;;; Procedure:
;;;   no-failure
;;; Parameters:
;;;   none
;;; Purpose:
;;;   Creates a new image with the universal sign for "No Fs"
;;; Produces:
;;;   Nothing.  You call this only for the side effect of
;;;   drawing a new image.
;;; Preconditions:
;;;   Must be called from within Script-Fu.
;;; Postconditions:
;;;   A new image appears on the screen.
(define no-failure
  (lambda ()
    ; Draw everything on white
    (set-bgcolor WHITE)
    (let ((image (create-image 256 256)))
      ; Draw the silly letter F in blue
      (set-fgcolor BLUE)
      (set-brush "Circle (11)")
      (line image 96 40 176 40) ; Top stroke
      (line image 96 40 96 216) ; Down stroke
      (line image 96 112 148 112) ; Middle stroke
      ; Draw a nice red circle.
      (set-fgcolor RED)
      (set-brush "Circle (07)")
      (select-ellipse image REPLACE 8 8 240 240)
      (stroke image)
      (select-nothing image)
      ; Now we're ready to draw the slash.  Basic math tells us that
      ; the endpoints are offset by radius/(sqrt 2) from the center 
      ; of the circle.
      (let* ((center 128)
             (radius 120)
             (offset (/ radius (sqrt 2))))
        (line image
              (- center offset) (- center offset)
              (+ center offset) (+ center offset)))
      ; And display the image
      (show-image image))))