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Twang.h

00001 #ifndef STK_TWANG_H
00002 #define STK_TWANG_H
00003 
00004 #include "Stk.h"
00005 #include "DelayA.h"
00006 #include "DelayL.h"
00007 #include "Fir.h"
00008 
00009 namespace stk {
00010 
00011 /***************************************************/
00032 /***************************************************/
00033 
00034 class Twang : public Stk
00035 {
00036  public:
00038   Twang( StkFloat lowestFrequency = 50.0 );
00039 
00041   ~Twang( void );
00042 
00044   void clear( void );
00045 
00047   void setLowestFrequency( StkFloat frequency );
00048 
00050   void setFrequency( StkFloat frequency );
00051 
00053   void setPluckPosition( StkFloat position );
00054 
00056 
00062   void setLoopGain( StkFloat loopGain );
00063 
00065 
00070   void setLoopFilter( std::vector<StkFloat> coefficients );
00071 
00073   const StkFrames& lastFrame( void ) const { return lastFrame_; };
00074 
00076   StkFloat tick( StkFloat input );
00077 
00079 
00087   StkFrames& tick( StkFrames& frames, unsigned int channel = 0 );
00088 
00090 
00098   StkFrames& tick( StkFrames& iFrames, StkFrames &oFrames, unsigned int iChannel = 0, unsigned int oChannel = 0 );
00099 
00100  protected:  
00101 
00102   DelayA   delayLine_;
00103   DelayL   combDelay_;
00104   Fir      loopFilter_;
00105 
00106   StkFrames lastFrame_;
00107   StkFloat frequency_;
00108   StkFloat loopGain_;
00109   StkFloat pluckPosition_;
00110 };
00111 
00112 inline StkFloat Twang :: tick( StkFloat input )
00113 {
00114   lastFrame_[0] = delayLine_.tick( input + loopFilter_.tick( delayLine_.lastOut() ) );
00115   lastFrame_[0] -= combDelay_.tick( lastFrame_[0] ); // comb filtering on output
00116 
00117   return lastFrame_[0] * 0.5;
00118 }
00119 
00120 inline StkFrames& Twang :: tick( StkFrames& frames, unsigned int channel )
00121 {
00122 #if defined(_STK_DEBUG_)
00123   if ( channel >= frames.channels() ) {
00124     oStream_ << "Twang::tick(): channel and StkFrames arguments are incompatible!";
00125     handleError( StkError::FUNCTION_ARGUMENT );
00126   }
00127 #endif
00128 
00129   StkFloat *samples = &frames[channel];
00130   unsigned int hop = frames.channels();
00131   for ( unsigned int i=0; i<frames.frames(); i++, samples += hop )
00132     *samples = tick( *samples );
00133 
00134   return frames;
00135 }
00136 
00137 inline StkFrames& Twang :: tick( StkFrames& iFrames, StkFrames& oFrames, unsigned int iChannel, unsigned int oChannel )
00138 {
00139 #if defined(_STK_DEBUG_)
00140   if ( iChannel >= iFrames.channels() || oChannel >= oFrames.channels() ) {
00141     oStream_ << "Twang::tick(): channel and StkFrames arguments are incompatible!";
00142     handleError( StkError::FUNCTION_ARGUMENT );
00143   }
00144 #endif
00145 
00146   StkFloat *iSamples = &iFrames[iChannel];
00147   StkFloat *oSamples = &oFrames[oChannel];
00148   unsigned int iHop = iFrames.channels(), oHop = oFrames.channels();
00149   for ( unsigned int i=0; i<iFrames.frames(); i++, iSamples += iHop, oSamples += oHop )
00150     *oSamples = tick( *iSamples );
00151 
00152   return iFrames;
00153 }
00154 
00155 } // stk namespace
00156 
00157 #endif
00158 

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