com.vividsolutions.jts.geomgraph.DirectedEdgeStar Maven / Gradle / Ivy
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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.geomgraph;
import java.io.PrintStream;
import java.util.*;
import com.vividsolutions.jts.geom.*;
import com.vividsolutions.jts.util.*;
/**
* A DirectedEdgeStar is an ordered list of outgoing DirectedEdges around a node.
* It supports labelling the edges as well as linking the edges to form both
* MaximalEdgeRings and MinimalEdgeRings.
*
* @version 1.7
*/
public class DirectedEdgeStar
extends EdgeEndStar
{
/**
* A list of all outgoing edges in the result, in CCW order
*/
private List resultAreaEdgeList;
private Label label;
public DirectedEdgeStar() {
}
/**
* Insert a directed edge in the list
*/
public void insert(EdgeEnd ee)
{
DirectedEdge de = (DirectedEdge) ee;
insertEdgeEnd(de, de);
}
public Label getLabel() { return label; }
public int getOutgoingDegree()
{
int degree = 0;
for (Iterator it = iterator(); it.hasNext(); ) {
DirectedEdge de = (DirectedEdge) it.next();
if (de.isInResult()) degree++;
}
return degree;
}
public int getOutgoingDegree(EdgeRing er)
{
int degree = 0;
for (Iterator it = iterator(); it.hasNext(); ) {
DirectedEdge de = (DirectedEdge) it.next();
if (de.getEdgeRing() == er) degree++;
}
return degree;
}
public DirectedEdge getRightmostEdge()
{
List edges = getEdges();
int size = edges.size();
if (size < 1) return null;
DirectedEdge de0 = (DirectedEdge) edges.get(0);
if (size == 1) return de0;
DirectedEdge deLast = (DirectedEdge) edges.get(size - 1);
int quad0 = de0.getQuadrant();
int quad1 = deLast.getQuadrant();
if (Quadrant.isNorthern(quad0) && Quadrant.isNorthern(quad1))
return de0;
else if (! Quadrant.isNorthern(quad0) && ! Quadrant.isNorthern(quad1))
return deLast;
else {
// edges are in different hemispheres - make sure we return one that is non-horizontal
//Assert.isTrue(de0.getDy() != 0, "should never return horizontal edge!");
DirectedEdge nonHorizontalEdge = null;
if (de0.getDy() != 0)
return de0;
else if (deLast.getDy() != 0)
return deLast;
}
Assert.shouldNeverReachHere("found two horizontal edges incident on node");
return null;
}
/**
* Compute the labelling for all dirEdges in this star, as well
* as the overall labelling
*/
public void computeLabelling(GeometryGraph[] geom)
{
//Debug.print(this);
super.computeLabelling(geom);
// determine the overall labelling for this DirectedEdgeStar
// (i.e. for the node it is based at)
label = new Label(Location.NONE);
for (Iterator it = iterator(); it.hasNext(); ) {
EdgeEnd ee = (EdgeEnd) it.next();
Edge e = ee.getEdge();
Label eLabel = e.getLabel();
for (int i = 0; i < 2; i++) {
int eLoc = eLabel.getLocation(i);
if (eLoc == Location.INTERIOR || eLoc == Location.BOUNDARY)
label.setLocation(i, Location.INTERIOR);
}
}
//Debug.print(this);
}
/**
* For each dirEdge in the star,
* merge the label from the sym dirEdge into the label
*/
public void mergeSymLabels()
{
for (Iterator it = iterator(); it.hasNext(); ) {
DirectedEdge de = (DirectedEdge) it.next();
Label label = de.getLabel();
label.merge(de.getSym().getLabel());
}
}
/**
* Update incomplete dirEdge labels from the labelling for the node
*/
public void updateLabelling(Label nodeLabel)
{
for (Iterator it = iterator(); it.hasNext(); ) {
DirectedEdge de = (DirectedEdge) it.next();
Label label = de.getLabel();
label.setAllLocationsIfNull(0, nodeLabel.getLocation(0));
label.setAllLocationsIfNull(1, nodeLabel.getLocation(1));
}
}
private List getResultAreaEdges()
{
//print(System.out);
if (resultAreaEdgeList != null) return resultAreaEdgeList;
resultAreaEdgeList = new ArrayList();
for (Iterator it = iterator(); it.hasNext(); ) {
DirectedEdge de = (DirectedEdge) it.next();
if (de.isInResult() || de.getSym().isInResult() )
resultAreaEdgeList.add(de);
}
return resultAreaEdgeList;
}
private final int SCANNING_FOR_INCOMING = 1;
private final int LINKING_TO_OUTGOING = 2;
/**
* Traverse the star of DirectedEdges, linking the included edges together.
* To link two dirEdges, the pointer for an incoming dirEdge
* is set to the next outgoing edge.
*
* DirEdges are only linked if:
*
* - they belong to an area (i.e. they have sides)
*
- they are marked as being in the result
*
*
* Edges are linked in CCW order (the order they are stored).
* This means that rings have their face on the Right
* (in other words,
* the topological location of the face is given by the RHS label of the DirectedEdge)
*
* PRECONDITION: No pair of dirEdges are both marked as being in the result
*/
public void linkResultDirectedEdges()
{
// make sure edges are copied to resultAreaEdges list
getResultAreaEdges();
// find first area edge (if any) to start linking at
DirectedEdge firstOut = null;
DirectedEdge incoming = null;
int state = SCANNING_FOR_INCOMING;
// link edges in CCW order
for (int i = 0; i < resultAreaEdgeList.size(); i++) {
DirectedEdge nextOut = (DirectedEdge) resultAreaEdgeList.get(i);
DirectedEdge nextIn = nextOut.getSym();
// skip de's that we're not interested in
if (! nextOut.getLabel().isArea()) continue;
// record first outgoing edge, in order to link the last incoming edge
if (firstOut == null && nextOut.isInResult()) firstOut = nextOut;
// assert: sym.isInResult() == false, since pairs of dirEdges should have been removed already
switch (state) {
case SCANNING_FOR_INCOMING:
if (! nextIn.isInResult()) continue;
incoming = nextIn;
state = LINKING_TO_OUTGOING;
break;
case LINKING_TO_OUTGOING:
if (! nextOut.isInResult()) continue;
incoming.setNext(nextOut);
state = SCANNING_FOR_INCOMING;
break;
}
}
//Debug.print(this);
if (state == LINKING_TO_OUTGOING) {
//Debug.print(firstOut == null, this);
if (firstOut == null)
throw new TopologyException("no outgoing dirEdge found", getCoordinate());
//Assert.isTrue(firstOut != null, "no outgoing dirEdge found (at " + getCoordinate() );
Assert.isTrue(firstOut.isInResult(), "unable to link last incoming dirEdge");
incoming.setNext(firstOut);
}
}
public void linkMinimalDirectedEdges(EdgeRing er)
{
// find first area edge (if any) to start linking at
DirectedEdge firstOut = null;
DirectedEdge incoming = null;
int state = SCANNING_FOR_INCOMING;
// link edges in CW order
for (int i = resultAreaEdgeList.size() - 1; i >= 0; i--) {
DirectedEdge nextOut = (DirectedEdge) resultAreaEdgeList.get(i);
DirectedEdge nextIn = nextOut.getSym();
// record first outgoing edge, in order to link the last incoming edge
if (firstOut == null && nextOut.getEdgeRing() == er) firstOut = nextOut;
switch (state) {
case SCANNING_FOR_INCOMING:
if (nextIn.getEdgeRing() != er) continue;
incoming = nextIn;
state = LINKING_TO_OUTGOING;
break;
case LINKING_TO_OUTGOING:
if (nextOut.getEdgeRing() != er) continue;
incoming.setNextMin(nextOut);
state = SCANNING_FOR_INCOMING;
break;
}
}
//print(System.out);
if (state == LINKING_TO_OUTGOING) {
Assert.isTrue(firstOut != null, "found null for first outgoing dirEdge");
Assert.isTrue(firstOut.getEdgeRing() == er, "unable to link last incoming dirEdge");
incoming.setNextMin(firstOut);
}
}
public void linkAllDirectedEdges()
{
getEdges();
// find first area edge (if any) to start linking at
DirectedEdge prevOut = null;
DirectedEdge firstIn = null;
// link edges in CW order
for (int i = edgeList.size() - 1; i >= 0; i--) {
DirectedEdge nextOut = (DirectedEdge) edgeList.get(i);
DirectedEdge nextIn = nextOut.getSym();
if (firstIn == null) firstIn = nextIn;
if (prevOut != null) nextIn.setNext(prevOut);
// record outgoing edge, in order to link the last incoming edge
prevOut = nextOut;
}
firstIn.setNext(prevOut);
//Debug.print(this);
}
/**
* Traverse the star of edges, maintaing the current location in the result
* area at this node (if any).
* If any L edges are found in the interior of the result, mark them as covered.
*/
public void findCoveredLineEdges()
{
//Debug.print("findCoveredLineEdges");
//Debug.print(this);
// Since edges are stored in CCW order around the node,
// as we move around the ring we move from the right to the left side of the edge
/**
* Find first DirectedEdge of result area (if any).
* The interior of the result is on the RHS of the edge,
* so the start location will be:
* - INTERIOR if the edge is outgoing
* - EXTERIOR if the edge is incoming
*/
int startLoc = Location.NONE ;
for (Iterator it = iterator(); it.hasNext(); ) {
DirectedEdge nextOut = (DirectedEdge) it.next();
DirectedEdge nextIn = nextOut.getSym();
if (! nextOut.isLineEdge()) {
if (nextOut.isInResult()) {
startLoc = Location.INTERIOR;
break;
}
if (nextIn.isInResult()) {
startLoc = Location.EXTERIOR;
break;
}
}
}
// no A edges found, so can't determine if L edges are covered or not
if (startLoc == Location.NONE) return;
/**
* move around ring, keeping track of the current location
* (Interior or Exterior) for the result area.
* If L edges are found, mark them as covered if they are in the interior
*/
int currLoc = startLoc;
for (Iterator it = iterator(); it.hasNext(); ) {
DirectedEdge nextOut = (DirectedEdge) it.next();
DirectedEdge nextIn = nextOut.getSym();
if (nextOut.isLineEdge()) {
nextOut.getEdge().setCovered(currLoc == Location.INTERIOR);
//Debug.println(nextOut);
}
else { // edge is an Area edge
if (nextOut.isInResult())
currLoc = Location.EXTERIOR;
if (nextIn.isInResult())
currLoc = Location.INTERIOR;
}
}
}
public void computeDepths(DirectedEdge de)
{
int edgeIndex = findIndex(de);
Label label = de.getLabel();
int startDepth = de.getDepth(Position.LEFT);
int targetLastDepth = de.getDepth(Position.RIGHT);
// compute the depths from this edge up to the end of the edge array
int nextDepth = computeDepths(edgeIndex + 1, edgeList.size(), startDepth);
// compute the depths for the initial part of the array
int lastDepth = computeDepths(0, edgeIndex, nextDepth);
//Debug.print(lastDepth != targetLastDepth, this);
//Debug.print(lastDepth != targetLastDepth, "mismatch: " + lastDepth + " / " + targetLastDepth);
if (lastDepth != targetLastDepth)
throw new TopologyException("depth mismatch at " + de.getCoordinate());
//Assert.isTrue(lastDepth == targetLastDepth, "depth mismatch at " + de.getCoordinate());
}
/**
* Compute the DirectedEdge depths for a subsequence of the edge array.
*
* @return the last depth assigned (from the R side of the last edge visited)
*/
private int computeDepths(int startIndex, int endIndex, int startDepth)
{
int currDepth = startDepth;
for (int i = startIndex; i < endIndex ; i++) {
DirectedEdge nextDe = (DirectedEdge) edgeList.get(i);
Label label = nextDe.getLabel();
nextDe.setEdgeDepths(Position.RIGHT, currDepth);
currDepth = nextDe.getDepth(Position.LEFT);
}
return currDepth;
}
public void print(PrintStream out)
{
System.out.println("DirectedEdgeStar: " + getCoordinate());
for (Iterator it = iterator(); it.hasNext(); ) {
DirectedEdge de = (DirectedEdge) it.next();
out.print("out ");
de.print(out);
out.println();
out.print("in ");
de.getSym().print(out);
out.println();
}
}
}