double EaseCircInOut(num t, num b, num c, num d) { if ((t/=d/2.0) < 1.0) { return (-c/2.0*(math.sqrt(1.0 - t*t) - 1.0) + b); } t -= 2.0; return (c/2.0*(math.sqrt(1.0 - t*t) + 1.0) + b); }