Wurley.cpp

/***************************************************/
/*! \class Wurley
    \brief STK Wurlitzer electric piano FM
           synthesis instrument.

    This class implements two simple FM Pairs
    summed together, also referred to as algorithm
    5 of the TX81Z.

    \code
    Algorithm 5 is :  4->3--\
                             + --> Out
                      2->1--/
    \endcode

    Control Change Numbers: 
       - Modulator Index One = 2
       - Crossfade of Outputs = 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--2023.
*/
/***************************************************/

#include "Wurley.h"

namespace stk {

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

  this->setRatio(0, 1.0);
  this->setRatio(1, 4.0);
  this->setRatio(2, -510.0);
  this->setRatio(3, -510.0);

  gains_[0] = fmGains_[99];
  gains_[1] = fmGains_[82];
  gains_[2] = fmGains_[92];
  gains_[3] = fmGains_[68];

  adsr_[0]->setAllTimes( 0.001, 1.50, 0.0, 0.04);
  adsr_[1]->setAllTimes( 0.001, 1.50, 0.0, 0.04);
  adsr_[2]->setAllTimes( 0.001, 0.25, 0.0, 0.04);
  adsr_[3]->setAllTimes( 0.001, 0.15, 0.0, 0.04);

  twozero_.setGain( 2.0 );
  vibrato_.setFrequency( 8.0 );
}  

Wurley :: ~Wurley( void )
{
}

void Wurley :: setFrequency( StkFloat frequency )
{
#if defined(_STK_DEBUG_)
  if ( frequency <= 0.0 ) {
    oStream_ << "Wurley::setFrequency: argument is less than or equal to zero!";
    handleError( StkError::WARNING ); return;
  }
#endif

  baseFrequency_ = frequency;
  waves_[0]->setFrequency( baseFrequency_ * ratios_[0]);
  waves_[1]->setFrequency( baseFrequency_ * ratios_[1]);
  waves_[2]->setFrequency( ratios_[2] );	// Note here a 'fixed resonance'.
  waves_[3]->setFrequency( ratios_[3] );
}

void Wurley :: noteOn( StkFloat frequency, StkFloat amplitude )
{
  gains_[0] = amplitude * fmGains_[99];
  gains_[1] = amplitude * fmGains_[82];
  gains_[2] = amplitude * fmGains_[82];
  gains_[3] = amplitude * fmGains_[68];
  this->setFrequency( frequency );
  this->keyOn();
}

} // stk namespace