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

111 lines
3.1 KiB
C++

#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 - 2009.
*/
/***************************************************/
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 );
//! 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 );
protected:
DelayA delayLine_;
BiQuad lipFilter_;
PoleZero dcBlock_;
ADSR adsr_;
SineWave vibrato_;
unsigned long length_;
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];
}
} // stk namespace
#endif