1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.geometry.euclidean.twod;
18
19 import java.util.List;
20
21 /** Interface for objects that support linecast operations in Euclidean 2D space.
22 *
23 * <p>
24 * Linecasting is a process that takes a line or convex line subset and intersects it with
25 * the boundaries of a region. This is similar to
26 * <a href="https://en.wikipedia.org/wiki/Ray_casting">raycasting</a> used
27 * for collision detection with the exception that the intersecting element can be a
28 * line or convex line subset and not just a ray.
29 * </p>
30 */
31 public interface Linecastable2D {
32
33 /** Intersect the given line against the boundaries in this instance, returning a
34 * list of all intersections in order of increasing position along the line. An empty
35 * list is returned if no intersections are discovered.
36 * @param line line the line to intersect
37 * @return a list of computed intersections in order of increasing position
38 * along the line
39 */
40 default List<LinecastPoint2D> linecast(final Line line) {
41 return linecast(line.span());
42 }
43
44 /** Intersect the given line subset against the boundaries in this instance, returning
45 * a list of all intersections in order of increasing position along the line. An empty
46 * list is returned if no intersections are discovered.
47 * @param subset line subset to intersect
48 * @return a list of computed intersections in order of increasing position
49 * along the line
50 */
51 List<LinecastPoint2D> linecast(LineConvexSubset subset);
52
53 /** Intersect the given line against the boundaries in this instance, returning
54 * the first intersection found when traveling in the direction of the line from
55 * infinity.
56 * @param line the line to intersect
57 * @return the first intersection found or null if no intersection
58 * is found
59 */
60 default LinecastPoint2D linecastFirst(final Line line) {
61 return linecastFirst(line.span());
62 }
63
64 /** Intersect the given line subset against the boundaries in this instance, returning
65 * the first intersection found when traveling in the direction of the line subset
66 * from its start location.
67 * @param subset line subset to intersect
68 * @return the first intersection found or null if no intersection
69 * is found
70 */
71 LinecastPoint2D linecastFirst(LineConvexSubset subset);
72 }