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

@title{IndexL}
 Index into a table with a signal, linear interpolated@section{categories}
  UGens>Buffer
@section{related}
  Classes/Index, Classes/IndexInBetween

@section{description}

The input signal value is used as an index into the table, with linear interpolation.
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{examples}
 

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

// with mouse control
(
{
	SinOsc.ar(
		IndexL.kr(
			LocalBuf.newFrom([ 200, 300, 400, 500, 600, 800 ].scramble),
			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(
			IndexL.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(
			IndexL.kr(
				i_bufnum,
				MouseX.kr(0, BufFrames.ir(i_bufnum))
			),
			0,
			0.5
		)
	)
}).play(s, [\i_bufnum, b]);
)

b.free;
::
]