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(define-module (starlet effects)
#:use-module (starlet base)
#:export (flash
sinewave))
(define pi (* 2 (acos 0)))
(define (square-wave time hz)
(if (> (sin (* 2 pi hz time))
0)
100
0))
(define (flash hz)
(lambda (time)
(square-wave time hz)))
(define (sinewave hz range-min range-max)
(lambda (time)
(+ range-min
(* (/ (- range-max range-min) 2)
(+ 1 (sin (* 2 pi hz time)))))))
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