https://blog.wongcw.com/2019/08/29/id-software%e8%81%af%e5%90%88%e5%89%b5%e5%a7%8b%e4%ba%ba%e8%ab%87%e9%81%8a%e6%88%b2%e6%a5%ad%e7%95%8c%e5%8a%a0%e7%8f%ad%e5%95%8f%e9%a1%8c%ef%bc%9a%e9%80%99%e6%98%af%e5%a5%bd%e4%ba%8b/