Files
stk/src/Wurley.cpp
Gary Scavone 27d9b79dc7 Version 4.3.0
2013-09-29 23:07:00 +02:00

114 lines
3.1 KiB
C++

/***************************************************/
/*! \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 - 2007.
*/
/***************************************************/
#include "Wurley.h"
Wurley :: Wurley()
: 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, 1.0);
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 Wurley :: setFrequency(StkFloat frequency)
{
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();
#if defined(_STK_DEBUG_)
errorString_ << "Wurley::NoteOn: frequency = " << frequency << ", amplitude = " << amplitude << '.';
handleError( StkError::DEBUG_WARNING );
#endif
}
StkFloat Wurley :: computeSample()
{
StkFloat temp, temp2;
temp = gains_[1] * adsr_[1]->tick() * waves_[1]->tick();
temp = temp * control1_;
waves_[0]->addPhaseOffset( temp );
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_[0] * adsr_[0]->tick() * waves_[0]->tick();
temp += control2_ * 0.5 * gains_[2] * adsr_[2]->tick() * waves_[2]->tick();
// Calculate amplitude modulation and apply it to output.
temp2 = vibrato_.tick() * modDepth_;
temp = temp * (1.0 + temp2);
lastOutput_ = temp * 0.5;
return lastOutput_;
}