Class SegmentNode

1	/*
2	* Copyright (c) 2016 Vivid Solutions.
3	*
4	* All rights reserved. This program and the accompanying materials
5	* are made available under the terms of the Eclipse Public License 2.0
6	* and Eclipse Distribution License v. 1.0 which accompanies this distribution.
7	* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v20.html
8	* and the Eclipse Distribution License is available at
9	*
10	* http://www.eclipse.org/org/documents/edl-v10.php.
11	*/
12	package org.locationtech.jts.noding;
13
14	import java.io.PrintStream;
15
16	import org.locationtech.jts.geom.Coordinate;
17
18	/**
19	* Represents an intersection point between two {@link SegmentString}s.
20	*
21	* @version 1.7
22	*/
23	public class SegmentNode
24	implements Comparable
25	{
26	private final NodedSegmentString segString;
27	public final Coordinate coord; // the point of intersection
28	public final int segmentIndex; // the index of the containing line segment in the parent edge
29	private final int segmentOctant;
30	private final boolean isInterior;
31
32	public SegmentNode(NodedSegmentString segString, Coordinate coord, int segmentIndex, int segmentOctant) {
33	this.segString = segString;
34	this.coord = new Coordinate(coord);
35	this.segmentIndex = segmentIndex;
36	this.segmentOctant = segmentOctant;
37	isInterior = ! coord.equals2D(segString.getCoordinate(segmentIndex));
38	}
39
40	/**
41	* Gets the {@link Coordinate} giving the location of this node.
42	*
43	* @return the coordinate of the node
44	*/
45	public Coordinate getCoordinate()
46	{
47	return coord;
48	}
49
50	public boolean isInterior() { return isInterior; }
51
52	public boolean isEndPoint(int maxSegmentIndex)
53	{
54	if (segmentIndex == 0 && ! isInterior) return true;
55	if (segmentIndex == maxSegmentIndex) return true;
56	return false;
57	}
58
59	/**
60	* @return -1 this SegmentNode is located before the argument location;
61	* 0 this SegmentNode is at the argument location;
62	* 1 this SegmentNode is located after the argument location
63	*/
64	public int compareTo(Object obj)
65	{
66	SegmentNode other = (SegmentNode) obj;
67
68	if (segmentIndex < other.segmentIndex) return -1;
69	if (segmentIndex > other.segmentIndex) return 1;
70
71	if (coord.equals2D(other.coord)) return 0;
72
73	// an exterior node is the segment start point, so always sorts first
74	// this guards against a robustness problem where the octants are not reliable
75	if (! isInterior) return -1;
76	if (! other.isInterior) return 1;
77
78	return SegmentPointComparator.compare(segmentOctant, coord, other.coord);
79	//return segment.compareNodePosition(this, other);
80	}
81
82	public void print(PrintStream out)
83	{
84	out.print(coord);
85	out.print(" seg # = " + segmentIndex);
86	}
87
88	public String toString() {
89	return segmentIndex + ":" + coord.toString();
90	}
91	}
92