// f: voidfunc(float)
static JSlider liveSliderZeroToOne(float def, final O f) {
  final int max = 9999;
  final JSlider slider = new JSlider(0, max, iround(def*max));
  slider.addChangeListener(new ChangeListener {
    int lastValue = slider.getValue();
    public void stateChanged(ChangeEvent e) {
      int value = slider.getValue();
      if (value != lastValue) {
        lastValue = value;
        pcallF(f, value/(float) max);
      }
    }
  });
  ret slider;
}