Revert velocity damping.

Bug: 4364920

Velocity damping proved to be a bad idea because it would
cause a significant ramp in velocity at the beginning of
a gesture, instead of the desired smooth behavior.  Oh well.

Change-Id: Ie631946f47ef2492bd71fbed1ab44bbb39a875a8

2 files changed, 0 insertions, 14 deletions

diff --git a/include/ui/Input.h b/include/ui/Input.h
index d603441..074b38f 100644
--- a/include/ui/Input.h
+++ b/include/ui/Input.h
@@ -608,11 +608,6 @@ private:
     // Oldest sample to consider when calculating the velocity.
     static const nsecs_t MAX_AGE = 200 * 1000000; // 200 ms
 
-    // When the total duration of the window of samples being averaged is less
-    // than the window size, the resulting velocity is scaled to reduce the impact
-    // of overestimation in short traces.
-    static const nsecs_t MIN_WINDOW = 100 * 1000000; // 100 ms
-
     // The minimum duration between samples when estimating velocity.
     static const nsecs_t MIN_DURATION = 10 * 1000000; // 10 ms
 
diff --git a/libs/ui/Input.cpp b/libs/ui/Input.cpp
index 50b75d5..1fc46aa 100644
--- a/libs/ui/Input.cpp
+++ b/libs/ui/Input.cpp
@@ -677,7 +677,6 @@ bool MotionEvent::isTouchEvent(int32_t source, int32_t action) {
 
 const uint32_t VelocityTracker::HISTORY_SIZE;
 const nsecs_t VelocityTracker::MAX_AGE;
-const nsecs_t VelocityTracker::MIN_WINDOW;
 const nsecs_t VelocityTracker::MIN_DURATION;
 
 VelocityTracker::VelocityTracker() {
@@ -868,14 +867,6 @@ bool VelocityTracker::getVelocity(uint32_t id, float* outVx, float* outVy) const
 
         // Make sure we used at least one sample.
         if (samplesUsed != 0) {
-            // Scale the velocity linearly if the window of samples is small.
-            nsecs_t totalDuration = newestMovement.eventTime - oldestMovement.eventTime;
-            if (totalDuration < MIN_WINDOW) {
-                float scale = float(totalDuration) / float(MIN_WINDOW);
-                accumVx *= scale;
-                accumVy *= scale;
-            }
-
             *outVx = accumVx;
             *outVy = accumVy;
             return true;