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https://github.com/thestk/stk
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75 lines
1.8 KiB
C++
75 lines
1.8 KiB
C++
/***************************************************/
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/*! \class Fir
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\brief STK general finite impulse response filter class.
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This class provides a generic digital filter structure that can be
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used to implement FIR filters. For filters with feedback terms,
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the Iir class should be used.
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In particular, this class implements the standard difference
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equation:
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y[n] = b[0]*x[n] + ... + b[nb]*x[n-nb]
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The \e gain parameter is applied at the filter input and does not
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affect the coefficient values. The default gain value is 1.0.
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This structure results in one extra multiply per computed sample,
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but allows easy control of the overall filter gain.
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by Perry R. Cook and Gary P. Scavone, 1995--2023.
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*/
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/***************************************************/
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#include "Fir.h"
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#include <cmath>
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namespace stk {
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Fir :: Fir()
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{
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// The default constructor should setup for pass-through.
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b_.push_back( 1.0 );
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inputs_.resize( 1, 1, 0.0 );
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}
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Fir :: Fir( std::vector<StkFloat> &coefficients )
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{
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// Check the arguments.
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if ( coefficients.size() == 0 ) {
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oStream_ << "Fir: coefficient vector must have size > 0!";
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handleError( StkError::FUNCTION_ARGUMENT );
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}
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gain_ = 1.0;
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b_ = coefficients;
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inputs_.resize( b_.size(), 1, 0.0 );
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this->clear();
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}
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Fir :: ~Fir()
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{
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}
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void Fir :: setCoefficients( std::vector<StkFloat> &coefficients, bool clearState )
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{
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// Check the argument.
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if ( coefficients.size() == 0 ) {
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oStream_ << "Fir::setCoefficients: coefficient vector must have size > 0!";
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handleError( StkError::FUNCTION_ARGUMENT );
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}
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if ( b_.size() != coefficients.size() ) {
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b_ = coefficients;
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inputs_.resize( b_.size(), 1, 0.0 );
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}
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else {
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for ( unsigned int i=0; i<b_.size(); i++ ) b_[i] = coefficients[i];
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}
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if ( clearState ) this->clear();
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}
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} // stk namespace
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