/**
* Copyright (C) 2011 Brian Ferris <bdferris@onebusaway.org>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.onebusaway.geospatial;
import java.util.HashMap;
import java.util.Map;
import org.onebusaway.geospatial.model.CoordinateBounds;
import org.onebusaway.geospatial.services.SphericalGeometryLibrary;
import com.vividsolutions.jts.geom.Envelope;
import com.vividsolutions.jts.index.strtree.STRtree;
public class HierarchicalSTRtreeFactory<T> {
private Map<CoordinateBounds, STRtree> _treesByBounds = new HashMap<CoordinateBounds, STRtree>();
private double _latStep = 0;
private double _lonStep = 0;
public void setLatStep(double latStep) {
_latStep = latStep;
}
public void setLonStep(double lonStep) {
_lonStep = lonStep;
}
public void setLatAndLonStep(double lat, double lon, double gridSize) {
CoordinateBounds b = SphericalGeometryLibrary.bounds(lat, lon, gridSize / 2);
_latStep = b.getMaxLat() - b.getMinLat();
_lonStep = b.getMaxLon() - b.getMinLon();
}
public void add(double lat, double lon, T element) {
STRtree tree = null;
for (Map.Entry<CoordinateBounds, STRtree> entry : _treesByBounds.entrySet()) {
CoordinateBounds bounds = entry.getKey();
if (bounds.contains(lat, lon)) {
tree = entry.getValue();
break;
}
}
if (tree == null) {
double gLat = Math.floor(lat / _latStep) * _latStep;
double gLon = Math.floor(lon / _lonStep) * _lonStep;
CoordinateBounds b = new CoordinateBounds(gLat, gLon, gLat + _latStep,
gLon + _lonStep);
tree = new STRtree();
_treesByBounds.put(b, tree);
}
Envelope env = new Envelope(lon, lon, lat, lat);
tree.insert(env, element);
}
public HierarchicalSTRtree<T> create() {
STRtree parentTree = new STRtree();
for (Map.Entry<CoordinateBounds, STRtree> entry : _treesByBounds.entrySet()) {
CoordinateBounds b = entry.getKey();
Envelope env = new Envelope(b.getMinLon(), b.getMaxLon(), b.getMinLat(),
b.getMaxLat());
STRtree tree = entry.getValue();
tree.build();
parentTree.insert(env, tree);
}
parentTree.build();
return new HierarchicalSTRtree<T>(parentTree);
}
}