Hsl Struct

Namespace: Meziantou.Framework.Imaging
Assembly: Meziantou.Framework.Imaging.dll
Package: Meziantou.Framework.Imaging 1.2.11
Source: Hsl.cs
Available in package assets: net10.0net11.0

A color given by its hue, saturation and lightness (HSL), a cylindrical form of the encoded RGB values of a device.

public readonly struct Hsl : IEquatable<Hsl>

Remarks

HSL describes RGB values, not colors: it has no color space of its own, and its conversions read and write the stored RGB values as they are, whatever their color space. The equations are those of CSS Color 4 (hslToRgb and rgbToHsl). The conversions from RGB give the hue in [0, 360); a gray has no hue: it is 0.

The values are not validated: the conversion to RGB clips each component to [0, 1].

Implements

IEquatable<Hsl>

Constructors

Name	Description
Hsl(double, double, double)	Initializes a new instance of the `Hsl` struct.

Hsl(double, double, double)

Initializes a new instance of the Hsl struct.

public Hsl(double h, double s, double l)

Parameters

h double: The hue angle, in degrees: 0 is red, 120 green, 240 blue.
s double: The saturation, from 0 (gray) to 1.
l double: The lightness, from 0 (black) to 1 (white); 0.5 is the pure hue.

Properties

Name	Description
H	Gets the hue angle, in degrees: 0 is red, 120 green, 240 blue.
L	Gets the lightness, from 0 (black) to 1 (white); 0.5 is the pure hue.
S	Gets the saturation, from 0 (gray) to 1.

H

Gets the hue angle, in degrees: 0 is red, 120 green, 240 blue.

public double H { get; }

Property value

L

Gets the lightness, from 0 (black) to 1 (white); 0.5 is the pure hue.

public double L { get; }

Property value

S

Gets the saturation, from 0 (gray) to 1.

public double S { get; }

Property value

Methods

Name	Description
Equals(Hsl)	Indicates whether the current object is equal to another object of the same type.
Equals(object?)	Indicates whether this instance and a specified object are equal.
FromRgb(Rgba32)	Converts an 8-bit RGB color to HSL. Alpha is ignored.
FromRgb(Rgba64)	Converts a 16-bit RGB color to HSL. Alpha is ignored.
GetHashCode()	Returns the hash code for this instance.
Parse(ReadOnlySpan<char>, double)	Parses a color written with the CSS Color 4 `hsl()` function, such as `hsl(120 50% 25%)`.
ToCssString(double)	Formats this color with the CSS Color 4 `hsl()` function, the components after the hue as percentages: `hsl(120 50% 25%)`.
ToRgba32()	Converts this color to an opaque 8-bit RGB color, each component clipped to [0, 1].
ToRgba64()	Converts this color to an opaque 16-bit RGB color, each component clipped to [0, 1].
ToString()	Returns the fully qualified type name of this instance.
TryParse(ReadOnlySpan<char>, Hsl, double)	Tries to parse a color written with the CSS Color 4 `hsl()` function, as `Hsl.Parse` does.

Equals overloads

Equals(Hsl)

Indicates whether the current object is equal to another object of the same type.

public bool Equals(Hsl other)

Parameters

other Hsl: An object to compare with this object.

Returns

bool true if the current object is equal to the other parameter; otherwise, false.

Equals(object?)

Indicates whether this instance and a specified object are equal.

public override bool Equals(object? obj)

Parameters

obj object?: The object to compare with the current instance.

Returns

bool true if obj and this instance are the same type and represent the same value; otherwise, false.

FromRgb overloads

FromRgb(Rgba32)

Converts an 8-bit RGB color to HSL. Alpha is ignored.

public static Hsl FromRgb(Rgba32 color)

Parameters

color Rgba32: The color.

Returns

Hsl The color.

FromRgb(Rgba64)

Converts a 16-bit RGB color to HSL. Alpha is ignored.

public static Hsl FromRgb(Rgba64 color)

Parameters

color Rgba64: The color.

Returns

Hsl The color.

GetHashCode()

Returns the hash code for this instance.

public override int GetHashCode()

Returns

int A 32-bit signed integer that is the hash code for this instance.

Parse(ReadOnlySpan<char>, double)

Parses a color written with the CSS Color 4 hsl() function, such as hsl(120 50% 25%).

public static Hsl Parse(ReadOnlySpan<char> value, out double alpha)

Parameters

value ReadOnlySpan<char>: The text.
alpha double: The alpha of the color, in [0, 1]: 1 when the text has none.

Returns

Hsl The color.

Exceptions

FormatException: value is not a hsl() color.

Remarks

The modern syntax (hsl(120 50% 25%), with an optional / alpha) and the legacy syntax (hsl(120, 50%, 25%) and hsla()) are accepted. The hue is a number of degrees or an angle (deg, grad, rad, turn), brought to [0, 360); the saturation and the lightness are percentages, or numbers of the same value in the modern syntax, and a negative saturation is clamped to 0. Each component may be none, read as 0. Function names, units and keywords are ASCII case-insensitive, and white space may surround the text; calc() and relative colors are not supported.

ToCssString(double)

Formats this color with the CSS Color 4 hsl() function, the components after the hue as percentages: hsl(120 50% 25%).

public string ToCssString(double alpha = 1d)

Parameters

alpha double: The alpha, in [0, 1]. It is written after a / when it is not 1.

Returns

string The text; Hsl.Parse reads it back.

Exceptions

ArgumentOutOfRangeException: alpha is not in [0, 1], or a component is not a finite number.

ToRgba32()

Converts this color to an opaque 8-bit RGB color, each component clipped to [0, 1].

public Rgba32 ToRgba32()

Returns

Rgba32 The color.

ToRgba64()

Converts this color to an opaque 16-bit RGB color, each component clipped to [0, 1].

public Rgba64 ToRgba64()

Returns

Rgba64 The color.

ToString()

Returns the fully qualified type name of this instance.

public override string ToString()

Returns

string The fully qualified type name.

TryParse(ReadOnlySpan<char>, Hsl, double)

Tries to parse a color written with the CSS Color 4 hsl() function, as Hsl.Parse does.

public static bool TryParse(ReadOnlySpan<char> value, out Hsl result, out double alpha)

Parameters

value ReadOnlySpan<char>: The text.
result Hsl: The color, or the default value when the text is not a hsl() color.
alpha double: The alpha of the color, in [0, 1]: 1 when the text has none.

Returns

bool true if the text is a hsl() color.

Operators

Name	Description
operator ==(Hsl, Hsl)	Compares two colors for equality, component by component.
operator !=(Hsl, Hsl)	Compares two colors for inequality, component by component.

operator ==(Hsl, Hsl)

Compares two colors for equality, component by component.

public static bool operator ==(Hsl left, Hsl right)

Parameters

left Hsl: The first color.
right Hsl: The second color.

Returns

bool true if all the components are equal; otherwise false.

operator !=(Hsl, Hsl)

Compares two colors for inequality, component by component.

public static bool operator !=(Hsl left, Hsl right)

Parameters

left Hsl: The first color.
right Hsl: The second color.

Returns

bool true if a component differs; otherwise false.