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 * https://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
18 /*
19 * This is not the original file distributed by the Apache Software Foundation
20 * It has been modified by the Hipparchus project
21 */
22 package org.hipparchus.geometry.partitioning;
23
24 import org.hipparchus.geometry.Point;
25 import org.hipparchus.geometry.Space;
26
27 /** This interface represents an hyperplane of a space.
28
29 * <p>The most prominent place where hyperplane appears in space
30 * partitioning is as cutters. Each partitioning node in a {@link
31 * BSPTree BSP tree} has a cut {@link SubHyperplane sub-hyperplane}
32 * which is either an hyperplane or a part of an hyperplane. In an
33 * n-dimensions euclidean space, an hyperplane is an (n-1)-dimensions
34 * hyperplane (for example a traditional plane in the 3D euclidean
35 * space). They can be more exotic objects in specific fields, for
36 * example a circle on the surface of the unit sphere.</p>
37
38 * <p>
39 * Note that this interface is <em>not</em> intended to be implemented
40 * by Hipparchus users, it is only intended to be implemented
41 * within the library itself. New methods may be added even for minor
42 * versions, which breaks compatibility for external implementations.
43 * </p>
44
45 * @param <S> Type of the space.
46
47 */
48 public interface Hyperplane<S extends Space> {
49
50 /** Copy the instance.
51 * <p>The instance created is completely independant of the original
52 * one. A deep copy is used, none of the underlying objects are
53 * shared (except for immutable objects).</p>
54 * @return a new hyperplane, copy of the instance
55 */
56 Hyperplane<S> copySelf();
57
58 /** Get the offset (oriented distance) of a point.
59 * <p>The offset is 0 if the point is on the underlying hyperplane,
60 * it is positive if the point is on one particular side of the
61 * hyperplane, and it is negative if the point is on the other side,
62 * according to the hyperplane natural orientation.</p>
63 * @param point point to check
64 * @return offset of the point
65 */
66 double getOffset(Point<S> point);
67
68 /** Project a point to the hyperplane.
69 * @param point point to project
70 * @return projected point
71 */
72 Point<S> project(Point<S> point);
73
74 /** Get the tolerance below which points are considered to belong to the hyperplane.
75 * @return tolerance below which points are considered to belong to the hyperplane
76 */
77 double getTolerance();
78
79 /** Check if the instance has the same orientation as another hyperplane.
80 * <p>This method is expected to be called on parallel hyperplanes. The
81 * method should <em>not</em> re-check for parallelism, only for
82 * orientation, typically by testing something like the sign of the
83 * dot-products of normals.</p>
84 * @param other other hyperplane to check against the instance
85 * @return true if the instance and the other hyperplane have
86 * the same orientation
87 */
88 boolean sameOrientationAs(Hyperplane<S> other);
89
90 /** Build a sub-hyperplane covering the whole hyperplane.
91 * @return a sub-hyperplane covering the whole hyperplane
92 */
93 SubHyperplane<S> wholeHyperplane();
94
95 /** Build a sub-hyperplane covering nothing.
96 * @return a sub-hyperplane covering nothing
97 * @since 1.4
98 */
99 SubHyperplane<S> emptyHyperplane();
100
101 /** Build a region covering the whole space.
102 * @return a region containing the instance
103 */
104 Region<S> wholeSpace();
105
106 }