rsc3/doc-schelp/HelpSource/Tutorials/JITLib/the_lazy_proxy.schelp

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2022-08-24 13:53:18 +00:00
title:: the_lazy_proxy
summary:: the lazy proxy
categories:: Libraries>JITLib>Tutorials
related:: Overviews/JITLib, Classes/NodeProxy, Classes/ProxySpace
The class link::Classes/NodeProxy:: (and link::Classes/BusPlug::) uses a lazy evaluation scheme to derive its appropriate rate and numChannels from the first meaningful input that is assigned to it. see link::Classes/NodeProxy:: and link::Classes/ProxySpace:: helpfiles for basic info. So as long as the source is not set, the proxy is strong::neutral:: :
code::
p = ProxySpace.push;
~x.isNeutral;
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as soon as the first time the source is set, it derives its bus arguments from that input
code::
~x = { Array.fill(14, { SinOsc.kr(1.0.rand, 0, 100) }) }; //~x is now 14 channels control rate
~x;
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in order to reset these properties, clear is used:
code::
~x.clear;
//note that no other proxy should be reading from ~x when this is done:
//for simplicity nodeproxy currently does not care for its children, only for its parents.
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for a quick initialisation, also code::defineBus:: can be used:
code::
~x.defineBus(\control, 5);
// or in another way:
~x.kr(5)
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the properties are also set when some other proxy reads from it:
code::
~x = { LFPulse.kr * ~b.kr(7) }; //the first arg to kr / ar is the default number of channels
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if no number of channels is passed in, the default value is used:
code::
~test.ar; // 2
~krtest.kr; // 1
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the default can be set in the class NodeProxy:
code::
NodeProxy.defaultNumAudio = 3;
NodeProxy.defaultNumControl = 13;
~test3.ar; // 3
~krtest3.kr; // 13
// set them back:
NodeProxy.defaultNumAudio = 2;
NodeProxy.defaultNumControl = 1;
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also if a proxy is used as a map source, control rate is assumed:
code::
~u;
~x.map(\zzz, ~u);
~u;
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when unary or binary operations are performed, the highest rate / numChannels is used to initialize all uninitialized proxies:
code::
~x.clear;
~x.defineBus(\control, 5);
~x = ~e + ~f;
~x.clear; ~e.clear; ~f.clear;
~e.defineBus(\audio, 1);
~x = ~e + ~f.squared + ~r;
~x;
~x.clear; ~e.clear; ~f.clear;
~e.defineBus(\audio, 3);
~x = ~e;
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if a rate-1 proxy is used as rate-2 input, the rate is converted and the channels are expanded in the usual multichannel expansion pattern:
code::
~f.defineBus(\control);
~f.ar(2);
~f.defineBus(\audio);
~f.kr(2);
// if the number of channels passed in is less, it only uses the first n channels
~f.defineBus(\audio, 8);
~f.ar(2);
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an offset can be passed in as second argument to ar/kr
code::
//modulate offset:
p = ProxySpace.push(s.boot);
~out.play;
~src = { SinOsc.ar(Array.rand(5, 400, 500.0), SinOsc.ar(Array.exprand(5, 2.1, 500.0)), 0.1) };
~out = { ~src.ar(1, MouseX.kr(0, 5)) };
~out = { Mix(~src.ar(3, MouseX.kr(0, 5))) }; //the wrapping offset is moved accordingly
::