Function oscillation

oscillation(
    a: number,
    b: number,
    t: number,
    p?: number,
    f?: (x: number) => number,
): number
Returns the value of the oscillation between a and b at time t.
Parameters
- a: number
  The minimium value of the oscillation
- b: number
  The maximum value of the oscillation
- t: number
  The time
- Optionalp: number = 1
  The period (must be nonzero)
- Optionalf: (x: number) => number = Math.cos
  The periodic function (its period must be 2π)
Returns number
((b - a) * (f(2π * t / p) + 1) / 2) + a