Image Class Reference

Represents an image composed of pixels with values in [0,1]. Provide image loading/saving utilities, for both LDR and HDR images. More...

#include <Image.hpp>

Public Types
enum class	Save : uint { NONE = 0 , FLIP = 1 << 0 , IGNORE_ALPHA = 1 << 1 , SRGB_LDR = 1 << 2 }
	Options for saving an image to disk. More...

Public Member Functions
	Image ()=default
	Image (unsigned int awidth, unsigned int aheight, unsigned int acomponents, float value=0.0f)
glm::vec4 &	rgba (int x, int y)
glm::vec3 &	rgb (int x, int y)
float &	r (int x, int y)
const glm::vec4 &	rgba (int x, int y) const
const glm::vec3 &	rgb (int x, int y) const
const float &	r (int x, int y) const
glm::vec3	rgbl (float x, float y) const
glm::vec3	rgbn (float x, float y) const
glm::vec4	rgbal (float x, float y) const
int	load (const std::string &path, unsigned int channels, bool flip, bool externalFile)
int	save (const std::string &path, Save options) const
Image &	operator= (const Image &)=delete
	Image (const Image &)=delete
Image &	operator= (Image &&)=default
	Image (Image &&)=default

Static Public Member Functions
static bool	isFloat (const std::string &path)

Public Attributes
unsigned int	width = 0
	The width of the image.
unsigned int	height = 0
	The height of the image.
unsigned int	components = 0
	Number of components/channels.
std::vector< float >	pixels
	The pixels values of the image.

Private Member Functions
int	saveAsLDR (const std::string &path, Save options) const
int	saveAsHDR (const std::string &path, Save options) const
int	loadLDR (const std::string &path, unsigned int channels, bool flip, bool externalFile)
int	loadHDR (const std::string &path, unsigned int channels, bool flip, bool externalFile)

Detailed Description

Represents an image composed of pixels with values in [0,1]. Provide image loading/saving utilities, for both LDR and HDR images.

Member Enumeration Documentation

Save

enum class Image::Save : uint

strong

Options for saving an image to disk.

Enumerator
NONE	No specific options.
FLIP	Flip the image vertically.
IGNORE_ALPHA	Force alpha to 1.
SRGB_LDR	Apply gamma sRGB correction before saving, ignored for HDR images.

Constructor & Destructor Documentation

Image() [1/4]

Image::Image ( )

default

Default constructor.

Image() [2/4]

Image::Image	(	unsigned int	awidth,
		unsigned int	aheight,
		unsigned int	acomponents,
		float	value = 0.0f
	)

Constructor that allocates an empty image with the given dimensions.

Parameters

awidth	the width of the image
aheight	the height of the image
acomponents	the number of components of the image
value	the default value to use

Image() [3/4]

Image::Image ( const Image &  )

delete

Copy constructor (disabled).

Image() [4/4]

Image::Image ( Image &&  )

default

Move constructor.

Member Function Documentation

isFloat()

bool Image::isFloat ( const std::string &  path )

static

Query if a path points to an image loaded in floating point, based on the extension.

Parameters

path	the path to the image

Returns

true if the file is loaded as a floating point numbers image

Note

Extensions checked: .exr

load()

int Image::load	(	const std::string &	path,
		unsigned int	channels,
		bool	flip,
		bool	externalFile
	)

Load an image from disk. Will contain the image raw data as [0,1] floats.

Parameters

path	the path to the image
channels	the number of channels to load from the image
flip	should the image be vertically flipped
externalFile	if true, skip the resources manager and load directly from disk

Returns

a success/error flag

loadHDR()

int Image::loadHDR ( const std::string &  path, unsigned int  channels, bool  flip, bool  externalFile  )

private

Load a HDR image from disk using tiny_exr, assuming 3-channels.

Parameters

path	the path to the image
channels	will contain the number of channels of the loaded image
flip	should the image be vertically flipped
externalFile	if true, skip the resources manager and load directly from disk

Returns

a success/error flag

loadLDR()

int Image::loadLDR ( const std::string &  path, unsigned int  channels, bool  flip, bool  externalFile  )

private

Load a LDR image from disk using stb_image.

Parameters

path	the path to the image
channels	the number of channels to load from the image
flip	should the image be vertically flipped
externalFile	if true, skip the resources manager and load directly from disk

Returns

a success/error flag

operator=() [1/2]

Image & Image::operator= ( const Image &  )

delete

Copy assignment operator (disabled).

Returns

a reference to the object assigned to

operator=() [2/2]

Image & Image::operator= ( Image &&  )

default

Move assignment operator .

Returns

a reference to the object assigned to

r() [1/2]

float & Image::r	(	int	x,
		int	y
	)

Accessor to the red/first component of a pixel

Parameters

x	horizontal coordinate
y	vertical coordinate

Returns

reference to the given pixel first component

Warning

no access or component check is done

r() [2/2]

const float & Image::r	(	int	x,
		int	y
	)		const

Const accessor to the red/first component of a pixel

Parameters

x	horizontal coordinate
y	vertical coordinate

Returns

reference to the given pixel first component

Warning

no access or component check is done

rgb() [1/2]

glm::vec3 & Image::rgb	(	int	x,
		int	y
	)

Accessor to the RGB part of a pixel

Parameters

x	horizontal coordinate
y	vertical coordinate

Returns

reference to the given pixel

Warning

no access or component check is done

rgb() [2/2]

const glm::vec3 & Image::rgb	(	int	x,
		int	y
	)		const

Const accessor to the RGB part of a pixel

Parameters

x	horizontal coordinate
y	vertical coordinate

Returns

reference to the given pixel

Warning

no access or component check is done

rgba() [1/2]

glm::vec4 & Image::rgba	(	int	x,
		int	y
	)

Accessor to a RGBA pixel

Parameters

x	horizontal coordinate
y	vertical coordinate

Returns

reference to the given pixel

Warning

no access or component check is done

rgba() [2/2]

const glm::vec4 & Image::rgba	(	int	x,
		int	y
	)		const

Const accessor to a RGBA pixel

Parameters

x	horizontal coordinate
y	vertical coordinate

Returns

reference to the given pixel

Warning

no access or component check is done

rgbal()

glm::vec4 Image::rgbal	(	float	x,
		float	y
	)		const

Bilinear UV image read.

Parameters

x	horizontal unit float coordinate
y	vertical unit float coordinate

Returns

the bilinearly interpolated color value

Note

Wrapping is applied on both axis.

rgbl()

glm::vec3 Image::rgbl	(	float	x,
		float	y
	)		const

Bilinear UV image read.

Parameters

x	horizontal unit float coordinate
y	vertical unit float coordinate

Returns

the bilinearly interpolated color value

Note

Wrapping is applied on both axis.

rgbn()

glm::vec3 Image::rgbn	(	float	x,
		float	y
	)		const

Nearest-neighbour UV image read.

Parameters

x	horizontal unit float coordinate
y	vertical unit float coordinate

Returns

the color of the nearest pixel

Note

Wrapping is applied on both axis.

save()

int Image::save	(	const std::string &	path,
		Image::Save	options
	)		const

Save an image to disk, either in HDR (when using "exr" extension) or in LDR (any other extension).

Parameters

path	the path to the image
options	options to use when writing the image on disk

Returns

a success/error flag

saveAsHDR()

int Image::saveAsHDR ( const std::string &  path, Image::Save  options  ) const

private

Save a HDR image to disk using tiny_exr.

Parameters

path	the path to the image
options	options to use when writing the image on disk

Returns

a success/error flag

saveAsLDR()

int Image::saveAsLDR ( const std::string &  path, Image::Save  options  ) const

private

Save a LDR image to disk using stb_image.

Parameters

path	the path to the image
options	options to use when writing the image on disk

Returns

a success/error flag

---

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

• src/engine/resources/Image.hpp
• src/engine/resources/Image.cpp