Move library tree where it belongs

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

@@ -0,0 +1,90 @@
+/***************************************************/
+/*! \class PitShift
+    \brief STK simple pitch shifter effect class.
+
+    This class implements a simple pitch shifter
+    using delay lines.
+
+    by Perry R. Cook and Gary P. Scavone, 1995 - 2005.
+*/
+/***************************************************/
+
+#include "PitShift.h"
+#include <cmath>
+
+using namespace Nyq;
+
+const int maxDelay = 5024;
+
+PitShift :: PitShift()
+{
+  delayLength = maxDelay - 24;
+  halfLength = delayLength / 2;
+  delay_[0] = 12;
+  delay_[1] = maxDelay / 2;
+
+  delayLine_[0].setMaximumDelay( maxDelay );
+  delayLine_[0].setDelay( delay_[0] );
+  delayLine_[1].setMaximumDelay( maxDelay );
+  delayLine_[1].setDelay( delay_[1] );
+  effectMix_ = 0.5;
+  rate_ = 1.0;
+}
+
+PitShift :: ~PitShift()
+{
+}
+
+void PitShift :: clear()
+{
+  delayLine_[0].clear();
+  delayLine_[1].clear();
+  lastOutput_[0] = 0.0;
+  lastOutput_[1] = 0.0;
+}
+
+void PitShift :: setShift(StkFloat shift)
+{
+  if (shift < 1.0) {
+    rate_ = 1.0 - shift; 
+  }
+  else if (shift > 1.0) {
+    rate_ = 1.0 - shift;
+  }
+  else {
+    rate_ = 0.0;
+    delay_[0] = halfLength+12;
+  }
+}
+
+StkFloat PitShift :: computeSample(StkFloat input)
+{
+  // Calculate the two delay length values, keeping them within the
+  // range 12 to maxDelay-12.
+  delay_[0] += rate_;
+  while (delay_[0] > maxDelay-12) delay_[0] -= delayLength;
+  while (delay_[0] < 12) delay_[0] += delayLength;
+
+  delay_[1] = delay_[0] + halfLength;
+  while (delay_[1] > maxDelay-12) delay_[1] -= delayLength;
+  while (delay_[1] < 12) delay_[1] += delayLength;
+
+  // Set the new delay line lengths.
+  delayLine_[0].setDelay((long)delay_[0]);
+  delayLine_[1].setDelay((long)delay_[1]);
+
+  // Calculate a triangular envelope.
+  env_[1] = fabs( (delay_[0] - halfLength + 12) * (1.0 / (halfLength+12) ) );
+  env_[0] = 1.0 - env_[1];
+
+  // Delay input and apply envelope.
+  lastOutput_[0] =  env_[0] * delayLine_[0].tick(input);
+  lastOutput_[0] += env_[1] * delayLine_[1].tick(input);
+
+  // Compute effect mix and output.
+  lastOutput_[0] *= effectMix_;
+  lastOutput_[0] += (1.0 - effectMix_) * input;
+  lastOutput_[1] = lastOutput_[0];
+
+  return lastOutput_[0];
+}