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00001 #ifndef STK_BIQUAD_H 00002 #define STK_BIQUAD_H 00003 00004 #include "Filter.h" 00005 00006 namespace stk { 00007 00008 /***************************************************/ 00018 /***************************************************/ 00019 00020 class BiQuad : public Filter 00021 { 00022 public: 00023 00025 BiQuad(); 00026 00028 ~BiQuad(); 00029 00031 void ignoreSampleRateChange( bool ignore = true ) { ignoreSampleRateChange_ = ignore; }; 00032 00034 void setCoefficients( StkFloat b0, StkFloat b1, StkFloat b2, StkFloat a1, StkFloat a2, bool clearState = false ); 00035 00037 void setB0( StkFloat b0 ) { b_[0] = b0; }; 00038 00040 void setB1( StkFloat b1 ) { b_[1] = b1; }; 00041 00043 void setB2( StkFloat b2 ) { b_[2] = b2; }; 00044 00046 void setA1( StkFloat a1 ) { a_[1] = a1; }; 00047 00049 void setA2( StkFloat a2 ) { a_[2] = a2; }; 00050 00052 00063 void setResonance( StkFloat frequency, StkFloat radius, bool normalize = false ); 00064 00066 00072 void setNotch( StkFloat frequency, StkFloat radius ); 00073 00075 00081 void setEqualGainZeroes( void ); 00082 00084 StkFloat lastOut( void ) const { return lastFrame_[0]; }; 00085 00087 StkFloat tick( StkFloat input ); 00088 00090 00098 StkFrames& tick( StkFrames& frames, unsigned int channel = 0 ); 00099 00101 00109 StkFrames& tick( StkFrames& iFrames, StkFrames &oFrames, unsigned int iChannel = 0, unsigned int oChannel = 0 ); 00110 00111 protected: 00112 00113 virtual void sampleRateChanged( StkFloat newRate, StkFloat oldRate ); 00114 }; 00115 00116 inline StkFloat BiQuad :: tick( StkFloat input ) 00117 { 00118 inputs_[0] = gain_ * input; 00119 lastFrame_[0] = b_[0] * inputs_[0] + b_[1] * inputs_[1] + b_[2] * inputs_[2]; 00120 lastFrame_[0] -= a_[2] * outputs_[2] + a_[1] * outputs_[1]; 00121 inputs_[2] = inputs_[1]; 00122 inputs_[1] = inputs_[0]; 00123 outputs_[2] = outputs_[1]; 00124 outputs_[1] = lastFrame_[0]; 00125 00126 return lastFrame_[0]; 00127 } 00128 00129 inline StkFrames& BiQuad :: tick( StkFrames& frames, unsigned int channel ) 00130 { 00131 #if defined(_STK_DEBUG_) 00132 if ( channel >= frames.channels() ) { 00133 errorString_ << "BiQuad::tick(): channel and StkFrames arguments are incompatible!"; 00134 handleError( StkError::FUNCTION_ARGUMENT ); 00135 } 00136 #endif 00137 00138 StkFloat *samples = &frames[channel]; 00139 unsigned int hop = frames.channels(); 00140 for ( unsigned int i=0; i<frames.frames(); i++, samples += hop ) { 00141 inputs_[0] = gain_ * *samples; 00142 *samples = b_[0] * inputs_[0] + b_[1] * inputs_[1] + b_[2] * inputs_[2]; 00143 *samples -= a_[2] * outputs_[2] + a_[1] * outputs_[1]; 00144 inputs_[2] = inputs_[1]; 00145 inputs_[1] = inputs_[0]; 00146 outputs_[2] = outputs_[1]; 00147 outputs_[1] = *samples; 00148 } 00149 00150 lastFrame_[0] = outputs_[1]; 00151 return frames; 00152 } 00153 00154 inline StkFrames& BiQuad :: tick( StkFrames& iFrames, StkFrames& oFrames, unsigned int iChannel, unsigned int oChannel ) 00155 { 00156 #if defined(_STK_DEBUG_) 00157 if ( iChannel >= iFrames.channels() || oChannel >= oFrames.channels() ) { 00158 errorString_ << "BiQuad::tick(): channel and StkFrames arguments are incompatible!"; 00159 handleError( StkError::FUNCTION_ARGUMENT ); 00160 } 00161 #endif 00162 00163 StkFloat *iSamples = &iFrames[iChannel]; 00164 StkFloat *oSamples = &oFrames[oChannel]; 00165 unsigned int iHop = iFrames.channels(), oHop = oFrames.channels(); 00166 for ( unsigned int i=0; i<iFrames.frames(); i++, iSamples += iHop, oSamples += oHop ) { 00167 inputs_[0] = gain_ * *iSamples; 00168 *oSamples = b_[0] * inputs_[0] + b_[1] * inputs_[1] + b_[2] * inputs_[2]; 00169 *oSamples -= a_[2] * outputs_[2] + a_[1] * outputs_[1]; 00170 inputs_[2] = inputs_[1]; 00171 inputs_[1] = inputs_[0]; 00172 outputs_[2] = outputs_[1]; 00173 outputs_[1] = *oSamples; 00174 } 00175 00176 lastFrame_[0] = outputs_[1]; 00177 return iFrames; 00178 } 00179 00180 } // stk namespace 00181 00182 #endif 00183
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