org.locationtech.jts.algorithm.PointLocation Maven / Gradle / Ivy
/*
* 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.algorithm;
import org.locationtech.jts.geom.Coordinate;
import org.locationtech.jts.geom.CoordinateSequence;
import org.locationtech.jts.geom.Location;
/**
* Functions for locating points within basic geometric
* structures such as lines and rings.
*
* @author Martin Davis
*
*/
public class PointLocation {
/**
* Tests whether a point lies on the line defined by a list of
* coordinates.
*
* @param p the point to test
* @param line the line coordinates
* @return true if the point is a vertex of the line or lies in the interior
* of a line segment in the line
*/
public static boolean isOnLine(Coordinate p, Coordinate[] line)
{
LineIntersector lineIntersector = new RobustLineIntersector();
for (int i = 1; i < line.length; i++) {
Coordinate p0 = line[i - 1];
Coordinate p1 = line[i];
lineIntersector.computeIntersection(p, p0, p1);
if (lineIntersector.hasIntersection()) {
return true;
}
}
return false;
}
/**
* Tests whether a point lies on the line defined by a
* {@link CoordinateSequence}.
*
* @param p the point to test
* @param line the line coordinates
* @return true if the point is a vertex of the line or lies in the interior
* of a line segment in the line
*/
public static boolean isOnLine(Coordinate p, CoordinateSequence line)
{
LineIntersector lineIntersector = new RobustLineIntersector();
Coordinate p0 = new Coordinate();
Coordinate p1 = new Coordinate();
int n = line.size();
for (int i = 1; i < n; i++) {
line.getCoordinate(i-1, p0);
line.getCoordinate(i, p1);
lineIntersector.computeIntersection(p, p0, p1);
if (lineIntersector.hasIntersection()) {
return true;
}
}
return false;
}
/**
* Tests whether a point lies inside or on a ring. The ring may be oriented in
* either direction. A point lying exactly on the ring boundary is considered
* to be inside the ring.
*
* This method does not first check the point against the envelope of
* the ring.
*
* @param p
* point to check for ring inclusion
* @param ring
* an array of coordinates representing the ring (which must have
* first point identical to last point)
* @return true if p is inside ring
*
* @see locatePointInRing
*/
public static boolean isInRing(Coordinate p, Coordinate[] ring)
{
return PointLocation.locateInRing(p, ring) != Location.EXTERIOR;
}
/**
* Determines whether a point lies in the interior, on the boundary, or in the
* exterior of a ring. The ring may be oriented in either direction.
*
* This method does not first check the point against the envelope of
* the ring.
*
* @param p
* point to check for ring inclusion
* @param ring
* an array of coordinates representing the ring (which must have
* first point identical to last point)
* @return the {@link Location} of p relative to the ring
*/
public static int locateInRing(Coordinate p, Coordinate[] ring)
{
return RayCrossingCounter.locatePointInRing(p, ring);
}
}