[gameprogrammer] Re: development model

[Matthew Weigel <unique@idempot.net>]

Kevin Jenkins wrote:

> I'm sorry but this is wrong and a huge oversimplification.  In practice,
> multiplayer games have some of the code on the client and some of the
> code on the server.  Sometimes some parts of the code is shared.  The
> model of a necessity differs between system.  As does the view.

Pardon me, but I'm not really sure what it is that you're saying here.
The view and model of a necessity differ between system[s]?  Certainly,
but that doesn't have much of anything to do with MVC.  MVC is not a
design pattern focused on code reuse, so the fact that a particular
program's architecture does not provide for code reuse does not mean
it's not MVC.

MVC is a way to encapsulate data and logic, so that changes in one place
minimally impact others.

>  The
> controller is shared among the client and server, sometimes on one,
> sometimes on the other, sometimes on both.

I think it would be hard for you to argue that the server handles input.

>  Some examples of this are:
> 
> Scoping: Not all systems know about all data

That's the whole point of encapsulation?

> Interpolation: What you see is an interpolation of the last known
> network data, which in itself isn't necessarily what is on the server.

True, but this is essentially just a matter of having a model proxy on
the client.  Are you going to argue that the client interpolation can
control what happens on the server, and to other players?

> Local updates: So you can see your gun start shooting before the network
> actually knows about it.

See above.  The client can guess what will happen next, but it can't
propagate that through the model.

> Anti-cheating: Server overrides the input of the client.

It's entirely within the scope of the model to ignore or override the
controller.

> I've written 7 multiplayer games and am working on an MMOG and not once
> have I even considered model / view / controller for the client / server
> networking part.

The way you've described the purpose and practice of MVC, I don't doubt
it looks unrelated to any work you might do.  But perhaps your idea of
MVC is a little out of whack...?
-- 
 Matthew Weigel




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