juce::dsp::FirstOrderTPTFilter< SampleType > Class Template Reference

A first order filter class using the TPT (Topology-Preserving Transform) structure. More...

#include <juce_FirstOrderTPTFilter.h>

Collaboration diagram for juce::dsp::FirstOrderTPTFilter< SampleType >:

Public Types
using	Type = FirstOrderTPTFilterType

Public Member Functions
	FirstOrderTPTFilter ()
	Constructor. More...
SampleType	getCutoffFrequency () const noexcept
	Returns the cutoff frequency of the filter. More...
Type	getType () const noexcept
	Returns the type of the filter. More...
void	prepare (const ProcessSpec &spec)
	Initialises the filter. More...
template<typename ProcessContext >
void	process (const ProcessContext &context) noexcept
	Processes the input and output samples supplied in the processing context. More...
SampleType	processSample (int channel, SampleType inputValue)
	Processes one sample at a time on a given channel. More...
void	reset ()
	Resets the internal state variables of the filter. More...
void	reset (SampleType newValue)
	Resets the internal state variables of the filter to a given value. More...
void	setCutoffFrequency (SampleType newFrequencyHz)
	Sets the cutoff frequency of the filter. More...
void	setType (Type newType)
	Sets the filter type. More...
void	snapToZero () noexcept
	Ensure that the state variables are rounded to zero if the state variables are denormals. More...

Private Member Functions
void	update ()

Private Attributes
SampleType	cutoffFrequency = 1000.0
Type	filterType = Type::lowpass
SampleType	G = 0
std::vector< SampleType >	s1 { 2 }
double	sampleRate = 44100.0

Detailed Description

template<typename SampleType>
class juce::dsp::FirstOrderTPTFilter< SampleType >

A first order filter class using the TPT (Topology-Preserving Transform) structure.

This filter can be modulated at high rates without producing audio artefacts. See Vadim Zavalishin's documentation about TPT structures for more information.

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

see StateVariableFilter, IIRFilter, SmoothedValue

@tags{DSP}

Member Typedef Documentation

Type

template<typename SampleType >

using juce::dsp::FirstOrderTPTFilter< SampleType >::Type = FirstOrderTPTFilterType

Constructor & Destructor Documentation

FirstOrderTPTFilter()

template<typename SampleType >

juce::dsp::FirstOrderTPTFilter< SampleType >::FirstOrderTPTFilter

(

)

Constructor.

Member Function Documentation

getCutoffFrequency()

template<typename SampleType >

SampleType juce::dsp::FirstOrderTPTFilter< SampleType >::getCutoffFrequency ( ) const

inlinenoexcept

Returns the cutoff frequency of the filter.

References juce::dsp::FirstOrderTPTFilter< SampleType >::cutoffFrequency.

getType()

template<typename SampleType >

Type juce::dsp::FirstOrderTPTFilter< SampleType >::getType ( ) const

inlinenoexcept

Returns the type of the filter.

References juce::dsp::FirstOrderTPTFilter< SampleType >::filterType.

prepare()

template<typename SampleType >

void juce::dsp::FirstOrderTPTFilter< SampleType >::prepare

(

const ProcessSpec &

spec

)

Initialises the filter.

process()

template<typename SampleType >

template<typename ProcessContext >

void juce::dsp::FirstOrderTPTFilter< SampleType >::process ( const ProcessContext &  context )

inlinenoexcept

Processes the input and output samples supplied in the processing context.

References jassert, juce::dsp::FirstOrderTPTFilter< SampleType >::processSample(), juce::dsp::FirstOrderTPTFilter< SampleType >::s1, and juce::dsp::FirstOrderTPTFilter< SampleType >::snapToZero().

processSample()

template<typename SampleType >

SampleType juce::dsp::FirstOrderTPTFilter< SampleType >::processSample	(	int	channel,
		SampleType	inputValue
	)

Processes one sample at a time on a given channel.

Referenced by juce::dsp::FirstOrderTPTFilter< SampleType >::process().

reset() [1/2]

template<typename SampleType >

void juce::dsp::FirstOrderTPTFilter< SampleType >::reset

(

)

Resets the internal state variables of the filter.

reset() [2/2]

template<typename SampleType >

void juce::dsp::FirstOrderTPTFilter< SampleType >::reset

(

SampleType

newValue

)

Resets the internal state variables of the filter to a given value.

setCutoffFrequency()

template<typename SampleType >

void juce::dsp::FirstOrderTPTFilter< SampleType >::setCutoffFrequency

(

SampleType

newFrequencyHz

)

Sets the cutoff frequency of the filter.

Parameters

newFrequencyHz

cutoff frequency in Hz.

setType()

template<typename SampleType >

void juce::dsp::FirstOrderTPTFilter< SampleType >::setType

(

Type

newType

)

Sets the filter type.

snapToZero()

template<typename SampleType >

void juce::dsp::FirstOrderTPTFilter< 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.

Referenced by juce::dsp::FirstOrderTPTFilter< SampleType >::process().

update()

template<typename SampleType >

void juce::dsp::FirstOrderTPTFilter< SampleType >::update ( )

private

Member Data Documentation

cutoffFrequency

template<typename SampleType >

SampleType juce::dsp::FirstOrderTPTFilter< SampleType >::cutoffFrequency = 1000.0

private

Referenced by juce::dsp::FirstOrderTPTFilter< SampleType >::getCutoffFrequency().

filterType

template<typename SampleType >

Type juce::dsp::FirstOrderTPTFilter< SampleType >::filterType = Type::lowpass

private

Referenced by juce::dsp::FirstOrderTPTFilter< SampleType >::getType().

G

template<typename SampleType >

SampleType juce::dsp::FirstOrderTPTFilter< SampleType >::G = 0

private

s1

template<typename SampleType >

std::vector<SampleType> juce::dsp::FirstOrderTPTFilter< SampleType >::s1 { 2 }

private

Referenced by juce::dsp::FirstOrderTPTFilter< SampleType >::process().

sampleRate

template<typename SampleType >

double juce::dsp::FirstOrderTPTFilter< SampleType >::sampleRate = 44100.0

private

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

• juce_FirstOrderTPTFilter.h