void Node::flush()
{
    auto registeredNum = getRegisteredObjNum();

    if (registeredNum == 0) {
        return;
    }

    if (!m_fp) {
        std::string path(BasePath);

#if 0
        auto depth = getDepth();
        auto mortonNumber = getMortonNumber();

        path += "r";
        uint32_t mask = 0x07 << (3 * (depth - 1));

        for (uint32_t i = 1; i < depth; i++) {
            auto n = mortonNumber & mask;

            path += n;

            mask >>= 3;
        }

        path += ".spcd";

        fopen_s(&m_fp, path.c_str(), "wb");
        IZ_ASSERT(m_fp);

        // ヘッダー分空ける.
        fseek(m_fp, sizeof(m_header), SEEK_SET);

        m_header.magic_number = FOUR_CC('S', 'P', 'C', 'D');
        m_header.version = 0;

        m_header.depth = depth;
        m_header.mortonNumber = mortonNumber;
#else
        auto id = getId();

        char tmp[10];
        sprintf(tmp, "%d\0", id);

        path += tmp;

        path += ".spcd";

        fopen_s(&m_fp, path.c_str(), "wb");
        IZ_ASSERT(m_fp);

        // ヘッダー分空ける.
        fseek(m_fp, sizeof(m_header), SEEK_SET);

        m_header.magic_number = FOUR_CC('S', 'P', 'C', 'D');
        m_header.version = 0;
#endif
    }