audacia/plug-ins/tremolo.ny

52 lines
1.5 KiB
Common Lisp

;nyquist plug-in
;version 3
;type process
;preview linear
;categories "http://lv2plug.in/ns/lv2core#ModulatorPlugin"
;name "Tremolo..."
;action "Applying Tremolo..."
;author "Steve Daulton"
;copyright "Released under terms of the GNU General Public License version 2"
;; tremolo.ny by Steve Daulton (www.easyspacepro.com) July 2012.
;; Based on Tremolo by Dominic Mazzoni and David R. Sky."
;; Released under terms of the GNU General Public License version 2:
;; http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
;;
;; For information about writing and modifying Nyquist plug-ins:
;; http://wiki.audacityteam.org/wiki/Nyquist_Plug-ins_Reference
;control wave "Waveform type" choice "sine,triangle,sawtooth,inverse sawtooth,square" 0
;control phase "Starting phase (degrees)" int "" 0 -180 180
;control wet "Wet level (percent)" int "" 40 0 100
;control lfo "Frequency (Hz)" real "" 4 0 10
; Limit to sensible range
(setq lfo (min 1000 (max lfo (/ (get-duration 1)))))
; Convert % to linear
(setq wet (/ wet 200.0))
; set tremolo waveform
(setq waveform
(abs-env
(case wave
(0 *sine-table*)
(1 *tri-table*)
; sawtooth
(2 (maketable (pwlv -1 0.995 1 1 -1)))
; inverse sawtooth
(3 (maketable (pwlv -1 0.005 1 1 -1)))
; square
(4 (maketable (pwlv -1 0.005 1 0.5 1 0.505 -1 1 -1))))))
;;; Generate modulation wave
(defun mod-wave (level)
(when (= wave 0)
(setq phase (- phase 90)))
(sum (- 1 level)
(mult level
(osc (hz-to-step lfo) 1.0 waveform phase))))
(mult s (mod-wave wet))