;;; Synthesis of a musical tone.
;;;
;;; Creates the following files:
;;;
;;;     sine1.data
;;;     sine2.data
;;;     sine3.data

(load "/course/cs5500f14/Examples/FFT/modulate.sch")

(define sine1 (make-sine-wave 128 0.5))
(define sine2 (make-sine-wave  64 0.125))
(define sine3 (make-sine-wave  32 0.25))

(define bytes/sample 2)
(define nchannels 2)
(define samples/second 44100)
(define bytes/second (* nchannels bytes/sample samples/second))

(define n (* 10 bytes/second))    

(define signal1 (make-bytevector n 0))
(modulate! signal1 sine1 0 n)
(modulate! signal1 sine1 2 n)

(define signal2 (bytevector-copy signal1))
(modulate! signal2 sine2 (+ 0 (* 1 bytes/second)) n)
(modulate! signal2 sine2 (+ 2 (* 1 bytes/second)) n)

(define signal3 (bytevector-copy signal2))
(modulate! signal3 sine3 (+ 0 (* 2 bytes/second)) n)
(modulate! signal3 sine3 (+ 2 (* 2 bytes/second)) n)

(define (save-to-file signal filename)
    (let ((p (open-file-output-port filename)))
      (put-bytevector p signal)
      (close-output-port p)))

(save-to-file signal1 "sine1.data")
(save-to-file signal2 "sine2.data")
(save-to-file signal3 "sine3.data")

; sine3