Files
stk/include/StifKarp.h
Gary Scavone 2cbce2d8bd Version 4.2.1
2013-09-29 23:06:23 +02:00

97 lines
2.5 KiB
C++

/***************************************************/
/*! \class StifKarp
\brief STK plucked stiff string instrument.
This class implements a simple plucked string
algorithm (Karplus Strong) with enhancements
(Jaffe-Smith, Smith, and others), including
string stiffness and pluck position controls.
The stiffness is modeled with allpass filters.
This is a digital waveguide model, making its
use possibly subject to patents held by
Stanford University, Yamaha, and others.
Control Change Numbers:
- Pickup Position = 4
- String Sustain = 11
- String Stretch = 1
by Perry R. Cook and Gary P. Scavone, 1995 - 2005.
*/
/***************************************************/
#ifndef STK_STIFKARP_H
#define STK_STIFKARP_H
#include "Instrmnt.h"
#include "DelayL.h"
#include "DelayA.h"
#include "OneZero.h"
#include "Noise.h"
#include "BiQuad.h"
class StifKarp : public Instrmnt
{
public:
//! Class constructor, taking the lowest desired playing frequency.
StifKarp(StkFloat lowestFrequency);
//! Class destructor.
~StifKarp();
//! Reset and clear all internal state.
void clear();
//! Set instrument parameters for a particular frequency.
void setFrequency(StkFloat frequency);
//! Set the stretch "factor" of the string (0.0 - 1.0).
void setStretch(StkFloat stretch);
//! Set the pluck or "excitation" position along the string (0.0 - 1.0).
void setPickupPosition(StkFloat position);
//! Set the base loop gain.
/*!
The actual loop gain is set according to the frequency.
Because of high-frequency loop filter roll-off, higher
frequency settings have greater loop gains.
*/
void setBaseLoopGain(StkFloat aGain);
//! Pluck the string with the given amplitude using the current frequency.
void pluck(StkFloat amplitude);
//! 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);
protected:
StkFloat computeSample( void );
DelayA delayLine_;
DelayL combDelay_;
OneZero filter_;
Noise noise_;
BiQuad biquad_[4];
unsigned long length_;
StkFloat loopGain_;
StkFloat baseLoopGain_;
StkFloat lastFrequency_;
StkFloat lastLength_;
StkFloat stretching_;
StkFloat pluckAmplitude_;
StkFloat pickupPosition_;
};
#endif