anchor.diff:  
           //if ContextHandle.primaryContext <> null then
           //    ContextHandle.primaryContext.MakeCurrent()
  -
  -        base.OnHandleCreated(e)
  -        loaded <- true
  -
  +        
           x.KeyDown.Add(fun e ->
               if e.KeyCode = System.Windows.Forms.Keys.End && e.Control then
                   renderContinuously <- not renderContinuously
  
positive.code:                 x.Invalidate()
          
      override x.OnPaint(e) =
          if x.OnPaintRender then
              x.Render()
                      
  
negative.code:         with get () = autoInvalidate
          and set v = autoInvalidate <- v
  
      /// <summary> Returns true if the control has been fully initialized.</summary> 
      member x.IsLoaded 
          with get () = loaded
  
      interface IInvalidateControl with
          member x.IsInvalid = needsRedraw
  