chorus.cpp

来自「Mobile STK for Symbian OS V0.1」· C++ 代码 · 共 64 行

/***************************************************/
/*! \class Chorus
    \brief STK chorus effect class.

    This class implements a chorus effect.

    by Perry R. Cook and Gary P. Scavone, 1995 - 2005.
*/
/***************************************************/

#include "Chorus.h"
#if !defined(SYMBIAN)
#include <iostream>
#endif

Chorus :: Chorus(StkFloat baseDelay)
{
  delayLine_[0].setMaximumDelay( (unsigned long) (baseDelay * 1.414) + 2);
  delayLine_[0].setDelay( baseDelay );
  delayLine_[1].setMaximumDelay( (unsigned long) (baseDelay * 1.414) + 2);
  delayLine_[1].setDelay( baseDelay );
  baseLength_ = baseDelay;

  mods_[0].setFrequency(0.2);
  mods_[1].setFrequency(0.222222);
  modDepth_ = 0.05;
  effectMix_ = 0.5;
  this->clear();
}

Chorus :: ~Chorus()
{
}

void Chorus :: clear()
{
  delayLine_[0].clear();
  delayLine_[1].clear();
  lastOutput_[0] = 0.0;
  lastOutput_[1] = 0.0;
}

void Chorus :: setModDepth(StkFloat depth)
{
  modDepth_ = depth;
}

void Chorus :: setModFrequency(StkFloat frequency)
{
  mods_[0].setFrequency(frequency);
  mods_[1].setFrequency(frequency * 1.1111);
}

StkFloat Chorus :: computeSample(StkFloat input)
{
  delayLine_[0].setDelay( baseLength_ * 0.707 * (1.0 + modDepth_ * mods_[0].tick()) );
  delayLine_[1].setDelay( baseLength_  * 0.5 *  (1.0 - modDepth_ * mods_[1].tick()) );
  lastOutput_[0] = input * (1.0 - effectMix_);
  lastOutput_[0] += effectMix_ * delayLine_[0].tick(input);
  lastOutput_[1] = input * (1.0 - effectMix_);
  lastOutput_[1] += effectMix_ * delayLine_[1].tick(input);
  return Effect::lastOut();
}