public virtual void GLRedraw(C2DGraphics gr, int x, int y)
 {
     if (!GLVisible || !Visible)
     {
         return;
     }
     gr.SetDrawingRegion(x, y, Width, Height);
     OnGLBackgroundPaint(gr);
     OnGLPaint(gr);
     foreach (Control subctl in Controls)
     {
         if (subctl.GetType().IsSubclassOf(typeof(ctlUserPanel)))
         {
             ((ctlUserPanel)subctl).GLRedraw(gr, x + subctl.Location.X, y + subctl.Location.Y);
         }
     }
 }