EnvGen

An envelope generator UGen. It uses a break point description in its envelope input, typically coming from an Env object. The envelope may be re-triggered using the gate input. Upon start and upon re-triggering, the envelope , levelScale , levelBias and timeScale parameters are polled and remain constant for the duration of the envelope.

To construct a manual envelope without the use of the Env class, the format should be as follows:

val env = Seq[GE](startLevel, numSegments, releaseNode, loopNode,
targetLevel1, duration1, curveType1, curvature1,
targetLevel2, duration2, curveType2, curvature2,
...)

Where the curve-type is one of Curve.step.id , Curve.lin.id , Curve.exp.id , etc. The curvature values are only relevant for the parametric curve type. The releaseNode and loopNode parameters are segment indices or the special value -99 indicating that there are no release or loop segments.

Note: The actual minimum duration of a segment is not zero, but one sample step for audio rate and one block for control rate. This may result in asynchronicity when in two envelopes of different number of levels, the envelope times add up to the same total duration. Similarly, when modulating times, the new time is only updated at the end of the current segment; this may lead to asynchronicity of two envelopes with modulated times.

Examples

// percussive one-shot
play { PinkNoise.ar(EnvGen.kr(Env.perc, doneAction = freeSelf)) }

// fixed duration amplitude envelope
play {
  val env = Env(0, Seq(0.01 -> 1, 0.5 -> 0.5, 0.02 -> 1, 0.5 -> 0))
  SinOsc.ar(470) * EnvGen.kr(env, doneAction = freeSelf)
}

// amplitude and frequency modulation
play {
  val env  = Env(0, Seq(0.01 -> 1, 0.5 -> 0.5, 0.02 -> 0.8, 0.5 -> 0, 0.2 -> 1.2, 0.5 -> 0))
  val gate = Impulse.kr(MouseX.kr(0.2, 3), 0.5)
  val gen  = EnvGen.kr(env, gate)
  SinOsc.ar(270, SinOsc.ar(gen * 473)) * gen * 0.2
}

// Dust-triggered envelope
play {
  val c   = Curve.parametric(-4)
  val env = Env(0, Seq((0.05,0.5,c), (0.1,0.0,c), (0.01,1.0,c), (1.0,0.9,c), (1.5,0.0,c)))
  val gen = EnvGen.ar(env, Dust.ar(1))
  SinOsc.ar(gen * 1000 + 440) * gen * 0.1
}

// two channels
play {
  val p = Curve.parametric(-4)

  def mkEnv(a: Double, b: Double) = {
    val env = Env(0.0, Seq((0.05,a,p), (0.1,0.0,p), (0.01,1.0,p), (1.0,b,p), (1.5,0.0,p)))
    EnvGen.ar(env, Dust.ar(1))
  }

  val gen: GE = Seq(mkEnv(-0.2, -0.4), mkEnv(0.5, 0.9))
  SinOsc.ar(gen * 440 + 550) * gen * 0.1
}

// control gate and done-action
val x = play {
  var gen = EnvGen.kr(Env.adsr(), "gate".kr(0), doneAction = "done".kr(0))
  SinOsc.ar(440) * gen * 0.1
}

x.set("gate" -> 1)  // turn on
x.set("gate" -> 0)  // turn off
x.set("gate" -> 1)  // turn on
x.set("done" -> freeSelf.id, "gate" -> 0) // turn off and free

// fast triggering
play {
  val freq = MouseX.kr(1, 100, 1)
  val gate = Impulse.ar(freq)
  val env  = Env.perc(0.1, 0.9)
  val gen  = EnvGen.ar(env, gate = gate, timeScale = freq.reciprocal)
  SinOsc.ar(440) * gen * 0.1
}

See also: Decay
Linen
XLine
Line
IEnvGen
Env

Linear Supertypes

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def ar(envelope: GE, gate: GE = 1, levelScale: GE = 1.0f, levelBias: GE = 0.0f, timeScale: GE = 1.0f, doneAction: GE = doNothing): EnvGen

envelope
the description of the envelope break-points. Typically you pass an instance of Env which will then automatically expand to the correct format.
gate
triggers the envelope and holds it open while greater than zero. If the envelope is of fixed duration (e.g. Env.linen , Env.perc ), the gate argument is used as a simple trigger. If it contains a sustained segment (e.g. Env.adsr , Env.asr ), the envelope is held open until the gate becomes 0, at which point is released. If gate is less than zero, a release is enforced with duration -1.0 - gate .
levelScale
amplitude factor with which the nominal envelope is multiplied.
levelBias
amplitude offset which is added to the nominal envelope.
timeScale
time scale factor with which the envelope segment durations are multiplied.
doneAction
action to be performed when the envelope reaches its end point.
final def asInstanceOf[T0]: T0

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def clone(): AnyRef

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final def eq(arg0: AnyRef): Boolean

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def kr(envelope: GE, gate: GE = 1, levelScale: GE = 1.0f, levelBias: GE = 0.0f, timeScale: GE = 1.0f, doneAction: GE = doNothing): EnvGen

envelope
the description of the envelope break-points. Typically you pass an instance of Env which will then automatically expand to the correct format.
gate
triggers the envelope and holds it open while greater than zero. If the envelope is of fixed duration (e.g. Env.linen , Env.perc ), the gate argument is used as a simple trigger. If it contains a sustained segment (e.g. Env.adsr , Env.asr ), the envelope is held open until the gate becomes 0, at which point is released. If gate is less than zero, a release is enforced with duration -1.0 - gate .
levelScale
amplitude factor with which the nominal envelope is multiplied.
levelBias
amplitude offset which is added to the nominal envelope.
timeScale
time scale factor with which the envelope segment durations are multiplied.
doneAction
action to be performed when the envelope reaches its end point.
final def ne(arg0: AnyRef): Boolean

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final def notify(): Unit

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final def notifyAll(): Unit

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final def synchronized[T0](arg0: ⇒ T0): T0

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def toString(): String

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final def wait(): Unit

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final def wait(arg0: Long): Unit

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object EnvGen extends Serializable

Examples

Value Members

final def !=(arg0: AnyRef): Boolean

final def !=(arg0: Any): Boolean

final def ##(): Int

final def ==(arg0: AnyRef): Boolean

final def ==(arg0: Any): Boolean

def ar(envelope: GE, gate: GE = 1, levelScale: GE = 1.0f, levelBias: GE = 0.0f, timeScale: GE = 1.0f, doneAction: GE = doNothing): EnvGen

final def asInstanceOf[T0]: T0

def clone(): AnyRef

final def eq(arg0: AnyRef): Boolean

def equals(arg0: Any): Boolean

def finalize(): Unit

final def getClass(): Class[_]

def hashCode(): Int

final def isInstanceOf[T0]: Boolean

def kr(envelope: GE, gate: GE = 1, levelScale: GE = 1.0f, levelBias: GE = 0.0f, timeScale: GE = 1.0f, doneAction: GE = doNothing): EnvGen

final def ne(arg0: AnyRef): Boolean

final def notify(): Unit

final def notifyAll(): Unit

final def synchronized[T0](arg0: ⇒ T0): T0

def toString(): String

final def wait(): Unit

final def wait(arg0: Long, arg1: Int): Unit

final def wait(arg0: Long): Unit

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