diff options
| -rw-r--r-- | include/androidfw/VelocityTracker.h | 6 | ||||
| -rw-r--r-- | libs/androidfw/VelocityTracker.cpp | 31 |
2 files changed, 30 insertions, 7 deletions
diff --git a/include/androidfw/VelocityTracker.h b/include/androidfw/VelocityTracker.h index 69645889dc92..cbb078299c2e 100644 --- a/include/androidfw/VelocityTracker.h +++ b/include/androidfw/VelocityTracker.h @@ -37,6 +37,9 @@ public: struct Estimator { static const size_t MAX_DEGREE = 2; + // Estimator time base. + nsecs_t time; + // Polynomial coefficients describing motion in X and Y. float xCoeff[MAX_DEGREE + 1], yCoeff[MAX_DEGREE + 1]; @@ -48,6 +51,7 @@ public: float confidence; inline void clear() { + time = 0; degree = 0; confidence = 0; for (size_t i = 0; i <= MAX_DEGREE; i++) { @@ -58,7 +62,6 @@ public: }; VelocityTracker(); - VelocityTracker(VelocityTrackerStrategy* strategy); ~VelocityTracker(); // Resets the velocity tracker state. @@ -96,6 +99,7 @@ public: inline BitSet32 getCurrentPointerIdBits() const { return mCurrentPointerIdBits; } private: + nsecs_t mLastEventTime; BitSet32 mCurrentPointerIdBits; int32_t mActivePointerId; VelocityTrackerStrategy* mStrategy; diff --git a/libs/androidfw/VelocityTracker.cpp b/libs/androidfw/VelocityTracker.cpp index a212948f5631..5dbafd8ebafb 100644 --- a/libs/androidfw/VelocityTracker.cpp +++ b/libs/androidfw/VelocityTracker.cpp @@ -33,6 +33,16 @@ namespace android { +// Nanoseconds per milliseconds. +static const nsecs_t NANOS_PER_MS = 1000000; + +// Threshold for determining that a pointer has stopped moving. +// Some input devices do not send ACTION_MOVE events in the case where a pointer has +// stopped. We need to detect this case so that we can accurately predict the +// velocity after the pointer starts moving again. +static const nsecs_t ASSUME_POINTER_STOPPED_TIME = 40 * NANOS_PER_MS; + + static float vectorDot(const float* a, const float* b, uint32_t m) { float r = 0; while (m--) { @@ -89,15 +99,10 @@ static String8 matrixToString(const float* a, uint32_t m, uint32_t n, bool rowMa // --- VelocityTracker --- VelocityTracker::VelocityTracker() : - mCurrentPointerIdBits(0), mActivePointerId(-1), + mLastEventTime(0), mCurrentPointerIdBits(0), mActivePointerId(-1), mStrategy(new LeastSquaresVelocityTrackerStrategy()) { } -VelocityTracker::VelocityTracker(VelocityTrackerStrategy* strategy) : - mCurrentPointerIdBits(0), mActivePointerId(-1), - mStrategy(strategy) { -} - VelocityTracker::~VelocityTracker() { delete mStrategy; } @@ -125,6 +130,18 @@ void VelocityTracker::addMovement(nsecs_t eventTime, BitSet32 idBits, const Posi idBits.clearLastMarkedBit(); } + if ((mCurrentPointerIdBits.value & idBits.value) + && eventTime >= mLastEventTime + ASSUME_POINTER_STOPPED_TIME) { +#if DEBUG_VELOCITY + ALOGD("VelocityTracker: stopped for %0.3f ms, clearing state.", + (eventTime - mLastEventTime) * 0.000001f); +#endif + // We have not received any movements for too long. Assume that all pointers + // have stopped. + mStrategy->clear(); + } + mLastEventTime = eventTime; + mCurrentPointerIdBits = idBits; if (mActivePointerId < 0 || !idBits.hasBit(mActivePointerId)) { mActivePointerId = idBits.isEmpty() ? -1 : idBits.firstMarkedBit(); @@ -467,6 +484,7 @@ bool LeastSquaresVelocityTrackerStrategy::getEstimator(uint32_t id, uint32_t n = degree + 1; if (solveLeastSquares(time, x, m, n, outEstimator->xCoeff, &xdet) && solveLeastSquares(time, y, m, n, outEstimator->yCoeff, &ydet)) { + outEstimator->time = newestMovement.eventTime; outEstimator->degree = degree; outEstimator->confidence = xdet * ydet; #if DEBUG_LEAST_SQUARES @@ -483,6 +501,7 @@ bool LeastSquaresVelocityTrackerStrategy::getEstimator(uint32_t id, // No velocity data available for this pointer, but we do have its current position. outEstimator->xCoeff[0] = x[0]; outEstimator->yCoeff[0] = y[0]; + outEstimator->time = newestMovement.eventTime; outEstimator->degree = 0; outEstimator->confidence = 1; return true; |