(use tween)

(assert (= 3628800 (factorial 10)))
(assert (= 1.0 (rationalize 4 0.99999998 0.0001)))

;; Linear ease

(assert (= (tween linear-ease 'in 0 10 0) 0))
(assert (= (tween linear-ease 'in 0 10 1) 10))
(assert (= (tween linear-ease 'in 0 10 0.5) 5))

(assert (= (tween linear-ease 'out 0 10 0) 0))
(assert (= (tween linear-ease 'out 0 10 1) 10))
(assert (= (tween linear-ease 'out 0 10 0.5) 5))

(assert (= (tween linear-ease 'inout 0 10 0) 0))
(assert (= (tween linear-ease 'inout 0 10 1) 10))
(assert (= (tween linear-ease 'inout 0 10 0.5) 5))

;; Quadratic ease

(assert (= (tween quadratic-ease 'in 0 10 0) 0))
(assert (= (tween quadratic-ease 'in 0 10 1) 10))
(assert (= (tween quadratic-ease 'in 0 10 0.5) 2.5))

(assert (= (tween quadratic-ease 'out 0 10 0) 0))
(assert (= (tween quadratic-ease 'out 0 10 1) 10))
(assert (= (tween quadratic-ease 'out 0 10 0.5) 7.5))

(assert (= (tween quadratic-ease 'inout 0 10 0) 0))
(assert (= (tween quadratic-ease 'inout 0 10 1) 10))
(assert (= (tween quadratic-ease 'inout 0 10 0.5) 5.0))

;; Cubic ease

(assert (= (tween cubic-ease 'in 0 10 0) 0))
(assert (= (tween cubic-ease 'in 0 10 1) 10))
(assert (= (tween cubic-ease 'in 0 10 0.5) 1.25))

(assert (= (tween cubic-ease 'out 0 10 0) 0))
(assert (= (tween cubic-ease 'out 0 10 1) 10))
(assert (= (tween cubic-ease 'out 0 10 0.5) 8.75))

(assert (= (tween cubic-ease 'inout 0 10 0) 0))
(assert (= (tween cubic-ease 'inout 0 10 1) 10))
(assert (= (tween cubic-ease 'inout 0 10 0.5) 5.0))

;; Quartic ease
 
(assert (= (tween quartic-ease 'in 0 10 0) 0))
(assert (= (tween quartic-ease 'in 0 10 1) 10))
(assert (= (tween quartic-ease 'in 0 10 0.5) 0.625))

(assert (= (tween quartic-ease 'out 0 10 0) 0))
(assert (= (tween quartic-ease 'out 0 10 1) 10))
(assert (= (tween quartic-ease 'out 0 10 0.5) 9.375))

(assert (= (tween quartic-ease 'inout 0 10 0) 0))
(assert (= (tween quartic-ease 'inout 0 10 1) 10))
(assert (= (tween quartic-ease 'inout 0 10 0.5) 5.0))

;; Quintic ease
 
(assert (= (tween quintic-ease 'in 0 10 0) 0))
(assert (= (tween quintic-ease 'in 0 10 1) 10))
(assert (= (tween quintic-ease 'in 0 10 0.5) 0.3125))

(assert (= (tween quintic-ease 'out 0 10 0) 0))
(assert (= (tween quintic-ease 'out 0 10 1) 10))
(assert (= (tween quintic-ease 'out 0 10 0.5) 9.6875))

(assert (= (tween quintic-ease 'inout 0 10 0) 0))
(assert (= (tween quintic-ease 'inout 0 10 1) 10))
(assert (= (tween quintic-ease 'inout 0 10 0.5) 5.0))

;; Sinusoidal ease
 
(assert (= (tween sinusoidal-ease 'in 0 10 0) 0))
(assert (= (rationalize 4 (tween sinusoidal-ease 'in 0 10 1) 0.00001) 10))
(assert (= (rationalize 4 (tween sinusoidal-ease 'in 0 10 0.5) 0.00001) 2.9289))

(assert (= (tween sinusoidal-ease 'out 0 10 0) 0))
(assert (= (rationalize 4 (tween sinusoidal-ease 'out 0 10 1) 0.00001) 10))
(assert (= (rationalize 4 (tween sinusoidal-ease 'out 0 10 0.5) 0.00001) 7.0710))

(assert (= (tween sinusoidal-ease 'inout 0 10 0) 0))
(assert (= (rationalize 4 (tween sinusoidal-ease 'inout 0 10 1) 0.00001) 10))
(assert (= (rationalize 4 (tween sinusoidal-ease 'inout 0 10 0.5) 0.00001) 5.0))

;; Exponential ease
 
(assert (= (tween exponential-ease 'in 0 10 0) 0))
(assert (= (rationalize 4 (tween exponential-ease 'in 0 10 1) 0.00001) 10))
(assert (= (rationalize 4 (tween exponential-ease 'in 0 10 0.5) 0.00001) 0.3125))

(assert (= (tween exponential-ease 'out 0 10 0) 0))
(assert (= (rationalize 4 (tween exponential-ease 'out 0 10 1) 0.00001) 10))
(assert (= (rationalize 4 (tween exponential-ease 'out 0 10 0.5) 0.00001) 9.6875))

(assert (= (tween exponential-ease 'inout 0 10 0) 0))
(assert (= (rationalize 4 (tween exponential-ease 'inout 0 10 1) 0.00001) 10))
(assert (= (rationalize 4 (tween exponential-ease 'inout 0 10 0.5) 0.00001) 5.0))

;; Circular ease
 
(assert (= (tween circular-ease 'in 0 10 0) 0))
(assert (= (rationalize 4 (tween circular-ease 'in 0 10 1) 0.00001) 10))
(assert (= (rationalize 4 (tween circular-ease 'in 0 10 0.5) 0.00001) 1.3397))

(assert (= (tween circular-ease 'out 0 10 0) 0))
(assert (= (rationalize 4 (tween circular-ease 'out 0 10 1) 0.00001) 10))
(assert (= (rationalize 4 (tween circular-ease 'out 0 10 0.5) 0.00001) 8.6602))

(assert (= (tween circular-ease 'inout 0 10 0) 0))
(assert (= (rationalize 4 (tween circular-ease 'inout 0 10 1) 0.00001) 10))
(assert (= (rationalize 4 (tween circular-ease 'inout 0 10 0.5) 0.00001) 5.0))

;; Elastic ease
 
(assert (= (tween elastic-ease 'in 0 10 0) 0))
(assert (= (rationalize 4 (tween elastic-ease 'in 0 10 1) 0.00001) 10))
(assert (= (rationalize 4 (tween elastic-ease 'in 0 10 0.5) 0.00001) 0.0))

(assert (= (tween elastic-ease 'out 0 10 0) 0))
(assert (= (rationalize 4 (tween elastic-ease 'out 0 10 1) 0.00001) 10))
(assert (= (rationalize 4 (tween elastic-ease 'out 0 10 0.5) 0.00001) 10.0))

(assert (= (tween elastic-ease 'inout 0 10 0) 0))
(assert (= (rationalize 4 (tween elastic-ease 'inout 0 10 1) 0.00001) 10))
(assert (= (rationalize 4 (tween elastic-ease 'inout 0 10 0.5) 0.00001) 9.0066))

;; Back ease
 
(assert (= (tween back-ease 'in 0 10 0) 0))
(assert (= (rationalize 4 (tween back-ease 'in 0 10 1) 0.00001) 10))
(assert (= (rationalize 4 (tween back-ease 'in 0 10 0.5) 0.00001) 0.0))

(assert (= (tween back-ease 'out 0 10 0) 0))
(assert (= (rationalize 4 (tween back-ease 'out 0 10 1) 0.00001) 10))
(assert (= (rationalize 4 (tween back-ease 'out 0 10 0.5) 0.00001) 10.0))

(assert (= (tween back-ease 'inout 0 10 0) 0))
(assert (= (rationalize 4 (tween back-ease 'inout 0 10 1) 0.00001) 10))
(assert (= (rationalize 4 (tween back-ease 'inout 0 10 0.5) 0.00001) 5.0))

;; Bounce ease
 
(assert (= (tween bounce-ease 'in 0 10 0) 0))
(assert (= (rationalize 4 (tween bounce-ease 'in 0 10 1) 0.00001) 10))
(assert (= (rationalize 4 (tween bounce-ease 'in 0 10 0.5) 0.00001) 2.3437))

(assert (= (tween bounce-ease 'out 0 10 0) 0))
(assert (= (rationalize 4 (tween bounce-ease 'out 0 10 1) 0.00001) 10))
(assert (= (rationalize 4 (tween bounce-ease 'out 0 10 0.5) 0.00001) 7.6562))

(assert (= (tween bounce-ease 'inout 0 10 0) 0))
(assert (= (rationalize 4 (tween bounce-ease 'inout 0 10 1) 0.00001) 10))
(assert (= (rationalize 4 (tween bounce-ease 'inout 0 10 0.5) 0.00001) 5.0))

;; Selectors

(define test-set (list->vector '(0 1 2 3 4 5 6 7 8 9 10)))

;; Linear select

(assert (= (linear-select test-set 0) 0))
(assert (= (linear-select test-set 0.5) 5.0))
(assert (= (linear-select test-set 1) 10.0))

;; Bezier select

(assert (= (bezier-select test-set 0) 0))
(assert (= (bezier-select test-set 0.5) 5.0))
(assert (= (bezier-select test-set 1) 10.0))

;; Catmullrom select

(assert (= (catmullrom-select test-set 0) 0))
(assert (= (catmullrom-select test-set 0.5) 5.0))
(assert (= (catmullrom-select test-set 1) 10.0))

;; Test everything!

(define test-percents '(0.0 0.1 0.2 0.3 0.4 0.5 0.66 0.75 0.95 1.0))
(define test-eases (list linear-ease quadratic-ease cubic-ease quartic-ease quintic-ease sinusoidal-ease exponential-ease circular-ease elastic-ease back-ease bounce-ease))
(define (test-ease ease start stop)
  (let ((in '())
        (out '())
        (inout '()))
    (map (lambda (p)
           (set! in (cons (rationalize 2 (tween ease 'in start stop p)) in))
           (set! out (cons (rationalize 2 (tween ease 'out start stop p)) out))
           (set! inout (cons (rationalize 2 (tween ease 'inout start stop p)) inout))
           )
         (reverse test-percents))
    `((in . ,in) (out . ,out) (inout . ,inout))))

(define (test-select selector values)
  (map (lambda (p)
         (rationalize 2 (interpolate selector values p)))
       test-percents))

(map (lambda (e) (display (list e 0 10 (test-ease e 0 10))) (newline)) 
     (list linear-ease quadratic-ease cubic-ease quartic-ease quintic-ease sinusoidal-ease exponential-ease circular-ease elastic-ease back-ease bounce-ease))

(let ((v '(0 1 2 3 4 5 10 15 20 25 30 35 40 45 50)))
  (map (lambda (s) (display (list s v (test-select s (list->vector v)))))
       (list linear-select bezier-select catmullrom-select)))