Steam Integration

[assemblaj]

Looking into Steam integration to help folks who don't want to trade IPs. If included, this will just be an option and will not necessarily replace the original netcode. I've put together an experimental Steam build. I would be willing to go full tilt on matchmaking and lobbies, the primary issue is UI. Building out such modes requires a bit of mastery over both MUGEN's UI system and IKEMEN's Lua which I don't have. If anyone's interested in contributing in that regard, let me know.

Below is what I posted on Discord along with the build. I will go into further detail on later posts with regards to how it works.

Experimental Steam Build:
https://drive.google.com/file/d/1Hn2gGDTsxMy6effdk3eYnL-x53ykG0uT/view?usp=sharing
A few notes:

• This is based on the IKEMEN "developer" branch (i.e. later than .99)
• Delay based for now to test out Steam
• All players need to have the same appid in steam_appid.txt, and it has to be from a game you both own. By default, I used The Black Heart's (an IKEMEN Game that's on Steam) AppID, I have not tested other games.
• The way this works right now is that your online friends will be selectable in the Join Game Menu
• The only friends that show up in the Join Game Menu will be the one's online at the time of starting the application.
• For testing purposes, there's a Transport option in SteamConfig in config.json, there are 4 options: "Reliable", "Unreliable", "Reliable_With_Buffering", and "Unreliable_No_Delay". Unreliable is said to be faster, but IKEMEN's delay based netcode normally uses TCP, so I defaulted things to Reliable. Feel free to play around with that but also make sure everyone has the same configs in this regard.
• Someone reported that one player exiting netcode can caused both players' games to crash, looking in to that.
• Someone reported a desync, I'd suggest trying out different transport options for now if that persists.

[assemblaj]

How it works:
The Steam Build essentially uses a Rust-based launcher, to leverage Rust's very good Steam bindings. That launcher starts the game and acts as a proxy that forwards Steam API calls from Go and vice versa. Go side acts as client and Rust side acts as a server. Right now I have 2 builds (one that isn't fully functional yet) that do this in different ways. One of which (which is out now) uses gRPC. The other communicates via Stdin/Stdout pipes created by starting the process. I use Protobufs to simplify the code with regards to maintaining a unified messaging interface between both the applications, but I can write my own binary messaging protocol if necessary.

In the current released build, I have IKEMEN compiled as a .dll. This isn't necessary, it's mainly a holdover for a different idea, but it certainly helps enforce the parameters of the test (i.e. that you have to use the Steam launcher to use IKEMEN). In the other build I load it as an executable. I think we'll probably go that route down the line.

Here is the current source code for the Rust launcher. The section in /src/grpc/bin is the current build. Main.rs is the stdin/stdout build.