Merge "Rename a constant in VelocityTracker" (d037b79e) · Commits · e / os / android_frameworks_native

libs/input/VelocityTracker.cpp

+3 −3

Original line number	Diff line number	Diff line
		@@ -1090,7 +1090,7 @@ static float kineticEnergyToVelocity(float work) {
		static float calculateImpulseVelocity(const nsecs_t* t, const float* x, size_t count) {
		// The input should be in reversed time order (most recent sample at index i=0)
		// t[i] is in nanoseconds, but due to FP arithmetic, convert to seconds inside this function
		static constexpr float NANOS_PER_SECOND = 1E-9;
		static constexpr float SECONDS_PER_NANO = 1E-9;

		if (count < 2) {
		return 0; // if 0 or 1 points, velocity is zero
		@@ -1103,7 +1103,7 @@ static float calculateImpulseVelocity(const nsecs_t* t, const float* x, size_t c
		ALOGE("Events have identical time stamps t=%" PRId64 ", setting velocity = 0", t[0]);
		return 0;
		}
		return (x[1] - x[0]) / (NANOS_PER_SECOND * (t[1] - t[0]));
		return (x[1] - x[0]) / (SECONDS_PER_NANO * (t[1] - t[0]));
		}
		// Guaranteed to have at least 3 points here
		float work = 0;
		@@ -1113,7 +1113,7 @@ static float calculateImpulseVelocity(const nsecs_t* t, const float* x, size_t c
		continue;
		}
		float vprev = kineticEnergyToVelocity(work); // v[i-1]
		float vcurr = (x[i] - x[i-1]) / (NANOS_PER_SECOND * (t[i] - t[i-1])); // v[i]
		float vcurr = (x[i] - x[i-1]) / (SECONDS_PER_NANO * (t[i] - t[i-1])); // v[i]
		work += (vcurr - vprev) * fabsf(vcurr);
		if (i == count - 1) {
		work *= 0.5; // initial condition, case 2) above