Checking if certain characters are supported by a font

Question

I found this on StackOverflow: Is there a way to programmatically determine if a font file has a specific Unicode Glyph?

However, I need to also check UTF-32 characters. What I am trying to do is parse the Unihan data over at unicode.org and ignore all characters that are not supported by "Arial Unicode MS". I started work on the CheckIfCharInFont() method by modifying the arg to take a string (for utf-32) and checking if it is a surrogare pair. I then get the Int32 by doing a char.ConvertToUtf32(surrogate1, surrogate2), but the problem is the current CheckIfCharInFont() method only supports Uint16... you can see where I placed a "Debugger.Break" that this is a bit of a problem. Any experts out there that can help me figure this thing out?

Thanks

public static bool CheckIfCharInFont(string character, Font font)
        {
            UInt16 value = 0;
            int temp = 0;
            if (character.Length > 1) //UTF-32
            {
                temp = char.ConvertToUtf32(character[0], character[1]);
            }
            else
            {
                temp = (int)character[0];
            }

            if (temp > UInt16.MaxValue)
            {
                Debugger.Break();
                return false;
            }
            value = (UInt16)temp;

            //UInt16 value = Convert.ToUInt16(character);
            List<FontRange> ranges = GetUnicodeRangesForFont(font);
            bool isCharacterPresent = false;
            foreach (FontRange range in ranges)
            {
                if (value >= range.Low && value <= range.High)
                {
                    isCharacterPresent = true;
                    break;
                }
            }
            return isCharacterPresent;
        }

Answer 1

You would have to do your own thing. Maybe starting from the specs (http://www.microsoft.com/typography/otspec/cmap.htm)

It is what this tool does: http://mihai-nita.net/2007/09/08/charmapex-some-kind-of-character-map/