Do you want a good foundation? Go for TFS 1.5 with Nekiro 8.0, ideal for DBKO, because 8.0 has more resources. Alternatively, you can also go for TFS 1.5 with Nekiro 8.6. If you want to expand the field of view to full screen, both options I mentioned based on Nekiro are suitable only for TFS 1.x
Choose any of the bases I mentioned, then open the source code with Visual Studio and make necessary changes. Compile it, and you're ready with an expanded field of view. The commit is here.
A free and open-source MMORPG server emulator written in C++, compatible with OTClientV8 - Added extended map size · OTCv8/forgottenserver@266a569
github.com