Raycasting FPS

A small multiplayer FPS prototype written in Rust, using a classic raycasting rendering technique inspired by early 3D games.

The project is split into two binaries:

• server: hosts the multiplayer session and loads the map.
• client: connects to a server, renders the game, and lets the player move around.

Features

• Real-time raycasting renderer
• Multiplayer client/server architecture
• UDP-based networking
• JSON map loading
• Texture-based walls and entities
• Minimap display
• Basic player movement and collision
• Shooting mechanic
• Configurable server port and map file
• Nickname-based client connection

Tech Stack

• Rust
• SDL2
• SDL2_image
• SDL2_ttf
• Serde
• serde_json
• Clap

Project Structure

.
├── assets/
│   ├── fonts/
│   └── img/
├── conf/
│   ├── map1.json
│   ├── map2.json
│   └── map_template_rework.jsonc
├── src/
│   ├── client/
│   ├── display/
│   ├── entities/
│   ├── resources/
│   ├── server/
│   ├── world/
│   ├── camera.rs
│   ├── rays.rs
│   └── lib.rs
├── Cargo.toml
└── README.md

Requirements

You need Rust and Cargo installed.

You also need the SDL2 native libraries installed on your system.

Linux

For Debian or Ubuntu-based distributions:

sudo apt install libsdl2-dev libsdl2-image-dev libsdl2-ttf-dev

macOS

Using Homebrew:

brew install sdl2 sdl2_image sdl2_ttf

Build

cargo build --release

Run

Start the server

cargo run --release --bin server -- --map "conf/map1.json" --port 5000

This starts a server using the map file conf/map1.json on port 5000.

You can also use another map:

cargo run --release --bin server -- --map "conf/map2.json" --port 5000

Start a client

Open another terminal and run:

cargo run --release --bin client -- --host 127.0.0.1 --port 5000 --nickname "guest1"

To connect another player, open a new terminal and use another nickname:

cargo run --release --bin client -- --host 127.0.0.1 --port 5000 --nickname "guest2"

Controls

Key	Action
W	Move forward
S	Move backward
A	Strafe left
D	Strafe right
Q	Rotate left
E	Rotate right
Space	Shoot
Esc	Quit

Server Options

cargo run --release --bin server -- [OPTIONS]

Available options:

Option	Description
--map <FILE>	Map file to load
--port <PORT>	Server port
--max-hosts <NUMBER>	Maximum number of connected players

Example:

cargo run --release --bin server -- --map "conf/map1.json" --port 5000 --max-hosts 4

Client Options

cargo run --release --bin client -- [OPTIONS]

Available options:

Option	Description
--host <IP>	Server IP address
--port <PORT>	Server port
--nickname <NAME>	Player nickname

Example:

cargo run --release --bin client -- --host 127.0.0.1 --port 5000 --nickname "guest1"

Map Format

Maps are stored as JSON files inside the conf/ directory.

A map contains:

• layout: the tile grid of the map.
• textures_bindings: links between tile values and texture names.
• spawnpoints: available player spawn positions.
• resources: texture and font paths.

Example:

{
  "layout": [
    [1, 1, 1],
    [1, 0, 1],
    [1, 1, 1]
  ],
  "placeholder": "placeholder",
  "textures_bindings": {
    "1": "redbrick"
  },
  "spawnpoints": [
    {
      "x": 1,
      "y": 1
    }
  ],
  "resources": {
    "textures_directory": "assets/img/",
    "font_directory": "assets/fonts/",
    "textures": {
      "redbrick": "redbrick.png",
      "placeholder": "placeholder.png"
    },
    "fonts": {}
  }
}

Notes

This project is a learning-oriented prototype.

It focuses on implementing low-level game programming concepts such as:

• raycasting
• map parsing
• SDL2 rendering
• multiplayer synchronization
• UDP networking
• basic entity management

It is not meant to be a complete production-ready FPS engine.

Possible Improvements

• Add mouse-based camera rotation
• Add health and score display
• Improve shooting feedback
• Add proper player death and respawn delay
• Add menu and lobby system
• Add sound effects
• Improve network reliability
• Add server-side anti-cheat checks
• Add more maps and entities

License

No license has been specified yet.