    001    /*
    002     * Licensed to the Apache Software Foundation (ASF) under one or more
    003     * contributor license agreements.  See the NOTICE file distributed with
    004     * this work for additional information regarding copyright ownership.
    005     * The ASF licenses this file to You under the Apache License, Version 2.0
    006     * (the "License"); you may not use this file except in compliance with
    007     * the License.  You may obtain a copy of the License at
    008     *
    009     *      http://www.apache.org/licenses/LICENSE-2.0
    010     *
    011     * Unless required by applicable law or agreed to in writing, software
    012     * distributed under the License is distributed on an "AS IS" BASIS,
    013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014     * See the License for the specific language governing permissions and
    015     * limitations under the License.
    016     */
    017
    018    package org.apache.commons.math.geometry;
    019
    020    /**
    021     * This class is a utility representing a rotation order specification
    022     * for Cardan or Euler angles specification.
    023     *
    024     * This class cannot be instanciated by the user. He can only use one
    025     * of the twelve predefined supported orders as an argument to either
    026     * the {@link Rotation#Rotation(RotationOrder,double,double,double)}
    027     * constructor or the {@link Rotation#getAngles} method.
    028     *
    029     * @version $Revision: 811827 $ $Date: 2009-09-06 17:32:50 +0200 (dim. 06 sept. 2009) $
    030     * @since 1.2
    031     */
    032    public final class RotationOrder {
    033
    034        /** Set of Cardan angles.
    035         * this ordered set of rotations is around X, then around Y, then
    036         * around Z
    037         */
    038        public static final RotationOrder XYZ =
    039          new RotationOrder("XYZ", Vector3D.PLUS_I, Vector3D.PLUS_J, Vector3D.PLUS_K);
    040
    041        /** Set of Cardan angles.
    042         * this ordered set of rotations is around X, then around Z, then
    043         * around Y
    044         */
    045        public static final RotationOrder XZY =
    046          new RotationOrder("XZY", Vector3D.PLUS_I, Vector3D.PLUS_K, Vector3D.PLUS_J);
    047
    048        /** Set of Cardan angles.
    049         * this ordered set of rotations is around Y, then around X, then
    050         * around Z
    051         */
    052        public static final RotationOrder YXZ =
    053          new RotationOrder("YXZ", Vector3D.PLUS_J, Vector3D.PLUS_I, Vector3D.PLUS_K);
    054
    055        /** Set of Cardan angles.
    056         * this ordered set of rotations is around Y, then around Z, then
    057         * around X
    058         */
    059        public static final RotationOrder YZX =
    060          new RotationOrder("YZX", Vector3D.PLUS_J, Vector3D.PLUS_K, Vector3D.PLUS_I);
    061
    062        /** Set of Cardan angles.
    063         * this ordered set of rotations is around Z, then around X, then
    064         * around Y
    065         */
    066        public static final RotationOrder ZXY =
    067          new RotationOrder("ZXY", Vector3D.PLUS_K, Vector3D.PLUS_I, Vector3D.PLUS_J);
    068
    069        /** Set of Cardan angles.
    070         * this ordered set of rotations is around Z, then around Y, then
    071         * around X
    072         */
    073        public static final RotationOrder ZYX =
    074          new RotationOrder("ZYX", Vector3D.PLUS_K, Vector3D.PLUS_J, Vector3D.PLUS_I);
    075
    076        /** Set of Euler angles.
    077         * this ordered set of rotations is around X, then around Y, then
    078         * around X
    079         */
    080        public static final RotationOrder XYX =
    081          new RotationOrder("XYX", Vector3D.PLUS_I, Vector3D.PLUS_J, Vector3D.PLUS_I);
    082
    083        /** Set of Euler angles.
    084         * this ordered set of rotations is around X, then around Z, then
    085         * around X
    086         */
    087        public static final RotationOrder XZX =
    088          new RotationOrder("XZX", Vector3D.PLUS_I, Vector3D.PLUS_K, Vector3D.PLUS_I);
    089
    090        /** Set of Euler angles.
    091         * this ordered set of rotations is around Y, then around X, then
    092         * around Y
    093         */
    094        public static final RotationOrder YXY =
    095          new RotationOrder("YXY", Vector3D.PLUS_J, Vector3D.PLUS_I, Vector3D.PLUS_J);
    096
    097        /** Set of Euler angles.
    098         * this ordered set of rotations is around Y, then around Z, then
    099         * around Y
    100         */
    101        public static final RotationOrder YZY =
    102          new RotationOrder("YZY", Vector3D.PLUS_J, Vector3D.PLUS_K, Vector3D.PLUS_J);
    103
    104        /** Set of Euler angles.
    105         * this ordered set of rotations is around Z, then around X, then
    106         * around Z
    107         */
    108        public static final RotationOrder ZXZ =
    109          new RotationOrder("ZXZ", Vector3D.PLUS_K, Vector3D.PLUS_I, Vector3D.PLUS_K);
    110
    111        /** Set of Euler angles.
    112         * this ordered set of rotations is around Z, then around Y, then
    113         * around Z
    114         */
    115        public static final RotationOrder ZYZ =
    116          new RotationOrder("ZYZ", Vector3D.PLUS_K, Vector3D.PLUS_J, Vector3D.PLUS_K);
    117
    118        /** Name of the rotations order. */
    119        private final String name;
    120
    121        /** Axis of the first rotation. */
    122        private final Vector3D a1;
    123
    124        /** Axis of the second rotation. */
    125        private final Vector3D a2;
    126
    127        /** Axis of the third rotation. */
    128        private final Vector3D a3;
    129
    130        /** Private constructor.
    131         * This is a utility class that cannot be instantiated by the user,
    132         * so its only constructor is private.
    133         * @param name name of the rotation order
    134         * @param a1 axis of the first rotation
    135         * @param a2 axis of the second rotation
    136         * @param a3 axis of the third rotation
    137         */
    138        private RotationOrder(final String name,
    139                              final Vector3D a1, final Vector3D a2, final Vector3D a3) {
    140            this.name = name;
    141            this.a1   = a1;
    142            this.a2   = a2;
    143            this.a3   = a3;
    144        }
    145
    146        /** Get a string representation of the instance.
    147         * @return a string representation of the instance (in fact, its name)
    148         */
    149        @Override
    150        public String toString() {
    151            return name;
    152        }
    153
    154        /** Get the axis of the first rotation.
    155         * @return axis of the first rotation
    156         */
    157        public Vector3D getA1() {
    158            return a1;
    159        }
    160
    161        /** Get the axis of the second rotation.
    162         * @return axis of the second rotation
    163         */
    164        public Vector3D getA2() {
    165            return a2;
    166        }
    167
    168        /** Get the axis of the second rotation.
    169         * @return axis of the second rotation
    170         */
    171        public Vector3D getA3() {
    172            return a3;
    173        }
    174
    175    }