class Perlin {

  RPoint pt;
  float noise_pos = random(100);
  float amplitude = 100.0;

  Perlin(float x, float y, float amplitude) {
    pt = new RPoint(x,y);
    this.amplitude = amplitude;
  }

  void update(float speed) {
    noise_pos += speed;
    pt.x = ((2 * noise(noise_pos)) - 1) * amplitude;
  }

}