Parameter Class Reference

Advanced parameter class with modulation, real-time callbacks, and host automation. More...

#include <gin_parameter.h>

Inheritance diagram for Parameter:

Classes
class	ParameterListener
struct	ParamState

Public Types
using	Ptr = Parameter*
using	ConversionFunction = std::function<std::variant<float, juce::String> (const Parameter&, const std::variant<float, juce::String>&)>
	Bidirectional user value <-> text conversion.

Public Member Functions
	Parameter (Processor &, juce::String uid, juce::String name, juce::String shortName, juce::String label, float minValue, float maxValue, float intervalValue, float defaultValue, float skewFactor=1.0f, ConversionFunction conversionFunction=nullptr)
	Parameter (Processor &, juce::String uid, juce::String name, juce::String shortName, juce::String label, juce::NormalisableRange< float > range, float defaultValue, ConversionFunction conversionFunction=nullptr)
juce::String	getUid () const
void	setInternal (bool i)
bool	isInternal () const
void	setModIndex (int i)
int	getModIndex () const
void	setModMatrix (IModMatrix *m)
IModMatrix *	getModMatrix () const
void	setMidiLearn (MidiLearn *m)
MidiLearn *	getMidiLearn () const
virtual void	prepareToPlay (double, int)
virtual void	reset ()
float	getProcValue ()
virtual float	getProcValue (int)
float	getUserValue () const
int	getUserValueInt () const
bool	getUserValueBool () const
float	getUserDefaultValue () const
virtual void	setUserValue (float v)
virtual void	setUserValueNotifingHost (float f)
void	setUserValueAsUserAction (float f)
juce::String	getUserValueText () const
juce::String	userValueToText (float val)
bool	isOnOff ()
bool	isOn ()
virtual bool	isSmoothingActive ()
void	beginUserAction ()
void	beginUserTimedAction ()
void	endUserAction ()
juce::NormalisableRange< float >	getUserRange () const
float	getUserRangeStart () const
float	getUserRangeEnd () const
void	addListener (ParameterListener *listener)
void	removeListener (ParameterListener *listener)
ParamState	getState ()
void	setState (const ParamState &state)
juce::String	getParameterID () const override
float	getValue () const override
bool	getBoolValue () const
void	setValue (float newValue) override
float	getDefaultValue () const override
juce::String	getName (int maximumStringLength) const override
juce::String	getShortName () const
juce::String	getLabel () const override
int	getNumSteps () const override
juce::String	getText (float value, int) const override
float	getValueForText (const juce::String &text) const override
bool	isOrientationInverted () const override
bool	isAutomatable () const override
bool	isMetaParameter () const override
float	getSkew ()
bool	isSkewSymmetric ()
Public Member Functions inherited from RealtimeAsyncUpdater
	RealtimeAsyncUpdater ()
	Creates a RealtimeAsyncUpdater.
virtual	~RealtimeAsyncUpdater ()
	Destructor.
void	triggerAsyncUpdate ()
	Triggers an asynchronous update.
void	cancelPendingUpdate () noexcept
	Cancels any pending update.
void	handleUpdateNowIfNeeded ()
	Handles the update immediately if one is pending.
bool	isUpdatePending () const noexcept
	Checks if an update is currently pending.

Public Attributes
std::function< float(float)>	conversionFunction

Protected Member Functions
void	handleAsyncUpdate () override
	Called asynchronously when an update is triggered.
void	timerCallback () override
virtual void	changed ()

Protected Attributes
Processor &	processor
const juce::NormalisableRange< float >	range
bool	internal = false
IModMatrix *	modMatrix = nullptr
MidiLearn *	midiLearn = nullptr
int	modIndex = -1
std::atomic< float >	value {0.0f}
const float	defaultValue = 0.0f
const juce::String	uid
const juce::String	name
const juce::String	shortName
const juce::String	label
const ConversionFunction	textConversionFunction
int	userActionCount = 0
juce::ListenerList< ParameterListener >	listeners

Detailed Description

Advanced parameter class with modulation, real-time callbacks, and host automation.

Parameter provides a comprehensive plugin parameter implementation with features needed for professional audio plugins. It extends JUCE's parameter system with modulation support, user/processing value separation, and real-time safe callbacks.

Value Formats: Parameter values are represented in three formats:

• value: Normalized 0..1 range (for host automation)
• user value: Range as displayed to user (e.g., -100 to +10 dB)
• proc value: Range used for DSP processing (e.g., 0 to 3.1623 for gain)

By default, user value and proc value are identical. To provide custom processing values, set the conversionFunction (e.g., converting dB to linear gain).

Parameter Types:

• External: Exposed to host, can be automated and modulated
• Internal: Hidden from host, cannot be modulated (e.g., UI-only settings)

Key Features:

• Host automation support
• Modulation matrix integration
• Real-time safe value callbacks
• User action tracking (begin/end gestures)
• Custom text formatting
• Skewed parameter ranges
• Optional parameter smoothing
• Listener callbacks for UI updates

Usage:

// Create a gain parameter with dB display but linear processing
auto* gain = new Parameter(processor,
    "gain", "Gain", "Gain", "dB",
    -100.0f, 10.0f,   // User range: -100 to +10 dB
    0.1f,             // Step size
    0.0f,             // Default value
    1.0f);            // No skew
 
// Convert dB to linear for processing
gain->conversionFunction = [](float db) {
    return juce::Decibels::decibelsToGain(db);
};
 
// In DSP code
float linearGain = gain->getProcValue();
// In UI
String displayText = gain->getUserValueText(); // "0.0 dB"

See also

Processor, ModMatrix, SmoothedParameter

Member Typedef Documentation

Ptr

using Parameter::Ptr = Parameter*

ConversionFunction

using Parameter::ConversionFunction = std::function<std::variant<float, juce::String> (const Parameter&, const std::variant<float, juce::String>&)>

Bidirectional user value <-> text conversion.

Called with a float it returns the display text for that user value; called with a juce::String it returns the user value for that text.

Constructor & Destructor Documentation

Parameter() [1/2]

Parameter::Parameter	(	Processor &	,
		juce::String	uid,
		juce::String	name,
		juce::String	shortName,
		juce::String	label,
		float	minValue,
		float	maxValue,
		float	intervalValue,
		float	defaultValue,
		float	skewFactor = 1.0f,
		ConversionFunction	conversionFunction = nullptr )

References conversionFunction, defaultValue, label, name, shortName, and uid.

Referenced by Parameter::ParameterListener::valueUpdated().

Parameter() [2/2]

Parameter::Parameter	(	Processor &	,
		juce::String	uid,
		juce::String	name,
		juce::String	shortName,
		juce::String	label,
		juce::NormalisableRange< float >	range,
		float	defaultValue,
		ConversionFunction	conversionFunction = nullptr )

References conversionFunction, defaultValue, label, name, range, shortName, and uid.

Member Function Documentation

getUid()

juce::String Parameter::getUid

(

)

const

References uid.

setInternal()

void Parameter::setInternal

(

bool

i

)

References internal.

isInternal()

bool Parameter::isInternal

(

)

const

References internal.

setModIndex()

void Parameter::setModIndex

(

int

i

)

References modIndex.

getModIndex()

int Parameter::getModIndex

(

)

const

References modIndex.

setModMatrix()

void Parameter::setModMatrix

(

IModMatrix *

m

)

References modMatrix.

getModMatrix()

IModMatrix * Parameter::getModMatrix

(

)

const

References modMatrix.

setMidiLearn()

void Parameter::setMidiLearn

(

MidiLearn *

m

)

References midiLearn.

getMidiLearn()

MidiLearn * Parameter::getMidiLearn

(

)

const

References midiLearn.

prepareToPlay()

virtual void Parameter::prepareToPlay ( double , int  )

virtual

reset()

virtual void Parameter::reset ( )

virtual

getProcValue() [1/2]

float Parameter::getProcValue

(

)

References conversionFunction, and getUserValue().

getProcValue() [2/2]

virtual float Parameter::getProcValue ( int )

virtual

References conversionFunction, and getUserValue().

getUserValue()

float Parameter::getUserValue

(

)

const

References range, and value.

Referenced by getProcValue(), getProcValue(), and isOn().

getUserValueInt()

int Parameter::getUserValueInt

(

)

const

References range, and value.

getUserValueBool()

bool Parameter::getUserValueBool

(

)

const

References range, and value.

getUserDefaultValue()

float Parameter::getUserDefaultValue

(

)

const

References defaultValue.

setUserValue()

virtual void Parameter::setUserValue ( float v )

virtual

setUserValueNotifingHost()

virtual void Parameter::setUserValueNotifingHost ( float f )

virtual

setUserValueAsUserAction()

void Parameter::setUserValueAsUserAction

(

float

f

)

getUserValueText()

juce::String Parameter::getUserValueText

(

)

const

References getText(), getValue(), and label.

userValueToText()

juce::String Parameter::userValueToText

(

float

val

)

References getText(), label, and range.

isOnOff()

bool Parameter::isOnOff

(

)

References range.

isOn()

bool Parameter::isOn

(

)

References getUserValue(), and range.

isSmoothingActive()

virtual bool Parameter::isSmoothingActive ( )

virtual

beginUserAction()

void Parameter::beginUserAction

(

)

beginUserTimedAction()

void Parameter::beginUserTimedAction

(

)

endUserAction()

void Parameter::endUserAction

(

)

getUserRange()

juce::NormalisableRange< float > Parameter::getUserRange

(

)

const

References range.

getUserRangeStart()

float Parameter::getUserRangeStart

(

)

const

References range.

getUserRangeEnd()

float Parameter::getUserRangeEnd

(

)

const

References range.

addListener()

void Parameter::addListener

(

ParameterListener *

listener

)

Referenced by MultiParamComponent::watchParam().

removeListener()

void Parameter::removeListener

(

ParameterListener *

listener

)

Referenced by MultiParamComponent::unwatchParam().

getState()

ParamState Parameter::getState

(

)

setState()

void Parameter::setState

(

const ParamState &

state

)

getParameterID()

juce::String Parameter::getParameterID ( ) const

override

References uid.

getValue()

float Parameter::getValue ( ) const

override

References range, and value.

Referenced by getBoolValue(), and getUserValueText().

getBoolValue()

bool Parameter::getBoolValue

(

)

const

References getValue().

setValue()

void Parameter::setValue ( float newValue )

override

getDefaultValue()

float Parameter::getDefaultValue ( ) const

override

References defaultValue, and range.

getName()

juce::String Parameter::getName ( int maximumStringLength ) const

override

getShortName()

juce::String Parameter::getShortName

(

)

const

References shortName.

getLabel()

juce::String Parameter::getLabel ( ) const

override

References label.

getNumSteps()

int Parameter::getNumSteps ( ) const

override

getText()

juce::String Parameter::getText ( float value, int  ) const

override

References value.

Referenced by getUserValueText(), and userValueToText().

getValueForText()

float Parameter::getValueForText ( const juce::String & text ) const

override

isOrientationInverted()

bool Parameter::isOrientationInverted ( ) const

override

isAutomatable()

bool Parameter::isAutomatable ( ) const

override

isMetaParameter()

bool Parameter::isMetaParameter ( ) const

override

getSkew()

float Parameter::getSkew

(

)

References range.

isSkewSymmetric()

bool Parameter::isSkewSymmetric

(

)

References range.

handleAsyncUpdate()

void Parameter::handleAsyncUpdate ( )

overrideprotectedvirtual

Called asynchronously when an update is triggered.

Override this method to perform your update logic. This will be called on a dedicated background thread (not the message thread).

Implements RealtimeAsyncUpdater.

timerCallback()

void Parameter::timerCallback ( )

overrideprotected

changed()

virtual void Parameter::changed ( )

protectedvirtual

Member Data Documentation

conversionFunction

std::function<float (float)> Parameter::conversionFunction

Referenced by getProcValue(), getProcValue(), Parameter(), and Parameter().

processor

Processor& Parameter::processor

protected

range

const juce::NormalisableRange<float> Parameter::range

protected

Referenced by getDefaultValue(), getSkew(), getUserRange(), getUserRangeEnd(), getUserRangeStart(), getUserValue(), getUserValueBool(), getUserValueInt(), getValue(), isOn(), isOnOff(), isSkewSymmetric(), Parameter(), and userValueToText().

internal

bool Parameter::internal = false

protected

Referenced by isInternal(), and setInternal().

modMatrix

IModMatrix* Parameter::modMatrix = nullptr

protected

Referenced by getModMatrix(), and setModMatrix().

midiLearn

MidiLearn* Parameter::midiLearn = nullptr

protected

Referenced by getMidiLearn(), and setMidiLearn().

modIndex

int Parameter::modIndex = -1

protected

Referenced by getModIndex(), and setModIndex().

value

std::atomic<float> Parameter::value {0.0f}

protected

Referenced by getText(), getUserValue(), getUserValueBool(), getUserValueInt(), and getValue().

defaultValue

const float Parameter::defaultValue = 0.0f

protected

Referenced by getDefaultValue(), getUserDefaultValue(), Parameter(), and Parameter().

uid

const juce::String Parameter::uid

protected

Referenced by getParameterID(), getUid(), Parameter(), and Parameter().

name

const juce::String Parameter::name

protected

Referenced by Parameter(), and Parameter().

shortName

const juce::String Parameter::shortName

protected

Referenced by getShortName(), Parameter(), and Parameter().

label

const juce::String Parameter::label

protected

Referenced by getLabel(), getUserValueText(), Parameter(), Parameter(), and userValueToText().

textConversionFunction

const ConversionFunction Parameter::textConversionFunction

protected

userActionCount

int Parameter::userActionCount = 0

protected

listeners

juce::ListenerList<ParameterListener> Parameter::listeners

protected

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

• gin_parameter.h