Edge.java
/*
* 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 2.0
* and Eclipse Distribution License v. 1.0 which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v20.html
* and the Eclipse Distribution License is available at
*
* http://www.eclipse.org/org/documents/edl-v10.php.
*/
package org.locationtech.jts.geomgraph;
import java.io.PrintStream;
import org.locationtech.jts.algorithm.LineIntersector;
import org.locationtech.jts.geom.Coordinate;
import org.locationtech.jts.geom.Envelope;
import org.locationtech.jts.geom.IntersectionMatrix;
import org.locationtech.jts.geom.Position;
import org.locationtech.jts.geomgraph.index.MonotoneChainEdge;
/**
* @version 1.7
*/
public class Edge
extends GraphComponent
{
/**
* Updates an IM from the label for an edge.
* Handles edges from both L and A geometries.
* @param label Label defining position
* @param im intersection matrix
*/
public static void updateIM(Label label, IntersectionMatrix im)
{
im.setAtLeastIfValid(label.getLocation(0, Position.ON), label.getLocation(1, Position.ON), 1);
if (label.isArea()) {
im.setAtLeastIfValid(label.getLocation(0, Position.LEFT), label.getLocation(1, Position.LEFT), 2);
im.setAtLeastIfValid(label.getLocation(0, Position.RIGHT), label.getLocation(1, Position.RIGHT), 2);
}
}
Coordinate[] pts;
private Envelope env;
EdgeIntersectionList eiList = new EdgeIntersectionList(this);
private String name;
private MonotoneChainEdge mce;
private boolean isIsolated = true;
private Depth depth = new Depth();
private int depthDelta = 0; // the change in area depth from the R to L side of this edge
public Edge(Coordinate[] pts, Label label)
{
this.pts = pts;
this.label = label;
}
public Edge(Coordinate[] pts)
{
this(pts, null);
}
public int getNumPoints() { return pts.length; }
public void setName(String name) { this.name = name; }
public Coordinate[] getCoordinates() { return pts; }
public Coordinate getCoordinate(int i)
{
return pts[i];
}
public Coordinate getCoordinate()
{
if (pts.length > 0) return pts[0];
return null;
}
public Envelope getEnvelope()
{
// compute envelope lazily
if (env == null) {
env = new Envelope();
for (int i = 0; i < pts.length; i++) {
env.expandToInclude(pts[i]);
}
}
return env;
}
public Depth getDepth() { return depth; }
/**
* The depthDelta is the change in depth as an edge is crossed from R to L
* @return the change in depth as the edge is crossed from R to L
*/
public int getDepthDelta() { return depthDelta; }
public void setDepthDelta(int depthDelta) { this.depthDelta = depthDelta; }
public int getMaximumSegmentIndex()
{
return pts.length - 1;
}
public EdgeIntersectionList getEdgeIntersectionList() { return eiList; }
public MonotoneChainEdge getMonotoneChainEdge()
{
if (mce == null) mce = new MonotoneChainEdge(this);
return mce;
}
public boolean isClosed()
{
return pts[0].equals(pts[pts.length - 1]);
}
/**
* An Edge is collapsed if it is an Area edge and it consists of
* two segments which are equal and opposite (eg a zero-width V).
*
* @return zero-width V area edge, consisting of two segments which are equal and of oppose orientation
*/
public boolean isCollapsed()
{
if (! label.isArea()) return false;
if (pts.length != 3) return false;
if (pts[0].equals(pts[2]) ) return true;
return false;
}
public Edge getCollapsedEdge()
{
Coordinate newPts[] = new Coordinate[2];
newPts[0] = pts[0];
newPts[1] = pts[1];
Edge newe = new Edge(newPts, Label.toLineLabel(label));
return newe;
}
public void setIsolated(boolean isIsolated)
{
this.isIsolated = isIsolated;
}
public boolean isIsolated()
{
return isIsolated;
}
/**
* Adds EdgeIntersections for one or both
* intersections found for a segment of an edge to the edge intersection list.
* @param li Determining number of intersections to add
* @param segmentIndex Segment index to add
* @param geomIndex Geometry index to add
*/
public void addIntersections(LineIntersector li, int segmentIndex, int geomIndex)
{
for (int i = 0; i < li.getIntersectionNum(); i++) {
addIntersection(li, segmentIndex, geomIndex, i);
}
}
/**
* Add an EdgeIntersection for intersection intIndex.
* An intersection that falls exactly on a vertex of the edge is normalized
* to use the higher of the two possible segmentIndexes
*
* @param li Determining number of intersections to add
* @param segmentIndex Segment index to add
* @param geomIndex Geometry index to add
* @param intIndex intIndex is 0 or 1
*/
public void addIntersection(LineIntersector li, int segmentIndex, int geomIndex, int intIndex)
{
Coordinate intPt = new Coordinate(li.getIntersection(intIndex));
int normalizedSegmentIndex = segmentIndex;
double dist = li.getEdgeDistance(geomIndex, intIndex);
//Debug.println("edge intpt: " + intPt + " dist: " + dist);
// normalize the intersection point location
int nextSegIndex = normalizedSegmentIndex + 1;
if (nextSegIndex < pts.length) {
Coordinate nextPt = pts[nextSegIndex];
//Debug.println("next pt: " + nextPt);
// Normalize segment index if intPt falls on vertex
// The check for point equality is 2D only - Z values are ignored
if (intPt.equals2D(nextPt)) {
//Debug.println("normalized distance");
normalizedSegmentIndex = nextSegIndex;
dist = 0.0;
}
}
/**
* Add the intersection point to edge intersection list.
*/
EdgeIntersection ei = eiList.add(intPt, normalizedSegmentIndex, dist);
//ei.print(System.out);
}
/**
* Update the IM with the contribution for this component.
* A component only contributes if it has a labelling for both parent geometries
*/
public void computeIM(IntersectionMatrix im)
{
updateIM(label, im);
}
/**
* equals is defined to be:
* <p>
* e1 equals e2
* <b>iff</b>
* the coordinates of e1 are the same or the reverse of the coordinates in e2
*/
public boolean equals(Object o)
{
if (! (o instanceof Edge)) return false;
Edge e = (Edge) o;
if (pts.length != e.pts.length) return false;
boolean isEqualForward = true;
boolean isEqualReverse = true;
int iRev = pts.length;
for (int i = 0; i < pts.length; i++) {
if (! pts[i].equals2D(e.pts[i])) {
isEqualForward = false;
}
if (! pts[i].equals2D(e.pts[--iRev])) {
isEqualReverse = false;
}
if (! isEqualForward && ! isEqualReverse) return false;
}
return true;
}
/* (non-Javadoc)
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + pts.length;
if (pts.length > 0) {
Coordinate p0 = pts[0];
Coordinate p1 = pts[pts.length - 1];
if (1 == p0.compareTo(p1)) {
p0 = pts[pts.length - 1];
p1 = pts[0];
}
result = prime * result + p0.hashCode();
result = prime * result + p1.hashCode();
}
return result;
}
/**
* Check if coordinate sequences of the Edges are identical.
*
* @param e Edge
* @return true if the coordinate sequences of the Edges are identical
*/
public boolean isPointwiseEqual(Edge e)
{
if (pts.length != e.pts.length) return false;
for (int i = 0; i < pts.length; i++) {
if (! pts[i].equals2D(e.pts[i])) {
return false;
}
}
return true;
}
public String toString()
{
StringBuilder builder = new StringBuilder();
builder.append("edge " + name + ": ");
builder.append("LINESTRING (");
for (int i = 0; i < pts.length; i++) {
if (i > 0) builder.append(",");
builder.append(pts[i].x + " " + pts[i].y);
}
builder.append(") " + label + " " + depthDelta);
return builder.toString();
}
public void print(PrintStream out)
{
out.print("edge " + name + ": ");
out.print("LINESTRING (");
for (int i = 0; i < pts.length; i++) {
if (i > 0) out.print(",");
out.print(pts[i].x + " " + pts[i].y);
}
out.print(") " + label + " " + depthDelta);
}
public void printReverse(PrintStream out)
{
out.print("edge " + name + ": ");
for (int i = pts.length - 1; i >= 0; i--) {
out.print(pts[i] + " ");
}
out.println("");
}
}