rsc3/doc-schelp/HelpSource/Classes/BufDelayN.scrbl

92 lines
1.9 KiB
Racket

#lang scribble/manual
@(require (for-label racket))
@title{BufDelayN}
Buffer based simple delay line with no interpolation.@section{related}
Classes/BufDelayC, Classes/BufDelayL, Classes/DelayN
@section{categories}
UGens>Delays>Buffer
@section{description}
Simple delay line with no interpolation which uses a buffer for its
internal memory. See also link::Classes/BufDelayL:: which uses linear
interpolation, and link::Classes/BufDelayC:: which uses cubic
interpolation. Cubic interpolation is more computationally expensive
than linear, but more accurate.
@section{classmethods}
@section{method}
ar, kr
@section{argument}
buf
Buffer number.
@section{note}
The buffers provided to any of the BufDelay units must be one channel. If you want to delay a multichannel signal, you must provide as many separate (one-channel) buffers as there are input channels.::
@section{argument}
in
The input signal.
@section{argument}
delaytime
Delay time in seconds.
@section{argument}
mul
@section{argument}
add
@section{discussion}
@section{Warning}
For reasons of efficiency, the effective buffer size is limited to the previous power of two. So, if 44100 samples are allocated, the maximum delay would be 32768 samples.
::
@section{Examples}
@racketblock[
// allocate buffer
b = Buffer.alloc(s,44100,1);
(
// Dust randomly triggers Decay to create an exponential
// decay envelope for the WhiteNoise input source
{
z = Decay.ar(Dust.ar(1,0.5), 0.3, WhiteNoise.ar);
BufDelayN.ar(b.bufnum, z, 0.2, 1, z); // input is mixed with delay via the add input
}.play
)
b.free;
// multichannel
// two channels, two buffers
b = Buffer.allocConsecutive(2, s, 32768, 1);
a = { |bufs = #[0, 1]|
var sig = SinOsc.ar([440, 880]) * Decay2.kr(Impulse.kr([2, 4]), 0.01, 0.15);
sig + BufDelayN.ar(bufs, sig, delaytime: 0.125)
}.play(args: [bufs: b]);
a.free;
b.do(_.free);
::
]