/** {@inheritDoc} */
  public void preRender(DrawContext dc) {
    if (!this.isVisible()) {
      return;
    }

    if (this.rings == null) {
      this.createShapes(dc);
    }

    this.determineActiveAttributes();

    for (SurfaceCircle ring : this.rings) {
      ring.preRender(dc);
    }
  }