private void fieldRender(){
        if (dbImage == null){
           dbImage = createImage(GWIDTH, GHEIGHT);
            if (dbImage == null){
                System.err.println("dbImage still null");
                return;
            }else{
              dbg = dbImage.getGraphics();
            }
        }
        //clear the screen
        dbg.setColor(Color.WHITE);
        dbg.fillRect(0,0,GWIDTH, GHEIGHT);
        //draw field elements
        draw(dbg);
    }