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#include <Filter.h>
Inheritance diagram for Filter:
This class implements a generic structure that can be used to create a wide range of filters. It can function independently or be subclassed to provide more specific controls based on a particular filter type.
In particular, this class implements the standard difference equation:
a[0]*y[n] = b[0]*x[n] + ... + b[nb]*x[n-nb] - a[1]*y[n-1] - ... - a[na]*y[n-na]
If a[0] is not equal to 1, the filter coeffcients are normalized by a[0].
The 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 - 2007.
Public Member Functions | |
Filter (void) | |
Default constructor creates a zero-order pass-through "filter". | |
Filter (std::vector< StkFloat > &bCoefficients, std::vector< StkFloat > &aCoefficients) | |
Overloaded constructor which takes filter coefficients. | |
virtual | ~Filter (void) |
Class destructor. | |
void | clear (void) |
Sets all internal states of the filter to zero. | |
void | setCoefficients (std::vector< StkFloat > &bCoefficients, std::vector< StkFloat > &aCoefficients, bool clearState=false) |
Set filter coefficients. | |
void | setNumerator (std::vector< StkFloat > &bCoefficients, bool clearState=false) |
Set numerator coefficients. | |
void | setDenominator (std::vector< StkFloat > &aCoefficients, bool clearState=false) |
Set denominator coefficients. | |
virtual void | setGain (StkFloat gain) |
Set the filter gain. | |
virtual StkFloat | getGain (void) const |
Return the current filter gain. | |
virtual StkFloat | lastOut (void) const |
Return the last computed output value. | |
virtual StkFloat | tick (StkFloat input) |
Input one sample to the filter and return one output. | |
virtual 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. |
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Overloaded constructor which takes filter coefficients. An StkError can be thrown if either of the coefficient vector sizes is zero, or if the a[0] coefficient is equal to zero. |
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Set filter coefficients.
An StkError can be thrown if either of the coefficient vector sizes is zero, or if the a[0] coefficient is equal to zero. If a[0] is not equal to 1, the filter coeffcients are normalized by a[0]. The internal state of the filter is not cleared unless the clearState flag is |
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Set numerator coefficients.
An StkError can be thrown if coefficient vector is empty. Any previously set denominator coefficients are left unaffected. Note that the default constructor sets the single denominator coefficient a[0] to 1.0. The internal state of the filter is not cleared unless the clearState flag is |
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Set denominator coefficients.
An StkError can be thrown if the coefficient vector is empty or if the a[0] coefficient is equal to zero. Previously set numerator coefficients are unaffected unless a[0] is not equal to 1, in which case all coeffcients are normalized by a[0]. Note that the default constructor sets the single numerator coefficient b[0] to 1.0. The internal state of the filter is not cleared unless the clearState flag is |
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Set the filter gain. The gain is applied at the filter input and does not affect the coefficient values. The default gain value is 1.0. Reimplemented in BiQuad, OnePole, OneZero, PoleZero, TwoPole, and TwoZero. |
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Take a channel of the StkFrames object as inputs to the filter and replace with corresponding outputs.
The Reimplemented in BiQuad, Delay, OnePole, OneZero, PoleZero, TwoPole, and TwoZero. |
The Synthesis ToolKit in C++ (STK) |
©1995-2007 Perry R. Cook and Gary P. Scavone. All Rights Reserved. |