PixelBuffer Class Reference

Non owning, writable view of a caller owned pixel buffer. More...

#include <gz/rendering/PixelBuffer.hh>

Public Member Functions
	PixelBuffer (const PixelBuffer &_other)
	Copy constructor. Copies of a view share the same buffer.
	PixelBuffer (Image &_image)
	View the storage of an existing image. The view is only valid while the image, or a copy of it, is alive.
	PixelBuffer (unsigned int _width, unsigned int _height, PixelFormat _format, void *_data, std::size_t _size)
	Describe a caller owned buffer.
	~PixelBuffer ()
	Destructor. Does not free the buffer.
unsigned char *	Data () const
	Get a pointer to the first byte of the buffer. The pointer is writable even through a const view: this is a span, not a read only view.
PixelFormat	Format () const
	Get the pixel format.
unsigned int	Height () const
	Get the height in pixels.
std::size_t	MemorySize () const
	Get the number of bytes Width x Height pixels of Format need.
PixelBuffer &	operator= (const PixelBuffer &)=delete
	Views cannot be rebound.
PixelBuffer &	operator= (PixelBuffer &&)=delete
	Views cannot be rebound.
std::size_t	Size () const
	Get the size of the buffer in bytes, as given by the caller.
bool	Valid () const
	Check that the buffer can hold a frame: the pointer is not null and Size() is at least MemorySize().
unsigned int	Width () const
	Get the width in pixels.

Detailed Description

Non owning, writable view of a caller owned pixel buffer.

A PixelBuffer describes where a frame should be written: dimensions, pixel format, the start of a contiguous row major buffer and its size in bytes. It owns nothing and never frees the memory. Build one right before handing it to Camera::CopyTo and let it die when the call returns; nothing in the library keeps a pointer to the memory after that.

Every field is immutable and assignment is deleted, so code that receives a PixelBuffer can write through it but cannot point it somewhere else. That is what lets the render engines write straight into caller memory without being able to drop it by mistake.

Constructor & Destructor Documentation

PixelBuffer() [1/3]

PixelBuffer	(	unsigned int	_width,
		unsigned int	_height,
		PixelFormat	_format,
		void *	_data,
		std::size_t	_size
	)

Describe a caller owned buffer.

Parameters

[in]	_width	Width in pixels
[in]	_height	Height in pixels
[in]	_format	Pixel format of the buffer
[in]	_data	Start of the buffer. Not owned.
[in]	_size	Size of the buffer in bytes

PixelBuffer() [2/3]

PixelBuffer ( Image &  _image )

explicit

View the storage of an existing image. The view is only valid while the image, or a copy of it, is alive.

Parameters

[in]

_image

Image whose buffer is viewed

PixelBuffer() [3/3]

PixelBuffer

(

const PixelBuffer &

_other

)

Copy constructor. Copies of a view share the same buffer.

Parameters

[in]

_other

View to copy

~PixelBuffer()

~PixelBuffer

(

)

Destructor. Does not free the buffer.

Member Function Documentation

Data()

unsigned char * Data

(

)

const

Get a pointer to the first byte of the buffer. The pointer is writable even through a const view: this is a span, not a read only view.

Returns

Pointer to the buffer

Format()

PixelFormat Format

(

)

const

Get the pixel format.

Returns

Pixel format

Height()

unsigned int Height

(

)

const

Get the height in pixels.

Returns

Height in pixels

MemorySize()

std::size_t MemorySize

(

)

const

Get the number of bytes Width x Height pixels of Format need.

Returns

Required size in bytes

operator=() [1/2]

PixelBuffer & operator= ( const PixelBuffer &  )

delete

Views cannot be rebound.

operator=() [2/2]

PixelBuffer & operator= ( PixelBuffer &&  )

delete

Views cannot be rebound.

Size()

std::size_t Size

(

)

const

Get the size of the buffer in bytes, as given by the caller.

Returns

Buffer size in bytes

Valid()

bool Valid

(

)

const

Check that the buffer can hold a frame: the pointer is not null and Size() is at least MemorySize().

Returns

True if a frame can be written into the buffer

Width()

unsigned int Width

(

)

const

Get the width in pixels.

Returns

Width in pixels

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

• PixelBuffer.hh