Comments for gafferongames.com

Comment on What every programmer needs to know about game networking by Glenn Fiedler

Glenn Fiedler — Tue, 31 Jan 2012 03:56:23 +0000

There are cheating considerations, network model considerations (eg. if P2P lockstep then you don’t gain anything… async, sure), also, bandwidth! There is much more data to upload and you’ll find yourself being able to support less players with P2P than c/s. I’d recommend P2P for 4 or maybe 8 player games max. cheers

Comment on What every programmer needs to know about game networking by Glenn Fiedler

Glenn Fiedler — Tue, 31 Jan 2012 03:55:01 +0000

It’s clearly faster to go P2P, but much more complex than client/server – also, I need to know more about the type of game you are making to advise you on whether client/server or P2P is the way to go.

cheers

Comment on Reliability and Flow Control by Glenn Fiedler

Glenn Fiedler — Tue, 31 Jan 2012 03:53:10 +0000

Hi! It’s not for security reasons but so that it can do NAT punch-through for you — eg. connect P2P through firewalls. It’s hard to code that yourself, and error prone, using a library like RakNet or OpenTNL to do that for you is wise. Also, look at “ENet”

Good luck!

Comment on What every programmer needs to know about game networking by MrShankly

MrShankly — Mon, 30 Jan 2012 23:09:36 +0000

Hi I have a question i hope you would be able to answer!

If developing a multiplayer game where the main problem is network latency, would that suit a p2p architecture over client server as you are cutting out transmission to the “middle man”?
Thanks!

Comment on Reliability and Flow Control by Walid Baccari

Walid Baccari — Mon, 30 Jan 2012 13:13:37 +0000

Hi Glenn,

Thanks for tutorials, they have been very helpful for me.

I intend to start working with a team of friends on our first multiplayer online game. I read all the articles of the series networking for game programmers and my only question is how do i change the code in the last example to make the server handle multiple clients each with his own IP address, sequence, ack, and ack_bits?

Also, you mentioned in the commentaries that, for security reasons, a PC programmer should use RackNet or OpenNTL. Does OpenNTL use UDP? And, does it provide reliability and flow control?

Comment on Floating Point Determinism by RSG

RSG — Mon, 23 Jan 2012 14:26:51 +0000

If you know bounds on the approximate magnitude of all the values before hand, you can apply shifts to avoid overflow (or use C++ templates to make it automatic). I’ve made a physics intensive fixed point game in C++ before, and it works pretty well. The main problem with this approach is that the code is no longer generic, so it’s only useful if you know exactly what you’ll be doing ahead of time.

Comment on UDP vs. TCP by Glenn Fiedler

Glenn Fiedler — Sat, 21 Jan 2012 01:51:45 +0000

I’ve never coded an MMO so I don’t know!

Comment on UDP vs. TCP by Austin Keller

Austin Keller — Fri, 20 Jan 2012 20:05:27 +0000

Networking is completely new to me, but I do understand your explanations (Thank you for that). Can you quickly explain the different in information between an MMO and FPS. I’ve always thought MMO’s were fairly quick paced games as well, at least when it comes to PvPing.

Would they change the way packets are sent if a player was in PvP mode?

Any help would be great! Thanks again for this!

Comment on Fix Your Timestep! by Ingo

Ingo — Wed, 18 Jan 2012 10:21:55 +0000

Thanks, Glenn. I can see why simple extrapolation can be more jerky, at least generally.

Comment on Fix Your Timestep! by William C

William C — Mon, 16 Jan 2012 20:22:43 +0000

Hi,

There’s something I’ve always been curious about interpolating between the two different states. If say sprite animations were based off specific update states, how is that handle when the states are interpolated? For example, a player is at rest at the last state but now moving in the current state. When the player moves in the current frame, an animation is triggered. If alpha = 0.5, what do you do with the animation? If it is played, then the time passed for the animation will be a negative number. If I had to guess, I’d say to start the animation and if the time elapsed for the anim is less than 0, just display the first frame and if the time is positive, then the animation time is the actual program time minus a fixed step time. Can you clarify if this makes any sense? Thanks!