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

160 lines
3.1 KiB
Racket

#lang scribble/manual
@(require (for-label racket))
@title{Osc}
Interpolating wavetable oscillator.@section{related}
Classes/COsc, Classes/OscN, Classes/VOsc, Classes/VOsc3, Classes/Wavetable
@section{categories}
UGens>Generators>Deterministic
@section{description}
Linear interpolating wavetable lookup oscillator with frequency and
phase modulation inputs.
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 achieved by creating a Buffer object and sending it one of
the "b_gen" messages ( link::Classes/Buffer#-sine1::, link::Classes/Buffer#-sine2::, link::Classes/Buffer#-sine3:: ) with the wavetable flag set
to true.
This can also be achieved by creating a link::Classes/Signal:: object and sending it
the 'asWavetable' message, thereby creating a Wavetable object in the required format. Then, the wavetable data may be transmitted to the server using the link::Classes/Buffer#*sendCollection:: or link::Classes/Buffer#*loadCollection:: methods.
@section{classmethods}
@section{method}
ar, kr
@section{argument}
bufnum
Buffer index.
@section{argument}
freq
Frequency in Hertz.
@section{argument}
phase
Phase offset or modulator in radians.
(Note: phase values should be within the range +-8pi. If your phase values are larger then simply use
@racketblock[.mod(2pi):: to wrap them.)
]
@section{argument}
mul
Output will be multiplied by this value.
@section{argument}
add
This value will be added to the output.
@section{Examples}
@racketblock[
(
s = Server.local;
b = Buffer.alloc(s, 512, 1);
b.sine1(1.0/[1,2,3,4,5,6], true, true, true);
SynthDef("help-Osc",{ arg out=0,bufnum=0;
Out.ar(out,
Osc.ar(bufnum, 200, 0, 0.5)
)
}).play(s,[\out, 0, \bufnum, b.bufnum]);
)
(
s = Server.local;
b = Buffer.alloc(s, 512, 1);
b.sine1(1.0/[1,2,3,4,5,6], true, true, true);
SynthDef("help-Osc",{ arg out=0,bufnum=0;
Out.ar(out,
Osc.ar(bufnum, XLine.kr(2000,200), 0, 0.5)// modulate freq
)
}).play(s,[\out, 0, \bufnum, b.bufnum]);
)
(
s = Server.local;
b = Buffer.alloc(s, 512, 1);
b.sine1([1.0], true, true, true);
SynthDef("help-Osc",{ arg out=0,bufnum=0;
Out.ar(out,
Osc.ar(bufnum,
Osc.ar(bufnum,
XLine.kr(1,1000,9),
0,
200,
800),
0,
0.25)
)
}).play(s,[\out, 0, \bufnum, b.bufnum]);
)
(
// modulate phase
s = Server.local;
b = Buffer.alloc(s, 512, 1);
b.sine1([1.0], true, true, true);
SynthDef("help-Osc",{ arg out=0,bufnum=0;
Out.ar(out,
Osc.ar(bufnum,
800,
Osc.ar(bufnum,
XLine.kr(20,8000,10),
0,
2pi),
0.25)
)
}).play(s,[\out, 0, \bufnum, b.bufnum]);
)
(
// change the buffer while its playing
s = Server.local;
b = Buffer.alloc(s, 4096, 1);
b.sine1(1.0/[1,2,3,4,5,6], true, true, true);
SynthDef("help-Osc",{ arg out=0,bufnum=0;
Out.ar(out,
Osc.ar(bufnum, [80,80.2], 0, 0.2)
)
}).play(s,[\out, 0, \bufnum, b.bufnum]);
)
(
fork {
var n = 32;
50.do {
b.sine1(Array.rand(n,0,1).cubed, true, true, true);
0.25.wait;
};
};
)
::
]