Version 4.0

src/Sitar.cpp

@@ -0,0 +1,107 @@
+ /******************************************/  
+/*  Karplus-Strong Sitar1 string model   */
+/*  by Perry Cook, 1995-96                */
+/*					  */
+/*  There exist at least two patents,     */
+/*  assigned to Stanford, bearing the     */
+/*  names of Karplus and/or Strong.       */
+/******************************************/
+
+#include "Sitar.h"
+#include <math.h>
+
+Sitar :: Sitar(MY_FLOAT lowestFrequency)
+{
+  length = (long) (Stk::sampleRate() / lowestFrequency + 1);
+  loopGain = (MY_FLOAT) 0.999;
+  delayLine = new DelayA( (MY_FLOAT)(length / 2.0), length );
+  delay = length / 2.0;
+  targetDelay = delay;
+
+  loopFilter = new OneZero;
+  loopFilter->setZero(0.01);
+
+  envelope = new ADSR();
+  envelope->setAllTimes(0.001, 0.04, 0.0, 0.5);
+
+  noise = new Noise;
+  this->clear();
+}
+
+Sitar :: ~Sitar()
+{
+  delete delayLine;
+  delete loopFilter;
+  delete noise;
+  delete envelope;
+}
+
+void Sitar :: clear()
+{
+  delayLine->clear();
+  loopFilter->clear();
+}
+
+void Sitar :: setFrequency(MY_FLOAT frequency)
+{
+  MY_FLOAT freakency = frequency;
+  if ( frequency <= 0.0 ) {
+    cerr << "Sitar: setFrequency parameter is less than or equal to zero!" << endl;
+    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(MY_FLOAT amplitude)
+{
+  envelope->keyOn();
+}
+
+void Sitar :: noteOn(MY_FLOAT frequency, MY_FLOAT amplitude)
+{
+  setFrequency(frequency);
+  pluck(amplitude);
+  amGain = 0.1 * amplitude;
+
+#if defined(_STK_DEBUG_)
+  cerr << "Sitar: NoteOn frequency = " << frequency << ", amplitude = " << amplitude << endl;
+#endif
+}
+
+void Sitar :: noteOff(MY_FLOAT amplitude)
+{
+  loopGain = (MY_FLOAT) 1.0 - amplitude;
+  if ( loopGain < 0.0 ) {
+    cerr << "Plucked: noteOff amplitude greater than 1.0!" << endl;
+    loopGain = 0.0;
+  }
+  else if ( loopGain > 1.0 ) {
+    cerr << "Plucked: noteOff amplitude less than or zero!" << endl;
+    loopGain = (MY_FLOAT) 0.99999;
+  }
+
+#if defined(_STK_DEBUG_)
+  cerr << "Plucked: NoteOff amplitude = " << amplitude << endl;
+#endif
+}
+
+MY_FLOAT Sitar :: tick()
+{
+  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;
+}