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stk/include/BeeThree.h
Gary Scavone eccd8c9981 Version 4.4.0
2013-09-29 23:11:39 +02:00

91 lines
2.3 KiB
C++

#ifndef STK_BEETHREE_H
#define STK_BEETHREE_H
#include "FM.h"
namespace stk {
/***************************************************/
/*! \class BeeThree
\brief STK Hammond-oid organ FM synthesis instrument.
This class implements a simple 4 operator
topology, also referred to as algorithm 8 of
the TX81Z.
\code
Algorithm 8 is :
1 --.
2 -\|
+-> Out
3 -/|
4 --
\endcode
Control Change Numbers:
- Operator 4 (feedback) Gain = 2
- Operator 3 Gain = 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 - 2009.
*/
/***************************************************/
class BeeThree : public FM
{
public:
//! Class constructor.
/*!
An StkError will be thrown if the rawwave path is incorrectly set.
*/
BeeThree( void );
//! Class destructor.
~BeeThree( void );
//! Start a note with the given frequency and amplitude.
void noteOn( StkFloat frequency, StkFloat amplitude );
//! Compute and return one output sample.
StkFloat tick( unsigned int channel = 0 );
protected:
};
inline StkFloat BeeThree :: tick( unsigned int )
{
register StkFloat temp;
if ( modDepth_ > 0.0 ) {
temp = 1.0 + ( modDepth_ * vibrato_.tick() * 0.1 );
waves_[0]->setFrequency( baseFrequency_ * temp * ratios_[0] );
waves_[1]->setFrequency( baseFrequency_ * temp * ratios_[1] );
waves_[2]->setFrequency( baseFrequency_ * temp * ratios_[2] );
waves_[3]->setFrequency( baseFrequency_ * temp * ratios_[3] );
}
waves_[3]->addPhaseOffset( twozero_.lastOut() );
temp = control1_ * 2.0 * gains_[3] * adsr_[3]->tick() * waves_[3]->tick();
twozero_.tick( temp );
temp += control2_ * 2.0 * gains_[2] * adsr_[2]->tick() * waves_[2]->tick();
temp += gains_[1] * adsr_[1]->tick() * waves_[1]->tick();
temp += gains_[0] * adsr_[0]->tick() * waves_[0]->tick();
lastFrame_[0] = temp * 0.125;
return lastFrame_[0];
}
} // stk namespace
#endif