Merge "Clarify documentation for sensor placement" into qt-dev

    public static final int TYPE_VEC3_CALIBRATION = 0x10002;

    /**

     * Sensor placement. Describes location and installation angle of the sensor device.

     * Sensor placement.

     *

     * Payload:

     *     floatValues[0..11]: First 3 rows of homogeneous matrix in row major order that describes

     *     the location and orientation of the sensor. Origin of reference will be the mobile device

     *     geometric sensor. Reference frame is defined as the same as Android sensor frame.

     * Provides the orientation and location of the sensor element in terms of the

     * Android coordinate system. This data is given as a 3x4 matrix consisting of a 3x3 rotation

     * matrix (R) concatenated with a 3x1 location vector (t). The rotation matrix provides the

     * orientation of the Android device coordinate frame relative to the local coordinate frame of

     * the sensor. Note that assuming the axes conventions of the sensor are the same as Android,

     * this is the inverse of the matrix applied to raw samples read from the sensor to convert them

     * into the Android representation. The location vector represents the translation from the

     * origin of the Android sensor coordinate system to the geometric center of the sensor,

     * specified in millimeters (mm).

     * <p>

     * <b>Payload</b>:

     *     <code>floatValues[0..11]</code>: 3x4 matrix in row major order [R; t]

     * </p>

     * <p>

     * <b>Example</b>:

     *     This raw buffer: <code>{0, 1, 0, 0, -1, 0, 0, 10, 0, 0, 1, -2.5}</code><br>

     *     Corresponds to this 3x4 matrix:

     *     <table>

     *      <thead>

     *       <tr><td colspan="3">Orientation</td><td>Location</tr>

     *      </thead>

     *      <tbody>

     *       <tr><td>0</td><td>1</td><td>0</td><td>0</td></tr>

     *       <tr><td>-1</td><td>0</td><td>0</td><td>10</td></tr>

     *       <tr><td>0</td><td>0</td><td>1</td><td>-2.5</td></tr>

     *      </tbody>

     *     </table>

     *     The sensor is oriented such that:

     *     <ul>

     *        <li>The device X axis corresponds to the sensor's local -Y axis

     *        <li>The device Y axis corresponds to the sensor's local X axis

     *        <li>The device Z axis and sensor's local Z axis are equivalent

     *     </ul>

     *     In other words, if viewing the origin of the Android coordinate system from the positive

     *     Z direction, the device coordinate frame is to be rotated 90° counter-clockwise about the

     *     Z axis to align with the sensor's local coordinate frame. Equivalently, a vector in the

     *     Android coordinate frame may be multiplied with R to rotate it 90° clockwise (270°

     *     counter-clockwise), yielding its representation in the sensor's coordinate frame.

     *     Relative to the origin of the Android coordinate system, the physical center of the

     *     sensor is located 10mm in the positive Y direction, and 2.5mm in the negative Z

     *     direction.

     * </p>

     */

    public static final int TYPE_SENSOR_PLACEMENT = 0x10003;