46 lines
1.4 KiB
Text
46 lines
1.4 KiB
Text
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#lang scribble/manual
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@(require (for-label racket))
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@title{(pluck in tr maxdelaytime delaytime decaytime coef)}
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Karplus-Strong synthesis.
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in - an excitation signal
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tr - upon a negative to positive transition, the excitation signal
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will be fed into the delay line
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maxdelaytime - the max delay time in seconds (initializes the
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internal delay buffer).
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delaytime - delay time in seconds.
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decaytime - time for the echoes to decay by 60 decibels. Negative
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times emphasize odd partials.
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coef - the coef of the internal one-pole filter. Values should be
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between -1 and +1 (larger values will be unstable... so be
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careful!).
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Excitation signal is white-noise, triggered twice a second with
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varying one-pole coef.
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(let ((n (mul (white-noise ar) 0.1))
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(t (impulse kr 2 0))
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(x (mouse-x kr -0.999 0.999 0 0.1))
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(dl (/ 1 440)))
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(audition (out 0 (pluck n t dl dl 10 x))))
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(let* ((n 25)
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(gen (lambda (n f) (mce-fill n (lambda (_) (f)))))
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(f (gen n (lambda () (rand 0.05 0.2))))
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(p (gen n (lambda () (rand 0 1))))
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(x (mouse-x kr 60 1000 1 0.1))
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(o (lin-lin (sin-osc kr f p) -1 1 x 3000))
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(w (clone n (mul (white-noise ar) 0.1)))
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(i (impulse kr (gen n (lambda () (rand 10 12))) 0))
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(ks (pluck w i 0.01 (fdiv 1 o) 2 (rand 0.01 0.2)))
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(l (gen n (lambda () (rand -1 1)))))
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(audition (out 0 (leak-dc (mix (pan2 ks l 1)) 0.995))))
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