void playStep(bool play, int *timer, int *step) {
  *timer = *timer >= *step ? 0 : *timer+1;
  usleep(1000);

  if(*timer == 0) {
    printf("%d\n", *timer);

    Mix_PlayChannel(-1, _sample[1], 0);
  }
}

void playSample(int sample) {
  Mix_PlayChannel(-1, _sample[sample-1], 0);
}