/*
* 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.Iterator;
import java.util.List;
import org.locationtech.jts.algorithm.PointLocator;
import org.locationtech.jts.geom.Coordinate;
import org.locationtech.jts.geom.Geometry;
import org.locationtech.jts.geom.util.ComponentCoordinateExtracter;
import org.locationtech.jts.noding.SegmentStringUtil;
/**
* Computes the <tt>intersects</tt> spatial relationship predicate
* for a target {@link PreparedLineString} relative to other {@link Geometry} classes.
* Uses short-circuit tests and indexing to improve performance.
*
* @author Martin Davis
*
*/
class PreparedLineStringIntersects
{
/**
* Computes the intersects predicate between a {@link PreparedLineString}
* and a {@link Geometry}.
*
* @param prep the prepared linestring
* @param geom a test geometry
* @return true if the linestring intersects the geometry
*/
public static boolean intersects(PreparedLineString prep, Geometry geom)
{
PreparedLineStringIntersects op = new PreparedLineStringIntersects(prep);
return op.intersects(geom);
}
protected PreparedLineString prepLine;
/**
* Creates an instance of this operation.
*
* @param prepPoly the target PreparedLineString
*/
public PreparedLineStringIntersects(PreparedLineString prepLine)
{
this.prepLine = prepLine;
}
/**
* Tests whether this geometry intersects a given geometry.
*
* @param geom the test geometry
* @return true if the test geometry intersects
*/
public boolean intersects(Geometry geom)
{
/**
* If any segments intersect, obviously intersects = true
*/
List lineSegStr = SegmentStringUtil.extractSegmentStrings(geom);
// only request intersection finder if there are segments (ie NOT for point inputs)
if (lineSegStr.size() > 0) {
boolean segsIntersect = prepLine.getIntersectionFinder().intersects(lineSegStr);
// MD - performance testing
// boolean segsIntersect = false;
if (segsIntersect)
return true;
}
/**
* For L/L case we are done
*/
if (geom.getDimension() == 1) return false;
/**
* For L/A case, need to check for proper inclusion of the target in the test
*/
if (geom.getDimension() == 2
&& prepLine.isAnyTargetComponentInTest(geom)) return true;
/**
* For L/P case, need to check if any points lie on line(s)
*/
if (geom.getDimension() == 0)
return isAnyTestPointInTarget(geom);
return false;
}
/**
* Tests whether any representative point of the test Geometry intersects
* the target geometry.
* Only handles test geometries which are Puntal (dimension 0)
*
* @param geom a Puntal geometry to test
* @return true if any point of the argument intersects the prepared geometry
*/
protected boolean isAnyTestPointInTarget(Geometry testGeom)
{
/**
* This could be optimized by using the segment index on the lineal target.
* However, it seems like the L/P case would be pretty rare in practice.
*/
PointLocator locator = new PointLocator();
List coords = ComponentCoordinateExtracter.getCoordinates(testGeom);
for (Iterator i = coords.iterator(); i.hasNext(); ) {
Coordinate p = (Coordinate) i.next();
if (locator.intersects(p, prepLine.getGeometry()))
return true;
}
return false;
}
}