docs: protected void defineSmallRectangles(ZoomableGraphicsContext gc, T element) {
  		final double ptsSize = element.getPointSize() / 2.;
  		final Rectangle2afp<?, ?, ?, ?, ?, ?> visibleArea = gc.getVisibleArea();
  		for (final Point2d point : element.points()) {
  			if (visibleArea.contains(point)) {
  				final double x = point.getX() - ptsSize;
  				final double y = point.getY() - ptsSize;
  				final double mx = point.getX() + ptsSize;
  				final double my = point.getY() + ptsSize;
  				gc.moveTo(x, y);
  				gc.lineTo(mx, y);
  				gc.lineTo(mx, my);
  				gc.lineTo(x, my);
  				gc.closePath();
  			}
  		}
  	}