qrcode_UTF8.mjs

//---------------------------------------------------------------------
//
// QR Code Generator for JavaScript UTF8 Support (optional)
//
// Copyright (c) 2011 Kazuhiko Arase
//
// URL: http://www.d-project.com/
//
// Licensed under the MIT license:
//  http://www.opensource.org/licenses/mit-license.php
//
// The word 'QR Code' is registered trademark of
// DENSO WAVE INCORPORATED
//  http://www.denso-wave.com/qrcode/faqpatent-e.html
//
//---------------------------------------------------------------------

// http://stackoverflow.com/questions/18729405/how-to-convert-utf8-string-to-byte-array
function toUTF8Array(str) {
  var utf8 = [];
  for (var i=0; i < str.length; i++) {
    var charcode = str.charCodeAt(i);
    if (charcode < 0x80) utf8.push(charcode);
    else if (charcode < 0x800) {
      utf8.push(0xc0 | (charcode >> 6),
          0x80 | (charcode & 0x3f));
    }
    else if (charcode < 0xd800 || charcode >= 0xe000) {
      utf8.push(0xe0 | (charcode >> 12),
          0x80 | ((charcode>>6) & 0x3f),
          0x80 | (charcode & 0x3f));
    }
    // surrogate pair
    else {
      i++;
      // UTF-16 encodes 0x10000-0x10FFFF by
      // subtracting 0x10000 and splitting the
      // 20 bits of 0x0-0xFFFFF into two halves
      charcode = 0x10000 + (((charcode & 0x3ff)<<10)
        | (str.charCodeAt(i) & 0x3ff));
      utf8.push(0xf0 | (charcode >>18),
          0x80 | ((charcode>>12) & 0x3f),
          0x80 | ((charcode>>6) & 0x3f),
          0x80 | (charcode & 0x3f));
    }
  }
  return utf8;
}

export const stringToBytes = toUTF8Array;