cnf-qrcode/src/lib/core/utils.js

generate qrcode,support svg base64 utf8

let toSJISFunction;
const CODEWORDS_COUNT = [
  0, // Not used
  26, 44, 70, 100, 134, 172, 196, 242, 292, 346,
  404, 466, 532, 581, 655, 733, 815, 901, 991, 1085,
  1156, 1258, 1364, 1474, 1588, 1706, 1828, 1921, 2051, 2185,
  2323, 2465, 2611, 2761, 2876, 3034, 3196, 3362, 3532, 3706,
];

/**
 * Returns the QR Code size for the specified version
 *
 * @param  {Number} version QR Code version
 * @return {Number}         size of QR code
 */
export function getSymbolSize(version) {
  if (!version) throw new Error('"version" cannot be null or undefined');
  if (version < 1 || version > 40) throw new Error('"version" should be in range from 1 to 40');
  return version * 4 + 17;
};

/**
 * Returns the total number of codewords used to store data and EC information.
 *
 * @param  {Number} version QR Code version
 * @return {Number}         Data length in bits
 */
export function getSymbolTotalCodewords(version) {
  return CODEWORDS_COUNT[version];
};

/**
 * Encode data with Bose-Chaudhuri-Hocquenghem
 *
 * @param  {Number} data Value to encode
 * @return {Number}      Encoded value
 */
export function getBCHDigit(data) {
  let digit = 0;

  while (data !== 0) {
    digit++;
    data >>>= 1;
  }

  return digit;
};

export function setToSJISFunction(f) {
  if (typeof f !== 'function') {
    throw new Error('"toSJISFunc" is not a valid function.');
  }

  toSJISFunction = f;
};

export function isKanjiModeEnabled() {
  return typeof toSJISFunction !== 'undefined';
};

export function toSJIS(kanji) {
  return toSJISFunction(kanji);
};