anchor.diff:  var
     wa: TXWindowAttributes;
   begin
  -  XGetWindowAttributes(FDisplay, RootWindow, @wa);
  +  XGetWindowAttributes(FDisplay, FRootWindow, @wa);
     Result := wa.Height;
   end;
   
  
positive.code:     function    Screen_dpi_y: integer; override;
      function    Screen_dpi: integer; override;
      property    Display: PXDisplay read FDisplay;
      property    RootWindow: TfpgWinHandle read FRootWindow;
      property    EventFilter: TX11EventFilter read FEventFilter write FEventFilter;
    end;
  
  
  
negative.code: var
    wa: TXWindowAttributes;
  begin
    XGetWindowAttributes(FDisplay, FRootWindow, @wa);
    Result := wa.Width;
  end;
  
  