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* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch licenses this file to you 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.elasticsearch.index.search.geo;
import java.io.IOException;
import java.util.Arrays;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.search.DocIdSet;
import org.apache.lucene.search.DocValuesDocIdSet;
import org.apache.lucene.search.Filter;
import org.apache.lucene.util.Bits;
import org.elasticsearch.common.Nullable;
import org.elasticsearch.common.geo.GeoPoint;
import org.elasticsearch.index.fielddata.IndexGeoPointFieldData;
import org.elasticsearch.index.fielddata.MultiGeoPointValues;
/**
*
*/
public class GeoPolygonFilter extends Filter {
private final GeoPoint[] points;
private final IndexGeoPointFieldData indexFieldData;
public GeoPolygonFilter(IndexGeoPointFieldData indexFieldData, GeoPoint...points) {
this.points = points;
this.indexFieldData = indexFieldData;
}
public GeoPoint[] points() {
return points;
}
public String fieldName() {
return indexFieldData.getFieldNames().indexName();
}
@Override
public DocIdSet getDocIdSet(LeafReaderContext context, Bits acceptedDocs) throws IOException {
final MultiGeoPointValues values = indexFieldData.load(context).getGeoPointValues();
return new GeoPolygonDocIdSet(context.reader().maxDoc(), acceptedDocs, values, points);
}
@Override
public String toString() {
StringBuilder sb = new StringBuilder("GeoPolygonFilter(");
sb.append(indexFieldData.getFieldNames().indexName());
sb.append(", ").append(Arrays.toString(points)).append(')');
return sb.toString();
}
public static class GeoPolygonDocIdSet extends DocValuesDocIdSet {
private final MultiGeoPointValues values;
private final GeoPoint[] points;
public GeoPolygonDocIdSet(int maxDoc, @Nullable Bits acceptDocs, MultiGeoPointValues values, GeoPoint[] points) {
super(maxDoc, acceptDocs);
this.values = values;
this.points = points;
}
@Override
protected boolean matchDoc(int doc) {
values.setDocument(doc);
final int length = values.count();
for (int i = 0; i < length; i++) {
GeoPoint point = values.valueAt(i);
if (pointInPolygon(points, point.lat(), point.lon())) {
return true;
}
}
return false;
}
private static boolean pointInPolygon(GeoPoint[] points, double lat, double lon) {
boolean inPoly = false;
for (int i = 1; i < points.length; i++) {
if (points[i].lon() < lon && points[i-1].lon() >= lon
|| points[i-1].lon() < lon && points[i].lon() >= lon) {
if (points[i].lat() + (lon - points[i].lon()) /
(points[i-1].lon() - points[i].lon()) * (points[i-1].lat() - points[i].lat()) < lat) {
inPoly = !inPoly;
}
}
}
return inPoly;
}
}
}