mirror of
https://github.com/cookiengineer/audacity
synced 2025-07-03 06:03:13 +02:00
118 lines
2.9 KiB
C++
118 lines
2.9 KiB
C++
/***************************************************/
|
|
/*! \class Sitar
|
|
\brief STK sitar string model class.
|
|
|
|
This class implements a sitar 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 - 2005.
|
|
*/
|
|
/***************************************************/
|
|
|
|
#include "Sitar.h"
|
|
#include <math.h>
|
|
|
|
using namespace Nyq;
|
|
|
|
Sitar :: Sitar(StkFloat lowestFrequency)
|
|
{
|
|
unsigned long length = (unsigned long) (Stk::sampleRate() / lowestFrequency + 1);
|
|
delayLine_.setMaximumDelay( length );
|
|
delay_ = 0.5 * length;
|
|
delayLine_.setDelay( delay_ );
|
|
targetDelay_ = delay_;
|
|
|
|
loopFilter_.setZero(0.01);
|
|
loopGain_ = 0.999;
|
|
|
|
envelope_.setAllTimes(0.001, 0.04, 0.0, 0.5);
|
|
this->clear();
|
|
}
|
|
|
|
Sitar :: ~Sitar()
|
|
{
|
|
}
|
|
|
|
void Sitar :: clear()
|
|
{
|
|
delayLine_.clear();
|
|
loopFilter_.clear();
|
|
}
|
|
|
|
void Sitar :: setFrequency(StkFloat frequency)
|
|
{
|
|
StkFloat freakency = frequency;
|
|
if ( frequency <= 0.0 ) {
|
|
errorString_ << "Sitar::setFrequency: parameter is less than or equal to zero!";
|
|
handleError( StkError::WARNING );
|
|
freakency = 220.0;
|
|
}
|
|
|
|
targetDelay_ = (Stk::sampleRate() / freakency);
|
|
delay_ = targetDelay_ * (1.0 + (0.05 * noise_.tick()));
|
|
delayLine_.setDelay( delay_ );
|
|
loopGain_ = 0.995 + (freakency * 0.0000005);
|
|
if ( loopGain_ > 0.9995 ) loopGain_ = 0.9995;
|
|
}
|
|
|
|
void Sitar :: pluck(StkFloat amplitude)
|
|
{
|
|
envelope_.keyOn();
|
|
}
|
|
|
|
void Sitar :: noteOn(StkFloat frequency, StkFloat amplitude)
|
|
{
|
|
this->setFrequency( frequency );
|
|
this->pluck( amplitude );
|
|
amGain_ = 0.1 * amplitude;
|
|
|
|
#if defined(_STK_DEBUG_)
|
|
errorString_ << "Sitar::NoteOn: frequency = " << frequency << ", amplitude = " << amplitude << ".";
|
|
handleError( StkError::DEBUG_WARNING );
|
|
#endif
|
|
}
|
|
|
|
void Sitar :: noteOff(StkFloat amplitude)
|
|
{
|
|
loopGain_ = (StkFloat) 1.0 - amplitude;
|
|
if ( loopGain_ < 0.0 ) {
|
|
errorString_ << "Sitar::noteOff: amplitude is greater than 1.0 ... setting to 1.0!";
|
|
handleError( StkError::WARNING );
|
|
loopGain_ = 0.0;
|
|
}
|
|
else if ( loopGain_ > 1.0 ) {
|
|
errorString_ << "Sitar::noteOff: amplitude is < 0.0 ... setting to 0.0!";
|
|
handleError( StkError::WARNING );
|
|
loopGain_ = 0.99999;
|
|
}
|
|
|
|
#if defined(_STK_DEBUG_)
|
|
errorString_ << "Sitar::NoteOff: amplitude = " << amplitude << ".";
|
|
handleError( StkError::DEBUG_WARNING );
|
|
#endif
|
|
}
|
|
|
|
StkFloat Sitar :: computeSample()
|
|
{
|
|
if ( fabs(targetDelay_ - delay_) > 0.001 ) {
|
|
if ( targetDelay_ < delay_ )
|
|
delay_ *= 0.99999;
|
|
else
|
|
delay_ *= 1.00001;
|
|
delayLine_.setDelay( delay_ );
|
|
}
|
|
|
|
lastOutput_ = delayLine_.tick( loopFilter_.tick( delayLine_.lastOut() * loopGain_ ) +
|
|
(amGain_ * envelope_.tick() * noise_.tick()));
|
|
|
|
return lastOutput_;
|
|
}
|