@react-md/utils
Version:
General utils for react-md.
49 lines • 1.52 kB
JavaScript
var __read = (this && this.__read) || function (o, n) {
var m = typeof Symbol === "function" && o[Symbol.iterator];
if (!m) return o;
var i = m.call(o), r, ar = [], e;
try {
while ((n === void 0 || n-- > 0) && !(r = i.next()).done) ar.push(r.value);
}
catch (error) { e = { error: error }; }
finally {
try {
if (r && !r.done && (m = i["return"])) m.call(i);
}
finally { if (e) throw e.error; }
}
return ar;
};
import { hexToRGB } from "./hexToRGB";
var RED_MULTIPLIER = 0.2126;
var GREEN_MULTIPLIER = 0.7152;
var BLUE_MULTIPLIER = 0.0722;
/**
* I really couldn't figure out how to name these "magic" numbers since the
* formula doesn't really describe it much:
*
* @see https://www.w3.org/TR/WCAG20-TECHS/G17.html#G17-tests
* @internal
*/
function get8BitColor(color) {
color /= 255;
if (color <= 0.03928) {
return color / 12.92;
}
return Math.pow(((color + 0.055) / 1.055), 2.4);
}
/**
* A number closest to 0 should be closest to black while a number closest to 1
* should be closest to white.
*
* @see https://www.w3.org/TR/WCAG20-TECHS/G17.html#G17-tests
* @internal
*/
export function getLuminance(color) {
var _a = __read(hexToRGB(color), 3), r = _a[0], g = _a[1], b = _a[2];
var red = get8BitColor(r) * RED_MULTIPLIER;
var green = get8BitColor(g) * GREEN_MULTIPLIER;
var blue = get8BitColor(b) * BLUE_MULTIPLIER;
return red + green + blue;
}
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