class PDF::Reader::Encoding::SymbolEncoding

def to_utf8(str, tounicode = nil)
  array_symbol = str.unpack('C*')
  array_symbol = self.process_differences(array_symbol)
  array_enc = []
  array_symbol.each do |num|
    if tounicode && (code = tounicode.decode(num))
      array_enc << code
    elsif tounicode
      array_enc << PDF::Reader::Encoding::UNKNOWN_CHAR
    else
      case num
      when 0x22; array_enc << 0x2200
      when 0x24; array_enc << 0x2203
      when 0x27; array_enc << 0x220B
      when 0x2A; array_enc << 0x2217
      when 0x2D; array_enc << 0x2212
      when 0x40; array_enc << 0x2245
      when 0x41; array_enc << 0x0391
      when 0x42; array_enc << 0x0392
      when 0x43; array_enc << 0x03A7
      when 0x44; array_enc << 0x0394
      when 0x45; array_enc << 0x0395
      when 0x46; array_enc << 0x03A6
      when 0x47; array_enc << 0x0393
      when 0x48; array_enc << 0x0397
      when 0x49; array_enc << 0x0399
      when 0x4A; array_enc << 0x03D1
      when 0x4B; array_enc << 0x039A
      when 0x4C; array_enc << 0x039B
      when 0x4D; array_enc << 0x039C
      when 0x4E; array_enc << 0x039D
      when 0x4F; array_enc << 0x039F
      when 0x50; array_enc << 0x03A0
      when 0x51; array_enc << 0x0398
      when 0x52; array_enc << 0x03A1
      when 0x53; array_enc << 0x03A3
      when 0x54; array_enc << 0x03A4
      when 0x55; array_enc << 0x03A5
      when 0x56; array_enc << 0x03C2
      when 0x57; array_enc << 0x03A9
      when 0x58; array_enc << 0x039E
      when 0x59; array_enc << 0x03A8
      when 0x5A; array_enc << 0x0396
      when 0x5C; array_enc << 0x2234
      when 0x5E; array_enc << 0x22A5
      when 0x60; array_enc << 0xF8E5
      when 0x61; array_enc << 0x03B1
      when 0x62; array_enc << 0x03B2
      when 0x63; array_enc << 0x03C7
      when 0x64; array_enc << 0x03B4
      when 0x65; array_enc << 0x03B5
      when 0x66; array_enc << 0x03C6
      when 0x67; array_enc << 0x03B3
      when 0x68; array_enc << 0x03B7
      when 0x69; array_enc << 0x03B9
      when 0x6A; array_enc << 0x03D5
      when 0x6B; array_enc << 0x03BA
      when 0x6C; array_enc << 0x03BB
      when 0x6D; array_enc << 0x03BC
      when 0x6E; array_enc << 0x03BD
      when 0x6F; array_enc << 0x03BF
      when 0x70; array_enc << 0x03C0
      when 0x71; array_enc << 0x03B8
      when 0x72; array_enc << 0x03C1
      when 0x73; array_enc << 0x03C3
      when 0x74; array_enc << 0x03C4
      when 0x75; array_enc << 0x03C5
      when 0x76; array_enc << 0x03D6
      when 0x77; array_enc << 0x03C9
      when 0x78; array_enc << 0x03BE
      when 0x79; array_enc << 0x03C8
      when 0x7A; array_enc << 0x03B6
      when 0x7E; array_enc << 0x223C
      when 0xA0; array_enc << 0x20AC
      when 0xA1; array_enc << 0x03D2
      when 0xA2; array_enc << 0x2032
      when 0xA3; array_enc << 0x2264
      when 0xA4; array_enc << 0x2215
      when 0xA5; array_enc << 0x221E
      when 0xA6; array_enc << 0x0192
      when 0xA7; array_enc << 0x2663
      when 0xA8; array_enc << 0x2666
      when 0xA9; array_enc << 0x2665
      when 0xAA; array_enc << 0x2660
      when 0xAB; array_enc << 0x2194
      when 0xAC; array_enc << 0x2190
      when 0xAD; array_enc << 0x2191
      when 0xAE; array_enc << 0x2192
      when 0xAF; array_enc << 0x2193
      when 0xB2; array_enc << 0x2033
      when 0xB3; array_enc << 0x2265
      when 0xB4; array_enc << 0x00D7
      when 0xB5; array_enc << 0x221D
      when 0xB6; array_enc << 0x2202
      when 0xB7; array_enc << 0x2022
      when 0xB8; array_enc << 0x00F7
      when 0xB9; array_enc << 0x2260
      when 0xBA; array_enc << 0x2261
      when 0xBB; array_enc << 0x2248
      when 0xBC; array_enc << 0x2026
      when 0xBD; array_enc << 0xF8E6
      when 0xBE; array_enc << 0xF8E7
      when 0xBF; array_enc << 0x21B5
      when 0xC0; array_enc << 0x2135
      when 0xC1; array_enc << 0x2111
      when 0xC2; array_enc << 0x211C
      when 0xC3; array_enc << 0x2118
      when 0xC4; array_enc << 0x2297
      when 0xC5; array_enc << 0x2295
      when 0xC6; array_enc << 0x2205
      when 0xC7; array_enc << 0x2229
      when 0xC8; array_enc << 0x222A
      when 0xC9; array_enc << 0x2283
      when 0xCA; array_enc << 0x2287
      when 0xCB; array_enc << 0x2284
      when 0xCC; array_enc << 0x2282
      when 0xCD; array_enc << 0x2286
      when 0xCE; array_enc << 0x2208
      when 0xCF; array_enc << 0x2209
      when 0xD0; array_enc << 0x2220
      when 0xD1; array_enc << 0x2207
      when 0xD2; array_enc << 0xF6DA
      when 0xD3; array_enc << 0xF6D9
      when 0xD4; array_enc << 0xF6DB
      when 0xD5; array_enc << 0x220F
      when 0xD6; array_enc << 0x221A
      when 0xD7; array_enc << 0x22C5
      when 0xD8; array_enc << 0x00AC
      when 0xD9; array_enc << 0x2227
      when 0xDA; array_enc << 0x2228
      when 0xDB; array_enc << 0x21D4
      when 0xDC; array_enc << 0x21D0
      when 0xDD; array_enc << 0x21D1
      when 0xDE; array_enc << 0x21D2
      when 0xDF; array_enc << 0x21D3
      when 0xE0; array_enc << 0x25CA
      when 0xE1; array_enc << 0x2329
      when 0xE2; array_enc << 0xF8E8
      when 0xE3; array_enc << 0xF8E9
      when 0xE4; array_enc << 0xF8EA
      when 0xE5; array_enc << 0x2211
      when 0xE6; array_enc << 0xF8EB
      when 0xE7; array_enc << 0xF8EC
      when 0xE8; array_enc << 0xF8ED
      when 0xE9; array_enc << 0xF8EE
      when 0xEA; array_enc << 0xF8EF
      when 0xEB; array_enc << 0xF8F0
      when 0xEC; array_enc << 0xF8F1
      when 0xED; array_enc << 0xF8F2
      when 0xEE; array_enc << 0xF8F3
      when 0xEF; array_enc << 0xF8F4
      when 0xF1; array_enc << 0x232A
      when 0xF2; array_enc << 0x222B
      when 0xF3; array_enc << 0x2320
      when 0xF4; array_enc << 0xF8F5
      when 0xF5; array_enc << 0x2321
      when 0xF6; array_enc << 0xF8F6
      when 0xF7; array_enc << 0xF8F7
      when 0xF8; array_enc << 0xF8F8
      when 0xF9; array_enc << 0xF8F9
      when 0xFA; array_enc << 0xF8FA
      when 0xFB; array_enc << 0xF8FB
      when 0xFC; array_enc << 0xF8FC
      when 0xFD; array_enc << 0xF8FD
      when 0xFE; array_enc << 0xF8FE
      else
        array_enc << num
      end
    end
  end
  # replace charcters that didn't convert to unicode nicely with something valid
  array_enc.collect! { |c| c ? c : PDF::Reader::Encoding::UNKNOWN_CHAR }
  # convert any glyph names to unicode codepoints
  array_enc = self.process_glyphnames(array_enc)
  # pack all our Unicode codepoints into a UTF-8 string
  ret = array_enc.pack("U*")
  # set the strings encoding correctly under ruby 1.9+
  ret.force_encoding("UTF-8") if ret.respond_to?(:force_encoding)
  return ret
end