Version 4.0

src/Modal.cpp

@@ -0,0 +1,225 @@
+/***************************************************/
+/*! \class Modal
+    \brief STK resonance model instrument.
+
+    This class contains an excitation wavetable,
+    an envelope, an oscillator, and N resonances
+    (non-sweeping BiQuad filters), where N is set
+    during instantiation.
+
+    by Perry R. Cook and Gary P. Scavone, 1995 - 2002.
+*/
+/***************************************************/
+
+#include "Modal.h"
+#include <string.h>
+#include <stdlib.h>
+
+Modal :: Modal(int modes)
+  : nModes(modes)
+{
+  if ( nModes <= 0 ) {
+    char msg[256];
+    sprintf(msg, "Modal: Invalid number of modes (%d) argument to constructor!", modes);
+    handleError(msg, StkError::FUNCTION_ARGUMENT);
+  }
+
+  // We don't make the excitation wave here yet, because we don't know
+  // what it's going to be.
+
+  ratios = (MY_FLOAT *) new MY_FLOAT[nModes];
+  radii = (MY_FLOAT *) new MY_FLOAT[nModes];
+  filters = (BiQuad **) calloc( nModes, sizeof(BiQuad *) );
+  for (int i=0; i<nModes; i++ ) {
+    filters[i] = new BiQuad;
+    filters[i]->setEqualGainZeroes();
+  }
+
+  envelope = new Envelope;
+  onepole = new OnePole;
+
+  // Concatenate the STK RAWWAVE_PATH to the rawwave file
+  char file[128];
+  strcpy(file, RAWWAVE_PATH);
+  vibrato = new WaveLoop( strcat(file,"rawwaves/sinewave.raw"), TRUE);
+
+  // Set some default values.
+  vibrato->setFrequency( 6.0 );
+  vibratoGain = 0.0;
+  directGain = 0.0;
+  masterGain = 1.0;
+  baseFrequency = 440.0;
+
+  this->clear();
+
+  stickHardness =  0.5;
+  strikePosition = 0.561;
+}  
+
+Modal :: ~Modal()
+{
+  delete envelope; 
+  delete onepole;
+  delete vibrato;
+
+  delete [] ratios;
+  delete [] radii;
+  for (int i=0; i<nModes; i++ ) {
+    delete filters[i];
+  }
+  free(filters);
+}
+
+void Modal :: clear()
+{    
+  onepole->clear();
+  for (int i=0; i<nModes; i++ )
+    filters[i]->clear();
+}
+
+void Modal :: setFrequency(MY_FLOAT frequency)
+{
+  baseFrequency = frequency;
+  for (int i=0; i<nModes; i++ )
+    this->setRatioAndRadius(i, ratios[i], radii[i]);
+}
+
+void Modal :: setRatioAndRadius(int modeIndex, MY_FLOAT ratio, MY_FLOAT radius)
+{
+  if ( modeIndex < 0 ) {
+    cerr << "Modal: setRatioAndRadius modeIndex parameter is less than zero!" << endl;
+    return;
+  }
+  else if ( modeIndex >= nModes ) {
+    cerr << "Modal: setRatioAndRadius modeIndex parameter is greater than the number of operators!" << endl;
+    return;
+  }
+
+  MY_FLOAT nyquist = Stk::sampleRate() / 2.0;
+  MY_FLOAT temp;
+
+  if (ratio * baseFrequency < nyquist) {
+    ratios[modeIndex] = ratio;
+  }
+  else {
+    temp = ratio;
+    while (temp * baseFrequency > nyquist) temp *= (MY_FLOAT) 0.5;
+    ratios[modeIndex] = temp;
+#if defined(_STK_DEBUG_)
+    cerr << "Modal : Aliasing would occur here ... correcting." << endl;
+#endif
+  }
+  radii[modeIndex] = radius;
+  if (ratio < 0) 
+    temp = -ratio;
+  else
+    temp = ratio*baseFrequency;
+
+  filters[modeIndex]->setResonance(temp, radius);
+}
+
+void Modal :: setMasterGain(MY_FLOAT aGain)
+{
+  masterGain = aGain;
+}
+
+void Modal :: setDirectGain(MY_FLOAT aGain)
+{
+  directGain = aGain;
+}
+
+void Modal :: setModeGain(int modeIndex, MY_FLOAT gain)
+{
+  if ( modeIndex < 0 ) {
+    cerr << "Modal: setModeGain modeIndex parameter is less than zero!" << endl;
+    return;
+  }
+  else if ( modeIndex >= nModes ) {
+    cerr << "Modal: setModeGain modeIndex parameter is greater than the number of operators!" << endl;
+    return;
+  }
+
+  filters[modeIndex]->setGain(gain);
+}
+
+void Modal :: strike(MY_FLOAT amplitude)
+{
+  MY_FLOAT gain = amplitude;
+  if ( amplitude < 0.0 ) {
+    cerr << "Modal: strike amplitude is less than zero!" << endl;
+    gain = 0.0;
+  }
+  else if ( amplitude > 1.0 ) {
+    cerr << "Modal: strike amplitude is greater than 1.0!" << endl;
+    gain = 1.0;
+  }
+
+  envelope->setRate(1.0);
+  envelope->setTarget(gain);
+  onepole->setPole(1.0 - gain);
+  envelope->tick();
+  wave->reset();
+
+  MY_FLOAT temp;
+  for (int i=0; i<nModes; i++) {
+    if (ratios[i] < 0)
+      temp = -ratios[i];
+    else
+      temp = ratios[i] * baseFrequency;
+    filters[i]->setResonance(temp, radii[i]);
+  }
+}
+
+void Modal :: noteOn(MY_FLOAT frequency, MY_FLOAT amplitude)
+{
+  this->strike(amplitude);
+  this->setFrequency(frequency);
+
+#if defined(_STK_DEBUG_)
+  cerr << "Modal: NoteOn frequency = " << frequency << ", amplitude = " << amplitude << endl;
+#endif
+}
+
+void Modal :: noteOff(MY_FLOAT amplitude)
+{
+  // This calls damp, but inverts the meaning of amplitude (high
+  // amplitude means fast damping).
+  this->damp(1.0 - (amplitude * 0.03));
+
+#if defined(_STK_DEBUG_)
+  cerr << "Modal: NoteOff amplitude = " << amplitude << endl;
+#endif
+}
+
+void Modal :: damp(MY_FLOAT amplitude)
+{
+  MY_FLOAT temp;
+  for (int i=0; i<nModes; i++) {
+    if (ratios[i] < 0)
+      temp = -ratios[i];
+    else
+      temp = ratios[i] * baseFrequency;
+    filters[i]->setResonance(temp, radii[i]*amplitude);
+  }
+}
+
+MY_FLOAT Modal :: tick()
+{
+  MY_FLOAT temp = masterGain * onepole->tick(wave->tick() * envelope->tick());
+
+  MY_FLOAT temp2 = 0.0;
+  for (int i=0; i<nModes; i++)
+    temp2 += filters[i]->tick(temp);
+
+  temp2  -= temp2 * directGain;
+  temp2 += directGain * temp;
+
+  if (vibratoGain != 0.0)	{
+    // Calculate AM and apply to master out
+    temp = 1.0 + (vibrato->tick() * vibratoGain);
+    temp2 = temp * temp2;
+  }
+    
+  lastOutput = temp2;
+  return lastOutput;
+}