ImagePixelData Class Reference

This is a base class for holding image data in implementation-specific ways. More...

#include <juce_Image.h>

Inheritance diagram for ImagePixelData:

Classes
struct	Listener
	Used to receive callbacks for image data changes. More...

Public Types
using	BackupExtensions = ImagePixelDataBackupExtensions
using	NativeExtensions = ImagePixelDataNativeExtensions
using	Ptr = ReferenceCountedObjectPtr<ImagePixelData>

Public Member Functions
	ImagePixelData (Image::PixelFormat, int width, int height)
	~ImagePixelData () override
virtual std::unique_ptr< LowLevelGraphicsContext >	createLowLevelContext ()=0
	Creates a context that will draw into this image.
virtual Ptr	clone ()=0
	Creates a copy of this image.
virtual std::unique_ptr< ImageType >	createType () const =0
	Creates an instance of the type of this image.
virtual BackupExtensions *	getBackupExtensions ()
	Returns a raw pointer to an instance of ImagePixelDataBackupExtensions if this ImagePixelData provides this extension, or nullptr otherwise.
virtual const BackupExtensions *	getBackupExtensions () const
virtual void	initialiseBitmapData (Image::BitmapData &, int x, int y, Image::BitmapData::ReadWriteMode)=0
	Initialises a BitmapData object.
virtual int	getSharedCount () const noexcept
	Returns the number of Image objects which are currently referring to the same internal shared image data.
virtual void	applyGaussianBlurEffectInArea (Rectangle< int > bounds, float radius)
	Applies a native blur effect to this image, if available.
void	applyGaussianBlurEffect (float radius)
virtual void	applySingleChannelBoxBlurEffectInArea (Rectangle< int > bounds, int radius)
	Applies a native blur effect to this image, if available.
void	applySingleChannelBoxBlurEffect (int radius)
virtual void	multiplyAllAlphasInArea (Rectangle< int > bounds, float amount)
	Multiples all alpha-channel values in the image by the specified amount.
void	multiplyAllAlphas (float amount)
virtual void	desaturateInArea (Rectangle< int > bounds)
	Changes all the colours to be shades of grey, based on their current luminosity.
void	desaturate ()
void	sendDataChangeMessage ()
virtual NativeExtensions	getNativeExtensions ()
Public Member Functions inherited from ReferenceCountedObject
void	incReferenceCount () noexcept
	Increments the object's reference count.
void	decReferenceCount () noexcept
	Decreases the object's reference count.
bool	decReferenceCountWithoutDeleting () noexcept
	Decreases the object's reference count.
int	getReferenceCount () const noexcept
	Returns the object's current reference count.

Public Attributes
const Image::PixelFormat	pixelFormat
	The pixel format of the image data.
const int	width
const int	height
NamedValueSet	userData
	User-defined settings that are attached to this image.
ListenerList< Listener >	listeners

Additional Inherited Members
Protected Member Functions inherited from ReferenceCountedObject
	ReferenceCountedObject ()=default
	Creates the reference-counted object (with an initial ref count of zero).
	ReferenceCountedObject (const ReferenceCountedObject &) noexcept
	Copying from another object does not affect this one's reference-count.
	ReferenceCountedObject (ReferenceCountedObject &&) noexcept
	Copying from another object does not affect this one's reference-count.
ReferenceCountedObject &	operator= (const ReferenceCountedObject &) noexcept
	Copying from another object does not affect this one's reference-count.
ReferenceCountedObject &	operator= (ReferenceCountedObject &&) noexcept
	Copying from another object does not affect this one's reference-count.
virtual	~ReferenceCountedObject ()
	Destructor.
void	resetReferenceCount () noexcept
	Resets the reference count to zero without deleting the object.

Detailed Description

This is a base class for holding image data in implementation-specific ways.

You may never need to use this class directly - it's used internally by the Image class to store the actual image data. To access pixel data directly, you should use Image::BitmapData rather than this class.

ImagePixelData objects are created indirectly, by subclasses of ImageType.

See also

Image, ImageType

Member Typedef Documentation

BackupExtensions

using ImagePixelData::BackupExtensions = ImagePixelDataBackupExtensions

NativeExtensions

using ImagePixelData::NativeExtensions = ImagePixelDataNativeExtensions

Ptr

using ImagePixelData::Ptr = ReferenceCountedObjectPtr<ImagePixelData>

Constructor & Destructor Documentation

ImagePixelData()

ImagePixelData::ImagePixelData	(	Image::PixelFormat	,
		int	width,
		int	height )

~ImagePixelData()

ImagePixelData::~ImagePixelData ( )

override

Member Function Documentation

createLowLevelContext()

virtual std::unique_ptr< LowLevelGraphicsContext > ImagePixelData::createLowLevelContext ( )

pure virtual

Creates a context that will draw into this image.

clone()

virtual Ptr ImagePixelData::clone ( )

pure virtual

Creates a copy of this image.

createType()

virtual std::unique_ptr< ImageType > ImagePixelData::createType ( ) const

pure virtual

Creates an instance of the type of this image.

getBackupExtensions() [1/2]

virtual BackupExtensions * ImagePixelData::getBackupExtensions ( )

virtual

Returns a raw pointer to an instance of ImagePixelDataBackupExtensions if this ImagePixelData provides this extension, or nullptr otherwise.

getBackupExtensions() [2/2]

virtual const BackupExtensions * ImagePixelData::getBackupExtensions ( ) const

virtual

initialiseBitmapData()

virtual void ImagePixelData::initialiseBitmapData ( Image::BitmapData & , int x, int y, Image::BitmapData::ReadWriteMode  )

pure virtual

Initialises a BitmapData object.

getSharedCount()

virtual int ImagePixelData::getSharedCount ( ) const

virtualnoexcept

Returns the number of Image objects which are currently referring to the same internal shared image data.

This is different to the reference count as an instance of ImagePixelData can internally depend on another ImagePixelData via it's member variables.

applyGaussianBlurEffectInArea()

virtual void ImagePixelData::applyGaussianBlurEffectInArea ( Rectangle< int > bounds, float radius )

virtual

Applies a native blur effect to this image, if available.

This blur applies to all channels of the input image. It may be more expensive to calculate than a box blur, but should produce higher-quality results.

The default implementation will modify the image pixel-by-pixel on the CPU, which will be slow. Native image types may provide optimised implementations.

applyGaussianBlurEffect()

void ImagePixelData::applyGaussianBlurEffect

(

float

radius

)

See also

applyGaussianBlurEffectInArea()

applySingleChannelBoxBlurEffectInArea()

virtual void ImagePixelData::applySingleChannelBoxBlurEffectInArea ( Rectangle< int > bounds, int radius )

virtual

Applies a native blur effect to this image, if available.

This is intended for blurring single-channel images, which is useful when rendering drop shadows. This is implemented as several box-blurs in series. The results should be visually similar to a Gaussian blur, but less accurate.

The default implementation will modify the image pixel-by-pixel on the CPU, which will be slow. Native image types may provide optimised implementations.

applySingleChannelBoxBlurEffect()

void ImagePixelData::applySingleChannelBoxBlurEffect

(

int

radius

)

See also

applySingleChannelBoxBlurEffectInArea()

multiplyAllAlphasInArea()

virtual void ImagePixelData::multiplyAllAlphasInArea ( Rectangle< int > bounds, float amount )

virtual

Multiples all alpha-channel values in the image by the specified amount.

The default implementation will modify the image pixel-by-pixel on the CPU, which will be slow. Native image types may provide optimised implementations.

multiplyAllAlphas()

void ImagePixelData::multiplyAllAlphas

(

float

amount

)

See also

multiplyAllAlphasInArea()

desaturateInArea()

virtual void ImagePixelData::desaturateInArea ( Rectangle< int > bounds )

virtual

Changes all the colours to be shades of grey, based on their current luminosity.

The default implementation will modify the image pixel-by-pixel on the CPU, which will be slow. Native image types may provide optimised implementations.

desaturate()

void ImagePixelData::desaturate

(

)

See also

desaturateInArea()

sendDataChangeMessage()

void ImagePixelData::sendDataChangeMessage

(

)

getNativeExtensions()

virtual NativeExtensions ImagePixelData::getNativeExtensions ( )

virtual

Member Data Documentation

pixelFormat

const Image::PixelFormat ImagePixelData::pixelFormat

The pixel format of the image data.

width

const int ImagePixelData::width

height

const int ImagePixelData::height

userData

NamedValueSet ImagePixelData::userData

User-defined settings that are attached to this image.

See also

Image::getProperties().

listeners

ListenerList<Listener> ImagePixelData::listeners

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

• juce_Image.h