Implement a weighted least squares VelocityTracker strategy.
No change to the default strategy.
Bug: 6413587
Change-Id: I08eb6f9a511e65ad637359b55b5993c26ba93b40
diff --git a/include/androidfw/VelocityTracker.h b/include/androidfw/VelocityTracker.h
index e600c5a..262a51b 100644
--- a/include/androidfw/VelocityTracker.h
+++ b/include/androidfw/VelocityTracker.h
@@ -138,8 +138,23 @@
*/
class LeastSquaresVelocityTrackerStrategy : public VelocityTrackerStrategy {
public:
+ enum Weighting {
+ // No weights applied. All data points are equally reliable.
+ WEIGHTING_NONE,
+
+ // Weight by time delta. Data points clustered together are weighted less.
+ WEIGHTING_DELTA,
+
+ // Weight such that points within a certain horizon are weighed more than those
+ // outside of that horizon.
+ WEIGHTING_CENTRAL,
+
+ // Weight such that points older than a certain amount are weighed less.
+ WEIGHTING_RECENT,
+ };
+
// Degree must be no greater than Estimator::MAX_DEGREE.
- LeastSquaresVelocityTrackerStrategy(uint32_t degree);
+ LeastSquaresVelocityTrackerStrategy(uint32_t degree, Weighting weighting = WEIGHTING_NONE);
virtual ~LeastSquaresVelocityTrackerStrategy();
virtual void clear();
@@ -167,7 +182,10 @@
}
};
+ float chooseWeight(uint32_t index) const;
+
const uint32_t mDegree;
+ const Weighting mWeighting;
uint32_t mIndex;
Movement mMovements[HISTORY_SIZE];
};