Lock-step simulation is child’s play

Joachim Breitner demonstrates how pure functional programming simplifies implementing lock-step simulation with client prediction for multiplayer games.

Joachim Breitner C◦mp◦se :: Conference composeconference.org/2017/ May 18, 2017 Slides: github.com/nomeata/codeworld-talk When implementing a multi-player network game, programmers often choose to implement “lock step simulation with client prediction”, where each client independently calculates the global state of the game, and integrate the other player’s actions as soon as he learns about them, rewinding the state to when the action actually happened. This approach to networking is infamously hard to get right and in general requires great discipline from the game programmer to avoid the clients getting out of sync. Not so with strongly typed pure functional programming On the programming learning platform CodeWorld, even middle school create multi-player games, without having spend a single thought on these issues, and no matter what code they write, they end up with a working networked game. In this talk Joachim explains the interface that CodeWorld provides for this purpose, and show how it pulls this off under the hood.