class TTFunk::Table::Cff::Encoding

def encode(charmap)
  # Any subset encoding is all but guaranteed to be different from the
  # standard encoding so we don't even attempt to see if it matches. We
  # assume it's different and just encode it anew.
  return encode_supplemental(charmap) if supplemental?
  codes =
    charmap
      .reject { |_code, mapping| mapping[:new].zero? }
      .sort_by { |_code, mapping| mapping[:new] }
      .map { |(code, _m)| code }
  ranges = TTFunk::BinUtils.rangify(codes)
  # calculate whether storing the charset as a series of ranges is
  # more efficient (i.e. takes up less space) vs storing it as an
  # array of SID values
  total_range_size = (2 * ranges.size) +
    (element_width(:range_format) * ranges.size)
  total_array_size = codes.size * element_width(:array_format)
  if total_array_size <= total_range_size
    ([format_int(:array_format), codes.size] + codes).pack('C*')
  else
    element_fmt = element_format(:range_format)
    result = [format_int(:range_format), ranges.size].pack('CC')
    ranges.each { |range| result << range.pack(element_fmt) }
    result
  end
end