Stainless about the out-of-sync issue
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Toshiba-3 created Stainless about the out-of-sync issue on Tue Apr 13, 2010 9:03 pm
TOSH: Here's what we're up to: the IPX protocol was getting more and more annoying to deal with as Windows got updated. A coder then created a launcher for C2 that hooks winsock api calls and converts the IPX addresses to IPv4 ones. This allows us to play LAN games very easily (no need for IPX anymore) or even over the Internet by connecting to a master server, p2p or through a virtual lan as hamachi.
LAN games work perfectly and are very fun. However the netgames over the Internet are often problematic: unless the host has a high speed connection, the clients will soon get out of sync and client/host won't communicate correctly. Whatever we try the same thing happens. Peoples are correctly connected to eachother but positions, damages/collisions and crush data aren't updated at all.

I guess this is probably a vague question but do you have any idea what might cause this? I suppose the game is expecting a specific latency between both the clients and the host, and the internet connection can't match this transmission speed so clients instantly get out of sync. Maybe this timeout is hardcoded?

Related to this, I remember Matt Sullivan saying in an interview (it's at SCi's old site I think) that TCP/IP would be supported. Was there ever a TCP/IP featured build or patch actually made? That could have been very useful at the moment!

I know there is few that can be done to improve the multiplayer experience but at least we are trying!

Matt Edmunds from Stainless replies:
I wrote all the low level comms code, and even I can't remember! We don't have access to the source currently.

I vaguely remember the Windows (not DOS) version of Carma2 using TCP/IP (via Winsock), but I could easily be misremembering, as Winsock supports IPX/SPX too. Perhaps I was merely experimenting and it never made it.

To be honest, it's probably not the protocol that's the problem anyway - if you're can wrapping and unwrapping it correctly at each end.

The network synchronisation code was disgustingly complicated, and made use of the Action Replay system to reposition everything when the host machine issued its view of the world. I didn't write that part!

The problem might simply be that the main loop of the game is running too fast, exposing unintended consequences! Obviously it was written in the days when no processor was faster than 200MHz (or thereabouts). The main loop spins as fast as the processor will allow, completely independent of frame rate. If you can find a way of slowing it down, it could help. Maybe hook into the GetNextMessage() function somehow?!
Irmo on Tue Apr 27, 2010 12:38 pm
Hmmm..... There is C2 for DOS? Never seen it.

I remember there is project named C2O, that don't use ipx at all (as i think), and good programmer can understand how it works (since this project writed in java). Unfortunately, my coding abilities are too bad for this...

UPD: Seems c2o have no source codes 8(
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Toshiba-3 on Thu Apr 29, 2010 1:06 pm
Hello Irmo! Nice to see you around.

Yes at some point there was a DOS build of C2, the software mode is so very similar to C1 anyway.

I made a backup of C2O site and downloads at this address:

Personaly I never got it to work, but I know C2 mod "SOD" players got it working. There even was a tutorial at some point but it is now down. Gameplay was very laggy nonetheless.

Main problem of C2O was that Wolverine wanted to do too much directly. Especialy on the anticheat part. The way it wanted to support every mod as well. And finaly how we had to install it.
He should have started with a simple ripped down standalone C2 install without anticheat system. This is what I'm trying to do with BBQ.
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