bool setManglingKey(lString16 key) { if (key.startsWith(lString16(L"urn:uuid:"))) key = key.substr(9); _fontManglingKey.clear(); _fontManglingKey.reserve(16); lUInt8 b = 0; int n = 0; for (int i=0; i<key.length(); i++) { int d = hexDigit(key[i]); if (d>=0) { b = (b << 4) | d; if (++n > 1) { _fontManglingKey.add(b); n = 0; b = 0; } } } return _fontManglingKey.length() == 16; }