diff options
Diffstat (limited to 'java/tests/VrDemo/src/com/example/android/rs/vr/engine/Quaternion.java')
| -rw-r--r-- | java/tests/VrDemo/src/com/example/android/rs/vr/engine/Quaternion.java | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/java/tests/VrDemo/src/com/example/android/rs/vr/engine/Quaternion.java b/java/tests/VrDemo/src/com/example/android/rs/vr/engine/Quaternion.java new file mode 100644 index 00000000..bc0a0aef --- /dev/null +++ b/java/tests/VrDemo/src/com/example/android/rs/vr/engine/Quaternion.java @@ -0,0 +1,161 @@ +/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.example.android.rs.vr.engine;
+
+/**
+ * Generic Quaternion
+ * Written for maximum portability between desktop and Android
+ * Not in performance critical sections
+ */
+public class Quaternion {
+ private final double[] x = new double[4]; // w,x,y,z,
+
+ public void set(double w, double x, double y, double z) {
+ this.x[0] = w;
+ this.x[1] = x;
+ this.x[2] = y;
+ this.x[3] = z;
+ }
+
+ public void clone(Quaternion src) {
+ System.arraycopy(src.x, 0, x, 0, x.length);
+ }
+
+ private static double[] cross(double[] a, double[] b) {
+ double out0 = a[1] * b[2] - b[1] * a[2];
+ double out1 = a[2] * b[0] - b[2] * a[0];
+ double out2 = a[0] * b[1] - b[0] * a[1];
+ return new double[]{out0, out1, out2};
+ }
+
+ private static double dot(double[] a, double[] b) {
+ return a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
+ }
+
+ private static double[] normal(double[] a) {
+ double norm = Math.sqrt(dot(a, a));
+ return new double[]{a[0] / norm, a[1] / norm, a[2] / norm};
+ }
+
+ public void set(double[] v1, double[] v2) {
+ double[] vec1 = normal(v1);
+ double[] vec2 = normal(v2);
+ double[] axis = normal(cross(vec1, vec2));
+ double angle = Math.acos(dot(vec1, vec2));
+ set(angle, axis);
+ }
+
+ public static double calcAngle(double[] v1, double[] v2) {
+ double[] vec1 = normal(v1);
+ double[] vec2 = normal(v2);
+ return Math.acos(Math.min(dot(vec1, vec2), 1));
+ }
+
+ public static double[] calcAxis(double[] v1, double[] v2) {
+ double[] vec1 = normal(v1);
+ double[] vec2 = normal(v2);
+ return normal(cross(vec1, vec2));
+ }
+
+ public void set(double angle, double[] axis) {
+ x[0] = Math.cos(angle / 2);
+ double sin = Math.sin(angle / 2);
+ x[1] = axis[0] * sin;
+ x[2] = axis[1] * sin;
+ x[3] = axis[2] * sin;
+ }
+
+ public Quaternion(double x0, double x1, double x2, double x3) {
+ x[0] = x0;
+ x[1] = x1;
+ x[2] = x2;
+ x[3] = x3;
+ }
+
+ public Quaternion conjugate() {
+ return new Quaternion(x[0], -x[1], -x[2], -x[3]);
+ }
+
+ public Quaternion plus(Quaternion b) {
+ Quaternion a = this;
+ return new Quaternion(a.x[0] + b.x[0], a.x[1] + b.x[1], a.x[2] + b.x[2], a.x[3] + b.x[3]);
+ }
+
+ public Quaternion times(Quaternion b) {
+ Quaternion a = this;
+ double y0 = a.x[0] * b.x[0] - a.x[1] * b.x[1] - a.x[2] * b.x[2] - a.x[3] * b.x[3];
+ double y1 = a.x[0] * b.x[1] + a.x[1] * b.x[0] + a.x[2] * b.x[3] - a.x[3] * b.x[2];
+ double y2 = a.x[0] * b.x[2] - a.x[1] * b.x[3] + a.x[2] * b.x[0] + a.x[3] * b.x[1];
+ double y3 = a.x[0] * b.x[3] + a.x[1] * b.x[2] - a.x[2] * b.x[1] + a.x[3] * b.x[0];
+ return new Quaternion(y0, y1, y2, y3);
+ }
+
+ public Quaternion inverse() {
+ double d = x[0] * x[0] + x[1] * x[1] + x[2] * x[2] + x[3] * x[3];
+ return new Quaternion(x[0] / d, -x[1] / d, -x[2] / d, -x[3] / d);
+ }
+
+ public Quaternion divides(Quaternion b) {
+ Quaternion a = this;
+ return a.inverse().times(b);
+ }
+
+
+ public double[] rotateVec(double[] v) {
+
+ double v0 = v[0];
+ double v1 = v[1];
+ double v2 = v[2];
+
+ double s = x[1] * v0 + x[2] * v1 + x[3] * v2;
+
+ double n0 = 2 * (x[0] * (v0 * x[0] - (x[2] * v2 - x[3] * v1)) + s * x[1]) - v0;
+ double n1 = 2 * (x[0] * (v1 * x[0] - (x[3] * v0 - x[1] * v2)) + s * x[2]) - v1;
+ double n2 = 2 * (x[0] * (v2 * x[0] - (x[1] * v1 - x[2] * v0)) + s * x[3]) - v2;
+
+ return new double[]{n0, n1, n2};
+
+ }
+
+ void matrix() {
+ double xx = x[1] * x[1];
+ double xy = x[1] * x[2];
+ double xz = x[1] * x[3];
+ double xw = x[1] * x[0];
+
+ double yy = x[2] * x[2];
+ double yz = x[2] * x[3];
+ double yw = x[2] * x[0];
+
+ double zz = x[3] * x[3];
+ double zw = x[3] * x[0];
+ double[] m = new double[16];
+ m[0] = 1 - 2 * (yy + zz);
+ m[1] = 2 * (xy - zw);
+ m[2] = 2 * (xz + yw);
+
+ m[4] = 2 * (xy + zw);
+ m[5] = 1 - 2 * (xx + zz);
+ m[6] = 2 * (yz - xw);
+
+ m[8] = 2 * (xz - yw);
+ m[9] = 2 * (yz + xw);
+ m[10] = 1 - 2 * (xx + yy);
+
+ m[3] = m[7] = m[11] = m[12] = m[13] = m[14] = 0;
+ m[15] = 1;
+ }
+}
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