Home Information Classes Download Usage Mail List Requirements Links FAQ Tutorial
STK one-pole, one-zero filter class. More...
#include <PoleZero.h>
Public Member Functions | |
PoleZero () | |
Default constructor creates a first-order pass-through filter. | |
~PoleZero () | |
Class destructor. | |
void | setB0 (StkFloat b0) |
Set the b[0] coefficient value. | |
void | setB1 (StkFloat b1) |
Set the b[1] coefficient value. | |
void | setA1 (StkFloat a1) |
Set the a[1] coefficient value. | |
void | setCoefficients (StkFloat b0, StkFloat b1, StkFloat a1, bool clearState=false) |
Set all filter coefficients. | |
void | setAllpass (StkFloat coefficient) |
Set the filter for allpass behavior using coefficient. | |
void | setBlockZero (StkFloat thePole=0.99) |
Create a DC blocking filter with the given pole position in the z-plane. | |
StkFloat | lastOut (void) const |
Return the last computed output value. | |
StkFloat | tick (StkFloat input) |
Input one sample to the filter and return one output. | |
StkFrames & | tick (StkFrames &frames, unsigned int channel=0) |
Take a channel of the StkFrames object as inputs to the filter and replace with corresponding outputs. |
STK one-pole, one-zero filter class.
This class implements a one-pole, one-zero digital filter. A method is provided for creating an allpass filter with a given coefficient. Another method is provided to create a DC blocking filter.
by Perry R. Cook and Gary P. Scavone, 1995-2011.
void stk::PoleZero::setAllpass | ( | StkFloat | coefficient | ) |
Set the filter for allpass behavior using coefficient.
This method uses coefficient to create an allpass filter, which has unity gain at all frequencies. Note that the coefficient magnitude must be less than one to maintain filter stability.
void stk::PoleZero::setBlockZero | ( | StkFloat | thePole = 0.99 |
) |
Create a DC blocking filter with the given pole position in the z-plane.
This method sets the given pole position, together with a zero at z=1, to create a DC blocking filter. The argument magnitude should be close to (but less than) one to minimize low-frequency attenuation.
Take a channel of the StkFrames object as inputs to the filter and replace with corresponding outputs.
The channel
argument must be less than the number of channels in the StkFrames argument (the first channel is specified by 0). However, range checking is only performed if _STK_DEBUG_ is defined during compilation, in which case an out-of-range value will trigger an StkError exception.
Implements stk::Filter.
00090 { 00091 #if defined(_STK_DEBUG_) 00092 if ( channel >= frames.channels() ) { 00093 oStream_ << "PoleZero::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] + b_[1] * inputs_[1] - a_[1] * outputs_[1]; 00103 inputs_[1] = inputs_[0]; 00104 outputs_[1] = *samples; 00105 } 00106 00107 lastFrame_[0] = outputs_[1]; 00108 return frames; 00109 }
The Synthesis ToolKit in C++ (STK) |
©1995-2011 Perry R. Cook and Gary P. Scavone. All Rights Reserved. |