58 lines
1.4 KiB
Racket
58 lines
1.4 KiB
Racket
#lang scribble/manual
|
|
@(require (for-label racket))
|
|
|
|
@title{(peak-follower in decay)}
|
|
|
|
|
|
Track peak signal amplitude. outputs the peak amplitude of the
|
|
signal received at the input. If level is below maximum, the level
|
|
decreases by the factor given in decay.
|
|
|
|
in - input signal.
|
|
decay - decay factor.
|
|
|
|
internally, the absolute value of the signal is used, to prevent
|
|
underreporting the peak value if there is a negative DC offset. To
|
|
obtain the minimum and maximum values of the signal as is, use the
|
|
running-min and running-max UGens.
|
|
|
|
|
|
No decay
|
|
|
|
|
|
@racketblock[
|
|
(let* ((s (mul (dust ar 20) (line kr 0 1 4 do-nothing)))
|
|
(f (mul-add (peak-follower s 1.0) 1500 200)))
|
|
(audition (out 0 (mul (sin-osc ar f 0) 0.2))))
|
|
]
|
|
|
|
A little decay
|
|
|
|
|
|
@racketblock[
|
|
(let* ((s (mul (dust ar 20) (line kr 0 1 4 do-nothing)))
|
|
(f (mul-add (peak-follower s 0.999) 1500 200)))
|
|
(audition (out 0 (mul (sin-osc ar f 0) 0.2))))
|
|
]
|
|
|
|
Mouse x controls decay
|
|
|
|
|
|
@racketblock[
|
|
(let* ((x (mouse-x kr 0.99 1.0001 1 0.1))
|
|
(s (mul (dust ar 20) (line kr 0 1 4 do-nothing)))
|
|
(f (mul-add (peak-follower s (u:min x 1.0)) 1500 200)))
|
|
(audition (out 0 (mul (sin-osc ar f 0) 0.2))))
|
|
]
|
|
|
|
Follow a sine lfo
|
|
|
|
|
|
@racketblock[
|
|
(let* ((x (mouse-x kr 0.99 1.0001 1 0.1))
|
|
(s (sin-osc kr 0.2 0))
|
|
(f (mul-add (peak-follower s (u:min x 1.0)) 200 500)))
|
|
(audition (out 0 (mul (sin-osc ar f 0) 0.2))))
|
|
]
|
|
|
|
|