113 lines
1.1 KiB
TypeScript
113 lines
1.1 KiB
TypeScript
const DIGIT_CHARACTERS = [
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'0',
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'1',
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'2',
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'3',
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'4',
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'5',
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'6',
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'7',
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'8',
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'9',
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'A',
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'B',
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'C',
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'D',
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'E',
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'F',
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'G',
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'H',
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'I',
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'J',
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'K',
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'L',
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'M',
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'N',
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'O',
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'P',
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'Q',
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'R',
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'S',
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'T',
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'U',
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'V',
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'W',
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'X',
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'Y',
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'Z',
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'a',
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'b',
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'c',
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'd',
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'e',
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'f',
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'g',
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'h',
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'i',
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'j',
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'k',
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'l',
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'm',
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'n',
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'o',
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'p',
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'q',
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'r',
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's',
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't',
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'u',
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'v',
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'w',
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'x',
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'y',
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'z',
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'#',
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'$',
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'%',
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'*',
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'+',
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',',
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'-',
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'.',
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':',
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';',
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'=',
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'?',
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'@',
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'[',
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']',
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'^',
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'_',
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'{',
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'|',
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'}',
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'~',
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];
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export const decode83 = (str: string) => {
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let value = 0;
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let c, digit;
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for (let i = 0; i < str.length; i++) {
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c = str[i];
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digit = DIGIT_CHARACTERS.indexOf(c);
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value = value * 83 + digit;
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}
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return value;
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};
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export const intToRGB = (int: number) => ({
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r: Math.max(0, (int >> 16)),
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g: Math.max(0, (int >> 8) & 255),
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b: Math.max(0, (int & 255)),
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});
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export const getAverageFromBlurhash = (blurhash: string) => {
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if (!blurhash) {
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return null;
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}
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return intToRGB(decode83(blurhash.slice(2, 6)));
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};
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