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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;
import com.vividsolutions.jts.algorithm.CGAlgorithms;
import com.vividsolutions.jts.operation.BoundaryOp;
/**
* Models an OGC-style LineString.
* A LineString consists of a sequence of two or more vertices,
* along with all points along the linearly-interpolated curves
* (line segments) between each
* pair of consecutive vertices.
* Consecutive vertices may be equal.
* The line segments in the line may intersect each other (in other words,
* the linestring may "curl back" in itself and self-intersect.
* Linestrings with exactly two identical points are invalid.
*
* A linestring must have either 0 or 2 or more points.
* If these conditions are not met, the constructors throw
* an {@link IllegalArgumentException}
*
*@version 1.7
*/
public class LineString
extends Geometry
implements Lineal
{
private static final long serialVersionUID = 3110669828065365560L;
/**
* The points of this LineString.
*/
protected CoordinateSequence points;
/**
* Constructs a LineString with the given points.
*
*@param points the points of the linestring, or null
* to create the empty geometry. This array must not contain null
* elements. Consecutive points may be equal.
*@param precisionModel the specification of the grid of allowable points
* for this LineString
*@param SRID the ID of the Spatial Reference System used by this
* LineString
* @throws IllegalArgumentException if too few points are provided
*/
/** @deprecated Use GeometryFactory instead */
public LineString(Coordinate points[], PrecisionModel precisionModel, int SRID)
{
super(new GeometryFactory(precisionModel, SRID));
init(getFactory().getCoordinateSequenceFactory().create(points));
}
/**
* Constructs a LineString with the given points.
*
*@param points the points of the linestring, or null
* to create the empty geometry.
* @throws IllegalArgumentException if too few points are provided
*/
public LineString(CoordinateSequence points, GeometryFactory factory) {
super(factory);
init(points);
}
private void init(CoordinateSequence points)
{
if (points == null) {
points = getFactory().getCoordinateSequenceFactory().create(new Coordinate[]{});
}
if (points.size() == 1) {
throw new IllegalArgumentException("Invalid number of points in LineString (found "
+ points.size() + " - must be 0 or >= 2)");
}
this.points = points;
}
public Coordinate[] getCoordinates() {
return points.toCoordinateArray();
}
public CoordinateSequence getCoordinateSequence() {
return points;
}
public Coordinate getCoordinateN(int n) {
return points.getCoordinate(n);
}
public Coordinate getCoordinate()
{
if (isEmpty()) return null;
return points.getCoordinate(0);
}
public int getDimension() {
return 1;
}
public int getBoundaryDimension() {
if (isClosed()) {
return Dimension.FALSE;
}
return 0;
}
public boolean isEmpty() {
return points.size() == 0;
}
public int getNumPoints() {
return points.size();
}
public Point getPointN(int n) {
return getFactory().createPoint(points.getCoordinate(n));
}
public Point getStartPoint() {
if (isEmpty()) {
return null;
}
return getPointN(0);
}
public Point getEndPoint() {
if (isEmpty()) {
return null;
}
return getPointN(getNumPoints() - 1);
}
public boolean isClosed() {
if (isEmpty()) {
return false;
}
return getCoordinateN(0).equals2D(getCoordinateN(getNumPoints() - 1));
}
public boolean isRing() {
return isClosed() && isSimple();
}
public String getGeometryType() {
return "LineString";
}
/**
* Returns the length of this LineString
*
*@return the length of the linestring
*/
public double getLength()
{
return CGAlgorithms.length(points);
}
/**
* Gets the boundary of this geometry.
* The boundary of a lineal geometry is always a zero-dimensional geometry (which may be empty).
*
* @return the boundary geometry
* @see Geometry#getBoundary
*/
public Geometry getBoundary() {
return (new BoundaryOp(this)).getBoundary();
}
/**
* Creates a {@link LineString} whose coordinates are in the reverse
* order of this objects
*
* @return a {@link LineString} with coordinates in the reverse order
*/
public Geometry reverse()
{
CoordinateSequence seq = (CoordinateSequence) points.clone();
CoordinateSequences.reverse(seq);
LineString revLine = getFactory().createLineString(seq);
return revLine;
}
/**
* Returns true if the given point is a vertex of this LineString.
*
*@param pt the Coordinate to check
*@return true if pt is one of this LineString
* 's vertices
*/
public boolean isCoordinate(Coordinate pt) {
for (int i = 0; i < points.size(); i++) {
if (points.getCoordinate(i).equals(pt)) {
return true;
}
}
return false;
}
protected Envelope computeEnvelopeInternal() {
if (isEmpty()) {
return new Envelope();
}
return points.expandEnvelope(new Envelope());
}
public boolean equalsExact(Geometry other, double tolerance) {
if (!isEquivalentClass(other)) {
return false;
}
LineString otherLineString = (LineString) other;
if (points.size() != otherLineString.points.size()) {
return false;
}
for (int i = 0; i < points.size(); i++) {
if (!equal(points.getCoordinate(i), otherLineString.points.getCoordinate(i), tolerance)) {
return false;
}
}
return true;
}
public void apply(CoordinateFilter filter) {
for (int i = 0; i < points.size(); i++) {
filter.filter(points.getCoordinate(i));
}
}
public void apply(CoordinateSequenceFilter filter)
{
if (points.size() == 0)
return;
for (int i = 0; i < points.size(); i++) {
filter.filter(points, i);
if (filter.isDone())
break;
}
if (filter.isGeometryChanged())
geometryChanged();
}
public void apply(GeometryFilter filter) {
filter.filter(this);
}
public void apply(GeometryComponentFilter filter) {
filter.filter(this);
}
/**
* Creates and returns a full copy of this {@link LineString} object.
* (including all coordinates contained by it).
*
* @return a clone of this instance
*/
public Object clone() {
LineString ls = (LineString) super.clone();
ls.points = (CoordinateSequence) points.clone();
return ls;
}
/**
* Normalizes a LineString. A normalized linestring
* has the first point which is not equal to it's reflected point
* less than the reflected point.
*/
public void normalize()
{
for (int i = 0; i < points.size() / 2; i++) {
int j = points.size() - 1 - i;
// skip equal points on both ends
if (!points.getCoordinate(i).equals(points.getCoordinate(j))) {
if (points.getCoordinate(i).compareTo(points.getCoordinate(j)) > 0) {
CoordinateSequences.reverse(points);
}
return;
}
}
}
protected boolean isEquivalentClass(Geometry other) {
return other instanceof LineString;
}
protected int compareToSameClass(Object o)
{
LineString line = (LineString) o;
// MD - optimized implementation
int i = 0;
int j = 0;
while (i < points.size() && j < line.points.size()) {
int comparison = points.getCoordinate(i).compareTo(line.points.getCoordinate(j));
if (comparison != 0) {
return comparison;
}
i++;
j++;
}
if (i < points.size()) {
return 1;
}
if (j < line.points.size()) {
return -1;
}
return 0;
}
protected int compareToSameClass(Object o, CoordinateSequenceComparator comp)
{
LineString line = (LineString) o;
return comp.compare(this.points, line.points);
}
}