Struct lab::LCh

pub struct LCh {
    pub l: f32,
    pub c: f32,
    pub h: f32,
}

Struct representing a color in cylindrical CIELCh color space

Fields

l: f32

c: f32

h: f32

Implementations

impl LCh

pub fn from_rgb(rgb: &[u8; 3]) -> Self

Constructs a new LCh from a three-element array of u8s

Examples

let lch = lab::LCh::from_rgb(&[240, 33, 95]);
assert_eq!(lab::LCh { l: 52.334686, c: 78.15284, h: 0.25873056 }, lch);

pub fn from_rgba(rgba: &[u8; 4]) -> Self

Constructs a new LCh from a four-element array of u8s

The LCh struct does not store alpha channel information, so the last u8 representing alpha is discarded. This convenience method exists in order to easily measure colors already stored in an RGBA array.

Examples

let lch = lab::LCh::from_rgba(&[240, 33, 95, 255]);
assert_eq!(lab::LCh { l: 52.334686, c: 78.15284, h: 0.25873056 }, lch);

pub fn from_lab(lab: Lab) -> Self

Constructs a new LCh from a Lab

Examples

let lab = lab::Lab { l: 52.33686, a: 75.5516, b: 19.998878 };
let lch = lab::LCh::from_lab(lab);
assert_eq!(lab::LCh { l: 52.33686, c: 78.15369, h: 0.25877 }, lch);

let lab = lab::Lab { l: 52.33686, a: 0.0, b: 0.0 };
let lch = lab::LCh::from_lab(lab);
assert_eq!(lab::LCh { l: 52.33686, c: 0.0, h: 0.0 }, lch);

pub fn to_rgb(&self) -> [u8; 3]

Returns the LCh’s color in RGB, in a 3-element array

Examples

let mut lch = lab::LCh { l: 52.33686, c: 78.15369, h: 0.25877 };
assert_eq!([240, 33, 95], lch.to_rgb());

lch.h += std::f32::consts::TAU;
assert_eq!([240, 33, 95], lch.to_rgb());

pub fn to_lab(&self) -> Lab

Returns the LCh’s color in Lab

Note that due to imprecision of floating point arithmetic, conversions between Lab and LCh are not stable. A chain of Lab→LCh→Lab or LCh→Lab→LCh operations isn’t guaranteed to give back the source colour.

Examples

let lch = lab::LCh { l: 52.33686, c: 78.15369, h: 0.25877 };
let lab = lch.to_lab();
assert_eq!(lab::Lab { l: 52.33686, a: 75.5516, b: 19.998878 }, lab);

let lch = lab::LCh { l: 52.33686, c: 0.0, h: 0.25877 };
let lab = lch.to_lab();
assert_eq!(lab::Lab { l: 52.33686, a: 0.0, b: 0.0 }, lab);

let inp = lab::Lab { l: 29.52658, a: 58.595745, b: -36.281406 };
let lch = lab::LCh { l: 29.52658, c: 68.91881,  h: -0.5544043 };
let out = lab::Lab { l: 29.52658, a: 58.59575,  b: -36.281406 };
assert_eq!(lch, lab::LCh::from_lab(inp));
assert_eq!(out, lch.to_lab());

Trait Implementations

impl Clone for LCh

fn clone(&self) -> LCh

Returns a copy of the value.

pub fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for LCh

impl Debug for LCh

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for LCh

fn default() -> LCh

Returns the “default value” for a type.

impl PartialEq<LCh> for LCh

fn eq(&self, other: &LCh) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &LCh) -> bool

This method tests for !=.

impl StructuralPartialEq for LCh