38 lines
1.1 KiB
Racket
38 lines
1.1 KiB
Racket
#lang scribble/manual
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@(require (for-label racket))
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@title{(sweep trig rate)}
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triggered linear ramp. Starts a linear raise by rate/sec from zero
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when trig input crosses from non-positive to positive.
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Using sweep to modulate sine frequency
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(let* ((t (impulse kr (mouse-x kr 0.5 20 1 0.1) 0))
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(f (add (sweep t 700) 500)))
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(audition (out 0 (mul (sin-osc ar f 0) 0.2))))
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Using sweep to index into a buffer
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(with-sc3
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(lambda (fd)
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(async fd (b-alloc-read 0 "/home/rohan/audio/metal.wav" 0 0))))
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(let* ((t (impulse ar (mouse-x kr 0.5 20 1 0.1) 0))
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(i (sweep t (buf-sample-rate ir 0))))
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(audition (out 0 (buf-rd 1 ar 0 i 0 2))))
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Backwards, variable offset
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(let* ((t (impulse ar (mouse-x kr 0.5 10 1 0.1) 0))
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(r (buf-sample-rate ir 0))
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(i (add (sweep t (neg r)) (mul (buf-frames ir 0) (lf-noise0 kr 15)))))
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(audition (out 0 (buf-rd 1 ar 0 i 0 2))))
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Raising rate
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(let* ((t (impulse ar (mouse-x kr 0.5 10 1 0.1) 0))
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(r (add (sweep t 2) 0.5))
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(i (sweep t (mul (buf-sample-rate ir 0) r))))
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(audition (out 0 (buf-rd 1 ar 0 i 0 2))))
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