2 * Copyright © 2014 Keith Packard <keithp@keithp.com>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
19 package org.altusmetrum.altoslib_11;
21 public class AltosRotation extends AltosQuaternion {
22 private AltosQuaternion rotation;
24 public double tilt() {
25 double rotz = rotation.z * rotation.z - rotation.y * rotation.y - rotation.x * rotation.x + rotation.r * rotation.r;
27 double tilt = Math.acos(rotz) * 180.0 / Math.PI;
31 public void rotate(double dt, double x, double y, double z) {
32 AltosQuaternion rot = AltosQuaternion.half_euler(x * dt / 2.0, y * dt / 2.0, z * dt / 2.0);
33 rotation = rot.multiply(rotation).normalize();
36 /* Clone an existing rotation value */
37 public AltosRotation (AltosRotation old) {
38 this.rotation = new AltosQuaternion(old.rotation);
41 /* Create a new rotation value given an acceleration vector pointing down */
42 public AltosRotation(double x,
45 int pad_orientation) {
46 AltosQuaternion orient = AltosQuaternion.vector(x, y, z).normalize();
47 double sky = pad_orientation == 0 ? 1 : -1;
48 AltosQuaternion up = new AltosQuaternion(0, 0, 0, sky);
49 rotation = up.vectors_to_rotation(orient);
52 public AltosRotation() {
53 rotation = new AltosQuaternion();