/*
* 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.geomgraph;
import java.io.PrintStream;
import org.locationtech.jts.geom.Location;
import org.locationtech.jts.geom.TopologyException;
/**
* @version 1.7
*/
public class DirectedEdge
extends EdgeEnd
{
/**
* Computes the factor for the change in depth when moving from one location to another.
* E.g. if crossing from the INTERIOR to the EXTERIOR the depth decreases, so the factor is -1
*/
public static int depthFactor(int currLocation, int nextLocation)
{
if (currLocation == Location.EXTERIOR && nextLocation == Location.INTERIOR)
return 1;
else if (currLocation == Location.INTERIOR && nextLocation == Location.EXTERIOR)
return -1;
return 0;
}
protected boolean isForward;
private boolean isInResult = false;
private boolean isVisited = false;
private DirectedEdge sym; // the symmetric edge
private DirectedEdge next; // the next edge in the edge ring for the polygon containing this edge
private DirectedEdge nextMin; // the next edge in the MinimalEdgeRing that contains this edge
private EdgeRing edgeRing; // the EdgeRing that this edge is part of
private EdgeRing minEdgeRing; // the MinimalEdgeRing that this edge is part of
/**
* The depth of each side (position) of this edge.
* The 0 element of the array is never used.
*/
private int[] depth = { 0, -999, -999 };
public DirectedEdge(Edge edge, boolean isForward)
{
super(edge);
this.isForward = isForward;
if (isForward) {
init(edge.getCoordinate(0), edge.getCoordinate(1));
}
else {
int n = edge.getNumPoints() - 1;
init(edge.getCoordinate(n), edge.getCoordinate(n-1));
}
computeDirectedLabel();
}
public Edge getEdge() { return edge; }
public void setInResult(boolean isInResult) { this.isInResult = isInResult; }
public boolean isInResult() { return isInResult; }
public boolean isVisited() { return isVisited; }
public void setVisited(boolean isVisited) { this.isVisited = isVisited; }
public void setEdgeRing(EdgeRing edgeRing) { this.edgeRing = edgeRing; }
public EdgeRing getEdgeRing() { return edgeRing; }
public void setMinEdgeRing(EdgeRing minEdgeRing) { this.minEdgeRing = minEdgeRing; }
public EdgeRing getMinEdgeRing() { return minEdgeRing; }
public int getDepth(int position) { return depth[position]; }
public void setDepth(int position, int depthVal)
{
if (depth[position] != -999) {
// if (depth[position] != depthVal) {
// Debug.print(this);
// }
if (depth[position] != depthVal)
throw new TopologyException("assigned depths do not match", getCoordinate());
//Assert.isTrue(depth[position] == depthVal, "assigned depths do not match at " + getCoordinate());
}
depth[position] = depthVal;
}
public int getDepthDelta()
{
int depthDelta = edge.getDepthDelta();
if (! isForward) depthDelta = -depthDelta;
return depthDelta;
}
/**
* setVisitedEdge marks both DirectedEdges attached to a given Edge.
* This is used for edges corresponding to lines, which will only
* appear oriented in a single direction in the result.
*/
public void setVisitedEdge(boolean isVisited)
{
setVisited(isVisited);
sym.setVisited(isVisited);
}
/**
* Each Edge gives rise to a pair of symmetric DirectedEdges, in opposite
* directions.
* @return the DirectedEdge for the same Edge but in the opposite direction
*/
public DirectedEdge getSym() { return sym; }
public boolean isForward() { return isForward; }
public void setSym(DirectedEdge de)
{
sym = de;
}
public DirectedEdge getNext() { return next; }
public void setNext(DirectedEdge next) { this.next = next; }
public DirectedEdge getNextMin() { return nextMin; }
public void setNextMin(DirectedEdge nextMin) { this.nextMin = nextMin; }
/**
* This edge is a line edge if
* <ul>
* <li> at least one of the labels is a line label
* <li> any labels which are not line labels have all Locations = EXTERIOR
* </ul>
*/
public boolean isLineEdge()
{
boolean isLine = label.isLine(0) || label.isLine(1);
boolean isExteriorIfArea0 =
! label.isArea(0) || label.allPositionsEqual(0, Location.EXTERIOR);
boolean isExteriorIfArea1 =
! label.isArea(1) || label.allPositionsEqual(1, Location.EXTERIOR);
return isLine && isExteriorIfArea0 && isExteriorIfArea1;
}
/**
* This is an interior Area edge if
* <ul>
* <li> its label is an Area label for both Geometries
* <li> and for each Geometry both sides are in the interior.
* </ul>
*
* @return true if this is an interior Area edge
*/
public boolean isInteriorAreaEdge()
{
boolean isInteriorAreaEdge = true;
for (int i = 0; i < 2; i++) {
if (! ( label.isArea(i)
&& label.getLocation(i, Position.LEFT ) == Location.INTERIOR
&& label.getLocation(i, Position.RIGHT) == Location.INTERIOR) ) {
isInteriorAreaEdge = false;
}
}
return isInteriorAreaEdge;
}
/**
* Compute the label in the appropriate orientation for this DirEdge
*/
private void computeDirectedLabel()
{
label = new Label(edge.getLabel());
if (! isForward)
label.flip();
}
/**
* Set both edge depths. One depth for a given side is provided. The other is
* computed depending on the Location transition and the depthDelta of the edge.
*/
public void setEdgeDepths(int position, int depth)
{
// get the depth transition delta from R to L for this directed Edge
int depthDelta = getEdge().getDepthDelta();
if (! isForward) depthDelta = -depthDelta;
// if moving from L to R instead of R to L must change sign of delta
int directionFactor = 1;
if (position == Position.LEFT)
directionFactor = -1;
int oppositePos = Position.opposite(position);
int delta = depthDelta * directionFactor;
//TESTINGint delta = depthDelta * DirectedEdge.depthFactor(loc, oppositeLoc);
int oppositeDepth = depth + delta;
setDepth(position, depth);
setDepth(oppositePos, oppositeDepth);
}
public void print(PrintStream out)
{
super.print(out);
out.print(" " + depth[Position.LEFT] + "/" + depth[Position.RIGHT]);
out.print(" (" + getDepthDelta() + ")");
//out.print(" " + this.hashCode());
//if (next != null) out.print(" next:" + next.hashCode());
if (isInResult) out.print(" inResult");
}
public void printEdge(PrintStream out)
{
print(out);
out.print(" ");
if (isForward)
edge.print(out);
else
edge.printReverse(out);
}
}