dsp::StateVariableFilter::Filter< SampleType > Class Template Reference

An IIR filter that can perform low, band and high-pass filtering on an audio signal, with 12 dB of attenuation per octave, using a TPT structure, designed for fast modulation (see Vadim Zavalishin's documentation about TPT structures for more information). More...

#include <juce_StateVariableFilter.h>

Public Types
using	NumericType = typename SampleTypeHelpers::ElementType<SampleType>::Type
	The NumericType is the underlying primitive type used by the SampleType (which could be either a primitive or vector)
using	ParametersPtr = typename Parameters<NumericType>::Ptr
	A typedef for a ref-counted pointer to the coefficients object.

Public Member Functions
	Filter (const Filter &)=default
	Creates a copy of another filter.
	Filter (Filter &&)=default
	Move constructor.
void	prepare (const ProcessSpec &) noexcept
	Initialization of the filter.
void	reset () noexcept
	Resets the filter's processing pipeline.
void	snapToZero () noexcept
	Ensure that the state variables are rounded to zero if the state variables are denormals.
template<typename ProcessContext >
void	process (const ProcessContext &context) noexcept
SampleType JUCE_VECTOR_CALLTYPE	processSample (SampleType sample) noexcept
	Processes a single sample, without any locking or checking.

Public Attributes
Parameters< NumericType >::Ptr	parameters
	The parameters of the state variable filter.

Detailed Description

template<typename SampleType>
class dsp::StateVariableFilter::Filter< SampleType >

An IIR filter that can perform low, band and high-pass filtering on an audio signal, with 12 dB of attenuation per octave, using a TPT structure, designed for fast modulation (see Vadim Zavalishin's documentation about TPT structures for more information).

Its behaviour is based on the analog state variable filter circuit.

Note: The bandpass here is not the one in the RBJ CookBook as its gain can be higher than 0 dB. For the classic 0 dB bandpass, we need to multiply the result by R2.

Note 2: Using this class prevents some loud audio artefacts commonly encountered when changing the cutoff frequency using other filter simulation structures and IIR filter classes. However, this class may still require additional smoothing for cutoff frequency changes.

see IIRFilter, SmoothedValue

Member Typedef Documentation

NumericType

template<typename SampleType >

using dsp::StateVariableFilter::Filter< SampleType >::NumericType = typename SampleTypeHelpers::ElementType<SampleType>::Type

The NumericType is the underlying primitive type used by the SampleType (which could be either a primitive or vector)

ParametersPtr

template<typename SampleType >

using dsp::StateVariableFilter::Filter< SampleType >::ParametersPtr = typename Parameters<NumericType>::Ptr

A typedef for a ref-counted pointer to the coefficients object.

Constructor & Destructor Documentation

Filter() [1/2]

template<typename SampleType >

dsp::StateVariableFilter::Filter< SampleType >::Filter ( const Filter< SampleType > & )

default

Creates a copy of another filter.

Filter() [2/2]

template<typename SampleType >

dsp::StateVariableFilter::Filter< SampleType >::Filter ( Filter< SampleType > && )

default

Move constructor.

Member Function Documentation

prepare()

template<typename SampleType >

void dsp::StateVariableFilter::Filter< SampleType >::prepare ( const ProcessSpec & )

noexcept

Initialization of the filter.

References dsp::StateVariableFilter::Filter< SampleType >::reset().

reset()

template<typename SampleType >

void dsp::StateVariableFilter::Filter< SampleType >::reset ( )

noexcept

Resets the filter's processing pipeline.

Referenced by dsp::StateVariableFilter::Filter< SampleType >::prepare().

snapToZero()

template<typename SampleType >

void dsp::StateVariableFilter::Filter< SampleType >::snapToZero ( )

noexcept

Ensure that the state variables are rounded to zero if the state variables are denormals.

This is only needed if you are doing sample by sample processing.

References dsp::util::snapToZero().

process()

template<typename SampleType >

template<typename ProcessContext >

void dsp::StateVariableFilter::Filter< SampleType >::process ( const ProcessContext & context )

noexcept

processSample()

template<typename SampleType >

SampleType JUCE_VECTOR_CALLTYPE dsp::StateVariableFilter::Filter< SampleType >::processSample ( SampleType sample )

noexcept

Processes a single sample, without any locking or checking.

Use this if you need processing of a single value.

References jassertfalse, and dsp::StateVariableFilter::Filter< SampleType >::parameters.

Member Data Documentation

parameters

template<typename SampleType >

Parameters<NumericType>::Ptr dsp::StateVariableFilter::Filter< SampleType >::parameters

The parameters of the state variable filter.

It's up to the caller to ensure that these parameters are modified in a thread-safe way.

Referenced by dsp::StateVariableFilter::Filter< SampleType >::processSample().

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The documentation for this class was generated from the following file:

• juce_StateVariableFilter.h