Synth argument value , how come?

1

I tried to understand below link’s play method.
https://sccode.org/1-58T

synth argument \gate is not set in pbind.
But \gate value is changing.
(I check \gate value with poll )

What is this logic?
My understanding , \gate dose not have value cause not set value in pbind.

(
SynthDef(\gabberkick, {
    var snd, freq, high, lfo;
    freq = \freq.kr(440) * (Env.perc(0.001, 0.08, curve: -1).ar * 48 * \bend.kr(1)).midiratio;
    snd = Saw.ar(freq);
    snd = (snd * 100).tanh + ((snd.sign - snd) * -8.dbamp);
    high = HPF.ar(snd, 300);
    lfo = SinOsc.ar(8, [0, 0.5pi]).range(0, 0.01);
    high = high.dup(2) + (DelayC.ar(high, 0.01, lfo) * -2.dbamp);
    snd = LPF.ar(snd, 100).dup(2) + high;
    snd = RLPF.ar(snd, 7000, 2);
    snd = BPeakEQ.ar(snd, \ffreq.kr(3000) * XLine.kr(1, 0.8, 0.3), 0.5, 15);
    snd = snd * Env.asr(0.001, 1, 0.05).ar(2, \gate.kr(1).poll );
    Out.ar(\out.kr(0), snd * \amp.kr(0.1)  );
}).add;


//a=Synth(  \gabberkick ,[\freq:60 , \bend:1] );
//a.set(   \freq,60  ,\bend,1/2 , \ffreq, rand(1000,10000) , \amp,-23.dbamp   );


SynthDef(\hoover, {
    var snd, freq, bw, delay, decay;
    freq = \freq.kr(440);
    freq = freq * Env([-5, 6, 0], [0.1, 1.7], [\lin, -4]).kr.midiratio;
    bw = 1.035;
    snd = { DelayN.ar(Saw.ar(freq * ExpRand(bw, 1 / bw)) + Saw.ar(freq * 0.5 * ExpRand(bw, 1 / bw)), 0.01, Rand(0, 0.01)) }.dup(20);
    snd = (Splay.ar(snd) * 3).atan;
    snd = snd * Env.asr(0.01, 1.0, 1.0).kr(0, \gate.kr(1));
    snd = FreeVerb2.ar(snd[0], snd[1], 0.3, 0.9);
    snd = snd * Env.asr(0, 1.0, 4, 6).kr(2, \gate.kr(1));
    Out.ar(\out.kr(0), snd * \amp.kr(0.1));
}).add;
)

(
var durations;
durations = [1, 1, 1, 1, 3/4, 1/4, 1/2, 3/4, 1/4, 1/2];
Ppar([
    Pbind(*[
        instrument: \gabberkick,
        amp: -23.dbamp,
        freq: 60,
        legato: 0.8,
        ffreq: Pseq((0..(durations.size * 4 - 1)).normalize, inf).linexp(0, 1, 100, 4000),
        dur: Pseq(durations, inf),
        bend: Pfuncn({ |x| if(x < (1/2), 0.4, 1) }, inf) <> Pkey(\dur),
    ]),
    Pbind(*[
        instrument: \hoover,
        amp:   0.01 ,//-20.dbamp,
        midinote: 74,
        dur: durations.sum * 2,
        sustain: 7,
    ])
]).play(TempoClock(210 / 60));
)
2

gate is set in the default event prototype.

The division of labor has a couple of layers – this is not obvious at first.

  • The Pbind (pattern) layer only generates data into an Event object. It doesn’t set anything in the server.

  • When the Event is played, it looks inside the event for a play function and runs that.

  • In the default event prototype, this looks up an event type function. This function uses parameters in the event to take action.

Maybe you’re assuming that playing the event only sends the event’s parameters to the synth. But it might do more than that. The default event type, \note, also releases the synth automatically. To do this, it must set the gate to 0 after a delay. Otherwise an automatic gate release is impossible (and we all want it to be possible :grin: ).

hjh