altos/telefireone-v2.0: Remove build of ao_product.h from Makefile

[fw/altos] / altoslib / AltosRotation.java

diff --git a/altoslib/AltosRotation.java b/altoslib/AltosRotation.java
index 6db0b541595ce37f51acd0f78c413abd07b72c38..54b3b1f939a46d1d12fff739fe8b658994afd035 100644 (file)
--- a/altoslib/AltosRotation.java
+++ b/altoslib/AltosRotation.java
@@ -3,7 +3,8 @@
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2 of the License.
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -15,11 +16,33 @@
  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  */
 
-package org.altusmetrum.altoslib_11;
+package org.altusmetrum.altoslib_13;
 
-public class AltosRotation implements AltosJsonable {
+public class AltosRotation extends AltosQuaternion {
        private AltosQuaternion         rotation;
 
+       /* Compute pitch angle from vertical by taking the pad
+        * orientation vector and rotating it by the current total
+        * rotation value. That will be a unit vector pointing along
+        * the airframe axis. The Z value will be the cosine of the
+        * angle from vertical.
+        *
+        * rot = ao_rotation * vertical * ao_rotation°
+        * rot = ao_rotation * (0,0,0,1) * ao_rotation°
+        *     = ((a.z, a.y, -a.x, a.r) * (a.r, -a.x, -a.y, -a.z)) .z
+        *
+        *     = (-a.z * -a.z) + (a.y * -a.y) - (-a.x * -a.x) + (a.r * a.r)
+        *     = a.z² - a.y² - a.x² + a.r²
+        *
+        * rot = ao_rotation * (0, 0, 0, -1) * ao_rotation°
+        *     = ((-a.z, -a.y, a.x, -a.r) * (a.r, -a.x, -a.y, -a.z)) .z
+        *
+        *     = (a.z * -a.z) + (-a.y * -a.y) - (a.x * -a.x) + (-a.r * a.r)
+        *     = -a.z² + a.y² + a.x² - a.r²
+        *
+        * tilt = acos(rot)  (in radians)
+        */
+
        public double tilt() {
                double  rotz = rotation.z * rotation.z - rotation.y * rotation.y - rotation.x * rotation.x + rotation.r * rotation.r;
 
@@ -27,8 +50,11 @@ public class AltosRotation implements AltosJsonable {
                return tilt;
        }
 
-       public void rotate(double dt, double x, double y, double z) {
-               AltosQuaternion rot = AltosQuaternion.half_euler(x * dt / 2.0, y * dt / 2.0, z * dt / 2.0);
+       /* Given euler rotations in three axes, perform a combined rotation using
+        * quaternions
+        */
+       public void rotate(double x, double y, double z) {
+               AltosQuaternion rot = AltosQuaternion.euler(x, y, z);
                rotation = rot.multiply(rotation).normalize();
        }
 
@@ -48,22 +74,7 @@ public class AltosRotation implements AltosJsonable {
                rotation = up.vectors_to_rotation(orient);
        }
 
-       public AltosRotation(AltosJson j) {
-               rotation = new AltosQuaternion(j);
-       }
-
        public AltosRotation() {
                rotation = new AltosQuaternion();
        }
-
-       public AltosJson json() {
-               return rotation.json();
-       }
-
-       public static AltosRotation fromJson(AltosJson j, AltosRotation def) {
-               if (j == null)
-                       return def;
-
-               return new AltosRotation(j);
-       }
 }