com.vividsolutions.jts.noding.NodedSegmentString 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.noding;
import java.util.*;
import com.vividsolutions.jts.algorithm.LineIntersector;
import com.vividsolutions.jts.geom.Coordinate;
import com.vividsolutions.jts.geom.impl.CoordinateArraySequence;
import com.vividsolutions.jts.io.WKTWriter;
/**
* Represents a list of contiguous line segments,
* and supports noding the segments.
* The line segments are represented by an array of {@link Coordinate}s.
* Intended to optimize the noding of contiguous segments by
* reducing the number of allocated objects.
* SegmentStrings can carry a context object, which is useful
* for preserving topological or parentage information.
* All noded substrings are initialized with the same context object.
*
* @version 1.7
*/
public class NodedSegmentString
implements NodableSegmentString
{
/**
* Gets the {@link SegmentString}s which result from splitting this string at node points.
*
* @param segStrings a Collection of NodedSegmentStrings
* @return a Collection of NodedSegmentStrings representing the substrings
*/
public static List getNodedSubstrings(Collection segStrings)
{
List resultEdgelist = new ArrayList();
getNodedSubstrings(segStrings, resultEdgelist);
return resultEdgelist;
}
/**
* Adds the noded {@link SegmentString}s which result from splitting this string at node points.
*
* @param segStrings a Collection of NodedSegmentStrings
* @param resultEdgelist a List which will collect the NodedSegmentStrings representing the substrings
*/
public static void getNodedSubstrings(Collection segStrings, Collection resultEdgelist)
{
for (Iterator i = segStrings.iterator(); i.hasNext(); ) {
NodedSegmentString ss = (NodedSegmentString) i.next();
ss.getNodeList().addSplitEdges(resultEdgelist);
}
}
private SegmentNodeList nodeList = new SegmentNodeList(this);
private Coordinate[] pts;
private Object data;
/**
* Creates a new segment string from a list of vertices.
*
* @param pts the vertices of the segment string
* @param data the user-defined data of this segment string (may be null)
*/
public NodedSegmentString(Coordinate[] pts, Object data)
{
this.pts = pts;
this.data = data;
}
/**
* Gets the user-defined data for this segment string.
*
* @return the user-defined data
*/
public Object getData() { return data; }
/**
* Sets the user-defined data for this segment string.
*
* @param data an Object containing user-defined data
*/
public void setData(Object data) { this.data = data; }
public SegmentNodeList getNodeList() { return nodeList; }
public int size() { return pts.length; }
public Coordinate getCoordinate(int i) { return pts[i]; }
public Coordinate[] getCoordinates() { return pts; }
public boolean isClosed()
{
return pts[0].equals(pts[pts.length - 1]);
}
/**
* Gets the octant of the segment starting at vertex index.
*
* @param index the index of the vertex starting the segment. Must not be
* the last index in the vertex list
* @return the octant of the segment at the vertex
*/
public int getSegmentOctant(int index)
{
if (index == pts.length - 1) return -1;
return safeOctant(getCoordinate(index), getCoordinate(index + 1));
// return Octant.octant(getCoordinate(index), getCoordinate(index + 1));
}
private int safeOctant(Coordinate p0, Coordinate p1)
{
if (p0.equals2D(p1)) return 0;
return Octant.octant(p0, p1);
}
/**
* Adds EdgeIntersections for one or both
* intersections found for a segment of an edge to the edge intersection list.
*/
public void addIntersections(LineIntersector li, int segmentIndex, int geomIndex)
{
for (int i = 0; i < li.getIntersectionNum(); i++) {
addIntersection(li, segmentIndex, geomIndex, i);
}
}
/**
* Add an SegmentNode for intersection intIndex.
* An intersection that falls exactly on a vertex
* of the SegmentString is normalized
* to use the higher of the two possible segmentIndexes
*/
public void addIntersection(LineIntersector li, int segmentIndex, int geomIndex, int intIndex)
{
Coordinate intPt = new Coordinate(li.getIntersection(intIndex));
addIntersection(intPt, segmentIndex);
}
/**
* Adds an intersection node for a given point and segment to this segment string.
*
* @param intPt the location of the intersection
* @param segmentIndex the index of the segment containing the intersection
*/
public void addIntersection(Coordinate intPt, int segmentIndex) {
addIntersectionNode(intPt, segmentIndex);
}
/**
* Adds an intersection node for a given point and segment to this segment string.
* If an intersection already exists for this exact location, the existing
* node will be returned.
*
* @param intPt the location of the intersection
* @param segmentIndex the index of the segment containing the intersection
* @return the intersection node for the point
*/
public SegmentNode addIntersectionNode(Coordinate intPt, int segmentIndex) {
int normalizedSegmentIndex = segmentIndex;
//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;
}
}
/**
* Add the intersection point to edge intersection list.
*/
SegmentNode ei = nodeList.add(intPt, normalizedSegmentIndex);
return ei;
}
public String toString()
{
return WKTWriter.toLineString(new CoordinateArraySequence(pts));
}
}