void playPattern(int *timer, int duration, int *step) {
  *timer = *timer >= duration ? 0 : *timer+1;
  usleep(1000);

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

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

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