dispatch/client/js/utils/color.js

43 lines
924 B
JavaScript

/* eslint-disable no-bitwise */
import { hsluvToHex } from 'hsluv';
//
// github.com/sindresorhus/fnv1a
//
const OFFSET_BASIS_32 = 2166136261;
const fnv1a = string => {
let hash = OFFSET_BASIS_32;
for (let i = 0; i < string.length; i++) {
hash ^= string.charCodeAt(i);
// 32-bit FNV prime: 2**24 + 2**8 + 0x93 = 16777619
// Using bitshift for accuracy and performance. Numbers in JS suck.
hash +=
(hash << 1) + (hash << 4) + (hash << 7) + (hash << 8) + (hash << 24);
}
return hash >>> 0;
};
const colors = [];
for (let i = 0; i < 72; i++) {
colors[i] = hsluvToHex([i * 5, 40, 50]);
colors[i + 72] = hsluvToHex([i * 5, 70, 50]);
colors[i + 144] = hsluvToHex([i * 5, 100, 50]);
}
const cache = {};
export default function stringToRGB(str) {
if (cache[str]) {
return cache[str];
}
const color = colors[fnv1a(str) % colors.length];
cache[str] = color;
return color;
}