protected void drawToolTipInterior(
      DrawContext dc, double width, double height, ToolTipAttributes attributes) {
    GL2 gl = dc.getGL().getGL2(); // GL initialization checks for GL2 compatibility.

    this.applyColor(dc, attributes.getInteriorColor(), attributes.getInteriorOpacity());

    // Draw a filled rectangle with the background dimensions.
    gl.glRectd(0, 0, width, height);
  }