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Image::BitmapData Class Referencefinal

Retrieves a section of an image as raw pixel data, so it can be read or written to. More...

#include <juce_Image.h>

Classes

class  BitmapDataReleaser
 Used internally by custom image types to manage pixel data lifetime. More...
 

Public Types

enum  ReadWriteMode { readOnly , writeOnly , readWrite }
 

Public Member Functions

 BitmapData (Image &image, int x, int y, int w, int h, ReadWriteMode mode)
 
 BitmapData (const Image &image, int x, int y, int w, int h)
 
 BitmapData (const Image &image, ReadWriteMode mode)
 
 ~BitmapData ()
 
uint8getLinePointer (int y) const noexcept
 Returns a pointer to the start of a line in the image.
 
uint8getPixelPointer (int x, int y) const noexcept
 Returns a pointer to a pixel in the image.
 
Colour getPixelColour (int x, int y) const noexcept
 Returns the colour of a given pixel.
 
void setPixelColour (int x, int y, Colour colour) const noexcept
 Sets the colour of a given pixel.
 
Rectangle< int > getBounds () const noexcept
 Returns the size of the bitmap.
 

Public Attributes

uint8data
 The raw pixel data, packed according to the image's pixel format.
 
size_t size
 The number of valid/allocated bytes after data.
 
PixelFormat pixelFormat
 The format of the data.
 
int lineStride
 The number of bytes between each line.
 
int pixelStride
 The number of bytes between each pixel.
 
int width
 
int height
 
std::unique_ptr< BitmapDataReleaserdataReleaser
 

Detailed Description

Retrieves a section of an image as raw pixel data, so it can be read or written to.

You should only use this class as a last resort - messing about with the internals of an image is only recommended for people who really know what they're doing!

A BitmapData object should be used as a temporary, stack-based object. Don't keep one hanging around while the image is being used elsewhere.

Depending on the way the image class is implemented, this may create a temporary buffer which is copied back to the image when the object is deleted, or it may just get a pointer directly into the image's raw data.

You can use the stride and data values in this class directly, but don't alter them! The actual format of the pixel data depends on the image's format - see Image::getFormat(), and the PixelRGB, PixelARGB and PixelAlpha classes for more info.

Member Enumeration Documentation

◆ ReadWriteMode

Enumerator
readOnly 
writeOnly 
readWrite 

Constructor & Destructor Documentation

◆ BitmapData() [1/3]

Image::BitmapData::BitmapData ( Image & image,
int x,
int y,
int w,
int h,
ReadWriteMode mode )

◆ BitmapData() [2/3]

Image::BitmapData::BitmapData ( const Image & image,
int x,
int y,
int w,
int h )

◆ BitmapData() [3/3]

Image::BitmapData::BitmapData ( const Image & image,
ReadWriteMode mode )

◆ ~BitmapData()

Image::BitmapData::~BitmapData ( )

Member Function Documentation

◆ getLinePointer()

uint8 * Image::BitmapData::getLinePointer ( int y) const
noexcept

Returns a pointer to the start of a line in the image.

The coordinate you provide here isn't checked, so it's the caller's responsibility to make sure it's not out-of-range.

References y.

◆ getPixelPointer()

uint8 * Image::BitmapData::getPixelPointer ( int x,
int y ) const
noexcept

Returns a pointer to a pixel in the image.

The coordinates you give here are not checked, so it's the caller's responsibility to make sure they're not out-of-range.

References x, and y.

◆ getPixelColour()

Colour Image::BitmapData::getPixelColour ( int x,
int y ) const
noexcept

Returns the colour of a given pixel.

For performance reasons, this won't do any bounds-checking on the coordinates, so it's the caller's responsibility to make sure they're within the image's size.

◆ setPixelColour()

void Image::BitmapData::setPixelColour ( int x,
int y,
Colour colour ) const
noexcept

Sets the colour of a given pixel.

For performance reasons, this won't do any bounds-checking on the coordinates, so it's the caller's responsibility to make sure they're within the image's size.

◆ getBounds()

Rectangle< int > Image::BitmapData::getBounds ( ) const
noexcept

Returns the size of the bitmap.

Member Data Documentation

◆ data

uint8* Image::BitmapData::data

The raw pixel data, packed according to the image's pixel format.

◆ size

size_t Image::BitmapData::size

The number of valid/allocated bytes after data.

May be smaller than "lineStride * height" if this is a section of a larger image.

◆ pixelFormat

PixelFormat Image::BitmapData::pixelFormat

The format of the data.

◆ lineStride

int Image::BitmapData::lineStride

The number of bytes between each line.

◆ pixelStride

int Image::BitmapData::pixelStride

The number of bytes between each pixel.

◆ width

int Image::BitmapData::width

◆ height

int Image::BitmapData::height

◆ dataReleaser

std::unique_ptr<BitmapDataReleaser> Image::BitmapData::dataReleaser

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