would lead * to infinite recursion. Instead, use a heuristic of simply returning * the smallest existing node containing the query */ final boolean isZeroArea = IntervalSize.isZeroWidth(itemInterval.getMin(), itemInterval.getMax()); NodeBase node; if (isZeroArea) { node = tree.find(itemInterval); } else { node = tree.getNode(itemInterval); } node.add(item); } /** * The root node matches all searches */ @Override protected boolean isSearchMatch(final Interval interval) { return true; } }