Describes the layout and colours that should be used to paint a colour gradient. More...

#include <juce_ColourGradient.h>

Collaboration diagram for juce::ColourGradient:

[legend]

Classes
struct	ColourPoint

Public Member Functions
	ColourGradient () noexcept
	Creates an uninitialised gradient. More...

	ColourGradient (Colour colour1, float x1, float y1, Colour colour2, float x2, float y2, bool isRadial)
	Creates a gradient object. More...

	ColourGradient (Colour colour1, Point< float > point1, Colour colour2, Point< float > point2, bool isRadial)
	Creates a gradient object. More...

	ColourGradient (ColourGradient &&) noexcept

	ColourGradient (const ColourGradient &)

	~ColourGradient ()
	Destructor. More...

int	addColour (double proportionAlongGradient, Colour colour)
	Adds a colour at a point along the length of the gradient. More...

void	clearColours ()
	Removes any colours that have been added. More...

int	createLookupTable (const AffineTransform &transform, HeapBlock< PixelARGB > &resultLookupTable) const
	Creates a set of interpolated premultiplied ARGB values. More...

void	createLookupTable (PixelARGB *resultLookupTable, int numEntries) const noexcept
	Creates a set of interpolated premultiplied ARGB values. More...

Colour	getColour (int index) const noexcept
	Returns the colour that was added with a given index. More...

Colour	getColourAtPosition (double position) const noexcept
	Returns the an interpolated colour at any position along the gradient. More...

double	getColourPosition (int index) const noexcept
	Returns the position along the length of the gradient of the colour with this index. More...

int	getNumColours () const noexcept
	Returns the number of colour-stops that have been added. More...

bool	isInvisible () const noexcept
	Returns true if all colours are completely transparent. More...

bool	isOpaque () const noexcept
	Returns true if all colours are opaque. More...

void	multiplyOpacity (float multiplier) noexcept
	Multiplies the alpha value of all the colours by the given scale factor. More...

bool	operator!= (const ColourGradient &) const noexcept

ColourGradient &	operator= (ColourGradient &&) noexcept

ColourGradient &	operator= (const ColourGradient &)

bool	operator== (const ColourGradient &) const noexcept

void	removeColour (int index)
	Removes one of the colours from the gradient. More...

void	setColour (int index, Colour newColour) noexcept
	Changes the colour at a given index. More...

Static Public Member Functions
static ColourGradient	horizontal (Colour colour1, float x1, Colour colour2, float x2)
	Creates a horizontal linear gradient between two X coordinates. More...

template<typename Type >
static ColourGradient	horizontal (Colour colourLeft, Colour colourRight, Rectangle< Type > area)
	Creates a horizontal linear gradient from right to left in a rectangle. More...

static ColourGradient	vertical (Colour colour1, float y1, Colour colour2, float y2)
	Creates a vertical linear gradient between two Y coordinates. More...

template<typename Type >
static ColourGradient	vertical (Colour colourTop, Colour colourBottom, Rectangle< Type > area)
	Creates a vertical linear gradient from top to bottom in a rectangle. More...

Public Attributes
bool	isRadial
	If true, the gradient should be filled circularly, centred around point1, with point2 defining a point on the circumference. More...

Point< float >	point1

Point< float >	point2

Private Attributes
Array< ColourPoint >	colours

Detailed Description

Describes the layout and colours that should be used to paint a colour gradient.

See also: Graphics::setGradientFill

@tags{Graphics}

Constructor & Destructor Documentation

◆ ColourGradient() [1/5]

juce::ColourGradient::ColourGradient ( )

noexcept

Creates an uninitialised gradient.

If you use this constructor instead of the other one, be sure to set all the object's public member variables before using it!

◆ ColourGradient() [2/5]

juce::ColourGradient::ColourGradient ( const ColourGradient & )

◆ ColourGradient() [3/5]

juce::ColourGradient::ColourGradient ( ColourGradient && )

noexcept

◆ ColourGradient() [4/5]

juce::ColourGradient::ColourGradient	(	Colour	colour1,
		float	x1,
		float	y1,
		Colour	colour2,
		float	x2,
		float	y2,
		bool	isRadial
	)

Creates a gradient object.

(x1, y1) is the location to draw with colour1. Likewise (x2, y2) is where colour2 should be. In between them there's a gradient.

If isRadial is true, the colours form a circular gradient with (x1, y1) at its centre.

The alpha transparencies of the colours are used, so note that if you blend from transparent to a solid colour, the RGB of the transparent colour will become visible in parts of the gradient. e.g. blending from Colour::transparentBlack to Colours::white will produce a muddy grey colour midway, but Colour::transparentWhite to Colours::white will be white all the way across.

See also: ColourGradient

◆ ColourGradient() [5/5]

juce::ColourGradient::ColourGradient	(	Colour	colour1,
		Point< float >	point1,
		Colour	colour2,
		Point< float >	point2,
		bool	isRadial
	)

Creates a gradient object.

point1 is the location to draw with colour1. Likewise point2 is where colour2 should be. In between them there's a gradient.

If isRadial is true, the colours form a circular gradient with point1 at its centre.

The alpha transparencies of the colours are used, so note that if you blend from transparent to a solid colour, the RGB of the transparent colour will become visible in parts of the gradient. e.g. blending from Colour::transparentBlack to Colours::white will produce a muddy grey colour midway, but Colour::transparentWhite to Colours::white will be white all the way across.

See also: ColourGradient

◆ ~ColourGradient()

juce::ColourGradient::~ColourGradient ( )

Destructor.

Member Function Documentation

◆ addColour()

int juce::ColourGradient::addColour	(	double	proportionAlongGradient,
		Colour	colour
	)

Adds a colour at a point along the length of the gradient.

This allows the gradient to go through a spectrum of colours, instead of just a start and end colour.

Parameters

proportionAlongGradient	a value between 0 and 1.0, which is the proportion of the distance along the line between the two points at which the colour should occur.
colour	the colour that should be used at this point

Returns: the index at which the new point was added

◆ clearColours()

void juce::ColourGradient::clearColours ( )

Removes any colours that have been added.

This will also remove any start and end colours, so the gradient won't work. You'll need to add more colours with addColour().

◆ createLookupTable() [1/2]

int juce::ColourGradient::createLookupTable	(	const AffineTransform &	transform,
		HeapBlock< PixelARGB > &	resultLookupTable
	)		const

Creates a set of interpolated premultiplied ARGB values.

This will resize the HeapBlock, fill it with the colours, and will return the number of colours that it added. When calling this, the ColourGradient must have at least 2 colour stops specified.

Referenced by juce::RenderingHelpers::SoftwareRendererSavedState::fillWithGradient().

◆ createLookupTable() [2/2]

void juce::ColourGradient::createLookupTable	(	PixelARGB *	resultLookupTable,
		int	numEntries
	)		const

noexcept

Creates a set of interpolated premultiplied ARGB values.

This will fill an array of a user-specified size with the gradient, interpolating to fit. The numEntries argument specifies the size of the array, and this size must be greater than zero. When calling this, the ColourGradient must have at least 2 colour stops specified.

◆ getColour()

Colour juce::ColourGradient::getColour ( int index ) const

noexcept

Returns the colour that was added with a given index.

The index is from 0 to getNumColours() - 1.

◆ getColourAtPosition()

Colour juce::ColourGradient::getColourAtPosition ( double position ) const

noexcept

Returns the an interpolated colour at any position along the gradient.

Parameters

position the position along the gradient, between 0 and 1

◆ getColourPosition()

double juce::ColourGradient::getColourPosition ( int index ) const

noexcept

Returns the position along the length of the gradient of the colour with this index.

The index is from 0 to getNumColours() - 1. The return value will be between 0.0 and 1.0

◆ getNumColours()

int juce::ColourGradient::getNumColours ( ) const

noexcept

Returns the number of colour-stops that have been added.

◆ horizontal() [1/2]

static ColourGradient juce::ColourGradient::horizontal	(	Colour	colour1,
		float	x1,
		Colour	colour2,
		float	x2
	)

static

Creates a horizontal linear gradient between two X coordinates.

◆ horizontal() [2/2]

template<typename Type >

static ColourGradient juce::ColourGradient::horizontal	(	Colour	colourLeft,
		Colour	colourRight,
		Rectangle< Type >	area
	)

inlinestatic

Creates a horizontal linear gradient from right to left in a rectangle.

References juce::Rectangle< ValueType >::getRight(), and juce::Rectangle< ValueType >::getX().

◆ isInvisible()

bool juce::ColourGradient::isInvisible ( ) const

noexcept

Returns true if all colours are completely transparent.

◆ isOpaque()

bool juce::ColourGradient::isOpaque ( ) const

noexcept

Returns true if all colours are opaque.

◆ multiplyOpacity()

void juce::ColourGradient::multiplyOpacity ( float multiplier )

noexcept

Multiplies the alpha value of all the colours by the given scale factor.

◆ operator!=()

bool juce::ColourGradient::operator!= ( const ColourGradient & ) const

noexcept

◆ operator=() [1/2]

ColourGradient& juce::ColourGradient::operator= ( ColourGradient && )

noexcept

◆ operator=() [2/2]

ColourGradient& juce::ColourGradient::operator= ( const ColourGradient & )

◆ operator==()

bool juce::ColourGradient::operator== ( const ColourGradient & ) const

noexcept

◆ removeColour()

void juce::ColourGradient::removeColour ( int index )

Removes one of the colours from the gradient.

◆ setColour()

void juce::ColourGradient::setColour	(	int	index,
		Colour	newColour
	)

noexcept

Changes the colour at a given index.

The index is from 0 to getNumColours() - 1.

◆ vertical() [1/2]

static ColourGradient juce::ColourGradient::vertical	(	Colour	colour1,
		float	y1,
		Colour	colour2,
		float	y2
	)

static

Creates a vertical linear gradient between two Y coordinates.

◆ vertical() [2/2]

template<typename Type >

static ColourGradient juce::ColourGradient::vertical	(	Colour	colourTop,
		Colour	colourBottom,
		Rectangle< Type >	area
	)

inlinestatic

Creates a vertical linear gradient from top to bottom in a rectangle.

References juce::Rectangle< ValueType >::getBottom(), and juce::Rectangle< ValueType >::getY().

Member Data Documentation

◆ colours

Array<ColourPoint> juce::ColourGradient::colours

private

◆ isRadial

bool juce::ColourGradient::isRadial

If true, the gradient should be filled circularly, centred around point1, with point2 defining a point on the circumference.

If false, the gradient is linear between the two points.

◆ point1

Point<float> juce::ColourGradient::point1

Referenced by juce::RenderingHelpers::GradientPixelIterators::Linear::Linear(), and juce::RenderingHelpers::GradientPixelIterators::Radial::Radial().

◆ point2

Point<float> juce::ColourGradient::point2

Referenced by juce::RenderingHelpers::GradientPixelIterators::Linear::Linear(), and juce::RenderingHelpers::GradientPixelIterators::Radial::Radial().

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

juce_ColourGradient.h

Classes

Public Member Functions

Static Public Member Functions

Public Attributes

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ ColourGradient() [1/5]

◆ ColourGradient() [2/5]

◆ ColourGradient() [3/5]

◆ ColourGradient() [4/5]

◆ ColourGradient() [5/5]

◆ ~ColourGradient()

Member Function Documentation

◆ addColour()

◆ clearColours()

◆ createLookupTable() [1/2]

◆ createLookupTable() [2/2]

◆ getColour()

◆ getColourAtPosition()

◆ getColourPosition()

◆ getNumColours()

◆ horizontal() [1/2]

◆ horizontal() [2/2]

◆ isInvisible()

◆ isOpaque()

◆ multiplyOpacity()

◆ operator!=()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ operator==()

◆ removeColour()

◆ setColour()

◆ vertical() [1/2]

◆ vertical() [2/2]

Member Data Documentation

◆ colours

◆ isRadial

◆ point1

◆ point2