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
23 package org.hipparchus.geometry.euclidean.threed;
24
25 /**
26 * This enumerates is used to differentiate the semantics of a rotation.
27 * @see Rotation
28 */
29 public enum RotationConvention {
30
31 /** Constant for rotation that have the semantics of a vector operator.
32 * <p>
33 * According to this convention, the rotation moves vectors with respect
34 * to a fixed reference frame.
35 * </p>
36 * <p>
37 * This means that if we define rotation r is a 90 degrees rotation around
38 * the Z axis, the image of vector {@link Vector3D#PLUS_I} would be
39 * {@link Vector3D#PLUS_J}, the image of vector {@link Vector3D#PLUS_J}
40 * would be {@link Vector3D#MINUS_I}, the image of vector {@link Vector3D#PLUS_K}
41 * would be {@link Vector3D#PLUS_K}, and the image of vector with coordinates (1, 2, 3)
42 * would be vector (-2, 1, 3). This means that the vector rotates counterclockwise.
43 * </p>
44 * <p>
45 * This convention was the only one supported by Hipparchus up to version 3.5.
46 * </p>
47 * <p>
48 * The difference with {@link #FRAME_TRANSFORM} is only the semantics of the sign
49 * of the angle. It is always possible to create or use a rotation using either
50 * convention to really represent a rotation that would have been best created or
51 * used with the other convention, by changing accordingly the sign of the
52 * rotation angle. This is how things were done up to version 3.5.
53 * </p>
54 */
55 VECTOR_OPERATOR,
56
57 /** Constant for rotation that have the semantics of a frame conversion.
58 * <p>
59 * According to this convention, the rotation considered vectors to be fixed,
60 * but their coordinates change as they are converted from an initial frame to
61 * a destination frame rotated with respect to the initial frame.
62 * </p>
63 * <p>
64 * This means that if we define rotation r is a 90 degrees rotation around
65 * the Z axis, the image of vector {@link Vector3D#PLUS_I} would be
66 * {@link Vector3D#MINUS_J}, the image of vector {@link Vector3D#PLUS_J}
67 * would be {@link Vector3D#PLUS_I}, the image of vector {@link Vector3D#PLUS_K}
68 * would be {@link Vector3D#PLUS_K}, and the image of vector with coordinates (1, 2, 3)
69 * would be vector (2, -1, 3). This means that the coordinates of the vector rotates
70 * clockwise, because they are expressed with respect to a destination frame that is rotated
71 * counterclockwise.
72 * </p>
73 * <p>
74 * The difference with {@link #VECTOR_OPERATOR} is only the semantics of the sign
75 * of the angle. It is always possible to create or use a rotation using either
76 * convention to really represent a rotation that would have been best created or
77 * used with the other convention, by changing accordingly the sign of the
78 * rotation angle. This is how things were done up to version 3.5.
79 * </p>
80 */
81 FRAME_TRANSFORM;
82
83 }