Struct LCh

Source

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

Expand description

Struct representing a color in cylindrical CIELCh color space

Fields§

§l: f32§c: f32§h: f32

Implementations§

Source §

impl LCh

Source

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);

Source

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);

Source

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);

Source

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());

Source

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());