anchor.diff:  
   (defpackage :animation
  -  (:use :common-lisp :easing)
  +  (:use :common-lisp :cffi :wayland-server-core :easing)
     (:export
  +   initialize-animation
      animation
      sequential-animation
      parallel-animation
  
positive.code: 	  t))))
  
  (defun stop-animation (animation)
    (setf *animations* (remove animation *animations*)))
  
  (defun update-animations (callback)
    (when *animations*
  
negative.code: |#
  
  ;; Improvement: maybe we should be able to pass &rest rest parameters to finished-fn
  
  (defmethod start-animation :before ((animation animation) &key)
    (when (not *timer*)
      (start-timer)))
  
  (defmethod start-animation ((animation animation) &key (time (get-internal-real-time)) finished-fn (toplevel t))
    (setf (start-time animation) time)
    (setf (toplevel? animation) toplevel)
  