Function position

ola.js:3–9

(x0, v0, t1, t)

// Calculate the position based on the current position, speed and time:
//  https://www.wolframalpha.com/input/?i=x+%3D+2+*+t+%5E+3+-+3+*+t+%5E+2+%2B+1+from+t+%3D+0+to+t+%3D+1
const position = (x0, v0, t1, t) => {
  const a = (v0 * t1 + 2 * x0) / t1 ** 3;
  const b = -(2 * v0 * t1 + 3 * x0) / t1 ** 2;
  const c = v0;
  const d = x0;
  return a * t ** 3 + b * t ** 2 + c * t + d;
};

// Calculate the speed based on the current position, speed and time:
const speed = (x0, v0, t1, t) => {