Bowed.h

#ifndef STK_BOWED_H
#define STK_BOWED_H

#include "Instrmnt.h"
#include "DelayL.h"
#include "BowTable.h"
#include "OnePole.h"
#include "BiQuad.h"
#include "SineWave.h"
#include "ADSR.h"

namespace stk {

/***************************************************/
/***************************************************/

class Bowed : public Instrmnt
{
 public:
  Bowed( StkFloat lowestFrequency = 8.0 );

  ~Bowed( void );

  void clear( void );

  void setFrequency( StkFloat frequency );

  void setVibrato( StkFloat gain ) { vibratoGain_ = gain; };

  void startBowing( StkFloat amplitude, StkFloat rate );

  void stopBowing( StkFloat rate );

  void noteOn( StkFloat frequency, StkFloat amplitude );

  void noteOff( StkFloat amplitude );

  void controlChange( int number, StkFloat value );

  StkFloat tick( unsigned int channel = 0 );


  StkFrames& tick( StkFrames& frames, unsigned int channel = 0 );

 protected:

  DelayL   neckDelay_;
  DelayL   bridgeDelay_;
  BowTable bowTable_;
  OnePole  stringFilter_;
  BiQuad   bodyFilters_[6];
  SineWave vibrato_;
  ADSR     adsr_;

  bool     bowDown_;
  StkFloat maxVelocity_;
  StkFloat baseDelay_;
  StkFloat vibratoGain_;
  StkFloat betaRatio_;

};

inline StkFloat Bowed :: tick( unsigned int )
{
  StkFloat bowVelocity = maxVelocity_ * adsr_.tick();
  StkFloat bridgeReflection = -stringFilter_.tick( bridgeDelay_.lastOut() );
  StkFloat nutReflection = -neckDelay_.lastOut();
  StkFloat stringVelocity = bridgeReflection + nutReflection;
  StkFloat deltaV = bowVelocity - stringVelocity;             // Differential velocity

  StkFloat newVelocity = 0.0;
  if ( bowDown_ )
    newVelocity = deltaV * bowTable_.tick( deltaV );     // Non-Linear bow function
  neckDelay_.tick( bridgeReflection + newVelocity);      // Do string propagations
  bridgeDelay_.tick(nutReflection + newVelocity);
    
  if ( vibratoGain_ > 0.0 )  {
    neckDelay_.setDelay( (baseDelay_ * (1.0 - betaRatio_) ) + 
                         (baseDelay_ * vibratoGain_ * vibrato_.tick()) );
  }

  lastFrame_[0] = 0.1248 * bodyFilters_[5].tick( bodyFilters_[4].tick( bodyFilters_[3].tick( bodyFilters_[2].tick( bodyFilters_[1].tick( bodyFilters_[0].tick( bridgeDelay_.lastOut() ) ) ) ) ) );

  return lastFrame_[0];
}

inline StkFrames& Bowed :: tick( StkFrames& frames, unsigned int channel )
{
  unsigned int nChannels = lastFrame_.channels();
#if defined(_STK_DEBUG_)
  if ( channel > frames.channels() - nChannels ) {
    oStream_ << "Bowed::tick(): channel and StkFrames arguments are incompatible!";
    handleError( StkError::FUNCTION_ARGUMENT );
  }
#endif

  StkFloat *samples = &frames[channel];
  unsigned int j, hop = frames.channels() - nChannels;
  if ( nChannels == 1 ) {
    for ( unsigned int i=0; i<frames.frames(); i++, samples += hop )
      *samples++ = tick();
  }
  else {
    for ( unsigned int i=0; i<frames.frames(); i++, samples += hop ) {
      *samples++ = tick();
      for ( j=1; j<nChannels; j++ )
        *samples++ = lastFrame_[j];
    }
  }

  return frames;
}

} // stk namespace

#endif