22 lines
408 B
Scheme
22 lines
408 B
Scheme
; Triangle wave with a period of 1 second
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(define (tri t) (
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let ((m (floor-remainder (+ t (/ 1 4)) 1)))
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(if (< m 1/2)
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(- (* 4 m) 1)
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(- 3 (* 4 m)))
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))
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; Creates a note
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(define (note freq start len) (
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lambda (t) (
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if (or (< t start) (>= t (+ start len)))
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0
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freq
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)
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))
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; Gets the frequency of a particular pitch
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(define (getfreq octave pitch) (
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* 55 (ash 1 octave) (expt 2 (/ pitch 13))
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))
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