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

#lang scribble/manual
@(require (for-label racket))

@title{Index}
 Index into a table with a signal@section{related}
  Classes/WrapIndex, Classes/Shaper
@section{categories}
   UGens>Buffer

@section{description}

Index into a table with a signal.
The input signal value is truncated to an integer value and used as an
index into the table. Out-of-range index values are clipped to the valid
range.

@section{classmethods}
 

@section{method}
 ar, kr

@section{argument}
 bufnum
Index of the buffer.

@section{argument}
 in
The input signal.

@section{argument}
 mul
Output will be multiplied by this value.

@section{argument}
 add
This value will be added to the output.


@section{Examples}
 

@racketblock[
// indexing into a fixed table
(
{
	SinOsc.ar(
			Index.kr(
				LocalBuf.newFrom([ 200, 300, 400, 500, 600, 800 ]),
				LFSaw.kr(2.0).range(0, 7)
			),
			0,
			0.5
		)
}.play;
)

// with mouse control
(
{
	SinOsc.ar(
			Index.kr(
				LocalBuf.newFrom([ 200, 300, 400, 500, 600, 800 ]),
				MouseX.kr(0, 7)
			),
			0,
			0.5
		)
}.play;
)

(
// indexing into a changeable table
s = Server.local;
t = [ 200, 300, 400, 500, 600, 800 ];
b = Buffer(s, t.size, 1);

// alloc and set the values
s.listSendMsg( b.allocMsg( b.setnMsg(0, t) ).postln );

SynthDef(\help_Index, { arg out = 0, i_bufnum = 0;
	Out.ar(0,
		SinOsc.ar(
			Index.kr(
				i_bufnum,
				LFSaw.kr(2).range(0, 7)
			),
			0,
			0.5
		)
	)
}).play(s, [\i_bufnum, b]);
)

b.setn(*[ 200, 300, 400, 500, 600, 800 ].scramble.postln - 30);


(
SynthDef(\help_Index, { arg out=0,i_bufnum=0;
	Out.ar(0,
		SinOsc.ar(
			Index.kr(
				i_bufnum,
				MouseX.kr(0, BufFrames.ir(i_bufnum))
			),
			0,
			0.5
		)
	)
}).play(s, [\i_bufnum, b]);
)

b.free;
::

]