get-clipping-region

Gets the current rectangular clipping region. The clipping width and height are set to -1 if there is no current clipping region.

• (send a-wx:canvas get-clipping-region x y width height) -> void
      x : boxed inexact real
      y : boxed inexact real
      width : boxed inexact real
      height : boxed inexact real

  The x and y boxes are set to the top-left location of the clipping region (in DC coordinates), etc.