rsc3/doc/examples/ugen/chaos/fb-sine-c.help.scm

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2022-08-24 13:53:18 +00:00
;; (fb-sine-c rate freq im fb a c xi yi)
;; Feedback sine with chaotic phase indexing.
;; freq - iteration frequency in Hz - 22050
;; im - index multiplier amount - 1
;; fb - feedback amount - 0.1
;; a - phase multiplier amount - 1.1
;; c - phase increment amount - 0.5
;; xi - initial value of x - 0.1
;; yi - initial value of y - 0.1
;; A cubic-interpolating sound generator based on the difference
;; equations:
;; xn+1 = sin(im*yn + fb*xn)
;; yn+1 = (ayn + c) % 2pi
;; This uses a linear congruential function to drive the phase
;; indexing of a sine wave. For im = 1, fb = 0, and a = 1 a normal
;; sinewave results.
;; sclang default values
(audition
(out 0 (mul (fb-sine-c ar (fdiv sample-rate 4) 1 0.1 1.1 0.5 0.1 0.1)
0.2)))
;; increase feedback
(let ((fb (line kr 0.01 4 10 do-nothing)))
(audition
(out 0 (mul (fb-sine-c ar sample-rate 1 fb 1.1 0.5 0.1 0.1) 0.2))))
;; increase phase multiplier
(let ((a (line kr 1 2 10 do-nothing)))
(audition
(out 0 (mul (fb-sine-c ar sample-rate 1 0 a 0.5 0.1 0.1) 0.2))))
;; randomly modulate parameters
(let* ((x (mouse-x kr 1 12 0 0.1))
(f (lambda (m a) (mul-add (lf-noise2 kr x) m a))))
(audition
(out 0 (mul (fb-sine-c ar
(f 1e4 1e4)
(f 32 33)
(f 0.5 0)
(f 0.05 1.05)
(f 0.3 0.3)
0.1
0.1)
0.2))))