QuadTree.java

package org.oscim.utils;

import java.util.List;

import org.oscim.core.Box;
import org.oscim.utils.pool.Pool;
import org.oscim.utils.quadtree.BoxTree;
import org.oscim.utils.quadtree.BoxTree.BoxItem;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class QuadTree<T> extends BoxTree<BoxItem<T>, T> implements SpatialIndex<T> {

	public QuadTree(int extents, int maxDepth) {
		super(extents, maxDepth);
	}

	static final Logger log = LoggerFactory.getLogger(QuadTree.class);

	final Pool<BoxItem<T>> boxPool = new Pool<BoxItem<T>>() {
		@Override
		protected BoxItem<T> createItem() {
			return new BoxItem<T>();
		}
	};

	private BoxItem<T> getBox(Box box) {
		BoxItem<T> it = boxPool.get();
		it.x1 = (int) box.xmin;
		it.y1 = (int) box.ymin;
		it.x2 = (int) box.xmax;
		it.y2 = (int) box.ymax;
		return it;
	}

	@Override
	public void insert(Box box, T item) {
		insert(new BoxItem<T>(box, item));
	}

	@Override
	public boolean remove(Box box, T item) {
		BoxItem<T> bbox = getBox(box);
		boolean ok = remove(bbox, item);
		boxPool.release(bbox);
		return ok;
	}

	static class CollectCb<T> implements SearchCb<T> {
		@SuppressWarnings("unchecked")
		@Override
		public boolean call(T item, Object context) {
			List<T> l = (List<T>) context;
			l.add(item);
			return true;
		}
	}

	final CollectCb<T> collectCb = new CollectCb<T>();

	@Override
	public List<T> search(Box bbox, List<T> results) {
		BoxItem<T> box = getBox(bbox);
		search(box, collectCb, results);
		boxPool.release(box);
		return results;
	}

	@Override
	public int search(Box bbox, SearchCb<T> cb, Object context) {
		BoxItem<T> box = getBox(bbox);
		search(box, cb, context);
		boxPool.release(box);
		return 0;
	}
}