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

74 lines
1.7 KiB
Racket

#lang scribble/manual
@(require (for-label racket))
@title{PlazyEnvir}
instantiate new patterns from a function@section{related}
Classes/Plazy, Classes/PlazyEnvirN, Classes/Pfunc
@section{categories}
Streams-Patterns-Events>Patterns>Function
@section{description}
Evaluates a function that returns a pattern and embeds it in a stream. In difference to link::Classes/Plazy::, the function is evaluated using the environment passed in by the stream.
@section{ClassMethods}
@section{method}
new
@section{argument}
func
A link::Classes/Function:: that returns a pattern or any other valid pattern input.
@section{Examples}
@racketblock[
(
a = PlazyEnvir({ arg a=0, b=1; Pshuf([a, a, b], 2) }); // a, b default to 0,1
x = Pn(a, inf).asStream;
10.do { x.next.postln }; Post.nl;
e = (a:100);
10.do { x.next(e).postln }; Post.nl;
e = (a:100, b:200);
10.do { x.next(e).postln };
)
//PlazyEnvir used to produce a Pbind:
(
SynthDef(\help_sinegrain,
{ arg out=0, freq=440, sustain=0.05, pan=0;
var env;
env = EnvGen.kr(Env.perc(0.01, sustain, 0.2), doneAction: Done.freeSelf);
Out.ar(out, Pan2.ar(SinOsc.ar(freq, 0, env), pan))
}).add;
a = PlazyEnvir({ arg g=0, h=0, dur=1;
postf("g: %, h: %, dur: %\n", g, h, dur);
Pbind(
\instrument, \help_sinegrain,
\dur, dur,
\degree, Pseq([g, g, h, g, h], 2)
)
});
)
// different variants
(a <> (g: 0, h: 3, dur:0.2)).play; // single stream
(a <> (g: [0, 4], h: [3, -1], dur:0.2)).play; // same durations, two streams
::
For more about the composition operator ]
@racketblock[<>:: see: link::Classes/Pchain::.
Some parameters, like duration, cannot be used in the form of an array in the link::Classes/Pbind::. For full parallel expansion see link::Classes/PlazyEnvirN::.
]