NetCube - Netcode client/server game

Made by Borgar Barland and Anders Noël Lothe Morille

Introduction

This project aims to implement a simple 2D game to showcase/learn netcode functionality. The game consists of a client side application written in Rust with the Macroquad minimal game engine. Players can join the game and move/jump around, seeing the other player's position in realtime. The server-side application - also written in Rust - exposes a SocketIO (WebSocket) API to handle realtime-connections with the client and global state updates.

Functionality

• Graphical client-side game with movement and jumping
• Toggleable netcode functionality, namely interpolation, reconciliation and prediction
• Adjustable ping that is simulated on the client for both sending and receiving packets.
• Sound effects for joining the game and adjusting ping
• Server-side application that provides a SocketIO API, and can handle multiple client connections simultaneously

Roadmap/weaknesses

• Physics simulation; currently has constant movement speed in the X axis and virtual and jumping where height is calculated based on the time of the jump.
• Collisions; currently no collisions. Contact with ground based solely on min Y coordinates

Dependencies

Packages used in the project. The project is divided into 3 crates (rust packages): client, server and netcode. Dependencies that are shared between the three reside in the workspace dependencies.

Workspace

• serde: Generic serialization/deserialization library
• serde_json: Serialization of JSON values
• anyhow: Thin-pointer error types for coercible error fallback
• chrono: Date/time/duration handling with Timezone
• thiserror: Library error handling using enums

Server

• axum: Web-API server library. Bindings for TCP/HTTP
• socketioxide: SocketIO library. Bindings for SocketIO/WebSocket
• tokio: Asynchronous runtime for async/await

Client

macroquad: Minimal game engine for audio, graphics and game loop rust_socketio: SocketIO client

Installation

This project requires Rust. The project was written in with rustc v1.87.0. Rust can be installed using Rustup. The latest stable release should suffice.

Running the project

1. Run the server

cargo run --release --bin server

2. Run the client (must run the server first)

cargo run --release --bin client

You can omit the release flag to compile in debug mode, but this might affect performance.

How to use

Keybinds

• Space - Join the game
• W - Jump
• A - Move left
• D - Move right
• J - Reduce ping
• K - Increase ping
• I - Toggle interpolation
• R - Toggle reconciliation
• P - Toggle prediction

Adjust server update rate

The server's update rate can be changed by increasing or decreasing the STATE_UPDATE_INTERVAL constant at the top of the server/src/main.rs file, and restarting the server. This constant represents how many milliseconds the server waits before sending a new state update to the clients. It is recommended to keep this value above 15ms.

Running tests

Tests can be run with

cargo test