42 lines
760 B
Scheme
42 lines
760 B
Scheme
(use-modules (ice-9 binary-ports))
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(define bitrate 8000)
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(define (saw 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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(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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(saw (* freq t))
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)
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))
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(define (music t) (+
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((note 523.25 0 1) t)
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((note 587.33 1 1) t)
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((note 659.25 2 1) t)
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((note 698.46 3 1) t)
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((note 783.99 4 1) t)
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))
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(define (play t) (
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cons (music t) (if (< t 5)
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(play (+ t (/ 1 bitrate)))
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'()
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)
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))
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;(display (play 0))
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(for-each (lambda (a) (
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let ((b (modulo (inexact->exact (round (* (+ a 2) 32768))) 65536)))
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cons
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(put-u8 (current-output-port) (modulo b 256))
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(put-u8 (current-output-port) (quotient b 256))
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)) (play 0))
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