Echo.h

#ifndef STK_ECHO_H
#define STK_ECHO_H
 
#include "Effect.h" 
#include "Delay.h" 
 
namespace stk {
 
/***************************************************/
/***************************************************/
 
class Echo : public Effect
{
 public:
 
  Echo( unsigned long maximumDelay = (unsigned long) Stk::sampleRate() );
 
  void clear();
 
  void setMaximumDelay( unsigned long delay );
 
  void setDelay( unsigned long delay );
 
  StkFloat lastOut( void ) const { return lastFrame_[0]; };
 
  StkFloat tick( StkFloat input );
 
 
  StkFrames& tick( StkFrames& frames, unsigned int channel = 0 );
 
 
  StkFrames& tick( StkFrames& iFrames, StkFrames &oFrames, unsigned int iChannel = 0, unsigned int oChannel = 0 );
 
 protected:
 
  Delay delayLine_;
  unsigned long length_;
 
};
 
inline StkFloat Echo :: tick( StkFloat input )
{
  lastFrame_[0] = effectMix_ * ( delayLine_.tick( input ) - input ) + input;
  return lastFrame_[0];
}
 
inline StkFrames& Echo :: tick( StkFrames& frames, unsigned int channel )
{
#if defined(_STK_DEBUG_)
  if ( channel >= frames.channels() ) {
    oStream_ << "Echo::tick(): channel and StkFrames arguments are incompatible!";
    handleError( StkError::FUNCTION_ARGUMENT );
  }
#endif
 
  StkFloat *samples = &frames[channel];
  unsigned int hop = frames.channels();
  for ( unsigned int i=0; i<frames.frames(); i++, samples += hop ) {
    *samples = effectMix_ * ( delayLine_.tick( *samples ) - *samples ) + *samples;
  }
 
  lastFrame_[0] = *(samples-hop);
  return frames;
}
 
inline StkFrames& Echo :: tick( StkFrames& iFrames, StkFrames& oFrames, unsigned int iChannel, unsigned int oChannel )
{
#if defined(_STK_DEBUG_)
  if ( iChannel >= iFrames.channels() || oChannel >= oFrames.channels() ) {
    oStream_ << "Echo::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 ) {
    *oSamples = effectMix_ * ( delayLine_.tick( *iSamples ) - *iSamples ) + *iSamples;
  }
 
  lastFrame_[0] = *(oSamples-oHop);
  return iFrames;
}
 
} // stk namespace
 
#endif