Class FastSegmentSetIntersectionFinder

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
13	package org.locationtech.jts.noding;
14
15	import java.util.Collection;
16
17	/**
18	* Finds if two sets of {@link SegmentString}s intersect.
19	* Uses indexing for fast performance and to optimize repeated tests
20	* against a target set of lines.
21	* Short-circuited to return as soon an intersection is found.
22	*
23	* Immutable and thread-safe.
24	*
25	* @version 1.7
26	*/
27	public class FastSegmentSetIntersectionFinder
28	{
29	private final SegmentSetMutualIntersector segSetMutInt;
30	// for testing purposes
31	// private SimpleSegmentSetMutualIntersector mci;
32
33	/**
34	* Creates an intersection finder against a given set of segment strings.
35	*
36	* @param baseSegStrings the segment strings to search for intersections
37	*/
38	public FastSegmentSetIntersectionFinder(Collection baseSegStrings)
39	{
40	segSetMutInt = new MCIndexSegmentSetMutualIntersector(baseSegStrings);
41	}
42
43	/**
44	* Gets the segment set intersector used by this class.
45	* This allows other uses of the same underlying indexed structure.
46	*
47	* @return the segment set intersector used
48	*/
49	public SegmentSetMutualIntersector getSegmentSetIntersector()
50	{
51	return segSetMutInt;
52	}
53
54	/**
55	* Tests for intersections with a given set of target {@link SegmentString}s.
56	*
57	* @param segStrings the SegmentStrings to test
58	* @return true if an intersection is found
59	*/
60	public boolean intersects(Collection segStrings)
61	{
62	SegmentIntersectionDetector intFinder = new SegmentIntersectionDetector();
63	return intersects(segStrings, intFinder);
64	}
65
66	/**
67	* Tests for intersections with a given set of target {@link SegmentString}s.
68	* using a given SegmentIntersectionDetector.
69	*
70	* @param segStrings the SegmentStrings to test
71	* @param intDetector the intersection detector to use
72	* @return true if the detector reports intersections
73	*/
74	public boolean intersects(Collection segStrings, SegmentIntersectionDetector intDetector)
75	{
76	segSetMutInt.process(segStrings, intDetector);
77	return intDetector.hasIntersection();
78	}
79	}
80