973 lines
41 KiB
TypeScript
973 lines
41 KiB
TypeScript
/* eslint-disable @typescript-eslint/no-unused-vars */
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/* eslint-disable @typescript-eslint/no-namespace */
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/**
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* @license QR Code generator library (TypeScript)
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* Copyright (c) Project Nayuki.
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* SPDX-License-Identifier: MIT
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*/
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'use strict';
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namespace qrcodegen {
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type bit = number;
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type byte = number;
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type int = number;
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/*---- QR Code symbol class ----*/
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/*
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* A QR Code symbol, which is a type of two-dimension barcode.
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* Invented by Denso Wave and described in the ISO/IEC 18004 standard.
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* Instances of this class represent an immutable square grid of dark and light cells.
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* The class provides static factory functions to create a QR Code from text or binary data.
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* The class covers the QR Code Model 2 specification, supporting all versions (sizes)
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* from 1 to 40, all 4 error correction levels, and 4 character encoding modes.
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*
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* Ways to create a QR Code object:
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* - High level: Take the payload data and call QrCode.encodeText() or QrCode.encodeBinary().
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* - Mid level: Custom-make the list of segments and call QrCode.encodeSegments().
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* - Low level: Custom-make the array of data codeword bytes (including
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* segment headers and final padding, excluding error correction codewords),
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* supply the appropriate version number, and call the QrCode() constructor.
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* (Note that all ways require supplying the desired error correction level.)
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*/
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export class QrCode {
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/*-- Static factory functions (high level) --*/
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// Returns a QR Code representing the given Unicode text string at the given error correction level.
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// As a conservative upper bound, this function is guaranteed to succeed for strings that have 738 or fewer
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// Unicode code points (not UTF-16 code units) if the low error correction level is used. The smallest possible
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// QR Code version is automatically chosen for the output. The ECC level of the result may be higher than the
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// ecl argument if it can be done without increasing the version.
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public static encodeText(text: string, ecl: QrCode.Ecc): QrCode {
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const segs: Array<QrSegment> = qrcodegen.QrSegment.makeSegments(text);
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return QrCode.encodeSegments(segs, ecl);
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}
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// Returns a QR Code representing the given binary data at the given error correction level.
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// This function always encodes using the binary segment mode, not any text mode. The maximum number of
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// bytes allowed is 2953. The smallest possible QR Code version is automatically chosen for the output.
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// The ECC level of the result may be higher than the ecl argument if it can be done without increasing the version.
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public static encodeBinary(data: Readonly<Array<byte>>, ecl: QrCode.Ecc): QrCode {
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const seg: QrSegment = qrcodegen.QrSegment.makeBytes(data);
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return QrCode.encodeSegments([seg], ecl);
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}
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/*-- Static factory functions (mid level) --*/
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// Returns a QR Code representing the given segments with the given encoding parameters.
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// The smallest possible QR Code version within the given range is automatically
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// chosen for the output. Iff boostEcl is true, then the ECC level of the result
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// may be higher than the ecl argument if it can be done without increasing the
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// version. The mask number is either between 0 to 7 (inclusive) to force that
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// mask, or -1 to automatically choose an appropriate mask (which may be slow).
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// This function allows the user to create a custom sequence of segments that switches
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// between modes (such as alphanumeric and byte) to encode text in less space.
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// This is a mid-level API; the high-level API is encodeText() and encodeBinary().
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public static encodeSegments(
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segs: Readonly<Array<QrSegment>>,
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ecl: QrCode.Ecc,
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minVersion: int = 1,
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maxVersion: int = 40,
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mask: int = -1,
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boostEcl = true,
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): QrCode {
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if (
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!(
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QrCode.MIN_VERSION <= minVersion &&
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minVersion <= maxVersion &&
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maxVersion <= QrCode.MAX_VERSION
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) ||
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mask < -1 ||
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mask > 7
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)
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throw new RangeError('Invalid value');
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// Find the minimal version number to use
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let version: int;
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let dataUsedBits: int;
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for (version = minVersion; ; version++) {
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const dataCapacityBits: int = QrCode.getNumDataCodewords(version, ecl) * 8; // Number of data bits available
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const usedBits: number = QrSegment.getTotalBits(segs, version);
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if (usedBits <= dataCapacityBits) {
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dataUsedBits = usedBits;
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break; // This version number is found to be suitable
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}
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if (version >= maxVersion)
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// All versions in the range could not fit the given data
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throw new RangeError('Data too long');
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}
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// Increase the error correction level while the data still fits in the current version number
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for (const newEcl of [QrCode.Ecc.MEDIUM, QrCode.Ecc.QUARTILE, QrCode.Ecc.HIGH]) {
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// From low to high
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if (boostEcl && dataUsedBits <= QrCode.getNumDataCodewords(version, newEcl) * 8)
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ecl = newEcl;
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}
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// Concatenate all segments to create the data bit string
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const bb: Array<bit> = [];
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for (const seg of segs) {
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appendBits(seg.mode.modeBits, 4, bb);
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appendBits(seg.numChars, seg.mode.numCharCountBits(version), bb);
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for (const b of seg.getData()) bb.push(b);
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}
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assert(bb.length == dataUsedBits);
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// Add terminator and pad up to a byte if applicable
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const dataCapacityBits: int = QrCode.getNumDataCodewords(version, ecl) * 8;
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assert(bb.length <= dataCapacityBits);
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appendBits(0, Math.min(4, dataCapacityBits - bb.length), bb);
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appendBits(0, (8 - (bb.length % 8)) % 8, bb);
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assert(bb.length % 8 == 0);
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// Pad with alternating bytes until data capacity is reached
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for (let padByte = 0xec; bb.length < dataCapacityBits; padByte ^= 0xec ^ 0x11)
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appendBits(padByte, 8, bb);
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// Pack bits into bytes in big endian
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const dataCodewords: Array<byte> = [];
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while (dataCodewords.length * 8 < bb.length) dataCodewords.push(0);
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bb.forEach((b: bit, i: int) => (dataCodewords[i >>> 3] |= b << (7 - (i & 7))));
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// Create the QR Code object
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return new QrCode(version, ecl, dataCodewords, mask);
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}
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/*-- Fields --*/
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// The width and height of this QR Code, measured in modules, between
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// 21 and 177 (inclusive). This is equal to version * 4 + 17.
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public readonly size: int;
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// The index of the mask pattern used in this QR Code, which is between 0 and 7 (inclusive).
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// Even if a QR Code is created with automatic masking requested (mask = -1),
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// the resulting object still has a mask value between 0 and 7.
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public readonly mask: int;
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// The modules of this QR Code (false = light, true = dark).
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// Immutable after constructor finishes. Accessed through getModule().
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private readonly modules: Array<Array<boolean>> = [];
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// Indicates function modules that are not subjected to masking. Discarded when constructor finishes.
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private readonly isFunction: Array<Array<boolean>> = [];
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/*-- Constructor (low level) and fields --*/
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// Creates a new QR Code with the given version number,
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// error correction level, data codeword bytes, and mask number.
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// This is a low-level API that most users should not use directly.
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// A mid-level API is the encodeSegments() function.
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public constructor(
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// The version number of this QR Code, which is between 1 and 40 (inclusive).
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// This determines the size of this barcode.
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public readonly version: int,
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// The error correction level used in this QR Code.
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public readonly errorCorrectionLevel: QrCode.Ecc,
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dataCodewords: Readonly<Array<byte>>,
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msk: int,
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) {
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// Check scalar arguments
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if (version < QrCode.MIN_VERSION || version > QrCode.MAX_VERSION)
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throw new RangeError('Version value out of range');
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if (msk < -1 || msk > 7) throw new RangeError('Mask value out of range');
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this.size = version * 4 + 17;
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// Initialize both grids to be size*size arrays of Boolean false
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const row: Array<boolean> = [];
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for (let i = 0; i < this.size; i++) row.push(false);
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for (let i = 0; i < this.size; i++) {
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this.modules.push(row.slice()); // Initially all light
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this.isFunction.push(row.slice());
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}
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// Compute ECC, draw modules
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this.drawFunctionPatterns();
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const allCodewords: Array<byte> = this.addEccAndInterleave(dataCodewords);
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this.drawCodewords(allCodewords);
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// Do masking
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if (msk == -1) {
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// Automatically choose best mask
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let minPenalty: int = 1000000000;
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for (let i = 0; i < 8; i++) {
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this.applyMask(i);
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this.drawFormatBits(i);
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const penalty: int = this.getPenaltyScore();
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if (penalty < minPenalty) {
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msk = i;
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minPenalty = penalty;
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}
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this.applyMask(i); // Undoes the mask due to XOR
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}
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}
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assert(0 <= msk && msk <= 7);
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this.mask = msk;
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this.applyMask(msk); // Apply the final choice of mask
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this.drawFormatBits(msk); // Overwrite old format bits
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this.isFunction = [];
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}
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/*-- Accessor methods --*/
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// Returns the color of the module (pixel) at the given coordinates, which is false
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// for light or true for dark. The top left corner has the coordinates (x=0, y=0).
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// If the given coordinates are out of bounds, then false (light) is returned.
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public getModule(x: int, y: int): boolean {
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return 0 <= x && x < this.size && 0 <= y && y < this.size && this.modules[y][x];
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}
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// Modified to expose modules for easy access
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public getModules() {
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return this.modules;
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}
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/*-- Private helper methods for constructor: Drawing function modules --*/
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// Reads this object's version field, and draws and marks all function modules.
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private drawFunctionPatterns(): void {
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// Draw horizontal and vertical timing patterns
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for (let i = 0; i < this.size; i++) {
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this.setFunctionModule(6, i, i % 2 == 0);
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this.setFunctionModule(i, 6, i % 2 == 0);
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}
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// Draw 3 finder patterns (all corners except bottom right; overwrites some timing modules)
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this.drawFinderPattern(3, 3);
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this.drawFinderPattern(this.size - 4, 3);
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this.drawFinderPattern(3, this.size - 4);
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// Draw numerous alignment patterns
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const alignPatPos: Array<int> = this.getAlignmentPatternPositions();
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const numAlign: int = alignPatPos.length;
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for (let i = 0; i < numAlign; i++) {
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for (let j = 0; j < numAlign; j++) {
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// Don't draw on the three finder corners
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if (
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!((i == 0 && j == 0) || (i == 0 && j == numAlign - 1) || (i == numAlign - 1 && j == 0))
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)
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this.drawAlignmentPattern(alignPatPos[i], alignPatPos[j]);
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}
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}
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// Draw configuration data
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this.drawFormatBits(0); // Dummy mask value; overwritten later in the constructor
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this.drawVersion();
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}
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// Draws two copies of the format bits (with its own error correction code)
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// based on the given mask and this object's error correction level field.
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private drawFormatBits(mask: int): void {
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// Calculate error correction code and pack bits
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const data: int = (this.errorCorrectionLevel.formatBits << 3) | mask; // errCorrLvl is uint2, mask is uint3
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let rem: int = data;
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for (let i = 0; i < 10; i++) rem = (rem << 1) ^ ((rem >>> 9) * 0x537);
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const bits = ((data << 10) | rem) ^ 0x5412; // uint15
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assert(bits >>> 15 == 0);
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// Draw first copy
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for (let i = 0; i <= 5; i++) this.setFunctionModule(8, i, getBit(bits, i));
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this.setFunctionModule(8, 7, getBit(bits, 6));
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this.setFunctionModule(8, 8, getBit(bits, 7));
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this.setFunctionModule(7, 8, getBit(bits, 8));
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for (let i = 9; i < 15; i++) this.setFunctionModule(14 - i, 8, getBit(bits, i));
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// Draw second copy
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for (let i = 0; i < 8; i++) this.setFunctionModule(this.size - 1 - i, 8, getBit(bits, i));
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for (let i = 8; i < 15; i++) this.setFunctionModule(8, this.size - 15 + i, getBit(bits, i));
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this.setFunctionModule(8, this.size - 8, true); // Always dark
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}
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// Draws two copies of the version bits (with its own error correction code),
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// based on this object's version field, iff 7 <= version <= 40.
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private drawVersion(): void {
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if (this.version < 7) return;
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// Calculate error correction code and pack bits
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let rem: int = this.version; // version is uint6, in the range [7, 40]
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for (let i = 0; i < 12; i++) rem = (rem << 1) ^ ((rem >>> 11) * 0x1f25);
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const bits: int = (this.version << 12) | rem; // uint18
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assert(bits >>> 18 == 0);
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// Draw two copies
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for (let i = 0; i < 18; i++) {
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const color: boolean = getBit(bits, i);
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const a: int = this.size - 11 + (i % 3);
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const b: int = Math.floor(i / 3);
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this.setFunctionModule(a, b, color);
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this.setFunctionModule(b, a, color);
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}
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}
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// Draws a 9*9 finder pattern including the border separator,
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// with the center module at (x, y). Modules can be out of bounds.
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private drawFinderPattern(x: int, y: int): void {
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for (let dy = -4; dy <= 4; dy++) {
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for (let dx = -4; dx <= 4; dx++) {
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const dist: int = Math.max(Math.abs(dx), Math.abs(dy)); // Chebyshev/infinity norm
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const xx: int = x + dx;
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const yy: int = y + dy;
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if (0 <= xx && xx < this.size && 0 <= yy && yy < this.size)
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this.setFunctionModule(xx, yy, dist != 2 && dist != 4);
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}
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}
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}
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// Draws a 5*5 alignment pattern, with the center module
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// at (x, y). All modules must be in bounds.
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private drawAlignmentPattern(x: int, y: int): void {
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for (let dy = -2; dy <= 2; dy++) {
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for (let dx = -2; dx <= 2; dx++)
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this.setFunctionModule(x + dx, y + dy, Math.max(Math.abs(dx), Math.abs(dy)) != 1);
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}
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}
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// Sets the color of a module and marks it as a function module.
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// Only used by the constructor. Coordinates must be in bounds.
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private setFunctionModule(x: int, y: int, isDark: boolean): void {
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this.modules[y][x] = isDark;
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this.isFunction[y][x] = true;
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}
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/*-- Private helper methods for constructor: Codewords and masking --*/
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// Returns a new byte string representing the given data with the appropriate error correction
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// codewords appended to it, based on this object's version and error correction level.
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private addEccAndInterleave(data: Readonly<Array<byte>>): Array<byte> {
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const ver: int = this.version;
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const ecl: QrCode.Ecc = this.errorCorrectionLevel;
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if (data.length != QrCode.getNumDataCodewords(ver, ecl))
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throw new RangeError('Invalid argument');
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// Calculate parameter numbers
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const numBlocks: int = QrCode.NUM_ERROR_CORRECTION_BLOCKS[ecl.ordinal][ver];
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const blockEccLen: int = QrCode.ECC_CODEWORDS_PER_BLOCK[ecl.ordinal][ver];
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const rawCodewords: int = Math.floor(QrCode.getNumRawDataModules(ver) / 8);
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const numShortBlocks: int = numBlocks - (rawCodewords % numBlocks);
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const shortBlockLen: int = Math.floor(rawCodewords / numBlocks);
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// Split data into blocks and append ECC to each block
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const blocks: Array<Array<byte>> = [];
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const rsDiv: Array<byte> = QrCode.reedSolomonComputeDivisor(blockEccLen);
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for (let i = 0, k = 0; i < numBlocks; i++) {
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const dat: Array<byte> = data.slice(
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k,
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k + shortBlockLen - blockEccLen + (i < numShortBlocks ? 0 : 1),
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);
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k += dat.length;
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const ecc: Array<byte> = QrCode.reedSolomonComputeRemainder(dat, rsDiv);
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if (i < numShortBlocks) dat.push(0);
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blocks.push(dat.concat(ecc));
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}
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// Interleave (not concatenate) the bytes from every block into a single sequence
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const result: Array<byte> = [];
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for (let i = 0; i < blocks[0].length; i++) {
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blocks.forEach((block, j) => {
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// Skip the padding byte in short blocks
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if (i != shortBlockLen - blockEccLen || j >= numShortBlocks) result.push(block[i]);
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});
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}
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assert(result.length == rawCodewords);
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return result;
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}
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// Draws the given sequence of 8-bit codewords (data and error correction) onto the entire
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// data area of this QR Code. Function modules need to be marked off before this is called.
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private drawCodewords(data: Readonly<Array<byte>>): void {
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if (data.length != Math.floor(QrCode.getNumRawDataModules(this.version) / 8))
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throw new RangeError('Invalid argument');
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let i: int = 0; // Bit index into the data
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// Do the funny zigzag scan
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for (let right = this.size - 1; right >= 1; right -= 2) {
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// Index of right column in each column pair
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if (right == 6) right = 5;
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for (let vert = 0; vert < this.size; vert++) {
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// Vertical counter
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for (let j = 0; j < 2; j++) {
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const x: int = right - j; // Actual x coordinate
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const upward: boolean = ((right + 1) & 2) == 0;
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const y: int = upward ? this.size - 1 - vert : vert; // Actual y coordinate
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if (!this.isFunction[y][x] && i < data.length * 8) {
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this.modules[y][x] = getBit(data[i >>> 3], 7 - (i & 7));
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i++;
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}
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// If this QR Code has any remainder bits (0 to 7), they were assigned as
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// 0/false/light by the constructor and are left unchanged by this method
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}
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}
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}
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assert(i == data.length * 8);
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}
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// XORs the codeword modules in this QR Code with the given mask pattern.
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// The function modules must be marked and the codeword bits must be drawn
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// before masking. Due to the arithmetic of XOR, calling applyMask() with
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// the same mask value a second time will undo the mask. A final well-formed
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// QR Code needs exactly one (not zero, two, etc.) mask applied.
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private applyMask(mask: int): void {
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if (mask < 0 || mask > 7) throw new RangeError('Mask value out of range');
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for (let y = 0; y < this.size; y++) {
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for (let x = 0; x < this.size; x++) {
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let invert: boolean;
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switch (mask) {
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case 0:
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invert = (x + y) % 2 == 0;
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break;
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case 1:
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invert = y % 2 == 0;
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break;
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case 2:
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invert = x % 3 == 0;
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break;
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case 3:
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invert = (x + y) % 3 == 0;
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break;
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case 4:
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invert = (Math.floor(x / 3) + Math.floor(y / 2)) % 2 == 0;
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break;
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case 5:
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invert = ((x * y) % 2) + ((x * y) % 3) == 0;
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break;
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case 6:
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invert = (((x * y) % 2) + ((x * y) % 3)) % 2 == 0;
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break;
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|
case 7:
|
|
invert = (((x + y) % 2) + ((x * y) % 3)) % 2 == 0;
|
|
break;
|
|
default:
|
|
throw new Error('Unreachable');
|
|
}
|
|
if (!this.isFunction[y][x] && invert) this.modules[y][x] = !this.modules[y][x];
|
|
}
|
|
}
|
|
}
|
|
|
|
// Calculates and returns the penalty score based on state of this QR Code's current modules.
|
|
// This is used by the automatic mask choice algorithm to find the mask pattern that yields the lowest score.
|
|
private getPenaltyScore(): int {
|
|
let result: int = 0;
|
|
|
|
// Adjacent modules in row having same color, and finder-like patterns
|
|
for (let y = 0; y < this.size; y++) {
|
|
let runColor = false;
|
|
let runX = 0;
|
|
const runHistory = [0, 0, 0, 0, 0, 0, 0];
|
|
for (let x = 0; x < this.size; x++) {
|
|
if (this.modules[y][x] == runColor) {
|
|
runX++;
|
|
if (runX == 5) result += QrCode.PENALTY_N1;
|
|
else if (runX > 5) result++;
|
|
} else {
|
|
this.finderPenaltyAddHistory(runX, runHistory);
|
|
if (!runColor)
|
|
result += this.finderPenaltyCountPatterns(runHistory) * QrCode.PENALTY_N3;
|
|
runColor = this.modules[y][x];
|
|
runX = 1;
|
|
}
|
|
}
|
|
result +=
|
|
this.finderPenaltyTerminateAndCount(runColor, runX, runHistory) * QrCode.PENALTY_N3;
|
|
}
|
|
// Adjacent modules in column having same color, and finder-like patterns
|
|
for (let x = 0; x < this.size; x++) {
|
|
let runColor = false;
|
|
let runY = 0;
|
|
const runHistory = [0, 0, 0, 0, 0, 0, 0];
|
|
for (let y = 0; y < this.size; y++) {
|
|
if (this.modules[y][x] == runColor) {
|
|
runY++;
|
|
if (runY == 5) result += QrCode.PENALTY_N1;
|
|
else if (runY > 5) result++;
|
|
} else {
|
|
this.finderPenaltyAddHistory(runY, runHistory);
|
|
if (!runColor)
|
|
result += this.finderPenaltyCountPatterns(runHistory) * QrCode.PENALTY_N3;
|
|
runColor = this.modules[y][x];
|
|
runY = 1;
|
|
}
|
|
}
|
|
result +=
|
|
this.finderPenaltyTerminateAndCount(runColor, runY, runHistory) * QrCode.PENALTY_N3;
|
|
}
|
|
|
|
// 2*2 blocks of modules having same color
|
|
for (let y = 0; y < this.size - 1; y++) {
|
|
for (let x = 0; x < this.size - 1; x++) {
|
|
const color: boolean = this.modules[y][x];
|
|
if (
|
|
color == this.modules[y][x + 1] &&
|
|
color == this.modules[y + 1][x] &&
|
|
color == this.modules[y + 1][x + 1]
|
|
)
|
|
result += QrCode.PENALTY_N2;
|
|
}
|
|
}
|
|
|
|
// Balance of dark and light modules
|
|
let dark: int = 0;
|
|
for (const row of this.modules)
|
|
dark = row.reduce((sum, color) => sum + (color ? 1 : 0), dark);
|
|
const total: int = this.size * this.size; // Note that size is odd, so dark/total != 1/2
|
|
// Compute the smallest integer k >= 0 such that (45-5k)% <= dark/total <= (55+5k)%
|
|
const k: int = Math.ceil(Math.abs(dark * 20 - total * 10) / total) - 1;
|
|
assert(0 <= k && k <= 9);
|
|
result += k * QrCode.PENALTY_N4;
|
|
assert(0 <= result && result <= 2568888); // Non-tight upper bound based on default values of PENALTY_N1, ..., N4
|
|
return result;
|
|
}
|
|
|
|
/*-- Private helper functions --*/
|
|
|
|
// Returns an ascending list of positions of alignment patterns for this version number.
|
|
// Each position is in the range [0,177), and are used on both the x and y axes.
|
|
// This could be implemented as lookup table of 40 variable-length lists of integers.
|
|
private getAlignmentPatternPositions(): Array<int> {
|
|
if (this.version == 1) return [];
|
|
else {
|
|
const numAlign: int = Math.floor(this.version / 7) + 2;
|
|
const step: int =
|
|
this.version == 32 ? 26 : Math.ceil((this.version * 4 + 4) / (numAlign * 2 - 2)) * 2;
|
|
const result: Array<int> = [6];
|
|
for (let pos = this.size - 7; result.length < numAlign; pos -= step)
|
|
result.splice(1, 0, pos);
|
|
return result;
|
|
}
|
|
}
|
|
|
|
// Returns the number of data bits that can be stored in a QR Code of the given version number, after
|
|
// all function modules are excluded. This includes remainder bits, so it might not be a multiple of 8.
|
|
// The result is in the range [208, 29648]. This could be implemented as a 40-entry lookup table.
|
|
private static getNumRawDataModules(ver: int): int {
|
|
if (ver < QrCode.MIN_VERSION || ver > QrCode.MAX_VERSION)
|
|
throw new RangeError('Version number out of range');
|
|
let result: int = (16 * ver + 128) * ver + 64;
|
|
if (ver >= 2) {
|
|
const numAlign: int = Math.floor(ver / 7) + 2;
|
|
result -= (25 * numAlign - 10) * numAlign - 55;
|
|
if (ver >= 7) result -= 36;
|
|
}
|
|
assert(208 <= result && result <= 29648);
|
|
return result;
|
|
}
|
|
|
|
// Returns the number of 8-bit data (i.e. not error correction) codewords contained in any
|
|
// QR Code of the given version number and error correction level, with remainder bits discarded.
|
|
// This stateless pure function could be implemented as a (40*4)-cell lookup table.
|
|
private static getNumDataCodewords(ver: int, ecl: QrCode.Ecc): int {
|
|
return (
|
|
Math.floor(QrCode.getNumRawDataModules(ver) / 8) -
|
|
QrCode.ECC_CODEWORDS_PER_BLOCK[ecl.ordinal][ver] *
|
|
QrCode.NUM_ERROR_CORRECTION_BLOCKS[ecl.ordinal][ver]
|
|
);
|
|
}
|
|
|
|
// Returns a Reed-Solomon ECC generator polynomial for the given degree. This could be
|
|
// implemented as a lookup table over all possible parameter values, instead of as an algorithm.
|
|
private static reedSolomonComputeDivisor(degree: int): Array<byte> {
|
|
if (degree < 1 || degree > 255) throw new RangeError('Degree out of range');
|
|
// Polynomial coefficients are stored from highest to lowest power, excluding the leading term which is always 1.
|
|
// For example the polynomial x^3 + 255x^2 + 8x + 93 is stored as the uint8 array [255, 8, 93].
|
|
const result: Array<byte> = [];
|
|
for (let i = 0; i < degree - 1; i++) result.push(0);
|
|
result.push(1); // Start off with the monomial x^0
|
|
|
|
// Compute the product polynomial (x - r^0) * (x - r^1) * (x - r^2) * ... * (x - r^{degree-1}),
|
|
// and drop the highest monomial term which is always 1x^degree.
|
|
// Note that r = 0x02, which is a generator element of this field GF(2^8/0x11D).
|
|
let root = 1;
|
|
for (let i = 0; i < degree; i++) {
|
|
// Multiply the current product by (x - r^i)
|
|
for (let j = 0; j < result.length; j++) {
|
|
result[j] = QrCode.reedSolomonMultiply(result[j], root);
|
|
if (j + 1 < result.length) result[j] ^= result[j + 1];
|
|
}
|
|
root = QrCode.reedSolomonMultiply(root, 0x02);
|
|
}
|
|
return result;
|
|
}
|
|
|
|
// Returns the Reed-Solomon error correction codeword for the given data and divisor polynomials.
|
|
private static reedSolomonComputeRemainder(
|
|
data: Readonly<Array<byte>>,
|
|
divisor: Readonly<Array<byte>>,
|
|
): Array<byte> {
|
|
const result: Array<byte> = divisor.map(_ => 0);
|
|
for (const b of data) {
|
|
// Polynomial division
|
|
const factor: byte = b ^ (result.shift() as byte);
|
|
result.push(0);
|
|
divisor.forEach((coef, i) => (result[i] ^= QrCode.reedSolomonMultiply(coef, factor)));
|
|
}
|
|
return result;
|
|
}
|
|
|
|
// Returns the product of the two given field elements modulo GF(2^8/0x11D). The arguments and result
|
|
// are unsigned 8-bit integers. This could be implemented as a lookup table of 256*256 entries of uint8.
|
|
private static reedSolomonMultiply(x: byte, y: byte): byte {
|
|
if (x >>> 8 != 0 || y >>> 8 != 0) throw new RangeError('Byte out of range');
|
|
// Russian peasant multiplication
|
|
let z: int = 0;
|
|
for (let i = 7; i >= 0; i--) {
|
|
z = (z << 1) ^ ((z >>> 7) * 0x11d);
|
|
z ^= ((y >>> i) & 1) * x;
|
|
}
|
|
assert(z >>> 8 == 0);
|
|
return z as byte;
|
|
}
|
|
|
|
// Can only be called immediately after a light run is added, and
|
|
// returns either 0, 1, or 2. A helper function for getPenaltyScore().
|
|
private finderPenaltyCountPatterns(runHistory: Readonly<Array<int>>): int {
|
|
const n: int = runHistory[1];
|
|
assert(n <= this.size * 3);
|
|
const core: boolean =
|
|
n > 0 &&
|
|
runHistory[2] == n &&
|
|
runHistory[3] == n * 3 &&
|
|
runHistory[4] == n &&
|
|
runHistory[5] == n;
|
|
return (
|
|
(core && runHistory[0] >= n * 4 && runHistory[6] >= n ? 1 : 0) +
|
|
(core && runHistory[6] >= n * 4 && runHistory[0] >= n ? 1 : 0)
|
|
);
|
|
}
|
|
|
|
// Must be called at the end of a line (row or column) of modules. A helper function for getPenaltyScore().
|
|
private finderPenaltyTerminateAndCount(
|
|
currentRunColor: boolean,
|
|
currentRunLength: int,
|
|
runHistory: Array<int>,
|
|
): int {
|
|
if (currentRunColor) {
|
|
// Terminate dark run
|
|
this.finderPenaltyAddHistory(currentRunLength, runHistory);
|
|
currentRunLength = 0;
|
|
}
|
|
currentRunLength += this.size; // Add light border to final run
|
|
this.finderPenaltyAddHistory(currentRunLength, runHistory);
|
|
return this.finderPenaltyCountPatterns(runHistory);
|
|
}
|
|
|
|
// Pushes the given value to the front and drops the last value. A helper function for getPenaltyScore().
|
|
private finderPenaltyAddHistory(currentRunLength: int, runHistory: Array<int>): void {
|
|
if (runHistory[0] == 0) currentRunLength += this.size; // Add light border to initial run
|
|
runHistory.pop();
|
|
runHistory.unshift(currentRunLength);
|
|
}
|
|
|
|
/*-- Constants and tables --*/
|
|
|
|
// The minimum version number supported in the QR Code Model 2 standard.
|
|
public static readonly MIN_VERSION: int = 1;
|
|
// The maximum version number supported in the QR Code Model 2 standard.
|
|
public static readonly MAX_VERSION: int = 40;
|
|
|
|
// For use in getPenaltyScore(), when evaluating which mask is best.
|
|
private static readonly PENALTY_N1: int = 3;
|
|
private static readonly PENALTY_N2: int = 3;
|
|
private static readonly PENALTY_N3: int = 40;
|
|
private static readonly PENALTY_N4: int = 10;
|
|
|
|
private static readonly ECC_CODEWORDS_PER_BLOCK: Array<Array<int>> = [
|
|
// Version: (note that index 0 is for padding, and is set to an illegal value)
|
|
//0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 Error correction level
|
|
[
|
|
-1, 7, 10, 15, 20, 26, 18, 20, 24, 30, 18, 20, 24, 26, 30, 22, 24, 28, 30, 28, 28, 28, 28,
|
|
30, 30, 26, 28, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30,
|
|
], // Low
|
|
[
|
|
-1, 10, 16, 26, 18, 24, 16, 18, 22, 22, 26, 30, 22, 22, 24, 24, 28, 28, 26, 26, 26, 26, 28,
|
|
28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
|
|
], // Medium
|
|
[
|
|
-1, 13, 22, 18, 26, 18, 24, 18, 22, 20, 24, 28, 26, 24, 20, 30, 24, 28, 28, 26, 30, 28, 30,
|
|
30, 30, 30, 28, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30,
|
|
], // Quartile
|
|
[
|
|
-1, 17, 28, 22, 16, 22, 28, 26, 26, 24, 28, 24, 28, 22, 24, 24, 30, 28, 28, 26, 28, 30, 24,
|
|
30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30,
|
|
], // High
|
|
];
|
|
|
|
private static readonly NUM_ERROR_CORRECTION_BLOCKS: Array<Array<int>> = [
|
|
// Version: (note that index 0 is for padding, and is set to an illegal value)
|
|
//0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40 Error correction level
|
|
[
|
|
-1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 4, 4, 4, 4, 4, 6, 6, 6, 6, 7, 8, 8, 9, 9, 10, 12, 12, 12, 13,
|
|
14, 15, 16, 17, 18, 19, 19, 20, 21, 22, 24, 25,
|
|
], // Low
|
|
[
|
|
-1, 1, 1, 1, 2, 2, 4, 4, 4, 5, 5, 5, 8, 9, 9, 10, 10, 11, 13, 14, 16, 17, 17, 18, 20, 21,
|
|
23, 25, 26, 28, 29, 31, 33, 35, 37, 38, 40, 43, 45, 47, 49,
|
|
], // Medium
|
|
[
|
|
-1, 1, 1, 2, 2, 4, 4, 6, 6, 8, 8, 8, 10, 12, 16, 12, 17, 16, 18, 21, 20, 23, 23, 25, 27, 29,
|
|
34, 34, 35, 38, 40, 43, 45, 48, 51, 53, 56, 59, 62, 65, 68,
|
|
], // Quartile
|
|
[
|
|
-1, 1, 1, 2, 4, 4, 4, 5, 6, 8, 8, 11, 11, 16, 16, 18, 16, 19, 21, 25, 25, 25, 34, 30, 32,
|
|
35, 37, 40, 42, 45, 48, 51, 54, 57, 60, 63, 66, 70, 74, 77, 81,
|
|
], // High
|
|
];
|
|
}
|
|
|
|
// Appends the given number of low-order bits of the given value
|
|
// to the given buffer. Requires 0 <= len <= 31 and 0 <= val < 2^len.
|
|
function appendBits(val: int, len: int, bb: Array<bit>): void {
|
|
if (len < 0 || len > 31 || val >>> len != 0) throw new RangeError('Value out of range');
|
|
for (
|
|
let i = len - 1;
|
|
i >= 0;
|
|
i-- // Append bit by bit
|
|
)
|
|
bb.push((val >>> i) & 1);
|
|
}
|
|
|
|
// Returns true iff the i'th bit of x is set to 1.
|
|
function getBit(x: int, i: int): boolean {
|
|
return ((x >>> i) & 1) != 0;
|
|
}
|
|
|
|
// Throws an exception if the given condition is false.
|
|
function assert(cond: boolean): void {
|
|
if (!cond) throw new Error('Assertion error');
|
|
}
|
|
|
|
/*---- Data segment class ----*/
|
|
|
|
/*
|
|
* A segment of character/binary/control data in a QR Code symbol.
|
|
* Instances of this class are immutable.
|
|
* The mid-level way to create a segment is to take the payload data
|
|
* and call a static factory function such as QrSegment.makeNumeric().
|
|
* The low-level way to create a segment is to custom-make the bit buffer
|
|
* and call the QrSegment() constructor with appropriate values.
|
|
* This segment class imposes no length restrictions, but QR Codes have restrictions.
|
|
* Even in the most favorable conditions, a QR Code can only hold 7089 characters of data.
|
|
* Any segment longer than this is meaningless for the purpose of generating QR Codes.
|
|
*/
|
|
export class QrSegment {
|
|
/*-- Static factory functions (mid level) --*/
|
|
|
|
// Returns a segment representing the given binary data encoded in
|
|
// byte mode. All input byte arrays are acceptable. Any text string
|
|
// can be converted to UTF-8 bytes and encoded as a byte mode segment.
|
|
public static makeBytes(data: Readonly<Array<byte>>): QrSegment {
|
|
const bb: Array<bit> = [];
|
|
for (const b of data) appendBits(b, 8, bb);
|
|
return new QrSegment(QrSegment.Mode.BYTE, data.length, bb);
|
|
}
|
|
|
|
// Returns a segment representing the given string of decimal digits encoded in numeric mode.
|
|
public static makeNumeric(digits: string): QrSegment {
|
|
if (!QrSegment.isNumeric(digits))
|
|
throw new RangeError('String contains non-numeric characters');
|
|
const bb: Array<bit> = [];
|
|
for (let i = 0; i < digits.length; ) {
|
|
// Consume up to 3 digits per iteration
|
|
const n: int = Math.min(digits.length - i, 3);
|
|
appendBits(parseInt(digits.substring(i, i + n), 10), n * 3 + 1, bb);
|
|
i += n;
|
|
}
|
|
return new QrSegment(QrSegment.Mode.NUMERIC, digits.length, bb);
|
|
}
|
|
|
|
// Returns a segment representing the given text string encoded in alphanumeric mode.
|
|
// The characters allowed are: 0 to 9, A to Z (uppercase only), space,
|
|
// dollar, percent, asterisk, plus, hyphen, period, slash, colon.
|
|
public static makeAlphanumeric(text: string): QrSegment {
|
|
if (!QrSegment.isAlphanumeric(text))
|
|
throw new RangeError('String contains unencodable characters in alphanumeric mode');
|
|
const bb: Array<bit> = [];
|
|
let i: int;
|
|
for (i = 0; i + 2 <= text.length; i += 2) {
|
|
// Process groups of 2
|
|
let temp: int = QrSegment.ALPHANUMERIC_CHARSET.indexOf(text.charAt(i)) * 45;
|
|
temp += QrSegment.ALPHANUMERIC_CHARSET.indexOf(text.charAt(i + 1));
|
|
appendBits(temp, 11, bb);
|
|
}
|
|
if (i < text.length)
|
|
// 1 character remaining
|
|
appendBits(QrSegment.ALPHANUMERIC_CHARSET.indexOf(text.charAt(i)), 6, bb);
|
|
return new QrSegment(QrSegment.Mode.ALPHANUMERIC, text.length, bb);
|
|
}
|
|
|
|
// Returns a new mutable list of zero or more segments to represent the given Unicode text string.
|
|
// The result may use various segment modes and switch modes to optimize the length of the bit stream.
|
|
public static makeSegments(text: string): Array<QrSegment> {
|
|
// Select the most efficient segment encoding automatically
|
|
if (text == '') return [];
|
|
else if (QrSegment.isNumeric(text)) return [QrSegment.makeNumeric(text)];
|
|
else if (QrSegment.isAlphanumeric(text)) return [QrSegment.makeAlphanumeric(text)];
|
|
else return [QrSegment.makeBytes(QrSegment.toUtf8ByteArray(text))];
|
|
}
|
|
|
|
// Returns a segment representing an Extended Channel Interpretation
|
|
// (ECI) designator with the given assignment value.
|
|
public static makeEci(assignVal: int): QrSegment {
|
|
const bb: Array<bit> = [];
|
|
if (assignVal < 0) throw new RangeError('ECI assignment value out of range');
|
|
else if (assignVal < 1 << 7) appendBits(assignVal, 8, bb);
|
|
else if (assignVal < 1 << 14) {
|
|
appendBits(0b10, 2, bb);
|
|
appendBits(assignVal, 14, bb);
|
|
} else if (assignVal < 1000000) {
|
|
appendBits(0b110, 3, bb);
|
|
appendBits(assignVal, 21, bb);
|
|
} else throw new RangeError('ECI assignment value out of range');
|
|
return new QrSegment(QrSegment.Mode.ECI, 0, bb);
|
|
}
|
|
|
|
// Tests whether the given string can be encoded as a segment in numeric mode.
|
|
// A string is encodable iff each character is in the range 0 to 9.
|
|
public static isNumeric(text: string): boolean {
|
|
return QrSegment.NUMERIC_REGEX.test(text);
|
|
}
|
|
|
|
// Tests whether the given string can be encoded as a segment in alphanumeric mode.
|
|
// A string is encodable iff each character is in the following set: 0 to 9, A to Z
|
|
// (uppercase only), space, dollar, percent, asterisk, plus, hyphen, period, slash, colon.
|
|
public static isAlphanumeric(text: string): boolean {
|
|
return QrSegment.ALPHANUMERIC_REGEX.test(text);
|
|
}
|
|
|
|
/*-- Constructor (low level) and fields --*/
|
|
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// Creates a new QR Code segment with the given attributes and data.
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// The character count (numChars) must agree with the mode and the bit buffer length,
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// but the constraint isn't checked. The given bit buffer is cloned and stored.
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public constructor(
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// The mode indicator of this segment.
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public readonly mode: QrSegment.Mode,
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// The length of this segment's unencoded data. Measured in characters for
|
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// numeric/alphanumeric/kanji mode, bytes for byte mode, and 0 for ECI mode.
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// Always zero or positive. Not the same as the data's bit length.
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public readonly numChars: int,
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// The data bits of this segment. Accessed through getData().
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|
private readonly bitData: Array<bit>,
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) {
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|
if (numChars < 0) throw new RangeError('Invalid argument');
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this.bitData = bitData.slice(); // Make defensive copy
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}
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|
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/*-- Methods --*/
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// Returns a new copy of the data bits of this segment.
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public getData(): Array<bit> {
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|
return this.bitData.slice(); // Make defensive copy
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}
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// (Package-private) Calculates and returns the number of bits needed to encode the given segments at
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|
// the given version. The result is infinity if a segment has too many characters to fit its length field.
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|
public static getTotalBits(segs: Readonly<Array<QrSegment>>, version: int): number {
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|
let result = 0;
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|
for (const seg of segs) {
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|
const ccbits: int = seg.mode.numCharCountBits(version);
|
|
if (seg.numChars >= 1 << ccbits) return Infinity; // The segment's length doesn't fit the field's bit width
|
|
result += 4 + ccbits + seg.bitData.length;
|
|
}
|
|
return result;
|
|
}
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|
|
|
// Returns a new array of bytes representing the given string encoded in UTF-8.
|
|
private static toUtf8ByteArray(str: string): Array<byte> {
|
|
str = encodeURI(str);
|
|
const result: Array<byte> = [];
|
|
for (let i = 0; i < str.length; i++) {
|
|
if (str.charAt(i) != '%') result.push(str.charCodeAt(i));
|
|
else {
|
|
result.push(parseInt(str.substring(i + 1, i + 3), 16));
|
|
i += 2;
|
|
}
|
|
}
|
|
return result;
|
|
}
|
|
|
|
/*-- Constants --*/
|
|
|
|
// Describes precisely all strings that are encodable in numeric mode.
|
|
private static readonly NUMERIC_REGEX: RegExp = /^[0-9]*$/;
|
|
|
|
// Describes precisely all strings that are encodable in alphanumeric mode.
|
|
private static readonly ALPHANUMERIC_REGEX: RegExp = /^[A-Z0-9 $%*+.\/:-]*$/;
|
|
|
|
// The set of all legal characters in alphanumeric mode,
|
|
// where each character value maps to the index in the string.
|
|
private static readonly ALPHANUMERIC_CHARSET: string =
|
|
'0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ $%*+-./:';
|
|
}
|
|
}
|
|
|
|
/*---- Public helper enumeration ----*/
|
|
|
|
namespace qrcodegen.QrCode {
|
|
type int = number;
|
|
|
|
/*
|
|
* The error correction level in a QR Code symbol. Immutable.
|
|
*/
|
|
export class Ecc {
|
|
/*-- Constants --*/
|
|
|
|
public static readonly LOW = new Ecc(0, 1); // The QR Code can tolerate about 7% erroneous codewords
|
|
public static readonly MEDIUM = new Ecc(1, 0); // The QR Code can tolerate about 15% erroneous codewords
|
|
public static readonly QUARTILE = new Ecc(2, 3); // The QR Code can tolerate about 25% erroneous codewords
|
|
public static readonly HIGH = new Ecc(3, 2); // The QR Code can tolerate about 30% erroneous codewords
|
|
|
|
/*-- Constructor and fields --*/
|
|
|
|
private constructor(
|
|
// In the range 0 to 3 (unsigned 2-bit integer).
|
|
public readonly ordinal: int,
|
|
// (Package-private) In the range 0 to 3 (unsigned 2-bit integer).
|
|
public readonly formatBits: int,
|
|
) {}
|
|
}
|
|
}
|
|
|
|
/*---- Public helper enumeration ----*/
|
|
|
|
namespace qrcodegen.QrSegment {
|
|
type int = number;
|
|
|
|
/*
|
|
* Describes how a segment's data bits are interpreted. Immutable.
|
|
*/
|
|
export class Mode {
|
|
/*-- Constants --*/
|
|
|
|
public static readonly NUMERIC = new Mode(0x1, [10, 12, 14]);
|
|
public static readonly ALPHANUMERIC = new Mode(0x2, [9, 11, 13]);
|
|
public static readonly BYTE = new Mode(0x4, [8, 16, 16]);
|
|
public static readonly KANJI = new Mode(0x8, [8, 10, 12]);
|
|
public static readonly ECI = new Mode(0x7, [0, 0, 0]);
|
|
|
|
/*-- Constructor and fields --*/
|
|
|
|
private constructor(
|
|
// The mode indicator bits, which is a uint4 value (range 0 to 15).
|
|
public readonly modeBits: int,
|
|
// Number of character count bits for three different version ranges.
|
|
private readonly numBitsCharCount: [int, int, int],
|
|
) {}
|
|
|
|
/*-- Method --*/
|
|
|
|
// (Package-private) Returns the bit width of the character count field for a segment in
|
|
// this mode in a QR Code at the given version number. The result is in the range [0, 16].
|
|
public numCharCountBits(ver: int): int {
|
|
return this.numBitsCharCount[Math.floor((ver + 7) / 17)];
|
|
}
|
|
}
|
|
}
|
|
|
|
// Modification to export for actual use
|
|
export default qrcodegen;
|