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/*
* 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.vividsolutions.jts.geom.prep;
import java.util.List;
import com.vividsolutions.jts.geom.Geometry;
import com.vividsolutions.jts.noding.SegmentStringUtil;
/**
* Computes the intersects 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;
}
}