;; hackpact day 28 - scope
;; gabor papp http://mndl.hu/hackpact

(require scheme/math)

(clear)

(define s 128)

(define p (build-ribbon s))
(with-primitive p
    (hint-unlit)
    (pdata-index-map!
        (lambda (i w)
            (* .1 (expt (sin (* pi (/ i (pdata-size)))) 1.8)))
        "w"))

(every-frame
    (when (not (key-pressed " "))
        (let* ([a (ga)])
            (with-primitive p
                (pdata-index-map!
                    (lambda (i p)
                        (vector (* .25 (- i (/ (pdata-size) 2))) (* 10 (vector-ref a i)) 0))
                    "p")))))