Imprimis Dedicated Server

Written and © Alex "no-lex" Foster 2020, released CC0/WTFPL.

The Imprimis server is the only way to host multiplayer games using Imprimis. It is a separate standalone from the game, unlike other Cube games, but otherwise has similar functionality.

Compilation Dependencies

• zlib1g-dev
• make
• g++

Compilation Instructions

1. Clone the repository.

git clone https://github.com/project-imprimis/imprimis-gameserver.git --recurse-submodules

2. Go to src folder and compile the gameserver.

cmake -S . -B build

cd build && make

3. Execute the gameserver.

./imprimis_gameserver

The gameserver executable imprimis_gameserver can be run in the command line to create a game server.

Hardware Requirements

The hardware required to run Imprimis' server is rather trivial: modern single board computers are easily adequate to run Imprimis' server with sane client numbers. This is due to the clients, not the server, calculating the paths of entities on the level.

It is highly preferable, though not strictly necessary, to run the server on a stable broadband Ethernet connection. Wireless internet sources or wireless local connections lead to latency inconsistencies which cannot be resolved by server configuration, leading to inconsistent gameplay experiences for players.

Overview

Imprimis' client-server model utilizes the game itself (the client) and the server (this program). The Imprimis server is very lightweight and does not actually modulate much of the gameplay, acting more as a packet multicaster between clients which themselves largely control gameplay than as a centralized source for information. While this topology is not the most secure possible, it is a very responsive architecture that makes gameplay feel nearly local.

Imprimis' server uses the enet library to send packets over the UDP protocol, which is, unlike the typical TCP that sends webpages and most other traffic, a protocol that does not verify that packets make it to its destination. UDP, however, loses the overhead associated with making sure packets arrive, lowering its overhead and latency significantly.

The client-server model functions by having clients have domain over particular parts of the dynamic game (e.g. their own weapons, player locations, etc.) and being responsible for broadcasting updates for these entities. The server then tells the other clients on the game about these changes, which then apply this to their own clients.