Files
stk/projects/ragamatic/Drone.h
Gary Scavone eccd8c9981 Version 4.4.0
2013-09-29 23:11:39 +02:00

81 lines
2.0 KiB
C++

#ifndef STK_DRONE_H
#define STK_DRONE_H
#include "Instrmnt.h"
#include "DelayA.h"
#include "OneZero.h"
#include "ADSR.h"
#include "Noise.h"
namespace stk {
/***************************************************/
/*! \class Drone
\brief STK "drone" plucked string model.
This class implements a simple plucked string
physical model based on the Karplus-Strong
algorithm.
This is a digital waveguide model, making its
use possibly subject to patents held by
Stanford University, Yamaha, and others.
There exist at least two patents, assigned to
Stanford, bearing the names of Karplus and/or
Strong.
by Perry R. Cook and Gary P. Scavone, 1995 - 2009.
*/
/***************************************************/
class Drone : public Instrmnt
{
public:
//! Class constructor, taking the lowest desired playing frequency.
Drone( StkFloat lowestFrequency = 20 );
//! Class destructor.
~Drone( void );
//! Reset and clear all internal state.
void clear( void );
//! Set instrument parameters for a particular frequency.
void setFrequency( StkFloat frequency );
//! 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 );
//! Compute and return one output sample.
StkFloat tick( unsigned int channel = 0 );
protected:
DelayA delayLine_;
OneZero loopFilter_;
ADSR envelope_;
Noise noise_;
StkFloat loopGain_;
unsigned long length_;
};
inline StkFloat Drone :: tick( unsigned int )
{
// Here's the whole inner loop of the instrument!!
lastFrame_[0] = delayLine_.tick( loopFilter_.tick( delayLine_.lastOut() * loopGain_ )
+ ( 0.005 * envelope_.tick() * noise_.tick() ) );
return lastFrame_[0];
}
} // stk namespace
#endif