Improve VelocityTracker Strategy Handling
The native VelocityTracker class has been made 1-dimensional to allow
support for axes beyond the historically-supported X/Y axes. This means
that a given VelocityTracker instance does not necessarily handle data
for all supported axes. As such, this CL sets up tracking strategy for
an axis only on the first occassion a data arrives for the axis.
Furthermore, to support use cases where different strategies may suit
different axes better, we have introduced per-axis default strategies.
Bug: 32830165
Test: atest libinput_tests; manual on-device fling tests
Change-Id: I3f7115fdcec78d1577e90e9a55175e8868bf2dfb
diff --git a/include/input/VelocityTracker.h b/include/input/VelocityTracker.h
index 53603c5..da4d877 100644
--- a/include/input/VelocityTracker.h
+++ b/include/input/VelocityTracker.h
@@ -146,16 +146,12 @@
inline int32_t getActivePointerId() const { return mActivePointerId; }
private:
- // The default velocity tracker strategy.
+ // All axes supported for velocity tracking, mapped to their default strategies.
// Although other strategies are available for testing and comparison purposes,
- // this is the strategy that applications will actually use. Be very careful
+ // the default strategy is the one that applications will actually use. Be very careful
// when adjusting the default strategy because it can dramatically affect
// (often in a bad way) the user experience.
- // TODO(b/32830165): define default strategy per axis.
- static const Strategy DEFAULT_STRATEGY = Strategy::LSQ2;
-
- // Set of all axes supported for velocity tracking.
- static const std::set<int32_t> SUPPORTED_AXES;
+ static const std::map<int32_t, Strategy> DEFAULT_STRATEGY_BY_AXIS;
// Axes specifying location on a 2D plane (i.e. X and Y).
static const std::set<int32_t> PLANAR_AXES;
@@ -163,9 +159,17 @@
nsecs_t mLastEventTime;
BitSet32 mCurrentPointerIdBits;
int32_t mActivePointerId;
- std::map<int32_t /*axis*/, std::unique_ptr<VelocityTrackerStrategy>> mStrategies;
- void configureStrategy(int32_t axis, const Strategy strategy);
+ // An override strategy passed in the constructor to be used for all axes.
+ // This strategy will apply to all axes, unless the default strategy is specified here.
+ // When default strategy is specified, then each axis will use a potentially different strategy
+ // based on a hardcoded mapping.
+ const Strategy mOverrideStrategy;
+ // Maps axes to their respective VelocityTrackerStrategy instances.
+ // Note that, only axes that have had MotionEvents (and not all supported axes) will be here.
+ std::map<int32_t /*axis*/, std::unique_ptr<VelocityTrackerStrategy>> mConfiguredStrategies;
+
+ void configureStrategy(int32_t axis);
static std::unique_ptr<VelocityTrackerStrategy> createStrategy(const Strategy strategy);
};
@@ -181,7 +185,6 @@
public:
virtual ~VelocityTrackerStrategy() { }
- virtual void clear() = 0;
virtual void clearPointers(BitSet32 idBits) = 0;
virtual void addMovement(nsecs_t eventTime, BitSet32 idBits,
const std::vector<float>& positions) = 0;
@@ -213,7 +216,6 @@
LeastSquaresVelocityTrackerStrategy(uint32_t degree, Weighting weighting = WEIGHTING_NONE);
virtual ~LeastSquaresVelocityTrackerStrategy();
- virtual void clear();
virtual void clearPointers(BitSet32 idBits);
void addMovement(nsecs_t eventTime, BitSet32 idBits,
const std::vector<float>& positions) override;
@@ -254,7 +256,6 @@
IntegratingVelocityTrackerStrategy(uint32_t degree);
~IntegratingVelocityTrackerStrategy();
- virtual void clear();
virtual void clearPointers(BitSet32 idBits);
void addMovement(nsecs_t eventTime, BitSet32 idBits,
const std::vector<float>& positions) override;
@@ -287,7 +288,6 @@
LegacyVelocityTrackerStrategy();
virtual ~LegacyVelocityTrackerStrategy();
- virtual void clear();
virtual void clearPointers(BitSet32 idBits);
void addMovement(nsecs_t eventTime, BitSet32 idBits,
const std::vector<float>& positions) override;
@@ -320,7 +320,6 @@
ImpulseVelocityTrackerStrategy();
virtual ~ImpulseVelocityTrackerStrategy();
- virtual void clear();
virtual void clearPointers(BitSet32 idBits);
void addMovement(nsecs_t eventTime, BitSet32 idBits,
const std::vector<float>& positions) override;