The client source use Extern of Directx8 for more compatibility, I have upload extern of Directx9 and you can edit the source for update on it. I will update the source to for use Directx9 because the next project is to replace the whole render water system by a new one for implement water reflection.
-> Water reflection project:
The problem with the old one is the plane render system, instead to have a VertexBuffer for rendering the water, metin have choose to use a basic rendering system for render multiple plane, so if you implement reflection on the old system you can see duplicate texture reflection on the water and this is not good.
Official post link for download client: https://metin2dev.org/board/index.php?/topic/19421-metin-refresh-github/