/*
* Copyright (c) 2016 Vivid Solutions.
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* and Eclipse Distribution License v. 1.0 which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
*
* http://www.eclipse.org/org/documents/edl-v10.php.
*/
package org.locationtech.jts.geom.prep;
import java.util.List;
import org.locationtech.jts.geom.Geometry;
import org.locationtech.jts.noding.SegmentStringUtil;
/**
* Computes the <tt>intersects</tt> spatial relationship predicate for
* {@link PreparedPolygon}s relative to all other {@link Geometry} classes. Uses
* short-circuit tests and indexing to improve performance.
*
* @author Martin Davis
*
*/
class PreparedPolygonIntersects extends PreparedPolygonPredicate {
/**
* Computes the intersects predicate between a {@link PreparedPolygon} and a
* {@link Geometry}.
*
* @param prep
* the prepared polygon
* @param geom
* a test geometry
* @return true if the polygon intersects the geometry
*/
public static boolean intersects(PreparedPolygon prep, Geometry geom) {
PreparedPolygonIntersects polyInt = new PreparedPolygonIntersects(prep);
return polyInt.intersects(geom);
}
/**
* Creates an instance of this operation.
*
* @param prepPoly
* the PreparedPolygon to evaluate
*/
public PreparedPolygonIntersects(PreparedPolygon prepPoly) {
super(prepPoly);
}
/**
* Tests whether this PreparedPolygon intersects a given geometry.
*
* @param geom
* the test geometry
* @return true if the test geometry intersects
*/
public boolean intersects(Geometry geom) {
/**
* Do point-in-poly tests first, since they are cheaper and may result in a
* quick positive result.
*
* If a point of any test components lie in target, result is true
*/
boolean isInPrepGeomArea = isAnyTestComponentInTarget(geom);
if (isInPrepGeomArea)
return true;
/**
* If input contains only points, then at
* this point it is known that none of them are contained in the target
*/
if (geom.getDimension() == 0)
return false;
/**
* If any segments intersect, result is true
*/
List lineSegStr = SegmentStringUtil.extractSegmentStrings(geom);
// only request intersection finder if there are segments
// (i.e. NOT for point inputs)
if (lineSegStr.size() > 0) {
boolean segsIntersect = prepPoly.getIntersectionFinder().intersects(
lineSegStr);
if (segsIntersect)
return true;
}
/**
* If the test has dimension = 2 as well, it is necessary to test for proper
* inclusion of the target. Since no segments intersect, it is sufficient to
* test representative points.
*/
if (geom.getDimension() == 2) {
// TODO: generalize this to handle GeometryCollections
boolean isPrepGeomInArea = isAnyTargetComponentInAreaTest(geom,
prepPoly.getRepresentativePoints());
if (isPrepGeomInArea)
return true;
}
return false;
}
}