Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit de18f6c3 authored by Andrew de los Reyes's avatar Andrew de los Reyes
Browse files

InputResampling: Don't extrapolate for very low frame rates. 

In very low framerate situations, extrapolation is generally going to
either cause no benefit or make a mistake. We can safely turn it off
with no user-visible negative impact.

BUG=https://buganizer.corp.google.com/u/0/issues/24550942
TEST=Scrolled very slowly and saw mispredictions on Angler. With change,
saw the log message that the mispredictions were suppressed.

Change-Id: Ic9747d3ff098d7918047ada2ed1c2d21282c65b0
parent b0127aad

libs/input/InputTransport.cpp

+11 −2
Original line number Diff line number Diff line
@@ -51,6 +51,10 @@ static const nsecs_t RESAMPLE_LATENCY = 5 * NANOS_PER_MS; 
// Minimum time difference between consecutive samples before attempting to resample.

static const nsecs_t RESAMPLE_MIN_DELTA = 2 * NANOS_PER_MS;



// Maximum time difference between consecutive samples before attempting to resample

// by extrapolation.

static const nsecs_t RESAMPLE_MAX_DELTA = 20 * NANOS_PER_MS;



// Maximum time to predict forward from the last known state, to avoid predicting too

// far into the future.  This time is further bounded by 50% of the last time delta.

static const nsecs_t RESAMPLE_MAX_PREDICTION = 8 * NANOS_PER_MS;
@@ -724,7 +728,7 @@ void InputConsumer::resampleTouchState(nsecs_t sampleTime, MotionEvent* event, 
        nsecs_t delta = future.eventTime - current->eventTime;

        if (delta < RESAMPLE_MIN_DELTA) {

#if DEBUG_RESAMPLING

            ALOGD("Not resampled, delta time is %lld ns.", delta);

            ALOGD("Not resampled, delta time is too small: %lld ns.", delta);

#endif

            return;

        }
@@ -736,7 +740,12 @@ void InputConsumer::resampleTouchState(nsecs_t sampleTime, MotionEvent* event, 
        nsecs_t delta = current->eventTime - other->eventTime;

        if (delta < RESAMPLE_MIN_DELTA) {

#if DEBUG_RESAMPLING

            ALOGD("Not resampled, delta time is %lld ns.", delta);

            ALOGD("Not resampled, delta time is too small: %lld ns.", delta);

#endif

            return;

        } else if (delta > RESAMPLE_MAX_DELTA) {

#if DEBUG_RESAMPLING

            ALOGD("Not resampled, delta time is too large: %lld ns.", delta);

#endif

            return;

        }