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- #ifndef STK_BRASS_H
- #define STK_BRASS_H
-
- #include "Instrmnt.h"
- #include "DelayA.h"
- #include "BiQuad.h"
- #include "PoleZero.h"
- #include "ADSR.h"
- #include "SineWave.h"
-
- namespace stk {
-
- /***************************************************/
- /*! \class Brass
- \brief STK simple brass instrument class.
-
- This class implements a simple brass instrument
- waveguide model, a la Cook (TBone, HosePlayer).
-
- This is a digital waveguide model, making its
- use possibly subject to patents held by
- Stanford University, Yamaha, and others.
-
- Control Change Numbers:
- - Lip Tension = 2
- - Slide Length = 4
- - Vibrato Frequency = 11
- - Vibrato Gain = 1
- - Volume = 128
-
- by Perry R. Cook and Gary P. Scavone, 1995--2017.
- */
- /***************************************************/
-
- class Brass: public Instrmnt
- {
- public:
- //! Class constructor, taking the lowest desired playing frequency.
- /*!
- An StkError will be thrown if the rawwave path is incorrectly set.
- */
- Brass( StkFloat lowestFrequency = 8.0 );
-
- //! Class destructor.
- ~Brass( );
-
- //! Reset and clear all internal state.
- void clear( );
-
- //! Set instrument parameters for a particular frequency.
- void setFrequency( StkFloat frequency );
-
- //! Set the lips frequency.
- void setLip( StkFloat frequency );
-
- //! Apply breath pressure to instrument with given amplitude and rate of increase.
- void startBlowing( StkFloat amplitude, StkFloat rate );
-
- //! Decrease breath pressure with given rate of decrease.
- void stopBlowing( StkFloat rate );
-
- //! 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:
-
- DelayA delayLine_;
- BiQuad lipFilter_;
- PoleZero dcBlock_;
- ADSR adsr_;
- SineWave vibrato_;
-
- StkFloat lipTarget_;
- StkFloat slideTarget_;
- StkFloat vibratoGain_;
- StkFloat maxPressure_;
-
- };
-
- inline StkFloat Brass :: tick( unsigned int )
- {
- StkFloat breathPressure = maxPressure_ * adsr_.tick();
- breathPressure += vibratoGain_ * vibrato_.tick();
-
- StkFloat mouthPressure = 0.3 * breathPressure;
- StkFloat borePressure = 0.85 * delayLine_.lastOut();
- StkFloat deltaPressure = mouthPressure - borePressure; // Differential pressure.
- deltaPressure = lipFilter_.tick( deltaPressure ); // Force - > position.
- deltaPressure *= deltaPressure; // Basic position to area mapping.
- if ( deltaPressure > 1.0 ) deltaPressure = 1.0; // Non-linear saturation.
-
- // The following input scattering assumes the mouthPressure = area.
- lastFrame_[0] = deltaPressure * mouthPressure + ( 1.0 - deltaPressure) * borePressure;
- lastFrame_[0] = delayLine_.tick( dcBlock_.tick( lastFrame_[0] ) );
-
- return lastFrame_[0];
- }
-
- inline StkFrames& Brass :: tick( StkFrames& frames, unsigned int channel )
- {
- unsigned int nChannels = lastFrame_.channels();
- #if defined(_STK_DEBUG_)
- if ( channel > frames.channels() - nChannels ) {
- oStream_ << "Brass::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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