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- #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--2017.
- */
- /***************************************************/
-
- class Resonate : public Instrmnt
- {
- public:
- //! Class constructor.
- Resonate( void );
-
- //! Class destructor.
- ~Resonate( 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 );
-
- //! Fill a channel of the StkFrames object with computed outputs.
- /*!
- The \c channel argument must be less than the number of
- channels in the StkFrames argument (the first channel is specified
- by 0). However, range checking is only performed if _STK_DEBUG_
- is defined during compilation, in which case an out-of-range value
- will trigger an StkError exception.
- */
- StkFrames& tick( StkFrames& frames, 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];
- }
-
- inline StkFrames& Resonate :: tick( StkFrames& frames, unsigned int channel )
- {
- unsigned int nChannels = lastFrame_.channels();
- #if defined(_STK_DEBUG_)
- if ( channel > frames.channels() - nChannels ) {
- oStream_ << "Resonate::tick(): channel and StkFrames arguments are incompatible!";
- handleError( StkError::FUNCTION_ARGUMENT );
- }
- #endif
-
- StkFloat *samples = &frames[channel];
- unsigned int j, hop = frames.channels() - nChannels;
- if ( nChannels == 1 ) {
- for ( unsigned int i=0; i<frames.frames(); i++, samples += hop )
- *samples++ = tick();
- }
- else {
- for ( unsigned int i=0; i<frames.frames(); i++, samples += hop ) {
- *samples++ = tick();
- for ( j=1; j<nChannels; j++ )
- *samples++ = lastFrame_[j];
- }
- }
-
- return frames;
- }
-
- } // stk namespace
-
- #endif
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