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https://github.com/thestk/stk
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Version 4.0
This commit is contained in:
Gary Scavone
committed by
Stephen Sinclair
Stephen Sinclair
parent
3f126af4e5
commit
81475b04c5
121
src/Plucked.cpp
121
src/Plucked.cpp
@@ -1,21 +1,31 @@
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/******************************************/
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/* Karplus-Strong plucked string model */
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/* by Perry Cook, 1995-96 */
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/* */
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/* There exist at least two patents, */
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/* assigned to Stanford, bearing the */
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/* names of Karplus and/or Strong. */
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/******************************************/
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/***************************************************/
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/*! \class Plucked
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\brief STK plucked string model class.
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This class implements a simple plucked string
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physical model based on the Karplus-Strong
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algorithm.
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This is a digital waveguide model, making its
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use possibly subject to patents held by
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Stanford University, Yamaha, and others.
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There exist at least two patents, assigned to
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Stanford, bearing the names of Karplus and/or
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Strong.
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by Perry R. Cook and Gary P. Scavone, 1995 - 2002.
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*/
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/***************************************************/
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#include "Plucked.h"
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Plucked :: Plucked(MY_FLOAT lowestFreq)
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Plucked :: Plucked(MY_FLOAT lowestFrequency)
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{
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length = (long) (SRATE / lowestFreq + 1);
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length = (long) (Stk::sampleRate() / lowestFrequency + 1);
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loopGain = (MY_FLOAT) 0.999;
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delayLine = new DLineA(length);
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loopFilt = new OneZero;
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pickFilt = new OnePole;
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delayLine = new DelayA( (MY_FLOAT)(length / 2.0), length );
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loopFilter = new OneZero;
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pickFilter = new OnePole;
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noise = new Noise;
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this->clear();
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}
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@@ -23,62 +33,85 @@ Plucked :: Plucked(MY_FLOAT lowestFreq)
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Plucked :: ~Plucked()
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{
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delete delayLine;
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delete loopFilt;
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delete pickFilt;
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delete loopFilter;
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delete pickFilter;
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delete noise;
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}
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void Plucked :: clear()
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{
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delayLine->clear();
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loopFilt->clear();
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pickFilt->clear();
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loopFilter->clear();
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pickFilter->clear();
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}
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void Plucked :: setFreq(MY_FLOAT frequency)
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void Plucked :: setFrequency(MY_FLOAT frequency)
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{
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MY_FLOAT delay;
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delay = (SRATE / frequency) - (MY_FLOAT) 0.5; /* length - delays */
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MY_FLOAT freakency = frequency;
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if ( frequency <= 0.0 ) {
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cerr << "Plucked: setFrequency parameter is less than or equal to zero!" << endl;
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freakency = 220.0;
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}
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// Delay = length - approximate filter delay.
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MY_FLOAT delay = (Stk::sampleRate() / freakency) - (MY_FLOAT) 0.5;
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if (delay <= 0.0) delay = 0.3;
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else if (delay > length) delay = length;
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delayLine->setDelay(delay);
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loopGain = (MY_FLOAT) 0.995 + (frequency * (MY_FLOAT) 0.000005);
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if (loopGain>1.0) loopGain = (MY_FLOAT) 0.99999;
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loopGain = 0.995 + (freakency * 0.000005);
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if ( loopGain >= 1.0 ) loopGain = (MY_FLOAT) 0.99999;
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}
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void Plucked :: pluck(MY_FLOAT amplitude)
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{
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long i;
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pickFilt->setPole((MY_FLOAT) 0.999 - (amplitude * (MY_FLOAT) 0.15));
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pickFilt->setGain(amplitude * (MY_FLOAT) 0.5);
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for (i=0;i<length;i++)
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// fill delay with noise additively with current contents
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delayLine->tick(delayLine->lastOut() * (MY_FLOAT) 0.6
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+ pickFilt->tick(noise->tick()));
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MY_FLOAT gain = amplitude;
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if ( gain > 1.0 ) {
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cerr << "Plucked: pluck amplitude greater than 1.0!" << endl;
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gain = 1.0;
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}
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else if ( gain < 0.0 ) {
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cerr << "Plucked: pluck amplitude less than zero!" << endl;
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gain = 0.0;
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}
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pickFilter->setPole((MY_FLOAT) 0.999 - (gain * (MY_FLOAT) 0.15));
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pickFilter->setGain(gain * (MY_FLOAT) 0.5);
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for (long i=0; i<length; i++)
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// Fill delay with noise additively with current contents.
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delayLine->tick( 0.6 * delayLine->lastOut() + pickFilter->tick( noise->tick() ) );
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}
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void Plucked :: noteOn(MY_FLOAT freq, MY_FLOAT amp)
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void Plucked :: noteOn(MY_FLOAT frequency, MY_FLOAT amplitude)
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{
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this->setFreq(freq);
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this->pluck(amp);
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#if defined(_debug_)
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printf("Plucked : NoteOn: Freq=%lf Amp=%lf\n",freq,amp);
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#endif
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this->setFrequency(frequency);
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this->pluck(amplitude);
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#if defined(_STK_DEBUG_)
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cerr << "Plucked: NoteOn frequency = " << frequency << ", amplitude = " << amplitude << endl;
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#endif
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}
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void Plucked :: noteOff(MY_FLOAT amp)
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void Plucked :: noteOff(MY_FLOAT amplitude)
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{
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loopGain = (MY_FLOAT) 1.0 - amp;
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#if defined(_debug_)
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printf("Plucked : NoteOff: Amp=%lf\n",amp);
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#endif
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loopGain = (MY_FLOAT) 1.0 - amplitude;
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if ( loopGain < 0.0 ) {
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cerr << "Plucked: noteOff amplitude greater than 1.0!" << endl;
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loopGain = 0.0;
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}
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else if ( loopGain > 1.0 ) {
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cerr << "Plucked: noteOff amplitude less than or zero!" << endl;
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loopGain = (MY_FLOAT) 0.99999;
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}
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#if defined(_STK_DEBUG_)
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cerr << "Plucked: NoteOff amplitude = " << amplitude << endl;
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#endif
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}
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MY_FLOAT Plucked :: tick()
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{
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/* check this out */
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/* here's the whole inner loop of the instrument!! */
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lastOutput = delayLine->tick(loopFilt->tick(delayLine->lastOut() * loopGain));
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// Here's the whole inner loop of the instrument!!
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lastOutput = delayLine->tick( loopFilter->tick( delayLine->lastOut() * loopGain ) );
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lastOutput *= (MY_FLOAT) 3.0;
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return lastOutput;
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}
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