clear_area/[5,6]

     clear_area(+Window, +X, +Y,
                     +Width, +Height)
     clear_area(+Window, +X, +Y,
                     +Width, +Height, +Exposures)
     

Clear the region of Window defined by X, Y, Width, and Height. Exposures is either true or false (default false) indicating whether exposure events should be generated. The cleared portion of the window is filled with the window's background.