@abasb75/jpeg-lossless-decoder/utils.js

A JavaScript JPEG Lossless decoder.

// https://stackoverflow.com/a/12588826
export var createArray = function () {
    var dimensions = [];
    for (var _i = 0; _i < arguments.length; _i++) {
        dimensions[_i] = arguments[_i];
    }
    if (dimensions.length > 1) {
        var dim = dimensions[0];
        var rest = dimensions.slice(1);
        var newArray = [];
        for (var i = 0; i < dim; i++) {
            newArray[i] = createArray.apply(void 0, rest);
        }
        return newArray;
    }
    else {
        return Array(dimensions[0]).fill(undefined);
    }
};
// http://stackoverflow.com/questions/18638900/javascript-crc32
export var makeCRCTable = function () {
    var c;
    var crcTable = [];
    for (var n = 0; n < 256; n++) {
        c = n;
        for (var k = 0; k < 8; k++) {
            c = c & 1 ? 0xedb88320 ^ (c >>> 1) : c >>> 1;
        }
        crcTable[n] = c;
    }
    return crcTable;
};
export var crcTable = makeCRCTable();
export var crc32 = function (buffer) {
    var uint8view = new Uint8Array(buffer);
    var crc = 0 ^ -1;
    for (var i = 0; i < uint8view.length; i++) {
        crc = (crc >>> 8) ^ crcTable[(crc ^ uint8view[i]) & 0xff];
    }
    return (crc ^ -1) >>> 0;
};