easing.clj

(defn cubic-out [t b c]
  (+ b (* c t t t)))

(defn ease-chan
  [f b c step duration]
  (let [out (chan)]
    (go (doseq [t (range 0 duration step)]
          (put! out (+ b (* (- c b) (f (/ t duration) 0 1))))
          (<! (timeout step)))
        (put! out c))
    out))

(defn ease
  [ch f step duration]
  (let [out (chan)
        mix (async/mix out)]
    (go (loop [l nil e nil]
      (let [v (<! ch)]
        (when e (async/unmix mix e))
        (if l (let [e' (ease-chan f l v step duration)]
                (async/admix mix e')
                (recur v e'))
              (do
                (put! out v)
                (recur v nil))))))
    out))

(def inp (chan))
(def eased (ease inp cubic-out 100 1000))
(go (loop []
      (let [v (<! eased)]
        (print v)
        (recur))))

(go (doseq [v (range 0 10 1)]
      (<! (timeout 500))
      (println "WWW ---" v)
      (put! inp v)))