A UGen that reads buses that are local to the enclosing synth. These buses should be written using a LocalOut ugen. They behave like regular buses, but are more convenient for the implementation of a self contained effect that uses a feedback processing loop.

In a synth, there can be only each one control-rate and audio-rate LocalIn / LocalOut pair. The signal written to a LocalOut will not be read by the LocalIn until the next control block cycle, introducing a delay of ControlDur .

Warning: The argument has been changed numChannels: Int in version 1.15.3 to init: GE in version 1.16.0. The previous version was incompatible with SuperCollider 3.6.x. A previous usage such as LocalIn.ar(2) to create two channels must now be expressed as LocalIn.ar(Seq(0, 0)) !

Examples

// ping-pong delay with feedback
play {
  val src = Decay.ar(Impulse.ar(0.3), 0.1) * WhiteNoise.ar(0.2)
  val in  = LocalIn.ar(Seq(0, 0)) + Seq[GE](src, 0) // read feedback, add source to left chan
  val dly = DelayN.ar(in, 0.2, 0.2)         // delay sound
  val att = dly * 0.8                       // apply decay factor

  // reverse channels to give ping pong effect
  LocalOut.ar(Seq(att.out(1), dly.out(0)))
  dly
}

// tank
play {
  val tones = Mix.fill(12) {
    Pan2.ar(
      Decay2.ar(Dust.ar(0.05), 0.1, 0.5) * 0.1 *
        FSinOsc.ar(IRand(36,84).midiCps).cubed.max(0),
      Rand(-1,1))
  }
  val gen = tones + Pan2.ar(Decay2.ar(Dust.ar(0.03), 0.04, 0.3) * BrownNoise.ar, 0)

  val verb = Mix.fold(gen, 4) { z =>
    AllpassN.ar(z, 0.03, Seq.fill(2)(Rand(0.005,0.02)), 1)
  }

  val in  = LocalIn.ar(Seq(0, 0)) * 0.98
  val flt = OnePole.ar(in, 0.5)

  val pan = Rotate2.ar(flt.out(0), flt.out(1), 0.23)
  val v1  = AllpassN.ar(pan, 0.05, Seq.fill(2)(Rand(0.01,0.05)), 2)
  val v2  = DelayN.ar(v1, 0.3, Seq(0.19,0.26))
  val v3  = AllpassN.ar(v2 , 0.05, Seq.fill(2)(Rand(0.03,0.15)), 2)
  val out = LeakDC.ar(v3)
  val sig = gen + out

  LocalOut.ar(sig)
  sig
}

// resonator
play {
  val imp  = Impulse.ar
  val in   = LocalIn.ar
  val feed = imp + in * 0.995
  // must subtract block-size for correct tuning
  // (try removing the ControlDur to here the pitch change)
  val time = 440.reciprocal - ControlDur.ir
  val dly  = DelayC.ar(feed, time, time)
  LocalOut.ar(dly)

  // alternate between feedback and reference pitch
  val comp = Seq(dly, SinOsc.ar(440) * 0.2): GE
  comp * LFPulse.kr(1, Seq(0.0, 0.5))
}