Version 4.4.0

include/FormSwep.h

@@ -1,32 +1,35 @@
+#ifndef STK_FORMSWEP_H
+#define STK_FORMSWEP_H
+
+#include "Filter.h"
+
+namespace stk {
+
 /***************************************************/
 /*! \class FormSwep
     \brief STK sweepable formant filter class.
 
-    This public BiQuad filter subclass implements
-    a formant (resonance) which can be "swept"
-    over time from one frequency setting to another.
-    It provides methods for controlling the sweep
-    rate and target frequency.
+    This class implements a formant (resonance) which can be "swept"
+    over time from one frequency setting to another.  It provides
+    methods for controlling the sweep rate and target frequency.
 
-    by Perry R. Cook and Gary P. Scavone, 1995 - 2007.
+    by Perry R. Cook and Gary P. Scavone, 1995 - 2009.
 */
 /***************************************************/
 
-#ifndef STK_FORMSWEP_H
-#define STK_FORMSWEP_H
-
-#include "BiQuad.h"
-
-class FormSwep : public BiQuad
+class FormSwep : public Filter
 {
  public:
 
   //! Default constructor creates a second-order pass-through filter.
-  FormSwep();
+  FormSwep( void );
 
   //! Class destructor.
   ~FormSwep();
 
+  //! A function to enable/disable the automatic updating of class data when the STK sample rate changes.
+  void ignoreSampleRateChange( bool ignore = true ) { ignoreSampleRateChange_ = ignore; };
+
   //! Sets the filter coefficients for a resonance at \e frequency (in Hz).
   /*!
     This method determines the filter coefficients corresponding to
@@ -39,13 +42,13 @@ class FormSwep : public BiQuad
     the unit-circle (\e radius close to one), the narrower the
     resulting resonance width.
   */
-  void setResonance(StkFloat frequency, StkFloat radius);
+  void setResonance( StkFloat frequency, StkFloat radius );
 
   //! Set both the current and target resonance parameters.
-  void setStates(StkFloat frequency, StkFloat radius, StkFloat gain = 1.0);
+  void setStates( StkFloat frequency, StkFloat radius, StkFloat gain = 1.0 );
 
   //! Set target resonance parameters.
-  void setTargets(StkFloat frequency, StkFloat radius, StkFloat gain = 1.0);
+  void setTargets( StkFloat frequency, StkFloat radius, StkFloat gain = 1.0 );
 
   //! Set the sweep rate (between 0.0 - 1.0).
   /*!
@@ -56,7 +59,7 @@ class FormSwep : public BiQuad
     target values.  A sweep rate of 0.0 will produce no
     change in resonance parameters.  
   */
-  void setSweepRate(StkFloat rate);
+  void setSweepRate( StkFloat rate );
 
   //! Set the sweep rate in terms of a time value in seconds.
   /*!
@@ -64,11 +67,39 @@ class FormSwep : public BiQuad
     given time for the formant parameters to reach
     their target values.
   */
-  void setSweepTime(StkFloat time);
+  void setSweepTime( StkFloat time );
+
+  //! Return the last computed output value.
+  StkFloat lastOut( void ) const { return lastFrame_[0]; };
+
+  //! Input one sample to the filter and return a reference to one output.
+  StkFloat tick( StkFloat input );
+
+  //! Take a channel of the StkFrames object as inputs to the filter 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 filter 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 computeSample( StkFloat input );
+  virtual void sampleRateChanged( StkFloat newRate, StkFloat oldRate );
 
   bool dirty_;
   StkFloat frequency_;
@@ -87,4 +118,71 @@ class FormSwep : public BiQuad
 
 };
 
+inline StkFloat FormSwep :: tick( StkFloat input )
+{                                     
+  if ( dirty_ )  {
+    sweepState_ += sweepRate_;
+    if ( sweepState_ >= 1.0 )   {
+      sweepState_ = 1.0;
+      dirty_ = false;
+      radius_ = targetRadius_;
+      frequency_ = targetFrequency_;
+      gain_ = targetGain_;
+    }
+    else {
+      radius_ = startRadius_ + (deltaRadius_ * sweepState_);
+      frequency_ = startFrequency_ + (deltaFrequency_ * sweepState_);
+      gain_ = startGain_ + (deltaGain_ * sweepState_);
+    }
+    this->setResonance( frequency_, radius_ );
+  }
+
+  inputs_[0] = gain_ * input;
+  lastFrame_[0] = b_[0] * inputs_[0] + b_[1] * inputs_[1] + b_[2] * inputs_[2];
+  lastFrame_[0] -= a_[2] * outputs_[2] + a_[1] * outputs_[1];
+  inputs_[2] = inputs_[1];
+  inputs_[1] = inputs_[0];
+  outputs_[2] = outputs_[1];
+  outputs_[1] = lastFrame_[0];
+
+  return lastFrame_[0];
+}
+
+inline StkFrames& FormSwep :: tick( StkFrames& frames, unsigned int channel )
+{
+#if defined(_STK_DEBUG_)
+  if ( channel >= frames.channels() ) {
+    errorString_ << "FormSwep::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 );
+
+  return frames;
+}
+
+inline StkFrames& FormSwep :: tick( StkFrames& iFrames, StkFrames& oFrames, unsigned int iChannel, unsigned int oChannel )
+{
+#if defined(_STK_DEBUG_)
+  if ( iChannel >= iFrames.channels() || oChannel >= oFrames.channels() ) {
+    errorString_ << "FormSwep::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 );
+
+  return iFrames;
+}
+
+} // stk namespace
+
 #endif