A color class. More...

#include "murl_color.h"

Public Types
enum	Components { RED, GREEN, BLUE, ALPHA, NUM_COMPONENTS }
	Enumeration of the components raw data. More...

enum	StringFormat { STRING_FORMAT_UNKNOWN, STRING_FORMAT_FLOAT, STRING_FORMAT_INT, STRING_FORMAT_HEX, STRING_FORMAT_MIXED, STRING_FORMAT_INCOMPLETE, NUM_STRING_FORMATS }
	String formats. More...

Public Member Functions
	Color ()
	The default constructor.

	Color (Float value)
	Constructor to set all color components to a given value. More...

	Color (Float red, Float green, Float blue, Float alpha)
	Constructor to initialize a color with given component values. More...

void	Set (Float red, Float green, Float blue, Float alpha)
	Set all components of the color instance to a set of given component values. More...

void	SetInt (SInt32 red, SInt32 green, SInt32 blue, SInt32 alpha)
	Set all components of the color instance to a set of given integer component values. More...

Float	GetRed () const
	Get the red component. More...

void	SetRed (Float red)
	Set the red component. More...

SInt32	GetRedInt () const
	Get the red integer component. More...

void	SetRedInt (SInt32 red)
	Set the red integer component. More...

Float	GetGreen () const
	Get the green component. More...

void	SetGreen (Float green)
	Set the green component. More...

SInt32	GetGreenInt () const
	Get the green integer component. More...

void	SetGreenInt (SInt32 green)
	Set the green integer component. More...

Float	GetBlue () const
	Get the blue component. More...

void	SetBlue (Float blue)
	Set the blue component. More...

SInt32	GetBlueInt () const
	Get the blue integer component. More...

void	SetBlueInt (SInt32 blue)
	Set the blue integer component. More...

Float	GetAlpha () const
	Get the alpha component. More...

void	SetAlpha (Float alpha)
	Set the alpha component. More...

SInt32	GetAlphaInt () const
	Get the alpha integer component. More...

void	SetAlphaInt (SInt32 alpha)
	Set the alpha integer component. More...

Float	GetLuminance () const
	Get the luminance (gray scale) value calculated from R, G and B. More...

SInt32	GetLuminanceInt () const
	Get the luminance (gray scale) integer value calculated from R, G and B. More...

UInt32	ToUInt32 () const
	Get the 32 bit ABGR value of the color instance components. More...

UInt32	ToUInt32Clamped () const
	Get the 32 bit ABGR value of the color instance components, clamped to the range [0..255]. More...

void	FromUInt32 (UInt32 color)
	Set the color instance components from a 32 bit ABGR value. More...

void	FromUInt32ARGB (UInt32 color)
	Set the color instance components from a 32 bit ARGB value. More...

void	BlendSelf (const Color &foregroundColor)
	Blend a given foreground color over this color using alpha blending in place. More...

Color	Blend (const Color &foregroundColor) const
	Blend a given foreground color over this color using alpha blending and return the blended color. More...

Color &	operator+= (const Color &color)
	In-place addition operator. More...

Color &	operator-= (const Color &color)
	In-place subtraction operator. More...

Color &	operator*= (const Color &color)
	In-place multiplication operator. More...

Color &	operator*= (Float value)
	In-place multiplication operator. More...

Color &	operator/= (const Color &color)
	In-place division operator. More...

Color &	operator/= (Float value)
	In-place division operator. More...

Color	operator+ (const Color &color) const
	Addition operator. More...

Color	operator- (const Color &color) const
	Subtraction operator. More...

Color	operator* (const Color &color) const
	Multiplication operator. More...

Color	operator* (Float value) const
	Multiplication operator. More...

Color	operator/ (const Color &color) const
	Division operator. More...

Color	operator/ (Float value) const
	Division operator. More...

Bool	IsEqual (const Color &color) const
	Check if the color instance is equal to a given second color. More...

Bool	IsEqual (const Color &color, Float epsilon) const
	Check if the color instance is equal to a given second color. More...

const Float *	GetRawComponents () const
	Get a const pointer to the raw components data. More...

Float *	GetRawComponents ()
	Get a pointer to the raw components data. More...

String	ToString () const
	Get the string representation of the object. More...

Static Public Member Functions
static Color	FromInt (SInt32 red, SInt32 green, SInt32 blue, SInt32 alpha)
	Named constructor to set all components to a set of given integer component values. More...

static Float	GetLuminanceRedWeight ()
	Get the red component's weight for luminance conversion, according to the ITU-R BT.601 standard. More...

static Float	GetLuminanceGreenWeight ()
	Get the green component's weight for luminance conversion, according to the ITU-R BT.601 standard. More...

static Float	GetLuminanceBlueWeight ()
	Get the blue component's weight for luminance conversion, according to the ITU-R BT.601 standard. More...

Friends
bool	operator== (const Color &lhs, const Color &rhs)
	Equal to comparison operator. More...

bool	operator!= (const Color &lhs, const Color &rhs)
	Not equal to comparison operator. More...

Detailed Description

A color class.

This class holds four individual 32bit floating point values representing an RGBA color, each of them with a "regular" range of 0.0 (black) to 1.0 (full color). Actual values may lie beyond that range (in both directions), to define oversaturated colors or even "negative" ones.

When specified as an attribute value in an XML file, there exist a number of different notations. For specifying multiple components in one value, the following ones can be used:

A 6-digit hex string representing an unsigned 24bit integer RGB color value (100% alpha)
An 8-digit hex string representing an unsigned 32bit integer ARGB color value

For these, a trailing 'h' character defines the hex notation. For specifying individual values, either 3 (RGB) or 4 (RGBA) values must be given as a comma-separated string. Each of these values must be postfixed by one of the following characters:

'f' to specify a floating point value that directly maps to the internal range
'i' to specify an integer value, which will be divided by 255
'h' to specify a hex string, which will be converted and divided by 255

String-to-color conversion in the described way can also be done from code, by using the Util::StringToColor() function.

Examples:

"ffc080h": 100% alpha (implicitly), 100% red, 75% green and 50% blue (RGB)
"40ffc080h": 25% alpha, 100% red, 75% green and 50% blue (ARGB)
"1f,1f,1f,0.5f": 100% white with 50% alpha (RGBA)
"128i,64i,192i": 50% red, 25% green, 75% blue and (implicitly) 100% alpha (RGB)
"00h,00h,00h,ffh": black with 100% alpha (RGBA)
"0.5f,128i,80h": 50% grey with (implicitly) 100% alpha (RGB)

Member Enumeration Documentation

◆ Components

enum Murl::Color::Components

Enumeration of the components raw data.

Enumerator
RED	Index to the red component.
GREEN	Index to the green component.
BLUE	Index to the blue component.
ALPHA	Index to the alpha component.
NUM_COMPONENTS	Number of components.

◆ StringFormat

enum Murl::Color::StringFormat

String formats.

Enumerator
STRING_FORMAT_UNKNOWN	Unknown format.
STRING_FORMAT_FLOAT	Float format, e.g. "0.75f,0.5f,0.25f,1f" (RGBA)
STRING_FORMAT_INT	Integer format, e.g. "192i,128i,64i,255i" (RGBA)
STRING_FORMAT_HEX	Hex format, e.g. "ffc08040h" (ARGB)
STRING_FORMAT_MIXED	String contains different format identifiers.
STRING_FORMAT_INCOMPLETE	String does not contain a format identifier for all components.
NUM_STRING_FORMATS	Number of formats.

Constructor & Destructor Documentation

◆ Color() [1/2]

Murl::Color::Color ( Float value )

inline

Constructor to set all color components to a given value.

Parameters

value The value for the red, green, blue and alpha component.

References ALPHA, BLUE, GREEN, and RED.

◆ Color() [2/2]

Murl::Color::Color	(	Float	red,
		Float	green,
		Float	blue,
		Float	alpha
	)

inline

Constructor to initialize a color with given component values.

Parameters

red	The red component.
green	The green component.
blue	The blue component.
alpha	The alpha component.

References ALPHA, BLUE, GREEN, and RED.

Member Function Documentation

◆ FromInt()

static Color Murl::Color::FromInt	(	SInt32	red,
		SInt32	green,
		SInt32	blue,
		SInt32	alpha
	)

inlinestatic

Named constructor to set all components to a set of given integer component values.

The integer values are divided by 255.

Parameters

red	The red integer component.
green	The green integer component.
blue	The blue integer component.
alpha	The alpha integer component.

Returns: The color object.

References Color().

◆ Set()

void Murl::Color::Set	(	Float	red,
		Float	green,
		Float	blue,
		Float	alpha
	)

inline

Set all components of the color instance to a set of given component values.

Parameters

red	The red component.
green	The green component.
blue	The blue component.
alpha	The alpha component.

References ALPHA, BLUE, GREEN, and RED.

◆ SetInt()

void Murl::Color::SetInt	(	SInt32	red,
		SInt32	green,
		SInt32	blue,
		SInt32	alpha
	)

inline

Set all components of the color instance to a set of given integer component values.

The integer values are divided by 255.

Parameters

red	The red integer component.
green	The green integer component.
blue	The blue integer component.
alpha	The alpha integer component.

References ALPHA, BLUE, GREEN, and RED.

◆ GetRed()

Float Murl::Color::GetRed ( ) const

inline

Get the red component.

Returns: The red component.

References RED.

◆ SetRed()

void Murl::Color::SetRed ( Float red )

inline

Set the red component.

Parameters

red	The red component.

References RED.

◆ GetRedInt()

SInt32 Murl::Color::GetRedInt ( ) const

inline

Get the red integer component.

The component is multiplied by 255.

Returns: The red integer component.

References RED, and Murl::Math::Round().

◆ SetRedInt()

void Murl::Color::SetRedInt ( SInt32 red )

inline

Set the red integer component.

The component is divided by 255.

Parameters

red	The red integer component.

References RED.

◆ GetGreen()

Float Murl::Color::GetGreen ( ) const

inline

Get the green component.

Returns: The green component.

References GREEN.

◆ SetGreen()

void Murl::Color::SetGreen ( Float green )

inline

Set the green component.

Parameters

green The green component.

References GREEN.

◆ GetGreenInt()

SInt32 Murl::Color::GetGreenInt ( ) const

inline

Get the green integer component.

The component is multiplied by 255.

Returns: The green integer component.

References GREEN, and Murl::Math::Round().

◆ SetGreenInt()

void Murl::Color::SetGreenInt ( SInt32 green )

inline

Set the green integer component.

The component is divided by 255.

Parameters

green The green integer component.

References GREEN.

◆ GetBlue()

Float Murl::Color::GetBlue ( ) const

inline

Get the blue component.

Returns: The blue component.

References BLUE.

◆ SetBlue()

void Murl::Color::SetBlue ( Float blue )

inline

Set the blue component.

Parameters

blue	The blue component.

References BLUE.

◆ GetBlueInt()

SInt32 Murl::Color::GetBlueInt ( ) const

inline

Get the blue integer component.

The component is multiplied by 255.

Returns: The blue integer component.

References BLUE, and Murl::Math::Round().

◆ SetBlueInt()

void Murl::Color::SetBlueInt ( SInt32 blue )

inline

Set the blue integer component.

The component is divided by 255.

Parameters

blue	The blue integer component.

References BLUE.

◆ GetAlpha()

Float Murl::Color::GetAlpha ( ) const

inline

Get the alpha component.

Returns: The alpha component.

References ALPHA.

◆ SetAlpha()

void Murl::Color::SetAlpha ( Float alpha )

inline

Set the alpha component.

Parameters

alpha The alpha component.

References ALPHA.

◆ GetAlphaInt()

SInt32 Murl::Color::GetAlphaInt ( ) const

inline

Get the alpha integer component.

The component is multiplied by 255.

Returns: The alpha integer component.

References ALPHA, and Murl::Math::Round().

◆ SetAlphaInt()

void Murl::Color::SetAlphaInt ( SInt32 alpha )

inline

Set the alpha integer component.

The component is divided by 255.

Parameters

alpha The alpha integer component.

References ALPHA.

◆ GetLuminance()

Float Murl::Color::GetLuminance ( ) const

inline

Get the luminance (gray scale) value calculated from R, G and B.

Luminance calculation uses the standard conversion factors defined by the Rec 601 standard which can be found in PAL and NTSC color models.

Returns: The luminance (R * 0.2990 + G * 0.5864 + B * 0.1146).

References BLUE, GetLuminanceBlueWeight(), GetLuminanceGreenWeight(), GetLuminanceRedWeight(), GREEN, and RED.

Referenced by GetLuminanceInt().

◆ GetLuminanceInt()

SInt32 Murl::Color::GetLuminanceInt ( ) const

inline

Get the luminance (gray scale) integer value calculated from R, G and B.

Luminance calculation uses the standard conversion factors defined by the Rec 601 standard which can be found in PAL and NTSC color models, multiplied by 255.

Returns: The integer luminance.

References GetLuminance(), and Murl::Math::Round().

◆ ToUInt32()

UInt32 Murl::Color::ToUInt32 ( ) const

inline

Get the 32 bit ABGR value of the color instance components.

Returns: The 32 bit ABGR value.

References ALPHA, BLUE, GREEN, RED, and Murl::Math::Round().

◆ ToUInt32Clamped()

UInt32 Murl::Color::ToUInt32Clamped ( ) const

inline

Get the 32 bit ABGR value of the color instance components, clamped to the range [0..255].

Returns: The 32 bit ABGR value.

References ALPHA, BLUE, GREEN, RED, and Murl::Math::Round().

◆ FromUInt32()

void Murl::Color::FromUInt32 ( UInt32 color )

inline

Set the color instance components from a 32 bit ABGR value.

Parameters

color The 32 bit ABGR value.

References ALPHA, BLUE, GREEN, and RED.

◆ FromUInt32ARGB()

void Murl::Color::FromUInt32ARGB ( UInt32 color )

inline

Set the color instance components from a 32 bit ARGB value.

Parameters

color The 32 bit ARBG value.

References ALPHA, BLUE, GREEN, and RED.

◆ BlendSelf()

void Murl::Color::BlendSelf ( const Color & foregroundColor )

inline

Blend a given foreground color over this color using alpha blending in place.

Parameters

foregroundColor The foreground color to blend.

References ALPHA, BLUE, GREEN, and RED.

Referenced by Blend().

◆ Blend()

Color Murl::Color::Blend ( const Color & foregroundColor ) const

inline

Blend a given foreground color over this color using alpha blending and return the blended color.

Parameters

foregroundColor The foreground color to blend.

Returns: The alpha blended color.

References BlendSelf().

◆ operator+=()

Color& Murl::Color::operator+= ( const Color & color )

inline

In-place addition operator.

Parameters

color The color to add.

Returns: The object itself.

References ALPHA, BLUE, GREEN, and RED.

◆ operator-=()

Color& Murl::Color::operator-= ( const Color & color )

inline

In-place subtraction operator.

Parameters

color The color to subtract.

Returns: The object itself.

References ALPHA, BLUE, GREEN, and RED.

◆ operator*=() [1/2]

Color& Murl::Color::operator*= ( const Color & color )

inline

In-place multiplication operator.

Parameters

color The color to multiply.

Returns: The object itself.

References ALPHA, BLUE, GREEN, and RED.

◆ operator*=() [2/2]

Color& Murl::Color::operator*= ( Float value )

inline

In-place multiplication operator.

Parameters

value The value to multiply.

Returns: The object itself.

References ALPHA, BLUE, GREEN, and RED.

◆ operator/=() [1/2]

Color& Murl::Color::operator/= ( const Color & color )

inline

In-place division operator.

Parameters

color The color to divide.

Returns: The object itself.

References ALPHA, BLUE, GREEN, and RED.

◆ operator/=() [2/2]

Color& Murl::Color::operator/= ( Float value )

inline

In-place division operator.

Parameters

value The value to divide.

Returns: The object itself.

References ALPHA, BLUE, GREEN, and RED.

◆ operator+()

Color Murl::Color::operator+ ( const Color & color ) const

inline

Addition operator.

Parameters

color The right hand side color.

Returns: The added color.

◆ operator-()

Color Murl::Color::operator- ( const Color & color ) const

inline

Subtraction operator.

Parameters

color The right hand side color.

Returns: The subtracted color.

◆ operator*() [1/2]

Color Murl::Color::operator* ( const Color & color ) const

inline

Multiplication operator.

Parameters

color The right hand side color.

Returns: The multiplied color.

◆ operator*() [2/2]

Color Murl::Color::operator* ( Float value ) const

inline

Multiplication operator.

Parameters

value The right hand side value.

Returns: The multiplied color.

◆ operator/() [1/2]

Color Murl::Color::operator/ ( const Color & color ) const

inline

Division operator.

Parameters

color The right hand side color.

Returns: The divided color.

◆ operator/() [2/2]

Color Murl::Color::operator/ ( Float value ) const

inline

Division operator.

Parameters

value The right hand side value.

Returns: The divided color.

◆ IsEqual() [1/2]

Bool Murl::Color::IsEqual ( const Color & color ) const

inline

Check if the color instance is equal to a given second color.

Compares all values within the default epsilon range Limits::Epsilon().

Parameters

color The color to compare.

Returns: true if all components are equal.

◆ IsEqual() [2/2]

Bool Murl::Color::IsEqual	(	const Color &	color,
		Float	epsilon
	)		const

inline

Check if the color instance is equal to a given second color.

Compares all values within a given epsilon range.

Parameters

color	The color to compare.
epsilon	The epsilon to compare.

Returns: true if all components are equal.

References Murl::Math::Abs(), ALPHA, BLUE, GREEN, and RED.

◆ GetRawComponents() [1/2]

const Float* Murl::Color::GetRawComponents ( ) const

inline

Get a const pointer to the raw components data.

Returns: Const pointer to the raw data.

◆ GetRawComponents() [2/2]

Float* Murl::Color::GetRawComponents ( )

inline

Get a pointer to the raw components data.

Returns: Pointer to the raw data.

◆ ToString()

String Murl::Color::ToString ( ) const

Get the string representation of the object.

Returns: The string representation of the object.

◆ GetLuminanceRedWeight()

static Float Murl::Color::GetLuminanceRedWeight ( )

inlinestatic

Get the red component's weight for luminance conversion, according to the ITU-R BT.601 standard.

Returns: The weight of the red component.

Referenced by GetLuminance().

◆ GetLuminanceGreenWeight()

static Float Murl::Color::GetLuminanceGreenWeight ( )

inlinestatic

Get the green component's weight for luminance conversion, according to the ITU-R BT.601 standard.

Returns: The weight of the green component.

Referenced by GetLuminance().

◆ GetLuminanceBlueWeight()

static Float Murl::Color::GetLuminanceBlueWeight ( )

inlinestatic

Get the blue component's weight for luminance conversion, according to the ITU-R BT.601 standard.

Returns: The weight of the blue component.

Referenced by GetLuminance().

Friends And Related Function Documentation

◆ operator==

bool operator==	(	const Color &	lhs,
		const Color &	rhs
	)

friend

Equal to comparison operator.

Performs a test without an epsilon range, which can be used for detecting changes i.e. DoubleBuffer<Color> class. To compare within an epsilon range use Color::IsEqual().

Parameters

lhs	The left hand side color to compare.
rhs	The right hand side color to compare.

Returns: true if all components are exactly the same.

◆ operator!=

bool operator!=	(	const Color &	lhs,
		const Color &	rhs
	)

friend

Not equal to comparison operator.

Performs a test without an epsilon range, which can be used for detecting changes i.e. DoubleBuffer<Color> class. To compare within an epsilon range use Color::IsEqual().

Parameters

lhs	The left hand side color to compare.
rhs	The right hand side color to compare.

Returns: true if all components are exactly the same.

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

murl_color.h

Public Types

Public Member Functions

Static Public Member Functions

Friends

Detailed Description

Member Enumeration Documentation

◆ Components

◆ StringFormat

Constructor & Destructor Documentation

◆ Color() [1/2]

◆ Color() [2/2]

Member Function Documentation

◆ FromInt()

◆ Set()

◆ SetInt()

◆ GetRed()

◆ SetRed()

◆ GetRedInt()

◆ SetRedInt()

◆ GetGreen()

◆ SetGreen()

◆ GetGreenInt()

◆ SetGreenInt()

◆ GetBlue()

◆ SetBlue()

◆ GetBlueInt()

◆ SetBlueInt()

◆ GetAlpha()

◆ SetAlpha()

◆ GetAlphaInt()

◆ SetAlphaInt()

◆ GetLuminance()

◆ GetLuminanceInt()

◆ ToUInt32()

◆ ToUInt32Clamped()

◆ FromUInt32()

◆ FromUInt32ARGB()

◆ BlendSelf()

◆ Blend()

◆ operator+=()

◆ operator-=()

◆ operator*=() [1/2]

◆ operator*=() [2/2]

◆ operator/=() [1/2]

◆ operator/=() [2/2]

◆ operator+()

◆ operator-()

◆ operator*() [1/2]

◆ operator*() [2/2]

◆ operator/() [1/2]

◆ operator/() [2/2]

◆ IsEqual() [1/2]

◆ IsEqual() [2/2]

◆ GetRawComponents() [1/2]

◆ GetRawComponents() [2/2]

◆ ToString()

◆ GetLuminanceRedWeight()

◆ GetLuminanceGreenWeight()

◆ GetLuminanceBlueWeight()

Friends And Related Function Documentation

◆ operator==

◆ operator!=