Class TopologyLocation

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4	/*
5	* Copyright (c) 2016 Vivid Solutions.
6	*
7	* All rights reserved. This program and the accompanying materials
8	* are made available under the terms of the Eclipse Public License 2.0
9	* and Eclipse Distribution License v. 1.0 which accompanies this distribution.
10	* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v20.html
11	* and the Eclipse Distribution License is available at
12	*
13	* http://www.eclipse.org/org/documents/edl-v10.php.
14	*/
15	package org.locationtech.jts.geomgraph;
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18
19	import org.locationtech.jts.geom.Location;
20
21	/**
22	* A TopologyLocation is the labelling of a
23	* GraphComponent's topological relationship to a single Geometry.
24	* <p>
25	* If the parent component is an area edge, each side and the edge itself
26	* have a topological location. These locations are named
27	* <ul>
28	* <li> ON: on the edge
29	* <li> LEFT: left-hand side of the edge
30	* <li> RIGHT: right-hand side
31	* </ul>
32	* If the parent component is a line edge or node, there is a single
33	* topological relationship attribute, ON.
34	* <p>
35	* The possible values of a topological location are
36	* {Location.NONE, Location.EXTERIOR, Location.BOUNDARY, Location.INTERIOR}
37	* <p>
38	* The labelling is stored in an array location[j] where
39	* where j has the values ON, LEFT, RIGHT
40	* @version 1.7
41	*/
42	public class TopologyLocation {
43
44	int location[];
45
46	public TopologyLocation(int[] location)
47	{
48	init(location.length);
49	}
50	/**
51	* Constructs a TopologyLocation specifying how points on, to the left of, and to the
52	* right of some GraphComponent relate to some Geometry. Possible values for the
53	* parameters are Location.NULL, Location.EXTERIOR, Location.BOUNDARY,
54	* and Location.INTERIOR.
55	* @see Location
56	*/
57	public TopologyLocation(int on, int left, int right) {
58	init(3);
59	location[Position.ON] = on;
60	location[Position.LEFT] = left;
61	location[Position.RIGHT] = right;
62	}
63
64	public TopologyLocation(int on) {
65	init(1);
66	location[Position.ON] = on;
67	}
68	public TopologyLocation(TopologyLocation gl) {
69	init(gl.location.length);
70	if (gl != null) {
71	for (int i = 0; i < location.length; i++) {
72	location[i] = gl.location[i];
73	}
74	}
75	}
76	private void init(int size)
77	{
78	location = new int[size];
79	setAllLocations(Location.NONE);
80	}
81	public int get(int posIndex)
82	{
83	if (posIndex < location.length) return location[posIndex];
84	return Location.NONE;
85	}
86	/**
87	* @return true if all locations are NULL
88	*/
89	public boolean isNull()
90	{
91	for (int i = 0; i < location.length; i++) {
92	if (location[i] != Location.NONE) return false;
93	}
94	return true;
95	}
96	/**
97	* @return true if any locations are NULL
98	*/
99	public boolean isAnyNull()
100	{
101	for (int i = 0; i < location.length; i++) {
102	if (location[i] == Location.NONE) return true;
103	}
104	return false;
105	}
106	public boolean isEqualOnSide(TopologyLocation le, int locIndex)
107	{
108	return location[locIndex] == le.location[locIndex];
109	}
110	public boolean isArea() { return location.length > 1; }
111	public boolean isLine() { return location.length == 1; }
112
113	public void flip()
114	{
115	if (location.length <= 1) return;
116	int temp = location[Position.LEFT];
117	location[Position.LEFT] = location[Position.RIGHT];
118	location[Position.RIGHT] = temp;
119	}
120
121
122	public void setAllLocations(int locValue)
123	{
124	for (int i = 0; i < location.length; i++) {
125	location[i] = locValue;
126	}
127	}
128	public void setAllLocationsIfNull(int locValue)
129	{
130	for (int i = 0; i < location.length; i++) {
131	if (location[i] == Location.NONE) location[i] = locValue;
132	}
133	}
134
135	public void setLocation(int locIndex, int locValue)
136	{
137	location[locIndex] = locValue;
138	}
139	public void setLocation(int locValue)
140	{
141	setLocation(Position.ON, locValue);
142	}
143	public int[] getLocations() { return location; }
144	public void setLocations(int on, int left, int right) {
145	location[Position.ON] = on;
146	location[Position.LEFT] = left;
147	location[Position.RIGHT] = right;
148	}
149	public boolean allPositionsEqual(int loc)
150	{
151	for (int i = 0; i < location.length; i++) {
152	if (location[i] != loc) return false;
153	}
154	return true;
155	}
156
157	/**
158	* merge updates only the NULL attributes of this object
159	* with the attributes of another.
160	*/
161	public void merge(TopologyLocation gl)
162	{
163	// if the src is an Area label & and the dest is not, increase the dest to be an Area
164	if (gl.location.length > location.length) {
165	int [] newLoc = new int[3];
166	newLoc[Position.ON] = location[Position.ON];
167	newLoc[Position.LEFT] = Location.NONE;
168	newLoc[Position.RIGHT] = Location.NONE;
169	location = newLoc;
170	}
171	for (int i = 0; i < location.length; i++) {
172	if (location[i] == Location.NONE && i < gl.location.length)
173	location[i] = gl.location[i];
174	}
175	}
176
177	public String toString()
178	{
179	StringBuffer buf = new StringBuffer();
180	if (location.length > 1) buf.append(Location.toLocationSymbol(location[Position.LEFT]));
181	buf.append(Location.toLocationSymbol(location[Position.ON]));
182	if (location.length > 1) buf.append(Location.toLocationSymbol(location[Position.RIGHT]));
183	return buf.toString();
184	}
185	}
186