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PercFlut.cpp

/***************************************************/
/*! \class PercFlut
    \brief STK percussive flute FM synthesis instrument.

    This class implements algorithm 4 of the TX81Z.

    \code
    Algorithm 4 is :   4->3--\
                          2-- + -->1-->Out
    \endcode

    Control Change Numbers: 
       - Total Modulator Index = 2
       - Modulator Crossfade = 4
       - LFO Speed = 11
       - LFO Depth = 1
       - ADSR 2 & 4 Target = 128

    The basic Chowning/Stanford FM patent expired
    in 1995, but there exist follow-on patents,
    mostly assigned to Yamaha.  If you are of the
    type who should worry about this (making
    money) worry away.

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

#include "PercFlut.h"

00031 PercFlut :: PercFlut()
  : FM()
{
  // Concatenate the STK rawwave path to the rawwave files
  for ( unsigned int i=0; i<3; i++ )
    waves_[i] = new WaveLoop( (Stk::rawwavePath() + "sinewave.raw").c_str(), true );
  waves_[3] = new WaveLoop( (Stk::rawwavePath() + "fwavblnk.raw").c_str(), true );

  this->setRatio(0, 1.50 * 1.000);
  this->setRatio(1, 3.00 * 0.995);
  this->setRatio(2, 2.99 * 1.005);
  this->setRatio(3, 6.00 * 0.997);
  gains_[0] = fmGains_[99];
  gains_[1] = fmGains_[71];
  gains_[2] = fmGains_[93];
  gains_[3] = fmGains_[85];

  adsr_[0]->setAllTimes( 0.05, 0.05, fmSusLevels_[14], 0.05);
  adsr_[1]->setAllTimes( 0.02, 0.50, fmSusLevels_[13], 0.5);
  adsr_[2]->setAllTimes( 0.02, 0.30, fmSusLevels_[11], 0.05);
  adsr_[3]->setAllTimes( 0.02, 0.05, fmSusLevels_[13], 0.01);

  twozero_.setGain( 0.0 );
  modDepth_ = 0.005;
}  

00057 PercFlut :: ~PercFlut()
{
}

00061 void PercFlut :: setFrequency(StkFloat frequency)
{    
  baseFrequency_ = frequency;
}

00066 void PercFlut :: noteOn(StkFloat frequency, StkFloat amplitude)
{
  gains_[0] = amplitude * fmGains_[99] * 0.5;
  gains_[1] = amplitude * fmGains_[71] * 0.5;
  gains_[2] = amplitude * fmGains_[93] * 0.5;
  gains_[3] = amplitude * fmGains_[85] * 0.5;
  this->setFrequency( frequency );
  this->keyOn();

#if defined(_STK_DEBUG_)
  errorString_ << "PercFlut::NoteOn: frequency = " << frequency << ", amplitude = " << amplitude << '.';
  handleError( StkError::DEBUG_WARNING );
#endif
}

StkFloat PercFlut :: computeSample()
{
  register StkFloat temp;

  temp = vibrato_.tick() * modDepth_ * 0.2;    
  waves_[0]->setFrequency(baseFrequency_ * (1.0 + temp) * ratios_[0]);
  waves_[1]->setFrequency(baseFrequency_ * (1.0 + temp) * ratios_[1]);
  waves_[2]->setFrequency(baseFrequency_ * (1.0 + temp) * ratios_[2]);
  waves_[3]->setFrequency(baseFrequency_ * (1.0 + temp) * ratios_[3]);
    
  waves_[3]->addPhaseOffset( twozero_.lastOut() );
  temp = gains_[3] * adsr_[3]->tick() * waves_[3]->tick();

  twozero_.tick(temp);
  waves_[2]->addPhaseOffset( temp );
  temp = (1.0 - (control2_ * 0.5)) * gains_[2] * adsr_[2]->tick() * waves_[2]->tick();

  temp += control2_ * 0.5 * gains_[1] * adsr_[1]->tick() * waves_[1]->tick();
  temp = temp * control1_;

  waves_[0]->addPhaseOffset(temp);
  temp = gains_[0] * adsr_[0]->tick() * waves_[0]->tick();
    
  lastOutput_ = temp * 0.5;
  return lastOutput_;
}

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