de.sciss.fscape.graph.OnePole.scala Maven / Gradle / Ivy

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/*
 *  OnePole.scala
 *  (FScape)
 *
 *  Copyright (c) 2001-2016 Hanns Holger Rutz. All rights reserved.
 *
 *  This software is published under the GNU General Public License v2+
 *
 *
 *  For further information, please contact Hanns Holger Rutz at
 *  [email protected]
 */

package de.sciss.fscape
package graph

import de.sciss.fscape.stream.{StreamIn, StreamOut}

import scala.collection.immutable.{IndexedSeq => Vec}

/** A one pole (IIR) filter UGen. Implements the formula :
  * {{{
  * out(i) = ((1 - abs(coef)) * in(i)) + (coef * out(i-1))
  * }}}
  *
  * @param in   input signal to be processed
  * @param coef feedback coefficient. Should be between -1 and +1
  */
final case class OnePole(in: GE, coef: GE) extends UGenSource.SingleOut {
  protected def makeUGens(implicit b: UGenGraph.Builder): UGenInLike =
    unwrap(Vector(in.expand, coef.expand))

  protected def makeUGen(args: Vec[UGenIn])(implicit b: UGenGraph.Builder): UGenInLike =
    UGen.SingleOut(this, args)

  private[fscape] def makeStream(args: Vec[StreamIn])(implicit b: stream.Builder): StreamOut = {
    val Vec(in, coef) = args
    stream.OnePole(in = in.toDouble, coef = coef.toDouble)
  }
}