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

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* commit '29c99aaaaed00c605fb6cd64de169fafad0e40ed':
  Added check to make orientation calculations more robust
This commit is contained in:
Dianne Hackborn
2011-01-14 15:39:41 -08:00
committed by Android Git Automerger
parent ff3a2c1892 29c99aaaae
commit 544ff558a8
1 changed files with 11 additions and 0 deletions
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11
core/java/android/view/WindowOrientationListener.java
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@@ -234,6 +234,14 @@ public abstract class WindowOrientationListener {
// high time constant. // high time constant.
private static final float MAX_DEVIATION_FROM_GRAVITY = 1.5f; 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 // Actual sampling period corresponding to SensorManager.SENSOR_DELAY_NORMAL. There's no
// way to get this information from SensorManager. // way to get this information from SensorManager.
// Note the actual period is generally 3-30ms larger than this depending on the device, but // Note the actual period is generally 3-30ms larger than this depending on the device, but
@@ -347,6 +355,9 @@ public abstract class WindowOrientationListener {
float deviation = Math.abs(magnitude - SensorManager.STANDARD_GRAVITY); float deviation = Math.abs(magnitude - SensorManager.STANDARD_GRAVITY);
handleAccelerationDistrust(deviation); 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 // only filter tilt when we're accelerating
float alpha = 1; float alpha = 1;