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OnePole.h

00001 #ifndef STK_ONEPOLE_H
00002 #define STK_ONEPOLE_H
00003 
00004 #include "Filter.h"
00005 
00006 namespace stk {
00007 
00008 /***************************************************/
00018 /***************************************************/
00019 
00020 class OnePole : public Filter
00021 {
00022 public:
00023 
00025   OnePole( StkFloat thePole = 0.9 );
00026 
00028   ~OnePole();
00029 
00031   void setB0( StkFloat b0 ) { b_[0] = b0; };
00032 
00034   void setA1( StkFloat a1 ) { a_[1] = a1; };
00035 
00037   void setCoefficients( StkFloat b0, StkFloat a1, bool clearState = false );
00038 
00040 
00048   void setPole( StkFloat thePole );
00049 
00051   StkFloat lastOut( void ) const { return lastFrame_[0]; };
00052 
00054   StkFloat tick( StkFloat input );
00055 
00057 
00065   StkFrames& tick( StkFrames& frames, unsigned int channel = 0 );
00066 
00068 
00076   StkFrames& tick( StkFrames& iFrames, StkFrames &oFrames, unsigned int iChannel = 0, unsigned int oChannel = 0 );
00077 
00078 };
00079 
00080 inline StkFloat OnePole :: tick( StkFloat input )
00081 {
00082   inputs_[0] = gain_ * input;
00083   lastFrame_[0] = b_[0] * inputs_[0] - a_[1] * outputs_[1];
00084   outputs_[1] = lastFrame_[0];
00085 
00086   return lastFrame_[0];
00087 }
00088 
00089 inline StkFrames& OnePole :: tick( StkFrames& frames, unsigned int channel )
00090 {
00091 #if defined(_STK_DEBUG_)
00092   if ( channel >= frames.channels() ) {
00093     oStream_ << "OnePole::tick(): channel and StkFrames arguments are incompatible!";
00094     handleError( StkError::FUNCTION_ARGUMENT );
00095   }
00096 #endif
00097 
00098   StkFloat *samples = &frames[channel];
00099   unsigned int hop = frames.channels();
00100   for ( unsigned int i=0; i<frames.frames(); i++, samples += hop ) {
00101     inputs_[0] = gain_ * *samples;
00102     *samples = b_[0] * inputs_[0] - a_[1] * outputs_[1];
00103     outputs_[1] = *samples;
00104   }
00105 
00106   lastFrame_[0] = outputs_[1];
00107   return frames;
00108 }
00109 
00110 inline StkFrames& OnePole :: tick( StkFrames& iFrames, StkFrames& oFrames, unsigned int iChannel, unsigned int oChannel )
00111 {
00112 #if defined(_STK_DEBUG_)
00113   if ( iChannel >= iFrames.channels() || oChannel >= oFrames.channels() ) {
00114     oStream_ << "OnePole::tick(): channel and StkFrames arguments are incompatible!";
00115     handleError( StkError::FUNCTION_ARGUMENT );
00116   }
00117 #endif
00118 
00119   StkFloat *iSamples = &iFrames[iChannel];
00120   StkFloat *oSamples = &oFrames[oChannel];
00121   unsigned int iHop = iFrames.channels(), oHop = oFrames.channels();
00122   for ( unsigned int i=0; i<iFrames.frames(); i++, iSamples += iHop, oSamples += oHop ) {
00123     inputs_[0] = gain_ * *iSamples;
00124     *oSamples = b_[0] * inputs_[0] - a_[1] * outputs_[1];
00125     outputs_[1] = *oSamples;
00126   }
00127 
00128   lastFrame_[0] = outputs_[1];
00129   return iFrames;
00130 }
00131 
00132 } // stk namespace
00133 
00134 #endif

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