41 lines
1.1 KiB
TypeScript
41 lines
1.1 KiB
TypeScript
function hashToInteger(id: string) {
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let hash = 0;
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if (id.length === 0) {
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return hash;
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}
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for (let i = 0; i < id.length; i++) {
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const char = id.charCodeAt(i);
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hash = (hash << 5) - hash + char;
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}
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return hash;
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}
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export const getClientColor = (
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/**
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* any uniquely identifying key, such as user id or socket id
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*/
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id: string,
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) => {
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// to get more even distribution in case `id` is not uniformly distributed to
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// begin with, we hash it
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const hash = Math.abs(hashToInteger(id));
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// we want to get a multiple of 10 number in the range of 0-360 (in other
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// words a hue value of step size 10). There are 37 such values including 0.
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const hue = (hash % 37) * 10;
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const saturation = 100;
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const lightness = 83;
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return `hsl(${hue}, ${saturation}%, ${lightness}%)`;
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};
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/**
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* returns first char, capitalized
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*/
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export const getNameInitial = (name?: string | null) => {
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// first char can be a surrogate pair, hence using codePointAt
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const firstCodePoint = name?.trim()?.codePointAt(0);
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return (
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firstCodePoint ? String.fromCodePoint(firstCodePoint) : "?"
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).toUpperCase();
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};
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