set-rounded-rectangle in region%

Sets the region to the interior of the specified rounded rectangle.

See also draw-rounded-rectangle in dc<%>.

• (send a-region set-rounded-rectangle x y width height radius) -> void
     x : real number
     y : real number
     width : non-negative real number
     height : non-negative real number
     radius = 20 : real number

  Restrictions on the magnitude of drawing coordinates are described with dc<%>.