Function oscillation

oscillation(a, b, t, p?, f?): 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
- Optional p: number = 1
  The period (must be nonzero)
- Optional f: ((x) => number) = Math.cos
  The periodic function (its period must be 2π)
  - - (x): number
    - Parameters
      x: number
      Returns number
Returns number
((b - a) * (f(2π * t / p) + 1) / 2) + a