(define-gboxed-cstruct rectangle "GdkRectangle"
  (:export t
   :type-initializer "gdk_rectangle_get_type")
  (x :int :initform 0)
  (y :int :initform 0)
  (width :int :initform 0)
  (height :int :initform 0))  

The gdk:rectangle structure is holding the position and size of a rectangle.

The intersection of two rectangles can be computed with the gdk:rectangle-intersect function. To find the union of two rectangles use the gdk:rectangle-union function.

The cairo:region-t structure is usually used for managing clipping of graphical operations.