SuperCollider CLASSES

Pdefn

non event stream reference definition

Description

Pdefn provides an interface to its superclass PatternProxy, keeping a reference to a stream that can be replaced while playing. One pattern may be used in many streams in different places. A change in the pattern definition propagates through all streams.

Pdef and Pdefn use separate global collections.

Pdefn(key)    //returns the instance
Pdefn(key, pat)    //defines the pattern and returns the instance, like Pdef, Tdef and Ndef.

It is very similar to PatternProxy.

Pdefn can be used to store value patterns globally (for event patterns, see Pdef). Overview: JITLib

First Example

s.boot;

Pdefn(\x, Pbrown(0, 6, 0.1, inf));
Pbind(\note, Pdefn(\x), \dur, 0.3).play;
Pbind(\note, Pdefn(\x), \dur, 0.1, \ctranspose, 15).play;
// now change the definition
Pdefn(\x, Pseq([0, 3, 5, 7, 9, 11], inf));
Pdefn(\x, Pseq([0, 3, 3, 7], inf) + Pseq([0, [0, 3], [0, 5, 7]], inf));

Class Methods

Creation

*new (key, item)

Store the pattern in a global dictionary under key, replacing its pattern with the new one. If the pattern is a function, Pdefn creates a Prout with this function, passing in the envir, if given(see below).

Using *new(key) you can access the pattern at that key (if none is given, a default silent event is created)

// pattern as an argument
Pdefn(\x, Pseq([1, 2, 5, 6, 7], inf));
Pdefn(\x); // omitting the second argument, we can access the proxy
Pdefn(\x).asStream.nextN(20); // ... play one event stream
Pdefn(\x).source.postcs; // ... and inspect the event pattern itself.


// function as an argument, create a new pattern each time it is called
Pdefn(\x, { Pseq({ 10.rand } ! 8) });
Pn(Pdefn(\x)).asStream.nextN(16);

// the function is called in the incoming event as current environment, so parameters can be passed:
Pdef(\stut, { Pstutter(~stutter ? 1, ~pattern) }); // we use here a Pdef (not a Pdefn!)
Pdefn(\y, Pdef(\stut) <> (pattern: Pdefn(\x), stutter: Pseq([2, 2, 4, 3], inf))).asStream.nextN(16);

*default

From superclass: PatternProxy

Default source, if none is given. The default is a Pattern that returns 1.0 (This is 1 and not 0 to avoid deadlocks when used as a duration pattern. In a sense, 1 is just as generic as 0).

*removeAll

From superclass: PatternProxy

Remove all proxies from the global dictionary ( *all)

*clear

From superclass: PatternProxy

Clear all proxies, setting their source to silence.

*all

*all = value

Set or return the environment ( IdentityDictionary ) that stores all Pdefns.

Inherited class methods

Undocumented class methods

*hasGlobalDictionary

Instance Methods

Inherited instance methods

Undocumented instance methods

-copy (toKey)

-key

-map ( ... args)

Examples

Pdefn in expressions

Pdefn(\c, Pdefn(\a) + Pdefn(\b));

t = Pdefn(\c).asStream; // create a stream from Pdefn(\c)

t.value; // default value for a Pdefn is 1, so that it is a good time value default.

Pdefn(\a, 100); // (re)define Pdefn(\a) as 100

t.value;

Pdefn(\b, Pseq([1, 2, 3], inf)); // (re)define Pdefn(\b) as Pseq([1, 2, 3], inf)

3.do { t.value.postln };

Pdefn(\c, Pdefn(\a) * Pdefn(\b) - Pdefn(\a)); // (re)define Pdefn(\c)

8.do { t.value.postln };

Pdefn(\a, Prand([1, 4, 2], inf)); // (re)define Pdefn(\a)

Embedding Pdefn in other patterns

Pdefn(\x, Pseq([1, 2, 3], inf));

x = Pseq([0, 0, Pdefn(\x)], inf).asStream;

t = Task({ loop({ x.next.postln; 0.3.wait }) }).play;


Pdefn(\x, Pseq([55, 66, 77],inf));
Pdefn(\x, Pseq([55, 66, 77],1));

t.stop;



// Pdefn can be accessed in multiple streams

(
SynthDef("Pdefhelp", { arg out, freq, sustain=1, amp=1, pan;
    var env, u=1;
    env = EnvGen.kr(Env.perc(0.03, sustain), 1, doneAction:2);
    5.do { var d; d = exprand(0.01, 1); u = SinOsc.ar(d * 300, u, rrand(0.1,1.2) * d, 1) };
    Out.ar(out, Pan2.ar(SinOsc.ar(u + 1 * freq, 0, amp * env), pan));

}).add;
s.boot;
)

(
Pdefn(\deg, Pseq([0, 3, 2],inf));

Pset(\instrument, \Pdefhelp,
    Ppar([
        Pbind(\degree, Pdefn(\deg), \pan, -0.8),
        Pbind(\degree, Pdefn(\deg), \dur, 1/3, \pan, 0.8)
])
).play;
)

Pdefn(\deg, Prand([0, 3, [1s, 4]],inf));

Pdefn(\deg, Pn(Pshuf([0, 3, 2, 7, 6],2),inf));

(
Pdefn(\deg, Plazy { var pat;
    pat = [Pshuf([0, 3, 2, 7, 6],2), Pseries(0, 1, 11), Pseries(11, -1, 11)].choose;
    Pn(pat, inf)
});
)

Timing

When does the definition change?

If quant is set, the update is done at the next beat or whatever is specified:

Pdefn(\deg).quant = 4;
Pdefn(\deg, Pn(Pseries(0, 1, 8),inf));

Pdefn(\deg).quant = nil; // activate immediately again

(
Pdefn(\deg, {
    loop {
    5.do { |i|
        #[1, 3, 4].choose.yield;
        #[5, 0, 12].choose.yield;
        #[14, 3, 4].choose.do { |j| (i % j).postln.yield };
    }
    }
})
)

update condition

In order to be able to switch to a new pattern under a certain condition, the instance variable condition can be set to a function that returns a boolean. Value and a count index are passed to the function. The condition is always valid for the next pattern inserted. For stuck conditions, the reset message can be used.

As counting up (such as "every nth event, a swap can happen") is a common task, there is a method for this, called count(n).

z = Pbind(\degree, Pdefn(\x, \), \dur, 0.25).play;
Pdefn(\x, Pseq((0..5), inf)).condition_({ |val, i| i.postln % 6 == 0 });
Pdefn(\x, Pseq((7..0), inf)).condition_({ |val, i| i.postln % 8 == 0 });


// the above is equvalent to:
Pdefn(\x, Pseq((7..0), inf)).count(8);

Reset

// reset to change immediately:
Pdefn(\x).reset;

Pdefn(\x).stop;

Functions as arguments to Pdefn

Pdefn(\deg, { loop { yield(0.1.rand.round(0.01) + [2, 3, 9].choose) } });

// equivalent to:

Pdefn(\deg, Prout { loop { yield(0.1.rand.round(0.01) + [2, 3, 9].choose) } });

// this is not exactly true, see below..

The (inner) environment

// set() creates a local environment that overrides the outer currentEnvironment

Pdefn(\z).set(\a, 1, \b, 5);
(
Pdefn(\z, { |e|
    loop { yield((e.a + e.b) + 0.1.rand.round(0.01)) }
})
); // [1]

t = Pdefn(\z).asStream;

t.nextN(3);

(
Pdefn(\z, { |e|
    //(e.a + e.b) + 0.1.rand.round(0.01) 1
    Pseq([1, 2, e.a], 1)
})
);

Pdefn(\z, Pseq([1, 2, 3], 1));

e = Pdefn(\z).envir


Pdefn(\z).set(\a, 3);

t.next;

Pdefn(\z).set(\a, Pseq([1, 2, 3], inf));

t.reset;
t.nextN(3);

Pdefn(\z).envir; // post the envir



// if you want to keep using the currentEnvironment at the same time,
// assign the currentEnvironment to the envir's parent (or proto) field
// (this shouldn't be a proxy space of course.)

Pdefn(\z).envir.parent = currentEnvironment;
~a = 9;
~b = 10;

t.nextN(3);