rsc3/doc/examples/ugen/oscillators/v-osc.help.scm

52 lines
1.6 KiB
Scheme

;; (v-osc rate bufpos freq phase)
;; Variable wavetable oscillator. A wavetable lookup oscillator which
;; can be swept smoothly across wavetables. All the wavetables must be
;; allocated to the same size. Fractional values of table will
;; interpolate between two adjacent tables.
;; This oscillator requires a buffer to be filled with a wavetable
;; format signal. This preprocesses the Signal into a form which can
;; be used efficiently by the oscillator. The buffer size must be a
;; power of 2.
;; This can be acheived by creating a Buffer object and sending it one
;; of the "b_gen" messages ( sine1, sine2, sine3 ) with the wavetable
;; flag set to true.
;; This can also be acheived by creating a Signal object and sending
;; it the 'asWavetable' message, saving it to disk, and having the
;; server load it from there.
;; Note about wavetables: Vosc requires the b_gen sine1 wavetable flag
;; to be ON.
;; Allocate and fill tables 0 to 7 [see also Vosc3]
(with-sc3
(lambda (fd)
(let* ((square
(lambda (a) (* a a)))
(nth
(lambda (i)
(async fd (b-alloc i 1024 1))
(let* ((n (expt (+ i 1) 2))
(a (map1 (lambda (j) (square (/ (- n j) n)))
(enum-from-to 0 (- n 1)))))
(async fd (b-gen1 i "sine1" (cons 7 a)))))))
(for-each nth (enum-from-to 0 7)))))
;; oscillator at buffers 0 through 7.
(let ((b (mouse-x kr 0 7 0 0.1))
(f (mce2 120 121)))
(audition (out 0 (mul (v-osc ar b f 0) 0.3))))
;; Reallocate buffers while oscillator is running.
(with-sc3
(lambda (fd)
(for-each
(lambda (i)
(async fd (b-gen1 i "sine1" (cons 7 (replicate-m 16 (random 0 1))))))
(enum-from-to 0 7))))