DelayL.h

#ifndef STK_DELAYL_H
#define STK_DELAYL_H
 
#include "Filter.h"
 
namespace stk {
 
/***************************************************/
/***************************************************/
 
class DelayL : public Filter
{
public:
 
 
  DelayL( StkFloat delay = 0.0, unsigned long maxDelay = 4095 );
 
  ~DelayL();
 
  unsigned long getMaximumDelay( void ) { return inputs_.size() - 1; };
 
 
  void setMaximumDelay( unsigned long delay );
 
 
  void setDelay( StkFloat delay );
 
  StkFloat getDelay( void ) const { return delay_; };
 
 
  StkFloat tapOut( unsigned long tapDelay );
 
  void tapIn( StkFloat value, unsigned long tapDelay );
 
  StkFloat lastOut( void ) const { return lastFrame_[0]; };
 
 
  StkFloat nextOut( void );
 
  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:
 
  unsigned long inPoint_;
  unsigned long outPoint_;
  StkFloat delay_;
  StkFloat alpha_;
  StkFloat omAlpha_;
  StkFloat nextOutput_;
  bool doNextOut_;
};
 
inline StkFloat DelayL :: nextOut( void )
{
  if ( doNextOut_ ) {
    // First 1/2 of interpolation
    nextOutput_ = inputs_[outPoint_] * omAlpha_;
    // Second 1/2 of interpolation
    if (outPoint_+1 < inputs_.size())
      nextOutput_ += inputs_[outPoint_+1] * alpha_;
    else
      nextOutput_ += inputs_[0] * alpha_;
    doNextOut_ = false;
  }
 
  return nextOutput_;
}
 
inline void DelayL :: setDelay( StkFloat delay )
{
  if ( delay + 1 > inputs_.size() ) { // The value is too big.
    oStream_ << "DelayL::setDelay: argument (" << delay << ") greater than  maximum!";
    handleError( StkError::WARNING ); return;
  }
 
  if (delay < 0 ) {
    oStream_ << "DelayL::setDelay: argument (" << delay << ") less than zero!";
    handleError( StkError::WARNING ); return;
  }
 
  StkFloat outPointer = inPoint_ - delay;  // read chases write
  delay_ = delay;
 
  while ( outPointer < 0 )
    outPointer += inputs_.size(); // modulo maximum length
 
  outPoint_ = (long) outPointer;   // integer part
 
  alpha_ = outPointer - outPoint_; // fractional part
  omAlpha_ = (StkFloat) 1.0 - alpha_;
 
  if ( outPoint_ == inputs_.size() ) outPoint_ = 0;
  doNextOut_ = true;
}
 
inline StkFloat DelayL :: tick( StkFloat input )
{
  inputs_[inPoint_++] = input * gain_;
 
  // Increment input pointer modulo length.
  if ( inPoint_ == inputs_.size() )
    inPoint_ = 0;
 
  lastFrame_[0] = nextOut();
  doNextOut_ = true;
 
  // Increment output pointer modulo length.
  if ( ++outPoint_ == inputs_.size() )
    outPoint_ = 0;
 
  return lastFrame_[0];
}
 
inline StkFrames& DelayL :: tick( StkFrames& frames, unsigned int channel )
{
#if defined(_STK_DEBUG_)
  if ( channel >= frames.channels() ) {
    oStream_ << "DelayL::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 ) {
    inputs_[inPoint_++] = *samples * gain_;
    if ( inPoint_ == inputs_.size() ) inPoint_ = 0;
    *samples = nextOut();
    doNextOut_ = true;
    if ( ++outPoint_ == inputs_.size() ) outPoint_ = 0;
  }
 
  lastFrame_[0] = *(samples-hop);
  return frames;
}
 
inline StkFrames& DelayL :: tick( StkFrames& iFrames, StkFrames& oFrames, unsigned int iChannel, unsigned int oChannel )
{
#if defined(_STK_DEBUG_)
  if ( iChannel >= iFrames.channels() || oChannel >= oFrames.channels() ) {
    oStream_ << "DelayL::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 ) {
    inputs_[inPoint_++] = *iSamples * gain_;
    if ( inPoint_ == inputs_.size() ) inPoint_ = 0;
    *oSamples = nextOut();
    doNextOut_ = true;
    if ( ++outPoint_ == inputs_.size() ) outPoint_ = 0;
  }
 
  lastFrame_[0] = *(oSamples-oHop);
  return iFrames;
}
 
} // stk namespace
 
#endif