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

118 lines
1.6 KiB
Racket

#lang scribble/manual
@(require (for-label racket))
@title{LinExp}
Map a linear range to an exponential range@section{related}
Classes/LinLin
@section{categories}
UGens>Maths
@section{description}
Converts a linear range of values to an exponential range of values.
@section{classmethods}
@section{method}
ar, kr
@section{argument}
in
The input signal to convert.
@section{argument}
srclo
Lower limit of input range.
@section{argument}
srchi
Upper limit of input range.
@section{argument}
dstlo
Lower limit of output range.
@section{argument}
dsthi
Upper limit of output range.
@section{discussion}
The
@racketblock[dstlo:: and ]
@racketblock[dsthi:: arguments
must be nonzero and have the same sign.
]
@section{Examples}
@racketblock[
// compare:
(
{
var mod = SinOsc.kr(Line.kr(1, 10, 10));
SinOsc.ar(mod * 400 + 500) * 0.1
}.play;
)
(
{
var mod = SinOsc.kr(Line.kr(1, 10, 10));
SinOsc.ar(LinExp.kr(mod, -1,1, 100, 900)) * 0.1
}.play;
)
// modulating destination values.
(
{
var mod = LFNoise2.ar(80);
SinOsc.ar(LinExp.ar(mod, -1,1, MouseX.kr(200, 8000, 1), MouseY.kr(200, 8000, 1))) * 0.1
}.play;
)
::
]
@racketblock[linexp:: and ]
@racketblock[exprange:: can be used to create a LinExp implicitly from a ugen, mapping its output values from linear range to an exponential one. The rate is derived from the ugen.
]
@racketblock[
// linexp
(
{
var mod = LFNoise2.ar(80);
SinOsc.ar(mod.linexp(-1,1, MouseX.kr(200, 8000, 1), MouseY.kr(200, 8000, 1))) * 0.1
}.play;
)
// exprange
(
{
var mod = LFNoise2.ar(80).exprange(MouseX.kr(200, 8000, 1), MouseY.kr(200, 8000, 1));
SinOsc.ar(mod) * 0.1
}.play;
)
::
]