Chorus.h

#ifndef STK_CHORUS_H
#define STK_CHORUS_H
 
#include "Effect.h"
#include "DelayL.h"
#include "SineWave.h"
 
namespace stk {
 
/***************************************************/
/***************************************************/
 
class Chorus : public Effect
{
 public:
 
  Chorus( StkFloat baseDelay = 6000 );
 
  void clear( void );
 
  void setModDepth( StkFloat depth );
 
  void setModFrequency( StkFloat frequency );
 
 
  StkFloat lastOut( unsigned int channel = 0 );
 
 
  StkFloat tick( StkFloat input, unsigned int channel = 0 );
 
 
  StkFrames& tick( StkFrames& frames, unsigned int channel = 0 );
 
 
  StkFrames& tick( StkFrames& iFrames, StkFrames &oFrames, unsigned int iChannel = 0, unsigned int oChannel = 0 );
 
 protected:
 
  DelayL delayLine_[2];
  SineWave mods_[2];
  StkFloat baseLength_;
  StkFloat modDepth_;
 
};
 
inline StkFloat Chorus :: lastOut( unsigned int channel )
{
#if defined(_STK_DEBUG_)
  if ( channel > 1 ) {
    oStream_ << "Chorus::lastOut(): channel argument must be less than 2!";
    handleError( StkError::FUNCTION_ARGUMENT );
  }
#endif
 
  return lastFrame_[channel];
}
 
inline StkFloat Chorus :: tick( StkFloat input, unsigned int channel )
{
#if defined(_STK_DEBUG_)
  if ( channel > 1 ) {
    oStream_ << "Chorus::tick(): channel argument must be less than 2!";
    handleError( StkError::FUNCTION_ARGUMENT );
  }
#endif
 
  delayLine_[0].setDelay( baseLength_ * 0.707 * ( 1.0 + modDepth_ * mods_[0].tick() ) );
  delayLine_[1].setDelay( baseLength_  * 0.5 *  ( 1.0 - modDepth_ * mods_[1].tick() ) );
  lastFrame_[0] = effectMix_ * ( delayLine_[0].tick( input ) - input ) + input;
  lastFrame_[1] = effectMix_ * ( delayLine_[1].tick( input ) - input ) + input;
  return lastFrame_[channel];
}
 
inline StkFrames& Chorus :: tick( StkFrames& frames, unsigned int channel )
{
#if defined(_STK_DEBUG_)
  if ( channel >= frames.channels() - 1 ) {
    oStream_ << "Chorus::tick(): channel and StkFrames arguments are incompatible!";
    handleError( StkError::FUNCTION_ARGUMENT );
  }
#endif
 
  StkFloat *samples = &frames[channel];
  unsigned int hop = frames.channels() - 1;
  for ( unsigned int i=0; i<frames.frames(); i++, samples += hop ) {
    delayLine_[0].setDelay( baseLength_ * 0.707 * ( 1.0 + modDepth_ * mods_[0].tick() ) );
    delayLine_[1].setDelay( baseLength_  * 0.5 *  ( 1.0 - modDepth_ * mods_[1].tick() ) );
    *samples = effectMix_ * ( delayLine_[0].tick( *samples ) - *samples ) + *samples;
    samples++;
    *samples = effectMix_ * ( delayLine_[1].tick( *samples ) - *samples ) + *samples;
  }
 
  lastFrame_[0] = *(samples-hop);
  lastFrame_[1] = *(samples-hop+1);
  return frames;
}
 
inline StkFrames& Chorus :: tick( StkFrames& iFrames, StkFrames& oFrames, unsigned int iChannel, unsigned int oChannel )
{
#if defined(_STK_DEBUG_)
  if ( iChannel >= iFrames.channels() || oChannel >= oFrames.channels() - 1 ) {
    oStream_ << "Chorus::tick(): channel and StkFrames arguments are incompatible!";
    handleError( StkError::FUNCTION_ARGUMENT );
  }
#endif
 
  StkFloat *iSamples = &iFrames[iChannel];
  StkFloat *oSamples = &oFrames[oChannel];
  unsigned int iHop = iFrames.channels(), oHop = oFrames.channels();
  for ( unsigned int i=0; i<iFrames.frames(); i++, iSamples += iHop, oSamples += oHop ) {
    delayLine_[0].setDelay( baseLength_ * 0.707 * ( 1.0 + modDepth_ * mods_[0].tick() ) );
    delayLine_[1].setDelay( baseLength_  * 0.5 *  ( 1.0 - modDepth_ * mods_[1].tick() ) );
    *oSamples = effectMix_ * ( delayLine_[0].tick( *iSamples ) - *iSamples ) + *iSamples;
    *(oSamples+1) = effectMix_ * ( delayLine_[1].tick( *iSamples ) - *iSamples ) + *iSamples;
  }
 
  lastFrame_[0] = *(oSamples-oHop);
  lastFrame_[1] = *(oSamples-oHop+1);
  return iFrames;
}
 
} // stk namespace
 
#endif