Files
stk/src/OnePole.cpp
2014-04-11 09:10:58 -04:00

62 lines
1.4 KiB
C++

/***************************************************/
/*! \class OnePole
\brief STK one-pole filter class.
This class implements a one-pole digital filter. A method is
provided for setting the pole position along the real axis of the
z-plane while maintaining a constant peak filter gain.
by Perry R. Cook and Gary P. Scavone, 1995--2014.
*/
/***************************************************/
#include "OnePole.h"
namespace stk {
OnePole :: OnePole( StkFloat thePole )
{
b_.resize( 1 );
a_.resize( 2 );
a_[0] = 1.0;
inputs_.resize( 1, 1, 0.0 );
outputs_.resize( 2, 1, 0.0 );
this->setPole( thePole );
}
OnePole :: ~OnePole()
{
}
void OnePole :: setPole( StkFloat thePole )
{
if ( std::abs( thePole ) >= 1.0 ) {
oStream_ << "OnePole::setPole: argument (" << thePole << ") should be less than 1.0!";
handleError( StkError::WARNING ); return;
}
// Normalize coefficients for peak unity gain.
if ( thePole > 0.0 )
b_[0] = (StkFloat) (1.0 - thePole);
else
b_[0] = (StkFloat) (1.0 + thePole);
a_[1] = -thePole;
}
void OnePole :: setCoefficients( StkFloat b0, StkFloat a1, bool clearState )
{
if ( std::abs( a1 ) >= 1.0 ) {
oStream_ << "OnePole::setCoefficients: a1 argument (" << a1 << ") should be less than 1.0!";
handleError( StkError::WARNING ); return;
}
b_[0] = b0;
a_[1] = a1;
if ( clearState ) this->clear();
}
} // stk namespace