class FPS {
  int frames = 0;
  long startTime = 0;
  int fps = 0;
  FPS() {
  }
  void frame() {
    if (startTime==0)
      startTime = millis();
    frames++;
    long t = millis() - startTime;
    if (t>1000) {
      fps = (int)(1000*frames/t);
      startTime += t;
      frames = 0;
    }
  }
}