Version 4.4.3

include/Cubic.h

@@ -0,0 +1,138 @@
+#ifndef STK_CUBIC_H
+#define STK_CUBIC_H
+
+#include "Function.h"
+#include <cmath>
+
+namespace stk {
+
+/***************************************************/
+/*! \class Cubic
+    \brief STK cubic non-linearity class.
+
+    This class implements the cubic non-linearity
+    that was used in SynthBuilder.
+
+    The formula implemented is:
+ 
+    \code
+    output = gain * (a1 * input + a2 * input^2 + a3 * input^3)
+    \endcode
+
+    followed by a limiter for values outside +-threshold.
+
+    Ported to STK by Nick Porcaro, 2007. Updated for inclusion
+    in STK distribution by Gary Scavone, 2011.
+*/
+/***************************************************/
+
+class Cubic : public Function
+{
+public:
+  //! Default constructor.
+  Cubic( void ) : a1_(0.5), a2_(0.5), a3_(0.5), gain_(1.0), threshold_(1.0) {};
+
+  //! Set the a1 coefficient value.
+  void setA1( StkFloat a1 ) { a1_ = a1; };
+
+  //! Set the a2 coefficient value.
+  void setA2( StkFloat a2 )  { a2_ = a2; };
+
+  //! Set the a3 coefficient value.
+  void setA3( StkFloat a3 )  { a3_ = a3; };
+
+  //! Set the gain value.
+  void setGain( StkFloat gain ) { gain_ = gain; };
+
+  //! Set the threshold value.
+  void setThreshold( StkFloat threshold ) { threshold_ = threshold; };
+
+  //! Input one sample to the function and return one output.
+  StkFloat tick( StkFloat input );
+
+  //! Take a channel of the StkFrames object as inputs to the function and replace with corresponding outputs.
+  /*!
+    The StkFrames argument reference is returned.  The \c channel
+    argument must be less than the number of channels in the
+    StkFrames argument (the first channel is specified by 0).
+    However, range checking is only performed if _STK_DEBUG_ is
+    defined during compilation, in which case an out-of-range value
+    will trigger an StkError exception.
+  */
+  StkFrames& tick( StkFrames& frames, unsigned int channel = 0 );
+
+  //! Take a channel of the \c iFrames object as inputs to the function and write outputs to the \c oFrames object.
+  /*!
+    The \c iFrames object reference is returned.  Each channel
+    argument must be less than the number of channels in the
+    corresponding StkFrames argument (the first channel is specified
+    by 0).  However, range checking is only performed if _STK_DEBUG_
+    is defined during compilation, in which case an out-of-range value
+    will trigger an StkError exception.
+  */
+  StkFrames& tick( StkFrames& iFrames, StkFrames &oFrames, unsigned int iChannel = 0, unsigned int oChannel = 0 );
+
+protected:
+
+  StkFloat a1_;
+  StkFloat a2_;
+  StkFloat a3_;
+  StkFloat gain_; 
+  StkFloat threshold_;
+};
+
+inline StkFloat Cubic :: tick( StkFloat input )
+{
+  StkFloat inSquared = input * input;
+  StkFloat inCubed = inSquared * input;
+
+  lastFrame_[0] = gain_ * (a1_ * input + a2_ * inSquared + a3_ * inCubed);
+
+  // Apply threshold if we are out of range.
+  if ( fabs( lastFrame_[0] ) > threshold_ ) {
+    lastFrame_[0] = ( lastFrame_[0] < 0 ? -threshold_ : threshold_ );
+  }
+
+  return lastFrame_[0];
+}
+
+inline StkFrames& Cubic :: tick( StkFrames& frames, unsigned int channel )
+{
+#if defined(_STK_DEBUG_)
+  if ( channel >= frames.channels() ) {
+    oStream_ << "Cubic::tick(): channel and StkFrames arguments are incompatible!";
+    handleError( StkError::FUNCTION_ARGUMENT );
+  }
+#endif
+
+  StkFloat *samples = &frames[channel];
+  unsigned int hop = frames.channels();
+  for ( unsigned int i=0; i<frames.frames(); i++, samples += hop )
+    *samples = tick( *samples );
+
+  lastFrame_[0] = *(samples-hop);
+  return frames;
+}
+
+inline StkFrames& Cubic :: tick( StkFrames& iFrames, StkFrames& oFrames, unsigned int iChannel, unsigned int oChannel )
+{
+#if defined(_STK_DEBUG_)
+  if ( iChannel >= iFrames.channels() || oChannel >= oFrames.channels() ) {
+    oStream_ << "Cubic::tick(): channel and StkFrames arguments are incompatible!";
+    handleError( StkError::FUNCTION_ARGUMENT );
+  }
+#endif
+
+  StkFloat *iSamples = &iFrames[iChannel];
+  StkFloat *oSamples = &oFrames[oChannel];
+  unsigned int iHop = iFrames.channels(), oHop = oFrames.channels();
+  for ( unsigned int i=0; i<iFrames.frames(); i++, iSamples += iHop, oSamples += oHop )
+    *oSamples = tick( *iSamples );
+
+  lastFrame_[0] = *(oSamples-oHop);
+  return iFrames;
+}
+
+} // stk namespace
+
+#endif