PerceptualColor Namespace Reference

Classes
class	AbstractDiagram
class	ChromaHueDiagram
class	ColorDialog
class	ColorPatch
class	ColorWheel
class	GradientSlider
struct	LchaDouble
struct	LchDouble
class	MultiSpinBox
class	MultiSpinBoxSection
class	RgbColorSpaceFactory
class	WheelColorPicker

Typedefs
using	QColorFloatType = decltype(std::declval< QColor >().redF())
using	QListSizeType = decltype(std::declval< QList< int > >().count())
using	QStringLength = decltype(std::declval< QString >().length())
using	QStringSize = decltype(std::declval< QString >().size())
using	Quartet = QGenericMatrix< 1, 4, double >
using	SquareMatrix3 = QGenericMatrix< 3, 3, double >
using	Trio = QGenericMatrix< 1, 3, double >

Enumerations
enum	ColorModel {   ColorModel::CielabD50, ColorModel::CielchD50, ColorModel::Hsl360_1_1, ColorModel::Hwb360_1_1,   ColorModel::Invalid, ColorModel::OklabD65, ColorModel::OklchD65, ColorModel::Rgb1,   ColorModel::XyzD50, ColorModel::XyzD65 }
enum	ColorSchemeType { ColorSchemeType::Light, ColorSchemeType::Dark }

Functions
template<int N, int M, typename T , typename... Args>
constexpr QGenericMatrix< N, M, T >	createMatrix (Args... args)
SquareMatrix3	createSquareMatrix3 (double r0c0, double r0c1, double r0c2, double r1c0, double r1c1, double r1c2, double r2c0, double r2c1, double r2c2)
Trio	createTrio (double first, double second, double third)
int	decimalPlaces (const int rangeMax, const int significantFigures)
template<typename T = void>
void	delayedEventProcessing (unsigned long msecWaitInitially=50, unsigned long msecWaitBetweenEventLoopPasses=50, int numberEventLoopPasses=3)
void	drawQWidgetStyleSheetAware (QWidget *widget)
template<typename T >
QString	enumerationToFullString ()
template<typename T >
QString	enumeratorToFullString (const T &enumerator)
template<typename T >
QString	enumeratorToString (const T &enumerator)
template<typename T >
constexpr quint8	fromFloatingToEightBit (const T &original)
QString	fromMnemonicToRichText (const QString &mnemonicText)
QPair< QString, QString >	getPrefixSuffix (const QString &formatString)
std::optional< ColorSchemeType >	guessColorSchemeTypeFromWidget (QWidget *widget)
void	initializeLibraryResources ()
void	initializeTranslation (QCoreApplication *instance, std::optional< QStringList > newUiLanguages)
std::optional< SquareMatrix3 >	inverseMatrix (const SquareMatrix3 &matrix)
template<typename First , typename... T>
bool	isIn (First &&first, T &&...t)
template<typename A , typename B >
constexpr bool	isNearlyEqual (A a, B b)
template<typename T >
constexpr bool	isNearlyEqual (T a, T b, T epsilon)
template<typename T >
constexpr bool	isOdd (const T &number)
template<typename T >
T	normalizedAngle360 (T value)
template<typename T >
void	normalizePolar360 (T &radius, T &angleDegree)
QDebug	operator<< (QDebug dbg, const PerceptualColor::GenericColor &value)
QDebug	operator<< (QDebug dbg, const PerceptualColor::LchaDouble &value)
QDebug	operator<< (QDebug dbg, const PerceptualColor::LchDouble &value)
QDebug	operator<< (QDebug dbg, const PerceptualColor::MultiSpinBoxSection &value)
QDebug	operator<< (QDebug dbg, const PerceptualColor::PolarPointF value)
QDebug	operator<< (QDebug dbg, const PerceptualColor::RgbColor &value)
QVersionNumber	perceptualColorRunTimeVersion ()
template<typename T >
QColor	qColorFromRgbDouble (T red, T green, T blue)
QIcon	qIconFromTheme (const QStringList &names, const QString &fallback, ColorSchemeType type)
template<typename T >
constexpr T	roundToDigits (T value, int precision)
void	setTranslation (QCoreApplication *instance, const QStringList &newUiLanguages)
qreal	standardWheelStepCount (QWheelEvent *event)
cmsCIELab	toCmsLab (const cmsCIELCh &value)
cmsCIELCh	toCmsLch (const LchDouble &value)
LchDouble	toLchDouble (const cmsCIELab &value)
LchDouble	toLchDouble (const cmsCIELCh &value)
QImage	transparencyBackground (qreal devicePixelRatioF)
Array2D< QColor >	wcsBasicColors (const QSharedPointer< PerceptualColor::RgbColorSpace > &colorSpace)

Variables
constexpr qreal	gamutPrecisionCielab = 0.001
constexpr qreal	gamutPrecisionOklab = gamutPrecisionCielab / 100
constexpr int	overlap = 2
constexpr qreal	pageStepAlpha = 10 * singleStepAlpha
constexpr int	pageStepChroma = 10 * singleStepChroma
constexpr int	pageStepHue = 10 * singleStepHue
constexpr int	pageStepLightness = 10 * singleStepLightness
constexpr auto	pi = M_PI
const QString	richTextMarker = QStringLiteral(u"<a/>")
constexpr qreal	scaleFromMinumumSizeHintToSizeHint = 1.2
constexpr qreal	singleStepAlpha = 0.01
constexpr int	singleStepChroma = 1
constexpr int	singleStepHue = 360 / 100
constexpr int	singleStepLightness = 1
constexpr double	singleStepOklabc = 0.01
constexpr cmsCIEXYZ	whitePointD65TwoDegree {0.95047, 1.00000, 1.08883}

Detailed Description

The namespace of this library.

All symbols that are provided in this library are encapsulated within this namespace.

Enumeration Type Documentation

ColorModel

enum PerceptualColor::ColorModel

strong

Identifiers for color models.

Enumerator
CielabD50	Cielab color space using a D50 illuminant. Lightness: [0, 100]. a: unbound. b: unbound.
CielchD50	Cielch color space using a D50 illuminant. Lightness: [0, 100]. Chroma: unbound. Hue: [0, 360[.
Hsl360_1_1	A HSL color space. Hue: [0, 360[. Saturation: [0, 1]. Lightness: [0, 1].
Hwb360_1_1	A HWB color space. Hue: [0, 360[. Whiteness: [0, 1]. Blackness: [0, 1].
Invalid	Represents invalid data.
OklabD65	Oklab color space, which by definition always and exclusively uses a D65 illuminant. Lightness: [0, 1]. a: unbound. b: unbound.
OklchD65	Oklch color space, which by definition always and exclusively uses a D65 illuminant. Lightness: [0, 1]. Chroma: unbound. Hue: [0, 360[.
Rgb1	An Rgb color space. R: [0, 1]. G: [0, 1]. B: [0, 1].
XyzD50	Xyz color space using a D50 illuminant. X: unbound. Y: [0, 1]. Diffuse white has a luminance (Y) of 1.0 Z: unbound.
XyzD65	Xzy color space using a D65 illuminant. X: unbound. Y: [0, 1]. Diffuse white has a luminance (Y) of 1.0 Z: unbound.

Definition at line 30 of file helperconversion.h.

ColorSchemeType

enum PerceptualColor::ColorSchemeType

strong

Represents the appearance of a theme.

Enumerator
Light	Light theme.
Dark	Dark theme.

Definition at line 33 of file helper.h.

Function Documentation

decimalPlaces()

int PerceptualColor::decimalPlaces	(	const int	rangeMax,
		const int	significantFigures
	)

Calculates the required number of decimals to achieve the requested number of significant figures within the given range.

Parameters

rangeMax	The maximum value of the range [0, rangeMax].
significantFigures	The requested number of significant figures.

maxRange	decimalPlaces(maxRange, 2)	decimalPlaces(maxRange, 3)	decimalPlaces(maxRange, 4)
1	1	2	3
2	1	2	3
100	0	0	1
255	0	0	1
360	0	0	1

Returns

The number of decimal places after the decimal point (in addition to the whole number part) required to achieve the requested number of significant figures within the given range.

Definition at line 108 of file helpermath.cpp.

enumerationToFullString()

template<typename T >

QString PerceptualColor::enumerationToFullString

(

)

The full-qualified C++ identifier as QString.

This can be useful for debugging purposes.

Template Parameters

T	The enumeration.

Precondition

The enumeration type is declared with Q_ENUM or Q_ENUM_NS.

Returns

The full-qualified C++ identifier as QString.

Definition at line 245 of file helper.h.

enumeratorToFullString()

template<typename T >

QString PerceptualColor::enumeratorToFullString

(

const T &

enumerator

)

The full-qualified C++ identifier as QString.

This can be useful for debugging purposes.

Template Parameters

T	The enumeration type. Can usually be omitted.

Parameters

enumerator

An enumerator.

Precondition

The enumeration type of the enumerator is declared with Q_ENUM or Q_ENUM_NS.

Returns

The full-qualified C++ identifier as QString, followed by the underlying integer value in parenthesis. If the enumerator does not exist (for example because you have done a static_cast of an invalid integer to the enum class), an empty String is returned instead. If the enumerator has synonyms (that means, there exist other enumerators that share the same integer with the current enumerator), all synonym enumerators are returned.

See also

enumeratorToString()

Definition at line 274 of file helper.h.

enumeratorToString()

template<typename T >

QString PerceptualColor::enumeratorToString

(

const T &

enumerator

)

The C++ identifier as QString.

This can be useful for debugging purposes.

Template Parameters

T	The enumeration type. Can usually be omitted.

Parameters

enumerator

An enumerator.

Precondition

The enumeration type of the enumerator is declared with Q_ENUM or Q_ENUM_NS.

Returns

The C++ identifier as QString, followed by the underlying integer value in parenthesis. If the enumerator does not exist (for example because you have done a static_cast of an invalid integer to the enum class), an empty String is returned instead. If the enumerator has synonyms (that means, there exist other enumerators that share the same integer with the current enumerator), all synonym enumerators are returned.

See also

enumeratorToFullString()

Definition at line 316 of file helper.h.

operator<<() [1/3]

PERCEPTUALCOLOR_IMPORTEXPORT QDebug PerceptualColor::operator<<	(	QDebug	dbg,
		const PerceptualColor::LchaDouble &	value
	)

Adds QDebug() support for data type PerceptualColor::LchaDouble.

Parameters

dbg	Existing debug object
value	Value to stream into the debug object

Returns

Debug object with value streamed in

Definition at line 58 of file lchadouble.cpp.

operator<<() [2/3]

PERCEPTUALCOLOR_IMPORTEXPORT QDebug PerceptualColor::operator<<	(	QDebug	dbg,
		const PerceptualColor::LchDouble &	value
	)

Adds QDebug() support for data type PerceptualColor::LchDouble.

Parameters

dbg	Existing debug object
value	Value to stream into the debug object

Returns

Debug object with value streamed in

Definition at line 60 of file lchdouble.cpp.

operator<<() [3/3]

PERCEPTUALCOLOR_IMPORTEXPORT QDebug PerceptualColor::operator<<	(	QDebug	dbg,
		const PerceptualColor::MultiSpinBoxSection &	value
	)

Adds QDebug() support for data type PerceptualColor::MultiSpinBoxSection.

Parameters

dbg	Existing debug object
value	Value to stream into the debug object

Returns

Debug object with value streamed in

Definition at line 245 of file multispinboxsection.cpp.

perceptualColorRunTimeVersion()

PERCEPTUALCOLOR_IMPORTEXPORT QVersionNumber PerceptualColor::perceptualColorRunTimeVersion

(

)

Against which version of this library you are running.

Returns

The library version with major, minor and patch version. Note that there is no pre-release identifier included. For example, if your application is running against version 1.2.3-alpha of this library, this function will return QVersionNumber(1, 2, 3).

To use this function, include version.h

See also

Version information at compiletime and runtime

Definition at line 33 of file version.cpp.

setTranslation()

void PERCEPTUALCOLOR_IMPORTEXPORT PerceptualColor::setTranslation	(	QCoreApplication *	instance,
		const QStringList &	newUiLanguages
	)

Set the translation for the whole library.

After calling this function, all objects of this library that are created from now on are translated according to translation that was set.

Objects that were yet existing when calling are not always automatically updated: When calling this function, Qt sends a QEvent::LanguageChange event only to top-level widgets, and these will get updated then. You can send the event yourself to non-top-level widgets to update those widgets also. Note that also RgbColorSpaceFactory generates objects that might have localized properties; these objects do not support translation updates.

If you create objects that use translations before a translation has been set explicitly, than automatically an environment-dependant translation is loaded.

You might call this function again after a change of QLocale() to change the translation. Also, call this function again after destroying the QCoreApplication object and creating a new one.

It is safe to call this function multiple times.

Precondition

There exists exactly one instance of QCoreApplication to which the parameter points. This function is called from the same thread in which the QCoreApplication instance lives.

Parameters

instance	A pointer to the QCoreApplication instance for which the initialization will be done.
newUiLanguages	List of translations, ordered by priority, most important ones first, like in QLocale::uiLanguages().

Definition at line 55 of file settranslation.cpp.

wcsBasicColors()

Array2D< QColor > PerceptualColor::wcsBasicColors

(

const QSharedPointer< PerceptualColor::RgbColorSpace > &

colorSpace

)

Palette derived from the basic colors as by WCS (World color survey).

The palette contains various tints and shades of the basic colors. The choice of the basic colors is based on the study by Brent Berlin and Paul Kay, who suggest that the basic color terms in almost all languages on earth follow a universal pattern. They propose that there are eleven basic color terms that appear in this order during the evolution of a language:

1. black, white
2. red
3. green, yellow
4. blue
5. brown
6. purple, pink, orange, gray

Additionally, people worldwide seem to agree quite well on the typical values of each of these color terms. This theory is a fascinating one and forms a good basis for choosing basic colors for this palette.

This widget's colors have been arranged largely according to the color wheel of the perceptually uniform color space. We start with the saturated basic colors: red, orange, yellow, green, blue, and purple in order of their hue angles. Next, we have pink and brown, which have roughly the same hue as red or orange but are less saturated. These are simply the less chromatic parts of this hue but are nevertheless perceived by humans as independent colors. For each of these basic colors, there are five variants in the order of tint, pure color, and shade. Following the saturated colors and eventually the less saturated ones, the gray axis comes in last place.

What exact colors are used? What exactly is a typical “red” or a “green”? Doesn’t every human have a slightly different feeling what a “typical” red or a “typical” blue is? We need a focal color, which is, according to Oxford Reference:

“A colour that is a prototypical instance of a particular colour name, such as a shade of red that a majority of viewers consider to be the best example of a red colour.”

The World Color Survey (WCS) is a significant study about focal colors of speakers of different languages across the world. The data from this survey is available online, and while it does not provide direct values for focal colors, various studies have used this data to determine focal colors for some basic color terms and a naming centroid for others.

The table below shows the WCS grid coordinates for the basic color terms along with the corresponding Cielab values for the focal color (where available) or the naming centroid (where focal color data is unavailable).

Basic color term	WCS grid coordinates	Cielab³ L	Cielab³ a	Cielab³ b
white¹	A0	96.00	-0.06	0.06
black¹	J0	15.60	-0.02	0.02
red¹	G1	41.22	61.40	17.92
yellow¹	C9	81.35	7.28	109.12
green¹	F17	51.57	-63.28	28.95
blue¹	F29	51.57	-3.41	-48.08
brown³	G7	41.22	17.04	45.95
purple³	G34	41.22	33.08	-30.50
pink³	E1	61.70	49.42	18.23
orange³	E6	61.70	29.38	64.40
gray	not available

¹ Focal color as proposed by Focal colors are universal after all.

² Raw estimation of the naming centroid based on Fig. 4 of this document. (Fig. 5 would be the better choice, as it gives the focal color instead of the naming centroid, but unfortunately contains only red, yellow, green and blue, for which we have yet direct data.)

³ Lookup table providing Lab values for WCS grid coordinates and the corresponding explanation.

From this data, the colors in our palette have been derived as follows:

• The gray axis has been defined manually, ignoring the WCS data. Chroma is 0. The lightness is 100% for white, 0% for black, and 75%, 50%, and 25% for the intermediate grays.
• The other columns for chromatic colors use the WCS data for the swatch in the middle. Tints and shades are calculated by adding or reducing chroma and lightness within the Oklab color space. If the resulting color falls outside the color space, a nearby in-gamut color is chosen instead.

Parameters

colorSpace

The color space in which the return value is calculated.

Returns

Palette derived from the basic colors. Provides as a list of basic colors (in this order: red, orange, yellow, green, blue, purple, pink, brown, gray axis). Each basic color is a list of 5 swatches (starting with the lightest and finishing with the darkest: 2 tints, the tone itself, 2 shades).

Note

The RGB value is rounded to full integers in the range [0, 255].

Definition at line 459 of file helper.cpp.