/*
* 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.operation.polygonize;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import org.locationtech.jts.algorithm.CGAlgorithms;
import org.locationtech.jts.geom.Coordinate;
import org.locationtech.jts.geom.CoordinateArrays;
import org.locationtech.jts.geom.CoordinateList;
import org.locationtech.jts.geom.Envelope;
import org.locationtech.jts.geom.GeometryFactory;
import org.locationtech.jts.geom.LineString;
import org.locationtech.jts.geom.LinearRing;
import org.locationtech.jts.geom.Polygon;
import org.locationtech.jts.geom.impl.CoordinateArraySequence;
import org.locationtech.jts.io.WKTWriter;
import org.locationtech.jts.planargraph.DirectedEdge;
import org.locationtech.jts.util.Assert;
/**
* Represents a ring of {@link PolygonizeDirectedEdge}s which form
* a ring of a polygon. The ring may be either an outer shell or a hole.
*
* @version 1.7
*/
class EdgeRing {
/**
* Find the innermost enclosing shell EdgeRing containing the argument EdgeRing, if any.
* The innermost enclosing ring is the <i>smallest</i> enclosing ring.
* The algorithm used depends on the fact that:
* <br>
* ring A contains ring B iff envelope(ring A) contains envelope(ring B)
* <br>
* This routine is only safe to use if the chosen point of the hole
* is known to be properly contained in a shell
* (which is guaranteed to be the case if the hole does not touch its shell)
*
* @return containing EdgeRing, if there is one
* or null if no containing EdgeRing is found
*/
public static EdgeRing findEdgeRingContaining(EdgeRing testEr, List shellList)
{
LinearRing testRing = testEr.getRing();
Envelope testEnv = testRing.getEnvelopeInternal();
Coordinate testPt = testRing.getCoordinateN(0);
EdgeRing minShell = null;
Envelope minShellEnv = null;
for (Iterator it = shellList.iterator(); it.hasNext(); ) {
EdgeRing tryShell = (EdgeRing) it.next();
LinearRing tryShellRing = tryShell.getRing();
Envelope tryShellEnv = tryShellRing.getEnvelopeInternal();
// the hole envelope cannot equal the shell envelope
// (also guards against testing rings against themselves)
if (tryShellEnv.equals(testEnv)) continue;
// hole must be contained in shell
if (! tryShellEnv.contains(testEnv)) continue;
testPt = CoordinateArrays.ptNotInList(testRing.getCoordinates(), tryShellRing.getCoordinates());
boolean isContained = false;
if (CGAlgorithms.isPointInRing(testPt, tryShellRing.getCoordinates()) )
isContained = true;
// check if this new containing ring is smaller than the current minimum ring
if (isContained) {
if (minShell == null
|| minShellEnv.contains(tryShellEnv)) {
minShell = tryShell;
minShellEnv = minShell.getRing().getEnvelopeInternal();
}
}
}
return minShell;
}
/**
* Finds a point in a list of points which is not contained in another list of points
* @param testPts the {@link Coordinate}s to test
* @param pts an array of {@link Coordinate}s to test the input points against
* @return a {@link Coordinate} from <code>testPts</code> which is not in <code>pts</code>,
* or null if there is no coordinate not in the list
*
* @deprecated Use CoordinateArrays.ptNotInList instead
*/
public static Coordinate ptNotInList(Coordinate[] testPts, Coordinate[] pts)
{
for (int i = 0; i < testPts.length; i++) {
Coordinate testPt = testPts[i];
if (! isInList(testPt, pts))
return testPt;
}
return null;
}
/**
* Tests whether a given point is in an array of points.
* Uses a value-based test.
*
* @param pt a {@link Coordinate} for the test point
* @param pts an array of {@link Coordinate}s to test
* @return <code>true</code> if the point is in the array
*
* @deprecated
*/
public static boolean isInList(Coordinate pt, Coordinate[] pts)
{
for (int i = 0; i < pts.length; i++) {
if (pt.equals(pts[i]))
return true;
}
return false;
}
/**
* Traverses a ring of DirectedEdges, accumulating them into a list.
* This assumes that all dangling directed edges have been removed
* from the graph, so that there is always a next dirEdge.
*
* @param startDE the DirectedEdge to start traversing at
* @return a List of DirectedEdges that form a ring
*/
public static List findDirEdgesInRing(PolygonizeDirectedEdge startDE)
{
PolygonizeDirectedEdge de = startDE;
List edges = new ArrayList();
do {
edges.add(de);
de = de.getNext();
Assert.isTrue(de != null, "found null DE in ring");
Assert.isTrue(de == startDE || ! de.isInRing(), "found DE already in ring");
} while (de != startDE);
return edges;
}
private GeometryFactory factory;
private List deList = new ArrayList();
private DirectedEdge lowestEdge = null;
// cache the following data for efficiency
private LinearRing ring = null;
private Coordinate[] ringPts = null;
private List holes;
private EdgeRing shell;
private boolean isHole;
private boolean isProcessed = false;
private boolean isIncludedSet = false;
private boolean isIncluded = false;
public EdgeRing(GeometryFactory factory)
{
this.factory = factory;
}
public void build(PolygonizeDirectedEdge startDE) {
PolygonizeDirectedEdge de = startDE;
do {
add(de);
de.setRing(this);
de = de.getNext();
Assert.isTrue(de != null, "found null DE in ring");
Assert.isTrue(de == startDE || ! de.isInRing(), "found DE already in ring");
} while (de != startDE);
}
/**
* Adds a {@link DirectedEdge} which is known to form part of this ring.
* @param de the {@link DirectedEdge} to add.
*/
private void add(DirectedEdge de)
{
deList.add(de);
}
/**
* Tests whether this ring is a hole.
* @return <code>true</code> if this ring is a hole
*/
public boolean isHole()
{
return isHole;
}
/**
* Computes whether this ring is a hole.
* Due to the way the edges in the polygonization graph are linked,
* a ring is a hole if it is oriented counter-clockwise.
*/
public void computeHole()
{
LinearRing ring = getRing();
isHole = CGAlgorithms.isCCW(ring.getCoordinates());
}
/**
* Adds a hole to the polygon formed by this ring.
* @param hole the {@link LinearRing} forming the hole.
*/
public void addHole(LinearRing hole) {
if (holes == null)
holes = new ArrayList();
holes.add(hole);
}
/**
* Adds a hole to the polygon formed by this ring.
* @param hole the {@link LinearRing} forming the hole.
*/
public void addHole(EdgeRing holeER) {
holeER.setShell(this);
LinearRing hole = holeER.getRing();
if (holes == null)
holes = new ArrayList();
holes.add(hole);
}
/**
* Computes the {@link Polygon} formed by this ring and any contained holes.
*
* @return the {@link Polygon} formed by this ring and its holes.
*/
public Polygon getPolygon()
{
LinearRing[] holeLR = null;
if (holes != null) {
holeLR = new LinearRing[holes.size()];
for (int i = 0; i < holes.size(); i++) {
holeLR[i] = (LinearRing) holes.get(i);
}
}
Polygon poly = factory.createPolygon(ring, holeLR);
return poly;
}
/**
* Tests if the {@link LinearRing} ring formed by this edge ring is topologically valid.
*
* @return true if the ring is valid
*/
public boolean isValid()
{
getCoordinates();
if (ringPts.length <= 3) return false;
getRing();
return ring.isValid();
}
public boolean isIncludedSet() {
return isIncludedSet;
}
public boolean isIncluded() {
return isIncluded;
}
public void setIncluded(boolean isIncluded) {
this.isIncluded = isIncluded;
this.isIncludedSet = true;
}
/**
* Computes the list of coordinates which are contained in this ring.
* The coordinates are computed once only and cached.
*
* @return an array of the {@link Coordinate}s in this ring
*/
private Coordinate[] getCoordinates()
{
if (ringPts == null) {
CoordinateList coordList = new CoordinateList();
for (Iterator i = deList.iterator(); i.hasNext(); ) {
DirectedEdge de = (DirectedEdge) i.next();
PolygonizeEdge edge = (PolygonizeEdge) de.getEdge();
addEdge(edge.getLine().getCoordinates(), de.getEdgeDirection(), coordList);
}
ringPts = coordList.toCoordinateArray();
}
return ringPts;
}
/**
* Gets the coordinates for this ring as a {@link LineString}.
* Used to return the coordinates in this ring
* as a valid geometry, when it has been detected that the ring is topologically
* invalid.
* @return a {@link LineString} containing the coordinates in this ring
*/
public LineString getLineString()
{
getCoordinates();
return factory.createLineString(ringPts);
}
/**
* Returns this ring as a {@link LinearRing}, or null if an Exception occurs while
* creating it (such as a topology problem). Details of problems are written to
* standard output.
*/
public LinearRing getRing()
{
if (ring != null) return ring;
getCoordinates();
if (ringPts.length < 3) System.out.println(ringPts);
try {
ring = factory.createLinearRing(ringPts);
}
catch (Exception ex) {
System.out.println(ringPts);
}
return ring;
}
private static void addEdge(Coordinate[] coords, boolean isForward, CoordinateList coordList)
{
if (isForward) {
for (int i = 0; i < coords.length; i++) {
coordList.add(coords[i], false);
}
}
else {
for (int i = coords.length - 1; i >= 0; i--) {
coordList.add(coords[i], false);
}
}
}
/**
* Sets the containing shell ring of a ring that has been determined to be a hole.
*
* @param shell the shell ring
*/
public void setShell(EdgeRing shell) {
this.shell = shell;
}
/**
* Tests whether this ring has a shell assigned to it.
*
* @return true if the ring has a shell
*/
public boolean hasShell() {
return shell != null;
}
/**
* Gets the shell for this ring. The shell is the ring itself if it is not a hole, otherwise its parent shell.
*
* @return the shell for this ring
*/
public EdgeRing getShell() {
if (isHole()) return shell;
return this;
}
/**
* Tests whether this ring is an outer hole.
* A hole is an outer hole if it is not contained by a shell.
*
* @return true if the ring is an outer hole.
*/
public boolean isOuterHole() {
if (! isHole) return false;
return ! hasShell();
}
/**
* Tests whether this ring is an outer shell.
*
* @return true if the ring is an outer shell.
*/
public boolean isOuterShell() {
return getOuterHole() != null;
}
public EdgeRing getOuterHole()
{
if (isHole()) return null;
/*
* A shell is an outer shell if any edge is also in an outer hole.
* A hole is an outer hole if it is not contained by a shell.
*/
for (int i = 0; i < deList.size(); i++) {
PolygonizeDirectedEdge de = (PolygonizeDirectedEdge) deList.get(i);
EdgeRing adjRing = ((PolygonizeDirectedEdge) de.getSym()).getRing();
if (adjRing.isOuterHole()) return adjRing;
}
return null;
}
/**
* Updates the included status for currently non-included shells
* based on whether they are adjacent to an included shell.
*/
public void updateIncluded() {
if (isHole()) return;
for (int i = 0; i < deList.size(); i++) {
PolygonizeDirectedEdge de = (PolygonizeDirectedEdge) deList.get(i);
EdgeRing adjShell = ((PolygonizeDirectedEdge) de.getSym()).getRing().getShell();
if (adjShell != null && adjShell.isIncludedSet()) {
// adjacent ring has been processed, so set included to inverse of adjacent included
setIncluded(! adjShell.isIncluded());
return;
}
}
}
/**
* Gets a string representation of this object.
*
* @return a string representing the object
*/
public String toString() {
return WKTWriter.toLineString(new CoordinateArraySequence(getCoordinates()));
}
/**
* @return whether the ring has been processed
*/
public boolean isProcessed() {
return isProcessed;
}
/**
* @param isProcessed whether the ring has been processed
*/
public void setProcessed(boolean isProcessed) {
this.isProcessed = isProcessed;
}
/**
* Compares EdgeRings based on their envelope,
* using the standard lexicographic ordering.
* This ordering is sufficient to make edge ring sorting deterministic.
*
* @author mbdavis
*
*/
static class EnvelopeComparator implements Comparator {
public int compare(Object obj0, Object obj1) {
EdgeRing r0 = (EdgeRing) obj0;
EdgeRing r1 = (EdgeRing) obj1;
return r0.getRing().getEnvelope().compareTo(r1.getRing().getEnvelope());
}
}
}