hire-wx-houxuanren/components/xinyu-canvas-drawer/qrcode/QRPolynomial.js

import QRMath from "./QRMath";
export default class QRPolynomial {
	constructor(num, shift) {
		if (num.length == undefined) {
			throw new Error(num.length + "/" + shift);
		}
		var offset = 0;
		while (offset < num.length && num[offset] == 0) {
			offset++;
		}
		this.num = new Array(num.length - offset + shift);
		for (var i = 0; i < num.length - offset; i++) {
			this.num[i] = num[i + offset];
		}
	}
	get(index) {
		return this.num[index];
	}
	getLength() {
		return this.num.length;
	}
	multiply(e) {
		var num = new Array(this.getLength() + e.getLength() - 1);
		for (var i = 0; i < this.getLength(); i++) {
			for (var j = 0; j < e.getLength(); j++) {
				num[i + j] ^= QRMath.gexp(QRMath.glog(this.get(i)) + QRMath.glog(e.get(j)));
			}
		}
		return new QRPolynomial(num, 0);
	}
	mod(e) {
		if (this.getLength() - e.getLength() < 0) {
			return this;
		}
		var ratio = QRMath.glog(this.get(0)) - QRMath.glog(e.get(0));
		var num = new Array(this.getLength());
		for (var i = 0; i < this.getLength(); i++) {
			num[i] = this.get(i);
		}
		for (var i = 0; i < e.getLength(); i++) {
			num[i] ^= QRMath.gexp(QRMath.glog(e.get(i)) + ratio);
		}
		return new QRPolynomial(num, 0).mod(e);
	}
};