get Rotation Matrix From Vector - Android java.lang

Android examples for java.lang:Math Vector

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Description

get Rotation Matrix From Vector

Demo Code


//package com.java2s;

public class Main {
    /**//from w  ww .j a  v a 2 s  .co  m
     * this is a copy from
     * {@link SensorManager#getRotationMatrixFromVector(float[] R, float[] rotationVector)}
     * in newer android versions. Code from:
     * http://android.git.kernel.org/?p=platform/frameworks/base
     * .git;a=blob;f=core/java/android/hardware/SensorManager.java to keep
     * compatibility to older Android versions
     * 
     * TODO the "if lenght==3" stuff could be removed?
     * 
     * @param R
     * @param rotationVector
     */
    public static void getRotationMatrixFromVector(float[] R,
            float[] rotationVector) {

        float q0;
        float q1 = rotationVector[0];
        float q2 = rotationVector[1];
        float q3 = rotationVector[2];

        if (rotationVector.length == 4) {
            q0 = rotationVector[3];
        } else {
            q0 = 1 - q1 * q1 - q2 * q2 - q3 * q3;
            q0 = (q0 > 0) ? (float) Math.sqrt(q0) : 0;
        }

        float sq_q1 = 2 * q1 * q1;
        float sq_q2 = 2 * q2 * q2;
        float sq_q3 = 2 * q3 * q3;
        float q1_q2 = 2 * q1 * q2;
        float q3_q0 = 2 * q3 * q0;
        float q1_q3 = 2 * q1 * q3;
        float q2_q0 = 2 * q2 * q0;
        float q2_q3 = 2 * q2 * q3;
        float q1_q0 = 2 * q1 * q0;

        if (R.length == 9) {
            R[0] = 1 - sq_q2 - sq_q3;
            R[1] = q1_q2 - q3_q0;
            R[2] = q1_q3 + q2_q0;

            R[3] = q1_q2 + q3_q0;
            R[4] = 1 - sq_q1 - sq_q3;
            R[5] = q2_q3 - q1_q0;

            R[6] = q1_q3 - q2_q0;
            R[7] = q2_q3 + q1_q0;
            R[8] = 1 - sq_q1 - sq_q2;
        } else if (R.length == 16) {
            R[0] = 1 - sq_q2 - sq_q3;
            R[1] = q1_q2 - q3_q0;
            R[2] = q1_q3 + q2_q0;
            R[3] = 0.0f;

            R[4] = q1_q2 + q3_q0;
            R[5] = 1 - sq_q1 - sq_q3;
            R[6] = q2_q3 - q1_q0;
            R[7] = 0.0f;

            R[8] = q1_q3 - q2_q0;
            R[9] = q2_q3 + q1_q0;
            R[10] = 1 - sq_q1 - sq_q2;
            R[11] = 0.0f;

            R[12] = R[13] = R[14] = 0.0f;
            R[15] = 1.0f;
        }
    }
}

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