dx method

@override double dx(double time)

The velocity of the object in the simulation at the given time.

Implementation

@override
double dx(double time) {
  if (startValue.isNaN) return 0.0;
  if (startValue == endValue) return 0.0;
  double normalizedTime = time / duration;
  double normalizedVelocity =
      startVelocity / (endValue - startValue) * duration;
  double normalizedOutput = normalizedVelocity > 2
      ? velocityOfLinearAccelerationEaseInOutWithInitialVelocity(
          normalizedTime, normalizedVelocity)
      : velocityOfConstantAccelerationEaseInOutWithInitialVelocity(
          normalizedTime, normalizedVelocity);
  return normalizedOutput * (endValue - startValue) / duration;
}