Move library tree where it belongs

lib-src/libnyquist/nyquist/nyqstk/src/PRCRev.cpp

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+/***************************************************/
+/*! \class PRCRev
+    \brief Perry's simple reverberator class.
+
+    This class is based on some of the famous
+    Stanford/CCRMA reverbs (NRev, KipRev), which
+    were based on the Chowning/Moorer/Schroeder
+    reverberators using networks of simple allpass
+    and comb delay filters.  This class implements
+    two series allpass units and two parallel comb
+    filters.
+
+    by Perry R. Cook and Gary P. Scavone, 1995 - 2005.
+*/
+/***************************************************/
+
+#include "PRCRev.h"
+#include <math.h>
+
+using namespace Nyq;
+
+PRCRev :: PRCRev(StkFloat T60)
+{
+  // Delay lengths for 44100 Hz sample rate.
+  int lengths[4]= {353, 1097, 1777, 2137};
+  double scaler = Stk::sampleRate() / 44100.0;
+
+  // Scale the delay lengths if necessary.
+  int delay, i;
+  if ( scaler != 1.0 ) {
+    for (i=0; i<4; i++)	{
+      delay = (int) floor(scaler * lengths[i]);
+      if ( (delay & 1) == 0) delay++;
+      while ( !this->isPrime(delay) ) delay += 2;
+      lengths[i] = delay;
+    }
+  }
+
+  for (i=0; i<2; i++)	{
+	  allpassDelays_[i].setMaximumDelay( lengths[i] );
+	  allpassDelays_[i].setDelay( lengths[i] );
+
+    combDelays_[i].setMaximumDelay( lengths[i+2] );
+    combDelays_[i].setDelay( lengths[i+2] );
+  }
+
+  this->setT60( T60 );
+  allpassCoefficient_ = 0.7;
+  effectMix_ = 0.5;
+  this->clear();
+}
+
+PRCRev :: ~PRCRev()
+{
+}
+
+void PRCRev :: clear()
+{
+  allpassDelays_[0].clear();
+  allpassDelays_[1].clear();
+  combDelays_[0].clear();
+  combDelays_[1].clear();
+  lastOutput_[0] = 0.0;
+  lastOutput_[1] = 0.0;
+}
+
+void PRCRev :: setT60( StkFloat T60 )
+{
+  combCoefficient_[0] = pow(10.0, (-3.0 * combDelays_[0].getDelay() / (T60 * Stk::sampleRate())));
+  combCoefficient_[1] = pow(10.0, (-3.0 * combDelays_[1].getDelay() / (T60 * Stk::sampleRate())));
+}
+
+StkFloat PRCRev :: computeSample(StkFloat input)
+{
+  StkFloat temp, temp0, temp1, temp2, temp3;
+
+  temp = allpassDelays_[0].lastOut();
+  temp0 = allpassCoefficient_ * temp;
+  temp0 += input;
+  allpassDelays_[0].tick(temp0);
+  temp0 = -(allpassCoefficient_ * temp0) + temp;
+    
+  temp = allpassDelays_[1].lastOut();
+  temp1 = allpassCoefficient_ * temp;
+  temp1 += temp0;
+  allpassDelays_[1].tick(temp1);
+  temp1 = -(allpassCoefficient_ * temp1) + temp;
+    
+  temp2 = temp1 + (combCoefficient_[0] * combDelays_[0].lastOut());
+  temp3 = temp1 + (combCoefficient_[1] * combDelays_[1].lastOut());
+
+  lastOutput_[0] = effectMix_ * (combDelays_[0].tick(temp2));
+  lastOutput_[1] = effectMix_ * (combDelays_[1].tick(temp3));
+  temp = (1.0 - effectMix_) * input;
+  lastOutput_[0] += temp;
+  lastOutput_[1] += temp;
+    
+  return Effect::lastOut();
+}
+