sclass IIImageSurface extends ImageSurface {

  IBWIntegralImage ii;

  *() {}

  *(IBWIntegralImage *ii) {}

  *(IBWIntegralImage *ii, BufferedImage img) { super(img); }

  void drawImageItself(int w, int h, Graphics2D g) {

    if (ii == null)

      ret with super.drawImageItself(w, h, g);

    int iw = getZoomedWidth(), ih = getZoomedHeight();

    Rect r = toRect(getVisibleRect());

    //_print(visibleRect := r);

    // TODO: scale only the visible part

    //var scaled = scaledGrayImageFromBWIntegralImage(ii, iw, ih);

    var scaled = scaledGrayImageFromBWIntegralImage_clip(ii, doubleRatio(iw, ii.getWidth()), r);

    g.drawImage(scaled, r.x, r.y, null);

  }

  public void setImage(BufferedImage img) {

    ii = null;

    super.setImage(img);

  }

  void setImage(BWIntegralImage ii, BufferedImage img default null) {

    this.ii = ii;

    super.setImage(img);

  }

  bool hasImage() { ret ii != null || image != null; }

  int w() { ret ii != null ? ii.getWidth() : super.w(); }

  int h() { ret ii != null ? ii.getHeight() : super.h(); }

}