Files
gitea-docker/desktop/src-common/advent/tween.clj
2015-07-29 23:05:07 -07:00

66 lines
2.0 KiB
Clojure

(ns advent.tween)
(defn ease-in-expo [power t start delta duration]
(let [pct-done (/ t duration)
pct-done (Math/pow pct-done power)]
(+ start
(* delta pct-done))))
(def ease-linear (partial ease-in-expo 1.0))
(def ease-in-quadratic (partial ease-in-expo 2.0))
(def ease-in-cubic (partial ease-in-expo 3.0))
(def ease-in-quartic (partial ease-in-expo 4.0))
(def ease-in-quintic (partial ease-in-expo 5.0))
(def ease-in-dectic (partial ease-in-expo 10.0))
(defn ease-in-out-quadratic [t start delta duration]
(let [t (/ t (/ duration 2))]
(if (< t 1)
(+ (* (/ delta 2)
t t)
start)
(let [t (dec t)]
(+ (* (/ (- delta) 2)
(dec (* t (- t 2))))
start)))))
(defn ease-in-out-quintic [t start delta duration]
(let [t (/ t (/ duration 2))]
(if (< t 1)
(+ (* (/ delta 2)
t t t t t)
start)
(let [t (- t 2)]
(+ (* (/ (- delta) 2)
(- (* t t t t) 2))
start)))))
(defn ease-out-quadratic [t start delta duration]
(let [t (/ t duration)]
(+ (* (- delta) t (- t 2)) start)))
(defn ease-out-cubic [t start delta duration]
(let [t (dec (/ t duration))]
(+ (* delta (inc (* t t t))) start)))
(defn tween [id screen path start end duration & {:keys [finish ease entities]}]
(let [ease (or ease ease-linear)
finish (or finish identity)
start-time (or (:total-time screen) 0.0)
start (if (and entities (= start :current))
(get-in entities path)
start)
delta (- end start)
]
(fn [e total-time]
(let [delta-time (- total-time start-time)
pct-done (min (/ delta-time duration) 1.0)
new-val (ease delta-time start delta duration)
e (assoc-in e path (if (= 1.0 pct-done)
end
new-val))]
(if (= 1.0 pct-done)
(finish (update-in e [:tweens] dissoc id))
e)))))