mirror of
https://github.com/thestk/stk
synced 2026-01-12 12:31:53 +00:00
74 lines
1.8 KiB
C++
74 lines
1.8 KiB
C++
/***************************************************/
|
|
/*! \class Fir
|
|
\brief STK general finite impulse response filter class.
|
|
|
|
This class provides a generic digital filter structure that can be
|
|
used to implement FIR filters. For filters with feedback terms,
|
|
the Iir class should be used.
|
|
|
|
In particular, this class implements the standard difference
|
|
equation:
|
|
|
|
y[n] = b[0]*x[n] + ... + b[nb]*x[n-nb]
|
|
|
|
The \e gain parameter is applied at the filter input and does not
|
|
affect the coefficient values. The default gain value is 1.0.
|
|
This structure results in one extra multiply per computed sample,
|
|
but allows easy control of the overall filter gain.
|
|
|
|
by Perry R. Cook and Gary P. Scavone, 1995 - 2009.
|
|
*/
|
|
/***************************************************/
|
|
|
|
#include "Fir.h"
|
|
|
|
namespace stk {
|
|
|
|
Fir :: Fir()
|
|
{
|
|
// The default constructor should setup for pass-through.
|
|
b_.push_back( 1.0 );
|
|
|
|
inputs_.resize( 1, 1, 0.0 );
|
|
}
|
|
|
|
Fir :: Fir( std::vector<StkFloat> &coefficients )
|
|
{
|
|
// Check the arguments.
|
|
if ( coefficients.size() == 0 ) {
|
|
errorString_ << "Fir: coefficient vector must have size > 0!";
|
|
handleError( StkError::FUNCTION_ARGUMENT );
|
|
}
|
|
|
|
gain_ = 1.0;
|
|
b_ = coefficients;
|
|
|
|
inputs_.resize( b_.size(), 1, 0.0 );
|
|
this->clear();
|
|
}
|
|
|
|
Fir :: ~Fir()
|
|
{
|
|
}
|
|
|
|
void Fir :: setCoefficients( std::vector<StkFloat> &coefficients, bool clearState )
|
|
{
|
|
// Check the argument.
|
|
if ( coefficients.size() == 0 ) {
|
|
errorString_ << "Fir::setCoefficients: coefficient vector must have size > 0!";
|
|
handleError( StkError::FUNCTION_ARGUMENT );
|
|
}
|
|
|
|
if ( b_.size() != coefficients.size() ) {
|
|
b_ = coefficients;
|
|
inputs_.resize( b_.size(), 1, 0.0 );
|
|
}
|
|
else {
|
|
for ( unsigned int i=0; i<b_.size(); i++ ) b_[i] = coefficients[i];
|
|
}
|
|
|
|
if ( clearState ) this->clear();
|
|
}
|
|
|
|
} // stk namespace
|