qrcode-generator-ts/ts/qrcode/QRUtil.ts

Typescript QR Code generator based on https://github.com/kazuhikoarase/qrcode-generator

import { Mode } from './Mode';
import { ErrorCorrectLevel } from './ErrorCorrectLevel';
import { Polynomial } from './Polynomial';
import { QRMath } from './QRMath';
import { MaskPattern } from './MaskPattern';
import { QRCode } from './QRCode';

'use strict';
/**
 * QRUtil
 * @author Kazuhiko Arase
 */
export class QRUtil {

  constructor() {
    throw 'error';
  }

  public static getPatternPosition(typeNumber: number): number[] {
    return QRUtil.PATTERN_POSITION_TABLE[typeNumber - 1];
  }

  private static PATTERN_POSITION_TABLE = [
    [],
    [6, 18],
    [6, 22],
    [6, 26],
    [6, 30],
    [6, 34],
    [6, 22, 38],
    [6, 24, 42],
    [6, 26, 46],
    [6, 28, 50],
    [6, 30, 54],
    [6, 32, 58],
    [6, 34, 62],
    [6, 26, 46, 66],
    [6, 26, 48, 70],
    [6, 26, 50, 74],
    [6, 30, 54, 78],
    [6, 30, 56, 82],
    [6, 30, 58, 86],
    [6, 34, 62, 90],
    [6, 28, 50, 72, 94],
    [6, 26, 50, 74, 98],
    [6, 30, 54, 78, 102],
    [6, 28, 54, 80, 106],
    [6, 32, 58, 84, 110],
    [6, 30, 58, 86, 114],
    [6, 34, 62, 90, 118],
    [6, 26, 50, 74, 98, 122],
    [6, 30, 54, 78, 102, 126],
    [6, 26, 52, 78, 104, 130],
    [6, 30, 56, 82, 108, 134],
    [6, 34, 60, 86, 112, 138],
    [6, 30, 58, 86, 114, 142],
    [6, 34, 62, 90, 118, 146],
    [6, 30, 54, 78, 102, 126, 150],
    [6, 24, 50, 76, 102, 128, 154],
    [6, 28, 54, 80, 106, 132, 158],
    [6, 32, 58, 84, 110, 136, 162],
    [6, 26, 54, 82, 110, 138, 166],
    [6, 30, 58, 86, 114, 142, 170]
  ];

  private static MAX_LENGTH = [
    [[41, 25, 17, 10], [34, 20, 14, 8], [27, 16, 11, 7], [17, 10, 7, 4]],
    [[77, 47, 32, 20], [63, 38, 26, 16], [48, 29, 20, 12], [34, 20, 14, 8]],
    [[127, 77, 53, 32], [101, 61, 42, 26], [77, 47, 32, 20], [58, 35, 24, 15]],
    [[187, 114, 78, 48], [149, 90, 62, 38], [111, 67, 46, 28], [82, 50, 34, 21]],
    [[255, 154, 106, 65], [202, 122, 84, 52], [144, 87, 60, 37], [106, 64, 44, 27]],
    [[322, 195, 134, 82], [255, 154, 106, 65], [178, 108, 74, 45], [139, 84, 58, 36]],
    [[370, 224, 154, 95], [293, 178, 122, 75], [207, 125, 86, 53], [154, 93, 64, 39]],
    [[461, 279, 192, 118], [365, 221, 152, 93], [259, 157, 108, 66], [202, 122, 84, 52]],
    [[552, 335, 230, 141], [432, 262, 180, 111], [312, 189, 130, 80], [235, 143, 98, 60]],
    [[652, 395, 271, 167], [513, 311, 213, 131], [364, 221, 151, 93], [288, 174, 119, 74]]
  ];

  public static getMaxLength(
    typeNumber: number,
    mode: Mode,
    errorCorrectLevel: ErrorCorrectLevel
  ): number {

    var t = typeNumber - 1;
    var e = 0;
    var m = 0;

    switch (errorCorrectLevel) {
      case ErrorCorrectLevel.L: e = 0; break;
      case ErrorCorrectLevel.M: e = 1; break;
      case ErrorCorrectLevel.Q: e = 2; break;
      case ErrorCorrectLevel.H: e = 3; break;
      default:
        throw 'e:' + errorCorrectLevel;
    }

    switch (mode) {
      case Mode.MODE_NUMBER: m = 0; break;
      case Mode.MODE_ALPHA_NUM: m = 1; break;
      case Mode.MODE_8BIT_BYTE: m = 2; break;
      case Mode.MODE_KANJI: m = 3; break;
      default:
        throw 'm:' + mode;
    }

    return QRUtil.MAX_LENGTH[t][e][m];
  }

  public static getErrorCorrectPolynomial(
    errorCorrectLength: number): Polynomial {

    var a = new Polynomial([1]);

    for (var i = 0; i < errorCorrectLength; i += 1) {
      a = a.multiply(new Polynomial([1, QRMath.gexp(i)]));
    }

    return a;
  }

  public static getMaskFunc(
    maskPattern: number
  ): (i: number, j: number) => boolean {

    switch (maskPattern) {

      case MaskPattern.PATTERN000:
        return (i: number, j: number) => (i + j) % 2 == 0;
      case MaskPattern.PATTERN001:
        return (i: number, j: number) => i % 2 == 0;
      case MaskPattern.PATTERN010:
        return (i: number, j: number) => j % 3 == 0;
      case MaskPattern.PATTERN011:
        return (i: number, j: number) => (i + j) % 3 == 0;
      case MaskPattern.PATTERN100:
        return (i: number, j: number) => (~~(i / 2) + ~~(j / 3)) % 2 == 0;
      case MaskPattern.PATTERN101:
        return (i: number, j: number) => (i * j) % 2 + (i * j) % 3 == 0;
      case MaskPattern.PATTERN110:
        return (i: number, j: number) => ((i * j) % 2 + (i * j) % 3) % 2 == 0;
      case MaskPattern.PATTERN111:
        return (i: number, j: number) => ((i * j) % 3 + (i + j) % 2) % 2 == 0;

      default:
        throw 'mask:' + maskPattern;
    }
  }

  public static getLostPoint(qrCode: QRCode): number {

    var moduleCount = qrCode.getModuleCount();

    var lostPoint = 0;

    // LEVEL1

    for (var row = 0; row < moduleCount; row += 1) {

      for (var col = 0; col < moduleCount; col += 1) {

        var sameCount = 0;
        var dark = qrCode.isDark(row, col);

        for (var r = -1; r <= 1; r += 1) {

          if (row + r < 0 || moduleCount <= row + r) {
            continue;
          }

          for (var c = -1; c <= 1; c += 1) {

            if (col + c < 0 || moduleCount <= col + c) {
              continue;
            }

            if (r == 0 && c == 0) {
              continue;
            }

            if (dark == qrCode.isDark(row + r, col + c)) {
              sameCount += 1;
            }
          }
        }

        if (sameCount > 5) {
          lostPoint += (3 + sameCount - 5);
        }
      }
    }

    // LEVEL2

    for (var row = 0; row < moduleCount - 1; row += 1) {
      for (var col = 0; col < moduleCount - 1; col += 1) {
        var count = 0;
        if (qrCode.isDark(row, col)) count += 1;
        if (qrCode.isDark(row + 1, col)) count += 1;
        if (qrCode.isDark(row, col + 1)) count += 1;
        if (qrCode.isDark(row + 1, col + 1)) count += 1;
        if (count == 0 || count == 4) {
          lostPoint += 3;
        }
      }
    }

    // LEVEL3

    for (var row = 0; row < moduleCount; row += 1) {
      for (var col = 0; col < moduleCount - 6; col += 1) {
        if (qrCode.isDark(row, col)
          && !qrCode.isDark(row, col + 1)
          && qrCode.isDark(row, col + 2)
          && qrCode.isDark(row, col + 3)
          && qrCode.isDark(row, col + 4)
          && !qrCode.isDark(row, col + 5)
          && qrCode.isDark(row, col + 6)) {
          lostPoint += 40;
        }
      }
    }

    for (var col = 0; col < moduleCount; col += 1) {
      for (var row = 0; row < moduleCount - 6; row += 1) {
        if (qrCode.isDark(row, col)
          && !qrCode.isDark(row + 1, col)
          && qrCode.isDark(row + 2, col)
          && qrCode.isDark(row + 3, col)
          && qrCode.isDark(row + 4, col)
          && !qrCode.isDark(row + 5, col)
          && qrCode.isDark(row + 6, col)) {
          lostPoint += 40;
        }
      }
    }

    // LEVEL4

    var darkCount = 0;

    for (var col = 0; col < moduleCount; col += 1) {
      for (var row = 0; row < moduleCount; row += 1) {
        if (qrCode.isDark(row, col)) {
          darkCount += 1;
        }
      }
    }

    var ratio = Math.abs(100 * darkCount / moduleCount / moduleCount - 50) / 5;
    lostPoint += ratio * 10;

    return lostPoint;
  }

  public static getBCHTypeInfo(data: number): number {
    var d = data << 10;
    while (QRUtil.getBCHDigit(d) - QRUtil.getBCHDigit(QRUtil.G15) >= 0) {
      d ^= (QRUtil.G15 << (QRUtil.getBCHDigit(d) -
        QRUtil.getBCHDigit(QRUtil.G15)));
    }
    return ((data << 10) | d) ^ QRUtil.G15_MASK;
  }

  public static getBCHTypeNumber(data: number): number {
    var d = data << 12;
    while (QRUtil.getBCHDigit(d) - QRUtil.getBCHDigit(QRUtil.G18) >= 0) {
      d ^= (QRUtil.G18 << (QRUtil.getBCHDigit(d) -
        QRUtil.getBCHDigit(QRUtil.G18)));
    }
    return (data << 12) | d;
  }

  private static G15 = (1 << 10) | (1 << 8) | (1 << 5)
  | (1 << 4) | (1 << 2) | (1 << 1) | (1 << 0);

  private static G18 = (1 << 12) | (1 << 11) | (1 << 10)
  | (1 << 9) | (1 << 8) | (1 << 5) | (1 << 2) | (1 << 0);

  private static G15_MASK = (1 << 14) | (1 << 12) | (1 << 10)
  | (1 << 4) | (1 << 1);

  private static getBCHDigit(data: number): number {
    var digit = 0;
    while (data != 0) {
      digit += 1;
      data >>>= 1;
    }
    return digit;
  }
}