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STK one-zero filter class. More...
#include <OneZero.h>
Public Member Functions | |
OneZero (StkFloat theZero=-1.0) | |
The default constructor creates a low-pass filter (zero at z = -1.0). | |
~OneZero () | |
Class destructor. | |
void | setB0 (StkFloat b0) |
Set the b[0] coefficient value. | |
void | setB1 (StkFloat b1) |
Set the b[1] coefficient value. | |
void | setCoefficients (StkFloat b0, StkFloat b1, bool clearState=false) |
Set all filter coefficients. | |
void | setZero (StkFloat theZero) |
Set the zero 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. | |
StkFrames & | tick (StkFrames &iFrames, StkFrames &oFrames, unsigned int iChannel=0, unsigned int oChannel=0) |
Take a channel of the iFrames object as inputs to the filter and write outputs to the oFrames object. |
STK one-zero filter class.
This class implements a one-zero digital filter. A method is provided for setting the zero position along the real axis of the z-plane while maintaining a constant filter gain.
by Perry R. Cook and Gary P. Scavone, 1995-2011.
void stk::OneZero::setZero | ( | StkFloat | theZero | ) |
Set the zero position in the z-plane.
This method sets the zero position along the real-axis of the z-plane and normalizes the coefficients for a maximum gain of one. A positive zero value produces a high-pass filter, while a negative zero value produces a low-pass filter. This method does not affect the filter gain value.
Take a channel of the StkFrames object as inputs to the filter and replace with corresponding outputs.
The StkFrames argument reference is returned. 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.
00089 { 00090 #if defined(_STK_DEBUG_) 00091 if ( channel >= frames.channels() ) { 00092 oStream_ << "OneZero::tick(): channel and StkFrames arguments are incompatible!"; 00093 handleError( StkError::FUNCTION_ARGUMENT ); 00094 } 00095 #endif 00096 00097 StkFloat *samples = &frames[channel]; 00098 unsigned int hop = frames.channels(); 00099 for ( unsigned int i=0; i<frames.frames(); i++, samples += hop ) { 00100 inputs_[0] = gain_ * *samples; 00101 *samples = b_[1] * inputs_[1] + b_[0] * inputs_[0]; 00102 inputs_[1] = inputs_[0]; 00103 } 00104 00105 lastFrame_[0] = *(samples-hop); 00106 return frames; 00107 }
StkFrames & stk::OneZero::tick | ( | StkFrames & | iFrames, | |
StkFrames & | oFrames, | |||
unsigned int | iChannel = 0 , |
|||
unsigned int | oChannel = 0 | |||
) | [inline] |
Take a channel of the iFrames
object as inputs to the filter and write outputs to the oFrames
object.
The iFrames
object reference is returned. Each channel argument must be less than the number of channels in the corresponding 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.
00110 { 00111 #if defined(_STK_DEBUG_) 00112 if ( iChannel >= iFrames.channels() || oChannel >= oFrames.channels() ) { 00113 oStream_ << "OneZero::tick(): channel and StkFrames arguments are incompatible!"; 00114 handleError( StkError::FUNCTION_ARGUMENT ); 00115 } 00116 #endif 00117 00118 StkFloat *iSamples = &iFrames[iChannel]; 00119 StkFloat *oSamples = &oFrames[oChannel]; 00120 unsigned int iHop = iFrames.channels(), oHop = oFrames.channels(); 00121 for ( unsigned int i=0; i<iFrames.frames(); i++, iSamples += iHop, oSamples += oHop ) { 00122 inputs_[0] = gain_ * *iSamples; 00123 *oSamples = b_[1] * inputs_[1] + b_[0] * inputs_[0]; 00124 inputs_[1] = inputs_[0]; 00125 } 00126 00127 lastFrame_[0] = *(oSamples-oHop); 00128 return iFrames; 00129 }
The Synthesis ToolKit in C++ (STK) |
©1995-2011 Perry R. Cook and Gary P. Scavone. All Rights Reserved. |