Lisp Game Programming <Step11-4>

Step11の最後はshipが全て無くなったときにメッセージを出して終了するプログラム

;; Step11 <Game Over Message>
;; -----------------------------------------------------------------------------------------------
(defgeneric Game-over-message (score))

(defmethod Game-over-message (score) ; message Draw
  "Draw game over message"
  (when (= (n-ship score) 0)
    (stop-sound) ; BGM stop
    (sdl:draw-string-solid-* "GAME OVER" 208 232 :color sdl:*white* :font *menu-font*)
  (sdl:update-display)
  (sleep 5)
  (sdl:push-quit-event)))