cs225::PNG Class Reference

Collaboration diagram for cs225::PNG:

Public Member Functions
	PNG ()
	Creates an empty PNG image. More...
	PNG (unsigned int width, unsigned int height)
	Creates a PNG image of the specified dimensions. More...
	PNG (PNG const &other)
	Copy constructor: creates a new PNG image that is a copy of another. More...
	~PNG ()
	Destructor: frees all memory associated with a given PNG object. More...
PNG const &	operator= (PNG const &other)
	Assignment operator for setting two PNGs equal to one another. More...
bool	operator== (PNG const &other) const
	Equality operator: checks if two images are the same. More...
bool	operator!= (PNG const &other) const
	Inequality operator: checks if two images are different. More...
bool	readFromFile (string const &fileName)
	Reads in a PNG image from a file. More...
bool	writeToFile (string const &fileName)
	Writes a PNG image to a file. More...
HSLAPixel &	getPixel (unsigned int x, unsigned int y)
	Pixel access operator. More...
const HSLAPixel &	getPixel (unsigned int x, unsigned int y) const
	Pixel access operator. More...
unsigned int	width () const
	Gets the width of this image. More...
unsigned int	height () const
	Gets the height of this image. More...
void	resize (unsigned int newWidth, unsigned int newHeight)
	Resizes the image to the given coordinates. More...

Private Member Functions
void	_copy (PNG const &other)
	Copies the contents of other to self. More...
HSLAPixel &	_getPixelHelper (unsigned int x, unsigned int y) const
	Common function for powering the following signature stubs. More...

Private Attributes
unsigned int	width_
unsigned int	height_
HSLAPixel *	imageData_

Constructor & Destructor Documentation

PNG() [1/3]

cs225::PNG::PNG

(

)

Creates an empty PNG image.

PNG() [2/3]

cs225::PNG::PNG	(	unsigned int	width,
		unsigned int	height
	)

Creates a PNG image of the specified dimensions.

Parameters

width	Width of the new image.
height	Height of the new image.

PNG() [3/3]

cs225::PNG::PNG

(

PNG const &

other

)

Copy constructor: creates a new PNG image that is a copy of another.

Parameters

other

PNG to be copied.

~PNG()

cs225::PNG::~PNG

(

)

Destructor: frees all memory associated with a given PNG object.

Invoked by the system.

Member Function Documentation

_copy()

void cs225::PNG::_copy ( PNG const &  other )

private

Copies the contents of other to self.

_getPixelHelper()

HSLAPixel & cs225::PNG::_getPixelHelper ( unsigned int  x, unsigned int  y  ) const

private

Common function for powering the following signature stubs.

HSLAPixel & getPixel(unsigned int x, unsigned int y); const HSLAPixel & getPixel(unsigned int x, unsigned int y) const;

getPixel() [1/2]

HSLAPixel & cs225::PNG::getPixel	(	unsigned int	x,
		unsigned int	y
	)

Pixel access operator.

Gets a reference to the pixel at the given coordinates in the image. (0,0) is the upper left corner. This reference allows the image to be changed.

Parameters

x	X-coordinate for the pixel reference to be grabbed from.
y	Y-coordinate for the pixel reference to be grabbed from.

Returns

A reference to the pixel at the given coordinates.

getPixel() [2/2]

const HSLAPixel & cs225::PNG::getPixel	(	unsigned int	x,
		unsigned int	y
	)		const

Pixel access operator.

Gets a const reference to the pixel at the given coordinates in the image. (0,0) is the upper left corner. This const reference DOES NOT allow the image to be changed.

Parameters

x	X-coordinate for the const pixel reference to be grabbed from.
y	Y-coordinate for the const pixel reference to be grabbed from.

Returns

A const reference to the pixel at the given coordinates.

height()

unsigned int cs225::PNG::height

(

)

const

Gets the height of this image.

Returns

Height of the image.

operator!=()

bool cs225::PNG::operator!=

(

PNG const &

other

)

const

Inequality operator: checks if two images are different.

Parameters

other

Image to be checked.

Returns

Whether the current image differs from the other image.

operator=()

PNG const & cs225::PNG::operator=

(

PNG const &

other

)

Assignment operator for setting two PNGs equal to one another.

Parameters

other

Image to copy into the current image.

Returns

The current image for assignment chaining.

operator==()

bool cs225::PNG::operator==

(

PNG const &

other

)

const

Equality operator: checks if two images are the same.

Parameters

other

Image to be checked.

Returns

Whether the current image is equal to the other image.

readFromFile()

bool cs225::PNG::readFromFile

(

string const &

fileName

)

Reads in a PNG image from a file.

Overwrites any current image content in the PNG.

Parameters

fileName

Name of the file to be read from.

Returns

true, if the image was successfully read and loaded.

resize()

void cs225::PNG::resize	(	unsigned int	newWidth,
		unsigned int	newHeight
	)

Resizes the image to the given coordinates.

Attempts to preserve existing pixel data in the image when doing so, but will crop if necessary. No pixel interpolation is done.

Parameters

newWidth	New width of the image.
newHeight	New height of the image.

width()

unsigned int cs225::PNG::width

(

)

const

Gets the width of this image.

Returns

Width of the image.

writeToFile()

bool cs225::PNG::writeToFile

(

string const &

fileName

)

Writes a PNG image to a file.

Parameters

fileName

Name of the file to be written.

Returns

true, if the image was successfully written.

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

• cs225/PNG.h
• cs225/PNG.cpp