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

104 lines
3.0 KiB
C++

/***************************************************/
/*! \class HevyMetl
\brief STK heavy metal FM synthesis instrument.
This class implements 3 cascade operators with
feedback modulation, also referred to as
algorithm 3 of the TX81Z.
Algorithm 3 is : 4--\
3-->2-- + -->1-->Out
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 - 2007.
*/
/***************************************************/
#include "HevyMetl.h"
HevyMetl :: HevyMetl()
: 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 * 1.000);
this->setRatio(1, 4.0 * 0.999);
this->setRatio(2, 3.0 * 1.001);
this->setRatio(3, 0.5 * 1.002);
gains_[0] = fmGains_[92];
gains_[1] = fmGains_[76];
gains_[2] = fmGains_[91];
gains_[3] = fmGains_[68];
adsr_[0]->setAllTimes( 0.001, 0.001, 1.0, 0.01);
adsr_[1]->setAllTimes( 0.001, 0.010, 1.0, 0.50);
adsr_[2]->setAllTimes( 0.010, 0.005, 1.0, 0.20);
adsr_[3]->setAllTimes( 0.030, 0.010, 0.2, 0.20);
twozero_.setGain( 2.0 );
vibrato_.setFrequency( 5.5 );
modDepth_ = 0.0;
}
HevyMetl :: ~HevyMetl()
{
}
void HevyMetl :: noteOn(StkFloat frequency, StkFloat amplitude)
{
gains_[0] = amplitude * fmGains_[92];
gains_[1] = amplitude * fmGains_[76];
gains_[2] = amplitude * fmGains_[91];
gains_[3] = amplitude * fmGains_[68];
this->setFrequency( frequency );
this->keyOn();
#if defined(_STK_DEBUG_)
errorString_ << "HevyMetl::NoteOn: frequency = " << frequency << ", amplitude = " << amplitude << '.';
handleError( StkError::DEBUG_WARNING );
#endif
}
StkFloat HevyMetl :: 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]);
temp = gains_[2] * adsr_[2]->tick() * waves_[2]->tick();
waves_[1]->addPhaseOffset( temp );
waves_[3]->addPhaseOffset( twozero_.lastOut() );
temp = (1.0 - (control2_ * 0.5)) * gains_[3] * adsr_[3]->tick() * waves_[3]->tick();
twozero_.tick(temp);
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_;
}