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

64 lines
1.4 KiB
Racket

#lang scribble/manual
@(require (for-label racket))
@title{Pconst}
constrain the sum of a value pattern@section{related}
Classes/Pfindur, Classes/Pfin, Classes/Pfinval
@section{categories}
Streams-Patterns-Events>Patterns>Repetition
@section{description}
Similar to link::Classes/Pfindur::, but works with the value directly.
@section{note}
Be careful if this is used, directly or indirectly, for a note-length parameter! The difference may be very small and this could result in zombie nodes, due to a bug in link::Classes/EnvGen:: for very short sustain times.
::
@section{ClassMethods}
@section{method}
new
Embeds elements of the strong::pattern:: into the stream until the sum comes close enough to strong::sum::. At that point, the difference between the specified sum and the actual running sum is embedded.
@section{Examples}
@racketblock[
(
var a, x;
a = Pconst(5, Prand([1, 2, 0.5, 0.1], inf));
x = a.asStream;
9.do({ x.next(Event.default).postln; });
)
//Pconst used as a sequence of pitches
(
SynthDef(\help_sinegrain,
{ arg out=0, freq=440, sustain=0.05;
var env;
env = EnvGen.kr(Env.perc(0.01, sustain, 0.2), doneAction: Done.freeSelf);
Out.ar(out, SinOsc.ar(freq, 0, env))
}).add;
)
(
Pn(
Pbind(
\dur, Pconst(1, Prand([1, 0.02, 0.2], inf)),
\instrument, \help_sinegrain,
\degree, Pseries(0, 1, inf),
\octave, 6
)
).play;
)
::
]