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

128 lines
3 KiB
Racket

#lang scribble/manual
@(require (for-label racket))
@title{BinaryOpUGen}
Apply a binary operation to the values of an input UGen@section{related}
Classes/UnaryOpUGen, Classes/BinaryOpFunction, Classes/Pbinop, Overviews/Operators
@section{categories}
UGens>Algebraic
@section{description}
BinaryOpUGens are created as the result of a binary operator applied to a link::Classes/UGen::.
@racketblock[
(SinOsc.ar(200) * ClipNoise.ar).dump;
(SinOsc.ar(200).thresh(0.5)).dump;
::
The use of the binary operators ]
@racketblock[*:: and ]
@racketblock[thresh:: above each instantiate a BinaryOpUGen. The operators themselves (which are methods) are not to be confused with the resulting BinaryOpUGen (which is an object). The unary and binary operators are defined in link::Classes/UGen::'s superclass link::Classes/AbstractFunction::, which creates the
BinaryOpUGen as a result of the operation.
When operating on UGens instead of numbers, what results is not a result of the calculation, but a structure that represents that calculation. For the immediate operations on numbers, see for example link::Classes/SimpleNumber::.
See link::Overviews/Operators:: for an overview of common operators.
]
@section{classmethods}
@section{private}
new1
@section{method}
new
return a new instance that applies the operator
@racketblock[selector:: to the UGens ]
@racketblock[a:: and ]
@racketblock[b:: normally, this is implicitly called when applying an operator to a link::Classes/UGen::.
]
@section{argument}
selector
The selector symbol for the binary operator
@section{argument}
a
left operand
@section{argument}
b
right operand
@section{returns}
A new instance of BinaryOpUGen
@section{instancemethods}
@section{private}
init, optimizeGraph, constantFolding
@section{examples}
@racketblock[
a = WhiteNoise.ar; // a WhiteNoise
b = a + 2; // a BinaryOpUGen.
b.operator; // +
// sound example
(
{
var a = LFSaw.ar(300);
var b = LFSaw.ar(329.1);
a % b * 0.1
}.play;
)
::
]
@section{subsection}
The comparison operators
The operators
@racketblock[ >, >=, <, <= :: are particularly useful for triggering. They should not be confused with their use in conditionals. Compare:
]
@racketblock[
if(1 > 0) { "1 is greater than 0".postln }; // > returns a boolean
::
with
]
@racketblock[
// trigger an envelope
(
{
var trig;
trig = SinOsc.ar(1) > 0.1;
EnvGen.kr(Env.perc, trig, doneAction: Done.none) * SinOsc.ar(440,0,0.1)
}.play
) // > outputs 0 or 1
::
See link::Overviews/Operators:: or the implementation of these in link::Classes/AbstractFunction:: for more detail.
Since the equality operator ( ]
@racketblock[==:: ) is used to distinguish objects including UGens, it cannot be used to create a BinaryOpUGen by application. Instead, to get a trigger value each time two signals are the same (instead of just finding out whether two UGens are the same), one can instantiate a BinaryOpUGen directly:
]
@racketblock[
(
{
var a = SinOsc.ar(1).round(0.1);
var b = SinOsc.ar(1.2).round(0.1);
BinaryOpUGen('==', a, b) * 0.1
}.play;
)
::
]