Make VelocityTracker 1D

Currently, VelocityTracker is strictly tied to X and Y axes. It's APIs
act on both axes, and its component structs (e.g. Position, Estimator)
are tied to both X and Y axes. As a step towards supporting more axes
for velocity tracking, this change:
- removes the Position struct: stores/processes data as pure floats, one
  axis at a time
- makes Estimator and Strategy specific to a single axis, instead of
  dealing with both/only X and Y at the same time
Furthermore, we have pulled into VelocityTracker the logic to compute
all velocity. This helps making the immediate JNI layer light-weight in
addition to allowing us to test the logic (which is non-trivial and
benefits from tests).

Bug: 32830165
Test: VelocityTracker_test unaffected (atest libinput_tests)

Change-Id: I181af7a033eb647e9cb97db9b86a36ae972290a5

1 files changed, 14 insertions, 12 deletions

diff --git a/libs/input/VelocityControl.cpp b/libs/input/VelocityControl.cpp
index 6e991e98bb..e2bfb508e1 100644
--- a/libs/input/VelocityControl.cpp
+++ b/libs/input/VelocityControl.cpp
@@ -44,8 +44,8 @@ void VelocityControl::setParameters(const VelocityControlParameters& parameters)
 
 void VelocityControl::reset() {
     mLastMovementTime = LLONG_MIN;
-    mRawPosition.x = 0;
-    mRawPosition.y = 0;
+    mRawPositionX = 0;
+    mRawPositionY = 0;
     mVelocityTracker.clear();
 }
 
@@ -61,17 +61,20 @@ void VelocityControl::move(nsecs_t eventTime, float* deltaX, float* deltaY) {
 
         mLastMovementTime = eventTime;
         if (deltaX) {
-            mRawPosition.x += *deltaX;
+            mRawPositionX += *deltaX;
         }
         if (deltaY) {
-            mRawPosition.y += *deltaY;
+            mRawPositionY += *deltaY;
         }
-        mVelocityTracker.addMovement(eventTime, BitSet32(BitSet32::valueForBit(0)), {mRawPosition});
+        mVelocityTracker.addMovement(eventTime, BitSet32(BitSet32::valueForBit(0)),
+                                     {{AMOTION_EVENT_AXIS_X, {mRawPositionX}},
+                                      {AMOTION_EVENT_AXIS_Y, {mRawPositionY}}});
 
-        float vx, vy;
+        std::optional<float> vx = mVelocityTracker.getVelocity(AMOTION_EVENT_AXIS_X, 0);
+        std::optional<float> vy = mVelocityTracker.getVelocity(AMOTION_EVENT_AXIS_Y, 0);
         float scale = mParameters.scale;
-        if (mVelocityTracker.getVelocity(0, &vx, &vy)) {
-            float speed = hypotf(vx, vy) * scale;
+        if (vx && vy) {
+            float speed = hypotf(*vx, *vy) * scale;
             if (speed >= mParameters.highThreshold) {
                 // Apply full acceleration above the high speed threshold.
                 scale *= mParameters.acceleration;
@@ -85,10 +88,9 @@ void VelocityControl::move(nsecs_t eventTime, float* deltaX, float* deltaY) {
 
             if (DEBUG_ACCELERATION) {
                 ALOGD("VelocityControl(%0.3f, %0.3f, %0.3f, %0.3f): "
-                        "vx=%0.3f, vy=%0.3f, speed=%0.3f, accel=%0.3f",
-                        mParameters.scale, mParameters.lowThreshold, mParameters.highThreshold,
-                        mParameters.acceleration,
-                        vx, vy, speed, scale / mParameters.scale);
+                      "vx=%0.3f, vy=%0.3f, speed=%0.3f, accel=%0.3f",
+                      mParameters.scale, mParameters.lowThreshold, mParameters.highThreshold,
+                      mParameters.acceleration, *vx, *vy, speed, scale / mParameters.scale);
             }
 
         } else {