sclass SineSoundSource extends VF1<double[]> {
  double freq, sampleRate = 44100, step;
  double phase;
  
  *(double freq) {
    step = pi()*2*freq/sampleRate;
  }
  
  *() { ret 44100; }
  
  public void get(double[] lr) {
    fillDoubleArray(lr, Math.sin(phase)*32767);
    phase += step;
  }
}