title: Add GeneralPath shape in XYShapeAnnotation of JFreechart
body: <p>I am trying to adding a general shape to highlight an area where Y is greater than X in JFreechart.</p>
  
  <p>for that i have defined a general path.</p>
  
  <pre><code>int x3Points[] = {0, (int) Math.max(maxX, maxY), (int) Math.max(maxX, maxY), 0};
  int y3Points[] = {0, (int) Math.max(maxX, maxY), (int) maxY, (int) maxY};
  GeneralPath filledPolygon = new GeneralPath(GeneralPath.WIND_EVEN_ODD, x3Points.length);
  filledPolygon.moveTo(x3Points[0], y3Points[0]);
      for (int index = 1; index &lt; x3Points.length; index++) {
           filledPolygon.lineTo(x3Points[index], y3Points[index]);
       }
          filledPolygon.lineTo(x3Points[0], y3Points[0]);
          filledPolygon.closePath();
  
  Graphics graphics = getGraphics(); // i am not sure if calling getGraphics() method of JFrame is a good idea. but if not how to get Graphics() to draw on chart 
  
     Graphics2D g2d = (Graphics2D) graphics;
     g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                  RenderingHints.VALUE_ANTIALIAS_ON);
  
     g2d.setRenderingHint(RenderingHints.KEY_RENDERING,
                  RenderingHints.VALUE_RENDER_QUALITY);
     g2d.setPaint(Color.gray);
     g2d.fill(filledPolygon);
     g2d.dispose();
     XYShapeAnnotation xyShapeAnnotation = new XYShapeAnnotation(filledPolygon, new BasicStroke(2.f), Color.black);
  
   renderer.addAnnotation(xyShapeAnnotation, Layer.BACKGROUND);
  </code></pre>
  
  <p>the shape is added to the chart but it is not filled with black color. i guess the getGraphics() method that i am using is not correct. but how to get graphics of JFreechart.</p>