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

91 lines
2.2 KiB
C++

#ifndef STK_RESONATE_H
#define STK_RESONATE_H
#include "Instrmnt.h"
#include "ADSR.h"
#include "BiQuad.h"
#include "Noise.h"
namespace stk {
/***************************************************/
/*! \class Resonate
\brief STK noise driven formant filter.
This instrument contains a noise source, which
excites a biquad resonance filter, with volume
controlled by an ADSR.
Control Change Numbers:
- Resonance Frequency (0-Nyquist) = 2
- Pole Radii = 4
- Notch Frequency (0-Nyquist) = 11
- Zero Radii = 1
- Envelope Gain = 128
by Perry R. Cook and Gary P. Scavone, 1995 - 2009.
*/
/***************************************************/
class Resonate : public Instrmnt
{
public:
//! Class constructor.
Resonate( void );
//! Class destructor.
~Resonate( void );
//! Reset and clear all internal state.
void clear( void );
//! Set the filter for a resonance at the given frequency (Hz) and radius.
void setResonance( StkFloat frequency, StkFloat radius );
//! Set the filter for a notch at the given frequency (Hz) and radius.
void setNotch( StkFloat frequency, StkFloat radius );
//! Set the filter zero coefficients for contant resonance gain.
void setEqualGainZeroes( void ) { filter_.setEqualGainZeroes(); };
//! Initiate the envelope with a key-on event.
void keyOn( void ) { adsr_.keyOn(); };
//! Signal a key-off event to the envelope.
void keyOff( void ) { adsr_.keyOff(); };
//! Start a note with the given frequency and amplitude.
void noteOn( StkFloat frequency, StkFloat amplitude );
//! Stop a note with the given amplitude (speed of decay).
void noteOff( StkFloat amplitude );
//! Perform the control change specified by \e number and \e value (0.0 - 128.0).
void controlChange( int number, StkFloat value );
//! Compute and return one output sample.
StkFloat tick( unsigned int channel = 0 );
protected:
ADSR adsr_;
BiQuad filter_;
Noise noise_;
StkFloat poleFrequency_;
StkFloat poleRadius_;
StkFloat zeroFrequency_;
StkFloat zeroRadius_;
};
inline StkFloat Resonate :: tick( unsigned int )
{
lastFrame_[0] = filter_.tick( noise_.tick() );
lastFrame_[0] *= adsr_.tick();
return lastFrame_[0];
}
} // stk namespace
#endif