1pub fn linear_channel(c: f32) -> f32 {
2 if c <= 0.04045 {
3 c / 12.92
4 } else {
5 ((c + 0.055) / 1.055).powf(2.4)
6 }
7}
8
9pub fn encode_channel(c: f32) -> f32 {
10 if c <= 0.003_130_8 {
11 c * 12.92
12 } else {
13 1.055 * c.powf(1.0 / 2.4) - 0.055
14 }
15}
16
17pub fn srgb_hex(hex: u32) -> [f32; 3] {
18 let r = ((hex >> 16) & 0xff) as f32 / 255.0;
19 let g = ((hex >> 8) & 0xff) as f32 / 255.0;
20 let b = (hex & 0xff) as f32 / 255.0;
21 [linear_channel(r), linear_channel(g), linear_channel(b)]
22}
23
24pub(crate) fn luminance(c: [f32; 3]) -> f32 {
25 0.2126 * c[0] + 0.7152 * c[1] + 0.0722 * c[2]
26}