Method ConvertUTF32ToUTF8

3rdparty/tinyxml2/tinyxml2.cpp:417–467

void XMLUtil::ConvertUTF32ToUTF8( unsigned long input, char* output, int* length )
{
    const unsigned long BYTE_MASK = 0xBF;
    const unsigned long BYTE_MARK = 0x80;
    const unsigned long FIRST_BYTE_MARK[7] = { 0x00, 0x00, 0xC0, 0xE0, 0xF0, 0xF8, 0xFC };

    if (input < 0x80) {
        *length = 1;
    }
    else if ( input < 0x800 ) {
        *length = 2;
    }
    else if ( input < 0x10000 ) {
        *length = 3;
    }
    else if ( input < 0x200000 ) {
        *length = 4;
    }
    else {
        *length = 0;    // This code won't convert this correctly anyway.
        return;
    }

    output += *length;

    // Scary scary fall throughs are annotated with carefully designed comments
    // to suppress compiler warnings such as -Wimplicit-fallthrough in gcc
    switch (*length) {
        case 4:
            --output;
            *output = static_cast<char>((input | BYTE_MARK) & BYTE_MASK);
            input >>= 6;
            //fall through
        case 3:
            --output;
            *output = static_cast<char>((input | BYTE_MARK) & BYTE_MASK);
            input >>= 6;
            //fall through
        case 2:
            --output;
            *output = static_cast<char>((input | BYTE_MARK) & BYTE_MASK);
            input >>= 6;
            //fall through
        case 1:
            --output;
            *output = static_cast<char>(input | FIRST_BYTE_MARK[*length]);
            break;
        default:
            TIXMLASSERT( false );
    }
}


const char* XMLUtil::GetCharacterRef(const char* p, char* value, int* length)