mirror of
https://github.com/zulip/zulip.git
synced 2025-11-03 13:33:24 +00:00
6ec808b8df
ES and TypeScript modules are strict by default and don’t need this directive. ESLint will remind us to add it to new CommonJS files and remove it from ES and TypeScript modules. Signed-off-by: Anders Kaseorg <anders@zulip.com>
62 lines
1.6 KiB
JavaScript
62 lines
1.6 KiB
JavaScript
"use strict";
|
|
|
|
// Convert an sRGB value in [0, 255] to a linear intensity
|
|
// value in [0, 1].
|
|
//
|
|
// https://en.wikipedia.org/wiki/SRGB#The_reverse_transformation
|
|
exports.sRGB_to_linear = function (v) {
|
|
v = v / 255.0;
|
|
if (v <= 0.04045) {
|
|
return v / 12.92;
|
|
}
|
|
return Math.pow((v + 0.055) / 1.055, 2.4);
|
|
};
|
|
|
|
// Compute luminance (CIE Y stimulus) from linear intensity
|
|
// of sRGB / Rec. 709 primaries.
|
|
exports.rgb_luminance = function (channel) {
|
|
return 0.2126 * channel[0] + 0.7152 * channel[1] + 0.0722 * channel[2];
|
|
};
|
|
|
|
// Convert luminance (photometric, CIE Y)
|
|
// to lightness (perceptual, CIE L*)
|
|
//
|
|
// https://en.wikipedia.org/wiki/Lab_color_space#Forward_transformation
|
|
exports.luminance_to_lightness = function (luminance) {
|
|
let v;
|
|
if (luminance <= 216 / 24389) {
|
|
v = (841 / 108) * luminance + 4 / 29;
|
|
} else {
|
|
v = Math.pow(luminance, 1 / 3);
|
|
}
|
|
|
|
return 116 * v - 16;
|
|
};
|
|
|
|
exports.getDecimalColor = function (hexcolor) {
|
|
return {
|
|
r: parseInt(hexcolor.substr(1, 2), 16),
|
|
g: parseInt(hexcolor.substr(3, 2), 16),
|
|
b: parseInt(hexcolor.substr(5, 2), 16),
|
|
};
|
|
};
|
|
|
|
exports.getLighterColor = function (rgb, lightness) {
|
|
return {
|
|
r: Math.round(lightness * 255 + (1 - lightness) * rgb.r),
|
|
g: Math.round(lightness * 255 + (1 - lightness) * rgb.g),
|
|
b: Math.round(lightness * 255 + (1 - lightness) * rgb.b),
|
|
};
|
|
};
|
|
|
|
exports.getHexColor = function (rgb) {
|
|
return (
|
|
"#" +
|
|
parseInt(rgb.r, 10).toString(16) +
|
|
parseInt(rgb.g, 10).toString(16) +
|
|
parseInt(rgb.b, 10).toString(16)
|
|
);
|
|
};
|
|
|
|
window.colorspace = exports;
|