am 29c99aaa: Merge "Added check to make orientation calculations more robust" into gingerbread

        // high time constant.

        private static final float MAX_DEVIATION_FROM_GRAVITY = 1.5f;

        // Minimum acceleration considered, in m/s^2. Below this threshold sensor noise will have

        // significant impact on the calculations and in case of the vector (0, 0, 0) there is no

        // defined rotation or tilt at all. Low or zero readings can happen when space travelling

        // or free falling, but more commonly when shaking or getting bad readings from the sensor.

        // The accelerometer is turned off when not used and polling it too soon after it is

        // turned on may result in (0, 0, 0).

        private static final float MIN_ABS_ACCELERATION = 1.5f;

        // Actual sampling period corresponding to SensorManager.SENSOR_DELAY_NORMAL.  There's no

        // way to get this information from SensorManager.

        // Note the actual period is generally 3-30ms larger than this depending on the device, but

            float deviation = Math.abs(magnitude - SensorManager.STANDARD_GRAVITY);

            handleAccelerationDistrust(deviation);

            if (magnitude < MIN_ABS_ACCELERATION) {

                return; // Ignore tilt and orientation when (0, 0, 0) or low reading

            }

            // only filter tilt when we're accelerating

            float alpha = 1;