com.vividsolutions.jts.geom.prep.PreparedLineStringIntersects Maven / Gradle / Ivy
The newest version!
/*
* 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.*;
import com.vividsolutions.jts.algorithm.*;
import com.vividsolutions.jts.geom.*;
import com.vividsolutions.jts.noding.*;
import com.vividsolutions.jts.geom.util.*;
/**
* Computes the intersects 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;
}
}